EP0327630A1

EP0327630A1 - Device for swivelling a motor vehicle mirror from a normal position to a non-dazzling position

Info

Publication number: EP0327630A1
Application number: EP88907069A
Authority: EP
Inventors: Willi KÜHN
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-08-13
Filing date: 1988-08-11
Publication date: 1989-08-16
Also published as: JPH01503618A; DE3727033C1; EP0303263A1; US4985667A; WO1989001428A1; KR890701391A

Abstract

A device for swivelling a mirror in or on a motor vehicle from the normal position (fully reflecting state T) to a non- dazzling position (partially reflecting state T) in the event of a dazzling beam from the headlights of the following vehicle, allowance being made for ambient glare (U), has a voltage source and a motor (M) the shaft (10) of which is connected via a tilting mechanism to the mirror and which is supplied by thyristors (T1, T2). The thyristors are controlled by transistors (TR1, TR2, TR3) with the aid of photodiodes or photoresistors (B, U) for dazzle and ambient glare. A bipolar rotary switch (DS) connected in series to the motor (M) cuts off the current through the motor after a given angle of rotation of the shaft, disconnects the previously conducting thyristor (T1 or T2) from the voltage source and switches it off. The tilting mechanism has a crank disk (11) driven by the motor with a crank pin (12) and a connecting rod (13) which is moved to and fro by the crankpin. The connecting rod is connected to the mirror and has an essentially elliptical opening (14) sur rounding the crankpin. The outer regions (15) on the major axis are associated with the switch region of the rotary switch (DS) and the outer regions (16) on the minor axis are associated with the normal and non-dazzling positions (V, T) of the mirror. A device for swiveling a mirror in or on a motor vehicle from the normal position (fully reflecting state T) to a non- dazzling position (partially reflecting state T) in the event of a dazzling beam from the headlights of the following vehicle, allowance being made for ambient glare (U), has a voltage source and a motor (M) the shaft (10) of which is connected via a tilting mechanism to the mirror and which is supplied by thyristors (T1, T2). The thyristors are controlled by transistor (TR1, TR2, TR3) with the aid of photodiodes or photoresistors (B, U) for dazzle and ambient glare. A bipolar rotary switch (DS) connected in series to the motor (M) cuts off the current through the motor after a given angle of rotation of the shaft, disconnects the previously conducting thyristor (T1 or T2) from the voltage source and switches it off. The tilting mechanism has a crank disk (11) driven by the motor with a crank pin (12) and a connecting rod (13) which is moved to and fro by the crankpin. The connecting rod is connected to the mirror and has an essentially elliptical opening (14) sur rounding the crankpin. The outer regions (15) on the major axis are associated with the switch region of the rotary switch (DS) and the outer regions (16) on the minor axis are associated with the normal and non-dazzling positions (V, T) of the mirror.

Description

Device for pivoting a motor vehicle mirror from a normal position into a dimmer position.

The invention relates to a device for pivoting a motor vehicle mirror from the normal position (fully reflecting state V) to a dipped position (partially reflecting state T) with excessive glare (B) by the headlights of a following one

Vehicle and taking into account disturbing ambient light (U), having a voltage source, a motor (M), the shaft (10) of which acts on the mirror via a tilting mechanism and which is fed via thyristors (T1 and T2), which in turn are supplied via Transistors (TR1, TR2 and TR3) with

Are controlled by means of photodiodes or resistors (B and U) for glare and disturbing ambient light.

