JP2000060099A - Motor for starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor for starter with improved durability by preventing the occurrence of sparking, even if the frequency of use of the motor for starter increases as in the case of idle stoppage. SOLUTION: This motor 10 for starter is provided with a plurality of main field poles 30a, 30b, 30c, and 30d secured on the inner circumference of a yoke 20 at equal intervals, and an armature 60 rotatably supported inside the main field poles 30a, 30b, 30c, and 30d. In addition, the motor is provided with auxiliary poles 40a, 40b, 40c, and 40d in the same number as the main field poles 30a, 30b, 30c, and 30d, placed in the positions of intermediate axes of symmetry between the main field poles 30a, 30b, 30c, and 30d, and exciting windings 50a, 50b, 50c, and 50d are wound with the main field poles 30a, 30b, 30c, and 30d and the interpoles 40a, 40b, 40c, and 40d embraced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for a starter, and more particularly to a motor for a starter used to start an engine of an automobile or the like.

[0002]

2. Description of the Related Art A conventional starter motor is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-248327.
On the outer periphery of the armature having a slot in which the armature winding is arranged,
A yoke in which a plurality of field poles 3 and field windings 4 are fixed at equal intervals is arranged.

[0003] Further, in a general DC machine, for example, “Fumio Goto,“ Introduction to Electricity ”, 1967, Maruzen,
p. As described at 20, it is known to place the brush on the commutator in a position that is counter-rotated from the electrical neutral axis to reduce sparking under the brush. Have been.

[0004]

[0005] In recent years, in order to prevent destruction of the global environment, a method of reducing the CO ₂ that automobile exhausts have been investigated. As one measure to reduce CO ₂ , it has been proposed that when a car stops at a red light or the like, the engine is stopped, and when the vehicle starts to change to a green light, the engine is restarted using a starter. It is an idle stop system. By using such a method, unnecessary idle rotation is prevented, and the generation of CO ₂ during idling is reduced.

When such an idle stop system is employed, the engine must be restarted using the starter each time the vehicle is stopped, so that the number of times the starter is used is about ten times as large as the conventional one. Is believed to be something.
Therefore, it is necessary to improve the durability of the starter to about ten times that of the conventional one.

[0006] However, even if the method described in the above "General Description of Electric Machines" is applied to a starter, the durability of the starter cannot be significantly improved. Among the components constituting the starter, the brush having the lowest durability is a brush. Since the starter uses a larger current than a general DC machine, the life of the brush is reduced due to the generation of sparks. In the case where the load temporarily changes from the stop state to the high-speed rotation, such as when starting the engine, the brush position needs to be changed according to the change in the load according to the method described in the “General Description of Electric Machinery”. However, it is difficult to mechanically change the position of the brush according to a change in load.
Therefore, in the conventional method, it is difficult to effectively prevent the generation of sparks of the starter motor, and there is a problem that the durability of the starter motor is reduced.

The inventors of the present invention have previously disclosed a starter motor in which a plurality of auxiliary poles and a plurality of auxiliary pole windings are arranged between a plurality of field poles and field windings as Japanese Patent Application No. 10-24292. is suggesting. When such a method is adopted, the generation of sparks of the electric motor can be significantly suppressed by the rectification improving effect of the auxiliary pole,
The durability of the starter motor can be greatly improved.

However, when the above-mentioned proposed method was further studied, the load current was caused to flow through the auxiliary pole excitation winding, so that copper loss due to the resistance of the excitation winding occurred, resulting in an increase in motor loss. It has been found that the characteristics of the starter motor deteriorate, such as the generated torque decreases.

[0009] An object of the present invention is to provide a starter motor which is frequently used even when the starter motor is frequently used as in the case of an idle stop.
An object of the present invention is to provide a starter motor that can prevent generation of sparks and has improved motor characteristics.

[0010]

(1) In order to achieve the above-mentioned object, the present invention provides a plurality of main pole field poles fixed at equal intervals on the inner peripheral side of a yoke, and a plurality of these main poles. An excitation winding wound around each of the field poles, and a starter motor having an armature rotatably supported inside the plurality of main pole field poles, wherein the starter motor includes a portion between the plurality of main pole field poles. An auxiliary pole disposed at a position of an intermediate symmetry axis, wherein the excitation winding is wound around the main pole field pole and an auxiliary pole disposed at a position adjacent to one of the main pole field poles. It is. With such a configuration, a rectified electromotive force can be generated without winding a dedicated excitation winding around the auxiliary pole, and a reactance voltage generated by the armature winding can be canceled, so that the idle stop can be performed. Even if the frequency of use of the starter motor increases, sparks can be prevented, durability can be improved, and copper loss due to exciting windings can be reduced, and motor characteristics can be improved. .

