WO2018100021A1

WO2018100021A1 - Method for producing an electrical or mechanical element

Info

Publication number: WO2018100021A1
Application number: PCT/EP2017/080899
Authority: WO
Inventors: David Ayza Parra
Original assignee: Robert Bosch Gmbh
Priority date: 2016-11-30
Filing date: 2017-11-30
Publication date: 2018-06-07
Also published as: DE102016223816A1

Abstract

The invention relates to a method for producing an electrical or mechanical element (1), said element (1) comprising a component (2) overmoulded with plastic, and the method comprising the following steps: at least one first overmoulding of the component (2) with a first plastic layer (3), and one second overmoulding of the component (2) with a second plastic layer (4), a pocket (5) being formed during the first overmoulding step, which can be used to secure the component (2) for the second overmoulding step.

Description

Description title

Method for producing an electrical or mechanical element prior art

The present invention relates to a method for producing a

electrical or mechanical element, in particular a heater.

In particular, the heater is usable in a fuel filter.

Filter devices are known from the prior art with which

Liquids are filterable. Such filter devices often have a heater to prevent freezing of the filter medium. For example, filter devices are known from the publications DE 10 2006 034 077 A1 and DE 10 2007 005 771 A1.

If heaters or other electrical or mechanical elements such as e.g. Sensors, reinforcements or similar elements used in liquid filters, it must be ensured that the liquid to be filtered with

metallic parts of the heater or the mechanical or electrical elements does not come into contact. If this happens, there is a risk of corrosion. Therefore, from the prior art, an encapsulation of metallic components or components with a plastic known.

During the extrusion coating, the heating or the electrical or mechanical element must be held by auxiliary elements. These

Auxiliary elements prevent full encapsulation of the heater or the electrical or mechanical element, so that subsequent steps are necessary to achieve a complete and thus in particular fluid-tight surrounding the heater or the electrical or mechanical element with plastic.

Disclosure of the invention

The inventive method allows a fluid-tight encapsulation of components, in particular heating elements, with a plastic. In this way, it is ensured that the component, in particular the heating element, which is preferably made of a metallic material, does not come into contact with liquids. In particular, the component, in particular the

Heating element, a sensor or a reinforcing element, in one

Liquid filter used so that the liquid to be filtered by the liquid filter can not come into contact with the component, in particular the heating element. Thus, corrosion of the component, in particular of the

Heating element, avoided. At the same time, the method allows a simple and inexpensive overmolding, wherein the component, in particular the heating element, is securely and reliably encapsulated by a plastic.

The method also allows the overmolding of a pliable component with a plastic. Under limb components is particularly understood that such components considerably deformed by the pure injection pressure of in particular between 400 bar and 1500 bar, preferably between 500 bar and 1000 bar, the spray jet or non-uniform flow fronts on the two sides of the insert or the component can be. The inventive method also ensures that the plastic extrusion has uniform wall thicknesses. The method for producing an electrical or mechanical element comprises the following steps: First, a first encapsulation of a component with a first plastic layer takes place. The component is preferably made of a metallic material and can advantageously be heated, in particular by an electric current, or generate and / or conduct electrical signals in the manner of a sensor. After the at least one first encapsulation takes place a second encapsulation of the one with the first

Plastic layer overmolded component with a second plastic layer.

During the first encapsulation, a pocket is formed which, for the second encapsulation, is overmolded with the first plastic layer

Component serves. Under bag is to understand a basically concave area. In particular, the pocket has a recess into which a holding element can be inserted. This means that holding elements can be used to hold the component in the pocket, in order subsequently to enable a second encapsulation of the component. The at least one pocket is thus attached to the component by the first encapsulation, in that the pocket is a part of the first plastic layer. An internal volume of the pocket is, advantageously completely, separated from the component. Depending on the design of the first encapsulation, however, a part of the first with the first

Plastic layer overmolded component lie within the bag open, that is: be accessible bare without plastic layer within the bag.

