Abstract:
An AC generator structure allows the assembly of a stator thereof to be easily automatized for rationalization of the manufacturing process, while ensuring suppression of heat generation and providing an enhanced cooling function during operation. The stator includes a core and a winding assembly having stator windings. A rotor is enclosed by the core. A rectifier device rectifies an AC power taken out from the winding assembly. In the stator, outgoing conductors form output conductor end portions and connecting conductor end portions, which are substantially parallel to the core&#39;s center axis. The connecting conductor end portions are connected to a connecting member distinct from the rectifier device and disposed offset laterally from the stator&#39;s center axis. The stator windings are interconnected in a predetermined connection pattern through the connecting member. The output conductor end portions, through which the AC power is taken out, are connected to the rectifier device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an alternating current or AC generator destined for use in an automobile or motor vehicle (hereinafter, this type generator will also be referred to as the vehicle-onboard AC generator). More particularly, the present invention is concerned with an improvement concerning an arrangement for interconnection of stator windings of the vehicle-onboard AC generator. 
     2. Description of Related Art 
     Before entering into description of the vehicle-onboard AC generator according to the present invention, technical background thereof will be reviewed in some detail for having better understanding of the concept underlying the invention. FIG. 15 is a sectional view showing a conventional AC generator which has heretofore been known. Referring to the figure, the illustrated AC generator is comprised of a housing or case  3  made of aluminum, which case includes a front bracket  1  and a rear bracket  2 . A shaft  6  is rotatably mounted on the brackets  1  and  2  by means of roll bearings within the case  3 , and a pulley  4  is mounted at one end thereof. A landaulet type rotor  7  is fixedly mounted on the shaft  6  for corotation therewith. A pair of fans  5  are fixedly secured to both surfaces, respectively, of the rotor  7  for the purpose of cooling. A stator  8  is stationarily mounted on an inner wall of the case  3 . A slip ring  9  is fixedly mounted on the shaft  6  at the other end portion thereof for supplying an electric current to the rotor  7 . A pair of brushes  10  are disposed in slidable contact with the slip ring  9 . A brush holder  11  is so disposed as to accommodate therein and support the brushes  10 . A rectifier device  12  is electrically connected to the windings of the stator  8  for rectifying an alternating current induced in the stator windings into a direct current. A heat sink  17  is physically coupled to the brush holder  11 . Further, a regulator  18  is fixedly secured onto the heat sink  17  for adjusting or regulating the magnitude of an AC voltage induced in the stator winding assembly. 
     The armature rotor  7  is composed of a rotor coil  13  through which a direct current supplied from a battery (not shown) is caused to flow for generating magnetic fluxes. A pole core is so disposed as to encase therein the rotor coil  13  and has magnetic poles formed by the magnetic fluxes. More specifically, the pole core is constituted by a first pole core member  20  and a second pole core member  21  which are complementarily meshed together for thereby constituting the pole core. 
     On the other hand, the stator  8  is constituted by a stator core  15  and stator windings (also referred to generically as the stator winding assembly)  16  each of which is formed by winding an electric conductor on the stator core  15  and in which an alternating current is induced under the effect of changing of the magnetic fluxes emanated from the rotor coil  13 . Incidentally, arrows shown in FIG. 15 represent flows of cooling air generated by the fans  5 . 
     In the vehicle-onboard AC generator implemented in the structure described above, a DC current is supplied to the rotor coil  13  from a battery (not shown) by way of the brushes  10  and the slip ring  9 , whereby magnetic fluxes are generated by the rotor coil  13 . As a result of this, the first pole core member  20  is magnetized in N-polarity while the second pole core member  21  is magnetized in S-polarity. On the other hand, the pulley  4  of the AC generator is driven by an engine such as an internal combustion engine of the motor vehicle on which the AC generator is installed, whereby the shaft  6  and hence the rotor  7  are caused to rotate in unison. Consequently, the stator windings are exposed to the rotating magnetic fields, which results in generation of an alternating current in the stator winding assembly  16  under the effect of electromagnetic induction. The alternating current as generated is supplied to the rectifier device  12  to be thereby rectified into a direct current, the magnitude of which can be adjusted by the regulator  18 . The direct current outputted from the rectifier device  12  is ultimately charged in the battery. 
