JPH0491370A - Starter - Google Patents

Abstract

PURPOSE:To detect an overrun condition and a coasting rotary condition of a starter motor by a single detecting element by providing a magnetism-sensing element in a position, where a flow of current in an armature can be detected, and discriminating a direction and a level of the current, flowing in the armature, from a signal of this magnetism-sensing element. CONSTITUTION:A starter motor 1 is provided with a field magnet 11, consisting of a permanent magnet, to connect one end of an armature of the starter motor to the earth and the other end to a fixed contact 22 of a magnet switch 2. A positive pole of a battery 10 is connected to a key switch 4 and an auxiliary relay 3, and a start contact 41 of the key switch 4 is input to an input terminal (a) of a microcomputer 5 and also to a timer 6. Here, a magnetism-sensing element 7 is provided closely attached to a lead wire 13 for connecting an armature 12 of the starter motor 1 to the fixed contact 22. An output of this magnetism-sensing element 7 is input to the microcomputer 5 through a signal converter circuit 8, and after a predetermined time, driving of the auxiliary relay 3 is inhibited in the case that an armature current is smaller than a predetermined value and that a direction of the armature current is negative.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starter for starting an internal combustion engine, and more particularly to a control device for preventing starter overrun or jamming.

[Conventional technology]

When starting the engine, the starter does not stop even after the engine has started due to a failure in returning the key switch, resulting in an overrun failure, or when restarting after a failed start, the pinion of the starter motor, which is rotating due to inertia, hits the ring gear of the engine. If they mesh together, they can cause a huge impact and destroy the starter.

As a countermeasure to this problem, Utility Model Application No. 58-62172, Japanese Unexamined Patent Publication No. 6
Publication No. 2-162773 discloses a relay that detects the voltage of a dynamo or motor and interlocks the operation of the starter. [Problem to be solved by the invention] However, the key switch Overrun failure due to return failure and failure at restart during inert rotation have different failure modes, and if you try to prevent both failures, multiple voltage detection relays will be required, making the circuit complicated. was there.

The present invention was made in view of the above problems, and its purpose is to detect the two operating states of the starter, the overrun state and the inertial rotation state, with a single sensor, and to use a simple circuit. Therefore, it is an object of the present invention to provide a starter that can prevent overrun failures and remeshing failures.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an electromagnetic push type starter for an internal combustion engine, as illustrated in FIG. 1 armature 12 and power supply 10
A magnetic switch 2 having a solenoid coil consisting of contacts 21, 22, 23 for connecting and disconnecting the pinion, a plunger 26 for moving the pinion, a suction coil 24 for moving the plunger 26, and a holding coil 25;
One end of the armature 12 is connected to one end of the suction coil 24, and the solenoid coil 24.25
an auxiliary relay 3 having a contact 32 for connecting and disconnecting the current flowing through the armature 12 and the power supply 10; a magnetically sensitive element 7 provided at a position where the current flowing through the armature 12 can be detected; a determining means 8 for determining the direction and magnitude of the current flowing through the starting switch 4; a timer means 6 for determining whether a predetermined time has elapsed since the starting switch 4 was turned on; and a drive for driving the auxiliary relay 3 in accordance with a signal from the starting switch 4. According to the determination results from the determination means 8 and the timer means 6, if the armature current is smaller than a predetermined value after at least the predetermined time has elapsed, and if the direction of the armature current is negative, the auxiliary relay 3 A starter characterized in that it is provided with a prohibition means 5 for prohibiting driving.

[Effect]

In the starter configured as described above, the magnetically sensitive element 7 detects the direction and magnitude of the armature current of the starter motor 1. During normal starting, armature current as a load current flows in the positive direction (arrow A). On the other hand, in an overrun state in which the engine has completed starting and the starter is rotationally driven by the engine, the load current of the armature 12 is extremely reduced. In addition, in the inertial rotation state of the starter motor 1, the starter motor 1, which has the permanent magnet 11 in the field and the armature 12 is connected to the attraction coil 24, acts as a generator, and the negative direction opposite to the load current ( Armature current flows in the direction of arrow B). Therefore, the inhibiting means 5 prohibits the driving of the auxiliary relay 3 and the driving of the magnetic switch 2 in the two operating states of overrun state and inertial rotation state, thereby preventing overrun failure and re-engagement failure. prevent.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram showing a starter control circuit according to the present invention. The starter motor 1 includes a field magnet 11 made of a permanent magnet, one end of an armature 12 of which is grounded, and the other end connected to a fixed contact 22 of the magnetic switch 2 via a lead wire 13. The magnet switch 2 is a normal electromagnetic push type, and includes a plunger 26 provided with a pair of fixed contacts 21, a fixed contact 22, and a movable contact 23.
, a solenoid coil 24,25 consisting of a suction coil 24 and a holding coil 25 that drive the plunger 26. One end of the attraction coil 24 is connected to the armature 12 via the fixed contact 22, one end of the holding coil 25 is grounded, and the connection point between the attraction coil 24 and the holding coil 25 is connected to the contact 32 of the auxiliary relay 3. There is.

