EP1847785B1 - Heating device - Google Patents

Abstract

A heater has a heat exchanger (200), and a heating unit (300) is arranged in the receiving cavity (206) of the heat exchanger. The plastic shaped part (100) has fixing units for clamp fixing at front side of the heat exchanger. The plastic shaped part has guide units (109) which engages form fit with counter guide units (404, 405) at the housing (600).

Description

The invention relates to a heater according to the preamble of claim 1.

Such heaters are widely used, e.g. In control cabinets, to keep the electronics contained therein at low outside temperatures to operating temperature. They are manufactured with different heat outputs in high quantities. The price accepted in the market is relatively low.

A heater of the type mentioned is, for example FR 2 805 336 A1 known. Similar heaters are in EP 0 957 595 A2 . EP 1 432 287 A1 and US 2003/015520 A1 described.

The invention is therefore based on the object to keep the manufacturing and assembly costs for heaters of the type mentioned as low as possible.

This object is achieved by a heater according to claim 1.

In particular, the object is achieved by a heater, comprising a heat exchanger, a heating unit, which is arranged in a receiving cavity of the heat exchanger, and a housing in which the heat exchanger is mounted, characterized in that plastic moldings, on the one hand fixing means for clamping fixing the Plastic moldings on end faces of the heat exchanger and on the other hand guide means which are in positive engagement with counter guide means on the housing.

An essential point of the invention thus lies in the fact that the heater can be easily and quickly mounted by simple mating and positive insertion with few manufacturing steps.

According to the invention, the heat exchanger is designed as an extruded profile and the extruded profile has continuous recesses in the strand direction, in which fixings formed as bendable extensions of the plastic molded parts can be inserted under elastic deformation.

Characterized in that the extruded profile is formed with additional recesses into which the plastic moldings are used by clamping, additional processing steps on the heat exchanger are not necessary to create holding, clamping or locking devices.

Preferably, the through recesses are formed in pairs and the receiving cavity between them and formed substantially symmetrically to these, which has the advantage that the plastic molding can be formed symmetrically.

As a result, the insertion of the plastic molding is facilitated during manufacture, because a given installation position or direction does not have to be considered. Furthermore, only a single type of plastic moldings has to be produced.

Also, the assembly is further facilitated if advantageously the guide and the counter guide devices are arranged as tongue and groove devices such that the heat exchanger from one direction into a U-shaped base of the housing can be inserted. Thereby, the heat exchanger can be inserted in a manufacturing step from above into the housing until it touches the bottom of the base.

Such a U-shaped base is preferably obtained by virtue of the fact that the base preferably has a base plate and two grid walls arranged at a distance from one another, on whose inner surfaces the counter guide devices are preferably arranged centrally. Due to the central arrangement of the counter guide devices is given a defined position for the insertion and insertion of the heat exchanger, whereby the production is further facilitated.

Preferred is an embodiment in which the housing has a cover with a U-shaped hood in cross section, which is designed such that it surrounds the grid walls with end cap edges or adjoins this, to form a permeable through the lattice walls cavity. Such a configuration is easy to prefabricate and mount with a manufacturing step on the base.

So that the heat exchanger is firmly anchored in the housing, the hood preferably has further fixing means for mutually connecting the grid walls with each other, wherein the further fixing engage in locking pieces of the grid walls, which safely and permanently engage each other without further manufacturing effort and the heat exchanger and the lid hold in a defined position.

Advantageously, the cover comprises a cover portion, which covers the closed housing mounted on the base clamps, which eliminates additional effort for a safe power supply.

So that the heat flow exits the heater with the least possible losses, the hood is preferably lined with a metal sheet or a sheet of heat-reflecting material.

Preferably, when the housing forms a chimney to form a convection flow through the heat exchanger, directed heat flow to an object to be heated is achieved with good efficiency.

Particularly preferred is an embodiment of the heater, in which the housing is designed as a plastic injection molded part, because characterized in one operation, all necessary structural parts, such as grid formation, counter guide devices, lattice wall strips, locking pieces, lugs, moldings, etc. are formed.

