CN109301674B

CN109301674B - Method and injection molding system for producing conductor rail composite bodies

Info

Publication number: CN109301674B
Application number: CN201810781658.9A
Authority: CN
Inventors: 圭多·霍夫
Original assignee: Lisa Draexlmaier GmbH
Current assignee: Lisa Draexlmaier GmbH
Priority date: 2017-07-24
Filing date: 2018-07-17
Publication date: 2021-05-28
Anticipated expiration: 2038-07-17
Also published as: CN109301674A; DE102017116723B4; DE102017116723A1

Abstract

The invention relates to a method for producing a conductor rail composite (800), wherein the method comprises a stamping step, an injection molding step and a separating step. An integrally united stamping grid (406) is stamped out of the flat conductive plate in a stamping step. The stamped grid (406) comprises at least two conductive rails (400) for transmitting power in the high voltage range. The conductive tracks (400) are interconnected by at least one biplate (408) comprising two plates (410) separated by an intermediate space (412). A support structure (416) made of an electrically insulating plastic material is injection molded in an injection molding step. The plastic material is injected at least into the intermediate space (412) of the biplate (408). The bi-sheet (408) is separated in a separation step by punching electrically insulating gaps (424) into the sheet (410). The support structure (416) is not detached.

Description

Method and injection molding system for producing conductor rail composite bodies

Technical Field

The invention relates to a method for producing a plurality of conductor rail composites, to a three-dimensional conductor rail structure, to an injection molding system for producing a conductor rail composite, and to a disconnection system for producing a plurality of conductor rail composites.

Background

The invention is described below primarily in connection with a switching element (contactor) for an on-board electrical system. The invention may be used in any application where electrical loads are to be switched.

To be able to conduct high currents, conducting rails made of solid metal plates can be used. The large material thickness of the metal plate and the width of the matching conductor track make it possible to match the conductor cross section to the desired current. The conductor rails may be individually stamped and bent. The conductor rails can then be connected to components, such as plugs, loads and switches, by using screws or rivets to form an electrical circuit.

DE 19713008C 1 describes a central electronic device for a motor vehicle with at least two stamped grids arranged parallel at a distance from one another, which stamped grids have sheet conductors formed by stamping. In order to simply manufacture the central electronic device, the invention proposes that: each stamped grid is provided with a holding frame made of plastic for injection molding, then the sheet conductors connected to each other at the separation position are separated from each other, the connecting contacts are bent and erected at right angles, the holding frames are combined and bent as sheet conductor connectors, and the bent parts of the sheet conductors (20) of the stamped grid are conductively connected with the sheet conductors of the other stamped grid, for example, by ultrasonic welding. With the invention, a central electronic component with complex wiring with fewer stamped grids can be produced in a simple manner.

DE 102015207128 a1 describes an embedded-and-collected circuit board including a plate-shaped resin material and a plurality of metal collecting conductors embedded in the resin material by encapsulation casting and having a connection portion exposed to a mounting surface which is one of main surfaces of the resin material. The collecting conductors are formed as a collecting conductor arrangement before casting before potting, wherein the ends different from the connecting sections are connected to one another by means of brackets, which are cut open after potting. The embedded/integrated circuit board (matrix body) is formed by an encapsulation molding, which is designed in such a way that two identically shaped integrated conductor arrangements are arranged opposite each other before the encapsulation molding, so that the two connection sections are positioned between the two supports.

Disclosure of Invention

The technical problem to be solved by the invention is therefore to simplify and speed up the installation of circuits for high power by using means that are constructively as simple as possible.

The invention relates to a method for producing a plurality of conductor rail composites, wherein the method comprises the following steps:

a) punching an integrally united punched grid out of a flat, electrically conductive plate, wherein the punched grid comprises at least two conductor rails for transmitting electrical power in a high voltage range, wherein the conductor rails are connected to each other by at least one biplate comprising two plates separated by an intermediate space;

b) injection moulding a support structure made of an electrically insulating plastic material, wherein the plastic material is injected at least into the intermediate space of the biplate; and separating the double sheets by punching electrically insulating gaps in the sheets, wherein the support structure is not separated.

The invention also relates to a conductor rail composite having the following features:

at least two conductor rails stamped out of the same plate for transmitting electric power in the high voltage range;

a support structure for mutually positioning the conductor rails, wherein the support structure is made of an electrically insulating plastic material which is injection-molded at least into an intermediate space between two sheets of at least one biplate arranged between the conductor rails;

each of the biplates has at least one electrically insulating gap, wherein the gaps are punched out of the plates after injection molding of the support structure.

