EP1515587A1 - Electrical heated device with sealed heating element - Google Patents

Abstract

Electric heater for supplementary heating of vehicles comprises a casing fastened by a spring clip. This contains a heating unit consisting of a PTC heater (4) between two metal contact sheets (2, 10) which supply current to it and a radiator element (5). One of the sheets (2) has a lacquer coating and the gap between the heater and this sheet is sealed by lacquer (12) which is squeezed out from it. Independent claims are included for: (a) the heating unit; and (b) a method for making it.

Description

The invention relates to an electric heater, in particular as additional heating for motor vehicles, a structural unit for such a heating device and a corresponding Production method.

For use in motor vehicles, especially motor vehicles with new ones Consumption-optimized engines in which a smaller amount of heat energy is generated, Electric auxiliary heaters are used to heat the interior and engine. However, such electric heaters are also for other purposes suitable, for example in the field of home installations, in particular Room air conditioning, in industrial plants and the like.

For an electric booster heater for a motor vehicle are preferably PTC heating elements used with radiator elements in thermally conductive connection. The of The heat generated by the PTC heating elements is transmitted to the flowing through the radiator elements Air discharged. The overall arrangement of a layered structure of PTC heating elements, radiator elements and contact plates, the power supply serve is to increase the efficiency of the heating in a clamping pressure kept in a frame. Due to the clamping is a high electrical and thermal Contacting of the PTC heating elements achieved.

The layered structure is in a stable frame with preferably U-shaped Cross section held. The frame is designed so that it is the layered Construction compresses. The clamping may alternatively be effected by spring elements which are arranged in the layered structure. So that the frame the spring forces it can be mechanically very stable, preferably with one U-shaped cross section formed. Such a conventional heater is for example from DE-A-101 21 568.

The minimum height of the longitudinal beams of such a frame with U-shaped cross-section (or C-shaped cross section according to DE-A-101 21 568) is in the required Clamping forces in about 11 mm. This results in one for the entire heater Non-usable height of at least 22 mm. Such a design with external clamping or outside holding frame thus has a high surface area, which is not available for the air flow. For this reason are such electric heaters for use at very low installation heights not suitable.

When assembling electrical heaters with external support frame or external clamping complicated measures are required, the counteract during assembly obstructive pressure forces of the springs / frame.

Because of these drawbacks are heaters with a conventional support frame for modern air conditioning units, in particular for installation in motor vehicles, in less and less suitable. Air conditioning units for multi-zone air conditioning in one comfort-stressed motor vehicle increasingly require heaters larger Length but low height.

In addition, conventional constructions have a holding frame, in particular made of metal, a heavy weight up. For installation in motor vehicles, however, it is in In view of the total weight of the vehicle desirable, electric booster heaters to be used with a particularly low weight.

Another disadvantage of metal support frames is their conductive surface. To the Increasing safety in motor vehicles, metal surfaces are increasing in increasing Dimensions are avoided so that their touch is safely possible, i. E. without electrical or thermal line. For this purpose, the heating devices described above are preferred provided with a plastic envelope, such as in DE-A-101 21 568 heater shown.

Another disadvantage of conventional electric heaters is the risk of corrosion contact plates that supply the heating elements with electricity. The possibility, contact plates come into contact with moisture during both of the manufacturing process as well as in operation. Corrosion between a PTC heating element and a contact plate, which is made of aluminum, for example, can cause a power loss of up to about 30%.

The object of the invention is an electric heater, a structural unit for a electric heating device and a manufacturing method for an electric heater having an improved structure, the above-mentioned Disadvantages not owns.

This object is achieved with the features of the independent claims.

According to the invention in the manufacture of the electric heater first one of the contact plates, which contact the PTC heating element, with a lacquer layer Mistake. About this paint layer, the PTC heating element "provisionally" on the Contact plate fixed and sealed.

Such a heater has several advantages. In particular, the additional effect On the electrode applied paint layer a more extensive corrosion protection than Conventionally achievable. The paint protects the contact plate and the connection between PTC element and contact plate against moisture penetration. A corrosion over Moisture with which the contact plate during manufacture or during operation in Touch comes, is excluded.

The lacquer coating is applied to the PTC heating elements during the manufacturing process facing side of an electrode applied. Then be positioned on the paint layer, the PTC heating elements. By the spring element caused clamping pressure is between the PTC element and the contact plate Existing paint largely expelled. The pressed-out varnish seals over a bead the space between the PTC heating element and the contact plate from. About this sealing of the transition between the electrode and the PTC heating element is an efficient corrosion protection possible.

In addition, the invention enables a simplified production of such electrical Heater. The prefabricated units are the PTC heating elements held over the paint at predetermined positions on the contact plate. As a result, during the manufacturing process, an individual positioning of the Individual elements, in particular the PTC elements, by hand or machine superfluous and the manufacturing process can be significantly shortened.

In addition, eliminates the need for a position frame or positioning means use that hold the PTC heating elements spaced from each other. By prefixing the PTC heating elements over the paint are sufficient for the production firmly connected. The mechanical stability of the compound PTC heating element and contact sheet only has to outlast the manufacturing process. Subsequently is the mechanical stability and fixation of the heating elements over the Clamping pressure causes, which is generated by the spring element. With prefabricated units Thus, the manufacturing process can be shortened in a simple manner.

Preferably, the paint is an electrically non-conductive paint. In this way, the reliability of the heater is increased because exposed Metal surfaces are avoided. At the same time there is a corrosion of the surface of the contact sheet prevented. For this purpose, in particular a silicone varnish used. Such a silicone varnish is not only electrically non-conductive, but also capable of different coefficients of expansion of the PTC heating element and the contact sheet, which is preferably made of aluminum, compensate. It is therefore particularly advantageous to use an elastic paint.

According to a further advantageous embodiment, a highly viscous lacquer is used. The paint has a viscosity lower than 900 mPa.s. Such a paint can therefore be processed particularly easily, for example, is a simple paint job by a brush or stripping coating, in particular by a drip coating via standard dosing devices, possible. This way you can the manufacture of prefabricated units are particularly simplified.

A further simplification of the production can be achieved by the prefabricated units from a radiator element, one attached to this Contact plate and on this over the paint attached PTC heating elements. With such a larger prefabricated unit, the production can be further simplify and accelerate.