- Fig. 1

eine perspektivische Skizze von Einzelteilen eines Heizgerätes gemäß der Erfindung vor der Montage, mit einem Gehäuse aus Sockel und Deckel und einem Wärmetauscher mit eingesetzter Heizeinheit;

- Fig. 2

Ansichten eines Kunststoff-Formteils zum Befestigen eines Deckels an einen Sockel gemäß der Erfindung;

- Fig. 3

einen Querschnitt durch einen Wärmetauscher gemäß einer Ausführungsform, wie er im Heizgerät nach der Erfindung Verwendung findet;

- Fig. 4

Schnitte A-A und B-B einer in den Wärmetauscher gemäß Fig. 3 eingebrachten Heizeinheit gemäß einer Ausführungsform;

- Fig. 5

Ansichten und Schnitte A-A, B-B, C-C, D-D, F-F und G-G eines Sockels gemäß einer Ausführungsform;

- Fig. 6

Ansichten und Schnitte A-A und B-B eines Deckels gemäß einer Ausführungsform.

The invention will be explained in more detail with reference to an embodiment. Show here

- Fig. 1

a perspective sketch of parts of a heater according to the invention prior to assembly, with a housing of base and cover and a heat exchanger with inserted heating unit;

- Fig. 2

Views of a plastic molding for attaching a lid to a socket according to the invention;

- Fig. 3

a cross section through a heat exchanger according to an embodiment as it is used in the heater according to the invention;

- Fig. 4

Cut AA and BB into the heat exchanger according to Fig. 3 incorporated heating unit according to an embodiment;

- Fig. 5

Views and sections AA, BB, CC, DD, FF and GG of a socket according to an embodiment;

- Fig. 6

Views and sections AA and BB of a lid according to an embodiment.

In the following description, the same reference numerals are used for the same and like parts.

According to Fig. 1 For example, the not yet installed heater has a heat exchanger 200 and a housing 600, which consists of a base 400 with two spaced apart mesh walls 402,403 and a hood-shaped cover 500. In a receiving cavity 206 of the heat exchanger 200, a heating unit 300 is used, which is in particular equipped with PTC elements (see Fig. 4 ), wherein surfaces of the receiving cavity 206 are pressed to surfaces of the heating unit 300 to obtain a good heat transfer. The receiving cavity 206 is closed at both ends of the heat exchanger 200, each with a plastic molding 100, which is equipped with a guide device 109. Through one of the plastic molded parts 100 are lines 311, 312 for power supply devices 303 of the heating unit 300 (see FIG Fig. 4 ) led to the outside. The grid walls 402, 403 have counter guide means 404, 405 arranged centrally on inner sides, which engage in the guide means 109 when the heater is mounted. The housing 600 is closed with the hood-shaped cover 500 to form a cavity through which the mesh walls 402,403 can flow.

The plastic molding 100 according to Fig. 2 is in the form of a strip and has a first pair of bendable extensions 104,105 on one strip surface 101 as fixing means 104,105,106,107 spaced from the one end of the strip and a second pair of bendable further extensions 106,107 spaced correspondingly from the other end, with the extensions of a pair each spaced from a center line 103 of the plastic molding 100 extend to the edge of the plastic molding 100, so that a total of four fixing devices 104,105,106,107 are formed. The extensions of the first pair and the further extensions of the second pair are angled to each other.

At one and at the other end of the bar hook-shaped formations 108 are provided, the openings have to one side and to the other end and through which the lines 12,13 for the power supply means 303 are led to the outside (see Fig. 3 ). On the other strip surface 102 is formed as a guide means a longitudinal groove (109). Like the Fig. 2 shows the plastic molding 100 is formed symmetrically.

According to Fig. 3 For example, the heat exchanger 200 has a heat exchanger body 201 with fins that form a first surface 203 that serves to exchange heat between the heat exchanger body 201 and the ambient air or other fluid medium.

Inside the heat exchanger body 201, a second surface 204 is arranged, which faces a pressure surface 205. This pressure surface 205 is formed by a pressure element 202, which in the present embodiment is identical to Heat exchanger body 201 is formed; the heating unit 300 thus sits between two identical heat exchanger bodies 201,202 so that optimum heat dissipation is ensured.

