Abstract:
An alternator (AC generator), which is to be attached to an engine mounted to a vehicle, comprises an output terminal to which one end of a cable for supplying a battery with power generated by the alternator is coupled. The battery is mounted on the vehicle. The alternator further comprises an insulator, a guide, and a direction setting member. The insulator, made from an electric insulative material, is for protecting the output terminal. The guide guides the cable along a desired direction from the output terminal. The direction setting member enables the guide to selectively set a direction among a plurality of predetermined directions along which the cable is allowed to be guided.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based on and claims the benefit of priority from earlier Japanese Patent Application No. 2005-110838 filed on Apr. 7, 2005, the description of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Technical Field of the Invention  
         [0003]     The present invention relates to an alternator (on-vehicle AC generator) which is mounted on an engine installed in a vehicle, and in particular, to an alternator equipped with a mechanism for setting a wiring direction of a cable to supply power to be outputted by the alternator.  
         [0004]     2. Related Art  
         [0005]     Most of engine-driven vehicles are generally equipped with alternators (on-vehicle AC generators), which generate power using the rotation of the engines. The alternator has a cable (output cable) connected to an on-vehicle battery and other necessary accessories, so that the alternator provides the power via the cable.  
         [0006]     Such a structure for wiring the cable is disclosed for example by Japanese. Unexamined Patent Application Publication No. 2002-010568. In the structure of this publication, an insulator for insulating and protecting an output terminal of an alternator has been positioned by providing a main unit of the alternator with an engaging portion to establish a whirl-stop mechanism for the insulator. This positioning has prevented the insulator from rotating about an axis of the output terminal when nuts for fixing the insulator and vehicle side nuts for fixing the output terminal are tightened for fixation of the insulator.  
         [0007]     The positioning in the conventional positioning structure, however, has limited the number of directions of an insulator to only one.  
         [0008]     Generally, a vehicle side cable is run differently depending on individual vehicles. Insulators having directivity, i.e. having guides for determining directions for leading (wiring) cables, and having an identical shape have thus suffered from having to be newly constructed to set the guides at proper positions for the different leading directions as required by the respective vehicles.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention has been made in view of the problem described above, and has an object of providing an alternator with which a cable can be wired to different directions without the necessity of newly producing an insulator.  
         [0010]     As one aspect of the present invention, there is provided an alternator to be attached to an engine mounted to a vehicle, comprising: an output terminal to which one end of a cable for supplying a battery with power generated by the alternator is coupled, the battery being mounted on the vehicle; an insulator, made from an electric insulative material, for protecting the output terminal; a guide guiding the cable along a desired direction from the output terminal; and a direction setting member enabling the guide to selectively set a direction among a plurality of predetermined directions along which the cable is allowed to be guided.  
         [0011]     Since the alternator of the present invention can cope with a plurality of directions for wiring (leading) a cable through the guide, a new insulator does not have to be built every time a different leading direction is demanded. Thus the one type of insulator is enough for different vehicles, so that the insulator can be enhanced in versatility.  
         [0012]     By way of example, the direction setting member include engaging portions which enable both the insulator and a component fixed in the Alternator to be engaged with each other in a condition where the direction is selectively set.  
         [0013]     In the alternator of the present invention, the recesses and projections of the engaging portion of the alternator and the insulator, respectively, enable mounting of the insulator at any desired engageable position so as to cope with a plurality of directions for leading a cable through the guide. At the same time, the insulator can be prevented from rotating about an axis of the vehicle side output terminal when nuts for fixing the insulator and nuts for fixing the output terminal are tightened for fixation of the insulator. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     In the accompanying drawings:  
         [0015]      FIG. 1  is a partly broken cross section showing the structure of an alternator (on-vehicle AC generator) according to an embodiment of the present invention;  
         [0016]      FIG. 2  is a side elevation of the alternator according to the embodiment, as viewed from a rear cover thereof;  
         [0017]      FIG. 3  is a side view showing an engaging portion of a first rectifier block composing part of a rectifying device installed in the alternator according the embodiment, the side view being viewed from a thickness direction of the block;  
         [0018]      FIG. 4  is a side view showing an engaging portion of an insulator installed in the alternator according to the embodiment, the side view being viewed from a thickness direction of the insulator;  
         [0019]      FIG. 5  is a side view explaining an assembly between the first rectifier block and the insulator;  
         [0020]      FIG. 6  is a side view taken along a VI-VI line in  FIG. 5 ; and  
         [0021]      FIG. 7  is an illustration for engaging portions between a rectifier block and an insulator, which is according to a variation of the structure shown in  FIG. 6 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]     Hereinafter is described in detail an embodiment of an alternator (i.e., on-vehicle AC generator) to which the present invention has been applied, with reference to the accompanying drawings.  
         [0023]      FIGS. 1 and 2  each show a general configuration of the alternator according to the embodiment.  
         [0024]     An alternator  100  includes a front housing  1 , a rear housing  2 , a stator  4 , a rotor  10 , a rectifying device  24 , a voltage control unit  25 , a brush device  26 , and a cover  27 .  
