EP3537849A1 - Container heating - Google Patents

Abstract

Described is a container heating, in particular tank heating, with a PTC heater (7), which contains a PTC heating resistor (19) and a contact element (21), a housing part (1) made of metal. According to the invention, it is provided that the housing part (1) carries an annular wall (2) made of plastic, which surrounds the PTC heater (7).

Description

A container heater having the features specified in the preamble of claim 1 is known from DE 10 2011 011 367 B4 known.

Container heaters, in particular tank heaters, for heating liquids in motor vehicles, for example water or other liquids, usually have a metal housing in which a PTC heater with a PTC heating resistor and a contact element is arranged, since metal housing of the PTC heater generated heat can deliver well to a liquid to be heated.

The metal case of the DE 10 2011 011 367 B4 known tank heater is provided by powder coating with a plastic jacket. This tank heater is inserted into an opening in a tank and then welded to the surrounding edges of a plastic wall of the tank. Because of the low strength of such a plastic sheath is a reliable welding with a Tank wall problematic and possibly with great effort to realize. Plastic sheaths of greater thickness, which are easier to weld to a tank wall, can be made by overmolding the metal housing. However, as the strength of the plastic jacket increases, the thermal coupling of the PTC heater to the liquid contained in the tank worsens.

The object of the present invention is to show a way in which a good heat coupling of the PTC heater to a liquid contained in the container can be combined with a simple mounting of the container heater in the tank in a container heater.

This object is achieved by a container heating with the features specified in claim 1. Advantageous developments of the invention are the subject of dependent claims.

A container heater according to the invention has a housing part made of metal, for example a support plate, a PTC heater, which is fixed to the housing part, and a plastic ring wall, which surrounds the PTC heater. The circumference of the ring wall can have any geometric shapes. In this way, an excellent thermal coupling to liquid to be heated can be combined with a simple installation in a tank via the metallic housing part. Namely, by the container heater is inserted into an opening of a tank, the edge of a tank wall with the annular wall of the container heater can easily be tightly connected, in particular welded. Advantageously, the thermal coupling of the metallic housing part in the tank to the tank contents is not impaired by the annular wall.

The annular wall can for example be made separately as an injection molded part and attached to the housing part, for example by means of rivets. Other fasteners such as bolts or tabs are also conceivable. The annular wall can be liquid-tightly connected to the metallic housing part on one side, preferably its front side, for example by a seal between the housing part and the annular wall sits.

A container heater according to the invention can, for. B. be designed as a water heater for heating a pipe, as tank heating or battery container heating.

An advantageous development of the invention provides that a spring element is attached to improve the heat coupling to the housing part, which generates a spring force that presses the PTC heater against a heat transfer surface of the housing part. The spring element is preferably made of an alloy based on aluminum, for example a spring-hard alloy such as AlMgSi. Aluminum alloys have a good thermal conductivity, so that heat generated by the PTC heater can then advantageously be dissipated via the spring element. The spring element may be produced, for example, as a sheet metal part or as an extruded part.

Preferably, the spring element is latched or caulked to the housing part. For example, the spring element can be attached to the housing part by being clipped onto the housing part. Another possibility is that the spring element is fixed by caulking to the housing part, for example by means of fastening devices such as rivets or tabs. Advantageously, such a simple production can be realized. In addition, in the latching or caulking of the spring element with the housing part less the risk that form metal chips that can cause electrical problems, as in the conventional insertion of a spring plate into a groove. It is also conceivable to brace spring element and housing part with fastening devices by means of an additional fastening part such as Speednuts or nuts.

In addition, it can be provided that spring element and housing part are still pressed. As a result, the contact pressure can be further increased and thus the heat transfer can be improved.

An advantageous development of the invention provides that the fastening devices such as rivets are formed integrally with the housing part, which is a easy manufacturing possible. A housing part with integrated pins or projections, which can be used as rivets, can be produced for example by extrusion. Such rivets can be inserted through openings of the spring element and then caulked, so that then the spring element is riveted to the housing part. Preferably, the spring element is riveted under tension.

