Method for producing a control unit housing made of plastic for a motor vehicle, and associated control unit housing

Abstract

The subject matter of the invention is a method for producing a control unit housing made of plastic for a motor vehicle and a corresponding control unit housing. A printed circuit board (1) is placed between two housing parts (5, 6), and the two housing parts (5, 6) are connected to one another media-tight with the printed circuit board (1) accommodated in the interior. In addition, at least one housing part equipped with an outer plug housing (5a) is equipped with a plug (7) engaging therein for the peripheral electrical connection of the printed circuit board (1). For this purpose, the plug (7) is accommodated in the outer plug housing (5a) and, together with the two housing parts (5, 6), is closed to the outside media-tight. According to the invention, an inner opening (10) to the interior of the two housing parts (5, 6) remains in the outer plug housing (5a), said inner opening being closed by means of the plug (7) in the installed state.

Description

[0001] Kiekert AG

[0002] P24013

[0003] 1

[0004] Description

[0005] Method for manufacturing a plastic control unit housing for a motor vehicle and associated control unit housing

[0006] The invention relates to a method for manufacturing a control unit housing made of plastic for a motor vehicle, wherein a circuit board is placed between two housing parts and the two housing parts are connected to each other in a media-tight manner with the circuit board received inside, and wherein at least one housing part equipped with an external connector housing can receive a connector engaging therein for the peripheral electrical connection of the circuit board and is sealed media-tight to the outside together with the two housing parts.

[0007] Plastic control unit housings are widely used in or on motor vehicles. Inside, the housing contains a circuit board, which in turn carries a control unit, a controller, or more generally, a control device. In this way, control functions can be implemented, either within the separate control unit housing itself, or by integrating the housing, for example, as a vehicle lock housing, in addition to the circuit board and control unit, also incorporating mechanical components within the housing.In addition to vehicle lock housings, the term "control unit housing" also includes, for example, locking mechanisms for charging plugs and their housings, window regulator drives and their housings, sliding door drives with housings, opening devices and their housings, electric motor drives for door opening including housings, drives for tailgates including housings, and vehicle seat drives with housings, to name just a few examples, without being exhaustive. Kiekert AG.

[0008] P24013

[0009] 2

[0010] The term "plastic control unit housing" is therefore to be understood and interpreted broadly as per the application and is ultimately characterized by the printed circuit board (PCB) placed between the two housing parts, which in turn carries the control unit. The control unit does not necessarily have to be designed as an electronic (integrated) circuit, but can, in principle, be quite simply a switch. A discrete control unit on the PCB is also conceivable in this context.

[0011] In a method for manufacturing a control unit housing according to the prior art defined in DE 197 55 407 C1, the control unit housing comprises a base and a cover, as well as a connector strip. At least two openings are provided in the base and / or cover. At least one of these openings accommodates the connector strip, which is connected to the circuit board. The openings not occupied by connector strips are closed with a cover. A plastic welding process is used for this purpose, by means of which the cover is tightly bonded to the base and the cover. Plastic welding processes, and in particular laser welding, can be used for this purpose.

[0012] The established procedure has generally proven successful, but still offers room for improvement. For example, the hermetic sealing of the housing after manufacturing means that if the welding is incomplete, the entire control unit housing becomes scrap. Considering the internal, and in some cases expensive, electronic components, this is unacceptable from a cost perspective and also in terms of resource conservation. The invention aims to remedy this situation. Kiekert AG

[0013] P24013

[0014] 3

[0015] The invention is based on the technical problem of providing such a method for manufacturing a control unit housing as well as a control unit housing made of plastic, in which it is possible to carry out a test for media tightness before installation.

[0016] To solve this technical problem, the invention proposes, in a generic method for manufacturing a control unit housing made of plastic, that an inner opening to the interior of the two housing parts remains in the outer connector housing, which is closed by means of the connector in the installed state.

