SI23376A - Implementation of two-stage or soft start-up of internal combustion engine starter - Google Patents

Abstract

The invention relates to the implementation of a two-phase or soft start up of internal combustion engine starter. The invention improves the two-phase start-up system where during the first phase of the start-up tractive coil of electromagnetic switch is used as serial resistor of the motor assembly so that it can reduce tractive force of electromagnetic switch independently of holding force. By reducing tractive force of electromagnetic switch the hits of the pinion into the geared rim of the engine flywheel are reduced and consequently the damage of the face area of the both gearwheels is also reduced. By reducing tractive force in the case of "tooth to tooth" switching on the sliding conditions of the pinion teeth on the teeth of geared rim are improved. Both facts enable a smooth engagement of the pinion into the geared rim of the engine flywheel and prolongate the lifetime of both gearwheels.

Description

METHOD OF PERFORMANCE OF A TWO-STAGE OR SOFT START OF THE BURNER FOR INTERNAL COMBUSTION ENGINES

The object of the invention is a method of performing a two-stage or soft start of the starter for internal combustion engines. The invention belongs to the international patent classification F2N11 / 00.

The problem solved by the invention is the provision of a reliable and affordable two-stage system for switching on the starter for internal combustion motors by means of a special method of tying the windings of the starter solenoid switch. The two-stage or soft-start system is mainly used for higher-power starters above 5 kW to provide a longer starter drive sprocket and flywheel flywheel. The principle of operation of the system is that it allows the starter to operate with a rated power only when the starter sprocket of the starter is fully engaged with the toothed ring of the internal combustion engine.

The electric starter contemplated by the invention is a higher-power starter consisting of a motor part, a gearbox, a single clutch, a drive sprocket, an actuator lever and an electromagnetic switch. The electromagnetic switch consists of a pull and hold coil, a movable core and a mandrel on which the contact plate is mounted, a stationary contact pair, and various springs that return the movable parts to the basic - off position. The starter is attached to the internal combustion engine and is electrically connected to the starter switch in the driver's cab and to a battery pack as a source of electricity. When the engine start switch is switched on, ·· ·· ··· occurs.

axial displacement of the drive gear and engagement (gear) with the flywheel of the flywheel of the engine and then, with the motor operation of the starter, until the internal combustion engine is rotated. The motor part of the starter motor is a DC motor with serially coupled stator and rotor windings, providing the torque on the starter shaft required to rotate the internal combustion engine. The clutch on the shaft transmits torque only in the direction of the motor part of the drive gear and thus protects the motor part from destruction at a time when the internal combustion engine is already operating with its own drive and the drive gear is still in contact with the flywheel of the flywheel. After the engine start switch is switched on, the pull and hold coils of the solenoid switch are electrically powered, creating an electromagnetic force that moves the moving core to the center position of the magnetic field. Simultaneously with the displacement of the core, the drive gear is shifted to the gear flywheel of the internal combustion engine, while the contact plate moves towards the stationary contact pair, which in a certain position closes the battery - the motor part of the starter. When the contacts of the solenoid switch are concluded and the motor part of the starter motor starts to operate, the first stage is completed and the second stage of the starter operation begins. Due to the method of tying the solenoid windings, the electrical supply to the traction winding is interrupted when the ignition switch contact is closed, and only the retaining winding, which provides the force to hold the drive gear in contact with the flywheel gearwheel and hold the closed contact of the solenoid switch, remains electrically powered. The described condition is maintained until the end of the start, which is performed by switching off the start switch normally in the cab of the vehicle. The life of the starter depends, among other things, on the wear and damage of the starter sprocket gear teeth and the flywheel on the flywheel, which are generated during the start and run of the starter with rated power. During the teeth, the teeth are mostly damaged on the frontal surfaces of the teeth, while during the operation, the flanks of the teeth are mainly subject to wear.