Automatically adjustable interior rearview mirrors for motor vehicles are known (DE-OS 34 37 775). In the known interior rear view mirror, a mirror glass housed in a housing is pivoted from a normal position with high reflection into a dipped position with reduced reflection by means of an electric motor. Its drive shaft is connected to the mirror glass via a gear. The gearbox is a worm gear, through which the drive shaft is drive-connected to a shaft carrying switching cams. It is equipped with at least one eccentric partially connected, which is guided in the housing in a guide extending transversely to the axis of the shaft. In order to detect the influence of disturbing ambient light, an electrical bridge circuit is provided which feeds the motor by comparing the (electrical) lead light and ambient light signals and an amplifier. Neither the electronic circuit nor the drive mechanism meet the current requirements for pivoting devices for motor vehicle mirrors, since the electronic circuit only responds to the light ratio of glare to ambient light and because many mechanical parts have to be accelerated and braked to adjust the mirror, whereby It cannot even be achieved that the mirror is brought into its precise position, which is also due, among other things, to the trailing properties of the motor and the transmission, but also to the elongated hole through which the rotary movement is converted into a tilting movement becomes. In addition, the electronic circuit is extremely complicated and expensive. The invention has for its object to provide a device of the type mentioned in such a way that its electronic circuit responds to the absolute magnitudes of the incidence of light (glare, ambient light) and its mechanism consists of only a few and relatively small mechanical parts for pivoting the mirror .

This object is achieved with a device according to claim 1. Further developments of the device according to claim 1 are specified in the sub-claims.

A particular advantage of the invention is that a circuit has been implemented with a few electronic components that responds to absolute sizes, controls the motor so that it stops in stable end positions and even caster movements of the motor and the transmission cannot lead to the Mirror is adjusted ("fluttering" contributes to this by the transmission mechanism of the device according to the invention, by the rotary movements of the Motors can be converted into swivel or tilt movements.

The device according to the invention responds to a certain amount of light from glare and brings the mirror from the normal position (V) to the dipped position (T), unless a certain amount of light of ambient light is present at the same time. In this case, suitable amounts of light can be used for the response without the ratio of these variables to one another being important, as is the case with known bridge circuits.

An embodiment of the invention is explained below with reference to the drawings. 1 shows a circuit for the device according to the invention. Fig. 2 shows some parts of the tilting mechanism for the

Device according to the invention. 3 shows a sectional view according to III-III in FIG. 2. FIG. 1 shows an embodiment of a circuit according to the invention.

The circuit is connected to the positive pole and the negative pole of a DC voltage source, for example 12V DC voltage of a motor vehicle. The circuit can be switched on or off via a main switch HS, so that the device according to the invention can be switched off if an automatic adjustment of the mirror is not desired by the driver. A diode connected downstream of the main switch HS secures the circuit against swapping the connections.

M denotes a DC motor that acts on the adjustment mechanism for the mirror via a gear. Other drive options can be used instead of a revolution motor. It is significant that on the output part, here the output shaft, a rotary switch DS is arranged, which has two positions, T and V. A bipolar switch can be used for the present purpose, ie a switch that does not establish an electrical connection between the two contact pieces T and V when switching. Since the rotary switch DS and also the pivoting mechanism are arranged on the shaft of the motor, the one switch position, namely T, corresponds to the position of the mirror in which light falling on the mirror is only partially reflected. It is therefore the so-called dimming position of the

Rearview mirror. The position of the switch DS designated V corresponds to the normal position of the mirror, i. H. light falling on it is fully reflected.

In the circuit it can be seen that two current paths are available for the motor M, which drive the motor from one position to the other position, so the position T is assigned a thyristor T1 and the position V is a thyristor T2. If a current flows from the voltage source via the motor and the switch DS in its position T and via the thyristor T1, the motor M is set in rotation, it takes the switching part of the rotary switch DS with it and thus interrupts the current flow through the Motor M. In a corresponding manner, thyristor T2 ensures that the motor is rotated in such a way that rotary switch DS moves from position V to position T.

The thyristor T1 is driven by a transistor TR2, which is connected via a resistor (1?) To its anode and another resistor to its gate. Furthermore, a transistor TR3 is connected to the gate of the thyristor T1 via a capacitor C3. The base of transistor TR3 is connected to the negative pole of the voltage source via a capacitor C2.

