JPH02261039A - Manufacturing of cage rotor and device therefor - Google Patents

Abstract

PURPOSE:To obtain a perfect rotor conductor without any shrinkage cavity by a method wherein a high pressure is applied on the whole of molten material of the conductor, which forms the conductor of slots and end rings, until the solidification of the material is finished. CONSTITUTION:A predetermined amount of molten aluminum 6 is poured into the molten metal holding cavity section 9a of a bottom force 9. Next, an intermediate mold 10 is engaged with the bottom force 9 and a rotor core 1, clamped by a preliminary shaft 2 and a nut 3, is put thereon. The moving table 16 of a press, to which a top force 11 is attached, is descended to pressurize the rotor core 1. When a pressurizing plunger 8 is elevated under this condition, the molten aluminum 6 arrives at an upper end ring section 11b through a gate 10a, a lower end ring 10b and slots 1b. According to this method, the molten aluminum 6 in the upper end ring section 11b may be solidified under a high pressure more than 400kg/cm<2> without being left behind in molten or semi-molten condition under a normal pressure or a low pressure even when the molten aluminum 6 in the slots 1 is solidified earlier.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method and apparatus for manufacturing a squirrel cage rotor.
In particular, the present invention relates to a method of forming a rotor conductor by pressurizing and filling a rotor core with molten conductor material.

[Prior Art] Figures 17(a) and 17(b) show a squirrel-cage rotor, that is, a rotor core, before being cast, and (a) is a front view with a portion cut away to show the cross section. Figure 1 (b) is a side view, and (1) in the figure is the rotor core, which is formed by laminating circular steel plates (1a) and penetrates in the lamination direction with a thrower (lb) and a rotating shaft insertion part. (1c). Conventionally, this squirrel cage rotor is manufactured by laminating a required number of punched circular steel plates (LA), including a thrower) (LB), a rotating shaft insertion part (LC), and a rotor core, and then forming the rotor core by aluminum die-casting. Conductor (composed of slot conductor and end ring)
This is a cross-sectional view showing a conventional squirrel-cage rotor casting device in which a rotating shaft is formed, and (2) is a provisional shaft, (3) is a collar, and (4) is a nut to cast a rotor core (1). ) are tightened and integrated with a nut (4) via a temporary shaft (2) and a collar (3).

(5) is an extrusion rod for taking out the product after molding, (6) is a conductor material such as molten aluminum, (7) is a sleeve for injecting the molten conductor material (6), and (8) is a plunger that applies casting pressure. , (9) are fixed molds, (10) are intermediate molds, and (11) are movable molds. The arrows represent the flow of molten conductor material (6).

The conventional die-casting method for squirrel cage rotors consists of a rotor core (1) that is integrally fixed with a temporary shaft (2), a collar (3), and a nut (4).
) is inserted into the cylindrical hole of the intermediate mold (lO), and the intermediate mold (10) and the movable mold (11) are pressed against the fixed mold (9) to perform mold clamping. Thereafter, the molten conductor material (6) injected into the sleeve (7) is pressurized by the plunger (8) and flows through the thrower (lb) of the rotor core (1), forming the slot portion and the end ring portion. After being filled at high speed and rapidly cooled, the fixed mold (9) and intermediate mold (
10), and the rotor core (1) with the slot conductors and end rings formed therein is extruded by the extrusion rod (5).

FIGS. 19(a) and 19(b) show the conventional squirrel cage rotor obtained in this way, where (a) is a cross-sectional view and (b) is a cross-sectional view.
is a side view, (1d) is an end ring, (1e) is a slot conductor, and (6a) is a shrinkage hole. In the die casting method, the molten conductor material (6) is filled at high speed, which entrains air and gas, and does not maintain high pressure until solidification is complete, as shown in Figure 19 (b). Shrinkage holes (6a) were formed in the slot conductor (1e) and end ring (ld), leading to a decrease in density. For example, the density of pure aluminum is 2.7g/
cm3, but the aluminum density of the rotor conductor in this conventional example was as low as around 2.63/cm3. This decrease in density hinders the conduction of secondary current induced in the rotor, which in turn reduces rotational torque. Therefore, at present, no design has been made to fully utilize the material properties of the rotor conductor, taking into account the reduction in conductivity due to the reduction in density (shrinkage cavities). Therefore, in order to obtain desired motor characteristics, measures such as increasing the thickness of the rotor and thickening the windings of the stator on the negative side have been taken. As a result, the motor itself becomes larger, which not only becomes an obstacle to reducing the size and weight of the motor, but also requires extra materials, leading to increased costs.

Furthermore, the strength of the rotor is reduced due to the cavities generated in the slot conductor (Ie), which may lead to disconnection and destruction during high-speed rotation.

In order to solve the above problems, recently, the space where the slot and end ring are formed (hereinafter referred to as the end ring part) is filled with molten conductive material, such as molten aluminum, at a slow flow rate. A molten metal forging method (pressure solidification casting method) in which molten aluminum is solidified under high pressure of 400 kg/cm2 or more has been introduced. 20th
The figure is a sectional view showing a conventional squirrel cage rotor casting device disclosed in, for example, Japanese Patent Application Laid-open No. 62-12357.
) is an extrusion rod, (14) is a knockout punch, and the extrusion rod (5) is raised in conjunction with the extrusion rod (5). (15) is punch, (1
6) is a pressurized mold clamping mechanism that applies mold clamping force, such as a movable table such as a press, (17) is a support, and (11) is an upper mold, which is connected to the movable table (16) by the support (17). . (9) is a lower mold, which is provided with a sump (9a) for containing molten conductive material, in this case molten aluminum (6), and is equipped with an extrusion rod (5). The upper mold (11) and lower mold (9) constitute a cavity (9c) into which the rotor core (1) can be fitted and inserted, and a gate (9b) through which molten aluminum (6) is introduced into the cavity (9C). There is.

