JP2020198700A - Starter and assembly method of starter - Google Patents

Abstract

To solve a problem that brush sliding noise due to axis deviation of an armature or partial wear of the brush is caused in a starter depending on positioning of a base and a yoke to which the brush is attached.SOLUTION: A protrusion part for positioning in contact with a one-end-side opening-part bore of the yoke is formed in an outer peripheral part of the base, and a bearing holding part holding a bearing which rotatably supports the armature is provided in a central part of the base.SELECTED DRAWING: Figure 2

Description

The present application relates to a starter.

Generally, in a DC motor such as a starter for starting an engine, a rectifying action is obtained by a commutator installed at the end of the armature shaft and a brush installed in the outer peripheral direction of the commutator.
The brush is slidably stored in the brush holder, and an electric motor having a brush holding device in which the brush holder is attached to the base by sliding contact while being pressed against the outer peripheral surface of the commutator by a spring also stored in the brush holder. It is known (see, for example, Patent Document 1).

JP-A-2009-71925

However, in the starter of Patent Document 1, a bearing that rotationally supports the armature shaft is installed in the rear bracket, and the brush that is in sliding contact with the outer peripheral surface of the commutator is held by the base via the brush holder, and the base and the base. It is configured to be fixed by tightening the rear bracket with screws. In this configuration, after positioning the base on the yoke, the rear bracket is positioned and fixed to the base. Therefore, if the base and the yoke cannot be positioned stably, the bearing and the yoke provided on the rear bracket will be used. Position accuracy deteriorates. Due to this effect, the load that presses the brush against the outer peripheral surface of the commutator by the spring is unbalanced, which causes noise due to vibration or uneven wear of the brush.
Further, as a method of directly positioning the rear bracket on the yoke, there is also known a method of positioning the rear bracket on the yoke by penetrating the base with a convex portion formed on the rear bracket. However, in order to achieve this, it is necessary to increase the thickness of the rear bracket, which has been a factor in increasing the weight and cost.

The present application has been made to solve the above problems, and aims to provide a lightweight and low-cost starter while suppressing noise caused by misalignment between the brush and the commutator and uneven wear of the brush. To do.

The starters disclosed in this application are:
A cylindrical yoke that forms a magnetic circuit, an armature that generates rotational torque due to the magnetic flux from this yoke, a commutator that is installed coaxially with the rotation axis of the armature, and a commutator that forms a sliding surface on the outer periphery. It is equipped with a brush that is pressed and slidably contacted with the sliding surface of the armature by a spring from the outer peripheral direction, a brush holder that stores the brush and the spring, and a disk-shaped base that holds the brush holder. It is characterized by having a protrusion for positioning in contact with the inner diameter of the opening on one end side of the yoke, and a bearing holding portion for holding a bearing that rotatably supports the armature at the center of the base.

According to the starter disclosed in the present application, the base and the yoke can be stably positioned by providing the protrusion. As a result, the axial misalignment between the armature and the brush can be eliminated, and the brush sliding noise and the occurrence of brush uneven wear can be suppressed. In addition, it is not necessary to increase the thickness of the rear bracket, which makes it possible to reduce the weight and cost.

It is a partial cross-sectional view of the starter of Embodiment 1. FIG. It is a perspective view of the base of Embodiment 1. FIG. It is a perspective view of the brush holding device of Embodiment 1. FIG.

Hereinafter, preferred embodiments of the starter according to the present application will be described with reference to the drawings. The same contents and corresponding parts are designated by the same reference numerals, and detailed description thereof will be omitted.

Embodiment 1.
FIG. 1 is a partial cross-sectional view showing the configuration of the starter according to the first embodiment. The starter includes a solenoid switch 1, a motor unit 2, a front bracket 18, and a rear bracket 6. The rear bracket 6 and the front bracket 18 are connected by a through bolt 16, and the motor portion 2 is sandwiched and fixed. A transmission mechanism unit (not shown) that transmits the rotational force generated by the motor unit 2 to the engine is mounted in the front bracket 18.

