JP2016046906A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a starter capable of establishing compatibility between high revolution performance for restarting an engine and high torque performance for normally starting the engine at a low temperature, without causing complication of a motor or the shortening of the life of the motor.SOLUTION: A starter includes a motor (5) that starts an engine, and a field part (11) that generates a field of the motor. The field part comprises both a permanent magnet (17) and a field coil (16). A field coil current control part controls an electric current to the field coil so that torque and the number of revolutions can be suitable for starting the engine.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a starter for starting an engine of a vehicle.

  In recent years, for the purpose of improving fuel efficiency, etc., the engine automatic stop / start control is adopted that automatically stops the engine when the engine output is not required and automatically restarts the engine with the starter when the engine output is required. It is being done.

  In such engine automatic stop / start control, when the vehicle is temporarily stopped due to a stop signal, traffic jam or the like, the fuel supply to the engine is cut and the engine is automatically stopped. After that, when the driver performs a release operation such as a brake pedal release operation or a shift operation to the drive range, the starter is automatically activated to restart the engine.

  Generally, when the engine is automatically restarted, since the engine is warmed up, the torque required to start the engine is low. Therefore, in the engine automatic stop start control, in order to start the engine quickly, it is necessary to increase the rotational speed in the low load region. On the other hand, it is necessary to output a high torque in a high load region where the engine friction torque is large, such as at low temperatures.

  Specifically, when the engine is automatically restarted, in order not to give the driver a sense of discomfort or discomfort due to vehicle start-up or acceleration delay, it takes 0.5 seconds compared to the normal start. It is required to start in a very short time.

  Therefore, for example, if the field coil is a series coil, the rotation speed of the starter can be set high. However, when the field coil is a direct-wound coil, the starter rotation speed at no load becomes high, and there is a concern about damage due to insufficient strength of the armature and shortening of the life of the brush and bearing parts. .

  As a starter for solving such a problem, there is a multi-turn type provided with both a series-wound coil connected in series with an armature and a shunt coil connected in parallel with the armature (for example, Patent Document 1). In the starter of Patent Document 1, when the contact is closed at a predetermined temperature or higher, the shunt coil is disconnected from the motor circuit, and the motor characteristics are switched. As a result, it is possible to reduce the no-load rotation at the normal start and to increase the motor rotation speed at the low load and no load at the restart.

JP 2006-149004 A

However, the prior art has the following problems.
Since the starter of Patent Document 1 has two types of coils, ie, a series-wound coil and a shunt coil, as a field coil for generating a field, the structure of the motor becomes complicated. As a result, there are problems such as deterioration of productivity due to the time required for coil connection, increase in current consumption, and increase in size and weight of the motor. In addition, in order to compensate for a decrease in output due to an increase in internal resistance, it is necessary to increase the cross-sectional area of the winding, and there is a problem that the motor is further increased in size and weight.

  The present invention has been made to solve the above-described problems, and has high rotational speed for restarting the engine and normal starting of the engine at low temperatures without complicating or shortening the life of the motor. An object of the present invention is to obtain a starter capable of achieving both high torque characteristics.

  A starter according to the present invention includes a motor for starting an engine and a field part for generating a field of the motor, and the field part includes both a permanent magnet and a field coil. is there.

  According to this invention, the structure which equips both the permanent magnet and the field coil in the field part which generates the field of a motor is employ | adopted. As a result, it is possible to obtain a starter that can achieve both high rotational performance for restarting the engine and high torque performance for normally starting the engine at low temperatures without complicating or shortening the life of the motor.

It is a section schematic diagram of a starter concerning Embodiment 1 of the present invention. It is a section schematic diagram of the motor of the starter concerning Embodiment 1 of the present invention. It is an illustration figure of the starter circuit which concerns on Embodiment 1 of this invention. When the conventional field coil starter, the conventional permanent magnet type starter, and the starter according to the first embodiment of the present invention including both the field coil and the permanent magnet are designed to have the same output It is an illustration figure of the characteristic of. It is an illustration figure of the starter circuit which concerns on Embodiment 2 of this invention. It is a figure which shows the change of the characteristic at the time of relay ON / OFF of the starter which concerns on Embodiment 2 of this invention.