Furthermore, the invention proposes an injection molding system comprising an injection molding tool and a punching grid, wherein the injection molding tool is designed for injection molding a support structure onto the punching grid, wherein a first part of a mold cavity forming the support structure is formed in a cavity of the injection molding tool and a second part of the mold cavity is formed in at least one recess of the punching grid, wherein a complete mold cavity is formed by the injection molding tool and an inserted punching grid when a nozzle side of the injection molding tool and an ejector side of the injection molding tool are sealed against opposite surfaces of the punching grid when closed, wherein a gap width between the nozzle side and the ejector side is determined by a material thickness of the punching grid in a closed state of the injection molding tool.

The second portion of the die cavity may be laterally defined by stamping a double-piece of the grid. The indentations may include intermediate spaces between the sheets.

A conductor rail composite is understood to mean groups of conductor rails which are fixed to one another by an injection-molded support structure. The conductor rail complex can thus be used as a whole. All the conductor rails of the conductor rail assembly can be stamped together in one piece. All the conductor rails of the conductor rail assembly can be installed jointly in one step. The conductor rail complex has an interface with further components of the circuit, which can be installed beforehand or subsequently. For example, the conductor rail assembly can have an interface to a switch or contactor, an electrical consumer, and/or a plug or socket. The conductor rails of the conductor rail composite are designed for this purpose to transmit high electrical power with low losses. For this purpose, the conductor rail can be designed for high currents. The insulation of the conductor rails from each other and from other conductors can be configured for voltages in the high-voltage range. In particular, the insulation can be produced by the insulation distance from the other conductor rails. The high voltage range in a vehicle comprises voltages between 60 volts and 1000 volts, in particular between 400 volts and 900 volts. In one embodiment, the air gap and the creepage distance are configured for voltages of 400 to 500 volts. In another embodiment, the air gap and the creepage distance are configured for voltages of 700 to 980 volts. The plate for the conductor rail may have a material thickness of between one and seven millimetres, in particular between two and six millimetres, in particular between three and five millimetres. The distance between the conducting tracks is large enough to satisfy the air gap and the creepage distance for the voltages used. The conductor tracks can also have a greater distance from each other. The stamped gap is also large enough to meet the air gap and creepage distance for the voltages used. The sheets of the biplate may run substantially parallel to each other. The mold cavity may be an enclosed volume formed by a nozzle side and an extractor side of the injection molding tool and a stamping grid clamped between the nozzle side and the extractor side. The mold cavity is filled with the plastic material during injection molding of the plastic material. The cavity may be a void or vacancy of the injection molding tool. The cavity may be formed by the contour of the nozzle side and/or the extractor side. The side walls of the cavity may be formed by portions of the conductive tracks.

The method may have a deformation step in which the stamped grid is partially deformed transversely to the plane of the plate to obtain a three-dimensional stamped grid. By deforming, the stamped grid can be matched to the contour of the housing. In this way, an air gap and a creepage distance from the housing can be met for all conductor rails.

The support structure can be injection-molded beyond the intermediate space onto the upper side and/or the lower side of at least one of the sheets to produce a form-fitting connection between the sheet and the plastic material. The form-fit connection remains unchanged, the metal material of the sheet not separating from the plastic material of the support structure even when the sheet separates. In this way, the support structure can reliably maintain the mutual position of the conductor rails also in the separated state.

The support structure may be injection molded with at least one rib oriented transverse to the plane of the plate. The ribs may be injection molded on at least one side of the biplate. The ribs strengthen the support structure. The rib allows better handling of the conductor rail complex. Due to the ribs, the risk of deformation of the conductor rail complex during mounting is lower.

The stamped grid may be stamped with at least one receiving portion for receiving a receiving boss. The plastic material can furthermore be injection-molded into the region of the receptacle. The receiving boss may be an integral part of the housing for the electrical circuit. The receiving boss secures the conductor rail composite within the housing. The receiving boss may have a landing surface in a plurality of axial directions. After insertion of the conductor rail complex, further components of the circuit can be mounted on the receiving projection. The plastics material may electrically insulate the respective conductive track from the receiving boss. The interface of the conductor rail complex with the housing can be defined by the support structure.

The receiving portion may be injection-molded with an annular surrounding sleeve made of plastic material. The sleeve reduces the diameter of the receiving portion. The plastic is therefore arranged in the mounted state in a circular manner between the electrically conductive rail and the electrically conductive receiving projection.

The support structure can be injection-molded with at least one distance holder oriented transversely to the plane of the plate. The distance holder can at least circumferentially surround one side of the sleeve. The distance holder may set the distance between the housing and the conductor rail complex. The distance holder can be designed as an extension of the sleeve. The distance holder can produce the required air gap and creepage distance from the receiving boss or housing.

