JP3751691B2 - Engine starter - Google Patents

Description

[0001]
BACKGROUND 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, a pinion and an electromagnetic device for driving a switch are coaxially arranged.
[0002]
[Prior art]
In a conventional engine starter, an output shaft that supports a pinion meshing with a ring gear so as to be axially movable and an axis of an electromagnetic device that drives the pinion in the axial direction are generally arranged in parallel with each other. is there. In this two-shaft configuration starter, since the electromagnetic device protrudes to the side of the electric motor, the radial dimension cannot be reduced, and there is a considerable limitation in securing the mounting space.
[0003]
In order to improve such inconvenience, various types of coaxial engine starting devices have been proposed in which an electromagnetic device is provided at a position surrounding the output shaft, but the external wiring is omitted without complicating the structure. However, the applicant of the present invention has previously presented a coaxial type engine starting device capable of further shortening the axial dimension in the specification of Japanese Patent Application No. 7-153818.
[0004]
[Problems to be solved by the invention]
Now, in the case of this new configuration of the coaxial starter, an electromagnetic device is arranged between the DC motor and the pinion, the commutator part of the DC motor is arranged on the electromagnetic device side, and the power supply to the DC motor is interrupted. The contact with the switch and the external connection terminal for feeding power to the electromagnetic device are arranged on an insulating member common to the brush stay. Then, the feeding wire to the exciting coil of the electromagnetic device is connected to the external connection terminal through a wire insertion hole penetrating the top plate that is a support for the reduction gear disposed between the electromagnetic device and the DC motor. ing.
[0005]
However, the external connection terminal for power supply is arranged on the outer peripheral side of the engine starter, and the excitation coil is arranged closer to the output shaft because it is desired to make the diameter dimension as small as possible. There is a problem in that the connecting position is greatly displaced in the radial direction, and the work of inserting the power supply wire into the wire insertion hole at the time of assembly becomes troublesome.
[0006]
[Means for Solving the Problems]
Therefore, in order to solve such problems and improve the assembly, in the present invention, a direct current motor, an output shaft driven by the direct current motor, a ring gear drive pinion that is splined to the output shaft, A switch disposed in the vicinity of the commutator portion of the DC motor to open and close a power supply path to the DC motor, and the DC motor and the pinion to apply axial displacement to the movable contact plate and the pinion of the switch. An electromagnetic device that surrounds the output shaft, a speed reducer disposed between the electromagnetic device and the DC motor, an external connection terminal disposed in proximity to the switch, and the electromagnetic device in the engine starting apparatus having the apparatus and reduction gear and a housing for the outer circumference, the power supply wires of the arranged output shaft toward the solenoid device, the interior of the housing A wire insertion hole is provided in the outer peripheral portion of the support of the speed reducer so as to connect to the external connection terminal, and expands in a funnel shape from the wire insertion hole toward the electromagnetic device; and A guide portion having a guide surface inclined so as to guide the power supply wire drawn from the electromagnetic device at a radially inner position toward a radially outer position having the wire insertion hole is a support body of the reduction device Provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the accompanying drawings.
[0008]
FIG. 1 is an overall view of a starter with a speed reducer as an engine starter 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 necessary for starting the engine, and includes an electric motor 3 provided with a planetary gear speed reducer 2, 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, and a movable contact plate 8 and the pinion 6 of the switch unit 7 in the axial direction And an electromagnetic device 9 for moving to the position.
[0009]
The motor 3 is a known commutator type DC motor, and the rotor shaft 10 has a right end in the figure pivoted to the center of the bottom plate 11 and a left end in the figure coaxially arranged with the rotor shaft 10. It is pivotally attached to the center of the right end of the output shaft 4.
[0010]
The speed reducer 2 is provided on the inner surface of the top plate 12 of the electric motor 3. The speed reducer 2 includes a sun gear 13 formed at a position adjacent to the 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 are meshed. The inner ring gear 15 is formed on the inner peripheral surface of the inner ring. A support plate 16 that supports a plurality of planetary gears 14 is coupled to the right end of the output shaft 4 that is pivotally supported at the center of the top plate 12.
[0011]
A pinion housing 17 that also serves 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.
[0012]
The inner peripheral portion of the clutch outer 18 of the one-way roller clutch 5 is coupled 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 moved to the right by a return spring 21 that is contracted between a connecting portion 18 a connected to the output shaft 4 by the helical spline 19 and a stopper plate 20 that is supported to be prevented from coming off at the left end of the output shaft 4. The bullet is being energized. The return spring 21 is wound around a gap defined between the inner peripheral surface of a 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.
[0013]
