JP3381608B2 - AC generator for vehicles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle alternator mounted on a passenger car, a truck or the like.

[0002]

[Background Art] [Problems to be Solved by the Invention] With the need for slant nose to reduce vehicle running resistance and securing a living space inside the vehicle, the engine room has become smaller and narrower in recent years, and AC power generation for vehicles has been increasing. The space for mounting the machine is running out. On the other hand, the engine rotation has been reduced and the rotation of the vehicle alternator has also been reduced to improve fuel economy, but on the other hand, there is a demand for an increase in the electrical load of safety control devices, etc. There is. That is, it is required to provide a small-sized and high-output vehicle AC generator at low cost.

Generally, an AC generator for a vehicle is a rotor having a Lundell type iron core (hereinafter referred to as a pole core) having a cylindrical portion, a yoke portion, and a claw-shaped magnetic pole portion as shown in the conventional example of FIG. Composed. Since the axial length of this rotor (hereinafter referred to as the axial length) determines the total length of the generator,
In particular, miniaturization and high performance of this rotor are desired. The magnetic flux Φ flowing in the rotor flows from the cylindrical portion to the yoke portion and the claw-shaped magnetic pole portion as shown in FIG. 2, and the magnetic flux gradually flows from the claw-shaped magnetic pole portion to the stator core.

As is well known, the magnetic flux Φ generated from the rotor is represented by (rotor generated magnetic flux Φ) = (coil AT) / (sum of magnetic resistances of respective parts). Here, the coil AT is the product of the current value A flowing in the field coil and the number of turns T, and is (coil AT) ∝√ (coil cross section) (magnetic resistance) ∝ (magnetic path length) / (cross section area) ).

In the conventional design, as shown in FIG. 2, the magnetic path cross sections S1, S2, S3 of each part of the pole core are designed to be substantially the same in order to avoid local magnetic flux saturation. Also coil A
The dimensions of each part are determined so as to secure the space required for T. Corresponding to the generated magnetic flux of the rotor designed in this way, the magnetic path cross section of the stator core is made substantially the same, the slot area is determined from the winding resistance value, and as a result, the axial length of the stator is determined. In the conventional magnetic circuit thus determined, as a result, the axial length L2 of the pole core cylindrical portion and the axial length L1 of the stator core are generally substantially the same.

In order to increase the amount of magnetic flux generated by the rotor in order to improve the output, the coil AT must be increased or the magnetic resistance must be decreased. However, in the conventional design method, when it is attempted to increase the generated magnetic flux without changing the size of the rotor, in order to increase the coil AT, the cross sectional area of each part must be made uniformly small in order to increase the coil cross sectional area. I have to. Further, in order to obtain a large magnetic path cross-sectional area in order to reduce the magnetic resistance, the coil cross-sectional area must be made small, so that it has been unavoidable to design the coil in the conventional range within a trade-off range between the two.

On the other hand, for the purpose of reducing the magnetic resistance of the air gap and the stator core, the dimensional relationship of the rotor remains the same, and as shown in FIG. 3, only the axial length L1 of the stator core is larger than L2. There is also a large design method. However, even if you try to reduce the magnetic resistance on the stator side to increase the magnetic flux, the magnetic flux does not increase much because the magnetic flux is regulated by the magnetic saturation of each part of the rotor, and the output per weight is fixed. The increase in weight of the child is offset by the increase in weight, and the effect can hardly be seen.

On the other hand, ignoring the conventional design method, for example, as shown in FIG. 4, the root section cross section S3 of the claw-shaped magnetic pole section is made narrower than the cylindrical section section S1 and the yoke section S2, forcing S.
There is also one in which the coil is wound by taking a large cross section of 1, S2 and the coil. In this case, however, the root cross section S3 of the claw-shaped magnetic pole portion causes magnetic flux saturation, and the magnetic resistance at S3 sharply increases despite the ability to sufficiently flow magnetic flux at S1 and S2. Will be reduced.
Further, since the magnetic flux is clogged in the claw-shaped magnetic pole portion and leaks in the axial direction, the magnetic flux that reaches the stator iron core is significantly reduced, and the output is rather reduced.

For this reason, a method of maintaining the coil AT with a small mounting area by reducing the coil resistance and increasing the field current is also taken, but the heat generation amount of the coil increases and cooling cannot be achieved, and the excitation is increased. There is a problem that the loss increases and the power generation efficiency deteriorates significantly. Further, Japanese Patent Laid-Open No. 61-85045 discloses that a magnet is inserted between the claw-shaped magnetic poles to prevent leakage magnetic flux and increase the amount of rotor magnetic flux.
This is because the cost of the magnet material and the cost of the retainer for fixing the magnet are high, and there is a problem that the magnet scatters due to centrifugal force, so that it has not been put to practical use.

[0010]

Means for Solving the Problems
It was discovered that the magnetic flux flowing in the pole core magnetic path is always uniform, which is due to the fact that it is designed with the same magnetic path cross section. Under the condition of L1 = L2 in FIGS. 2 and 4, of course, the magnetic flux tends to flow uniformly, so that it must be designed with the same magnetic path cross section as in the conventional case. Therefore, the cross section must be substantially the same as described above, and when the magnetic path cross section is increased, all of them act in the direction of reducing the coil cross section, and the coil AT is significantly lowered. However, FIG.
When L1> L2 as described above, since the yoke portion comes to face the stator core, the yoke portion should also directly flow into the stator. Therefore, since the amount of magnetic flux flowing through the claw-shaped magnetic pole portion is reduced, the root cross section of the claw-shaped magnetic pole portion should be reduced. Therefore, as shown in FIG. 5, when the cross sections S1 and S2 of the cylindrical portion and yoke portion are made large and the root cross section S3 of the claw-shaped magnetic pole portion is made small, the magnetic flux increased in S1 and S2 is partially It flows directly into the stator from the iron part,
It was found that the rest can pass through the claw-shaped magnetic poles and flow into the stator, that is, as a result, the cross section of the magnetic path can be increased while securing the cross section of the coil, and the amount of magnetic flux can be dramatically increased. It was Also, the fact that the yoke part faces the stator core means that the magnetic flux that leaks from the yoke part to the outside at the same time is minimized, and the recovery rate of the magnetic flux generated by the rotor should be able to be dramatically increased. .

FIG. 6 shows a conventional equivalent magnetic circuit, and FIG. 7 shows an equivalent magnetic circuit based on the above idea. As can be seen from this, the magnetic resistances r6 and r7 in FIG. 7 are added in parallel to FIG. Also, the magnetic resistance r leaking from the yoke to the outside
Since 0 is taken over by r7, leakage flux to the outside Φ
You can think that 0'is almost nonexistent. Therefore, in FIG. 6, a uniform magnetic flux Φ0 flows in the pole core when the claw-shaped magnetic pole portion is not saturated, whereas in FIG. 7, the magnetic flux Φ1 flowing in the claw-shaped magnetic pole portion and the stator core directly from the yoke portion. The magnetic flux Φ1 that is split into the magnetic flux Φ2 and the magnetic flux Φ1 that passes through the claw-shaped magnetic pole part is Φ1 = {(r6 + r7) Φ0} / (r3 + r4 + r6 +
r7), and the amount of magnetic flux of Φ1 decreases. Therefore, even if the magnetic path cross section of the claw-shaped magnetic pole portion is reduced by this ratio, magnetic flux saturation does not occur and the total magnetic flux amount Φ0 does not decrease.

Further, in FIG. 6, when r3 is saturated and the magnetic resistance becomes large, it leaks from the yoke portion to the outside via r0. However, in FIG. 7, even if r3 is saturated, the stator is leaked via r7. The magnetic flux can be made to flow into the iron core, and the claw-shaped magnetic pole portion can be further reduced. Reducing the cross section of the claw-shaped magnetic pole portion means increasing the extra space in the pole core.
If this is optimally distributed to the increase of the magnetic path cross section and the increase of the coil winding area, a remarkable output improvement that cannot be obtained by the conventional design can be expected.

Magnetic resistances r6 and r7 added in parallel
Varies depending on the difference between the axial length L1 of the stator core and the axial length L2 of the cylindrical portion. Therefore, the larger the difference, the smaller the cross section of the claw-shaped magnetic pole portion, and further improvement in output is expected. However, when the axial length L1 of the stator core is increased, the weight of the stator is increased in proportion thereto, and therefore, there should be a maximum value in the output per weight.

Based on the above idea, the present invention reduces the coil resistance due to the synergistic effect of taking the axial length L1 of the stator core larger than the axial length L2 of the cylindrical portion and taking appropriate dimensions for each portion at that time. (EN) Provided is a small-sized and high-output vehicular generator which has high cooling efficiency, high efficiency and low cost without using a magnet. According to the invention described in claim 1, the field coil, the cylindrical portion around which the field coil is wound, the yoke portion extending from the axial position of the cylindrical portion to the outer peripheral direction, and the yoke portion are connected. And a field rotor composed of a Lundell-type iron core having a claw-shaped magnetic pole portion formed so as to surround the field coil, and a laminated iron core arranged to face the outer circumference of the claw-shaped magnetic pole portion of the rotor. In a vehicle AC generator having a stator composed of an armature coil, the ratio (L1 / L2) of the axial length L1 of the stator laminated core and the axial length L2 of the cylindrical core is 1.25.
The ratio of the outer diameter R1 of the Lundell-type iron core to the outer diameter R2 of the cylindrical iron-core portion (R2 / R)
1) is characterized in that it is in the range of 0.54 to 0.60.

The ratio (L1 / L2) of the axial length L1 of the stator laminated iron core and the axial length L2 of the cylindrical portion is 1.0 or more and is 1.25 to 1.25.
Since the range is set to 1.75, the pole core yoke portion can face the stator core as shown in FIG. 3, and the magnetic flux can directly flow from the yoke portion to the stator core. As a result, the magnetic flux flowing from the claw-shaped magnetic pole portion can be reduced, and the cross section of the claw-shaped magnetic pole portion can be reduced in proportion thereto. As a result, an extra space is provided in the pole core, and the ratio (R2 / R1) of the outer diameter R1 of the claw-shaped magnetic pole portion to the outer diameter R2 of the cylindrical portion is 0.54 to
In the range of 0.60, it is possible to secure a larger magnetic path cross section than before, and it is possible to provide a small-sized, high-efficiency and high-output generator without increasing the field current.

According to the invention described in claim 2, the ratio (X1 / X2) of the axial thickness X2 of the yoke portion and the radial thickness X1 of the root portion of the claw-shaped magnetic pole portion is 0. It is characterized in that it is in the range of 5 to 0.9. Since the ratio is set to the above ratio, the magnetic flux density of the claw-shaped magnetic pole portion can be set to an appropriate value without excess or deficiency. That is, it is possible to prevent the radial thickness X1 of the root portion of the claw-shaped magnetic pole portion from being too thick to prevent the coil cross section from being obstructed, and to prevent X1 from being too thin to reduce the output.

According to the third aspect of the present invention, the radial cross section of the field coil is substantially symmetrical with respect to the axial center, and has a mountain-like shape whose outer diameter increases toward the center position. . As a result, the coil space factor can be improved and the output can be further improved. According to the invention of claim 4, the field coil is surrounded by a sheet-shaped resin-impregnated sheet,
It is characterized in that it is in contact with the inner peripheral surface of at least one of the claw-shaped magnetic pole portions. Since the coil is in contact with the claw-shaped magnetic pole portion, it is possible to prevent noise due to magnetic force resonance of the claw-shaped magnetic pole portion. Compared with the conventional art, the effect is particularly great because the claw-shaped magnetic pole portion is set thin and the rigidity is weakened. Also, since the coil is characterized by being surrounded by a sheet-shaped insulator, sufficient insulation can be maintained between the claw-shaped magnetic pole part and the outer diameter of the coil, and the pole core extra space can be used to the maximum extent. Can be improved. In addition, since the sheet-shaped insulator is a resin-impregnated sheet, the field coil can be fixed without attaching an adhesive or the like.

According to a fifth aspect of the present invention, the vehicle alternator includes a field current regulator, and a transistor of the field current regulator is connected to a high potential side of the field coil. Since the electric field coil is not applied with electric potential when the vehicle is not operating, electrolytic corrosion between the field coil and the pole core, especially the claw-shaped magnetic pole portion can be prevented.
Therefore, since the gap between the field coil and the pole core may be minimal, the space factor can be increased and the output can be further improved.

According to the invention of claim 6, the stator core is provided with slots, and the armature coil is composed of a plurality of electric conductors, and the electric conductors are arranged in a depth direction of the slots of the stator. Are insulated from each other, and a pair of two or more of the outer layer located at the back of the slot and the inner layer located at the opening side are bisected, and the conductors of the outer layer and the inner layer of different slots are connected in series. Is characterized by.

With the above arrangement, the coil ends of the armature coil are aligned and radial overlap can be avoided, so that the coil ends can be made smaller, and as a result the overall axial length of the stator can be suppressed. Therefore, the axial length L1 of the stator core is set to the axial length L2 of the cylindrical portion while the outer shell of the generator remains constant.
It can be made larger, and the above-mentioned optimum range can be set without restriction of the outer shell of the generator, and small size and high output can be achieved. In addition, since the coil length can be suppressed at the same time, L1 can be increased without increasing the coil resistance. As a result, an increase in copper loss can be prevented, so that a highly efficient and highly cooled generator can be provided.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Structure of Embodiments] FIGS.
1 shows an embodiment of the present invention, FIG. 1 is a view showing a main portion of a vehicle AC generator, and FIGS. 8 and 9 are explanatory views of a rotor of the vehicle AC generator of the present embodiment. Is.

The vehicle alternator 1 comprises a stator 2 acting as an armature, a rotor 3 acting as a field, the rotor,
It is composed of a housing 4 that supports the stator, a rectifier 5 that is directly connected to the stator and that converts AC power into DC, a voltage regulator 11 that increases or decreases the amount of field current and controls the amount of power generation, and the like. The voltage regulator 11 as a field current regulator is connected to the high potential side of the field coil so that no potential is applied to the field coil when the generator is not operating.

The rotor 3 rotates integrally with the shaft 6, and is composed of a set of Landel type pole cores 7, a cooling fan 12, a field coil 8, slip rings 9, 10 and the like. The shaft 6 is connected to the pulley 20 and is rotationally driven by a traveling engine (not shown) mounted on the automobile. The pole core 7 of the rotor 3 is composed of a cylindrical portion 71, a yoke portion 72, and a claw-shaped magnetic pole portion 73. The field coil 8 has a mountain-like shape with a large outer diameter at the axial center and a smaller outer diameter as it goes to the end, and the outer diameter has a shape along the claw-shaped magnetic pole portion 73 of the pole core. The insulating paper 81 is abutted against the inner diameter surface of the claw-shaped magnetic pole portion 73 with an appropriate compression force. The insulating paper 81 uses a sheet-shaped resin-impregnated sheet to surround the field coil 8, and the field coil 8 is fixed by heat treatment. The field coil 8 is enclosed by spirally winding a strip-shaped sheet or sandwiching petal-shaped sheets from above and below.

The stator 2 is composed of a stator core 32, an armature coil 33, and an insulator 34 that insulates the stator core 32 and the armature coil 33 from each other.
Supported by. The stator core 32 is formed by stacking thin steel plates. The pole core 7 described above corresponds to a Lundell-type iron core, and the stator core 32 corresponds to a laminated iron core.

Next, details of the magnetic circuit are shown in FIGS.
To explain. Axial length L of the cylindrical portion 71 of the pole core 7
2 is set smaller than the axial length L1 of the stator core 32, and the ratio (L1 / L2) is set in the range of 1.25 to 1.75. The axial thickness of the yoke portion 72 is X2, and its cross-sectional area is approximately the same (± 10% range) as the area obtained by dividing the cross-sectional area of the cylindrical portion 71 by the magnetic pole pair (6 in this embodiment). Is set. The ratio (X1 / X2) of the radial thickness X1 of the root portion of the claw-shaped magnetic pole portion 73 to X2 is set in the range of 0.5 to 0.9. The outer diameter R2 of the cylindrical portion 71 is set to a ratio (R2 / R1) to the outer diameter R1 of the claw-shaped magnetic pole portion 73 in the range of 0.54 to 0.60.

With respect to the outer diameter R2 of the cylindrical portion 71, the shaft cross-sectional area (the shaft diameter R3 is 18% of the outer diameter of the claw-shaped magnetic pole portion) is subtracted from this cross-sectional area and divided by the pole core pole pair number P to obtain the reference cross-sectional area. It was set to S1. S1 = {π / (4P)} (R2 ² −R3 ² ) The magnetic pole width W of the claw-shaped magnetic pole portion 73 is set to W = πR1 / (2P) obtained by dividing the claw-shaped magnetic pole portion outer diameter R1 by the number of poles P. The cross section S2 of the yoke portion 72 is set so that S2 = S1 = W · X2, where X2 is the axial thickness.

The axial length L0 of the pole core 7 is 55% of the outer diameter R1 which is a commonly used ratio.
The field coil 8 has a constant space factor of 68% and a constant resistance value of 2.3Ω with respect to the extra space formed by the inner surface of the cylindrical portion 71, the iron diameter portion 72, and the claw-shaped magnetic pole portion 73. The coil diameter was selected.

