JPH0549220A - Casting device for cage rotor - Google Patents

Abstract

PURPOSE:To obtain an electric conductor having no shrinkage cavity due to shrinkage of solidification upon molding the conductor of a rotor by filling the core of the rotor with molten conductor material by pressure. CONSTITUTION:In a rotor core 1 laminated on a temporary shaft 3, the core 1 is filled with molten conductor material by pressure to form conductor materials in end rings, fins, and slots of upper and lower parts of the same, then, the molten conductor material is pressurized locally by a pressurizing punch 9 provided at the intermediate part of the upper fin especially by the amount of volume in accordance with the amount of shrinkage of solidification of the molten conductor material while the pressurizing punch 9 is constituted so as to retain the pressure until the final solidification is finished. According to this method, the local pressurizing is effected until the final solidification of the molten conductor material is made whereby a sound rotor conductor having no shrinkage cavity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squirrel cage rotor casting apparatus, and more particularly to a casting apparatus for forming a rotor conductor by pressure-filling a rotor core with a molten conductor material.

[0002]

2. Description of the Related Art FIGS. 6 and 7 show a general squirrel cage rotor core. FIG. 6 is a front view showing a cross section with a part cut away, and FIG. 7 is a side view thereof. In the figure, 1 is a laminated rotor core, 1a is its slot, 1b is a rotary shaft insertion part, and 1c is a circular steel plate. Next, FIG. 8 shows a general cage rotor after casting.
Is a conductor material, 2a and 2b are end rings, 2c and 2d are fins.

Conventionally, this rotor is formed by laminating a required number of circular steel plates 1c having a slot 1a and a rotary shaft insertion portion 1b punched in advance and forming a rotor conductor as shown in FIG. 8 by aluminum die casting. It is manufactured by inserting the shaft.

FIG. 9 is a sectional view showing a conventional casting die. In the figure, reference numeral 1 is a rotor core, which is laminated on a temporary shaft 3. Reference numeral 4 is a lower die, and 5 is an upper die, which have end ring forming portions 4a and 5a and fin forming portions 4b and 5b, respectively. Further, the lower mold 4 and the temporary shaft 3 form a runner 4c. 13 is a moving platen, 15 is a base platen, 14 is a lower mold holder, 15a is a pot, and 16 is a pressure plunger.

Next, the operation will be described. In the conventional casting apparatus, the rotor core 1 laminated on the temporary shaft 3 is placed on the lower mold 4, and the upper mold 5 previously attached to the moving platen 13 is lowered to pressurize the rotor core 1. After that,
The molten conductor material previously injected into the pot 15a is pressurized by the pressure plunger 16 and flows through the runner 4c, the end ring forming portion 4a, and the slot 1a of the rotor core 1,
The slots 1a, the end ring forming portions 4a and 5a, and the fin forming portions 4b and 5b are filled at high speed. Then, after cooling, the pressure applied by the moving platen 13 and the upper die 5 is released, the die is opened, and the rotor core 1 is taken out.

[0006]

In the conventional method, the molten conductor material passes through the runner 4c, the lower end ring forming portion 4a, and the slot 1a, and then reaches the upper end ring, the end ring forming portion 5a, and the upper fin forming portion 5b. After pressure filling,
During the solidification process, the solidification starts from the slot 1a having a small cross-sectional area and cuts off the pressing force. Therefore, the pressing force after filling is not transmitted until the upper end ring is completely solidified. For this reason, in the upper end ring, there is a problem that shrinkage cavities are generated due to solidification and contraction of the molten conductor material, which lowers electrical conduction and adversely affects the torque efficiency of the motor.

The present invention has been made to solve the above problems, and an object thereof is to obtain a casting apparatus capable of preventing the occurrence of shrinkage cavities and obtaining a sound electric conductor having no cavities.

Another object of the present invention is to automatically cut the basin connected to the upper end ring when the mold is opened, and to discharge the residue in the basin without disassembling the mold.

[0009]

SUMMARY OF THE INVENTION A squirrel cage rotor casting apparatus according to the present invention is provided with a pressurizing punch for locally pressurizing the upper end ring in response to solidification contraction of the upper end ring. It is intended to prevent the occurrence of.