The housing part of a container heater according to the invention may for example be formed as a plate which carries the PTC heater. Such a plate can be inexpensively manufactured by extrusion and thereby provided with pin-shaped projections, which can then be used as rivets for fastening the spring element or other components. Extrusion also makes it possible to form on the housing part tabs, heat transfer elements or the like. It is also possible to produce the housing part as a sheet metal part or die-cast part. In particular, in the case of a die-cast part, the bearing surface for the PTC heater can be pressed in advance for this purpose. Fastening approaches such as rivet bolts can also be subsequently attached to the housing part. Regardless of the shape and manufacture of the housing part can be attached to him an additional heat-emitting element, for example by integrally formed with the housing part rivets or by soldering. Advantageously, both the housing part and the heat-emitting element can have almost any shape. As a result, the container heater can be flexibly adapted to the geometry and customer requirements. Also conceivable are variants in which the housing part has formed an upstanding wall as a slosh wall or has an all-up wall, so that a partial volume can be delimited in the container.

A further advantageous embodiment of the invention provides that the annular wall is made of polyethylene or a polyethylene weldable plastic, so that the annular wall can be welded to a container wall of polyethylene or similar plastic.

The annular wall can be advantageously secured by caulking to the metallic housing part, for example by trained as rivets or tabs Projecting projections of the housing part through corresponding openings of the annular wall.

Depending on the housing part design, the annular wall can alternatively be secured, for example, by screwing, Verclipsen, or bending the projections on the housing part.

It is particularly advantageous for the annular wall has a voltage applied to the support plate flange portion having openings for riveting corresponding. Depending on the housing part design, the annular wall can alternatively be secured, for example, by screwing, Verclipsen, or bending the projections on the housing part.

The flange portion may carry a cover which closes an interior containing the PTC heater. Preferably, the fastening lugs on the housing part also engage through corresponding openings of the cover. It is also conceivable, however, that additional own fastening lugs on the annular disk engage through openings on the cover and are fixed above the annular disk, in particular hot-caulked. Advantageously, the cover may include a connector for connecting the PTC heater and / or other electrical components, such as the PTC heater. Wear sensors. It when the cover is integrally formed with a connector housing is particularly advantageous.

To protect the cover from damage during riveting, the cover may carry on its side facing away from the housing part a metal washer which has openings for the fasteners such as rivets. Alternatively, the fastening parts may also be surrounded by individual washers.

But the annular wall can also be integrally formed with such a cover. For example, the annular wall can form a dome. If the cover is formed integrally with the annular wall or no cover is present, so the housing is an open housing, the annular wall can their side facing away from the housing part wear an annular disc made of metal having openings for rivets. The washer then protects the ring wall from damage during riveting.

Preferably, the rivets for fixing the annular wall are at least partially rotationally symmetrical, in particular arranged in a circle with the same distance to their respective neighbors. This design offers a great variability for the arrangement of the ring wall and cover Thus, it is possible to arrange both the ring wall, more importantly, but still the cover rasterized in Nietabstandsmaß variable in any orientation within the full 360 °. As a result, for example, an angled connector housing can be aligned according to customer needs without any structural change.

For electrically connecting the PTC heater to the connector terminals, free-wired lines from the PTC heater to the terminals are preferably provided. As a result, advantageously, the connector connection can be carried out according to customer requirements, without structural changes to the PTC heater must be made. The container heater may include a single or multiple PTC heaters.

A further flexibility results when, in an advantageous further development, the cover and the connector housing are designed in two parts and are connected to one another via press-fit, welding or engagement. It can be arranged between the cover and the connector housing, a sealing element.

Between the annular wall and the metallic housing part, a sealing ring may be arranged. Advantageously, such penetration of liquid into the interior of the container heating can be prevented. A sealing ring can also be arranged between the annular wall and the cover. Preferably, both seals are made equal.

The housing part and any metallic heat-dissipating element attached to it are preferably made of an aluminum-based alloy and can be protected with a plastic layer before contact with a liquid to be heated, for example by a powder coating or a coating produced by electrophoresis. If a metallic heat-emitting element is attached to the housing part, the plastic layer covers both the housing part and the heat-emitting element.

