JP3794366B2 - AC generator for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle AC generator mounted on a passenger car, a truck, or the like.
[0002]
[Prior art]
Conventionally, extraction of output power from a vehicular AC generator is performed using an output terminal provided in a rectifier circuit. For example, in an automotive alternator disclosed in Japanese Patent Application Laid-Open No. 9-107654, a resin bushing is attached around an output terminal for the purpose of insulation protection, and a nut for tightening and fixing the bushing; Further, the output line is attached by sandwiching a terminal provided at the end of the output line with another nut attached to the outside thereof.
[0003]
However, in such a structure in which a resin bushing is tightened with a nut, the bushing tends to shrink in the pressurizing direction over many years of use, and thus there is a disadvantage that the nut for tightening tends to loosen. As a conventional technique for avoiding this inconvenience, a generator disclosed in Japanese Patent Laid-Open No. 4-165949 is known. In this generator, a part of the + side heat sink (radiation fin) of the rectifier circuit provided for taking out the output power is protruded to a part of the output terminal, and the nut attached to the output terminal is an end of the protruding part. It has a structure which makes it contact | abut directly. Further, a resin bushing as a protective member is attached so as to cover the protruding portion from the outer peripheral side.
[0004]
[Problems to be solved by the invention]
By the way, in the structure in which a part of the + side heat sink of the rectifier circuit is protruded and its end is in contact with the nut, it is not easy to fix the bushing as a protective member of the output terminal arranged in the periphery thereof. was there. For example, in order to prevent the bushing from falling off and rotating, a part of the nut or a part of the washer tightened by the nut is partially engaged with the bushing to fix the bushing (FIG. 5 of the publication). However, since the pressure applied to the nut changes due to the deformation of the bushing and the nut is easily loosened, it is not a preferable fixing method for the bushing. Further, when a convex portion is formed on a part of the outer peripheral surface of the bushing and the convex portion is fitted into a concave portion provided on a resin terminal block to fix the bushing (FIG. 6 of the same publication). ), It is necessary to form a concave portion or a convex portion in each component, which leads to an increase in component cost, and is not a preferable fixing method when mass production is considered. For example, in the terminal block facing the bushing, it is necessary to form a recess in a part of the inner peripheral surface facing the convex portion of the bushing. This is not easy, and not only the shape of the mold but also the manufacturing process becomes complicated, which increases the cost of parts.
[0005]
The present invention was created in view of the above points, and an object of the present invention is to provide an AC generator for a vehicle that can easily fix a protective member of an output terminal.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, an automotive alternator according to the present invention provides a rear cover that covers a part of a protective member together with the rectifier circuit when the periphery of the output terminal provided in the rectifier circuit is insulated and protected by the protective member. The protective member is fixed by covering with. Since a part of the protective member arranged around the output terminal protruding from the inside of the rear cover to the outside is located inside the rear cover, the protective member can be easily fixed by using this part. be able to.
[0007]
Moreover, it is desirable to perform fastening of the fixing member which attaches an output line to the output terminal mentioned above without a protection member. Since the protective member is not tightened by a fixing member such as a nut to which the output line is attached, loosening of the fixing member when the protective member is deformed due to long-time use or the like can be prevented.
[0008]
Further, it is desirable to fix the protective member by forming an engaging portion on a part of the outer peripheral surface of the protective member and engaging a part of the edge of the rear cover with the engaging portion. Forming the engaging portion on the outer peripheral surface of the protective member can be dealt with by a simple mold shape change and the like, and the edge shape of the rear cover corresponding to the engaging portion can be easily changed. Manufacture is easy, and it is possible to suppress an increase in component costs.
[0009]
In addition, it is desirable to restrict movement of the protective member along the output terminal by covering a part of the protective member with the rear cover. By restricting the movement along the output terminal, it is possible to prevent the protective member from falling off from the periphery of the output terminal even when the protective member is not tightened by the fixing member that attaches the output line to the output terminal. .
[0010]
Further, it is desirable to constrain the rotation operation around the output terminal by covering a part of the protective member with the rear cover. Since the movement in the rotation direction can be restrained, the position in the rotation direction can be easily set even if the protection member has irregularities for positioning the output line, etc. Assembly work is easy. In particular, it is desirable to form the engaging surface of the engaging portion formed on the outer peripheral surface of the protection member so as to intersect at an angle other than a right angle with respect to the axis of the output terminal. By bringing the engaging surface into contact with the rear cover, the protective member can be prevented from rotating around the output terminal, and positioning in the rotational direction is facilitated.
[0011]
In addition, it is desirable to form a constraining facing part that restrains the rotation of the protective member on a part of the frame to which the rectifier circuit is attached, and to engage a part of the outer peripheral surface of the protective member with the constraining facing part. . By making a part of the frame and a part of the protective member face each other, the protective member can be reliably prevented from rotating around the output terminal, and positioning in the rotational direction can be performed more easily.