According to a preferred embodiment, the contact plate on which the PTC heating element fastened over the paint, made of aluminum. With this material allows a particularly good heat transfer between the PTC heating element and reach the radiator element.

Preferably, the elongated end faces are formed mechanically particularly stable and can therefore absorb particularly high forces. For this purpose are in openings the elongated end faces for the air flowing through cross braces provided which absorb the clamping forces generated by the spring element. In this way are high clamping forces at low height and much lighter materials such Plastic possible. With the structure according to the invention, electrical heating devices be used more diverse, especially at low levels available standing height.

According to an advantageous embodiment of the invention are in addition to the cross braces provided in the openings of the housing sides longitudinal struts, so that the struts form a lattice structure. This allows the struts even be kept particularly thin, so that they only slightly affect the air flow obstruct and still prevent bending of the housing effectively. One Housing for an electric heater is thus in a simple manner from a lightweight and also easy to process material such as plastic produced.

So that the air flow of the air to be heated does not hinder by the lattice struts In particular, the longitudinal struts are arranged so that they are located in the area of the PTC heating elements. As a result, the struts are so placed to coincide with sections where there is no airflow.

Preferably, the housing is made of plastic. A major advantage of a Plastic housing lies in its low weight, its flexible formability and its low production costs. With this material you can save the costs a heater can be kept very low.

According to an advantageous embodiment of the invention, the housing has a lateral Opening for insertion of the spring element after assembly of the heater. This makes the production of such a heater much easier, There are no special devices to overcome the spring forces during assembly required are. The spring is inserted into the housing only when the composite housing is able to withstand the forces generated by the spring To compress the layered structure. Preferably, the Spring guided in a groove. By the subsequent insertion of the spring in the housing, without the case itself must be opened, can be very much use lighter housing materials than conventional, preferably plastic.

According to an advantageous embodiment, the housing is composed of two half-shells. This is a particularly simple assembly of the heater possible. For this purpose, the half shells are designed to be plugged together. By the Use of locking pins or locking lugs, which when plugging the half shells cause a locking of both half shells of the housing, is a special faster assembly possible.

Both half-shells are preferably designed so that they approximately surround the housing separate centrally between the opposite, open housing sides. As a result, the housing is particularly stable on the open sides only in the middle, i. at the dividing line of both half-shells, the housing can not or record only small clamping forces.

In a particular embodiment, the two half-shells are at their parting lines provided with additional projections and depressions, which when mating interlock and interlock the half-shells. The housing can so also in the middle range, at the dividing lines of both half-shells, absorb higher forces. The projections and depressions entangle both half shells together and thereby cause an increase in the mechanical stability of the side surfaces. With such a construction, high clamping forces can also be applied to housing materials be used with a fundamentally lower stability.

The spring element is designed so that it has the clamping forces substantially on the reinforced trained housing sides transmits.

The spring element preferably consists of a sheet metal part with obliquely protruding Spring segments. Preferably, the spring element with the spring segments integrally formed. As a result, the spring can be produced for the first time as an endless part and be supplied in a simple manner from a role of manufacturing. conventional on the other hand, each spring must be manufactured separately and individually for different lengths getting produced. The spring element of the heating device according to the invention is in contrast, easily cut from roll to any length, so that elaborate individual manufacturing processes for the spring and adjustments to the manufacturing process be avoided when changing the structure of the heating element.

Due to the separation of the housing and spring, the thickness of the springs of conventional about 0.8 mm according to the new construction principle to a thickness of about 0.3 mm be reduced. As a result, the spring can be produced with little effort, without the efficiency of the heater is reduced.

To achieve a high efficiency of the electric heater is for each position of a PTC heating element provided a spring segment, so that individual clamping of each PTC heating element improves efficiency.

A particularly high efficiency can be achieved by increasing the clamping forces, if provided in the region of a PTC heating element, a plurality of spring segments is, preferably two or three individual spring segments. This will make each one PTC heating element kept clamped along its entire length.

According to a further preferred embodiment, the springs consist of a Sheet metal, from which obliquely projecting individual spring segments in the transverse direction, the Mechanically reinforce the spring so that there is a deflection around the longitudinal axis of the spring not possible. For this purpose, the spring segments each extend into the edge area the spring, so that the spring supported on the stable outer edge of the housing can. The housing must therefore absorb forces only at its edges and can be made less stable in the middle. This is a special way Use lightweight and easy-to-use housing material.

According to a particular embodiment of the electric heater is between the longitudinal struts and the layered structure provided a seal. Such a seal, in particular as a silicone seal, is preferably in one piece trained and seals the entire grid structure.

Further advantageous embodiments of the invention are the subject of the dependent claims.

Fig. 1

eine schematische Darstellung des Aufbringens einer Lackschicht auf einem Kontaktblech,

Fig. 2

eine schematische Darstellung des Aufsetzen eines PTC-Heizelementes auf die Lackschicht des Kontaktblechs,

Fig. 3

eine schematische Darstellung einer vorfabrizierten Baueinheit aus einem auf einem Kontaktblech fixierten PTC-Heizelement,

Fig. 4

eine alternative Ausführungsform einer vorfabrizierten Baueinheit, die in Ergänzung zu den Elementen der Fig. 3 ein Radiatorelement umfasst,

Fig. 5

eine schematische Darstellung eines Ausschnitts einer erfindungsgemäßen Heizvorrichtung mit einer in diese eingesetzte, vorfabrizierte Baueinheit gemäß Fig. 4,

Fig. 6

eine schematische Ansicht eines inneren Aufbaus einer erfindungsgemäßen Heizvorrichtung,

Fig. 7a

ein schematische Schnittansicht durch eine erfindungsgemäße Baueinheit aus einem Radiatorelement, einem über eine Lackschicht versiegelten Kontaktblech und ein auf dem Kontaktblech angeordneten PTC-Heizelement,

Fig. 7b

eine perspektivische Ansicht einer Baueinheit gemäß Fig. 7a,

Fig. 8

eine schematische Schnittansicht durch eine erfindungsgemäße Heizvorrichtung mit einem Kunststoffgehäuse und in diesem in mehreren Schichten angeordneten PTC-Heizelementen, Kontaktblechen und Radiatorelementen,

Fig. 9

eine aufgeschnittene, perspektivische Ansicht einer erfindungsgemäßen elektrischen Heizvorrichtung gemäß Fig. 8, wobei jedoch nur eine Halbschale des Gehäuses dargestellt ist,

