JP2731795B2 - 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 for a motor vehicle, and more particularly to a technique for restricting the movement of an armature shaft of a starter motor in a thrust direction.

[0002]

2. Description of the Related Art Conventionally, in a starter motor, for example, as disclosed in JP-A-63-309767,
A washer is fitted into a circumferential groove formed at one end of the armature shaft, and the washer is clamped between the inner wall of the end of the bracket and the brush holder holding plate (holder plate) attached to the inner wall of the bracket, thereby forming the armature shaft. Techniques for regulating movement in the thrust direction are known.

Further, as disclosed in US Pat. No. 4,387,315, two C-shaped washers obtained by halving a thrust control washer are combined and fitted into a circumferential groove of an armature shaft. While holding the washer between the inner wall of the bracket and the holder plate in the same manner as above, the protrusion provided on the holder plate is fitted into the recess provided on the outer periphery of the C-shaped washer, thereby preventing the washer from rotating. is there.

[0004]

SUMMARY OF THE INVENTION These prior arts are:
If the washer is displaced in the radial direction and the inner diameter of the washer and the outer diameter of the circumferential groove of the armature shaft come into contact with each other, it will prevent wear of the washer or smooth rotation of the armature shaft. And, there was a possibility that the washer co-rotates with the armature shaft or falls off. Therefore, a concave portion for fitting a washer is formed on the inner wall of the bracket, and the fitting is used to regulate the radial position of the washer.

However, when the washer is assembled, the washer may move in the radial direction by the clearance between the inner diameter of the washer and the outer diameter of the circumferential groove on the armature shaft side. In some cases, the washer protrudes from the fitting recess and rides on the inner wall of the bracket and is not set properly.

[0006] Also, in the case where a washer rotation preventing mechanism is provided, conventionally, the washer is divided into halves and these washer elements are engaged with the brush holder holding plate in an uneven manner. In addition, the number of washer parts is increased, and the positioning and fitting of the concave / convex engagement is troublesome, and there is a point to be improved in terms of assemblability.

The present invention has been made in view of the above points, and an object of the present invention is to improve the assemblability of this type of washer to a starter motor and to achieve a compatible set, thereby preventing the washer from rotating, co-rotating, and falling off. To ensure smooth operation of the starter motor.

[0008]

In order to achieve the above object, the present invention basically proposes the following problem solving means.

One of the techniques relates to a proper setting of a washer. The gist of the technique is that a washer is fitted in a circumferential groove formed at one end of an armature shaft of a starter motor, and this washer is used as an end of a bracket serving as a motor housing element. In a starter motor which is sandwiched between an inner wall (hereinafter, referred to as an inner wall of a bracket) and a brush holder holding plate attached to the inner wall of the bracket so as to regulate the thrust direction of the armature shaft, the washer is mounted on the inner wall of the bracket. A recess is formed for fitting
The concave portion has a circular edge concentric with the armature shaft at the edge surrounding the washer, and a tapered or round shape is formed at the peripheral edge of the circular concave portion. The distance to the outer peripheral edge) Y / 2 and the small radius of the circular recess (the distance from the center of the circular recess to the inner peripheral edge of the taper or radius) y / 2
And the maximum distance δ1 from the center of the armature shaft to the outer diameter of the washer when the washer is moved maximum in the radial direction by the clearance between the inner diameter of the washer and the outer diameter of the circumferential groove, y / 2 < δ1 <Y / 2 (this is the first problem solving means).

The other is a technique relating to a proper setting of a washer. The gist of the technique is that the recess formed for fitting the washer into the inner wall of the bracket does not necessarily have to be circular as in the first means for solving the problem. In this case, the edge of the recess is the part that protrudes inward (this is the protruding edge
) And the part that goes to the outside are arranged alternately,
The protruding edge has a plurality of arc lines surrounding the washer.
In I the armature shaft concentric Oh <br/> the imaginary circle on the line, Yes formed tapered or rounded at the edges out Ri該迫, tapered or rounded sincere the protruding edges in said recess distance and away Y / 2, of the recess to the outer peripheral edge of the
Sincerely and distance y / 2 until the inner periphery of the tapered or rounded of the protruding edge in, the outer span of the clearance of inner to the circumferential groove of the washer when the washer has a maximum moved radially The relationship with the maximum distance δ1 from the armature shaft center to the washer outer diameter is represented by y / 2 <δ1 <
Y / 2 (this is referred to as a second problem solving means).

