JPH1047215A - Engine starting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce repeating stress caused in a junction part with a movable contact plate of a pigtail when a power source is cut and prevent breaking of wire in an engine starting device in which the pigtail of a brush is directly connected to the movable contact plate of a switch for switching a feeding path to a DC motor disposed adjacent to a commutator part of the DC motor. SOLUTION: Axis of a terminal 40b of a pigtail 40 fixed to a movable contact plate 8 is extended toward actuation direction of the movable contact plate 8. In particular, a projected shoe 8a projecting to the actuation direction is mounted in the movable contact plate 8 and a terminal of the pigtail 40 fixed to the projected shoe 8a. Whereby, deformation amount of the pigtail 40 at disconnecting of power is reduced by movement of the movable contact plate 8 and disconnection due to fatigue is hard to be caused and durability of the pigtail 40 is improved.

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 a DC motor, a sliding shaft of a pinion, and an electromagnetic device for driving a pinion and a switch are coaxially arranged. Things.

[0002]

2. Description of the Related Art In a conventional engine starting device, a connection terminal for a battery and a connection terminal for a pigtail of a brush are respectively connected to fixed contacts, and both are fixed by movable contacts connected to an armature of a pinion driving electromagnetic device. It is common to be configured to provide an intermittent connection between the contacts.

According to the conventional switch mechanism, two fixed contacts for battery connection and pigtail connection must be provided, so that the number of parts cannot be reduced, and the radial dimension or shaft It was difficult to reduce the dimension in the direction. In order to solve these problems, the present applicant has filed Japanese Patent Application No. 7-15381.
In the specification such as No. 8, an engine starting device having a configuration in which a pigtail of a brush is directly connected to a movable contact plate has been previously presented.

[0004]

By the way, in the case of the switch mechanism having the above-mentioned novel structure, the pigtail bends and deforms in accordance with the movement of the movable contact plate when the power is turned on and off, and the pigtail repeats at the joint of the pigtail and the movable contact plate. Since stress occurs,
It is necessary to consider the pigtail connection method so that failures such as disconnection due to fatigue do not occur.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a DC motor and a DC motor for reducing the repetitive stress generated at the joint between the pigtail and the movable contact plate at the time of power supply interruption so as to prevent disconnection due to fatigue. An output shaft driven by the DC motor, a ring gear driving pinion spline-coupled to the output shaft, a switch for opening and closing a power supply path to the DC motor, and a movable contact plate of the switch and the pinion in an axial direction. An electromagnetic device provided so as to surround the output shaft so as to apply a displacement, wherein an pigtail of a brush is connected to a movable contact plate of the switch disposed close to a commutator portion of the DC motor. In the starting device,
An axis of a terminal of the pigtail fixed to the movable contact plate extends in a direction substantially along an operation direction of the movable contact plate.

In particular, it is preferable that a protrusion protruding in a direction substantially along the operating direction of the movable contact plate is provided on the movable contact plate, and the end of the pigtail is fixed to the protrusion.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

FIG. 1 is an overall view of a starter with a reduction gear as an engine starting device constructed in accordance with the present invention, wherein the upper side from the center line shows a stationary state, and the lower side shows an energized state. The starter 1 generates a rotational force required for starting the engine, and includes an electric motor 3 having a planetary gear type reduction gear 2, an output shaft 4 connected to the electric motor 3 via the reduction gear 2, and A one-way roller clutch 5 and a pinion 6 slidably provided on the output shaft 4, a switch unit 7 for opening and closing a power supply path to the electric motor 3, and 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 it.

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

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

A pinion housing 17 also serving 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.

An inner peripheral portion of a clutch outer 18 of the one-way roller clutch 5 is connected to an outer peripheral surface of an intermediate portion of the output shaft 4 via a helical spline 19. The clutch outer 18 is constantly moved to the right by a return spring 21 contracted between a coupling portion 18a of the output shaft 4 by a helical spline 19 and the stopper plate 20 supported at the left end of the output shaft 4. Has been urged to fire. The return spring 21 is wound around a gap defined between the inner peripheral surface of the sleeve-like portion 18 b 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 displaceable in the relative axial direction and to be relatively rotatable. A ring gear 23 of the engine is provided on the outer peripheral portion at the left end of the clutch inner 22.
The above-mentioned pinion 6 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 of the output shaft 4.

An excitation coil 24 surrounding the output shaft 4 formed 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 constituted by a cup-shaped holder 25 having an inward flange 25a through which the output shaft 4 passes and a ring-shaped disc 26. In the gap between the inner peripheral surface of the exciting coil 24 and the outer peripheral surface of the output shaft 4, an armature outer 27 and an armature inner 28 formed of a magnetic material are mounted so as to be relatively slidable inside and outside double. ing. The left end surfaces of the armatures 27 and 28 are opposed to the inner surface of the center of the inward flange 25a of the holder 25, and the center of the inward flange 25a is a pole for both the armatures 27 and 28.