By forming the pocket there is a fixation of the electrical or mechanical element for the second encapsulation. It is provided that the at least one first encapsulation mainly for

Reinforcing the component and for attaching the at least one bag is used. In this way, the device, which have a very low bending stiffness, which is also referred to below as limp, safely and reliably encapsulate with a plastic. Under a very small

Flexural rigidity is to be understood in particular that a deformation by

Bending can already be achieved by the spray pressure necessary for overmoulding.

In particular, the component of the element is formed as a stamped grid, particularly advantageously made of a metal sheet. The element is preferably a heater, so that the heating is particularly advantageously designed as a stamped grid heater. The component is preferably a heating element, wherein the heating element is particularly is preferably formed as a stamped grid, in particular of a metal sheet. This means that a deformation of the component could take place only by injection pressure. Such deformation can lead to the component not being completely surrounded by a plastic, but rather to areas which are not surrounded by a plastic. This can be the case in particular if the component is within a

Injection mold is pressed by the injection pressure against the wall of the injection mold. Thus, no plastic can be provided between the injection mold and the component, whereby a complete environment of the component is prevented by plastic. This is done by splitting the

Enveloping prevented in at least a first encapsulation and in a second encapsulation. In particular, the component is reinforced by the first encapsulation, in which case it is not a mandatory requirement that the component is completely surrounded by the first plastic layer after the first encapsulation. Rather, the now reinforced component by a second step of

Envelope be surrounded by the second plastic layer, wherein the first plastic layer additionally provides the pockets for mounting. Thus, as in the prior art, a holding element does not have to directly hold the component, which in turn would lead to an opening in the overmolded plastic after the extrusion coating process and the removal of the holding element.

Rather, a simple and inexpensive and at the same time fluid-tight encapsulation is thus made possible by the steps described above.

The dependent claims show preferred developments of the invention.

The element is preferably a heater of a liquid filter. Thus, the component is preferably a heating element. Such a heater can be produced in a particularly simple, low-effort, fluid-tight and cost-effective manner. The heating element can be heated so as to deliver a heat output to the liquid filter. In this way, a freezing of fluid within the

Liquid filter prevented or a frozen fluid defrostable. Due to the plastic extrusion coating, the heater is optimally suited for use in a liquid filter, since the plastic coating shields the heating element from the fluid. Thus, even highly corrosive fluids, such as urea solutions, can not lead to corrosion of the heater, particularly the heater

Heating element lead. The element is advantageously designed in the form of a sleeve. This means that the element has a hollow cylindrical shape, which in particular makes it possible to arrange a filter medium inside the element, which is preferred when the element is a heater. The

Element, in particular the heater, thus can enclose the filter element in a ring in a liquid filter, so as to heat the filter element and a liquid present therein. Such a shape of a cuff poses a great challenge during the overmolding because deformations of the component must be prevented. Otherwise, this would mean that the component is not completely surrounded by plastic and therefore can come into contact with the liquid to be filtered. In this case, the risk of corrosion would exist. Since such deformation is prevented by the at least one first encapsulation and by the second encapsulation of the component of the element, the sleeve shape represents a preferred form of the element, in particular the heater, since this optimally with the

Filter medium can be combined.

In principle, the method can also be used for mechanical or electrical elements that are not used in a liquid filter.

Particularly advantageous is provided that the component before the first

Enveloping is transformed by forming out of a flat basic shape out. The forming is advantageously done by at least partially reversible elastic deformation. In other words, while reshaping can, for the most part, cause plastic deformation. However, the component, e.g. a stamped grid, in the deformed state have a certain tendency to deform at least partially back towards the starting position. It is thus provided in particular that the component is produced from a plate-shaped material. Preferably, the component is produced from a sheet by punching. The component thus has a dimension in a spatial dimension which is considerably smaller than dimensions in the other two dimensions of space. Therefore, the component is plate-shaped. Before the first encapsulation, the component is formed out of this plate shape. The forming can in particular a bending of the component in a

hollow cylindrical shape. Thus, in particular restoring forces are present, the component of the deformed shape at least a bit far push back to the original shape. These restoring forces can be handled easily by means of the method according to the invention, since a comprehensive fixation of the component can take place during the first extrusion coating. As already described, it is not relevant for the first encapsulation whether a fluid-tight surrounding of the component by the first plastic layer can be achieved.