The other is a technique relating to simplification of a washer rotation preventing mechanism. The gist of the technique is that a washer is fitted into a circumferential groove provided on an armature shaft, and a radial direction is formed in the circumferential groove on the washer side. A groove for press-fitting is formed so as to communicate with the inner diameter of the washer. On the other hand, a small protrusion is provided on the washer holding surface of the inner wall of the bracket, and the small protrusion is engaged with the groove of the washer, thereby forming a washer. The rotation is stopped (this is referred to as a third problem solving means).

Another technique is related to simplification of a washer rotation preventing mechanism. The gist of the technique is to provide a blank in the washer so that the center of gravity of the washer matches the center of gravity of the armature shaft. Do).

[0013]

According to the first and second means for solving the problems, when the washer is moved to the maximum in the radial direction by the clearance between the inner diameter of the washer and the outer diameter of the circumferential groove on the armature shaft side when the washer is assembled to the starter motor, By the above-described condition setting (y / 2 <δ1 <Y / 2), a part of the washer is applied to the taper or the radius provided on the periphery of the recess for fitting the washer.

Therefore, even if the washer moves to the maximum in the radial direction, it does not run over the fitting recess from the fitting recess, and furthermore, clamps the inner wall of the bracket (the inner wall of the washer fitting recess) and the brush holder holding plate. When a force is applied, the washer is slid and guided on the tapered or round surface by the force and is pushed back so as to fit within the small diameter y of the concave portion. Due to the pushback (position correction) of the washer, the movement amount of the washer in the radial direction of the armature shaft becomes smaller than the maximum movement amount. This means that the inner diameter of the washer did not come into contact with the outer diameter of the circumferential groove of the armature shaft.In use after assembly, the inner diameter of the washer may contact the outer diameter of the circumferential groove of the armature shaft. Is prevented.

According to the third means for solving the problem, when the washer is press-fitted into the circumferential groove on the armature shaft side from the radial direction through the groove during the assembling, the inner diameter of the washer is expanded while the groove is pushed out by the elasticity of the washer. If the groove of this washer is aligned with the protrusion on the inner wall of the bracket or the brush holding plate, which serves as a washer holding element, the washer engages with the protrusion. The stop mechanism is simply configured. As a result, even if the inner diameter of the washer contacts the outer diameter of the circumferential groove of the shaft, the rotation can be prevented.

According to the fourth means for solving the problems, the center of gravity of the washer is made to coincide with the center of gravity of the armature shaft by the blank provided on the washer, so that, for example, the outer diameter of the circumferential groove of the armature shaft and the inner diameter of the holding washer come into contact. Even when a force for rotating the washer and a local rotational moment act, it does not rotate together.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a partially cutaway cross-sectional view of a starter motor according to a first embodiment of the present invention, and FIG. 2 shows an operation of correcting a washer position in the present embodiment (as viewed from arrows AA in FIG. 1). FIG. 7A is an explanatory view showing a state of the thrust regulating washer used in the above embodiment in the maximum radial movement, and FIG. 7B is an explanatory view showing a state of the washer after the position is corrected.

In FIG. 1, an armature shaft 2 of a starter motor (DC motor) 1 has one end supported by a bearing (not shown) provided on a gear cover 3 and the other end provided on a bracket (rear cover) 4. 5 supported. The motor housing is constituted by the bracket 4 and the yoke 7 with the field magnet 6.
An armature 8 is provided so as to be located inside the field magnet 6, and a commutator 9 of the armature 8 is disposed further rearward than the armature.

The brush 1 which contacts the outer periphery of the commutator 9
0 is stored in the holder 11. The holder 11 includes a holder holding plate (holder plate) 12 provided on the back surface thereof.
And a synthetic resin. This holder 11
And the holding plate 12 may be integrally assembled separately. The holder holding plate 12 has an annular shape of a thin plate, the inner diameter of which is slightly smaller than the outer diameter of a washer 15 for thrust control, which will be described later. The bracket 11 is attached to the inner wall 4a of the end of the bracket 4 by the bracket 13, and the holder 11 is held through the holding plate 12.

Of the outer circumference of one end of the armature shaft 2,
A circumferential groove 14 is formed between the bearing 5 and the commutator 9, and a washer 15 is fitted in the circumferential groove 14.

On the other hand, on the inner wall 4a at the end of the bracket 4,
A circular recess 16 is formed so as to be concentric with the shaft 2, and the circumferential groove 14 and the washer 15 are arranged at positions aligned with the circular recess 16.
It is fitted in. The recess 16 has a taper 16 at its periphery.
a.

