JP2001153007A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine starter in which miniaturization, weight- reduction, and cost reduction of a wiring around a key-switch are achieved, and in which the reliability is improved. SOLUTION: An engine starter 100 of this invention is provided with a magnet switch 1 and a starter motor 2. The magnet switch 1 is equipped with a main switch 10 having a main terminal 11 and a connecting terminal 12, and a coil current control element 15 in addition to a plunger 13 for opening or closing the main switch 10 and a coil 14. The coil current control element 15 is MOS-FET, and on-off controls current flowing from the main terminal 11 to energize the coil 14 based on an input signal from a key switch K. Since the current for input signal can be feeble, a signal wire L can be thin and light. Thus, the wire is difficult to be influenced by connection resistance, and thereby miniaturization, weight and cost reduction of the wiring, and the improvement of the reliability of the engine starter 100 itself are made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a starter for starting an engine by the rotational force of a starter motor.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Patent Laid-Open No. 59-18 / 1984.
A starter having a magnet switch disclosed in Japanese Patent No. 5869 and Japanese Patent Application Laid-Open No. 57-210533 is known.

A starter 10 for a motor vehicle according to the prior art
0 'has a magnet switch 1' connected to the positive terminal of the battery B and a starter motor (DC motor) 2 to which power is supplied via the magnet switch 1 ', as shown in FIG.

The magnet switch 1 ′ includes a main terminal 11 connected to a battery B, a connecting terminal 12 connected to a starter motor 2, and a movable contact held at one end of a plunger 13. It has a switch 10. The magnet switch 1 'further includes a plunger 13 for opening and closing the main switch 10,
And a coil 14 composed of a pull-in coil and a holding coil for sucking the plunger 13. And
The coil 14 is connected to the 50th terminal.

On the other hand, outside the starter 100 ', the coil wiring L' extends from the positive terminal of the battery B in the engine room to the 50th terminal via the key switch K 'in the driver's seat.

Therefore, when the key switch K 'is closed, a current flows from the battery B to the coil 14 via the key switch K', the coil wiring L 'and the 50th terminal. Then, the coil 14 generates a magnetic attraction to attract the plunger 13 and close the main switch 10. As a result, a large current flows through the starter motor 2 via the main switch 10, and the starter motor 2 rotates with a large output to start the engine.

[0007]

However, in the above-mentioned prior art, the key switch K is provided so that the coil 14 can exert a magnetic attraction force sufficient to attract the plunger 13 and close the main switch 10. It is necessary to flow a large amount of current to 'and the coil wiring L'.
Here, in a passenger car equipped with a normal gasoline engine, this current is about ten and several A. That is, the above-mentioned key switch K ′, coil wiring L ′ and terminal No. 50 are:
In order to be able to withstand a current of this magnitude with sufficient safety, it must be designed to be large and thick and have a sufficiently large current capacity.

As a result, the above-mentioned key switch K ', coil wiring L' and terminal No. 50 have to be thick and large to some extent, and it is difficult to reduce their size and weight. For the same reason, it is difficult to reduce the cost.

[0009] In addition, the coil wirings L 'and 5
Rust may be generated at the joint with the No. 0 terminal and the connection resistance may increase, or the resistance of the coil wiring L 'and the like may increase due to various environmental deterioration such as high temperature. If the resistance increases too much, the current flowing through the coil 14 decreases, and the coil 14
Cannot exert sufficient magnetic attraction, and the main switch 10 malfunctions. As a result, the starter 10
The reliability of 0 'may decrease.

[0010] Therefore, an object of the present invention is to provide a starter that can reduce the size and weight of the wiring around the key switch, reduce the cost, and improve the reliability.

[0011]

In order to solve the above problems, the inventor has invented the following means.

(First Means) A first means of the present invention is a starter according to claim 1.

That is, in the starter of the present means,
The magnet switch has a coil current control element for turning on / off the energization from the main terminal to the coil by an input signal.

