JP2009081934A - Three-phase ac power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply sufficient oil to all the coils of a stator to improve cooling efficiency. <P>SOLUTION: A three-phase AC power generator 10 includes an outer rotor integrally rotating with a crank shaft and a stator 16 opposed to the outer rotor. The stator 16 coil is formed by parallel connection of series coils having two sets each of U-, V-, W-phases. The coil 32 is formed by lead wires of two or more different wire diameters according to arrangement positions, and the wire diameters of the series coil lead wire, containing the coils 32v<SB>1</SB>, 32u<SB>3</SB>near an anchor fitting 40 being the drawing portion of the lead wire, is made larger. Whereas the wire diameters of the series coil lead wire, containing the lower end coil 32w<SB>2</SB>of the stator 16 low in temperature rise, are made smaller. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a three-phase AC generator for an internal combustion engine having a rotor that rotates integrally with a crankshaft and a stator that faces the rotor.

  A vehicle having an internal combustion engine such as a motorcycle is provided with a generator connected to a crankshaft of the internal combustion engine, and generates power in conjunction with rotation of the crankshaft to supply power to the vehicle auxiliary equipment and a battery. Charge the battery. As such a generator, a three-phase AC generator is generally used.

  In motorcycles and the like, space is limited, and not only the internal combustion engine body but also the generator is required to be smaller and lighter. When the generator is downsized, the surface area to dissipate heat decreases, the amount of heat dissipation decreases, the temperature rises, and power generation efficiency tends to decrease.

  For this reason, in the cooling device described in Patent Document 1, oil is jetted and cooled in a gap surrounded on three sides by the inner peripheral surface of the rotor and two adjacent coils, and the generator is cooled. We are trying to improve efficiency.

Japanese Patent No. 3769168

  By the way, in the three-phase AC generator used for the internal combustion engine, there is a space limitation, so the heat radiation effect varies depending on the location due to external factors, and if the cooling is uniform, the temperature rise is biased. And the cooling effect becomes insufficient.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a three-phase AC generator that is less susceptible to temperature rise and can be efficiently cooled.

  The three-phase AC generator according to the present invention has the following characteristics.

  1st characteristic: In the three-phase alternating current generator of the internal combustion engine which has the rotor which rotates integrally with a crankshaft, and the stator which opposes the said rotor, the some coil which comprises the said stator is the arrangement | positioning location, When the conductors of all the coils are formed with the same diameter in the state of use, the coil conductor of the coil with the highest temperature rise is the largest conductor. It is characterized by being.

  Thus, by making the wire diameter of the coil wire at the highest temperature rise the largest, the surface area to dissipate heat is increased, the conductor resistance is reduced, and the temperature rise at that portion is suppressed. The Therefore, the temperature rise is less biased and efficient cooling is possible.

  Second feature: The stator coil is formed by parallel connection of two series coils of U, V, and W phases, and the series coil is formed of a conducting wire having the same diameter. To do. Thereby, a series coil can be continuously wound with one conducting wire, and it becomes a simple structure.

  Third feature: In a three-phase AC generator for an internal combustion engine having a rotor that rotates integrally with a crankshaft, and a stator that faces the rotor, the plurality of coils that constitute the stator are arranged at different locations. It is formed by conducting wires having two or more different wire diameters, and the wire diameter of the coil conducting wire closest to the lead-out portion of the conducting wire is the largest. The lead-out portion of the conducting wire has a high temperature rise because heat dissipation is hindered. By making the diameter of the conducting wire of the coil at this point the largest, the surface area for heat dissipation increases, the conductor resistance decreases, and the temperature rise at that portion is suppressed. Therefore, the temperature rise is less biased and efficient cooling is possible.

  Fourth feature: The wire diameter of the series coil including the coil at the lower end of the stator is the smallest. The coil at the lower end of the stator is cooled by the oil being lifted from below and hitting the oil, so that a small-diameter conductor can be used.

  According to the three-phase AC generator according to the present invention, by setting the wire diameter of the coil wire at the highest temperature rise to the largest diameter, the surface area for heat dissipation is increased and the conductor resistance is reduced. , The temperature rise in that portion is suppressed. Therefore, the temperature rise is less biased and efficient cooling is possible.

