JP2000240541A - Magnetic switch controller for starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a contact of a magnetic switch and to improve the life of a magnetic switch including the contact, and a starter in the magnetic switch of the starter for starting an engine of an automobile. SOLUTION: This controller comprises a contact detecting means 201 for detecting the closing and opening of the electric contacts 8, 10B, 10M disposed on a magnetic switch 5 of a starter 4, a series connecting member of a semiconductor element 25 and a resistor 26 connected in parallel to both ends of the contact, an instruction detecting means 203 including a delay time generating means 202 and detecting a condition of a key switch 2 for switching on and off the magnetic switch 5, and a driving means 204 for connecting and cutting the semiconductor element 25. On this occasion, the semiconductor element 25 is conducted between the first closing and the opening of the contact on the basis of an ON signal of the instruction detecting means 203, and the semiconductor element 25 is cut after the lapse of the predetermined delay time from the opening of the contact on the basis of an OFF signal of the instruction detecting means 203.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic switch which is an internal component for starting and stopping a starter for starting an engine of a motor vehicle, and more particularly to a starter magnetic switch control device for protecting its contacts. About.

[0002]

2. Description of the Related Art A conventional starter magnetic switch is known from Japanese Patent Application Laid-Open No. Hei 9-177645 or the like, but does not include a control device for the magnetic switch.

[0003]

In recent years, interest in environmental issues has increased, and when an automobile is stopped at an intersection or a stop and the engine is idling, the engine is temporarily stopped and restarted when starting. A so-called idling stop is recommended. For this reason, the number of starts of the starter for starting the engine is increased, and the life of the magnetic switch contact for electrically turning on and off the starter motor is required to be extended.

When a pinion rotating from a rotation shaft of a starter motor via a speed reduction mechanism is engaged with a ring gear of the engine to start the engine, a current flowing through a magnetic switch contact point is 400.
A to 600A, and may reach as high as 1000A under heavy load at cryogenic temperature. The cause of the deterioration of the contact for opening and closing such a large current is an arc at the time of opening and closing of the contact, and it is required to reduce the arc in order to extend the life of the contact.

The present invention has been made in view of the above circumstances, and aims at protecting a magnetic switch contact of a starter for starting an automobile engine and improving the life of a magnetic switch including an electric contact and a starter. And

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a contact detecting means for detecting the closing and opening of an electric contact provided in a magnetic switch of a starter, and a contact detecting means provided in parallel with both ends of the contact. A semiconductor element and a resistor connected in series, a delay time generating means, an instruction detecting means for detecting a state of a key switch for turning on and off a magnetic switch, and a driving means for turning on and off the semiconductor element. A semiconductor element that conducts between the first closing and opening of the contact based on the on signal of the indication detecting means, and a preset delay from the opening of the contact based on the off signal of the indication detecting means. Technical means for shutting off the semiconductor element after a lapse of time is adopted.

According to the present invention provided with such means, when the magnetic switch is turned on, the contact is first contacted, and before the chattering phenomenon in which the contact repeatedly contacts and separates due to mechanical factors occurs, the resistance is reduced. A small current is passed through the contacts through the semiconductor element to prevent arcing, and the contacts are electrically connected by the resistor and the semiconductor element for a certain period of time even after the contacts are turned off.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention,
FIG. 2 is an operation timing chart for explaining the operation of FIG.

In FIG. 1, a battery 1 of a vehicle whose negative side is grounded, a key switch 2 operated when a driver starts an engine, and a starting relay 3 are provided. The starter 4 has a magnetic switch 5. The magnetic switch 5 includes a P coil 6 and an H coil 7 connected to a terminal C, a plunger 9 having a movable contact 8 at one end, and a pair of fixed contacts 10. Is provided. The fixed contact 10 has a fixed contact 10B connected to the positive side of the battery 1 and a fixed contact 10M connected to the starter terminal M. The plunger 9 includes a return spring 11 that is biased in a direction opposite to a direction in which the P coil 6 and the H coil 7 move when energized. The starter 4 is grounded by connecting a starter motor 12 and a field coil 13 in series via a terminal M. The rotation shaft of the starter motor 12 is connected to the pinion 14 via a speed reduction mechanism (not shown). The pinion 14 is linked to the other end of the plunger 9 via a lever 15 and moves back and forth.