Alternatively or additionally, the housing part as well as a possibly attached to him heat-emitting element made of aluminum or an aluminum-based alloy may also be coated with an anodized layer. An anodized layer can also be advantageously used to electrically isolate the housing part from the PTC heater. If the housing part (also) is coated with a plastic layer, this preferably has a recess in which the PTC heater is seated, so that the heat coupling of the PTC heater is affected as little as possible to the metallic housing part.

Furthermore, the housing part and possibly the heat-emitting element may be partially or completely coated with a lacquer layer.

• ∘ freie Wahl der Geometrie des Gehäuseteiles
• ∘ freie Wahl der Positionierung des Heizers auf dem Gehäuseteil
• ∘ freie Wahl beim Positionieren eines Gehäuseteiles auf einem weiteren Wärmeübertragungselement
• ∘ freie Wahl der Orientierung der Abdeckung (360° gerastert)
• ∘ freie Wahl des Steckers in Gestalt und Position durch flexible Anschlussleitungen
• ∘ freie Wahl der Beschichtung des Gehäuseteiles und damit verbundenem Wärmeübertragungselement

In contrast to known plastic-encapsulated container heaters, for each variant, a separate injection molding tool must be produced, so can be realized in both the one-piece and in the multi-part design very variable container heaters without much effort to change the customer

• ∘ free choice of the geometry of the housing part
• ∘ free choice of positioning of the heater on the housing part
• ∘ free choice when positioning a housing part on another heat transfer element
• ∘ free choice of the orientation of the cover (360 ° rastered)
• ∘ free choice of connector in shape and position through flexible connecting cables
• ∘ free choice of the coating of the housing part and associated heat transfer element

A container heater according to the invention may have a housing that encloses the PTC heater in an interior. When the tank heater is inserted into an opening in a tank wall, the ring wall and the metallic shell are sufficient to protect the PTC heater from the tank contents. A closed housing that surrounds the PTC heater on all sides is then not mandatory. In other words, therefore, the PTC heater can be freely accessible on its side facing away from the metallic housing part, the housing thus being open on this side.

In order to improve the heat release from the housing part to a liquid, it may be advantageous for the housing part to continue to be in contact with a capillary tissue. The arrangement of a capillary tissue e.g. as a mat, fleece or sponge has the advantage that regardless of the Auftaugrad always has a certain amount of liquid heat contact with the housing part and thus with the PTC heater by the liquid bound therein, and the heat absorbed in sloshing movements are passed on to the remaining liquid can. Particularly preferably, the capillary tissue simultaneously has a filter function. So the liquid z. B. filtered through the filter material before it is sucked through an outlet of the tank.

The capillary tissue can be attached by other fastening devices such as rivets on the housing part. Likewise, other components can be attached by fastening devices on the housing part. In this case, the components can be, for example, other identical or different types of heating elements, fluid or electrical lines or channels or sensors.

Fig. 1

eine schematische Darstellung einer Behälterheizung;

Fig. 2

eine Schnittansicht eines Tanks mit der Behälterheizung;

Fig. 3

eine Schnittansicht der Behälterheizung;

Fig. 4

ein Ausführungsbeispiel des metallischen Gehäuseteils;

Fig. 5

ein weiteres Ausführungsbeispiel des metallischen Gehäuseteils;

Fig. 6

das metallische Gehäuseteil mit PTC-Heizer und Federelement; und

Fig. 7

das metallische Gehäuseteil mit PTC-Heizer.

Further details and advantages of the invention will be explained with reference to embodiments with reference to the accompanying drawings. Identical and corresponding components are designated therein by corresponding reference numerals. Show it:

Fig. 1

a schematic representation of a container heater;

Fig. 2

a sectional view of a tank with the container heater;

Fig. 3

a sectional view of the container heater;

Fig. 4

an embodiment of the metallic housing part;

Fig. 5

a further embodiment of the metallic housing part;

Fig. 6

the metallic housing part with PTC heater and spring element; and

Fig. 7

the metallic housing part with PTC heater.

