SE436588B - CLUTCH DEVICE FOR CONTROL OF AN ELECTRIC DOOR LASER HEATING DEVICE - Google Patents

Description

The object of the invention is to further develop the known devices and to provide a control by means of electronic coupling means, which for protection against unauthorized connection of the door lock heating device only when multiple operating the door latch within a predetermined time period. the door lock heating device and disconnect again after a predetermined time and thereby prevent damage to the door lock, the heating element and the vehicle's battery as a result of overheating and incorrect operation of unauthorized persons.

This is advantageously achieved by the invention in that the door lock contact together with a temperature sensor controls monostable time control means, which in multiple operation of the door latch within a predetermined time interval and at temperatures below or around the freezing point switch on the door lock heating device during a certain first period. timer means triggered during the first operation of the door lock switch and during a certain period of time released; a second monostable timing means with delay, which second timing means is triggered by an additional door lock contact pulse within the triggering time of the first control means for switching on the electric door lock heating device.

The coupling according to the invention has the hard advantage that it has a simple construction and can be manufactured at low cost and thus enables economical mass production. During normal opening of the door by a single operation of the door latch and at the temperature over-freezing point, the door lock heating device will not be switched on. Only with multiple maneuvering of the door latch shortly after each other within a predetermined time does the current flow from the vehicle's battery through the door lock heating device, if the temperature is below or around the freezing point. Repeated tripping of the heating device by unauthorized persons, for example by children playing, is prevented by means of the coupling so that the battery is not discharged. Nor can the door lock overheat due to incorrect operation. Contact connections of the door lock contact do not affect the coupling, which is why no coupling technical measures are required to suppress the impulses triggered by the contact connections.

Advantageous further developments of the invention appear from claims 2-5.

The invention is explained in more detail below with reference to the accompanying drawing, which illustrates an exemplary embodiment.

Fig. 1 shows a block diagram of a control device for an end door lock heating device; Fig. 2 shows an embodiment of a coupling which is provided by simple means; and Fig. 3 shows a pulse diagram for the coupling according to Fig. 2.

Fig. 1 schematically shows a door lock switch 1, a monostable multivibrator 2, a delay element 3, an AND gate 4, a temperature sensor 5, a second monostable multivibrator 6, a switching transistor 7 and a heating resistor RH for the door lock heating device.

The AND gate only transmits an impulse for switching on the heating device RH, if its three input lines 15-17 have an H level. According to Fig. 2, two timing controllers 20,21 as monostable multivibrators connected timers are connected to each other via a capacitor C3 and each consists of two comparators 22,23 resp. 14, 25, which are connected to an SR flip-flop 26 resp. 27. The pulse length of the pulses generated by each flip-flop is set by means of the RC circuits R1, C1 and

R2, C2 30 and a resistor R5 connected, which together with a temp. At the output of the first timer 20, a diode temperature-dependent resistor RT forms a voltage divider for the capacitor C3. The load resistance of the capacitor C3 is denoted by R3.

At the output of the second timing means 21 are the switching transistor 7 and the heating resistor RH for the door lock heating device.

The pulse diagram according to Fig. 3 shows the voltage profile in the points a, b, c, d and e of the coupling in Fig. 2, namely for temperatures below and around the freezing point and for temperatures above the freezing point, the pulse length at the output of the first timer 20 ( point b) amounts to about 2 s, while the pulse length at the output of the second timer 21 (point c) amounts to about 60 s. The function of the coupling according to the invention will now be described in more detail with reference to the pulse »diagram according to fig. 3. When the door lock switch 1 is open, point a lies above the resistor R6 at positive potential. Diode 32 is in the blocking direction relative to this potential, and through Re permanently, point a is applied via this contact to ground potential. no current flows. If the door lock switch 1 is now closed for a short time, the time control means 20 is triggered, so that a rectangular pulse with a duration of about 2 s is generated at its output b.

The duration of the pulse is determined by the RC circuit R1, C1. At the same time as the door lock switch 1 is closed, the point c is connected to earth via the diode 32 and the RAW point. The point d is above the resistor R3 at n positive potential, so the capacitor C3 is charged via R3 and RA to the entire potential difference between plus and ground.

