JP3497881B2 - Starter motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter motor, and more particularly to a starter motor having a pinion gear bite-holding function capable of favorably engaging an engine ring gear and a pinion gear when the engine is started. .

[0002]

2. Description of the Related Art Generally, starter motors are used in automobiles and the like.
It is used to start equipment powered by an engine. In order to start the engine, the crankshaft must be rotated by the starter motor until the engine reaches the minimum rotational speed at which it can ignite and start rotating.

An example of this type of starter is Japanese Patent Laid-Open No. 58-62.
Japanese Patent No. 363 is known, and a proposal has been made to solve the problem of early departure of the pinion with a simple structure.

[0004]

In the above prior art, an electromagnet having a large outer diameter is required because an electromagnetic coil is provided between the motor section and the one-way clutch and the holding plate is attracted through a large gap. However, there is a drawback that the weight becomes heavy. In addition, the target is a configuration that uses the voltage drop at the field winding terminal of the starter motor to excite the electromagnetic coil, but recently there is a problem that there is no field winding instead of the wound field pole. There is also.

It is an object of the present invention to easily provide a compact starter motor having a strong pinion gear bite holding function.

[0006]

SUMMARY OF THE INVENTION The present invention transmits the rotational force of a motor to a pinion shaft,
The rotational force transmitted to the pinion shaft
Pinion gear is integrated with the tip of the sliding part
One-way clutch provided on the pinion shaft
Transmitted through the helical splines, there the pin <br/> Niongia inertial force and the rotational force generated in the pinion gear and the one-way clutch configured scan <br/> Tatamota as engaged to the ring gear Te, the gear on the inner peripheral surface of the gear case covering the periphery of the one-way clutch and the pin <br/> Niongia
A magnetic path of a cylindrical body attached along the shape of the case ,
While being arranged fixed to the inner peripheral surface of the magnetic passage, and a cylindrical electromagnetic coil is energized at least the pinion gear and meshing of the ring gear, said pinion gear
When the ring gear is engaged, the magnetic flux generated by the excitation of the electromagnetic coil passes through the magnetic path, and the one-way clutch
Through the gap between the magnetic path and
Incident on the latch, the pinion gear or the pinion
Pinion gear early separation preventing magnetic circuit extending to the magnetic path through the shaft, characterized in that is constituted.

[0007]

When the engine is started, the key switch is turned on and at the same time the starter motor is started to engage with the ring gear by the inertial force of the one-way clutch and the pinion. At the same time, a current is passed through the electromagnetic coil to maintain the meshed state of the pinion gear and the ring gear and start the engine. The key switch is turned off to cut off the electromagnetic coil current to remove the electromagnetic force, and the reaction force against the pinion gear accompanying the rotation of the ring gear causes the pinion gear to disengage from the ring gear, thus ending the starting operation.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic structure of a starter motor according to an embodiment of the present invention. There are two types of starter motors: a structure without a reduction gear, a reduction starter with two reduction gears, and a coaxial starter motor with a planetary gear as the reduction gear. To describe. The motor unit includes a field pole 2 made of a permanent magnet or a wound magnetic pole in a stator frame 1 made of an end bracket 1a and a yoke 1b, a brush holder 3 for supplying a current to the rotor from the stator side,
It is configured with the brush 4.

The rotor 5 is composed of a commutator 7 on a shaft 6 and an armature 8 having an armature winding 8a. On the other hand, a sun gear 9 is provided at the end of the shaft 6 on the side opposite to the commutator, the sun gear 9 meshes with a planetary gear 10 that constitutes a reduction mechanism, and the planetary gear 10 is connected to the stator frame 1. Internal gear 12 fixed between gear covers 11
Is meshed with. And the support shaft 10 of the planetary gear 10
a is assembled integrally with the pinion shaft 13,
It is configured to rotate in synchronization with the shaft.

A helical spline gear 14 is provided on the motor side of the pinion shaft 13, the outer periphery of a one-way clutch 15 is spline-engaged with the outer periphery of the helical spline gear 14, and an inner member that slides on the pinion shaft 13 is provided. A pinion gear 16 is provided at the tip of the.
The tip end portion of the pinion shaft 13 is supported by the gear cover 11 via a bearing 17, and the other end portion is supported by the central bracket 18 via a bearing. Incidentally, 19 is a pinion return spring, and 20 is an engine ring gear.

Next, the pinion holding mechanism, which is the main part of the present invention, will be described. The pinion holding mechanism is separately formed on the inner peripheral surface of the gear cover 11 made of an aluminum material, and has a cylindrical portion 21a and a semi-cylindrical portion 21b. A magnetic path 21 made of a magnetic material is attached by press fitting along the shape of the gear cover. A cylindrical electromagnetic coil 23 covered with an insulator (a cylindrical insulating bobbin may be used) 22 is arranged in the space of the outer peripheral portion of the pinion gear 16 when the starter motor is stationary. It is fixed to the inner peripheral surface of 21. In addition, in order to improve the vibration resistance of the magnetic passage, it is preferable to fix the magnetic passage by using an adhesive or the like.

