EP2877656B1 - Motor vehicle door lock - Google Patents

Description

The invention relates to a motor vehicle door lock, with a motor-operated lever chain, and with an electric motor with associated control unit, wherein the electric motor converts the lever chain in a predetermined position or applied from the predetermined position, and wherein the control unit uses data of the electric motor for its application, and the control unit evaluates gradients of performance data of the electric motor for position adjustment of the lever chain.

In a motor vehicle door lock of the structure described above, as for example in the generic DE 44 47 687 C2 or the parallel one US 5,634,677 is described, a control is applied by an electric motor. The start of the control against stop surfaces of a fork receptacle is detected by an associated increased power consumption or a timer and the electric motor drive is turned off as a result thereof. Ultimately, it is important to exceed a certain threshold of the current absorbed by the electric motor, so that it is turned off.

In this way, it is possible in principle to dispense with detectors, switches or comparable sensors, by means of which typically certain predetermined positions of the lever chain, in this case a locking lever chain, are detected. So you know at this point switch or Hall sensors, with their help, for example, a position "locked" or the "unlocked" position of the respective locking lever chain are detected. This is necessary in order to stop the energization of the electric motor and consequently to prevent electrical and / or mechanical damage (cf., for example DE 199 43 483 A1 ).

The state of the art has basically proven itself, as far as the sensory monitoring of individual positions of the lever chain is concerned. Because with the help of sensors or switches, the position can be defined, reproducible and clearly detected and reported to the control unit. In contrast, the doctrine works according to the DE 44 47 687 C2 or according to the US 5,634,677 as it indirectly, because it is inferred from the increased power consumption by the electric motor on the achievement of a specific position of the locking lever chain.

Although the detection of increased power consumption eliminates the need for sensors and can be implemented as a result of this cost. However, the procedure described suffers from accuracy or functional problems. Because an increased power consumption of the electric motor can also be caused by its stiffness, mechanical blockages, etc., without, for example, the actually detected position "unlocked" or "locked" is applied. For this reason, in practice with a time control for the electric motor is regularly worked, but which does not allow a clear conclusion on its position. Here, the invention aims to provide a total remedy.

The EP 1 371 802 A2 also discloses a motor vehicle door closure having an electromechanical central locking drive and a central locking element driven therefrom. The central locking element is driven by an electric motor, which in turn is controlled by a control unit to a desired position, such as the locking position. The control unit is provided with information about a motor state of the electric motor via a motor condition sensor, so that, for example, the speed of the electric motor can be regulated.

The WO 2008/101928 A1 discloses an apparatus and method for unlocking a lock by using power monitoring. In this case, the consumed current of an electric motor is recorded by means of a method, depending on the recorded power consumption, the lock can be unlocked or locked. The method considers it to compare the recorded power consumption with already stored power consumption.

The DE 102 43 893 A1 describes an actuator for example, a door lock with an electric motor, an actuator and a restoring device, the electric motor to be operated with reduced energy use. For this, the electric motor drives the actuator against the force of the return device to a stop in a blocking position. In this case, an adjustable delay time for an electric motor supplying electric power is just kept so low that the blocking position of the actuating element can still be achieved.

The invention is based on the technical problem of further developing such a motor vehicle door lock so that a flawless position detection succeeds with a structurally simple construction.

To solve this technical problem, a generic motor vehicle door lock in the invention is characterized in that the control unit, the electric motor after an activation command first applied in its opposite direction to verify the current position of the lever chain as the starting point of the desired movement. In addition, the control unit in a generic motor vehicle door lock or to evaluate such a position of the above described construction also position signals of the electric motor for position adjustment of the lever chain.

As a rule, the predetermined at least one position of the lever chain corresponds to a mechanical stop position. Since the lever chain is advantageously a locking lever chain and / or an actuating lever chain, the predetermined position corresponds to a locking lever chain, for example to its positions "locked" or "unlocked".