Fig. 10

eine Aufsicht auf die erfindungsgemäße Heizvorrichtung gemäß Fig. 9 mit den in einer Halbschale angeordneten Radiatorelementen, Kontaktblechen und PTC-Heizelementen,

Fig. 11

eine Ansicht eines geschichteten Aufbaus aus Radiatorelementen, Kontaktblechen und PTC-Heizelementen, wie er im Gehäuse einer erfindungsgemäßen elektrischen Heizvorrichtung angeordnet ist,

Fig. 12

eine perspektivische Ansicht einer Halbschale des Gehäuses der elektrischen Heizvorrichtung der Erfindung, die nur zum Teil bestückt ist,

Fig. 13

eine perspektivische Ansicht einer Halbschale des Gehäuses der elektrischen Heizvorrichtung gemäß Fig. 12, die vollständig bestückt ist,

Fig. 14

eine perspektivische Ansicht des zusammengesetzten Gehäuses der elektrischen Heizvorrichtung,

Fig. 15

eine perspektivische Ansicht der elektrischen Heizvorrichtung gemäß Fig. 14, bei der das Federelement teilweise eingeschoben ist,

Fig. 16

eine perspektivische Ansicht einer anderen Ausführungsform des Gehäuses der erfindungsgemäßen Heizvorrichtung,

Fig. 17

eine weitere perspektivische Ansicht der Ausführungsform nach Fig. 16, bei der die Gehäuseseite, an der die Kontaktstifte vorgesehen sind, beispielhaft an eine spezielle Steckergeometrie angepasst ist,

Fig. 18

eine weitere Detailansicht der Ausführungsform des Gehäuses der erfindungsgemäßen Heizvorrichtung nach Fig. 16,

Fig. 19

eine perspektivische Ansicht einer schematischen Darstellung einer weiteren Ausführungsform der erfindungsgemäßen Heizvorrichtung während des Zusammenbaus,

Fig. 20

eine perspektivische Ansicht der zusammengesetzten Ausführungsform nach Fig. 19,

Fig. 21

eine Detailansicht der Innenseite einer Gehäusehalbschale einer weiteren Ausführungsform der Erfindung,

Fig. 22

eine Schnittansicht durch die zusammengesetzten Halbschalen des Gehäuses der Ausführungsform nach Fig. 21,

Fig. 23

eine vergrößerte Ansicht eines Details der Gehäusedarstellung aus Fig. 22, bei dem die Einzelheiten des verschränkten Aufbaus der Gehäuseseiten für eine stärkere mechanische Belastbarkeit der Gehäuselängsseiten deutlich erkennbar ist,

Fig. 24

eine schematische Darstellungen einer Aufsicht auf das erfindungsgemäße Federelement,

Fig. 25

eine schematische Darstellungen einer Seitenansicht auf das erfindungsgemäße Federelement,

Fig. 26

eine schematische Darstellungen einer perspektivischen Ansicht des erfin- dungsgemäßen Federelementes,

Fig. 27a

eine Ansicht eines Wellrippenelements mit einem an diesem befestigten Kontaktblech und

Fig. 27b

eine Ansicht einer weiteren Ausgestaltung des Federelementes.

In the following, the present invention will be explained with reference to preferred embodiments in conjunction with the accompanying drawings. The drawings show in detail:

Fig. 1

a schematic representation of the application of a paint layer on a contact plate,

Fig. 2

a schematic representation of the placement of a PTC heating element on the lacquer layer of the contact sheet,

Fig. 3

2 a schematic representation of a prefabricated structural unit made of a PTC heating element fixed on a contact plate,

Fig. 4

an alternative embodiment of a prefabricated structural unit, which comprises a radiator element in addition to the elements of FIG. 3,

Fig. 5

1 is a schematic representation of a detail of a heating device according to the invention with a prefabricated structural unit according to FIG. 4 inserted therein;

Fig. 6

a schematic view of an internal structure of a heating device according to the invention,

Fig. 7a

FIG. 2 shows a schematic sectional view through an assembly according to the invention comprising a radiator element, a contact plate sealed via a lacquer layer and a PTC heating element arranged on the contact plate, FIG.

Fig. 7b

a perspective view of a structural unit according to FIG. 7a,

Fig. 8

FIG. 2 a schematic sectional view through a heating device according to the invention with a plastic housing and in this PTC heating elements, contact plates and radiator elements arranged in several layers, FIG.

Fig. 9

8 is a cutaway, perspective view of an electric heater according to the invention, but only a half shell of the housing is shown,

Fig. 10

9 shows a plan view of the heating device according to the invention according to FIG. 9 with the radiator elements, contact plates and PTC heating elements arranged in a half shell, FIG.

Fig. 11

a view of a layered structure of radiator elements, contact plates and PTC heating elements, as it is arranged in the housing of an electric heating device according to the invention,

Fig. 12

a perspective view of a half-shell of the housing of the electric heater of the invention, which is only partially equipped,

Fig. 13

a perspective view of a half-shell of the housing of the electric heater of FIG. 12, which is fully populated,

Fig. 14

a perspective view of the assembled housing of the electric heater,

Fig. 15

a perspective view of the electric heater of FIG. 14, in which the spring element is partially inserted,

Fig. 16

a perspective view of another embodiment of the housing of the heating device according to the invention,

Fig. 17

16 is a further perspective view of the embodiment according to FIG. 16, in which the housing side on which the contact pins are provided is adapted, for example, to a specific plug geometry,

Fig. 18

a further detail view of the embodiment of the housing of the heating device according to the invention of FIG. 16,

Fig. 19

a perspective view of a schematic representation of another embodiment of the heating device according to the invention during assembly,

Fig. 20

a perspective view of the assembled embodiment of FIG. 19,

Fig. 21

a detailed view of the inside of a housing half shell of a further embodiment of the invention,

Fig. 22

a sectional view through the composite half-shells of the housing of the embodiment of FIG. 21,

Fig. 23

an enlarged view of a detail of the housing illustration of FIG. 22, in which the details of the entangled structure of the housing sides for a stronger mechanical load capacity of the housing longitudinal sides is clearly visible,

Fig. 24

a schematic representations of a plan view of the spring element according to the invention,

Fig. 25

a schematic representation of a side view of the spring element according to the invention,

Fig. 26

1 a schematic representation of a perspective view of the spring element according to the invention,

Fig. 27a

a view of a corrugated fin element with a contact plate attached thereto and

Fig. 27b

a view of a further embodiment of the spring element.

