CS223364B1 - Connection for overload protection of the electric starter of the internal combustion engine - Google Patents

Abstract

If the key of the electric starter switch box is in the start position for too long even after the combustion engine has been started, the starter will suffer mechanical and thermal wear and overload of the power source, usually the battery. This causes malfunctions and shortens the service life of starters and batteries. The purpose of the invention is to limit the flow of current to the starter input of the starter for the necessary time, independent of the person performing the start. * In the device according to the invention, a relay contact (3) is connected between the contact (1) of the electric starter switch box (2) and the control input of the electric starter (2), the winding of which is connected to the output of the timing circuit (4). After a preset time has elapsed, the device switches off the current supply to the control input of the electric starter. A new start is possible after returning the key of the electric starter switch box to the zero position. The invention is particularly suitable for motor vehicles in driving schools, on which pupils learn to start an internal combustion engine without the direct supervision of a teacher.

Description

223364

BACKGROUND OF THE INVENTION The invention relates to a circuit for protecting the overload of the electric starter of a combustion engine.

This protection comes into play in particular in driving driving lessons when students learn to drive a car engine in an unattended coach. Pupils leave the ignition key in the starter position too long after the engine has been started. There is a mechanical thermal wear of the electric trigger, and at the same time the power supply, usually the accumulator, is overloaded. As a result of overloading, there are frequent failures on the electric actuators, whereby the service life is very short, despite the need for frequent repairs. Vehicle lockout for transport time reduces the time for efficient vehicle use.

It is known to switch off the electric starter of the relay contacts which is actuated by the voltage of the dynamo or alternator driven by the lowered motor at certain speeds. The advantage of this device is that the switch-off point of the electric starter is not unambiguously defined, and the electric starter can be switched on again when the engine speed drops. In the event of failure or exhaustion of the fuel, the electric starter does not switch off at all.

These drawbacks are eliminated by the connection according to the invention, in that a relay contact is connected between the switch contact of the electric starter and the control input of the electric starter, the winding of which is connected to the output of the timing switch circuit.

By means of the connection according to the invention, the function of the electric starter independently of the pupil's activity is limited in time. The wiring ensures that the motor starter is switched off independently of the pupil's activity if the key switch key is kept in the starter position for longer than the specified time. There is thus no unwanted heating of the electric starter, thus reducing the current flow from the power supply, reducing the failure of the electric starter and extending its life. An exemplary embodiment of an overload protection circuit of an electric starter of an internal combustion engine is shown in the drawing, in which FIG. 1 shows a schematic diagram of an apparatus according to the invention and FIG. In parallel to the power supply 16, typically a battery, a timing circuit 4 and a trigger circuit 3 of the relay connected in series with the electric solenoid 2 are connected via a switch box contact 1 of the electric starter 2. .

A separate timing circuit input 4 forms a separate 5-voltage stabilizer input coupled to conductor 12 connecting the contact 1 of the switch box of the electric starter 2 to the relay contact 3. Common input and stabilizer output S voltage is connected by a common 1S device wire. The separate output and the common input and output of the voltage stabilizer 5 are connected to each other by a serial circuit formed by a timing resistor 6 and a timing capacitor 7. The central circuit center point 8 is connected by a discharging diode 13 to a separate voltage stabilizer input 5 and directly with the control input 17 of the Schmitt flip-flop 10, the input of which is connected to a separate output of the voltage stabilizer 5, the common input and output 9 of which are connected to the common conductor 15 of the device and whose separate output, which forms simultaneously the separate output of the timing circuit 4 is coupled to the winding 11 of the relay. A discharge resistor 14 is connected between a separate voltage stabilizer 5 and a common device conductor 15. The amplifier may be provided as required between the Schmitt flip-flop 10 and the relay 11. The relay solenoid 11 is mechanically coupled to the relay contact.

An apparatus having an earthed negative supply power supply field 16 has been described, whereby the conductor 15 of the device is connected to the negative pole of the power supply 16 and the conductor 12 connecting the contact 1 of the switching actuator 2 to the contact 3 of the relay is connected to the positive pole of the solder source 16. In the case of the grounded storage pole of the voltage source 16, the discharge diode 13 will be polarized in the opposite direction to that shown in FIG.

The wiring function of the invention is as follows. When the ignition key of the electric starter 2 is turned into the starter position, the contact 1 of the electric starter switch box 2 is closed and the relay contact 3 from the power supply 16 is fed through both contacts to the electric actuator control magnet. 2, bringing the setento into operation. At the same time, the current flows into the voltage stabilizer 5. The voltage stabilizer 5 is charged by the timing condenser 7 via the timing resistor 6. If the ignition key of the electric starter 2 is held in the start position for too long, the voltage on the timing condenser 7 exceeds the input voltage level required for flipping the Schmitt flip-flop. This will tilt, as a result, the contact 3 will open and remain open when the key of the switchgear of the electric starter 2 is in the starting position. If the contact of the electric starter box 2 is closed, the current flow to the timing circuit 4 is interrupted, the timing capacitor 7 is interrupted.

Claims (2)

223364 5 6 is discharged through discharge diode 13 and discharge resistor 14, and timing capacitor 7 is prepared for a further cycle of operation. The time after which the electric actuator 2 is switched off even if the pupil keeps the switchgear key of the electric actuator 2 in the start position is determined by the voltage needed to flip the Schmitt tilting circuit 10, which evaluates the voltage on the timing capacitor 7, and the size of the timing resistor 6 and the timing condenser 7. pRedmEt 1. An overload protection circuit for an electric starter motor, characterized in that a relay contact (3) is connected between the electric starter switch contact (1) and the electric starter control input (2); See (11) is connected to the output of the timing circuit (4). 2. Connection according to claim 1, characterized in that the separate input of the timing circuit (1) (4) constitutes a separate stabilizer input (5) voltage connected to the conductor (12) connecting the contact (1) switch boxes of the electric actuator (2) with the contact (3) the relay, the common input and output of the voltage stabilizer (5) is connected to the common conductor (15) and the separate output and the common input and the invention are connected by a serial circuit formed by a timing resistor (6) and a timing condenser (7) ), wherein the serial point (8) of the serial circuit is connected via a discharge diode (13) with a separate voltage stabilizer input (5) and directly to the control input (17) of the Schmitt flip-flop (10), whose supply input is connected to a separate stabilizer output (5) the voltage whose common input and output (9) is connected by a common conductor (15), the output of the Schmitt flip-flop (10) constituting a separate timing circuit output (4) is connected to the winding (11) of the relay, while the discharging resistance (14) is connected to the inter-independent voltage stabilizer input (5) and the common conductor (15). the voltage stabilizer (5) step is one sheet of drawings i