Drawings

Advantageous embodiments of the invention are explained below by referring to the drawings. The figures are as follows:

FIG. 1 illustrates a stamped grid according to an embodiment;

FIG. 2 shows a detail of a biplate according to an embodiment;

FIG. 3 illustrates a partially overmolded stamped grid according to a variation of the embodiment;

FIG. 4 illustrates a partial cross-section of a partially overmolded stamped grid according to an embodiment;

FIG. 5 illustrates a separated partially overmolded stamped grid according to an embodiment; and

fig. 6 shows a nozzle side of an injection molding tool for injection molding a support structure onto a stamping grid according to an embodiment.

The drawings are only schematic representations and are intended to be only illustrative of the present invention. Identical or functionally identical elements are provided with the same reference numerals throughout.

Detailed Description

The measures proposed here can be used for the automated production of Battery Junction Boxes (BJBs). The battery connection box may also be referred to as a switchgear box.

The switchgear cabinet houses a plurality of electrical components, which must be electrically connected. Components such as contactors, conductor rails, safety devices and resistors are arranged in the switchgear cabinet. For connections which can carry high currents, conductor rails made of copper or aluminum plates have proven to be suitable. Different mounting directions and screwing directions are produced by different geometries of the components. The number of parts and the tight construction space make automated assembly difficult.

At present, the electrical connection of the components takes place with several individual conductor rails, which are individually made of a surface material or plate material. Since there is no access to the screw points in the housing at all times, a pre-mounted assembly can be formed, which can be made, for example, of the contactor and its conductor rails.

For example, seven contactors may be arranged and electrically connected within the switchgear cabinet. In conventional implementations, 14 conducting rails and three high-current lines are required for this purpose. In the measures proposed here, the number of components can be significantly reduced. The 14 conducting rails and the three high current wires are replaced by two conducting rail complexes plus two additional conductors. Thereby resulting in lower installation costs and shorter installation times. The manufacturing can be automated. The logistics cost for purchase, transportation and storage is reduced. Furthermore, fewer tools are required. Furthermore, simpler data maintenance results.

For easier understanding, reference numerals in fig. 1 to 6, which are referred to in the following description, remain the same.

Fig. 1 shows a stamped grid 406 according to an embodiment. The punch grid 406 is punched out of a planar plate using a punch tool. The stamped grid 406 illustrated here includes nine metallic conductive tracks 400 for conducting large currents and high voltages in the high voltage range exceeding 400 volts. For this purpose, the conductor rail has a material thickness of approximately four millimeters. The conductor rails 400 are arranged with respect to each other, respectively, as said conductor rails 400 are also mounted in the mounting position. The conductor rail 400 is fixed in this position by the biplate 408. Each conductive track 400 abuts on at least one biplate 408. A majority of the conductive rails 400 are held in place by two or more double tabs 408.

In the measure proposed here, a plurality of conductive tracks 400 are combined into a stamped grid 406. For example, all positive conductor rails and all negative conductor rails may be combined into one stamped grid each. Positive and negative conductor rails may also be arranged in a mixture. The stamped grids 406 are each made from a single plate. The conductor rails or conductor rails 400 are arranged within the stamped grid 406 such that they "fan out", i.e. are placed side-by-side without crossing. The stamping of the stamped grid 406 is performed by removing unwanted material between the conductors but leaving the tabs so that they are still integrally united.

The sheet 410 is double, i.e. configured as two parallel sheets. Thus, in the case of subsequent post-injection molding, the two wafers 410 cooperate with the injection mold to form a closed cavity without the need to expensively seal the mold to the plate portion. Thus, the parting surfaces of the two tool halves, i.e. the ejector side and the nozzle side, are formed in one plane. The tool is coordinated with the plate thickness and seals to the sheet 410, so the cutting accuracy of the plate is insignificant relative to the sealing of the injection molding tool.

Fig. 2 shows details of a biplate 408 according to an embodiment. The biplate 408 corresponds to the biplate in fig. 1. The double sheet 408 comprises two sheets 410 running substantially parallel to each other and an elongated intermediate space 412 generally between the sheets 410. The different biplate pieces 410 each have substantially the same mutual distance. Thus, in the case of the biplate 408 in fig. 1 where the distance is greater than the length, the intermediate space 412 is longer than the width. The segments 410 of the double segment 408 may also have different lengths when the connected edges of the conductor rails 400 run at an angle to each other.

