EP1253032A2 - Electrical heating device with a heater block mounted in a frame - Google Patents

Abstract

The device has a heating block (1) with several parallel electrical heating elements and intermediate heat conducting ribs and a frame in which the heating block is mounted with two longitudinal legs (4a,4b) spanning the block and two cross-legs (5a,5b). The cross-legs have enclosure sections on their ends with which they enclose the corresponding longitudinal leg ends.

Description

The invention relates to an electric heating device with a Heating block, the several electrical heating elements and arranged in parallel includes intermediate thermal fins, and a frame in which the heating block is held and the two formed block-bracing Longitudinal leg and two transverse legs arranged perpendicular to it having. Such electrical heating devices are used, for example, in Heating systems of motor vehicles for heating a vehicle interior used. Strip elements are often used as heating elements PTC heating register is used, which consists of two sheets and between these in Openings of a sealing profile held PTC elements are constructed.

In one described in the published patent application DE 197 06 199 A1 PTC heating device of this type, the frame consists of two rotating, opposite frame parts parallel to the heating block level made of thermoplastic material, whereby the longitudinal legs block-locking are trained to be relaxed, not assembled Condition slightly from the center area to its two end areas are curved on the outside. In the assembled state, the longitudinal legs are braced due to their elasticity, the heating block between them. Furthermore describes an alternative in which the frame consists of two Frame parts exist, which are divided by dividing the cross legs along one to the heating block plane and the transverse legs perpendicular division plane result. In this case, the block is braced by connecting the frame parts using spring clips or spring-assisted screws.

More similar in a PTC heating device disclosed in EP 0 893 937 A2 The cross legs of the block-holding frame are at least of the construction type longitudinally divided at their ends, and the longitudinal legs are at their corresponding Ends with at least one wedge-like in cross section Provide area and with the corresponding wedge surfaces between the End parts of the cross legs held clamped. The wedge surfaces are preferred realized in that the longitudinal legs as a profile with trapezoidal triangular cross-section are formed. When assembling the heating block is inserted into the frame, after which the divided transverse leg end areas be connected to each other via connecting means and a force tensing the heating block over the wedge surfaces exercise the longitudinal legs. The frame legs are preferably as Extruded aluminum profiles. Serve as a lanyard Screws or rivets.

The invention is a technical problem of providing an electrical Heating device of the type mentioned, which is special assemble advantageous and largely automated if necessary leaves.

The invention solves this problem by providing an electrical one Heating device with the features of claim 1. In this The heating device is the cross legs at their ends with surrounding sections provided with which they the corresponding longitudinal leg ends embrace in the transverse direction to the outside. This Measure enables in connection with the block-bracing training the longitudinal leg is a largely automated pre-assembly of the heating block with the frame surrounding and holding it. Because the two longitudinal legs can be placed on the heating block and then on one side between the two surrounding sections of one Cross legs are introduced. Then the other cross leg under compression at the end, which tightens the block Longitudinal legs are placed. As soon as he too with its two surrounding sections includes the corresponding longitudinal leg ends, the structure is pre-assembled in a self-retaining manner, since the longitudinal legs have the Press the heating block together and thereby stabilize its structure and the longitudinal leg ends simultaneously against yielding by the Surrounding sections of the cross legs are secured. In this self-holding pre-assembled state can then all the necessary fastenings can be manufactured without the pre-assembled structure by hand or must be held together mechanically.

In an advantageous development of the invention according to claim 2 is at least one of the two cross legs is designed as a ring part. This can laterally on the held together structure from heating block and Longitudinal legs are pushed on, with the ring sections in the area the longitudinal leg also function as the surrounding sections, which therefore do not have to be specially trained. The ring shape allows optimal power distribution and low component weight.

In a development of the invention according to claim 3, the attachment points through self-tapping screws or laser welding points realized. These connections are very tolerant of production, since they follow the pre-assembly according to the invention made at the desired locations can be made without the need for precise mutual positioning the parts to be connected must be observed. Effect at the same time these types of mounting a safe mechanical and electrical Connection.

