Electronic control unit comprising a shaped sealing element

Abstract

The invention relates to an electronic control unit (1) comprising at least one conductor-supporting element (5) arranged on a base plate (4), the conductor-supporting element (5) being covered by a shaped sealing element (2) on at least one side, the shaped sealing element (2) having a flat main body (11) made of a metallic material, the main body (11) having two substantially opposed main surfaces, and the length and width being substantially greater than the thickness of the main body (11), the main body (11) having on at least one of the edges delimiting one of the main surfaces a circumferential portion made of a soft component and forming at least one sealing lip (6), the main body (11) having at least one locking recess (15) which faces the electronic control unit (1) in the fully assembled state.

Description

[0001] Description

[0002] Electronic control unit with molded sealing element

[0003] Technical area

[0004] The invention relates to an electronic control unit with at least one line-carrying element which is arranged on a base plate, wherein the line-carrying element is covered on at least one side by a shaped sealing element, wherein the shaped sealing element has a plate-shaped base body which is formed from a metallic material, wherein the base body has two essentially opposite main surfaces, and the length and width are considerably greater than the thickness of the base body.

[0005] State of the art

[0006] Control units for use in motor vehicles typically have a complex internal structure with a multitude of electrical circuits. The electronic assemblies, constructed using printed circuit boards (PCBs) or other circuit-carrying elements, are housed in housings that are typically encapsulated with plastics or cast resins to minimize damage to the electronics due to mechanical influences or corrosive media.

[0007] In order to be able to contact the electronics and to integrate the control units into the communication network of the vehicle and to control the components to be controlled, feedthroughs must be provided through the housing, via which electrical contact is made with the electronics inside the control units.

[0008] To prevent the ingress of disruptive fluids or other external influences, the feedthroughs must be sealed. For this purpose, the state of the art allows for the feedthroughs to be equipped with individual seals, which are inserted manually or automatically. The disadvantage of these individual seals, or so-called molded seals, is that they can slip or fall out completely during final assembly of the component or during transport. This results in significant additional effort, as either appropriate securing devices must be provided to hold the molded seals in place, or additional manual work is required when the molded seals have to be replaced.

[0009] In addition, thermal management must be provided for the control units to safely dissipate the heat generated during operation of the electronics, preventing performance limitations or a shortened service life due to excessive temperatures. Heat sinks are typically provided for this purpose, allowing heat to dissipate. A particular disadvantage is that highly complex components are used for heat dissipation, which are generally not removable and therefore not reusable.

[0010] To ensure process-reliable interfaces to the control unit and reliable contact, for example, through connectors or screw-in contact systems, the sockets used for this purpose must be highly precise and feature a so-called spacer geometry to ensure that the sockets are positioned within tightly defined tolerance windows. The sockets used are often elaborately manufactured from metal, completely overmolded, and / or directly connected to the electronics. Manufacturing and reliable assembly are therefore very complex, error-prone, and costly.

[0011] Description of the invention, task, solution, advantages

[0012] Therefore, the object of the present invention is to create an electronic control unit with a molded sealing element, which, on the one hand, ensures that the molded sealing element is secure against loss, on the other hand, the time-consuming and costly assembly of multiple seals is avoided, and on the other hand, the overall manufacturing effort is reduced. Furthermore, the reusability of the molded sealing element is ensured.

[0013] The problem with regard to the electronic control unit is solved by an electronic control unit having the features of claim 1.

[0014] An embodiment of the invention relates to an electronic control unit with at least one line-carrying element which is arranged on a base plate, wherein the line-carrying element is covered on at least one side by a shaped sealing element, wherein the shaped sealing element has a plate-shaped base body which is formed from a metallic material, wherein the base body has two essentially opposite main surfaces, and the length and width are significantly greater than the thickness of the base body, wherein the base body has, on at least one of the edges delimiting one of the main surfaces, a section which runs around the circumference and is formed from a soft component and forms at least one sealing lip, wherein the base body has at least one locking pocket which, in the finally assembled state, faces the electronic control unit.

[0015] A molded sealing element is formed by a base body that has at least one sealing lip and can thus seal a spatially limited area against a medium. A soft component forming the sealing lip can be formed, for example, by an elastomer, such as rubber, or a correspondingly soft plastic. The base body of the molded sealing element can, for example, be overmolded or over-injected.

