Lock for a motor vehicle

Abstract

The invention relates to a lock (1) for a motor vehicle, comprising a locking mechanism with a rotary catch and at least one locking pawl, wherein the rotary catch can be latched by means of the locking pawl in at least one latching position, a lock housing (2) with at least one housing cover (3), a printed circuit board (5) which is arranged in the interior of the lock housing (2), wherein the printed circuit board (5) is arranged in a dry chamber (11) which is separated at least from the locking mechanism, and wherein the dry chamber (11) can be sealed by way of a plastics film (21).

Description

[0001] Description

[0002] Lock for a motor vehicle

[0003] The invention relates to a lock for a motor vehicle comprising a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be locked in at least one locking position by means of the pawl, a lock housing with at least one housing cover, a circuit board arranged in the interior of the lock housing, wherein the circuit board is arranged in a dry space which is at least separate from the locking mechanism.

[0004] Motor vehicle locks are used wherever movable components on the vehicle, such as doors, flaps, covers, and / or sliding doors, need to be held or secured in position. The locks' primary task is to hold the movable component securely in position, even in extreme situations, and thus protect the operator or user of the vehicle from injury. Such locks are also used in areas that are subject to environmental influences and may therefore come into contact with moisture, dust, and / or other environmental influences.

[0005] The locking mechanism area in particular comes into contact with moisture or can even be directly affected by moisture. In addition to the pure security function of holding the moving component, the lock is increasingly taking on other tasks. In addition to the purely mechanical holding of the moving component, the lock can also contain electronics that are particularly susceptible to moisture. The electronics can, for example, be used to control a motor located in the vehicle lock and supply it with the necessary electrical power, or the vehicle lock can contain switching devices, which can be used, for example, to query the positions of functional components in the vehicle lock.

[0006] DE 10 2009 027 415 A1 discloses a lock for a motor vehicle which offers protection against external influences such as dust, moisture or tampering. The lock comprises a lock housing and a housing cover for the lock housing, with a circumferential slot remaining between the lock housing and the cover through which moisture can penetrate the lock. In order to protect the internal components of the lock, it is proposed to wrap the lock at least partially several times with an adhesive film in order to thus reliably and permanently protect the lock from external influences.

[0007] To protect the circuit board and / or other electronic components in the motor vehicle lock from moisture penetration, the motor vehicle lock can be divided into a dry area and a wet area. Such a lock is known, for example, from EP 2 754 799 A1. The circuit board and the other electronic components are arranged in a moisture-tight manner between a cover cap and a lock cover.

[0008] In addition to the influence of direct moisture, automotive locks are also subject to significant temperature fluctuations. Automotive locksmiths must therefore cover temperature ranges from -40°C to +80°C to function properly in all climates. Temperature influences can, however, affect humidity, and particularly during significant temperature fluctuations, moisture can escape from the air, potentially affecting electronic components.

[0009] DE 102 59 465 A1 discloses an actuator in which pressure differences occur inside the actuator due to the movement of the actuating means. The actuator can also be arranged in the wet area of ​​a motor vehicle, so that the internal components, as well as the actuating means, must be tightly sealed. In order to equalize these pressure differences and at the same time prevent moisture from getting into the interior of the actuator, the document proposes providing a vent hole which is designed to be moisture-impermeable and at the same time permeable to air. For this purpose, a membrane is inserted into the vent hole through which pressure equalization can take place, but which is also made of a semi-permeable plastic material that prevents moisture from penetrating.

[0010] From the unpublished DE 10 2021 119 652 . 3 a lock for a lock for a motor vehicle has become known, comprising a locking mechanism with a rotary latch and at least one pawl, a lock housing with at least one housing cover, and a printed circuit board arranged in an interior of the lock housing, wherein the printed circuit board is arranged in a dry space separate from the locking mechanism. By separating the printed circuit board, the electronics can be protected from moisture. As already explained above, motor vehicle locksmiths are subject to extreme temperature fluctuations or must at least ensure consistent functionality at all times within the temperature ranges mentioned. In this case, large temperature jumps can also occur, for example if a very hot motor vehicle is immediately and drastically cooled down.The strong temperature fluctuations can lead to negative pressures developing inside the vehicle lock, which can allow moisture or humidity to enter and / or be drawn into the vehicle lock. Completely sealing off a dry compartment in the vehicle lock can only be guaranteed to a limited extent, since a mechanism and / or electrical control lines or electrical components are connected to the locking mechanism and / or the mechanisms for actuating the locking mechanism. This is where the invention comes in.