The washer 15 is sandwiched between the inner wall of the recess 16 and the brush holder holding plate 12 while being fitted into the recess 16. When the washer 15 is properly set in the recess 16, a small clearance G is maintained between the inner diameter of the washer 15 and the outer diameter of the circumferential groove 14 on the shaft 2 side, and the inner diameter of the washer 15 and the circumferential groove 14 are maintained. The outer diameter is in a non-contact state.

The amount of movement of the armature shaft 2 in the thrust direction is adjusted (regulated) by the gap in the thrust direction between the circumferential groove 14 and the washer 15. In addition,
21 is a magnetic switch, 22 is a pinion, the pinion 22 is fitted on a pinion shaft (not shown) so as to be movable in the axial direction, and the pinion 22 can be linked with a shift lever (not shown) of the magnetic switch 21. Is joined to. The pinion shaft is connected to the armature shaft via a reduction gear (not shown).

As shown in FIG. 2A, the large radius of the recess 16 on the inner wall 4a side of the bracket (the taper 1 from the center of the recess 16).
The distance from the outer periphery of 6a) Y / 2 and the small radius of the recess 16 (the distance from the center of the recess 16 to the inner periphery of the taper 16a).
Relationship between y / 2 and the maximum distance δ1 from the center of the armature shaft 2 to the outer diameter of the washer 15 when the washer 15 is moved maximum in the radial direction due to the clearance G between the inner diameter of the washer 15 and the outer diameter of the circumferential groove 14. With y / 2 <δ1 <Y /
2 In FIG. 2, the moving state is exaggerated for the purpose of easily illustrating the maximum moving amount of the washer 15.

As shown in FIGS. 2A and 2B, the washer 15 has a width slightly larger than the outer diameter of the circumferential groove 14 in addition to the inner diameter 15a of the washer fitted to the outer diameter of the circumferential groove 14 of the shaft 2. A narrow radial slot 15b is formed.
When the washer 15 is press-fitted into the outer diameter of the circumferential groove 14 from the radial direction through the groove b, the slot 15b is pushed open by elasticity, and the inner diameter of the washer 15 is fitted to the outer diameter of the circumferential groove 14.

Now, when a current is supplied to the starter motor 1, the armature 8 generates torque and the armature shaft 2 rotates and is transmitted to the pinion 22 via the reduction gear and the pinion shaft. At the same time, the magnetic switch 21 to which current has already been supplied connects the pinion 22 via the shift lever to the ring gear (not shown) of the engine.
And start the starter operation.

When the pinion 22 and the engine ring gear mesh with each other, a force in the thrust direction acts on the armature shaft 2. As described above, the engagement between the washer 15 and the circumferential groove 14 on the shaft 2 side causes the thrust direction. Movement is regulated.

According to this embodiment, when assembling the starter motor, the washer 15 is fitted into the outer diameter of the circumferential groove 14 of the armature shaft 2 and then the washer 15 is fitted.
Is fitted into the circular recess 16 of the inner wall of the bracket 4, and then the holding plate 12 with the brush holder is attached to the inner wall 4 a of the bracket 4. In this assembly, the clearance G causes the washer 15 to have an inner diameter in contact with the outer diameter of the circumferential groove 14. A displacement (maximum displacement) occurs.

In this embodiment, even if such a displacement occurs, the large radius Y / 2 of the circular concave portion 16 and the small radius y /
2 and the shaft 2 at the time of the maximum radial movement of the washer 15
By setting the relationship between the center and the maximum distance δ1 from the outer diameter of the washer 15 to y / 2 <δ1 <Y / 2, a part of the washer 15 is Will be applied to the taper 16a provided on the periphery of.

For this reason, even if the washer 15 moves maximally in the radial direction (maximum displacement), the bracket 4 a
If the brush holder holding plate 12 and the inner wall of the bracket do not run on the inner wall, and the clamping force between the inner wall of the bracket and the brush holder holding plate 12 acts, the washer 15 is tapered by the force.
It is slid on the surface a and pushed back so as to fit within the small diameter y of the concave portion as shown in FIG. This washer 15
, The amount of movement of the washer 15 in the radial direction becomes smaller than the maximum amount of movement (when the maximum distance from the center of the armature shaft 2 after the pushing back to the outer diameter of the washer 15 is δ2, δ2 ≦ y / 2). .

