JPH08319924A - Engine stating device - Google Patents

Abstract

PURPOSE: To more reduce the size of the engine starting device in an axial direction whose rotating shaft of an electric motor, sliding shaft of a pinion, pinion and electromagnetic device for driving a switch are co-axially disposed. CONSTITUTION: This device has a pinion 6 for driving a ring gear which is joined with a spline to an output shaft 4 driven by an electric motor 3, a switch 7 for opening and closing an electric power supply circuit to the electric motor and an electromagnetic device 9 comprising armatures 27, 28 and an exciting coil 24 surrounding the output shaft so as to give a displacement in an axial direction to the pinion and the movable contact plate 8 of the switch. The armature comprises two parts which engages with each other inside and outside such that they can move relatively in an axial direction and the first part 25 of them is connected to the movable contact plate 8 and the second part 26 is connected to the pinion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine starting device, and more particularly to an engine starting device in which a rotating shaft of an electric motor, a sliding shaft of a pinion, an electromagnetic device for driving a pinion and a switch are coaxially arranged. .

[0002]

2. Description of the Related Art In a conventional engine starting device, an output shaft supporting a pinion meshing with a ring gear so as to be axially movable, and an axial center of an electromagnetic device for driving the pinion in the axial direction,
It is generally arranged in parallel with each other. In this two-axis starting device, since the electromagnetic device projects to the side of the electric motor, the radial dimension cannot be reduced, and there are considerable restrictions in securing the installation space.

In order to improve such inconvenience, Japanese Unexamined Patent Publication No. 1-208564 proposes a coaxial starter in which an electromagnetic device is provided at a position surrounding an output shaft.

[0004]

In the case of this coaxial starter, the movable contact plate of the switch that opens and closes the power supply path to the electric motor and the shifter that pushes out the pinion in the direction that meshes with the ring gear of the engine are excited. It is connected to each end of an armature that axially moves on the inner peripheral side of the coil. Therefore, according to this type, the movement allowance corresponding to the movement amount of the pinion is given to the armature, and the movement space of the movable contact plate is provided on the opposite side of the pinion across the exciting coil and so as not to interfere with the movement of the pinion. Therefore, it is difficult to further reduce the axial dimension.

The present invention has been devised in order to eliminate such disadvantages of the prior art, and its main purpose is to:
It is an object of the present invention to provide a coaxial engine starter capable of further reducing the axial dimension.

[0006]

According to the present invention, there is provided an electric motor, an output shaft driven by the electric motor, and
A ring gear drive pinion splined to the output shaft, a switch that opens and closes the power supply path to the motor, and a cylindrical armature that surrounds the output shaft to provide axial displacement to the movable contact plate of the pinion and the switch. And an electromagnetic starter including an exciting coil, the armature includes a first part connected to the movable contact plate and a second part connected to the pinion.
It is achieved by comprising two parts, which are engaged with each other inside and outside so as to be displaceable in the relative axial direction.

[0007]

According to this structure, the pinion and the movable contact plate are driven by the armatures which are separate from each other. Therefore, it is possible to optimally set the movement allowance of each of the two-divided armatures in response to the required stroke of the pinion and the required stroke of the movable contact plate being different from each other, so that the protrusion amount of the armature from the exciting coil can be further shortened. Can be reduced in size.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to specific embodiments shown in the accompanying drawings.

FIG. 1 is an overall view of a starter with a speed reducer as an engine starting device constructed according to the present invention. The upper side of the center line shows a stationary state and the lower side shows a conducting state. The starter 1 generates a rotational force necessary for starting the engine, has an electric motor 3 having a planetary gear type speed reducer 2, and an output shaft 4 connected to the electric motor 3 via the speed reducer 2. A one-way roller clutch 5 and a pinion 6 slidably provided on the output shaft 4, a switch unit 7 that opens and closes a power supply path to the electric motor 3, a movable contact plate 8 and a pinion 6 of the switch unit 7 in the axial direction. And an electromagnetic device 9 for moving the same.

The electric motor 3 comprises a known commutator type DC electric motor, and the rotor shaft 10 has its right end in the figure pivoted at the center of the bottom plate 11 and its left end in the figure as the rotor shaft 10. It is pivotally attached to the center of the right end of the output shaft 4 coaxially arranged.

