JP4100366B2 - AC generator rectifier for vehicle - Google Patents

Description

  The present invention relates to a rectifier for a vehicle AC generator mounted on a passenger car, a truck, or the like.

2. Description of the Related Art A vehicular AC generator uses a rectifier to rectify an AC voltage generated in a stator winding and convert it into a DC voltage. As a conventional structure of this rectifier, in order to suppress the outer dimensions, the positive side radiating fin and the negative side radiating fin are arranged to overlap, and the lead of the rectifying element attached to one radiating fin is connected to the other radiating fin. What was pulled out through the hole formed in (2) is known (for example, see Patent Document 1). By adopting such a structure, the lead of the rectifying element attached to the positive-side radiating fin and the lead of the rectifying element attached to the negative-side radiating fin can be drawn out in the same direction. A predetermined rectifier circuit can be configured by bonding to the terminal electrode of the terminal block.
JP 2002-119028 A (page 3-5, FIG. 1-11)

  By the way, in the rectifier disclosed in Patent Document 1, when the size of the alternator in the direction of the rotation axis of the vehicle alternator is shortened to reduce the size of the entire generator, the rectifier element attached to one of the heat radiating fins and However, if the distance is too close, the gap between them becomes small, and foreign matter such as mud and salt accumulates in this gap and rectifies. There is a problem that the durability of the rectifier deteriorates because the element is corroded or the resistance of the cooling air flowing through the gap is increased to raise the temperature of the rectifier element and reduce the life.

  This invention is created in view of such a point, and the objective is to provide the rectifier of the alternating current generator for vehicles which can improve durability.

  In order to solve the above-described problem, a rectifier for an AC generator for a vehicle according to the present invention includes first and second heat dissipating fins arranged at predetermined intervals along a rotation axis direction, A first rectifying element attached to the first radiating fin, a second rectifying element attached to the second radiating fin, and a terminal block for wiring the first and second rectifying elements; The radiation fin has an opening where the opening area on the first radiation fin side is larger than the opening area on the opposite side, at a position corresponding to the first rectifying element attached to the first radiation fin. ing. As a result, the gap near the rectifying element attached to one of the radiating fins can be enlarged, so that foreign matter such as mud and salt accumulates in the gap between the two radiating fins near the opening to corrode the rectifying element. As a result, it is possible to prevent the ventilation resistance of the cooling air from increasing and the temperature of the rectifying element to rise to reduce the lifetime, thereby improving the durability of the rectifying device.

  Moreover, it is desirable that the first rectifying element described above has a convex portion that protrudes toward the second radiating fin from the surface of the first radiating fin. In the case of having a convex portion, foreign matter is more likely to accumulate in the gap between the convex portion and the heat dissipating fin opposite to the convex portion, but the opening area of the opening formed at a position corresponding to the convex portion is set on the convex portion side. By increasing the size, it is possible to effectively prevent foreign matter from staying in the gap.

  Moreover, it is desirable that the opening area on the first radiating fin side of the opening described above is larger than the transverse area of the first rectifying element perpendicular to the rotation axis direction. Thereby, the stay of the foreign material between a rectifier and a radiation fin can be prevented reliably.

  Moreover, it is desirable that the opening area on the first radiating fin side of the opening described above is larger than the cross-sectional area of the protrusion perpendicular to the rotation axis direction. Accordingly, it is possible to reliably prevent foreign matter from staying between the convex portions formed on the rectifying element and the heat radiating fins.

  The first rectifying element described above preferably has a lead portion that extends through an opening provided in the second heat dissipating fin. By eliminating the retention of foreign matter between the rectifying element and the radiating fin, it is possible to prevent the lead portion extending through the opening from being short-circuited to the surrounding radiating fin via the foreign matter, which is good for a long period of time. Rectifying characteristics can be maintained.

  Further, the lead portion of the second rectifying element described above faces the same direction as the lead portion of the first rectifying element along the rotation axis direction, and each lead portion of the first and second rectifying elements is It is desirable that the wiring is provided by the terminal block outside the space between the first and second radiating fins. As a result, the terminal block can be arranged outside the space sandwiched between the two types of radiating fins, so that the cooling air introduced from the opposite side of the terminal block can be efficiently applied to these two types of radiating fins. it can. In addition, when the arrangement of such a radiation fin and terminal block is realized, the lead portion of the rectifying element attached to one radiation fin intersects with the other radiation fin. Since the accumulation of foreign matter in the gap can be eliminated, the durability of the rectifier having such a structure can be improved.