In Fig. 1 is schematically shown a tank heater, more precisely a tank heater. The container heater has a metallic housing part 1 in the form of a carrier plate to which an annular wall 2 made of plastic is attached. On the annular wall 2, a cover 3 is fixed, which carries a housing 4 of an electrical connector for connecting the container heater to a power source. The connector housing 4 may be formed integrally with the cover 3.

FIG. 2 shows a sectional view of the in FIG. 1 illustrated container heater together with a liquid tank 5, in which it is installed. In the tank, a liquid level 6 is shown schematically. A comparison of Figures 1 and 2 shows that the container heating in FIG. 1 is shown with a view from below.

In principle, the arrangement of the container heating at all points of the container wall and in all mounting positions is conceivable.

The metallic housing part 1, the annular wall 2 and the cover 3 together enclose a sealed inner space 30, in which a PTC heater 7 is arranged. The container heater is inserted into an opening of the liquid tank 5 and closes it. For this purpose, the annular wall 2 can be welded to the wall of the tank 5. A corresponding weld 24 is in FIG. 2 indicated. As walls of liquid tanks, especially of water tanks, often made of plastic are, it is advantageous if the annular wall 2 is also made of plastic, such as polyethylene or a polyethylene weldable plastic. Such plastics can be advantageously used for water tanks in motor vehicles.

The heat generated by the PTC heater 7 is discharged via the housing part 1 to the liquid 6 in the tank 5. In order to increase the heat dissipation area, it can be advantageous if the housing part 1 designed as a carrier plate extends laterally beyond the annular wall 2. Between a wall of the tank 5 and a section of the housing part 1 projecting beyond the annular wall 2, capillary tissue 8 or filter material can be arranged. The arrangement of a capillary tissue e.g. as a mat, fleece or sponge has the advantage that regardless of the Auftaugrad always has a certain amount of fluid thermal contact with the housing part 1 and thus with the PTC heater 7 by the liquid bound therein, and the heat absorbed in sloshing the remaining liquid can be passed on. The capillary web 8 particularly preferably has a filter function at the same time. So the liquid 6 z. B. filtered through the Kapillargewebe 8 before it flows out of an outlet 9 of the tank.

To improve the seal between the metallic housing part 1 and the annular wall 2, a sealing ring 10 may be arranged between the metallic housing part 1 and the annular wall 2, for example an O-ring. To receive the sealing ring 10 may be provided in the annular wall 2 and / or the metallic housing part 1 a matching annular groove in which the sealing ring 10 is seated. In the embodiment shown, a sealing ring 11 is also arranged between the cover 3 and the annular wall 2, for example, a flat gasket. Through them, the interior 30 and thus the PTC heater 7 is sealed to the outside. Alternatively, the interior can also be partially or completely potted.

The PTC heater 7 includes at least a PTC heating resistor 19 and a contact member, such as a contact plate 21. The PTC heater 7 is supported by a metallic spring member 12 against a heat transfer surface of the Housing part 1 pressed, namely against the inside of the housing part 1. The metallic spring element 12 can be made inexpensively, for example, from sheet metal or extruded part. As FIG. 2 shows, the spring element 12 has a to the center of the PTC heater 7 out bent pressure surface, which presses against the PTC heater 7. The spring element 12 may be latched or caulked to the metallic housing part 1. In the illustrated embodiment, the spring element 12 is caulked by means of rivets to the housing part 1. The housing part 1 has for this purpose pin-like projections which engage through rivets 13 through matching openings of the spring element 12.

The metallic housing part 1 may additionally comprise further projections formed as rivets 14 with which the annular wall 2 is fastened to the housing part 1. The integrally formed with the housing part 1 rivets 14 engage through corresponding axially extending openings of the annular wall 2 and the cover 3 therethrough. Thus, the plastic cover, such as polyamide, formed cover 3 is not damaged when caulking the rivets 14, a metallic annular disc 15, preferably a stainless steel sheet may be provided, which lies outside of the cover 3 and has openings through which the rivet 14 extend through , When caulking the rivet 14, the metallic washer 15 can absorb the forces occurring and distribute it over the surface, so that the cover 3 is not damaged.

