FR2731460A1 - Device for detection of motorised window position in motor vehicle to avoid trapping person - Google Patents

Abstract

The window position detector has a source (12) of a magnetic field fitted in the frame (11) of the door. A magnetic field detector (13) is also fitted in the door frame, in the vicinity of the field source. The edge of the glass has a metal channel (15) fitted over it, or carries a metallised coating. When the glass nears its extreme position it passes between the magnetic source and the detector, altering the flux path. The components are set so that the detector moves between two states: one when the edge of the glass is in the vicinity and the other when it is not. The magnetic source is a permanent magnet and the detector a Hall effect transducer.

Description

 The present invention relates to a device for detecting the position of a motor vehicle window, pinch protection device and window regulator system incorporating it, as well as its control method.

 It finds application in the automotive field, and more particularly in that of electric window systems for vehicles.

 For safety reasons, such systems must, especially when the raising of the glass can be controlled automatically, incorporate a protection device against pinching of objects or parts of the human or animal body during the raising of the glass. This safety function is commonly known as the anti-pinch function and includes an action to lower the window to free the pinched object.

 It has already been proposed to use a direct pinch detection device using a sensor placed in the upper sensor rebate.

 An example of such a sensor is given in document EP 489 610. It is a resistive seal with two insulated faces, placed in the upper rebate of the door, and which is itself pinched when an object is trapped by the window so that, its two faces coming into contact, the level of an electrical voltage between the two sides is changed, this change being detected to control the descent of the window.

 Other sensors are constituted by a flexible pipe also disposed in the upper rebate of the door and inside which is kept a fluid whose pressure increases when an object is compressed between the flexible pipe and the window up.

An increase in the pressure of this fluid is detected to control the descent of the window. Such a sensor is described in document DE 33 28 696.

 However, the use of a sensor of a type as specified above considerably increases the complexity and the cost of the electric window system.

 This is why it has also been proposed to use an indirect pinch detection device constituted by a device for monitoring the increase in torque of the electric drive motor. In fact, in the case where an obstacle opposes mechanical resistance to the progression of the window, there is an increase in the current flowing in the armature of the electric drive motor, reflecting the effort provided by the motor to overcome the mechanical resistance due to the obstacle.

 The detection of an increase in this current can be interpreted as the presence of an object trapped between the window and the top of the door. However, it can also be due to the arrival of the window in a high stop situation in the upper rabbet of the door, this situation being perfectly normal and requiring no action to bring the window down, which would have indeed contrary to that sought in the context of an automatic closing device.

 This is why such a device for detecting the rise in the armature current of the motor must be supplemented by a device intended to provide information on the position of the window. Knowledge of this information does not make it possible to distinguish an increase in the torque of the electric drive motor due to the arrival of the window in high stop in the upper rebate of the door from a similar increase which would be due to the presence of an obstacle on the path of the winding up window.

 It is known to count the number of revolutions made by the drive motor from a determined position of the window, either using a sensor of the type of an incremental sensor mounted on an axis of the motor or using a device for detecting the switching phases of the motor by analyzing the effect of these switching on the change in the armature current of the drive motor.

 Such a device requires the use of up / down counting and storage means of an initial position of the window used as a reference for the calculation of the instantaneous position thereof. This makes the system complex and expensive and remains unreliable since a loss of information on the rotation of the motor can induce a difference between the estimated position of the window and its actual position.

 In order to solve the drawbacks of the aforementioned prior art, the present invention provides a device for detecting the position of a door leaf of a motor vehicle which is simple and reliable.

In fact, the present invention relates to a device for detecting the position of a door leaf of a motor vehicle, which is characterized in that it comprises
- at least one means for generating a magnetic field, disposed in the rebate of the door
- at least one means for detecting a magnetic field, disposed in the rebate of the door near said generation means, these two means constituting a logic unit which can take a first or a second state depending on whether the magnetic field generated by the generation means is detected or not by the detection means
- At least one means for ensuring the conduction of a magnetic flux, carried by the window and adapted to switch said logic unit from said first state to said second state or vice versa, depending on the position of the window.

