JPH09310665A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration resistance by a fixing system having a so-called cantilever structure where only housing side is fixed. SOLUTION: The housing 19 of a starter 1 has a spigot part 21 and a flange part 22 which serve for attaching to a frame body (an engine body or a flywheel housing) on an engine side. The spigot part 21 is circular in an outer peripheral form in an axial view, and spigot-fitted in a fitting hole 20b provided on the attaching face 20a of the frame body 20. But the outside diameter HO is set up to be larger than a distance from the attaching face 20a of the frame body 20 to the center of gravity W of an armature 8 (center of an armature core 12).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a starter for starting an engine.

[0002]

2. Description of the Related Art In a starter, a spigot portion of a housing is spigot-fitted into a fitting hole formed in a frame body on an engine side, and a mounting flange provided on the housing is brought into contact with a mounting surface of the frame body. Then, it is fixed in a so-called cantilever state, which is fixed to the frame body by tightening bolts or the like. On the vehicle side, on the other hand, vibration is increasing due to higher engine speeds, friction is increasing due to higher displacement, and the engine room is becoming more and more dense due to increasing auxiliary machinery. There is a demand for a high-performance, small-sized, high-output starter. In response to this demand, a starter equipped with a speed reduction mechanism has been provided, but when a speed reduction mechanism with external teeth meshing is used, the heavy weight motor part and the output shaft are eccentric, so a cantilevered fixing method is used. Then there is a problem in vibration resistance. Further, when the planetary gear speed reduction mechanism is used, the motor section can be arranged coaxially with the output shaft, but since the speed reduction mechanism section is arranged between the output shaft and the motor section, the motor section with a large weight has a frame body. Since it is separated from the mounting surface, vibration resistance still becomes a problem.

Therefore, Japanese Utility Model Laid-Open No. 63-65861 proposes a method in which a stay is formed on the rear cover of the starter and the rear cover is fixed to the engine side through the stay, in addition to fixing the housing side. There is. Further, in another conventional technique, a screw portion is processed on the head portion (rear cover side) of the through bolt that fixes the starter in the axial direction,
There is also a method of fixing the rear cover to the engine side via a stay attached to the screw portion.

[0004]

However, in the prior art, a stay is required as a separate component, and a screw portion or a bolt portion for fixing the stay needs to be formed on the engine side. Further, in order to fix the starter at the front and rear (on the housing side and the rear cover side), it is necessary to take measures such as accuracy or stay shape capable of absorbing the tolerance of the position of the rear end of the starter assembled with various parts. Furthermore,
There is a problem that the number of steps for mounting the starter on the engine is increased and the mountability of the starter is limited to secure the space for the stay. The present invention has been made based on the above circumstances, and its purpose is to
It is an object of the present invention to provide a starter with improved vibration resistance by a so-called cantilevered fixing method in which only the housing side is fixed.

[0005]

According to the present invention, the outer diameter of the fitting portion provided in the housing of the starter is larger than the distance from the mounting surface of the engine side frame to the center of gravity of the armature. It is set. In this case, considering the center of gravity of the heaviest armature as the load point and the mounting surface of the frame receiving the load as the fixed end of the cantilever, the length from the fixed end to the load point is The stress increases sharply as the distance increases. In other words, if the distance from the fixed end to the load point is smaller than the length of the fixed end, the stress applied to the fixed end becomes smaller. As a result, according to the present invention, the outer diameter of the fitting portion is set to be larger than the distance from the mounting surface of the frame body to the center of gravity of the armature. The stress on the mounting surface formed around the can be reduced. Accordingly, even in a cantilever state in which only the housing side is fixed to the engine side, it is possible to improve vibration resistance against an increase in vibration due to higher engine speed.

In the invention of claim 3, the outer diameter of the fitting portion provided in the housing of the starter is greater than the distance from the mounting surface of the engine-side frame to the end surface of the armature core of the armature on the side opposite to the mounting surface. It is set large. In this case, when considering the above-mentioned cantilever, the length of the fixed end is further increased with respect to the distance from the fixed end to the load point, so that the vibration resistance can be further improved.