The heating unit 300 is located between the second surface 204 and the pressure surface 205 after insertion into the receiving cavity 206.

The second surface 204 and the pressing surface 205 are identically shaped and formed so as to fully fit surfaces of the heating unit 300. In an area between the second surface 204 and the pressure surface 205 directed to an outer side of the heat exchanger body 201, and the pressure element 202 out, recesses 207 are provided in which in the receiving cavity 206 projecting further ribs 208 are provided as further guide means with the heating unit 300 cooperate such that the heating unit 300 is inserted into a defined position in the receiving cavity 206.

In the recesses 207 adjacent to the second surface 204 and the pressure surface 205 and protruding into the recesses 207 further surfaces 209,210,211,212 are formed. Between these and the other ribs 208, the fixing devices 104,105,106,107 are arranged after the insertion of the plastic molded parts 100, wherein they rest in clamping on the other surfaces 209,210,211,212. In another embodiment of the heat exchanger 200,201,202 without further ribs 208, the further surfaces 209,210,211,212 also serve as further guide means for the positioning of the heating unit 300.

The heat exchanger body 201 and the identically shaped pressure element 202 are connected to one another via connecting sections 230, 230 ', wherein the heat exchanger body 201, the connecting sections 230, 230' and the pressure element 202 are integrally formed as an extruded part, in particular made of aluminum. The production can be done in "yard goods", so that only the heating units to be mounted correspondingly long pieces must be cut, which further facilitates the assembly and further reduces the price.

The heating unit 300 after Fig. 4 comprises a plurality of heating elements 301, but at least one PTC element, which are arranged in a frame 302, in particular made of plastic, and between plate-shaped electrodes 303, esp. Of aluminum. Via terminal lugs 304,305 of the plate-shaped electrodes 303, the heating elements 301 are supplied with power.

The frame 302 has a rectangular or square base surface and has frame strips 306 on two opposite sides. In the frame 302, extending separators 307, esp. Spacers or windows are provided over the length of the frame 302, with which one or more heating elements 301 separately, preferably equidistantly, in the frame 302 can be fixed. In the areas between the molded-on strips 306 and the separating devices 307, on each side and on the edge of the frame 302, angle pieces 308 in the form of right-angled elevations and on each side between the rectangular elevations two spaced-apart snap-in hooks 309 are provided. With the latching hooks 309, the plate-shaped electrodes 303 are held, wherein the angle pieces 308 fix them in a predetermined position.

The assembled heating unit 300 consists of the electrodes 303 inserted in the latching hooks 309 and fixed in position by the angle pieces 308 with the connection lugs 304, 305 and the heating elements 301 inserted between the electrodes 303. Before the heating unit 300 is inserted into the receiving cavity 206, the electrodes become 303 covered with insulators 310. For assembly, a prefabrication can thus be carried out here.

According to Fig. 4 the heating unit 300 produced in this way is introduced into the receiving cavity 206, wherein the frame strips 106 and the further ribs 208 cooperate as further guide means such that the heating unit 300 can be inserted into a defined position.

At both ends of the receiving cavity 206 is closed by the plastic moldings 100. By one of the hook-shaped formations 108 of a plastic molding 100, the leads 311, 312 connected to the terminal lugs 303, 305 are led to the outside.

In order to mount the heating unit 300 in the heat exchanger body 200 so that the second surface 204 and the pressing surface 205 rest firmly on the surfaces of the heating unit 300, as shown in FIG Fig. 3 worked with pressing tools 240,241,242,243 which can attack in the region of the recesses 207 on the surface 203 of the heat exchanger body 201 and on the corresponding surface of the pressure element 202. The connecting portions 230, 230 'have a V-shaped cross section, so that buckling bending at forces perpendicular to the surface of the heating unit 300 is easy to accomplish. In particular, the connecting sections 230, 230 'each comprise a buckling element 231, which is connected to the heat exchanger body 201 or the pressure element 202 via thinned material points, which act like hinges 232, 233. In such buckling elements only a relatively small force must be used to ensure plastic deformation in order to ensure plastic deformation. In addition, it can be ensured in this way that the material deforms in exactly the place that is desired by the designer. Between the innermost part of the connecting portion 230 acting as the bending element 234 and the hinges 232, 233 are relatively stiff connecting portions 235, 236.

The pressure for deformation is therefore applied outside the region of the heating unit 300, so that the necessary, slight overstretching of the connecting portions 230, 230 'can be carried out safely for the heating unit 300. A certain overstretching is in fact necessary because the buckling elements 231 can spring back somewhat even during plastic deformation and thus a sufficient spring action is maintained even when the heat exchanger 200 is heated.

As these dies are moved toward each other, the second surface 204 and the pressing surface 205 approach the surfaces of the heating unit 300 until they come to rest.

In this case, the buckling elements bend 231. On the heat exchanger body 201 and the pressure element 202 no bending moment is exerted, so that their deformation by additional, the contact pressure non-reinforcing forces is prevented. The surfaces on which the heating unit 300 rests are thus not bent, which permanently improves the heat transfer.

Characterized in that the buckling element 231 protrudes into a recess of the heat exchanger body 200, the installation of the heat exchanger 200 is facilitated.

By preforming the buckling elements 231 with a V-shaped or U-shaped cross section, a precise deformation of the connecting sections 230, 230 'is possible by simple means.

Alternatively, where appropriate, in addition to the pressing tools 240,241,242,243, which are moved perpendicular to the surface of the heating unit 300, it is also possible with pressing tools 244, 245 (see Fig. 3 ), which engage directly in the connecting portions 230, 230 'and the buckling elements 231 and are moved toward each other parallel to the surfaces of the heating unit 100. In this application of force, the bending angle α (see Fig. 3 ) of the buckling elements 231 is also reduced, so that the second surface 204 and the pressing surface 205 are pressed onto the surfaces of the heating unit 300.

According to Fig. 5 For example, the U-shaped base consists of a base plate 401 and two mesh walls 402, 403, with the one rear mesh wall 403 at the rear end of the base plate 401 and the other front mesh wall 402 spaced from the front end of the base plate 401. On inner surfaces of the grid walls 402,403 the counter guide means 404,405 are centrally formed, which engage in the insertion of the heat exchanger 200 in the base 400 in the guide means 109 of the plastic molded parts 100. On the inner surfaces of the lattice walls 402, 403, inwardly directed lattice wall ledges 406, 407, 408, 40 spaced from each edge of the lattice walls 402, 403 are integrally formed; that is, on each grid wall 402; 403 two grid wall strips 406, 407; 408, 409, which extend upwards from the base plate 401 and are formed at the end in the form of latching pieces 410, 41, 412, 433. The base plate 401 has between the mesh walls 402,403 and at the edges of the base plate 401 upstanding first lugs 414,415 in front of the front grid wall 402 and upwardly projecting second lugs 416.417 in front of the rear grid wall 403. Before the second lugs 416.417, a rectangular opening 418.419 is formed in each case. The front grid wall 402 is spaced from the front end of the base plate 401. Between the front grid wall 402 and the front end of the base plate 401 are elongated formations 420,421 on the base plate 401 and spaced apart on the outer surface of the front grid wall 402 of the base plate 401 and the front end facing third lugs 422,423 for receiving a Lustererklemme on a front portion the base plate 401 is arranged.

According to Fig. 6 The cover 500 has a hood 501 with a U-shaped cross section, which surrounds the grid walls 402, 403 of the base 400. Both at the one front end of the hood 501 and at the other rear end of the hood 501 are formed with a distance which corresponds approximately to a wall thickness of the mesh walls 402,403, circumferential ridges forming the end cap edges 501,502 and at which edges of the mesh walls 402,403 after the Insert the lid 500 on the base 400 abut.

Corresponding to the locking pieces 406,407,408,409 on the two lattice walls 402,403 are on the hood 501 on the hood edges 501,502 aufsitzend fourth lugs 506,507,508,509 as further fixing and corresponding to the rectangular openings 418,419 each at the rear edge and each at the bottom of the hood 501, a first locking element 518 and a second locking element 519 integrally formed. In the region between the circumferential elevations or cover edges 501, 502, the hood 501 is lined with a sheet or foil of heat-reflecting material. The lid 500 includes a box-shaped cover portion 520 which, when the case 200 is closed, covers the luster terminals mounted on the front portion of the base plate 401 of the pedestal 400.