In a development of the invention according to claim 4, all attachments are made in a common assembly direction perpendicular to the heating block level. This measure can be used to manufacture the fixings automated with very little effort. An advantageous one Designing this measure according to claim 5 provides that the attachment points are in a common plane. In another Embodiment of this measure are a cross leg according to claim 6 and heating element connection ends to be contacted with it designed so that these heating element connection ends on one corresponding contact surface of the cross leg in said common mounting direction can be attached, in which all other fasteners are made.

Fig. 1

eine perspektivische Draufsicht auf eine PTC-Heizeinrichtung mit einem Heizblock und einem diesen haltenden Rahmen für eine Kraftfahrzeug-Heizungsanlage,

Fig. 2

eine Draufsicht auf die in Fig. 1 linke Stirnseite der Heizeinrichtung,

Fig. 3

eine Draufsicht auf einen als Ringteil ausgebildeten Querschenkel des Rahmens von Fig. 1,

Fig. 4

eine Perspektivansicht des anderen Querschenkels des Rahmens von Fig. 1,

Fig. 5

eine Seitenansicht eines der im Heizblock von Fig. 1 verwendeten PTC-Heizregister und

Fig. 6

eine Perspektivansicht der mit einem Kunststoff-Außenrahmen komplettierten Heizeinrichtung von Fig. 1.

An advantageous embodiment of the invention is shown in the drawings and is described below. Here show:

Fig. 1

2 shows a perspective top view of a PTC heating device with a heating block and a frame holding it for a motor vehicle heating system,

Fig. 2

2 shows a top view of the left end face of the heating device in FIG. 1,

Fig. 3

2 shows a plan view of a cross leg of the frame from FIG. 1 designed as a ring part,

Fig. 4

2 shows a perspective view of the other cross leg of the frame from FIG. 1,

Fig. 5

a side view of one of the PTC heating register used in the heating block of Fig. 1 and

Fig. 6

2 shows a perspective view of the heating device from FIG. 1 completed with a plastic outer frame.

The electrical heating device shown is particularly suitable as additional heating in a motor vehicle to lead into the vehicle interior Heating air as long as or as far as possible from a heating and cooling circuit one commonly used as a drive in a motor vehicle The heat emitted by the internal combustion engine is not sufficient for this. As in 1, the heating device has a heating block 1 which of several electrical heating elements arranged next to each other at a distance in the form of strip-shaped PTC heating registers 2 and between these introduced, heat-conducting corrugated fins 3 assembled is.

The rectangular heating block 1 is held in a surrounding frame, the two on opposite block sides to the heating elements parallel longitudinal legs 4a, 4b and two perpendicular thereto arranged cross legs 5a, 5b includes. All four frame legs 4a, 4b, 5a, 5b preferably consist of an aluminum material. Approximately halfway up the heating block are two neighboring PTC heating registers instead of a corrugated fin by a spring strip 6 with a A plurality of spring tongues spread apart in opposite directions spaced from each other. The spring strip 6 is used to achieve a Elastic manufacturing tolerances compensating, play-free heating block construction and, like the corrugated fins, is made of heat-conducting and electrical made of conductive material.

The two longitudinal legs 4a, 4b consist of a C-profile, as for the a profile 4a of Fig. 2 can be seen, with its open side of the heating block 1 faces outwards. The C-shaped longitudinal leg profiles 4a, 4b are slightly outward from the center area to the two ends prefabricated curved, i.e. to their open profile page. The material thickness is e.g. in the range between 1mm and 2mm chosen so that the longitudinal leg 4a, 4b when mounting in the direction of a straight line can be pressed, which enables them to build the heater block 1 press together without play and thereby brace.

A special design is suitable for this longitudinal leg design the cross leg 5a, 5b is provided, which is suitable for the heating block structure 1 self-retaining to be able to pre-assemble, in order then Make connections to the pre-assembled body without these are held together by hand or mechanically got to. For this purpose, the cross legs 5a, 5b have at both ends, i.e. End faces, respective surrounding sections 7a, 8a and 7b, 8b. This comprise in the assembled state of the heating block, as shown in Fig. 1, the corresponding longitudinal leg ends 9, 10, 11, 12. This makes the latter secured against moving outwards in the transverse direction, i.e. the Cross legs 5a, 5b hold the longitudinal legs 4a, 4b in their tensioned Installation state in which you clamp the heating block 1.

