EP1037507A2 - Manufacturing process of electrical heating elements in an injection moulding tool - Google Patents

Abstract

The method involves embedding a heating filament (2) in insulating material (3) in a cladding tube. The cladding tube is sealed using a rolling process, and is provided with the desired contour (5) at the same time. The contour may be an annular shaft contour, a threaded contour, or a threaded, annular shaft contour.

Description

The invention relates to a method for manufacturing of electric radiators from Injection molds, in the form of a heating cartridge or a tubular heater consisting of a metallic jacket tube, heating conductors and Insulating compound, in a first step the heating conductors in insulating material in the jacket tube be embedded. Are in the prior art different processes for the production of electric radiators in the form of a heating cartridge or a tubular heater known. So is known for example from DE 42 42 505 C2 that the jacket pipe through a flexible corrugated hose is formed.

It is disadvantageous here that the compression of the Isolating compound is done either just by shaking what adversely affect the load capacity of the radiator affects, or the compression takes place in that acted on two parallel sides of the radiator to reduce this in diameter what but not for a uniform compression of the Insulating compound leads over the entire cross section.

Furthermore, for example from DE 195 41 504 A1 an electric radiator of the generic type known in which a ring or on the jacket tube Spiral corrugated hose is pushed on, the remaining between the hose and the jacket tube Annular gap and the cavities facing it Hose with good heat conductive metal powder are filled. Here, the casing tube is smooth Pipe, which is easy to reduce, but is the structure is complicated and relatively expensive.

Based on this state of the art Invention, the object of a method for Production of a radiator of the generic type create, in which the production is simplified and an even, high compression over the entire cross section is created.

To solve this problem it is proposed that in a further process step, the casing tube compacted by means of a rolling or rolling process and is simultaneously contoured.

By rolling the casing tube into a contour shape is easy to bend and therefore the Possibility of manual, easy adjustment to a later installation location was created. By such a uniform compression can Volume reduction of up to 15% achieved become.

It can preferably be provided that the Provide the casing tube with an annular corrugated shape becomes.

Furthermore, it can preferably be provided that the Jacket tube is provided with a thread contour.

In addition, it can preferably be provided that the Jacketed pipe with a thread contour in a corrugated shape is trained.

According to the invention, an electric radiator generic type are produced, which in Avoids known disadvantages of also an inexpensive production at high Quality and thus long life.

Preferred developments are in the claims specified.

The method according to the invention is as follows explained using a schematic drawing.

Figur 1 elektrische Heizkörper, Mantelmaterial mit Ringwellformkontur im Schnitt;

Figur 2 elektrische Heizkörper, Mantelmaterial mit Ringwellformkontur;

Figur 3 und 4 desgleichen in Gewindekontur des Mantels;

Figur 5 und 6 unterschiedliche Heizkörperformen im Querschnitt gesehen;

Figur 7 und 8 eine Darstellung gemäß Figur 1 und 2 mit einer Gewindekontur in Ringwellform.

It shows:

Figure 1 electric radiator, jacket material with ring wave shape contour in section;

Figure 2 electric radiator, jacket material with a corrugated contour;

Figures 3 and 4 likewise in the thread contour of the jacket;

Figures 5 and 6 different radiator shapes seen in cross section;

7 and 8 a representation according to FIGS. 1 and 2 with a thread contour in the form of a corrugated ring.

In all shown in the drawings electric radiators are on the axial End areas of the cylindrical Radiator connector pins 1 provided to which Heating conductor 2 are connected, which are inside the Radiators are arranged. The cavity of the Radiator is with insulating material 3, for example Magnesium oxide filled. Axial can be a seal by means of ceramic insulators 6 and fastening nut 7 take place on the thread formation of the Pin 1 is screwed on.

The cladding material can, for example, be nickel or also preferably be stainless steel. Stainless steel is under preferred also because another Embrittlement in a bending area causing the fracture of the Radiator could result when using Stainless steel does not occur as a material.

After installing and filling the radiator and if necessary after sealing (for example at 4 in Figure 2) the radiator 1 and 2 by means of a rolling tool compacted by rolling and simultaneously into the Contour 5 deformed, as in particular in the Sectional view in Figure 1 can be seen. It is a so-called Ring wave shape contour, with the larger rings larger Diameter over narrow rings smaller Diameter are interconnected. The narrow ones Rings are opposite in terms of their wall thickness the wide ring elements reduced. Through this Training becomes a particularly good manual Malleability (bending of the radiator around its Central longitudinal axis) allows, but still a uniform all-round compression of the insulating material 3 he follows.

In the training according to Figures 3 and 4 that Sheath tube formed into a thread contour, whereby between wide flat ring elements that the Form the outer skin of the radiator, V-shaped notches in Thread form are provided all around. Also at this training is the bendability through the V-shaped Notches relieved, yet one over the cross section constant reduction and Compression of the insulating material 3 is reached.

The cross-sectional shape of the radiators can be round, as indicated in Figure 5, or square, as indicated in Figure 6.

A further embodiment is shown in FIGS. 7 and 8, in which the casing tube with a thread contour in Ring wave shape is formed. The training is similar in principle of the training of Figures 1 and 2, wherein only the individual elements not circulating, in are closed rings, but the broad ones Rings and the narrow rings are in the form of revolving thread-like spirals shaped.

Here too, the narrow channels make it a good one Bendability around the central longitudinal axis of the radiator achieved and still a uniform compression the insulating compound 3 ensured.

The radiators are deformed after Filling and installing the individual elements for example by a rolling or pressing process or also by a process of the type of Thread rolling. Here, the ring contour or Helix contour generated, with a reduction in Diameter of up to 15% is effected.

The radiators designed according to the invention are relatively easy to manufacture and despite being more uniform Compression can be bent manually.

The invention is not limited to the exemplary embodiments limited, but within the scope of the revelation often variable.

All new, in the description and / or drawing disclosed individual and combination features regarded as essential to the invention.

Claims (6)

A process for the production of electrical heating elements of injection molds in the form of a heating cartridge or a tubular heating element, consisting of a metallic jacket tube, heating conductors and insulating compound, the heating conductors being embedded in insulating compound in the jacket tube in a first process step, characterized in that in a further process step the The casing tube is compressed by means of a rolling or rolling process and at the same time provided with a contour. A method according to claim 1, characterized in that the jacket tube is provided with an annular corrugated shape. A method according to claim 1, characterized in that the jacket tube is provided with a threaded contour. A method according to claim 1, characterized in that the jacket tube is formed with a threaded contour in a corrugated shape. Method according to one of claims 1 to 4, characterized in that the contour is formed in a meandering manner, wide ring zones being applied alternately with narrow ring zones, the wall thickness in the area of the narrow ring zones preferably being reduced compared to the wall thickness of the wide ring zones and the narrow ring zones are reduced in diameter more than the wide ring zones, which results in good flexibility in the area of the narrow ring zones around the longitudinal central axis of the radiator. Method according to one of claims 1 to 4, characterized in that the contour is formed into flat ring elements, each of which is followed by radially indented regions in the form of a V in order to enable the heating element to be bent about its central longitudinal axis in the region of V-shaped regions.

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