(20) is a press bolster, and (21) is a lower plate for knockout, which is screwed to the knockout punch (14). (41) is a gate at the upper end of cavity (9C))
This is a gas exhaust port provided at a position opposite to (9h). In addition, FIG. 21 shows the filling that is pushed into the pool (9a) of the lower mold (9) when the punch (15) in FIG. 20 descends.
FIG. 3 is an enlarged cross-sectional view showing a pressurized state.

First, a large number of slots (1b) evenly provided in the circumferential direction.
and a circular thin iron plate (l
A large number of a) are stacked so that the throwers (Ib) penetrate in the stacking direction to form a rotor core. Next, the upper mold (11
) and the lower mold (9) to about 250°C, and then heat the lower mold (
9) The above-mentioned multiple throwers are placed in the cavity (9C) of
(lb) of the squirrel cage rotor core with its slots (l
b) is fitted and inserted so that it is in the direction of gravity, the moving table (16) is lowered, and the upper mold (
II) is applied to the lower mold (9) to clamp the mold. after that,
Inject molten aluminum (6) from the injection port (lla) of the upper mold (11) into the pool (9a) of the lower mold (9) so that the liquid level is below the gate (9b), and immediately press the upper punch. (15) is lowered to extrude the molten aluminum (6) accumulated in the pool (9a) and melt it at a slow flow rate into the slot (lb) and end ring of the rotor core (1) in the cavity (9C). Pour aluminum (6). The flow rate of the molten aluminum (6) is controlled while controlling the speed of the upper punch (15). Molten aluminum (6)
(9a) The gas is filled upward in order from the nearby slot, and reaches the gas discharge port (41) from the upper end ring portion in the vicinity (9a). Molten aluminum (6
) After filling, a high pressure of about 400 J/cm2 or more is applied to solidify it in a molten or semi-molten state. Upper mold (11) and lower mold (
9) and extrude the rotor core on which the rotor conductors are formed using the extrusion rod (5).

Figures 22 (a) and (b) show that the diameter obtained by molten metal forging is 1
This figure shows an example of an extremely small squirrel cage rotor of 00 mm or less, in which (a) is a cross-sectional view and (+1) is a side view. As shown in this figure, in the molten metal forging method, molten aluminum is filled at a low speed, so there is less entrainment of air and gas, and high pressure is maintained until solidification is complete, so a high-density electrical conductor is formed without shrinkage cavities. can be obtained.

Figure 23 shows that the aluminum density obtained by molten metal forging is 2.
It is a characteristic diagram showing the torque characteristics and efficiency of a 673/cm3 squirrel cage rotor in comparison with a 2.573/c+n3 die-cast product. The vertical axis represents torque (kg-cm) and efficiency (z), and the horizontal axis represents rotation speed (rpm).
0) is the torque characteristic curve of the die-cast product, (c) is the efficiency characteristic curve of the molten metal forged product, and (d) is the efficiency characteristic curve of the die-cast product. As is clear from the figure, the torque characteristics and efficiency of the motor are improved when the aluminum is made from molten metal and has a higher density.

In this way, molten metal forging can improve motor characteristics compared to die casting. Therefore, the limit design of the rotor has been made to fully utilize the material characteristics of the rotor conductor, and the motor can be made smaller and lighter. This makes it possible to reduce costs, save materials, and reduce costs.

However, even when using the above-mentioned molten metal forging method, if the cross-sectional area of each slot is relatively small compared to the cross-sectional area of the end ring, the molten aluminum may flow from the lower end ring part to the slot, roughly to the upper end ring part. In the process of filling and solidifying, the slot portion solidifies earlier than the end ring portion at the upper end. At this time, pressing force is also transmitted from the end ring to the slot and then to the upper end ring, but if the slot solidifies first, the pressure will not be transmitted to the upper end ring.

Therefore, high pressure cannot be applied to the upper end ring until solidification is complete, and shrinkage cavities occur. In the conventional molten metal forging method, pressure was applied from one direction in the filling direction of the molten conductor material, which resulted in variations in solidification (as in -), and the pressure was applied to the filled molten conductor material metal. If the middle part of the molten conductor material solidifies before it is sufficiently transmitted, high pressure cannot be applied to the molten conductor material beyond that point, and it will solidify under normal pressure or insufficient pressure. Shrinkage foci may occur. That is, it was difficult to apply sufficient pressure to every corner of the filled molten conductor material.

[Problems to be Solved by the Invention] As described above, in the conventional die-casting method, shrinkage cavities occur throughout the rotor conductor of the squirrel cage rotor.

In addition, in the molten metal forging method, the solidification of the molten conductor material may have irregularities, and it is difficult to apply high pressure to every corner of the filled molten conductor material. For example, the slot portion solidifies earlier than the end ring portion at the upper end. In this case, shrinkage nests occur in the upper end ring. Therefore, there was a problem in that electrical continuity was reduced, which adversely affected the torque and efficiency of the motor.