  Hereinafter, preferred embodiments of a starter according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and demonstrated about the part which is the same or it corresponds in each figure.

Embodiment 1 FIG.
FIG. 1 is a schematic sectional view of a starter according to Embodiment 1 of the present invention. The starter shown in FIG. 1 includes an electromagnetic switch 1, a suction coil 2, a plunger 3, a lever 4, a motor 5, an output shaft 6, an internal speed reduction unit 7, an overrunning clutch 8, and a pinion gear 9.

  When the starter starts the engine, first, the suction coil 2 of the electromagnetic switch 1 is energized. Thereby, the excited plunger 3 is attracted and moved in the left direction (arrow A direction) in FIG. 1, and the lever 4 whose one end is engaged with the plunger 3 is counterclockwise about the lever fulcrum 40. Rotate the seesaw.

  As a result, the overrunning clutch 8 engaged with the other end of the lever 4 moves on the output shaft 6 in the right direction (arrow B direction) in FIG. 1, and the ring gear 10 and the pinion gear 9 connected to the engine. Mesh with each other.

  Further, when the plunger 3 moves to the left in FIG. 1, the contact (not shown) of the electromagnetic switch 1 is closed, and current from the battery 18 (see FIG. 3 described later) is supplied to the motor 5. The Torque generated in the motor 5 is sequentially transmitted to the internal speed reduction unit 7, the output shaft 6, the overrunning clutch 8, and the pinion gear 9, and the ring gear 10 is rotated via the pinion gear 9 to start the engine.

  The motor 5 shown in FIG. 1 includes a field part 11 for generating a field, an armature 13 having a commutator 12 at one end, and a brush 14 disposed on the outer periphery of the commutator 12. The

  FIG. 2 is a schematic cross-sectional view of the starter motor 5 according to Embodiment 1 of the present invention. As shown in FIG. 2, the field part 11 of the motor 5 includes a yoke 15 forming a magnetic circuit, and a field coil 16 and a permanent magnet 17 arranged at equal intervals along the inner periphery thereof. Is done.

  Here, for example, the magnetic pole of the field part 11 is composed of a plurality of pairs of N poles and S poles, one pole is composed of the permanent magnet 17, and the other pole is composed of the field coil 16. In the starter, since the magnetic force is balanced, an offset load is not applied to the rotation shaft, and the starter can be rotated stably. Further, since the number of permanent magnets 17 and field coils 16 can be halved, the cost can be reduced as compared with the case where all the poles are constituted by field coils 16. Further, by concentrating the field coil 16 on the pole on one side, connection is facilitated and productivity is improved.

  In FIG. 2, the field coils 16 and the permanent magnets 17 are alternately and alternately arranged on different magnetic poles, but the present invention is not limited to such a configuration. For example, it is possible to arrange the field coil 16 and the permanent magnet 17 in the same magnetic pole.

  FIG. 3 is an exemplary diagram of the starter circuit according to the first embodiment of the present invention. The field portion of the starter of the first embodiment shown in FIG. 3 includes both a permanent magnet and a field coil 16. The field coil 16 is connected in series with the armature 13.

  The electromagnetic switch 1 shown in FIG. 3 illustrates the electromagnetic switch 1 of FIG. 1 as a circuit diagram. The battery 18 supplies power to the motor 5, and the starter switch 19 starts the starter. The functions of these components are as described above with reference to FIG.