(2) In the above (1), preferably,
A yoke at an intermediate portion between the main pole field pole and the auxiliary pole around which the exciting winding is wound is provided with a through hole connecting the inner peripheral side and the outer peripheral side. With this configuration, the cooling air can be guided to the armature surface through the space between the main pole field pole and the auxiliary pole, and the temperature rise of the starter motor can be reduced.

(3) In the above (2), preferably,
The through-hole is arranged to be inclined so as to be inverted in the rotation direction of the armature. With this configuration, the ventilation resistance can be reduced, so that the cooling air flowing into the armature surface can be increased, and the temperature rise of the starter motor can be further reduced.

(4) In the above (2), preferably,
The through-hole is arranged so as to be deviated in the rotational direction from an intermediate portion between the main pole field pole and the auxiliary pole. With this configuration, the ventilation resistance can be further reduced, so that the temperature rise of the starter motor can be further reduced.

(5) In the above (2), preferably,
In the yoke, a portion where the through hole is provided is thicker than other portions. With this configuration, it is possible to prevent the magnetic flux passage area of the yoke cross section from decreasing due to the provision of the through holes, and to prevent the characteristics of the electric motor from deteriorating due to the magnetic flux saturation phenomenon.

(6) In the above (2), preferably,
A spacer made of a magnetic material is arranged inside the yoke provided with the through hole. With such a configuration, the cost increase can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A starter motor according to an embodiment of the present invention will be described below with reference to FIGS. First, the configuration of a starter motor according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating a configuration of a starter motor according to an embodiment of the present invention.

The starter motor 10 includes a yoke 20,
The yoke 20 has four main pole field poles 30a, 30b, 30c, and 30d fixed on the inner peripheral side. In addition,
The illustrated starter motor 10 is a four-pole motor. The main pole field poles 30a, 30b, 30c, and 30d are arranged at equal intervals on the inner peripheral side of the yoke 20, and are fixed to the yoke 20 by set screws (not shown). The inner diameter side ends of the main pole field poles 30a, 30b, 30c, 30d protrude in the circumferential direction, forming so-called shoe portions 32a, 32b, 32c, 32d.
The inner diameter side ends of the main pole field poles 30a, 30b, 30c, 30d including the shoe portions 32a, 32b, 32c, 32d are:
It has an arc shape, and the gap length between the armature 60 and an outer peripheral portion described later is constant.

Further, the adjacent main pole field poles 30a, 30
b, 30c, and 30d, the position of the middle central portion, that is, the position of the middle symmetric axis of the main pole field pole, and the corresponding position (electrically neutral axis) of the armature winding to be rectified, It has poles 40a, 40b, 40c, 40d. The auxiliary poles 40a, 40b, 40c, and 40d are arranged at equal intervals on the inner peripheral side of the yoke 20, and each is fixed to the yoke 20 by a not-shown set screw or the like. Complementary pole 40a,
The inner diameter side ends of 40b, 40c, and 40d protrude in the circumferential direction, so-called shoe portions 42a, 42b, 42.
c, 42d. The shoe parts 42a, 42b,
Complementary poles 40a, 40b, 40c, 4 including 42c, 42d
0d has a flat plate-shaped end, and the armature 60
The length of the gap between the outer peripheral portion of each of the shoe portions 42a, 42
b, 42c, and 42d, and the auxiliary poles 40a, 40b, and 40
At the center end on the inner diameter side of c and 40d, the width is narrow. The average gap length between the armature 60 and the inner diameter side end of the auxiliary poles 40a, 40b, 40c, 40d is determined by the main pole field poles 30a, 30
The gap length between the inner diameter side ends of b, 30c, and 30d and the outer peripheral portion of the armature 60 is made wider.