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 to be relatively rotatable. The above-described pinion 6 is integrally formed on the outer peripheral portion of the left end of the clutch inner 22 so as to mesh with the ring gear 23 of the engine and drive the engine. The clutch inner 22 integrally formed with the pinion 6 is fitted to the left end portion of the output shaft 4 so as to be rotatable and axially displaceable.
[0014]
An excitation coil 24 that surrounds the output shaft 4 made of a nonmagnetic material is fixed to an intermediate portion of the pinion housing 17. The exciting coil 24 is surrounded by a yoke constituted by a cup-shaped holder 25 having an inward flange 25 a through which the output shaft 4 passes and a ring-shaped disk 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 slidable relative to each other inside and outside. ing. The left end surfaces of these armatures 27 and 28 are opposed to 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 is a pole for both armatures 27 and 28.
[0015]
The right end of the armature outer 27 is connected to the movable contact plate 8 of the switch unit 7 disposed adjacent to the commutator 31 of the electric motor 3 through the connecting plate 29 and the connecting rod 30 penetrating the top plate 12 of the electric motor 3. Has been. The movable contact plate 8 is attached to the connecting rod 30 so as to be axially displaceable, and is floatingly supported by a coil spring 32. The movable contact plate 8 is fixed to a brush stay 33 provided around the commutator portion 31. It can be moved toward and away from the fixed contact plate 34 of the switch unit 7 provided. The armature outer 27 is always elastically urged to the right by a return spring 35 that is contracted between an inward flange 25a provided on the holder 25 of the exciting coil 24, and normally the contact is opened. Stand still.
[0016]
The armature inner 28 is always elastically biased leftward from the top plate 12 by a coil spring 36 having a spring force weaker than the elastic force of the return spring 21 provided in the clutch outer 18. The armature inner 28 is coupled with a shifter member 37 formed of a nonmagnetic material whose left end is in contact with the right end of the clutch inner 22.
[0017]
The exciting coil 24 is electrically connected to an ignition switch (not shown) via a flat pin terminal 38 (see FIG. 2) provided in the switch unit 7.
[0018]
A battery anode (not shown) is electrically connected to the fixed contact plate 34 of the switch unit 7, and a pair of anode brushes 39 are connected to the movable contact plate 8 of the switch unit 7 as shown in FIG. A pair of pigtails 40 connected to each other is fixed by spot welding. In addition, a pair of cathode brushes 41 are provided at positions symmetrical with the pair of anode brushes 39. The pigtail 42 of the cathode brush 41 is connected to a center plate 43 described later, and is 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 a space between the pair of anode brushes 39.
[0019]
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. A cylindrical portion 43 a whose inner peripheral surface faces the outer peripheral surface of the rotor shaft 10 with a minute gap is formed at the center portion of the center plate 43 so as to protrude toward the commutator portion 31. The free end of the cylindrical portion 43a enters the recess 31a formed on the end surface in the axial direction of the commutator portion 31 to prevent the grease of the speed reducer 2 from leaking to the commutator portion 31 side.
[0020]
The switch unit 7 is positioned above the starter 1, and contact portions such as a fixed contact plate 34 and a movable contact plate 8 fixed to the brush stay 33 are disposed in a brush stay in a motor casing 44 as a yoke. 33 and the cover 45, which prevents the brush powder from entering the contact portion of the switch unit 7.
[0021]
By the way, as shown in FIG. 3, a feeding wire 47 is drawn from the end surface on the top plate 12 side from the exciting coil 24 of the electromagnetic device 9, and this feeding wire 47 is an internal tooth at the center of the top plate 12. The base portion of the flat pin terminal 38 protruding from the bottom surface of the recess of the female connector 46 formed on the outer surface of the brush stay 33 through the wire insertion hole 48 provided in the outer peripheral portion of the top plate 12 while avoiding the ring gear 15. It is fixed to.
[0022]
The top plate 12 is integrally provided with a guide portion 49 for guiding a power supply wire 47 extending from the exciting coil 24 disposed near the output shaft 4 to a wire insertion hole 48 provided in the outer peripheral portion of the top plate 12. Is formed. The guide portion 49 is formed with an inclined guide surface 49 a on the inner surface, and as a whole, the exciting coil side expands and has a funnel shape with a diameter gradually reduced toward the wire insertion hole 48.
[0023]
In the brush stay 33, a guide hole 50 having a conical shape in which the top plate 12 side is widened is opened in order to guide the power supply wire 47 that has passed through the wire insertion hole 48 to the joint portion of the base of the flat pin terminal 38.
[0024]
As shown in FIG. 4, the surface 49 b of the guide portion 49 facing the guide surface 49 a is along the axis of the wire insertion hole 48 provided at a position shifted in the circumferential direction with respect to the connecting rod insertion hole 51. The cross section with the enlarged diameter on the exciting coil side forms a semicircular curved surface. On the other hand, the guide surface 49a also has a curved surface with a semicircular arc-shaped cross section that gradually increases in diameter from the wire insertion hole 48 toward the excitation coil side, and is excited in the radial and circumferential directions with respect to the wire insertion hole 48. The inclination direction is determined so that the opening end portion of the guide surface 49a faces the position where the power supply wire 47 is drawn from the coil 24.
[0025]
Next, the operation 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 is urged by the return spring 35 and moves fully to the right, and the movable contact plate 8 connected thereto is a fixed contact plate. 34. At the same time, the clutch outer 18 biased by the return spring 21 is moved fully to the right along with the clutch inner 22, the shifter member 37 and the armature inner 28 which are integrated with the pinion 6. The coupling with the ring gear 23 is broken.