  Hereinafter, a three-phase AC generator according to the present invention will be described with reference to FIGS. The three-phase AC generator 10 according to the present embodiment is a small and lightweight one mounted on, for example, a motorcycle.

  As shown in FIGS. 1 and 2, a three-phase AC generator 10 according to the present embodiment is attached to a side surface of a main body case 12 of an internal combustion engine. And the outer rotor 22 fixed to the axis C of the end of the crankshaft 18 with a bolt 20.

  The cover 14 is cup-shaped and protrudes from the main body case 12 in the X1 direction on the left side in FIG. A plurality of substantially radial ribs 14a (see FIG. 3) are provided at the X1 direction end of the inner cavity of the cover 14.

  The crankshaft 18 is rotatably supported by a hole 12a of the main body case 12, and is connected to a connecting rod and a piston (not shown). The distal end portion 18a of the crankshaft 18 has a tapered shape. A bottomed screw hole 18b in which a female screw is provided is provided in the axial center portion of the distal end portion 18a. A part of the crankshaft scoops up the lower oil and applies it to the three-phase AC generator 10 or the like for lubrication and cooling.

  The three-phase AC generator 10 further includes a gear body 26 that is rotatably supported by a bearing 24 with respect to the crankshaft 18, and a clutch 28 provided between the outer rotor 22 and the gear body 26. The gear body 26 meshes with a starter motor (not shown).

The stator 16 has a six-pole structure, and a coil is wound around each tooth 30. These coils are represented, for example, as a coil 32u ₁ or as a representative coil 32 depending on the phase and arrangement. Each coil 32 is formed by winding a conducting wire (for example, enamel-coated copper wire).

  The center portion of the stator 16 is positioned by being partially fitted to the support pillar 34 of the cover 14 and fixed by bolts 36. Three harnesses 38 a, 38 b, and 38 c for drawing out conductive wires are connected to the stator 16, and are fixed together by a fastener 40. The fastener 40 is fixed by screws on the right side (Y2 direction) in FIG.

  The outer rotor 22 includes a central boss portion 42, a cylindrical body 44 disposed around the stator 16, an end face plate 46 connecting the boss portion 42 and the cylindrical body 44, and an inner peripheral surface of the cylindrical body 44. 18 magnets 48 provided. The outer rotor 22 and the crankshaft 18 rotate clockwise when viewed from the front (see FIG. 1). The cylinder 44 has a flywheel action. The end face plate 46 is provided with a plurality of lightening holes 46a.

  The boss portion 42 and the cylindrical body 44 protrude from the end face plate 46 in the X1 direction, and the protruding length of the cylindrical body 44 is slightly longer than that of the boss portion 42. The stator 16 is disposed in the space between the boss portion 42 and the cylindrical body 44. The gap between the magnet 48 and the stator 16 is very small. The magnet 48 of the outer rotor 22 and the coil 32 of the stator 16 are arranged in an annular shape and face each other.

  The boss portion 42 has a hole 42a that opens in the X2 direction on the right side in FIG. The hole 42a has a tapered shape that expands in the X2 direction, and is fitted to the tip end portion 18a of the crankshaft 18 without a gap and positioned without eccentricity. A spacer 50 is inserted in a connection portion between the tip end portion 18a and the boss portion 42. The hole 42a also opens in the X1 direction according to the outer diameter of the bolt 20.

  The bolt 20 passes through the hole 42 a of the boss portion 42 and the spacer 50, and is screwed into the screw hole 18 b of the crankshaft 18, thereby fixing the outer rotor 22 to the crankshaft 18. The head 20 a of the bolt 20 protrudes slightly in the X1 direction from the end surfaces of the cylindrical body 44 and the stator 16 and is close to the inner surface of the cover 14.

  The cover 14 is provided with an oil passage 60 and an oil outlet 64.

  The oil passage 60 includes a first passage 60a, a second passage 60b, and a third passage 60c. The first passage 60 a extends in the lateral direction (X direction) in FIG. 2 at the lower part of the cover 14, and the end opening in the X2 direction communicates with an oil supply path 68 provided in the main body case 12. Yes. The oil supply path 68 is connected to an oil pump (not shown) and is supplied with pressurized oil.

