JP3855453B2 - AC generator for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular AC generator mounted on a passenger car, a truck or the like.
[0002]
[Prior art]
In recent years, the slant nose for reducing vehicle running resistance and improving visibility has brought the entire engine and electrical components closer to the road surface, and the flooding conditions due to water splashed from the tires during running have become severe. In cold areas, a large amount of salts such as calcium chloride and sodium chloride are sprayed to prevent road freezing in winter, so that these accumulate on the road surface as an electrolytic solution, and these electrolytic solutions are involved when driving. As a result, the engine room is more severely corrosive. As described above, since the vehicular generator mounted on the engine is exposed to a severe environment, a problem may occur due to corrosion by water or salt.
[0003]
On the other hand, with the narrowing of the engine room, there is no room for the vehicle AC generator mounting space. In addition, weight reduction for improving fuel efficiency and improvement in power generation capacity accompanying an increase in electrical loads such as safety control devices are also required. Needless to say, cost reduction is required.
That is, there is a need for an automotive alternator that has excellent corrosion resistance and is small, light, and low in cost. In this case, the main cause of power generation stoppage due to corrosion is that the insulating coating on the surface of the stator coil is damaged due to mechanical friction in the process of mounting the stator coil in the slot of the stator core and molding it. When water, particularly salt water, which is an electrolytic solution, is applied, it reacts with copper, which is the electrical conductor of the coil, to produce a conductive compound. The progress of this reaction further accelerates the release of the film and copper, and finally the stator. This is because an electrical short-circuit occurs between the iron core and the coil or between the coils, and local rapid heat generation occurs as the output decreases, and finally the stator coil is disconnected.
[0004]
On the other hand, it is conceivable to increase the thickness of the stator coil film or to improve the scratch resistance. Further, in the impregnation treatment with a resin generally performed for vibration resistance and environmental resistance after winding of the stator coil, it is generally used to apply the impregnation resin thickly. In addition, as described in Japanese Patent Laid-Open No. 3-235644, there is a case where a drip-proof cover is attached to the cooling air intake side of the generator to block a direct water entering path from the outside.
[0005]
[Problems to be solved by the invention]
Increasing the thickness of the stator coil film not only increases the material cost of the film, but also increases the man-hours for manufacturing the coil material in order to increase the number of times the film is coated, and thus the cost of the stator coil increases significantly. In addition, as the coating becomes thicker in the slot, the occupied area ratio of the cross-sectional area of the stator coil housed in the throttle relative to the cross-sectional area of the slot (hereinafter referred to as the space factor) increases, so that the stator coil can be inserted and assembled. The occurrence of film scratches increases, and the corrosion resistance performance does not improve as expected. Also, if the coating is made thicker to have the same space factor, the copper cross-sectional area will be narrowed, so that the electrical resistance value of the stator coil will increase and the output will decrease. There is also a problem that the temperature rises due to the deterioration of heat dissipation of the stator coil itself, and the output decreases accordingly. If the slot area is increased so that the same space factor is obtained in order to compensate for this decrease in output, the physique must be increased to secure the magnetic path cross section of each part of the stator core from the surface of the magnetic circuit. This is contrary to the demand for miniaturization.
[0006]
If the coating has excellent scratch resistance, the cost rises naturally. However, for a generator having a high cost ratio of the stator coil in the entire components, the effect of the cost increase is greater than other components. In addition to increasing the thickness of the film, increasing the heat resistance of the film as the temperature increases further increases the cost.
Even when the impregnating resin is applied thickly, it goes without saying that, as described above, there are problems of an increase in material cost, an increase in production cost due to an increase in man-hours, and a decrease in output due to a temperature rise.
[0007]
In the method disclosed in Japanese Patent Laid-Open No. 3-235644, in a recent small and high-power vehicle generator, as shown in the embodiment of the publication (Attached FIG. 13), a fan is attached to the side surface of the rotor. After the cooling air is taken in by rotation, the stator coil is cooled by using the air discharged through the window provided in the radial direction of the frame. That is, since the stator coil is located near the ventilation window provided in the radial direction of the frame, water and salt water from the outside in the radial direction of the generator can easily reach the periphery of the stator. In order to prevent this, a drip-proof cover is attached to the outside of the window provided in the radial direction of the frame, or, among the windows provided in the radial direction of the frame as shown in FIG. In either case, the ventilation resistance increases and the cooling air volume decreases, and in addition, the escape of hot air after cooling the heating elements such as the stator coil and rectifier is hindered. The problem arises that the temperature rises significantly. In addition, the addition of the drip-proof cover increases the material and production costs due to an increase in the number of parts.