The magnetic switch controller 20 includes a photocoupler 21 serving as a contact detecting means 201, a resistor 22, a capacitor 23, a diode 24, and an IGBT of a semiconductor element.
25 and resistor 26 connected in series, delay time generating means 20
2. A diode 29 including a capacitor 27 and a resistor 28
, Zener diode 30, resistor 31, and transistor 3
2, an insulated power supply 33 serving as a driving means 204 for turning on and off the IGBT 25, and resistors 34 and 35.

The collector terminal of the IGBT 25 is connected to one end of the resistor 26, and the emitter terminal is connected to a terminal M 'electrically connected to the fixed contact 10M of the magnetic switch 5. The other end of the resistor 26 is connected to a fixed contact 10B of the magnetic switch 5 and a terminal B 'electrically connected to the positive side of the battery 1. Therefore, the IGBT 25 and the resistor 2
The series connection members 6 are connected in parallel to both ends of the fixed contact 10 of the magnetic switch 5.

The contact detecting means is connected from the terminal M 'to the input side photodiode 21a of the photocoupler 21 via the diode 24, and when a voltage is applied to the terminal M' and a transistor 32 described later becomes conductive. The input photodiode 21a of the photocoupler 21 emits light and a signal is transmitted to the output side. Note that the capacitor 23 is for noise elimination for stable operation.

The instruction detecting means includes a starting relay 3
A terminal C ′ connected to the terminal C of the magnetic switch 5 is connected to the base terminal of the transistor 32 via the diode 29, the resistor 28, and the Zener diode 30 in series. A resistor 31 is connected between the base terminal of the transistor 32 and the ground, and a capacitor 27 is connected between the node between the diode 29 and the resistor 28 and the ground. Among these, the capacitor 27 and the resistor 28 play a role as delay time generating means.

The insulation power supply 33, which is an element of the driving means, receives a voltage between the terminal B 'and the ground as an input, and is electrically insulated from the input and outputs a DC converted voltage. The positive side of the output of the insulated power supply 33 is connected to one end of the resistor 34, and the other end is connected to the collector terminal of the output phototransistor 21b of the photocoupler 21. The emitter terminal of the output-side phototransistor 21b of the photocoupler 21 is connected to one end of the resistor 35 and the base terminal of the IGBT 25. Note that the negative side of the output of the insulated power supply 33 is connected to the other end of the resistor 35 and the emitter terminal of the IGBT 25.

The operation of the apparatus of the present invention will be described with the above configuration. When the driver sets the key switch 2 to the starting position for starting the engine, the driving coil of the starting relay 3 is started from the battery 1 via the key switch 2. Current flows through the relay contact. As a result, a current flows from the battery 1 to the P coil 6 via the terminal C of the magnetic switch 5 of the starter 4 to drive the plunger 9 having the movable contact 8 at the tip in the direction of the fixed contact 10 and to rotate the pinion 14 of the engine. Push in the direction of the ring gear (not shown). At the same time, a current flows from the battery 1 to the starter motor 12 and the field coil 13 via the H coil 7 and the terminal M of the starter 4, and the starter motor 12 rotates slowly, so that the pinion 14 connected to the rotating shaft is also loose. And easily mesh with the ring gear. Pinion 14
When the ring gear completely meshes with the movable contact 8, the movable contact 8 bridges the fixed contact 10, and the voltage of the battery 1 is applied to the terminal M of the starter 4 via the bridged fixed contact 10, so that the starter motor 12 rotates at full power and starts the engine.

When the movable contact 8 of the magnetic switch 5 bridges the fixed contact 10, the movable contact 8 at the tip of the plunger 9 moves toward the fixed contact 10 while bending the return spring 11, and is fixed to the movable contact 8. The contacts 10 collide. At that time, the composite force of the reaction force and the return spring 11 causes
A so-called chattering phenomenon occurs in which the movable contact 8 and the fixed contact 10 repeat contact and separation.

If the starter motor current 400A to 1000A during cranking is interrupted between the movable contact 8 and the fixed contact 10 during this chattering phenomenon, an arc will fly between the contacts, causing significant damage to the contacts and the welding of the contacts. there is a possibility. Therefore, the magnetic switch control device 20
Accordingly, the arc can be reduced by flowing an auxiliary current through the resistor 26 when the contact is opened and closed.