  The 2nd channel | path 60b is extended in the vertical direction in the end surface board of the X1 direction in the cover 14, and the lower part is connected to the edge part of the 1st channel | path 60a. The 2nd channel | path 60b is provided in the center of the three-phase alternating current generator 10 by front view. As shown in FIG. 1, on the side surface of the cover 14, a built-up portion 74 is provided at a lower end portion where the second passage 60 b is provided to ensure strength and a cross-sectional area of the second passage 60 b.

  As shown in FIG. 1, the oil jet port 64 is provided in the vicinity of the Y1 direction end portion of the third passage 60 c, and can jet oil to a part of the upper portion of the stator 16.

  After the oil is ejected from the oil ejection port 64, the oil is guided by the rib 14 a (see FIG. 3), gathers at the center, flows downward, guides the oil to the flywheel side, and is applied to the stator 16 by the rotational force of the flywheel Apply and cool. Further, a part of the oil can flow to the lower part of the stator 16 to be cooled. That is, the rib 14a is basically a reinforcing member for the cover 14, but also acts as an oil guide member. Further, a part of the oil ejected from the oil ejection port 64 is given a rotational force by the cylindrical body 44 as a flywheel, and can also cool against each coil 32.

  The oil ejected from the oil ejection port 64 is collected on the bottom surface by the cover 14 without leaking to the outside, and is returned to the oil pump through collection means (not shown).

As shown in FIG. 4, the stator 16 has a parallel three-phase Δ connection. In other words, a set of series coils 32u ₁ , 32u ₂ , 32u _{3 and} a set of series coils 32u ₄ , 32u ₅ , 32u ₆ are connected in parallel to the U phase. In the V phase, a set of series coils 32v ₁ , 32v ₂ , 32v _{3 and} a set of series coils 32v ₄ , 32v ₅ , 32v ₆ are connected in parallel. In the W phase, a set of series coils 32w ₁ , 32w ₂ , 32w _{3 and} a set of series coils 32w ₄ , 32w ₅ , 32w ₆ are connected in parallel. The three coils 32 in series are formed by winding one continuous conductor, and the conductors in the series coil have the same diameter. The arrangement of these coils 32 is as shown in FIG. That is, the three coils 32 constituting the series coil are arranged adjacent to each other, and the two sets of parallel series coils are arranged at positions separated by 180 °.

  Each coil 32 of the stator 16 generates heat when a current flows along with power generation, and the temperature rises considerably as it is, and power generation efficiency tends to decrease. Therefore, as described above, cooling is performed by ejecting oil, and further, the oil below is scooped up and scattered by a part of the crankshaft to cool.

  By the way, although each coil 32 of the stator 16 has the same electrical effect, the heat dissipation effect differs depending on the location due to external factors, and the temperature rise tends to be biased, and the cooling effect tends to be insufficient. is there.

  The inventor of this application has measured the temperature rise of each coil when all the coils 32 are formed of conducting wires having the same diameter. The result is shown in FIG. FIG. 5 is a graph in which the center point is 140 ° C. and the temperature increases toward the outside. A solid line 70 in FIG. 5 indicates a temperature distribution in a use state in which the three-phase AC generator is mounted on the engine of the motorcycle. For comparison, a temperature distribution in a single unit of the three-phase AC generator is indicated by a broken line 72.

As shown in FIG. 5, the solid line 70 showed the highest temperature rise at the 3 o'clock position, specifically, at the coil 32v ₁ and coil 32u ₃ portions. This is considered to be because the fasteners 40 and the harnesses 38a, 38b, and 38c are disposed in these portions, and the heat dissipation effect is inferior.

Further, on the lower side in FIG. 5, the position in the 6 o'clock direction, specifically, the temperature of the coil 32w ₂ portion was considerably low. This is presumably because the oil below was scooped up and scattered by a part of the crankshaft, and the coil 32w ₂ received the oil best and was deprived of heat. Although the temperature of the coil 32W _{3 in} the 0 o'clock direction is also considerably low, it is considered that this is because it is arranged in the vicinity of the oil jet port 64.