[0012]
Further, it is desirable to form the rear cover from a resin material. Since the protective member used for the purpose of insulation protection is formed using a resin material, the hardness of the rear cover is made close by forming the rear cover using the resin material. Therefore, abnormal wear of only one component due to vibration of the contact surface of the protective member or the like can be prevented. In addition, since the resin rear cover can easily expand the contact area with the protective member,
By reducing the applied pressure per unit area of the contact surface, the wear of the contact surface can be further reduced.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an AC generator for a vehicle according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.
[0014]
FIG. 1 is a cross-sectional view showing the overall configuration of an automotive alternator. The vehicle alternator 1 shown in FIG. 1 includes a stator 2, a rotor 3, a brush device 4, a rectifier circuit 5, a frame 6, a rear cover 7, a pulley 8, and the like.
[0015]
The stator 2 includes a stator core 21 and three-phase stator windings 23 wound around a plurality of slots 22 formed in the stator core 21 at a predetermined interval.
[0016]
The rotor 3 has a structure in which a field winding 31 in which an insulated copper wire is wound cylindrically and concentrically is sandwiched from both sides through a shaft 33 by a pole core 32 having six claws. Have. Further, an axial flow type cooling fan 34 is attached to the end face of the pole core 32 on the front side by welding or the like in order to discharge the cooling air sucked from the front side in the axial direction and the radial direction. Similarly, a centrifugal cooling fan 35 is attached to the end surface of the pole core 32 on the rear side by welding or the like in order to discharge the cooling air sucked from the rear side in the radial direction.
[0017]
The brush device 4 is for passing an exciting current from the rectifier circuit 5 to the field winding 31 of the rotor 3 and presses the flip rings 36 and 37 formed on the shaft 33 of the rotor 3. Brushes 41 and 42 are provided.
[0018]
The rectifier circuit 5 is for rectifying a three-phase AC voltage, which is an output voltage of the three-phase stator winding 23, to obtain a DC output power, a terminal block 51 including wiring electrodes therein, A positive-side radiating fin 52 and a negative-side radiating fin 53 each having three rectifying elements attached thereto, and an output terminal 54 attached to the positive-side radiating fin 52 and used for taking out output power to the outside It has. Three-phase full-wave rectification is performed by a total of six rectifying elements attached to the radiation fins 52 and 53. A resin bushing 9 is provided around the output terminal 54 as a protective member for the purpose of insulation protection. The detailed shape of the bushing 9 and the details of the mounting structure will be described later.
[0019]
The frame 6 accommodates the stator 2 and the rotor 3, is supported in a state where the rotor 3 can rotate around the shaft 33, and a predetermined gap is provided on the outer peripheral side of the pole core 32 of the rotor 3. The stator 2 arranged via is fixed. The frame 6 is provided with a cooling air discharge window 61 at a portion facing the stator winding protruding from the axial end surface of the stator core 21 and a cooling air suction window 62 at the axial end surface. .
[0020]
The rear cover 7 covers and protects the brush device 4, the rectifier circuit 5 and the IC regulator (not shown) that are attached to the outside of the frame 6 on the rear side. In the present embodiment, a rear cover 7 in which an iron plate is inserted in part for reinforcement and the other part is formed of a resin material is used.
[0021]
In the vehicle alternator 1 having the above-described structure, the rotor 3 rotates in a predetermined direction when a rotational force from an engine (not shown) is transmitted to the pulley 8 via a belt or the like. In this state, by applying an excitation voltage from the outside to the field winding 31 of the rotor 3, each claw portion of the pole core 32 is excited, and a three-phase AC voltage can be generated in the stator winding 23. DC output power is taken out from the output terminal 54 of the rectifier circuit 5.
[0022]
Next, the details of the shape and mounting structure of the bushing 9 arranged around the output terminal 54 will be described. FIG. 2 is a cross-sectional view in which the periphery of the output terminal 54 is cut in the axial direction (longitudinal direction) of the output terminal 54. FIG. 3 is a side view of the bushing 9. FIG. 4 is a front view of the bushing 9. FIG. 5 is a perspective view showing a state in which the bushing 9 is attached to the output terminal 54. FIG. 6 is a perspective view showing a partial shape of the rear cover 7 corresponding to the bushing 9.
[0023]
As shown in FIG. 2, the output terminal 54 has a knurl formed in the vicinity of the root portion thereof, and after passing the knurl through a through hole provided in an end portion of the radiating fin 52 on the positive electrode side, a metal nut By tightening at 55, the heat radiating fins 52 are attached. The length of the nut 55 along the axial direction of the output terminal 54 is set to be longer than the length of the opposing portion of the bushing 9, and when the bushing 9 is attached, one end face 56 of the nut 55 is attached to the bushing 9. It protrudes outward from the end surface 91 of the. For this reason, when the output line 92 is fixed to the end surface 56 by the nut 93 as a fixing member, only the nut 55 formed of a metal material is interposed between the output line 92 and the heat-radiating fin 52 on the positive electrode side. Thus, loosening of the nut 93 due to shrinkage or the like as in the case of interposing a resin material can be prevented.