Advantageously, it is also provided that the at least one pocket represents the only fixation of the component during the second encapsulation. This means that only those holding elements are used for fixing the component, which engage in the at least one pocket. In particular, the pocket has a cylindrical inner volume into which holding elements in the form of cylindrical pins can engage. Since the bag is formed exclusively by the first plastic layer, thus a full encapsulation of the component is possible because the component in any

Contact to one of the retaining elements is. In this way it is possible in particular to realize a fluid-tight encapsulation of the component with plastic.

During the second extrusion coating, the component is preferably held over the pocket in such a way that a seam lies between the first plastic layer and the second plastic layer within the pocket. In particular, the seam lies exclusively within the second pocket. This is the bag

advantageously increased by the second plastic layer. This means in particular that the inner volume of the bag through the second

Plastic layer is increased. By the second encapsulation results in a

Contact surface on which the second plastic layer occurs on the first plastic layer. Since the second plastic layer surrounds the first plastic layer, no contact surface between the first plastic layer and the second plastic layer is visible. Only within the pockets, a seam between the first plastic layer and the second plastic layer can be seen, which corresponds to an outer edge of the contact surface. This is due to the fact that a holding element rests against the first plastic layer inside the pocket, so that there is no second one here during the second encapsulation

Plastic layer can be formed.

Such a seam may result in penetration of fluid between the first plastic layer and the second plastic layer. This is possible avoid in particular such an element according to the invention that for complete sealing of the seam only the bag must be closed. Outside the bag, only the second plastic layer is present. The bag can be closed by simply welding, in particular the fact that the bag as a suspension point of the

Elements is used. Thus, the element can be welded to other components, in particular to a housing of a liquid filter, wherein an opening of the pocket is sealed. Thus, the inner volume of the bag is sealed from the environment, whereby penetration of fluid into the pocket and thus in the seam between the first plastic layer and second plastic layer is prevented. Thus, by providing the seam exclusively within the pocket, sealing of the element is made simple and low in effort. In other embodiments, the seam on the free edge or on the

Front side of the bag or pocket border lie. In such a case, the seam can be made e.g. sealed fluid-tight by a welding process in a particularly simple and low-effort. Particularly advantageous is the component through the second plastic layer, with

Exception of the seam, surrounded fluid-tight. This means that the component is fully protected from the influence of fluids by the second plastic layer. For complete protection of the component, therefore, only the at least one bag is to be sealed. Once the bag is sealed, the penetration of fluid into the plastic extrusion is prevented, whereby no fluid can reach the component. This is true even for aggressive fluids such as

Urea solutions.

During the first extrusion coating, the component is preferably held by a plurality of fixing elements. The fixing elements hold the component in a predefined position. At the same time, the use of the fixing elements leads to a non-fluid-tight encapsulation of the component during the first

Insert molding. However, it does not adversely affect, since such, in particular fluid-tight encapsulation, takes place by the second encapsulation. At the same time there is the advantage that the component can be safely and reliably held in the predefined position, so as to ensure that the element produced has a desired contour. Thus can be Create elements that have very accurate contours. In particular, manufacturing tolerances are lower than in the prior art. In the context of this invention, a plurality of fixing elements is understood in particular to mean that at least two fixing elements are used.