[0008]
The present invention solves the above-mentioned conventional problems, achieves a long life by preventing corrosion due to moisture from the outside, is excellent in cost, and does not cause new problems such as temperature rise. An object is to provide an AC generator for a vehicle that can be reduced in size and weight.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the alternator for vehicles of the present invention uses aluminum as the electric conductor material of the stator coil, so that a conductive compound is not generated even when it is flooded with salt water or the like. Sufficient cooling ventilation is ensured, the output is not reduced, and further weight reduction is achieved.
[0010]
According to the first aspect of the present invention, there is provided a vehicular AC generator including a field rotor, a stator disposed opposite to the outer periphery of the rotor, and a frame that supports the rotor and the stator. The stator includes a laminated core having a plurality of slots, an electric conductor made of aluminum and an electric insulator accommodated in the slot, and the electric conductor is different from the accommodating portion located in the slot. It is composed of a connecting portion that connects the two storage portions of the inside, and forms a winding as a whole, and the frame is arranged so as to surround the connecting portion of the electric conductor from the outer peripheral side, and on the radially outer side of the connecting portion It has a plurality of windows.
[0011]
  As a result, when electrolytic water droplets containing salt or the like reach the stator coil, the electrical conductor of the stator coil is made of aluminum, so that no conductive compound is deposited even if the electrical conductor is corroded by corrosion. . For this reason, even if stator coil corrosion progresses due to water on the stator coil, it is possible to prevent an electrical short circuit between the coil and the stator core and between the coils. Therefore, the cross-sectional area of the electric conductor can be enlarged, that is, the space factor can be increased. In addition, the frame window in the direction of flooding is blocked and a drip-proof cover is not required, and a plurality of windows can be provided over almost the entire outer diameter of the transition portion of the stator coil. A sufficient path can be secured, and the stator coil can be sufficiently cooled without a significant temperature rise of the entire generator. From the above, since the stator coil can be highly cooled and the cross-sectional area of the electric conductor can be increased, it is possible to use aluminum having a larger specific electric resistance value than copper. Moreover, it is not necessary to increase the physique in order to ensure output, and weight reduction can be realized by the difference in specific gravity between copper and aluminum. Furthermore, by changing from copper to aluminum, the material cost is greatly reduced, and there is no need to thicken the coating, apply the impregnating resin thickly, or add a drip-proof cover. Is possible.
  Furthermore, the space factor of the electric conductor accommodated in the slot is 50% or more and less than 80%. Conventionally, the space factor is generally around 40%, but as shown in FIG. 3B, in the present invention in which the electrical conductor is aluminum, the specific electric resistance value is larger than copper, but as described above. Electric conductor cooling performance by reducing the resistance value by expanding the cross-sectional area of the conductor, significantly improving the cooling performance by securing a cooling ventilation path, and improving the heat transfer from the stator coil to the stator core by further increasing the space factor Therefore, if the space factor is set to 50% or more, the same output as when copper is used can be obtained.
  In addition, when the space factor is further increased, in the life test under water spray conditions, the conventional copper electrical conductor is inserted into the stator slot, and the scratches generated in the insulating film during the assembly process increase. Since the conductive compound is generated due to the corrosion, the life is shortened. However, when the electrical conductor is made of aluminum, the conductive compound is not generated by the corrosion, so that a long life is ensured. FIG. 3 (a) shows the number of cycles until the occurrence of an abnormality in a test in which a voltage was applied to the stator coil under the salt spray condition according to JIS-Z-2371. Whereas abnormalities in conventional stators using copper for electrical conductors are due to poor voltage resistance due to electrical shorts, abnormalities in the present invention where aluminum is used for electrical conductors elutes aluminum, resulting in thinning of electrical conductors. This shows how the electrical resistance value of the stator increases. From FIG. 3 (a), the average number of cycles until failure when the conventional electrical conductor is copper and the space factor is 40% is 20 cycles. However, when the electrical conductor is aluminum, the failure occurs in 20 cycles. The product rate is 80%.
  Therefore, by setting the space factor to 50% or more and less than 80% in the present invention, it is possible to provide a power generator that is superior to the conventional one in terms of both output and environmental resistance.
[0012]
According to a second aspect of the present invention, in the vehicular AC generator according to the first aspect, the transition portion of the stator coil is arranged to receive cooling air from the inner peripheral side of the stator. Yes. As a result, drying of the water to the stator crossing portion is promoted, so that there is an effect of suppressing the progress of corrosion. In addition, the wind hitting the crossing portion allows the output to be increased by reducing the temperature of the stator coil.
[0013]
According to a third aspect of the present invention, in the vehicular AC generator according to the first or second aspect, a fan is provided on at least one side of both axial ends of the rotor facing the stator. It is characterized by having. As a result, it is possible to greatly increase the flow rate of the cooling air sucked from the outside in the axial direction to be discharged in the radial direction, further improve the cooling of the stator coil made of aluminum, and increase the output.
[0014]
According to a fourth aspect of the present invention, in the vehicle alternator according to any one of the first to third aspects, the space factor of the electric conductor housed in the slot is 50% or more and less than 80%. It is characterized by being.
Conventionally, the space factor is generally around 40%, but as shown in FIG. 3 (b), in the present invention in which the electric conductor is aluminum, the specific electric resistance value is larger than copper, but as described above. Electric conductor cooling performance by reducing the resistance value by expanding the cross-sectional area of the conductor, significantly improving the cooling performance by securing a cooling ventilation path, and improving the heat transfer from the stator coil to the stator core by further increasing the space factor Therefore, if the space factor is set to 50% or more, the same output as when copper is used can be obtained.
[0015]
In addition, when the space factor is further increased, in the life test under water spray conditions, the conventional copper electrical conductor is inserted into the stator slot, and the scratches generated in the insulating film during the assembly process increase. Since the conductive compound is generated due to the corrosion, the life is shortened. However, when the electrical conductor is made of aluminum, the conductive compound is not generated by the corrosion, so that a long life is ensured. FIG. 3 (a) shows the number of cycles until the occurrence of an abnormality in a test in which a voltage was applied to the stator coil under salt spray conditions according to JIS-Z-2371. Whereas abnormalities in conventional stators using copper for electrical conductors are due to poor voltage resistance due to electrical shorts, abnormalities in the present invention where aluminum is used for electrical conductors elutes aluminum, resulting in thinning of electrical conductors. This shows how the electrical resistance value of the stator increases. From FIG. 3 (a), the average number of cycles to failure when the conventional electrical conductor is copper and the space factor is 40% is 20 cycles. However, when the electrical conductor is aluminum, the failure occurs in 20 cycles. The product rate is 80%.
[0016]
  Claim 4According to the invention described in claim 1,3In the vehicular AC generator according to any one of the above, at least a part of the electric conductor has a substantially rectangular shape along a slot shape. As a result, the space factor is increased to increase the winding cross-sectional area. As a result, the winding resistance value can be reduced to increase the output, making it easy to manufacture even when the space factor is 50% or more. Can be reduced.
[0017]
  Claim5According to the invention described in claim 1,4In the vehicular AC generator according to any one of the above, a pair of two or more of the electric conductors divided into an outer layer located in the back of the slot and an inner layer located on the entrance side are disposed, and the different conductors in the different slots The inner and outer layer conductors are connected in series. Thereby, since interference between different phases at the crossing portion of the electric conductor can be avoided, the electric conductor can be easily arranged to the back of the slot, and high output can be achieved by increasing the space factor.
[0018]
  Claim6According to the invention described in claim 1,5In the vehicular AC generator according to any one of the above, the electrical conductor is a bare conductor, and an electrical insulating member is provided between each abutment surface and the stator core in the storage portion in the slot. In the crossing portion outside the slot, each of the electrical conductors is insulated spatially apart from each other. Since the cooling air passes through the space at the crossing section, the cooling air passes through this area, so that drying in the case of water is promoted and the effect of suppressing the progress of corrosion is improved. The effect of further reducing the temperature of the stator coil is coupled with the improvement in heat dissipation of the electrical conductor due to the absence. In addition, since there is no film, the material cost can be further reduced, and the production process can be greatly simplified, such as press production of a conductor, and the cost can be reduced.