[0024]
The bushing 9 has a cylindrical shape having an inner diameter dimension substantially equal to the outer diameter of the nut 55 used for attaching the output terminal 54, and a curved surface shape with a curved surface is formed on a part of the outer peripheral surface thereof. A flange 93 is formed. The flange 93 has a non-circular shape, and is formed with a linear portion 94 that faces the frame 6 on the rear side. It is possible to prevent the bushing 9 from rotating about the output terminal 54 as an axis by engaging a part or all of the straight line portion 94 with a constraining facing portion 63 formed on the facing surface of the frame 6. it can. In particular, as shown in FIG. 4 and the like, when the groove portion 95 for positioning and turning prevention of the output line 92 is formed on the end surface 91 of the bushing 9, it is necessary to set the mounting angle accurately. Such rotation prevention means is particularly effective.
[0025]
In this embodiment, in order to prevent such rotation, the straight portion 94 is formed on a part of the flange 93 of the bushing 9, but it is not always necessary to have a straight portion. You may make it form the convex part etc. in which the surface shape was formed in the curved surface in a part of outer peripheral surface. The same applies to the constraining facing portion 63 formed on the frame 6, and any shape may be used as long as a part of the outer peripheral surface interferes when the bushing 9 rotates. .
[0026]
The flange 93 formed on the outer peripheral surface of the bushing 9 is formed so that the angle of the surface is inclined at an angle other than a right angle with respect to the axis of the output terminal 54. When the rear surface of the rear cover 7 is brought into surface contact with the flange 93, the rotation of the bushing 9 is restrained by the tightening margin between the flange 93 and the rear cover 7 caused by the inclination of the surface of the flange 93. As described above, since the linear portion 94 formed on a part of the flange 93 is also provided for the purpose of preventing the bushing 9 from rotating, only one of these two means for preventing rotation is provided. You may make it employ | adopt. For example, when the distance between the frame 6 and the bushing 9 is long, it is preferable to prevent rotation by inclining the surface of the flange 93. In order to prevent the bushing 9 from rotating in a state where there is almost no play, it is preferable that a part of the outer peripheral surface of the bushing 9 is engaged with the constraining facing portion 63 of the frame 6.
[0027]
A recess 71 corresponding to the outer diameter shape of the bushing 9 is formed in the rear cover 7, and when the rear cover 7 is attached to the vehicle alternator 1, the edge 72 of the recess 71 is the entire flange 93 of the bushing 9. By covering from the outside, it is possible to restrain the bushing 9 from the outside and prevent the bushing 9 from falling off along the output terminal 54.
[0028]
Further, since the rear cover 7 is formed of a resin material, it is easy to increase the thickness of the edge 72 that contacts the outer peripheral surface of the bushing 9, and the contact area of this portion can be easily increased. If the contact area is increased, the applied pressure per unit area is reduced accordingly, so that the wear of the contact portion that occurs when vibration during vehicle travel is applied can be reduced. In addition, since the bushing 9 is also made of a resin material, the hardness of the rear cover 7 and the bushing 9 are relatively close to each other, and it is possible to prevent only one component from being abnormally worn when vibration is applied. it can.
[0029]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. In the embodiment described above, the resin rear cover 7 is used, but the rear cover 7 may be formed using a metal material such as aluminum or iron.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall configuration of a vehicle AC generator.
FIG. 2 is a cross-sectional view of the periphery of the output terminal cut in the axial direction of the output terminal.
FIG. 3 is a side view of the bushing.
FIG. 4 is a front view of a bushing.
FIG. 5 is a perspective view showing a state in which a bushing is attached to an output terminal.
FIG. 6 is a perspective view showing a partial shape of a rear cover corresponding to a bushing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle alternator 2 Stator 3 Rotor 4 Brush device 5 Rectifier circuit 6 Frame 7 Rear cover 9 Bushing 54 Output terminal 63 Opposing part for restraint 93 Flange 94 Straight line part

Claims (4)

A frame that houses the stator and the rotor, a rectifier circuit that is attached to the frame and has an output terminal that extracts output power, and the output terminal are provided through a gap to insulate the periphery of the output terminal In a vehicle AC generator comprising a protective member for protection and a rear cover provided at a position covering at least the rectifier circuit,
The protective member has a cylindrical shape, and has a non-circular flange having a curved surface with a curved surface on a part of the outer peripheral surface thereof,
By engaging this flange with a constraining opposing portion formed on the opposing surface of the frame, the protective member is prevented from rotating around the output terminal as an axis, and a part of the frame and the flange By engaging a part of the edge of the rear cover, the protective member is fixed so that the movement operation along the output terminal is restrained ,
The flange is formed such that the angle of the surface thereof is inclined at an angle other than a right angle with respect to the axis of the output terminal. The vehicle alternator is characterized in that the rotation of the protective member is restricted .   2. The vehicle alternator according to claim 1, wherein a straight portion is formed on the flange, and the straight portion is engaged with the restraining facing portion. 3. The recess according to claim 1, wherein a recess corresponding to the protection member is formed in the rear cover, and the edge of the recess covers the entire flange of the protection member from the outside, thereby restraining the protection member from the outside. A vehicle alternator characterized by the above. In any one of claims 1 to 3, a vehicle AC generator, wherein the rear cover is formed of a resin material.

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