JPH07123343B2 - Rotor electric motor rotor molding method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for molding a rotor used in a rotary electric motor.

(Prior Art) A rotor of a rotary electric motor is shown in FIG. An iron core portion 1 which is a rotor yoke formed by stacking a number of punched thin steel plates.
Is formed, and the rotary shaft 2 is inserted into the shaft hole of the iron core portion 1. The rotating shaft 2 and the iron core part 1 are integrated by shrink fitting, welding, etc., and the iron core part 1 and the rotating shaft 2 are supported by the rotating shaft 2 being supported by a frame (not shown) via a bearing 3. It is designed to rotate integrally. A key 4 is fitted to the left end of the rotary shaft 2 and connected to an actuating member (not shown) to output a rotational force. Such an iron core part 1
End rings 5 formed by die-casting are joined to both ends of the sheet to maintain the laminated state of the thin steel sheets. Next, a conventional method of forming such end rings 5 at both ends of the iron core portion 1 will be described with reference to FIGS. 7 and 8. FIG. 7 is a cross-sectional view of a die-casting die for die-casting. A movable base 7 on the left side is slidably arranged with respect to a fixed base 6 on the right side. A fixed die 8 and a movable die 9 are attached to the facing surfaces of the fixed base 6 and the movable base 7, respectively, and a body 11 is supported between them via a core 10. The core 10 is provided in a plurality of stages at regular intervals and communicates with a runner 12 to which a molten metal 13 such as aluminum is supplied. The iron core portion 1 in which thin steel plates are laminated is inserted into the body 11 and the end rings are die-cast at both ends, but the mandrel 14 is inserted in the shaft hole into which the rotary shaft is inserted.
Is inserted to prevent the molten metal from entering the shaft hole. Reference numeral 15 is an ejector pin for pressing the mandrel 14. The molten metal 13 is fed from the runner 12 into the space between the cores 10 by sliding the injection piston 16 to fill the cores 10. After the molten metal 13 is cooled and hardened, the movable base 7 slides, and the mandrel is inserted into the shaft hole.
The rotor is taken out with 14 still inserted. After taking out from the die cast mold, the mandrel 14 is pulled out from the rotor, and the molding is completed. FIG. 8 is a perspective view of this state, in which the end ring 5 having the fins 5a is formed.
Are integrated with both ends of the iron core 1. Mandrel 14
Is composed of a head portion 14a and a shaft portion 14b, and the shaft portion 14b is pulled out from the shaft hole 17 of the rotor by pulling the head portion 14a with a hook or the like. In addition,
An axial key 14c is formed on the shaft portion 14b, which is used when thin steel plates are skew-laminated.

(Problems to be Solved by the Invention) In such a molding method, it is necessary to match the outer diameter of the mandrel 14 with the inner diameter of the shaft hole 17 of the rotor.
However, the inner diameter of the shaft hole 17 of the rotor differs depending on the horsepower and size of the rotary motor, the diameter of the rotor, the thickness of the rotor, and the like. Therefore, there are problems that the number of mandrels is increased and that selection is time-consuming and die-casting is troublesome.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a molding method capable of adapting a single mandrel to shaft holes having different diameters.

(Means for Solving Problems) As means for solving the above problems, the present invention forms an iron core part by laminating thin steel plates having a shaft hole for inserting a rotary shaft, and then forming the iron core part. With the mandrel inserted inside the shaft hole, form the end ring by die casting, and then pull out the mandrel from this shaft hole and mount the rotary shaft in this shaft hole. In the method, a temporary core portion having a mandrel hole for inserting the mandrel and connected to the shaft hole by a joint portion having a slight width is formed inside the shaft hole of the thin steel plate,
The core portion is formed by stacking the thin steel sheets, and
After forming the end ring by the die casting in a state where the mandrel is inserted in the mandrel hole of the iron core part, by applying a force in the axial direction of the shaft hole to the temporary core part, the temporary core A part is removed from the iron core part, and the rotary shaft is mounted in the shaft hole after removal of the temporary core part.

(Operation) According to the above configuration, even if the diameter of the rotating shaft to be mounted changes, it is only necessary to change the diameter of the shaft hole accordingly, and the diameter of the mandrel hole can be made constant. Therefore, it is possible to perform die casting on the iron core portions of the rotating shafts having different diameters with the mandrel having a single diameter.

Since the temporary core part into which this mandrel is inserted is connected to the inside of the shaft hole by the joint part of a slight width, it can be easily separated from the iron core by applying a certain amount of axial force. can do.

(Example) Hereinafter, the present invention will be described more specifically.

According to the present invention, a temporary core is formed in a shaft hole of an iron core formed by laminating thin steel plates, and the temporary core is removed after die casting.