In an operating lever chain, the one or more predetermined positions may correspond to, for example, the operating positions "operated" or "not operated". These all positions or positions of the respective lever chains correspond to a corresponding mechanical stop position as a rule. That is, once the relevant and previously indicated position, for example, "unlocked", "locked", "actuated" or "not operated" is reached, the lever chain in question in the confirmation direction can not continue to apply, because this is an associated attack prevented. This explains the realized mechanical stop position. - A renewed action on the electric motor must therefore correspond to the fact that the lever chain in question in the opposite direction, starting from the predetermined position experiences an act of loading.

In order to sense the predetermined position of the lever chain or the respective mechanical stop position, the control unit in the context of the invention evaluates gradients of performance data of the electric motor. In this way, the position adjustment of the lever chain is determined, namely in the present case the achievement of the predetermined position or the associated mechanical stop position.

In contrast to the prior art after the DE 44 47 687 C2 or the US 5,634,677 At this point, no threshold values of the current absorbed by the electric motor, for example, are detected and evaluated in the sense of an increased current consumption. Rather, it is a matter of the invention to detect and evaluate gradients of performance data of the electric motor. As the performance of the electric motor whose recorded current or the applied voltage come into question, because their product reflects the power absorbed. The gradient is mathematically differential operators applied to a respective scale field.

In the present case, the slope is determined as a rule, for example, the current increase per unit time of the current for acting on the electric motor. In principle, a voltage change per unit time can be detected and evaluated in order to detect the achievement of the predetermined position by the lever chain. A current-dependent voltage change can also be evaluated by the control unit. That is, it is the derivative of the voltage after the current detected by the control unit and used for the application or non-loading of the electric motor.

As a rule, however, the procedure is such that the time profile of the electric current is evaluated to act on the electric motor. For this purpose, the control unit has a differentiator, which can be implemented hardware and / or software. With its help, the current change per unit time can be determined. If certain gradients are exceeded at this point, this is interpreted as reaching the predetermined position by the lever chain in the control unit. That is, the exceeding of a certain predetermined slope in the example case corresponds to the sensor signal, which for example belongs to the position "unlocked" or "locked".

The control unit thus generally evaluates temporal current / voltage characteristics for driving the electric motor. For this purpose, the control unit differentiates the respective current / voltage curves in time or in time. A certain increase in the time of the current or the voltage at the electric motor is identified as a result of reaching the predetermined position.

Incidentally, the invention regularly proceeds in such a way that the control unit initially acts on the electric motor in its opposite direction following an activation command. In this way, the current position of the lever chain as the starting point for the desired movement can be determined or verified. If, for example, the locking lever chain is "locked" in its position and an activation command is given in the sense of "unlocking", then the electric motor is initially charged in its opposite direction. This means that the electric motor in the example case - despite the already adopted position "locked" - again applied in the direction "lock". Since the locking lever chain in the direction of movement "lock" is blocked (due to the assumed mechanical stop position), this immediately results in a steeply rising absorbed current of the electric motor per unit time, which is interpreted or verified as reaching or concern of the position "locked" directly ,

It is understood that the control unit from the history or the already completed adjusting movements of the respective lever chain out "white", in which each predetermined position is the lever chain, in the example "locked" in the position. However, to be sure that yourself the locking lever chain is "locked" unchanged in this assumed by the control unit position, the electric motor is first acted upon in the opposite direction as described following the activation command.

The invention is also a method for operating a motor vehicle door lock, as described in claim 8 ff. Closer. To act on the electric motor or implementation of appropriate activation commands this can be controlled wirelessly via a remote control. Alternatively or additionally, a wired control of the electric motor via, for example, a key is possible. The wireless control of the electric motor is typically realized via a radio remote control. The wired loading by means of the key can be done by the key is inserted into a lock cylinder and rotated accordingly herein, for example, to realize the functional position "locked".