In one embodiment, the conductive rail 400 has a receiving portion 414 for receiving a receiving boss. The receiving portion 414 is here a circular through-hole through the plate of the conductor rail 400. The conductor rails are configured such that the conductor cross-section of the respective conductor rail 400 is guided around the receptacle 414.

The processing of a stamped grid 406 of only two layers is simpler than a single conductive track. Thus, instead of using pre-tinned material, subsequent tinning can be used. This reduces the costs due to the trimming, since only the finished stamped grid 406 is finished. Aluminum can alternatively be used as the material of the conductor rail 400, since nickel plating and tin plating are simple. The surface is finished on the stamped part before the deformation or at least before the post-injection, so that the chemical properties of the plastic are not changed and the plastic can be removed again.

If this sheet blank is now inserted into the injection molding tool, the plastic frame is injection molded, strengthening the stamped grid 406. Since plastic and metal do not form a reliable adhesive connection, the post-injection molding needs to be carried out in a form-fitting manner. Each individual conductor rail 400 has at least one form-fitting connection to the plastic frame.

Fig. 3 shows a modified, partially injection molded stamped grid 406 according to an embodiment. The stamped grid 406 substantially corresponds to the stamped grid in fig. 1. In contrast, the stamped grid 406 is deformed into a three-dimensional stamped grid 406 by a deformation process. In particular, the connection areas of the conductor rails 400 are chamfered transversely to the plane of the board. Furthermore, planar stepping or parallel movements are introduced into the stamped grid 406 or into the conductive tracks 400.

The punching grid 406 furthermore has a support structure 416. Support structure 416 comprises an electrically insulating plastic material injection molded into the intermediate space between sheets 410 of double sheet 408. The support structure 416 furthermore has a rib 418 made of plastic material in each case in the intermediate space. Ribs 418 are injection molded extending beyond the intermediate spaces across the surface of the stamped grid 406 and connect the individual intermediate spaces to one another.

The support structure 416 is formed as a closed, annularly encircling sleeve 420 within the receiving portion 414. The sleeve 420 insulates the conductive rail 400 from the receiving boss. Furthermore, a distance holder 422 is injection-molded on the sleeve 420, at least on one side of the plate. The spacer 422 is here an annularly encircling rib.

In a next step, the stamped grid 406 is deformed such that the required orientation of the contact surfaces is produced. In this example, the contact surface is perpendicular to the protective thread connection and is in a different height position horizontally than the thread surface of the outwardly guided pin.

Fig. 4 shows a partial cross-sectional illustration of a partially overmolded stamped grid 406, in accordance with an embodiment. There is illustrated a cross-section of the stamped grid shown in figure 3. Support structures 416 are formed as ribs 418 on the upper side of the punch grid 406. On the underside of the punch grid 406 opposite the upper side, a support structure 416 is injection-molded at least in the region of the receptacle 414, except for the underside. The sleeve 420 thereby forms a form-fitting connection with the punching grid 406 on the upper side and the lower side.

Fig. 5 illustrates a conductive rail composite 800 according to an embodiment. The resulting conductor rail composite 800 substantially corresponds to the stamped grid of fig. 3. In addition, electrically insulating gaps 424 are punched out in the electrically conductive sheet 410 of the double sheet 408 of the punched grid 406. The support structure 416 is not separated when the sheet 410 is separated. The conductor rails are electrically separated from each other by gaps 424, while the support structure 416 maintains the mutual relative position of the conductor rails 400.

In the conductor rail complex 800, the conductor rails 400 have a defined mutual position, since the conductor rails 400 are held by the injection-molded plastic frame 416. The conductor rails 400 are additionally fixed to the protective fixing in the mounted state. This results in advantages in the event of vibrations or impacts. The component carrier can be designed to be small, since it is not used for fixing and insulating the conductor rail. Thereby, many fixing parts, such as distance bushings, threaded inserts and screws, can be eliminated.

The stamped grid 406 can now be singulated. Here, the connecting tabs are cut so that no electrical path exists anymore. The forms are united because the plastic frame connects the parts.

The feature of the double web is again effective here, since the simple web with the injection-molded plastic frame does not have to be separated and does not have to be cut off, which has to be prevented to ensure integrity.

A second stamped grid sheet is made in the same manner but with a different geometry.

The result is two parts, both of which are the conductor tracks required for the connection parts.

