RU2303706C2 - Engine electric starting system - Google Patents

Abstract

FIELD: transport engineering; electric starting of engine.

SUBSTANCE: proposed electric starting system of engine contains storage battery, ignition and starter switch, energy storage capacitor, diode, starter switch-on relay and electric starter. To provide delay of energy supply to starter supply circuit from energy storage capacitor the following devices are installed additionally: diode, relay to connect energy storage capacitor, voltage divides limiting current at comparator inputs, time setting chain consisting of capacitor and resistor, comparator connected by one of its inputs to said chain and by other input, to storage battery to provide comparing of voltage across both inputs, and power transistor controlled by signal from comparator output. Said power transistor controls relay connecting energy storage capacitor to starter.

EFFECT: improved reliability of starter operation by delaying support of energy from storage capacitor, prevention of impact loads in engagement of starter drive pinion and flywheel rim.

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Description

The invention relates to the field of electrical equipment for automotive vehicles, in particular to a system for electric starting of an engine.

A known system of electric starting the engine, containing a battery, an ignition switch and a starter, a starter relay and an electric starter [1].

The disadvantages of this system, containing the battery, the ignition switch and starter, starter relay, electric starter, are the low specific energy and power of the battery, as well as the duration of its charge. In addition, with decreasing ambient temperature, the internal resistance of the electrolyte increases significantly, and at temperatures below -20 ° C the battery becomes inoperative [2].

This leads to the fact that the speed of the crankshaft when starting the engine becomes insufficient to ensure high-quality mixture formation and ignition of the working mixture.

Closest to the technical nature of the claimed invention is an electric starter engine starting system containing a battery, ignition and starter switch, capacitive energy storage, diode, starter relay and electric starter [2].

This system allows for reliable start-up at low temperatures due to the fact that drives with relatively low specific energy have high specific power. The charge and discharge time of capacitive energy storage is determined by the parameters of the charging and discharge circuits. They are able to quickly charge, accumulate and give energy. The given energy in a short period of time allows the electric starter to develop significant power and crank the crankshaft with a high starting frequency, thereby increasing the reliability of starting the engine. The positive characteristics of capacitive energy storage are: superiority in capacity, power and weight over batteries; low dependence on ambient temperature; high service life.

This system allows you to rotate the motor shaft with a high starting frequency even with a discharged battery. The disadvantage of this system is that when the starter is switched on, dynamic loads on the drive gear increase, which take on an impact character. Due to the presence of gaps not selected at the moment the electric motor is turned on, the starter drive and the large inertia of the flywheel cause significant shock loads, which lead to breakdowns of the starter drive and the flywheel teeth.

The technical result is aimed at improving the reliability of the starter, by delaying the supply of energy to it from the energy storage device and eliminating shock loads in engagement of the starter drive gear with the flywheel crown.

The technical result is achieved by the fact that in the electric start-up system of the engine, comprising: a battery, an ignition and starter switch, a capacitive energy storage device, a diode, a starter ON relay and an electric starter, to additionally provide a delay in supplying energy to the starter power supply circuit from the capacitive energy storage device : diode, relay for connecting the energy storage device, voltage dividers limiting the current at the inputs of the comparator, a timing chain consisting of a capacitor and a resistor, com a parator, connected by one of the inputs to this circuit, and the other to the battery in such a way that the voltages at both inputs are compared, and a power transistor controlled by the signal from the output of the comparator, and the power transistor controls the relay connecting the energy storage device to the starter.

Distinctive features of the prototype is that in the system of electric start-up of the engine, to ensure a delay in the supply of energy to the starter's power supply circuit from the capacitive energy storage device, the following are additionally installed: diode, relay for connecting the energy storage device, voltage dividers that limit the current at the inputs of the comparator, timing circuit, consisting of a capacitor and a resistor, a comparator connected by one of the inputs to this circuit and the other to the battery in such a way that a voltage comparison is carried out s on both inputs, and a power transistor controlled by a signal from the comparator, wherein the power transistor controls the relay to connect the energy storage starter.