While in conventional electric heaters, the PTC heating elements via Positioning means, such as a position frame between contact plates be positioned, according to the invention electric heaters so manufactured, that at least one of the contact plates is provided with a lacquer layer and on this the PTC heating elements before mounting in the electric heater be positioned. These manufacturing steps are illustrated in FIGS. 1 to 3 Played way.

Fig. 1 shows a schematic view of the side view of a contact plate 2, with a paint layer 3 on the side facing the PTC heating laterally provided becomes. On this paint layer 3, the PTC heating element 4 is then placed (Figure 2). The contact plate 2 with the lacquer layer 3 and the PTC heating element arranged thereon 4 form a prefabricated structural unit 1, which is shown schematically in FIG is.

The strength of the fixation of PTC heating elements 4 via the paint 3 on the contact plate is designed to withstand mechanical stresses that occur during and during manufacture an electric heater occur, sufficiently withstand. Stronger mechanical stress does not withstand this fixation. About such Lacquer layer 3, on which the PTC heating elements 4 are placed, can the production electrical heaters are significantly simplified. In particular, over the thus prefabricated units 1 reduces the number of parts to be assembled become. In addition, the assembly is simplified because no tedious positioning the individual elements in a housing is required. In addition, there are no positioning means required, because the PTC heating elements at certain on Be held in position.

A particular advantage achieved by the paint is improved moisture protection. The achievable during assembly of the heater additional seal the compound PTC heating element 4 and contact plate 2 is below. Referring to Fig. 5 described.

A variant of a prefabricated unit is shown in Fig. 4. At the contact plate 2, a radiator element 5 is additionally attached. This prefabricated unit, in which on the contact plate 2, a PTC heating element 4 according to that in the figures 1 to 3 illustrated manufacturing process is attached, allows further reduction the assembly steps required in the fabrication of an electric heater, since a separate insertion of the radiator elements 5 is omitted.

According to a further embodiment, other elements of the heating device then integrated into the prefabricated component on the radiator element 5 become. With each additional element of the prefabricated unit, the number decreases the manufacturing steps required in the fabrication of the heater.

When installing the prefabricated unit 1 according to the invention (as shown in FIG. 4) into a Housing of the heater, the individual elements of the heater after Insertion of a spring element (not shown in Figures 1 to 8) via a Clamping held under a bias. A section of an inventive electric heating device that represents the clamping pressure and its effect, is shown in FIG.

FIG. 5 shows, in addition to the prefabricated structural unit 1 from FIG. 4, radiator element 5, contact plate 2, paint layer 3 and PTC heating element 4 a to the PTC heating element 4 subsequent contact plate 10 and this adjacent another Radiator 11. The pressure caused by the clamping pressure is by black arrows in Fig. 5 symbolizes. The contact pressure causes the between the PTC heating element 4 and the contact plate 2 located paint 3 on the sides of the Gap 13 between the PTC heating element 4 and the contact plate 2 pressed out becomes. The extruded from the gap 13 paint forms on the outer Edges of the gap 13 Lackwülste 12, the gap 13 against seal in penetrating moisture.

The heating device according to the invention is about the coating of the contact plate with a lacquer layer and the resulting sealing of the contact point PTC heating element and contact sheet in an efficient manner against moisture damage, in particular Corrosion, and associated power loss protected. The Heating device according to the invention is thus particularly for extreme conditions suitable, in which the danger is particularly great that the heater with moisture comes into contact.

Preferably, an electrically non-conductive paint is used for the paint 3. By the pressing of the heater components during the manufacturing process the paint is pressed out of the gap 13 and realized so an electrically conductive contact between the contact plate 2 and the PTC heating element 4th

The thickness of the coating application is preferably in the range between 10 and 20 μl / cm ² , particularly preferably in the range of 14 μl / cm ² .

The paint 3 is in a simple manner by a brush, stripping or drip coating coatable. This coating is made possible by a particularly high viscosity, which is preferably in the range of 900 mPa.s to 750 mPa.s. Especially preferable the paint has a viscosity of about 850 mPa.s. The paint forms a permanent Cover as protection against moisture and atmospheric contaminants.

When applying the paint on a drip coating of this is dropwise over applied a commercial metering device. As dosing preferably serves a Dosiemadel.

For this purpose, a high-viscosity paint is to be used. This is to increase the Environmental compatibility used a paint containing only a low proportion of solvents having.

According to a preferred embodiment, the contact plate 2 is made of aluminum. Aluminum allows a particularly good advertising transition between the PTC heating element 4 and the radiator element 5.

Preferably, the contact plate 10, which is the PTC heating element 4 on the contact plate 2 opposite side contacted, made of brass, preferably tinned Made of brass.

Fig. 6 shows schematically a preferred embodiment for the clamped held components of the heating device according to the invention. The structure includes two prefabricated building units 1 each having at least one PTC heating element 4, a contact plate 2 and a radiator element 5. In addition, the structure comprises another contact plates 20, 21, which on the opposite sides of the PTC heating elements 4 abuts, and a final radiator element 22. The two contact plates 20 and 21 are at different potential. Moreover, that is in Fig. 6 shown lower radiator element 5 to a power supply with plus potential connected.

Overall, the internal structure shown in Fig. 6 comprises an advantageous embodiment of the heating element according to the invention only five components to be mounted, namely two prefabricated units 1, two contact plates 20, 21 and an additional Radiator element 22. Such a layered structure is thus particularly simple and easy to produce.

In FIGS. 7a and 7b is a perspective view and a sectional view of a preassembled unit 30 shown schematically. The assembly 30 consists of a radiator element 35 which is connected to a contact plate 32. On the contact plate 32, a paint layer 33 is applied, via which the PTC heating elements 31 the contact plate 32 are fixed.

In Fig. 7a is a sectional view of the assembly 30 shown in a heating device is mounted under a clamping voltage. Due to the clamping pressure is between the PTC heating element 31 and the contact plate 32 located paint 33 laterally from the gap pushed out, so that he has the space above ridges 34, the so-called Adhesive meniscus, against the ingress of moisture and contaminants is sealed or sealed.