The right end of the armature outer 27 has a movable contact plate of the switch unit 7 disposed adjacent to the commutator portion 31 of the motor 3 through a connecting plate 29 and a connecting rod 30 penetrating the top plate 12 of the motor 3. 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 31. The switch unit 7 can be moved toward and away from the fixed contact plate 34 of the provided switch unit 7. The armature outer 27 is provided with an inward flange 25a provided on the holder 25 of the exciting coil 24.
The spring is constantly urged to the right by a return spring 35 contracted between the contact points, and is usually stationary with the contacts open.

The armature inner 28 is constantly urged leftward from the top plate 12 by a coil spring 36 having a spring force weaker than that of the return spring 21 provided on the clutch outer 18. The armature inner 28 has a clutch inner 22 at the left end.
Member 37 made of a non-magnetic material abutting on the right end of
Are combined.

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

The fixed contact plate 34 of the switch unit 7 is electrically connected to the anode of a battery (not shown). The movable contact plate 8 of the switch unit 7 has a pair of movable contacts, as shown in FIG. A pair of pigtails 40 connected to the anode brush 39 are fixed by spot welding. A pair of cathode brushes 41 are provided at a position symmetrical with 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 to the cathode of the battery via the pinion housing 17 and a vehicle body (not shown). Note that the switch unit 7 is provided in a space between the pair of anode brushes 39.

A ring-shaped metal center plate 43 is interposed between the brush stay 33 and the top plate 12 to isolate the speed reducer 2 from the electric motor 3. At the center of the center plate 43, a cylindrical portion 43a whose inner circumferential surface is opposed to the outer circumferential surface of the rotor shaft 10 with a small gap is formed so as to protrude toward the commutator portion 31 side. The free end of the cylindrical portion 43a enters the concave portion 31a formed on the axial end surface of the commutator portion 31, and prevents the grease of the speed reducer 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 provided in a motor casing 44 as a yoke. And brush stay 3
3 and the cover 45, and the switch unit 7
To prevent the brush powder from entering the contact points of the brush.

Next, the operation 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 is
The movable contact plate 8 connected to the movable contact plate 8 is separated from the fixed contact plate 34 by being biased by 5 and moving fully to the right. At the same time, the clutch outer 18 biased by the return spring 21 is fully moved rightward with the clutch inner 22, the shifter member 37 and the armature inner 28 integral with the pinion 6, and the pinion 6
And the ring gear 23 is disconnected.

When the ignition switch is set to the starter ON position, the exciting coil 24 is energized to be excited. Then both outer and inner armature 27
A magnetic path through which the magnetic flux passes through 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 center portion (pole) of the inward flange 25a of the holder 25, it moves prior to the armature inner 28. Then, the movable contact plate 8 moves to the left 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, 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, when the outward flange 27a integrally formed on the right end side of the armature outer 27 abuts on the ring-shaped disk 26, a gap is formed between the left end surface thereof and the center of the inward flange 25a. To stop in

When the rotor shaft 10 rotates, the torque is reduced 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 tends to stop due to inertial resistance, so that an axial force due to the action of the helical spline 19 is applied to the clutch outer 18 and the clutch outer 18 is disengaged. Start moving to the left. At the same time, the leftward attractive force of the exciting coil 24 and the pressing force of the coil spring 36 are simultaneously acting on the armature inner 28, and the armature inner 28 also starts moving leftward. Thus, the moving force is also applied to the clutch outer 18 via the shifter member 37 as an axial force.

By these axial forces, the clutch outer 18 is pushed to the left against the urging force of the return spring 21, and the pinion 6 integral with the clutch inner 22 integrally coupled with the clutch outer 18 also moves to the left. It is pushed out to. Then, the clutch outer 18 is connected to the stopper plate 2.
When the pinion 6 comes into contact with the ring gear 23 and reaches the position where the pinion 6 is normally meshed with the ring gear 23, 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 face of the armature inner abuts against the center of the inward flange 25a of the holder 25, and a small gap is formed between the left end face of the shifter member 37 that has moved integrally with the armature inner and the clutch outer. Are formed. By contacting the center of the inward flange 25a of the holder 25 in this manner, the attractive force of the exciting coil 24 acts on the armature inner 28 to the maximum, so that the force coming out of the ring gear 23 acts on the pinion 6. Also, the rightward movement of the clutch outer 18 is prevented via the shifter member 37, so that the pinion 6 is prevented from coming out of the ring gear 23.

Here, the armature 2 having a full stroke
The current required to keep the 7.28 stationary can be smaller than the current required to activate the armatures 27.28. That is, as described above, the helical spline 1
The output of the exciting coil 24 can be reduced by using the axial force by 9 as the starting force of the one-way roller clutch 5 including the pinion 6, so that the diameter of the exciting coil 24 can be further reduced. Note that, when the engine starts and exceeds the rotation speed of the pinion 6, 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 on the clutch outer 18 and the urging force of the return spring 35 on the armature outer 27, and the movable contact plate is moved. 8 is separated from the fixed contact plate 34, and the motor 3 stops.