LIST OF REFERENCE NUMBERS

100

Plastics molding

101

last surface

102

other groin surface

103

center line

104,105, 106,107

fixing

108

hook-shaped training

109

Guide device, longitudinal groove

200

heat exchangers

201

heat exchanger body

202

presser

203

first surface

204

second surface

205

pressure surface

206

receiving cavity

207

recess

208

further guide device, further rib

209,210, 211,212

other surfaces

230, 230 '

connecting portion

231

buckling member

232

hinge

233

hinge

234

flexure

235

connecting portion

236

connecting portion

240-245

press tool

300

heating unit

301

Heating element, PTC element

302

frame

303

Power supply devices, electrodes

304

terminal lug

305

terminal lug

306

frame strip

307

Separators, windows

308

elbow

309

latch hook

310

insulating

311

management

312

management

400

base

401

baseplate

402

front grid wall

403

rear grid wall

404.405

Against guide devices

406,407, 408,409

Grid wall strips

410,411, 412,413

snap-on pieces

414.415

first noses

416.417

second noses

418.419

perforation

420.421

formations

422.423

third noses

500

cover

501

Hood

502, 503

end cap edge

506,507, 508,509

fourth noses, more fixation devices

518.519

first and second latching element

520

cover

600

casing

Claims (10)

1. A heating apparatus, comprising:

   a heat exchanger (200), a heating unit (300) arranged inside a housing cavity (206) of the heat exchanger (200), a case (600) into which the heat exchanger (200) is fastened, wherein plastic molded parts (100), which on the one hand have fastening devices (104, 105, 106, 107) for clamp fastening of the plastic molded parts (100) to the front sides of the heat exchanger (200) and on the other hand guiding devices (109), are positively engaged into mating guiding devices (404, 405) on the case (600),

   characterized in that the heat exchanger (200) is made as an extruded profile, and said extruded profile has continuous recesses (207) in the extruding direction, into which fastening devices (104, 105, 106, 107) made as flexible extensions of the plastic molded parts (100) can be inserted under elastic deformation.
2. The heating apparatus according to claim 1, characterized in that the continuous recesses (207) are made in pairs and the housing cavity (206) is made therebetween and substantially symmetrically thereto.
3. The heating apparatus according to any of the preceding claims, characterized in that the guiding devices (109) and the mating guiding devices (404, 405) are arranged as key and slot devices so that the heat exchanger (200) can be pushed from one direction into a U-shaped base (400) of the case (600).
4. The heating apparatus according to claim 3, characterized in that the base (400) has a base plate (401) and two grid walls (402, 403) arranged at a distance from each other, on the inner surfaces of which the mating guiding devices (404, 405) are arranged preferably in the center.
5. The heating apparatus according to claim 4, characterized in that the case has a lid (500) with a hood (501) having a U-shaped cross-section and which is made so as to enclose the grid walls (402, 403) with terminal hood edges (502, 503) or is adjacent thereto, by forming a cavity which allows for cross-flow through the grid walls (402, 403).
6. The heating apparatus according to claim 5, characterized in that the hood (501) has additional fastening devices (506, 507, 508, 509) for mutually connecting the grid walls together, wherein the additional fastening devices (506, 507, 508, 509) come into engagement with locking pieces (406, 407, 408, 409) of the grid walls (402, 403).
7. The heating apparatus according to any of claims 5 or 6, characterized in that the lid (500) includes a cover portion (520) covering clamps mounted on the base, when the case (600, 400, 500) is closed.
8. The heating apparatus according to any of claims 5 to 7, characterized in that the hood (501) is fitted with a piece of sheet metal or a film of heat reflecting material.
9. The heating apparatus according to any of the preceding claims, characterized in that the case (600, 400, 500) forms a chimney for forming a convection flow through the heat exchanger (200).
10. The heating apparatus according to any of the preceding claims, characterized in that the case (600, 400, 500) is made as an injection-molded plastic part.

Images