The motor unit 2 has a cylindrical yoke 4 forming a magnetic circuit, an armature 7 in which a rear bracket 6 is fitted into an opening on one end side of the yoke 4, an armature 7 housed therein, and an armature that is an axis of the armature 7. A shaft 8, a commutator 9 installed at the end of the armature shaft 8, and a brush 10 that slides on the outer periphery of the commutator 9 are provided. Further, the brush holding device 20 is composed of a spring 11 that urges the brush 10 on the outer peripheral side of the commutator 9, a brush holder 12 that holds the brush 10, and a disk-shaped base 13 to which the brush holder 12 is fixed.

Next, the operation of the starter of the present application will be described. When the solenoid switch 1 is turned on, a current is supplied from the battery (not shown) to the armature coil 3 via the brush 10 and the commutator 9. The current flowing through the armature coil 3 interlinks with the magnetic flux from the magnet 5 installed in the yoke 4 to generate a rotational force, and the armature 7 rotates. When the armature 7 rotates, rectification is performed by the commutator 9 disposed integrally with the armature 7 and the brush 10 sliding on the outer peripheral surface of the commutator 9.

FIG. 2 is a perspective view of the base 13. The base 13 is formed with a pair of guide walls 13f that are cut up from the base 13 and bent into a hook shape (L-shape) for assembling the brush holder 12. The pair of guide walls 13f are provided at predetermined intervals in the circumferential direction of the base 13, and both are bent in a direction facing each other in the circumferential direction to form a slide groove 13a inside. The bottom plate portion of the brush holder 12 is inserted into the slide groove 13a.

A plurality of protrusions 13b are installed in the vicinity of the outer periphery of the base 13. The protrusions 13b are formed in a convex shape extending in the circumferential direction, and the outer peripheral side formed in the convex shape of the protrusions 13b and the yoke. When the inner diameter of the opening of 4 is in surface contact with a certain width, the base 13 is positioned and the movement of the base 13 to the outside in the radial direction of the yoke 4 is prevented. In this state, the base 13 and the opening on one end side of the yoke 4 are brought into contact with each other. After that, the rear bracket 6 is covered from above, and the rear bracket 6 and the front bracket 18 are connected by the through bolt 16, so that the base 13 is sandwiched between the rear bracket 6 and the yoke 4. As a result, the base 13 is fixed. Further, in the central portion of the base 13, a bearing holding portion 13c formed of a hole formed by burring in the armature 7 direction is formed. As a result, the bearing 14 that rotationally supports the armature shaft 8 can be held. In FIG. 2, the bearing holding portion 13c is provided on the armature 7 side, but the same effect can be obtained by providing the bearing holding portion 13c on the rear bracket 6 side.

Further, a through hole 13e for inserting a jig 15 for temporarily fixing the brush holder 12 is formed between the guide wall 13f of the base 13 and the bearing holding portion 13c.

Next, the assembly process of the brush holding device 20 will be described with reference to FIGS. 2 and 3. First, with the spring 11 and the brush 10 inserted inside the four brush holders 12, the four brush holders 12 are assembled to the base 13. At this time, the brush holder 12 inserts the bottom plate portion into the slide groove 13a between the pair of guide walls 13f from the outer peripheral side or the inner peripheral side of the base 13.

As shown in FIG. 3B, the jig 15 is inserted into the through hole 13e from the lower part, and the leg portion 15a extending from the jig 15 comes into contact with the brush 10. As a result, the brush 10 urged by the spring 11 in the direction of coming out of the brush holder 12 is held. Further, the brush holder 12 is fixed to the base 13 by cutting up the retaining 13d which is a part of the base 13 so that the brush holder 12 does not come off from the base 13 in the outer peripheral direction due to the reaction force of the spring 11.

With such a configuration, the brush holder 12 is positioned. After that, when assembling the starter, the jig 15 is pulled out downward while inserting the commutator 9 from above. With such a configuration, the jig 15 can be easily inserted and removed even in the base 13 on which the bearing holding portion 13c is formed, as compared with the comparative example shown in FIG. 3A in which the side surface of the jig 15 comes into contact with the brush 10. Can be done.

In this way, the brush holding device 20 has a shape in which the base 13 is provided with through holes 13e for each brush 10, and the starter is assembled by inserting the jig 15 into the through holes 13e for assembly provided in the base 13. Previously, it can be configured in the same way as before, and workability does not deteriorate.