The speed reducer 2 is a top plate 1 of the electric motor 3.
It is provided on the inner surface of 2. The speed reducer 2 includes a sun gear 13 formed at a position adjacent to a support portion of the rotor shaft 10 for the output shaft 4, a plurality of planetary gears 14 meshed with the sun gear 13, and a plurality of planetary gears 14 so that the planetary gears 14 mesh with each other. The inner toothed ring gear 15 is formed on the inner peripheral surface of the. A support plate 16 supporting a plurality of planetary gears 14 is connected to the right end of the output shaft 4 pivotally supported at the center of the top plate 12.

A pinion housing 17, which also functions as a fixing bracket for the engine, is joined to the top plate 12. The left end of the output shaft 4 is pivotally attached to the center of the inner surface of the left wall of the pinion housing 17.

The inner peripheral portion of the clutch outer 18 of the one-way roller clutch 5 is connected to the outer peripheral surface of the intermediate portion of the output shaft 4 via a helical spline 19. The clutch outer 18 is always in the right direction by a return spring 21 that is contracted between a connecting portion 18a of the helical spline 19 with the output shaft 4 and a stopper plate 20 that is supported at the left end of the output shaft 4 so as not to come off. Has been urged to repel. The return spring 21 is wound in a gap defined between the inner peripheral surface of the sleeve-shaped portion 18b formed on the inner peripheral portion of the clutch outer 18 and the outer peripheral surface of the output shaft 4.

A clutch inner 22 of the one-way roller clutch 5 is engaged with the clutch outer 18 so as not to be displaced in the relative axial direction and relatively rotatable. The ring gear 23 of the engine is provided on the outer peripheral portion of the left end of the clutch inner 22.
The pinion 6 described above is integrally formed in order to mesh with and drive the engine. The clutch inner 22 integrally formed with the pinion 6 is rotatably and axially displaceably fitted to the left end portion of the output shaft 4.

An exciting coil 24, which surrounds the output shaft 4 made of a non-magnetic material, is provided at an intermediate portion of the pinion housing 17.
Is fixed. The exciting coil 24 is surrounded by a yoke composed of a cup-shaped holder 25 having an inward flange 25a through which the output shaft 4 penetrates and a ring-shaped disc 26. An armature outer 27 and an armature inner 28 made of a magnetic material are mounted in a space between the inner peripheral surface of the exciting coil 24 and the outer peripheral surface of the output shaft 4 so as to be slidable relative to each other inside and outside. ing. The left end surfaces of these armatures 27 and 28 face the inner surface of the center portion of the inward flange 25a of the holder 25, and the center portion of the inward flange 25a serves as a pole for both armatures 27 and 28.

The right end of the armature outer 27, which is the first part of the armature, is disposed adjacent to the commutator portion 31 of the electric motor 3 via the connecting plate 29 and the connecting rod 30 penetrating the top plate 12 of the electric motor 3. The switch unit 7 is connected to the movable contact plate 8. The movable contact plate 8 is attached to the connecting rod 30 so as to be displaceable in the axial direction, is floatingly supported by a coil spring 32, and is fixed to a brush stay 33 provided around the commutator portion 31. The fixed contact plate 34 of the installed switch unit 7 can be moved toward and away from the fixed contact plate 34. Further, the armature outer 27 is constantly elastically urged to the right by a return spring 35 that is compressed between the armature outer 27 and the inward flange 25a provided on the holder 25 of the exciting coil 24, and normally the contacts are opened. It stands still.

The armature inner 28, which is the second part of the armature, has a coil spring 36, which has a spring force weaker than that of the return spring 21 provided on the clutch outer 18, and always springs from the top plate 12 to the left. Being energized. A shifter member 37 made of a non-magnetic material, the left end of which is in contact with the right end of the clutch inner 22, is connected to the armature inner 28.

The exciting coil 24 is electrically connected to an ignition switch (not shown) via a connector 38 (see FIG. 2) provided in the switch unit 7.

