JP3609745B2 - Method for manufacturing rotor core for permanent magnet alternator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an AC generator, particularly a vehicle, including a rotor in which a pair of rotor cores having a plurality of claw portions are coupled in a face-to-face state and permanent magnets are locked between the claw portions of the facing rotor cores. The present invention relates to a method for manufacturing a rotor core for a permanent magnet AC generator for use in a ship or a ship.
[0002]
[Prior art]
The rotor of this type of alternator has a central boss part, a connecting plate part extending radially outward from the outer periphery of the boss part in the radial direction, and the connecting part parallel to the central axis of the boss part. Generally, two rotor cores composed of a plurality of claw portions protruding from the outer peripheral portion of the plate portion are combined. The two rotor cores are joined with both bosses facing each other, and the two claws are combined so that the mutual claws are inserted into the valleys between the mutual claws. The rotating shaft is fitted and fixed in the shaft hole of the part.
[0003]
In many cases, field windings are provided on the outer periphery of the boss portion, and when the field winding is excited, the claw portions alternately form different polarities in the circumferential direction. A rotating magnetic field is applied to the armature disposed outside by rotating the rotor configured as described above.
[0004]
Recently, in an AC generator for a vehicle, it has been attempted to dispose a permanent magnet between the claw portions instead of the field winding, and in this case as well, a rotor provided with the same Needless to say, if the armature is rotated, a rotating magnetic field is applied to the armature disposed around the armature. In this case, it is necessary to form a stepped portion for locking the permanent magnet corresponding to the side portion of the claw portion of the rotor core.
[0005]
Conventionally, generally, there are a hot forging method, a cold forging method, and a sheet metal bending method as a method of manufacturing a rotor core of this type of AC generator, and these techniques are independently developed. Have been implemented. There are various problems inherent to each, but from the viewpoint of technological development, the manufacturing method centered on forging technology is excellent, and the applicant has repeatedly improved mainly on forging technology. .
[0006]
Incidentally, the manufacturing method (hereinafter referred to as the current manufacturing method) of the rotor core of the alternator currently performed by the present applicant is as follows (Japanese Patent Publication No. 7-118891).
[0007]
Forging with a predetermined volume of material using a mold having an internal shape in which the space for forming the nail portion described later rises at an angle in the range of 45 degrees to 80 degrees from the lower surface extension surface of the space for forming the connecting plate portion described later A central boss portion having approximate dimensions with respect to the product, and a connecting plate portion continuous to the outer periphery thereof, protruding from the connecting plate portion at a constant angle interval, slightly shorter than the product and extending from the bottom surface of the connecting plate portion Molded into a general shape product consisting of a plurality of claws with an angle between 45 degrees and 80 degrees,
Next, the forging burrs generated on both sides of the outer peripheral edge of the connecting plate part and the claw part of the outline product in the above process are punched and removed,
After that, the shaft hole of the central boss part of the outline product is punched out, and at the same time, the claw part is bent to a 90 degree angle with the connecting plate part and the ironing process is performed to obtain a predetermined dimension,
Furthermore, the present invention provides a method for manufacturing a rotor core of an alternator in which the above-mentioned general product is pressure-regulated to obtain a precise product having a predetermined size.
[0008]
The above-mentioned current manufacturing method solves the problems of the manufacturing method (existing manufacturing method) of the rotor core of the alternator based on the combined technology of hot forging, cold forging, and mechanical cutting performed so far.
[0009]
One of the improvements is in the process of forming the material first performed in the process of the existing manufacturing method into an approximate product having a shape approximate to the product by hot forging.
[0010]
The process is generally “by hot forging a material of a predetermined volume, a central boss portion that is an approximate dimension to the finished product, a connecting plate portion that continues to the outer periphery thereof, and a plurality of slightly short pieces that protrude from the connecting plate portion. The shape is literally a shape product, so that the angle between the claw portion and the connecting plate portion at this point is 90 degrees. In addition, the mold for molding the general shape product was divided into an upper mold and a lower mold in the vicinity of the outer periphery of the space for molding the connecting plate portion.
[0011]
Therefore, even if a downward pressing force is applied to the lower mold and the material placed on the lower mold during the molding operation, the downward pressing force of the upper mold is immediately 90 degrees. The flow of the material in the upper direction of the molding space for molding each nail part that rises to the upper side is not generated, and a certain amount or more is provided between the upper mold and the lower mold, that is, near the outer periphery of the connecting plate part. Forging burrs would be overhanged, and this would increase the internal pressure of the mold and ensure upward flow of the material up to the upper part of the molding space for molding each claw part.
