FR2756318A1 - Motorised automobile window-lift, with terminal stressing relief - Google Patents

Abstract

The window (V) base is fixed to a carriage (7) travelling on a vertical slide (6). Through a worm-gear (2) the reversible driving motor (1) rotates a plastic sprocket-wheel (3) moving the carriage via an endless chain or toothed belt (4). After manual initiation, the drive is electronically controlled. Window closing is detected by a chain tension sensor, or a position sensor within the drive unit, but the controller continues to apply tension briefly to ensure a good air- and water-tight seal. To prevent possible deformation of the sprocket this additional tension is then relieved by reversing the drive, over either a brief time interval, or a small angular deflection. An obstacle detector circuit, with automatic wind-down, is disabled during final closing.

Description

 The present invention relates to an electric window system, in particular for a motor vehicle, and more specifically an electric window system equipped with an anti-pinch device.

 Certain known electric window regulator systems for a motor vehicle comprise a kinematic chain connecting the window to an electric motor, the latter producing a torque to drive the window in an up and down movement and maintaining this torque for a few fractions of a second at the end. closing stroke of the window to urge it to stop against the upper slide of the window frame, in order to ensure correct closing of the window, and to avoid any problem of watertightness, airtightness to eliminate aerodynamic noise, and untimely lowering of the window when the door is slammed.

 However, this abutment of the window at the end of the closing stroke creates stresses throughout the kinematic chain of the window lifter, which can cause deformation of the components of the kinematic chain when the window remains for a long time in this position without be used. Such deformation can cause the appearance of parasitic forces during the subsequent actuation of the window regulator and lead to premature wear and therefore to a breakdown of the system.

 In particular, when the kinematic chain comprises a plastic toothed wheel meshing with a worm screw driven by the electric motor, the plastic wheel can creep under the effect of stresses and give rise to an eccentricity causing an abnormal force during operation subsequent of the mechanism for raising and lowering the window regulator.

 This problem is all the more sensitive if the window regulator system is fitted with an anti-pinch device to prevent a person from being pinched by the hand or the head between the window and its frame during the automatic raising of the window. window. Such an anti-pinch system stops the rise of the window and lowers it when the kinematic chain is stressed, in particular under the effect of the pinching of a part of the user's body. Of course, this device is disconnected or inhibited at the very end of the window closing stroke to allow it to be brought into abutment.

 In this case, the parasitic force resulting from a possible deformation of the kinematic chain would then be interpreted by the anti-pinch device as a pinch force, which would cause it to come into untimely action and the glass to lock in the low position. opened.

 The invention therefore aims to eliminate the aforementioned drawbacks and to propose an electric window lifter system which frees the kinematic chain from the deformation constraints at the end of the closing stroke of the window without altering the correct closing thereof. from the point of view of its airtightness and water tightness as of its resistance in the event of a door slamming.

 The invention also aims to provide an electric window system which prevents, if necessary, the untimely activation of an anti-pinch device.

 Of course, the problem of deformation of the kinematic chain could also arise if the window was pressed into abutment at the end of the opening stroke.

 To this end, the subject of the invention is an electric window regulator system, in particular for a motor vehicle, comprising an electric motor driving the window in an up and down movement by means of a kinematic chain, characterized in that that it comprises means for canceling the stresses appearing in the kinematic chain when the window is pressed into the end of travel stop.

 According to another characteristic, the electric motor is of reversible voltage and the stress cancellation means is a means for automatically reversing the voltage of the motor for a short period of time after the window has been biased as a limit stop.

 In a first embodiment, the reversing means is arranged to reverse the voltage of the motor for a predetermined period.

 In another embodiment, the reversing means is arranged to reverse the voltage of the motor during a predetermined fraction of a turn thereof. In this case, the system of the invention can include a window end-of-travel sensor, this sensor detecting the angular position of the motor. A HALL effect sensor is particularly suitable. Advantageously, this sensor can be placed in the immediate vicinity of the motor rotor.

 According to another characteristic of the invention, the motor is arranged to produce a torque at the end of the window closing stroke in order to urge it into abutment.

 Of course, the system of the invention is managed by a central control unit such as an electronic computer.

 According to yet another characteristic, the kinematic chain of the system may include an endless screw driven by the electric motor and meshing with a plastic toothed wheel functionally connected to a mechanism for raising and lowering the window.

 The system of the invention may also include an anti-pinch device for stopping the rise of the window and lowering it when the kinematic chain is under stress, this device being inhibited at the very end of the window closing stroke.

The invention will be better understood, and other objects, details, advantages and characteristics thereof will appear more clearly during the explanatory description which will follow of a particular currently preferred embodiment of the invention, given only by way of illustration and not limitation, with reference to the accompanying schematic drawings, in which
- Figure 1 is a very schematic view of an electric window system according to the invention, for a door of a motor vehicle
- Figure 2 is a schematic, partial and enlarged view of a detail of Figure 1, indicated by arrow II and
FIG. 3 is a diagrammatic and enlarged view of a detail of the rotor of the motor illustrated in FIG. 2.