In the first plastic layer advantageously predefined kinks are introduced. The predefined kinks serve to deform the element by kinking or folding after the first encapsulation. The kinks are in particular a film hinge or a film hinge. This means that the kinks correspond in particular to those places where a

Material thickness of the first plastic layer is reduced locally. This results in the application of a bending load on the component to a deformation of the plastic layer takes place at the kinks. In this way, in particular a predefined shape of the element can be achieved in that a plate-shaped component by the first encapsulation such a first

Plastic layer having a corresponding by kinking

allow predefined deformation. Subsequently, the component can be deformed, wherein this deformation is reliable and in particular avoids damage to the component. In addition, predefined deformations can be achieved exactly in this way. In particular, can be through the

Kinking realize the previously described cuff shape of the element.

It is particularly advantageously provided that the first plastic layer has at least one holding element. In particular, the holding element can enable a latching with a partial area of the first plastic layer. By the

Retaining element, the component is stable after deforming in a deformed position. Thus, it is dispensed with that a large number of additional components must be provided, which hold the component in a predefined position. If the component, as described above, made of a plate-shaped material and is to be brought by elastic deformation in a final shape, this is by the above-described kinks and by the

described holding element simple and low effort feasible. In contrast, in the prior art, a plurality of retaining elements must be used to compensate for the elastic restoring forces after deformation.

The first plastic layer and the second Kunststoffschi cht are preferably made of the same material. Thus, it is particularly avoided that thermal stresses can occur within the element. At the same time, the manufacture of the element is simplified. As a result, the thermal expansion coefficients of the two plastic layers are particularly advantageously the same, so that the risk of stress cracking is low. Furthermore, this is advantageous the same shrinkage behavior after the

Spraying process for both plastic layers given, so the risk of the occurrence of cracks along the interface between the two

Plastic layers is minimized. In other embodiments, it may be provided that a first material of the first encapsulation differs from a second material of the second encapsulation.

In a further advantageous embodiment, the second plastic layer surrounds the first plastic layer and the component. Particularly advantageously, the second plastic layer surrounds the first plastic layer and the component completely. This means that a user can only see the second plastic layer when looking outside the mechanical or electrical element. Thus, a bore that would be introduced from outside into the element, first the second plastic layer and then the first plastic layer and the component or without the first plastic layer directly hit the component. By definition, the inner volume of the bag is not considered

To look at exterior of the element. By, in particular, complete, surrounded by the second plastic layer ensures that the component is fluid-tight surrounded by plastic. Finally, it is preferably also provided that the component has at least one electrical contacting point. On the contact point no first plastic layer and no second plastic layer are applied. Alternatively or additionally, it is provided that a contact pocket is formed from the first plastic layer and / or the second plastic layer, within which the contacting point is arranged. It is thus provided in particular that an electrical connection to the component, in particular the heating element, is made possible. This is known from the prior art. Since the contact pocket preferably lies outside of regions of a liquid filter which can come into contact with the fluid to be filtered, such a partial non-extrusion coating of the at least one electrical

Contacting point and / or the shaping of a contact pocket not harmful with respect to the fluid-tight encapsulation of the component. The invention also relates to a heating of a liquid filter. The heater comprises a heating element, a first plastic layer and a second plastic layer. It is provided that the first plastic layer surrounds the heating element and the second plastic layer surrounds the first plastic layer and the heating element. The second plastic layer ensures a fluid-tight surrounding of the heating element. By the first

Plastic layer is formed at least one pocket, wherein a seam between the first plastic layer and the second plastic layer is disposed within the pocket. In addition, the pocket may be additionally enlarged by the second plastic layer. Thus, only the bag is to be sealed in order to achieve reliable and reliable sealing of the heater, in particular of the heating element, with respect to fluids. In particular, after the bag has been sealed, a continuous second layer of plastic is audible from outside the heater, thereby creating a

Ingress of fluid is prevented.

