Motor vehicle lock

Abstract

The invention relates to a motor vehicle lock (1), comprising an electrically actuable locking device (2), an energy storage device (3) for supplying the locking device (2) with power, and a housing (4) in which the energy storage device (3) is arranged, wherein the housing (4) has a fixing element (5) for fixing the energy storage device (3) in the housing (4), and the fixing element (5) has an open-cell foam. This achieves the object of providing a fixing that compensates both the tolerances and the dynamic changes in geometry of the energy storage device (3) during operation and at the same time ensures reliable protection against mechanical loads.

Description

[0001] STRICTLY CONFIDENTIAL

[0002] Motor vehicle lock

[0003] The invention relates to a motor vehicle lock, with an electrically operated locking device, an energy storage device for supplying the locking device and a housing in which the energy storage device is arranged, wherein the housing has a fixing element for fixing the energy storage device in the housing.

[0004] Automotive locks are locks for motor vehicles, which can be located in various parts of the vehicle. The automotive lock, specifically the locking mechanism, interacts with a locking bolt as soon as a corresponding vehicle door, hatch, sliding door, or similar is closed. For this purpose, the automotive lock is usually located in or on the vehicle door, hatch, or sliding door. The locking bolt, on the other hand, is located on the vehicle body, for example, on a B- or C-pillar. The locking bolt, also known as the lock pin, and the automotive lock together define a vehicle door lock.

[0005] Modern automotive locks incorporate a variety of functions, such as central locking, child safety locks, anti-theft devices, and crash protection systems, which perform safety-related functions or enhance comfort within the vehicle. These functions typically utilize an electric motor, either directly or indirectly. To control these automotive locks, electronic control units are used. An electronic control unit for controlling an automotive lock conventionally consists of a circuit board and the electronic components and energy storage devices mounted on it. The electronic control unit is usually located in the vehicle door, hatch, sliding door, or similar structure.

[0006] Modern automotive locks increasingly contain electronic controls and circuit boards that enable a wide range of functions. These electronics are STRICTLY CONFIDENTIAL.

[0007] However, they are exposed to strong mechanical stresses, such as vibrations and impacts, as well as various environmental factors, which occur particularly during vehicle use. These stresses can significantly impair the functionality of the sensitive components, especially if they are heavy components that are particularly susceptible to mechanical stresses due to their mass.

[0008] Another essential element of modern automotive locks can therefore be energy storage devices integrated into the lock, which supply the locking mechanism with electrical energy. This energy storage device ensures that the locking mechanism remains functional even in the event of a failure of the central vehicle power supply or in special operating situations, such as an emergency. Integrating such an energy storage device into the automotive lock places additional demands on the design and protection of the electronic components, as the storage unit must also be protected against external influences and mechanical stress.

[0009] In electronic systems that use supercapacitor energy storage, the secure mounting of these capacitors presents a particular challenge. Supercapacitors are sensitive components that, on the one hand, must be protected from harmful influences such as vibrations and shocks, while on the other hand, their specific properties require flexible mounting. These components not only exhibit comparatively large tolerances in their dimensions, especially in length and diameter, but also change their geometry during operation. Such changes can be caused by temperature fluctuations or variations in the state of charge, with a characteristic bulging of the cylindrical structure ("barrel") being particularly noticeable. In addition to these mechanical requirements, there is also a need to protect the soldered connections of the supercapacitors to the circuit board from harmful mechanical stress.In particular, bending or tensile forces can compromise the stability and functionality of the soldered joints. STRICTLY CONFIDENTIAL.

[0010] From DE 10 2022 114 890 A1 a motor vehicle lock with a control unit is known, wherein the control unit is a circuit board with a first level arranged on it electronic components connected to the circuit board and an energy storage device connected to the circuit board in a second level offset to the first level and at least partially above the electronic components.

[0011] Based on this, the object of the invention is to provide a fixing that compensates for both the tolerances and the dynamic geometric changes of energy storage devices, such as supercapacitors, during operation, while simultaneously ensuring reliable protection against mechanical stresses.

[0012] This problem is solved by the subject matter of claim 1. Preferred embodiments are found in the dependent claims.

[0013] According to the invention, a motor vehicle lock is provided, comprising an electrically operated locking device, an energy storage device for supplying the locking device, and a housing in which the energy storage device is arranged. The housing includes a fixing element for securing the energy storage device within the housing, and the fixing element comprises an open-cell foam. The energy storage device can be a supercapacitor (supercap).

