JP4683018B2 - Starter - Google Patents

Description

  The present invention relates to a starter that drives a shift lever by an electromagnetic switch and pushes a pinion in the direction opposite to the motor.

As a prior art, there is a starter described in Patent Document 1.
The starter includes a motor that generates a rotational force when the armature is energized, and an electromagnetic switch that opens and closes a main contact provided in a motor circuit for energizing the armature with a current flowing from the battery. This is a system in which the shift lever is driven using the generated suction force, and the pinion and the clutch are integrally pushed out in the counter-motor direction via the shift lever.
Japanese Patent No. 3478211

The starter has a structure in which the pinion and the clutch move together, and the mass of the moving body is large, so that it is inevitably necessary to increase the attractive force of the electromagnetic switch.
In other words, the electromagnetic switch has a suction coil and a holding coil. When the plunger is sucked, both the suction coil and the holding coil are energized to reduce the combined resistance of both coils, thereby increasing the operating current. The suction power is increased. Further, when the plunger is sucked and the main contact is closed, the suction coil is short-circuited by the main contact, and the plunger is held by the magnetic force generated by the holding coil. Therefore, the suction coil is energized only for a short time until the main contact is closed.

However, in a two-coil electromagnetic switch having a suction coil and a holding coil, it is necessary to connect the suction coil to a motor circuit. Specifically, a connection terminal is attached to an M terminal bolt fixed to the contact cover of the electromagnetic switch, and the end of the suction coil is connected to the connection terminal by welding or the like. In this configuration, the number of parts is increased, and a process of attaching the connection terminal to the M terminal bolt and a process of connecting (welding) the end of the suction coil to the connection terminal are also required, resulting in an increase in cost.
Further, since the operating current of the electromagnetic switch is large (about 40 A), the operating current cannot be directly controlled by the ECU (electronic control unit). Therefore, for example, as shown in FIG. 6, between the energization terminal 120 (generally referred to as 50 terminal) of the switch coil (attraction coil 100 and holding coil 110) and the ignition switch (hereinafter referred to as IG switch 130). There is known a starter circuit in which a starter relay 140 is arranged and an excitation current of the starter relay 140 is controlled by an ECU 150.

However, in the above starting circuit, it is necessary to provide a switch circuit for energizing the energizing terminal 120 via the starter relay 140 and a relay circuit for controlling the excitation current of the starter relay 140 by the ECU 150. The circuit configuration is complicated, and this is a factor for increasing the cost of the vehicle system. Further, in order to connect the switch circuit and the relay circuit, it is necessary to configure the IG switch 130 in two systems, and there is a problem that the IG switch 130 is complicated and expensive.
The present invention has been made based on the above circumstances, and an object of the present invention is to provide a starter capable of realizing cost reduction by reducing the number of parts.

(Invention of Claim 1)
The present invention relates to a motor that generates a rotational force by energizing an armature by closing a main contact provided in a motor circuit, an output shaft to which the rotational force of the motor is transmitted via a clutch, and the output shaft A pinion that fits a helical spline on the outer periphery of the switch, a switch coil that generates a magnetic force when energized, and a plunger that moves by receiving the magnetic force generated by the switch coil. The main contact is linked to the movement of the plunger. The starter is provided with an electromagnetic switch that opens and closes and pushes the pinion in a direction opposite to the motor via a shift lever. The motor uses a permanent magnet for the field, and the electromagnetic switch is an armature. as the counter electromotive voltage generated during inertia rotation of never around to switch coil, 1 the switch coil is electrically isolated from the motor circuit Characterized in that it consists of yl.