The present invention was made in order to solve the above-mentioned problems, and high pressure is applied to the entire molten conductor material forming the slot conductor and end ring until solidification is completed, resulting in a healthy state without shrinkage cavities. The purpose of the present invention is to provide a method and apparatus for manufacturing a squirrel cage rotor that yields a rotor conductor.
As a result, the present invention attempts to obtain a squirrel cage rotor that improves the efficiency and torque characteristics of the motor and allows the motor to be made smaller and lighter.

[Means for Solving the Problems] A method for manufacturing a squirrel cage rotor according to the present invention includes filling a rotor core with a molten conductor material under pressure and solidifying it, and forming a slot conductor and a slot conductor connected to the rotor core. When forming the end rings disposed on both end faces, the filled molten conductor material is pressurized from both one end ring and the other end ring.

Further, the filled molten conductor material is pressurized from the rotor core axial direction of one end ring and the rotor core axial direction of the other end ring, and also from the rotor core radial direction of at least one of the end rings. It is designed to be pressurized.

Further, in a squirrel cage rotor having fins, pressure is applied between the fins of a plurality of fins included in the end ring.

Furthermore, the heat dissipation of the molten conductive material filled into the filling opening is relaxed to delay solidification.

Moreover, the heat dissipation of the molten conductor material filled in one end ring on the filling port side and the other end ring opposite to each other is relaxed and solidification is delayed, and the material is filled in the pressurizing part.

Further, a plurality of radially arranged fin molds are compressed and moved to the center in the radial direction, and the filled molten conductor material is pressurized from the radial direction of the rotor core of the end ring.

In the apparatus for manufacturing a squirrel cage rotor as described above, the end ring is engaged with one of the plurality of engaging parts disposed opposite to the end ring, and presses the end ring. A pressurizing mold clamping mechanism for tightening an end ring pressurizing means having a pressurizing punch and a pressurizing mechanism that drives the pressurizing punch and applies a pressing force via the engaging portion to a casting mold of the squirrel cage rotor. It was established in

[Function] In the present invention, since pressure is applied from both one end ring and the other end ring, even if the slot conductor portion solidifies first, both end rings can be pressurized and shrinkage holes can be prevented. can be prevented from occurring.

In addition, in addition to applying pressure from the axial direction of the rotor core of both end rings, pressure is also applied from the radial direction of at least one of the rotor cores, so it can widely respond to cases where, for example, variations in solidification of molten conductor material occur. It is possible to reduce the portion where no pressure is applied and solidify under normal pressure or low pressure, the entire molten conductor material can be sufficiently pressurized, and the generation of shrinkage cavities can be prevented.

In addition, by relaxing the heat dissipation of the molten conductive material filled into the filling port and delaying solidification, the pressing force from the pressurizing means that pushes the molten conductive material can be applied sufficiently to the end ring on the filling port side. It is possible to prevent the occurrence of shrinkage cavities without requiring additional pressure means.

In addition, by relaxing the heat dissipation of the molten conductive material filled in one end ring on the filling port side and the other end ring facing the other end ring, and delaying solidification, there is a greater margin in the timing of pressurizing the other end ring. .

Further, by filling the pressurized portion with the molten conductor material in excess of the amount of shrinkage caused by pressurization, it is possible to form the conductor material flush with the pressure portion, thereby increasing the space factor.

Furthermore, by compressing and moving multiple radially placed fin molds to the center in the radial direction and pressurizing the filled molten conductor material from the radial direction of the rotor core of the end ring, the fin molds are pressurized at the same time as fin formation. can be done.

The pressure punch that presses the end ring is configured to engage one of the plurality of engagement parts and be driven by the pressure mechanism via the engagement part, so the size of the rotor core can be reduced. Even if the pressure mechanism changes, it can be generalized without changing the pressurizing mechanism.

[Example] The present invention will be explained below with reference to the drawings. Embodiment 1 FIG. 1 is a cross-sectional configuration diagram showing an apparatus for manufacturing a squirrel cage rotor according to Embodiment 1 of the present invention. In the figure, (10) is an intermediate mold, and a lower end ring portion where one end ring is formed. (10b)
and molten conductive material, in this case molten aluminum (
A gate (10a) serving as a filling port for introducing 6) is provided. (8) is a pressure plunger that applies casting pressure and pressurizes the filled molten aluminum (6) from the axial direction of the rotor core (1) of one end ring, (11) is the upper mold, and (llb) is the upper mold. The upper end ring part (3) is provided at the lower end of the mold (11) where the other end ring is formed, and is a nut attached to the tip of the temporary shaft (2), which tightens the rotor core (1) and tightens the upper end ring. It also plays the role of forming the inner wall of the end ring portion (llb). (41) is a gas discharge port that communicates from the upper end ring portion (llb) to the outside of the mold and for discharging air and gas within the cavity. (16) is a pressure mold clamping mechanism, in this case a moving table of the press, which fixes the upper mold (11) and lowers the rotor core (1) and intermediate mold (10) via the upper mold (11). Tighten to mold (9). (18) is the upper mold (
11) and pressurizes the filled molten aluminum (6) from the axial direction of the rotor core (1) of the other end ring, that is, a ring-shaped upper pressurizer that presses the upper end of the upper end ring part (llb). Use a punch to press the upper part (19)
, in this case it is driven by the upper hydraulic cylinder. (19a)
is a hydraulic pipe that supplies oil to the upper hydraulic cylinder (19). The arrows represent the flow of molten aluminum (6).