 This device is used to detect the closed position of the window, that is to say also its arrival in the upper stop during the automatic ascent or not. In practice, in fact, only information with the window closed is necessary in order to be able to discriminate an increase in the armature current of the electric drive motor due to the arrival of the window in high stop in the upper rebate of the door. a similar increase which would be due to the presence of an obstacle on the course of the window in ascent.

According to other features of the invention
- the means for generating a magnetic field is a magnet
- the magnetic field detection means is a Hall effect cell
the means for ensuring the conduction of the magnetic flux comprises a conductive layer obtained by metallization of the surface of the end of the glass
- The conductive layer covers the upper surface of the glass and descends on each side of it of a determined length, so that in a cutting plane perpendicular to the plane of the glass, the means for ensuring the conduction of the magnetic flux have the general shape of an inverted U.

 - The means for ensuring the conduction of the magnetic flux comprises a part made of a conductive material of magnetic flux such as a metal part, which is clipped or glued to the end of the glass.

 According to another characteristic of the invention, according to the principle of double glazing, the glass comprises two plates of transparent material such as glass or plastic, these two plates being kept spaced from each other by a piece made made of a magnetic flux conducting material such as a metal part, which contributes to the means for ensuring the conduction of the magnetic flux.

 The invention also relates to a pinch protection device for a system for automatically closing the doors of a vehicle, such as door windows, of the type comprising a means for detecting a mechanical resistance to the progression of the window, which is characterized in that it further comprises a device for detecting the closed position of the window as described above, which is associated with said means for detecting resistance to the progress of the window in order to be able to distinguish a situation real pinching of a window position in high stop.

 According to a characteristic of the invention, the means for detecting a mechanical resistance to the progression of the window comprises a means for monitoring the current flowing in the armature of the motor, and a means for comparing this current with a predetermined threshold.

 The invention also relates to a system for electrically closing the doors of a vehicle, characterized in that it comprises a pinch protection device as described above.

The invention also relates to a method for controlling such an electric closing system, characterized in that, starting from an initial situation where the window is lowered, and where the motor is controlled to turn in a first direction intended to make reassemble the glass, it includes the following steps
a) detection of the value of the motor current
b) comparison of this value with a first predetermined threshold value
c) then, if the value of the motor current is greater than said first predetermined threshold value, detection of the position of the window,
otherwise, repeat steps a) and b)
d) if the window has not returned to the upper rebate of the door, then modification of the engine control so that its direction of rotation is reversed to bring the window down
e) if the window is retracted into the upper rabbet of the door, the engine control stops.

According to another characteristic, starting from an initial situation where the window is closed, that is to say also re-entered in the upper rebate of the door, and where the motor is controlled to turn in a second direction intended to lower the window , the invention comprises the following steps
a) detection of the value of the motor current
b) comparison of this value with a second predetermined threshold value
c) then, if the value of the motor current is greater than said second predetermined threshold value, detection of the position of the window
d) if the window is in the closed position, the engine control stops and a blocking signal is produced.

Other characteristics and advantages of the present invention will appear on reading the description which follows, with reference to the accompanying drawings which are
- In Figure 1: a diagram of a detection device according to the invention showing a first embodiment of the means for ensuring the conduction of the magnetic flux carried by the window
- In Figure 2 (a): a diagram of a second embodiment of said means carried by the glass
- In Figure 2 (b): a diagram of a third embodiment of said means carried by the glass
- In Figure 3: a diagram of a window regulator incorporating the anti-pinch function according to the invention.

 In Figure 1, there is shown in section a portion of a window 10 of the vehicle door corresponding to the upper part of this window can enter a space 14 of the rebate 11 of the door.

 On one side of the space 14 of the rebate is disposed a means for generating a magnetic field such as a magnet 12.

 On the other side of the space 14 of the rebate is also arranged a means for detecting a magnetic field such as a Hall effect cell 13.