According to the invention of claim 4, since the vibration resistance of the starter can be improved as described above, the magnet switch can be arranged on the side opposite to the pinion of the armature.
That is, since the influence of vibration from the engine to the starter side is reduced by improving the vibration resistance, it is possible to adopt a configuration in which the magnet switch is arranged at a position away from the mounting surface of the frame body. In this case, the magnet switch can reduce the projected area in the axial direction as compared with the starter provided on the outer side in the radial direction of the starting motor, so that the mountability of the starter is improved. In addition, in comparison with the above starter (starter in which a magnet switch is provided side by side on the radial outside of the starting motor),
Since the position of the center of gravity of the magnet switch can be brought close to the rotation axis of the armature in the radial direction, the influence of vibration on the magnet switch can be reduced.

[0008]

Next, a starter according to the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is an overall sectional view of a starter 1.
The starter 1 according to the present embodiment includes a starting motor 2 that generates a rotational force when energized, an output shaft 3 that is rotationally driven by the starting motor 2, and a pinion that is axially movable on the output shaft 3. 4. A planetary gear speed reducer (to be described later) that reduces the rotational speed of the starting motor 2 and the output shaft 3 from this speed reducer.
It is composed of a one-way clutch (described later) for transmitting a rotational force to, a magnet switch 5 for controlling the energization of the starting motor 2, and for generating the pushing force of the pinion 4.

The starting motor 2 has a substantially cylindrical motor casing 6, a field device 7 fixed to the inner peripheral surface of the motor casing 6, an armature 8 arranged on the inner peripheral side of the field device 7, The armature 8 is composed of a brush 10 that is in sliding contact with a commutator 9 formed on one end side (the right end side in FIG. 1), a brush holder 11 that holds the brush 10, and the like. The armature 8 includes an armature core 12 and the armature core 12
The armature conductor 13 held by the armature conductor 13 and the shaft 14 press-fitted into the central portion of the armature core 12.
A commutator 9 is formed on one end side of the. Also, shaft 1
4 is a bearing portion 1 whose one end side is provided in the brush holder 11.
1a is rotatably supported via a bearing 15, and the other end side is rotatably supported via a bearing 16 arranged in a recess on one end side of the output shaft 3. The brush 10 is held by a brush holder 11 so as to be movable in the axial direction, and is pressed against the commutator 9 by a brush spring 18 held by a motor cover 17. The outer peripheral portion of the brush holder 11 is sandwiched between the motor casing 6 and the motor cover 17, and the bearing portion 11a is centered.

The motor cover 17 is a motor casing 6
Of the housing 19 together with the motor casing 6 by a plurality of unillustrated through bolts.
Has been concluded. The housing 19 has a spigot portion 21 (fitting portion of the present invention) and a flange portion 22 (see FIG. 2) for attachment to a frame body 20 on the engine side (engine body, flywheel housing, or the like). The spigot portion 21 is provided with a circular outer peripheral shape when viewed from the axial direction, and has a fitting hole 20 formed in the mounting surface 20 a of the frame body 20.
The spigot is fitted to b. However, the outer diameter H0 of the pilot portion 21 is set to be larger than the distance Lw from the mounting surface 20a of the frame 20 to the center of gravity W of the armature 8 (the center of gravity of the armature is considered to be substantially the center of the armature core 12). Has been done. The flange portion 22 is provided radially larger on the motor side (right side in FIG. 1) than the spigot portion 21 and has a mounting hole 22a through which a mounting bolt (not shown) is inserted into the end face.
Are open in two places (see Figure 2). The mounting bolt is
The housing 19 is fixed to the frame body 20.
It is screwed into a screw hole (not shown) provided in the.

The output shaft 3 is arranged coaxially with the shaft 14 on the other side of the armature 8, one end side of which is rotatably supported by the center case 24 via a bearing 23, and the other end side of which is connected via a bearing 25 to the housing. 19 is rotatably supported. A helical spline 3a is provided on the outer periphery of the output shaft 3.
Is formed, and the pinion 4 is fitted into the helical spline 3a. The pinion 4 meshes with the ring gear 26 of the engine and transmits the rotational force of the starting motor 2 to the ring gear 26, and is provided so as to be able to move forward and backward along the helical spline 3a on the output shaft 3. The forward movement of the pinion 4 is regulated by contacting a stop collar 27 provided on the outer circumference of the output shaft 3.