[0012]
Therefore, in the above process, the overhang of the corresponding forging burr is inevitable in order to ensure the extension of the claw portion to a predetermined length, and therefore, the excess volume of the material by the amount of the forging burr. As a result, in the existing manufacturing method, it was inevitable that the yield of excess volume was reduced.
[0013]
In the above-mentioned current manufacturing method, the problem of the above yield is that the claw part protruding from the connecting plate part is formed so that the angle with the connecting plate part is 45 degrees to 80 degrees in the process of forming the first outline product. This has been achieved by improving the flow of the material into the molding space for molding the mold nails and eliminating the need for generating forged burrs to increase the mold internal pressure. is there.
[0014]
The second improvement is in the process of correcting the obtained outline product to an appropriate volume.
This process of the existing manufacturing method is generally “slow cooling the outline product obtained by the hot forging, and then cutting both ends of the central boss part of the outline product and the outer surface part of the connecting plate part. This process is a process of “correcting the volume”, and this process is a machining process with a different character included in a series of forging processes, which makes it difficult to automate the entire process.
[0015]
In the current manufacturing method, this process is performed by changing the previous process as described above, thereby improving the accuracy and omitting it.
[0016]
As described above, the current manufacturing method solves the problem of the yield of the existing manufacturing method and the problem due to the fact that the process includes machining cutting with different characteristics.
[0017]
Both the current manufacturing method and the existing manufacturing method are methods for manufacturing a rotor core for constituting a rotor having field windings. Therefore, on the premise of these rotor core manufacturing methods, a rotor core for a permanent magnet generator, that is, a rotation provided with a stepped portion for locking the permanent magnet to the side portion of the claw portion as described above. We studied the production of a child iron core.
[0018]
According to the results, in the existing manufacturing method, it is not easy to form the stepped portion for locking the permanent magnet on the side portion of the claw portion in the forging process, and this must be formed by cutting or the like. The conclusion has been reached. That is, in this case, as described above, when forming the outline product, the claw portion is formed in a state of 90 degrees with the connecting plate portion if it is viewed in parallel with the central boss portion. This is because, even if an attempt is made to form a stepped portion on the side surface of the claw portion in a subsequent process, it is difficult to form a mold that enables the stepped portion.
[0019]
On the other hand, as described above, the current manufacturing method is intended to improve the yield of the above existing manufacturing method, and omit the steps with different characteristics and limit it to only the forging process, thereby enabling full automation. Improvements have been made to achieve this, but by improving this manufacturing method, the permanent magnets can be locked to the side of the claw without using the cutting process, which is a processing technique with a different character. We found the possibility of forming the step part.
[0020]
[Problems to be solved by the invention]
The present invention uses a forging technique, which is an excellent machining technique with high accuracy, and without using a machining technique such as other cutting work, a step for locking a permanent magnet on the side part of the claw part. An object of the present invention is to provide a method for manufacturing a rotor core for a permanent magnet alternator that manufactures a rotor core having a section.
[0021]
[Means for Solving the Problems]
In the present invention, a material having a predetermined volume has an internal shape in which a molding space for forming a nail portion described later rises at an angle in a range of 45 to 80 degrees from a lower surface extension surface of a molding space for forming a connecting plate portion described later. By forging using a die, a central boss portion having a size approximate to the product and a connecting plate portion continuing to the outer periphery thereof, projecting at a constant angle interval from the connecting plate portion, slightly shorter than the product and the connecting plate Molded into a general shape product composed of a plurality of claw parts having an angle between the lower surface extension surface of the part and 45 degrees to 80 degrees,
Next, the forging burrs generated on both sides of the outer peripheral edge of the connecting plate part and the claw part of the outline product in the above process are punched and removed,
Thereafter, the approximate shape products, an upward state of the central boss part, placed in a lower die having a surface shape corresponding to the lower surface shape, and the該概shaped piece, presses the upper mold from above, the Molding space into which each nail part is fitted with a surface constituting a molding space into which each nail part of the upper mold is fitted, and a surface located on both sides thereof and facing the inner surface of the lower mold with a predetermined gap. To form a stepped portion for locking a permanent magnet on the inner surfaces on both sides of each claw portion of the outline product, by flowing a predetermined excess volume between the surfaces on both sides and the inner surface of the lower mold,
After that, the above-mentioned outline product is placed in a lower mold having a molding surface corresponding to the product shape in the downward state of the central boss portion, and the upper mold is allowed to act on the outline product from above, With a punch suspended at the center of the upper mold and a die at the center of the lower mold, a shaft hole is punched into the central boss part of the outline product, and at the same time, a molding surface configured in each corresponding part of the upper mold, The nail part is ironed and bent while being bent until it reaches an angle of 90 degrees with the connecting plate part, whereby the stepped part on both inner surfaces of each nail part is formed on the molding surface for shaping the lower nail part. And press to form the stepped portion,
Finally, it is a method for manufacturing a rotor core for a permanent magnet alternator in which the above-mentioned general shape product is pressure-controlled using a mold having a shaped shaping space to obtain a product having a precise predetermined dimension.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
This invention is a manufacturing method which manufactures the rotor core for permanent magnet alternating current generators by performing the formation process of an outline product, the punching process of a forging burr | flash, the nail | claw part formation process, and a pressure regulation process one by one.