 According to the embodiment shown in the drawings, the electric window regulator system of the invention comprises an electric motor 1 for driving a window V in an up and down movement by means of a kinematic chain which will detailed later.

 We see in Figure 1 that the window V is mounted in a door P indicated in dotted lines and shown in its closed position.

 We will now describe the kinematic chain between the engine 1 and the window V.

 The motor 1 drives an endless screw 2 meshing with a toothed wheel 3, for example of plastic, which in turn drives an endless cable or belt 4 to actuate an up and down mechanism 5.

 This up and down mechanism 5 comprises a vertical slide 6 on which slides a window lift slider or carriage 7 which is connected to the aforementioned cable 4, the latter passing over two pulleys 8 provided at the two lower and upper ends of the slide 6.

 The kinematic chain and the up and down mechanism will not be described in more detail because they are conventional in the art and can be replaced by any other equivalent system.

 It can be seen in FIG. 3 that sensors 9 are installed around the rotor 1a of the motor and in the vicinity of the carbon brushes 1b thereof to detect the relative angular position of the rotor. Of course, these sensors are connected to a central electronic control unit, such as a computer, to manage the entire system of the invention.

 The central control unit actuates the rotation of the motor l in one direction or the other depending on whether the window V is to be raised or lowered and has in memory a predetermined duration or a predetermined fraction of a turn for reversing the motor in order to cancel the constraints appearing at the end of the stroke.

 Of course, the system of the invention could be equipped with an anti-pinch device although this is not shown.

 We will now briefly describe the operation of the invention.

 When the window V reaches the end of the closing stroke, the motor 1 continues to apply its engine torque for a few fractions of a second to urge the window V to abut against the upper slide of the window frame.

 Then, the control unit reverses the voltage of the motor 1 for the predetermined duration or the predetermined fraction of a turn in order to release the stresses generated thereby in the kinematic chain.

 Thus, even if the user leaves the window in this closed position for a long period of time, the kinematic chain, and in particular the plastic toothed wheel, will not risk being deformed and causing an abnormal force during a subsequent use.

 In the absence of the stress cancellation means, the toothed wheel in particular could creep along the profile indicated at 3 'in FIG. 2.

 Although the invention has been described in connection with a particular embodiment, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these are within the scope of the invention. In particular, the sensors 9 could be replaced by any other end-of-travel sensor of the window indicating that it is in abutment, for example a cable tension sensor 4 (this tension increases when the window comes into abutment) , a sensor for the position of the carriage 7 or a sensor for the angular position of the wheel 3.

Claims (13)

 1. Electric window regulator system, in particular for a motor vehicle, comprising an electric motor (1) driving the window (V) in an up and down movement by means of a kinematic chain, characterized in that it comprises means for canceling the stresses appearing in the kinematic chain when the window is pressed into the end of travel stop.  2. System according to claim 1, characterized in that the electric motor is of reversible voltage and the stress cancellation means is a means for automatically reversing the voltage of the motor for a short period of time after the window has been activated. at the end of travel stop.  3. System according to claim 2, characterized in that the reversing means is arranged to reverse the voltage of the motor for a predetermined period.  4. System according to claim 2, characterized in that the reversing means is arranged to reverse the voltage of the motor during a predetermined fraction of a turn thereof.  5. System according to claim 4, characterized in that it comprises a sensor (9) for the end of travel of the window capable of controlling the reversing means when it detects that the window is in abutment.  6. System according to claim 5, characterized in that said sensor is a sensor (9) detecting the angular position of the motor (1), this sensor (9) being preferably placed in the immediate vicinity of the rotor (la) of the motor ( 1).  7. System according to claim 5, characterized in that, the window being driven by means of a cable (4), said sensor is a cable tension sensor (4).  8. System according to claim 5, characterized in that, the kinematic chain comprising a wheel (3) functionally connected to the mechanism for raising and lowering the window (V), said sensor is a sensor for the angular position of the wheel ( 3).  9. System according to claim 5, characterized in that, the window being driven by a window-lifting carriage (7), said sensor is a sensor of the position of the carriage.  10. System according to one of the preceding claims, characterized in that the motor (1) is arranged to produce a torque at the end of the closing stroke of the window (V) to urge it into abutment.  11. System according to one of the preceding claims, characterized in that it is managed by a central control unit such as an electronic computer.  12. System according to one of the preceding claims, characterized in that the kinematic chain comprises an endless screw (2) driven by the electric motor (1) and meshing with a plastic toothed wheel (3) functionally connected to the mechanism of up and down the window (V).  13. System according to one of the preceding claims, characterized in that it comprises an anti-pinch device for stopping the rise of the window and lowering it when the kinematic chain is stressed, this device being inhibited in all window closing limit switch.