1 and 2 are a side view and a perspective view of the iron core portion 20. Shaft hole in the center by punching
The core 21 is formed by stacking a number of thin steel plates 23 having a plurality of slots 22 formed at equal intervals on the periphery. In this embodiment, the thin steel plates 21 are skew-laminated,
The shaft hole 21 and each slot 22 are skewed and communicate with each other in the axial direction of the iron core portion. The shaft hole 21 is for inserting the rotary shaft of the rotary motor, and is formed to have an inner diameter substantially equal to the diameter of the corresponding rotary shaft. Then, a temporary core portion 24 is formed in the shaft hole 21. Temporary core 24
Is partially joined to the thin steel plate 23, and the other part is formed to have an outer diameter smaller than the diameter of the shaft hole 21. That is, most of the temporary core portion 24 except the joint portions 25, 25 is separated from the thin steel plate 23, and is easily removed by applying a small force. In this embodiment,
A mandrel hole 26 for mandrel insertion is formed inside the temporary core portion 24 so that a die-cast type mandrel can be inserted. The temporary core portion 24 and the mandrel hole 26 are formed by punching similarly to the shaft hole 21 and the slot 22. In addition, the temporary core 24 is crimped to the V crimp and the like.
27 are formed, and similar caulking portions are also formed on the temporary core portions 24 of the adjacent thin steel plates, and the iron core portions 20 are formed by caulking and joining each other. By forming the caulking portion 27 on the temporary core portion 24 in this manner, it is not necessary to form the caulking portion on the thin steel plate 23, and since the temporary core portion 24 is finally removed, the caulking portion 27 is an iron core portion. Will never remain in 20. Therefore, it is possible to prevent the deterioration of the electric characteristics of the rotor due to the formation of the crimped portion.

The iron core portion 20 thus formed is then set in a die-casting mold to form end rings 28 at both ends. Since the same die-cast mold as the conventional technique can be used as it is, the process is omitted, but the mandrel 14 is inserted into the mandrel hole 26 of the temporary core part 24 to perform the die-casting process. FIG. 3 shows a cross-sectional view in which the end rings 28 are formed at both ends of the iron core portion 20 by die casting, and in this state, when the pushing tool 29 is abutted and pressed from one end portion of the temporary core portion 24, The temporary core portion 24 is easily removed from the iron core portion 20, and the mandrel 14 is also removed at the same time.
FIG. 4 is a perspective view in which the temporary core portion 24 is removed, FIG. 5 (a) is a side view of the iron core portion 20, and FIG. 4 (b) is a side view of the temporary core portion 24. After removing the temporary core portion 24, the shaft hole 21 is formed in the iron core portion 20, so that the rotation shaft can be easily fitted. According to such a method, since the diameter of the mandrel hole of the temporary core portion 24 can be unified to a single diameter, it can be applied to shaft holes of any diameter by using a single mandrel.

In the present invention, the caulking portion 27 may not be formed on the temporary core portion 24 when the thin steel plates are laminated well.

〔The invention's effect〕

As described above, according to the present invention, since the temporary core portion that is removed after die casting is formed in the shaft hole, die casting can be performed using a single mandrel, and the die casting process becomes easy.

[Brief description of drawings]

1 and 2 are a side view and a perspective view of an iron core formed by the present invention, FIG. 3 is a cross-sectional view of a temporary core removing step, FIG. 4 is a perspective view thereof, and FIG. ) And (b) are side views of the iron core and the temporary core, FIG. 6 is a front view of an example of a rotor, FIG. 7 is a cross-sectional view of a die-cast type in a conventional method, and FIG. It is a perspective view of the mandrel pulling-out process by a method. 20 …… Iron core, 21 …… Shaft hole, 23 …… Thin steel plate, 24…
… Temporary core part, 25 …… Joint part, 27 …… Caulking part.

Claims (2)

[Claims] 1. An iron core is formed by laminating thin steel plates having a shaft hole for inserting a rotary shaft, and then an end ring is formed by die casting with a mandrel inserted inside the shaft hole of the iron core. Then, after that, pull out the mandrel from this shaft hole and attach the rotating shaft to this shaft hole.In the rotor molding method of the rotary electric motor, there is a mandrel hole for inserting the mandrel and a small width. A temporary core part connected to the shaft hole by the joint part is formed inside the shaft hole of the thin steel plate, and the iron core part is formed by stacking the thin steel plates.
After forming the end ring by the die casting in a state where the mandrel is inserted in the mandrel hole of the iron core part, by applying a force in the axial direction of the shaft hole to the temporary core part, Part is removed from the iron core part, and the rotary shaft is mounted in the shaft hole after removal of the temporary core part. 2. The method for forming a rotor of a rotary electric motor according to claim 1, wherein a caulking portion for connecting adjacent temporary core portions is provided on the temporary core portion of each of the laminated thin steel plates. A method for forming a rotor of a rotary electric motor, comprising: