FR2775848A1 - DRIVE SYSTEM FOR MOVING A WORKPIECE SUCH AS A SLIDING WINDOW OR ROOF OF A VEHICLE - Google Patents

Abstract

Drive installation for moving a part such as a window or a sliding roof of a vehicle, characterized in that:. the electric motor (3) is a polyphase electric brushless switching motor, comprising field coils (17-22) connected to a switching circuit (4) and ,. the current line (25, 26, 27) of the motor is a line connected to a field coil.

Description

State of the art: The present invention relates to an installation

  drive for moving a part such as a window, a sliding roof, a seat of a vehicle using an electric motor capable of rotating in two directions of rotation,

  this motor comprising at least one coil and at least one li-

  current supply to the motor and a circuit

  safety to at least stop the electric motor in operation

  risk of injury to a part of the body of a person

  sounds by the moving part according to an exploitation of a variation of a frequency of the signals, proportional to the speed of rotation of the motor, from

  variations in current or voltage in the line

engine rant.

  According to documents DE-30 34 118 C2, DE-31 36 746 C2, there are known electronic monitoring methods for opening and closing operations, in particular of windows and sliding roofs, controlled by drive installations comprising electric motors and

transmissions.

  For example, such transmissions can

  wind may be a screw transmission and a lever transmission or a screw transmission and a traction medium transmission. According to the process, the electric motor is connected

  to a monitoring circuit itself connected to a means of

  tection or sensor providing digital signals.

  The digital sensor can be integrated into or mounted on the electric motor or transmission

  for example being on the path of a window. At ti-

  For example, a sensor providing such digital signals

  ques consists of a Hall effect sensor and a permanent magnet element moved relative to the Hall effect sensor, for example a pole wheel carried on the shaft of the electric motor or transmission. The monitoring circuit is designed to measure time intervals for example between the rising edges to give signals from the digital sensor, and form a reference value after starting the electric motor, memorize this reference value and measure repeatedly time intervals, switch between two digital signals and compare the measured time to the reference value to stop the electric motor if the time exceeds the reference value or switch the motor to run in

  opposite direction of rotation.

  These process steps make it possible to avoid met-

  being in danger from parts of the human body by pinching

  limited by the moving glass or the movement of the roof

  smoothing. It is advantageous that by using the ef- sensors

  fet Hall or for example an electro-optical barrier, signals are obtained which are easy to use even if the speed of rotation of the electric motor or the speed of movement relative to the mobile elements is relatively low. This

  digital sensor is also suitable for measuring

  direct or indirect travel of the window or the roof

  sliding so that using an automatic positioning

  you can move the indicated parts from a predetermined or predetermined position, then

stop them.

  A known training facility according to

  document US 4,001,661 with a collector motor for displacement

  cer a window and a safety circuit to cut the collector motor, intentionally avoids the mounting or installation of digital sensors and plans to measure the current in a brush conductor, corresponding to the frequency of the ripple, proportional at the speed of rotation of the collector motor. For this, a

  measuring circuit made up of capacitors, diodes and

  sistances upstream from the base of a transistor coupled to the motor current line by a measurement transformer;

  this transformer is made in the form of a coil

  rolled around the motor current line. When the frequency drops below a limit value, the voltage

  decreases in the measurement capacitor and it de-

  load in a resistor. The passing down of the

  limit value leads to shutdown of the collector motor.

  Document DE-42 17 664 Ai describes a drive unit for positioning a steering wheel or a seat in a passenger compartment. The drive unit includes a three-phase brushless motor, three Hall effect switches for retrieving rotation position signals from a three-phase motor rotor and a three-phase field control which controls success

  field coils of the motor shaft depending on the rotational positions. The rotation position signals are counted to directly measure the position10 of the steering wheel or seat using a counting circuit. Thanks to a memory for the position value and an instal-

  Comparison lation connected to the counting circuit and to the memory makes it possible to automatically stop the three-phase motor. The document US 5,015,927 describes a circuit for

  switching, for example for a three-phase electric motor.