In the normal starter startup or "direct" startup, the design of the starter startup mechanism is such that it permits the operation of the motor part at rated power even in situations where the starter sprocket is not sprouted - position "tooth to tooth" or not yet fully toothed the flywheel of the engine. This can lead to unwanted conditions that increase tooth wear and fracture. The first is that the starter drive sprocket remains in the "tooth-to-tooth" position, with the motor part already operating at rated power, resulting in heavy wear, the characteristic sound of metal rubbing against the metal and an increased likelihood of breaking. The second situation is when the drive sprocket does not fully engage and the motor part is already operating at rated power whereby the rated torque is transmitted over the reduced contact surface between the drive pinion gear teeth and the flywheel gear. This increases the likelihood of fracture and tooth wear. The problems described are compounded by the increase in starter power.

· · · · ·.

The disadvantages of the "direct" switching system mentioned above are solved by the "two-stage" or "soft" switching systems for which several solutions are known and in use. Known solutions solve the problem of "direct" startup by ensuring that the drive gear is rotated at a lower speed than the nominal speed during the first startup phase. Such rotation increases the likelihood that the gearwheel tooth finds a gap between the teeth of the flywheel of the engine flywheel, thus reducing the frequency of "tooth to tooth" states. Furthermore, the "two-stage" switching mechanisms are designed so that when the contacts are made in the solenoid switch, the drive gear is in perfect alignment with the teeth of the flywheel of the flywheel. There are also known solutions, especially electronic ones, in which the variable thrust of the traction winding regulates the thrust of the drive gear, such that the initial impulse required for the initial axial displacement is followed by a reduced force in the region of the gear wheel approximation to the flywheel and finally an increased force, which holds the drive gear in the end position until the start of the startup.

There are many known protected startup starter startup solutions, including older electromechanical ones such as US 2,542,712 awarded GMC in 1951, US 4,418,289 awarded Facet Enterprises in 1983, and newer ones using electronic solutions such as US 6,104,157 and US 6,308,674 awarded R. Bosch in 2000 and 2001, SI 20991 awarded to Iskra Avtoelektrika in 2003. Known solutions in use are based on electromechanical solutions.

Known electromechanical solutions differ in the manner in which they provide a suitable electrical current for powering the motor part of the starter in the first stage of start-up, as well as in different systems for detecting a failed start or a tooth-to-tooth condition and protecting the assembly in the latter case.

In the first stage of start-up, the motor part of the starter must be energized in such a way that it operates at reduced power, which requires a relatively high electrical current, usually from 200A to 450 A. The power can be done in three ways: by means of an additional stator winding, by means of a resistor and by means of a pull winding in the switch. The additional stator winding solution is design-intensive and increases the dimensions of the starter, so the known in-use solutions are based on a solution that uses a traction winding to prevent the motor part of the starter.

The block diagram of the known solution described is shown in Figure 1. The assembly consists of the motor part of the starter (1), solenoid switch (2) with pull (3) and holding (4) winding, additional relay (5), motor start switch (6) and rechargeable batteries (7) as sources of electricity. The power supply to the motor part (1) during the first start-up phase, when the contact of the solenoid switch (2) has not yet been concluded, is accomplished by means of an additional relay (5) which is supplied via the motor start switch (6). An additional relay is supplied when the start switch (6) is closed • · ·· ··· ...

(5), resulting in the contact of the relay (5), providing power to the traction (3) and coil (4) coils of the solenoid switch (2). electrical current flows through the retaining winding to the motor part of the starter (1). An adequate current size for the power supply of the motor part (1) with a power less than the nominal power is ensured by selecting the appropriate resistance of the traction winding (2). When the solenoid switch (2) is contacted, electricity flows only through the retaining winding (4), since both ends of the traction winding (3) are connected to the same electrical potential and the motor part (1) is supplied directly from the battery (7). and operates at rated power. The holding winding (4) holds the closed contact of the solenoid switch until the start switch (6) is closed. The magnitude of the current through the holding winding is determined so that the winding does not overheat and the holding force is provided by an adequate number of winding wrappers. After a successful start of the motor, the motor start switch (6) interrupts the supply of the auxiliary relay (5), which further interrupts the supply of the holding coil (4). As the contact of the solenoid switch (2) is closed at the moment, the traction (3) and the holding (4) windings are now energized, which are now connected in series. In order to break the contacts of the solenoid switch, the electromagnetic force of the coiled windings must be equal to or less than the forces of the spring which return the solenoid switch to its basic - off position.