[0011] The invention is based on the technical problem of further developing a motor vehicle lock of the type mentioned at the outset in such a way that the electronic and / or electrical components and in particular a circuit board arranged in the motor vehicle lock can be protected against the ingress of moisture.

[0012] According to the invention, the object is achieved by the features of independent patent claim 1. Advantageous embodiments are specified in the subclaims. However, it should be noted that the exemplary embodiments described below are not limiting; rather, any desired variations of the features described in the description, the patent claims, and the drawings are possible.According to patent claim 1, the object of the invention is achieved in that a lock for a motor vehicle is provided, comprising a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be locked in at least one detent position by means of the pawl, a lock housing with at least one housing cover, a circuit board arranged inside the lock housing, wherein the circuit board is arranged in a dry space which is at least separate from the locking mechanism and wherein the dry space can be sealed with a flexible sealing element, in particular a plastic film. By using a plastic film to seal the dry space, temperature differences can be taken into account in an advantageous manner. If the plastic film covers the conductor track and / or electrical components, the plastic film can compensate for pressure differences due to its flexibility.This prevents moisture from penetrating the electronic or electrical components due to negative pressure. The sealing element, or plastic film, covers the electrical and electronic components and is firmly connected to the lock housing all the way around. Pressure differences in the lock housing can be compensated for by flexibly adjusting the sealing element, or plastic film.

[0013] If, in the sense of the invention, reference is made to a lock for a motor vehicle, this includes all locking systems which are used to hold a movable component in the motor vehicle. These locking systems have a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be brought into engagement with a lock holder and the pawl can hold the rotary latch in at least one detent position. Such a lock can be used, for example, in a side door, a flap, a hood and / or a sliding door, to name just a few examples of the use of the motor vehicle lock according to the invention.

[0014] If the motor vehicle lock is used in a side door, for example, the locking mechanism must have two detent positions. When the side door is closed, the locking mechanism first moves into a pre-detent position and then into a main detent position for complete closing. The rotary latch can be secured in the detent position by means of a pawl or a pawl and a blocking or locking lever, depending on whether the locking mechanism is subject to a closing or opening moment. The locking mechanism is mounted on a metal lock case in the motor vehicle lock and can be additionally secured in the axle mounts by means of a reinforcement plate.

[0015] In order to protect the locking mechanism and the other functional components contained in the motor vehicle lock from dirt and / or moisture and to provide receptacles or storage points for the functional components of the lock, the lock has a lock housing with at least one housing cover. In addition to the housing cover, a cover cap can be located in the lock, particularly if the motor vehicle lock contains weather-sensitive components. This cover cap then has the task of forming a wet area and a dry area in the motor vehicle lock. This makes it possible to arrange the wetness or moisture-sensitive components separately in the motor vehicle lock and to provide additional security in the motor vehicle lock. Such moisture-sensitive components are, for example, electronic components, a circuit board or an electric motor.These components located inside the lock housing are particularly sensitive to moisture, as moisture ingress can impair the functionality of these components.

[0016] According to the invention, the printed circuit board is arranged in a dry space which is at least separate from the locking mechanism. The dry space is characterized in that at least no direct moisture can penetrate into the dry space. The dry space can be formed by the lock housing in interaction with the housing cover and a shape of the lock housing and / or a cover cap as an intermediate layer. The printed circuit board and / or further electrical components are therefore arranged in an insulated and / or sealed dry space or dry area of ​​the motor vehicle lock and are connected there via an electrical component carrier and / or a connection plug and / or control lines to, for example, a control system of the motor vehicle lock. By arranging the electrical components in the dry space, the printed circuit board and / or the electronic components can be at least directly protected from the penetration of moisture.

[0017] However, the high temperature fluctuations between -40 ° C and + 80 ° C that occur in motor vehicle locks mean that humidity can escape from the air and that strong pressure differences can arise in the different temperature ranges, with the result that moisture can diffuse and / or penetrate seals and, in turn, moisture can get into the area of ​​the electronic components. The use of the sealing element or the plastic film according to the invention prevents the different pressures caused by the temperature differences from leading to moisture penetrating the drying space. The elastic sealing element can equalise the pressure differences and thus prevent air and / or moisture from being drawn into the drying space due to air pressure.