Finally, the invention relates to a fluid filter having a housing with an inlet and an outlet. In addition, the liquid filter has a, in particular hohizylinderformiges, filter medium and a heater. The

Filter medium and the heater are disposed within the housing. The heating is a heating as described above. This ensures that the heating element of the heater can not get in contact with liquids inside the liquid filter. As a result, the heating element is protected against corrosion. Nevertheless, the heater allows safe and reliable, the liquid filter, in particular the filter medium to protect against freezing of the liquid contained. Particularly advantageous surrounding the heater, the filter medium to annularly. Brief description of the drawings

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawings:

Figure 1 is a schematic view of a heater according to a

Embodiment of the invention, wherein the individual layers of the heater are shown broken, 2 a schematic representation of a heating element as used in the heating according to the exemplary embodiment, a schematic plan view of the heating according to the exemplary embodiment of the invention, a schematic sectional view according to the section line AA shown in FIG. 3, a schematic detail view of that in FIG. 4

marked area B, a schematic view of fluid flows within the area B shown in Figure 4, before sealing the pockets, a schematic representation of fluid flows within the area B shown in Figure 4, after sealing the pockets, a schematic representation of a heating element of a heater according to an alternative embodiment of the invention, a schematic representation of the heating element of the heater according to the alternative embodiment of the invention after a first encapsulation, a schematic plan view of the heating element of the heater according to the alternative embodiment of the invention after the first encapsulation and after deformation, a schematic isometric view of the heating element of the heater according to the alternative embodiment of the invention after the first encapsulation and after the

Deform, Figure 12 is a schematic view of a liquid filter according to the

Embodiment of the invention.

Embodiments of the invention

As an exemplary embodiment for producing a mechanical or electrical element, the production of a heater for a liquid filter is described below. In it, the heating element provides the above

described component.

1 shows schematically a heater 1. The heater 1 can be used in particular in a liquid filter 12 (see FIG. In Figure 1, the heater 1 is shown with multiple outbreaks, so that all the components of the heater 1 can be seen. It is understood that the heater 1 is just one example of an embodiment of the invention. In principle, the proposed method can also be applied to electrical components, e.g. for installation in liquid filters, e.g. for sensors. It is also conceivable to provide the method for the encapsulation of mechanical elements which are to be encapsulated in a fluid-tight manner.

The heater 1 comprises a heating element 2. The heating element 2 is shown in FIG. The heating element 2 is a stamped grid element which is punched out of a metal sheet. It is a thickness of the

Metal sheet and thus of the heating element 2 in particular less than 1, 0 mm, advantageously 0.6 mm. Thus, the heating element 2 is a pliable element which has only a low rigidity. As can be seen from FIG. 2, the heating element 2 comprises a multiplicity of heating coils, wherein an electrical voltage can be applied to the heating element 2 via contacting points 10, so that an electric current resulting therefrom can be applied

Heating element 2 can heat up.

To prevent the heating element 2 in contact with corrosive

Liquids can enter, the heating element 2 is encapsulated in plastic. In this case, the injection pressure may for example be between 400 bar and 1500 bar, preferably between 500 bar and 1000 bar. This is done in two steps, so that the heater 1, as shown in Figure 1, a first Plastic layer 3 and a second plastic layer 4 has. The first plastic layer 3 and the second plastic layer 4 are advantageously formed from the same plastic. By overmolding with the first

Plastic layer 3 and the second plastic layer 4 ensures that no fluid can reach the heating element 2.

FIG. 1 schematically shows a fixing element 7. The fixing element 7 is used to hold the heating element 2 during the first encapsulation to form the first plastic layer 3. For reasons of clarity, only a single fixing element 7 is shown in FIG. It is conceivable that a plurality of fixing elements 7 so at least two fixing elements 7 are provided. Since, as already described, the heating element 2 is executed in a slippery manner, a fixing of the heating element 2 by means of said

Fixing 7 required to prevent deformation of the heating element 2 during the first encapsulation. Such deformation would otherwise take place due to the injection pressure.

Due to the large number of fixing elements 7 is thus a full-scale

Enveloping of the heating element 2 with the first plastic layer 3 is not possible. Rather, openings remain within the first plastic layer 3 to the

Locations where the fixing 7 hold the heating element 2, since no plastic between fixing elements 7 and 2 heating element can get.