This is ensured if both the drawbar (3) and the support winding (4) are wound in opposite directions and have the same number of wrappers.

The disadvantages of this system are three and are related to the fact that in the first phase of start-up, the motor part must be powered by a relatively high electrical current. This results in the first time that in order to protect the engine start switch, it is necessary to switch the starter on and off by means of an additional relay (5), which requires an additional element on the starter and increases the price, and secondly, due to increased electric current, electromagnetic forces are greatly increased, created mainly by the traction winding (3). Due to the increased pulling forces of the solenoid switch and, consequently, the drive gear thrust in the first phase of activation, two additional problems arise: the increased energy of the drive gear bumps against the flywheel gear wheel increases the damage to both gear teeth. Damaged gear faces and, at the same time, a large thrust of the drive gear in the case of engaging "tooth to tooth", make it difficult or impossible to slide the drive gear teeth through the teeth of the gear wheel to the position when the gearing can occur. Thirdly, due to the high electrical current through the traction winding, it is subjected to intense heating, which, if the tooth-to-tooth is switched on and the contacts of the solenoid switch are not closed, very quickly leads to overheating and thus destruction of the traction winding. In conventional electromagnetic switches, the pulling force cannot be reduced due to the interdependence of the traction and holding windings, which must be designed so as to enable the starter to be switched off, but this is ensured in ·· ·· ...

cases where the products of the number of coils of traction winding and current and the number of wrappers of holding winding and current are approximately equal.

The present invention relates to the improvement of a system with traction winding as a resistance to the motor part of the starter in the first stage of start-up, and is described in embodiments and figures showing:

Figure 1: Electrical block diagram of an electromechanical design in use

Figure 2: first implementation of a two-stage startup with two separate additional one-pole relays

Figure 3: Second version of two-stage start-up with two-pole additional relay

Figure 4: Third design of a two-stage start-up with a single-pole additional relay with additional contact

Figure 2 shows a block diagram of a solution of a two-stage starter startup according to the invention according to the first embodiment. The assembly consists of the motor part of the starter (1), the solenoid switch (2) with pull (3) and holding (4) winding, an additional single-pole relay (5), the engine start switch (6) and the battery (7) as sources electricity. In the first start-up phase, when the contact of the solenoid switch (2) is not yet closed, the motor part (1) is electrically powered by two additional relays (5) which are powered and controlled via the motor start switch (6). When the starter switch (6) is closed, the first auxiliary relay (51) is energized, resulting in the relay contact (5-1), thereby closing the supply circuit of the traction coil (3). At the same time, a second additional relay (5-2) is supplied, which results in contacting the relay contacts (5-2), thereby closing the supply circuit of the solenoid switch (4) of the solenoid switch (2). The electrical current flowing through the retaining winding simultaneously feeds the motor part of the starter (1), which operates at a power less than the rated one. A suitable magnitude of the current for supplying the motor part (1), with a power less than the nominal one, is ensured by selecting the appropriate resistance of the traction winding (2). When the contact of the solenoid switch (2) is concluded, the electric current flows only through the retaining winding (4), since both ends of the traction winding (3) are connected to the same electrical potential, while the motor part (1) is supplied directly from the battery ( 7) and therefore operates at rated power. The holding winding (4) holds the closed contact of the solenoid switch (2) until the start switch (6) is closed. The magnitude of the current through the holding winding (4) is determined so that the winding does not overheat, and sufficient holding force is provided by an adequate number of wraps of the holding winding (4). After successful start of the motor, the power start switch (6) interrupts the supply circuit of the two additional relays (5-1) and (5-2), which further interrupts the supply circuit of the retaining coil (4). Although the contact of the solenoid switch (2) is still closed at this moment, the circuit of the traction (3) and the winding (4) windings, which are now connected in series, is interrupted and therefore is terminated • · · ·· ··.