 It will be said hereinafter that the assembly formed by the means for generating a magnetic field, that is to say the magnet, and the means for detecting a magnetic field, that is to say the effect cell Hall, constitute a logical unit 12,13 which can take two states.

 When the magnetic field generated by the magnet is detected by the Hall effect cell, it will be said that the logic unit is in a first state.

When, conversely, the magnetic field generated by the magnet is not detected by the effect cell
Hall, we will say that the logical unit is in a second state different from the first state.

 The distance between the magnet 12 and the Hall effect cell 13 is fixed such that, in the absence of any magnetic flux conductor in the space 14 of the rebate, the magnetic field generated by the magnet is not not detected by the Hall effect cell, i.e. the logic unit is in the second state defined above.

 The end of the window 10 carries a means for ensuring conduction of a magnetic flux, such as a layer 15 of substance conducting magnetic flux, for example a layer of metallic substance deposited by metallization of the end of the window .

When the window 10 rises in position in the rebate 11, the layer 15 of conductive substance of magnetic flux, hereinafter called conductive layer 15, is located in the space 14 of the rebate so that a magnetic flux closes between the magnet 12 on the one hand and the Hall effect cell on the other hand when said end of the window is retracted into the rebate of the door. Thus, the magnetic field generated by the magnet 12 is detected by the effect cell
Hall and the logic unit 12,13 enters the first aforementioned state.

 In fact, the relative arrangement of the magnet 12 and of the Hall effect cell 13 can be defined other than in FIG. 1, insofar as the logic unit 12, 13 is in the first state when the window 10 is entered in the rebate 11, and is in the second state otherwise.

In particular, the magnet 12, the effect cell
Hall 13 and the means for ensuring the conduction of the magnetic flux 15 are not necessarily aligned when the latter is located in the space 14 of the rebate, that is to say when the window 10 is in position in the rebate 11.

 Indeed, the magnet 12 can for example be arranged in the rebate above the space 14, in the axis of the window 10, the Hall effect cell 13 remaining disposed on the right side of the space 14 in the same position as in Figure 1.

 We can also reverse the position of the magnet and that of the Hall effect cell as described in the previous paragraph.

 The magnet and the cell can also be placed side by side either on one side of the space 14 of the rebate or above it.

 In fact, all the configurations are possible as long as it remains guaranteed that the logic unit 12, 13 is in the first state when the window 10 has returned to the rebate 11, and is in the second state otherwise.

 To preserve the general character of the invention, the arrangement visible in FIG. 1 constituting only one possible embodiment, it will be said below that the means generating the magnetic field, that is to say the magnet 12, and the magnetic field detector means, that is to say the Hall effect cell 13, are arranged close to one another.

 The Hall effect cell is connected to an operating device not shown in FIG. 1 via three wires, the first of which is connected to the electrical ground, the second of which is connected to a positive supply voltage, and the third of which is brought to a voltage equal to said positive supply voltage when the logic unit 12,13 is in the first state and is brought to zero voltage when the logic unit 12,13 is in the second state .

 This third wire therefore delivers a signal which is representative of the state of the logic unit 12, 13. This signal is therefore representative of the position of the window 10 with respect to the portion of the rebate in which the device for detecting the position of the window thus produced is disposed.

 It is also possible to envisage using several devices for detecting the position of the glass, by placing them at several determined locations on the rebate so as to provide a plurality of signals representative of the position of the glass relative to the rebate of the window. door.

 In Figure 2 (a), there is shown in section another embodiment of the means for ensuring the conduction of a magnetic field which bore the reference 15 in Figure 1. In Figure 2 (a) this means consists by a metal part 16 which is held by clipping on the end of the glass 10. The metal part 16 can also be held by gluing on the glass, or both by clipping and gluing. The length of this mechanical part 16 along the axis perpendicular to the plane of Figure 2 (a) is variable and is only determined by the fact that it must be sufficient to ensure the conduction of the magnetic flux which is required to make switch the logic unit 12,13 from one state to another.