[0016] The base body is essentially formed by a plate which is characterized by significantly greater extensions in two of the three spatial directions than in the third spatial direction. These significantly greater extensions in two of the three spatial directions can be defined as the length and width of the base body. A thickness of the plate-shaped base body can be defined with respect to the third spatial direction, for example as the plate thickness of the base body, in particular as the maximum plate thickness. A significantly greater or significantly greater extension can occur, for example, if the ratio is at least two to one, in particular at least five to one, in particular at least ten to one. Such a plate has an edge on each of its main surfaces which spatially delimits the plate.A sealing lip, which creates a sealing space beneath the plate, thus preferably runs circumferentially around the edge of the plate that defines the spatial boundary. In a simple design, the plate has at least one such sealing lip on one of its main surfaces, for example, to create a one-sided seal. In more complex designs, sealing lips can also be provided on both sides to create a two-sided seal.

[0017] Several sealing lips can also be provided per main surface, for example if the sealing space under the plate is to be divided into several areas, or if the plate has penetrations that need to be additionally sealed.

[0018] The metallic base body is preferably made of aluminum, which is both easily formable and has excellent thermal conductivity. The base body is preferably deep-drawn from aluminum sheet, which allows for the creation of even very complex shapes.

[0019] The sections of the base body referred to as locking pockets are preferably characterized by a bulge that extends from the plane of the base body towards the electronic control unit. This region is preferably pot-shaped. In addition, at least two openings are assigned to each locking pocket, which are arranged next to the pot-shaped region. Corresponding locking lugs can be pushed through these openings and engage behind the base body, thereby creating a certain fixation of the base body to the electronic control unit. The bottom region of the bulge is preferably flat, and in the final assembled state, this flat bottom region lies directly against a section of the line-carrying element of the electronic control unit, which can in particular be formed by a printed circuit board (PCB).

[0020] The direct mechanical contact between the base body and the PCB allows for advantageous heat dissipation from the electronics to the metal base body, and from the metal base body to the environment via convection. The metal base body thus acts as a cooling element.

[0021] Particularly preferably, the base body has a plurality of circumferential sealing lips, which are formed circumferentially along edges that delimit one of the main surfaces. The base body preferably has four such sealing lips. Furthermore, the base body preferably has five locking pockets.

[0022] There are two assembly states. In the first assembly state, the locking lugs engage in the locking recess, or more precisely, in the openings in the locking recesses. The molded sealing element is thus securely fixed to the electronic control unit, but is still movable relative to it. The relative mobility is possible in all three spatial directions.

[0023] In the second state, the final assembled state, the molded sealing element is screwed to the electronic control unit by means of screw connections or with screws through the electronic control unit against a mounting surface serving as an abutment.

[0024] In the final assembled state, the sealing lips rest against the sealing grooves of the electronic control unit, the bottom of the locking pocket rests against the cable-carrying element, and relative movement of the molded sealing element to the electronic control unit is prevented. It is particularly advantageous if the base body has a circumferentially extending section on both sides of an edge bordering one of the respective main surfaces. This section is formed from a soft component and forms at least one sealing lip per main surface.

[0025] Preferably, there are several sealing lips formed by a soft component on both sides. Preferably, a sealing lip is formed on both sides around each penetration of the base body in order to completely seal the respective penetration on both sides. Likewise, a completely circumferential sealing lip is preferably formed on both sides around the sealing space in which the line-carrying element is arranged. This bilateral arrangement of the sealing lips is particularly advantageous for creating a seal both against the electronic control unit and against the mounting surface serving as an abutment.

[0026] It is also advantageous if the electronic control unit has locking lugs which correspond to the locking pocket of the base body and engage in the locking pocket in the final assembled state and securely connect the base body to the electronic control unit.

[0027] The locking lugs are preferably made of plastic and formed integrally with the electronic control unit. Particularly preferably, the locking lugs can be formed on the line-carrying element of the control unit. Even in the first tightened state, the locking lugs engage in the openings next to the cup-shaped bulge and secure the base body relative to the electronic control unit in such a way that the molded sealing element cannot be lost.

