JPS6216050A - Casting device for squirrel-cage rotor - Google Patents

Abstract

PURPOSE:To prevent the generation of mold cavities, and to cast each cavity uniformly by pressure-feeding a molten metal into the cavities in a plurality of rotor cores arranged to sections upper than a molten-well surface in the periphery of a well section for a metal and forming a plurality of vent sections. CONSTITUTION:A top force 13 and a bottom force 17 shaping a plurality of cavities 12 on a concentric circle in the periphery of an upper punch 23 are disposed. A molten-well section 17a for a molten metal 6 is formed to the bottom force 17, and the molten metal 6 is pressure-fed into the cavities 12 through a gate 18. The cavity 12 is shaped to a section upper than the surface of the molten metal in the basin section 17a, and a rotor core 1 is held by a press bar 16 and a push-up bar 20. A vent hole 19 is formed to the cavity 12 by first-third vent sections 19a-19c, and volume/surface areas there of are made larger previously in order of the third, the first and the second. The second vent section 19b has the function of a basin. Accordingly, each cavity is filled uniformly with the molten metal, thus allowing casting through which no shrinkage void is generated in slots for respective core.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a casting device for a squirrel cage rotor used in an induction motor or the like.

[Conventional technology]

FIG. 5 is a sectional view showing a conventional casting device for a squirrel cage rotor using aluminum die casting.

In the figure, (1) is a rotor core made of laminated circular steel plates, (2)
is a temporary core bar, (3) is a collar, and (4) is a nut.The two-rotor core (1) is tightened and integrated with the nut (4) through the temporary core bar (2) and collar (3). There is. (5) is an extrusion rod for taking out the product after molding, (6) is a metal material for electric conductor such as aluminum or copper, (7) is a sleeve for injecting the molten metal scrap material (6), and (8) is A plunger for applying casting pressure, (9) is a fixed mold, αG is an intermediate mold, and αυ is a moving mold.

Conventional squirrel cage rotor die-casting equipment uses temporary core metal (2)
, the rotor core (1) integrated with the collar 131 and the nut (4) is inserted into the cylindrical cavity of the intermediate mold Ql, and the intermediate mold OQ and the movable mold aI) are placed in the fixed mold (9). Apply pressure to clamp the mold. Thereafter, the molten metal material, in this case aluminum (6), injected into the sleeve (7) is pressurized by the plunger (8) as shown by the arrow at a plunger (8) speed of approximately 1 l to form one rotor core. (1) Slot) Flow through (1a) at a speed of 1.5 m/sec or more.

After filling the slot (1a) and the end ring at high pressure and high speed within 1 second and cooling rapidly, the mold is opened between the fixed mold (9) and the intermediate mold Ql, and the extrusion rod (5) Push out the rotor core (1).

Figures 6 (a) and (b) show the squirrel cage rotor obtained in this way, where (a) is a cross-sectional view, (b) is a side view, and (6a) is a nest. . As can be seen from Fig. 6(a), shrinkage cavities (sink cavities) (6
a) occurred, leading to a decrease in density and a decrease in filling rate. For example, the density of pure aluminum is 2. ry/am
3, but the aluminum density of one rotor conductor is 2.51
It was about y/cm'. This reduction in density and filling rate impedes the conduction of secondary current induced in the rotor, which in turn reduces rotational torque. Therefore, at present, shrinkage nests (6
Considering the decrease in conductivity caused by a), the rotor is designed with a safety factor, and there is no limit to fully exploiting the material properties of the nine-rotor conductor. Therefore, in order to obtain the 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, which makes the motor itself larger, which not only becomes an obstacle to miniaturization and weight reduction, but also creates unnecessary This required additional materials, leading to increased costs. Furthermore, the strength of the rotor was reduced due to the cavities (6a) formed inside the slots, and there was a risk of wire breakage and destruction during high-speed rotation.

Therefore, the inventor proposed a casting apparatus shown in FIG. 1 as a casting apparatus that solves the above-mentioned problems.

In the figure, α2 is a cavity into which the rotor core il+ is inserted so that its rotating shaft insertion portion is in one force direction.