     FIG. 16 is a perspective view showing a structure of the stator of the conventional AC generator, and FIG. 17 is an equivalent circuit diagram thereof. Referring to FIG. 16, the stator windings  16  are each formed by winding a round wire conductor and accommodated or housed stationarily within slots formed in the stator core  15 . As can be seen in FIG. 16, the stator winding assembly  16  is comprised of lodged portions  161  housed within the slots and coil end portions  162  projecting, respectively, beyond both ends of the stator core  15 . 
     Referring to FIG. 17, the stator windings  16  are interconnected in a star connection in order to realize a three-phase AC generator circuit. End portions of the three conductors led out from the individual windings of the stator winding assembly are connected together to form a neutral point in the form of a neutral point junction  22 . Further, interconnecting portions  23  are provided for interconnecting the conductors brought out from the stator windings and terminals of the three-phase rectifier device  12 . Further, for the purpose of taking out the output power from the neutral point junction  22 , an output power conductor  24  is electrically connected to the neutral point junction  22 , although it depends on the design conditions. In that case, the neutral point junction  22  is realized by connecting together the end portions of four electric conductors in total. 
     In this conjunction, it is further noted that in recent years, there is a tendency that a thick conductor of a large diameter is employed for forming the stator winding assembly in an attempt for implementing the three-phase AC generator having a high output capacity. To this end, a so-called bifilar-winding or W-winding in which a single winding conductor is divided into two coextensive conductors is increasingly adopted. In the case of the stator composed of the bifilar type windings, one neutral point junction  22  is provided at one location on one side, while in the case of the W-winding type, two neutral point junctions  22  have to be provided at two locations on both sides, respectively, as can be seen in FIG.  17 . In any case, the output power conductors  24  have to be brought out from the neutral point junction(s)  22 . 
     The output power conductor  24  mentioned above is made of tough pitch copper, and each joint forming the interconnecting portion is realized by soldering. After the soldering, the conductor portions forming the neutral point junction  22  are encased within an insulation tube  25 . In succession, the encased conductor portion is laid or bent along the coil end portion to be subsequently fixed by applying a varnish or the like with a view to ensuring a vibration withstanding capability. Of course, the joint described above may be realized by using heterogeneous metal, as disclosed in Japanese Patent Application Laid-Open Publication No. 115743/1995 (JP-A-7-115743). 
     In the conventional vehicle-onboard AC generator of the structure described above, when interconnection of the conductors brought out from the individual windings has to be made internally of the stator  8 , the output power conductor  24  extending from the round wire conductors have to be wired along the circumference defined by the coil end portions  162 , involving difficulty in automatization of the wiring by machine. 
     Further, since the conductor portions forming the neutral point junction  22  are encased within the insulation tube  25  and laid on and along the coil end portions  162  to be subsequently fixed by a varnish, a heat radiation property of these conductor portions is poor when compared with the conductors of other winding portions, incurring high temperature rise. Consequently, thermal deterioration of these conductor portions as well as the adjacent conductor portions is promoted, providing a major factor for degradation of the durability of the stator as a whole. 
     Besides, the process for securing the connected and tube-inserted conductors onto the coil end portion  162  is difficult to automative, providing a problem in reduction of the cost of processing or treatment. 
     In the case of the AC generator disclosed in Japanese Patent Application Laid-Open Publication No. 19119/1997 (JP-A-9-19119) a single circuit board is employed for connections/interconnections of all the conductors. In that case, the rigidness of the stator as a whole is increased remarkably, which however means that difficulty will be encountered in correcting positional misalignment between the stator and the rectifier device upon assembling the stator onto the main body of the AC generator. In many cases, the circuit board is forcibly distorted, providing a cause for degradation of the durability. Besides, the work for assembling the AC generator becomes very troublesome. In some case, the circuit board is cracked, to a great disadvantage. 
     Furthermore, the circuit board disclosed in Japanese Patent Application Laid-Open Publication No. 19119/1997 is equipped integrally with an intermediate connecting member and an output terminal member and thus poor in respect to the cooling performance, exerting adverse influence to the temperature characteristics or behavior of the rectifier device. Besides, upon occurrence of a short-circuit fault, the connecting terminal member implemented in a large length and thus exhibiting high electrical resistance gives rise to another problem that relevant molded portions are burnt under the heat generated due to a large short-circuit current. For these reasons and because of spatial restriction imposed on the circuit board, realization of the vehicle-onboard AC generator with high output capacity encounters unavoidably a limitation. 