[0017] That is, according to the invention, when the two housing parts are joined in a media-tight manner, the inner opening remains in the outer connector housing. This inner opening is provided and open to the interior of both housing parts, even after the media-tight joining of both housing parts. This allows a plug dummy to be inserted into the outer connector housing instead of the actual plug when it is installed or closed. The plug dummy does not perform the function of the plug and is therefore not equipped with electrical leads. Rather, the plug dummy has the same external dimensions and external routing, if required, as the plug inserted into the outer connector housing when installed.

[0018] Additionally, the dummy connector is typically connected to a pressure line, allowing the interior between the two housing parts to be pressurized (e.g., overpressure or underpressure) via the inner opening in the outer connector housing. This enables a leak test of the control unit housing and, in particular, the verification of whether the media-tight connection between the two housing parts has been successfully established. This means that any leaks between the two housing parts can be detected by the Kiekert AG device described above.

[0019] P24013

[0020] 4. Pressure applied via the dummy plug can be easily detected and, if necessary, located.

[0021] In this way, a comprehensive leak test of the plastic control unit housing is possible, reliably preventing any malfunctions during operation, whether immediately or after potentially several years of operation. This is because the leak test ensures that the media-tight connection between the two housing parts exists and that, according to the invention, any moisture ingress through a previously undetected leak is expressly prevented. This applies even, and especially, over long periods.

[0022] Since the circuit board inside the two media-tightly connected housing parts typically contains more or less sensitive electronic components, it is possible to effectively prevent these electrical or electronic components from coming into contact with moisture and thus avoid malfunctions or even complete failure. This increases operational reliability and prevents potential complaints. Furthermore, any defective control unit housings can be rejected outright, and the circuit board and its components can be reused after the housing is opened. This results in a particularly resource-efficient approach and also saves costs.

[0023] In any case, the inner opening remaining in the outer connector housing for the described pressure test, leading to the interior of the two housing parts, is sealed media-tight at the latest when the connector engages in the outer connector housing in its installed state. Using the connector and the conductors connected to it, the circuit board located inside between the two housing parts, with its electrical / electronic components, is contacted, for example, with peripheral devices. Kiekert AG

[0024] P24013

[0025] 5

[0026] The components are connected. Since the outer connector housing generally has an internal and circumferential seal to ensure a tight seal for the connector within the outer connector housing, it is guaranteed that the connector, when installed, not only seals the outer connector housing to the outside, but also closes the internal opening in the outer connector housing to the interior of the two housing parts. This is where the main advantages lie.

[0027] To implement this in detail, the housing part equipped with the outer connector housing is usually also equipped with an inner connector that engages with the outer connector housing. This means that, when installed, the connector engaging with the outer connector housing is contacted with the circuit board via this inner connector. For this purpose, the inner connector is generally connected to the outer connector housing, for example, by a locking or clipping mechanism. With this connection, the inner opening in the outer connector housing to the interior between the two housing parts remains uncovered, or rather, is defined by this process.

[0028] This means that the inner connector, when connected to the outer connector housing, defines the relevant inner opening. The connection of the inner connector to the circuit board can be made in virtually any way. For example, it is conceivable that the circuit board is connected to the plug contacts of the inner connector. This can generally be done without soldering. That is, the plug contacts of the inner connector advantageously form a solderless connection with the circuit board. Connections of the plug contacts of the inner connector to the circuit board in the form of an insulation displacement connector (IDC) have proven particularly advantageous. Such an IDC connection is created directly when the circuit board is inserted into the outer connector housing. Kiekert AG

[0029] P24013

[0030] 6

[0031] This simplifies assembly because, to produce the control unit housing, only the remaining housing part, the cover housing part, needs to be adhesively bonded to the outer connector housing part. This adhesive bond can be a plastic welding joint. This can be achieved by applying heat, similar to a plastic welding process, which is generally limited to the edges between the two housing parts being joined.