The fixed contact plate 34 of the switch unit 7 is electrically connected to an anode of a battery (not shown), and the movable contact plate 8 of the switch unit 7 is provided with a pair of electrodes as shown in FIG. A pair of pigtails 40 connected to the anode brush 39 are fixed by spot welding. Further, a pair of cathode brushes 41 are provided at positions symmetrical to the pair of anode brushes 39. This cathode brush 41
The pigtail 42 is connected to a center plate 43, which will be described later, and is also connected to the cathode of the battery via the pinion housing 17 and a vehicle body (not shown). The switch unit 7 is provided in the space sandwiched between the pair of anode brushes 39.

A ring-shaped metal center plate 43 is interposed between the brush stay 31 and the top plate 12 to isolate the reducer 2 and the electric motor 3 from each other. At the center of the center plate 43, a cylindrical portion 43a whose inner peripheral surface faces the outer peripheral surface of the rotor shaft 10 with a minute gap is formed to project toward the commutator portion 31 side. The free end of the cylindrical portion 43a enters the recess 31a formed on the axial end face of the commutator portion 31 and prevents the grease of the reduction gear 2 from leaking to the commutator portion 31 side.

The switch unit 7 is located above the starter 1, and the contact portions such as the fixed contact plate 34 and the movable contact plate 8 fixed to the brush stay 33 are inside the motor casing 44 as a yoke. Brush stay 3
1 and the cover 45, and the switch unit 7
Prevents brush powder from entering the contact point of.

Next, the operating procedure of the above embodiment will be described. In a stationary state in which no current is applied to the exciting coil 24, the armature outer 27 holds the return spring 35.
The movable contact plate 8 connected to the movable contact plate 8 is spaced apart from the fixed contact plate 34.
At the same time, the clutch outer 18 biased by the return spring 21 causes the clutch inner 22, the shifter member 37, and the armature inner 2 which are integrated with the pinion 6.
It has moved all the way to the right along with 8, and the connection between the pinion 6 and the ring gear 23 is broken.

When the ignition switch is set to the starter on position, the exciting coil 24 is energized and excited. Then, both outer and inner armatures 27
A magnetic path through which magnetic flux passes through 28 is formed, and the outer and inner armatures 27 and 28 move to the left. At this time, since the armature outer 27 side is closer to the central portion (pole) of the inward flange 25a of the holder 25, this moves ahead of the armature inner 28. Then, the movable contact plate 8 moves leftward via the connecting plate 29 and the connecting rod 30, and comes into contact with the fixed contact plate 34. Thereby, the electric power of the battery is supplied to the electric motor 3, and the rotor shaft 10 rotates. Here, since the movable contact plate 8 comes into contact with the fixed contact plate 34 earlier than the full stroke of the armature outer 27, and the movable contact plate 8 is floatingly supported so as to be axially displaceable with respect to the connecting rod 30. The pressing force of the coil spring 32 is applied between the contacts 8 and 34. On the other hand, in the armature outer 27, when the outward flange 27a integrally formed on the right end side of the armature comes into contact with the ring-shaped disc 26, a gap is formed between the left end surface of the armature outer 27 and the center of the inward flange 25a. Stop in the closed state.

When the rotor shaft 10 rotates, this rotational force is decelerated by the speed reducer 2 and transmitted to the output shaft 4. At this time, the clutch outer 18 engaged with the output shaft 4 via the helical spline 19 tries to stand still due to inertial resistance, and therefore the axial force due to the action of the helical spline 19 is applied to the clutch outer 18 to cause the clutch outer 18 to move. Start moving to the left. At the same time, the attraction force to the left by the exciting coil 24 and the pressing force of the coil spring 36 act on the armature inner 28 at the same time, and the armature inner 28 also starts to move to the left. However, the moving force of the lever is also applied as an axial force to the clutch outer 18 via the shifter member 37.

Due to these axial forces, the clutch outer 18 is pushed to the left against the biasing force of the return spring 21, and the pinion 6 integrated with the clutch inner 22 integrally connected to the clutch outer 18 is also moved to the left. Is pushed to. And the clutch outer 18 is the stopper plate 2
When the pinion 6 reaches the normal meshing position with the ring gear 23 while coming into contact with 0, the rotational force of the output shaft 4 is transmitted to the ring gear 23 and the engine is started. At this time, the left end surface of the armature inner 28 abuts on the central portion of the inward flange 25a of the holder 25, and a small gap is formed between the left end surface of the shifter member 37 that moves integrally with the armature inner 28 and the clutch outer 18. Are formed. In this way, the attraction force of the exciting coil 24 acts on the armature inner 28 at the maximum by contacting the center portion of the inward flange 25a of the holder 25, so that the force that comes out of the ring gear 23 acts on the pinion 6. Also, the clutch outer 18 is prevented from moving to the right through the shifter member 37, and the pinion 6 is prevented from coming out of the ring gear 23.

Armature 2 with a full stroke here
The current required to keep the 7/28 stationary is smaller than the current required to activate the armatures 27/28. That is, as described above, the helical spline 1
By utilizing the axial force of 9 as the starting force of the one-way roller clutch 5 including the pinion 6, the output of the exciting coil 24 can be reduced, so that the exciting coil 24 can be made even smaller in diameter. Note that, when the engine is started and the rotational speed of the pinion 6 is exceeded, the pinion 6 idles due to the action of the one-way roller clutch 5, which is exactly the same as the conventional configuration.

When the energization of the exciting coil 24 is stopped, the pinion 6 is disengaged from the ring gear 23 by the urging force of the return spring 21 against the clutch outer 18 and the urging force of the return spring 35 against the armature outer 27, and the movable contact plate is moved. 8 separates from the fixed contact plate 34, and the electric motor 3 stops.

[0028]

As described above, the opening / closing stroke of the switch can be significantly smaller than the engagement / disengagement stroke of the pinion with the ring gear. However, in the past,
Since the pinion and the switch were driven by a common armature, a movement allowance equivalent to that of the pinion had to be provided on the switch side as well, and the protrusion amount of the armature from the exciting coil on the switch side could not be reduced in particular. . According to the present invention, as shown in the above embodiment, the driving armature for the switch and pinion of the electric motor is divided, and these can be moved independently of each other. There is no need to provide a wasteful axial space. Therefore, according to the present invention, a great effect can be exerted in promoting the shortening of the axial dimension of the engine starting device.

[Brief description of drawings]

1 is a cross-sectional view of an engine starting device constructed according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

 1 Starter 2 Reduction Gear 3 Electric Motor 4 Output Shaft 5 One-Way Roller Clutch 6 Pinion 7 Switch Unit 8 Moving Contact Plate 9 Electromagnetic Device 10 Rotor Shaft 11 Bottom Plate 12 Top Plate 13 Sun Gear 14 Planetary Gear 15 Internal Gear Ring 16 Support Plate 17 Pinion Housing 18 Clutch Outer 19 Helical Spline 20 Stopper Plate 21 Return Spring 22 Clutch Inner 23 Ring Gear 24 Excitation Coil 25 Holder, 25a Inward Flange 26 Ring-shaped Disc 27 Armature Outer 28 Armature Inner 29 Connecting Plate 30 Connecting Rod 31 Commutator, 31a Recessed portion 32 Coil spring 33 Brush stay 34 Fixed contact plate 35 Return spring 36 Coil spring 37 Shifter member 38 Connector 9 anode brush 40 pigtails 41 cathode brush 42 pigtail 43 center plate, 43a cylindrical portion 44 motor casing 45 covers

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location F02N 15/06 F02N 15/06 A (72) Inventor Shinichi Nagashima 1268-1, Hirosawa-cho, Kiryu-shi, Gunma Address Mitsuba Electric Co., Ltd. (72) Inventor Eiichi Kimura 1-2681 Hirosawa-cho, Kiryu-shi, Gunma Mitsuba Electric Co., Ltd.

Claims (1)

[Claims] 1. An electric motor, an output shaft driven by the electric motor, a ring gear drive pinion spline-coupled to the output shaft, a switch for opening and closing a power feeding path to the electric motor, and an axial direction on a movable contact plate of the pinion and the switch. An engine starting device comprising: a cylindrical armature provided around an output shaft to give a displacement and an electromagnetic device including an exciting coil, wherein the armature is a first member connected to the movable contact plate.
And a second part connected to the pinion,
An engine starter characterized by being engaged with inner and outer double elements so as to be displaceable in a relative axial direction.