JP2003083209A - Starter generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a starter generator capable of securing motor performance that engine starting needs to have and suppressing excessive charge performance. SOLUTION: This starter generator has function as a starter motor during the starting of the engine and function as a generator after the starting of the engine. A starter generator coil 1d used during the starting of the engine and during the generation, and exclusive coils 1a-1c for stating used only during the starting of the engine are connected in parallel mutually. Relays 4a-4c are arranged between the coils 1a-1d and an inverter 3 of a control system 5. When the engine starts, all relays 4a-4c are turned on, and the starter motor is composed by using the starter generator coil 1d and the exclusive coils 1a-1c for starting. After the engine starts, the relays 4b, 4c are turned off, and the starter motor is composed only of the exclusive starter generator coil 1d. Therefore, the motor performance is secured and generation performance is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined starter / generator device for use in a small motorcycle engine or a general-purpose engine, and more particularly to a starter / generator having an improved balance between motor performance and charging performance.

[0002]

2. Description of the Related Art In recent years, in small motorcycles and engine generators, many starter / generators are starter / generators that also serve as a starter motor for starting the engine and a generator for power generation driven by the engine. Has been used. Conventionally, the motor and the generator have the same basic configuration, but the starter motor is used only at the time of starting and the magnet generator is used after the starting, and two devices having a similar structure coexist. There was a bad effect that there was a lot of waste. Therefore, a starter generator that uses both the fielder and armature of a starter motor as the rotor and stator of a power generator is proposed, and its use is increasing in recent years because of its space efficiency. .

In such a start-up generator, higher performance as a starter motor is required as the engine displacement increases. That is, the cranking torque at the engine start increases significantly due to the increase in displacement, and accordingly, the output of the starter motor also needs to increase significantly. For example, if the displacement is increased from 50cc to 125cc, the motor output required for starting will be about 2.2 times. In this case, when the motor output is increased, the power generation capacity is also increased accordingly, and the power generation amount obtained at the same rotation speed is also increased as compared with the case where the exhaust amount is small.

[0004]

However, the power generation performance required for the starter generator does not increase so much in the high rotation range with the increase in the displacement. FIG. 5 is a graph showing changes in the required power generation performance, and shows the relationship between the engine speed and the required amount of power generation in a 50 cc engine and a 125 cc engine. As described above, the difference in the motor output between the two engines is 2.2 times, but the required power generation amount is not as large as the displacement or the motor output in the region exceeding 5000 rpm, as shown in FIG. . In Figure 6,
The table below shows the relationship between the displacement, motor performance, and power generation.

Generally, in a starting generator, the engine is started first. For this reason,
The starter generator itself is a specification that emphasizes starter motor performance, for example, if the engine displacement is 50cc → 125cc,
The motor output has to be 2.2 times. In this case as well, the power generation capacity naturally increases as the motor output increases. However, as shown in FIG. 6, at 10000 rpm, the required power generation performance increases only 1.2 times, and the power generation capacity becomes excessive for the vehicle. This difference increases as the displacement increases, and it is necessary to suppress such excess power generation.

However, it is difficult to reduce the difference between the same windings while keeping the same windings and to achieve both starter performance and power generation performance. Therefore, in the conventional start-up generator, short-circuit control is performed by using a large-capacity FET in the rectifier circuit, or open control is performed by disconnecting the inverter circuit by using a relay or a backflow prevention diode, etc. I am trying to However, if the motor performance is emphasized by performing the short control, there is a problem that the heat generation due to the copper loss and the iron loss becomes large. Further, in the open control, there is a problem that the voltage drop becomes large and the control circuit may be complicated, or the motor performance may not be satisfied.