 The advantage of this embodiment is that it makes it possible to carry out the invention without the need to metallize the window, which has an undeniable advantage in cost and simplicity. In particular, this embodiment makes it possible to apply the principle of the invention to vehicles already in service since it can be mounted on a conventional window glass as found today on all vehicles.

 In Figure 2 (b), there is shown a third embodiment of the invention, suitable for the use of a window comprising at least two plates 10a and 10b of transparent material such as glass or plastic for example , according to the principle of double glazing known in other fields than the automotive field. In this embodiment, the means for ensuring the conduction of the magnetic field consists of a metal part 17 or at least made of any material conducting the magnetic flux such as ferrite or glass or doped plastic, or even a doped resin.

 According to an essential aspect of the invention, this piece 17 conducting magnetic flux is a piece ensuring the maintenance in position of the glass plates 10a and 10b, so that they are spaced from one another by a determined distance.

 In one possible embodiment, this part therefore extends over the total periphery of the window.

The essential advantage of this embodiment of the means for ensuring the conduction of a magnetic flux is that the conductive part 17 is a part already present in the glass, which does not require a specific treatment of the latter or when adding an additional room.

 A device for detecting the position of the window incorporating the logic unit 12, 13 and the means for ensuring the conduction of the magnetic flux according to one of the embodiments described can be placed in the upper rebate of the door so as to detect the window in the closed position, closed meaning here completely closed. However, it can also be used in the side rebate of the door so as to detect any intermediate position of the window between the fully open position and the fully closed position.

 In Figure 3, there is shown a diagram of a window regulator system incorporating a pinch protection device proceeding from the principle of detecting the position of the window as described above.

 Indeed, the door 31 is equipped with a window 10 and includes a device 33 for detecting the closed position of the window as previously described.

 This device 33 for detecting the closed position of the window comprises in particular the logic unit 12, 13 and the means for ensuring the conduction of the magnetic flux 15.

 The logic unit 12, 13 is connected to the ground Gnd of the vehicle and to a positive supply voltage Vcc such as a regulated voltage coming from the vehicle battery. In addition, the logic unit is connected via its third wire to a first input O / F of a control circuit 35. As has been said, the logic unit 12, 13 supplied by this wire a binary signal such as a voltage equal to the positive supply voltage Vcc when it is in the first state a zero voltage when it is in the second state.

 In other words, the input O / F receives a voltage equal to the positive supply voltage Vcc when the window is closed and a zero voltage otherwise.

The control circuit 35 also has three inputs A, B and C to which is connected a control button 150 actuable by the user. This control button 150 has three positions
- a middle position, or zero position, for which two contacts 151 and 152 are open
- an up position for which the contact 152 is open, and the contact 151 is closed bypassing the inputs A and B of the control circuit 35 to which it is connected
- A lowering position for which the contact 151 is open and the contact 152 is closed bypassing the inputs B and C of the control circuit 35 to which it is connected.

The control circuit 35 has four outputs on which it delivers control signals E1, E2,
E3 and E4 which are applied to a bridge of transistors 41, 42, 43 and 45 for controlling an electric motor 40 as is well known to those skilled in the art, so as to rotate the electric motor 40 in one way or the other.

 In a preferred embodiment, the transistors 41 and 42 are bipolar transistors of the PNP type and the transistors 43 and 44 are bipolar transistors of the NPN type.

 The electric motor 40 mounted in the transistor bridge is the drive motor for the window 10.

 The emitters of transistors 43 and 44, which are interconnected, are also connected to ground through a resistor R. Whatever the direction of the current flowing in the motor, that is to say also regardless of the state from the transistor bridge, the current flowing in the resistor R, denoted Imot in FIG. 3, is equal to it in intensity.

 The point common to the two emitters of transistors 43 and 44 is also connected to a MOT input of the control circuit 35, in order to measure the voltage present at this point.