The gate of thyristor T2 can be triggered via a transistor TR1. The base of the transistor TR1 is connected to the positive pole of the voltage source via a capacitor C1. There are also two diodes connected in series provided that are connected in parallel to the capacitor C1 to the emitter of the transistor TR ^' l.

The transistor TR1 is a pnp transistor, while the transistors TR2 and TR3 are npn transistors. The capacitors C1 and C2 have a capacitance of about 10 uF, the capacitor C3 35 JJF.

Light-emitting diodes LD1 and LD2 indicate the conduction states of the thyristors T1 and T2.

There are two elements labeled U and B in the circuit. These can be diodes that become conductive when light is incident. It can also be a so-called photoresistor, the resistance of which decreases to a low value when the light falls.

The element denoted by B is the element which responds to bleπ light, for example if a motor vehicle drives up too close from behind and / or has the headlights on.

The element labeled U responds to ambient light. This is light that falls into the car from the side, for example by driving past a street lamp, by lighting a lighter or even by daylight.

All in all, when the circuit is considered, it turns out that this is a logic evaluation circuit which only brings the motor and thus also the rotary switch DS into the T position when light falls on the diode B, but no light on the Diode U falls, ie when the driver is blinded by a subsequent motor vehicle when driving at night. Under all other conditions of incidence of light on the diodes U and B, the circuit should bring the motor and the rotary switch DS into position V or leave it there, ie the mirror is in its normal position, so that the incident light is fully reflected. Some operating states are explained below using the circuit. Starting from the state shown in FIG. 1, ie the switch DS is in the position T, in which the mirror only partially reflects incident light.

In this operating state, the thyristor T2 is switched through, the thyristor T1 is not, so that only the light-emitting diode LD1 lights up. In the switched-on state of the thyristor T2, its gate is at a high positive potential, so that the base of the transistor TR2 is also at a high potential via the corresponding connection, ie. H. transistor TR2 is conductive. When the transistor TR2 is conductive, the gate of the thyristor Tl is at negative potential, i. H. he cannot ignite.

If no light falls on the photodiode B, i. H. If the driver is not dazzled by a subsequent motor vehicle, the photodiode B is blocked and the base of the transistor TR2 drops to a low potential, so that the transistor TR2 becomes non-conductive. Then, however, the gate of the thyristor T1 can go to a high potential via the resistors shown, so that the thyristor T1 ignites. The diode LD1 goes out and the motor M receives current from the voltage source via the rotary switch DS. As a result, the rotary switch DS is brought into the switching position V from the position shown, i.e. H. the current through the motor M is switched off. In position V of the rotary switch DS, the mirror is in the normal position.

If ambient light falls on the photodiode U in the normal position of the mirror, it switches through, so that the base of the transistor TR1 goes to a high potential. In this state, however, the pnp transistor TR1 cannot switch on. As a result, the gate of the thyristor T2 is at a low potential, so that the thyristor T2 cannot fire.

If light falls on the photodiode B, it switches through. However, the transistor TR1 cannot switch through, so that again the thyristor T2 cannot ignite and ultimately the motor receives no current, so that the mirror in the normal position V remains.

A particular advantage of the switching of the device according to the invention lies in the way in which the previously conductive thyristor is switched off. This is due to the fact that the thyristors Tl and T2 are in a circuit which is interrupted by the rotary switch DS, i.e. the previously conductive transistor is disconnected from the voltage source by interrupting the connection of its anode to the voltage source via the switch DS, and the thyristor is thereby forcibly switched off.

The special case which occurs when the motor vehicle is stopped and the circuit is switched off is considered below, the mirror being in the T position. If the motor vehicle is then started again in daylight, it must be ensured that the mirror reaches position V immediately after starting.