[0023]
The process of forming the outline product is performed by forming a predetermined volume of material into an outline product using a predetermined mold.
The material having the predetermined volume can be obtained, for example, by press-cutting round steel into a predetermined size.
Thereafter, as shown in FIGS. 1A and 1C, the material is formed on the lower surface of the molding space x, x,... For molding the claw portions 4a, 4a, and the molding space y for molding the connecting plate portion 3a. Forging is performed into an approximate shape having a shape and dimension approximate to the product using an internal shape die M1 having an angle θ with the extended surface z in the range of 45 ° to 80 °.
[0024]
More specifically, the mold M1 has an inner molding space in which the claw portions 4a, 4a... Molding space x, x... Are formed with respect to a lower surface extension surface z of the molding space y for molding the connecting plate portion 3a. Of the surface forming the internal molding space, the lower surface side, that is, the surface side having an upward element is defined by the lower mold M1b. The upper surface side, that is, the surface side having the downward elements is a mold constituted by the upper mold M1a.
[0025]
The forging by the mold M1 can be performed either hot, warm or cold. Of course, it goes without saying that the strength of the mold M1, the necessary pressure, etc. should be made to correspond to each.
[0026]
Further, in detail, as shown in FIG. 1 (c), the outline product obtained by the forging is a central boss portion 2a having a dimensional shape approximate to a product and a connecting plate portion 3a continuous in the circumferential direction from one end thereof. And a plurality of claws 4a, 4a,... Projecting from the connecting plate portion 3a, slightly shorter than the product, and having an angle θ of 45 degrees to 80 degrees with the lower surface extension surface z of the connecting plate portion 3a. It is equipped with. Therefore, thereafter, in order to make the above-described outline product into a product, the angle at which the claw portions 4a, 4a,... Are bent is 10 degrees to 45 degrees.
[0027]
The angle θ is determined experimentally and empirically. When the material placed on the lower mold M1b is pressed by the upper mold M1a, the upper mold M1a and the lower mold M1b are Since the material is divided as described above, the material flows into the molding spaces x, x,... For molding the claws 4a, 4a,. More specifically, as a result of the above configuration, the material flow direction is good when pressed, and there is no material escape space between the upper mold M1a and the lower mold M1b other than the molding space. . In addition, when the angle θ is set to an angle other than the above-mentioned range, the above operation cannot be obtained.
[0028]
In the forging burr punching process, as shown in FIG. 1B, the connecting plate portion 3a and the claw portions 4a, 4a generated in the forming step of the general shape product are performed as shown in FIG. This is a step of punching and removing the forging burr 9 that is thinly formed around.
[0029]
Specifically, the claw part forming step is performed in two steps.
As shown in FIG. 2 (a), the first step includes a lower mold M2b having a surface shape substantially corresponding to the shape opposite to the protruding side of the central boss portion 2a of the outline product, and the lower mold M2b. When the outline product is arranged with the central boss portion 2a facing upward, the step portions 4a1, 4a1 for locking the permanent magnets are formed on the surfaces facing the inner surfaces on both sides of the claw portions 4a, 4a. For this purpose, a mold M2 configured with an upper mold M2a configured with molding surfaces F1, F1,. Specifically, the molding surface F1 of the upper mold M2a for molding the stepped parts 4a1, 4a1 is located on both sides of the molding space into which the claw parts 4a, 4a,. It is comprised from the inner surface of M2b, and the surface which opens a predetermined clearance and faces.