The shoe sections 42a, 42b, 42c,
The inner-diameter end portions of the auxiliary poles 40a, 40b, 40c, and 40d including the 42d are formed in a flat plate shape, so that the gap length between the outer peripheral portion of the armature 60 and the shoe portions 42a, 42b, and 4 is reduced.
2c and 42d, the width of the adjacent main pole field pole 30
a, 30b, 30c, 30d to complementary poles 40a, 40b,
It becomes difficult for the magnetic flux to leak directly to 40c and 40d, and it is possible to reduce the magnetic flux leaking. Needless to say, the flat shape is not an essential condition of the present invention.

Further, the starter motor 10 according to the present embodiment includes the main pole magnetic poles 30a, 30b, 30c, 3
The excitation windings 50a, 50b, 50c, 50d are wound so as to include 0d and the supplementary poles 40a, 40b, 40c, 40d. Here, for example, the excitation winding 50 is formed of one main pole field pole 30 and the armature 60 so that the excitation winding 50a is wound around the adjacent main pole field pole 30a and auxiliary pole 40a. It is wound around the auxiliary pole 40 adjacent to the rotation direction R side.

Here, the main pole field poles 30a, 30b, 30
The polarities N and S of c and 30d and the complementary poles 40a, 40b and 40
The relationship between the polarities n and s of c and 40d may be N, n, S, and s in the direction of rotation of the electric motor. The adjacent main pole field poles 30a, 30b, 30c, 30d and the supplementary pole 4 are arranged so that the pole field pole 30a and the supplement pole 40a have the same polarity, and the main pole field pole 30b and the supplement pole 40b have the same polarity.
0a, 40b, 40c, and 40d can be wound by being included in one excitation winding 50a, 50b, 50c, and 50d, respectively.

Further, the main pole magnetic poles 30a, 30b, 30
Although the required magnetomotive force differs between c and 30d and the auxiliary poles 40a, 40b, 40c and 40d, as in the present embodiment, the main pole magnetic poles 30a, 30b, 30c and 30d and the auxiliary poles 40a and 4 are different.
0b, 40c, and 40d are wound by including one excitation winding, the main pole field poles 30a, 30b, 30c, 30
It can be adjusted by changing the gap length of each of d and the auxiliary poles 40a, 40b, 40c, 40d.

For example, as described above, the average gap length between the armature 60 and the inner diameter side end of the auxiliary poles 40a, 40b, 40c, 40d is determined by the main pole field poles 30a, 30b, 30c,
The gap length is larger than the gap length between the inner diameter side end of 30d and the outer peripheral portion of the armature 60. As in the previously proposed method, when the excitation winding wound around the main pole field pole and the excitation winding wound around the auxiliary pole are made independent and the same current flows through each excitation winding, Assuming that the number of windings of the exciting winding wound around the magnetic pole is 10 and the number of windings of the exciting winding wound around the auxiliary pole is 4, the ratio of the magnetomotive force of the main pole field pole and the auxiliary pole is 10: 4. Becomes Therefore, the armature 60 and the auxiliary poles 40a, 40b, 40
The average gap length between the inner diameter side ends of the c and 40d is (10 /／) of the gap length between the inner diameter side ends of the main pole field poles 30a, 30b, 30c and 30d and the outer peripheral portion of the armature 60. 4) By making it twice, it is possible to obtain a magnetomotive force equivalent to that of the previously proposed method. As a method of changing the magnetomotive force of the main pole field pole and the magnetomotive force of the auxiliary pole, in addition to changing the gap length, the axial length of the auxiliary pole is shorter than the axial length of the main pole field pole. And other methods.

The starter motor 10 includes main pole magnetic poles 30a, 30b, 30c, 30d and auxiliary poles 40a, 4a.
An armature 60 is provided on the inner peripheral side of Ob, 40c, and 40d. The armature 60 includes a shaft 62 and the shaft 6.
And a core 64 in which a plurality of plates fixed to 2 are laminated. A plurality of slots 66 extending in parallel with the shaft 62 are formed in the core 64. The slot 66 is provided with an armature winding (not shown). The end of the armature winding is connected to a not-shown commutator. The armature 60 includes the commutator, the armature winding, the core 64, and the shaft 62.