On the other hand, in a power generator, the power generation characteristic is switched to adjust the amount of power generation.
Devices such as the 838 and Japanese Patent Laid-Open No. 7-87799 are known. In the former device, a coil is separately added to the generator coil of an alternator for automobiles to improve brake characteristics and assist engine output, and a motor coil and a generator coil are provided as dedicated coils. Also,
In the latter device, a switching element is arranged between a set of three-phase coils of a three-phase AC generator and a rectifier circuit, and the switching amount of the switching element is appropriately controlled according to the engine speed to stabilize the amount of power generation. It is intended to be. Where,
The switching elements are controlled to output three phases at low speed, two phases at medium speed, and one phase at high speed, so that a stable and constant DC output can always be obtained regardless of the engine speed. It has become.

However, in the apparatus disclosed in Japanese Patent Laid-Open No. 62-2838, the motor coil is not normally used during power generation, and a driver and a rectifier circuit are required for each coil, which complicates the configuration. In addition, the motor coil mentioned here is used exclusively to enhance the braking force,
Even in the case of forward rotation, it is used to assist the engine output and is not expected to be used as a starter motor.

An object of the present invention is to provide a starting generator capable of suppressing excessive charging performance while ensuring the motor performance required for engine starting.

[0010]

The starting generator of the present invention comprises:
A starting generator that is connected to a crankshaft of an engine, functions as a starter motor when the engine is started, and functions as a generator after the engine is started, and includes a plurality of sets of multiphase coils connected in parallel with each other. A winding unit provided with the winding unit; a control unit that is connected to the winding unit and that includes an inverter circuit using a semiconductor element; and the multi-phase coil that is interposed between the winding unit and the inverter circuit. And switch means for controlling a conduction state between the inverter circuit and the inverter circuit.

In the starting generator of the present invention, by controlling the switch means, the connection between the inverter circuit and the polyphase coil is such that the starting generator functions as a starter motor. It can be appropriately switched depending on whether it functions as. Therefore, it is possible to suppress the power generation performance while satisfying the motor performance, and it is possible to provide a starting generator in which both performances are well balanced. Further, according to the starting generator, the excess current is reduced while securing a necessary and sufficient amount of power generation, so that a resistor or the like for consuming the excess current is not necessary, and loss and heat generation can be reduced and the current can be reduced. The amount can be easily controlled.

In the starting generator, when the engine is started, all the multi-phase coils are used to form a starter motor by turning on all the switch means. Alternatively, the generator may be configured by a part of the multiphase coils by turning off the switch means.

Further, in the starter / generator, the multi-phase coil is composed of a starter / generator coil used at both engine start and power generation, and a start-only coil used only at engine start, The switch means may be provided between the starting power generation coil and the inverter circuit and between the starting coil and the inverter circuit, respectively. In this case, at the time of starting the engine, a starter motor is configured by using all of the start generating coils and the start-dedicated coils by turning on all the switch means, and after the engine is started, the start-dedicated coil and the start-dedicated coil are connected. A generator may be configured by the starting power generation coil by turning off the switch means provided between the inverter circuit and the inverter circuit.

In addition, in the starting generator, a relay may be used as the switch means, whereby
The polyphase coil can be physically separated completely from the inverter circuit, and the reliability can be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. The starter / generator according to the present embodiment has a structure that also serves as an engine starter (starter) and a generator (ACG), and is used integrally with an engine to be used in a motorcycle, an engine generator, or the like. . The starting generator has a structure in which a rotor having a permanent magnet is arranged around a stator around which a coil is wound, and the rotor is directly connected to a crankshaft of an engine. When the engine is started, the coil on the stator side is energized to function as a starter motor, and after the engine is started, an electromotive force is generated in the coil due to the rotation of the permanent magnet to function as a generator. The starter generator is classified into an inner rotor type and an outer rotor type depending on whether the rotor or the stator is arranged outside, but the starter generator of the present invention can be applied to any type. Is.

FIG. 1 is an explanatory diagram showing a circuit configuration of a starting generator which is an embodiment of the present invention. Here, the stator side is provided with a winding portion 1 including coils (polyphase coils) 1a to 1d in which three-phase windings of U, V, and W are connected in a star shape. In the winding unit 1, the coils 1a to 1d are connected in parallel with each other. In the present embodiment, of the coils of the winding unit 1, the coil 1d is a starting power generation coil used both during startup and during power generation. On the other hand, the remaining coils 1a to 1c are start-up coils that are used only at the start.