     SUMMARY OF THE INVENTION 
     In the light of the state of the art described above, it is an object of the present invention to provide a vehicle-onboard AC generator of an improved structure which allows the process for assembling the stator of the AC generator to be easily automatized for rationalization of the AC generator manufacturing process while ensuring positive suppression of heat generation as well as enhanced cooling performance in operation of the AC generator. 
     In view of the above and other objects which will become apparent as the description proceeds, there is provided according to an aspect of the present invention a vehicle-onboard AC generator which includes a stator comprised of a stator core and a stator winding assembly including a plurality of stator windings, a rotor disposed in a state enclosed by the stator core, and a rectifier device for rectifying an AC power taken out from the stator winding assembly, wherein in the stator, a plurality of outgoing conductors forming output conductor end portions and connecting conductor end portions, respectively, are brought out substantially in parallel with a center axis of the stator core. The connecting conductor end portions are connected to an intermediate connecting member provided independently from the rectifier device and disposed on the stator at a position offset laterally from the center axis thereof. The stator windings are interconnected in a predetermined connection pattern through the medium of the intermediate connecting member. The output conductor end portions through which the AC power is taken out are connected to corresponding terminals of the rectifier device. 
     By virtue of the stator structure in which the intermediate connecting member is employed for interconnecting the stator windings in a predetermined connection pattern such as the star connection, as described above, the wiring process to be performed internally of the stator which will otherwise be required can be spared, to an advantage. More specifically, the processes for interconnection of the winding end conductors, insertion of the conductors in the insulation tubes, securing of the tube-encased conductor portions to the stator coil end portion and others which are difficult to automatize can be spared. This feature in turn contributes to rationalization of the manufacture of the vehicle-onboard AC generator, to a further advantage. To say in another way, since the wiring process which has heretofore been required can be spared owing to provision of the intermediate connecting member (or wiring terminal member) as the terminals dedicated to the wiring for interconnection of the stator winding end conductors in the circuit board of the rectifier device, the manufacturing cost on the whole can be reduced remarkably because of rationalization of the manufacturing process although the material cost increases to some extent due to increase of the number of parts. 
     Additionally, because heat generation in the coil end portions of the stator winding assembly can be suppressed with the cooling susceptibility of the AC generator being thereby enhanced, high reliability can be ensured for the operation of the vehicle-onboard AC generator. 
     Besides, because the intermediate connecting member is neither physically connected to the stator nor implemented integrally with the stator and because the intermediate connecting member is provided independently or separately from the rectifier device, a distortion force which would be applied to the rectifier device upon assembling of the stator in the main body of the AC generator can be mitigated, whereby assembling efficiency can be enhanced while the possibility of the circuit board being unwantedly cracked can positively be excluded. 
     Furthermore, since the intermediate connecting member is provided independently or separately from the rectifier device, the intermediate connecting member can be so disposed that the metal portion thereof is exposed exteriorly, which contributes to enhancing the cooling susceptibility of the stator and hence that of the AC generator. 
     In a mode for carrying out the present invention, a neutral point output conductor which is connected to the rectifier device should preferably be formed by the connecting conductor end portions as well. 
     Owing to the arrangement mentioned above, the structure for taking out the AC output power from the neutral point can easily be implemented, which also contributes to increasing the efficiency of generator manufacturing process. 
     In another mode for carrying out the present invention, the intermediate connecting member should preferably be implemented as a wiring terminal member which is formed of a same copper series metal as a wiring conductor. 
     By forming the intermediate connecting member of a same copper series metal as the winding conductor which exhibits a high electric conductivity, heat generation brought about upon rectification can be suppressed, whereby the temperature is prevented from rising excessively. 
     In yet another preferred mode for carrying out the present invention, the wiring terminal member may be molded. 
     By covering or coating the wiring terminal member with a resin or the like material, the surface of the wiring terminal member which faces oppositely to the cooling fan can be made smooth, whereby generation of disturbing noise can be suppressed significantly. Besides, corrosion resistance of the wiring terminal member can be increased. 
     In still another mode for carrying out the present invention, the wiring terminal member should preferably be secured fittingly in a circuit board on which at least said rectifier device is implemented. 