At the same time, due to deformations of the

Heating element 2, the wall thickness of the first plastic layer 3 fluctuate. Thus, it is conceivable that by the injection pressure, the heating element 2 to a wall of a

Injection molding tool is pressed, whereby a complete encapsulation with the first plastic layer 3 is no longer possible because no plastic between the heating element 2 and the wall of the injection mold can penetrate. The first plastic layer 3 is therefore not used for fluid-tight encapsulation of the heating element 2. Rather, the heating element 2 by the first

Plastic layer 3 structurally reinforced, so that a simple and low-cost further processing of the heating element 2 with the first plastic layer 3 is made possible. The heating element 2 with the first plastic layer 3 is then encapsulated by a second encapsulation process with a second plastic layer 4. As already described, the second plastic layer 4 is preferably made of same material as the first plastic layer 3. The second

Plastic layer 4 surrounds the heating element 2 in a fluid-tight manner. Thus, penetration of fluid into the heater 1 is prevented, so that the heating element 2 is protected from corrosion. The fluid-tight encapsulation of the heating element 2 with the first plastic layer 3 by the second encapsulation is achieved in particular by the fact that the first plastic layer 3 has pockets 5 which are used to hold the heating element 2 encapsulated with the first plastic layer 3 during the second encapsulation. This will be described below with reference to FIGS. 3 to 7.

FIG. 3 shows schematically a plan view of the heater 1. There is one

Section line A-A drawn, the section of which is shown in Figure 4. FIG. 4 thus shows the sectional view along the section A-A. It can be seen here that the heater 1 has, in addition to the heating element 2, the first plastic layer 3 and the second plastic layer 4. Furthermore, it can be seen that the second

Plastic layer 4, the heating element 2 completely and in particular fluid-tight surrounds, since in particular the resulting from the fixing elements 7 openings 19 of the first plastic layer 3 are filled by the second plastic layer 4.

It can also be seen from FIG. 4 that pockets 5 are formed by the first plastic layer 3, wherein the pockets 5 are advantageously enlarged by the second plastic layer 4, in particular along a central axis of the pockets 5. The pockets 5 are shown in detail in FIGS. 5 to 7, with FIGS. 5 to 7 each schematically showing the area B in FIG. 4 in detail.

As can be seen from FIG. 5, the basic shape of each pocket 5 is formed by the first plastic layer 3. The pocket 5 has in particular an inner volume, wherein a retaining pin or the like can engage in the inner volume of the pocket 5, so as to hold the over-molded with the first plastic layer 3 heating element 2 for the second encapsulation. At the same time that is

Heating element 2 separated by the first plastic layer 3 of the inner volume of the bag 5. In particular, the inner volume of the pocket 5 is a cylinder volume, so that cylindrical retaining pins in the pockets

5 can be inserted to the overmoulded with the first plastic layer 3

To keep heating element 2 for the second encapsulation. In particular, on this Way a safe and reliable holding of the molded with the first plastic layer 3 heating element 2 allows.

Due to the concerns of the retaining pins on the pocket 5 and thus on the first plastic layer 3, the first plastic layer 3 is thus not surrounded by the second plastic layer 4 within the pocket 5, since penetration of plastic between the retaining pin and the first plastic layer 3 during the second Umspritzens is not possible. Rather, a seam 6 is formed between the first plastic 3 and the second plastic layer 4. However, this seam 6 lies inside the pocket 5.

Basically, a seam 6 between the first plastic layer 3 and the second plastic layer 4 is a weak point, since fluid could possibly penetrate between the first plastic layer 3 and the second plastic layer 4 and thus could reach the heating element 2. In order to prevent this case of the penetration of the fluid into the pocket 5 shown in FIG. 6, the pocket 5 is advantageously sealed. The sealing of the pocket 5 is advantageously carried out by welding, this

in particular with a fastening of the heater 1 in a housing 14 of a liquid filter 12 can be carried out. This case is shown in FIG. Out

FIG. 7 shows that the pockets 5 are the only points of the heater 1 which have a seam 6 between the first plastic layer 3 and the second plastic layer 4. Therefore, a sealing of the said seams is made easy and little effort. In particular, by fixing the heater 1 to the filter housing 14, said sealing is achieved. Thus, the

Heating 1 easy and inexpensive to manufacture, while preventing the penetration of fluid into the heater 1.

