EP3069584A1

EP3069584A1 - Electronics module for an ignition unit

Info

Publication number: EP3069584A1
Application number: EP14781224.2A
Authority: EP
Inventors: Werner Steinberger
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2013-11-14
Filing date: 2014-10-08
Publication date: 2016-09-21
Also published as: US20160312756A1; WO2015071030A1; BR112016010953A2; DE102014209185A1; CN105706538A

Abstract

The invention concerns an electronics module (20) and an ignition unit (10) comprising such an electronics module (20), which comprise: a housing (21) with a holder (22) for an electronics unit (23) and an electrical interface for connection to an ignition coil (41). The housing (21) has a mechanical interface (25) for securing to an ignition coil housing (31). According to the invention, the mechanical interface (25) further comprises a collar which is arranged to be bonded by a casting compound to be introduced into the ignition coil housing (31).

Description

description

title

Electronic module for an ignition unit prior art

The present invention relates to an electronic module for an ignition unit.

In particular, the present invention relates to improvements in the

Connection of an electronic module with an ignition coil unit.

Ignition units are known in the art to be combustible

Ignite fuel mixtures in internal combustion engines at predefined times. The ignition voltage is often generated by the intermediary of an ignition coil, which is housed in some embodiments in a separate housing or housing part. For monitoring and control of

Zündvorgänge an electronic module is connected to the ignition coil, wherein the electronic module in some embodiments has its own housing or a separate housing part. The electronic module usually comprises an electronic board on which power electronics, for example in the form of an ignition IGBT, diagnostic electronics or a Multisparkansteuerung executed. Conventionally, the electronic module is at the

Ignition coil housing bolted or fixed via a Ultraschallverschwei tion. Even if a separate embodiment of the housing (or housing parts) for the electronic module and the ignition coil unit means more components and a higher assembly costs, a better (modular) adjustment of the ignition unit to customer-specific wishes without changing the

Base ignition coil done. In addition to a mechanical connection of the two Gehäusemuss but an additional electrical contact between the electronic module and the ignition coil unit can be made. A thermal decoupling between the ignition coil unit and the

However, electronic modules can be implemented more easily with separate housings. It is an object of the present invention to provide a connection between an electronic module and an ignition coil unit easier and less expensive to design in the assembly.

Disclosure of the invention

The above object is achieved by a

Solved electronic module for an ignition unit and by an ignition unit and a method for filling an ignition unit. Accordingly, an electronic module for an ignition unit is proposed with a housing in which a receptacle for an electronic assembly is arranged. The

Electronic assembly may be provided, for example, for controlling the ignition coil and comprise a circuit board or be configured substantially as a circuit board. The ignition coil is not part of the

inventive electronic module. The housing of the electronic module according to the invention further has a mechanical interface for attachment to an ignition coil, in which the ignition coil is arranged.

According to the invention, the mechanical interface has a collar connected to the housing of the electronic module according to the invention. The collar is set up to be materially connected to a potting compound to be filled into the ignition coil housing. According to the invention, a cohesive connection does not exclude that a mechanical

Undercut or other suitable compounds are present or received by the potting compound. Such a potting compound is used in particular for the electrical insulation of the ignition coil and leads to a higher mechanical strength of the assembly. For example, a

Epoxy resin (possibly with a filling material) poured under low pressure into the housing to achieve a particularly complete filling. The housing of the electronic module can also be equipped with a positioning device which is set up, the electrical interface and the mechanical interface with respect to the ignition coil housing in the course of a

Plugging relative to each other to position and lead the mating process. In this case, the electronic module is attached in the course of the plug-in operation on an ignition coil unit and connected via electrical contacts with the ignition coil. The electrical contacts can be arranged in such a way, in particular within a circumferential collar, that they are enclosed in a fluid-tight manner in the course of the plugging operation between the housing of the electronic module and the ignition coil housing. After a solidification of the potting compound the housing of the electronic module according to the invention and the

Ignition coil housing via the potting compound materially connected, which an additional connection (for example, screw) is unnecessary and the optional

Connection via the positioning device added. The electronic module according to the invention allows a cost-effective and easy to manufacture

Ignition unit, in which uses the electronic module with a large variety of variants of the ignition coil unit and therefore different

Ignition units can be modularly realized. The dependent claims show preferred developments of the invention.

Advantageously, an electrical interface is provided in the housing of the electronic module according to the invention for connecting the electronic assembly to an ignition coil. This can be configured as part of a plug connection, so that when merging the housing of the electronic module according to the invention with the ignition coil housing the

Pickup for the electronics assembly is automatically electrically connected to the ignition coil or with an electrical interface thereof. The positioning device preferably has a latching element. It can the

Positioning device in addition to the guide during the insertion process a positive connection between the electronic module and the

Realize ignition coil unit. The positive connection can

For example, as a bayonet connection and additionally or alternatively have a snap-lock connection. This will be a simple one

Connection between the housing of the electronic module and the

Ignition coil produced until the potting compound is introduced and solidified. This simplifies the production and lowers the manufacturing costs. More preferably, the collar is adapted to be in a cavity of

Immerse ignition coil housing, and in particular has a form-fitting undercuts favoring surface, preferably in the form of multiple openings and / or holes on. The mechanical

Interface both a relative positioning and a material and / or positive connection of the housing of the invention

Implement electronic module and the ignition coil housing. According to a development, the electronic module according to the invention comprises a filling channel which has a second opening facing the mechanical interface and a first opening opposite the second opening. About the filling channel can pass a potting compound from the housing of the electronic module in a cavity within the ignition coil housing. In this way, the potting compound is passed, for example, to the receptacle for the electronic module or to the electronic module of the electronic module and a separate filling of the ignition coil with the potting compound can be omitted. This also simplifies the manufacturing process of the electronic module according to the invention.

The second opening of the filling channel preferably has a structure projecting in the direction of the ignition coil housing, which is set up to dip into the casting compound to be filled. If the structure is executed circumferentially, the surface of the potting compound outside the filling channel is hermetically separated from the surface within the filling channel after filling, whereby the penetration of impurities and water is prevented.

More preferably, a wall between the receptacle for the

Electronic assembly and the filling channel to be arranged. The wall can, for example, represent a part of the filling channel and represent a kind of dam or overflow for filling compound filled in the first housing or in the receptacle. In this way it is ensured that when filling potting compound in the housing or in the receptacle, a suitable filling level of the potting compound is achieved before the potting compound can run over the filling channel in the ignition coil housing. If it is desired to fill the volume comprising the ignition coil with a first potting compound and the volume comprising the receptacle for the electronic assembly with a second potting compound of different material, no overflow is necessary. In this case, to facilitate the filling process, a kind of funnel can be provided at the first opening of the filling channel.

More preferably, the filling channel can be oriented substantially in one direction of the plugging operation. If, for example, the electronics module is placed on the ignition coil unit from above, the filling channel for the ignition coil also runs Potting compound from top to bottom. In this way, the distributed

Potting compound within the ignition unit solely due to gravity.

More preferably, the housing of the electronic module according to the invention further comprises a circumferential collar, which in the housing

arranged electronics assembly, as well as the first opening of the

Filling channel, encloses. In this way, the circumferential collar during filling of the electronic module according to the invention serve to hold the potting compound over the electronics assembly in position.

Preferably, in the region of the first opening, a wall of the

Filling channel provided with a extending in the direction of the second opening recess. In other words, an e. G. designed as the upper edge ausgestalteter area of the first opening of the filling channel with respect to surrounding edge portions designed so that a kind

Overflow or drain for potting compound applied to the electronic module. In this way, the potting compound runs from one through the

Recess certain level automatically into the channel, thereby leading to a filling of the ignition coil, whereby a separate filling can be omitted. An overflow of the potting compound is e.g. prevented by the circumferential collar.

More preferably, the housing of the electronic module according to the invention is set up, the ignition unit is mechanically connected to a periphery of the ignition unit, e.g. an engine block. For this purpose, the housing in particular

Have screw points. In this way, all commonly specified by customer requirements interfaces such as electrical and

mechanical connections are arranged in the housing of the electronic module according to the invention. In the manufacture of the ignition coil housing therefore unnecessary expensive insertion tools and one required for this

Handling unit, which reduces the costs to cover a required variety of variants.

More preferably, a level of the potting compound within the

Ignition coil housing selected such that a cavity for thermal insulation between the ignition coil and the receptacle for the electronics assembly remains. In other words, the ignition coil is not completely with Filling compound filled, so that the surface of the potting compound does not directly adjoin an upper limit of that volume through which connects the ignition coil housing in the direction of the housing of the electronic module according to the invention. In this way, heating the ignition coil can only to a lesser extent heat the electronics assembly. Malfunctions or required power reductions of the electronic module can thus be avoided.

More preferably, the collar of the mechanical interface is configured such that it forms a gap or a plurality of gaps, for example capillary gaps, in cooperation with the ignition coil housing or with a corresponding structure arranged thereon. For this purpose, the collar of the mechanical interface can be provided, for example, as a proportionately or completely circumferential collar on the underside of the housing, which collar is arranged directly inside a corresponding collar provided on the ignition coil housing. The capillary action between these two aforementioned collar leads to the fact that filled potting compound over a large area leads to a cohesive connection between the housing and the ignition coil housing. According to a second aspect of the present invention, an ignition unit comprising an ignition coil unit having a

Ignition coil and an ignition coil housing and an electronic module proposed, with the above statements apply accordingly for the electronics module. The ignition coil housing and the housing of the

Electronic modules are inserted into each other via the mechanical interface and electrically contacted with each other. About a potting compound according to the invention a material and / or positive connection of the housing of the electronic module according to the invention and the ignition coil housing can be realized. The combination of features and their advantages will be apparent according to the first aspect of the invention.

Preferably, the ignition unit according to the invention is configured such that a filling channel is formed which is set up from a first cavity in the

Housing of the electronic module overflowing fluid to lead into a second cavity in the housing of the ignition coil unit. In this way, a single filling can fill two cavities within the ignition unit according to the invention with a potting compound, so that a separate filling of the two cavities can be omitted. Also, the filling channel of the invention Ignition unit may be configured according to the embodiments in connection with the first-mentioned aspect of the invention.

According to a third aspect of the present invention, a method of filling an ignition unit comprising an electronic module and a

Ignition coil unit, proposed with a potting compound. The ignition unit can, as described in connection with the second-mentioned aspect of the invention, be configured. The potting compound is first measured according to the invention, so that there is a predefined amount of potting compound. The amount can be determined on the basis of the volumes to be filled in the first cavity and the second cavity. This can be done by calculation or by a trial or a series of experiments. To improve the

Filling degree and avoid foreign body and air inclusions, the ignition unit can now be evacuated. The predefined amount potting compound is then poured into an upper cavity of the electronic module, so that a

Part of the amount of potting compound passes over an overflow of the upper cavity in a lower cavity of the ignition coil unit. It is not necessary that the ignition unit has the same orientation during the casting process, as it takes during a subsequent curing period for curing the potting compound. In this way, the volume of the

Potting compound, which runs into the lower cavity, are determined regardless of a curing position. In other words, the overflow or the first opening of the filling channel is only to be defined in such a way that during casting a volume defined by the overflow of the channel remains in the upper cavity during the subsequent curing. This allows a simple filling of an ignition unit with a potting compound.

To ensure a proper transfer of the potting compound from the upper cavity into the lower cavity, the overflow of the upper cavity opens into a channel which houses a housing of the electronic module and a

Ignition coil housing of the ignition coil unit connects to each other. In other words, the channel is designed so that overflowing potting compound from the upper cavity automatically into the lower cavity within the

Ignition coil housing is running. A connection via a filling channel allows a particularly process-reliable filling of both cavities.

Brief description of the drawings Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. Show it:

Figure 1 is a perspective view of a first embodiment of an ignition unit according to the invention;

Figure 2 is a perspective view of a second

Embodiment of an ignition unit according to the invention;

Figure 3 is a perspective detail view of an embodiment of a channel with a drain for a potting compound;

Figure 4 is a sectional side view of an embodiment of an ignition unit according to the invention, illustrating Vergussmassenfüllstände; and

Figure 5 is a flow chart illustrating steps of a

Embodiment of a method according to the invention.

Embodiments of the invention

Figure 1 shows an embodiment of an ignition unit 10 according to the invention, the ignition coil unit 30 and the electronic module 20 have not yet been assembled. The housing 21 of the electronic module 20 has at its lower edge on a collar 25 which rotates a substantially square base. The corners of the substantially square base are, for example, rounded, wherein at the rounded corners in each case a rib 26 is arranged as a positioning device. In addition, in each case a latching element of a latching connection can be provided at the corners. Within the circumferential collar 25 are two in the direction of

Ignition coil unit 30 oriented electrical contacts 24 recognizable. By the ribs 26 of the collar 25, the electrical contacts 24 so

prepositioned that they are securely inserted into the electrical mating contacts of the ignition coil. About the collar 25 and the ribs 26 and the locking elements 27 as a mechanical interface, the electronic module 20 is thus configured, the ignition coil housing 31 of the ignition coil unit 30 via a Contact plugging permanently. Anschraubpunkte 43 integrally molded to the housing 21 allow a mechanical fixing of the ignition unit 10 at a periphery of the ignition unit 10. Figure 2 shows in an upper part of a) a perspective top view of a

Electronic module according to FIG. 1 with an electronic assembly 23 arranged within a collar 40 and with a filling channel 28 arranged in a corner region of the collar 40. The filling channel 28 is bounded laterally on the one hand by the collar 40 and on the other hand by a wall 28a forming a chord. At this point, a first (upper) opening 28b of the

Filling channel 28 is arranged. In this case, the filling channel 28 runs on

Electronics module 23 passing in the direction of the ignition coil unit 30. To the

Housing 21 integrally molded screw 43 allow mechanical fixing of the ignition unit 10 at a periphery of the ignition unit

The electronic module 20 according to the invention has a housing 21 with a receptacle 22 for the electronic assembly 23. The receptacle 22 is formed by the collar 40 and a bottom. At the receiving 22 remote from the underside of the bottom of the annular or rectangular circumferential

Collar 25 is arranged, which is the mechanical interface 25 for

Ignition coil housing 31 forms. The filling channel 28 according to the invention is arranged within the collar 40 of the receptacle 22, but is completely or at least partially separated from the receptacle 22. The filling channel 28 according to the invention runs through the floor through into the area enclosed by the collar 25. According to the embodiment, the filling channel 28 is provided in a corner of the collar 40, wherein a

Partition wall 28a extends from one side of the collar 40 to an adjacent side of the collar 40 and forms the filling channel 28 together with the collar 40.

On the electronic module 20 electrical contacts 24 are provided which electrically connect the electronic assembly 23 with the ignition coil 41 via a plug connection when the electronic module 20 is fitted onto the ignition coil housing 31.

In the lower part of figure b) is a partially cutaway perspective view of an ignition unit 10 is shown, in which the electronic module 20 with the Ignition coil unit 30 is connected. The channel 28 is also cut open, so that it can be seen how it represents a continuous connection to a second (lower) opening 28c between an upper region of the electronic module 20 and a space containing the ignition coil 41 within the housing 31.

FIG. 3 shows a perspective top view of an electronics module 20 which is open at the top, wherein the first (upper) opening 28b of a channel 28 can be seen in detail. The filling height of a potting compound, which is to be filled into the collar 40 for pouring the electronics assembly 23, is determined by a recess 29, via which a potting compound (not shown) can run through the channel 28 in the direction of the ignition coil 41 after reaching a predetermined level.

Figure 4 shows a sectional side view of the embodiment shown in Figure 2 b), in which levels F1, F2 for a potting compound within the collar 40 of the electronic module 20 and within a cavity of the ignition coil housing 31 of the ignition coil unit 30 are marked. In this case, the filling level F1 is determined by the recess 29, while the filling level F2 is determined by the volume within the ignition coil housing 31 and the volume below the recess 29 within the housing 21 in conjunction with a predefined amount of potting compound. A collar 42 as a protruding structure is arranged on a lower opening 28 c of the channel 28, that it is adapted to immerse in the einzuzulende potting compound within the volume within the ignition coil housing 31 and hermetically seal their surface au ßerhalb the channel, whereby a

Penetration of impurities and water is prevented. In this case, the fill level F2 of the potting compound can be selected such that a material connection between the potting compound and the mechanical interface 25 takes place. FIG. 5 is a flow chart illustrating steps of FIG

Embodiment of a method according to the invention. In step 100, an amount of a potting compound, which is to be filled in the ignition unit according to the invention, predefined. On the basis of desired filling heights F1, F2 and on the basis of the volumes to be filled and the position of the recess 29, the result to be achieved can be significantly influenced by the amount of potting compound. Subsequently, in step 200, the predefined amount of potting compound is poured into an upper cavity of the electronic module 20, so a part of the quantity of potting compound passes over an overflow of the upper cavity into a lower cavity of the ignition coil unit. It will be apparent to those skilled in the art that the position of the ignition unit 10 according to the invention during the filling of the ignition unit 10 with the (not shown)

Potting compound does not have to be the same as the position in which the

Curing compound hardens.

Even if the aspects of the invention and advantageous

Embodiments with reference to the attached

Drawings illustrated embodiments have been described in detail, modifications and combinations of features of the illustrated embodiments are possible for the skilled person without departing from the scope of the present invention, the scope of which is defined by the appended claims.

Claims

Electronic module (20) for an ignition unit (10) comprising

a housing (21) with a receptacle (22) for a

Electronic assembly (23), and

the housing (21) having a mechanical interface (25) for attachment to an ignition coil housing (31),

characterized in that the mechanical interface (25) has a collar (25) connected to the housing (21), which is arranged to be materially connected to a potting compound to be filled into the ignition coil housing (31).

The electronic module according to claim 1, wherein the collar (25) is adapted to immerse in a cavity of the ignition coil housing (31), and

in particular a form-fitting undercuts favoring surface, preferably in the form of several openings and / or

Holes, has.

Electronics module according to claim 1, wherein the receptacle (22) has a bottom, wherein the collar (25) is arranged on the receiving side (22) facing away from the bottom.

Electronic module according to one of the preceding claims, further comprising a filling channel (28), wherein the filling channel (28)

a first opening (28b) on a first side of the receptacle (22), and

a second opening (28c) on a second side of the receptacle (22),

wherein in particular the first side of the second side is opposite.

Electronics module according to claim 3, wherein the second opening (28c) of the filling channel (28) has a in the direction of the ignition coil housing (31) protruding structure (42) which is adapted to immerse in the einzufüllende potting compound.

6. Electronic module according to one of claims 3 or 4, wherein a wall (28a) between the receptacle (22) and the filling channel (28) is arranged.

Electronics module according to claim 5, wherein the wall (28a) in the region of the first opening (28b) of the filling channel (28) with a in the direction of the second opening (28c) extending recess (29) is provided.

An electronic module according to any one of the preceding claims, wherein the housing (21) further comprises a peripheral collar (40) opposite the mechanical interface (25) arranged to define an electronics assembly (23) disposed within the housing (21) and the first opening (Fig. 28b) of the filling channel (28) to enclose.

Electronic module according to one of the preceding claims, wherein the housing (21) is adapted to fix the ignition unit (10) mechanically at a periphery of the ignition unit (10), to which the housing (21) in particular screw-on points (43). 10. Electronic module according to one of the preceding claims, wherein the

Collar (25) in cooperation with the ignition coil housing (31) forms one or more gaps for the potting compound.

Electronic module according to one of the preceding claims further comprising an electrical interface (24) for connecting the

Electronic assembly (23) to an ignition coil (41) in the ignition coil housing (31), wherein the electrical interface (24) is designed in particular as part of a plug connection. 12. Ignition unit comprising

an ignition coil unit (30) having an ignition coil (41) and an ignition coil housing (31), and

An electronic module (20) according to one of the preceding claims, wherein the ignition coil housing (31) and the housing (21) of the electronic module (20) via the mechanical interface (25) are inserted into one another and in particular are materially connected by a potting compound.

13. Ignition unit according to claim 1 1, comprising a filling channel (28) which is arranged, from a first cavity in the housing (21) of the

Electronic module (20) overflowing fluid in a second cavity in the ignition coil housing (31) to lead.

14. Ignition unit according to one of claims 1 1 or 12, wherein a level (F2) of the potting compound is selected such that for thermal insulation between the ignition coil (41) and a receptacle (22) for in the housing (21) provided for electronic assembly (23) a cavity remains.

15. A method for filling an ignition unit (10), in particular according to

Claim 1 1, 12 or 13, comprising an electronic module (20) and an ignition coil unit (30), with a potting compound, comprising the steps:

Predefining (100) an amount of a potting compound,

Pouring the predefined amount of the potting compound in an upper cavity of the electronic module (20), so that a portion of the amount of the potting compound via an overflow of the upper cavity in a lower cavity of the ignition coil unit (30) runs.

16. The method of claim 14, wherein the overflow of the upper cavity in a filling channel (28) opens, which a housing (21) of the

Electronic module (20) and an ignition coil housing (31) of

Ignition coil unit (30) interconnects.