JPH0221592Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electric starting device such as a magnetic starter using a permanent magnet as a field device.

[Conventional technology]

FIG. 3 shows a conventional electric starter disclosed, for example, in Japanese Utility Model Application No. 58-139583.

In this figure, reference numeral 1 indicates an electromagnetic push-type magnet type starter consisting of a DC motor 2 and an electromagnetic switch 3 attached to the DC motor 2. Reference numeral 4 indicates a permanent magnet, which connects the armature 5 of the DC motor. 6A is a positive electric brush that is in sliding contact with the armature 5, 6B is a negative electric brush, and 7 is a main contact of an electromagnetic switch, which is a pair of normally open fixed contacts 8A, 8.
B, a pair of normally closed fixed contacts 9A and 9B, and a movable contact 10 that is movably disposed between each of the fixed contacts and is normally in contact with the normally closed contacts 9A and 9B.
and a movable iron core 11 fixed to this movable contact.

Note that a spring (not shown) acts on the movable core 11, so that the normally closed contacts 9A,
The movable contact 9B and the movable contact 10 are kept in contact with each other, and are cam-engaged with a pinion (not shown) spline-engaged with the output rotating shaft of the armature 5 via a shift lever (not shown).
Reference numeral 12 denotes a current coil that attracts and energizes the movable iron core 11, which moves the movable iron core 11 to the left in the figure when energized. 13 is a voltage coil for maintaining the movable iron core 11 in an adsorbed state;
4 is a battery, and 15 is a key switch.

In such a configuration, the starting switch 15 is closed and the voltage of the battery 14 is changed to the current coil 12.
is applied to the voltage coil 13, and the movable iron core 11 is moved to the left in the figure by the biasing forces of both coils 12 and 13. As a result, the armature 5 is is energized and rotated with low power, that is, auxiliary rotation.

As a result, the pinion (not shown) is engaged with the internal combustion engine (not shown), and the movable contact 10 comes into contact with the normally open contacts 8A, 8B to close the two contacts, so that the voltage of the battery 14 is applied to the armature 5. Then, the DC motor 2 generates a rated output and the internal combustion engine (not shown) is started. After starting the engine, when the starting switch 15 is opened, the movable core 11 is released from the suction state and returns to the state shown in the drawing. By this return, the normally closed contacts 9A and 9B are closed by the movable contact 10, and the positive electrode brush 6A of the armature 5 is connected to the normally open contact 8B - normally closed contact 9B - movable contact 10 - normally closed. Since the contact point 9A is grounded via the line 16, the inertial rotation of the DC motor 2 is rapidly stopped.

[Problem that the invention attempts to solve]

However, in the conventional device described above,
Since mechanical contacts were used to form the grounding circuit, the reliability was insufficient.

This invention was made in order to eliminate such drawbacks, and is an attempt to obtain a highly reliable electric starting device.

[Means for solving problems]

The electric starter according to this invention operates when the starting switch is turned on to close the energizing circuit of the main switch current coil, and operates in response to the opening of the closed main switch, grounding the motor and causing inert rotation. It is equipped with a semiconductor switch to stop the operation.

[Effect]

By using a common semiconductor switch to form the current coil energizing circuit and motor grounding circuit of the main switch, there is no mechanical contact between the contacts, making it possible to dramatically improve reliability. .

〔Example〕

An embodiment of this invention shown in FIG. 1 will be described below.

In this figure, 17A and 17B are fixed contacts, 1
Reference numeral 0 denotes a movable contact that opens and closes the fixed contact, and is constructed in the same manner as the conventional movable contact shown in FIG. 1
8A and 18B are diodes, and 19 is a semiconductor switch, which is a feature of this invention, and is constructed by connecting a PNP transistor 20 and an NPN power transistor 21 as shown in the figure.

Further, 22 is a charging/discharging circuit that is charged and discharged in connection with the opening/closing operation of the starting switch 15, and a capacitor 24
and a resistor 25. The rest of the configuration is the same as the conventional device shown in FIG. 3, so the explanation will be omitted.

In this device, when the start switch 15 is turned on, the capacitor 24 of the charging/discharging circuit is charged.
Until the potential reaches a predetermined value, the PNP transistor 20 is conductive, and therefore the NPN power transistor 21 is also conductive, so the current coil 12 and the voltage coil 13 are energized, and the movable contact 10 is connected between the fixed contacts 17A and 17B. Closing the switch, rotating the DC motor 2, and starting the internal combustion engine (not shown) are similar to conventional ones.