In Figure 1 and Figure 3, a contact pocket 1 1 is also shown. The

Contact pocket 1 1 serves to receive the contacting points 10 of

Heating element 2, so that by the contact pocket 1 1 electrical contact with the heating element 2 can be made. The contact pocket 1 1 is located in particular outside of the filter housing 14, so that the contact pocket 1 1 and in particular the contacting points 10 can not get in contact with corrosive fluid. FIGS. 8 to 11 describe an alternative embodiment for the production of the heater 1. While in the previously described

Embodiment of a sleeve shape of the heating element 2 was assumed during the first encapsulation is in the alternative

Embodiment, the heating element 2 plate-shaped. Again, the heating element 2 is a stamped grid, which has been punched out of a metal sheet, wherein the thickness of the metal sheet and thus of the heating element 2 is in particular less than 1, 0 mm, advantageously 0.6 mm. In principle, the method is not limited to such material thicknesses. It can e.g. also be provided for material thicknesses greater than 1, 0 mm. For example, It can be designed for material thicknesses up to 3mm or up to 10mm or even for even larger material thicknesses.

In contrast to the embodiment described above, in the alternative embodiment, the heating element 2 does not become out of the plate shape

(see Figure 8) deformed out, so as to reach the sleeve shape. Rather, the first encapsulation is to form the first

Plastic layer 3 in the undeformed state of the heating element 2, that is, in the state of the plate shape. The heating element 2 after the first encapsulation is shown in FIG. It is intended that the first

Plastic layer 3 has a plurality of predefined kinks 8, wherein the predefined kinks 8 are provided for buckling of the first plastic layer 3. In particular, a number of at least two kinks 8 are considered here among a multiplicity. The predefined kinks 8 are generated by a locally reduced material thickness of the first plastic layer 3. In other embodiments, exactly one kink 8 may be provided.

Thus, by folding at the kinks 8 a deformation of the

Heating element 2 are executed. This is schematically shown in FIG. 10 and in FIG

Figure 1 1 shown. Thus, the sleeve shape of the heater 1 can be achieved by deforming the heating element 2 with the first plastic layer 3 after the first encapsulation, which is made possible by the kinks 8 of the first plastic layer 3. In addition, in the illustrated

Embodiment, the first plastic layer 3, a holding element 9, wherein with the holding element 9, the deformation is fixed. The holding element 9 may be formed, for example in the form of a snap hook or in the manner of a Clipses. Thus, the heating element 2 with the first plastic layer 3 by the holding member 9 in the sleeve shape is preserved. In principle, the pockets 5 are also provided, so that a simple fixing of the heating element 2 during the second encapsulation is made possible. In other embodiments, it is also possible to dispense with the provision of holding elements 9.

The heating element 2 shown in Figure 10 and Figure 1 1 with the first

Plastic layer 3 can thus analogously as in the previously described

Embodiment provided with the second plastic layer 4 by the second encapsulation. By the second encapsulation, in turn, the fluid-tight surrounding of the heating element 2 with the second plastic layer 4 takes place. In this case, the alternative embodiment has compared to the previously

described embodiment has the advantage that during the first encapsulation no expensive fixing of the heating element 2 in one

Injection mold must be made.