In FIG. 2, the horizontal axis represents time t, and the vertical axis represents time (a).
Shows the mechanical connection state between the fixed contacts 10B and 10M at the start of the start, (b) shows the on / off state of the IGBT 25 at the start of the start, and (c) shows the fixed contacts 10B and 10M at the end of the start.
(D) shows the mechanical connection state between M and IG at the end of startup.
The on / off state of the BT 25 is shown. 2, the operation of the magnetic switch control device 20 will be described in detail. When the key switch 2 is set to the starting position and the relay contact of the starting relay 3 is connected ((a) and ( b)), the battery 1 voltage is applied to the terminal C '.
The current is converted into an appropriate base current by the diode 29, the resistor 28, the Zener diode 30, and the resistor 31, and the transistor 32 is turned on. When the plunger 9 moves and the movable contact 8 at the tip contacts the fixed contact 10 for the first time (closed: t = 0), the battery 1 voltage is applied to the terminal M ′,
A current flows through the input-side photodiode 21a of the photocoupler 21 via the diode 24 and the resistor 22 to emit light, and a signal is transmitted to the output side.
b is turned on, and the IGBT 25 is turned on from the output of the insulated power supply 33 via the resistor 34 (T1). Therefore, the fixed contact 10B of the magnetic switch 5 and the resistor 26 and the IGB
A small current flows through the fixed contact 10M through T25.

According to an experiment conducted by the inventor, the bounce time (timing at which the contact is separated (open) and the arc flies) is 100 microseconds (T
Experiments have shown that if the semiconductor element can be turned on within 2), no arc will be generated.
25 has been confirmed to work well within this time. The time required for the movable contact 8 and the fixed contact 10 to completely contact each other is about several tens of milliseconds (T3), and the subsequent cranking current (400 A to 600 A) flows through the contact.

Next, when the engine is started and the key switch 2 is returned (FIGS. 2C and 2D), the starting relay 3 is turned off and the H coil 7 of the plunger 9 of the magnetic switch 5 is turned off. The excitation is canceled, and the movable contact 8 is separated from the fixed contact 10 by the action of the return spring 11 (opening: t =
tf) At the same time as the starter motor 12 stops, the pinion 14 also returns and separates from the ring gear.

At this time, a large current for rotating the starter motor 12 flows through the contact, though not as much as the cranking current, and there is a possibility that an arc may fly at the moment when the contact is separated. However, since the electric charge stored in the capacitor 27 of the magnetic switch control device 20 supplies the base current of the transistor 32 via the resistor 28 for a certain period (delay effect: td), it is possible to keep the IGBT 25 conductive. At the moment when the contacts are separated, the potential difference between the movable contact 8 and the fixed contact 10 is small, and the occurrence of arc can be prevented.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in the above embodiment, the semiconductor device
Although the GBT is used, a transistor or an FET may be used.

[0025]

According to the present invention, there is provided a contact detecting means for detecting the closing and opening of an electric contact provided in a magnetic switch of a starter, and a series connection member of a semiconductor element and a resistor connected in parallel at both ends of the contact. And delay time generating means,
An instruction detecting means for detecting a state of a key switch for turning on and off a magnetic switch, and a driving means for turning on and off the semiconductor element, and first closing and opening of a contact based on an ON signal of the instruction detecting means. Since the semiconductor device is provided with a technical means for turning on the semiconductor device during a predetermined delay time from the opening of the contact based on the OFF signal of the indication detecting means, and the semiconductor device being cut off, the magnetic switch contact of the starter is provided. Can be protected from remarkable damage and welding of the contacts due to the arc, and the life of the magnetic switch and the starter can be improved by extending the life of the contacts.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of the present invention.

FIG. 2 is an operation timing chart for explaining the operation of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Battery 12 ... Starter motor 8, 10B, 10M ... Contact 5 ... Magnetic switch 2 ... Key switch 20 ... Magnetic switch controller 201 ... Contact Detecting means 25 ... Semiconductor element 26 ... Resistance 202 ... Delay time generating means 203 ... Instruction detecting means 204 ... Driving means

Claims (1)

[Claims] An automotive engine starting system comprising: a magnetic switch having electrical contacts between a battery and a starter motor for a vehicle for interrupting the connection thereof; and a key switch for turning on and off the magnetic switch. In the magnetic switch control device according to the above, the contact detection means for detecting the closing and opening of the contact, a series connection member of a semiconductor element and a resistor connected in parallel to both ends of the contact, a delay time generating means An instruction detecting means for detecting the on / off of the key switch, and a driving means for conducting and blocking the semiconductor element, between the first closing and opening of the contact based on the ON signal of the instruction detecting means. A predetermined delay time from the opening of the contact based on the off signal of the indication detection means while the semiconductor element is turned on. A magnetic switch control device for a starter, wherein the semiconductor element is shut off after a lapse of the time.