     Owing to the arrangement described above, possibility of the wiring terminal member being inadvertently removed in the course of assembling the AC generator can positively be excluded. Thus, the manufacturing efficiency can be enhanced. Further, the existing manufacturing equipment can be used without modification. Besides, since the wiring terminal member is secured fittingly as described above, it is possible to suppress generation of noise due to resonance which may take place between the circuit board and the wiring terminal member during operation of the AC generator. Thus, an enhanced vibration withstanding capability can be ensured for the AC generator. 
     In a further preferred mode for carrying out the present invention, the wiring terminal member should be welded to an insert terminal member in advance to be subsequently molded. 
     The structure mentioned above can profitably be applied to the AC generator of a relatively low capacity. Since the wiring terminal member is made integrally with the insert terminal member in advance by resistance welding or fusion welding, the process or step for mounting or inserting the wiring terminal member formed as a discrete member can be spared, whereby the generator assembling efficiency can be enhanced significantly. 
     In a yet further preferred mode for carrying out the present invention, the wiring terminal member may be made of a metal plate undergone a surface treatment. 
     Owing to the feature mentioned above, the wiring terminal member is imparted with a high corrosion withstanding capability. Thus, high reliability of operation can be ensured for the AC generator over an extended use life thereof. 
     In a still further preferred mode for carrying out the present invention, the wiring terminal member may be made of a bare copper wire. 
     By employing the wiring terminal member constituted by the bare copper wire, the wiring or interconnecting structure can be realized inexpensively with the yield of manufacture being increased. 
     In another preferred mode for carrying out the present invention, the wiring terminal member may be implemented in a structure having an L-shaped cross-section. 
     By forming the wiring terminal member in the L-like shape in cross-section, the mechanical strength thereof is increased, whereby the reliability of the AC generator can be enhanced correspondingly. 
     In yet another preferred mode for carrying out the present invention, the connecting conductor end portions may be provided with round terminals, respectively, wherein connection of the connecting conductor end portions with the intermediate connecting member is realized by means of screws. 
     With the arrangement described above, works involved in the connection are simplified and facilitated, which can enhance the efficiency of assembling the AC generator. Besides, the electrical and mechanical connection of high reliability can be realized. 
     In still another preferred mode for carrying out the present invention, the output conductor end portions may also be provided with round terminals, respectively, wherein connection of the output conductor end portions to the rectifier device is realized by means of screws. 
     With the arrangement described above, works involved in the connection are simplified and facilitated, which can enhance the efficiency of assembling the AC generator. Besides, the electrical and mechanical connections of high reliability can be realized. 
     In a further mode for carrying out the present invention, each connecting portion of the intermediate connecting member for connection with the connecting conductor end portions should preferably be implemented in the form of a U-like segment, and the connecting conductor end portion may be fixedly secured to the U-like segment through press fitting. 
     With the arrangement described above, work for connecting the connecting conductor end portions to the intermediate connecting member is facilitated, whereby efficiency of assembling the generator is enhanced while ensuring high reliability for the connection. 
     The above and other objects, features and attendant advantages of the present invention will more easily be understood by reading the following description of the preferred embodiments thereof taken, only by way of example, in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the course of the description which follows, reference is made to the drawings, in which: 
     FIG. 1 is a perspective view showing schematically a structure of a stator of a vehicle-onboard AC generator according to a first embodiment of the present invention; 
     FIG. 2 is a partial end view of the stator; 
     FIG. 3 is an equivalent circuit diagram of the stator according to the first embodiment of the present invention; 
     FIG. 4 is a development view showing a positional relationship among the stator, a wiring terminal member serving as an intermediate connecting member and a rectifier device according to the first embodiment of the present invention; 
     FIG. 5A is a top plan view showing in detail a structure of the wiring terminal member; 
     FIG. 5B is a sectional view of the same taken along a line D—D in FIG.  5 A and viewed in the direction indicated by arrows; 
     FIG. 6 is a perspective view showing a circuit board disposed on a rear surface of the rectifier device and the wiring terminal member; 