Unlike traditional electric heaters for use in Motor vehicles, the heater according to the invention of two plastic half shells built up. In the first production can be in a simple way Fit the housing half and then the housing by placing the completed second housing half. The installation of the electric heater will be described below with reference to Figures 12 to 15.

In FIGS. 8 to 10, various views of one of several layers are constructed electric heating device according to an embodiment of the present invention Invention shown. A sectional view through the electric heater is shown in FIG. 8 FIG. 9 is a perspective view and FIG. 10 is a plan view on the arranged in a half-shell of the housing components of the heater demonstrate. The housing consists of two interlocking half-shells 40a and 40b. In these half-shells, the units of the invention are made of a Radiator 44, a contact plate 42 connected thereto and on the contact plate fixed heating elements 41 arranged. The units are each through Spacer 43 separately in one of the half-shells 40a, 40b used.

In each housing half-shell 40a, 40b are to reinforce the narrow housing longitudinal sides Provided reinforcing elements. In particular, grab when mating both housing halves 40a, 40b preferably latching tabs 46, 47 into each other. In this way, the narrow housing longitudinal sides are mechanically reinforced and can therefore absorb higher clamping forces. Details and alternatives for a mechanically reinforced training of the narrow housing sides are under With reference to the following figures explained.

The clamping pressure is generated via a spring element 49, which is the layered structure composed of PTC elements 41, contact plates 42 and radiator elements 44, so that the electrical and thermal transition between the contact plates 42 and the PTC heating elements 41 is improved. This can increase the efficiency of the heater be increased.

The PTC heating elements 41 are prepositioned on first contact plates 42 via a lacquer. On the opposite sides of the PTC heating elements 41 is during assembly another contact plate provided. One of the two contacting a PTC heating element Contact sheets, as shown in Fig. 10, for electrical power supply led out of the housing 40. About the contact tabs 50 of the led out Contact sheets are supplied to the electric heater during operation power. For Easier installation and secure positioning of the protruding from the housing Contact plates 50, these are each positioning aids 49 to the Housing sides held.

The layered structure of a plurality of units, which in the housing 40th is used is shown in Fig. 11.

FIGS. 12 to 15 show successive stages of the assembly of the invention Heating device, the structure of the heating device according to the invention clarify. FIG. 12 shows a perspective view of a half-shell 62 a of FIG Half shells 62a, 62b of the housing. In the half-shell 62a are a contact plate 66, a radiator element 64 and adjacent PTC heating elements 4 used. To make things easier of the assembly are each guide rails or positioning intended for all components. In particular, the position of the contact plate 66 with the contact pin 66a when inserted via the guide 66b (or 67b for the contact plate 67 in Fig. 13). The radiator elements 64 are preferably in shape formed by corrugated rib elements. On one side is the corrugated fin element with provided a contact plate. For the ends of the contact plate of the corrugated fin element 64 are provided laterally in the inside of the housing guides 64 a. These guides serve only to facilitate assembly. in an alternative embodiment Therefore, they can be waived.

As shown in Fig. 13, above the PTC heating elements 4 are again a radiator element 64 and a contact plate 67 with a plug contact 67a provided - accordingly to the structure shown in FIG. On the so equipped first half shell 62a, the second housing half-shell 62b can be plugged on. Both housing halves are preferably formed so that its dividing line is approximately in the middle between the two elongated Gehäusestimseiten (which have the passage openings) extends.

The assembly of the housing can be simplified in particular by that both half-shells 62a, 62b with locking pin 78 and corresponding holes 79th are provided in each opposite half-shell. When mating Both half-shells lock as soon as the second half-shell 62b completely on the first Half shell 62a is attached.

The composite housing of the electric heater is shown in FIG. In Fig. 14 it can be seen that each of the housing halves 62a, 62b to the elongated end has openings for the air flowing through.

To increase the efficiency of heat generation by the PTC heating elements, are these in the layered manner described in connection with FIGS. 12 and 13 Construction held clamped within the housing. This clamping is by a additional spring element 72 causes. Preferably, the spring element is at least inserted between a housing inside and the layered structure. In addition, such a spring element and between the opposite Housing inside and the layered structure or at a position within the layered structure can be inserted.

In order for the housing to be able to withstand the clamping forces without deforming the housing absorb, the elongated Gehäusestimseiten are mechanically reinforced. Between the mechanically reinforced Gehäusestimseiten, especially in the area of Dividing line, the housing is unable to absorb high clamping forces.

In order to accommodate very high clamping forces are within the lateral Opening for the air to be heated cross braces 69 provided. These cross braces allow the housing to have sufficiently high clamping forces without a Can accommodate deflection or deformation of the housing. The half-shells with the struts are each integrally formed and preferably made of plastic produced.

In a particularly advantageous embodiment, the cross braces 69 supplemented by one or more longitudinal struts 70, so that the struts 69 and 70 have the shape of a grid structure. Such a lattice structure allows that the cross braces 69 can be kept very thin and the air flow not hindered. At the same time effectively prevents bending of the housing.

The stability of the housing between the mechanically reinforced housing sides is in an advantageous embodiment by a special design of the upper and lower sides of the half shells reinforced. For this purpose, on the housing top and underside of each half-shell 62a, 62b respectively have projections 76 and recesses 77 provided which are arranged so that they mate when mating to grab. In this way, the mechanical stability of the upper and lower sides by entanglement of the sides of the two half-shells also between the mechanical reinforced elongated housing sides increased.

Since the housing is only able to withstand high clamping forces after assembly To accommodate deformation of the housing, the spring element 72 after the Assembly of the housing can be used. For this purpose, the housing 62 on a housing side an opening 71. Such an opening is preferably on provided the narrow sides of the housing 62. Each housing half 62a, 62b has corresponding recesses, which in the composite housing 62 for Add slot 71 for insertion of the spring element 72. A special design the housing inner sides to form a spring channel for insertion of the spring element 72 will be described below with reference to FIGS. 21 to 23.

The positioning means 64a, 66b, 67b provided in the housing are arranged such that that the prepositioned elements of the heater have sufficient space for leave the spring element. In particular, the prepositioned elements are in the fixed by the spring clamping direction with game fixed to keep it moving and to receive the clamping pressure generated by the spring.