First, the laminated rotor core (1) is tightened together with a temporary shaft (2) and a nut (3). Next, the lower mold (9)
A predetermined amount of molten aluminum (6) is poured into the pool (9a). Next, the intermediate mold (10) is fitted to the lower mold (9), and the rotor core (1) fastened with the temporary shaft (2) and nuts (3) is placed thereon. At this time, it is preferable that the head of the temporary shaft (2) is fitted into the intermediate mold (10).

The upper mold (11) is attached in advance to the moving table (16) of the press, and the moving table (16) is lowered to pressurize the rotor core (1). In this state, pressurize plunger (
When the gate (8) is raised, the molten aluminum (6) reaches the gate (
10a), lower end ring part (10b), slot (1
b) and reaches the upper end ring part (llb).

At this time, the flow rate of the molten aluminum (6) is preferably set to a relatively low speed (Reynolds number of 20,000 or less) so as not to excessively involve gas or air. Most of the gas and air that were previously in the mold and slots are exhausted through the gas outlet (41), and the molten aluminum (6) is discharged through this gas outlet (41).
41), this part of the molten aluminum (6)
is rapidly cooled and solidified. From this point on, the pressurizing force by the pressurizing plunger (8) rapidly rises, and the product (filled molten aluminum ) is applied a high pressure of 400 kg/cm2 or more, and the hydraulic piping (1
Oil is sent to the upper hydraulic cylinder (19) through 9a), and the upper pressurizing punch (18) is lowered to pressurize the product from the rotor core axial direction of the other end ring. 10b) 400J/cm
Pressurize with 2 or more high pressures.

For example, a slot (lb) 2 with a cross-sectional area of 1.85 cm2
Molten aluminum (6) is cast into a rotor core (1) with a diameter of 220 mm and a length of 370 mm+, which has 8 pieces.
8 slot conductors with a cross-sectional area of 17 cm2 and a height of 4
When forming an end ring of 0 mm, the diameter is 190 m.
Using a pressure plunger (8) of m, the Reynolds number is approximately 1.
The filled molten aluminum (6) was filled with molten aluminum (6) at a flow rate of 1 m/5 ec in the slot.
5 with the pressure plunger (8) and upper pressure punch (18).
It was solidified by applying a pressure of 00 kg/cIi2.

Generally, the cross-sectional area of the slot (1b) is the same as that of the end ring (1
d) is smaller than the cross-sectional area of the end ring (
1d) is connected in a ring shape as its name suggests.

Therefore, depending on the balance between the dimensions of the slot (1b) and the end ring (1d), the molten aluminum (6) in the slot (1b) may solidify much faster than the end ring (1d). In such a case, the pressure applied by the pressurizing plunger (8) in the axial direction of the rotor core (1) does not reach the upper end ring portion (llb).

Therefore, the molten aluminum (6) in the upper end ring (llb) will solidify under normal pressure or insufficient pressure, and a shrinkage cavity will be formed approximately in the center of the cross section of the upper end ring (Ilb). .

However, in this embodiment, in addition to the pressure applied from below by the pressure plunger (8), an upper pressure punch (18) is provided to press the upper end ring part (llb) from above.
) is pressurized in the axial direction, and even if the molten aluminum (6) in the thrower (lb) solidifies first, the molten aluminum (6) in the upper end ring part (llb) will be under normal pressure or low pressure. It can be solidified under high pressure of 400 kg/cm2 or more without being left in a molten or semi-molten state, and the generation of shrinkage cavities can be prevented.

Embodiment 2 FIG. 2 is a sectional view showing a squirrel cage rotor manufacturing apparatus according to a second embodiment of the present invention. In this embodiment, a plurality of upper pressure punches (
18) is arranged to press the side surface of the upper end ring portion (llb) and pressurize the molten aluminum filled from the radial direction of the rotor core (1) of the other end ring.

In this embodiment as well, the slot portion (1
Even if the molten aluminum (6) in b) solidifies first, in addition to the pressure applied from below by the pressure plunger (8) and from the axial direction of the rotor core (1), the upper end ring part (llb) is Since more pressure is applied, the molten aluminum in that area (
6) can also be solidified under high pressure of 400 kg/cm2 or more, and can prevent the occurrence of shrinkage nests.

FIG. 3 is a sectional configuration diagram showing a manufacturing apparatus for a squirrel cage rotor according to Embodiment 3 of the present invention, and in the figure (23) is an intermediate type (23).
10) and filled with molten aluminum (6
) from the radial direction of the rotor of one end ring, that is, a lower pressurizing punch that presses the outer surface of the lower end ring part (10h). It is driven by a pressure mechanism, in this case a lower hydraulic cylinder (24). (24a) is a hydraulic pipe that supplies oil to the lower hydraulic cylinder (24).

When the molten aluminum (6) is filled, the filled molten aluminum (6) is pressurized by the pressurizing plunger (8) from the axial direction of the rotor core (1) of the lower end ring, that is, from below, and the upper hydraulic cylinder ( 19) and the lower hydraulic cylinder (24), and the upper pressurizing punch (18)
presses the upper end surface of the upper end ring and applies pressure from the axial direction of the upper end ring, and the lower pressing punch (23) presses the outer R (side) surface of the lower end ring and applies pressure from the radial direction of the lower end ring.

