Motor vehicle door lock and method for electrically actuating a locking mechanism

Abstract

The invention relates to a motor vehicle door lock and to a method for electrically actuating a locking mechanism in said type of motor vehicle door lock. Said motor vehicle door lock comprises a locking mechanism and an electric drive (1, 2, 3) for the locking mechanism. It also comprises at least one signal transmitter (8) for impinging upon the electric drive (1, 2, 3). According to the invention, a first flank (F.sub.S) and also a second flank (F.sub.E) of a signal (S) generated by the signal generator (8) are evaluated for controlling the electric drive (1, 2, 3).

Claims

1. Motor vehicle door lock comprising a locking mechanism; a handle; a blocking lever connected to the handle; an electric drive that moves the locking mechanism between a closed position and an open position; at least one signal generator that produces a signal that defines a first flank and a second flank, wherein interaction between the blocking lever and the signal generator generates the signal when the handle is acted upon; and a control unit that evaluates the first and second flank and controls operation of the electric drive based on the first and second flank wherein, upon detecting the first flank, the control unit is programmed to operate the electric drive a specified starting time sufficient to ensure that the locking mechanism reliably moves from the closed position to the open position and wherein the blocking lever blocks the locking mechanism from moving to the open position if the handle is not acted upon.

2. Motor vehicle door lock according to claim 1, wherein, after the specified starting time, the control unit is programmed to move the electric drive into a holding phase that maintains the locking mechanism in the open position.

3. Motor vehicle door lock according to claim 2, wherein the holding phase ends after the control unit detects the second flank of the signal generator.

4. Motor vehicle door lock according to claim 1, wherein the electric drive comprises at least one electric motor, and a worm gear driven by the motor as well as a driven pulley meshing with the worm gear.

5. Motor vehicle door lock according to claim 1, wherein interaction between a handle and the signal generator generates the signal when the handle is acted upon.

6. Motor vehicle door lock according to claim 1, wherein the signal generator contains a leaf spring for its actuation.

7. Method for the motorized actuating of the locking mechanism in the motor vehicle door lock according to claim 1, comprising, the control unit evaluating, the first flank and the second flank of the signal generated by the signal generator and controlling operation of the electric drive with the control unit based on the evaluated first and second flank.

8. Motor vehicle door lock according to claim 1, wherein the control unit starts the electric drive when the first flank is detected and switches off the electric drive when the second flank is detected.

9. Motor vehicle door lock according to claim 1, wherein, after the specified starting time, the electric drive moves into a holding phase that maintains the locking mechanism in the open position.

10. Motor vehicle door lock according to claim 9, wherein the holding phase ends after the second flank of the signal generator is received by the control unit.

11. Motor vehicle door lock according to claim 9, wherein the holding phase ends after both the end of the specified starting time and receipt of the second flank by the control unit.

12. Motor vehicle door lock according to claim 10, further comprising a spring that biases the locking mechanism to the closed position.

13. Motor vehicle door lock according to claim 10, wherein the specified starting time is between 20 ms and 100 ms.

14. Motor vehicle door lock according to claim 2, further comprising a spring that biases the locking mechanism to the closed position.

15. Motor vehicle door lock according to claim 2, wherein the specified starting time is between 20 ms and 100 ms.

Description

(1) Below, the invention is explained in detail with reference to a drawing showing only one embodiment, in which:

(2) FIGS. 1 and 2 show the motor vehicle door lock of the invention in different functional positions and

(3) FIG. 3 shows two principal time diagrams explaining the opening process.

(4) FIGS. 1 and 2 show a motor vehicle door lock containing a not expressly shown locking mechanism. The locking mechanism comprises actually as usual a rotary latch and a pawl. The pawl is directly or indirectly acted upon by an electric drive 1, 2, 3. The electric drive 1, 2, 3 comprises an electric motor 1, a worm gear 2 acted upon by the electric motor 1 as well as a driven pulley 3 meshing with the worm gear 2.

(5) As a result, the driven pulley 3 can rotate around its axis 4. Rotary movements of the driven pulley 3 around axis 4 in counter-clockwise direction result in the said pawl being directly or indirectly lifted off the rotary latch by a not expressly shown triggering lever. As soon as the pawl is no longer engaging the rotary latch or is lifted off it, the rotary latch can be opened with the aid of a spring and release a previously retained closing bolt. As a result, the locking mechanism is open. This basic functionality is known and disclosed in detail in the prior art documents of DE 196 00 524 A1 or of DE 203 07 347 U1 already mentioned above.

(6) The lifted-off position of the pawl in relation to the rotary latch corresponds to the electric drive 1, 2, 3 or the stop 5 of its driven pulley 3 being moved in counter clockwise direction against the counter stop 6, fixed to the housing. The displacement from the base position (neutral position) or starting position A of the electric drive 1, 2, 3 or of the driven pulley 3 shown in FIGS. 1 and 2 into the aforementioned stop position (end position E) with stop 5 moved against the counter stop 6, is also apparent from FIG. 3

(7) The top diagram of FIG. 3 shows the base position or starting position A and the stop position or end position E of the electric drive 1, 2. 3. If the electric drive 1, 2, 3 is no longer in the stop or end position E or if the associated electric motor 1 is no longer impinged upon, a spring 7 only indicated in FIGS. 1 and 2 ensures that the electric drive 1, 2, 3 assumes its base position or starting position A with the aid of a spring.