[0030]
In the first step, as shown in FIG. 2 (a), the outline product is disposed in the lower mold M2b in an upward state of the central boss portion 2a, and the outline product is placed on the outline product from above. As shown in FIGS. 2 (b) and 2 (c), the claw portions 4a, 4a,... Of the outline product are formed by pressing the upper mold M2a and forming surfaces F1, F1,. The step portions 4a1 and 4a1 for locking the permanent magnets are respectively formed on the inner surfaces of the two sides. As described above, when the outline product is arranged in the lower mold M2b, the lower mold M2b is configured to have a surface shape corresponding to the lower surface side of the outline product. In the above-described state, the positioning is ensured and the device is arranged in a stable state. Further, as described above, when the upper mold M2a is pressed down, the claw portions 4a, 4a,... Are formed in the surfaces constituting the molding spaces into which the claw portions of the molding surfaces F1, F1,. In order to be pressed while being inserted, the planned excess volume of each of the claw portions 4a, 4a,..., Faces both sides of the surfaces constituting each molding space, that is, both surfaces of the claw portion molding space, and faces each other. It flows between the lower mold M2b and the inner surface of the lower mold M2b and creates hook-shaped overhanging portions on both outer surface sides of the claw portions 4a, 4a. And the level | step difference between the inner surface of this bowl-shaped overhang | projection part and the inner surface of the nail | claw part 4a becomes the level | step-difference part 4a1 for the said permanent magnet latching.
[0031]
In this step, the step portions 4a1, 4a1 for locking the permanent magnets can be easily formed by pressing in the rational pressing direction that causes a smooth flow of the material to the claw portions 4a, 4a. .
[0032]
As shown in FIGS. 3 (a) and 3 (b), the second step of the nail portion forming step includes punching p of the central portion and the claw portions 4a, 4a,. An upper die M3a having a molding surface for bending, and a lower die having a molding surface corresponding to a product shape with the central boss portion facing downward, and a die d corresponding to the punch p at the center This is performed using a mold M3 constituted by M3b. Of the molding surfaces of the lower mold M3b, the molding surfaces F2, F2,... For shaping the stepped portions 4a1, 4a1 on the inner surfaces of both sides of the claw portions 4a, 4a,. It is configured.
[0033]
In the second step, as shown in FIG. 3 (a), the rough product obtained by forming the stepped portions 4a1, 4a1,... On the lower mold M3b of the mold M3, with the central boss portion 2a facing downward. As shown in FIG. 3B, the upper mold M3a is applied to the outline product from above, and the outline p is formed by the punch p of the upper mold M3a and the die d at the center of the lower mold M3b. A shaft hole is punched in the central boss portion 2a of the molded product, and at the same time, the claw portions 4a, 4a,... Is bent until it reaches an angle of degrees, whereby the stepped portions 4a1, 4a1 on both inner surfaces of the claws 4a, 4a ... are pressed against the shaping surfaces F2, F2, ... for shaping the claws of the lower mold M3b. Shape it.
[0034]
In this process, the pressing direction is rational and natural, so that the claw portions 4a, 4a,... Are properly stretched and bent, and the stepped portions 4a1, 4a1 are well regulated. It becomes.
[0035]
More specifically, the stepped portions 4a1 and 4a1 are configured by cutting out the inner surfaces on both sides of each claw portion 4a, that is, the surface facing the central boss portion 2a of each claw portion 4a. Is. The step portions 4a1 and 4a1 can also be configured by molding the outer surface sides on both sides of each claw portion 4a into a state in which the hook pieces protrude, depending on the way of viewing.
[0036]
Thereafter, the pressure adjusting step is performed.
In the pressure adjusting step, the rough shaped product obtained in the above claw portion forming step is pressure-controlled to obtain a product having a precise predetermined dimension.
[0037]
【Example】
Hereinafter, embodiments to which the present invention is applied will be described in detail with reference to the drawings.
4 to 15 sequentially show the steps of the embodiment.
[0038]
First, as shown in FIG. 4, a round steel is press-cut to a predetermined size to form a material 1 having a predetermined volume. The volume of the material 1 is preferably as accurate as possible in order to minimize material loss and facilitate post-processing. Although various round steels can be used, they are generally made of a low carbon product and a magnetic material suitable as a rotor core of an AC generator.
[0039]
Next, the material 1 is heated, and, as shown in FIG. 5, the molding space x, x... For molding the claw portions 4a, 4a. Forging is carried out into a rough product approximate to the product using a space-shaped mold m1 having an angle α of 70 ° with the lower surface y of the extended surface 10. It goes without saying that the shape of the other part of the internal space is suitable for molding a rough product having the shape described later. The mold m1 includes a lower mold m1b on the lower surface side of the surface constituting the internal space, that is, a surface side having an upward element, and an upper mold surface on the upper surface side, that is, a surface side having a downward element. It is constituted by m1a.