  FIG. 4 shows that the output P of the conventional field coil starter, the conventional permanent magnet starter, and the starter according to the first embodiment of the present invention including both the field coil 16 and the permanent magnet is equal. It is an illustration figure of the characteristic at the time of designing so that it may become. As shown in FIG. 4, in the conventional field coil starter (dotted line), compared with the conventional permanent magnet starter (dashed line), high torque is generated in a high load region where the starter current i flowing to the motor 5 is large. Can be generated. Further, high rotation can be achieved in a low load region where the starter current i is small.

  Since the starter (solid line) of the first embodiment is also provided with the field coil 16, the field magnet 16 forms a field magnet compared with a permanent magnet type starter (chain line) in a high load range. High torque can be generated. As a result, the engine can be reliably started even when the friction torque of the engine is large, for example, at low temperatures.

  Further, in the starter (solid line) of the first embodiment, since the number of permanent magnets can be reduced as described above, the conventional permanent magnet type starter is used in a low load range where the engine starts to rotate and the load becomes light. Compared with (dashed line), the motor 5 becomes a high speed and the engine can be started quickly. Thereby, the operation time of the starter is shortened and the quietness is improved.

  Further, in the starter (solid line) of the first embodiment, even if the field magnet 16 is reduced in the low load region, the rotational speed of the motor 5 at no load is increased by the field due to the permanent magnet. It can be suppressed. As a result, compared to a field coil starter (dotted line), wear of sliding portions such as the brush 14 and the bearing is suppressed, so that the life of the starter can be shortened.

  As described above, since both the permanent magnet and the field coil 16 are provided, a high torque can be generated in a high load range at the time of starting, so that the engine can be reliably started even when the engine friction torque is large, such as at low temperatures. be able to. Further, in a low load range where the engine starts to rotate and the load becomes light, the field current is reduced and the engine speed is increased, so that the engine can be started quickly. In addition, the operation time of the starter is shortened and quietness is improved. Moreover, it can suppress that the rotation speed of the motor 5 at the time of no load becomes high too much, and it leads to lifetime improvement.

  Further, since the shunt coil is replaced with a permanent magnet, the structure of the motor 5 is simplified as compared with the conventional compound winding type.

  As described above, according to the first embodiment, the configuration in which both the permanent magnet and the field coil are provided in the field part that generates the field of the motor is employed. As a result, it is possible to obtain a starter that can achieve both high rotational performance for restarting the engine and high torque performance for normally starting the engine at low temperatures without complicating or shortening the life of the motor.

Embodiment 2. FIG.
In the second embodiment, in the low load region where the torque required to start the engine is small, the starter in the low load region is suppressed by suppressing the current to the current to the field coil 16 from flowing. A method for further improving the high rotation performance as compared with the case of the first embodiment will be described.

  FIG. 5 is an exemplary diagram of a starter circuit according to the second embodiment of the present invention. In the starter of the second embodiment shown in FIG. 5, a field coil current control unit 20 that controls a current to the field coil 16 is provided in parallel to the field coil 16. The field coil current control unit 20 suppresses, for example, the current to the field coil 16 hardly flows by closing (“ON”) the contact, and opens the contact (“OFF”). This can be realized by using a relay that supplies a current to the magnetic coil 16. Other configurations are the same as those in FIG. 3 of the first embodiment.

  The starter of the second embodiment shown in FIG. 5 keeps the relay of the field coil current control unit 20 open in a high load range. As a result, as in the first embodiment, the starter is driven using both the field coil 16 and the permanent magnet 17 to start the engine, so that the high load region is the same as in the first embodiment. The effect of can be obtained. That is, by increasing the motor torque, the engine can be started quickly, the operation time of the starter is shortened, and silence is improved.

  On the other hand, in the low load region where the torque required to start the engine is small, the field coil current control unit 20 switches the relay when, for example, the starter current i flowing through the motor 5 falls below a predetermined threshold. Close and suppress the current to the field coil 16 to weaken the field. As a result, since the motor 5 becomes a high rotation type in the low load region, the engine can be started more quickly. Moreover, since the copper loss by the field coil 16 is eliminated, the efficiency is improved.