The speed reducer comprises a sun gear 28 formed on the outer periphery of the shaft 14, a plurality of planet gears 29 meshing with the sun gear 28, and an internal gear 30 meshing with each planet gear 29. The sun gear 28 is the shaft 1
By rotating together with 4, the rotation of the shaft 14 is transmitted to each planetary gear 29. Each planetary gear 29 is rotatably supported by a pin 32 that is press-fitted and fixed to an outer 31 of a one-way clutch through a bearing 33, meshes with a sun gear 28 and an internal gear 30, and rotates while rotating. Revolve around the circumference. The internal gear 30 is
It is formed on the inner peripheral surface of the center case 24 so as not to rotate (the center case 24 itself is provided so as not to rotate with respect to the housing 19).

The one-way clutch includes an inner 34 and an outer 3
1, a roller 35, and the like. Inner 34
Is a large-diameter portion provided at one end of the output shaft 3, and is rotated integrally with the output shaft 3 by transmitting the rotational force from the outer 31 through the roller 35. The outer 31 is the inner 34
A plurality of wedge-shaped cam chambers (not shown) are formed on the inner peripheral surface of the inner 34 facing the outer peripheral surface of the inner 34. The roller 35 is housed in the cam chamber and is biased in the narrow direction of the cam chamber by a spring (not shown).

The magnet switch 5 is arranged on the outer side in the radial direction of the starting motor 2, and a switch casing 36 forming an outer shell is fixed to the housing 19 by fastening a bolt and a nut (not shown), and an opening portion on one end side of the switch casing 36. Are covered by the switch cover 37. Inside the switch casing 36, an exciting coil 38 that generates a magnetic force when energized, a plunger 39 movably provided in the hollow inside of the exciting coil 38, and the exciting coil 3 are provided.
Stationary core 40 attached to one end side of 8,
When the excitation coil 38 is de-energized, the plunger 3
Spring 4 for returning 9 to the initial position (position in FIG. 1)
1 and the like are arranged, and the stationary core 40, the switch casing 36, and the plunger 39 form a magnetic circuit.

The switch cover 37 has a power supply terminal (not shown) electrically connected to the battery via a cable (not shown) and a lead wire 42 for starting the motor 2.
A motor terminal 43 that energizes to is attached. Inside the switch cover 37, a pair of fixed contacts 44 integrally provided with the power supply terminal and the motor terminal 43 and a movable contact 45 corresponding to each fixed contact 44 are provided, and the movable contact 45 is a plunger. It is attached to the tip of a plunger rod 46 protruding to one end side of 39 and moves integrally with the plunger 39.

The magnet switch 5 attracts the plunger 39 by the magnetic force generated by the exciting coil 38 (moves the plunger 39 to the stationary core 40 side) so that the movable contact 45 contacts the fixed contact 44 and the starting motor 2 The pinion 4 can be pushed out to the ring gear 26 side by energizing the pinion 4 and transmitting the plunger suction force to the pinion 4 via the shift lever 47. One end and the other end of the shift lever 47 are swingably provided about a fulcrum 48 supported by the housing 19, and one end of the shift lever 47 is provided with a plunger 39.
Of the pinion 4 is engaged with a joint 49 provided on the other end side of the pinion 4 and the other end is engaged with the pinion 4.

Next, the operation of this embodiment will be described. When a key switch (not shown) is turned on, the exciting coil 38 of the magnet switch 5 is energized and the plunger 39 is attracted. Along with the movement of the plunger 39, the movable contact 45 attached to the plunger rod 46 abuts the pair of fixed contacts 44, and the power supply terminal and the motor terminal 43 are electrically connected to each other, so that the armature 8 is energized from the battery through the brush 10. To be done. As a result, a rotational force is generated in the armature 8, the rotational force is decelerated by the speed reducer, and then transmitted to the output shaft 3 via the one-way clutch. On the other hand, as the plunger 39 moves, the shift lever 47 moves the fulcrum 4
By rotating about 8 (clockwise in FIG. 1), the pinion 4 moves on the output shaft 3 along the helical spline 3a.
The engine is started when the rotational force of the starting motor 2 is transmitted from the pinion 4 to the ring gear 26 by meshing with the ring gear 26.