This means that the inner diameter of the washer 15a is not in contact with the outer diameter of the circumferential groove 14 of the armature shaft 2, and when used after assembly, the inner diameter of the washer 1
The situation where 5a contacts the outer diameter of the circumferential groove 14 of the armature shaft is prevented.

As a result, erroneous assembly with the washer 15 riding on the inner wall 4a of the bracket does not occur, and the assembling property can be improved.

Further, it is possible to always maintain the clearance G between the inner diameter of the washer 15a and the outer diameter of the circumferential groove 14 of the shaft 2, so that the armature 8 rotates smoothly, and the washer 15 comes off and falls off. Can be prevented from rotating together.

Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 3 is a cross-sectional view showing a part of the starter motor according to the second embodiment, and FIG. 4 is a view taken along the line BB of FIG. Or indicate common elements.

The present embodiment is different from the first embodiment in that a recess 16 'in which a washer 15 for thrust control is fitted.
(Corresponding to the recess 16 of the first embodiment).

That is, in this embodiment, the end of the bracket 4 is press-formed to form the recess 16 'for fitting the washer.
Forming a but edge surrounding the washer 15 of the recess 16 'is not intended to present a circular as shown in FIG. 4, the inner
Part that protrudes to the side (this is the protruding edge) 16a
′ And the part that goes to the outside (between 16a ′ and 16a ′
Part) are arranged alternately with each other.
The portion 16 a ′ has a total of 4 arranged around the washer 15.
The arc lines are set to be on a virtual circle line concentric with the armature shaft 2. That is, a plurality (four in this case) of protruding edges 16a 'are arranged at equal intervals in the circumferential direction, and these edges 16a' are similar to the taper 16a of the first embodiment. A round having a function is formed (hereinafter, the round is also denoted by reference numeral 16a ').

[0039] In the present embodiment, a distance Y / 2 up to the outer peripheral edge of Earl 16a' sincerely the protruding edge in the recess 16 ', in a recess 16' sincerely said Earl 16a
The distance from the center of the armature shaft 2 to the outer diameter of the washer 15 when the washer 15 has moved in the radial direction due to the distance y / 2 to the inner peripheral edge of the 'and the clearance G between the inner diameter of the washer 15 and the outer diameter of the circumferential groove 14. The relationship with the distance δ1 is represented by y
/ 2 <δ1 <Y / 2.

Further, a part of the recess 16 'of the inner wall of the bracket is raised in an annular shape (a portion indicated by reference numeral 4b), and a small protrusion 23 of a part of the annular raised portion 4b is provided. Part of washer 15 (here, slot 15b)
To prevent rotation of the washer 15. Further, the washer 15 is provided with a blank 24 for matching the center of gravity of the washer 15 with the center of gravity of the armature shaft 2.

According to this embodiment, y / 2 <δ1 <Y / 2
Is set, and the radius 16a 'is changed to the taper 16a.
In the same manner as in the first embodiment, it is possible to prevent the washer 15 from climbing out of the recess 16a 'and being erroneously assembled, and to provide a clearance between the inner diameter of the washer and the outer diameter of the circumferential groove on the shaft side during use. G) is maintained, so that the washer is prevented from being worn, co-rotating, falling off, and the like, and has the following advantages in addition to ensuring smooth rotation of the armature.

That is, even if the inner diameter of the washer 15 comes into contact with the outer diameter of the circumferential groove 14,
5b can prevent the washer 15 from rotating together with the shaft 2, and the center of gravity of the washer 15 is made to coincide with the center of gravity of the armature shaft 2 by the blank 24 provided on the washer 15, so that, for example, the armature shaft Even if the outer diameter of the circumferential groove 14 and the inner diameter of the holding washer 15 come into contact with each other and the force for rotating the washer acts, the washer 15 also has an action of suppressing rotation by itself, and the co-rotation in the range of the slot 15b also occurs. Can be effectively prevented.

In the above embodiment, the engagement between the projection 23 and the slot 15b serving as a detent mechanism and the blank 24 are provided together. However, they may be independently incorporated in these starter motors. Further, the tapered portion 16a of the first embodiment may be replaced with a radius, and the radius 16a 'of the second embodiment may be replaced with a taper.

[0044]

According to the first and second means for solving the problems, the positional deviation of the washer is automatically corrected at the time of assembling so that erroneous assembling can be eliminated, and the thrust regulating washer can be set properly. , Co-rotation, falling off, etc. to prevent the armature and thus the starter motor from running smoothly.