In Fig. 15 it can be seen that the spring element 72 a plurality of individual spring segments has, which generate the clamping pressure. On preferred embodiments of the spring element 72 will be described below in connection with FIGS. 26a, 26b and 26c.

In the illustrated embodiments, the contact plates 66 and 67 are each outside arranged in the layered structure, so that the power supply via the Radiator 64 to the PTC heating elements 74 takes place. This structure leads to a particularly good heat transfer between the PTC heating elements 4 and the Radiator 64, which give the heat to the air flowing through, and heat conduction losses are therefore particularly low.

Due to the arrangement of the contact plates at the top and bottom of the layered Construction of elements of the heater, the air flow is particularly little with special needs. This allows the height without reducing the air passage volume kept small.

Due to the inventive design of the housing with mechanically particular stable pronounced elongated sides of the housing, the clamping forces are not like conventionally received by the side rails of the support frame. The narrow sides of the housing can therefore be designed as desired. Preferably, the housing narrow sides designed so that they have a mechanical fixation and an electrical Allow contacting the heater. For electrical contact is at least one housing narrow side to the geometry of a plug to Power supply customizable.

The design of the narrow sides is shown by way of example in FIGS. 12 to 15. On the left side of the case is a plug shape from each of the two housing halves molded projections 73a, 73b formed. In this plug, the connector tabs protrude 66a and 67a of the two contact plates 66, 67 into it. On the opposite Side is a plug 74 from the projections 64 a, 64 b formed substantially the mechanical attachment of the electric heater is used. Because the Narrow sides of the housing 62 have to absorb high forces, they can be designed as desired for mechanical and / or electrical fastening.

FIGS. 16 to 18 show a further embodiment of a housing and a housing corresponding electric heating device shown. Fig. 16 shows a perspective view View of an embodiment of an electric heater 80, opposite the embodiment of Figures 12 to 15 narrower, but with a larger cross-sectional area is designed for a higher air flow. For this purpose, the heater PTC heating elements 4 in a plurality of planes in the layered structure on. In contrast to the embodiment of FIGS. 12 to 15, the PTC heating elements are 4, which have a rectangular shape, with their longitudinal sides parallel to aligned with the elongated Gehäusestimseiten the heater.

Corresponding to each layer with PTC heating elements 4 in the layered structure of radiator elements 64, PTC heating elements 4 and electrode plates 81, 82 are each provided at the height of the layers with PTC heating elements 4 longitudinal struts 70. In the illustrated embodiment, a total of four layers with PTC heating elements 4 present and accordingly also four longitudinal struts 70 are provided. Due to the greater longitudinal extent of the heater compared to Heater of Figures 12 to 15, this embodiment also has a larger Number of cross struts 69 on.

In contrast to the first embodiment of Figures 12 to 15 are shown in the illustrated Heating device uses two spring elements 72, each at the top and lower end to be inserted on the narrow side of the housing. The feathers are each inserted so that the spring segments 86, which consists of the spring element 72 protrude from the housing surface in the direction of the layered structure protrude. Although not shown, other spring elements 72 between pushed the two spring positions shown in the layered structure become.

Due to the majority of layers shown in this embodiment PTC heating elements 4 is also a correspondingly higher number of contact plates required. The uppermost and lowermost of the contact sheets 82 are adjacent to each arranged upper or lower housing inside. The three middle contact sheets are each arranged adjacent to the three lower layers with PTC heating elements, i.e. corresponding to the three lower of the longitudinal struts 70th

Each of the contact sheets 81, 82 has protruding contact tongues from the frame 81a, 82a. The housing side 83, from which the contact tongues 81a, 82a protrude, can be configured arbitrarily. A particular embodiment is shown in FIG. 17. On the housing 83 shown in Fig. 16 is in each case an individually adapted plug shape 85 attached or glued. This glued plug form can be attached to the respective Be adapted to needs, for example, to install the heater in Vehicles of different car manufacturers, the different types of plug contacts use. In the embodiment shown in Fig. 17, the attachable Plug attachment 85 from a mechanical stop with mounting holes and a plug shoe 85a, in which the contact tongues 81a, 82a are arranged.

Preferably, transverse struts 69 of the lattice structure are at a distance of 30 to 40 mm arranged. At a distance of the cross struts, which is greater than 40 mm, in particular from about 60 mm distance, the clamping forces can not be sufficient Measurements taken from the cross struts. Below a distance of Cross struts of less than 30 mm, in particular less than 20 mm, hinder this contrast, the air flow through the elongated ends of the heater clearly.

Figures 21 to 23 show a particular embodiment for the embodiment of Inner sides of the two housing half-shells. The inner structure of the housing half shells has a spring channel into which the spring 72 after assembling both Half shells of the housing can be used. The spring channel causes a leadership of Spring during insertion, via each laterally extending grooves. The grooves for example, by the projections 94 and either the housing top or, as in the illustrated embodiment, via latching tabs 92a, 92b.

The projection 94 not only forms one side of the spring channel for insertion of the spring, but he also serves as a positioning aid of the elements of the heater. These are (pre) fixed by the projection 94 with play in the housing to a slide-in channel for the spring to be inserted after assembly.

The embodiment shown in Figures 21 to 23 also has an increased Stiffness up. Such additional stiffening may include among others Reasons are needed. To be used also in "large area heaters", i. heaters the narrow but designed with a large area for a high air flow are to achieve high efficiency, very high clamping forces are required. At case temperatures of about 170 degrees Celsius, however, the rigidity of the used plastic after. In addition, the springs can not force only on the Transmitted edge of the housing, since the spring segments used a distance from a minimum of about 2 mm to 2.5 mm to the edge of the spring. Nevertheless, one To avoid bending of the upper and lower sides of the housing, these are preferably additionally stiffened. These are opposite in each case half shells arranged latching tabs 92a, 92b provided. The latching tabs protrude each in the direction of the opposite half of the housing and are about locking lugs 91 locked together during assembly. Through this gearing on the upper and lower sides of the housing, the mechanical stiffness is increased and prevents sagging.

A further increase in rigidity can be achieved via an additional side wall 95, 96 be achieved. This side wall 95, 96 is respectively above the previous side walls arranged and connected via support members 93 thereto. This way you can the mechanical rigidity of the top and bottom surfaces are increased so that the housing can absorb very high clamping forces. This is a "large-scale construction" possible, ie a heater with a plurality of stacked Layers of PTC elements and intermediate radiator elements.

