JP2004248338A - Alternator for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alternator for vehicle in which vibration of a metallic cover can be prevented and damage, e.g. cracks or chippings, can be prevented at the end part. <P>SOLUTION: The alternator for vehicle comprises a rear housing 2 for holding a rotor and a stator, electric components, e.g. a rectifier 24, fixed to the outside of the rear housing 2, and a cover 27 for covering the electric components. The cover 27 has a metallic cover body 27A, and a coating part 27B formed of a resin material softer than the cover body 27A and covering the end part of the cover body 27A. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle alternator mounted on a passenger car, a truck, and the like.
[0002]
[Prior art]
Some conventional AC generators for vehicles include a metal cover for protecting electric components such as a rectifier and a brush device (for example, see Patent Document 1). This cover is manufactured, for example, by press-forming an iron plate or an aluminum plate. However, since a thin plate material is used, the flat portion is likely to vibrate and may be a noise source. For this reason, there is a method of suppressing the vibration of the cover itself by pressing the cover end against the rear housing by assembling with an appropriate interference between the cover end and the aluminum die-cast rear housing. It has been used conventionally.
[0003]
[Patent Document 1]
JP 2001-37142 A (page 3-4, FIG. 1-3)
[0004]
[Problems to be solved by the invention]
By the way, in the conventional vehicle alternator described above, the end of the metal cover is pressed against the rear housing for the purpose of suppressing vibration, and both the cover and the rear housing, which are the pressed portions, are made of metal. It is hard and causes a large stress to be generated on the cover side made of thin plate material. Especially, when an automotive alternator is mounted on an engine that generates large vibrations, cracks or chippings occur at the end of the cover. There is a problem that damage such as the like may occur.
[0005]
The present invention has been made in view of the above points, and an object of the present invention is to provide a vehicle AC that can prevent vibration of a metal cover and prevent breakage such as a crack or a chip at an end. It is to provide a generator.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, a vehicular alternator of the present invention includes a housing for holding a rotor and a stator, an electric component attached to the outside of the housing, and a metal cover for covering the electric component. The cover includes a metal cover main body and a coating portion that covers an end of the cover main body with a material softer than the cover main body. By covering the end of the metal cover main body with a coating portion softer than the cover main body, it is possible to suppress vibration at the end and prevent breakage such as cracks and chips.
[0007]
Further, it is desirable that the above-mentioned cover is assembled in a state where the coating portion is pressed against the housing along the radial direction. Alternatively, it is desirable that the above-described cover is assembled with the coating portion pressed against the housing along the axial direction. By pressing the coating portion provided at the end of the cover against the housing in the radial direction or the axial direction, the coating portion can be absorbed and suppressed. Further, by pressing the cover end portion against the housing via the coating portion, the stress generated at the cover end portion by the coating portion is relieved, so that damage such as cracking or chipping at the cover end portion can be prevented. it can.
[0008]
Further, it is desirable that the material of the above-mentioned coating portion is a resin. Since the coating portion can be formed with a resin that is softer than the metal that is the material of the cover main body and the cover end portion can be pressed, vibration suppression and breakage of the cover can be reliably achieved.
[0009]
Further, the end of the cover and the housing are in contact with each other at a plurality of contact portions, and the coating portion is desirably formed at a plurality of locations corresponding to the plurality of contact portions. As a result, it is possible to reduce the area of the coating portion and reduce costs while realizing vibration suppression and breakage prevention of the cover.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an automotive alternator according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating an overall configuration of an automotive alternator according to an embodiment. The automotive alternator 100 shown in FIG. 1 includes a front housing 1, a rear housing 2, a stator 4, a rotor 10, a rectifier 24, a voltage controller 25, a brush device 26, a cover 27, and the like. I have.
[0011]
The front housing 1 and the rear housing 2 each have a bowl shape, and are fixed to each other by a plurality of bolts 3 in a state where their openings are in direct contact with each other. A stator 4 is fixed to the inner periphery of the front housing 1. Further, a cylindrical bearing box 7 is formed integrally with the front housing 1, and an iron bearing box 8 is attached to the rear housing 2 by bolts 9 having knurls.
[0012]
The stator 4 includes a stator core 5 and a stator winding 6.
The rotor 10 includes a field winding 11, pole cores 12, 13, a shaft 14, and the like, and is rotatably held by a pair of bearings 15, 16 fixed to bearing boxes 7, 8. Centrifugal cooling fans 17 and 18 are attached to the axial end surfaces of the pole cores 12 and 13. The cooling fan 17 on the front side is of a mixed flow type in which blades are inclined forward with respect to the rotation direction of the rotor 10 in order to generate cooling air to the field winding 11. A pulley 19 is connected to a front end of the shaft 14 by a nut 20, and is driven to rotate by a vehicle engine (not shown). Further, a pair of slip rings 21 and 22 are provided at a rear end of the shaft 14 located outside the rear housing 2, and are electrically connected to the field winding 11 via a conductor 23.
[0013]
So-called electric components such as a rectifier 24, a voltage controller 25, and a brush device 26 are fixed to the outer axial end surface of the rear housing 2 by fixing means such as bolts 9. The rectifier 24 rectifies, for example, a three-phase AC voltage, which is an output voltage of the three-phase stator winding 6, and converts it into a DC output voltage. The voltage control device 25 controls the output voltage of the vehicle alternator 100 by adjusting the exciting current flowing through the field winding 11. The brush device 26 is for passing an exciting current from the rectifier 24 to the field winding 11 of the rotor 10, and a brush that presses each of the slip rings 21 and 22 formed on the shaft 14 of the rotor 10. Is provided.