 In a preferred embodiment of the invention, the control circuit 35 is a microcontroller, the MOT input of which is an analog type input connected to an analog / digital converter internal to the control circuit 35 and not shown in FIG. 3 .

 The measurement of the voltage taken at the point common to the two emitters of the transistors 43 and 44 is also a measurement of the current Imot since it is proportional to this voltage, the proportionality factor being equal to the value of the resistance R (law d 'Ohm).

 The control circuit 35 therefore has information on the value of the motor current Imot.

 We will now describe the operation of this control circuit 35.

When the window is initially lowered, the logic unit 12, 13 is in the second state defined above, the window 10 not having entered the rebate of the door 31, and the device 33 for detecting the position of the glass delivers a signal in the low logic state on the input O / F of the control circuit 35. When the user actuates the control button 150 in the upward direction, the contact 151 closes and the inputs
A and B of the control circuit 35 are short-circuited.

 The control circuit 35 then delivers control signals E1, E2, E3, and E4 so as to rotate the motor 40 in a first direction intended to raise the window. For example, the control signals E1 and E3 are brought to the high logic state so that the transistors 41 and 43 are conducting, and the control signals E2 and E4 are brought to the low logic state so that that the transistors 42 and 44 are blocked.

 During this operation, the motor current Imot is measured, indirectly, as has been said above, by measuring the voltage across the resistance R.

When the value of this current passes above a threshold constituted by a first predetermined value, corresponding to a maximum permissible rise in the motor current Imot and recorded in a first memory of the control circuit 35, the latter performs the following test
- if the signal supplied on the input O / F by the device for detecting the position of the window has passed to a high logic state, that is to say if the window has returned to the rebate, then this means that the elevation of the motor current Imot is due to the arrival of the window 10 in high abutment in the rebate of the door 31 and that everything is in order: the control circuit 35 therefore brings back all the control signals El,
E2, E3, and E4 in a low state so as to cut off the power to the motor
- if on the contrary the signal supplied on the input
O / F by the window position detection device remains in the low logic state, i.e. if the window has not entered the rebate, then this means that the rise in the motor current Imot is due to the presence of an obstacle on the path of the window 10: the control circuit 35 therefore reverses the state of the control signals El, E2, E3, and E4 so as to control the rotation of the motor 40 in the direction reverse to lower the window in order to clear said obstacle.

 Said first predetermined value of the motor current Imot, recorded in said first memory of the control circuit 35, defined above as corresponding to a maximum admissible rise in the motor current Imot, is determined on the one hand as being less than the value of the current Imot producing damage or even destruction of the engine, and on the other hand as being significant of a pinch of such intensity that it can be dangerous for the Man if the pinched obstacle is a finger or the head of a child.

 When the window is initially closed, that is also when it has entered the rebate, the logic unit 12, 13 is in the first state and the device 33 for detecting the position of the window delivers a signal to the high logic state on the O / F input of the control circuit 35. When the user actuates the control button 150 in the direction of descent, the contact 152 closes and the inputs B and C of the control circuit 35 are short-circuited.

 The control circuit 35 then delivers control signals E1, E2, E3, and E4 so as to rotate the motor 40 in a first direction intended to lower the window. The control signals E1 and E3 are brought to the low logic state so that the transistors 41 and 43 are blocked, and the control signals E2 and E4 are brought to the high logic state so that the transistors 42 and 44 are on.

In a possible embodiment of the invention, if during this operation, the motor current Imot which is measured passes above a threshold defined as a second predetermined value, corresponding to a maximum admissible rise in the motor current Imot and recorded in a second memory of the control circuit 35, while the signal delivered on the input O / F by the device for detecting the position of the window 33, is not returned to the low logic state, it is that is to say the window has not left the upper rebate of the door, the control module 35 returns all the control signals El, E2,
E3, and E4 in the low state so as to cut off the power supply to the motor.

 Indeed the fact that the window does not leave the upper rebate of the window when the motor is actuated to lower it means that the window is blocked, for example by frost, in the upper rabbet of the door. It is therefore necessary to cut off the power to the electric drive motor 40 so as not to damage it.