[0026]
When the ignition switch is set to the starter on position, the exciting coil 24 is energized and excited. Then, a magnetic path through which the magnetic flux passes through both the outer and inner armatures 27 and 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, it moves in advance of 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 contacts 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, in the armature outer 27, when an outward flange 27a integrally formed on the right end side thereof abuts on the ring-shaped disk 26, a gap is formed between the left end surface of the armature outer 27 and the central portion of the inward flange 25a. Stop in the state.
[0027]
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, since the clutch outer 18 engaged with the output shaft 4 via the helical spline 19 tries to be stationary by inertial resistance, the axial force due to the action of the helical spline 19 is applied to the clutch outer 18, and the clutch outer 18 is Start moving to the left. At the same time, the attractive force to the left by the exciting coil 24 and the pressing force of the coil spring 36 are simultaneously applied to the armature inner 28, and the armature inner 28 also starts to move to the left. However, this moving force is also applied as an axial force to the clutch outer 18 via the shifter member 37.
[0028]
Due to these axial forces, the clutch outer 18 is pushed leftward against the urging force of the return spring 21, and the pinion 6 integrated with the clutch inner 22 integrally coupled with the clutch outer 18 is also pushed leftward. . When the clutch outer 18 comes into contact with the stopper plate 20 and the pinion 6 reaches the normal meshing position 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 surface of the armature inner 28 is in contact with the center portion of the inward flange 25 a of the holder 25, and a minute 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. Is formed. In this way, by contacting the central portion of the inward flange 25a of the holder 25, the attraction force of the exciting coil 24 acts on the armature inner 28 to the maximum, so that the force that pulls out from the ring gear 23 acts on the pinion 6. However, the rightward movement of the clutch outer 18 is blocked via the shifter member 37, and the pinion 6 is prevented from coming off from the ring gear 23.
[0029]
Here, the current required to keep the armatures 27 and 28 that have made full strokes smaller than the current required to start the armatures 27 and 28 may be small. That is, as described above, by using the axial force by the helical spline 19 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. The diameter can be further reduced. Note that when the engine is started and the rotational speed of the pinion 6 is exceeded, the pinion 6 is idled by the action of the one-way roller clutch 5, which is exactly the same as the conventional configuration.
[0030]
When the energization of the exciting coil 24 is stopped, the pinion 6 is detached from the ring gear 23 and the movable contact plate 8 is fixed 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. The electric motor 3 stops after being separated from the contact plate 34.
[0031]
【The invention's effect】
As described above, according to the present invention, since the feeding wire is smoothly and reliably inserted into the wire insertion hole by being guided by the funnel-shaped inner surface of the guide portion, a great effect can be obtained in improving the assembling property. In addition, since the power supply wire does not bend suddenly, it is effective in enhancing durability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an engine starter constructed according to the present invention.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a cross-sectional view of the periphery of a wire insertion hole.
FIG. 4 is a front view of a main part of a top plate.
[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 9 Electromagnetic device 10 Rotor shaft 11 Bottom plate 12 Top plate 13 Sun gear 14 Planetary gear 15 Internal 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 Excitation 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 portion, 31a Recess 32 Coil spring 33 Brush stay 34 Fixed contact plate 35 Return spring 36 Coil spring 37 Shifter member 38 Flat pin terminal 9 Anode brush 40 Pigtail 41 Cathode brush 42 Pigtail 43 Center plate, 43a Cylindrical portion 44 Motor casing 45 Cover 46 Female connector 47 Feeding wire 48 Wire insertion hole 49 Guide portion, 49a Guide surface, 49b Opposing surface 50 Guide hole 51 Connecting rod Insertion hole

Claims (1)

Arranged in the vicinity of the DC motor, the output shaft driven by the DC motor, the ring gear drive pinion splined to the output shaft, and the commutator portion of the DC motor to open and close the power supply path to the DC motor And an electromagnetic device provided to surround the output shaft between the DC motor and the pinion so as to give an axial displacement to the movable contact plate and the pinion of the switch, the electromagnetic device and the An engine starter having a reduction gear disposed between the DC motor, an external connection terminal disposed in proximity to the switch, and a housing surrounding the electromagnetic device and the reduction gear ;
A wire insertion hole is formed in the outer peripheral portion of the support of the speed reducer so as to connect the power supply wire of the electromagnetic device disposed near the output shaft to the external connection terminal through the inside of the housing. With
The power supply wire that expands in a funnel shape from the wire insertion hole toward the electromagnetic device and is drawn out from the electromagnetic device at a radially inner position is guided toward a radially outer position where the wire insertion hole is located. An engine starter characterized in that a guide portion having a guide surface inclined so as to be provided is provided on a support body of the speed reducer.

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