[0040]
6 (a) and 6 (b) show an outline product formed by the above hot forging. In other words, the outline product has an angle between the boss portion 2a and the connection plate portion 3a having dimensions approximately similar to the product, and a slightly shorter size than the product, and the extension surface 10 on the lower surface of the connection plate portion 3a. .alpha. is formed to include claw portions 4a, 4a... formed at 70 degrees.
[0041]
As described above, since the mold m1 is divided into the upper mold m1a and the lower mold m1b at the above-mentioned part and the angle α is set to 70 degrees, the material 1 is made up of the claw portions 4a, 4a,. The flow to the molding spaces x, x. This is considered to be due to the fact that the flow direction of the material 1 has become appropriate and that the escape location of the material 1 has disappeared.
[0042]
Therefore, as a result, in order to improve the flow of the material 1, there is no need to specially increase the die pressure, and it is not necessary to generate a large forging burr as a means for that purpose. . Thus, the material 1 does not need to take into account the excessive volume for producing a large forging burr as described above, and may be of a size slightly larger than the product volume.
[0043]
Note that a shaft hole is not yet formed in the boss portion 2a in this step. Further, in this step, as shown in FIGS. 6A and 6B, a slight excess volume of the material 1 becomes a thin forged burr 9 around the connecting plate portion 3a and the claw portions 4a, 4a. Generate.
[0044]
Therefore, in the next step, the forged burr 9 of the above-mentioned general shape product is immediately removed. This is performed by a punching method using a press device and using a punching die. It is a general technique. 7 (a) and 7 (b) show the appearance of the outline product after punching.
[0045]
After the above punching process, it is gradually cooled. This slow cooling can be performed by leaving the molded outline product to cool naturally after the hot forging step. And this slow cooling gives an annealing effect, without passing through a special annealing process, and gives a favorable effect to a subsequent process.
[0046]
After the slow cooling, first, using a mold m2, step portions 4a1, 4a1 for locking permanent magnets are formed on the inner surfaces of both sides of the claw portions 4a, 4a.
[0047]
As shown in FIGS. 8 (a) and 8 (b), the mold m2 includes a lower mold m2b having a surface shape substantially corresponding to the shape opposite to the protruding side of the central boss portion 2a of the outline product, When the central boss part 2a is arranged upward in the mold m2b, a molding part for molding the step parts 4a1, 4a1 for locking the permanent magnets on the surfaces facing the inner surfaces on both sides of the claw parts 4a, 4a,. It consists of an upper mold m2a that forms the stepped portion f1.
[0048]
More specifically, the step portion f1 for forming the upper mold m2a for forming the step portions 4a1, 4a1 is, as shown in FIG. 8 (c), a molding space into which the claw portions 4a, 4a,. , And surfaces f1b and f1b that are located on both sides of the surface f1a and face each other with a predetermined gap from the inner surface of the lower mold m2b.
[0049]
Thus, the step of forming the step portions 4a1, 4a1 for locking the permanent magnets on the inner surfaces on both sides of the claw portions 4a, 4a,... Of the outline product using the mold m2 is performed as follows.
First, as shown in FIG. 8A, the outline product is arranged in the lower mold m2b with the central boss portion 2a facing upward. As described above, the lower mold m2b is formed in a surface shape corresponding to the lower surface side of the outline product. Therefore, the outline product is reliably positioned and stable in the above state. Be placed. Thereafter, as shown in FIG. 8 (b), the upper mold m2a is pressed against the outline product from above, and the forming step portion f1 formed in each corresponding portion thereof, Steps 4a1 and 4a1 are formed on the inner surfaces of the claws 4a, 4a. 9 (a) and 9 (b) show an outline product in which the step portions 4a1 and 4a1 are formed in this step.
[0050]
As described above, in this step, the step part f1 for forming the claw part of the upper mold m2a is brought into pressure contact with the inner surfaces on both sides of the claw parts 4a, 4a. The step portions 4a1, 4a1 for locking the permanent magnet are formed. More specifically, when the upper mold m2a is lowered, as shown in FIG. 8 (c), the claw portions 4a, 4a,... Are pressed into the molding spaces formed by the surfaces f1a, f1a,. Therefore, the planned excess volume of each of the claw portions 4a, 4a,... Is formed between the surfaces f1a on both sides of the surface f1a, that is, the surfaces f1b and f1b on both sides of the claw portion forming space, and the inner surface of the lower mold m2b facing them. It flows in between, and a hook-like overhanging part is created on both outer surface sides of the claw parts 4a, 4a. The step between the inner surface of the hook-like overhanging portion and the inner surface of the claw portion 4a is the step portion 4a1 for locking the permanent magnet.