When the starter motor rotates, the current i of the rectifying armature winding changes. At this time, a reactance voltage er (= −L · di / dt (V)) is generated due to the inductance L of the armature winding, which prevents a change in current in the armature winding during rectification and delays rectification. do. This rectification delay causes sparks,
In order to promote the rectification by overcoming the reactance voltage and make the rectification as close to the linear rectification as possible, it is necessary to induce a voltage equal in magnitude in the opposite direction to the reactance voltage er from the outside to the coil under rectification. For this purpose, in the present embodiment, the auxiliary poles 40a, 40b, 40c, 40
d is placed on the neutral axis so that the rectified voltage is induced in the rectified coil. Since the reactance voltage is directly proportional to the load current, the rectified voltage also needs to be proportional to the load current. For this purpose, the auxiliary pole is excited by a load current. As a result, the reactance voltage can be effectively canceled by the rectified electromotive force regardless of the state of the load from the stop state to the high-speed operation of the starter motor.

Further, in the present embodiment, the exciting winding 50 also has a structural feature. That is, as shown in FIG. 1, the excitation windings 50a, 50b, 50c, 50d
Are the auxiliary poles 40a, 40b, 40c, adjacent to the main pole field poles 30a, 30b, 30c, 30d on the rotation direction R side.
And 40d. Since the main pole excitation winding and the auxiliary pole excitation winding are the same,
The auxiliary pole excitation current can be completely assimilated to the load current. Further, since no auxiliary pole excitation winding is provided separately from the main pole excitation winding unlike the related art, the number of windings can be the same as the number of main poles.

Here, referring to FIG. 2, in the starter motor according to the present embodiment, the main pole field pole and the auxiliary pole are wound using the same excitation winding, thereby reducing the copper loss by the excitation winding. Will be described. FIG. 2 is a coil configuration diagram illustrating the effect of reducing copper loss by the excitation winding in the starter motor according to one embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

Excitation windings 50a, 50b, 50c, 50d
Are the auxiliary poles 40a, 40b, 40c, adjacent to the main pole field poles 30a, 30b, 30c, 30d on the rotation direction R side.
And 40d, respectively, and are wound. A connection line 5 is provided between the excitation winding 50a and the excitation winding 50b.
2ab, the exciting winding 50c and the exciting winding 50
Connections d are connected by a connection line 52cd. The connection line is a conductor used to connect the excitation windings or to connect the excitation windings to other parts.It is a part that is not directly related to the magnetomotive force generated by the main pole field pole or the auxiliary pole. is there.
The exciting winding 50a is connected to the battery 120 by a connecting line 52a, and the exciting winding 50c is connected to the connecting line 52c.
Is connected to the battery 120. Further, the excitation winding 50b is connected to the brushes 70A, 7A by the connecting wire 52b.
0C, and the excitation winding 50d is connected to the brushes 70A, 70C by a connecting line 52d. Brush 70
B and 70D are grounded. This figure shows an embodiment in the case of two-coil series-parallel connection.

Here, the main pole field pole 30a and the auxiliary pole 40a
As an example, how the entire length of the exciting winding can be reduced as compared with the previously proposed method will be described. In the figure, windings 54a and 56a indicated by alternate long and short dash lines schematically show the case where the main pole field pole 30a and the auxiliary pole 40a are wound by separate excitation windings. Main pole field pole 3
When 0a and the auxiliary pole 40a are wound by the same winding 50a, the windings 54a and 56a become unnecessary. Assuming that the lengths of the windings 54a and 56a are L1, 1T
Around 2 · L1. On the other hand, the main pole field pole 30a
Assuming that the length between L and the auxiliary pole 40a is L2, the length is 2 · L2. Further, the main pole field pole 30a and the auxiliary pole 4
0a is wound by separate excitation windings, the excitation winding of the auxiliary pole has a smaller number of turns than the excitation winding of the main pole field pole. When wound by the wire 50a, since the number of turns is equal,
Accordingly, the length of the winding becomes longer. Considering these factors comprehensively, when the main pole field pole 30a and the auxiliary pole 40a are wound by separate excitation windings, the main pole field pole 3a
When the 0a and the auxiliary pole 40a are wound by the same winding 50a, the total length of the exciting winding can be reduced by 20 to 30%. Therefore, the copper loss due to the excitation winding is reduced to 20 to 3
0% can be reduced. As a result, in the present embodiment, it is possible to prevent the torque generated by the motor from being reduced due to the resistance loss of the auxiliary pole excitation winding, and to improve the motor characteristics.

Further, since the total length of the exciting winding can be shortened, the material cost of the winding used can be reduced. Furthermore, the number of turns of the exciting winding around the main pole field pole and the auxiliary pole can be reduced by half, so that the cost required for winding work can be reduced.