According to the third and fourth means for solving the problems, it is possible to realize such a washer rotation preventing mechanism capable of simplifying the mechanism and improving the assembling property.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view of a starter motor according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing an operation of correcting a washer position in the first embodiment (a view taken along the line AA in FIG. 1).

FIG. 3 is a partial sectional view showing a second embodiment of the present invention.

FIG. 4 is a view taken along line BB of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Starter motor, 2 ... Armature shaft, 4 ... Bracket, 4a bracket inner wall, 8 ... Armature, 10
... brush, 11 ... brush holder, 12 ... brush holder holding plate, 14 ... circumferential groove, 15 ... washer, 15a ... washer inner diameter, 15b ... slot, 16, 16 '... washer fitting recess, 16a ... taper, 16a '... R, 23 ... Protrusion, 24 ... Blank

Continuing from the front page (72) Inventor Masayuki Shizuka 2520 Takada, Kata-shi, Ibaraki Pref. Inspector, Automotive Equipment Division, Hitachi, Ltd. Kiyoshi Tarashima (56) References JP-A-63-309767 (JP, A)

Claims (4)

(57) [Claims] A washer is fitted into a circumferential groove formed at one end of an armature shaft of a starter motor, and the washer is used as a motor housing element at an end inner wall of a bracket (hereinafter referred to as a bracket inner wall) and at an inner wall of the bracket. A starter motor which is held by a brush holder holding plate attached to the starter motor so as to regulate the thrust direction of the armature shaft; a recess for fitting the washer into the inner wall of the bracket is formed; An edge surrounding the washer has a circular shape concentric with the armature shaft, and a tapered or round shape is formed at a peripheral edge of the circular concave portion. A large radius of the circular concave portion (from the center of the circular concave portion to the outer peripheral edge of the tapered or rounded portion) The distance is defined as the large radius) Y / 2
And the small radius of the circular recess (the distance from the center of the circular recess to the inner peripheral edge of the taper or radius is defined as the small radius) y
The relationship between // 2 and the maximum distance δ1 from the center of the armature shaft to the outer diameter of the washer when the washer moves maximum in the radial direction due to the clearance between the inner diameter of the washer and the outer diameter of the circumferential groove is represented by y / A starter motor, wherein 2 <δ1 <Y / 2. 2. A washer is fitted into a circumferential groove formed at one end of an armature shaft of a starter motor, and the washer is used as a motor housing element at an end inner wall of a bracket (hereinafter referred to as a bracket inner wall) and an inner wall of the bracket. to the starter motor is clamped by a brush holder holding plate are to perform the regulation of the thrust direction of the armature shaft which is mounted, the recess for fitting the washer to the bracket inner wall is formed, the edges of the recess Is the part that protrudes inward (this
Alternately with the protruding edge)
And the protruding edge is provided with the washer.
What the armature shaft concentric imaginary circle line on the near by a plurality of arcs lines surrounding, Yes formed tapered or rounded at the edges out Ri該迫, tapered dearly the protruding edges in said concave portion or a distance Y / 2 up to the outer peripheral edge of the radius, heart within said recess
And <br/> distance y / 2 until the inner periphery of the tapered or rounded of the protruding edge, the washer has a maximum moved radially by an outer span of clearance of inner to the circumferential groove of the washer A starter motor characterized in that the relationship with the maximum distance δ1 from the center of the armature shaft to the outer diameter of the washer at the time is represented by y / 2 <δ1 <Y / 2. 3. A washer is fitted in a circumferential groove formed at one end of an armature shaft of a starter motor, and the washer is used as an inner wall of an end portion of a bracket serving as a motor housing element (hereinafter referred to as an inner wall of the bracket). A starter motor which is clamped by a brush holder holding plate mounted on the starter motor so as to regulate the thrust direction of the armature shaft, wherein the washer is for press-fitting the washer into the circumferential groove from a radial direction. The slot is formed so as to communicate with the inner diameter of the washer. On the other hand, a small projection is provided on the washer holding surface of the inner wall of the bracket, and the small projection is engaged with the slot of the washer, thereby preventing the washer from rotating. A starter motor. 4. A washer is fitted into a circumferential groove formed at one end of an armature shaft of a starter motor, and the washer is used as a motor housing element at an end inner wall of a bracket (hereinafter, referred to as a bracket inner wall) and an inner wall of the bracket. In the starter motor, the thrust direction of the armature shaft is regulated by being held by a brush holder holding plate attached to the armature shaft, the washer is provided with a blank for matching the center of gravity of the washer with the center of gravity of the armature shaft. A starter motor, comprising: