Motor vehicle lock

Abstract

The subject matter of the invention is a motor vehicle lock, in particular a motor vehicle door lock, and preferably a motor vehicle side door lock. The motor vehicle lock is fundamentally constructed with a locking mechanism (1, 2) consisting essentially of a rotary latch (1) and at least one pawl (2) as locking mechanism components (1, 2). Furthermore, at least one sensor (3, 4) is provided for sensing the position of the rotary latch (1) and / or the pawl (2). According to the invention, at least two differently designed sensors (3, 4) are provided, with a diagnostic-capable sensor (3) being configured for function-sensitive scanning and a non-diagnosable sensor (4) being configured for function-independent scanning.

Description

The invention relates to a motor vehicle lock, in particular a motor vehicle door lock, preferably a motor vehicle side door lock, having a locking mechanism consisting essentially of a rotary latch and at least one pawl as locking mechanism components, and having at least one sensor for detecting the position of the rotary latch and / or of the pawl.Motor vehicle locks and in particular motor vehicle side door locks or motor vehicle tailgate locks are often equipped with additional functions in addition to their original locking function or are integrated into such additional functions. For example, an additional closing aid can be provided. With the aid of the closing aid, a closing process of the motor vehicle door or motor vehicle flap equipped with the relevant motor vehicle lock can be initiated. This generally presupposes that the closing process is started when a pre-ratchet position of the locking mechanism is assumed. The assumption of the pre-ratchet position is detected with the aid of the sensor for the position interrogation of the rotary latch and / or the pawl.Other functions are also conceivable in this context, for example a theft function. This theft function is activated as soon as the locking mechanism has assumed its main ratchet position. In this case, too, the position interrogation takes place with the aid of the sensor. This has proven its worth in principle and is widely used in practice.For example, DE 10 2019 107 572 A1 by the applicant discloses a motor vehicle lock of this type in which a sensing element is additionally provided between the sensor and the associated locking mechanism component. The sensing element is configured to sense a closing position of, on the one hand, the pawl and, on the other hand, the rotary latch. Upon each deviation of at least one locking mechanism component from its closed position, the associated sensor is acted upon. The sensor can be a Hall sensor, which responds to movements of an associated and opposite permanent magnet. In principle, a cyclically operating microswitch can also be used at this point.DE 102021 117 277A1 relates to a control arrangement for the operation of a motor-driven flap arrangement of a motor vehicle. In addition, a closing drive is provided. The control arrangement can determine the flap position and / or flap speed by means of a displacement sensor arrangement assigned to the flap drive, the closing drive and / or the flap. The travel sensor arrangement can be designed as a Hall sensor arrangement and / or as a position switch and in particular as a lock latch switch.DE 10 2020 101 428 A1 relates to an actuating device for a motor vehicle lock. In this case, a lever arrangement is realized which is equipped with two actuating levers which are prestressed against one another by a spring and are connected to one another in a rotationally articulated manner. In addition, a sensor detecting a relative movement of the two levers with respect to one another is provided. The sensor can be a contactless sensor which functions inductively and is preferably designed as a Hall sensor.The prior art has in principle proved successful if it is concerned with inquiring individual positions of the locking mechanism. In this case, switches as well as Hall sensors are used. Hall sensors are equipped with the basic advantage that they are capable of diagnosis or can be designed in principle. That is, the functional reliability of the Hall sensor can be checked before or during operation. Such a self-check, on the other hand, is generally not possible in a conventional switch or microswitch. This explains that Hall sensors are expensive, whereas switches and in particular microswitches are available at a low price. However, there have not been any approaches to optimizing the sensor system in such a motor vehicle lock in this direction at a cost.Accordingly, the invention is based on the technical problem of further developing such a motor vehicle lock and in particular a motor vehicle door lock in such a way that a cost-optimized sensor system is observed and is available.To solve this technical problem, a motor vehicle lock of the generic type is, within the scope of the invention, characterized in that at least two differently designed sensors are provided, wherein a diagnostic-capable sensor is or are each set up for function-sensitive scanning and a non-diagnostic-capable sensor is or are each set up for function-independent scanning.According to the invention, therefore, firstly a (single) sensor for detecting the position of the rotary latch and / or of the pawl is not used. Rather, two sensors are used. In this case, the procedure is usually such that one sensor is designed as a main ratchet sensor and another sensor is designed as a pre-ratchet sensor. With the aid of the main ratchet sensor, the assumption of a main ratchet position of the locking mechanism realized according to the invention, which is essentially made up of a rotary latch and at least one pawl, can be detected as locking mechanism components. In contrast, the pre-ratchet sensor serves to detect an associated pre-ratchet position of the locking mechanism.According to a particularly advantageous embodiment, the overall procedure is such that the sensor capable of diagnosis is designed as a main ratchet sensor and the sensor not capable of diagnosis is designed as a pre-ratchet sensor. The term "diagnostic sensor" means according to the invention a sensor which is designed and capable of self-checking. For this purpose, both sensors are usually connected to a control unit which initiates at least the self-checking of the sensor capable of diagnosis. Within the scope of this self-checking of the diagnostic-capable sensor, not only is its fundamental functionality checked, but also the functionality of a signal line originating from the sensor up to the control unit. In addition, in connection with this self-checking, the correct voltage supply of the sensor is also checked in this connection.In this case, it is usually the case that the diagnostic sensor is subjected to a self-test in the non-exposed state. Alternatively or additionally, the self-test can also be carried out with each switch-on process of the sensor. This achieves a particular gain in safety and at the same time leads to the cost savings pursued according to the invention. The safety gain is explained in that the self-test carried out, for example, during each switch-on process of the sensor ensures that malfunctions or incorrect signals of the sensor are virtually ruled out. This is relevant in particular against the background when the diagnostic-capable sensor is configured for function-sensitive scanning.According to the invention, the "function-sensitive sensing" means a sensing process by the diagnostic-capable sensor, which is particularly relevant for the function of the motor vehicle lock. This also applies, and in particular, to safety requirements. For example, a function-sensitive scanning corresponds to the locking mechanism scanned with the aid of the sensor having reliably assumed its main ratchet position. This is of particular importance in particular in the case of a closing drive with the aid of a closing aid.This is because, as a result of the activation of the closing aid, the locking mechanism is generally transferred into an overstroke position before the main ratchet position is assumed, so that in this overstroke position the pawl can reliably engage in the rotary latch and perfectly blocks the rotary latch in the main ratchet position. Only then can the locking mechanism develop its full effect, in particular in the event of a crash, and prevents a motor vehicle door or motor vehicle flap equipped therewith from accidentally jumping open, for example. In addition, the functionality of additional safety devices such as airbags, belt tensioners, etc. is generally coupled to the safe assumption of the main ratchet position.That is, a perfect and suspect main latch signal is not only relevant with regard to functionally reliable operation of the motor vehicle lock according to the invention, but also represents an essential safety criterion. This is because only the reliable assumption of the main latching position ensures optimum protection of occupants of the passenger car.In contrast, the "functionally independent scanning" of the non-diagnostic sensor is a scanning process which has no fundamental meaning for safety or does not put into consideration the general functionality of the motor vehicle lock. For example, such a function-independent scanning is simply an on / off signal for the control unit already discussed above. If the sensor that is not capable of diagnosis has a malfunction at this point, the control unit is still usually switched on or, for example, a wake-up function is initiated for the control unit. The fundamental functionality of the motor vehicle lock is consequently not asked as a result.If, for example, the pre-ratchet position assumed by the locking mechanism is not correctly scanned by the sensor or pre-ratchet sensor that is not capable of diagnosis, this only leads to the closing drive or the closing aid not being acted upon by the control unit in the example. Then, an operator must, for example, manually ensure that the associated motor vehicle door or motor vehicle flap is completely closed and reaches the main latching position. The fundamental functionality of the motor vehicle lock according to the invention consequently does not alter any failure or malfunction of the sensor that is not capable of diagnosis, because the main ratchet position is important to be assumed for the correct safety, which must in turn be assumed in a correct and testable manner with the aid of the sensor that is capable of diagnosis as the main ratchet sensor.In this way, the required safety and functionality of the motor vehicle lock is ensured overall and at the same time a particularly cost-effective construction is observed. This is because the sensor that is not capable of diagnosis is used for functionally independent scanning, for example to scan the assumption of the pre-ratchet position by the locking mechanism as a pre-ratchet sensor. The assumption of the pre-ratchet position corresponds, for example, to the fact that the operation of the closing aid is thereby started. Alternatively or additionally, the assumption of the pre-ratchet position ensures that the control unit is "awakened" with its aid because it has previously assumed its "sleep mode" in the open state of the locking mechanism. In this case, too, malfunctions in connection with the wake-up function can be accepted in principle and are not particularly relevant to safety.This is because, if the wake-up function of the control unit has not been initiated and consequently the control unit remains unlit, in the example, either the closing aid cannot enter into operation and pull an associated wing of the motor vehicle door or motor vehicle flap into the main ratchet. Or, for example, an theft function cannot be implemented, which then leads to a malfunction signal, but does not put into consideration the basic mechanical functioning of the motor vehicle lock according to the invention.In particular, this mechanical functionality and thus the safety aspect for the vehicle occupants is depicted because the main ratchet sensor is responsible for sensing the main ratchet position, which is designed as a diagnosticable sensor and is consequently subjected to the self-checking in turn with regard to its functionality. In this way, the motor vehicle lock according to the invention combines a reliable functionality, on the one hand, in particular with regard to the sensing of the main ratchet position, with a cost-effective design, on the other hand, because the non-diagnostic and consequently cost-effective sensors are used for the function-independent sensing or the checking of positions of the non-diagnostic and consequently cost-effective sensors that are unimportant for the function or are unimportant for the mechanical safety.In this case, the invention is additionally based on the finding that, for example, the assumption of the pre-latch position is generally additionally sensed in a motor vehicle by door contact switches which generate a corresponding warning signal if the associated motor vehicle door does not assume its completely closed position. The essential advantages can be seen here.According to an advantageous embodiment, the diagnostic sensor is at least two-pole. One pole serves for supplying current. The further second pole serves for signal output and / or for diagnosis. In addition, it has proven to be useful in this context if the diagnostic sensor is designed as a Hall sensor or switch, the electrical connections of which are connected to at least one electrical resistor. In the case where the diagnostic sensor is designed as a Hall sensor, the control unit applies a voltage simulating a magnetic field to the sensor in question for self-testing. In addition, the control unit senses the response of the sensor including the signal path in order to carry out the self-checking described. This will be explained in more detail with reference to the description of the figures.The sensor that is not capable of diagnosis is usually a switch without resistors, which is constructed in a particularly cost-effective manner. The control unit can in turn be configured to activate an anti-theft device and / or a closing aid and / or an installation unit. In the case of the installation unit, the signals of the pre-ratchet sensor and main ratchet sensor can be used again. This is because such a raising unit is normally only acted upon and ensures that the leaf of the motor vehicle door or motor vehicle flap is raised when both the pre-latching position and the main latching position of the locking mechanism have been left.In any case, the motor vehicle lock according to the invention is on the one hand particularly securely constructed, because in particular the assumption of the main latching position is reliably sensed. This is because the sensor capable of diagnosis provides a main ratchet sensor. As a result, any false triggerings of airbags, a belt tensioner, etc., for example, can be avoided because the main latch sensor is normally subjected to the self-checking described above and malfunctions or false signals can be ruled out on the basis of the principle. At the same time and on the other hand, a particularly cost-effective construction is observed because the pre-ratchet sensor is typically configured as a non-diagnostic sensor and here usually as a particularly simple and cost-effective switch and in particular microswitch. The acceptance of the pre-latch position is of minor importance with regard to safety aspects and the trouble-free functioning of the motor vehicle lock according to the invention.The invention is explained in more detail below with reference to a drawing which merely represents an exemplary embodiment; it shows: FIG. 1 shows the motor vehicle lock according to the invention in a schematic overview, FIGS. 2A and 2B show two different variants of a diagnostic-capable switch, and FIG. 3 schematically shows a Hall sensor capable of diagnosis.FIGS. 1A and 1B show a motor vehicle lock which is equipped with a locking mechanism 1, 2. The motor vehicle lock is, within the scope of the exemplary embodiment, a motor vehicle door lock and, even more specifically, a motor vehicle side door lock. This naturally applies only by way of example and is in no way restrictive. This is because, in principle, it can also be a motor vehicle tailgate lock. The locking mechanism 1, 2 is in turn composed of a rotary latch 1 and a pawl 2 interacting therewith in the usual manner. In principle, more than one pawl 2 can also be realized, which is not shown, however. The rotary latch 1 and the pawl 2 are respective locking mechanism components 1, 2.In addition, at least one sensor 3, 4 is provided for detecting the position of the rotary latch 1 and / or of the pawl 2. According to the exemplary embodiment, two sensors 3, 4 are realized, namely a main ratchet sensor 3 and a pre-ratchet sensor 4. Also connected to the control unit 5 is a closing drive or closing aid 6, which is merely indicated, with the aid of which the rotary latch 1 is transferred starting from the pre-ratchet position shown in FIG. 1A into the main ratchet position according to the representation in FIG. 1B.According to the invention, the two sensors 3, 4 are configured differently. In fact, the main ratchet sensor 3 according to the exemplary embodiment is configured as a diagnostic sensor 3 for functionally sensitive scanning of the locking mechanism 1, 2. That is to say, the exact, reproducible and permanent functionality of the diagnostic sensor 3 is essential and relevant for the function of the motor vehicle lock and in particular of its locking mechanism 1, 2. This means specifically and in the exemplary embodiment that the assumption of the main ratchet position according to the illustration in FIG. 1B must be able to be determined reliably with the aid of the main ratchet sensor 3. For this purpose, the diagnostic sensor or main ratchet sensor 3 in question is subjected to a self-check.The self-checking of the diagnostic-capable sensor 3 is typically carried out in its non-exposed state and regularly with each switching-on process. For this purpose, the diagnostic sensor 3 according to the exemplary embodiment is at least two-pole. In fact, according to the embodiment, three poles are realized.Based on the specific exemplary embodiment of the diagnostic sensor 3 corresponding to the representation in FIG. 3, a Hall sensor 10 is first of all identified, which reacts to approaches of the rotary latch 1 or an edge 1 aof the rotary latch 1. For this purpose, a permanent magnet may additionally be provided in or on the edge 1 a. In addition, the Hall sensor 10 is connected to a series resistor 8 and a capacitor 9. In addition, a diode 7 is provided, which is designed as a Schottky diode, for example. The diagnostic sensor 3 is supplied with the required electrical energy by means of a power source 11. The current source 11 is a battery on the motor vehicle side, which is merely indicated in FIG. 3. The sensor 3 capable