  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.

  FIG. 1 is a cross-sectional view showing the overall configuration of an automotive alternator according to an embodiment. The vehicle alternator 1 shown in FIG. 1 includes a stator 2, a rotor 3, a brush device 4, a rectifier 5, a frame 6, a rear cover 7, a pulley 8, and the like.

  The stator 2 includes a stator core 21 and three-phase stator windings 23 wound around a plurality of slots formed in the stator core 21 at predetermined intervals. The rotor 3 has a structure in which a field winding 31 in which an insulated copper wire is wound in a cylindrical and concentric manner is sandwiched from both sides through a rotating 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. The brush device 4 is for passing an exciting current from the rectifying device 5 to the field winding 31 of the rotor 3, and presses each of the slip rings 36 and 37 formed on the rotating shaft 33 of the rotor 3. Brushes 41 and 42 are provided.

  The rectifier 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, and includes a terminal block 51 including a wiring electrode 50 therein. A positive-side radiating fin 52 and a negative-side radiating fin 53 arranged at predetermined intervals, and a plurality of rectifying elements 54 and 55 attached by press-fitting into driving holes provided in the respective radiating fins. It consists of The rectifying device 5 is configured by stacking two heat radiating fins 52 and 53 in an electrically insulating manner. The rectifying device 5 is configured in a shape that can be referred to as a substantially C-shape or U-shape around the rotation shaft 33 of the vehicle alternator 1. The rectifying device 5 is fixed to the frame 6 by a fixing means such as a bolt through a member that electrically insulates at least the positive-side radiation fin 52 from the frame 6 at a plurality of positions separated along the circumferential direction. . Details of the rectifier 5 will be described later.

  The frame 6 accommodates the stator 2 and the rotor 3, is supported in a state where the rotor 3 can rotate around the rotation shaft 33, and a predetermined amount is provided on the outer peripheral side of the pole core 32 of the rotor 3. A stator 2 arranged via a gap is fixed. The frame 6 is provided with a cooling air discharge window 61 at a portion facing the stator winding 23 protruding from the axial end surface of the stator core 21 and a cooling air suction window 62 at the axial end surface. Yes. The rear cover 7 covers the entire brush device 4, the rectifying device 5, and the IC regulator 12 that are attached to the outside of the rear frame 6, and protects them.

  Next, details of the rectifier 5 will be described. FIG. 2 is a partial enlarged cross-sectional view of the rectifying device 5.

  As shown in FIG. 2, the negative side heat radiation fin 53 is formed with a driving hole for press-fitting and attaching the rectifying element 55. This driving hole is a through hole, and the diameter thereof is set to a value slightly smaller than the outer shape of the rectifying element 55. The rectifying element 55 is formed by soldering one surface of the semiconductor pellet 162 on a cylindrical pedestal 160 made of a metal material (for example, copper) having substantially the same thickness as that of the negative-side radiation fin 53, and further, the other surface of the semiconductor pellet 162. The lead portion 164 is formed by soldering. The circumference | surroundings of the semiconductor pellet 162 mentioned above are covered with the cylindrical resin ring 166, and in order to protect the whole semiconductor pellet 162, the inside is filled with protective layers, such as a silicon resin. The cylindrical resin ring 166 is a protrusion that protrudes toward the positive-side radiation fin 52 side from the surface of the negative-side radiation fin 53. A knurled portion 168 is formed on the outer periphery of the pedestal 160 described above. By forming the outer diameter of the knurled portion 168 slightly smaller than the inner diameter of the driving hole formed in the negative-side radiating fin 53, when the base 160 of the rectifying element 55 is press-fitted into the driving hole, the knurled portion 168 Combined with deformation. The detailed structure and the mounting method are the same for the positive-side radiating fin 52 and the rectifying element 54.

  By the way, the negative electrode side heat radiating fin 53 and the positive electrode side heat radiating fin 52 described above are arranged so as to overlap each other at a predetermined interval in the direction along the rotation shaft 33, and terminals arranged outside the space between them. The lead portions of the rectifying elements 54 and 55 are electrically connected to the wiring electrode 50 of the base 51. Thus, the rectifying element 55 and the terminal block 51 attached to the negative electrode side radiating fin 53 are arranged on the opposite side across the positive electrode side radiating fin 52, and the lead portion 164 of the rectifying element 55 is connected to the terminal block 51. In order to connect to the wiring electrode 50, an opening 150 is formed in the positive-side radiating fin 52.