The structure of the spring element 72 will be described below with reference to FIG. 24, Fig. 25 and Fig. 26 described. In Fig. 24 is a plan view of the spring element 72, in Fig. 25 is a side view and in Fig. 26 is a perspective view of the spring element 72 reproduced.

The spring element 72 consists of a sheet metal part 85 and protruding from this Spring segments 86. Preferably, the spring element 72 is integrally formed, wherein the spring segments punched out on three sides of the sheet metal part 85 and are bent about an axis 89 in the transverse direction of the sheet metal part 85. The angle α, um The punched out the segments are bent, is approximately between 5 ° and 30 °, preferably between 15 ° and 20 °. By this structure of the spring element 72nd no deflection in the transverse direction is possible, but only in the longitudinal direction. Thereby the spring element acts only on the edge of the housing, in which it is produced the clamping force is supported. Thus, the spring interacts ideally with the housing, the can accommodate greater forces only in the housing sides due to its construction and in the middle, in the area of the dividing line, less loadable. Preferably, the side ends of the spring segments arranged very close to the edge of the spring element.

The illustration in FIGS. 24, 25 and 26 is merely schematic. The spring segments 86 need not be rectangular, but can also have areas include different width and inclination. For example, each spring segment have a wider end portion which is slightly flattened, to allow a better insertion of the spring element in the housing.

In Fig. 27a is a radiator element 64 and a contact plate 66 connected thereto in an elongated embodiment for a "large surface heating device" (eg according to FIG Fig. 20). The corresponding spring element is shown in Fig. 27b. The spring element has a plurality of successively arranged spring segments 86 on. Each of the spring segments 86 is capable of a pressing force of about 15 N exercise. To increase the pressure force, the spring segments of FIG. 27b positioned one behind the other, so that over the surface of a PTC element two or three spring segments 86 are arranged. As a result, the clamping pressure can be doubled or even tripled. The clamping pressure is in contrast to conventional Frame mounts applied evenly over the entire length of the spring.

Thus, the clamping forces generated by the spring segments 86 received by the housing can be, the elongated housing sides are so with cross braces 69 equipped that between two consecutive cross struts 69 two to a maximum of five spring segments 86 are arranged.

The embodiment according to FIG. 15 shows a spring element 72 with two or more side by side arranged spring segments. This embodiment is advantageous in Housing shapes that have a large depth.

While conventionally springs are used with a thickness of about 0.8 mm, can in the new design principle spring elements with a thickness of 0.2 to 0.5 mm, preferably about 0.3 mm are used. This allows a spring action reach the spring segments 86 even at a short length of a spring segment.

A particular advantage of the heating device according to the invention is that the spring element can be produced for the first time as an endless part and thus from a roll during production can be supplied. Conventionally, each spring segment is manufactured separately and individually manufactured for all different heater lengths. In addition is it is sufficient to provide only one spring element per heater.

In addition to the low height is a particular advantage of the heating device according to the invention, that this can be produced in a particularly simple manner. The assembly the heating device takes place as described in connection with FIGS. 12 to 15. According to the assembly of the individual elements takes place in contrast to conventional heaters without the clamping forces on the layered Interacting construction. Only after assembly of the housing, the spring is in the composite Housing inserted (see Fig. 15).

In summary, the invention relates to a new construction principle for electric heaters, where the functions of frame and spring are separated are. As a frame for an electric heater, a housing is used, the consists of two half-shells. In the housing are positioning aids for the PTC heating elements arranged. The longitudinal sides of the housing are substantially open designed to allow an air flow through the heater.

Before installing the heater, the PTC heaters are painted over attached to a contacting the PTC heating elements contact plate. The so prefabricated Modules facilitate assembly and avoid additional positioning means for the correct position of the PTC heating elements during production.

The paint was also a protection against the ingress of moisture. On This way, an effective corrosion protection is achieved at the same time.

In addition, a spring is incorporated in the housing, which is the layered structure consisting of radiator elements, PTC heating elements and contact plates. The Spring can be retrofitted by an opening provided laterally in the housing the housing are inserted. As a result, the housing is only after assembly, if it is mechanically strong, exposed to the spring forces.

The new construction principle has a number of advantages. On the one hand can with the inventive Construction the weight at the same heat output can be significantly reduced, because no metal frame is used, up to about 50 percent. Furthermore has the heater without additional measures and without additional weight no exposed metal surfaces. Another advantage is the low height that um up to 30 percent below conventional heaters. As a result, too much smaller heaters than conventionally realizable, but still a high Efficiency due to the clamping principle used to increase the electrical and achieve thermal contact. In addition, longer heating elements can be produced, with the conventional holding frame design only with great effort are feasible.

In addition, there is no conventional positioning frame for spacing and protection the PTC heating elements used but the PTC heating elements are by pre-positioning fixed on the contact plate over a varnish and separated from each other.

In addition, the production cost over conventional heaters significantly reduced. The production of the heating device according to the invention is very much easier, because no special device to overcome the spring forces of the frame during the manufacturing process is required.

The construction principle requires no special design of the side rails of a holding frame, to absorb the clamping force acting on the longitudinal beams. The narrow sides the housing according to the invention are therefore in their design to any desired Plug geometry customizable, the projecting from the housing connector tongues surrounds the contact sheets.

In addition, the spring is much cheaper to produce in this way. For one thing, the Thickness of the spring can be reduced and thus a material saving can be achieved. On the other hand, the spring element can now be produced for the first time as Endlosteil and of be supplied to a role in manufacturing. In addition, a single spring element sufficient.