In the starter of the present invention, the switch coil of the electromagnetic switch is constituted by one coil, and a suction force for sucking the plunger by the one switch coil and a holding force for holding the plunger are generated. In this case, there is no need to connect the switch coil to the motor circuit, and the switch coil and the motor circuit can be electrically separated. Therefore, a conventional connection terminal for electrically connecting the suction coil and the M terminal bolt is provided. Further, the process of connecting the end of the suction coil to the connection terminal by welding or the like is unnecessary. As a result, it is possible to keep costs low by reducing the number of parts and man-hours.
Also, in a starter that uses a permanent magnet for the motor field and has a two-coil electromagnetic switch consisting of a suction coil and a holding coil, this occurs during inertial rotation of the armature after the IG switch is turned off. Since the back electromotive voltage circulates to the switch circuit, the motor is turned on again by detecting the back electromotive voltage when detecting the voltage applied to the switch circuit and determining the starter operation state (motor operation and stop). There is a risk of misjudging it.
On the other hand, in the starter of the present invention, since the switch coil of the electromagnetic switch is one coil and the switch coil is not electrically connected to the motor circuit, the counter electromotive voltage generated during inertial rotation of the armature. Does not sneak into the switch circuit. Thus, it is possible to accurately determine the operation state of the starter without erroneously determining that the motor is turned on again by detecting the back electromotive voltage.

(Invention of Claim 2)
2. The starter according to claim 1, wherein the electromagnetic switch has a contact cover in which a main contact is disposed, and an energization terminal for energizing the switch coil with a current flowing from the battery is fixed to the contact cover. The switch coil is characterized in that an end on one end side is connected to the energizing terminal and an end on the other end side is connected to the ground side.
Since the switch coil is one coil, the end portion on one end side of the switch coil is connected to the energization terminal in the same manner as a conventional two-coil electromagnetic switch having a suction coil and a holding coil. Also, the other end of the switch coil does not need to be connected to the motor circuit. For example, the switch coil is electrically connected to a switch case that is a casing of the electromagnetic switch or a fixed iron core that forms a part of the magnetic circuit. Can be connected to earth ground.

(Invention of Claim 3)
3. The starter according to claim 1, wherein after the pinion pushed in the direction opposite to the motor by the action of the electromagnetic switch comes into contact with the ring gear of the engine, the main contact is moved until the main contact is closed. When the reaction force has a drive spring acting in the direction of biasing the pinion to the ring gear side via the shift lever, and the reaction force stored in the drive spring is called a switch pushing force, By setting the mass of the pinion to 100 g or less and the switch pushing force to 70 N (Newton) or less, the energizing current to the switch coil is set to 12 A or less.

The starter of the present invention is a system that pushes out only the pinion separately from the clutch, and the mass of the moving body can be reduced as compared with a conventional starter that extrudes the clutch and the pinion integrally. The magnetic switch's attractive force (magnetic force generated by the switch coil) can be reduced.
Specifically, the mass of the pinion can be set to 100 g or less, the switch pushing force is set to 70 N (Newton) or less, and the energization current to the switch coil can be set to 12 A or less. Thereby, even when the switch coil is composed of one coil, the electromagnetic switch can be reduced in size and weight.

Further, by suppressing the energization current to the switch coil to 12 A or less, the current to be energized to the switch coil can be directly controlled by the ECU. As a result, the starter relay can be eliminated and the switch circuit can be simplified, and there is no need to pass a large current (for example, a current of about 40 A) through the switch circuit. Arise.
Note that ECUs equipped with many electronic components generally dislike heat generation, and thus cannot directly control a large current of about 40 A, but if the current is 12 A or less, the starter operation time for each time Is short (several seconds), so there is no particular problem.

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

FIG. 1 is a side view including a partial cross section of the starter 1, and FIG. 2 is a start circuit diagram of the starter 1.
As shown in FIG. 1, the starter 1 of the present embodiment includes a motor 3 that generates a rotational force in the built-in armature 2 (see FIG. 2), a reduction device 4 that reduces the rotation of the motor 3, and this deceleration An output shaft 6 connected to the device 4 via a clutch 5, a pinion 7 fitted in a helical spline on the outer periphery of the output shaft 6, and a motor circuit for energizing the armature 2 from a battery 8 (see FIG. 2) And an electromagnetic switch 10 or the like that opens and closes a main contact (to be described later) and pushes the pinion 7 in the counter-motor direction (left direction in the figure) via the shift lever 9.
The motor 3 uses a permanent magnet (not shown) for the field, and is a magnet field type that is energized to the armature 2 via a brush 11 (see FIG. 2) that is in sliding contact with a commutator (not shown). This is a commutator motor.