In this embodiment, as in the first embodiment, the upper pressure punch (18) can prevent the occurrence of shrinkage cavities in the upper end ring portion (llb). On the other hand, the lower end ring part (1,
Qb) is ring-shaped, whereas gate (1,0a)
For example, since there are only a plurality of pieces on the same circumference, the molten aluminum (6) in that part is transferred to the lower end ring part (10b).
) coagulates faster. Therefore, the lower end ring part (10h)
The molten aluminum (6) is the inlet gate) (10
If a) is closed, the pressure applied by the pressurizing plunger (8) cannot be received, and it may solidify under normal pressure or relatively low pressure to form a shrinkage cavity. However, in this embodiment, the lower pressure punch (23) presses the side surface of the molten or semi-molten aluminum of the lower end ring part (JOb) from the radial direction.
Even if 0a) solidifies, the generation of shrinkage nests can be prevented.

FIG. 4 is a cross-sectional configuration diagram showing an apparatus for manufacturing a squirrel cage rotor according to a fourth embodiment of the present invention, and shows an example of indirect pressing with multiple peeling. In the figure, the same reference numerals as in FIG. 20 indicate the same parts. (I5) is a punch that applies casting pressure and pressurizes the filled molten aluminum (6) from one end ring, and (18) is installed in the upper mold (11) for each rotor core (1). filled and filled molten aluminum (
6) with the other entry pressure punch, press the upper pressure mechanism (
19), in this case it is driven by the upper hydraulic cylinder. (1
9a) is the oil pressure i that supplies oil to the upper hydraulic cylinder (19)
It is an EA tube. (23) is placed in a lower die (9) in multiple stages for each rotor core (1), and pressurizes the filled molten aluminum (6) from the rotor radial direction of one end ring, that is, the lower end ring. A lower pressurizing punch that presses the outer surface of the part is driven by a lower pressurizing mechanism disposed on the lower mold (9), in this case a lower hydraulic cylinder (24). (24
a) is a hydraulic pipe that supplies oil to the lower hydraulic cylinder (24).

As in the case of direct pushing in the above embodiment, even if the molten aluminum (6) in the throat part solidifies faster than in the upper end ring part, the upper end ring part is pressed in the upper rotor core axial direction by the upper pressure punch (18). It is possible to pressurize the soil end ring, thereby preventing the formation of shrinkage cavities in the soil end ring. Also, game) (9b
) has a small cross-sectional area, the molten aluminum (6) in that part solidifies faster than the lower end ring part. When the gate (9b) is left open, the molten aluminum (6) in the lower end ring cannot receive the pressure applied by the punch (15), and solidifies and contracts under normal pressure or relatively low pressure. A nest may be formed. However, in this embodiment, the lower pressure punch (23) further presses the molten or semi-molten aluminum of the lower end ring on the side.
Since the pressure is applied from the radial direction, even if the gate (9b) solidifies, the generation of shrinkage cavities can be prevented.

FIG. 5 and FIG. 6 are FIG. 7 (
Upper end ring pressurizing means for locally pressurizing the upper end ring part of the main part of the apparatus for manufacturing a squirrel cage rotor having cooling fins shown in the cross-sectional view of a) and the side view of (b) from the axial direction of the rotor core. 5 is a cross-sectional configuration diagram, and FIG. 6 is a front view seen from the side facing the rotor core. In the figure,
(if) is a plurality of cooling fins stepped on the end ring (1d), and (llc) is a plurality of cooling fins intermittently provided on the upper end ring part (llb) in the upper mold (11). A space (hereinafter referred to as a fin portion) (18) is provided in the upper mold (11) so as to fill in the space between the fin portions (lie), and a space (18) is provided in the upper mold (11) so as to fill the space between the fin portions (llie).
c) a plurality of upper pressure punches that press the filled molten aluminum from between the fins of the upper end ring;
(18a) is an even pressure ring arranged on the upper pressure punch (18), (19) is a plurality of upper pressure mechanisms provided on concentric circles, in this case three upper hydraulic cylinders are provided, and the melting When the aluminum (6) is filled, the ram (not shown) of the upper hydraulic cylinder (19) presses the equal pressure ring (18a).
) and then the upper pressurizing punch (18), the molten aluminum (6) in the upper end ring part (llb) is pressurized from the axial direction of the rotor core.

In this embodiment as well, an upper pressure punch (18) is provided to apply pressure between the fin portions (llc) of the upper end ring portion (llb) from above in the axial direction of the rotor core, so that the molten aluminum in the slots is Even if the molten aluminum in the upper end ring part (11b) solidifies at 40°C, the molten aluminum in the upper end ring part (11b) will not be left behind in a molten or semi-molten state under normal pressure or low pressure.
It can be solidified under high pressure of 0 kg/cm2 or more, and can prevent the generation of shrinkage nests. In the case of this embodiment, there is no problem even if the fins (if) have holes, so the fin portion (tic) is not pressed, but the end ring between the fins is pressed. Further, the pressure equalization ring (18a) is connected to the upper pressure punch (18) from the center of the upper hydraulic cylinder (19).
) can be pressurized without any problem even if it is misaligned.

That is, the upper hydraulic cylinder (19
) can be generalized to some extent.

FIG. 8 is a cross-sectional configuration diagram showing an apparatus for manufacturing a squirrel cage rotor according to Embodiment 6 of the present invention, and (9b) shows the upper end of the sump (9a) provided in the lower mold (9). Intermediate mold (1
0), the intermediate mold (10) is heated by the molten aluminum (6) collected here.