As a result, a motor vehicle door lock is made available, which is initially very simple and inexpensive. Because individual predefined positions of the inevitably realized lever chain can be queried and evaluated, as it were, without a sensor. For this purpose, the control unit accesses gradients of performance data of the electric motor acting on the lever chain and evaluates these to the effect that the position of the lever chain can be deduced. In this case, the invention is based on the recognition that a certain predetermined position of the relevant lever chain corresponds to the fact that the lever chain is mechanically blocked in at least one direction of movement. That is, the predetermined position corresponds to the mechanical stop position in the respective direction of movement.

As soon as the electric motor travels "on block", the current absorbed by it rises sharply over time. This current increase is evaluated in the example case. As soon as its gradient has exceeded a certain threshold value, the control unit concludes from the associated gradient of the current absorbed by the electric motor that the predetermined position or mechanical stop position has been reached in the direction of movement of the lever chain that has been introduced.

Now, if the lever chain is activated starting from this predetermined position or acted upon in an opposite direction, the invention proceeds in such a way that the control unit initially acts on the electric motor in its opposite direction following such an activation command. The electric motor is thus acted upon in the mechanical stop position so that it first - again - moves against the stop, which in turn is associated with a strong increase in time current in the example. This can be evaluated and interpreted by the control unit to the effect that the lever chain as a starting point for their desired movement, in fact, the position assumed by the control unit based on the history unchanged. Proceeding from this, then the electric motor is acted upon in the opposite direction and the lever chain moves according to the desired activation command.

Comparable advantages and effects are achieved in the case and observed that the control unit additionally evaluates position signals of the electric motor for position adjustment of the lever chain. Such position signals of the electric motor can be present for example in the form of a step control. By detecting the steps completed by the electric motor with the aid of the control unit, the exact position of the lever chain can be reproduced reproducibly at any time. - However, since such stepper motors according to the invention are relatively expensive, it will be in favor of cost-optimized production of the motor vehicle door lock according to the invention on this regularly waived, although such stepper motors are of course included in the invention.

Fig. 1

das erfindungsgemäße Türschloss schematisch und

Fig. 2A bis 2C

verschiedene Zeitverläufe des seitens des Elektromotors aufgenommenen Stromes zur Auswertung der vorgegebenen Position der zugehörigen Hebelkette.

In the following the invention will be explained in more detail with reference to a drawing showing only one embodiment; show it:

Fig. 1

the door lock according to the invention schematically and

Fig. 2A to 2C

different time courses of the current absorbed by the electric motor for evaluation of the predetermined position of the associated lever chain.

In the figures, a motor vehicle door lock is shown, which has a not explicitly shown locking mechanism of catch and pawl. On the locking mechanism or the pawl operates a release lever 1, which in the Fig. 1 is shown only in section and connected to a central locking lever 2. The central locking lever 2 is coupled in the exemplary embodiment with an inner locking lever 3, on which in turn an inner locking element or an inner locking rod 4 operates. As an alternative to the inner locking element and the inner locking lever 3, however, an outer locking with associated outer locking lever, outer locking element and indicated key 5 with associated lock cylinder 6 can also be realized at this point.

The central locking element 2 is acted upon by a control element 7 in the form of a driven pulley with two eccentric control pins 8. For this purpose, the control pins 8 engage, depending on the direction of rotation D of the control element or the driven pulley 7, in a fork receptacle 9 of the central locking element 2.

The control element 7 or the driven pulley 7 is acted on by means of an electric motor 10, which in turn is controlled by a control unit 11. In the context of the embodiment, a lever chain or locking lever chain 2, 3, 4, 5, 6 is realized, which is composed of the central locking lever 2, the inner locking lever 3, the inner locking element 4 and finally the outer lock in the form of the key 5 including lock cylinder 6. The lever chain or locking lever chain 2, 3, 4, 5, 6 is transferred by the electric motor 10 in a plurality of predetermined positions, for example, in the positions "locked" or "unlocked". In the Fig. 1 the position "locked" is shown. This corresponds in the present case to that in the Fig. 1 right control pin 8 is moved against a stop surface, thus the predetermined position "locked" the locking lever chain 2 to 6 corresponds to an associated mechanical stop position.

