JP2006149004A - Starter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a starter which can improve its startability at start of economical running by switching the property of a motor between the time of normal start when it controls the engine start by the switch operation of a user and the time of start of economical running when it automatically controls the restart of the engine by computer. <P>SOLUTION: The field winding of the motor is provided with a series coil 13 which is connected in series with an armature 8 to a motor circuit M, and a shunt coil 15 which is connected in parallel with the armature 8 via a bimetal 14 to the motor circuit M. The bimetal 14 has such temperature properties that an open/close contact switches from its open state to its close state at a specified temperature (for example 50°C) or over. Therefore, since it is constituted as a double-wound motor at normal start, the number of no-load revolutions can be reduced. On the other hand, since it is constituted as a series-wound motor at start of economical running, the number of motor revolutions in low-load range or at no-load goes higher, and the engine startability improves. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a starter having a compound motor.

In general, engine start by a starter is performed by energizing a motor by a user's key switch operation. The operation time of the key switch by the user varies widely. Usually, even after the engine is completely exploded, the ON state of the key switch is maintained for about 1 to 3 seconds, and the motor often overruns. At this time, the starter is separated from the engine and the motor by the action of the one-way clutch, and the motor is rotating at high speed with no load, so the life of the brush and the durability of the bearing parts become problems. Yes.
As means for solving this problem, a method of suppressing the no-load rotational speed by adopting a multi-winding motor provided with a shunt coil in parallel with the armature in addition to the series-wound coil is known (Patent Document). 1).
JP-A-5-164027

In recent years, a system that automatically controls stop and restart of an engine by a computer is known. In this system, when restarting the engine, it is necessary to start the engine in a very short time (for example, about 0.5 seconds) compared to when starting with a normal key switch operation. It is necessary to increase the starter rotation speed.
However, the compound motor disclosed in Patent Document 1 is difficult to apply to the above system because the rotational speed in a low load region and no load is suppressed as compared with a series motor.

As a method of increasing the number of revolutions in the low load range and no load, it is conceivable to switch (increase) the speed reduction ratio of the speed reduction mechanism provided in the starter. Will lead to a significant increase in the number of people and starter build.
The present invention has been made on the basis of the above circumstances, and the purpose of the present invention is to provide a motor at a normal start in which the engine is started by a user's switch operation, and at an eco-run start in which the restart of the engine is automatically controlled by a computer. It is an object of the present invention to provide a starter that can improve startability at the time of eco-run start-up without changing the life of the brush and impairing the durability of the bearing parts.

(Invention of Claim 1)
According to the present invention, the motor is energized by a normal start in which the motor is started by energizing the motor by a user's switch operation, and by an engine automatic stop / restart system that automatically controls stop and restart of the engine by a computer. A starter that is used at the time of eco-run start that is automatically controlled to start the engine, and the motor is connected to the armature in series with the armature and a motor circuit for energizing the battery current to the armature A series-wound coil and a shunt coil connected to the motor circuit in parallel with the armature via an opening / closing means are provided.
In addition, the switching means has an open / close contact that can mechanically connect the shunt coil to the motor circuit, and during normal start-up, the open / close contact is kept closed to connect the shunt coil to the motor circuit. When the eco-run is started, the shunt coil is disconnected from the motor circuit by switching the open / close contact to the open state.

  In the starter described above, when the engine is started by a user's switch operation, the shunt coil is connected to the motor circuit via the opening / closing means, so that the characteristics as a multi-turn motor can be obtained. In this case, since the no-load rotation speed can be reduced as compared with the direct-winding motor, the motor rotation speed after the complete explosion of the engine (the rotation speed of the motor rotating in the no-load state) can be suppressed. As a result, the wear of the brush, bearing parts, and the like accompanying the overrun of the motor is suppressed, so that the life of the brush is extended and the durability of the bearing part is maintained.

  On the other hand, when the eco-run is started, the shunt coil is separated from the motor circuit by the opening / closing means, so that the characteristics as a series winding motor can be obtained. In this case, as compared with the compound motor, the motor rotation speed in the low load region and no load is increased and the engine startability is improved, so that the engine can be started in a short time. Further, in the engine automatic stop / restart system, the restart of the engine is automatically controlled by a computer, so that the motor overrun time is very short (for example, 0.5 seconds) compared to the normal start by the user's switch operation. The impact on the life of the brush and the durability of the bearing parts is small.