As shown in FIG. 1, the winding portion 1 is an FET.
It is connected to a control system (control means) 5 including an inverter (inverter circuit) 3 including a bridge circuit formed by using (semiconductor elements) 2a to 2f. The inverter 3 supplies a current that forms a rotating magnetic field based on the detection result of a rotor position sensor (not shown) to the coils 1a to 1d.
6 field effect transistors FETs 2a to 2f and six parasitic diodes 6a connected in parallel to them, which have both the energization control function of energizing the coils 1a to 1d and the rectification function of rectifying the generated current by the coils 1a to 1d. It is configured to have ~ 6f.

In this inverter 3, each bridge row of three rows is connected in series with each FET 2a, 2c, 2e on the high side and each FET 2b, 2d, 2f on the low side. In this case, the FETs 2a, 2c, 2e are common,
It is connected to the power supply potential connected to the battery 7. The FETs 2b, 2d, 2f are commonly connected to the ground potential. Each FET 2a, 2c, 2e and each F of each bridge row
At each connection node with ET 2b, 2d, 2f, coil 1a
Each of the phases 1d to 1d is connected. That is, F
A U-phase coil is connected between the ETs 2a and 2b, a V-phase coil is connected between the FETs 2c and 2d, and a W-phase coil is connected between the FETs 2e and 2f. The gates of the FETs 2a to 2f are connected to the three-phase bridge driver 8.

In the control system 5, the inverter 3
An output monitoring circuit 9 for monitoring the rectified output voltage is provided on the High side of the. Further, a CPU 10 that controls the three-phase bridge driver 8 and the like based on the monitoring result is provided in the subsequent stage of the output monitoring circuit 9.
The FETs 2a to 2f are gate-controlled by the three-phase bridge driver 8 based on the command from the CPU 10.

On the other hand, relays (switch means) 4a-4c are provided between the winding unit 1 and the inverter 3. As shown in FIG. 1, the relays 4a and 4b are FET2c,
The relay 4c is provided between the FETs 2e and 2f and between the coils 1a to 1d and the V-phase coils of the coils 1a to 1d.
It is disposed between the a- to 1-d W-phase coils. in this case,
The relay 4a is composed of the V-phase coil of the coil 1d and the FETs 2c, 2
During d, the relay 4b is connected to the V-phase coils of the coils 1a to 1c on the rear side of the V-phase coil of the coil 1d. The relays 4a to 4c are arranged in a normally open state.

By the way, the coils 1a to 1d are usually connected as shown in FIG. 2 (a). However, in the case of such an arrangement, only the black-painted coil 1d is functioning at the time of power generation, the magnetic balance becomes poor, and noise and vibration problems such as magnetic noise and eccentricity of the rotor occur. Therefore, in the starting generator, in order to equalize the magnetic balance, as shown in FIG.
The wirings are arranged in three equal parts between the coils 1a to 1c. As a result, the bias of the magnetic balance is eliminated even during power generation, and the magnetic noise and vibration caused by the deterioration of the balance can be reduced.

Further, in this embodiment, as shown in FIG. 3, the teeth shape of the core around which the winding is wound is different between the coils 1a to 1c and the coil 1d. in this case,
Of course, it is possible to use teeth of the same shape in all the coils, but if the power generation performance is taken into consideration while giving importance to the motor function, the shape tends to be set so as to suppress the power generation output to some extent. Such a setting may make it difficult to obtain sufficient power generation performance, which becomes more difficult to balance as engine displacement increases and the difference between motor performance and power generation required performance increases. . Therefore, in the starting generator, the core teeth of the coil 1d used for power generation have a shape / winding specification that emphasizes power generation performance, and the core teeth of the other coils 1a to 1c have the optimum shape / winding specification for motor performance. As a result, we are trying to balance the performance of both motor and power generation.