In this means, the current to the starter motor is:
It is turned ON / OFF by opening and closing the main switch.
The energization of the coil that attracts the plunger that opens and closes the main switch is controlled by a coil current control element. That is, the coil current control element turns ON / OFF the energization from the main terminal to the coil based on the input signal.
Then, the main switch is opened and closed.

Here, it is desirable at this stage that the coil current control element is a semiconductor switching element as described in the second means, but other switching means such as a relay may be used. I do. Also,
The input signal to the coil current control element may be an electric signal or a signal other than an electric signal such as an optical signal. When the starter of the present means is mounted on an automobile, an input signal is operated via a signal line from a key switch in a driver's seat. However, when the starter is not necessarily for an automobile, a key switch or a signal is used. Lines are not required. It should be noted that key switches and signal lines are not indispensable components of the starter of the present means, even if the starter is for an automobile.

Further, the coil current control element turns on / off the energization from the main terminal to the coil, but need not be connected so as to directly take out the current from the main terminal. In other words, the coil current control element only needs to be provided so that the main terminal and the coil are connected over a short distance. In short, the connection between the main terminal and the coil within the starter of the present means is the coil current control element. It is only necessary to be connected so as to be controlled by the control element. Even if a part of the wiring connecting the main terminal, the coil and the coil current control element protrudes out of the frame of the starter of the present invention, the wiring is a part of the starter of the present invention and is located inside. Is considered.

In this means, if the signal line from the battery (or from the main terminal) to the coil current control element via the key switch is an electric wire, a signal line having an extremely small amount of current is sufficient. That is, thick wiring from the battery (or from the main terminal) to the coil via the key switch is not required, and the current capacity of the contact of the key switch can be reduced. In addition, since a large current does not need to flow through the connection portion of the signal line, a small and simple connection method can be used.

That is, in the configuration of the starter of this means,
A relatively large current flowing through the coil only flows through a short wiring connecting the main terminal, the coil and the coil current control element. Therefore, it is not necessary to dispose a long electric wire having a large current capacity and to use a thick and heavy wiring such as connecting the engine room to the starter of the engine room via the key switch of the driver's seat and the engine room. Instead, a thin and light signal line for transmitting an input signal is provided.

As a result, it is possible to reduce the size, weight, and cost of the thin and light signal lines by the weight, capacity and cost of the thick and heavy electric wires having a large current capacity. Here, the coil current control element is relatively inexpensive, small and lightweight, and the wiring connecting the main terminal and the coil to the coil current control element is sufficiently short. There is little hindrance.

In addition, if the input signal is a voltage signal, even if the resistance of the signal line increases to some extent, the signal line only needs to be able to mainly transmit the voltage, and a large current cannot flow through the signal line. Since it is not required, the coil current control element operates with high reliability. As a result, if there is an input signal from the signal line, the coil current control element operates reliably and the coil exerts a specified magnetic attraction, so that the main switch also operates reliably. If the signal line is a signal line other than an electric wire such as an optical fiber, there is a great possibility that the reliability is further improved.

Therefore, according to the starter of this means,
There is an effect that the wiring around the key switch can be reduced in size and weight, the cost can be reduced, and the reliability can be improved.

(Second Means) A second means of the present invention is a starter according to claim 2.

That is, in this means, a semiconductor switching element is employed as the coil current control element. As a semiconductor switching element, a power transistor, F
Typical are transistors such as ET and IGBT. It is also possible to employ not only a transistor that receives a gate current but also a semiconductor switching element that uses an optical signal as an input signal by combining a phototransistor and an FET.

The operation and effect will be described below when a semiconductor switching element whose input signal is an electric signal is used as a coil current control element.

The gate current of the semiconductor switching element required to flow the coil current for attracting the plunger to the semiconductor switching element is orders of magnitude smaller than the coil current, for example, about one hundredth. Therefore, the signal line can be formed of an extremely thin and light lead wire, and the effect of reducing the size and weight and reducing the cost is great. Further, unlike a relay or the like, a semiconductor switching element has no mechanical contact and is a solid state, and therefore has extremely high reliability.

Therefore, according to this means, there is an effect that the effect of the first means is further enhanced.