(Invention of Claim 2)
The starter described in claim 1 is characterized in that the switching means is a bimetal whose switching contacts are switched from a closed state to an open state at a predetermined temperature or higher.
The engine is restarted by the engine automatic stop / restart system after the engine is started once. That is, since the engine is restarted in a state where the temperature has risen to some extent, the starter itself mounted in the vicinity of the engine also receives heat generated by the engine and becomes a certain high temperature. Therefore, by using a bimetal having temperature characteristics as the opening / closing means, it is possible to switch the characteristics of the motor according to the temperature.

Specifically, at the time of normal starting when the bimetal is lower than a predetermined temperature (for example, 50 ° C. higher than the highest temperature in midsummer), the shunt coil is connected to the motor circuit in order to keep the open / close contact closed. Characteristics as a motor can be obtained. On the other hand, at the time of eco-run starting when the bimetal is at a predetermined temperature or higher, the switching contact is switched from the closed state to the open state, so that the shunt coil is disconnected from the motor circuit and the characteristics as a direct-winding motor are obtained.
Also, the starter temperature rises differently depending on the type of vehicle and engine, etc., but with bimetal, the predetermined temperature when the switching contact is switched from the closed state to the open state can be freely set according to the rising trend of the temperature. Can be set.

(Invention of Claim 3)
The starter according to claim 1 or 2, wherein the motor circuit is provided with a connection bar to which an end on the high potential side of the series-wound coil is connected, and the opening / closing means is provided between the connection bar and the shunt coil. It is connected.
Usually, a shunt coil used for a compound motor has a high potential side (anti-earth side) end connected to a connection bar. Therefore, by connecting the opening / closing means between the connection bar and the shunt coil, there is no need to newly provide a connection site, and the opening / closing means can be easily arranged.

(Invention of Claim 4)
The starter according to claim 1 or 2, wherein the opening / closing means is connected between the shunt coil and the ground portion.
Usually, a shunt coil used for a multi-turn motor is grounded to, for example, a motor yoke or the like. Therefore, by connecting the opening / closing means between the shunt coil and the ground portion, there is no need to newly provide a connection site, and the opening / closing means can be easily arranged.

  The best mode for carrying out the present invention will be described in detail by the following examples.

FIG. 1 is an electric circuit diagram of a motor, and FIG. 3 is a side view including a partial cross section of a starter.
As shown in FIG. 3, the starter 1 according to the first embodiment includes a motor 2 that generates a rotational force, an output shaft 4 that supports a pinion gear 3 on the shaft, an electric current supplied to the motor 2, and a rod 5 The electromagnetic switch 6 has a function of pushing the output shaft 4 to the engine side (the left side in FIG. 3) via the motor, a speed reducer (described later) that decelerates the rotation of the motor 2, and a rotation decelerated by the speed reducer. The clutch 7 is transmitted to the shaft 4.
This starter 1 is an engine automatic that automatically controls the engine start and stop and restart by a computer when a user turns on a start switch (not shown) and energizes the motor 2 to start the engine. The stop / restart system is used at the time of eco-run starting in which the energization of the motor 2 is automatically controlled to start the engine.

  The engine automatic stop / restart system automatically stops the engine when the vehicle is temporarily stopped due to an intersection or traffic jam, for example, and then when a predetermined start condition is met (for example, the driver steps on the accelerator pedal from the brake pedal). This is a system that automatically restarts the engine at the time of replacement, and is generally called an idle stop system or an eco-run system.

The motor 2 is a DC motor having a field (described below) that generates magnetic flux, an armature 8 disposed on the inner periphery of the field, a brush 10 that is in sliding contact with the commutator 9, and the like. When a starting current is supplied from the battery 11 to the armature 8 through the motor circuit M shown in FIG. 1, a rotational force is generated in the armature 8.
The field magnet is configured by arranging field windings at equal intervals in the circumferential direction on the inner circumference of the yoke 12 forming the magnetic circuit. The field winding includes a series coil 13 connected in series with the armature 8 with respect to the motor circuit M, and the armature 8 with respect to the motor circuit M via the bimetal 14 (see FIG. 1A). A shunt coil 15 connected in parallel is provided, and is wound around a pole core 16 fixed to the inner periphery of the yoke 12, as shown in FIG.