  Further, in the starter of the second embodiment, similarly to the first embodiment, the rotational speed of the motor 5 at the time of no load can be suppressed from being excessively increased by the field by the permanent magnet 17. As a result, it is possible to suppress the life of the starter from being shortened.

  FIG. 6 is a diagram showing a change in characteristics of the starter according to the second embodiment of the present invention when the relay is ON / OFF. The solid line in FIG. 6 indicates the case where the relay is opened (when the relay is OFF), and the dotted line in FIG. 6 indicates the case where the relay is closed (when the relay is ON). When the relay of the field coil current control unit 20 is closed, almost no current flows through the field coil 16, and the field is almost only a permanent magnet. Here, in the starter (solid line and dotted line) of the second embodiment shown in FIG. 6, the number of permanent magnets is smaller than that of the permanent magnet type starter (chain line). Since the field and the rotational speed are in an inversely proportional relationship, the starter (dotted line) when the relay is ON is higher than the permanent magnet type starter (chain line). Further, since the field and torque are in a proportional relationship, the starter (dotted line) when the relay is ON is lower than the permanent magnet type starter (chain line). Further, since the resistance by the field coil 16 is reduced when the relay is ON, the output P ′ (dotted line) when the relay is ON is larger than the output P (solid line) when the relay is OFF.

  Since the frequency of restarting the engine is higher than the frequency of normal starting, using a normally closed relay as the field coil current control unit 20 reduces the frequency of operation of the relay. Can improve the service life.

  In the above description, the field coil current control unit 20 has been described using an example of using a relay that suppresses the current to the field coil 16 by opening and closing its contact point. A semiconductor that can continuously control the current may be used. As a result, the rotation speed and torque of the starter in the vicinity of a predetermined current threshold can be continuously controlled more flexibly.

  As described above, according to the second embodiment, the field portion that generates the field of the motor includes both the permanent magnet and the field coil, and the current to the field coil can be suppressed as necessary. Is further provided. As a result, by suppressing so that the current to the field coil hardly flows in the low load region, in addition to the same effect as in the first embodiment, the high speed of the starter in the low load region is further improved. Can be made.

  In the second embodiment, the engine friction torque generally depends on the temperature. Therefore, the engine can be started more efficiently by controlling the current to the field coil 16 in accordance with the temperature of any one of outside air, engine room, engine oil, and cooling water.

  Specifically, when any one of the above temperatures is measured and the measured temperature value is lower than a predetermined value, the field coil current control unit 20 supplies current to the field coil 16. To control. Generally, the lower the temperature, the higher the viscosity of the engine oil and the greater the friction torque. By energizing the field coil 16, the field can be strengthened to increase the torque of the motor 5 and the engine can be started reliably.

  On the other hand, when the measured temperature value is higher than the predetermined value, the field coil current control unit 20 suppresses the current to the field coil 16. The higher the temperature, the lower the viscosity of the engine oil and the smaller the friction torque. By suppressing the current to the field coil 16, the field is weakened and the motor 5 is rotated at a higher speed, so that the engine can be started more quickly. . Thereby, the operation time of the starter is shortened and the quietness is improved.

  Further, in a starter that performs automatic engine stop / start control for automatically stopping or restarting the engine when a predetermined condition is satisfied, the engine is normally started by a driver's switch operation, and the engine automatic stop / start is started. A different method of controlling the current to the field coil 16 is used depending on whether the control is automatically restarted.

  Specifically, when the engine is normally started by a driver's switch operation, the engine is generally cold and requires high torque. Therefore, by supplying a current to the field coil 16, the field is strengthened and the motor 5 is increased in torque, so that the engine can be started more reliably.

  On the other hand, when the engine is automatically restarted by the engine automatic stop / start control, it is required that the engine is warmed up and does not require high torque, and can be started in a shorter time than when the switch is operated. Therefore, by suppressing the current to the field coil 16, the field is weakened and the motor 5 is rotated at a high speed, so that the engine can be started more quickly.