The protrusions 13b have a configuration in which convex portions are formed at four locations in FIG. 2, but two convex portions having a length sufficient for positioning are installed at opposite positions of the base 13. But it may be. When installing at three places, the protrusion 13b may be located at the apex of an equilateral triangle or an isosceles triangle. Further, it is possible to install the protrusions 13b at four or more places. Further, the protrusions 13b may be formed by arranging a plurality of protrusions having a length shorter than that of the convex portions at regular intervals in the circumferential direction of the base 13.

By configuring the brush holding device 20 as described above, the base 13 and the yoke 4 are positioned by the protrusions 13b, so that the base 13 and the yoke 4 can be stably positioned, and the rear bracket 6 can be used. The positional accuracy between the provided bearing and the yoke 4 is no longer deteriorated. As a result, the load that presses the brush 10 against the outer peripheral surface of the commutator 9 by the spring 11 is not unbalanced, and the generation of noise due to vibration and the uneven wear of the brush 10 are eliminated.

Further, even in the configuration in which the bearing 14 that supports the axial rotation of the armature 7 is held in the rear bracket 6, by configuring the bearing holding portion 13c in the base 13, the rear bracket 6 has a cylindrical bearing holding portion. It becomes unnecessary, and the processing process can be simplified and the number of members can be reduced.

Further, in order to position the rear bracket 6 directly on the yoke 4, it is necessary to increase the thickness of the rear bracket 6 in order to form a convex portion penetrating the base 13, but the protrusion on the base 13. By providing the portion 13b, it is not necessary to increase the thickness, the weight can be reduced, and the rear bracket 6 can be easily processed, resulting in low cost.

Although exemplary embodiments are described in the present application, the various features, embodiments, and functions described in the embodiments are not limited to the application of a particular embodiment, either alone or. It can be applied to embodiments in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted.

1: Solenoid switch, 2: Motor part, 3: Armature coil, 4: Yoke, 5: Magnet, 6: Rear bracket, 7: Armature, 8: Armature shaft, 9: Commutator, 10: Brush, 11 : Spring, 12: Brush holder, 13: Base, 13a: Slide groove, 13b: Protrusion, 13c: Bearing holder, 13d: Retainer, 14: Bearing, 15: Jig, 16: Through bolt, 18: Front Bracket, 20: Brush holder

The starters disclosed in this application are:
A cylindrical yoke that forms a magnetic circuit, an armature that generates rotational torque due to magnetic flux from this yoke, a commutator that is installed coaxially with the armature's rotation axis and forms a sliding surface on the outer periphery, and a commutator. It is equipped with a brush that is pressed and slidably contacted with the sliding surface of the armature by a spring from the outer peripheral direction, a brush holder that stores the brush and the spring, and a disk-shaped base that holds the brush holder. A bearing holder that holds a bearing that rotatably supports the armature, consisting of a protrusion for positioning that contacts the inner diameter of the opening on one end of the yoke and a hole formed by burring in the center of the base. It is characterized by having and.

Claims (4)

A cylindrical yoke forming a magnetic circuit, an armature that generates rotational torque by magnetic flux from the yoke, a commutator installed coaxially with the rotation axis of the armature and forming a sliding surface on the outer peripheral portion, the commutator. In a starter provided with a brush that is pressed and slidably contacted with the sliding surface of the commutator by a spring from the outer peripheral direction, a brush holder that houses the brush and the spring, and a disk-shaped base that holds the brush holder.
A bearing holder that is formed on the outer peripheral portion of the base and holds a bearing that rotatably supports the armature at the central portion of the base and a protrusion for positioning that contacts the inner diameter of the opening on one end side of the yoke. A starter characterized by having a part. In a state where the base is positioned on the yoke by the protrusion for positioning, the base abuts on one end side opening of the yoke and is sandwiched between the rear bracket that fits the yoke and the yoke. The starter according to claim 1, wherein the starter is fixed with. The starter according to claim 1 or 2, wherein the protrusion has a convex shape extending in the circumferential direction. The claim is characterized in that a through hole for attaching a jig for holding the brush is provided in the base between a guide wall for holding the brush holder provided in the base and the bearing holding portion. The starter according to any one of 1 to 3.

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