CN112423528A

CN112423528A - Method for connecting and sealing electrical components

Info

Publication number: CN112423528A
Application number: CN202010824238.1A
Authority: CN
Inventors: M.弗里德里希; M.多林; N.费雷拉
Original assignee: Volkswagen Automotive Co ltd
Current assignee: Volkswagen Automotive Co ltd
Priority date: 2019-08-21
Filing date: 2020-08-17
Publication date: 2021-02-26
Anticipated expiration: 2040-08-17
Also published as: DE102019212461A1; KR102433519B1; DE102019212461B4; CN112423528B; KR20210023707A

Abstract

The present invention relates to a method for connecting and sealing electrical components and at least one conductor, and a correspondingly constructed assembly. For this purpose, electrical components are provided, preferably a busbar in a vehicle for the high-voltage on-board electrical system and at least one line with de-insulated ends. Push the sealing sleeve onto the at least one line and position the sealing sleeve in such a way that the sealing sleeve does not interfere with the injection molding of the electrical components or that the sealing sleeve itself does not come together Encapsulated by injection molding. The electrical components are then connected to at least one conductor. Next, the component is injection-molded and encapsulated, wherein an overlapping region of the injection-molded encapsulation portion and the insulating portion of the at least one wire is also formed. The sealing sleeve is then moved into this overlapping area. Since the sealing sleeve has a smaller diameter than the injection-molded encapsulation in the overlapping area, a squeeze seal is formed between the sealing sleeve, the injection-molded envelope and the insulation of the at least one wire, so that no moisture can escape and other aggressive media penetrate the components.

Description

Method for connecting and sealing electrical components

Technical Field

The invention relates to a method for connecting and sealing an electrical component encapsulated by a non-conductive material to at least one conductor, and to an electrical component connected to at least one conductor, encapsulated and sealed.

Background

Electrical components, in particular for energy distribution in the high-voltage on-board electrical system of a vehicle, have to be increasingly smaller. Various solutions have been developed in the past to seal these electrical components against the effects of moisture and aggressive media in the vehicle. Said solutions mainly propose to envelope the components with a separate housing. To further seal, a sealing device is mounted at the cable end. However, this measure is time-consuming and requires a plurality of separate steps. Furthermore, due to the presence of vibrations and lateral forces in the vehicle and environmental conditions in which aggressive media such as water, brake fluid, fuel, salt, etc. act, the installed seals may loosen or quickly wear.

In a different embodiment, the electrical components arranged in the housing are filled with a non-conductive potting compound, which nevertheless serves as a seal. However, for this purpose, additional equipment for producing the cast component must be provided, and the formation of the usable component here also requires a plurality of separate steps.

More recent developments in the prior art suggest injection molding of the components. For example, the electrical components are inserted into an injection mold, where they are then encapsulated with a non-conductive, simultaneously hermetically acting material. However, if electrical components which are already connected to the electrical lines are to be encapsulated in this way, the problem arises that electrical lines, in particular for high-voltage vehicle electrical systems, are mostly insulated by silicone-coated casings and are injection-molded, for example, by polyamides which do not adhere to silicone or cannot be sealed with respect to silicone.

Disclosure of Invention

The object of the invention is to provide a method for insulating and effectively sealing an electrical component connected to at least one line.

The object of the invention is achieved by a method according to the invention and a component according to the invention.

In the method according to the invention for connecting and sealing an electrical component that is encapsulated in a non-conductive material and is to be connected to at least one line, at least the following steps are carried out:

providing at least one conductor and a component to be connected to the conductor, the conductor having an end portion with insulation removed (or with an insulation sheath stripped) in a connection region,

pushing the sealing sleeve over the at least one conductor,

positioning the respective sealing sleeve outside the connection region and at least one region of overlap (or overlap region) to be realized of the injection-molded part and the insulation of the at least one line,

connecting the component to at least one line in the connecting region,

injection molding the component, the connecting region and the corresponding overlap region to be realized in a non-conductive material,

the press sealing arrangement (Pressdichtung) is produced by positioning the respective sealing sleeve in the overlap region.

Electrical components in the sense of the present invention are components or assemblies into and/or out of which an electrical current is conducted. The electrical component can be, in particular, a distributor for electrical energy or current or, for example, an electrical consumer (or a power consumer) which contains a lighting device and is operated by current. The term "component" may be used synonymously with "electrical component" in the following.