(Third Means) A third means of the present invention is a starter according to claim 3.

In this means, since the input signal is an electric signal that is energized via the key switch, it can be easily modified for a conventional vehicle model, and can be implemented when a minor model change is made. . Further, since the configuration is simple, the reliability is also high.

Therefore, according to this means, in addition to the effects of the first means or the second means described above, there is an effect that it is easy to modify a conventional vehicle model.

(Fourth Means) A fourth means of the present invention is the starter according to claim 4.

According to the present invention, since the magnet switch has a control circuit for controlling the input signal based on the electric signal from the key switch and a predetermined condition, more advanced control of the starter motor is possible. For example, it is possible to prevent the starter motor from being overheated by detecting the operation time of the starter motor and not driving the starter motor for more than a predetermined time. In a starter of the type in which the plunger pushes out the pinion and engages with the ring gear of the engine, the magnetic attraction of the coil is adjusted with a chopper or the like until the main switch is closed so that the pinion slowly comes into contact with the ring gear of the engine. You can also.
Alternatively, if a rotational speed sensor or a temperature sensor for the starter motor is provided and input signals from these sensors are taken into the control circuit, centrifugal damage due to overspeed can be prevented, and burnout due to overheating can be more effectively prevented. Also becomes possible.

Therefore, according to this means, in addition to the effects of the first means or the second means, more advanced control of the starter motor becomes possible, and the reliability of the starter can be further improved. It has the effect of becoming.

(Fifth Means) A fifth means of the present invention is the starter according to the fifth aspect.

That is, in this means, one end of the coil is connected to one of the main terminal and the connecting terminal, and the other end is connected to the other of the main terminal and the connecting terminal via the coil current control element.
Here, being connected to the connecting terminal is electrically equivalent to being connected to the positive terminal of the starter motor.

Therefore, since the coil is grounded to the terminal of the starter motor, the current flowing in the coil flows through the starter motor when the coil is energized, and the starter motor rotates slowly with relatively weak power. Start.
As a result, in a starter in which the pinion pops out and meshes with the ring gear of the engine, the meshing impact between the pinion and the ring gear is reduced, reducing noise and impact.
The pinion and ring gear will last longer. Also, the starter motor will last longer as much as the impact load is reduced.

Therefore, according to this means, in addition to the effects of the above-described first means to the fourth means, the engagement impact between the pinion and the ring gear is reduced, so that the noise is reduced, and the starter motor and the gear can last longer. This has the effect.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the starter of the present invention will be more clearly and fully described in the following examples so that those skilled in the art can understand the present invention.

[First Embodiment] (Configuration of First Embodiment) As shown in FIG. 1, a starter 100 according to a first embodiment of the present invention mainly includes a magnet switch 1 and a starter motor 2. here,
FIG. 1 is a circuit diagram in which a starter 100 of the present embodiment is illustrated in a state where the starter 100 is mounted on an automobile equipped with a normal piston engine.

The magnet switch 1 has positive and negative terminals 1
The main switch 10 includes a main switch 10, a plunger 13 for opening and closing the main switch 10, and a coil 14 for attracting the plunger 13. Here, main switch 1
0 has a main terminal 11 connected to the positive terminal of the battery B as a DC power supply, and a connecting terminal 12 connected to the starter motor 2. A movable contact (not shown) is fixed to one end of the plunger 13 on the side of the main switch 10. When the plunger 13 is attracted to the coil 14, the movable contact connects the positive and negative terminals 11 and 12 to each other. Switch 10 is closed.

On the other hand, a drive lever (not shown) is connected to the other end of the plunger 13. When the plunger 13 is attracted to the coil 14, the drive lever has a magnetic attractive force acting on the plunger 13. Lean. The drive lever projects a pinion driven by the starter motor 2 like a lever toward a ring gear on the engine side (both not shown).

The magnet switch 1 is of a so-called two-coil type, and the coil 14 is composed of a pull-in coil for attracting the plunger 13 and a holding coil for holding the attracted plunger.