The stator 2 has an outer diameter dimension R4 of the pole core 7
129% of the outer diameter R1 of the claw-shaped magnetic pole portion. Stator core 3
The dimensions of each part of 2 are set so that the cross-sectional area is 66% which is a generally used ratio in consideration of the leakage magnetic flux component with respect to S1 described above. For the armature coil 33, the coil diameter was selected so that the space factor was 44% with respect to the slot area determined by the above dimensions.

Further, the air gap δ is set to 0.35 mm which is generally used in a vehicle AC generator. Other detailed dimensions such as the tip thickness of the claw-shaped magnetic pole portion 73 are set in the same ratio as in the conventional vehicle generator. The outer diameter R1 of the claw-shaped magnetic pole portion 73 was 92 mm. The armature coil 33 is composed of a substantially U-shaped electric conductor 231 having two linear portions 232 as shown in FIG. As shown in FIG. 17, one of the straight portions 232 is arranged on the inner diameter side which is the opening side in the radial direction of the slot to form an inner layer, and the other is arranged on the outer diameter side located inside the slot to form the outer layer. I am doing it. Furthermore, the turn portion 233 that connects the end portions of the linear portions 232 of the electric conductor 231 is a coil end portion. The plurality of electric conductors 231 are stacked and inserted from one end surface of the stator core 32 so that the coil ends are aligned. Then, each linear portion 232 of the inner layer or the outer layer protruding from the other end surface of the slot is bent in the circumferential direction of the stator core 32 and connected to each linear portion 232 of a different layer of each electric conductor 231 which is offset by one pole. Therefore, the armature coil 33 is configured.

[Effects of the Embodiment] The ratio (L1 / L2) of the axial length L1 of the stator core 32 and the axial length L2 of the cylindrical portion 71 of the pole core 7 is set within the range of 1.25 to 1.75. Therefore, as described above, the pole core yoke portion 72 can be opposed to the stator core 32, and the magnetic flux can directly flow from the yoke portion 72 into the stator core 32. Thereby, the magnetic flux flowing from the claw-shaped magnetic pole portion 73 can be reduced,
The cross section of the claw-shaped magnetic pole portion can be reduced in proportion to this. As a result, an extra space is provided in the pole core 7, and the ratio (R2 / R1) between the outer diameter R1 of the claw-shaped magnetic pole portion 73 and the outer diameter R2 of the cylindrical portion 71 is set larger than that of the conventional magnetic pole while securing the coil cross section. It can be ensured on the road cross section, and by setting this ratio within the optimum value range of 0.54 to 0.60, the output can be dramatically improved as compared with the conventional one.

The ratio of the axial thickness X2 of the yoke portion 72 to the radial thickness X1 of the base of the claw-shaped magnetic pole portion 73 (X1
Since / X2) is set in the range of 0.5 to 0.9, which is 1 or less, the magnetic flux density of the claw-shaped magnetic pole portion 73 can be set to an appropriate value without excess or deficiency. That is, it is possible to prevent the claw-shaped magnetic pole portion 73 from being too thick and obstruct the coil cross section, and to prevent the claw-shaped magnetic pole portion 73 from being thinned to reduce the output.

FIGS. 10, 11 and 12 show the results of confirming the effects of this embodiment. FIG. 10 shows the pole core 7 on the vertical axis.
The ratio (L1 / L2) between the axial length L2 of the cylindrical portion 71 and the axial length L1 of the stator core 32 is represented by the ratio of the outer diameter R1 of the claw-shaped magnetic pole portion 73 and the outer diameter R2 of the cylindrical portion 71 to the horizontal axis ( R2 / R1) is taken, and the output K per weight at that time is shown in contour lines. The output K per weight is the number of generator revolutions 2
A value obtained by dividing the maximum output at the time of saturation at 000 rpm and a generator voltage of 13.5 V under heat by the weight sum of the rotor and the stator is shown.

11 and 12 show L near the maximum point in FIG.
When 1 / L2 is fixed and R2 / R1 is changed, R2 /
The case where R1 is fixed and L2 / L1 is changed is shown. As shown in FIG. 10, the output increases in a region where both L1 / L2 and R2 / R1 are increased relative to the conventional range near L1 / L2 = 1, and L1 / L2 = 1.5,
The maximum value is obtained in the vicinity of R2 / R1 = 0.56. This is because the optimum range of R2 / R1 is changed by changing L1 / L2 with respect to the conventional range, and the optimum point is obtained when a larger magnetic path cross section than the conventional one, that is, when the outer diameter R2 of the cylindrical portion is large,
It shows that the maximum output can be further improved. However, L
If 1 / L2 is increased to some extent or more, the weight of the stator 2 will increase. Therefore, the range in which the output improvement effect is higher than that of the conventional one is that L1 / L2 is in the range of 1.25 to 1.75
It can be seen that 2 / R1 is in the range of 0.54 to 0.60.