After starting the internal combustion engine, when the starting switch 15 is opened, the capacitor 24 discharges through the resistor 25 and its potential gradually drops. conducts, and the semiconductor switch 19 is closed.

As a result, the positive electrode brush 6A of the DC motor 2 is grounded through the semiconductor switch 19, and the inertial rotation of the DC motor is stopped.

Incidentally, even if another fixed contact is provided in place of the above-mentioned charging/discharging circuit, similar effects can be obtained, and an embodiment in this case is shown in FIG. 2. In this figure, 2
Reference numeral 6 denotes a third fixed contact, which is closed like the other fixed contacts 17A and 17B when the movable contact 10 moves. Further, the third fixed contact 26 is connected to the connecting wire 2
7 to the base of the PNP transistor 20 and each fixed contact 17 by a movable contact 10
When A, 17B, 26 are closed, the voltage of the battery 14 is applied to the base of the PNP transistor 20 via the third fixed contact 26, turning off this transistor. Further, 28 is a resistor for overcurrent prevention.

The rest of the configuration is the same as that of the device shown in FIG. 1, so the explanation will be omitted.

In this device, when the start switch 15 is turned on, the PNP transistor 20 and therefore the NPN power transistor 21 are also turned on, so the current coil 12 and the voltage coil 13 are energized, the movable contact 10 is attracted, and the fixed contacts 17A, 17B and the third The fixed contact 26 is closed.

As a result, the DC motor 2 is energized and the internal combustion engine (not shown) is started. On the other hand, the PNP transistor 20 and the NPN power transistor 21 are each turned off, and the current coil 12 is deenergized, but since the voltage coil 13 is energized, each fixed contact 1
The closed states of 7A, 17B, and 26 are maintained. When the internal combustion engine is started and the starting switch 15 is opened, the voltage coil 13 is also deenergized and the movable contact 10 returns to the state shown.

At this time, the voltage of the armature 5 is applied to the semiconductor switch 19, and the PNP transistor 20 and NPN
Both power transistors 21 are turned on, and a grounding circuit for the armature 5 is formed. Then, the inertia rotation of the DC motor is stopped. In this case, fixed contact 1
If 7A, 17B, and 26 are not released, braking will not occur, so the operation is reliable.

In addition, in the above embodiment, as a semiconductor switch
Although we have shown examples using PNP transistors and NPN power transistors, as a semiconductor switch,
Similar effects can also be expected by using field effect transistors (FETs) and thyristors.

[Effect of idea]

This invention is constructed as described above, and connects the other end of the current coil of the main switch and the armature of the DC motor.
Since each of the switches is grounded by a common semiconductor switch, the reliability of the switch is significantly improved, and the drive of the main switch and the stop of inertia rotation can be reliably performed.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of this invention, Figure 2 is a circuit diagram showing another embodiment of this invention, and Figure 3 is a circuit diagram showing another embodiment of this invention.
The figure is a circuit diagram showing a conventional configuration. In the diagram, 1 is a magnetic starter, 2 is a DC motor, and 3
is an electromagnetic switch, 4 is a magnetic pole, 5 is an armature, 7 is a main contact, 8A, 8B are normally open fixed contacts, 9A, 9B are normally closed fixed contacts, 10 is a movable contact, 11 is a movable iron core, 12 is a current coil , 13 is a voltage coil, 14
is the battery, 15 is the start switch, 18A, 1
8B is a diode, 17A, 17B are fixed contacts,
19 is a semiconductor switch, and 22 is a charging/discharging circuit. Note that the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) Comprising a current coil and a voltage coil, the current coil is closed when the starting switch is turned on, and the voltage coil is deenergized when the starting switch is opened. A main switch that opens in response to the current coil and energizes the motor for starting the engine when the starter switch is closed; An electric starter equipped with a semiconductor switch that operates in response to opening of a main switch to ground the motor and stop inertial rotation. (2) Claim 1 of the utility model registration, which is characterized in that a capacitor is provided which is charged and discharged in connection with the operation of the starting switch, and the operation of the semiconductor switch is controlled by the potential of this capacitor. Electric starting device as described. (3) The first claim for utility model registration is that the semiconductor switch is composed of transistors.
The electric starting device according to item 1 or 2. (4) The electric starting device according to claim 1 or 2, wherein the semiconductor switch is composed of a thyristor.