It is particularly preferred that the electrical component is a distributor for electrical energy in a high-voltage on-board electrical system in a vehicle. Such a distributor can preferably be realized in the form of a so-called Busbar or Busbar (Busbar). Since the bus bars are connected to all the input and output lines, the bus bars or bus bars are generally understood in the art as conductor arrangements which act as central distributors of electrical energy. The busbars are typically uninsulated. According to the invention, the insulation is carried out in one of the subsequent steps of the disclosed method.

The on-board electrical system contains all electrical components in the vehicle and is used for the power supply and the communication of information between the components of the vehicle and the control device. High-voltage vehicle electrical systems describe vehicle electrical systems which are operated with an alternating voltage of more than 30V up to 1KV or with a direct voltage of more than 60V up to 1.5 KV.

In the method according to the invention, the electrical component is to be connected to at least one line. A conductor is understood here to mean an electrical line, i.e. a device for transmitting electrical current and information. The wire may be made up of one or more individual conductors, also known as litz wires, and is usually insulated outwards. Different plastics, also including silicone, are generally used as insulating materials, which surround the individual conductors and insulate them from one another.

In order to carry out the method according to the invention, at least one line to be connected to the electrical component must be insulated in the region in which the connection is to be carried out. I.e. where the insulating layer should be removed. This region is typically one of the ends of the respective wire. In the context of the method, the region from which the insulation is removed is to be referred to below as the connection region.

At least one conductor with an end section with insulation removed and an electrical component which is to be connected to the at least one conductor are now provided for carrying out the subsequent steps. The sealing sleeves are respectively pushed and sleeved on at least one wire. The sealing sleeve is a substantially cylindrical body with a bore or through hole along a longitudinal axis which is guided through the center of the substantially circular base surface of the cylindrical body. As long as bores or through-holes are formed in the sealing sleeve, any other shape can naturally also be selected for the sealing sleeve.

The inner diameter of the sealing sleeve should be adapted to the intended dimensions of the injection molding of the electrical components and the lines to be connected in a subsequent step. The inner diameter is selected such that the sealing sleeve can be pushed loosely onto the respective line, but is also selected such that a press-fit sealing structure can then be realized as will still be explained.

The sealing sleeve must be positioned outside the connection area. In addition, in the method according to the invention, an overlap region of the encapsulation of the electrical component and the insulation of the at least one electrical line should be realized. In this region, the encapsulation should cover the insulation of the at least one line at least in sections. I.e. the sealing sleeve, must also be positioned sufficiently far away from the electrical components on the line in order to be able to form this overlap region. The sealing sleeve must therefore be positioned at least with the dimensions of the connecting region and the overlap region away from the electrical component.

The component is now connected to the at least one line in the connection region of the at least one line. As will be explained in more detail elsewhere, the connection can be effected in a friction-fit, material-bonded and/or form-fitting manner.

If all the required wires are connected to the electrical component, the electrical component is encapsulated by injection molding with a non-conductive material, i.e. with a material that does not conduct current, which thus serves as an insulation of the electrical component. The envelope or the injection-molded envelope is produced by an injection molding process, preferably an injection molding process.

In an injection molding process, a component having at least one connected conductor is placed in an injection mold, and the injection mold is filled with a non-conductive material. The thickness of the envelope is defined by the injection mold. In addition to the electrical components, the injection molding or the envelope should also cover the connection region of the at least one line and the overlap region of the at least one line.

If the encapsulation has already been carried out and cured, the pinch seal is formed in the overlap region by means of the sealing sleeve by moving the sealing sleeve into the overlap region. A press-fit sealing arrangement is achieved if the inner diameter of the sealing sleeve is at least slightly smaller than the outer diameter of the at least one line together with the injection molding compound in the overlap region. By moving the sealing sleeve into the overlap region, the non-conductive material of the insulating part and the encapsulation part is pressed through the sealing sleeve and sealed against one another in the overlap region.

The steps described above are carried out for each conductor connected to the electrical component, except that the electrical component and the at least one conductor connected to the electrical component are encapsulated. In this case, the steps can be carried out either individually for each line or else separately for each line to be connected, and then the next step can be carried out.