[0028] A preferred embodiment is characterized in that the locking pocket is formed by a cup-shaped region and at least two openings arranged outside the cup-shaped region and penetrating the base body. The cup-shaped region, with an advantageously flat bottom, can be brought into contact with the PCB to ensure good thermal contact. The openings serve to pass through the locking lugs and enable engagement behind the base body.

[0029] According to one embodiment, a base, in particular a flat base, of the pot-shaped region is brought into contact with the conductor-carrying element. This can be beneficial for heat transfer from the conductor-carrying element, for example, a PCB, to the base plate. The base plate can therefore advantageously combine a variety of functions, including fastening by means of the locking elements, sealing by means of the sealing lip, and heat transfer.

[0030] According to one embodiment, the base body is designed such that, when the electronic control unit is mounted on a wall, a surface of the base body outside the cup-shaped region makes thermally conductive contact with the wall. This surface can, in particular, be an edge around the cup-shaped region or comprise such an edge. In combination with the previous embodiment, the base plate can thus efficiently dissipate heat from the conductor-carrying element to the wall.

[0031] It is also preferable if the electronic control unit has at least one sealing groove which corresponds to the at least one sealing lip on the base body and is aligned with the at least one sealing lip in the final assembled state.

[0032] To create a secure seal, the sealing lips formed on the base body require a sealing surface against which they can be pressed. Such a sealing surface can preferably be formed by a sealing groove on the electronic control unit, into which the sealing lip engages upon contact.

[0033] Furthermore, it is advantageous if the at least one sealing lip formed on the base body is not compressed relative to the sealing grooves formed on the electronic control unit when the locking lugs engage the locking pocket. This is advantageous because, in this state, the purpose is not only to prevent the molded sealing element from becoming lost, but also to ensure the most flexible possible relative positioning of the two elements relative to each other.

[0034] Furthermore, it is advantageous if the base body has at least one bore which completely penetrates the base body from main surface to main surface, wherein the electronic control unit has at least one pin which has a smaller cross-section than the bore and engages in the bore in the tightened state and in the finally assembled state. The bore can be designed as a classic bore or as a slotted hole. The engaging pin always has a smaller diameter than the bore so that relative movement in all three spatial directions is still guaranteed. The degree of possible relative movement can be defined by the relative size of the bore to the pin. Preferably, the pin already protrudes through the bore in the rusted state.

[0035] It is also expedient if the base body has at least one first recess into which a spacer bushing can be inserted, wherein the electronic control unit has at least one second recess corresponding to the first recess.

[0036] The spacer bushing serves to ensure the distance between the molded sealing element and the electronic control unit. For this purpose, both the base body and the electronic control unit form a support surface for the spacer bushing. In the final assembled state, the spacer bushing rests on both sides. The spacer bushing is preferably made of steel and is inserted into the first recess on the base body before assembly. In the rusted state, the spacer bushing is positioned between the molded sealing element and the electronic control unit in such a way that the latter cannot fall out of the first recess in the base body. Furthermore, it is advantageous if the second recess on the electronic control unit is formed in a section of the electronic control unit made of plastic.

[0037] The second recess is preferably conical, so that self-centering is achieved during insertion of the spacer sleeve. The spacer sleeve can also be conical at its end region facing the electronic control unit, thereby further improving self-centering. Particularly preferably, the spacer sleeve rests on the line-carrying element, the PCB, of the electronic control unit. The plastic section thus forms the receptacle into which the spacer sleeve is inserted. The use of plastic can create electrical insulation and also prevent damage to the PCB.

[0038] Furthermore, it is advisable for the diameter of the first recess in the base body to be smaller than the largest diameter of the section of the spacer sleeve facing the electronic control unit. This ensures that the spacer sleeve cannot fall out through the recess in the base body.

[0039] Preferably, the total tolerances of the spacer bushing in the assembly direction of the molded sealing element do not exceed the smallest material thickness of the base body. The total tolerances are preferably approximately half the material thickness of the base body. This prevents the spacer bushing from becoming detached from its seat in the electronic control unit and the base body when securely fastened and from migrating between the electronic control unit and the base body, which would necessitate disassembly. In the rusted state, the spacer bushing always protrudes into the first recess in the base body. By screwing it together, which creates the final assembled state, the spacer bushing is also pressed into its seat in the electronic control unit.It is also preferable if, in the final assembled state, at least one sealing lip of the base body rests compressed against the sealing groove of the electronic control unit, wherein the base body of the shaped sealing element is clamped between the line-carrying element of the electronic control unit and a contact surface serving as an abutment, wherein the base body is in contact with both the line-carrying element and the contact surface serving as an abutment.