Further, FIG. 10 shows that changing only L1 / L2 and R2 / R1 as in the prior art has almost no effect and, in some cases, reduces the output per weight. . The present embodiment can obtain an output characteristic that has not been available in the past due to the synergistic effect of changing both. 13, 14, and 15 use L1 / L2 as a parameter, and based on FIG. 10, the outer diameter R2 of the cylindrical portion is set to the optimum value under the outer diameter R1 of the claw-shaped magnetic pole portion R1 = 92 mm, and the root of the claw-shaped magnetic pole portion 73 is set. It is the result of plotting the output value while changing the radial thickness X1 of the part. In FIG. 13, the vertical axis indicates the cylindrical portion 7 of the pole core 7.
The ratio of the shaft length L2 of No. 1 to the shaft length L1 of the stator core 32 (L
1 / L2) is the ratio of the radial thickness X1 of the base of the claw-shaped magnetic pole portion 73 to the axial thickness X2 of the yoke portion 72 (X1 /
X2) is taken and the output K per weight at that time is shown in contour lines.

14 and 15 show L near the maximum point in FIG.
When 1 / L2 is fixed and X1 / X2 is changed, X1 / X
2 shows the case where 2 is fixed and L1 / L2 is changed. As shown in FIG. 13, it is possible to change X by changing L1 / L2.
The optimum range of 1 / X2 has changed, and the claw-shaped magnetic pole portion 7 is more than conventional.
It is shown that the cross-sectional area of the root portion of No. 3, that is, the radial thickness X1 of the root portion of the claw-shaped magnetic pole portion 73 can take an optimum point with a small value, and the maximum output can be further improved. However, L1
If / L2 is increased to some extent or more, the weight of the stator will increase. Therefore, the range in which the output improvement effect is higher than that of the conventional one is that L1 / L2 is in the range of 1.25 to 1.75,
It can be seen that / X2 is in the range of 0.5 to 0.85. Since the above ratio is set, the magnetic flux density of the claw-shaped magnetic pole portion 73 can be set to an appropriate value without excess or deficiency. That is, it is possible to prevent the claw-shaped magnetic pole portion 73 from being too thick and obstructing the coil cross section, and prevent the claw-shaped magnetic pole portion 73 from being too thin to reduce the output.

Further, FIG. 13 also shows that changing only L1 / L2 and X1 / X2 as in the prior art has almost no effect and, in some cases, rather reduces the output per weight. There is. The present embodiment can obtain an output characteristic that has not been available in the past due to the synergistic effect of changing both. Since the present embodiment is set within the optimum range shown in the above confirmation result, it is possible to secure an iron cross section and a coil cross section that could not be set in the past without increasing the size of the rotor 3, and it is possible to reduce the size and output. Can be achieved. Of course, since the amount of heat generated by the coil is the same as that of the conventional one, there is no problem that the field coil 8 becomes highly heated. On the contrary, the area where the coil end, which acts as a cooling fin of the stator 2, faces the cooling fan 12 increases, and the armature coil 33 is cooled well.

Further, in this embodiment, since the field coil 8 is substantially mountain-shaped, the winding area of the coil is increased and the output can be further increased. In addition, since the claw-shaped magnetic pole portion 73 is brought into contact with the inner peripheral surface of the claw-shaped magnetic pole portion 73 with an appropriate compression force, it is possible to prevent noise due to magnetic force resonance of the claw-shaped magnetic pole portion 73. Therefore, the root thickness can be reduced without worrying about the rigidity of the claw-shaped magnetic pole portion 73, and the maximum output can be obtained without restriction of noise. Further, in this embodiment, since the field coil 8 is surrounded by the insulating paper 81 which is a sheet-shaped resin-impregnated sheet, sufficient insulation is maintained between the claw-shaped magnetic pole portion 73 and the coil outer diameter, so that the pole core You can make the most of the extra space,
The output can be further increased. In addition, an adhesive agent for fixing the field coil 8 is not needed, and there is an effect that the equipment can be simplified.