[0032] Typically, the outer connector housing and the cover housing are adhesively bonded together using laser radiation. For this purpose, the outer connector housing is generally transparent (to laser radiation), whereas the cover housing, due to its opaque nature, largely absorbs the laser radiation, thereby bringing it into a meltable state, at least superficially. In other words, the transparent outer connector housing usually absorbs little or no laser radiation, while the opaque cover housing absorbs the majority of the laser radiation, thus bringing it into a meltable state, at least superficially.

[0033] In this way, the cover housing part, at least along its surrounding edge, transitions to a meltable state and is thus adhesively bonded to the transparent outer connector housing part. This allows for a completely media-tight design.

[0034] To verify the leak-tight connection between the two housing parts, the assembled control unit housing is tested for leaks. This is done by inserting the previously mentioned connector dummy into the outer connector housing and pressurizing it. Kiekert AG

[0035] P24013

[0036] 7

[0037] This means that, via a hose connected to the dummy connector, the interior of the two housing parts is pressurized or depressed relative to the surrounding atmospheric pressure, and the pressure curve is simultaneously measured as a function of the pressure (overpressure or underpressure) supplied by an overpressure or underpressure source. Based on this pressure curve, it can then be determined relatively reliably whether the media-tight connection between the two device housing parts is sealed or leaks.

[0038] In the event of any leaks, the two housing parts are generally opened, the circuit board inside is removed, and it is installed in a different plastic control unit housing. This prevents potential malfunctions from the outset and ensures the continued functionality of the control unit housing and, in particular, the control circuitry or control unit located on the circuit board. This is where the main advantages lie. - The invention also relates to the control unit housing itself, as described in independent claim 10.

[0039] The invention will now be explained in more detail with reference to a drawing that illustrates only one embodiment; the drawing shows:

[0040] Fig. 1 shows the control unit housing according to the invention in its assembled state.

[0041] Current state from a perspective standpoint,

[0042] Figs. 2A to 2C show different process steps for manufacturing the control unit housing.

[0043] Figs. 3A and 3B show different views of the outer connector housing in the area of ​​the outer connector and the inner connector installed therein, Kiekert AG

[0044] P24013

[0045] 8

[0046] Fig. 4 shows the process for welding the two housing parts together.

[0047] Figs. 5A to 5C show the assembly process of the inner plug into the

[0048] External connector housing part and the attachment of the

[0049] Plug dummies for pressure testing and

[0050] Fig. 6 shows the pressure test of the finished control unit housing.

[0051] Plastic.

[0052] The figures show a plastic control unit housing for a motor vehicle. Specifically, in this exemplary embodiment, the plastic control unit housing is a motor vehicle lock housing, which contains not only the necessary locking mechanism but also, and in particular, a circuit board 1, best illustrated in Fig. 2B. The circuit board 1 is equipped, for example, with a control unit 2, which, in the case of the motor vehicle lock and the illustrated motor vehicle lock housing, controls individual lock functions, such as the "electrically opening" function of a locking mechanism 4. The locking mechanism 4 may actually be arranged in a vertical section of the motor vehicle lock housing, while the circuit board 1 is arranged in a horizontal section.

[0053] It can be seen that, in addition to the electronic control unit 2, the circuit board 1 also accommodates an emergency power source 3 in the form of two capacitors, according to the exemplary embodiment. With the help of the emergency power source 3, an emergency opening of the locking mechanism 4 can be triggered in the event of a failure of a vehicle battery or accumulator. The control unit 2 on the circuit board 1 may also be responsible for this. The locking mechanism 4 itself, as is generally the case, consists of a rotary latch and a pawl interacting with it. Furthermore, there is a Kiekert AG component, not explicitly shown, which can be actuated by the control unit 2.

[0054] P24013

[0055] 9 An electric motor drive is provided inside the lock housing, with the aid of which the lock mechanism 4 can be opened electrically or in an emergency. In the latter case, the required energy is supplied by the emergency power source 3.