As FIG. 2 shows, formed as rivets 14 projections of the metallic housing part 1 can pass through a radially inwardly extending flange portion of the annular wall 2, which carries the cover 3.

Especially from the Fig. 5-7 it can be seen that the rivets 14 are arranged in a circle with the same adjacent spacing. This design offers a large variability for the arrangement of the annular wall 2 and cover 3. Thus, it is possible to arrange the cover 3 and thus the angled connector housing 4 rasterized in Nietabstandsmaß variable in any orientation within the full 360 °.

FIG. 3 shows a modified embodiment of the container heating described above. The essential difference from the exemplary embodiment described above is that the metallic housing part 1 is made smaller and does not extend substantially radially outward from the annular wall 2. To increase the heat transfer surface therefore a heat transfer element 23 is attached to the metallic housing part 1. The heat transfer element 23 may be riveted to the metallic housing part 1. The metallic housing part 1 can for this purpose be formed in one piece with rivets 16 which project through suitable openings of the heat transfer element 23. The advantage of this multi-part design is also the great variability. Thus, almost any desired heat transfer contour can be realized with a single prefabricated heating insert. Only the heat transfer element 23 has to be adapted in each case.

A metallic housing part 1 with rivets 13, 14, 16 can be produced inexpensively as extruded part, for example in the form of a support plate. Pin-like projections for the formation of rivets 13, 14, 16 can be produced inexpensively in one piece with the metallic housing part 1 in this way. It is particularly advantageous that the shape of the metallic housing part 1, in particular its underside or outer contour can be adapted with little effort to given requirements as the geometric relationships of a liquid tank.

FIG. 4 shows an embodiment of the metallic housing part 1, the rivets 13 for fixing the spring element 12, rivets 14 for fixing the annular wall 2 and on its outer side projections 17 for increasing the surface area and improving the heat dissipation.

FIG. 5 shows by way of example another embodiment of the metallic housing part 1, which differs from the in FIG. 4 shown embodiment differs essentially only in that it has instead of the pin-like projections 17 of the base surface bent side walls 18. When installed, these side walls 18 may protrude upward as heat-conducting ribs into the container.

FIG. 6 shows the metallic housing part 1 with the PTC heater 7 and the spring element 12. The spring element 12 is secured to the housing part 1 with rivets 13, which are integrally formed with the housing part 1. FIG. 7 shows a view FIG. 6 without the spring element 12. In FIG. 7 It can be seen that the PTC heater 7 contains a plurality, for example two PTC heating resistors 19. In order to be able to press both PTC heating resistors 19 to the housing part 1 with a high force even in the case of possible manufacturing tolerances with regard to the thickness of the PTC heating resistors 19, the spring element 12 can have a slot 25 between adjacent PTC heating resistors 19. In this way, the portions of the spring element 12 on both sides of the slot 25 substantially independently exert a spring force on the PTC heating resistors 19 and press them against the housing part 1.

The PTC heating resistors 19 can be held by a mounting frame 20, which is also a contact element 21 (see Fig. 2 ), for example, holds a contact plate, which rests flat against the electrical contacting of the PTC heating resistors 19 thereto. The housing part 1 may form one or more stops (not shown) which position the PTC heater 7 and the mounting frame 20 and secure against displacement. Furthermore, in the illustrated embodiment, the contact plate 21 on a projection 24 which is bent into a hook, in which the mounting frame 20 is hooked for fixing.

In the embodiment shown, the contact element 21 is located between the housing part 1 and the PTC heating resistors 19. The contact element 21 may have an extension 21a, to which a ring cable lug 22 (see Fig. 3 ) or another connection element a line (not shown) can be connected to a corresponding contact pin of the connector 4. Via a further ring cable lug 29, which is taken with a rivet 13 of the spring element 12, a second line is connected to a contact pin of the connector 4. In the embodiment of the FIGS. 6 and 7 The PTC heating resistors 19 are electrically contacted on their side remote from the contact element 21 side of the spring element 12. The housing part 1 is electrically insulated from the contact element 21 by an insulating layer. A suitable insulating layer can be realized inexpensively in a housing part 1 produced from aluminum or an aluminum-based alloy, for example by an anodized layer. This variant is especially advantageous when the entire housing part 1 is provided with an anodized coating as corrosion protection.