In the squirrel cage rotor casting apparatus according to the second aspect of the present invention, a part of the upper die is made movable so that when the die is opened, the basin formed by connecting to the end ring is formed. It is designed to be automatically disconnected.

[0011]

The local pressurization by the pressure punch according to the present invention is performed by operating the upper cylinder so that the pressure punch is semi-solidified through the pressure ring built in the upper mold and the pressure pin. It is done by pushing in.

The cutting and taking-out of the basin according to the second aspect of the invention are performed by the outer mold moving downward and being held by the guide pin when the mold is opened after the filling is completed.

[0013]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a state of completion of filling, FIG. 2 is a plan view of an upper mold, and FIG. 3 is a cross-sectional view showing a state of performing local pressure after completion of filling. In these figures, 1 is a rotor core laminated on a temporary shaft 3, 2 is a conductor material, 4 is attached to a slider 14, and has a lower end ring forming portion 4a and a lower fin forming portion 4b. A lower mold 5 for forming a runner 4c between the upper mold 5 and an upper fin forming part 5b, which is connected to the upper platen 8, and 6 an end ring forming part, which is connected to the upper mold 5. An outer die forming 5a, 9 is a pressure punch inserted into a through hole formed in an intermediate portion of the upper fin forming portion 5b of the upper die 5, and the pressure pin 1
It is connected to the pressure ring 11 via 0. Reference numeral 17 is a support spring for pushing back the pressure ring 11, the pressure pin 10, and the pressure punch 9, 12 is a pressure cylinder for local pressure, 13
Is a moving platen for mounting the upper surface plate, and 16 is a pressure plunger for filling. In addition, 19 and 20 in the figure
Is a basin and a degassing groove provided on the outer peripheral portion of the outer mold 6.

Next, the operation will be described. First, temporary shaft 3
Then, the required number of rotor cores 1 are stacked and placed on the lower mold 4 inserted into the slider 14. Then, the slider 14 is moved to a predetermined position on the base platen 15. Next, the upper mold 5 attached to the moving platen 13 in advance via the upper surface plate 8 is lowered to pressurize the rotor core 1. If the pressure plunger 16 is raised in this state,
The molten conductor material that has been poured into the pot 15a in advance passes through the runner 4c, the lower end ring forming portion 4a and the lower fin forming portion 4b, and the slot 1a to fill the upper end ring forming portion 5a and the upper fin forming portion 5b. To be done. Next, after the completion of filling, when the molten conductor material is in a semi-solidified state, the pressure cylinder 12 presses the pressure punch 9 via the pressure ring 11 and the pressure pin 10 to correspond to the solidification shrinkage amount of the molten conductor material. The above-mentioned volume is pushed into the conductive material filled in the upper end ring forming portion 5a. The pressure applied by the pressure cylinder 12 is preferably maintained until the final solidification of the molten conductor material. At this time, the slot 5b and the basin 19 have already been pre-solidified, and the local pressing force is not transmitted to the outside of the end ring. When the solidification is completed, the mold clamping by the moving platen 13 is released, the upper mold 5 is raised, and the rotor is taken out.

In the above embodiment, the pressurizing punch 9 has a different shape as shown in FIG. 2, but it may be a circular pressurizing punch depending on the solidification shrinkage of the molten conductor material.

Example 2. Next, FIGS. 4 and 5 show another embodiment of the present invention. FIG. 4 is a sectional view after completion of filling the molten conductor material, and FIG. Is. In the drawing, 1 is a rotor core laminated on a temporary shaft 3, 5 is an upper die connected to an upper surface plate 8, 6 is an outer die, and is guided by a guide pin 18 connected to the upper die 5. While sliding vertically, it is held by the guide pin 18 at the stroke end. Also, the outer die 6 is an upper die 5
It has a gas vent groove 20 and a basin 19 on its contact surface with.