In order to now set the "unlocked" position of the motor vehicle door lock, first the control unit 11 must be acted upon accordingly. This is done in the present case with the aid of a merely indicated radio remote control unit 12. As a result, the control unit 11 ensures that the in the Fig. 1 left control pin 8 dips into the fork receptacle 9 and the central locking lever 2 is pivoted clockwise about its axis 13 until in the Fig. 1 right control pin 8 comes to rest on the left stop surface of the fork seat 9, as described in the basic operation in detail DE 44 47 687 C2 which is expressly referred to in this context.

In this process of starting against the stop surface, in principle, a course of the recorded current from the electric motor 10 over the time t, as shown in the exemplary FIGS. 2A to 2C is shown.

In fact, the show Fig. 2A to 2C different temporal current curves for the current I as it is recorded by the electric motor 10 in the example case in the described process "unlock".

With the help of the control unit 11, this current profile or data of the electric motor 10 is now used when it is acted upon respectively to its admission. This is ensured by the electric motor 10 acting on the control unit 11. Actually, the control unit 11 evaluates the relevant data.

gebildet. Hierfür sorgt jeweils die Steuereinheit 11.In detail, the control unit 11 evaluates gradients of performance data of the electric motor 10 for position adjustment of the lever chains 2 to 6. Transferred to the concrete individual case, this means that the control unit 11 converts gradients of the current I received by the electric motor 11 to the position adjustment of the lever chain 2 to 6. The gradient of the absorbed current I in the exemplary embodiment is in each case the slope of the absorbed current I on the part of the electric motor 10, specifically per time unit t. In essence, therefore, the current profile I (t) is differentiated after the time t, ie the differential quotient $$\frac{\mathit{dl}}{\mathit{dt}}$$

educated. This is ensured by the control unit 11.

Since the predetermined position of the lever chain 2 to 6 corresponds to a respective mechanical stop position, it is observed upon reaching this mechanical stop position that the current I picked up by the electric motor 11 rises sharply over the time t. By way of example, courses of the current I over the time t occur, as they are described in FIGS Fig. 2A and 2B are shown. As soon as the here entered maximum current I _max . is reached, a further increase in current would correspond to the fact that the electric motor 10 is damaged. Consequently, the control unit 11 ensures that the electric motor 10 is no longer energized.

To achieve this in detail, is in the example after the FIGS. 2A and 2B the time course of the current I absorbed by the electric motor 10, starting at a minimum threshold I _min . evaluated until reaching the maximum allowable current I _max . The minimum current I _min corresponds to the fact that the electric motor 10 requires a minimum current supply in order to be able to act on the lever chain 2 to 6 at all and to overcome any frictional forces.

Based on the examples in the FIGS. 2A and 2B it can be seen that at the beginning of the "block drive", the current I, starting from the required current I _min to act on the lever chain 2 to 6, rises more or less within an associated time interval Δt. Within this time interval Δt, the current I _min rises to the maximum permissible value I _max . For this corresponds a slope $$\mathrm{S}=\frac{\mathrm{\Delta }l}{\mathrm{\Delta }t},$$

As soon as this example of the FIGS. 2A and 2B explained slope S is exceeded within the time interval At, this interpreted the control unit 11 to the effect that then the mechanical stop position is reached, in the present case so that the electric motor 10, the central locking lever 2 of his before and in the Fig. 1 shown position "locked" in the position "unlocked" has convicted. Since the slope S is exceeded, the control unit 11 after the time interval .DELTA.t ensures that the electric motor 10 is no longer energized.

Alternatively, of course, it is also possible to work with smaller time intervals dt, like the Fig. 2C suggests. Here, in each case the gradient S is shown for different temporal current curves of the current absorbed by the electric motor 10. As soon as the gradient S (shown in solid lines) is exceeded (compare the dot-dashed curve), this interprets the control unit 11 in such a way that the desired mechanical stop position is reached. For example, may include gradients of 10 amps per second. That depends on the design of the associated electric motor 10. Otherwise, ie when falling below the slope S (shown in phantom), the electric motor 10 is energized unchanged.