Next, the configuration of an engine starting device using the electric motor for a starter according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration of an engine starting device using a starter motor according to an embodiment of the present invention.

The excitation winding 50 of the starter motor 10 is
The excitation winding of the main pole field pole and the excitation winding of the auxiliary pole are also used, and are connected to the armature winding of the armature 60 via the brush 70 and the commutator 72. With such a configuration, the auxiliary pole can be excited by the load current I, and the self-induced electromotive force of the short-circuit wire by the brush 70, that is,
The reactance voltage is changed to the auxiliary poles 40a, 40b, 40c, 4
It can be canceled by the rectified electromotive force generated by Od.

The starter 100 includes a starter motor 10
And a magnet switch 90.
The magnet switch 90 is connected to the battery 120 via the key switch 110. The magnet switch 90 includes a suction coil 92 and a holding coil 94.
, A plunger 96 and a main contact 98.

The key switch 1 is used to start the engine.
When 10 is closed, a current flows from the battery 120 to the suction coil 92, and the plunger 96 is sucked in the direction of arrow A,
The main contact 98 is closed. When the main contact 98 is closed, the starter motor 10 is connected from the battery 120 via the main contact 98.
, The current also flows through the holding coil 94, and the plunger 96 is held with the main contact 98 closed. When the plunger 96 moves in the direction of arrow A, the pinion gear 74 of the starter motor 10 is moved by a shift mechanism (not shown) engaged with the plunger 96.
Moves in the direction of arrow B, and the pinion gear 74 is moved to the ring gear 132 attached to the drive shaft of the internal combustion engine main body 130.
And mesh with each other.

The current from the battery 120 flows through the main pole and auxiliary pole excitation windings 50, and also flows through the brush 70 and the commutator 72 to the armature windings of the armature 60, so that the armature 60 rotates. The rotation force of the pinion gear 74 connected to the armature 60 is
The power is transmitted to the internal combustion engine main body 130, and the internal combustion engine 130 starts.

At this time, the current flowing through the exciting winding 50 is
The auxiliary pole is excited to generate a rectified electromotive force, and the armature 40
The sparks are suppressed by canceling the reactance voltages generated at a, 40b, 40c, and 40d.

When the key switch 110 is opened after the start of the internal combustion engine body 130, the power supply to the holding coil 94 is interrupted, the plunger 96 returns in the direction of arrow C, the main contact 98 is opened, and the starter motor is opened. As the rotation of the pinion gear 10 stops, the pinion gear 74 also returns in the direction of arrow D, and the engagement between the pinion gear 74 and the ring gear 132 is released.

As described above, according to the present embodiment, the reactance voltage generated by the self-induced electromotive force of the armature winding is canceled by the rectified electromotive force generated by the auxiliary pole. Sparks can be reduced. In addition, since the load current flows through the excitation winding of the auxiliary pole, even if the reactance voltage increases, the rectified electromotive force also increases, so that the reactance voltage is rectified regardless of the load state. Power can effectively counteract it. Furthermore, since the winding is wound by the exciting winding including the main pole field pole and the auxiliary pole, it is possible to reduce copper loss, prevent a reduction in torque generated by the motor, and improve motor characteristics. Can be improved.

Next, a starter motor according to a second embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 4 is a partial cross-sectional view illustrating a configuration of a starter motor according to a second embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The overall configuration of this embodiment is the same as that shown in FIG. 1, and the adjacent main pole field pole 30 and auxiliary pole 40 are adjacent to each other.
Are wound by the exciting winding 50 so as to include

Further, in the present embodiment, the yoke 20 in the portion between the main pole field pole 30 and the auxiliary pole 40 has:
A through hole 150 that connects the inner peripheral side and the outer peripheral side is provided. In a system in which the main pole excitation winding and the auxiliary pole excitation winding are independent from each other as in the previously proposed system, the main pole 3
A space is not formed between the zero and the auxiliary pole 40 because a part of the winding is accommodated in each. On the other hand, in the present embodiment, the space X exists between the main pole 30 and the auxiliary pole 40 by sharing the main pole excitation winding and the auxiliary pole excitation winding. Therefore, the through hole 15 is provided in the yoke equivalent part.
0, and the fan action by the rotation of the armature 60
The cooling air drawn in from the axial direction of the armature cools the armature surface, the pole surface, and the coil inner surface, flows in the direction of arrow E, and flows out. Thereby, the temperature rise of the starter motor can be suppressed.