an electromagnetic force equal to zero and the spring forces in the solenoid switch (2) can open the contact of the solenoid switch (2) and interrupt the power supply circuit of the motor part (1). In the described binding method, the traction (3) and the holding (4) windings can be selected independently. This allows for an arbitrary and independent choice of both the pulling force and the holding force of the electromagnetic switch (2) ·

Figure 3 shows a block diagram of a solution of a two-stage starter startup according to the invention according to the second embodiment. The difference between the first embodiment and the second is that in the scheme one-pole additional relays (5-1) and (5-2) are replaced by a two-pole additional relay. When the starter switch (6) is closed, the supply circuit of the additional two-pole relay (8) is closed, which results in the conclusion of both relay contacts (8), thus simultaneously closing the supply circuit of the traction (3) and the holding (4) winding of the solenoid switch (8). 2). The electrical current flowing through the retaining winding simultaneously energizes the motor part of the starter (1), which operates at a power less than the nominal one. A suitable magnitude of the current for supplying the motor part (1), with a power less than the nominal one, is ensured by selecting the appropriate resistance of the traction winding (2). When the contact of the solenoid switch (2) is concluded, the electric current only flows through the retaining winding (4), since the two ends of the traction winding (3) are connected to the same electrical potential, while the motor part (1) is supplied directly from the battery ( 7) and therefore operates at rated power. The holding winding (4) holds the closed contact of the solenoid switch (2) until the start switch (6) is closed. The magnitude of the current through the holding winding (4) is determined so that the winding does not overheat, and sufficient holding force is provided by an adequate number of wraps of the holding winding (4). After successful start of the motor, the supply circuit of the auxiliary two-pole relay (8) is interrupted by the engine start switch (6), which further interrupts the supply circuit of the retaining winding (4). However, at this moment the contact of the solenoid switch (2) is still closed, the circuit of the traction (3) and the coil bracket (4), which are now connected in series, is interrupted, so that the electromagnetic force is zero and the spring forces in the solenoid switch (2) they may unlock the solenoid switch contact (2) and interrupt the power supply circuit of the motor part (1). In the second binding mode, both the traction (3) and the holding (4) windings can be selected independently, allowing for an arbitrary and independent selection of both the pulling force and the holding force of the electromagnetic switch (2).

Figure 4 shows a block diagram of a solution of a two-stage starter startup according to the invention according to the third embodiment. The difference between the second embodiment and the third is the implementation of the additional relay (9) used to replace the two-pole additional relay (8). After operation, the second and third embodiment are the same.

Claims (3)

PATENT APPLICATIONS A method of executing a two-stage or soft starter starter for internal combustion engines, characterized in that it contains electromechanical elements (5-1), (5-2), (8) and (9) in conjunction with the start switch (6 ), a rechargeable battery (7), an electromagnetic switch (2), and a motor part (1) which, in the first stage of commissioning, switches the electrical current to the motor part (1) of the starter required to operate at a power less than rated. Electrical connections according to claim 1, characterized in that the electromechanical elements (5-1), (5-2), (8) and (9) interrupt the power supply circuits of the traction (3) when the startup is interrupted by switching off the starter switch (6). ) and the starter solenoid switch (2) of the starter solenoid switch (2). Electrical connections according to claim 1, characterized in that, to limit the electric current, for operation with a power less than the nominal in the first stage of startup of the starter, the resistance of the traction winding (3) of the starter solenoid switch (2) is exploited to the required value.