The method according to the invention is used to connect an electrical component to at least one line, is surrounded in its entirety by an insulating material as far as the overlapping region of the at least one line, and is sealed and protected against the ingress of water, fuel, brake fluid and other aggressive media by means of a sealing sleeve by pressing a sealing structure. The method is easy to implement without incurring significant additional expense.

In a first preferred embodiment of the invention, it is provided that the press-fit sealing arrangement is formed by applying force and/or at least heating the sealing sleeve. Since the inner diameter of the sealing sleeve is at least slightly smaller than the outer diameter of the overlapping region of the at least one injection-molded conductor, a displacement into the overlapping region can be made easier by applying a force on the sealing sleeve. The sealing sleeve can be pressed in the direction of the overlap region with pressure and into the desired target position, or can be moved into the overlap region by applying a tensile force. Alternatively or additionally, the sealing sleeve can be heated, so that it expands and can therefore be moved more easily into the desired position in the overlap region. The temperature at which the sealing sleeve is heated should be selected such that the sealing sleeve itself or the non-conductive material of the injection molding does not have an adverse effect on account of the elevated temperature.

The connection of the at least one line to the electrical component is effected in a friction-fit, material-bonded and/or form-fitting manner. In a preferred embodiment, the at least one line is connected to the electrical component by ultrasonic welding or laser welding.

Ultrasonic welding belongs to the category of friction welding. The joining of the components to be joined is effected here by high-frequency mechanical vibrations which, due to molecular and boundary surface friction, lead to a temperature increase between the components.

Laser beam welding, also known as laser welding, is carried out by means of a laser beam. Laser welding is primarily suitable for welding components that must be joined with high welding speeds, narrow and elongated weld shapes, and less thermal warping.

The connection of the at least one line to the electrical component can alternatively also be realized as a plug connection.

In a further preferred embodiment, it is provided that the encapsulation is realized by a thermoplastic, in particular polyamide 12. Thermoplastics are plastics which can be deformed in a defined temperature range. The deformation is a reversible process as long as the material is not overheated and a so-called thermal decomposition of the material takes place here. Furthermore, thermoplastics are weldable. It is further preferred to use polyamides, since they have very good strength and toughness as well as processability and chemical stability.

Polyamide 12 may be used, for example, as a non-conductive material for injection molding the component and the at least one conductor connected to the component. Polyamide 12 (also abbreviated as PA12) is a partially crystalline thermoplastic having the lowest water absorption of all polyamides. Polyamide 12 is distinguished by high toughness and good chemical stability and resistance to thermal deformation up to 50 ℃ and, owing to its properties, is particularly suitable for use in moist environments or when high dimensional stability is required.

In a further preferred embodiment, the sealing sleeve is made of a plastic or ceramic material. Plastics are suitable because of their chemical stability, flexible shaping and at the same time being light. Ceramic sealing sleeves are made of or made of so-called industrial ceramics and are advantageously suitable for their high hardness, chemical stability, wear resistance and corrosion resistance.

Both the sealing sleeve and the injection-molded part may be formed from a fiber-reinforced structure. In this case, fibers are added to the base material of the non-conductive material of the sealing sleeve or the injection molding, respectively, in order to form a composite material with improved properties. The fibers also increase the strength of the material surrounding the fibers. The fibers may be, for example, glass fibers suitable for the respective use. However, ceramic, carbon or nylon fibers may also be used. In any case, the properties of the fibers should be adapted in harmony with the properties of the material surrounding the fibers.

In a further preferred embodiment of the method according to the invention, the sealing sleeve is positioned in such a way that it surrounds the conductor-side end of the overlap region. The conductor-side end of the overlap region is the region of the at least one conductor in which the overlap of the non-conductive material with the insulation of the at least one conductor ends. The region is in particular the terminal edge of the injection-molded part. In this embodiment of the method, it is provided that the edge or the conductor-side end of the overlap region is surrounded by a sealing sleeve. That is to say the sealing sleeve should be positioned such that it covers the conductor-side end of the overlap region, i.e. the conductor-side end of the overlap region is covered by the sealing sleeve. The sealing sleeve thus provides additional protection in the overlap region for the edge region of the conductor-side end of the injection molded part against the penetration of aggressive media and also against mechanical damage.