Before in the example shown after the Fig. 1 and starting from the position "locked" the electric motor 10 is acted upon in such a way that it acts on the locking lever chain 2 to 6 in the direction "unlocked", carried out in the context of the invention, first a verification of the assumed position of the lever chain 2 to 6. This verification is so made that the control unit 11, the electric motor 10 after a corresponding activation command ("unlock" in the example) initially applied in its opposite direction. That is, the control unit 11, following the aforementioned activation command first ensures that the electric motor 10 is energized so that it acts on the lever chain 2 to 6 in the direction "lock". Since the lever chain 2 to 6 is already in the "locked" position, this application in the opposite direction in comparison to the desired command corresponds to the fact that the current I picked up by the electric motor 10 rises sharply over the time t. A corresponding increase of the current I over the time t can now according to the illustration of the Fig. 2A to 2C be evaluated again to the effect that the control unit 11 detects the position "locked" respectively verified.

The verification results from the fact that the control unit 11 in principle "white" due to the history of previously and in the past made positioning movements of the lever chain 2 to 6, that the lever chain 2 to 6 is in the example "locked" in the example. This position is verified again with the described routine, namely before the electric motor 10 is acted upon by the control unit 11 so that the lever chain 2 to 6 is "unlocked" in the desired position.

Claims (9)

1. Motor vehicle door latch with a lever chain (2 to 6) which can be acted on in a motorized manner, and with an electromotor (10) with an associated control unit (11), wherein the electromotor (10) transfers the lever chain (2 to 6) into a specified position or acts on it starting from the specified position, and whereby the control unit (11) uses data from the electromotor (10) for its action, and the control unit (11) evaluates gradients from power data of the electromotor (10) for position setting of the lever chain (2 to 6), characterized in that the control unit (11) acts on the electromotor (10) subsequently to an activation command at first in its counterdirection in order to verify the current position of the lever chain (2 to 6) as a starting point for the desired movement.
2. Motor vehicle door latch according to claim 1, characterized in that the control unit (11) evaluates position signals of the electromotor (10) for position setting of the lever chain (2 to 6).
3. Motor vehicle door latch according to claim 1 or 2, characterized in that the specified position of the lever chain (2 to 6) corresponds to a mechanical stop position.
4. Motor vehicle door latch according to one of the claims 1 to 3, characterized in that the lever chain (2 to 6) is formed as a bolting lever chain (2 to 6) and/or an operating lever chain.
5. Motor vehicle door latch according to one of the claims 1 to 4, characterized in that the control unit (11) evaluates current/voltage courses to control the electromotor (10).
6. Motor vehicle door latch according to claim 5, characterized in that the control unit (11) temporally differentiates the current/voltage courses.
7. Motor vehicle door latch according to claim 5 or 6, characterized in that a certain temporal increase of the current / voltage on the electromotor (10) is identified with attainment of the specified position.
8. Method for operating a motor vehicle door latch with a lever chain (2 to 6) which can be acted on in a motorized manner, and with an electromotor (10) with an associated control unit (11), wherein the electromotor (10) transfers the lever chain (2 to 6) into a specified position or acts on it starting from the specified position, and wherein the control unit (11) uses data from the electromotor (10) for its action, and the control unit (11) evaluates gradients from power data of the electromotor (10) for position setting of the lever chain (2 to 6), characterized in that the control unit (11) acts on the electromotor (10) subsequently to an activation command at first in its counterdirection in order to verify the current position of the lever chain (2 to 6) as a starting point for the desired movement.
9. Method according to claim 8, characterized in that the control unit (11) is controlled to act on the electromotor (10), for example wirelessly by means of remote control (12) and/or in a wired manner via a key (5), for example.

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