That is, Immediately after switching on the circuit, the switch DS is in the T position. The photodiode U is switched through since it receives ambient light, but there is no connection to the positive pole of the voltage source because the DS switch is in the T position . The photodiode B is also conductive because daylight is incident. Correspondingly, the gate of the thyristor Tl is high, the thyristor Tl cannot ignite.

When the switch HS is inserted, the capacitor Cl is charged via the resistor (I ^). As a result, the base of the transistor TR1 is brought to a high potential, so that the transistor TR1 opens. As a result, the lower connection of the photodiode B can drop to a low potential, so that the transistor TR2 opens and the gate of the thyristor T1 reaches a positive potential. As a result, the thyristor T1 can ignite, feed the motor and bring the rotary switch DS into the V position. In this position, the thyristor T2 cannot fire because the photodiode U receives light and is therefore switched on has, although the switch DS is in the V position. This is because the base of the transistor TRl is at a high potential, so that the transistor TRl is open. As a result, the gate of the thyristor T2 is at a high potential, ie the thyristor T2 cannot ignite, the motor cannot run and the switch DS remains in the position V.

Starting from the position shown in FIG. 1, in which glare falls on the mirror, the case is considered when this glare is removed. The mirror should not abruptly return to the normal position, but this should be carried out with a delay of the order of approximately 1 second, which the circuit achieves as follows. (A setting element, e.g. a potentiometer, can be provided to set this period of time, so that individual adjustment to shorter or longer times is possible). So that the thyristor Tl can ignite, the capacitor C3 must first be charged. The capacitor C3 is connected to voltage via the conductive transistor TR3. After the capacitor C3 has been charged, when the ignition voltage at the gate of the thyristor Tl is reached, it becomes conductive and brings the motor and thus the switch DS into position V.

Simultaneously with the charging of the capacitor C2, the capacitor C1 is charged after the switch HS has been inserted. If C2 has reached a sufficiently high voltage, the transistor TR3 turns on, whereby the return delay is made effective by the charging of the capacitor C3. If the transistor TR3 is not turned on, the capacitor C3 cannot be charged.

The invention also ensures that the mirror is only tilted in the event of a long-term fault. If the photodiode B only briefly receives a strong light, then the thyristor T2 switches through, but the transistor TR2 has not yet switched because the gate of the thyristor T2 has an additional resistor is connected to the base of transistor TR2.

2 and 3 show some essential parts of the tilting elements for the device according to the invention, it is not a complete construction drawing, but merely the reproduction of some parts, the mode of operation of the tilting elements according to the invention to be able to explain.

The motor, not shown in FIG. 2, is provided with an output shaft on which a worm 10 is arranged. The worm 10 meshes with a worm gear toothing which is attached to the outer circumference of a crank disk 11. The crank disk 11 is fastened on a shaft 19, which in turn is supported in bearings 17 and 18. Outside the center of the crank disk 11, a crank pin 12 is provided which projects outward in the axial direction and is formed with a radially directed holding part 20 at its free end. The bracket part 20 is also attached to the shaft 19. In the space between the crank disk 11 and the holding part 20, a link 13 is arranged, which, as shown in FIG. 3 by a double arrow, can perform reciprocating movements. The associated guides and bearings are not shown. Likewise, the connection of the link 13 to the mirror is not shown. It should only be emphasized here that through the back and forth

Movement of the handlebar 13 of the mirror Schweπkbeweguπgeπ between its two positions V and T, the normal position or the fully reflecting position and the dimmed position or the partially reflecting position can perform.

The link 13 is formed with an essentially elliptical opening 14, in which the crank pin 12 can move in rotation. The opening 14 is formed with areas 15 of greater radial extent and areas 16 of smaller radial extent. In the regions 15, a partially circular bulge with a Radius can be provided, which is slightly larger than the diameter of the crank pin "12.

In the positions shown in FIGS. 2 and 3, the crank pin 12 is located in the upper region 16, this corresponds to the position V of the mirror.

