JPH0723575Y2 - Starter protection device for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a starter protection device for a vehicle, which protects a starter by preventing re-dip of the starter during inertial rotation of an engine or a starter.

[Conventional technology]

FIG. 2 is a circuit diagram showing a conventional vehicle starter protection device, in which 1 is an on-vehicle battery and 2 is a coil 21.
a starter consisting of an electromagnetic drive device 21 having a and 21b, a main contact 21c and a motor 22 and 3 is a starter auxiliary relay, the coil 3a of which is the ST terminal of the key switch 4 and the output transistor 619.
And the contact 3b is connected between the positive electrode of the on-vehicle battery 1 and the electromagnetic drive device 21.

The key switch 4 has a fixed terminal such as an ST terminal, an OFF terminal and an ON terminal and a movable terminal, and the movable terminal is connected to the positive electrode of the vehicle battery 1.

Reference numeral 5 is an AC generator, and 6 is a protection device that drives and controls the starter auxiliary relay 3 to protect the starter 2. The protection device includes the following parts.

That is, 60 is a frequency-voltage converter (hereinafter referred to as FV converter) 601, 602, 62 for converting the frequency of the AC voltage generated according to the engine rotation of the AC generator 5 into a DC voltage.
4 constitutes a kind of hysteresis circuit, and a comparator 6 described later
A resistor for setting a predetermined value of 05, 605 is a predetermined value set by the resistors 601, 602, 624 and the output voltage of the FV converter 60, or
It is a comparator that compares the voltage applied through the harness L ₁ with the voltage generated during inertial rotation after the power source of the motor 22 is released.

The output transistor 619 drives the starter auxiliary relay 3 according to the output of the comparator 605, and the base of the output transistor 619 is connected to the power supply via the base resistor 621.

622 is a Zener diode which constitutes the power source of the protection device 6,
23 is a resistor that supplies a bias current to the Zener diode 622, 625 is a Zener diode that conducts when the contacts of the starter auxiliary relay 3 are closed, 626 is a resistor that supplies a bias current to the Zener diode, and 627 and 628 are biases. A resistor, 629, is a diode that clamps the voltage applied through harness L ₁ .

Next, the operation will be described. When the key switch 4 is turned on to the ON terminal side, the voltage of the vehicle battery 1 is applied to the Zener diode 622 via the resistor 623, the Zener diode 622 becomes conductive, the power supply circuit is configured, and the inversion of the comparator 605 is performed. The input on the input end side ((-) input side) is zero, so the comparator
The output of 605 is cut off, and the output transistor 619 is made conductive.

Next, when the key switch 4 is turned on to the ST terminal side, the coil 3a of the starter auxiliary relay 3 is energized and its contact 3b is closed. Because the contact 3b is closed, the harness L ₁ resistance
A battery voltage is applied to the Zener diode 625 via 626, and the Zener diode 625 becomes conductive.

As a result, the first pressure set by the partial pressure of the resistors 601 and 602 is set.
The predetermined value of is a second predetermined value that is determined by the voltage division ratio of the resistor 602 and the parallel combined resistance of the resistors 601 and 624.

At the same time, the coil 21 of the electromagnetic drive device 21 of the starter 2
Power is supplied to a and 21b, the main contact 21c is closed, the motor 22 starts to rotate, and the engine is started.

As the engine speed increases, the AC generator 5 starts power generation, and the frequency of the AC voltage of the AC generator 5, which is the input of the FV converter 60, increases as the engine speed increases.
The output of the FV converter 60 also increases in proportion to the input.

When the engine speed reaches the starter separation speed,
The output of the FV converter 60 exceeds the second predetermined value set by the resistors 601, 602, 624, and the comparator 605 switches to the conductive state.

As a result, the output transistor 619 is cut off, the coil 3a of the starter auxiliary relay 3 is de-energized, and the contact
3b is opened, the power supply to the electromagnetic drive device 21 of the starter 2 is stopped, the motor 22 is stopped, the starter 2 is separated from the engine, and is prevented from being swung in reverse by the engine.