     FIG. 7 is a fragmentary top plan view for illustrating an arrangement for securing fixedly the wiring terminal member onto the circuit board; 
     FIG. 8 is a sectional view taken along a line E—E in FIG.  7  and viewed in the direction indicated by arrows; 
     FIG. 9 is a top plan view showing an insert terminal member adapted to be secured onto the circuit board of the rectifier device by molding; 
     FIG. 10A is a top plan view showing in detail a structure of the intermediate connecting member according to a second embodiment of the present invention; 
     FIG. 10B is a sectional view of the same taken along a line F—F in FIG.  10 A and viewed in the direction indicated by arrows; 
     FIG. 11 is a view showing a positional relationship between the intermediate connecting member according to the second embodiment and the rectifier device to be connected to each other; 
     FIG. 12A is a top plan view showing in detail a structure of the intermediate connecting member according to a third embodiment of the present invention; 
     FIG. 12B is a sectional view of the same taken along a line G—G in FIG.  12 A and viewed in the direction indicated by arrows; 
     FIG. 13A is a top plan view showing in detail a structure of the intermediate connecting member according to a fourth embodiment of the present invention; 
     FIG. 13B is a sectional view of the same taken along a line H—H in FIG.  13 A and viewed in the direction indicated by arrows; 
     FIG. 14 is a top plan view showing an insert terminal member molded integrally on a circuit board mounted on the stator according to a fifth embodiment of the present invention; 
     FIG. 15 is a sectional view showing a structure of a conventional AC generator; 
     FIG. 16 is a perspective view showing a structure of a stator of the same; and 
     FIG. 17 is an equivalent circuit diagram of the same. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be described in detail in conjunction with what is presently considered as preferred or typical embodiments thereof by reference to the drawings. In the following description, like reference characters designate like or corresponding parts throughout the several views. 
     Embodiment 1 
     FIG. 1 is a perspective view showing schematically a structure of the stator of the vehicle-onboard AC generator according to a first embodiment of the present invention. Further, FIG. 2 is a partial end view of a stator of the same. In the vehicle-onboard AC generator now under consideration, the windings or coils of a stator winding assembly  16  are each constituted by a winding round wire conductor. More specifically, the stator winding assembly  16  is constituted by two sets of coils or windings  16   a  and  16   b  each formed by winding a bundle of two conductors in and along each of discrete slots of a stator core  15  (i.e., so-called bifilar winding). The stator winding assembly  16  formed in this way has coil end portions  162  projecting beyond both sides, respectively, of the stator core  15  and lodged portions  161  accommodated within the stator core  15 . 
     Brought out from winding or coil end portions  162  of the stator winding assembly at one side thereof substantially in parallel with the center axis of the stator core  15  are output conductor end portions a 1 , a 2 , b 1 , b 2 , c 1  and c 2  and connecting conductor end portions Na 1 , Na 2 , Nb 1 , Nb 2 , Nc 1  and Nc 2  as outgoing conductors, respectively. 
     At the tip ends of the individual conductor portions mentioned above, pairs of bifilar conductors a 1  and a 2 , b 1  and b 2 , c 1  and c 2 , Na 1  and Na 2 , Nb 1  and Nb 2  and Nc 1  and Nc 2  are mutually joined together, and round terminals A, B and C and Na, Nb and Nc are press-fit onto the joined conductor tip end portions, respectively. The round terminals (terminals having respective circular through-holes) A, B and C as well as Na, Nb and Nc are disposed circumferentially with a predetermined angular distance therebetween so that they can easily be connected to a wiring terminal member  30  and a rectifier device  12 , as will be described later on. 
     FIG. 3 is an equivalent circuit diagram of the stator  8  according to the instant embodiment of the present invention. As can be seen in this figure, the AC power is taken out from the stator winding assembly  16  via the paired output conductor end portions a 1 ; a 2 , b 1 ; b 2  and c 1 ; c 2  which are electrically connected to terminals Ar, B and C of the rectifier device  12 , respectively. 
     On the other hand, the paired connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  serve for bringing out the ends of the stator winding or coil conductors for the purpose of forming the neutral point of star connection. To this end, the paired connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  brought out externally are connected to terminals Nat, Nbt and Nct, respectively, of a wiring terminal member  30  which serves as an intermediate connecting member, so that the phase windings or coils of the stator winding assembly  16  are interconnected in the form of the star connection. The wiring terminal member  30  has a terminal Nbt which serves as the neutral point of the interconnected stator windings. This terminal Nbt is electrically connected to a terminal Nr of the rectifier device  12 . 