α3 is the upper mold, 04 is the upper pressure plate of a pressure mechanism such as a press, which applies mold clamping force, a51 is the strut that connects the upper mold αj and the upper pressure plate αS, and αe is the upper mold Q3. established.

A presser rod 2 for pressurizing the rotor core [1] is connected to a pressurizing mechanism (not shown) such as an air cylinder.

al is the lower mold, which has a pool part (17) that holds the molten metal material.
a) is provided, and the cavity α3 is a hot water reservoir (17a).
A plurality of them are arranged, for example, in a radial pattern, around the water reservoir surface. 0e is a gate that connects the cavity α2 and the sump (17a), and the cross-sectional area of this gate is the same as that of the rotor core fil in which the molten metal material is inserted into the cavity αδ.
The filling speed when filling slot (1a) is 1.
It is configured so that the speed is 5 m/sec or less. α9 is a gas vent provided above cavity α4 on the opposite side of gate 0 ladder, c! Qi is raised in conjunction with the knockout punch Qυ by means of a knockout lower plate 2 which is screwed to the knockout punch Qυ, for example. This is the upper punch for filling the cavity α with molten metal material.

In the above casting device, the molten metal material held in the sump (17a) fills the lower end ring from near the gate αυ, and at the same time slowly rises through the slot near the gate αυ, After filling the upper end ring, the molten metal material finally reaches the gas vent α9.

Since this filling speed is controlled to 1.5 m/see or less, the flow of the molten metal material becomes a laminar flow, reducing entrainment of air. Approximately 50 mm with presser bars Q and B
Since solidification is performed while applying a high pressure of 0 k19//c7712 degrees, it is possible to manufacture a squirrel cage rotor having electric tatami bodies that are densely packed with few cavities.

However, in the above-mentioned casting equipment, the sump (17
The plurality of cavities 02 arranged around a) are not uniformly filled with molten metal material, resulting in a difference in the speed. Furthermore, when the opening on the cavity 03 side of the gas vent σ9 was filled with molten metal material and solidified, the gas could no longer escape and the filling of the molten metal phase into the two-rotor core (1) was unstable.

[Problem that the invention seeks to solve]

As mentioned above, in conventional die-casting equipment, shrinkage cavities occur inside the rotor conductor, leading to a decrease in density and filling rate, resulting in a decrease in rotational torque. The limit design of the rotor to achieve maximum performance was not done, which hindered efforts to reduce the size and weight, and resulted in a decrease in the strength of the two rotors.

There is a risk of wire breakage and destruction during high speed rotation.
5 problems were encountered.

In addition, with casting equipment that applies high pressure after slowly filling the metal material, the metal material does not fill the multiple cavities uniformly, and the metal material forms a laminar flow starting near the gate and gradually fills the slots. 9. There was a problem in that the filling that finally reached the gas venting port was unstable due to the solidification of the metal material formed at the gas venting port.

This invention was made in order to solve the above-mentioned problems. It stabilizes the filling of metal material into one rotor core, absorbs the unbalance of filling into multiple cavities, and achieves reliability without shrinkage cavities. An object of the present invention is to provide a squirrel cage rotor casting device that can stably manufacture a squirrel cage rotor with improved properties.

[Means for solving problems]

The squirrel-cage rotor casting device of the present invention comprises: a sump portion for holding molten metal material; a plurality of cavities into which the rotor core is inserted; A gate that communicates the cavity and the water reservoir is provided above the cavity and on the opposite side of the gate, with first and second gates extending from the cavity side. A gas venting port consisting of a third gas venting portion is provided, and the volume/surface area of the gas venting portion is the third. 1st
゜When the cavity is filled with metal material, the second gas vent part becomes a pool of metal material.

[Effect]

In this invention, even if the gas venting port is filled with molten metal material, it does not solidify because the volume/surface area of the first gas venting part is large, and it solidifies because the volume/surface area of the third gas venting part is small. Therefore, the filling of the rotor core with metal can be stabilized. Also.

Since the second gas venting portion serves as a pool of hot water, it is possible to absorb imbalances in the filling of the plurality of cavities. From this, the molten metal material is stably and slowly filled into the gas vent from the vicinity of the gate of the rotor core in the cavity, making it possible to manufacture a squirrel cage rotor fc with improved reliability and no shrinkage cavities. A casting device is obtained.