of diagnosis is connected to the control unit 5 via two external connections 12, 13.In the case of correct polarity reversal and continuous connection of the current source 11, the sensor 3 capable of diagnosis has a current consumption of approximately 10 to 20 mA in the exemplary embodiment in the activated state. The activated state corresponds to the catch 1 being in the main ratchet position, as shown in FIG. 1B, and the Hall sensor 10 being acted upon accordingly by the approach of the edge 1 a.In contrast, the deactivated state of the Hall sensor 10 and therefore of the diagnostic sensor 3 corresponds to the current consumption decreasing to values of significantly below 10 mA, for example 5 mA and less up to 2 mA. If a short circuit to ground is observed, the current consumption is above 20 mA. A short circuit to battery voltage leads to a current consumption of less than 2 mA.Consequently, the different functional states, namely the activated Hall sensor 10, the deactivated Hall sensor 10 and any short circuits as well as polarity reversals can be respectively determined, wherein the control unit 5 measures the respective current consumption of the diagnostic-capable sensor 3 and derives the functional state therefrom. That is, with the aid of the diagnostic-capable sensor 3, a functionally sensitive scanning of the locking mechanism 1, 2 is possible in the specific example case, namely the clear distinction between the pre-ratchet position in FIG. 1A and the main ratchet position according to FIG. 1B. This is because the current consumption is interpreted as activation of the Hall sensor 10 and accordingly the main locking position of the rotary latch 1 is assumed. If, on the other hand, the current consumption is between 2 mA and 5 mA, this corresponds to deactivation of the Hall sensor 10 and consequently of the diagnostic-capable sensor 3 as a whole. Then, for example, the pre-ratchet position or an open position is assumed by the rotary latch 1. A current consumption of more than 20 mA or of less than 2 mA is interpreted as a short circuit in each case.Alternatively or additionally, the diagnostic sensor 3 can, as shown in FIG. 3, also be supplied with a voltage simulating a magnetic field by means of the control unit 5 for self-testing. In this case, the control unit 5 ensures that the Hall sensor 10 is supplied with current via the voltage supply 11 and detects the reaction of the Hall sensor 10 including the signal path to the effect that the current consumption via the two poles or connections 12, 13 is measured with the aid of the control unit 5. In any case, the diagnostic sensor 3 or the Hall sensor 10 can be subjected to a self-check with the aid of the control unit 5 in the described manner.Another exemplary embodiment of a diagnostic-capable sensor 3 is shown in FIGS. 2A and 2B. It can be seen here that a contact device 14 is realized which has two electrical connections 15, 16 which are led out and which are electrically connected to one another via a high-resistance resistor R 1. In addition, a second high-resistance resistor R 2 is provided between the second terminal 16 and a further third terminal 17. In the variant according to FIG. 2B, the two resistors R 1 and R 2 are realized in a plastic body which is designed to be correspondingly conductive. However, the mode of operation corresponds to the basic principle according to FIG. 2A.If the contact device 14 is in the position according to FIGS. 2A and 2B, the resistance value across the two connections 15, 16 is zero. For this purpose, the three connections 15, 16, 17 are again connected to the control unit 5. If, however, the resistance value across the two connections 15, 16 is as much as the high-resistance resistor R1 specifies, the contact device 14 is open. In this case, zero resistance is observed between the terminals 15 and 17. If, on the other hand, infinitely large resistances are observed between the contact points 15 and 16 and 16 and 17, a fault is present in each case in the supply line or in the contacting of the contact device 14.The diagnostic sensor 3 according to the illustration in FIGS. 2A and 2B is a switch, the electrical connections 15, 16, 17 of which are connected to at least one electrical resistor R 1, R 2 according to the exemplary embodiment. In contrast, a sensor 4 which cannot be diagnosed in the embodiment is sufficient as a switch without resistors without the resistors R 1, R 2 in question, namely is reduced to the contact device 14 in the exemplary embodiment according to FIGS. 2A and 2B.As already explained in the introduction, the control unit 5 is configured to activate an anti-theft device or the closing aid 6 shown in FIG. 1. In the case of theft protection, the control unit 5 evaluates the signal of the non-diagnostic sensor 4 when reaching the pre-locking position according to FIG. 1A to the effect that this signal is used as a wake-up signal for the control unit 5. At the same time, the signal of the pre-ratchet sensor 4 in this example case leads to the closing aid 6 being activated with the aid of the control unit 5, which then pivots the rotary latch 1 about its axis in the clockwise direction indicated during the transition from the position according to FIG. 1A to FIG. 1B. This closing process is continued into an overstroke position beyond the main latching position shown in FIG. 1B, so that the pawl 2 can latch securely. The locking mechanism 1, 2 then moves into the main ratchet position, as shown in FIG. 1B. The reaching of the main ratchet position is reported to the control unit 5 with the aid of the diagnostic sensor 3 or the main ratchet sensor 3 and ensures that the closing aid 6 is not (any longer) energized.At the same time, reaching the main locking position according to FIG. 1B corresponds to the anti-theft device being activated and safety devices, not shown, being subject to loading during a vehicle movement in the event of a crash.List of reference characters1, 2 Locking mechanism 1 Rotary latch 1 a Edge 2 Locking pawl 3, 4 Sensor 4 Pre-ratchet sensor 5 Control unit 6 Closing aid 7 Diode 7 Hall sensor 8 Series resistor 9 Capacitance 10 Hall sensor 11 Current source 12, 13 External connections 14 Contact device 15 Contact points 15, 16 connections 17 Connection R 1, R 2 ResistorReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2019 107 572 A1