[0051]
Therefore, in this step, the claw portions 4a, 4a... Are stepped portions for forming the upper mold m2a from the direction (upward) of approximately 30 degrees with respect to the inner surface thereof toward the connecting plate portion 3a (downward). The step portions 4a1, 4a1 are formed by pressing with f1, and a natural flow of the material is obtained. Therefore, it can be accurately formed with a small applied pressure.
[0052]
Next, using the mold m3, the shaft hole 2b of the central boss 2a of the outline product is punched, the claw portions 4a, 4a... Are ironed and bent, and the step portions 4a1, 4a1 on the inner surfaces of both sides are shaped. .
[0053]
As shown in FIGS. 10A and 10B, the mold m3 includes an upper mold m3a and a lower mold m3b.
As shown in the figure, the upper mold m3a includes a punch p that hangs down at the center, and a molding surface for crushing and bending of the claw portions 4a, 4a,. Inner surface).
The lower mold m3b has a die d having a molding space corresponding to the center boss portion 2a in the downward state and a hole corresponding to the punch p at the lower center of the molding space, as shown in FIG. Further, on the outer peripheral side, there is provided a reversing shaped shaping step portion f2 for shaping the step portions 4a1, 4a1 on the inner surfaces on both sides of the claw portions 4a, 4a... Into more accurate step portions 4b, 4b. .
[0054]
More specifically, as shown in FIG. 10 (c), the shaping step portion f2 formed on the lower mold m3b includes a surface f2a that forms a shaping space into which the claw portions 4a, 4a,. It consists of surfaces f2b and f2b that are located on both sides and face each other with a predetermined gap from the inner surface of the upper mold m3a.
[0055]
Accordingly, in the process using this mold m3, as shown in FIG. 10 (a), the above-mentioned general shape product in which stepped portions 4a1, 4a1,... As shown in FIG. 10 (b), the upper mold m3a is applied from above to the rough product, and the punch p of the upper mold m3a and the die at the center of the lower mold m3b are arranged. The shaft hole 2b is punched into the central boss portion 2a of the outline product at d, and at the same time, the claw portions 4a, 4a,... The plate 3a is bent to an angle of 90 degrees so that the stepped portions 4a1, 4a1 on both inner surfaces of the claw portions 4a, 4a, ... are pressed against the stepped portion f2 for shaping the claw portion of the lower mold m3b. Then, the stepped portions 4b and 4b are shaped.
[0056]
In the above process, when the upper mold m3a is moved downward, first, the lower end of the center punch p is brought into contact with the center of the central boss 2a of the outline product, and this is suppressed. Immediately thereafter, the outer peripheral side molding surface of the upper mold m3a comes into contact with the claw portions 4a, 4a. Therefore, the punching of the shaft hole 2b by the punch p and the die d, and the outer periphery side of the upper mold m3a are stably performed by suppressing the rough shape by both the punch p and the outer mold surface of the upper mold m3a. The claw portions 4a, 4a... Are squeezed and bent and the stepped portions 4b, 4b... Are shaped satisfactorily by the stepped portion f2 on the molding surface and the outer surface side of the lower mold m3b.
[0057]
The shaping of the stepped portions 4a1, 4a1 in the above process is more specifically described when the upper mold m3a is lowered and the claw portions 4a, 4a,. ), The claw portions 4a, 4a,... Are press-fitted into the shaping spaces formed by the surfaces f2a, f2a, and the like by the pressing operation from the outer peripheral side to the inside of the upper mold m3a. The inner surfaces of the hook-like projecting portions on both sides of the portions 4a, 4a,... Are pressed against the surfaces f2b and f2b on both sides of the molding space, and are shaped between the upper mold m3a located on the outer side.
[0058]
As described above, the stepped portions 4a1, 4a1 of the respective claw portions 4a, 4a,... Are shaped so that the respective claw portions 4a, 4a,. The stepped portions f2, f2,... For shaping are pressed almost at right angles, and since the pressing direction is rational in this way, the stepped portions 4b, 4b,. Will be done.
[0059]
In this way, the outline product shown in FIGS. 11A, 11B and 12 is obtained. This is very close to the product.