(8) For this purpose, the spring 7 is designed as a centre/zero spring 7, ensuring irrespective of the direction of actuation of the electric drive 1, 2, 3 or the direction of rotation of the driven pulley 3 around its axis 4, that once the electric drive 1, 2, 3 is no longer impinged upon, the electric drive 1, 2, 3 assumes the base position or neutral position or starting position A.

(9) FIG. 3 also shows the respective time sequence of a signal S transmitted by a signal generator 8 to a control unit 9. The signal generator 8 is assigned to a handle 10. In the example, the handle 10 acts upon a lever 11, designed as a blocking lever 11. As soon as the handle 10 is acted upon, and in the opening sense, the lever or the blocking lever 11 is pivoted around its axis 12 in clockwise direction, as apparent from the transition from FIG. 1 to FIG. 2.

(10) As a result of the handle 10 being acted upon, as described, the blocking lever 11 acts upon the signal generator 8. The signal generator 8 in turn contains a leaf spring 13. As soon as the handle 10 is acted upon, the signal generator 8 generates a signal S, moving from “0” to “1” as shown in FIG. 3. The released handle 10 causes the signal S to drop back again from “1” to “0”. At the same time, a first flank FS and a second flank FE are observed in FIG. 3 during the period of the signal S and during time t. The first flank Fs and the second flank FE of the signal S generated by the signal generator 8 are now evaluated as part of the invention and for triggering the electric drive 1, 2, 3. In the example, the evaluation is carried out by the control unit 9.

(11) The overall design is such that the electric drive 1, 2, 3, is started by the first flank Fs of the signal S of the signal generator 8. This is apparent when comparing the time diagrams arranged underneath each other in FIG. 3. The first flank Fs does actually correspond to the electric drive 1, 2, 3 moving from its base position A into the end position E or being energized accordingly by the control unit 9. In contrast, the second flank FE of the signal S of the signal generator 8 ensures that the electric drive 1, 2, 3 is switched off. From FIG. 3 it is apparent that consequently the second flank FE coincides again with the transition of the electric drive 1, 2, 3 from the end position E to base position A.

(12) FIG. 3 also shows that the energizing of the electric drive 1, 2, 3 during the assumption of its end position E, i.e. when the stop 5 of the driven pulley 3 rests against the counter stop 6 fixed on the housing, is divided into two phases, a start phase PS and a holding phase PH. During the start phase PS the electric drive 1, 2, 3 is actively energized with the aid of the control unit 9, by the control unit 9 respectively acting upon the electric motor 1. In contrast, the holding phase PH corresponds to the electric motor 1 in question being short-circuited, as a result of which holding forces are exerted on the electric drive 1, 2, 3 in the example in such a way that the force of the spring 7 is overcome so that the stop 5 still rests against the counter stop 6.

(13) The start phase PS corresponds to a specified starting time tS. This starting time is can in the example last between 20 ms and 100 ms. Within the starting time tS it is ensured that the electric drive 1, 2, 3 is reliably moved from its base position A to the end position E. This start phase PS or starting time tS is followed immediately by the holding phase PH of the electric drive 1, 2, 3. A holding time tH corresponds to a holding phase PH. The holding time tH directly follows the starting time tS. During the holding phase PH the electric drive 1, 2, 3 retains its position—as already described—in such a way that the stop 5 rests against the counter stop 6 and that, as a result, the pawl lifted off with the aid of the driven pulley 3 is still retained in the lifted-off position.

(14) Only when the control unit 9 registers the second flank FE of signal S of the signal generator 8 is the holding phase PH and thus also the holding time tH terminated.

(15) In order to initiate the described functional change, the handle 10 is acted upon, which in turn acts upon the blocking lever 11 acting in turn upon the signal generator 8. In the embodiment, the blocking lever 11 ensures that incorrect energizing of the electric drive 1, 2, 3 can not cause an unintentional opening of the locking mechanism. Actually the blocking lever 11 engages in the electric drive 1, 2, 3 as shown in the functional position of FIG. 1 until the blocking lever 11 is moved clockwise around its axis 12 without the help of the handle 10. Only then and when the functional position shown in FIG. 2 is assumed, can the electric drive 1, 2, 3 start and open the locking mechanism. Any incorrect energizing can thus be combated as it corresponds to the handle 10 not being deflected. In the event of the electric drive 1, 2, 3 being subjected to such an incorrect energizing, the still engaged blocking lever 11 reliably ensures in such a case that the electric drive 1, 2, 3 is blocked and that the acted upon locking mechanism is not opened.

(16) It is in any case ensured that after completion of the holding phase PH and thus also at the end of the holding time tH the electric drive 1, 2, 3 is moved into its neutral position or base position A. This is directly apparent from FIG. 3. This is actually achieved by the centre/zero spring 7 integrated in the driven pulley 3. In this base or neutral position A, a new starting command can be processed by the handle 10.

(17) Only once the start phase PS and thus the starting time tS has been completed, is the electric drive 1, 2, 3 able to process a further and deviating signal S of the signal generator 8.