Further, the positive electrode of the battery 10 is connected to the movable contact 40 of the key switch 4 and the coil 31 of the auxiliary relay 3.

The negative electrode of battery 10 is grounded. The on contact 42 of the switch 4, which serves as a starting switch, is connected to the power terminal of the microcomputer 5, and supplies power to the microcomputer 5. Microcomputer 5 is RO
This is a well-known microcomputer 5 that includes M, RAM, CP, U, and the like. The starting contact 41 of the key switch 4 is
The signal is input to the input terminal a of the microcomputer 5 and is also input to the timer 6. The timer 6 outputs an H level signal for a predetermined period of time, for example, one second, after the input signal becomes H level (high level), and thereafter outputs an L level (low level) signal.

The output signal of the timer 6 is input to the input terminal of the microcomputer 5.

A magnetically sensitive element 7 is provided in close contact with a lead wire 13 connecting an armature 12 of the starter motor 1 and a fixed contact 22. The magnetically sensitive element 7 is made of, for example, a Hall element 7, and is a member that detects a magnetic field caused by an armature current.

Hall element 7 is connected to signal conversion circuit 8 . The signal conversion circuit 8 is a signal conversion circuit 8 that identifies the Hall voltage vh from the Hall element 7, encodes the range to which the Hall voltage vh belongs, and outputs the encoded range to the input terminals c and d of the microcomputer 5. The output (c, d) from the signal conversion circuit 8 indicates that the Hall voltage vh is larger than the predetermined threshold value VS (Vh≧V
s), (c, d) (H, H), Hall voltage vh
is larger than 0 and smaller than the predetermined threshold Vs (0≦Vh<Vs
), then (c, d) - (LSI), Hall voltage v
When h is smaller than 0 (Vh<0), (c, d) − (L
, L). Here, the Hall voltage vh is positive when the armature current flows in the direction of the arrow A shown in the figure (the direction of the load current).

The output terminal of the microcomputer 5 is connected to the relay drive circuit 9
It is connected to the. The relay drive circuit 9 is a circuit that connects and connects the coil 31 of the auxiliary relay 3 and the negative electrode of the battery 10, and when it receives an H level signal from the microcomputer 5, it allows energization and excites the auxiliary relay 3. The microcomputer 5 determines the state of the starter according to the conditions input to input terminals a, b, , c, and d, drives the auxiliary relay 3, and controls the magnetic switch 2.

FIG. 2 is a flowchart showing the processing in the microcomputer 5.

The driver starts the stopped engine (by operating the key switch 4. First, when the movable contact 40 is connected to the on contact 42, power is supplied to the microcomputer 5 and the flow shown in FIG. 2 starts. 40 is on contact 4
2, in step 501 an L level is output to the relay drive circuit 9, the auxiliary relay 3 is de-energized, the contact 32 is opened, and the process waits in step 502.

When the driver further turns the key switch 4 and the movable contact 40 is connected to the starting contact 41, the input terminal a becomes H level, and the process proceeds from step 502 to step 503. At this time, no current is flowing through the armature 12 yet, the output vh of the Hall element 7 is 0, and the output of the 5-signal conversion circuit 8, that is, the inputs (c, d) of the microcomputer 5 are (L, H )
becomes.

Therefore, the process advances from step 503 to step 504. At this time, since the key switch 4 has just been switched and the output of the signal conversion circuit 8 is H, input terminal b=H.
The process advances from step 504 to step 505.

In step 505, the microcomputer 5 outputs an H level to the relay drive circuit 9, energizes the auxiliary relay 3, and starts operating the magnetic switch 2. Since the movable contact 40 of the key switch 4 remains connected to the starting contact 41, the process returns from step 506 to step 503, and steps 503, 504, 505, and 506 are repeated.

In a short period of time, the contacts 21, 22, 23 close, a large current begins to flow through the armature 12 of the starter motor 1, the output voltage vh of the Hall element 7 becomes larger than the threshold value Vs, and the microcomputer 5 Input terminals (c, d) are (H, H
). Therefore, from step 503 to step 50
7 and repeats steps 503, 507, 505, and 506, during which engine cranking continues.