[0004] DE 102021 117 277A1

[0005] DE 10 2020 101 428 A1

[0006]

Claims

Motor vehicle lock, in particular a motor vehicle door lock, having a locking mechanism (1, 2) consisting essentially of a rotary latch (1) and at least one pawl (2) as locking mechanism components (1, 2), and having at least one sensor (3, 4) for detecting the position of the rotary latch (1) and / or of the pawl (2), characterized in that at least two differently designed sensors (3, 4) are provided, wherein a sensor (3) capable of diagnosis is set up for function-sensitive sensing and a sensor (4) not capable of diagnosis is set up for function-independent sensing, respectively.Motor vehicle lock according to Claim 1, characterized in that the diagnostic sensor (3) is subjected to a self-test in the non-exposed state.Motor vehicle lock according to Claim 1 or 2, characterized in that the self-test is carried out on each switch-on operation of the sensor (3).Motor vehicle lock according to one of Claims 1 to 3, characterized in that both sensors (3, 4) are connected to a control unit (5) which initiates at least the self-testing of the diagnostic-capable sensor (3).Motor vehicle lock according to one of Claims 1 to 4, characterized in that the sensor (3) capable of diagnosis is of at least two-pole design, one pole serving for the power supply and the further pole serving for the signal output and / or for the diagnosis.Motor vehicle lock according to one of Claims 1 to 5, characterized in that, for self-checking, the control unit (5) applies a voltage simulating a magnetic field to the diagnostic-capable sensor (3) and scans the reaction of the sensor (3) including the signal path.Motor vehicle lock according to one of Claims 1 to 6, characterized in that the diagnostic sensor (3) is designed as a Hall sensor (10) or contains such a sensor or is designed as a switch, the electrical connections (15, 16, 17) of which are connected to at least one electrical resistor (R1, R2).Motor vehicle lock according to one of Claims 1 to 7, characterized in that the sensor (4) which cannot be diagnosed is designed as a switch without resistors.Motor vehicle lock according to one of Claims 1 to 8, characterized in that the diagnostic sensor (3) is designed as a main ratchet sensor (3) and the non-diagnostic sensor (4) is designed as a pre-ratchet sensor (4).Motor vehicle lock according to one of Claims 1 to 9, characterized in that the control unit (5) is configured to activate an anti-theft device and / or a closing aid (6) and / or a setup unit.

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