Next, the operation will be described. Slot 1a
The molten conductor material filled in the upper fin forming portion 5a and the upper end ring forming portion 5b through the water reaches the hot water pool portion 19 together with the compressed air, gas, and defective material at the filling tip portion along with the filling, The gas is removed from the degassing groove 20. Upon completion of the filling, local pressing by the pressing cylinder 12 is started, and the pressing punch 9 is pushed into the conductive material filled in the upper mold end ring forming portion 5a by the amount of solidification contraction of the molten conductive material. Next, after the solidification is completed, the mold clamping by the moving platen 13 is released, and the upper mold 5 is pulled upward. At the same time, the outer mold 6 is pulled down by the contact resistance with the upper end ring and supported by the guide pin 18. If you raise the moving platen further,
The outer die 6 held by the guide pin 18 also rises, the connection portion of the basin 19 formed by connecting to the upper end ring is automatically cut, and the die surface is opened as shown in FIG. In this state, it remains on the upper surface of the outer mold 6 and can be easily removed.

[0018]

As described above, according to the first aspect of the present invention, after the molten conductor material is completely filled, the upper end ring is locally pressurized while the solidification proceeds, and the pressure is maintained until the final solidification. As a result, a sound electric conductor having no shrinkage cavities due to solidification shrinkage can be obtained in the upper end ring and the fins, and there is an effect that the efficiency and torque characteristics of the motor are improved.

Next, according to the second aspect of the present invention, the mold is constructed such that cutting of the molten metal pool formed by connecting to the upper end ring is performed when the mold is released and the mold is opened. Therefore, it is not necessary to disassemble the mold to remove the molten metal pool, and efficient casting can be performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a filling completed state according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an upper mold and a pressure punch shape according to the first embodiment.

FIG. 3 is a cross-sectional view showing a completed state of local pressure according to the first embodiment.

FIG. 4 is a sectional view showing a filling completed state according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a mold released state according to the second embodiment.

FIG. 6 is a side view in which a general rotor core is partially sectioned.

FIG. 7 is a plan view of a circular steel plate forming a general rotor core.

FIG. 8 is a cross-sectional view showing a rotor after completion of general casting.

FIG. 9 is a cross-sectional view showing a filling completed state using a conventional mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotor core 2 conductor material 3 temporary shaft 4 lower mold 4a lower end ring forming part 4b lower fin forming part 4c runner 5 upper mold 5a upper end ring forming part 5b upper fin forming part 6 outer mold 8 upper surface plate 9 Presser Punch 10 Pressurizing Pin 11 Pressurizing Ring 12 Pressurizing Cylinder 13 Moving Platen 14 Slider 15 Base Platen 16 Pressurizing Plunger 17 Support Spring 18 Guide Pin 19 Hot Water Pool 20 Gas Vent Groove

Claims (2)

[Claims] 1. A rotor core formed by laminating circular steel plates and having a slot penetrating in the laminating direction, a conductor material filled in the slot, and formed on both end faces of the rotor core. What is claimed is: 1. A cage rotor casting apparatus comprising: an end ring connected to the conductor material; and a fin formed on an end surface of the end ring and connected to the conductor material together with the end ring. In the case of forming a conductor material in the lower and upper end rings, fins and slots by pressure filling from a lower mold, a punch for pressing from above is arranged in the middle portion of the upper fin, and the molten conductor material is After completion of filling, the upper end ring is locally pressed by the pressure punch according to the solidification shrinkage amount of the molten conductor material. Place 2. A rotor core formed by stacking circular steel plates and having a slot penetrating in the stacking direction, a conductor material filled in the slot, and formed on both end faces of the rotor core, What is claimed is: 1. A cage rotor casting apparatus comprising: an end ring connected to the conductor material; and a fin formed on an end surface of the end ring and connected to the conductor material together with the end ring. In the case of press-filling from the lower mold to form the lower and upper end rings and the conductor material in the fins and slots,
An outer die, which is a vertically movable end ring forming part, is provided in the lower part of the upper die, and a basin is formed on the outer peripheral portion of the upper end surface of the outer die. A squirrel cage casting device characterized in that it automatically disconnects the basin formed by connection and enables immediate discharge of the residue.