[0019]
  Claim7According to the invention described in claim4From6In the vehicle alternator according to any one of the above, the electrical conductor has a plurality of substantially U-shaped conductor segments having straight portions accommodated in the slots, and the U core is disposed on one side of the stator core. It is characterized in that the turn portions of the letter-shaped conductor segments are aligned. Thereby, the electrical connection part which connects the edge part of a some U-shaped conductor segment can be arranged on one side, and the production process of winding formation becomes easy.
[0020]
  Claim8According to the invention described in claim4From6In the vehicular AC generator according to any one of the above, each of the inner and outer layer electric conductors has an inner conductor which is a straight portion accommodated in the slot, and outer conductors extending on both sides of the inner conductor. It has a plurality of conductor segments. Thereby, since the shape of the conductor segment is further simplified, the manufacturing process of the segment itself is facilitated, and it can be handled with inexpensive equipment.
[0021]
  Claim9According to the invention described in claim5From8In the vehicle alternator according to any one of the above, the axially pulley-side end surface of the rotor facing the stator and the inner wall surface of the outer peripheral portion of the pulley-side intake port of the frame are closely opposed to each other. It is characterized by having. As a result, this inner wall plays the role of a fan shroud, so the fan capacity of the pole core disk part is increased, and the same number of parts and processing man-hours can be achieved without increasing the number of parts and processing man-hours compared to the case where cooling fans are provided on both sides. Cooling performance can be achieved and costs can be reduced.
[0022]
  Claim10According to the invention described in claim7Or8In the vehicular AC generator described in the above, the connecting portion of the conductor segment is formed by welding the ends of the electric conductors adjacent in the radial direction, and the radial and circumferential thicknesses of the connecting portions are fusion-bonded. It is characterized by almost equality in the front and rear. Thereby, since the distance between connection parts can be ensured, the insulation defect can be prevented easily. Therefore, the manufacturing cost can be reduced.
[0023]
  Claim11According to the invention described in claim10In the vehicle alternator described in 1), the fusion spliced connecting portion remains a bare conductor. Since aluminum oxide (alumina), which is an insulator, is formed on the surface of aluminum, post-treatment for insulation is unnecessary. Thereby, manufacturing cost can be reduced.
[0024]
As described above, according to the present invention, it is possible to prevent corrosion due to water from the outside, no new problems such as a rise in temperature occur, excellent cost performance, and also realize a small size and light weight. Can be provided.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an AC generator for a vehicle according to the present invention will be described based on each embodiment shown in the drawings.
(First embodiment)
1 and 2 show a first embodiment of the present invention. FIG. 1 shows a main part of an alternator for a vehicle, here an automobile, and FIG. 2 shows a stator of this embodiment. A partial cross-sectional view is shown.
[0026]
The vehicle alternator 1 includes a stator 2 that serves as an armature, a rotor 3 that serves as a field, and a frame 4 that supports the rotor 3 and the stator 2.
The rotor 3 rotates integrally with the shaft 31, and is constituted by a set of Landel-type pole cores 32, a cooling fan 33, a field coil 34, a slip ring 35, and the like. The shaft 31 is connected to the pulley 5 and is rotationally driven by a traveling engine (not shown) mounted on the automobile.
[0027]
The frame 4 is provided with a cooling air discharge port 41 at an outer peripheral position of the stator 2 facing the transition portion 21b of the stator coil 21 and an inlet port 42 at an end surface in the axial direction. The stator 2 includes a stator core 22 and a stator coil 21 that forms a winding, and an insulator 23 that electrically insulates between the stator core 22 and the stator coil 21, and is supported by a frame 4. The stator core 22 is formed by superposing thin steel plates, and a plurality of slots 24 having openings are formed on the inner peripheral surface thereof. The end opening of the slot 24 is set to be narrower than the distance between the side surfaces in the circumferential direction in the slot 24.
[0028]
The wound stator coil 21 includes a storage portion 21a stored in the slot 24 and a crossover portion 21b connecting the storage portions 21a. Aluminum is used for the material of the electric conductor, and the space factor is set to 50% or more and less than 80%.
Fig.3 (a) has shown the result of the salt spray test by changing the space factor about the stator of the same physique. In the test, a voltage of 12 volts was applied between the stator coil and the stator core for a certain period of time under salt spray conditions in accordance with JIS-Z-2371, and then dried, between the stator coil and the stator core. The dielectric strength and the electric resistance of the stator coil were measured, and the above was repeated as one cycle until an abnormality occurred. As for the abnormality determination, with respect to the dielectric strength, an AC voltage of 800 volts was applied for 5 seconds between the stator coil and the stator core and between each phase coil to examine whether or not a short circuit occurred. Further, regarding the electric resistance value of the stator coil, it was determined that an abnormality occurred when a change of 5% or more with respect to the resistance value before the test occurred. As a result, the winding damage increases as the space factor increases, so that the conventional generator becomes abnormal with an average of 20 cycles, whereas the conductive compound of the present embodiment does not increase even if the winding damage increases. Since it is not generated, no short circuit abnormality occurs between the conductor, the stator core, and the conductors at the same number of cycles. And, although it becomes abnormal in about 40 cycles, it is an abnormal mode in which the electrical resistance value rises due to the decrease in cross section due to the progress of corrosion of aluminum itself, and in order to achieve a life of 20 cycles or more equivalent to the conventional product, It has been found that the space factor of the stator coil of the embodiment can be increased to 80%.
[0029]
FIG. 3 (b) shows a vehicle AC generator of the same physique with a conventional space factor of 40% at a rotational speed of 4000 rpm, which is generally the highest temperature of the stator coil 21, from the relationship between the output and the cooling capacity of the fan. When the copper wire is used, the output power ratio is shown when the saturation output value is 1, the space factor is changed, and the conductor material is changed to aluminum. In the case where the electrical conductor is copper, the built-in frame is used which has no window in an angle range of about 120 degrees as shown in FIG. In the case of aluminum, a frame in which all windows are open was used. From FIG. 3 (b), if the space factor is 50% or more in this embodiment, it is possible to obtain an output equivalent to the conventional one.
[0030]
In this embodiment, since the fan 3 is mounted on the rotor 3, it is possible to apply a uniform and large amount of wind to the crossover portion 21b. Therefore, since the drying of the water to the transition part 21b is accelerated | stimulated, there exists an effect which suppresses advancing of corrosion. Furthermore, since the wind which hits the crossover part 21b accelerates | stimulates cooling, the temperature of the stator coil 21 is reduced and the output increase is enabled.
[0031]
(Second embodiment)
5 to 9 show a second embodiment of the present invention. FIG. 5 is a partial sectional view of the stator, FIG. 6 is a perspective view of the electric conductor segments, and FIG. FIG. 8 is a perspective view of the connecting portion, FIG. 8 is a side view of the stator from the radial direction, and FIG. 9 is a perspective view of the stator.
[0032]
In the first embodiment, the stator coil 21 is indicated by a round line. However, as shown in FIG. 5, if at least a portion located in the slot has a substantially rectangular shape along the slot shape, the space factor is 50% or more. It will be easier to increase.
Moreover, the substantially U-shaped conductor segment 61 which has the turn part 61c as shown in FIG. 6 is used for a stator coil instead of a continuous line. The conductor segment 61 includes a storage portion 61a stored in the slot 24 and a crossing portion 61b that connects the storage portions 61a. The pitch P2 of the conductor segment 61 is previously matched with the predetermined magnetic pole pitch P1 of the stator slot 24 into which the segment 61 is to be inserted, and the straight turn is aligned from the axial direction of the stator core. The conductor outside the slot on the side is bent to connect the end portions 61d to each other to form a winding. At this time, the end 61d of each conductor segment 61 may be connected by electrical continuity such as ultrasonic welding, arc welding, brazing, or machining means such as caulking. Among them, in arc welding, aluminum has a lower melting point and lower thermal conductivity than copper, which is a normal conductor material, and as a result, the connection part is locally melted as shown in FIG. 7, affecting the surrounding shape. It is easy to control so that there is no. As shown in FIG. 7, the two end portions 61 d of the two conductor segments 61 are arranged in parallel, and the melting portion 61 e is formed only in the adjacent portion. For this reason, the end 61d after welding substantially maintains the shape before welding and has a sharp angle except for the adjacent portion. Therefore, it becomes easy to ensure the distance between the connection parts. Further, aluminum oxide is also formed on the aluminum surface of the connecting portion, as with other aluminum surfaces. Since this aluminum oxide is an insulator, post-processing after welding is not necessary, so that the manufacturing cost can be reduced. At this time, each conductor segment 61 is divided into two or more halves of the outer layer located in the back of the slot 24 and the inner layer located on the entrance side, and the conductors in the inner and outer layers of different slots 24 are arranged in series. Since they are connected, as shown in FIG. 9, it is possible to avoid interference between different phases at the crossover 61b.