[0056] The lock housing, or more generally the control unit housing, made of plastic according to the invention comprises two housing parts 5 and 6. One housing part 5 is equipped with an outer connector housing 5a. An inner connector 7 can be plugged into the outer connector housing 5a when installed. For this purpose, the outer connector housing 5a is equipped with an inner and circumferential seal 8, which is only visible in Fig. 3B. Since the two housing parts 5 and 6 are connected to each other in a media-tight manner – as will be described in more detail below – when the connector 7 is plugged into the outer connector housing 5a, the control unit housing is sealed in a media-tight manner when installed.On the one hand, the two housing parts 5, 6 are connected to each other in a media-tight manner, usually by plastic welding, and on the other hand, the outer connector housing 5a is also sealed media-tight by the plug 7, which is inserted when installed, together with the surrounding seal 8. According to the exemplary embodiment, the outer connector housing 5a, like the plug 7, is designed in two parts, which is of course only an example and is in no way a limitation.

[0057] The connector 7, in turn, has only the electrical conductors shown in Fig. 1, which enable the control unit 2 on the circuit board 1 inside the vehicle lock housing to communicate with a body-side control unit. For example, the body-side control unit sends corresponding release signals to the lock-side control unit 2 on the circuit board 1 when an authorized user approaches a vehicle equipped with the vehicle lock and the vehicle lock housing. Kiekert AG

[0058] P24013

[0059] 10

[0060] The electrical connection between the connector 7 and the circuit board 2 is established via an inner connector 9 that engages in the outer connector housing 5a. The inner connector 9 can be easily adapted to specific requirements because it is a plug-in or add-on component. This allows for the realization and implementation of vehicle-specific features, enabling virtually any vehicle to be equipped with the corresponding vehicle lock housing and lock designed in this way. The inner connector 9, which engages in the outer connector housing 5a, serves for the peripheral electrical connection of the circuit board 2 and is sealed to the outside, together with the two housing parts 5 and 6, in a media-tight manner. This is ultimately ensured by the connection in the installed state, as shown in the figure.1 Plug 7 inserted into the external plug housing 5a together with the circumferential seal 8 provided inside the external plug housing 5a.

[0061] According to the exemplary embodiment, the design is such that an inner opening 10 remains in the outer connector housing 5a even after the installation of the inner connector 9 and the media-tight connection of the two housing parts 5, 6. According to the exemplary embodiment, this inner opening 10 is located in or on the inner connector 9 and ensures that, even when the inner connector 9 is installed in the outer connector housing 5a, the interior between the two housing parts 5, 6 can communicate with the exterior or the ambient air, namely via the opening to the interior of the two housing parts 5, 6.

[0062] 6. Open inner opening 10. However, this inner opening 10 is closed in the installed state by means of the plug 7, as shown in Fig. 1. Because in this installed state, the plug ensures

[0063] 7 in conjunction with the circumferential seal 8 in the outer connector housing 5a ensures that the outer connector housing 5a is sealed media-tight and hermetically from the outside. This also applies to the inner opening 10. Kiekert AG

[0064] P24013

[0065] 11

[0066] To realize and implement this in detail, the process is carried out as illustrated in the individual steps shown in Figures 2A to 2C. First, the housing part 5, which is equipped with the outer connector housing 5a, is additionally fitted with the inner connector 9 that engages in the outer connector housing 5a. For this purpose, the inner connector 9 is connected to the outer connector housing 5a. According to the exemplary embodiment, the connection is made by inserting the inner connector 9, as shown in the supplementary illustration in Figure 5A, into a recess in the outer connector housing part 5 adjacent to the outer connector housing 5a.

[0067] The inner connector 9 is then moved towards the outer connector housing 5a, as can be seen in the transition from Figure 5A to Figure 5B and indicated by the arrow there. This secures or clips the inner connector 9 to the outer connector housing 5a. In principle, other connections between the inner connector 9 and the outer connector housing 5a are also conceivable, for example, a plastic weld. However, a simple and quick-to-install snap-fit ​​or clip connection is typically used, especially since this also allows for easy definition of the inner opening 10 in or on the inner connector 9. In this embodiment, the inner opening 10 is a slot-like opening in the inner connector 9.In principle, the inner opening 10 can also be defined on the edge between the inner plug 9 and the outer plug housing 5a during or after the installation of the inner plug 9 into the outer plug housing 5a.

[0068] In either case, the inner plug 9, when connected to the outer plug housing 5a, defines the inner opening 10. Thus, as shown in Fig. 5C or Fig. 6, it is possible to subsequently insert a plug dummy 7' into the outer plug housing 5a instead of the plug 7. The plug dummy 7' corresponds to Kiekert AG P24013.

[0069] 12, in terms of its external dimensions, corresponds to the connector 7, so that when the connector dummy 7' is inserted into the outer connector housing 5a, a media-tight connection is observed between the connector dummy 7' and the outer connector housing 5a. If positive or negative pressure is now supplied to the interior of the housing between the two housing parts 5, 6 from a pressure source 12 via a hose 11 connected to the connector dummy 7', it can be easily determined, depending on the pressure profile, whether the media-tight welded connection between the two housing parts 5, 6, which will be described in more detail below, is properly executed and has no leaks.

[0070] Returning to Fig. 5B or Fig. 2A, after the inner connector 9 has been mounted, the circuit board 1 is first placed inside the outer connector housing part 5. During this process, the circuit board 1 is simultaneously connected to the inner connector 9. For this purpose, the inner connector 9 has plug contacts 13, which, according to the exemplary embodiment, are designed to be raised and are connected to corresponding mating plug contacts 15 of the circuit board 1. This can be done via a respective insulation displacement connection or generally without soldering. A soldered connection between the plug contacts 13 of the inner connector 9 and the mating plug contacts 15 of the circuit board 1 is also possible and conceivable.In addition to these plug contacts 13, the inner plug 9 also has front-side plug contacts 14, which are contacted with mating plug contacts inside the plug 7 (not explicitly shown) as soon as the plug 7 is inserted into the outer plug housing 5a in the installed state as shown in Fig. 1.

[0071] Following the assembly of the circuit board 1 inside the outer connector housing part 5 as shown in Fig. 2B, the further housing part 6, the cover housing part 6, is connected to the outer connector housing part 5 and adhesively coupled to it. This is done via a plastic welding connection between the two Kiekert AG

[0072] P24013

[0073] 13 Housing parts 5, 6, specifically in their respective edge regions. This plastic weld joint between the two housing parts 5, 6 is shown in detail in Fig. 4.

[0074] The plastic weld between the two housing parts 5 and 6 is manifested in a weld contour 16, which, according to the exemplary embodiment, is designed as a laser weld contour. The laser weld contour 16 is implemented such that a laser, for example an infrared laser, can penetrate the outer connector housing part 5, which is transparent to the laser radiation. In contrast, the cover housing part 6 is opaque to the laser radiation and consequently absorbs the infrared radiation emitted by the laser. Since the laser radiation is sharply focused on the connection area or edge area between the two housing parts 5 and 6 and defines the weld contour 16, the two housing parts 5 and 6 can be coupled together in a media-tight manner by moving the laser along the weld contour 16 using a 3D movement unit, following the outline of the outer connector housing part 5, according to the exemplary embodiment.As a result, along the weld contour 16, at least the opaque cover housing part 6 melts locally in the area of ​​the weld contour 16 and both housing parts 5, 6 are joined together in a media-tight manner.