 Therefore, said second predetermined value of the motor current Imot recorded in said second memory of the control circuit 35, defined above as corresponding to a maximum admissible rise in the motor current Imot, is determined to be less than the value of the current Imot causing damage or even destruction of the engine.

Claims (12)

 1. Device for detecting a position of an opening leaf of a motor vehicle such as a window driven using an electric motor, characterized in that it comprises  - at least one means for generating (12) a magnetic field, disposed in the rebate (11) of the door (31)  - at least one means (13) for detecting a magnetic field, disposed in the rebate of the door near said generation means (12), these two means constituting a logic unit (12-13) which can take a first or a second state depending on whether the magnetic field generated by the generation means is detected or not by the detection means  - At least one means (15) for ensuring the conduction of a magnetic flux, carried by the glass and adapted to tilt said logic unit (12-13) from said first state to said second state or vice versa, depending on the position of the glass .  2. Device according to claim 1, characterized in that said means for generating (12) a magnetic field is a magnet.  3. Device according to claim 1, characterized in that said means for detecting (13) a magnetic field is a Hall effect cell.  4. Device according to claim 1, characterized in that the means (15) for ensuring the conduction of the magnetic flux comprises a conductive layer obtained by metallization of the surface of the end of the glass.  5. Device according to claim 4, characterized in that the conductive layer covers the upper surface of the window (10) and descends on each side of the latter by a determined length, so that in a cutting plane perpendicular to the plane of the window, the means (15) for ensuring the conduction of the magnetic flux has the general shape of an inverted U.  6. Device according to claim 1, characterized in that the means for ensuring the conduction of the magnetic flux comprises a part (16) made of a conductive material of magnetic flux such as a metal part, which is clipped or glued to the end of the glass (10).  7. Device according to claim 1, characterized in that, according to the principle of double glazing, the glass comprises two plates (10a, 10b) of transparent material such as glass or plastic, these two plates (10a, 10b) being maintained spaced from each other by a part (17) made of a magnetic flux conducting material such as a metal part, which contributes to the means for ensuring the conduction of the magnetic flux.  8. Pinch protection device for a system for automatically closing the doors of a vehicle, such as door windows, of the type comprising a means for detecting mechanical resistance to the progress of the window, characterized in that it further comprises a device for detecting (33) the closed position of the window according to one of the preceding claims, which is associated with said means for detecting a mechanical resistance to the progress of the window in order to be able to distinguish a real situation pinching of a window position in high stop.  9. Device according to the preceding claim characterized in that the means for detecting a mechanical resistance to the progression of the window comprises a means of monitoring (R, 35) of the current flowing in the armature of the motor, and a means of comparison of this current with a predetermined threshold.  10. System for electrically closing the openings of a vehicle, characterized in that it comprises a pinch protection device according to claim 8 or claim 9.  11. Method for controlling an electrical closing system as defined in the preceding claim, characterized in that, starting from an initial situation where the window is lowered, and where the motor is controlled to turn in a first direction intended to raise the glass, it includes the following steps  a) detection of the value of the motor current  b) comparison of this value with a first predetermined threshold value  c) then, if the value of the motor current is greater than said first predetermined threshold value, detection of the position of the window,  otherwise, repeat steps a) and b)  d) if the window has not returned to the upper rebate of the door, then modification of the engine control so that its direction of rotation is reversed to bring the window down  e) if the window is retracted into the upper rabbet of the door, the engine control stops.  12. Control method according to the preceding claim, characterized in that, starting from an initial situation where the window is closed, that is to say also re-entered in the upper rebate of the door, and where the motor is controlled to turn in a second direction intended to lower the window, it includes the following steps  a) detection of the value of the motor current  b) comparison of this value with a second predetermined threshold value  c) then, if the value of the motor current is greater than said second predetermined threshold value, detection of the position of the window  d) if the window is in the closed position, the engine control stops and a blocking signal is produced.