The armature 8 is rotatably supported by a front housing 19 and an end frame 20 through a pair of bearings 17 and 18 at both ends of the armature shaft 8a. The commutator 9 is configured by arranging a plurality of segments in a cylindrical shape at an end side end portion (right end portion in FIG. 3) of the armature shaft 8a, and each segment is electrically and mechanically connected to the armature coil 8b. Is bound to.
As shown in FIG. 1, the brush 10 is provided with a plus-side brush 10a connected to the low potential side of the series-wound coil 13 and a minus-side brush 10b connected to the yoke 12 and the like. 9 is pressed against the outer peripheral surface of the commutator 9 by a brush spring 21 (see FIG. 3).

The output shaft 4 is helically splined to the inner periphery of the spline tube 22 that forms the inner ring of the clutch 7, and is provided so as to be movable in the axial direction (left-right direction in FIG. 3) with respect to the spline tube 22.
The pinion gear 3 is splined to the non-switch side end of the output shaft 4 and rotates together with the output shaft 4.
The electromagnetic switch 6 is energized from the battery 11 when the start switch is closed and generates a magnetic force. The electromagnetic switch 6 is inserted inside the exciting coil 23 and acts by the magnetic force generated in the exciting coil 23 as shown in FIG. A plunger (not shown) that is attracted and moved in the left direction and a motor contact that opens and closes in response to the movement of the plunger.

The motor contact is composed of a movable contact (not shown) movable integrally with the plunger or interlocked with the movement of the plunger, and a set of fixed contacts (not shown) connected to the motor circuit M. The contact between the two fixed contacts and the connection between the two fixed contacts causes the motor contact to close, and the movable contact separates from both the fixed contacts and the connection between the two fixed contacts is interrupted. Open state.
In one set of fixed contacts, one fixed contact is connected to the in-vehicle battery 11 via a battery cable, and the other fixed contact is connected to a connection bar 25 (see FIG. 4) via a motor lead 24.

The speed reduction device includes a drive gear 26 provided at the front side end of the armature shaft 8a, an idle gear 27 that meshes with the drive gear 26, and a clutch gear 28 that meshes with the idle gear 27. The rotation is transmitted from the drive gear 26 → the idle gear 27 → the clutch gear 28 and decelerated.
The clutch 7 transmits the rotation transmitted to the clutch gear 28 to the spline tube 22, and when the rotational speed of the spline tube 22 exceeds the rotational speed of the clutch gear 28 due to the start of the engine, the clutch 7 The one-way clutch which interrupts | blocks the power transmission to 28 is comprised.

Next, the bimetal 14 will be described.
The bimetal 14 has a switching contact (not shown) that can mechanically connect the shunt coil 15 to the motor circuit M, and the switching contact closes at a predetermined temperature (for example, 50 ° C. higher than the highest summer temperature). It has a temperature characteristic that switches from a state to an open state. Thereby, at the time of the normal start which starts an engine by a user's switch operation, since the temperature of the bimetal 14 does not exceed the outside air temperature and becomes lower than a predetermined temperature (50 ° C.), the open / close contact is maintained in a closed state. On the other hand, at the time of eco-run start in which the restart of the engine is automatically controlled by a computer, the engine has already been started once, so the engine temperature is higher than a predetermined temperature (50 ° C.). For this reason, the temperature of the bimetal 14 becomes equal to or higher than a predetermined temperature, and the switching contact is switched from the closed state to the open state.

Subsequently, the operation and effect of the present embodiment will be described.
a) During normal start-up, the temperature of the bimetal 14 is lower than a predetermined temperature (50 ° C.) and the switching contact is kept closed, so that the shunt coil 15 is connected via the bimetal 14 as shown in FIG. It is connected to the motor circuit M and configured as a compound motor. In this case, as shown in FIG. 2, since the no-load rotation speed can be reduced as compared with the series-wound motor, the motor rotation speed after the complete explosion of the engine (the rotation speed of the motor 2 rotating in the no-load state) can be suppressed. . As a result, since the wear of the brush 10 and the bearings 17 and 18 due to the overrun of the motor 2 is suppressed, the life of the brush 10 is extended and the durability of the bearings 17 and 18 is maintained.

  b) At the time of eco-run starting, the temperature of the bimetal 14 becomes equal to or higher than a predetermined temperature (50 ° C.), and the switching contact is switched from the closed state to the open state, so that the shunt coil 15 is disconnected from the motor circuit M, and FIG. As shown in FIG. In this case, as shown in FIG. 2, the motor speed at the low load region and no load is higher than that of the compound motor, and the engine startability is improved, so that the engine can be started in a short time. . In the engine automatic stop / restart system, the restart of the engine is automatically controlled by a computer, so that the overrun time of the motor 2 is very short (for example, 0.5%) compared to the normal start by the user's switch operation. The impact on the life of the brush 10 and the durability of the bearings 17 and 18 is small.