  The opening 150 is formed as a through hole, for example, at a position corresponding to the rectifying element 55 attached to the negative-side radiation fin 53. The opening 150 has a stepped cross-sectional shape in which the opening area on the negative-side radiating fin 53 side is larger than the opening area on the opposite side (terminal block 51 side). For example, the diameter of the opening 150 on the terminal block 51 side is set to be approximately the same as the diameter of the resin ring 166 of the rectifying element 55, and the diameter of the opening 150 on the negative-side radiating fin 53 side is The resin ring 166 and the knurled portion 168 are set to values larger than the respective diameters.

  The lead portion 164 of the rectifying element 55 extends through substantially the center of the opening 150 having such a shape, reaches the wiring electrode 50 of the terminal block 51, and is electrically connected. In this embodiment, the lead portion 164 passes through the opening 150 provided in the positive-side radiating fin 52. A lead portion 164 extending from the rectifying element 55 mounted on the negative-side radiation fin 53 that is one of the radiation fins extends across the rear side and the front side of the positive-side radiation fin 52 that is the other radiation fin. It is electrically connected to the wiring electrode 50 provided on the terminal block 51 provided on the side opposite to the negative electrode side radiation fin 53 of the positive electrode side radiation fin 52. Further, the lead part of the rectifying element 54 is also electrically connected to the wiring electrode 50. In this way, the rectifier elements 54 and 55 are connected to form a rectifier circuit. In this embodiment, one of the two radiating fins is mounted with a rectifying element having a lead portion extending between the radiating fins. The lead portion extends through an opening provided in the other radiating fin so as to be connected to an electrode disposed on the outer side of the other radiating fin. The opening is formed so as to open largely on the surface on the side of one of the radiating fins and to open small on the surface on the opposite side. The opening section defines an opening on both sides of the lead on the side of one of the radiating fins. As a result, the distance between the other radiating fin and the lead portion is longer on the surface on the one radiating fin side and shorter on the surface on the opposite side. The other radiating fin defines an opening that extends toward the one radiating fin.

  As described above, the opening 150 of the positive-side radiating fin 52 that penetrates the lead portion 164 of the rectifying element 55 is formed in a stepped shape so that the opening area on the rectifying element 55 side is increased. Therefore, foreign matter such as mud and salt accumulates in the gap between the two types of heat dissipating fins 52 and 53 in the vicinity of the opening 150 to corrode the rectifying element 55, and accompanying this, the ventilation of cooling air It is possible to prevent the resistance from increasing and the temperature of the rectifying element 55 from rising to shorten the life, and the durability of the rectifying device 5 can be improved.

  Further, even when the resin ring 166 serving as the convex portion is formed on the rectifying element 55, it is possible to effectively retain foreign matter in the gap between the resin ring 166 and the positive-side radiating fin 52 facing the resin ring 166. It becomes possible to prevent.

  Further, the opening area of the opening 150 on the negative electrode side radiating fin 53 side is defined as a cross-sectional area of the rectifying element 55 perpendicular to the direction of the rotation axis 33 (cross-sectional area of the knurled portion 168) or a cross-sectional area of the resin ring 166 that is a convex By setting it to be larger than this, it is possible to reliably prevent foreign matter from staying between the rectifying element 55 and the positive-side radiating fin 52.

  Further, since the foreign matter does not stay between the rectifying element 55 and the positive-side radiating fin 52, the lead portion 164 penetrating the opening 150 is short-circuited with the surrounding positive-side radiating fin 52 through the foreign matter. Can be prevented and good rectification characteristics can be maintained over a long period of time.

  Further, in the rectifying device 5 of the present embodiment, the respective lead portions of the rectifying elements 54 and 55 face the same direction along the direction of the rotation axis 33 and are sandwiched between the positive-side radiating fins 52 and the negative-side radiating fins 53. It is wired by the terminal block 51 outside the space. By arranging the terminal block 51 outside the space sandwiched between the two types of heat radiation fins 52 and 53 in this way, the cooling air introduced from the opposite side (rear cover 7 side) to the terminal block 51 can be supplied to these two types of cooling air. It can be applied to the heat radiation fins 52 and 53 efficiently. Further, when such an arrangement of the radiation fins 52 and 53 and the terminal block 51 is realized, the lead portion 164 of the rectifying element 55 attached to one negative-side radiation fin 53 is connected to the other positive-side radiation fin 52. Although it intersects, the provision of the stepped opening 150 can eliminate the retention of foreign matter in the gap near the intersection, thus improving the durability of the rectifier 5 having such a structure. be able to.