The reduction gear 4 is a known planetary gear reduction gear that can reduce the speed by arranging the armature shaft 2a (see FIG. 1) of the motor 3 and the output shaft 6 on the same axis.
The clutch 5 transmits the driving torque of the motor 3 amplified by the reduction gear 4 to the output shaft 6. On the other hand, when the engine starts and enters an overrun state, the rotational torque of the engine is transmitted to the armature 2 via the reduction gear 4. The one-way clutch 5 is configured to block the transmission of torque between the output shaft 6 and the reduction gear 4 so as not to be transmitted.
The output shaft 6 has an end on the side opposite to the motor (the left side in the drawing) rotatably supported by the housing 13 via a bearing 12, and an end on the motor side is configured integrally with the clutch 5.
The pinion 7 moves in the direction opposite to the motor from the stop position shown in FIG. 1 and meshes with the ring gear 14 on the engine side, and rotates together with the output shaft 6 to rotationally drive the ring gear 14. The pinion 7 of the present embodiment is formed with a mass of 100 g or less.

The electromagnetic switch 10 has a known solenoid that forms an electromagnet when energized, and a contact cover 15 fixed to the solenoid, and a main contact is disposed inside the contact cover 15.
The solenoid has a switch coil 16 that will be described in detail below, and a plunger 17 that can move the inner periphery of the switch coil 16 in the axial direction (left-right direction in FIG. 1), and an electromagnet is formed by energizing the switch coil 16. When the plunger 17 is sucked, the main contact is closed in conjunction with the movement of the plunger 17. When the energization of the switch coil 16 is stopped and the magnetic force of the electromagnet disappears, the plunger 17 is pushed back by the return spring 18 (see FIG. 1) to open the main contact.

The switch coil 16 is connected at one end to an energizing terminal (hereinafter referred to as 50 terminal 19) fixed to the contact cover 15, and the other end forms part of a solenoid case or a magnetic circuit. It is electrically connected to a fixed iron core or the like, connected to the ground side, and constituted by one coil electrically separated from the motor circuit. That is, one switch coil 16 generates a suction force for sucking the plunger 17 to close the main contact and a holding force for holding the plunger 17 to maintain the closed state of the main contact.
The plunger 17 is formed with a recess on the side opposite to the contact point in the axial direction (left side in FIG. 1). In this recess, the lever hook 20 that transmits the movement of the plunger 17 to the shift lever 9 and the pinion 7 to the ring gear 14 are formed. A drive spring 21 that stores a reaction force for pushing is inserted. When the reaction force stored in the drive spring 21 is defined as the switch pushing force, in the starter 1 of this embodiment, the switch pushing force is set to 70 N or less.

The main contact is connected to the high potential side (battery side) of the motor circuit via the B terminal bolt 22 and connected to the low potential side (motor side) of the motor circuit via the M terminal bolt 24. The M fixed contact 25 and the movable contact 26 which is movable integrally with the plunger 17 and intermittently connects between the two fixed contacts 23, 25 are formed. The main contact is closed when the fixed contacts 23 and 25 are conducted, and the main contact is opened when the movable contact 26 is separated from the fixed contacts 23 and 25 and the conduction between the fixed contacts 23 and 25 is interrupted. It becomes a state.
Both the B terminal bolt 22 and the M terminal bolt 24 are fixed to the contact cover 15, and the terminal of the battery cable is connected to the tip end side of the B terminal bolt 22 protruding in the axial direction from the contact cover 15. A terminal 27 of the motor lead wire is connected to the tip end side of the M terminal bolt 24 that protrudes in the axial direction. The motor lead wire is connected to the brush 11 (see FIG. 2) on the positive electrode side inside the motor 3.

Next, the starting circuit of the starter 1 will be described with reference to FIG.
As shown in FIG. 2, the starting circuit of the present embodiment includes the motor circuit (a circuit for energizing the armature 2 from the battery 8) and the energizing switch coil 16 of the electromagnetic switch 10 from the battery 8. It consists of a switch circuit.
In the switch circuit, an ECU 29 related to the start control of the starter 1 is connected between the 50 terminal 19 and the IG switch 28, and the voltage applied to the 50 terminal 19 by the ECU 29 is controlled to a predetermined value (12 V in this embodiment). Has been.