[0018] When referring to a sealing element in the context of the invention, this primarily refers to a plastic foil. However, alternative sealing elements are also conceivable, such as a metal foil or a component made of a rubber-elastic plastic. In any case, the sealing element is capable of compensating for a pressure difference flexibly or elastically.

[0019] In an advantageous embodiment, the plastic film can be connected at least in part to a contact surface of the housing cover. The plastic film can be arranged as a waterproof and pressure-equalizing film between the circuit board and the housing cover of the lock housing. This makes it possible to create a seal in the direction of the housing cover. The housing cover and lock housing are usually connected by means of circumferential seals and screwed or clipped together. This type of seal cannot guarantee absolute tightness in all cases. Manufacturing and assembly reasons as well as environmental influences must be mentioned here. By using and connecting the plastic film to the contact surface of the housing cover, tightness in the area of ​​the electronic components and in particular the circuit board can be ensured by the plastic film.The plastic film can be arranged in the area of ​​the contact surface of the housing cover at least as far as the housing cover encloses the electronic components.

[0020] It can also be advantageous if the plastic film is arranged at least in some areas between the housing cover and the lock housing. Depending on the design of the lock housing, the circuit board or the at least one electronic component can be arranged between the housing cover and the lock housing and / or a cover cap. Depending on the embodiment, an intermediate area between the housing cover and the lock housing and / or the housing cover and cover cap thus forms the dry area provided for the electrical components. If the plastic film is arranged between these components of the lock housing, the dry area can provide additional protection against moisture penetrating the dry space. The plastic film can also be arranged in some areas on the housing cover, the lock housing and / or a cover cap.

[0021] Advantageously, the plastic film can be firmly connected, in particular permanently, to the lock housing and / or a cover cap all the way around, so that a drying chamber can be formed by the lock housing and / or the cover cap and the plastic film. The drying chamber is additionally sealed by the plastic film and prevents moisture and / or wetness from penetrating the drying chamber.

[0022] Of course, the plastic film also protects against dust or other contaminants that can occur in the lock, such as grease or oil, although at least dust cannot have such a harmful effect on the functionality of the electronic components. The plastic film is permanently bonded to the housing or housing components. A laser beam process, for example, can be used for this. Similar processes that enable a material-to-material bond can of course also be used. A laser beam process offers the advantage of being easy to automate in series production. It is also conceivable, however, that a material-to-material bond, such as gluing, is used to permanently bond the plastic film to the lock housing.The plastic film can thus be connected to the lock housing by means of the permanent connection and at the same time be fixed to the lock housing by means of another housing part.

[0023] The plastic film can advantageously be designed to be elastic. The plastic film can adapt to the ambient conditions thanks to its flexibility or elasticity. If, for example, the vehicle heats up significantly, e.g., due to sunlight, the air inside the vehicle lock expands. This expansion of the air can be elastically absorbed by the plastic film. If the vehicle then cools down significantly, causing the air to contract again, the change in volume can be absorbed by the elasticity of the plastic film. In particular, this allows pressure differences to be compensated, which can prevent, for example, the diffusion of moist air.

[0024] Advantageously, the plastic film can also be wave-shaped. By forming the plastic film in a wave shape, at least in some areas, the plastic film can be provided with additional, greater mobility above the circuit board. This also reduces the risk of cracking if the plastic film is stretched due to temperature differences. The plastic film therefore prevents pressure differences in the drying chamber, and in particular negative pressures in the drying chamber, from enabling or supporting the penetration of moisture.

[0025] If an opening is arranged in the lock housing and / or in the housing cover and / or in the cover cap, then again an advantageous embodiment of the invention can be achieved. Penetrating moisture can escape through openings in the lock. In particular, however, an opening in the lock can allow temperature equalization to take place so that even during operation under extreme loads, such as extreme heat or extreme cold, temperature equalization can take place within a corresponding time. The plastic film protects the dry space and the electronic and / or electrical components. Advantageously, the housing opening can be closeable by means of a membrane, in particular by means of a semi-permeable membrane. This makes it possible to form an installation space, for example above the electronic components, wherein the installation space above the plastic film can be closed by a housing cover.For example, there is a housing shell into which electronic components are inserted, and the electronic components are covered with the plastic film.