The starter motor 2 is a DC motor,
When the main switch 10 is closed, a large current is supplied from the battery B via the main switch 10, and the pinion gear is rotationally driven to start the engine.

The feature of the starter 100 of this embodiment is that the magnet switch 1 has a coil current control element 15 for turning on / off the energization from the main terminal 11 to the coil 14 by an input signal. Coil current control element 15
Is housed in a small internal space formed in a portion of the frame of the magnet switch 1 adjacent to the main terminal 11. One end of the coil current control element 15 is in the main terminal 11, and the other end is in the middle of the coil 14. It is connected to the.

That is, the coil lead from which the coil current control element 15 supplies a current to the pull-in coil of the coil 14 is connected to the connection terminal between the pull-in coil and the holding coil from the main terminal 11 of the magnet switch 1 via the coil current control element. Extends to Here, since the coil current control element 15 is disposed close to both the main terminal 11 and the coil 14, the coil lead is very short.

As the coil current control element 15, a MOS-FET, which is a semiconductor switching element, is employed. The signal line L is connected so that the gate voltage is supplied from the positive terminal of the battery B via the key switch K. I have. That is, the signal line L is a thin signal-coated electric wire branched from somewhere in the thick wiring between the positive terminal of the battery B and the main terminal 11 of the main switch 10. Signal line L
Extends from inside the engine room to the starter 100 in the engine room again via the key switch K in the driver's seat,
It is as long as the coil wiring L 'of the prior art. However, since the signal line L need only flow a current that is about two orders of magnitude smaller than that of the conventional coil wiring L ', it is extremely light and inexpensive for its length.

For the same reason, the contacts of the key switch K are reduced in size and weight, and the size and weight of the key switch K are reduced and the cost is reduced. Further, since the input signal of the coil current control element 15 is an electric signal that is supplied through the key switch K, the conventional starter can be changed from the conventional starter to the starter 100 according to the present embodiment with almost no modification to a conventional car. Can be replaced with

(Operation and Effect of First Embodiment) The starter 100 of this embodiment is configured as described above, and exhibits the following operation and effect.

As described above, the starter 100 of this embodiment is
Then, the current to the coil 14 when the pull-in coil is activated is
The power is supplied through a very short coil lead via a coil current control element 15 arranged near the main terminal 11 and the coil 14. An input signal for controlling the coil current control element 15 is applied to the base terminal of the coil current control element 15 from the battery B via a very thin and light signal line L via the key switch K. In other respects, the operations of the magnet switch 1 and the starter motor 2 are the same as those of the starter 100 '(see FIG. 5) having the ordinary two-coil magnet switch 1'.

As described above, the starter 100 of this embodiment is
In this case, the signal line L from the wiring of the positive terminal of the battery B to the coil current control element 15 via the key switch K may be a thin and light lead wire. Therefore, a thick coil wiring L 'that reaches the coil 14 via the key switch K (see FIG. 5).
Is unnecessary, and the current capacity of the contact of the key switch K can be reduced. Also, since a large current does not need to flow through the connection portion of the signal line L, each connection portion of the signal line L is also compact and simple.

As a result, from the weight, capacity, and cost from the thick and heavy coil wiring L ′ (see FIG. 5) having a large current capacity, the thin and light signal lines L are subtracted from the weight, capacity and cost.
It is possible to reduce the size and weight and reduce the cost. Here, the coil current control element 15 is relatively inexpensive, small and lightweight, and the coil lead is very short. Therefore, any of these does not hinder reduction in size and weight and cost reduction.

In addition, since the input signal is mainly a voltage signal and the current capacity is small, even if the resistance of the signal line L is increased to some extent, the coil current control element 15 operates with high reliability. I do. As a result, if there is an input signal from the signal line L, the coil current control element 15
Operates reliably, and the coil 14 exerts a prescribed magnetic attraction, so that the main switch 10 also operates reliably. Further, the coil current control element 15 is a MOS-FET,
Since it is a solid state without moving parts, its reliability is extremely high.

Therefore, according to the starter 100 of the present embodiment, it is possible to significantly reduce the size and weight of the wiring around the key switch K, reduce the cost, and improve the reliability.