In a further preferred embodiment, it is provided that the press-fit seal is formed by at least one latching point (or latching point) and/or that the press-fit seal is formed by at least one latching point. In the sense of the present invention, this is to be understood as meaning a form-fitting connection between the sealing sleeve and the encapsulation by forming at least one latching point in order to lock the position of the sealing sleeve in the use state in which vibrations and forces act from the outside on the encapsulated component. For this purpose, projections or indentations can be provided in the sealing sleeve, i.e. in the through-hole or bore, and corresponding recesses or indentations can be formed in the overlapping region of the injection-molded part. If the sealing sleeve is moved into the overlap region, the projections and the corresponding recesses engage with one another and thus form a form-fitting connection which locks the position of the sealing sleeve.

However, it is also possible within the scope of the invention to form the projections or the evaginations in the overlapping region of the injection molding and to form corresponding recesses or indentations in the interior of the sealing sleeve, i.e. along the through-holes or bores in the sealing sleeve. The recess may also be a split in the sealing sleeve or a hole in the sealing sleeve.

The projections or the evaginations can each be point-shaped or linear, independently of the element on which they are formed, in order to form at least one latching point. More than one latching point can be formed, and the individual projections or the evaginations can have the same or different shapes. However, the recess or indentation on the counter element should correspond as far as possible to the projection or the evagination in order to form a reliable holding.

According to the invention, a sealed electrical component is also claimed, which is encapsulated by a non-conductive material and is connected to at least one line, wherein the component is connected to the end of the at least one line, which end is insulated in the connecting region. The component, the connecting region and the overlap region of the at least one line are encapsulated by a non-conductive material, wherein the insulation of the at least one line is also encapsulated in the overlap region. In each case a press-fit sealing structure is formed in the overlap region by means of a sealing sleeve.

The method according to the invention and the injection-molded electrical component according to the invention provide a reliable seal of the electrical component connected to the electrical line, which can be produced simply and cost-effectively. A very small design can be achieved in this case.

The various embodiments of the invention mentioned in the present application can advantageously be combined with one another as long as they are not specified otherwise in individual cases.

The invention is elucidated below in the examples with reference to the accompanying drawings. In the drawings:

fig. 1a to 1d show an exemplary sequence of the method according to the invention in a schematic view, and

fig. 2a to 2b show a detail of fig. 1.

Fig. 1a to 1d show exemplary sequences for carrying out the method according to the invention in schematic views. For reasons of intuition, all components are no longer individually labeled in fig. 1b to 1 d. The reference lines show the mutual orientation of the individual elements and make the correspondence easier.

By means of the method according to the invention, for example, an electrical component 30 is connected to the exemplary three lines 10, and the component 30 is encapsulated by a non-conductive material and the lines 10 are encapsulated in regions in order to insulate the assembly. In the exemplary embodiment, electrical component 30 is a bus bar, by means of which electrical energy is distributed to a high-voltage on-board electrical system of the vehicle.

As can be seen in fig. 1a, three wires 10 are provided with insulation removed in the connection area 12. Fig. 1b shows that the sealing sleeve 20 is pushed onto each conductor 10 and, as can be seen from the overall view of fig. 1, is removed from the connection region 12 and the overlap region 14 to be realized. In each overlap region 14, the encapsulation 40 which is then realized should cover the insulation of the line 10 at least in sections, with the aid of which encapsulation 40 the busbar 30 is insulated. In fig. 1b, the busbar 30 is connected to each of the three lines 10 in its connecting region 12 by means of ultrasonic welding.

As can be seen from fig. 1c, the injection molding 40 of the bus bar 30 is realized with a thermoplastic, for example polyamide 12. This is achieved in an intermediate step by means of an injection molding process. The fibers may also already be embedded in the plastic to reinforce the injection molded part 40. During the encapsulation, an overlap region 14 is also realized on each conductor 10, in which overlap region the polyamide 12 also envelops the conductor 10 in each case.

Then, the sealing sleeves 20 are respectively moved into the overlapping regions 14 in the directions indicated by the arrows by the pressing force. The sealing sleeve 20 is made of plastic, so that it is resistant (or stable) to aggressive media in the engine compartment of the vehicle. The sealing sleeve 20 is now positioned in such a way that the respective conductor-side end of the injection-molded part 40, i.e. the edge formed there, is surrounded and covered by the sealing sleeve 20.