[0026] Above the plastic film there is then a build space which is closed off by the housing cover, with a semi-permeable membrane arranged in the housing cover. Pressure equalization can take place through the semi-permeable membrane, thus compensating the build space in terms of temperature fluctuations in terms of volume. The temperature and pressure-related changes in the build space above the plastic film can be compensated through the membrane, with the plastic film adapting elastically and / or deforming to the pressure differences or temperature differences. Advantageously, the volume of the dry space below the film is always greater than the volume between the plastic film and the housing cover. The housing cover encloses or covers the plastic film in such a way that protection is provided for the plastic film.The space above the plastic film serves to equalize the pressure, with the housing cover providing a protective function for the.

[0027] plastic film.

[0028] The plastic film that is glued and / or attached using a remelting process is sufficient under normal operating conditions to protect the electrical and electronic components from the ingress of water and / or moisture and / or lubricants. However, if the vehicle is submerged in water, the water pressure counteracts the air volume in the installation space and water can penetrate the vehicle lock. To counteract this situation, the plastic film can elastically or flexibly adapt to the pressure changes. The air in the installation space or drying chamber, which may be cooled by the water, can create an additional suction effect. The plastic film's job is to provide a compensating volume to compensate for the water penetrating the vehicle lock due to the increased water pressure and to keep moisture away from the electronics.The inventive construction and the use of the plastic film ensure that the electrics and electronics continue to function even in a submerged vehicle, and the electrically provided functions in the vehicle lock, such as door opening, can continue to be ensured.

[0029] The inventive construction of the motor vehicle lock ensures the security and, in particular, the longevity of the motor vehicle lock.

[0030] The invention is explained in more detail below with reference to an exemplary embodiment and the accompanying drawings. However, the principle applies that the exemplary embodiment does not limit the invention, but merely represents an advantageous embodiment. The features presented can be implemented individually or in combination with other features of the description and the patent claims.

[0031] It shows :

[0032] Figure 1 is a three-dimensional view of a motor vehicle lock designed according to the invention with a membrane in the housing cover, and

[0033] Figure 2 shows a section along the line I I- II according to Figure 1 through the motor vehicle lock according to Figure 1.

[0034] Figure 1 shows a three-dimensional view of a motor vehicle lock 1. The lock housing 2 and a housing cover 3 mounted on the lock housing can be seen. A membrane 4 is arranged in the housing cover 3 for pressure equalization within the motor vehicle lock 1.

[0035] In Figure 1, the housing cover 3 is shown transparent so that the printed circuit board 5 arranged underneath the housing cover 3 can be seen. Electronic components 6, 7 are fastened to the printed circuit board 5 and an electric motor 8 is electrically connected to the printed circuit board 5. Overall, the electrics or electronics 5, 6, 7, 8 in the motor vehicle lock 1 are connected to the on-board electronics of the motor vehicle via a plug 9 on the housing 2. Additional capacitive components 10 are also arranged underneath the housing cover 3. Below the housing cover 3 there is a drying chamber 11 in which the printed circuit board and the electronic or electrical components 5, 6, 7, 8, 10 are arranged. The membrane 4 is arranged above the printed circuit board 5 in the housing cover 3 so that the motor vehicle lock 1 can be ventilated and thus dehumidified via the membrane 4.

[0036] Basically, a seal is arranged all around the edge 12 of the motor vehicle lock 1 and the housing cover is fastened to the lock housing 2 by means of screws 13.

[0037] Figure 2 shows a section through the motor vehicle lock 1 in the area of ​​the membrane 4 along the line I I- II from Figure 1. The membrane 4 is in an opening

[0038] 4 of the housing cover 3 and above the circuit board

[0039] 5 is arranged. The circuit board 5 is arranged in the dry area 11 of the motor vehicle lock 1. The dry area 11 can be delimited by a cover cap 15 so that the dry area 11 can be separated from the wet area 16 by means of the cover cap 15. The membrane 4 is accommodated in an opening 14 in the lock housing cover 3 and held in a sealed manner. If temperature fluctuations and / or leaks cause air present in an interior space 17 to heat up, the pressure can be equalized through the membrane 4 in the direction of the arrow P. For this purpose, the membrane 4 is permeable to air in the direction of the arrow P, but impermeable to moisture. Moisture striking the membrane 4, which is symbolized by the arrow P1, is pushed back by the membrane 4 or is not allowed to pass through, so that no moisture can penetrate the membrane.However, air can be exchanged between the interior 17 of the lock 1 and the outside environment 18. Moisture that occurs in the interior 17 of the motor vehicle lock 1 can thus be compensated for by the membrane 4 as part of an air circulation through the membrane 4. For this purpose, the membrane 4 is designed to be permeable to air in the direction of arrow P2.