Fig. 6 shows a nozzle side 902 of an injection molding tool 900 for injection molding a support structure onto a stamping grid according to an embodiment. The injection molding tool 900 and the punch grid form an injection molding system herein, wherein a first portion of a mold cavity 904 forming the support structure is formed within a cavity 906 of the injection molding tool 900. A second portion of the mold cavity 904 is formed by stamping the grid. The second part is formed by the intermediate space between the two plates and the annular gap surrounding the receptacle. Here, the mold cavity 904 is first closed by moving the nozzle side 902 of the injection molding tool 900 together with the respective ejector side towards the inserted stamping grid. The nozzle side 902 and the extractor side seal against opposing surfaces of the punch grid when closed. Here, the punching grid is arranged between the nozzle side 902 and the extractor side, and the gap width between the nozzle side and the extractor side is determined by the material thickness of the punching grid.

List of reference numerals

400 conductive rail

406 stamped grid

408 double slice

410 pieces

412 intermediate space

414 receiving part

416 support structure

418 rib

420 sleeve

422 distance keeper

424 gap

800 conductor rail complex

900 tool of moulding plastics

902 nozzle side

904 mold cavity

906 cavity

Claims

1. A method for producing a conductor rail composite (800), wherein the method comprises the following steps:

a) stamping an integrally united stamped grid (406) from a flat, electrically conductive plate, wherein the stamped grid (406) comprises at least two electrically conductive tracks (400) for transmitting electrical power in a high voltage range, wherein the electrically conductive tracks (400) are connected to each other by at least one biplate (408) comprising two plates (410) separated by an intermediate space (412);

b) injection moulding a support structure (416) made of an electrically insulating plastic material, wherein the plastic material is injection moulded at least into the intermediate space (412) of the biplate (408); and

c) separating the double sheet (408) by punching an electrically insulating gap (424) in the sheet (410), wherein the support structure (416) is not separated.

2. Method according to claim 1, with a deformation step in which the punched grid (406) is deformed partially transversely to the plane of the plate to obtain a three-dimensional punched grid (406).

3. Method according to any one of the preceding claims, wherein the support structure (416) is injection-moulded in an injection-moulding step beyond the intermediate space (412) onto the upper side and/or the lower side of at least one of the sheets (410) to produce a form-fitting connection between the sheet (410) and the plastic material.

4. The method according to claim 1, wherein in the step of injection molding the support structure (416) is injection molded with at least one rib (418) oriented transverse to the plane of the plate, wherein the rib (418) is injection molded at least on one side of the biplate (408).

5. The method according to claim 1, wherein the stamping grid (406) is stamped in a stamping step with at least one receptacle (414) for receiving a receiving boss, which is an integral part of a housing in which the conductor rail composite is fixed, wherein in the injection step a plastic material is also injected into the region of the receptacle (414).

6. The method according to claim 5, wherein the receiving portion (414) is injection molded with an annular surrounding sleeve (420) made of a plastic material in the injection molding step.

7. Method according to claim 6, wherein in the injection-moulding step the support structure (416) is injection-moulded with at least one distance holder (422) oriented transversely to the plane of the plate, the distance holder (422) surrounding annularly at least on one side of the sleeve (420).

8. A conductor rail composite (800), the conductor rail composite (800) having the following characteristics:

at least two conductor rails (400) stamped out of the same plate for transmitting electric power in the high voltage range;

-a support structure (416) for mutually positioning the conductor rails (400), wherein the support structure (416) is made of an electrically insulating plastic material which is injection-molded at least into an intermediate space (412) between two sheets (410) of at least one biplate (408) arranged between the conductor rails (400);

each of the two plates (410) of the biplate (408) is provided with at least one electrically insulating gap (424), wherein the gap (424) is stamped out of the plate (410) after the injection molding of the support structure (416).

9. An injection molding system for the conductor rail composite according to claim 8, comprising an injection molding tool (900) and a stamping grid (406), wherein the stamping grid (406) comprises at least two conductor rails (400) for transmitting electrical power in a high voltage range, wherein the conductor rails (400) are interconnected by at least one biplate (408) comprising two plates (410) separated by an intermediate space (412), wherein the injection molding tool (900) is configured for injection molding a support structure (416) made of an electrically insulating plastic material onto the stamping grid (406) for mutually positioning the conductor rails (400), wherein a first part of a mold cavity (904) forming the support structure (416) is formed in a cavity (906) of the injection molding tool (900) and a second part of the mold cavity (904) is formed in at least one indentation of the stamping grid (406), wherein the complete mold cavity (904) is formed by the injection molding tool (900) and the inserted stamping grid (406) when the nozzle side (902) of the injection molding tool (900) and the stripper side of the injection molding tool (900) are sealed on opposite surfaces of the stamping grid (406) when closed, wherein a gap width between the nozzle side (902) and the stripper side is determined in the closed state of the injection molding tool (900).