[0014] An open-cell foam is a porous material whose internal structure is characterized by interconnected cavities. This open-cell structure allows for high air permeability and gives the material excellent moisture absorption and release capabilities. Unlike closed-cell foams, where the cells are completely isolated from one another, the structure of an open-cell foam remains permeable, making it particularly well-suited for applications requiring controlled air and moisture circulation. Open-cell foam offers several advantages when used to house energy storage devices. Its ability to dissipate or reduce electrostatic charges protects sensitive components from electrostatic discharges that could compromise their performance.

[0015] Functionality could be impaired. Furthermore, its high damping capacity helps to absorb mechanical shocks and vibrations, minimizing the risk of mechanical damage during transport or storage. The open-cell structure also facilitates rapid heat dissipation, which is particularly advantageous for temperature-sensitive electronic components. Another benefit is the ability to customize the foam to the shape of the components, ensuring secure fixation. Overall, open-cell foam offers a combination of protection, flexibility, and functionality that makes it a good choice for storing energy storage devices.

[0016] Various open-cell foams can be used for the invention, chosen for their elastic properties, compressibility, resilience, and excellent damping characteristics. Open-cell polyurethane foam is a commonly used material, valued for its high flexibility and good damping properties. Both ester- and ether-based variants can be considered, depending on whether higher chemical resistance or better mechanical strength is required. Another suitable material is melamine resin foam, known, for example, under the trade name Basotect®, which is characterized by its lightness, high flexibility, and excellent thermal stability, making it particularly attractive for applications with elevated temperature requirements.EPDM foam, an elastomeric material with an open cell structure, is also suitable because it has high weather resistance and a pronounced resistance to temperature fluctuations and therefore withstands mechanical stresses well.

[0017] Furthermore, nylon or polyester foams can be an alternative, as they possess high mechanical strength and dimensional stability and are frequently used in technical applications. Reticulated foams, characterized by a particularly uniform cell structure, are also suitable for use, as they can meet precise requirements for air and liquid permeability. Finally, silicone foam, which is characterized by STRICTLY CONFIDENTIAL

[0018] It is characterized by its high heat resistance and flexibility and is particularly suitable for applications subject to strong temperature changes, as it exhibits low permanent deformation and retains its elasticity over long periods of time.

[0019] The vehicle lock can advantageously be designed such that the fixing element is formed as a multi-layered housing with a fixed first part and a fixed second part. The energy storage device is held between these two housing parts under pressure from the fixing element. This multi-layered design enables reliable fixing of the energy storage device.

[0020] To ensure secure fixation throughout operation, the first and second parts can be designed to exert a permanent preload on the energy storage device. This preload ensures that the energy storage device remains securely in position even under the influence of vibrations or other mechanical stresses. At the same time, it allows for a degree of flexibility, enabling the compensation of temperature- or charge-state-related changes in the geometry of the energy storage device.

[0021] A further advantage of the embodiment according to the invention is that the energy storage device is electrically connected to a circuit board, the housing having a mounting surface for receiving the energy storage device. In this configuration, both the circuit board and the connected energy storage device are securely held in the housing. This ensures a mechanically stable and orderly arrangement of the components, thereby improving the structural integrity of the entire system.

[0022] To further improve the fixation, the housing can have special partial surfaces for the flat contact of the energy storage device at the front and rear. These partial surfaces ensure that even if the diameter of the energy storage device changes due to temperature or charging conditions, the fixation remains secure. STRICTLY CONFIDENTIAL

[0023] Changes ensure a uniform and secure support. This prevents point loads and reduces the risk of mechanical damage.

[0024] The positioning of the fixing element within the housing can be such that it applies targeted pressure to the energy storage device at its front and rear. This targeted pressure ensures a secure hold and prevents uncontrolled displacement of the energy storage device, especially under dynamic loads such as those that can occur during ferry operations or external influences.

[0025] The fixing element itself is preferably permanently elastic, enabling it to reliably compensate for tolerances and geometric changes occurring during operation. This elasticity allows the fixing element to dynamically adapt to the changing dimensions of the energy storage device while simultaneously maintaining a constant holding force.

[0026] A further advantageous feature of the invention is that the energy storage device's longitudinal expansion is preferably enabled by sliding movements on specially provided sliding surfaces within the housing. This ensures that the energy storage device is not subjected to mechanical constraints during expansion, which could lead to damage to the soldered joints or the housing.

[0027] Furthermore, the energy storage device is preferably fixed in part by a shear deformation of the fixing element within the housing. This feature allows the system to flexibly accommodate axial expansions of the energy storage device without compromising its structural integrity or mechanical fixation.