[0033]
As described above, since the conductor segment 61 can be easily arranged to the back of the slot, it becomes easier to increase the space factor in the slot 24. FIG. 9 shows a case where the number of conductors per slot is four turns, that is, two pairs of outer layer and inner layer, and the connecting portions are close to each other in the radial direction. Therefore, it is further advantageous to use aluminum that is easily melted locally in order to ensure insulation between the connecting portions. From FIG. 9, it is the same that interference between different phases can be avoided even if the logarithm changes. Further, by dividing the winding into conductor segments, it is easy to make the conductor cross-section rectangular, and conductors can be created with a press or the like, so that material and processing costs can be reduced.
[0034]
In addition, iron, which is a material of a stator core, and copper, which is a material of a general stator coil, have the same specific gravity, so that it is difficult to separate even when melted. However, if aluminum is used for the stator coil, the specific gravity is about one-third that of iron, so separation by melting is possible. As described above, the reuse of the material can be promoted.
(Other embodiments)
In the second embodiment, the turn portion 61c of the conductor segment 61 is provided on one side of the stator side surface. However, it may be separated and both sides may be joined by welding or the like. The conductor segment 62 in this case is shown in FIG. The conductor segment 62 includes a storage portion 62a which is a substantially linear portion inserted into the slot, and a crossing portion 62b which is a substantially linear portion extending on both sides of the stator core on both sides of the inner conductor. The crossing portion 62b has an angle and a length that circulates about half the distance of the magnetic pole pitch. Also in this case, it is easy to increase the space factor in the slot, and the shape of the conductor segment 62 is simplified compared to the substantially U-shape, so that the manufacturing process of the segment itself becomes easy and inexpensive. Can be manufactured with simple equipment.
[0035]
Further, as the electric conductor, a bare conductor without a film is used, and as shown in FIG. 11, an electric insulation member 23 is arranged between the contact surface of each electric conductor and the stator core 22 in the accommodating portion 21a in the slot. Then, the conductors may be insulated from each other, and the conductors may be insulated by spatially separating each of the electric conductors at the crossing portion outside the slot. At this time, since the cooling air passes through the space of the transition part, the drying in the case of water is further promoted and the effect of suppressing the progress of corrosion is improved, and the cooling air hits each electric conductor, so the heat radiation of the electric conductor without the film Combined with the improvement of the performance, the cooling performance of the electrical conductor is further improved. In addition, since there is no film, the material cost can be reduced further, and the production process can be greatly simplified and the cost can be reduced because there is no fear of film damage, as well as the production of press conductors.
[0036]
Furthermore, the electrical conductor may be a composite conductor of a rectangular conductor and a round wire. For example, when the inside of the slot is a rectangular conductor and the outside of the slot is a round wire, the effect of increasing the cooling performance by increasing the space factor inside the slot and improving the heat transfer of the stator core can be obtained similarly. On the other hand, if the inside of the slot is a round wire and the outside of the slot is a substantially flat conductor, the gap between the conductors in the coil end portion can be sufficiently secured, and the cooling resistance can be reduced and the cooling performance can be improved.
[0037]
Further, as shown in FIG. 12, the inner wall surface 43 of the outer peripheral portion of the intake port 41 of the frame may be made to approach and face the end surface where the cooling fan of the rotor is not installed. In this case, since the inner wall surface 43 of the frame 4 plays a role of a fan shroud, the fan capability of the pole core disk portion 35 is increased. Thereby, compared with the case where cooling fans are provided on both sides, the same cooling performance can be achieved and the size can be further reduced without increasing the number of parts and the number of processing steps.
[0038]
According to the embodiment described above, AC power generation for vehicles that can prevent corrosion due to external moisture, does not cause new problems such as temperature rise, is excellent in cost, and is also small and lightweight. Machine can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of an automotive alternator according to a first embodiment of the present invention.
FIG. 2 is a partial cross-sectional view of a stator in the first embodiment of the present invention.
FIG. 3A is a graph showing the result of a salt spray test with respect to the space factor, and FIG. 3B is a graph showing the output ratio result with respect to the space factor.