In the figures, the rotary switch DS is not shown, which is attached to the crank disk 11, in such a way that it performs its switching functions when the crank pin is in the regions 15 of larger radial extensions.

Upon rotation of the Mo ^'tors the screw 10 and the crank disk 11 is rotated. As a result, the handlebar 13 initially moves relatively little. Where the Kurbe lzapfen ^'12 in the region 15 inside, the switch performs its switching operation and switches the Strom¬ inflow from the motor M. The motor performs a further movement, so that the crank pin 12 reaches the area 16 of the handlebar 13. 3, the handlebar 13 has been moved into its lower position, and in this position the mirror is in the semi-reflective position.

It can be seen that slight movements of the crank pin 12, whatever the cause of these movements may be, can hardly produce any back and forth movements of the link 13. As a result, the position of the mirror remains unchanged even if vibrations should be transmitted to the mechanism. This leads to a relatively stable mounting of the mirror in its two end positions. The end positions of the mirror can also be changed individually using mechanical or electronic means.

2, it can be seen that the crank disk 11 is supported in the immediate axial delimitation by the bearings 17 and 18 and the shaft 19. The

Bringing the bearings to the crank disk 11 leads to that the crank disc 11 and the crank pin 12 can not perform any tilting movements. In known tilting mechanisms, the part n corresponding to the crank disk 11 is supported on one side, which means that the tilting mechanism is relatively shaky and that these disturbing movements can also be transmitted to the mirror.

With the device according to the invention, interior mirrors and exterior mirrors can be adjusted automatically.

Claims

1. Device for pivoting a motor vehicle mirror from the normal position (fully reflecting state V) into a dipped position (partly reflecting state T) in the case of excessive headlights (B) by the headlights of a following vehicle and taking into account disturbing ambient light (U), Spannungs¬ comprising a source, a Mo ^~ or (M), the shaft (10) acting on the mirror via a Kipp¬ mechanism and which is fed via thyristors (Tl and T2), which in turn via transistors (TRI, TR2 and TR3 ) are controlled with the aid of phodiodes or resistors (B and U) for glare light and disturbing ambient light, characterized in that a bipolar rotary switch (DS) is connected in series to the motor (M), which follows the current flow through the motor interrupts a certain angle of rotation of its shaft, disconnects the previously conductive thyristor (Tl or T2) from the voltage source and switches it off, and that the tilting mechanism works eist: a crank disc (11) driven by the engine (M) with a crank pin (12) and a link (13) which can be moved back and forth by means of the crank pin (12), which is connected to the mirror and has an essentially elliptical shape , The crank pin (12) surrounding opening (14) is formed, the areas (15) of greater radial extent are assigned to the switching area of the rotary switch (DS) and the areas (16) of smaller radial extent are associated with the normal and the fading position (V and T) of the mirror .

2. Device according to claim 1, characterized in that parallel to the gate-cathode path of the motor (M) in the normal position (V) of the mirror driving thyristor (Tl, a capacitor (C3) and an npπ transistor (TR3) connected is whose base is connected to the cathode of this thyristor (Tl) via a further capacitor (C2).

3. Apparatus according to claim 2, characterized in that in series with the transistor (TRl) which controls the thyristor (T2) bringing the mirror into the dipped position (T), a parallel connection of two diodes (LD1 and LD2) on the one hand and one Capacitor (Cl) is provided on the other hand.

4. The device according to claim 3, characterized in that between the base of this transistor (TRl) and the rotary switch (DS) in its normal position (V) the element (photodiode or photoresistor) responding to the disturbing ambient light (U) - or with several spatially distributed elements - these elements (U) are switched.

5. The device according to claim 4, characterized in that the element responsive to ambient light (U) via the rotary switch (DS) is connected to the positive pole of the voltage source.

6. The device according to claim 2, characterized in that bearings (17 and 18) are provided in the immediate vicinity of the crank disc (11) or the crank (13).