  In the second embodiment, when the engine is automatically restarted by the engine automatic stop / start control, the field coil current control unit 20 first supplies a current to the field coil 16. Then, the current to the field coil 16 is suppressed after a predetermined first time (for example, 30 to 100 msec) from when the motor 5 is energized to start rotating.

  Thereby, since the internal resistance of the motor 5 increases when the starter is started, the start-up current is reduced, voltage drop at the starter start-up can be suppressed, and an instantaneous power failure or the like can be prevented. Reset can be prevented.

  Further, in the second embodiment, when starting the engine so that the current to the field coil 16 is suppressed, the field coil current control unit 20 performs a predetermined second time from the start of the starter drive. If the engine speed has not reached a predetermined value after the lapse of time, energization of the field coil 16 is started.

  As a result, even when the engine cannot be started due to insufficient torque of the motor 5, the motor 5 is increased in torque by energizing the field coil 16 after a predetermined second time has elapsed, and the engine can be reliably restarted. it can.

  1 Electromagnetic switch, 2 suction coil, 3 plunger, 4 lever, 40 lever fulcrum, 5 motor, 6 output shaft, 7 internal reduction part, 8 overrunning clutch, 9 pinion gear, 10 ring gear, 11 field part, 12 commutator, 13 armature, 14 brush, 15 yoke, 16 field coil, 17 permanent magnet, 18 battery, 19 starter switch, 20 field coil current controller.

A starter according to the present invention is a starter provided with a motor for starting an engine and a field part for generating a field of the motor, the field part comprising both a permanent magnet and a field coil, In the field part, the magnetic pole is composed of a plurality of pairs of N poles and S poles, one pole is composed of the permanent magnet, and the other pole is composed of the field coil .

Claims (10)

A starter comprising a motor for starting the engine by receiving a supply of electric power from a battery and generating a rotational force, and a field part for generating a field of the motor;
The field magnet section includes both a permanent magnet and a field coil. 2. The starter according to claim 1, wherein the magnetic field portion includes a plurality of pairs of N poles and S poles, one pole being the permanent magnet and the other pole being the field coil. . The starter according to claim 1, wherein the field coil is connected in series with an armature of the motor. A field coil current control unit for controlling a current to the field coil is provided in parallel with the field coil.
The field coil current control unit is configured by using a relay that supplies or suppresses current to the field coil by opening and closing a contact, and in a low load region where a torque required to start the engine is small. The starter according to claim 3, wherein a current to the field coil is suppressed. The field coil current control unit controls the current to the field coil based on a temperature measurement value of any temperature of outside air, engine room, engine oil, or cooling water. The starter according to item 1. The starter according to claim 5, wherein the field coil current control unit supplies a current to the field coil when the temperature measurement value is lower than a predetermined temperature. A starter mounted in an engine automatic stop start control for automatically stopping or restarting the engine when a predetermined condition is satisfied;
The field coil current control unit supplies current to the field coil when the engine is started by a driver's operation and when the engine is automatically restarted by the engine automatic stop / start control. The starter according to any one of claims 1 to 4, wherein the starter is controlled individually. When the engine is started by a driver's operation, the field coil current control unit supplies current to the field coil and automatically restarts the engine by the engine automatic stop / start control. The starter according to claim 7, wherein current to the field coil is suppressed. In the case where the engine is automatically restarted by the engine automatic stop / start control, the field coil current control unit is configured to start the restart before starting a predetermined first time. The starter according to claim 4, wherein a current is supplied to the coil and the current to the field coil is suppressed after the first time has elapsed. When the engine is started in a state where the current to the field coil is suppressed, the field coil current control unit is configured to start the engine after a predetermined second time has elapsed since the start. The starter according to any one of claims 5 to 9, wherein a current is supplied to the field coil if the rotational speed does not reach a predetermined value.

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