         [0025]     Both of the front housing  1  and the rear housing  2  have a bowl-shaped form, and are linked and fixed together through a plurality of bolts  3  with their opening portions being in direct contact with each other. The stator  4  is fixed to an inner periphery of the front housing  1 . A cylindrical bearing box  7  is integrated into the front housing  1 , and an iron bearing box  8  is attached to the rear housing  2  through a bolt  9  having a knurl.  
         [0026]     The stator  4  includes a stator iron core  5  and a stator coil  6 .  
         [0027]     The rotor  10  includes a field magnet coil  11 , pole cores  12 ,  13  and a shaft  14 , and is rotatably held by a pair of bearings  15 ,  16  which are fixed to the bearing boxes  7 ,  8 , respectively. Centrifugal cooling fans  17 ,  18  are attached to axial end faces of the pole cores  12 ,  13 , respectively. The front side cooling fan  17  is a mixed flow type fan with its blades being inclined forward with respect to the rotational direction of the rotor  10  so as to produce cooling air toward the field magnet coil  11 . A pulley  19  is coupled to a front end of the shaft  14  by means of a nut  20 , and rotated and driven by a vehicle engine, not shown. A pair of slip rings  21 ,  22  is provided at a rear end of the shaft  14  extending out of the rear housing  2 , and is electrically connected to the field magnet coil  11  through a conductor  23 .  
         [0028]     So-called electrical components, such as the rectifying device  24 , the voltage control unit  25  and the brush device  26  are fixed to an outer axial end face of the rear housing  2 , by using fixing means, such as the bolt  9 . The rectifying device  24  rectifies an output voltage of the three-phase stator coil  6 , or a three-phase AC voltage, for example, for conversion into a DC output voltage. The voltage control unit  25  controls the output voltage of the alternator  100  by controlling an exciting current that flows through the field magnet coil  11 . The brush device  26  is to flow the exciting current from the rectifying device  24  to the field magnet coil  11  of the rotor  10 , with a suppression brush being provided to each of the slip rings  21 ,  22  formed at the shaft  14  of the rotor  10 .  
         [0029]     The cover  27 , which is made of metal, covers and protects the electrical components, such as the rectifying device  24 , the voltage control unit  25  and the brush device  26 , which are attached to the outer face of the rear housing  2 . The cover  27  is fixed to the bolt  9  extending from the rear housing  2  by tightening a nut  28 , with the rectifying device  24  being clamped therebetween. The cover  27  has, in the vicinity of the brush device  26 , a window for introducing cooling air.  
         [0030]     In the alternator  100  having the configuration described above, when torque is transferred to the pulley  19  from the vehicle engine through a belt or the like, the rotor  10  rotates in a predetermined direction. In this state, with the application of the exciting voltage from outside onto the field magnet coil  11  of the rotor  10 , a claw portion of each of the pole cores  12 ,  13  is excited to enable generation of a three-phase AC voltage in the stator coil  6 , thereby taking out a predetermined DC current from a cylindrical output terminal  29  provided at the rectifying device  24 .  
         [0031]     A resin insulator  30  for insulating and protecting the output terminal  29  is engaged with and fixed to the alternator main unit GB by tightening a nut  31 . The alternator main unit GB is defined as, of the alternator  100 , a main body other than the insulator  30 . It should be noted that the insulator  30  is integrally provided with a guide  30 A for leading a cable CB (refer to  FIG. 5 ) connected to the output terminal  29  to a predetermined direction.  
         [0032]     Engaging portions of both the insulator  30  and the rectifying device  24  arranged in the alternator main unit GB will now be described.  
         [0033]     As shown in  FIGS. 3, 4  and  5 , the rectifying device  24  is provided with a first and second rectifier blocks  241  and  242 , each of which is formed into a substantially semi-annular plate and fixedly arranged around the shaft  14  in an approximately perpendicular attitude to the shaft  14 . Each of the first and second rectifier blocks  241  and  242  is an approximately semi-annular plate-like radiator FN and a plurality of rectifiers DD, arranged on the radiator FN, which performs the foregoing rectifying function.  
         [0034]     Of the first and second rectifying blocks  241  and  242 , one rectifying block, which is the first rectifying block  241  positioned nearer to the outside in the axial direction of the shaft  14 , has one end portion, which is extended by a plate-like, paddle-shaped extension member  40  in such a manner that the block  241  forms a unified single plate. In the present embodiment, the extension member  40  is part of the first rectifying block  241 .  
         [0035]     At one end of this extension member  40 , a resin-made engaging portion  24 A is formed on one wall surface in the thickness direction thereof, so as to serve as a rectifying-device-side engaging portion, where the portion  24 A is almost plate-like and round-shape. A through-hole  24 C with a predetermined radius is formed to pass through this engaging portion  24 A such that there is left an annular circumferential portion  24 B centered at a predetermined position at the engaging portion  24 A. Along an inner circumferential surface of this engaging portion  24 A, a protrusion-like portion (teeth)  24 D consisting of recesses and protrusions arranged at intervals along the inner circumferential surface.  