Fig. 2a is directed to fig. 1c and shows a detail with a circle, which is shown enlarged in fig. 2 b. Fig. 2b shows that the two latching points 42 are formed in the overlap region 14 in the form of projections for which two corresponding recesses 22 are provided in the sealing sleeve 20, so that, when the sealing sleeve 20 is pushed over, a positive-locking connection is produced between the respective sealing sleeve 20 and the encapsulation 40, which positive-locking connection can also lock the position of the sealing sleeve 20 under vehicle-specific action.

Since the inner diameter of the sealing sleeve 20 is smaller than the outer diameter of the encapsulation 40 in the overlap region 14, the sealing arrangement is compressed by the action of the push-on sealing sleeve 20, i.e. a compression is formed between the sealing sleeve 20, the encapsulation 40 in the overlap region 14 and the insulation of the line 10, which compression seals the connection.

As a result, an assembly is formed in which the busbar 30 is connected to the three wires 10 and is sealed against penetration of water, fuel, brake fluid or other media. By using the method according to the invention, the assembly can be constructed very compactly and compactly.

List of reference numerals

10 wire

12-wire connection region

14 overlap region

20 sealing sleeve

22 recess for receiving a latching point

30 electrical component

40 injection molding of the envelope part

42 latching location

Claims

1. A method for connecting and sealing an electrical component (30) encapsulated by injection molding of a non-conductive material with at least one wire (10), the method comprising at least the following steps:

providing at least one wire (10) and a component (30) to be connected with said wire, said wire having ends de-insulated in the connection area (12),

Push the sealing sleeve (20) over at least one wire (10) respectively,

Positioning the corresponding sealing sleeve (20) outside the at least one overlapping area (14) to be achieved of the connection area (12) together with the injection-molded encapsulation (40) and the insulation of the at least one wire (10),

connecting the component (30) with at least one conductor (10) in the connection area (12),

injection-molded encapsulation of the component ( 30 ), the connecting region ( 12 ) and the corresponding overlapping region ( 14 ) to be realized in a non-conductive material,

The extrusion sealing structure is produced separately by means of the positioning of the corresponding sealing sleeves (20) in the overlapping region (14).

2. The method according to claim 1, characterized in that the extrusion sealing structure is formed by applying force and/or at least heating the sealing sleeve (20).

3. The method according to claim 1 or 2, characterized in that the at least one wire (10) is connected to the component (30) by means of ultrasonic welding or laser beam welding.

4 . The method according to claim 1 , wherein the injection-molding encapsulation is carried out with a thermoplastic plastic. 5 .

5 . The method according to claim 1 , wherein the sealing sleeve ( 20 ) consists of a plastic or ceramic material. 6 .

6 . The method according to claim 1 , wherein the injection-molded encapsulation ( 40 ) consists of a fiber-reinforced structure and/or the sealing sleeve ( 20 ) consists of a fiber-reinforced structure. 7 .

7 . The method according to claim 1 , wherein the sealing sleeve ( 20 ) is positioned such that it encloses the wire-side end of the overlapping region ( 14 ). 8 .

8. The method according to one of the preceding claims, characterized in that the squeeze seal is formed by at least one latching point (42) and/or the squeeze seal is formed by at least one latching point (42) constituted.

9. The method according to one of the preceding claims, characterized in that the component (30) is a distributor for electrical energy, in particular a distributor for electrical energy in a high-voltage on-board electrical network of a vehicle, and/ Or the component (30) is an electrical appliance.

10. A hermetically sealed electrical component (30) encapsulated in a non-conductive material, which is connected to at least one conductor (10), wherein,

the part (30) is connected to the end of at least one wire (10) which is de-insulated in the connection area (12),

injection-molding the component (30), the connection area (12) of the at least one wire (10) and the overlapping area (14) of the at least one wire (10) with a non-conductive material, wherein in all The insulating portion of the at least one wire (10) is also injection-molded in the overlapping region (14), and

· In each case, in the overlapping region (14), an extrusion seal is formed by means of a sealing sleeve (20).