As described above, according to the present embodiment, the reactance voltage generated by the self-induced electromotive force of the armature winding is canceled by the rectified electromotive force generated by the auxiliary pole. Sparks can be reduced. Also, since the excitation winding of the auxiliary pole is shared with the excitation winding of the main pole, even if the load current flows through the auxiliary pole as it is and the reactance voltage increases, the rectified electromotive force also increases. Regardless of the state of the load, the reactance voltage can be canceled by the rectified electromotive force. Furthermore, since the winding is wound by the exciting winding including the main pole field pole and the auxiliary pole, it is possible to reduce copper loss, prevent a reduction in torque generated by the motor, and improve motor characteristics. Can be improved. Further, since the through hole is provided in the intermediate yoke between the main pole and the auxiliary pole, the armature surface, the pole surface, and the inner surface of the coil can be effectively cooled by the fan action of the armature. This can suppress a rise in the temperature of the starter motor.

Next, a starter motor according to a third embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 9 is a partial cross-sectional view illustrating a configuration of a starter motor according to a third embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The overall configuration of this embodiment is the same as that shown in FIG. 1, and the adjacent main pole field pole 30 and auxiliary pole 40
Are wound by the exciting winding 50 so as to include

Further, in the present embodiment, the yoke 20 at a portion between the main pole field pole 30 and the auxiliary pole 40 has:
A through hole 150A that connects the inner peripheral side and the outer peripheral side is provided. The through hole 150 </ b> A is rotated in the rotational direction R from the radiation axis 160.
It is provided to be inclined to the side. By doing this,
Since the ventilation resistance of the cooling air can be reduced, the cooling inside the electric motor can be more effectively increased, and the temperature rise of the electric motor for the starter can be further suppressed.

Next, a starter motor according to a fourth embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 9 is a partial cross-sectional view illustrating a configuration of a starter motor according to a fourth embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The overall configuration of this embodiment is the same as that shown in FIG. 1, and the adjacent main pole field pole 30 and auxiliary pole 40
Are wound by the exciting winding 50 so as to include

Further, in the present embodiment, the yoke 20 at the portion between the main pole field pole 30 and the auxiliary pole 40 has:
A through hole 150B that connects the inner peripheral side and the outer peripheral side is provided. The through-hole 150B is provided so as to be deviated from the radial axis 160 toward the rotation direction R. By doing so, since the side surface 40X of the auxiliary pole 40 can be used as a ventilation guide, the ventilation resistance of the cooling air can be further reduced, so that the cooling inside the motor can be more effectively increased, and the starter motor can be used. Can be further suppressed.

At this time, the through hole 150B is
It is needless to say that the same effect can be obtained even if it is inclined or provided in parallel to 0.

Next, a starter motor according to a fifth embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 9 is a partial cross-sectional view illustrating a configuration of a starter motor according to a fifth embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The overall configuration of this embodiment is the same as that shown in FIG. 1, and the adjacent main pole field pole 30 and auxiliary pole 40
Are wound by the exciting winding 50 so as to include

Further, in the present embodiment, the yoke 20 at the portion between the main pole field pole 30 and the auxiliary pole 40 is
A through hole 150 </ b> C that connects the inner peripheral side and the outer peripheral side is provided. The thickness of the yoke portion 22 provided with the through-hole 150C is increased by an area corresponding to the width of the hole.
By doing so, the circumferential cross-sectional area of the yoke of the portion 22 can be made equal to that of the yoke portion without the through hole 150C, and the through hole 150C can be formed without increasing the magnetic resistance to the magnetic flux 170 passing through the portion 22. Can be provided.

The through-hole 150C is, as in the through-hole 150A shown in FIG.
It may be provided to be inclined to the side, or may be provided so as to be deviated toward the rotation direction R side from the radial axis 160 like the through hole 150B.

In this embodiment, not only the temperature rise of the starter motor can be suppressed, but also the passage of the magnetic flux can be prevented, so that the deterioration of the motor characteristics can be prevented.

Next, a starter motor according to a sixth embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 13 is a partial cross-sectional view illustrating a configuration of a starter motor according to a sixth embodiment of the present invention. The same reference numerals as those in FIG. 1 indicate the same parts.