If now the door lock contact 1 is released, i.e. reopens, the grounding of point c over R4 disappears. Point c then lies on a positive voltage across the output of the first timer 20, the diode 30 and the resistor R5. The level of the positive voltage is determined by the voltage divider formed by R5 and the temperature-dependent resistor RT. The discharge time of the capacitor C3 is determined essentially by the time constant R5, C3 and preferably amounts to about 30 ms. This time of about 30 ms is necessary to suppress the harmful effect of sockets on the door lock switch 1.

If now the door lock contact 1 is closed a second time within the duration of the pulse given by the control means 20, the point is added; again at ground potential across RA and diode 32. Thereby up; - 10 15 20 25 30 35 8202042-1 5 stands in point d a voltage drop in the negative direction across capacitor C If this voltage drop is so large that it reaches below the other the trigger level 21 of the timer 21, the timer 21 is triggered and an impulse arises at its output e for about 60 s, which is determined by the timing circuit R2, CZ, which via the switching transistor 7 switches on the heating resistor RH to thaw the door lock. The resistor R5 is so dimensioned in relation to the resistor RT that at temperatures below and around the freezing point the voltage drop at point d falls below the trigger level of the second time control device 21, which level amounts to about one third of the supply voltage.

At temperatures above the freezing point, the resistor RT has a low resistance value, and the point c can after a first actuation of the contact 1 therefore only assume a small positive voltage, so that the voltage drop at point d upon re-actuation of the door lock switch 1 no longer reaches the timer 21. and no pulse is generated at point e, and consequently the heating resistor RH is not switched on either, as can be seen from the diagrams on the right-hand side in Fig. 3.

The temperature-dependent resistor is preferably built into thermal contact with the door lock. This avoids overheating of the door lock, since the temperature-dependent resistor only allows reconnection of the door lock heater if a cooling to the freezing point area has previously taken place, and the voltage drop at point d again falls below the trigger level.

If this were not possible for constructive reasons, it is also conceivable to separately heat the temperature-dependent resistor RT simultaneously with the door lock heating device, so that the renewed reconnection of the door lock heating device is allowed only after a safe cooling time.

Within the scope of the invention, it is also possible to control the duration of the heating pulse at point e depending on the temperature; In this case, the resistor R2 of the RC circuit for the second time control means is designed as a temperature-dependent resistor. The above description of the coupling constitutes only an embodiment of the invention, which, however, is not limited to this example. Thus, the person skilled in the art can, without departing from the inventive concept, carry out various modifications in the construction of the coupling, selection and placement of coupling elements, etc.

Claims (4)

8202042-1 'Jr P Ä T E N T K R A V 1. l. Coupling device for controlling an electric door lock heating device, in particular for motor vehicles, by means of a door lock switch operated by a door latch and time control means, which connects the door lock heating device for a certain period of time, characterized by a temperature sensor (RT) controls two monostable timer means (20, 21), which upon multiple operation of the door latch within a predetermined time interval and at temperatures below or around the freezing point switch on the door lock heating device (RH) for a certain period of time, the first monostable timer (20 ) is triggered during a first operation of the door lock switch (1) and for a certain period of time releases a second monostable timer (21) with delay, which second timer is triggered by a further door lock contact pulse within the trigger time of the first control member L (20) for switching on. of the electric door lock heater and (RH). 2. The coupling device according to claim 1, characterized in that the two timing means are interconnected via a delay device for suppressing contact nozzles of the door lock contact (1), which delay device consists of a voltage divider (R5, RT) and a capacitor (C3), the voltage divider (R5, RT) being connected to the output of the first timer (20) and its center point can be applied to ground potential via the door lock contact (1) and a diode (32), while the capacitor (C3) is located on the the trigger input of the second timer (31) and is connected to the supply voltage via a resistor (R3). Coupling device according to Claim 1 or 2, characterized in that the voltage divider (RS, RT) is temperature-sensitive in such a way that one or both resistors are temperature-sensitive. 82020424. 'B 1 Switching device according to Claim 1 or 2, characterized in that the resistor (R2) of an RC circuit (R2, C2) connected in front of the second time control means (21) is designed as a temperature sensor for temperature-dependent control of the door lock heating device (RH). ) switch-on time.