[0040] The membrane 4 itself has a two-layer structure, with a semi-permeable plastic layer 19 being arranged on the upper side, that is to say on the ambient side 18, the plastic layer 19 being supported and held on a carrier material 20.

[0041] The inventive design of the motor vehicle lock with a membrane for pressure equalization advantageously prevents condensation from forming in the interior 17 and in particular in a dry chamber 11. In particular, the longevity of electronic locks is improved as a result. In Figure 2, the plastic film 21 is shown above the circuit board 5. The plastic film 21 separates the dry chamber 21 from the interior 17, which defines an installation space between the plastic film 21 and the housing cover 3. The plastic film 21 is arranged between the housing cover 3 and the lock housing 2 and can be connected all the way around to the lock housing 2, for example by means of fusion welding. The plastic film 21 completely insulates the dry chamber from the interior 17. Pressure differences between the interior 17 and the environment 18 can be compensated by the plastic film 21.Likewise, pressure differences between the interior space 17 and the drying chamber 11 can be compensated by the plastic film 21. At the same time, a waveform 22 can be seen in the plastic film 21, which further increases the elasticity or deformability of the plastic film 21. The circuit board 5 and the other electronic or electrical components 6, 7, 8 can thus be efficiently protected against environmental influences and / or pollutants and function reliably and durably even under extreme conditions.

[0042] Reference symbol list

[0043] 1 vehicle lock

[0044] 2 lock housings

[0045] 3 housing cover

[0046] 4 Membran

[0047] 5 circuit board

[0048] 6 , 7 electronic components

[0049] 8 Electric motor

[0050] 9 plugs

[0051] 10 capacitive components

[0052] 11 Drying room

[0053] 12 edges

[0054] 13 screws

[0055] 14 Opening

[0056] 15 Cover cap

[0057] 16 Wet area

[0058] 17 Interior

[0059] 18 Surroundings

[0060] 19 plastic material

[0061] 20 carrier material

[0062] 21 plastic film

[0063] 22 Waveform

[0064] P, Pl , P2 arrow

Claims

Patent claims 1. Motor vehicle lock (1) for a motor vehicle comprising a locking mechanism with a rotary latch and at least one pawl, wherein the rotary latch can be locked in at least one detent position by means of the pawl, a lock housing (2) with at least one housing cover (3), a circuit board (5) arranged inside the lock housing (2), wherein the circuit board (5) is arranged in a dry chamber (11) separated at least from the locking mechanism, characterized in that the dry chamber (11) can be sealed with a plastic film (21).

2. Lock (1) according to claim 1, characterized in that the plastic film (21) is connected at least partially to a contact surface, in particular an edge (12) , of the lock housing (2).

3. Lock (1) according to one of claims 1 or 2, characterized in that the plastic film (21) is arranged at least partially between the housing cover (3) and the lock housing (2).

4. Lock (1) according to one of claims 1 to 3, characterized in that the plastic film (21) is firmly, in particular inseparably, connected around the perimeter to the lock housing (2) and / or a cover cap (15) in such a way that a dry space (11) formed by the lock housing (2) and the plastic film (21) can be created.

5. Lock (1) according to one of claims 1 to 4, characterized in that the plastic film (21) is elastic.

6. Lock (1) according to one of claims 1 to 5, characterized in that the plastic film (21) is at least partially corrugated.

7. Lock (1) according to one of claims 1 to 6, characterized in that an opening (14) is arranged in the lock housing (2) and / or in the housing cover (3).

8. Lock (1) according to one of claims 1 to 7, characterized in that the housing opening (14) can be closed by means of a membrane (4), in particular by means of a semipermeable membrane (4).

9. Lock (1) according to one of claims 1 to 8, characterized in that a volume of the drying chamber (11) is always larger than a volume between the plastic film (21) and the housing cover (3) .

10. Lock (1) according to one of claims 1 to 9, characterized in that the plastic film (21) can be connected to the lock housing (2) and / or the cover cap (15) by means of a forming process and / or material.

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