  A neutral switch 30 may be disposed between the 50 terminal 19 and the ECU 29. The neutral switch 30 is turned on when the shift position of the transmission is neutral, and is turned off when the transmission is not neutral. Therefore, when the neutral switch 30 is in the off state, the 50 terminal 19 is not energized even if the IG switch 28 is turned on. That is, when the IG switch 28 is turned on while the neutral switch 30 is in the on state, the current flowing from the battery 8 is energized to the 50 terminal 19 via the ECU 29.

By the way, when the voltage applied from the battery 8 to the 50 terminal 19 is 12V and the current flowing through the switch coil 16 through the 50 terminal 19 is defined as the operating current, the operating current is controlled to 12 A or less by the ECU 29. This operating current is determined based on the mass of the pinion 7.
That is, the starter 1 of the present embodiment is a system that pushes out only the pinion 7 using the attractive force of the electromagnetic switch 10 (the clutch 5 does not move), and the mass of the pinion 7 is set to 100 g or less. Here, for example, when the meshing life of the pinion 7 and the ring gear 14 is set to 50,000 times, in order to satisfy this meshing life of 100%, as shown in FIG. Hereinafter, it is necessary to set the operating current of the electromagnetic switch 10 to 12 A or less. The mass of the pinion 7 can be reduced by reducing the number of teeth. However, for example, when the number of teeth is 7 or less, the root strength is insufficient, and therefore a mass of 40 g or more is required at the minimum. In terms of the number of teeth, it can be selected between 8 and 11 sheets.

Next, the operation of the starter 1 will be described.
When the switch coil 16 is energized by the ON operation of the IG switch 28 and the plunger 17 is sucked, the movement of the plunger 17 is transmitted to the pinion 7 via the shift lever 9. As a result, the pinion 7 is pushed out on the output shaft 6 along the helical spline in the counter-motor direction, and the end surface of the pinion 7 comes into contact with the end surface of the ring gear 14 and stops temporarily. Thereafter, when the plunger 17 is further moved and the main contact is closed while accumulating the reaction force in the drive spring 21, the motor 3 is energized from the battery 8 to generate a rotational force in the armature 2. The rotation of the armature 2 is decelerated by the reduction gear 4 and transmitted to the output shaft 6 via the clutch 5.

When the pinion 7 rotates to a position where it can mesh with the ring gear 14 while the end surfaces of the pinion 7 and the ring gear 14 are in contact with each other due to the rotation of the output shaft 6, the reaction force (switch pushing force) stored in the drive spring 21 Thus, the pinion 7 is pushed out and meshed with the ring gear 14. As a result, the drive torque of the motor 3 amplified by the reduction gear 4 is transmitted from the pinion 7 to the ring gear 14 to crank the engine.
When the engine is completely exploded from the cranking and the engine speed exceeds the starter speed, the clutch 5 is idled so that the rotation of the engine is not transmitted to the armature 2 via the speed reducer 4. Overrun of the armature 2 can be prevented.

When the IG switch 28 is turned off after the engine is started, the energization to the switch coil 16 is stopped and the attractive force disappears, so that the plunger 17 is pushed back by the reaction force of the return spring 18. As a result, the main contact is opened and energization from the battery 8 to the motor 3 is stopped, so that the rotation of the armature 2 is gradually decelerated and stopped.
When the plunger 17 is pushed back, the shift lever 9 swings in the direction opposite to that at the start of the engine and the force for pushing out the pinion 7 is eliminated. Therefore, the pinion 7 is moved to the pinion spring 31 (see FIG. 1). After being urged and disengaged from the ring gear 14, it is pushed back to the stop position shown in FIG.

(Effect of Example 1)
The electromagnetic switch 10 of the present embodiment is a one-coil type that generates a suction force that sucks the plunger 17 with one switch coil 16 and a holding force that holds the plunger 17, and thus has a suction coil and a holding coil. Compared to the two-coil conventional technology, the number of coils can be reduced, and there is no need to electrically connect the switch coil 16 and the M terminal bolt 24. Thereby, the connection terminal for electrically connecting the conventional suction coil and the M terminal bolt can be eliminated, and the step of connecting the end of the suction coil to the connection terminal by welding or the like is unnecessary. As a result, the cost can be kept low by reducing the number of parts and man-hours.