Finally, FIG. 12 shows schematically a liquid filter 12

Liquid filter 12 has a housing 14, wherein the filter housing 14 comprises a lid 17 and a filter cup 18. The lid 17 has an inlet 15, while the filter cup 18 has an outlet 16. Within the

Housing 14, a filter medium 13 is arranged. The filter medium 13 is hollow-cylindrical, wherein fluid can be supplied via an end face and the filtered fluid can be removed via a jacket side. The heater 1 preferably extends in the form of a hollow cylinder around the filter medium 13. The first encapsulation and the second encapsulation of the heating element 2 with a plastic ensure that the heater 1 is completely fluid-tight. At the same time, the pockets 5 (not shown in FIG. 12) are welded to the filter housing 14 so that the pockets 5 are also sealed. The first plastic layer 3 and / or the second plastic layer 4 may preferably be formed from a thermoplastic and / or a duroplastic. As the thermoset epoxy resins, melamine resins, or phenolic resins are preferably used. The thermoplastics used are preferably H-PE, PP, PA, PBT or PEEK.

Claims

claims

1 . Method for producing an electrical or mechanical element (1), wherein the element (1) comprises a plastic-molded component (2), the method comprising the following steps:

At least a first encapsulation of the heating element (2) with a first

Plastic layer (3), and

A second encapsulation of the heating element (2) with a second

Plastic layer (4),

Wherein during the first encapsulation a pocket (5) is formed, which serves as a fixation of the heating element (2) for the second encapsulation.

2. The method of claim 1, wherein the element (1) is a heating of a

Liquid filter (12), and wherein the component (2) is a heating element.

3. The method according to claim 1 or 2, characterized in that the

Element (1) is formed in the form of a cuff.

4. The method according to any one of the preceding claims, characterized

characterized in that the component (2) before the first encapsulation by forming, in particular by reversible elastic deformation, from a flat basic shape is formed out.

5. The method according to any one of the preceding claims, characterized

in that the at least one pocket (5) represents the only fixation of the component (2) during the second extrusion coating.

6. The method according to any one of the preceding claims, characterized

in that, during the second encapsulation, the component (2) is held over the pocket (5) in such a way that a seam (6) between the first plastic layer (3) and the second plastic layer (4), in particular exclusively, inside the pocket ( 5), where Advantageously, the pocket (5) is enlarged by the second plastic layer (4).

7. The method according to claim 6, characterized in that the element (1) by the second plastic layer (4) with the exception of the seam (6) is surrounded fluid-tight.

8. The method according to any one of the preceding claims, characterized

characterized in that the component (2) is held during the first extrusion coating by a plurality of fixing elements (7) which hold the component (2) in a predefined position.

9. The method according to any one of the preceding claims, characterized

characterized in that in the first plastic layer (3) predefined

Kinking points (8) are introduced to deform the component (2) after the first encapsulation by kinking at the kinks (8).

10. The method according to claim 8, characterized in that the first

Plastic layer (3) has at least one holding element (9) through which the component (2) after deformation in a deformed position is preserved.

1 1. Method according to one of the preceding claims, characterized

characterized in that the first plastic layer (3) and the second

Plastic layer (4) are made of the same material.

12. The method according to any one of the preceding claims, characterized

characterized in that the second plastic layer (3) is the first

Plastic layer (4) and the component (2), in particular completely surrounds.

13. The method according to any one of the preceding claims, characterized

characterized in that the component (2) has at least one electrical

Contacting point (10), wherein on the contacting point (10) no first plastic layer (3) and no second plastic layer (4) is applied and / or wherein the first plastic layer (3) and / or the second plastic layer (4) has a contact pocket (1 1) is formed, within which the contacting point (10) is arranged.

14. heating (1) comprising a liquid filter (12)

A heating element (2), A first plastic layer (3) surrounding the heating element (2), and

A second plastic layer (4) surrounding the first plastic layer (3) and the heating element (2),

Wherein at least one pocket (5) is formed by the first plastic layer (3) and a seam (6) is arranged between the first plastic layer (3) and the second plastic layer (4) within the pocket (5).

Liquid filter (12) comprising

A housing (14) having an inlet (15) and an outlet (16),

• a filter medium (13), and

A heater (1) according to claim 14,

• wherein the filter medium (13) and the heater (1) within the

Housing (14) are arranged.