The overall configuration of this embodiment is the same as that shown in FIG. 1, and the adjacent main pole field pole 30 and auxiliary pole 40 are adjacent to each other.
Are wound by the exciting winding 50 so as to include

Further, in the present embodiment, the yoke 20 at a portion between the main pole field pole 30 and the auxiliary pole 40 has
A through hole 150D that connects the inner peripheral side and the outer peripheral side is provided. Further, a spacer 24 made of a magnetic material is provided in a yoke portion where the through hole 150D is provided. Thereby, the magnetic flux 170 disturbed by the through hole 150D becomes
Since the fluid can be dispersed and flow also in the spacer 24, the through hole can be provided without deteriorating the motor characteristics. In addition, since a thick yoke portion can be realized without processing a large yoke to form an area changing portion, an increase in cost can be prevented.

The through-hole 150D is, as in the through-hole 150A shown in FIG.
It may be provided to be inclined to the side, or may be provided so as to be deviated toward the rotation direction R side from the radial axis 160 like the through hole 150B.

In the present embodiment, not only the temperature rise of the starter motor can be suppressed, but also the passage of the magnetic flux can be prevented, so that the deterioration of the motor characteristics can be prevented.

In the embodiment shown in FIGS. 4 to 8, one or a plurality of through holes may be provided.

[0061]

According to the present invention, even when the frequency of use of the starter motor increases, such as in the case of idle stop,
The generation of sparks can be prevented, and the characteristics of the electric motor can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a starter motor according to an embodiment of the present invention.

FIG. 2 is a coil configuration diagram illustrating an effect of reducing copper loss by an exciting winding in a starter motor according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an engine starting device using a starter motor according to an embodiment of the present invention.

FIG. 4 is a partial sectional view showing a configuration of a starter motor according to a second embodiment of the present invention.

FIG. 5 is a partial sectional view showing a configuration of a starter motor according to a third embodiment of the present invention.

FIG. 6 is a partial cross-sectional view illustrating a configuration of a starter motor according to a fourth embodiment of the present invention.

FIG. 7 is a partial sectional view showing a configuration of a starter motor according to a fifth embodiment of the present invention.

FIG. 8 is a partial sectional view showing a configuration of a starter motor according to a sixth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Starter motor 20 ... Yoke 22 ... Yoke thick part 24 ... Spacer 30a, 30b, 30c, 30d ... Main pole field pole 40a, 40b, 40c, 40d ... Complementary pole 50 ... Excitation winding 60 ... Armature 62 ... Shaft 64 Core 66 Slot 72 Brush 72 Commutator 74 Pinion gear 90 Magnet switch 92 Attraction coil 94 Holding coil 96 Plunger 98 Main contact 100 Starter 110 Key switch 120 Battery 130 Internal combustion engine 132 ring gear 140 connection line 150 through hole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Keisuke Nishidate 2520 Odaiba, Hitachinaka-shi, Ibaraki F-term in the Automotive Equipment Division, Hitachi, Ltd. (Reference) 5H623 AA00 AA10 BB07 GG07 GG23 JJ03 LL06 LL12

Claims (6)

[Claims] 1. A plurality of main pole field poles fixed at equal intervals on an inner peripheral side of a yoke, an excitation winding wound around each of the plurality of main pole field poles, and the plurality of main poles A starter motor having an armature rotatably supported inside a field pole, comprising: an auxiliary pole disposed at a position of an intermediate symmetry axis between the plurality of main pole field poles; An electric motor for a starter, wherein the excitation winding is wound around a magnetic pole and an auxiliary pole arranged at a position adjacent to one side. 2. The motor for a starter according to claim 1, wherein a yoke at an intermediate portion between the main pole field pole and the auxiliary pole around which the exciting winding is wound has a through hole connecting the inner peripheral side and the outer peripheral side. An electric motor for a starter, wherein the electric motor is provided. 3. The electric motor for a starter according to claim 2, wherein said through-holes are arranged so as to be inclined in a direction of rotation of said armature. 4. The motor for a starter according to claim 2, wherein the through hole is arranged so as to be deviated in a rotational direction from an intermediate portion between the main pole field pole and the auxiliary pole. Electric motor. 5. The electric motor for a starter according to claim 2, wherein a portion of the yoke provided with the through hole is thicker than other portions. 6. The electric motor for a starter according to claim 2, wherein a spacer made of a magnetic material is arranged inside the yoke provided with the through hole.