In this example, as in Example 1, in addition to applying pressure from below with the pressurizing plunger (8), the upper end ring part (Ilb) is pressed from above with the pressurizing punch (18). 1) Since pressure is applied in the axial direction, it is possible to prevent the occurrence of shrinkage cavities in the upper end ring portion (llb). In addition,
The intermediate mold (10) is heated by the molten aluminum (6) stored in the sump (9a), especially the heating edge (9b), and the molten aluminum (6) is filled with the molten aluminum (10a). ) can reduce the heat dissipation of the molten aluminum (6) and delay its solidification. Therefore, it is possible to prevent the molten aluminum (6) of the gate (10a) from solidifying before the lower end ring part (10b), and to receive sufficient pressure from the pressure plunger (8). In addition to the pressurizing plunger (8), the lower end ring (jo
There is no need to pressurize b).

FIG. 9 is a cross-sectional configuration diagram showing an apparatus for manufacturing a squirrel cage rotor according to Embodiment 7 of the present invention, in which (9C) is provided on the outer circumference of the upper end of the sump (9a) of the lower mold (9). It is an insulating material such as ceramic.

In this example, the heat of the molten aluminum (6) accumulated in the sump (9a) is transferred to the lower mold (
The heat dissipation of the molten aluminum (6) in the part (10a) is relaxed and its solidification is delayed by preventing the heat from escaping to (9) and transmitting it to part (10a), similar to Example 6. There is an effect.

FIG. 10 is an enlarged cross-sectional configuration diagram showing an upper end ring pressurizing means for locally pressurizing the toe end ring part, which is a main part of the squirrel cage rotor manufacturing apparatus according to the eighth embodiment of the present invention, from the rotor core axial direction. It is. The figure shows the state before pressurization, and when manufacturing a squirrel cage rotor, the volume of the upper end ring is calculated in advance from the amount of shrinkage during solidification (volume that is compressed by pressurization; in this case, it is made of aluminum). 6% of the volume of the upper end ring, and the upper pressure punch (18) is moved back from the upper end of the upper end ring part (llb) by the amount of contraction. Therefore, the molten aluminum (6) is filled in excess of the shrinkage.

In the above example, by applying local pressure, the pressurized part is depressed by the amount of shrinkage after solidification, and cannot be formed flush, but in this example, by applying local pressure, it is possible to prevent the occurrence of shrinkage cavities in the upper end ring, and The molten aluminum (6) is filled in excess of the shrinkage due to pressure, so that it can be formed easily and the space factor can be reduced.

FIG. 11 is an enlarged cross-sectional configuration diagram showing an upper end ring pressurizing means for locally pressurizing the upper end ring part of the main part of the squirrel cage rotor manufacturing apparatus according to the ninth embodiment of the present invention from the axial direction of the rotor core. A heat insulating plate (22) is placed under the ring-shaped upper press punch (18), and a heat insulating material (
21) is arranged to insulate the upper part of the end ring part (llb). In addition, as in Example 8, an upper pressure punch (
18) by the amount of contraction caused by pressurization.
b) is set back from the upper end and filled with molten aluminum (6) to cover the shrinkage.

Therefore, in this example, in addition to the effects of Example 8, the upper end ring part (llb) is filled with molten aluminum (
6) Dissipate heat upward through the heat insulating board (22) and the heat insulating material (21).
) can be prevented (mitigated) and its coagulation delayed. That is, the solidification time of the upper end ring portion (llb) is increased. Pressurizing the molten aluminum (6) after most of it has solidified will not be very effective, but in this example, since the solidification time is longer, there is a margin in the timing of pressurization by the upper pressure punch (18). The degree increases.

FIGS. 12 and 13 show a main part of a manufacturing apparatus for a squirrel cage rotor having cooling fins according to Example IO of the present invention, in which the fins are formed and the upper end ring part is locally processed from the radial direction of the rotor core. The upper end ring pressurizing means is shown in FIG. 12 in the radial direction and FIG. 13 in the axial direction. FIGS. 14(a) and 14(b) show a squirrel cage rotor having cooling fins obtained in this example, where (a) is a sectional view and (b) is a side view. In the figure, (28) is a fin type provided in the upper mold (11) and has a fan-shaped tip so that cooling fins (if) can be formed at the end of the upper end ring, and in this case, there are four fins. Four fins (if) are arranged radially, and the upper hydraulic cylinder (19) compresses and moves the filled molten aluminum (6) to the center in the radial direction to the rotor core radius of the upper end ring. Pressure is applied from the direction to form fins (1f) and has the same effect as a pressure punch.

The two-dot chain line indicates the position of the fin mold (28) after compression movement (after pressurization). (Ig) is an inner ring formed at the tip of the end ring (ld) together with the fin (1f).

When the end ring part (llb) is filled with molten aluminum (6), the upper hydraulic cylinder (19) is activated, and the fin type (28) is driven to the radial center of the rotor core, which is indicated by the two-dot chain line in the figure. Compress and move to position. The amount of movement is determined by calculating the amount of shrinkage (6% in the case of aluminum) from the volume of the upper end ring, and is set to be equal to the volume. End ring of molded product (Id)
A fin (If) and an inner ring (1g) are formed at the tip.

In this embodiment, by applying local pressure to the upper end ring portion using a fin mold (28), it is possible to prevent shrinkage cavities from occurring in the upper end ring and at the same time form cooling fins. Further, for example, it is not necessary to configure the upper mold (11) itself to form fins, and the structure of the mold is simple and manufacturing becomes easy. It can also be applied to the lower end ring.