In addition, since the input signal is an electric signal that is supplied through the key switch K, it can be easily modified for a conventional car model, and is implemented when a minor model change of the car is performed. You can also. Therefore, according to the starter 100 of the present embodiment, it is extremely easy to mount it on a conventional vehicle type, and there is an effect that costs associated with a change in the design of a car and a change in manufacturing equipment can be saved.

[Embodiment 2] (Configuration of Embodiment 2) As shown in FIG. 2, the configuration of a starter 100 according to the present embodiment is such that an electric signal from a key switch K attached to a magnet switch 1 and a predetermined condition. This embodiment differs from the first embodiment in that a control circuit 16 for controlling an input signal based on the control signal is provided.

That is, the starter 100 of this embodiment is
An internal space is formed in the frame near the main terminal 11 and the coil 14 of the magnet switch 1, and a control circuit 16 is housed in the internal space together with the coil current control element 15 described above. The control circuit 16 is a microcomputer having a digital operation circuit, and has a function of applying an input signal of a predetermined voltage to the gate terminal of the coil current control element 15 based on an electric signal from the key switch K and predetermined conditions. have.

The control circuit 16 includes a coil current control element 15
Has a timer that measures the time during which an input signal is applied to the gate of the. The control circuit 16 has an input terminal such as an A / D converter, and can receive signals from various sensors provided at various locations.

That is, the starter motor 2 is provided with a current sensor (not shown) for inserting a shunt resistor and measuring the current flowing through the starter motor 2, and a thermistor temperature sensor (not shown). The temperature and current of the starter motor 2 are monitored by the control circuit 16.
Further, the output from the existing engine speed sensor is branched and taken into the control circuit 16, and the control circuit 16 also monitors the engine speed.

In addition, the control circuit 16 protects its own circuit when the input voltage is abnormally high and appropriately limits the voltage of the input signal to the coil current control element 15 (not shown). ). Further, the control circuit 16 has a chopper circuit (not shown) for turning on / off an input signal at a predetermined duty ratio as needed, for example, at the beginning of operation of the starter 100.

(Operation and Effect of Second Embodiment) Since the starter 100 of this embodiment has the control circuit 16 in the magnet switch 1 as described above, the same operation and effect as those of the first embodiment can be obtained. 2 enables more advanced control.

That is, in the starter 100 of this embodiment, the control circuit 16 has the following functions.

First, the control circuit 16 controls the key switch K
The protection circuit protects its own circuit even if the input signal from the device becomes high voltage due to some kind of trouble such as an electromagnetic pulse. At the same time, the control circuit 16 causes the input signal to be applied to the gate of the coil current control element 15 at an appropriate voltage. As a result, failure of the coil current control element 15 and the control circuit 16 due to the application of the high voltage is prevented,
The reliability of the starter 100 increases.

Second, the control circuit 16 limits the time during which the input signal to the coil current control element 15 is set to a high potential to within a predetermined time (for example, within 10 seconds) by measuring the time by a timer, and performs continuous operation. To prevent the starter motor 2 from being overheated and burned.

Third, the control circuit 16 detects the engine speed and, when the engine speed reaches a predetermined value, sets the input signal to a low potential to open the main switch 10 and the starter motor 2
Stop supplying power to As a result, it is possible to avoid a situation in which the engine is started and the starter motor 2 is kept energized despite the engine running at a sufficiently high speed due to a driver error or the like.
Centrifugal destruction can be prevented. Also, even if the key switch K is accidentally closed even though the engine is already running, the coil 14 is not energized, so that the pinion hits the rotating ring gear and produces abnormal noise. No vibration or vibration occurs.

Fourth, the control circuit 16 detects the current flowing through the starter motor 2 and, when the current deviates from a predetermined safe range, opens the main switch 10 to stop the power supply to the starter motor 2. That is, since the current flowing through the starter motor 2 decreases as the rotation speed of the starter motor 2 increases, the power supply to the starter motor 2 is stopped when the current falls below a predetermined value, and the starter motor 2 To prevent centrifugal destruction of Conversely, when there is an abnormality such as a short circuit in the starter motor 2 and a large current flows through the starter motor 2 beyond the range of the normal start-up current, the power supply to the starter motor 2 is stopped and the starter motor 2 is turned off. Prevent overheating burnout.

Fifth, the control circuit 16 monitors the temperature of the starter motor 2, and when the temperature exceeds a predetermined value, the main switch 10 is kept open and does not close. To prevent

Sixth, the control circuit 16 controls the key switch K
The input signal to the coil current control element 15 is finely turned on / off by a chopper circuit until the main switch 10 is closed and a large current flows to the starter motor 2 after the switch is closed.
Then, the magnetic attraction force of the coil 14 is appropriately reduced, the speed at which the plunger 13 is attracted to the coil 14 becomes slow, and the pinion pushed out by the plunger 13 projects slowly. As a result, the pinion and the ring gear gently abut against and engage with each other, so that the pinion and the ring gear are protected and the engagement between the two can be obtained stably.

Therefore, according to the present embodiment, the function of the control circuit 16 as described above allows the magnet switch 1
In addition, more advanced control of the starter motor 2 becomes possible. As a result, not only effects similar to those in the first embodiment are obtained, but also the effect that the reliability of the starter 100 can be further improved with a slight increase in cost required for the control circuit 16 is obtained.

(Modification 1 of Embodiment 2) As Modification 1 of this embodiment, a starter 100 in which the function of the control circuit 16 is appropriately selected and reduced or added in reverse according to the actual operation. Is possible. The function to be added is, for example, the coil 14 of the magnet switch 1.
And a function of monitoring the temperature of the steel to prevent overheating.

Third Embodiment (Configuration of Third Embodiment) A starter 100 according to a third embodiment of the present invention differs from the first embodiment in that a starter 100 according to a third embodiment of the present invention employs a one-coil magnet switch 1 as shown in FIG. Has adopted.
One end of the coil 14 ′ of the magnet switch 1 is connected to the main terminal 11, and the other end is grounded via the coil current control element 15.

The plunger 13 and the coil 14 ′
Since there is no action to push out the pinion (not shown), the coil 1
4 'only needs to have a magnetic attraction enough to operate the plunger 13 to open and close the main switch 10. Therefore, unlike the first embodiment, the starter 100 of the present embodiment does not include a drive lever for pushing the pinion by the plunger 13. In the configuration necessary for describing the present invention, the configuration of the starter 100 of the present embodiment is almost the same as that of the first embodiment in other points.

(Function and Effect of Third Embodiment) In the starter 100 of the third embodiment, the configuration of the magnet switch 1 is as follows.
Unlike the ordinary one-coil type magnet switch 1, there is almost no coil lead from the other end of the coil 14 'to the ground. That is, the other end of the coil 14 'is connected to the positive terminal of the coil current control element 15, and the negative terminal of the coil current control element 15 is directly grounded to the frame. There are almost no leads to earth. Therefore, it is not necessary to route a thick and heavy coil lead that can withstand a relatively large current from the engine room to the starter in the engine room again via the key switch K in the driver's seat. Instead, as in the first embodiment, it is only necessary to route the signal line L through which a weak current flows through a key switch K having a small current capacity.

Therefore, according to the starter 100 of this embodiment, as in the first embodiment, there is an effect that the size and weight can be reduced and the cost can be reduced by the difference between the coil lead and the signal line L.

The signal line L is connected to the coil current control element 15
It is sufficient that a gate voltage enough to open and close the switch can be transmitted. Since the gate current is weak, the magnet switch 1 is not sensitive to the connection resistance of the signal line L. therefore,
Unlike the prior art, the magnet switch 1 is no longer sensitive to an increase in the resistance of the coil lead, and the reliability of the operation of the magnet switch 1 is increased. Therefore, the reliability of the starter 100 is improved as in the first embodiment.