  The switching circuit includes a switch for power

  successively pulse field coils with excitation currents, it generates the switching signals by measuring the excitation currents in the field coils and by measuring the induction currents at the time when none field coil is supplied with excitation current and by observing the relationships of the two currents. The switching signals are also supplied to a speed regulator which acts on a pulse width modulator controlling

  itself directly the switching circuit.

  This switching circuit eliminates a

  Hall effect switch fitted to the motor.

  The document US Pat. No. 5,256,923 describes another electronically commutated motor giving position signals

  rotation and rotation speed signals without switching

  Hall effect sensor mounted on the motor shaft. To generate the switching signals, at least one pole of the stator and / or at least one pole of the rotor of the electric motor has a

  groove, so that normal variations in current

  during the rotation of the rotor are combined with bumps and troughs of intensity which make it possible to recover the signals of

  switching. For this, at least one coil wire or a line

  Coil feed through the cores of a transformer. The frequency of the switching pulses

  collected gives the engine speed.

  Advantages of the invention: The object of the present invention is to remedy the drawbacks of known solutions and to this end relates

  a training installation of the type defined above

  characterized in that: * the electric motor is a polyphase switching motor

  brushless electric, with field coils

  linked to a switching circuit and, * the motor current line is a line connected to a

field coil.

  The drive installation according to the invention

  has the advantage of providing a signal proportional to the

  rotation of the electric motor according to document US 4,001,661 and thus to present the low wear and

  silent operation of an electro- switching motor

  nique whose switching circuit generates signals

  switching from intensity variations and / or values

  voltage riations to give signals.

  According to another advantageous characteristic, all the sensors used to obtain signals from the voltage or current variations of all the coils

  field are connected to a collector circuit of the safety circuit

rite.

  So instead of a signal, we now have

  for example from three or more signals for each ro-

  motor, which allows the protection circuit to

  detect a person's danger earlier.

  According to another advantageous characteristic the

  collector circuit is an OR logic gate.

  So we come to a less expensive component,

  supplied by the electronic components market.

  Drawings: The present invention will be described below in more detail using an embodiment shown schematically in the accompanying drawings, in which: - Figure 1 shows a drive installation according to the invention and a part driven by it, - Figure 2 is a diagram of a stator with coils of

  field and an electric motor rotor.

  Description of the exemplary embodiment:

  The drive installation 2 according to the invention comprises a brushless electric motor 3, a switching circuit 4 and a safety circuit 5. To operate or arbitrarily cut the electric motor 3 by the

  switching circuit 4, the switching circuit has been connected

  tion 4 to a control installation 6. The installation of

  command 6 can be carried out in a relatively simple manner

  ple with buttons to plug the electric motor into

  a first direction of rotation and in a second direction of rotation

  tion as well as to stop the electric motor. The meaning of

  maneuver is chosen according to the state of the art.

  The electric motor 3 has for example a

  stator 10 with six pairs of polar teeth 11-16 and bo-

  field bines 17-22 surrounding the polar teeth, a rotor 23 with a north pole N and a south pole S as well as a rotor shaft 24. At least three motor current lines 25, 26, 27 start from the circuit of switching 4 to the field coils 17, 19, 21. According to the arrangement in pairs of the polar teeth, the coil 17 is connected to the coil 18, the coil

  19 to reel 20 and reel 21 to reel 22. For general

  rer the motor torque, the switching circuit 4 successively supplies the pairs of coils 17, 18; 19, 20; 21, 22 with an excitation current so that the supply of a pair of coils with the excitation current causes the

  two other pairs of coils then receive no

  rant of excitement. These pairs of coils not supplied with excitation current are those which are used to capture the position of the rotor by the exploitation of a magnetic field.

  induced by the rotor on the side of the switching circuit.

  Depending on the number of pairs of coils, for the exploitation of the respective magnetic fields, three sensors 28, 29, 30 are provided. The sensors can be according to

  the state of the art of functional inductive converters

  based on the transformer principle; depending on the mode of

  realization, the motor current lines 25, 26, 27 work

  pour coils or for example annular cores according to the state of the art. The signals from the sensors 28, 29 are used to control the switching circuit 4; through

  elsewhere, these circuits cross the protection circuit 5.