[0040] The molded sealing element is thus practically sandwiched between the electronic control unit and the contact surface serving as abutment, creating a complete seal via the sealing lips on both sides. The contact surface serving as abutment is colloquially known as the mounting location where the electronic control unit is screwed to the molded sealing element.

[0041] It is also advisable for the conductor-carrying element to be coated with a metallic coating in the contact area with the base of the locking pocket, with the metallic coating being connected to the electronic components of the electronic control unit in a heat-dissipating manner. The metallic coating on the PCB promotes heat transfer and thus achieves better heat dissipation.

[0042] Advantageous further developments of the present invention are described in the subclaims and in the following description of the figures.

[0043] Short description of the drawings

[0044] The invention is explained in detail below using exemplary embodiments with reference to the drawings. In the drawings:

[0045] Fig. 1 is a sectional view through an electronic control unit with a reinforced molded sealing element, Fig. 2 is a sectional view through an electronic control unit,

[0046] Fig. 3 is a sectional view through a molded sealing element,

[0047] Fig. 4 a detailed view of a rust pocket and the corresponding locking lugs on the electronic control unit,

[0048] Fig. 5 is a sectional view with a spacer sleeve inserted into the molded sealing element in the upper area and a sectional view, which additionally shows the electronic control unit, in the lower area, and

[0049] Fig. 6 is a sectional view of the electronic control unit with the molded sealing element mounted, both parts being mounted at one mounting location.

[0050] Preferred embodiment of the invention

[0051] Figure 1 shows a sectional view through an electronic control unit 1 with a molded sealing element 2 connected to the control unit 1. The control unit 1 is formed from a base plate 4 on which a line-carrying element 5, for example a PCB, is arranged. The line-carrying element 5 is preferably formed by a printed circuit board and, as known from the prior art, carries various conductor tracks and electronic components.

[0052] The molded sealing element 2 is formed by a deep-drawn aluminum sheet having a plurality of sealing lips 6 created by the application of a soft component. As can be seen in Figure 1, the molded sealing element 2 is in direct contact with the line-carrying element 5. The sealing lips 6 facing the electronic control unit 1 are also in direct contact with the electronic control unit 1 or are components directly connected to the control unit 1.

[0053] The reference number 3 represents a spacer bushing which separates the shaped sealing element 2 from the electronic control unit 1.

[0054] Figure 2 shows a sectional view of the electronic control unit 1 and the line-carrying element 5. The reference numerals are used unchanged for identical elements.

[0055] The two locking lugs 8 can be seen in detail, which are used to connect the molded sealing element 2 (not shown) to the electronic control unit 1. Furthermore, a pin 7 is shown, which protrudes from the line-carrying element 5 or a plastic coating 10 of the line-carrying element 5. This pin 7 serves to position the molded sealing element 2 relative to the control unit 1. For this purpose, bores 16 are provided in the molded sealing element 2, into which the pins 7 can engage. Furthermore, sealing grooves 9 are shown on the line-carrying element 5 or the plastic coatings 10, into which sealing grooves the sealing lips 6 formed on the molded sealing element 2 can engage and thus create a seal between the two elements.

[0056] Figure 3 shows a single view of the molded sealing element 2. The sealing lips 6 applied to both sides of the base body 11 can again be seen. These sealing lips 6 can be produced, for example, by a molding process in which the base body 11 is coated with an elastomer.

[0057] As shown in Figure 3, the sealing lips 6 are arranged on both sides of the base body 11 and are arranged, in particular, once circumferentially on both sides on the outer edge delimiting the base body 11 and once again around the opening 17 in the base body 11, through which, for example, electrical contact with the electronic control unit 1 can be made. The sealing lips 6 are preferably located on edges formed at holes in the base body 11 or delimit the base body 11 to the outside. In this way, a seal of the sealing space to be sealed by the molded sealing element can advantageously be achieved.