FIG. 15 is a cross-sectional configuration diagram showing an apparatus for manufacturing a squirrel cage rotor according to an eleventh embodiment of the present invention. In this embodiment, an upper hydraulic cylinder of an upper pressurizing mechanism ( 19) are installed. (19b) is a piston of the upper hydraulic cylinder (19), and a number of engaging portions (19c) are provided on the lower surface thereof facing the upper end ring. In this case, many screw holes are cut on multiple concentric circles. In addition, there is a screw hole (19) below the moving table (16).
c), the same number of through holes (19C) as the screw holes (19C)
9d) is opened. (19e) is a through hole (19d
), which is a bottle in this case, and which penetrates through the screw hole (19c) and engages with one of the screw holes (19c).
) is engaged with the screw hole (19c) via this pin (19e). The upper end ring pressurizing means (30) includes an upper hydraulic cylinder (19), an upper hydraulic pipe (19a), and a piston (
19b), a screw hole (19c), a bottle (19e), and an upper pressure punch (18).

A bottle (19e) is screwed to a screw at an appropriate radius position among the many screw holes (19c) according to the size of the rotor core, and the upper end ring part (l
lb) Push the upper pressure punch (18) placed above downward to pressurize the molten aluminum from the axial direction of the rotor core of the upper end ring. In this embodiment, similar to the first embodiment, it is possible to prevent the occurrence of shrinkage cavities in the upper end ring, and even if the size of the rotor core changes, the upper hydraulic cylinder (19)
This can be done by simply changing the screw hole (19c) that engages the upper pressurizing punch (18) without changing the upper pressurizing punch (18), making it versatile. In addition, the upper pressure punch (18)
The shape may be a ring, a block divided into many parts, a bottle, or any other shape.

FIG. 16 is a cross-sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to a twelfth embodiment of the present invention. It has the same effect as the eleventh embodiment, and in this embodiment, the movable table of the press (
An upper hydraulic cylinder (19) is disposed at the lower end of 16), and the upper die (11) is fitted into the lower end of the upper hydraulic cylinder (19).

Note that the present invention is not limited to the embodiments described above, and the molten conductor material filled in both end rings may be pressurized from the axial direction and radial direction of the rotor core, and by pressurizing from multiple directions, the molten conductor material It can respond more broadly to variations in coagulation. In other words, it is possible to reduce the portion where no pressure is applied and solidify under normal pressure or low pressure, and the entire molten conductor material can be sufficiently pressurized, thereby preventing the generation of shrinkage cavities.

Moreover, although the case has been described in which the pressure is applied in the rotor radial direction from the outer peripheral (side) surface of the end ring, it may be applied from the inner peripheral (side) surface, although the space is narrow.

[Effects of the Invention] As described above, according to the present invention, the rotor core is filled with a molten conductor material under pressure and solidified, and the slot conductor is connected to the slot conductor and disposed on both end surfaces of the rotor core. When manufacturing the squirrel-cage rotor, the filled molten conductor material is pressurized from both one end ring and the other end ring, thereby preventing the generation of shrinkage cavities. This cage provides a sound rotor conductor, which becomes strong and prevents damage caused by centrifugal force, reduces electrical resistance, improves the efficiency and torque characteristics of the motor, and allows the motor to be made smaller and lighter. This has the effect of providing a shaped rotor.

In addition, the filled molten conductor material is pressurized from the axial direction of the rotor core of one end ring and the axial direction of the rotor core of the other end link, and also from the radial direction of the rotor core of at least one of the end rings. Since the rotor is pressurized, the occurrence of shrinkage cavities can be largely prevented and a healthier rotor conductor can be obtained.

In addition, since the heat dissipation of the molten conductor material filled in the filling port part is relaxed and solidification is delayed, the end ring on the filling port side does not need to be pressurized from the radial direction of the rotor core. Shrinkage -36 = The formation of nests can be prevented.

In addition, the heat dissipation of the molten conductor material filled in one end ring on the filling port side and the other end ring facing each other is relaxed and solidification is delayed, so there is greater margin in the timing of pressurizing the other end ring. . ,
Furthermore, since the molten conductor material is filled in the pressurized part in excess of the amount of shrinkage per strand, it can be formed flush, increasing the space factor.

Roughly speaking, the multiple fin molds placed radially are compressed and moved to the center in the radial direction, and the filled molten conductor material is pressurized from the radial direction of the rotor core of the end ring.
Pressure can be applied at the same time as fin formation.

and (iii) In the apparatus for manufacturing a squirrel cage rotor as described above, a plurality of engaging portions are disposed opposite to the end ring, and a plurality of engaging portions are engaged with any of these engaging portions to press the end ring. A pressurizing mold clamping mechanism for tightening an end ring pressurizing means having a pressurizing punch and a pressurizing mechanism that drives the pressurizing punch and applies a pressing force via the engaging portion to a casting mold of the squirrel cage rotor. Since the pressurizing mechanism is provided in the rotor core, it can be used for general purposes without changing the pressurizing mechanism even if the size of the rotor core changes.