         [0036]     On the other hand, as shown in  FIG. 4 , the insulator  30  has the foregoing guide  30 A united with the insulator  30  and formed to extend from a side wall which can be seen when being installed. In addition, on the bottom of the insulator  30 , there is formed a resin-made engaging portion  30 B on the outer surface of the bottom. Both the guide  30 A and the engaging portion  30 B are integrally formed with the main body of the insulator  30  to form the resin-made insulator  30 . Alternatively, the guide  30 A and engaging portion  30 B may be formed as separate members, respectively, and then rigidly secured to the main body of the insulator  30 .  
         [0037]     The engaging portion  30 B is formed to have a through-hole  30 D whose radius is a predetermined value and whose center is located at the center of the bottom, such that there is left an approximately annular circumferential portion  30 C. That is, through both the bottom of the inverter  30  and the engaging portion  30 B, the through-hole  30 D is formed to pass therethrough along the axial direction of the shaft  14 . Along the outer circumferential surface of the circumferential portion  30 C, a recess-like portion (teeth)  30 E consisting of recesses and protrusions arranged at intervals along the circumferential direction. The recesses and protrusions are designed to be engageable with the recesses and protrusions (teeth) of the engaging portion  24 A. placed on the foregoing first rectifier block  241 .  
         [0038]     Thus, to allow the output terminal  29  to be inserted through the bottom of the insulator  30 , the recess-like portion  24 D of the extension member  40  extended from the first rectifier block  241  is subjected to a coaxial insertion of the protrusion-like portion  30 E of the insulator  30 . During this inserting operation, an engaging angle between the recess-like portion  24 D and the protrusion-like portion  30 E can be s adjusted in such a manner that the angle of the output terminal  29  around the axial direction thereof, that is, the wiring direction of the output cable CB agrees with a desired wiring direction derived from a request on vehicle conditions.  
         [0039]     In this way, the recesses and protrusions of the recess-like portion  24 D are arranged at equal pitches on the circumferential surface of the engaging portion  24 A on the side of the rectifying device  24 .  
         [0040]     Meanwhile the insulator  30  has the recesses and protrusions composing the protrusion-like portion  30 E, which is engageable with the recess-like portion  24 D. Hence as shown in  FIGS. 5 and 6 , the insulator  30  can be set at any engageable angular position in relation to the engaging portion  24 , that is, the main body BD of the alternator, which makes it possible that the guide  30 A of the insulator  30  can be oriented in a desired wiring direction depending on a request coming from vehicle design conditions.  
         [0041]     In short, when the engaging portion  30 B of the insulator  30  is made to be engaged with the engaging portion  24 A of the rectifying device  24 , the engaging angle (i.e., an angle around the axis of the output terminal  29 ) can be adjusted arbitrarily, with the result that the guide  30 A can be located selectively at a desired angle in an angular range of  30 A( 1 ),  30 A( 2 ), . . . . This angular positioning can be executed selectively around 360 degrees, though it is at pitches. Accordingly, if the guide  30 A is changed, i.e., the wiring direction from the output terminal  29  is changed, the insulator  30  of one type is still enough for different wiring directions of the cable CB, thus providing a higher so versatility to the insulator  30 .  
         [0042]     Further, while the engagement between the recess-like portion  24 D and the protrusion-like portion  30 E allows the insulator  30  to be fixed, the rotations around the output terminal  29 , which occur during tightening of the nut  31 , can also be avoided steadily.  
         [0043]     Moreover, the recess-like portion  24 D and protrusion-like portion  30 E are engaged with each other at predetermined pitches over their circumferential directions. This provides high resistance against the foregoing tightening operation. Thus, even when the engaging portions  24 A and  24 B both are made of resin, like the foregoing embodiment, the portions can bear high tightening pressure.  
         [0044]     The foregoing configurations may still be modified into various other forms. For example, though the foregoing embodiment provides the arrangement of both the recess-like portion  24 D and the protrusion-like portion  30 E which are arranged at equal intervals along each circumferential direction, this is not a decisive list. As long as the guide  30 A may be set in different directions, the arrangement of both the recess like portion  24 D and the protrusion-like portion  30 E is not always limited to the equal intervals. By way of example, as shown in  FIG. 7 , those recess-like portion  24 D and protrusion-like portion  30 E can be localized in different plural regions along their circumferential directions, where one or more engaging teeth are formed region by region. It is therefore possible that options for the wiring direction are obtained depending on the number of regions each subjected to formation of the engaging teeth. Meanwhile, the shapes of the recess-like portion  24 D and the protrusion-like portion  30 E are not necessarily confined to rectangles in section. For example, those of the portions  24 D and  30 E may be triangular in section.  
         [0045]     The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment and modifications are therefore to be considered in all respects as illustrative and not restrictive, the scope of the present invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.