[0058] Reference numeral 13 represents the openings formed adjacent to the cup-shaped recess 14 of the base body and, together with the cup-shaped recess, forming the locking pockets 15. During the assembly process, the openings 13 are penetrated by the locking lugs 8 of the electronic control unit 1, and the projections of the locking lugs 8 engage behind the base body 11.

[0059] The reference number 12 designates a recess in the base body 11, which serves as a seat for a spacer bushing (not shown).

[0060] The molded sealing element is assembled in two steps. In the first step, the base body 11 is locked to the electronic control unit 1 by engaging the locking lugs 8 through the openings 13 and the pins 7 through the bore 16. In this state, the base body 11 is still movable in all three spatial directions relative to the electronic control unit 1. Due to the positive locking between the openings 13 and the locking lugs 8, as well as the positive locking between the pin 7 and the bore 16, the relative movement is limited but fundamentally possible. The sealing lips 6 are not pressed into the sealing grooves 9 and, if at all, only lightly engage.

[0061] In the second part of the assembly, the base body 11 is screwed to the electronic control unit 1. For this purpose, one or more screws are preferably guided through openings in the electronic control unit 1 and the molded sealing element 2 and screwed against an abutment at a selected assembly location. The normal forces acting on the individual elements from the screws pull the molded sealing element 2 towards the electronic control unit 1 and the sealing lips 6 come into contact with the sealing grooves 9. In addition, the spacer bushings 3 are pulled into their respective seats in the molded sealing element 2 and the electronic control unit 1, thus creating a precisely defined distance between the molded sealing element 2 and the electronic control unit 1.If the abutment is a flat body, a seal is also created between the side of the shaped sealing element 2 facing away from the electronic control unit 1 and the flat abutment, for example a housing wall.

[0062] Figure 4 shows a detailed view of a locking pocket 15 with its cup-shaped recess 14 and the two openings 13 arranged to the right and left of the cup-shaped recess 14. Figure 4 shows the final assembled state, in which the cup-shaped recess 14 is in contact with the line-carrying element 5 and the locking lugs 8 engage behind the base body 11.

[0063] Figure 5 shows the upper section of the molded sealing element 2 with an inserted spacer bushing 3. The spacer bushing 3 is inserted into the recess 12 in the base body 11. The spacer bushing 3 has a first section that fits into the recess 12 and a second section, which faces the electronic control unit 1 and has a larger diameter. This geometry of the spacer bushing 3 ensures that it cannot slip through the recess 12 and become lost. At the same time, the shoulder formed at the transition between the two sections forms the support for the base body 11 on the spacer bushing 3.

[0064] The second section of the spacer bushing 3 is tapered, which facilitates insertion and centering in the receptacle of the electronic control unit 1.

[0065] The lower part of Figure 5 also shows the electronic control unit 1 with the line-carrying element 5, which is arranged above the molded sealing element 2. The spacer bushing 3 sits in a receptacle 18 of the electronic control unit 1. The conical cross-section of the receptacle 18 also supports the centering of the spacer bushing 3.

[0066] Finally, Figure 6 shows the electronic control unit 1 with the molded sealing element 2 in the final assembled state against a wall 19 serving as an abutment. All components are connected to one another via the screw shown with the reference numeral 20 and pressed together under the effect of the normal force generated by the screw.

[0067] It is particularly clearly visible that the pot-shaped formation 14 is in direct contact with the line-carrying element 5, which promotes heat dissipation from the electronic components.

[0068] The reference symbols in the figures have been used in the same way in all figures, as long as the parts are identical.

[0069] The embodiments of Figures 1 to 6 are in particular not restrictive in nature and serve to clarify the inventive concept.

