JPH0584136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new system configuration for a vehicle alternator.

[Background of the invention]

In recent years, there have been significant improvements in generators themselves, with the aim of making them smaller, faster, and more powerful.However, as pulleys have become smaller and load torque has increased, they have become increasingly disadvantageous in terms of belt slip. For example, in recent years, poly V belts have been widely used to accommodate pulleys with smaller diameters and higher speeds, but these belts have a characteristic that they are less likely to slip in warm conditions, but are more likely to slip in cold and cold conditions. When the engine starts in cold weather, momentary slips often occur due to the above-mentioned belt characteristics and the large generator load at the time of start. Such belt slips may cause discomfort to the vehicle user or may cause damage to the belt itself. In reality, excessive belt tension has been applied to prevent such instantaneous belt slip. In order to ensure the necessary durability against bearing damage and frame breakage in response to such excessive tension, generator bearings inevitably become larger, leading to problems such as increased generator costs and less freedom in functional design. was derived.

[Object of the present invention]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a vehicle charging device that prevents instantaneous belt slip when starting an engine without applying excessive tension to the belt.

[Configuration of the present invention]

The present invention provides means for detecting a slip in the generator drive belt, and also includes an excitation force control means for weakening the excitation of the field pole of the generator to reduce the power generated by the generator when a slip is detected.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described. FIG. 1 is a schematic diagram of an electric circuit showing the configuration of an embodiment of the vehicle charging device according to the present invention, in which 1 is a vehicle engine, which is connected to a pulley 4 by a crank pulley 2 via a generator drive belt 5. generator 3
The ignition pulse detector 6 of the engine 1 is also connected to this vehicle alternator 3. 7 is an excitation coil of the rotating field pole. A stator provided with a three-phase armature winding 8 is located on the outer periphery of the excitation coil 7 of the field pole. 9 is a voltage control device that adjusts the voltage of the output terminal 10 of the generator 3, and is connected to the storage battery 11, which is the vehicle electrical load, the vehicle key switch 12, the generator output section 13, and the armature winding 8. terminal 14, generator body ground terminal 15, excitation current switching element 16, and switching control element 1.
This is a conventionally known voltage control function section having a terminal 18 connected to 7. 19 is the field pole excitation coil 7
This is a flywheel diode that takes into account the current inertia effect of . 20 and 21 are F/V converters,
The comparators 22 and 23 are further connected to a duty controller 28, the engine ignition pulse detector 6, and the terminal 14. The voltage control function unit 24 of the generator 3 is a collection of the above-mentioned functional parts, and is built into the generator 3.

Next, the operation of the vehicle charging device configured as described above will be explained.

The generator field poles are rotated by the engine 1 via the belt 5, and the armature winding 8 is given a rotating magnetic field to generate three-phase power, and the rectifier 30 connected to the armature winding 8 is The power is converted into DC, and external storage batteries 11 and the like receive current supply from the output terminal 10. When the load demand is high, the potential of the storage battery 11 decreases, so the voltage control device 9 detects this and
8 is controlled to increase the conductivity of the switching element 16, the excitation current 25 flowing through the excitation coil 7 is increased, and the power generation output 26 is increased.As the power generation output increases relative to the load demand, the storage battery voltage gradually decreases. and exceeds a certain predetermined value,
Subsequently, the voltage control device 9 acts in the opposite manner to the series of actions described above, and lowers the power generation output. The above operation is a common voltage control operation known in conventional generators.

Next, the operation of the characteristic portion of the present invention will be explained. The F/V converter 20 is connected to a terminal 14 connected to the generator armature winding 8, receives the frequency of the electromotive force as a generator rotational speed signal 27, and converts this into a voltage value. , as one of the inputs of the comparator 22. On the other hand, F/V converter 2
1 receives an engine ignition pulse signal as an engine rotation signal 27', converts it into a voltage value, and sends it out as the other input of the comparator 22. The comparator 22 receives the generator rotational speed signal 27 and the engine rotational signal, and sends out the difference between the rotational speeds as an output to another comparator 23 .
The comparator 23 compares the voltage due to the deviation between the two rotational speeds with the reference voltage, and the duty controller 28 detects the difference, and sets 0 potential when there is no deviation between the engine rotational speed and the generator rotational speed. When there is a slip, the time proportion of the positive potential is increased in proportion to the magnitude of the slippage and is applied to the base of the switching control element 17 as an output signal. Due to this, the switching of the excitation current switching element 16 is controlled to be on or off in priority to the on (ON) command signal issued by the voltage control device 9 of the conventional function,
Excitation current 25 is lowered to forcefully reduce generated power 26.

The above-mentioned configuration achieves the effect of continuously reducing the required torque of the generator, which is one of the causes of slippage, until the slippage stops.

In the embodiment shown in FIG. 1, the slip signal is calculated and extracted from the generator electromotive force and the engine ignition pulse, but it is also possible to detect sound, vibration, or rapid changes in the generator rotation speed. It is also possible to use a method in which a slip signal is generated. Furthermore, in the above embodiment, the slip signal is directly applied to the excitation current switching element base as an ON/OFF command signal, but the excitation current is inputted to the storage battery voltage detection control function section so that it operates as if there is a change in the storage battery voltage. A control method may also be used. Alternatively, a method may be adopted in which the reference voltage of a comparator that detects changes in the storage battery voltage is lowered during a slip, thereby lowering the excitation current.

[Effects of the present invention]

As described above, the vehicle charging device of the present invention is provided with a slip detection device for the generator drive belt, and is also provided with an excitation force control means that weakens the excitation of the field pole to reduce power generation when a slip occurs. Because of this, it is possible to limit the amount of power generated by the generator by capturing the slight moment when a belt slip occurs and instantaneously lowering the excitation current to the state where the maximum amount of power is generated without belt slipping, which is an inexpensive and reliable method. It has the great effect of being able to detect slips and preventing belt slips. In addition, the opportunity for belt slip is at the moment when the engine is started in cold weather,
Alternatively, as shown in Figure 2, the generator torque curve A
Since it is limited to a small range of the rotation range S in which medium slips occur frequently, a decrease in the excitation current, that is, a restriction on the amount of power generation, does not cause drawbacks such as insufficient charging of the storage battery.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electric circuit showing the configuration of an embodiment of a vehicle charging device according to the present invention, and FIG. 2 is a generator drive torque characteristic diagram for explaining the effects of the present invention. 1... Engine, 3... Generator, 4... Pulley, 5... Generator drive belt, 6... Engine ignition pulse detector, 20, 21... F/
V converter, 22, 23... comparator, 28...
Duty controller, 16... Excitation current switching element, 17... Switching control element, 19...
...flywheel diode, 24...voltage control function section, 7...excitation coil.

Claims (1)

[Scope of Claims] 1. A slip detection means for detecting a slip in a generator drive belt; and when a slip is detected by the slip detection means, the excitation of a field pole of the generator is weakened to reduce the generated power of the generator. A vehicle charging device comprising: excitation force control means for reducing the excitation force.