After the engine is started, the pinion 4 is rotated by the engine via the ring gear 26, and when the rotational speed of the output shaft 3 (rotational speed of the inner 34) becomes higher than the rotational speed of the outer 31, the roller 35 has a wide cam chamber. It moves toward and spins in the cam room. As a result, the connection state between the inner 34 and the outer 31 is released and the rotational force of the inner 34 is not transmitted to the outer 31, and overrun of the armature 8 can be prevented. When the engine start is completed and the key switch is turned off, the energization of the exciting coil 38 is stopped, and the plunger 39 receives the biasing force of the spring 41 and returns to the initial position. With this, the armature 8
Power supply to the armature 8 is stopped and the rotation of the armature 8 is stopped, and the pinion 4 is disengaged from the ring gear 26 through the shift lever 47 and returns to the stationary position (the position shown in FIG. 1).

(Characteristics and Effects of the Present Embodiment) In the starter 1 of the present embodiment, the spigot portion 21 provided in the housing 19 is spigot-fitted into the fitting hole 20b formed in the frame body 20 to form the housing 19. The mounting bolts inserted into the mounting holes 22a formed in the flange portion 22 are fixed to the frame body 20 by being screwed into the screw holes of the frame body 20. That is,
In the starter 1, both sides of the housing 19 and the motor cover 17 are not fixed to the frame body 20 in the axial direction (left and right direction in FIG. 1), but only the housing 19 side is the frame body 20.
It is in a cantilevered state.

In this way, the starter 1 and the frame body 2 are cantilevered.
When fixed to 0, the outer diameter H0 of the spigot part 21 which is fitted in the fitting hole 20b of the frame body 20 is set to the center of gravity W of the heaviest armature 8 from the mounting surface 20a of the frame body 20.
To the mounting surface 20a
The stress applied to can be reduced. This is explained by using the center of gravity W of the heaviest armature 8 as a load point and the mounting surface 20a of the frame body 20 that receives the load as a fixed end of the cantilever, from the fixed end to the length of the fixed end. The stress increases rapidly when the distance to the load point becomes larger.
In other words, if the distance from the fixed end to the load point is smaller than the length of the fixed end, the stress applied to the fixed end becomes smaller.

As can be said from the above description, the spigot portion 2
By making the outer diameter H0 of 1 larger than the distance Lw from the mounting surface 20a of the frame 20 to the center W of gravity of the armature 8, the stress applied to the mounting surface 20a of the frame 20 can be reduced.
The load applied to the mounting surface 20a by vibrating the starter 1 is the circumference around which the mounting bolt is screwed and the upper and lower portions of the flange portion 22 in the vertical direction (a portion and b portion in FIG. 2).
Part) and the part corresponding to. As a result, the vibration resistance can be improved and the influence of vibration transmitted from the engine can be reduced as compared with the conventional cantilever fixed starter. As a result, it is possible to suppress wear of the bearing portion due to vibration of the armature 8 and performance deterioration, and thus it is possible to provide the starter 1 having high vibration resistance against vibration increase due to high engine rotation.

The outer diameter H0 of the spigot portion 21 is set to the frame 2
It goes without saying that a greater effect (improvement in vibration resistance) can be obtained by making the distance Lo from the mounting surface 20a of 0 to the end surface of the armature core 12 opposite to the mounting surface side larger than Lo. Note that H0 and Lw described in this embodiment are
(Or Lo), as shown in FIG.
This means that Lw (or Lo) is present in the cone of height H0 with the circle of 0 as the bottom. In particular, FIG.
If Lw (or Lo) exists in the cone limited to the width of the part corresponding to the parts a and b shown in (see FIG. 4), it is clear that the vibration resistance and strength are also good. Is.

(Second Embodiment) FIG. 5 is an overall sectional view of the starter 1. The starter 1 of the present embodiment shows an example in which the magnet switch 5 is arranged on the side opposite to the pinion of the armature 8. The magnet switch 5
The plunger 39 is arranged so that the operating direction of the plunger 39 is substantially perpendicular to the armature shaft 14, and the pinion shifting means 50 corresponding to the shift lever 47 of the first embodiment and the plunger 39.
And are connected by transmission means 51. Also in this embodiment, the outer diameter H0 of the spigot portion 21 is set to a distance Lw from the mounting surface 20a of the frame 20 to the center W of gravity of the armature 8.
(Or the distance Lo to the end surface of the armature core 12 on the side opposite to the mounting surface) to increase the vibration resistance, the magnet switch 5 can be arranged on the side opposite to the pinion of the armature 8.