[0060]
After the above, the obtained outline product is pressure-controlled using a mold m4 as shown in FIG. The mold m4 is composed of an upper mold m4a and a lower mold m4b in which an inner shape corresponds to a precise product having a predetermined size and shape, and this is configured by setting the approximate product downward in the lower mold m4b. The upper mold m4a is lowered and shaped and compressed.
[0061]
Due to the pressure regulation described above, as shown in FIGS. 14A and 14B, the slightly remaining excess volume protrudes around the connecting plate portion 3 a as the forged burr 11. The forging burr 11 is subsequently removed by a punching process using a press machine. In this way, as shown in FIGS. 15A and 15B, a product having a precise predetermined dimension can be obtained.
[0062]
【The invention's effect】
Therefore, according to the present invention, a rotor core having a stepped portion for locking a permanent magnet on both side portions of the claw portion, that is, a rotor core for a permanent magnet generator is machined with different characteristics during the process. This means that it can be easily manufactured by a process using only a forging technique without including a cutting process.
[0063]
In particular, the step portions on both sides of the claw portion for locking the permanent magnet are molded with a mold that presses from the upper surface side when the angle between the claw portion and the connecting plate portion is 45 to 80 degrees. Then, since the step portion is shaped in the subsequent claw portion stretching / bending process, an accurate step portion can be configured very easily.
[Brief description of the drawings]
FIG. 1A is a schematic cross-sectional explanatory view showing an outline of a mold used for forming a rough product from a material.
(B) is a schematic plan view of an outline product formed with the above mold and from which forging burrs are not removed.
(C) is a schematic cross-sectional explanatory drawing in which a rough product formed by the above mold and from which forging burrs have been removed is passed between the claws on both sides through the center.
[Fig. 2] (a) is to set a rough product from which the forged burrs have been removed to the lower die, lower the upper die, and form a stepped portion for locking the permanent magnet on both inner surfaces of the claw portion. FIG.
(B) is a plane explanatory drawing of the outline product in the state where the step part for permanent magnet locking was formed in the claw part with the above-mentioned type.
(C) is the VV sectional view explanatory drawing of (b).
FIG. 3 (a) shows that a rough product having a stepped portion formed on a claw portion is set on the lower die, the upper die is lowered, a shaft hole is opened, and the claw portion is placed on the connecting plate portion. Sectional schematic explanatory drawing of the type | mold which bends at 90 degree | times and is going to shape the level | step-difference part of the both inner surfaces of this nail | claw part in addition.
(B) is a rough product set in the lower mold, with a stepped part formed on the claw part, the upper mold is lowered to make a shaft hole, and the claw part is bent at 90 degrees with respect to the connecting plate part. FIG. 2 is a schematic cross-sectional explanatory diagram of a mold showing a state where step portions on both inner surfaces of the claw portion are shaped.
FIG. 4 is a schematic perspective view showing a press-cut material.
FIG. 5 is a schematic cross-sectional explanatory view showing an outline of a mold used for forming a general shape product from a material.
FIG. 6A is a schematic cross-sectional explanatory view in which a rough product formed by the above mold is passed through the center and cross-sectioned between the claws on both sides.
(B) is a schematic plane explanatory view of an outline product molded with the above mold.
FIG. 7 (a) is a schematic cross-sectional explanatory view in which a rough product obtained by punching and removing forging burrs passes through the center and is cross-sectioned between claws on both sides.
(B) is a schematic plan view of a general shape product obtained by punching and removing forging burrs.
FIG. 8 (a) sets a rough product from which forging burrs have been removed to its lower die, lowers its upper die, and attempts to form a stepped portion for locking a permanent magnet on both inner surfaces of the claw portion. FIG.
(B) is a cross section of the die showing a state in which the upper die is lowered on the general shape product from which the forging burr set in the lower die is removed, and a step portion for locking the permanent magnet is formed on both inner surfaces of the claw portion. Schematic explanatory drawing.
(C) is UU line sectional explanatory drawing of (b).
FIG. 9A is an explanatory plan view of a schematic product in a state in which a step portion for locking a permanent magnet is formed on a claw portion with the above mold.
(B) is the WW sectional view explanatory drawing of (a).
FIG. 10 (a) is a schematic product in which a step portion is formed on a claw portion is set on the lower die, the upper die is lowered to open a shaft hole, and the claw portion is 90 ° with respect to the connecting plate portion. The cross-sectional schematic explanatory drawing of the type | mold which is bent every time and is going to shape the level | step-difference part of the both inner surfaces of this nail | claw part in addition.