(Modification 1 of Embodiment 3) As Modification 1 of the present embodiment, the coil current control element 15 is connected to the main terminal 1
It is possible to implement a starter 100 with a magnet switch 1 inserted between the coil 1 and the coil 14. According to this modification, the same operation and effect as those of the third embodiment can be obtained.

(Modification 2 of Embodiment 3) As a modification 2 of the present embodiment, a starter 100 having a control circuit 16 (see FIG. 2) corresponding to the embodiment 2 and the modification 1 of the embodiment 1 is provided. Implementation is possible. According to the present modification, in addition to the same functions and effects as those of the third embodiment, effects equivalent to the second embodiment and the first modification of the first embodiment can be obtained.

Of course, it is also possible to implement a modification corresponding to this modification to modification 1 of the present embodiment described above, and in this case, the same operation and effect as those of this modification can be obtained. Can be

[Embodiment 4] (Configuration of Embodiment 4) In the starter 100 according to Embodiment 4 of the present invention, the negative terminal of the coil current control element 15 is directly grounded to the frame in Embodiment 3 described above. Instead, it is connected to the positive terminal side of the starter motor 2 as shown in FIG.

In practice, one end of the coil 14 ′ is connected to the main terminal 11, and the other end is connected to the connecting terminal 12 via the coil current control element 15. Therefore, the coil lead passes only through the magnet switch 1 and is extremely short. On the other hand, the signal line L surrounding the key switch K is long as in the third embodiment, but a thin and light coated conductor is used as in the third embodiment.

(Operation and Effect of Fourth Embodiment) In the starter 100 according to the fourth embodiment, the current flowing through the coil 14 'flows through the starter motor 2 when the coil 14' is energized. The motor 2 starts rotating slowly. Therefore, the meshing impact when the pinion (not shown) jumps out and meshes with the ring gear of the engine is reduced, so that the noise and the impact are reduced, and the pinion and the ring gear are further durable. In addition, the starter motor 2 also lasts longer as much as the impact load is reduced.

Therefore, according to the starter 100 of this embodiment, in addition to the effect of the third embodiment described above, there is an effect that the engagement impact between the pinion and the ring gear is reduced and the noise is reduced. In addition, there is an effect that the starter motor 2, the pinion, and the ring gear last longer.

(Modifications 1 and 2 of Embodiment 4) As Modifications 1 and 2 of this embodiment, it is possible to implement starters 100 corresponding to Modifications 1 and 2 of Embodiment 3 described above, respectively. In addition to the effects of the present embodiment, unique effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a configuration of a starter according to a first embodiment.

FIG. 2 is a circuit diagram illustrating a configuration of a starter according to a second embodiment.

FIG. 3 is a circuit diagram showing a configuration of a starter according to a third embodiment.

FIG. 4 is a circuit diagram showing a configuration of a starter according to a fourth embodiment.

FIG. 5 is a circuit diagram showing a configuration of a starter according to the related art.

[Explanation of symbols]

100: Starter 1: Magnet switch 11: Main terminal 12: Connecting terminal 13: Plunger 14, 14 ': Coil 15: Coil current control element (MOS-FET) 16: Control circuit (microcomputer) 2: Starter motor (DC motor) B: Battery (as power supply) K: Key switch
L: signal line

Claims (5)

[Claims] 1. A main switch having a main terminal connected to a power supply and a connecting terminal connected to a starter motor, a plunger for opening and closing the main switch, and a magnet switch having a coil for attracting the plunger. A starter motor to which electric power is supplied via the main switch, wherein the magnet switch has a coil current control element for turning on / off an energization from the main terminal to the coil by an input signal. Yes, the starter 2. The starter according to claim 1, wherein said coil current control element is a semiconductor switching element. 3. The starter according to claim 1, wherein the input signal is an electric signal supplied through a key switch. 4. The starter according to claim 1, wherein said magnet switch has a control circuit for controlling said input signal based on an electric signal from a key switch and a predetermined condition. 5. The coil according to claim 1, wherein one end of the coil is connected to one of the main terminal and the connecting terminal, and the other end is connected to the other via the coil current control element. A starter according to any of the above.