Here, the magnetic passage is generally formed by cold drawing of a steel sheet, but it may be formed by other cast molding or integrally cast during gear cover molding. Does not change the essence of.

FIG. 3 is a control circuit diagram of the starter motor. The main circuit including the armature winding 8a is connected to the battery 101 via the main fixed terminal 104 and the auxiliary moving terminal 107 of the motor current electromagnetic switch 100. There is. On the other hand, the exciting coil 103 of the motor current electromagnetic switch 100 is connected between the batteries 101 via a key switch 102, and a series circuit of a current adjusting resistor 23a and an electromagnetic coil 23 is connected in parallel with the exciting coil 103. .

In the case of this circuit configuration, the key switch 10
When 2 is turned on, the exciting coil 103 is excited, and the exciting magnetic force causes the auxiliary moving terminal 107 to short-circuit the main fixed terminal 104 and the battery 101 to the armature coil 8a and the electromagnetic coil 2.
Current simultaneously flows through the circuit of 3 to rotate the armature 8. The torque generated by the armature 8 is transmitted to the planetary gear 10 via the sun gear 9 provided on the shaft 6, and the transmitted torque is transmitted through the shaft supporting the planetary gear 10 to the pinion shaft 1
3 is transmitted. Then, the pinion gear 16 is pushed out to the ring gear 20 side by the inertial force, and at the same time, the electromagnetic coil 2
Electromagnetic force also works on 3, pinion gear 16 and ring gear 2
The biting state of 0 is maintained.

In such a structure, the torque from the pinion shaft 13 is transmitted to the one-way clutch 15 and the pinion gear 16 via the helical spline gear 14. When the motor starts, the one-way clutch 15 and the pinion gear 16 rotate integrally via the helical spline gear 14 and are pushed out to the ring gear side by inertial force.
The ring gear 20 and the pinion gear 16 mesh with each other to transmit the rotational force of the motor to the ring gear 20. Then, the engine rotation speed is increased according to the increase of the motor rotation speed.

Here, when a rotational force is generated in the engine, a reaction force of the ring gear 20 is usually generated and the pinion gear 16 tends to separate from the ring gear 20, but when an exciting current flows in the electromagnetic coil 23, the electromagnetic coil 23 The magnetic flux generated by the magnetomotive force passes through the pinion shaft 13, the one-way clutch 15 and the pinion gear 16, passes through the magnetic passage 21 and the semi-cylindrical portion 21b, and reaches the outer peripheral portion of the one-way clutch 15. A closed magnetic circuit that enters the one-way clutch 15 through a gap between the one-way clutch 21 and the one-way clutch 15 and passes through the pinion shaft 13 or the pinion gear 16 is formed. As a result, the one-way clutch and the pinion gear 16 are moved to the position where the most magnetic flux passes (the position where the electromagnetic force is large), and that position is the position where the pinion gear meshes with the ring gear.

Therefore, if a current flows through the electromagnetic coil 23, the pinion gear 16 and the ring gear 20 can be kept in mesh with each other. Further, if the current of the electromagnetic coil 23 is cut off immediately after the engine is started, the magnetic attraction force is lost,
The pinion gear 16 receives the reaction force from the ring gear 20,
In addition, the reaction force of the return spring 19 causes the pinion gear 16 and the one-way clutch 15 to automatically return to the motor side.

According to the above circuit configuration, when the engine is completely detonated and the motor is rotated by the engine, the operation of the electromagnetic coil can be surely stopped by turning off the key switch, which is highly reliable.

In the above embodiment, the current adjusting resistor 23 is connected in parallel with the exciting coil 103 of the motor current electromagnetic switch 100.
Although the one in which a series circuit of a and the electromagnetic coil 23 is connected is shown, even if the armature 8a and the electromagnetic coil 23 are connected in series, the same attractive force can be obtained and it is sufficient for holding the pinion gear.

FIG. 4 shows another embodiment, in which the position of the electromagnetic coil 231 is provided in the space between the speed reduction mechanism portion and the one-way clutch 15. In the magnetic circuit of this configuration, the central bracket 18 is made of a magnetic material, and the magnetic flux generated by passing a current through the electromagnetic coil 231 passes through the outer circumferences of the pinion shaft 13 and the one-way clutch 15 and passes through the gap from the magnetic material. The magnetic circuit 211 has a substantially cylindrical magnetic path 211, and is closed via the central bracket 18 to form a magnetic circuit. Therefore, it is preferable that the tip of the magnetic passage 211 extends to the maximum movement position (dimension l) of the one-way clutch 15 to increase the effective magnetic flux.
In the case of this embodiment, the outer diameter of the electromagnetic coil 231 is larger than that of the above-described embodiment, but the magnetic passage 211 is only required to have a tubular shape, and the mounting in the gear case 11 becomes easy.