Further, in the present embodiment, since the transistor of the voltage regulator 11 is connected to the field coil 8 on the high potential side, no electric potential is applied to the coil when the vehicle is not operating, and electrolytic corrosion occurs. It can be prevented. Therefore, as described above, even if the coil is a mountain-shaped coil, the environmental performance is not deteriorated and the space factor can be improved. Further, in the armature coil 33, since the U-shaped electric conductors 231 are aligned and arranged as shown in FIG. 17,
At the coil end, the conductors are spaced apart to form a uniform pattern in the circumferential direction. On the other hand, in the coil end portion of the conventional stator 2, there is a portion where the armature coils between different phases overlap each other in the radial direction. The radial thickness had to be reduced. Therefore, it is generally used to increase the axial height of the coil end portion to form a flat shape and reduce the radial thickness. That is, the height of the coil end portion must be kept above a certain value.
As a result, when the axial length L1 of the stator core 32 is increased, the axial total length of the stator 2 is increased accordingly, so that the stator 2 is arranged without changing the axial space of the generator outer shell. Becomes difficult. On the other hand, the coil end portion of the present embodiment has the same radial thickness as shown in FIG. 17, and the height of the coil end portion can be made lower than in the conventional case. Therefore, the stator core 3
Since the shaft length L1 of 2 can be made larger than the conventional one, it can be set in the above-mentioned optimum range without restriction of the outer shell of the generator, and small size and high output can be achieved. In addition, since the coil length can be suppressed at the same time, L1 can be increased without increasing the coil resistance. As a result, an increase in copper loss can be prevented, so that a highly efficient and highly cooled generator can be provided.

[Other Embodiments] In this embodiment, the ratio (L1 / L2) of the axial length L1 of the stator core 32 and the axial length L2 of the cylindrical portion 71 of the pole core 7 is in the range of 1.25 to 1.75. To the outer diameter R1 of the claw-shaped magnetic pole portion 73 and the cylindrical portion 71.
The ratio (R2 / R1) to the outer diameter R2 of 0.54 to 0.6
The ratio (X1 / X2) between the thickness X2 of the yoke portion 72 and the thickness X1 of the root portion of the claw-shaped magnetic pole portion 73 is set to 0.
The range is set to 5 to 0.9. As shown in FIGS. 10 and 13, in order to stabilize the output per weight at a high level, these ratio ranges are further limited, and the ratio (L1 / L
2) to 1.45 to 1.55, the ratio (R2 / R1) to 0.54 to 0.58, and the ratio (X1 / X2) to 0.6 to.
It may be set to 0.87.

In this embodiment, the result with the resistance value of 2.3Ω is shown. However, even if the resistance value is different, the principle is the same and the same result is obtained because the AT size is changed. 3. From the limit of the cooling capacity of the air-cooling type vehicle generator using the cooling fan of 1.2, a general value, that is, 1.2 to 3.6Ω in the 12V specification, and 4. in the 24V specification.
It goes without saying that the setting range of this embodiment is effective at 8 to 14.4Ω.

In this embodiment, the outer diameter R1 of the claw-shaped magnetic pole portion 73 is
Is 92 mm, the same is true even if the physique is changed, and it goes without saying that the same setting range is effective when R1 is 70 to 110 mm. In the present embodiment, the number of poles of the rotor 3 is 12, but other number of poles, for example 14,
It goes without saying that the same effect can be obtained even with 16 poles.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a vehicle AC generator according to an embodiment.

FIG. 2 is a diagram for explaining magnetic flux flowing in a conventional rotor in which the magnetic path cross sections of each part of the pole core are designed to be substantially the same.

FIG. 3 is a diagram illustrating magnetic flux flowing in a conventional rotor in which the axial length of a stator core is set larger than the axial length of a pole core cylindrical portion.

FIG. 4 is a diagram illustrating magnetic flux flowing in a conventional rotor in which a root section of a claw-shaped magnetic pole section of a pole core is set narrower than a cylindrical section section or a yoke section section and a coil section is enlarged.

FIG. 5 is a view showing the present invention in which the root section of the claw-shaped magnetic pole section of the pole core is set narrower than the section of the cylindrical section or the yoke section, and the axial length of the stator core is set larger than the axial length of the cylindrical section of the pole core. It is a figure explaining the magnetic flux which flows through this rotor.

FIG. 6 is a diagram showing an equivalent magnetic circuit of a conventional rotor.

FIG. 7 is a diagram showing an equivalent magnetic circuit of a rotor according to the present invention.