[0014]
The cover 27 is made of metal and covers and protects electrical components such as the rectifier 24, the voltage controller 25, and the brush device 26 which are attached to the outside of the rear housing 2. The cover 27 is fastened and fixed to a bolt 9 extending from the rear housing 2 by a nut 28 with the rectifying device 24 interposed therebetween. Further, the cover 27 has a cooling air introduction window formed concentrically around the brush device 26.
[0015]
In the vehicle alternator 100 having the above-described structure, when the rotational force from the vehicle engine is transmitted to the pulley 19 via a belt or the like, the rotor 10 rotates in a predetermined direction. In this state, by applying an excitation voltage to the field winding 11 of the rotor 10 from the outside, the claw portions of the pole cores 12 and 13 are excited, and a three-phase AC voltage is generated in the stator winding 6. A predetermined DC current is extracted from an output terminal provided on the rectifier 24.
[0016]
Next, details of the cover 27 will be described. FIG. 2 is a partially enlarged cross-sectional view near the side surface of the cover 27. FIG. 3 is a partially enlarged cross-sectional view near the end of the cover 27.
As shown in FIGS. 2 and 3, the cover 27 includes a metal cover main body 27A and a coating portion 27B that covers an end of the cover main body 27A. The coating portion 27B is formed of a material softer than the cover main body 27A, for example, a resin material, and covers a predetermined range of the inner peripheral surface and the outer peripheral surface from the end of the cover main body 27A.
[0017]
The inner diameter of the end of the cover 27 is slightly smaller than the outer diameter of the contact portion 2A of the rear housing 2 corresponding to the end at the time of assembly, and has a predetermined interference. Thus, when the nut 28 is tightened to the bolt 9, the cover 27 is assembled with the coating 27B at the end of the cover 27 pressed against the contact portion 2A of the rear housing 2 along the radial direction.
[0018]
As described above, by covering the end of the metal cover main body 27A with the resin coating 27B that is softer than the cover main body 27A, vibration at the end of the cover 27 can be suppressed by the coating 27B. In addition, by covering the end of the cover main body 27A with the coating portion 27B, it is possible to prevent the end from being damaged.
[0019]
In particular, in the above-described structure of the present embodiment, since the end of the cover body 27A is pressed against the contact portion 2A of the rear housing 2 via the coating portion 27B, the end of the cover body 27A is used as a fixed end for vibration. As a result, the vibration applied to the cover main body 27A from the contact portion 2A can be reduced, and the end of the cover 27 can be prevented from being broken or cracked.
[0020]
Note that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. In the above-described embodiment, the end of the cover 27 is abutted on the abutting portion 2A of the rear housing 2 in the radial direction, but may be abutted in the axial direction.
[0021]
FIG. 4 is a partially enlarged cross-sectional view near the side surface of the cover 27 in which the contact direction has been changed. FIG. 5 is a partially enlarged cross-sectional view near the end of the cover 27 shown in FIG. As shown in these drawings, the rear housing 2 is formed with a contact portion 2B having an axial end face 2C. Thus, when the nut 28 is tightened to the bolt 9, the cover 27 is assembled in a state where the coating portion 27B at the end of the cover 27 is pressed against the contact portion 2B of the rear housing 2 along the axial direction. Therefore, as in the case where the end of the cover 27 is pressed radially against the contact portion 2A of the rear housing 2, vibration can be reduced by using the end of the cover main body 27A as a fixed end of vibration, and It is possible to reduce the stress applied to the cover main body 27A from the abutting portion 2B, and it is possible to prevent the end of the cover 27 from being broken or cracked.
[0022]
In the above-described embodiment, the range in which the coating portion 27B is formed at the end of the cover main body 27A is not particularly described. In the case where the coating portions 27A are separately provided, the coating portions 27B may be dispersedly formed only at positions corresponding to the plurality of contact portions 2A and 2B. This makes it possible to reduce the area of the coating portion 27B and reduce costs while realizing vibration suppression and breakage prevention of the cover 27.
[0023]
Further, in the above-described embodiment, the case where the coating portion 27B is formed using a resin material has been described, but another material such as rubber may be used.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overall configuration of an automotive alternator according to an embodiment.
FIG. 2 is a partially enlarged cross-sectional view near a side surface of a cover.
FIG. 3 is a partially enlarged cross-sectional view near an end of a cover.
FIG. 4 is a partially enlarged cross-sectional view of the vicinity of a side surface of a cover in which a contact direction is changed.
FIG. 5 is a partially enlarged cross-sectional view near the end of the cover shown in FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front housing 2 Rear housing 2A, 2B Contact part 2C Axial end surface 4 Stator 10 Rotor 24 Rectifier 25 Voltage controller 26 Brush device 27 Cover 27A Cover main body 27B Coating part 100 Vehicle alternator

Claims (5)

In a vehicle AC generator having a housing that holds a rotor and a stator, an electric component attached to the outside of the housing, and a metal cover that covers the electric component,
The alternator for a vehicle, wherein the cover includes: the cover body made of metal; and a coating portion that is made of a material softer than the cover body and covers an end of the cover body. In claim 1,
The alternator for a vehicle, wherein the cover is assembled in a state where the coating portion is pressed against the housing along a radial direction. In claim 1 or 2,
The alternator for a vehicle, wherein the cover is assembled in a state where the coating portion is pressed against the housing along an axial direction. In any one of claims 1 to 3,
The alternator for a vehicle, wherein the material of the coating portion is a resin. In any one of claims 1 to 4,
The end of the cover and the housing are in contact at a plurality of contact portions,
The alternator for a vehicle, wherein the coating portion is formed separately at a plurality of locations corresponding to the plurality of contact portions.

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