[0075] To verify and ensure that the two housing parts 5 and 6 are indeed media-tightly coupled, the connector dummy 7' is inserted into the outer connector housing 5a, as shown in Fig. 5C or 6, after the control unit housing has been assembled according to the illustration in Fig. 2C. If the interior between the two housing parts 5 and 6 is then pressurized or depressurized via the pressure source 12 and hose 11 through the inner opening 10, any leaks indicating a faulty media-tight connection between the two housing parts 5 and 6 can be easily detected. Kiekert AG

[0076] P24013

[0077] 14

[0078] As an example, when the interior space between the two housing parts 5 and 6 is pressurized, the pressure is measured using a measuring device (not shown). Alternatively, the pressure source 12 could first pressurize the interior of the two housing parts 5 and 6 with overpressure or underpressure, then be switched off, and subsequently measure whether and for how long the overpressure or underpressure is maintained inside between the two housing parts 5 and 6 using the measuring device. Either way, this allows conclusions to be drawn as to whether the media-tight plastic weld or the weld contour 16 has been produced correctly. If not, the two housing parts 5 and 6 can be separated, and the circuit board 1 inside, with its electrical / electronic components, at least the control unit 2 and the emergency power source 3, can still be used. This is where the main advantages lie.

[0079] Kiekert AG

[0080] P24013

[0081] 15

[0082] Reference symbol list

[0083] Circuit board 1

[0084] Control unit 2

[0085] Emergency power source 3

[0086] Lock 4

[0087] Housing parts 5, 6

[0088] External connector housing 5a

[0089] Internal connector 7

[0090] Plug dummy 7'

[0091] Seal 8

[0092] Inner plug 9

[0093] Inner opening 10

[0094] Hose 11

[0095] Print source 12

[0096] Plug contacts 13

[0097] Plug contacts 14

[0098] Mating contacts 15

[0099] Laser welding contour 16

Claims

Patent claims 1. A method for manufacturing a plastic control unit housing for a motor vehicle, wherein a printed circuit board (1 ) is placed between two housing parts (5, 6) and the two housing parts (5, 6) are connected to each other in a media-tight manner with the printed circuit board (1 ) received inside, and wherein at least one housing part (5) equipped with an external connector housing (5a) can receive a connector (7) engaging therein for the peripheral electrical connection of the printed circuit board (1 ) and is sealed media-tight to the outside together with the two housing parts (5, 6), characterized in that an inner opening (10) to the interior of the two housing parts (5, 6) remains in the external connector housing (5a), which is closed by means of the connector (7) in the installed state.

2. Method according to claim 1, characterized in that the housing part (5) equipped with the outer plug housing (5a), the outer plug housing part (5), is additionally equipped with an inner plug (9) engaging in the outer plug housing (5a).

3. Method according to claim 2, characterized in that the inner plug (9) is connected to the outer plug housing (5a), for example by bracing or clipping.

4. Method according to claim 3, characterized in that the inner plug (9) when connecting to the external plug housing (5a) the inner opening (10) defined.

5. Method according to one of claims 2 to 4, characterized in that the circuit board (1 ) is connected to plug contacts (13) of the inner plug (9).

6. Method according to claim 5, characterized in that the plug contacts (13) of the inner plug (9) form a solderless connection with the circuit board (1 ), for example an insulation displacement connection.

7. Method according to one of claims 2 to 6, characterized in that the outer connector housing part (5) is adhesively connected to the further housing part (6), the cover housing part (6).

8. Method according to claim 7, characterized in that the outer connector housing part (5) is transparent and the cover housing part is opaque for laser radiation to connect both housing parts (5, 6).

9. Method according to one of claims 1 to 8, characterized in that the mounted control unit housing is checked for leak tightness by inserting a plug dummy (7') into the outer plug housing (5a) and applying pressure to it.

10. Control unit housing made of plastic for a motor vehicle, preferably manufactured according to one of claims 1 to 9, with a printed circuit board (1) placed between two housing parts (5, 6), wherein the two housing parts (5, 6) are connected to each other in a media-tight manner with the printed circuit board (1) received inside, and wherein at least one housing part (5) is equipped with an external connector housing (5a) which can receive a connector (7) engaging therein for the peripheral electrical connection of the printed circuit board (1) and is sealed media-tight to the outside together with the two housing parts (5, 6), characterized in that The outer plug housing (5a) has an inner opening (10) to the interior of the two housing parts (5, 6), which is closed by means of the plug (7) when installed.

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