Further, since the contact 3b of the starter auxiliary relay 3 is opened, the voltage applied via the harness L ₁ becomes almost 0 volt, the Zener diode 625 is cut off, and the comparator 605
The predetermined value of the non-inverting input terminal ((+) input side) of
Even if the key switch 4 is mistakenly turned on to the ST terminal side while the engine is rotating by itself, it becomes the first predetermined value due to the partial pressure of the resistors 601 and 602 which is equal to or less than the second predetermined value set by the 602, 624. Is closed, the contact 3b of the starter auxiliary relay 3 is not closed to prevent the starter 2 from jumping in again.

Next, even if the key switch 4 is put into the ST terminal side, the engine does not rotate by itself, the key switch 4 is returned to the ON side, and the key switch 4 is put into the ST terminal side again. Is rotating by inertia, so the voltage generated during motor inertial rotation is harness L ₁ and resistance 627,62.
A comparator 605 through 8 compares the voltage with a first predetermined value composed of resistors 601 and 602, and the generated voltage during motor inertia rotation is
When it is equal to or more than the predetermined value of, the output of the comparator 605 becomes conductive.

This turns off the output transistor 619,
Even if the key switch 4 is put in the ST terminal side again,
The jumping of the starter 2 is prohibited when the motor 22 is generating the generated voltage by inertial rotation, that is, when the starter 2 is rotating by inertia.

By the way, in the case of such a conventional vehicle starter protection device, the contacts of the starter auxiliary relay 3 are connected via the harness L _1.
Comparator 605 detects the battery voltage for vehicle when 3b is closed.
Since the predetermined value on the non-inverting input end side of is switched from the first to the second predetermined value, the contact of the terminal of the harness L ₁ is poor, the terminal is dislocated, and the starter 2 becomes a so-called early escape when the wire is disconnected, and the starter function is sufficient. No longer.

In addition, the voltage generated during starter inertial rotation cannot be detected when the terminals of the harness L ₁ are not properly contacted, the terminals are disconnected, or the wire is broken, and the starter protection does not function sufficiently.

[Problems to be solved by the invention]

Since the conventional vehicle starter protection device is configured as described above, disconnection of the harness L ₁ and poor contact of the terminals,
If the starter runs away quickly, the starter function may be defective and the starter protection function during starter inertial rotation may be insufficient. Then, there was a problem such as cost up of the harness and the terminals associated therewith.

The present invention has been made to solve the above problems, and to obtain a starter protection device for a vehicle, which can starter protection when the starter is stopped by the minimum required terminals and harnesses, by engine inertia rotation. With the goal.

[Means for solving problems]

A starter device for a vehicle according to the present invention includes a frequency-voltage converter for converting a frequency generated according to an engine speed of an AC generator driven by an engine into a voltage output,
The output voltage of the frequency-voltage converter is compared with a first predetermined value, which is a voltage corresponding to the number of revolutions at which the engine starts to rotate by itself, and when the output voltage is equal to or higher than the first predetermined value, the first conduction state is established. Of the comparator and the output voltage of the frequency-voltage converter are compared with a second predetermined value which is a voltage corresponding to a rotational speed slightly lower than the rotational speed at which the engine is rotated by the starter, and the second predetermined value or more. And a second comparator that switches from a cutoff state to a conduction state when the output voltage is equal to or less than a third predetermined value that is lower than the second predetermined value, and that changes from a conduction state to a cutoff state. A timer circuit that generates a predetermined voltage for a predetermined time after the second comparator is switched from a conductive state to a cutoff state, and an output voltage of the frequency-voltage converter that has passed through the second comparator are output from the timer circuit. Compare the voltage with the voltage of the timer circuit. A third comparator which is in a conductive state when it is less than, and an output transistor which controls the starter auxiliary relay to be in an open state when at least one of the first comparator and the third comparator is in a conductive state. including.

[Action]

In this invention, the first comparator detects that the engine is rotating by itself, and at this time, the starter is controlled to the inoperative state to protect the starter. In addition, the second comparator detects that the starter has once become inactive, and the third comparator and timer circuit
By maintaining the starter inactive for a predetermined time from the time when the starter enters the inactive state, re-dive in the inertial rotation of the starter is prohibited and the starter is protected.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, the circuit configuration is different from FIG. 2 only in the internal configuration of the protection device 6, and the same parts as in FIG. Reference numerals 601, 602, 603, and 604 are resistors that configure a hysteresis circuit and set a first predetermined value of a first comparator 605 described later.

The first comparator 605 compares the output of the FV converter 60 with a first predetermined value whose voltage is set by the resistors 601, 602, 603, 604.