     FIG. 4 is a development view showing a positional relationship among the stator  8 , the wiring terminal member  30  and the rectifier device  12  which are to be interconnected in the AC generator according to the instant embodiment of the present invention. The round terminals A, B and C and Na, Nb and Nc provided on the stator winding assembly  16  are disposed circumferentially with a predetermined angular distance therebetween, as mentioned previously. The intermediate terminal member  30  serving for wiring is provided with the terminals Nat, Nbt and Nct at such positions that they are positionally aligned with the aforementioned round terminals Na, Nb and Nc, respectively, of the stator winding assembly. The round terminals Na, Nb and Nc of the stator winding assembly and the terminals Nat, Nbt and Nct of the intermediate terminal member  30  are electrically and mechanically connected or joined together by using screws upon manufacturing of the stator assembly. On the other hand, the terminals Ar, Br and Cr provided on the circuit board of the rectifier device  12  are so disposed that they are positionally aligned with the round terminals A, B and C of the stator windings, respectively. Thus, the round terminals A, B and C of the stator winding assembly can electrically and mechanically be coupled with the terminals Ar, Br and Cr, respectively, of the rectifier device  12  by means of screws without any appreciable difficulty in the course of manufacturing the AC generator. The terminal Nbt of the wiring terminal member  30  also serves as the terminal for connecting the neutral point of the stator winding assembly to the rectifier device  12  and is adapted to be electrically and mechanically connected to the terminal Nr of the rectifier device  12  by using a screw. 
     FIG. 5A is a top plan view showing in detail a structure of the wiring terminal member  30  serving as the intermediate connecting member and FIG. 5B is a sectional view of the same taken along a line D—D in FIG.  5 A and viewed in the direction indicated by arrows. The wiring terminal member  30  is fabricated by punching or blanking a metal plate formed, for example, of a same copper series metal as the winding conductor and undergone a surface treatment and includes an arcuate portion  30   a  bent substantially arcuately so as to extend along the array of the round terminals Na, Nb and Nc and plural (e.g. three) terminal portions  30   b  projecting substantially radially from the arcuate portion  30   a.  At this juncture, it should be mentioned that the wiring terminal member  30  is designed to be accommodated within a recess formed in the circuit board  12   a  of the rectifier device  12 , as will be described hereinafter, wherein a major surface of the connecting terminal member  30  is exposed externally. Thus, the excellent heat dissipation property of the connecting terminal member  30  can be ensured. 
     FIG. 6 is a perspective view showing the circuit board  12   a  disposed on a rear surface of the rectifier device  12  and the wiring terminal member  30 . As can be seen in FIG. 6, a receiving recess  12   a   1  is formed in the circuit board  12   a  for receiving and accommodating therein the wiring terminal member  30 . More specifically, the receiving recess  12   a   1  is formed in a substantially same shape as the wiring terminal member  30  and has a bottom on which an insert terminal is disposed, as will be described later on. 
     Incidentally, the arcuate portion  30   a  of the wiring terminal member  30  is formed of a resin by molding, as will be described later on by reference to FIG.  13 . 
     FIG. 7 is a fragmentary top plan view for illustrating a manner in which the wiring terminal member  30  is fixedly secured within the receiving recess  12   a   1  formed in the circuit board  12   a  of the rectifier device  12 , and FIG. 8 is a sectional view taken along a line E—E in FIG.  7  and viewed in the direction indicated by arrows. The wiring terminal member  30  is accommodated or received within the receiving recess  12   a   1  and secured fittingly therein with the side edge of the connecting terminal member  30  being frictionally retained by a plurality of protrusions  12   a   2  formed in the side wall of the receiving recess  12   a   1 . Needless to say, once accommodated within the receiving recess  12   a   1 , the wiring terminal member  30  is positively prevented from being released therefrom owing to the frictional engagement with the protrusions  12   a   2 . 
     FIG. 9 is a top plan view showing an insert terminal member  12   a   3  integrally secured onto the circuit board  12   a  of the rectifier device  12  by molding. The insert terminal member  12   a   3  is fabricated by punching a steel plate formed, for example, of a same copper series metal as the winding conductor and has through-holes formed at positions which come to alignment with the positions of the round terminals A, B, C, Na, Nb and Nc, respectively. 