[0028] The housing can be made of a vibration-damping material, effectively reducing mechanical stresses caused by ferry operations or external influences. STRICTLY CONFIDENTIAL

[0029] This can be reduced. This helps to extend the service life of the energy storage device and its electrical connections.

[0030] Finally, the fixing element is preferably designed to accommodate temperature-induced deformations of the energy storage device, in particular bulging in its central diameter region. This prevents the energy storage device from pressing against rigid structures and thus being subjected to unnecessary stress. This ensures a long-lasting and reliable operation of the entire unit.

[0031] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings.

[0032] The drawings show

[0033] Fig. 1 schematically shows a housing with an energy storage device according to an embodiment of the invention.

[0034] Fig. 2 schematically shows a motor vehicle lock according to an embodiment of the invention,

[0035] Fig. 3a schematically shows the radial extent of an energy storage device and

[0036] Fig. 3b schematically shows the convex shape and the linear extent of an energy storage device.

[0037] Fig. 1 schematically shows a housing 4 in which two energy storage devices 3 in the form of supercapacitors are arranged. These energy storage devices 3 are held in the housing 4 by fixing elements 5, the fixing elements 5 being made of open-cell foam. The fixing elements 5 are designed such that they enable a permanent elastic mounting of the energy storage devices 3. The open-cell STRICTLY CONFIDENTIAL

[0038] The foam of the fixing elements 5 not only enables secure fixing through permanent pretension, but also compensates for manufacturing and tolerance deviations as well as operationally induced geometric changes of the energy storage devices 3. Of particular note is the ability of the open-cell foam to flexibly accommodate temperature- and charge-state-related volume changes, such as the characteristic bulging in the central section of the energy storage device 3.

[0039] As mentioned above, open-cell foam is a porous material with interconnected cavities that allow for high air permeability and good moisture absorption and release. Unlike closed-cell foams, its structure remains permeable, making it ideal for applications with controlled air and moisture circulation. When used to mount energy storage devices, open-cell foam protects against electrostatic discharge and, thanks to its high damping capacity, minimizes mechanical shocks and vibrations. Furthermore, the open-cell structure promotes rapid heat dissipation, which is particularly advantageous for temperature-sensitive components. Its conformability ensures secure mounting of components, combining protection, flexibility, and functionality in a single solution.

[0040] Various open-cell foams can be used. Open-cell polyurethane foam is particularly suitable, offering high flexibility and good damping. Both ester- and ether-based variants can be selected depending on the chemical or mechanical requirements. Melamine resin foam is characterized by its low weight, high thermal stability, and flexibility, making it ideal for applications with elevated temperature requirements. EPDM foam offers high weather resistance and resistance to temperature fluctuations, enabling it to withstand mechanical stress. Nylon and polyester foams impress with their high mechanical strength and dimensional stability and are frequently found in technical applications. Reticulated foams with a particularly uniform cell structure allow for precise air and liquid permeability.Silicone foam also offers high heat resistance and remains STRICTLY CONFIDENTIAL even under strong conditions.

[0041] It is elastic under temperature changes and exhibits low permanent deformation. The selection of the appropriate foam material depends on the specific requirements for temperature resistance, chemical resistance, and mechanical strength.

[0042] Fig. 2 schematically shows a motor vehicle lock 1 comprising an electrically operated locking device 2 and two energy storage devices 3 for supplying power to the locking device 2. These are housed in a casing 4, which has fixing elements 5 for securing the energy storage devices 3. The fixing elements 5 are made of open-cell foam, which dampens mechanical shocks and vibrations while simultaneously reducing or dissipating electrostatic charges, thus ensuring reliable operation of the electronic components. The positioning of the fixing elements 5 in the casing 4 is designed to ensure a uniform pressure distribution on the energy storage devices 3, particularly in their front and rear areas. This helps to increase mechanical stability and protect the solder joints at the electrical connections from bending and tensile forces.

[0043] As can be seen in Fig. 2, the energy storage devices 3 are connected to a circuit board 9 by means of electrical conductors 8. The housing 4 includes a bearing surface in which both the energy storage devices 3 and the circuit board 9 are securely held. The bearing surface provides a mechanically stable base for the energy storage devices 3, while the housing 4, through its vibration-damping properties, reduces mechanical loads on the circuit board 9 and the electrical connections. Fig. 1 also shows that the housing 4 has partial surfaces 11 that serve as flat bearing surfaces in the front and rear areas of the energy storage devices 3. These partial surfaces 11 are strategically arranged to ensure secure fixation even in the event of radial and axial expansion of the energy storage devices 3.