As shown in FIG. 3, the tooth 11 around which the coil 1d is wound has a larger tooth width X and pole width Y than the tooth 12 around which the other coils 1a to 1c are wound. In this case, if the teeth width X is increased, the magnetism easily leaks to the adjacent teeth, and
The amount of power generation is suppressed. Further, when the pole width Y is increased, the amount of effective magnetic flux during power generation is reduced, and the amount of power generation is suppressed accordingly. As a result, the amount of power generated by the coil 1d is suppressed, and by setting the other coils with emphasis on the motor specifications, it becomes easy to balance the motor performance and the power generation performance. The setting of X and Y is appropriately determined in consideration of the engine displacement and the like, but it is not always necessary to make both different from other teeth. That is, only one of the tooth width X and the pole width Y may be different from the other teeth 12.

Next, the operation of such a starting generator will be described. First, when starting the engine, first, all the relays 4a to 4c are turned on, and the winding unit 1 and the inverter 3 are connected. Then, a start switch (not shown) is turned on. At this time, the starter generator is configured as a brushless motor, and the three-phase bridge driver 8 supplies electric power from the battery 7 to the U, V, and W phases of the coils 1a to 1d, and these are sequentially excited. As a result, the rotor is driven, the crankshaft rotates, and the engine starts. That is, when the engine is started, the starter motor is configured by using all the coils 1a to 1d to satisfy the motor performance.

On the other hand, after the engine is started, the relays 4b, 4
c is turned off and only the relay 4a is turned on. As a result, the coils 1a to 1c are separated from the inverter 3, and the starter generator is configured as a power generator using the coil 1d. In this case, in the starting generator, the coils 1a to
Since the relay is used as a switch means for turning off 1c, the coils 1a to 1c are physically completely disconnected from the inverter 3. Of course, the FE that is the switch means
It is also possible to disconnect the coils 1a-1c using T2a-2f. However, since it is necessary to interrupt a relatively large current between the coils 1a to 1c and the inverter 3, it is more reliable to use the relays as the switch means as in the present embodiment.
Can be separated, and reliability can be improved.

Thus, in the starting generator, the coil 1d
Since only the power is generated, the amount of power generation is suppressed as shown in FIG. In this case, if power is generated using all the coils 1a to 1d, the power generation amount becomes extremely large and excessive power generation occurs as shown in FIG. 4, but the problem of excessive power generation does not occur in the starting generator. That is, at the time of start-up, the three-phase four-coil coil provides sufficient output to satisfy the motor performance, while
At the time of power generation, three sets of start-up coils are turned off, and one set of starter-generation coils is needed to obtain a sufficient amount of power generation.
A good balance of both motor and power generation performance is maintained. Therefore, it is possible to prevent the power generation capacity from becoming excessive for the vehicle, and it is possible to easily balance with the motor performance even when the engine displacement becomes large. Further, since a resistor or the like for consuming the excess current is unnecessary, loss and heat generation can be reduced, and the current amount can be easily controlled.

Further, as described above, the coil 1d at the time of power generation
2 is equally distributed between the other coils 1a to 1c as shown in FIG. 2B, so that the magnetic balance during power generation can be maintained well. Furthermore, since the teeth on which the coil 1d is wound are set so that the power generation performance is more important than the teeth on which the other coils 1a to 1c are wound, the power generation performance can be adjusted more accurately. it can.

It is needless to say that the present invention is not limited to the above-mentioned embodiment, and can be variously modified without departing from the scope of the invention. For example, in the above-described embodiment, the example in which only the coil 1d is used as the starting power generation coil is shown, but other coils may be appropriately used as the starting power generation coil in accordance with the required power generation amount. In this case, a switch means may be separately provided between the coils 1a to 1d and the inverter 3 for each coil, and any switch means may be appropriately turned off at the time of power generation. It is also possible to automatically control while monitoring.

Also, an example has been shown in which the relay 4a is turned on and the relays 4b and 4c are turned off during power generation, and three-phase power is generated by the coil 1d, but all the relays 4a to 4c are generated during power generation.
May be turned off to generate single-phase power. Further, the relays 4a to 4c are interlocked with the engine start switch, and
Alternatively, the relays 4a to 4c may be turned off in conjunction with the engine speed.