When the engine eventually starts successfully and the rotational speed increases, the starter motor 1 becomes overrun. At this time, the load on the starter motor 1 becomes extremely small, so
The current in the armature I2 is also extremely small. Therefore, the output voltage vh of the Hall element 7 becomes smaller than the threshold value Vs, and the input terminals (c, d) of the microcomputer 5 become (
and H). Therefore, the process advances from step 503 to step 504. On the other hand, the key switch 4 is connected to the starting contact 41
Since a sufficient amount of time has passed since the switch was made, the timer 6 has timed up and the input terminal (b) of the microcomputer 5 has changed to (L). Therefore, the process proceeds from step 504 to step 508, returns to step 501, outputs the L level to the relay drive circuit 9, and turns off the auxiliary relay 3. As a result, the excitation of the holding coil 25 of the magnetic switch 2 is cut off, the plunger 26 returns, and the magnetic switch 2 is separated from the engine. Even if the driver continues to turn the key switch 4 to the starting contact 41 position, steps 501.502.5
The process of 03.504.508 is repeated, the magnet switch 2 remains stopped, and an overrun failure is prevented.

While cranking the engine, the driver presses the key switch 4.
When the input terminal (a) of the microcomputer 5 becomes (L), the input terminal (a) of the microcomputer 5 becomes (L
), the process advances from step 506 to step 508 to exit the cranking loop, and in the next step 501 the auxiliary relay 3 is cut off by +1 to stop the operation of the magnetic switch 2. Then, step 502 is repeated to wait for the driver's next operation.

Immediately after cranking is interrupted, while the armature 12 is rotating by inertia, the driver presses the key switch 4 again to the start contact 4.
The processing when the operation is performed in step 1 will be explained. Armature 12
During inertia rotation, the starter motor 1 operates as a generator due to the field of the field magnet 11, and the armature 12 current, which becomes the brake current, flows from the armature 12 to the fixed contact 22 to the attraction coil in the direction of arrow B in the figure. 24, holding coil 25, and then to ground in the opposite direction. For this reason, the Hall element 7
The output voltage vh becomes negative, and the input terminals (c, d) of the microcomputer 5 become (L, L).

Therefore, the process advances from step 503 to step 508 via step 507. Result, step 501.50
The processes in steps 2, 503, 507, and 508 are repeated, and the magnetic switch 2 remains stopped, thereby preventing a meshing failure during inert rotation.

Even after the armature 12 has stopped, the driver can press the key switch 4.
If the start contact 41 remains operated, the Hall element 7
The output vh of the signal conversion circuit 8, that is, the input (c, d) of the microcomputer 5 becomes (L, H), but the timer 6 times up and the input terminal (b) of the microcomputer 5 becomes (L, H). has changed to (L), so
Proceeding from step 504 to step 508, the microcomputer 5 performs step 501.502.503.50.
4. The process of 508 is repeated, and the magnet switch remains stopped. Once the driver returns the key switch 4 to the ON contact 42, the timer 6 is reset and the engine is in the state before it is started, making it possible to restart the engine.

Among the processes in the microcomputer 5 explained above,
The processing in steps 503, 504, and 507 is performed when the armature current is smaller than a predetermined value after at least the predetermined time has elapsed according to the determination results from the determination means 8 and the timer means 6, and when the direction of the armature current is negative. A prohibition means for prohibiting the driving of the auxiliary relay 3 is provided.

〔Effect of the invention〕

The present invention provides a magnetically sensitive element having the above-mentioned configuration and provided at a position where the current flowing in the armature can be detected, and a determining means for determining the direction and magnitude of the current flowing in the armature from the signal of the magnetically sensitive element. Since it is equipped with It has the excellent effect of being able to be transformed into

Peter, 60. Timer, 70. Magnetically sensitive element (
Hall element), 8. , signal conversion circuit (discrimination means),
90. Relay drive circuit, 115. Field magnet, 1
21. Armature, 240. Suction coil, 259. holding coil, 261. plunger

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a circuit diagram of a starter device, and FIG. 2 is a flowchart showing actual processing by a microcomputer.

Claims (1)

[Scope of Claim] In an electromagnetic push-type starter for an internal combustion engine, there is provided a starter motor having a permanent magnet in its field, a contact that connects and disconnects the armature of the starter motor and a power source, a plunger that moves a pinion, and the plunger. a magnetic switch having a solenoid coil consisting of an attraction coil and a holding coil for moving the armature; one end of the armature is connected to one end of the attraction coil; and a contact point that connects and disconnects the solenoid coil and the power source. a magnetically sensitive element provided at a position capable of detecting the current flowing through the armature; a determining means for determining the direction and magnitude of the current flowing through the armature from a signal from the magnetically sensitive element; a timer means for determining whether a predetermined time has elapsed since the switch was turned on; a driving means for driving the auxiliary relay according to a signal from the starting switch; and a timer means for determining whether a predetermined time has passed since the switch was turned on; A starter comprising: prohibition means for prohibiting driving of the auxiliary relay when the armature current is smaller than a predetermined value and when the direction of the armature current is negative.