The one, in Fig. 1 left cross leg 5a is, as shown in Fig. 3, as closed ring or bracket part with two stiffening crosspieces 13, 14 trained. This design has the advantage of being easy to manufacture, easy assembly and optimal power distribution with low weight. The enclosing sections 7a, 8a for enclosing the longitudinal legs are of this rectangular cross leg ring Narrow side sections formed.

The other cross leg 5b is, as can be seen from FIGS. 1 and 4, of formed a U-shaped profile, the open side of the heating block assembly 1 facing away from the outside. At its ends is this U-cross leg profile 5b, on the one hand, each with a first 90 ° bend 7b, 8b Mistake. These two bends 7b, 8b extend vertically planes lying to the longitudinal axis of the profile and form the surrounding sections for the outer embracing of the corresponding longitudinal leg ends 11, 12. On the other hand, this cross leg 5b is at the end A second 90 ° bend 15, 16 is formed. These two bends 15, 16 extend in a common to the heating block level parallel plane and lie in the assembled state against the in Fig. 1 on the front side of the corresponding longitudinal leg ends. each of the two bends 15, 16 is provided with two fastening openings 17, 18 provided.

The second cross leg 5b also serves as a common connecting rail for electrical contact of one sheet every second PTC heating register of heating block 1 with a first pole of an associated one electrical power supply. The one U longitudinal flank functions for this 19 of this cross leg 5b as a connecting rail contact surface, which are parallel to the heating block level at the front in Fig. 1 Block side extends. 5 shows one of the connecting rails 19 on this PTC heating register to be connected. These have PTC heating registers just like the other PTC heating registers the conventional ones explained above Structure of two contact plates 20, 21, between which there are several PTC elements are located next to one another in openings of a sealing profile 22, on which the contact plates 20, 21 are guided in lateral longitudinal grooves are. With the PTC heating register to be connected to the busbar 19 has, as can be seen in Fig. 5, the one contact plate 20 on the corresponding Connection end on a contact angle 23 through a double 90 ° bend first by 90 ° around the transverse axis and then 90 ° around the vertical axis of the strip-shaped PTC heating register 2 is formed. As a result, the contact angle 23 has one at the end Contacting surface 23a with which he in the assembled state of FIG. 1st lies flat on the cross-leg contact surface 19, the Contact surface 23a of the heating register contact angle 23 with a fastening opening 24 is provided.

The other, alternately arranged in the block PTC heating register, that are not in contact with the busbar 19 point on the opposite At the end, one each formed by one of its two sheets Contact tab 25, as can be seen from FIGS. 1 and 2. About these there is a connection to the other pole of the supply voltage under Use of a corresponding cable harness, not shown. there can the PTC heating register 2 by a not shown, e.g. block externally arranged control device consisting of a control logic and Power electronics electrically connected in a desired manner e.g. parallel or serial or in a mixed form. The connection for the busbar 19 can take place via a connection bracket 26, which is formed on the one longitudinal leg 4a and on the same Block side is located as the connecting lugs 25, so that all cable connections can be produced on a common block side. The metallic design of the longitudinal and transverse legs 4a, 4b, 5a, 5b guaranteed the electrical connection between the connection bracket 26 and the connecting rail 19.

The described design of the heating block 1 shown with the surrounding one and holding frame 4a, 4b, 5a, 5b offers great advantages in terms of a largely automated assembly. This can be done like perform as follows. First, in the usual way, by alternating, suitable placement of corrugated fins 3 and PTC heating registers 2 with the central spring strip 6 of the heating block 1 loosely built. The loose Block structure is then from the outside on the longitudinal legs 4a, 4b pressing clamping means compressed, up to the two transverse sides the cross legs 5a, 5b can simply be plugged on. After loosening the clamping means hold the cross legs 4a, 4b the longitudinal legs 5a, 5b in their block-bracing state by their surrounding sections 7a, 8a, 7b, 8b the longitudinal leg ends 9, 10, 11, 12 hold tight. In this state, the block structure 1 is consequently clamped without play and self-holding by the four frame legs 4a, 4b, 5a, 5b secured against falling apart. The block-center spring strip 6 provides here for a uniform distribution of the frame 4a, 4b, 5a, 5b provided pressure force and compensates for manufacturing tolerances.