[0030]

According to the starter / generator of the present invention, the switch means for controlling the conduction state between each multiphase coil and the inverter circuit is provided between the winding portion and the inverter circuit of the control means. The connection between the inverter circuit and the polyphase coil can be appropriately switched depending on whether the starting generator functions as a starter motor or the generator. Therefore, it is possible to suppress the power generation performance while satisfying the motor performance, and it is possible to easily balance the two. Further, according to the starting generator, the excess current is reduced while securing a necessary and sufficient amount of power generation, so that a resistor or the like for consuming the excess current is not necessary, and loss and heat generation can be reduced and the current can be reduced. The amount can be easily controlled.

Further, since the relay is used as the switch means, the polyphase coil can be physically separated completely from the inverter circuit, and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a circuit configuration of a starter-generator according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a connection state of coils in the starter / generator of FIG. 1, (a) is a normal winding style,
(B) shows a winding style in the starting generator.

FIG. 3 is an explanatory diagram showing the shape of core teeth in the starting generator of FIG. 1.

FIG. 4 is a graph showing power generation performance in the starting generator of FIG.

FIG. 5 is a graph showing changes in required power generation performance, 50cc
It shows the relationship between the engine speed and the required amount of power generation for the No. engine and the 125cc engine.

FIG. 6 is a table summarizing the relationship between the exhaust amount, motor performance, and power generation amount.

[Explanation of symbols]

1 winding part 1a-1d coil 2a to 2f FET (semiconductor element) 3 Inverter (inverter circuit) 4a-4c relay 5 Control system (control means) 6a-6f Parasitic diode 7 battery 8 3-phase bridge driver 9 Output monitoring circuit 10 CPU 11 Teeth 12 Teeth X teeth width Y pole width

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H02K 3/18 H02K 3/18 P 19/34 19/34 19/36 19/36 D H02P 9/04 H02P 9/04 L // H02K 1/16 H02K 1/16 CF Term (reference) 5H002 AA04 AB05 AE07 5H590 AA01 AA04 AA05 AA06 CA07 CA23 CC02 CC18 CC24 CC34 CD01 CD03 CE05 EA01 EA10 EB12 EB14 FA05 FC14 FC26 GA02 GA06 GB05 5H603 BB02 BB07 BB09 BB12 CA01 CA05 CB02 CB16 CC11 CC17 5H619 AA01 AA10 BB01 BB03 BB06 BB15 PP01 PP04 PP14

Claims (5)

[Claims] 1. A start-up generator connected to a crankshaft of an engine, which functions as a starter motor when the engine is started, and functions as a generator after the engine is started, and a plurality of sets connected in parallel with each other. A winding unit having a multi-phase coil, a control unit connected to the winding unit, and having an inverter circuit using a semiconductor element, and interposed between the winding unit and the inverter circuit, A start-up generator comprising: switch means for controlling a conduction state between each of the multiphase coils and the inverter circuit. 2. The starter / generator according to claim 1, wherein when the engine is started, all of the switch means are turned on to form a starter motor using all of the polyphase coils. After that, by turning off any of the switch means, a part of the multiphase coils constitutes a generator, and a starting generator is characterized. 3. The starter / generator according to claim 1, wherein the multi-phase coil includes a starter / generator coil used at both engine start and power generation, and a start-only coil used only at engine start. And the switch means comprises:
A starter / generator is provided between the starter / generator coil and the inverter circuit and between the starter-only coil and the inverter circuit, respectively. 4. The starter / generator according to claim 3, wherein when the engine is started, all of the switch means are turned on to form a starter motor by using the starter generator coil and the starter-dedicated coil. After the engine is started, the starter generator is configured by turning off the switch means interposed between the start-up coil and the inverter circuit, thereby forming a generator with the starter generator coil. 5. The starting generator according to claim 1, wherein the switch means is a relay.