FIG. 8 is a sectional view of a pole core of a rotor included in the vehicle AC generator of this embodiment.

FIG. 9 is a plan view of a pole core of a rotor included in the vehicle alternator according to the present embodiment as viewed from the side of the cylindrical portion.

FIG. 10 is a diagram showing a result of confirming effects of the present embodiment.

FIG. 11 is a diagram showing a result of confirming effects of the present embodiment.

FIG. 12 is a diagram showing a result of confirming effects of the present embodiment.

FIG. 13 is a diagram showing another result of confirming the effect of the present embodiment.

FIG. 14 is a diagram showing another result of confirming the effect of the present embodiment.

FIG. 15 is a diagram showing another result of confirming the effect of the present embodiment.

FIG. 16 is a diagram showing a detailed shape of a substantially U-shaped electric conductor that constitutes an armature coil.

FIG. 17 is a diagram showing a detailed shape of an armature coil configured in the electrical state shown in FIG. 16.

[Explanation of symbols]

1 Vehicle AC generator 2 stator 3 rotor 6 shafts 7 pole core 8 field coil 9,10 slip ring 12 Cooling fan 32 Stator core 33 Armature coil 34 insulator 71 Cylindrical part 72 Yoke 73 Claw-shaped magnetic pole 81 insulating paper

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-28558 (JP, A) JP-A-9-154256 (JP, A) JP-A-9-172747 (JP, A) JP-A-60- 66656 (JP, A) JP-A-8-107644 (JP, A) JP-A-8-205441 (JP, A) JP-A-54-719 (JP, A) Actual Kaihei 1-123452 (JP, U) Actually open 2-122572 (JP, U) Actually open 50-34005 (JP, U) Actually open 52-42207 (JP, U) Actually open 57-111081 (JP, U) Actually open 55-100447 (JP, U) JP-B-38-16668 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 1/14

Claims (7)

(57) [Claims] 1. A field coil, a cylindrical portion around which the field coil is wound, a yoke portion extending from an axial position of the cylindrical portion to an outer peripheral direction, and the field coil connected to the yoke portion. A field rotor provided with a Lundell-type iron core having a claw-shaped magnetic pole portion formed so as to surround, and a stator composed of a laminated iron core and an armature coil, which is arranged to face the outer circumference of the claw-shaped magnetic pole portion. In the vehicle alternator, the ratio (L1 / L2) of the axial length L1 of the stator laminated core and the axial length L2 of the cylindrical portion is 1.25 to 1.75.
The ratio (R2 / R1) of the outer diameter R1 of the Lundell-type iron core and the outer diameter R2 of the cylindrical portion is in the range of 0.54 to 0.60, and the cross section S1 of the cylindrical portion is From the cross section S2 of the yoke part,
An alternator for vehicles, characterized in that the root section S3 is reduced . 2. The ratio (X1 / X2) of the axial thickness X2 of the yoke portion and the radial thickness X1 of the root portion of the claw-shaped magnetic pole portion according to claim 1, wherein the ratio (X1 / X2) is 0.5 to
An alternator for vehicles, which is in the range of 0.9. 3. The ratio (L1 / L2) according to claim 1 or 2, in the range of 1.45 to 1.55.
The ratio (R2 / R1) is in the range of 0.54 to 0.58.
And the ratio (X1 / X2) is in the range of 0.6 to 0.87 . 4. The axial cross section of the field coil according to claim 1 or 3 , wherein the axial cross section is substantially symmetrical with respect to the axial center, and the outer diameter is larger toward the center position. An alternator for vehicles, characterized in that 5. The vehicle according to claim 4 , wherein the field coil is surrounded by a sheet-shaped resin-impregnated sheet and is in contact with the inner peripheral surface of at least one of the claw-shaped magnetic pole portions. AC generator. In any one of claims 6] claims 1-5, wherein the vehicle AC generator includes a field current regulator, the transistor of the interfacial current regulator is connected to the high potential side with respect to the field coil AC alternator for vehicles. 7. The stator core according to any one of claims 1 to 6 , wherein the stator core includes a slot, the armature coil includes a plurality of electric conductors, and the electric conductor extends in a depth direction of a slot of the stator. Insulated from each other, a pair of two or more of the outer layer located at the back of the slot and the inner layer located at the opening side are bisected, and the conductors of the outer layer and the inner layer of different slots are connected in series. An alternator for vehicles, which is characterized in that