  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. For example, in the above-described embodiment, the step-shaped opening 150 is formed in the positive-side radiating fin 52, but as a cross-sectional shape other than this, the shape expands toward the negative-side radiating fin 53 as one radiating fin. An opening may be adopted.

  FIG. 3 is a view showing a modification of the opening formed in the positive-side radiating fin 52. In the modification shown in FIG. 3, the opening 152 formed in the positive-side radiating fin 52 has an opening area on the negative-side radiating fin 53 side that is gradually larger than the opening area on the opposite side (terminal block 51 side). Have side surfaces that are inclined to each other. Even when such a so-called tapered hole-shaped opening 152 is employed, the same effect as the stepped-shaped opening 150 can be obtained.

  FIG. 4 is a view showing another modification of the opening formed in the positive-side radiating fin 52. In the modification shown in FIG. 4, the opening 154 formed in the positive-side radiating fin 52 has an opening area on the negative-side radiating fin 53 side that gradually becomes larger from the middle than the opening area on the opposite side (terminal block 51 side). It has an inclined side surface. The same effect as that of the stepped opening 150 can be obtained also when the opening 154 in which a part on the terminal block 51 side has a straight hole shape and the remaining part has a tapered hole shape is adopted.

  In the above-described embodiment, the opening 150 is formed as the through hole. However, a slit-like opening extending from the outer edge of the positive-side radiating fin 52 may be employed. For example, as shown in FIG. 5, a stepped shape or a tapered hole-shaped opening 156 may be employed as a groove extending radially inward from the outer peripheral edge of the positive electrode side heat dissipating fin 52 in the radial direction. .

  In the above-described embodiment, the positive electrode side heat radiation fin 52 is disposed between the negative electrode side heat radiation fin 53 and the terminal block 51, but the negative electrode side heat radiation fin 53 is disposed between the positive electrode side heat radiation fin 52 and the terminal block 51. In this case, the present invention is applied by forming an opening having a stepped shape or the like in the negative-side radiating fin 53 and arranging the lead portion of the rectifying element mounted on the positive-side radiating fin 52 through the opening. Can do.

It is sectional drawing which shows the whole structure of the alternating current generator for vehicles of one Embodiment. It is a partial expanded sectional view of a rectifier. It is a figure which shows the modification of the opening part formed in the positive electrode side radiation fin. It is a figure which shows the other modification of the opening part formed in the positive electrode side radiation fin. It is a figure which shows the other modification of the opening part formed in the positive electrode side radiation fin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle alternator 5 Rectifier 50 Wiring electrode 51 Terminal block 52 Positive electrode side radiation fin 53 Negative electrode side radiation fin 54, 55 Rectifier 150 Opening part 160 Base 162 Semiconductor pellet 164 Lead part 168 Knurl part

Claims (3)

First and second heat dissipating fins arranged to be overlapped at predetermined intervals along the rotation axis direction;
A first rectifying element attached to the first radiation fin;
A second rectifying element attached to the second radiation fin;
A terminal block for wiring the first and second rectifying elements,
The second radiation fin has an opening area on the first radiation fin side larger than an opening area on the opposite side at a position corresponding to the first rectifying element attached to the first radiation fin. Has a circular opening,
The first rectifying element has a convex portion formed of a resin ring and a knurled portion that protrudes toward the second radiating fin from the surface of the first radiating fin,
The diameter of the opening on the first radiating fin side is set to a value larger than the diameter of the convex portion of the first rectifying element, and
The vehicular AC power generation is characterized in that the opening has a slit shape having an opening (156) as a groove extending radially inward from an outer peripheral edge on the outer side in the radial direction of the second radiating fin. Machine rectifier. In claim 1 ,
The rectifying device for an AC generator for a vehicle, wherein the first rectifying element has a lead portion that extends through the opening provided in the second radiating fin. In claim 2 ,
The lead portion of the second rectifying element faces the same direction as the lead portion of the first rectifying element along the rotational axis direction,
Each of the lead portions of the first and second rectifying elements is wired by the terminal block outside the space sandwiched between the first and second radiating fins. Rectifier.

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