[0044] Figures 3a and 3b show that the energy storage devices 3 can change their shape during operation due to changes in temperature and state of charge, in particular by developing a convex expansion in their central region. This constitutes a STRICTLY CONFIDENTIAL

[0045] This presents a special requirement for fixation, which is effectively met by the permanently elastic fixing elements 5. The permanent elasticity of the foam makes it possible to compensate for these changes without compromising the structural integrity of the overall system.

[0046] Between the areas of the housing 4 that are in direct contact with the energy storage device 3, there is a section 12 located at a distance from the energy storage device 3, without any part of the fixing element 5 being located there. This design enables targeted compensation for tolerances and geometric changes of the energy storage device 3 during operation, thereby preventing excessive stress on the components.

[0047] Another essential feature, as shown in Figures 1 and 2, is the sliding properties of the partial surfaces 11 of the housing 4, which exhibit low friction. This allows for controlled longitudinal expansion of the energy storage devices 3 on the sliding surfaces, thereby preventing mechanical stresses and resulting damage. The combination of the permanent elasticity of the fixing elements 5 and the sliding surfaces 11 achieves a flexible yet stable fixation.

[0048] In summary, the figures illustrate that the fixing element 5 comprises a multi-layered housing structure consisting of a fixed first part 6 and a fixed second part 7, between which the energy storage devices 3 are accommodated. This structure allows for permanent preload on the energy storage devices 3, thereby ensuring reliable fixing while effectively compensating for temperature and operational influences. STRICTLY CONFIDENTIAL

[0049] Reference symbol list

[0050] Motor vehicle lock

[0051] Locking device

[0052] Energy storage device

[0053] Housing

[0054] Fixing element

[0055] first part

[0056] second part

[0057] electrical wiring

[0058] circuit board

[0059] Subsurfaces of the housing

[0060] Area of ​​the housing that is at a distance from the energy storage device

Claims

STRICTLY CONFIDENTIAL Patent claims 1. Motor vehicle lock (1), comprising an electrically operated locking device (2), an energy storage device (3) for supplying the locking device (2) and a housing (4) in which the energy storage device (3) is arranged, wherein the housing (4) has a fixing element (5) for fixing the energy storage device (3) in the housing (4) and the fixing element (5) has an open-cell foam.

2. Motor vehicle lock (1) according to claim 1, wherein the fixing element (5) has a multi-layered housing (4) comprising a fixed first part (6) and a fixed second part (7), wherein the energy storage device (3) is received between the first part (6) and the second part (7) under pressure of the fixing element (5).

3. Motor vehicle lock (1) according to claim 2, wherein the first part (6) and the second part (7) are designed such that they exert a permanent bias on the energy storage device (3).

4. Motor vehicle lock (1) according to one of the preceding claims, wherein the energy storage device (3) is connected to a circuit board (9) by means of electrical lines (8), the housing (4) has a bearing surface for receiving the energy storage device (3) and the circuit board (9) is mounted in the housing (4).

5. Motor vehicle lock (1) according to one of the preceding claims, wherein the housing (4) has partial surfaces (11) for planar support on the energy storage device (3) in its front area and in its rear area.

6. Motor vehicle lock (1) according to one of the preceding claims, wherein the positioning of the fixing element (5) in the housing (4) is such that pressure is ensured on the energy storage device (3) in its front and rear areas. STRICTLY CONFIDENTIAL 7. Motor vehicle lock (1) according to one of the preceding claims, wherein the fixing element (5) is permanently elastic.

8. Motor vehicle lock (1) according to one of the preceding claims, wherein a longitudinal expansion of the energy storage device (3) is enabled by sliding movements on sliding surfaces of the housing (4).

9. Motor vehicle lock (1) according to one of the preceding claims, wherein the fixing of the energy storage device (3) is effected by a shear deformation of the fixing element (5) in the housing (4).

10. Motor vehicle lock (1) according to one of the preceding claims, wherein the housing (4) consists of a vibration-damping material to minimize mechanical loads on the energy storage device (3).

11. Motor vehicle lock (1) according to one of the preceding claims, wherein the fixing element (5) is designed to accommodate temperature-induced deformations of the energy storage device (3), in particular a bulge in its central diameter area.

12. Motor vehicle lock (1) according to one of the preceding claims, wherein the housing (4) is configured such that between areas of the housing (4) that are in direct contact with the energy storage device (3) there is at least one area which is at a distance from the energy storage device (3) without a part of the fixing element (5) being arranged there.

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