In addition, the starter 1 of this embodiment is a method of extruding only the pinion 7 separately from the clutch 5, and the mass of the pinion 7 is set to 100 g or less and the switch pushing force is set to 70 N or less. As a result, the attractive force of the electromagnetic switch 10 required to push the pinion 7 in the direction opposite to the motor, that is, the magnetic force generated by the switch coil 16 can be reduced. Alternatively, the electromagnetic switch 10 can be further reduced in size and weight.
Moreover, since the attractive force of the electromagnetic switch 10 can be reduced, the operating current of the electromagnetic switch 10 can be suppressed to 12 A or less. Thereby, since the operating current of the electromagnetic switch 10 can be directly controlled by the ECU 29, it is not necessary to use a starter relay in the switch circuit, and the IG switch 28 can be configured in one system for simplification. be able to. Furthermore, since it is not necessary to flow a large current (for example, a current of about 40 A) through the switch circuit, there is an advantage that the wiring used for the switch circuit can be made thin.

  Further, in the motor 3 using a permanent magnet as a field, after the IG switch 28 is turned OFF, a counter electromotive voltage is generated during inertial rotation of the motor 3. In this case, in the two-coil electromagnetic switch having the suction coil and the holding coil, the switch circuit and the motor circuit are electrically connected, so that a back electromotive voltage is applied to the switch circuit. As a result, as shown in FIG. 4, a voltage waveform (a circled portion in the figure) is generated at the 50 terminal, and the ECU may detect that the voltage waveform is erroneously determined to have been turned on again.

  On the other hand, in the present embodiment, the motor circuit and the switch circuit can be electrically separated by making the switch coil 16 of the electromagnetic switch 10 into one coil. That is, since the switch coil 16 is not connected to the motor circuit, the counter electromotive voltage does not enter the switch circuit. As a result, as shown in FIG. 5, since no back electromotive voltage is applied to the 50 terminal 19, the ECU 29 detects that the applied voltage to the 50 terminal 19 is "0V" The stop of energization to 19 can be determined instantaneously.

It is a side view including a partial cross section of a starter. It is a starter circuit diagram of a starter. It is a correlation diagram of pinion mass, switch pushing force, and switch current. It is a voltage waveform figure of 50 terminals concerning a prior art. It is a voltage waveform diagram of 50 terminals according to the present invention. It is a starting circuit diagram of the starter concerning a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Starter 2 Armature 3 Motor 5 Clutch 6 Output shaft 7 Pinion 8 Battery 9 Shift lever 10 Electromagnetic switch 14 Ring gear 15 Contact cover 16 Switch coil 17 Plunger 19 50 terminal (terminal for energization)
21 Drive spring 23 B fixed contact (main contact)
25 M fixed contact (main contact)
26 Movable contact (main contact)

Claims (3)

A motor that generates torque by energizing the armature by closing a main contact provided in the motor circuit;
An output shaft through which the rotational force of the motor is transmitted via a clutch;
A pinion that fits a helical spline on the outer periphery of the output shaft;
A switch coil that generates a magnetic force when energized, and a plunger that moves by receiving the magnetic force generated by the switch coil; opens and closes the main contact in conjunction with the movement of the plunger; and A starter comprising an electromagnetic switch having a function of pushing the pinion in the direction opposite to the motor;
The motor uses a permanent magnet for the field,
The electromagnetic switch is composed of a single coil in which the switch coil is electrically separated from the motor circuit so that a counter electromotive voltage generated during inertial rotation of the armature does not enter the switch coil. A starter characterized by that. The starter according to claim 1,
The electromagnetic switch has a contact cover in which the main contact is arranged, and a contact terminal for passing a current flowing from a battery to the switch coil is fixed to the contact cover.
One end of the switch coil is connected to the energization terminal, and the other end is connected to the ground side. The starter according to claim 1 or 2,
The reaction force is accumulated according to the amount of movement of the plunger after the pinion pushed in the anti-motor direction by the action of the electromagnetic switch comes into contact with the ring gear of the engine and before the main contact is closed. When the reaction force has a drive spring that acts in the direction of urging the pinion toward the ring gear via the shift lever, and the reaction force stored in the drive spring is called a switch push force,
The starter characterized in that the energizing current to the switch coil is set to 12 A or less by setting the mass of the pinion to 100 g or less and the switch pushing force to 70 N (Newton) or less.

Images