Reference numeral 606 is a backflow prevention diode that blocks a current when the first comparator 605 is cut off, and reference numerals 607, 608, 609 and 610 are resistors that configure a hysteresis circuit and set a voltage of a predetermined value of a second comparator 611 described later.

The second comparator 611 compares the output of the FV converter 60 with the second predetermined value set by the resistors 607, 608, 609, 610.

Reference numeral 612 is a transistor that is intermittently controlled according to the output of the second comparator 611, 613 is a resistor that defines a time constant when the capacitor 615 described later is charged, and 614 is a level shift diode.

The capacitor 615 is a capacitor that is charged when the transistor 612 is cut off, 616 is a resistor that defines a time constant when the capacitor 615 is discharged, 617 is an anode and cathode of the level shift diode 614, and a third for comparing with the potential as an input. Is a comparator. This third comparator 617 and capacitor 6
A timer circuit is composed of 15 and the resistor 616. The output of the timer circuit, that is, the output of the third comparator 617 and the output of the first comparator 605 are OR-connected.

Reference numeral 618 is a backflow prevention diode that blocks current when the third comparator 617 is cut off, and 620 is a level shift diode connected in series to the base of the output transistor 619.

The rest of the configuration is the same as in FIG.

Next, the operation will be described. When the key switch 4 is turned on to the ON terminal side, the output transistor 619 becomes conductive. Next, when the key switch 4 is turned on to the ST terminal side, the coil 3a of the starter auxiliary relay 3 is excited via the output transistor 619, whereby the output transistor 61
Through 9, the coil 3a of the starter auxiliary relay 3 is excited by the current from the vehicle battery 1, and the starter auxiliary relay 3
Contact 3a is closed, power is supplied to the coils 21a and 21b of the electromagnetic drive device 21 of the starter 2 via the starter auxiliary relay 3, its main contact 21c is closed, the motor 22 starts to rotate, and the engine is started. To do.

With this rotation of the engine, the alternator 5 starts to generate power, and F
The frequency of the AC voltage of the AC generator 5, which is the input of the −V converter 60, increases as the engine speed increases and becomes F−V.
The output of converter 60 also increases in proportion to the input.

Here, the set value of the second predetermined value set by the resistors 607, 608, 609, 610 is a set value lower than the voltage corresponding to the engine rotation speed of the motor 22 of the starter 2,
When the output of the FV converter 60 exceeds the predetermined value of, the output of the second comparator 611 is switched from the cutoff state to the conduction state.

In accordance with the output of the second comparator 611, the transistor 612 is cut off from conduction, and the capacitor 615 is charged with the time constant defined by the resistor 613, but the input of the third comparator 617 is not inverted. The output of the third comparator 617 does not change in the cutoff state.

The setting value set by the resistors 607, 608, 609, 610 becomes
It becomes a third predetermined value that is less than or equal to the second predetermined value, and the F-V converter
The second comparator 61 until the output of 60 becomes the third predetermined value or less
The output of 1 remains conductive. Then, the engine speed increases, and the output of the FV converter 60 is changed to resistors 601, 602, 603,
When the starter disconnection rotation speed, which is the first predetermined value set in 604, is reached, the first comparator 605 switches from the cutoff state to the conductive state, whereby the output transistor 619 is cut off and the contact of the starter auxiliary relay 3 is turned off. 3b is opened, the power supply to the electromagnetic drive device 21 of the starter 2 is stopped, the motor 22 is stopped, the starter 2 is separated from the engine, and conversely is prevented from being swung by the engine.

Further, since the first comparator 605 is switched to the conductive state, the set value set by the resistors 601, 602, 603, 604 becomes the fourth predetermined value equal to or lower than the first predetermined value, and the FV converter 60
The output of the first comparator 605 remains conductive until the output of the first comparator 605 becomes equal to or lower than the fourth predetermined value. That is, the starter 2 is prevented from re-jumping while the engine is rotating by itself.

Next, even if the key switch 4 is put in the ST terminal side, the engine does not rotate by itself, and if the key switch 4 is returned to the ON terminal side and the key switch 4 is put in the ST terminal side again, the key switch 4 is put in the ST position. The output of the FV converter 60 when the engine is rotated by the starter 2 and the motor 22 when the terminal is turned on, that is, during cranking rotation is the resistance 607,60.
It is equal to or greater than the second predetermined value set in 8,609,610, and the second
The output of the comparator 611 of the
In accordance with the output of the comparator 611, the transistor 612 is cut off, and the capacitor 615 starts charging with a time constant defined by the resistor 613. The time constant is a time constant for completing charging in a short time.