     In the stator assembly  8  of the vehicle-onboard AC generator implemented in the structure described above, a plurality of outgoing conductors constituting the output conductor end portions a 1 ; a 2 , b 1 ; b 2  and c 1 ; c 2  as well as the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2 , respectively, are brought out substantially in parallel with the center axis of the stator core  15 , wherein the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  are connected to the wiring terminal member  30  provided separately from the rectifier device  12  and disposed on the stator  8  at a position offset laterally from the center axis thereof and so wired that the stator windings or coils  16  are interconnected in a predetermined connection pattern such as star connection, while the output conductor end portions a 1 ; a 2 , b 1 ; b 2  and c 1 ; c 2  through which the AC power is taken out are electrically connected to the input terminals Ar, Br and Cr, respectively, of the rectifier device  12 . By virtue of this arrangement, the wiring process internally of the stator  8  which will otherwise be required can be spared, to an advantage. More specifically, the processes for interconnection of the winding conductors, insertion of the conductors in the insulation tubes, securing of the tube-encased conductor portions to the coil end portion  162  and others which are difficult to automatize can be spared. This feature in turn contributes to rationalization of the manufacture of the vehicle-onboard AC generator, to a further advantage. To say in another way, since the wiring process which has heretofore been required can be spared owing to additional provision of the wiring terminal member  30  as the terminals dedicated to the wiring in the circuit board  12   a  of the rectifier device  12 , the manufacturing cost on the whole can be reduced remarkably because of the rationalized manufacturing process described above although the material cost increases to some extent due to increase of the number of parts. 
     Additionally, heat generation in the coil end portion  162  of the stator winding assembly can be suppressed, as a result of which the cooling performance of the AC generator can be enhanced, which can ensure high reliability in operation of the vehicle-onboard AC generator. 
     Further, the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  which also serve as the neutral point power output conductors are connected to the rectifier device  12 . Thus, the structure for taking out the output power from the neutral point can be simplified, which contributes to enhancing the manufacturing efficiency of the vehicle-onboard AC generator. 
     Furthermore, the intermediate connecting member is implemented as the wiring terminal member  30  which is formed of a same copper series metal as the winding conductor. Thus, heat generation brought about upon rectification is suppressed and the temperature is prevented from rising excessively. 
     Furthermore, the wiring terminal member  30  can be secured fittingly onto the circuit board  12   a  in precedence to the assembling process. As a result of this, there arises no possibility of the wiring terminal member  30  being inadvertently removed in the course of assembling the AC generator. Thus, the manufacturing efficiency can be enhanced. Further, the existing manufacturing equipment can be used without modification. Besides, since the wiring terminal member  30  is secured fittingly as described previously, it is possible to suppress generation of noise due to resonance between the circuit board  12   a  and the wiring terminal member  30  in the operation of the generator. Thus, an enhanced vibration withstanding capability can be ensured for the AC generator. 
     Furthermore, the wiring terminal member  30  is fabricated of a metal plate undergone a surface treatment, as described hereinbefore. Owing to this feature, the wiring terminal member  30  is imparted with high corrosion withstanding capability. Thus, high reliability can be ensured for the AC generator over an extended use life. 
     It should further be mentioned that the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  as well as the output conductor end portions a 1 ; a 2 , b 1 ; b 2  and c 1 ; c 2  are each provided with the round terminal, wherein the mechanical and electrical connections between the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  and the wiring terminal member  30  as well as the mechanical and electrical connections between the output conductor end portions a 1 ; a 2 , b 1 ; b 2  and c 1 ; c 2  and the rectifier device  12  are realized by using the screws, as described hereinbefore. Consequently, works involved in these connections are simplified and facilitated, as a result of which efficiency of assembling the AC generator can be improved. Besides, the mechanical and electrical connections can be realized with high reliability. 
     At this juncture, it should also be mentioned that although the wiring terminal member  30  of the AC generator according to the first embodiment of the present invention is made of a metal plate, the present invention is never restricted thereto. Bare copper wires may be used to this end. By employing the wiring terminal member  30  constituted by the bare copper wires, the wiring or interconnecting structure can be realized inexpensively with the yield of manufacture being correspondingly increased. 
     Embodiment 2 
     Now, description will turn to a second embodiment of the present invention. FIGS. 10A and 10B are views showing in detail a structure of the intermediate connecting member of the vehicle-onboard AC generator according to a second embodiment of the present invention, in which FIG. 10A is a top plan view of the same and FIG. 10B is a sectional view taken along a line F—F in FIG.  10 A and viewed in the direction indicated by arrows. Further, FIG. 11 is a view showing a positional relationship for connection between the intermediate connecting member and the circuit board of the rectifier device. According to the teaching of the invention incarnated in the instant embodiment, the wiring terminal member  31  serving as the intermediate connecting member includes terminal portions  31   b  each having a stamped tip end formed in a U-like shape having legs bent substantially at a right angle, as can be seen in FIG.  10 B. 
     More specifically, in the vehicle-onboard AC generator according to the instant embodiment of the present invention, each connecting portion of the wiring terminal member  31  employed as the intermediate connecting member for connection with the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  is implemented in the former of U-like segment so that the connecting conductor end portion Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  can be fixedly secured to the U-like segment through press fitting. For this reason, each of the connecting conductor end portion Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  is provided with no round terminal in the AC generator according to the instant embodiment of the invention. With the structure of the wiring terminal member described above, the process for connecting the connecting conductor end portions Na 1 ; Na 2 , Nb 1 ; Nb 2  and Nc 1 ; Nc 2  to the wiring terminal member  31  can be much facilitated, whereby efficiency of assembling the vehicle-onboard AC generator can be enhanced while ensuring high reliability for the connection. 
     In this conjunction, it should also be mentioned that the U-shape portion is formed not only in each of the terminals portion or piece  31   b  of the wiring terminal member  31  but also in each of the corresponding terminals of the rectifier device  12  through stamping in the case of the AC generator according to the instant embodiment of the invention. 
     Embodiment 3 
     Next, a third embodiment of the present invention will be described by referring to FIGS. 12A and 12B, in which FIG. 12A is a top plan view showing in detail a structure of the intermediate connecting member of the vehicle-onboard AC generator according to the third embodiment of the invention and FIG. 12B is a sectional view of the same taken along a line G—G in FIG.  12 A and viewed in the direction indicated by arrows. 
     In the case of the AC generator according to the instant embodiment of the invention, the wiring terminal member  32  serving as the intermediate connecting member has one side edge portion which is bent substantially at a right angle relative to the major plane so that the wiring terminal member  32  exhibits approximately an L-shaped section, as can be seen in FIG.  12 B. By forming one side edge portion of the wiring terminal member  32  in the L-like shape in cross-section, the mechanical strength of the wiring terminal member is increased, which contributes to increasing the reliability of the AC generator. 
     Embodiment 4 
     A fourth embodiment of the present invention will be described by reference to FIGS. 13A and 13B, in which FIG. 13A is a top plan view showing in detail a structure of the intermediate connecting member of the vehicle-onboard AC generator according to the fourth embodiment of the invention and FIG. 13B is a sectional view of the same taken along a line H—H in FIG.  13 A and viewed in the direction indicated by arrows. According to the teaching of the invention incarnated in the instant embodiment, the wiring terminal member  33  serving as the intermediate connecting member includes an arcuate portion  33   a  whose surface facing in opposition to the cooling fan is coated with a molded resin. By covering or coating the wiring terminal member  33  with the molded resin in this manner, the surface facing oppositely to the cooling fan can be smoothed, whereby generation of disturbing noise can be suppressed remarkably. Besides, corrosion resistance of the wiring terminal member can be increased. 
     Embodiment 5 
     A fifth embodiment of the present invention will be described by reference to FIG. 14, which shows in a top plan view an insert terminal member molded integrally in the circuit board of the rectifier device mounted on the vehicle-onboard AC generator. According to the teaching of the present invention incarnated in the instant embodiment, the wiring terminal member  34  serving as the intermediate connecting member is welded to an insert terminal member  12   a   3  and subsequently the insert terminal member including the wiring terminal member fixedly mounted thereon is secured onto the rectifier circuit board  12   a  by molding. The wiring terminal member structure according to the instant embodiment of the present invention can profitably be applied to the AC generator of a relatively low capacity. Since the wiring terminal member  34  is realized integrally as a part of the insert terminal member  12   a   3  by resistance welding or fusion welding in advance, the process or step for mounting or inserting the wiring terminal member  34  formed as a discrete member can be spared, whereby the generator assembling efficiency can be improved significantly. 
     Many features and advantages of the present invention are apparent from the detailed description and thus it is intended by the appended claims to cover all such features and advantages of the structures and arrangements which fall within the true spirit and scope of the invention. Further, since numerous modifications and combinations will readily occur to those skilled in the art, it is not intended to limit the invention to the exact construction and operation illustrated and described. Accordingly, all suitable modifications and equivalents may be resorted to, falling within the spirit and scope of the invention.