Alternatively, it is also possible to use the housing part 1 as ground contact of the PTC heating resistors 19 and to arrange a contact element 21 on the side facing away from the housing part 1 side of the PTC heating resistors 19 and this contact element then electrically from the spring element 12 and the housing part 1, for example, by interposing a sheet of electrically insulating plastic or ceramic between the contact plate 21 and spring element 12th

The housing part 1 and a possibly attached to him heat-emitting element 23 can be inexpensively made of an aluminum-based alloy and protected by an anodized in front of a liquid 6 to be heated. Such Eloxalschicht can cover the housing part both on its inside and on its outside. Alternatively or additionally, the metallic housing part 1 and a possibly attached to him heat transfer element 23 may also be coated with a plastic layer. A corresponding plastic layer can be applied, for example, as a powder coating, but a coating produced by electrophoresis is preferred. For a plastic coating, for example, polyethylene, polypropylene, fluorinated thermoplastics and polyamides, in particular partially aromatic polyamides such as polyphthalamide are suitable.

If the housing part 1 carries a plastic layer, it may be advantageous to arrange the PTC heater 7 in a recess of the plastic layer, so that the thermal contact between PTC heater 7 and housing part 1 is not affected by the plastic layer.

LIST OF REFERENCE NUMBERS

1

housing part

2

ring wall

3

cover

4

connector housing

5

tank

6

liquid

7

PTC heater

8th

Kapilargewebe

9

outlet

10

seal

11

seal

12

spring element

13

rivet

14

rivet

15

washer

16

rivet

17

head Start

18

flap

19

PTC heating element

20

mounting frame

21

contact element

21a

extension

22

lug

23

Heat transfer element

24

head Start

25

slot

29

Ring terminal

30

inner space

Claims (15)

Container heating, in particular tank heating, with
a PTC heater (7) including a PTC heating resistor (19) and a contact element (21),
a housing part (1) made of metal,
characterized in that
the housing part (1) carries a plastic ring wall (2) surrounding the PTC heater (7). Container heater according to claim 1, characterized in that the annular wall on one side, in particular a front side is liquid-tightly attached to the housing part (1). Container heater according to one of the preceding claims, characterized in that a sealing ring (10) between the housing part (1) and the annular wall (2) is arranged. Container heater according to one of the preceding claims, characterized in that the annular wall (2) carries a cover (3) made of plastic. Container heater according to one of the preceding claims, characterized in that a sealing ring (11) between the annular wall (2) and the cover (3) is arranged. Container heater according to claim 4 or 5, characterized in that the cover (3) carries a housing (4) of an electrical connector, preferably integrally formed with a housing (4) of a connector. Container heater according to one of the preceding claims, characterized in that the annular wall (2) with the housing part (1) is riveted. Container heater according to one of the preceding claims, characterized in that the housing part (1) is formed integrally with rivets (14), with which the annular wall (2) on the housing part (1) is attached. Container heater according to one of the preceding claims 4 to 8, characterized in that the rivets (14), which connect the housing part (1) with the annular wall (2), at the same time hold the cover (3) on the annular wall (2). Container heater according to claim 9, characterized in that the cover (3) carries an annular disc (15) made of metal, through which the rivets (14) which connect the housing part (1) with the annular wall (2) and the cover (3) , protrude through. Container heater according to one of the preceding claims, characterized in that the annular wall (3) is made of plastic, preferably of polyethylene or a plastic weldable with polyethylene. Container heater according to one of the preceding claims, characterized in that the housing part (1) is produced by extrusion. Container heater according to one of the preceding claims, characterized in that the housing part (1) is coated with an electrically insulating layer, preferably an anodized layer, which electrically isolates the housing part (1) from the PTC heater (1). Container heater according to one of the preceding claims, characterized in that the housing part (1) is coated with a plastic layer, preferably a powder coating, a lacquer layer or a coating produced by electrophoresis. Liquid tank with a container heater according to one of the preceding claims, characterized in that the annular wall (2) is welded to a tank wall.

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