JPS6242457B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a voltage control device for a generator for a vehicle.
In particular, the present invention relates to a voltage limiting device that limits the excitation current of a generator to the necessary minimum when an automobile engine is in an idle region.

[Conventional technology]

In recent years, the electrical loads of automobiles have increased, and when the engine is in the idle region, the load on the generator has increased to supply electricity to these increased electrical loads.

[Problem that the invention seeks to solve]

Therefore, with the conventional systems mentioned above, this leads to an increase in the generator load and the engine load, and when the engine remains idle for a long time due to traffic jams, etc., fuel consumption increases significantly. is moving in the opposite direction.

[Means for solving problems]

Therefore, the present invention provides: a generator circuit that is driven by the rotation of an engine and generates a voltage in an armature winding by passing an excitation current through an excitation winding; and an idle detection means that detects an idle state of the engine. and a switching circuit that limits the excitation current flowing through the excitation winding when the idle state of the engine is detected by the idle detection means.

[Effect]

The idle state of the engine is detected by the idle detection means, and when the engine is in the idle state, the current flowing through the excitation winding is limited by the switching circuit.

〔Effect of the invention〕

As described above, the present invention has the excellent effect of substantially reducing the excitation current flowing through the excitation winding and reducing fuel consumption during idling.

〔Example〕

Hereinafter, a voltage control device according to the present invention will be explained with reference to the accompanying drawings. FIG. 1 shows an electrical circuit diagram of an embodiment of the voltage control device of the present invention. 1 is a generator circuit, which is driven by the rotation of the engine. Reference numeral 2 denotes a voltage control circuit, which is operated by a signal from the generator circuit 1 and controls the excitation current of the generator circuit 1. 3
is an engine switch, and 4 is a car battery. The generator circuit 1 includes an armature winding 10, an excitation winding 11, rectifying diodes 12, 13, 14, a diode 15, and a resistor 16.

The voltage control circuit 2 includes a regulator circuit 21, a rotation speed detection circuit 22 serving as idle detection means, and a switching circuit 23. Regulator circuit 2
1 are transistors 211, 214 and 216
, Tsuner diode 215, diode 217
and resistors 212, 213, and 218. The rotation speed detection circuit 22 is a frequency-voltage conversion circuit, and includes resistors 221, 226, 227, capacitors 222, 225, and diodes 223, 2.
24. The switching circuit 23 includes resistors 231 and 236, and a transistor switch 23.
2, 233 and diodes 234, 235. The resistor 231 is for controlling the excitation current.

The operation of the present invention will be explained. The engine is started by the engine switch 3, and the armature winding 1
AC output is generated at 0. The output signal from the armature winding 10 is applied to a rotation speed detection circuit 22, which generates a voltage dependent on the engine rotation speed. When the engine speed is below a set value slightly higher than the idle speed, the idle state of the engine is detected, and the transistor 233 of the switching circuit 23 is turned off.
2 is in the on state. In this state (idle), the current limiting resistor 231 is connected in series with the excitation winding 11 of the generator circuit 1 to limit the excitation current. When the engine speed is equal to or higher than the set value, transistor 233 is turned on, and therefore transistor 232 is turned off. In this state, the regulator circuit 21 performs a normal voltage limiting function.

FIG. 2 shows another embodiment of the switching circuit 23 in the above embodiment. In this embodiment, the switching circuit 23 is constituted by an oscillation circuit such as an astable multi-circuit. The astable multicircuit operates when the engine is below the set value, and a pulse signal having a constant duty ratio is generated at its output. This pulse signal is applied to the excitation winding 11 of the generator circuit 1 and substantially reduces the excitation current.

3A and 3B show yet another embodiment of the switching circuit 23. FIG. In this embodiment, the switching circuit 23 is composed of a comparator, a triangular wave signal generating circuit connected to one input thereof, and an integrating circuit connected to the other input. The DC output level of the integrating circuit changes depending on the engine speed, and this DC level and the triangular wave signal are compared in a comparator. A pulse signal having a duty ratio dependent on the magnitude of the DC level is generated at the output of the comparator, as shown in FIG. 3B. This pulse signal is applied to the excitation winding 11 to substantially reduce the excitation current. In this embodiment, even if the engine speed increases or decreases rapidly, the DC level changes gradually, so the load on the generator changes smoothly.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing one embodiment of the voltage control device according to the present invention, FIG. 2 is an electric circuit diagram showing another embodiment of the switching circuit in the embodiment of FIG. 1, and FIG. and B are diagrams showing still another embodiment of the switching circuit of FIG. 1 and its input/output waveforms. 1... Generator circuit, 2... Voltage control circuit, 10
... Armature winding, 11 ... Excitation winding, 22 ... Rotation speed detection circuit forming idle detection means, 23 ...
Switching circuit, 231... Excitation current limiting resistor.

Claims (1)

[Scope of Claims] 1. A generator circuit that is driven by the rotation of the engine and generates a voltage in an armature winding by passing an excitation current through an excitation winding; and an idle detection means that detects an idle state of the engine. A voltage control device for a vehicle generator, comprising: a switching circuit that limits the excitation current flowing through the excitation winding when the idle state of the engine is detected by the idle detection means. 2. The idle detection means includes a rotation speed detection circuit that detects the rotation speed of the engine, and compares a set value slightly higher than the idle rotation speed of the engine with the rotation speed detected by the rotation speed detection circuit. 2. The voltage control device for a vehicle generator according to claim 1, wherein the vehicle generator is brought into an idling state when the rotational speed is smaller than the set value. 3. Claim 2, wherein the rotational speed detection circuit is connected to an armature winding of the generator circuit, and detects the rotational speed of the engine based on the output of the armature winding. The voltage control device for the vehicle generator described above. 4. When the rotation speed detection circuit detects a rotation speed below the set value, the switching circuit connects a resistor in series with the excitation winding of the generator circuit to reduce the excitation current. A voltage control device for a vehicle generator according to claim 2, characterized in that: 5 When the rotation speed detection circuit detects a rotation speed below the set value, the switching circuit generates an on/off signal, and the on/off signal having a constant duty ratio causes the excitation to be activated. A voltage control device for a vehicle generator according to claim 2, characterized in that the excitation current of the winding is substantially reduced.