Furthermore, since the second comparator 611 is in the conductive state, the third predetermined value is equal to or lower than the second predetermined value set by the resistors 607, 608, 609, 610.

The third predetermined value is equal to or larger than the fourth predetermined value set by the resistors 601, 602, 603, 604. When the engine does not rotate by itself and the key switch 4 is returned to the ON terminal side, the engine speed decreases because it is not rotated by the starter 2 and the motor 22.

As a result, the output of the FV converter 60 is changed to the resistors 607, 608, 60.
When the voltage becomes equal to or lower than the third predetermined value set by 9,610, the output of the second comparator 611 is cut off from conduction and the transistor 612 is turned on, so that the non-inverting input terminal of the third comparator 617 is almost closed. Although the potential is the ground potential, the current is blocked by the diode 614 on the inverting input end side, so the potential charged in the capacitor 615 is discharged with the discharge time constant defined by the capacitor 615 and the resistor 616.

The discharge time of is equal to or longer than the starter inertial rotation time, so that while the potential of the capacitor 615 is discharged through the resistor 616, the third comparator 617 is in the conductive state and the output transistor 619 is cut off. Therefore, key switch 4
When is turned on to the ST terminal side again, that is, the starter 2 is prevented from re-jumping while the engine or the starter 2 is turning by inertia, and the starter 2 is protected.

By detecting the engine speed (cranking speed) by the starter 2 and the motor 22 in this way, the engine or the key switch 4 during inertial rotation of the starter is used.
It is possible to prevent the starter from jumping again when the ST terminal is re-closed, and it is possible to protect the starter.

[Effect of device]

As described above, according to the present invention, the first comparator detects the rotation of the engine by itself, disconnects the starter from the engine, and detects the engine rotation (cranking rotation) by the starter with the second comparator. However, since the output is used to operate the timer circuit to disconnect the starter from the engine, it is possible to prevent the starter from re-diving during engine self-rotation and during engine starter inertia rotation.
There is an effect that the starter can be protected without adding the number of terminals of the protective device and the external harness.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a vehicle starter protection device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional vehicle starter protection device. 1 ... In-vehicle battery, 2 ... Starter, 3 ... Starter auxiliary relay, 4 ... Key switch, 5 ... Alternator,
6 ... Protective device, 60 ... FV converter, 605 ... First comparator, 611 ... Second comparator, 615 ... Capacitor, 61
6 ... Resistance, 617 ... Third comparator, 619 ... Output transistor, In the figure, the same reference numerals indicate the same or corresponding portions.

Claims (1)

[Scope of utility model registration request] 1. A starter protection device for a vehicle, wherein a starter auxiliary relay is opened under a predetermined condition to protect a starter for starting an engine, and the starter is made inoperative, which is driven by the engine. Frequency that converts the frequency generated according to the engine speed of the alternator to voltage output
The output voltage of the voltage converter and the frequency-voltage converter is compared with a first predetermined value which is a voltage corresponding to the number of revolutions at which the engine starts self-rotation, and conduction is performed when the output voltage is equal to or higher than the first predetermined value. The first comparator in the state and the output voltage of the frequency-voltage converter are compared with a second predetermined value which is a voltage corresponding to a rotational speed slightly lower than the rotational speed at which the engine rotates by the starter, When it is determined that the value is equal to or more than the predetermined value of 2, the disconnection state is changed to the conduction state,
On the other hand, when the output voltage is equal to or lower than a third predetermined value lower than the second predetermined value, the second comparator is switched from the conductive state to the cutoff state, and the second comparator is changed from the conductive state to the cutoff state. And a timer circuit that generates a predetermined voltage for a predetermined period of time, and compares the output voltage of the frequency-voltage converter via the second comparator with the voltage of the timer circuit, and conducts when the voltage is less than the voltage of the timer circuit. A third comparator that is in a state, and an output transistor that controls the starter auxiliary relay to be in an open state when at least one of the first comparator and the third comparator is in a conductive state. Characteristic vehicle starter protection device.