FIGS. 4A and 4B show examples of a conventional window closing frame for shielding water, wherein FIG. 4A is a front view, and FIG. 4B is a side view, arranged on a common center line.
FIG. 5 is a partial cross-sectional view of the stator when the portion of the stator coil located in the slot has a substantially rectangular shape along the slot shape.
FIG. 6 is a segment perspective view when the stator coil is not a continuous line but a substantially U-shaped conductor segment having a turn portion.
FIG. 7 is a perspective view of a connection portion between conductor segments.
FIG. 8 is a side view of a stator incorporating a substantially U-shaped conductor segment.
FIG. 9 is a perspective view of a stator incorporating a conductor segment.
FIG. 10 is a perspective view of another conductor segment example.
FIG. 11 is a partial cross-sectional view of the stator when the electrical conductor is a bare conductor.
FIG. 12 is a partial cross-sectional view of an automotive AC generator using a pole core disk portion as a cooling fan.
FIG. 13 is a cross-sectional view showing an example of an automotive alternator having a conventional drip-proof cover.
[Explanation of symbols]
1 AC generator for vehicles
2 Stator
21 Stator coil
21a storage unit
21b Crossing section
22 Stator core
23 Insulator
24 slots
3 Rotor
32 shaft
32 pole core
33 fans
34 Field coil
4 frames
41 Discharge port
42 Suction port
43 inner wall
61 Conductor segment
62 Conductor segments

Claims (11)

In a vehicle AC generator having a field rotor, a stator disposed opposite to the outer periphery of the rotor, and a frame that supports the rotor and the stator,
The stator includes a laminated iron core having a plurality of slots, an electric conductor made of aluminum accommodated in the slot, and an electric insulator, and the electric conductor is disposed in the slot and in a different slot. Consists of a connecting part that connects two storage parts, and makes a whole winding,
The frame is arranged so as to surround the transition part of the electric conductor from the outer peripheral side, and has a plurality of windows on the radially outer side of the transition part ,
An AC generator for a vehicle , wherein an occupation area ratio of a cross-sectional area of an electric conductor accommodated in the slot with respect to a cross-sectional area of the stator slot is 50% or more and less than 80% . In the vehicle alternator according to claim 1,
An AC generator for a vehicle, wherein the transition portion of the stator is arranged to receive wind from an inner peripheral side of the stator. In the vehicle alternator according to claim 1 or 2,
An AC generator for a vehicle having a fan on at least one side of both end portions in the axial direction of the rotor facing the stator. In the vehicle alternator according to any one of claims 1 to 3 ,
The AC generator for vehicles, wherein at least a part of the electric conductor has a substantially rectangular shape along a slot shape. In the vehicle alternator according to any one of claims 1 to 4 ,
A pair of the electrical conductors divided into an outer layer located in the back of the slot and an inner layer located on the entrance side are disposed in pairs, and the inner and outer conductors of the different slots are connected in series. A featured vehicle alternator. In the vehicle alternator according to any one of claims 1 to 5 ,
The electrical conductor is a bare conductor, and has an electrical insulation member between each contact surface and the stator iron core in the housing portion in the slot to insulate each other. An AC generator for a vehicle, wherein each of the electrical conductors is spatially separated and insulated. In the vehicle alternator according to any one of claims 4 to 6 ,
The electrical conductor has a plurality of substantially U-shaped conductor segments having straight portions accommodated in the slots, and the U-shaped conductor segment turns are arranged on one side of the stator core. A vehicle alternator characterized by In the vehicle alternator according to any one of claims 4 to 6 ,
Each of the inner and outer layer electric conductors has a plurality of conductor segments each having an inner conductor that is a straight portion accommodated in the slot and outer conductors extending on both sides of the inner conductor. AC generator. In the vehicle alternator according to any one of claims 5 to 8 ,
An AC generator for a vehicle, characterized in that an axially pulley-side end surface of the rotor facing the stator and an inner wall surface of a pulley-side intake port outer peripheral portion of the frame are in close proximity to each other. In the vehicle alternator according to claim 7 or 8 ,
The connecting portion of the conductor segment is formed by fusion welding the ends of the electric conductors adjacent in the radial direction, and the thickness of the connecting portion in the radial direction and the circumferential direction is substantially equal before and after fusion welding. AC generator. In the vehicle AC generator according to claim 10 ,
The vehicular AC generator characterized in that the spliced connection portion remains a bare conductor.

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