FIG. 5 shows another circuit configuration for exciting the electromagnetic coil 23 (231).
The main fixed terminal 104 and the main moving terminal 105 constituting the above are provided with the sub fixed terminal 106 and the sub moving terminal 107 in parallel to form a double contact structure, and the series circuit of the current adjusting resistor 23a and the electromagnetic coil 23 is connected to the sub terminal. In this connection, the auxiliary moving terminal 107 is moved and short-circuited with a time delay with respect to the main moving terminal 105 by a current adjusting resistor.

Therefore, the pinion gear 16 is replaced by the ring gear 2.
Since the electromagnetic coil 23 can be made to work after it is bitten into 0, there is an advantage that the power consumption required for the meshing holding function can be suppressed to be smaller than that of the one energized from here.

[0024]

According to the present invention, since the electromagnetic coil for preventing the early pinion disengagement is arranged through the magnetic passage formed separately on the inner peripheral surface of the gear case, a compact and powerful pinion gear bite holding function is provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a starter showing an embodiment of the present invention.

2 is a perspective view of the magnetic path of FIG. 1. FIG.

FIG. 3 is a connection diagram showing an electric circuit according to an embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a starter showing another embodiment of the present invention.

FIG. 5 is a connection diagram showing an electric circuit of another embodiment of the present invention.

[Explanation of symbols]

8 ... Armature, 8a ... Armature coil, 11 ... Gear cover,
13 ... Pinion shaft, 15 ... One-way clutch, 16
... pinion gear, 18 ... central bracket, 20 ... ring gear, 21 ... magnetic path, 23 ... electromagnetic coil, 23a ... electromagnetic coil current adjusting resistor, 100 ... motor current electromagnetic switch, 101 ... battery, 102 ... key switch, 103
... Excitation coil, 104 ... Main fixed terminal, 105 ... Main moving terminal, 106 ... Sub fixed terminal, 107 ... Sub moving terminal.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Kambara 2520 Takaba, Katsuta-shi, Ibaraki Prefectural Automotive Equipment Division, Hitachi, Ltd. (72) Sadahiro Hamabata Katsuta-shi, Ibaraki Kashima Yatsu Kashima Yatsu Address 2477 3 Within Hitachi Automotive Engineering Co., Ltd. (56) Reference JP-A-6-123268 (JP, A) JP-A-60-104768 (JP, A) JP-A-58-62363 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F02N 11/00 F02N 11/08 F02N 15/06

Claims (7)

(57) [Claims] 1. A rotary force of a motor is transmitted to a pinion shaft.
The rotational force transmitted to the pinion shaft,
The pinion is attached to the tip of the part that slides on the pinion shaft.
The one-way clutch with an integrated gear
And <br/> transmitted via the helical spline provided on the shaft, the starter one-way clutch and said pinion gear by inertia force generated with the pinion gear and the rotational force is configured to mesh to the ring gear motor a is, instrumentation along the shape of the gear case to the inner peripheral surface of the gear case covering the periphery of the one-way clutch and said pinion gear
Comprising a magnetic path of the call is a cylindrical member, while being positioned and fixed to the inner circumferential surface of the magnetic passage, and a cylindrical electromagnetic coil is energized at least the pinion gear and meshing of the ring gear, the pinion When the gear meshes with the ring gear, the magnetic flux generated by the excitation of the electromagnetic coil passes through the magnetic path,
The gap between the one-way clutch and the magnetic passage
Incident on the one-way clutch through the pinion gear
Or, passing through the pinion shaft to the magnetic path
Starter motor pinion gear early separation preventing magnetic circuit lead is characterized in that it is configured. 2. The magnetic path according to claim 1, comprising a tubular body having a cylindrical portion and a semi-cylindrical portion that conform to the shape of the gear case, and an electromagnetic coil is provided on the inner peripheral surface of the gear case that abuts around the pinion gear. A starter motor characterized by being fixedly arranged. 3. The magnetic path according to claim 1, wherein the magnetic passage is substantially cylindrical, and a magnetic circuit is formed by the one-way clutch and the central bracket, and an electromagnetic coil is arranged and fixed between the one-way clutch and the central bracket. The starter motor is characterized by 4. The starter motor according to claim 1, wherein the electromagnetic coil is connected in parallel with the exciting coil of the motor current electromagnetic switch through a current adjusting resistor. 5. The starter motor according to claim 1, wherein the electromagnetic coil is connected in series with an armature winding of the starter motor. 6. The starter motor according to claim 1, wherein the electromagnetic coil is connected in parallel with the armature winding of the starter motor. 7. The electromagnetic coil according to claim 1, wherein the electromagnetic coil and the armature winding of the starter motor are connected in parallel, and the rising of the current of the electromagnetic coil is delayed from the rising of the current flowing through the armature winding. Starter motor featuring.