[Embodiment] FIG. 1 is a longitudinal sectional view showing the vicinity of a cavity of a casting device for a squirrel cage rotor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line It-It. In fig.

(19a), (19b), and (19c) are the first.
Second. The volume/surface area of the third gas venting portion is configured in the following order: the third gas venting portion (19c) (the first gas venting portion (19a)) (the second gas venting portion (19b)). When the gas is filled into the gas vent al through the cavity a force.

The second gas venting portion (19'b) forms a water reservoir.

In the above casting device, the molten metal material (6) held in the sump (17a) fills the lower end ring from near the gate 0 sand, slowly ascends the slot near the gate 6 seconds, The upper end ring near the gate 0 sand is filled and reaches the gas venting port (I9).Here, since the volume/surface area of the first gas venting part (19a) is large, the metal material does not solidify, and the third gas venting part (19a) does not solidify. Since the volume/surface area of the portion (19c) is small, it solidifies upon cooling.

Therefore, there is no possibility that the metal material (6) solidifies in the first gas venting part (19a) and degassing becomes impossible.

The metal material (6) can be stably filled into the cavity α2.

Furthermore, since the second gas venting part (19b) constitutes a hot water reservoir, it has a structure in which gas easily accumulates.

Unbalance when the plurality of cavities Q3 are filled with the metal material (6) can be absorbed. As a result, the metal material (6) can be stably filled into the rotor core (1) in the cavity 02, and a squirrel cage rotor casting device with no shrinkage cavities and improved reliability can be obtained. Also, 1st. Second. Third gas venting part (19a).

The shapes of (19b) and (19c) are not limited to the above embodiments, but as shown in FIGS. 3 and 4, the shapes of 1.
The second gas venting portions (19a) and (19b) are configured the same, and the second gas venting portion (19b) and the third gas venting portion (1
9c) to reduce the volume/surface area of the third gas venting part (19c), the same effect as in the above embodiment can be obtained.

In addition, although the above embodiment describes a casting device that uses pressure from the upper punch, the same effect can be obtained by blocking the upper punch insertion part, injecting molten metal material from below, and applying pressure from the lower punch. play.

〔Effect of the invention〕

As described above, according to the present invention, the molten metal material is held in the molten metal reservoir and the periphery of the molten metal reservoir.

A plurality of cavities into which the rotor core is inserted are arranged above the water pool surface, a gate communicates the cavities with the water pool, and a first cavities provided above the cavities and facing the gates from the cavity side. Equipped with a gas vent consisting of a second and third gas vent.

The volume/surface area of the gas venting part is 3rd. 1st. The size increases in the order of the second gas venting part, and when filling the cavity with metal material, the second gas venting part is configured to become a pool of metal material, thereby stabilizing the filling of the metal material into the two-rotor core. The effect of this is that it is possible to obtain a casting device for a cage-filled trochanter that can absorb the unbalance of filling into multiple cavities and stably produce the same type of reliable trochanter with no shrinkage cavities. There is.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a casting device for a cage-saiga trochanter according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line 1-1 in FIG. 1, and FIG. Vertical sectional view showing the embodiment, No. 4
The figure is a sectional view taken along the line ff-ff in Fig. 3, and Fig. 5 is a longitudinal sectional view showing a conventional die-casting device for casting a cage trochanter.
6(a) and Cb) are a cross-sectional view and a side view, respectively, showing a cage trochanter molded by the casting apparatus shown in FIG. 5, and FIG. FIG. (11... Rotor core, (6)... Molten metal material,
(I2...cavity, (17a)...water reservoir, (lS...gate, (19...gas vent,
(19a)...first gas venting section, (19b)...
2nd gas venting part, (19c)... 3rd gas venting part. Note that in the two figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A sump portion for holding molten metal material, a plurality of cavities arranged around this sump portion and into which a rotor core is inserted and arranged above the sump surface, a gate communicating this cavity with the sump portion, and the above. A first, a second,
A gas venting port consisting of a third gas venting portion is provided, the volume/surface area of the gas venting portion increases in the order of the third, first, and second gas venting portions, and the metal material is filled into the cavity. In the casting device for a squirrel-cage rotor, the second gas venting section is a pool of the metal material.