[0070] List of reference symbols

[0071] 1. electronic control unit

[0072] 2. Molded sealing element

[0073] 3. Spacer bushing

[0074] 4. Base plate

[0075] 5. cable-carrying element

[0076] 6. Sealing lip

[0077] 7. Cone

[0078] 8. Locking lug

[0079] 9. Sealing groove

[0080] 10. Plastic coating

[0081] 11 . Basic body

[0082] 12. Recess

[0083] 13. Opening

[0084] 14. cup-shaped shape

[0085] 15. Locking pocket

[0086] 16. Borehole

[0087] 17. Opening

[0088] 18th recording

[0089] 19. Wall

[0090] 20. Screw

Claims

Patent claims 1. An electronic control unit (1) comprising at least one line-carrying element (5) arranged on a base plate (4), wherein the line-carrying element (5) is covered at least on one side by a molded sealing element (2), wherein the molded sealing element (2) comprises a plate-shaped base body (11) formed from a metallic material, wherein the base body (11) has two substantially opposite main surfaces, and the length and width are substantially greater than the thickness of the base body (11), characterized in that the base body (11) has, on at least one of the edges delimiting one of the main surfaces, a circumferentially extending section formed from a soft component and forming at least one sealing lip (6), wherein the base body (11) has at least one locking pocket (15),which, in the final assembled state, faces the electronic control unit (1).

2. Electronic control unit (1) according to claim 1, characterized in that the base body (11) has on both sides, on an edge delimiting one of the respective main surfaces, a section which runs around the circumference and is formed from a soft component and forms at least one sealing lip (6) per main surface.

3. Electronic control unit (1) according to one of the preceding claims, characterized in that the electronic control unit has locking lugs (8) which correspond to the locking pocket (15) of the base body (11) and, in the finally assembled state, engage in the locking pocket (15) and connect the base body (11) to the electronic control unit (1) in a captive manner.

4. Electronic control unit (1) according to one of the preceding claims, characterized in that the locking pocket (15) is formed by a cup-shaped region (14) and at least two openings (13) arranged outside the cup-shaped region (14) and penetrating the base body (11).

5. Electronic control unit (1) according to the preceding claim, characterized in that a bottom of the pot-shaped region (14) is brought into contact with the line-carrying element (5).

6. Electronic control unit (1) according to the preceding claim, characterized in that the base body (11) is designed such that when the electronic control unit (1) is mounted on a wall (19), a surface of the base body (11) outside the pot-shaped region (14) makes thermally conductive contact with the wall (19).

7. Electronic control unit (1) according to one of the preceding claims, characterized in that the electronic control unit (1) has at least one sealing groove (9) which corresponds to the at least one sealing lip (6) on the base body (11) and is in alignment with the at least one sealing lip (6) in the finally assembled state.

8. Electronic control unit (1) according to one of the preceding claims, characterized in that the at least one sealing lip (6) formed on the base body (11) is not compressed relative to the sealing grooves (9) formed on the electronic control unit (1) in the state in which the locking lugs (8) engage in the locking pocket (15).

9. Electronic control unit (1) according to one of the preceding claims, characterized in that the base body (11) has at least one bore (16) which completely penetrates the base body (11) from main surface to main surface, wherein the electronic control unit (1) has at least one pin (7) which has a has a smaller cross-section than the bore (16) and engages in the bore (16) in the rusted state and in the finally assembled state.

10. Electronic control unit (1) according to one of the preceding claims, characterized in that the base body (11) has at least one first recess (12) into which a spacer bushing (3) can be inserted, wherein the electronic control unit (1) has at least one second recess corresponding to the first recess (12).

11. Electronic control unit (1) according to one of the preceding claims, characterized in that the second recess on the electronic control unit (1) is formed in a section (10) of the electronic control unit (1) made of plastic.

12. Electronic control unit (1) according to one of the preceding claims, characterized in that the diameter of the first recess (12) on the base body (11) is smaller than the largest diameter of the section of the spacer sleeve (3) facing the electronic control unit (1).

13. Electronic control unit (1) according to one of the preceding claims, characterized in that in the finally assembled state the at least one sealing lip (6) of the base body (11) bears compressed against the sealing groove (9) of the electronic control unit (1), wherein the base body (11) of the shaped sealing element (2) is clamped between the line-carrying element (5) of the electronic control unit (1) and a contact surface (20) serving as an abutment, wherein the base body (11) is in contact both with the line-carrying element (5) and with the contact surface (20) serving as an abutment.

14. Electronic control unit (1) according to one of the preceding claims, characterized in that the line-carrying element (5) is coated with a metallic coating in the contact area with the bottom (14) of the rust pocket (15), wherein the metallic Coating is heat-dissipatingly connected to the electronic components of the electronic control unit (1).

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