In the starter 1 of the present embodiment, since the shunt coil 15 is connected to the motor circuit M via the bimetal 14, the double-winding motor and the series-winding motor according to the state (closed state, open state) of the bimetal 14. You can switch between and use. For this reason, it is not necessary to switch the reduction gear ratio of the speed reducer between the normal start and the eco-run start, and the bimetal 14 is switched from the double-winding motor to the direct-winding motor, thereby increasing the rotation speed in the low load region and no load. be able to. As a result, even without using a variable speed reduction mechanism that causes an increase in the size of the starter 1 along with an increase in the number of parts, it is possible to suppress a decrease in the life of the brush 10 and a deterioration in the durability of the bearings 17 and 18 due to an overrun at the normal start. In addition, the startability at the start of the eco-run can be improved.
Also, although the temperature rise of the starter 1 varies depending on the type of vehicle and engine, etc., if the bimetal 14 is used, the predetermined temperature when the switching contact is switched from the closed state to the open state is set according to the rising tendency of the temperature. Can be set freely.

FIG. 5 is a connection diagram of the field windings (the series coil 13 and the shunt coil 15).
In the first embodiment, the position of the bimetal 14 is not specified. However, in the second embodiment, the connection bar 25 and the shunt coil 15 (see FIG. 5) or the ground side end of the shunt coil 15 is used. And a bimetal 14 is disposed between the ground portion (for example, the yoke 12).
Usually, the shunt coil 15 used for a multi-winding motor has a high potential side (anti-earth side) end connected to the connection bar 25 and a ground side end connected to the ground part of the motor 2 (for example, the yoke 12). Connected. Therefore, as shown in FIG. 5, the bimetal 14 is connected between the connection bar 25 and the shunt coil 15, or the bimetal is connected between the ground end of the shunt coil 15 and the ground portion (yoke 12). By connecting 14, there is no need to newly provide a connection site, and the bimetal 14 can be easily arranged.

(Modification)
The starter 1 described in the first embodiment has a configuration in which the output shaft 4 moves in the axial direction (the left-right direction in FIG. 3), but the present invention has a configuration different from the starter 1 described in the first embodiment (for example, The output shaft 4 can also be applied to a starter in which the pinion gear 3 moves on the output shaft 4 without moving.

(A) Circuit diagram of compound motor, (b) Circuit diagram of series motor. It is a characteristic view of a compound motor and a series motor. It is a side view including a partial cross section of a starter. It is sectional drawing which shows the internal structure of a motor. (Example 2) which is a connection diagram of the field winding used for a motor.

Explanation of symbols

1 Starter 2 Motor 8 Armature 12 Yoke (Ground)
13 Series coil 15 Divided coil 14 Bimetal (opening / closing means)
25 Connection bar M Motor circuit

Claims (4)

Energization of the motor is automatically controlled by a user's switch operation during normal start when the motor is energized to start the engine and by an engine automatic stop / restart system that automatically controls stop and restart of the engine by a computer. Starter used when starting an eco-run to start the engine,
The motor includes a motor circuit for supplying a battery current to the armature, a series coil connected to the motor circuit in series with the armature, and the motor circuit in parallel with the armature through an opening / closing means. A shunt coil connected to the
The open / close means has an open / close contact capable of mechanically interrupting the shunt coil with respect to the motor circuit, and during the normal start, the open / close contact maintains a closed state so that the shunt coil is A starter connected to a motor circuit and disconnecting the shunt coil from the motor circuit by switching the open / close contact to an open state when the eco-run is started. The starter according to claim 1,
The starter characterized in that the switching means is a bimetal whose switching contacts are switched from the closed state to the open state at a predetermined temperature or higher. The starter according to claim 1 or 2,
The motor circuit is provided with a connection bar to which an end on the high potential side of the series coil is connected,
The starter characterized in that the opening / closing means is connected between the connection bar and the shunt coil. The starter according to claim 1 or 2,
The starter characterized in that the opening / closing means is connected between the shunt coil and a ground part.

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