Then the necessary fastenings or mechanical and electrical connections to the block structure can be made without the latter are held together by hand or by machine got to. It is particularly advantageous here that due to the described Block and frame design all attachment points from a common Assembly direction can be operated from the front block side in Fig. 1 ago, all of these attachment points practically in a common, parallel to the block level Level. This includes both fastenings 27 of the heating register contact angle 23 on the connecting rail 19 as well as a respective fastening pair 28, 29 for fixing the two longitudinal legs 4a, 4b on Connection rail cross leg 5b.

In the example shown, all of these fastenings 27, 28, 29 are through realized self-tapping screws that are easily automated e.g. by an appropriate automatic screwdriver can be attached. The latter can be done very easily if, as mentioned all screw fastenings are made in one direction and in one common level, i.e. at the same height.

Other advantages of this type of fastening are that it is optimal electrical connection as well as a safe, backlash-free mechanical Represent connection for loosening a higher torque than to Screwing in is required. This type of attachment is also perfect regardless of manufacturing tolerances, as there are no corresponding mounting holes are to be brought into line, but the Screw can be inserted wherever after the pre-assembly the associated fastening opening 17, 18, 24 is located. As a mounting alternative offers e.g. Laser welding on, which is also manufacturing tolerant and is easy to automate and reliable, play-free leads mechanical and electrical connections.

Further advantages of the block frame design according to the invention are Recyclability if the four frame legs 4a, 4b, 5a, 5b like described are made exclusively from an aluminum material, the low due to the nature of the longitudinal and transverse legs 4a, 4b, 5a, 5b Weight of the structure and the comparatively low manufacturing costs. It goes without saying that in addition to the heating device described above further realizations according to the invention are possible, for example one in which both cross legs are designed as a closed ring part are. Instead of the PTC heating register mentioned, depending on the application other conventional electrical heating elements can also be used and instead of the strip shape mentioned, any other one is for a block construction suitable shape for the electrical heating elements possible.

As shown in Fig. 6, the heater block frame assembly manufactured as described can 1a are surrounded by a plastic outer frame, which is used for sealing, insulation and mounting in the heating system and consists of a temperature-resistant plastic material. there there is the possibility of the mentioned cable harness for the electrical To integrate the connection of the PTC heating register 2 in this outer frame 30, i.e. in it, so that the block frame structure 1a itself No electrical plug connections are required, which takes up space keeps low. The outer art frame 30 also has a defined Airflow window 31, which ensures that the airflow to be heated only through the area of the corrugated fins heated by the PTC heating registers 2 3 passes through and no unwanted bypass air flows e.g. in the Area of the frame legs or a cable harness opening.

Claims (6)

Electric heating device, in particular for a motor vehicle, with a heating block (1) with a plurality of electrical heating elements (2) arranged in parallel and intermediate thermal fins (3) and a frame in which the heating block is held, with two longitudinal legs (4a, 4b) and two transverse legs (5a, 5b) arranged perpendicular to the block, characterized in that the transverse limbs (5a, 5b) have at their ends surrounding sections (7a, 8a, 7b, 8b) with which they enclose the corresponding longitudinal limb ends (9, 10, 11, 12) in the transverse direction to secure them outwards. Electric heating device according to claim 1, further characterized in that at least one of the cross legs is designed as a closed ring part (5a). Electric heating device according to claim 1 or 2, further characterized in that fastening points (27, 28, 29) for connecting at least part of the frame legs (4a, 4b, 5a, 5b) to one another and / or for connecting at least part of the electrical heating elements (2) with one or more of the frame legs by self-tapping screws (27, 28, 29) or laser welding points. Electrical heating device according to one of claims 1 to 3, further characterized in that fastening points for connecting at least part of the frame legs (4a, 4b, 5a, 5b) to one another and / or for connecting at least part of the electrical heating elements (2) to one or more of the frame legs are made in a common, perpendicular to the heating block plane assembly direction. An electric heater according to claim 4, further characterized in that the attachment points (27, 28, 29) lie in a common plane. Electric heating device according to claim 4 or 5, further characterized in that at least one cross leg (5b) is designed as an electrically conductive heating element collective connection with a contact surface (19) parallel to the heating block plane and the heating elements connected to the collective connection have at their corresponding connection end a contacting angle (23) with a contacting surface (23a) via which they are fastened to the collective connection contacting surface (19).

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