(B) is a rough product set in the lower mold, with a stepped part formed on the claw part, the upper mold is lowered to make a shaft hole, and the claw part is bent at 90 degrees with respect to the connecting plate part. FIG. 2 is a schematic cross-sectional explanatory diagram of a mold showing a state where step portions on both inner surfaces of the claw portion are shaped.
(C) is the TT line | wire cross-section explanatory drawing of (b).
FIG. 11 (a) is a schematic cross-sectional explanatory view in which a shaft-shaped hole is drilled with the above mold and a rough product in a state in which the claw portion is machined is passed through the center and cut between the claw portions on both sides.
(B) is a plane explanatory view of the outline product in a state where the shaft hole is drilled with the above mold and the claw portion is processed.
FIG. 12 is an enlarged view of a part A in FIG.
FIG. 13 is a schematic cross-sectional explanatory view showing a state in which the rough shape is pressure-controlled with a die for adjusting the pressure of the rough shape in a state where a shaft hole is opened and a claw portion is processed.
FIG. 14 (a) is a schematic cross-sectional explanatory view in which the pressure-controlled rough shaped product passes through the center and is crossed between the claws on both sides.
(B) is a plane explanatory view of the shaped product that has been pressure-controlled.
FIG. 15 (a) is a schematic cross-sectional explanatory view in which a finished rotor core passes through the center and is cross-sectioned between claws on both sides.
(B) is a plane explanatory view of a finished rotor core.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Material 2a Center boss | hub part 2b Shaft hole 3a Connection board part 4 Product nail | claw part 4a Claw part 4a1 Step part 4b Step part 9 Forging burr | flash 10 Extension surface 11 of the lower surface of a connection plate part Forging burr | flash M1 type M1a Upper mold | type M1b Lower mold | type M2 type M2a upper type M2b lower type M3 type M3a upper type M3b lower type m1 type m1a upper type m1b lower type m2 type m2a upper type m2b lower type m3 type m3a upper type m3b lower type m4 type m4a upper type m4b lower type d die F1 Molding surface F2 Shaping surface f1 Molding step portion f2 Shaping step portion p Punch x Molding space for claw molding y Molding space for connecting plate molding z Lower surface extension surface of molding space for molding connecting plate θ Angle between the lower surface extension surface of the molding space for forming the connecting plate portion and the molding space for forming the claw portion α Angle between the molding space for forming the claw portion and the lower surface of the molding space for forming the connecting plate portion

Claims (1)

A material having a predetermined volume was used with a mold having an internal shape in which a molding space for forming a nail part described later rises at an angle in a range of 45 to 80 degrees from a lower surface extension surface of a molding space for forming a connecting plate part described later. By forging, a central boss part with approximate dimensions to the product and a connecting plate part that continues to the outer periphery of the center boss part, projecting at a constant angular interval from the connecting plate part, slightly shorter than the product and extending from the bottom of the connecting plate part Molded into a general shape product composed of a plurality of claws with an angle between the surface and 45 degrees to 80 degrees,
Next, the forging burrs generated on both sides of the outer peripheral edge of the connecting plate part and the claw part of the outline product in the above process are punched and removed,
Thereafter, the approximate shape products, an upward state of the central boss part, placed in a lower die having a surface shape corresponding to the lower surface shape, and the該概shaped piece, presses the upper mold from above, the Molding space into which each nail part is fitted with a surface constituting a molding space into which each nail part of the upper mold is fitted, and a surface located on both sides thereof and facing the inner surface of the lower mold with a predetermined gap. To form a stepped portion for locking a permanent magnet on the inner surfaces on both sides of each claw portion of the outline product, by flowing a predetermined excess volume between the surfaces on both sides and the inner surface of the lower mold,
After that, the above-mentioned outline product is placed in a lower mold having a molding surface corresponding to the product shape in the downward state of the central boss portion, and the upper mold is allowed to act on the outline product from above, With a punch suspended at the center of the upper mold and a die at the center of the lower mold, a shaft hole is punched into the central boss part of the outline product, and at the same time, a molding surface configured in each corresponding part of the upper mold, The nail part is ironed and bent while being bent until it reaches an angle of 90 degrees with the connecting plate part, whereby the stepped part on both inner surfaces of each nail part is formed on the molding surface for shaping the lower nail part. And press to form the stepped portion,
Finally, a method for producing a rotor core for a permanent magnet alternator in which the above-mentioned general shape product is pressure-controlled using a mold having a shaped shaping space to obtain a product having a precise predetermined size.

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