By the way, a pigtail 40 having one end 40a connected to a surface of the anode brush 39 along the radial direction is shown in FIG.
As shown in FIG. 5, after being curved into a substantially S-shape from a direction substantially perpendicular to the paper and extending toward the rotor of the electric motor 3, the other end 40b is bent in a direction away from the rotor.
On the other hand, as shown in FIG. 4, the movable contact plate 8 has its radial inner end bent along the axis of the connecting rod 30 toward the rotor of the electric motor 3 so that the movable contact plate 8 can be moved in the operating direction of the movable contact plate 8. A protruding piece 8a protruding along is formed.
A pigtail 40 is provided on the radially outer surface of the protruding piece 8a.
Is fixed to the movable contact plate 8 with its axis parallel to the operating direction of the movable contact plate 8.

Since the axis of the connection end 40b of the pigtail 40 with respect to the movable contact plate 8 is made parallel to the operating direction of the movable contact plate 8, the pigtail 40 is shown in FIG. The movable contact between the stationary state in which no current is applied to the exciting coil 24 of the electromagnetic device 9 and the state in which the movable contact plate 8 is moved to the left by being energized in the exciting coil 24 shown in FIG. Although the curved state slightly changes in accordance with the movement of the plate 8, the overall shape retains a substantially S-shape, and the pigtail 40 is deformed as a whole so that the bending stress is not locally concentrated. I have.

It should be noted that, instead of the protruding piece 8a of the movable contact plate 8,
As shown in FIG. 5, by bending both ends in the circumferential direction of the movable contact plate 8 toward the rotor of the electric motor 3, projecting pieces 8 b and 8 c projecting obliquely with respect to the operating direction of the movable contact plate 8 are formed. Pigtails 40 are provided on the inner surfaces of the protruding pieces 8b and 8c.
May be fixed to the other end 40b. At this time,
The pigtail 40 is bent in a substantially S-shape from one end 40a on the anode brush 39 side and routed to the rotor side of the electric motor 3, and then the other end 40b, in substantially the same manner as shown in FIG.
Are bent away from the rotor. Also in this case, the pigtail 40 generally retains a substantially S-shape with respect to the movement of the movable contact plate 8 so that the pigtail 40 is not subjected to local bending stress.

[0030]

As described above, according to the present invention, the pigtail connected to the movable contact plate is entirely deformed so as to follow the movement of the movable contact plate when the power is turned on and off. Since no bending stress is generated, disconnection due to fatigue is less likely to occur, and this has an extremely remarkable effect in improving the durability of the pigtail.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an engine starting device configured based on the present invention.

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

FIG. 3 is a top view of a pigtail peripheral portion.

FIG. 4 is a cross-sectional view of a main part, which includes a and b and shows a state of deformation of a pigtail accompanying movement of a movable contact plate.

FIG. 5 is a main part top view similar to FIG. 3, showing a second embodiment of the engine starting device configured according to the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Starter 2 Reduction gear 3 Electric motor 4 Output shaft 5 One-way roller clutch 6 Pinion 7 Switch unit 8 Movable contact plate, 8a, 8b, 8c Projection piece 9 Electromagnetic device 10 Rotor shaft 11 Bottom plate 12 Top plate 13 Sun gear 14 Planetary gear 15 Inside Tooth ring gear 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 Exciting coil 25 Holder, 25a Inward flange 26 Ring disk 27 Armature outer, 27a Outward flange 28 Armature Inner 29 Connecting plate 30 Connecting rod 31 Commutator part, 31a Recess 32 Coil spring 33 Brush stay 34 Fixed contact plate 35 Return spring 36 Coil spring 37 Shifter member 38 Connector 39 Anode brush 40 Pigtail 41 Cathode brush 42 Pigtail 43 Center plate, 43a Cylindrical part 44 Motor casing 45 Cover

Continued on the front page (72) Inventor Michio Okada 1-2681, Hirosawa-cho, Kiryu-shi, Gunma Co., Ltd. Inside Mitsuba Electric Manufacturing Co., Ltd. (72) Shinichi Nagashima 1-2681-1, Hirosawa-cho, Kiryu-shi, Gunma Co., Ltd. (72) Eiichi Kimura, Inventor 1-2681, Hirosawa-cho, Kiryu-shi, Gunma Mitsuha Electric Co., Ltd.

Claims (2)

[Claims] 1. A DC motor, an output shaft driven by the DC motor, a ring gear driving pinion spline-coupled to the output shaft, a switch for opening and closing a power supply path to the DC motor, and movement of the switch. A contact plate and an electromagnetic device provided so as to surround the output shaft so as to apply axial displacement to the pinion, wherein a brush is provided on a movable contact plate of the switch disposed close to a commutator portion of the DC motor. An engine starter comprising the pigtails connected to each other, wherein an axis of a terminal of the pigtail fixed to the movable contact plate is extended in a direction substantially along an operation direction of the movable contact plate. Engine starting device. 2. The moving contact plate according to claim 1, further comprising: a protruding piece projecting in a direction substantially along an operation direction of the movable contact plate, and fixing a terminal of the pigtail to the protruding piece. The described engine starting device.