The proposed circuit of the electric start system is presented in the diagram.

The system contains a starter M, a battery GB, a switch for devices and a starter SA1, a capacitive energy storage C1, a starter relay KV1, a relay for connecting a capacitive energy storage KV2, voltage dividers consisting of resistors R2, R3, R4 and R5, R6, R8, as well as resistor R7, resistor R1 and diode VD1 of the charging circuit of drive C1, comparator DA, a parametric stabilizer designed to protect the circuit from overvoltage in the on-board network, consisting of a Zener diode VD2 and resistor R7, which is simultaneously part of the timing chain with cond nsatorom C2, a resistor R9 load comparator DA, the resistance R10 the base of transistor VT, VT power transistor and a diode VD3, providing discharge storage capacitor C1 only via the starter motor M.

The system operates as follows. The capacitor C1 is charged from the GB battery through the charging circuit of the capacitive energy storage device - resistor R1 and diode VD1. When the instrument switch and starter SA1 are moved to the second non-fixed position, the starter relay KV1 is activated and voltage is applied via the closed contacts KV1.1 to the starter. The starter drive is engaged by the engagement mechanism without impact loads with the flywheel crown (not shown in the diagram). With the inclusion of a starter, the terminals of the comparator DA are supplied with voltage through voltage dividers R2, R3, R4 and R5, R6, R8, taking into account the voltage drop across the resistor R7. In this case, from the moment the starter M is turned on, the capacitor C2 is charged along the timing chain. The magnitude of the current voltage value is determined by the dependence [3].

where U _{with the} voltage of the capacitive energy storage, V;

U _b - battery voltage, V;

R7 - resistor, Ohm;

C2 is the capacitance of the capacitor, f;

t is the delay time, s.

This circuit causes a voltage equalization delay on the inverting and non-inverting inputs of the comparator DA. This ensures that the output of the comparator lacks a control signal based on the transistor VT. No current flows through it during the charging of capacitor C2, and the contacts of the relay KV2.1 are in the open state, the capacitive storage is disconnected from the starter motor.

When the capacitor C2 is charged, the voltage at the inputs of the comparator DA is equalized and a high voltage level appears to open the VT transistor, the current flows through the relay KV2, its contacts close and the drive is discharged through the starter M. The discharge of the capacitor C1 through the included starter increases the torque moments on the armature shaft and increases the engine speed at start-up.

A comparative analysis shows that the differences associated with the delay in connecting the capacitive energy storage device to the starter are novel, have a set of features that allow to obtain a positive effect, which consists in reducing the dynamic loads on the starter and engine flywheel.

The use of the claimed invention allows to delay the connection of a capacitive energy storage device to the starter, significantly reduce dynamic loads at the moment of gearing of the starter drive gear with the engine flywheel, and thereby increase the reliability of the electric starter starting system.

Information sources

1. Akimov S.V., Borovskikh Yu.I., Chizhkov Yu.P. Electrical and electronic equipment for cars. - M.: Mechanical Engineering, 1988.

2. Fesenko M.N., Chizhkov Yu.P. Capacitive energy storage in the electrical equipment of vehicles // Truck @. - 1999. - No. 8. - C.11-15.

3. Borisov Yu.M., Lipatov D.N., Zorin Yu.N. Electrical Engineering - M .: Energoatomizdat, 1985.

Claims (1)

An electric starter engine starting system comprising a battery, an ignition and starter switch, a capacitive energy storage device, a diode, a starter activation relay and an electric starter, characterized in that it further includes a diode, an energy storage connection relay, voltage dividers limiting the current at the comparator inputs , a timing chain consisting of a capacitor and a resistor, a comparator connected by one of the inputs to this chain, and the other to the battery in such a way that tsya comparison voltages on both inputs, and a power transistor controlled by a signal from the comparator, wherein the power transistor controls the connection of the power storage unit to the starter relay.