  For this, the frequency of the signals is related to the speed of rotation of the rotor 23 or the frequency of rotation

of the rotor 23 in a fixed ratio.

  The safety circuit 5 is for example designed

  to measure the frequency and compare it to a value of

  ference. It is possible to measure only the frequency of the signals from one of the sensors 28, 29, 30 or to use a collector circuit 51 for example in the form of a logic gate OR which measures the succession of the signals of all the sensors 28, 29, 30. It does not matter under these conditions that the reference value is fixed as the period duration according to the document DE 30 34 118 C2 or according to the document

  US 4,001,661 as voltage and only in the protection circuit

  tion 5, the frequency of the signals collected is converted into an essentially proportional voltage which is compared to the reference voltage. In the cases described, the reference values are in principle rotation speeds and in the event of overshooting downwards, the protection circuit 5 acts by the switching circuit 4 and controls this circuit

  4 to stop the electric motor 3 or even to run it-

  ner in the opposite direction. Furthermore, the safety circuit 5 can also be designed so that not a certain speed threshold, but a derivative as a function of time, of the speed of rotation or of the frequency obtained, proportional to the speed of rotation constitutes the criterion

stopping the electric motor 3.

  In the present exemplary embodiment, the shaft 3 of the rotor is the drive shaft of a window lifter 35. The

  window regulator 35 itself is not part of this in-

  vention and it suffices to indicate that it corresponds

  for example in the state of the art and includes a

  screw mission, not shown connected to the shaft 24 of the rotor as well as a transmission connected to this screw transmission to convert a rotational movement into a translational movement. The translational movement is itself transmitted by a support rail 35 to a window 37. The window 37 is guided in a known manner and shown schematically

by a chassis 38.

  As already indicated, the control installation 6 makes it possible to start the electric motor 3 in one or the other direction of rotation. By starting the electric motor 3 in the direction of lifting the window 37, the window 37, 38 shown in part open is closed. The upper edge 39 of

  the window 37 then approaches the upper edge 40 of the frame

  window sis 38. If then for example a person has a

  hand in the area between the upper edge 39 and the upper edge

  laughing 40, this results at least in the contact of the hand with the upper edge 39 of the window 37; this decreases the speed of rotation of the motor 3 and thus the frequency of

  signals applied to safety circuit 5. As already de-

  crit, the safety circuit 5 reacts according to the dimi-

  nution of the frequency and so for example to a decrease

  of the frequency reference value and stops the movement

  ment of raising the window 37 and preferably controls the lowering of the window 37, so that the person can

  again remove his hand from window 37, 38.

  The drive installation 2 according to the invention can also be combined in a manner not shown with

  a sliding roof. Like the sliding roofs and the trans-

  mission mounted between them and the electric motors res-

  pectifs are notoriously part of the state of

  technical, there is no need to describe them in more detail

  cut or make a drawing corresponding to such a des-

  cription. The use of the drive installation according to the invention is not limited to lifting windows or moving sliding roofs. The installation

  according to the invention can also be used to

  place sliding doors, seats, hoods or

covering elements.

Claims (3)

R E V E N D I C A T IONS   1) Drive installation for moving a part such as a window, a sliding roof, a seat of a vehicle using an electric motor capable of rotating in two directions of rotation, this motor comprising at least one coil and at least one current line supplying the motor   as well as a safety circuit to at least stop the mo-   electric tor according to a risk of injury to a part of a person's body by the moving part according to an exploitation of a variation of a frequency   of signals, proportional to the speed of rotation of the mo-   tor, from variations in current or voltage of the motor current line, characterized in that   * the electric motor (3) is a polyphase motor with switching   electric brushless? comprising field coils (17-22) connected to a switching circuit (4) and, * the current line (25, 26, 27) of the motor is a line   connected to a field coil (17, 18; 19, 20; 21, 22).   2) drive installation according to claim 1, characterized in that all the sensors (28, 29, 30) used to obtain signals from the voltage or current variations of all the field coils (17, 18; 19, 20; 21, 22) are related to   a collector circuit (51) of the safety circuit (5).   3) drive installation according to claim 2, characterized in that   the collector circuit (51) is an OR logic gate.