[Brief explanation of drawings]

FIG. 1 is a sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to Embodiment 1 of the present invention, FIG. 2 is a sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to Embodiment 2 of the present invention, 3 is a cross-sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to a third embodiment of the present invention, FIG. 4 is a cross-sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to a fourth embodiment of the present invention, FIG. 5 is a cross-sectional configuration diagram showing an upper end ring pressurizing means of a main part of a manufacturing apparatus for a squirrel cage rotor having fins according to a fifth embodiment of the present invention; aXb) indicates a squirrel cage rotor with cooling fins obtained according to Example 5;
(a) sectional view; (b) side view; FIG.
FIG. 9 is a cross-sectional configuration diagram showing a squirrel cage rotor manufacturing apparatus according to Embodiment 7 of the present invention, and FIG. 10 is an upper end of the main part of the squirrel cage rotor manufacturing apparatus according to Embodiment 8 of the present invention. FIG. 11 is an enlarged cross-sectional configuration diagram showing a ring pressurizing means; FIG. 13 and 13 are cross-sectional configuration diagrams showing the upper end ring pressurizing means of the main part of the squirrel cage rotor manufacturing apparatus having cooling fins according to the tenth embodiment of the present invention, and FIGS. 14(a) and (b) teeth,
15 shows a squirrel cage rotor having cooling fins obtained in Example 9, (a) sectional view, (b) side view, and FIG. 15 shows an apparatus for manufacturing a squirrel cage rotor according to Example 11 of the present invention. FIG. 16 is a cross-sectional diagram showing a squirrel cage rotor manufacturing apparatus according to a twelfth embodiment of the present invention, FIGS. ) is a partially cutaway front view showing a cross section, (b) is a side view, FIG. 18 is a cross-sectional view showing a conventional squirrel cage rotor casting device, and FIG. 19 (a)
(b) shows a conventional squirrel cage rotor, (a) is a cross-sectional view,
(b) is a side view, FIG. 20 is a sectional view showing a squirrel cage rotor casting device using the conventional molten metal forging method, and FIG.
22(a) and 22(b) show a squirrel cage rotor obtained by the molten metal forging method, (a) sectional view, (b)
), and FIG. 23 is a characteristic diagram showing the torque characteristics and efficiency of a squirrel-cage rotor produced by the molten metal forging method in comparison with a die-cast product. In the figure, (1) is the rotor core, (ld) is the end ring, (le) is the slot conductor, (If) is the cooling fin, (6) is the molten conductor material, (8) is the pressurizing plunger, (
9) is the lower mold, (9a) is the water reservoir, (9b) is the heating edge, (9C) is the insulation material, (10) is the intermediate mold, (10a) is the gate part that is the filling port, (16) ) is the movable table of the press which is the pressure mold clamping mechanism, (18) is the upper pressure punch, (
19) is the main hydraulic cylinder which is the upper pressure mechanism, (19c
) is a screw hole which is an engaging part, (19e) is a bottle which is an engaging member, (21) is a heat insulating material, (22) is a heat insulating plate, (23)
(24) is a lower hydraulic cylinder which is a lower pressurizing mechanism, (28) is a fin type, and (30) is an upper end ring pressurizing means. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Figure 5 Figure 6 Figure 7 Figure 8 Figure 17 (H) (b) Figure 19 (Figure 18/l /θ Kuku Figure 20 Figure 21 Figure 22 (H) (G)

Claims (8)

[Claims] (1) Manufacture of a squirrel cage rotor in which a rotor core is filled with molten conductor material under pressure and solidified to form slot conductors and end rings connected to the slot conductors and arranged on both end faces of the rotor core. A method for manufacturing a squirrel cage rotor, characterized in that the filled molten conductor material is pressurized from both one end ring and the other end ring. (2) The filled molten conductor material is pressurized from the axial direction of the rotor core of one end ring and the axial direction of the rotor core of the other end ring, and from the radial direction of the rotor core of at least one of the end rings. 2. The method of manufacturing a squirrel cage rotor according to claim 1, wherein the squirrel cage rotor is also pressurized. (3) The method for manufacturing a squirrel cage rotor according to claim 1, characterized in that the filled molten conductor material is pressurized from between the fins of a plurality of fins of the end ring. (4) The feature is that the heat dissipation of the molten conductor material filled into the filling opening is relaxed and solidification is delayed, and the molten conductor material filled is pressurized from both one end ring and the other end ring. A method of manufacturing a squirrel cage rotor according to claim 1. (5) While relaxing the heat dissipation of the molten conductor material filled in one end ring on the filling port side and the other end ring opposite to it and delaying solidification, the molten conductor material filled above is
2. The method of manufacturing a squirrel cage rotor according to claim 1, wherein pressure is applied from both one end ring and the other end ring. (6) The pressurizing part is filled with molten conductor material in excess of the shrinkage due to solidification, and the filled molten conductor material is pressurized from both one end ring and the other end ring. A method for manufacturing a squirrel cage rotor according to claim 1. (7) A claim characterized in that a plurality of radially arranged fin molds are compressed and moved to the center in the radial direction, and the filled molten conductor material is pressurized from the radial direction of the rotor core of the end ring. 1. A method for manufacturing a squirrel cage rotor according to 1. (8) Fill the rotor core with molten conductor material under pressure and solidify it to manufacture a squirrel cage rotor that forms slot conductors and end rings connected to the slot conductors and arranged on both end faces of the rotor core. a plurality of engaging portions disposed to face the end ring, a pressure punch that engages with any of these engaging portions and presses the end ring, and the engaging portion A car characterized in that an end ring pressurizing means having a pressurizing mechanism that drives the pressurizing punch and applies a pressing force via the pressurizing mold clamping mechanism for tightening the casting mold of the squirrel cage rotor is provided. Manufacturing equipment for shaped rotors.