In the stator 16 in the three-phase AC generator 10 according to the present embodiment, as shown in FIG. 4, a set of U-phase series coils 32u ₁ , 32u ₂ , 32u ₃ and a V-phase series coil 32v ₁ , 32v ₂ and 32v ₃ are used as the conductors having a larger diameter than the other coils 32. The thickness of the line in FIG. 4 schematically represents the thickness of the conductive wire of each coil 32. Here, also for the series of coil 32 coil 32w _1, 32w _2, 32w ₃ set in the W phase, but with a large diameter wire in order to balance the U-phase and V-phase, a small diameter by design conditions You may use the conducting wire.

The other coils 32u ₄ , 32u ₅ , 32u ₆ , 32v ₄ , 32v ₅ , 32v ₆ , 32w ₄ , 32w ₅ , 32w ₆ use thin wires having the same diameter.

Thereby, at least the coil 32v ₁ and the coil 32u ₃ having the highest temperature rise use large-diameter conductive wires, so that the surface area increases, the conductor resistance decreases, and the heat generation itself decreases. Temperature rise is suppressed, and uneven temperature rise is reduced. This enables efficient cooling. Although not shown in the drawing, a conductive wire having a smaller diameter than the other portions may be used for the series coils 32v ₁ , 32v ₂ , 32v ₃ in the V phase. This is because the coil 32w ₂ has a considerably low temperature and a small-diameter conductive wire is sufficient. Similarly, a small-diameter conducting wire may be used for the series coils 32w ₁ , 32w ₂ , 32w ₃ arranged in the vicinity of the oil jet port 64. However, since the arrangement of the oil jet port 64 differs depending on the design conditions, the conducting wire of the coil 32 at a position corresponding to the oil jet port 64 should have a small diameter.

As described above, in the three-phase AC generator 10 according to the present embodiment, the coil at the location where the temperature rise is the highest in comparison with the case where the conducting wires of all the coils 32 are formed with the same diameter in use. The wire diameters of 32v ₁ and 32u ₃ are increased. Thereby, there is little bias | inclination of the temperature rise of each coil 32, and efficient cooling is attained.

  Regarding the coil 32, it has been described that all three conductors in series use the same diameter, but the conductor diameter may be changed for each coil depending on design conditions.

  Thus, the three-phase AC generator 10 according to the present embodiment can be efficiently cooled and reduced in size, and can be suitably applied to a motorcycle or the like.

  Of course, the three-phase AC generator according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

It is a front view of the three-phase alternating current generator which concerns on this Embodiment. It is a section side view of the three-phase alternating current generator concerning this embodiment. It is a partial cross section back view of a cover. It is a connection diagram of a stator. FIG. 3 is a temperature distribution diagram of a three-phase AC generator when all the coil wires are formed to have the same diameter in a use state mounted on a motorcycle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Three-phase alternating current generator 12 ... Main body case 14 ... Cover 14a ... Rib 16 ... Stator 18 ... Crankshaft 22 ... Outer rotor 30 ... Teeth 32 ... Coil 48 ... Magnet 60 ... Oil passage 64 ... Oil outlet

Claims (4)

A rotor that rotates integrally with the crankshaft;
A stator facing the rotor;
In a three-phase AC generator of an internal combustion engine having
The plurality of coils constituting the stator are formed of two or more conductive wires having different wire diameters depending on the arrangement location.
A three-phase AC generator characterized in that when all the coil conductors are formed with the same diameter in use, the coil conductor at the highest temperature rise is the largest conductor. . The three-phase AC generator according to claim 1,
The stator coil is formed by parallel connection of two series coils each of the U, V and W phases.
The three-phase AC generator is characterized in that the series coil is formed of conducting wires having the same diameter. A rotor that rotates integrally with the crankshaft;
A stator facing the rotor;
In a three-phase AC generator of an internal combustion engine having
The plurality of coils constituting the stator are formed of two or more conductive wires having different wire diameters depending on the arrangement location.
A three-phase AC generator characterized in that the wire diameter of the coil closest to the conductor drawing portion is the largest. The three-phase AC generator according to claim 3,
A three-phase AC generator characterized in that the wire diameter of a series coil including the coil at the lower end of the stator is the smallest.

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