Claims (41)

Electric heating device, in particular as an auxiliary heater for motor vehicles, having a housing (62) which is open on the elongated Gehäusestimseiten open, and a layered structure of at least one PTC heating element (4), a radiator element (5), a first and a second Contact plate (2,10) for supplying power, wherein the PTC heating element (4) between the first and the second contact plate (2, 10) is arranged, and a spring element (72), wherein the layered structure by the spring element (72) in the housing (62) is clamped,
characterized in that
the first contact plate (2) is provided with a lacquer layer (3) on the side facing the PTC heating element (4), and the intermediate space between the PTC heating element (4) and the first contact plate (2) is pressed out of this intermediate space ( 12) is sealed. Electric heating device according to claim 1, characterized in that the lacquer is an electrically non-conductive silicone lacquer (3). Electric heating device according to claim 1 or 2, characterized in that the paint (3) has a viscosity lower than 900 mPa.s, preferably of about 800 mPa.s. Electric heating device according to one of claims 1 to 3, characterized in that the first contact plate (2) is made of aluminum. Electric heating device according to one of claims 1 to 4, characterized in that the second contact plate (10) is made of brass. Electric heating device according to one of claims 1 to 5, characterized in that the second contact plate (10) is tinned. Electric heating device according to one of claims 1 to 5, characterized by an opening (71) provided laterally in the housing (62) for insertion of the spring element (72). Electric heating device according to one of claims 1 to 7, characterized by a in the housing (62) formed spring channel for receiving the spring element (72). An electric heater according to any one of claims 1 to 8, characterized by positioning means (94) for prefixing the elements of the heater in the housing (62). Electric heating device according to claim 9, characterized in that the positioning means (94) in the housing (62) at the same time form a groove for guiding the spring element (72) during insertion. Electric heating device according to one of claims 1 to 10, characterized in that the elongate Gehäusestimseiten are mechanically reinforced by at least one cross-brace (69). Electric heating device according to claim 11, characterized in that the struts (69,70) in the elongated Gehäusestimseiten have the shape of a grid structure. Electric heating device according to claim 11 or 12, characterized in that the grid structure has at least one longitudinal strut (70) in the region of the PTC heating elements (4). Electric heating device according to one of claims 1 to 13, characterized in that the housing (62) is made of plastic. Electric heating device according to one of claims 1 to 11, characterized in that the housing (62) comprises two half-shells (62a, 62b). Electric heating device according to claim 15, characterized in that the half-shells (62a, 62b) of the housing (62) can be plugged together. Electric heating device according to claim 16, characterized by latching pins (78) or latching noses (91), which cause the latching of the two half-shells (62a, 62b) when the half-shells (62a, 62b) of the housing (62) are pushed together. Electric heating device according to one of claims 16 to 17, characterized in that the half-shells (62a, 62b) are formed so that they separate the housing (62) approximately centrally between the elongated Gehäusestimseiten. Electric heating device according to claim 18, characterized by respective opposing projections (76, 77; 92a, 92b) at the parting line of the half-shells (62a, 62b) which engage in the assembly of the half-shells (62a, 62b). Electric heating device according to one of claims 1 to 19, characterized in that the spring element (72) is formed so that it transmits the clamping forces substantially on the reinforced housing longitudinal sides. Electric heating device according to one of claims 1 to 20, characterized in that the spring element (72) consists of a sheet metal part (85) with protruding from this spring segments (86). Electric heating device according to claim 21, characterized in that the spring segments (86) each extend into the edge regions of the longitudinal sides of the spring element (72). Electric heating device according to claim 22, characterized in that the spring element (72) with the spring segments (86) is integrally formed. Electric heating device according to one of claims 1 to 23, characterized in that at least one spring segment (86) is provided for generating clamping forces at each PTC heating element position for a frictional clamping. Electric heating device according to claim 24, characterized in that at least two spring segments (86) are provided for each PTC heating element position. Assembly for an electric heating device, in particular as an auxiliary heater for motor vehicles, wherein the electric heating device has a housing (62) which is open at the elongated Gehäusestimseiten open, and a layered structure of at least one PTC heating element (4), a radiator element (4) a first and a second contact sheet (2, 10) for supplying power, the PTC heating element (4) being arranged between the first and second contact sheets (2, 10) and a spring element (72), the layered construction is held clamped in the housing (62) by the spring element (72),
characterized in that
the assembly of the first contact plate (66) and a PTC heating element (4) is formed, wherein the first contact plate (66) on the PTC heating element (4) side facing a lacquer layer (3) is provided and the space between the PTC heating element (4) and the first contact plate (2) is sealed by lacquer (12) pressed out of the intermediate space. Assembly according to claim 26, characterized in that the lacquer is an electrically non-conductive silicone lacquer (3). Assembly according to claim 26 or 27, characterized in that the paint (3) has a viscosity lower than 900 mPa.s, preferably of about 800 mPa.s. Assembly according to one of claims 26 to 28, characterized in that the first contact plate (2) is made of aluminum. Assembly according to one of claims 26 to 29, characterized in that the second contact plate (10) is made of brass. Assembly according to one of claims 29 to 33, characterized in that the second contact plate (10) is tinned. Method for producing an electrical heating device (20), in particular as an auxiliary heater for motor vehicles, comprising a housing (62) made up of two half-shells (62a, 62b) which is open at the longitudinal housing end sides, and a layered structure comprising at least one PTC heating element (4) a radiator element (5), first and second contact plates (2, 10) for supplying power and a spring element (72), the layered structure being held clamped in the housing (62) by the spring element (42), with the assembly steps: Fixing a PTC heating element (4) on the first contact plate (2) by means of a lacquer (3), Inserting the first contact plate (2) with the mounted on this PTC heating element (4) and the second contact plates (2,10) in a first half-shell (62 a) of the housing and Placing the second half-shell (62b) of the housing (62) on the first half-shell (62a). A method according to claim 32, characterized in that the lacquer (3) is an electrically non-conductive silicone lacquer. A method according to claim 32 or 33, characterized in that the paint (3) has a viscosity greater than 900 mPa.s, preferably of about 800 mPa.s. Method according to one of claims 32 to 34, characterized in that the attachment of the PTC heating element (4) on the paint (3) withstands only low mechanical loads. Method according to one of claims 32 to 35, characterized in that the spring element (72) through an opening (71) of the assembled housing (62) is inserted to effect a clamping of the layered structure. Method according to one of claims 32 to 36, characterized in that with the insertion of the spring element (72) of the paint (3) from the area between the PTC heating elements (4) and the contact plate (2) via the spring element (72 ) is pressed out. Method according to one of claims 32 to 38, characterized in that the lacquer (12) pressed out of the area between the PTC heating element (4) and the contact plate (2, 10) seals this area against moisture penetration. Method according to one of claims 32 to 38, characterized in that the first contact plate (2) is made of aluminum. Method according to one of claims 32 to 39, characterized in that the second contact plate (10) is made of brass. Method according to one of claims 32 to 40, characterized in that the second contact plate (10) is tinned.

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