As described above, according to the structure in which the magnet switch 5 is arranged on the side opposite to the pinion side of the armature 8, as shown in FIG.
Compared with the starter 100 (for example, the starter described in the first embodiment) in which the magnet switch 5 shown in (a) is provided outside the starting motor 2 in the radial direction, the present embodiment shown in FIG. Since the starter 1 can reduce the projected area in the axial direction, the mountability of the starter 1 is improved. Also,
Compared to the starter in which the magnet switch 5 is provided outside the starting motor 2 in the radial direction, the armature shaft 14
Since the center of gravity of the magnet switch 5 can be brought closer to the radial direction, the influence of vibration on the magnet switch 5 can be further reduced.

(Third Embodiment) FIG. 7 is a view showing the relationship between the frame 20 and the starter 1. The starter 1 of this embodiment is
The cylindrical portion 52 provided at the tip of the housing 19 is the frame body 2.
The center pitch P between the pinion 4 and the ring gear 26 is determined by fitting in the hole 20c opened at 0. In this starter 1, since the cylindrical portion 52 of the housing 19 is fitted and held in the hole 20c of the frame body 20, the convex portion 53 (fitting portion of the present invention) provided on the outer peripheral surface of the housing 19 is The spigot fitting is not performed in the fitting hole 20b formed in the mounting surface 20a of the frame body 20, but a slight gap is formed between the inner peripheral surface of the fitting hole 20b and the outer peripheral surface of the convex portion 53. Has been formed. In such a structure, the inner diameter H1 of the fitting hole 20b is set to the distance Lw from the mounting surface 20a of the frame 20 to the center of gravity W of the armature 8 (or the distance Lo to the end surface of the armature core 12 on the side opposite to the mounting surface). ) Vibration resistance can be improved by making it larger.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a starter.

FIG. 2 is a schematic view showing the shapes of a spigot portion and a flange portion.

FIG. 3 is a schematic diagram showing the relationship between the outer diameter of the spigot portion and the distance from the mounting surface of the frame body to the center of gravity of the armature.

FIG. 4 is another schematic diagram showing the relationship between the outer diameter of the spigot portion and the distance from the attachment surface of the frame body to the center of gravity of the armature.

FIG. 5 is an overall sectional view of a starter (second embodiment).

FIG. 6 is a diagram showing a projected area of a starter (second embodiment).

FIG. 7 is a diagram showing a relationship between a frame body and a starter (third embodiment)
Example).

[Explanation of symbols]

1 Starter 2 Starter Motor 3 Output Shaft 4 Pinion 5 Magnet Switch 8 Armature 12 Armature Core 19 Housing 20 Frame 20a Frame Attachment Surface 20b Fitting Hole 21 Inlay Part (Fitting Part) 26 Ring Gear 53 Convex Part (Fitting) H0) Outer diameter of spigot part Lw Distance from mounting surface to center of gravity of armature Lo Distance from mounting surface to end surface of armature core opposite to mounting surface

Claims (4)

[Claims] 1. A starter motor for generating a rotational force in an armature when energized, an output shaft rotatably driven by the starter motor, and an output shaft provided on the output shaft so as to be able to move forward and backward. A pinion that transmits the rotational force of the starting motor to the ring gear, and a housing that rotatably supports one end of the output shaft and is fixed to the engine-side frame are provided. It has a fitting portion that fits into a fitting hole formed in the mounting surface, and the outer diameter of the fitting portion is set to be larger than the distance from the mounting surface to the center of gravity of the armature. Starter to do. 2. The starter according to claim 1, wherein the center of the armature core portion of the armature is substantially the center of gravity of the armature. 3. A starting motor for generating a rotational force in an armature when energized, an output shaft rotatably driven by the starting motor, and an output shaft provided on the output shaft so as to be capable of advancing and retracting, and engaging with a ring gear of an engine. A pinion that transmits the rotational force of the starting motor to the ring gear, and a housing that rotatably supports one end of the output shaft and is fixed to the engine-side frame are provided. There is a fitting part that fits in a fitting hole provided in the mounting surface, and the outer diameter of this fitting part is greater than the distance from the mounting surface to the end surface of the armature core of the armature opposite to the mounting surface side. The starter is also characterized by being set large. 4. A magnet switch for generating a force for pushing the pinion to the ring gear side, the magnet switch being arranged on an anti-pinion side of the armature. Any starter described.