JP5184957B2 - Method for manufacturing cage rotor and apparatus for manufacturing the same - Google Patents

Description

  The present invention relates to a method of manufacturing a squirrel-cage rotor that is die-cast with molten metal and a manufacturing apparatus thereof.

  A squirrel-cage rotor of an induction motor is usually manufactured by die casting using a molten metal, for example, molten aluminum, but this manufacturing method tends to generate a casting nest such as a nest and a sink nest inside the product. For this reason, it is considered to adopt a non-porous die casting method (PF method) for aluminum die casting of a cage rotor.

In this PF method, oxygen, which is an active gas, is supplied and filled in a cavity of a mold, and then molten aluminum is supplied into the cavity. Becomes a reduced pressure state, and die casting with less bubbles is obtained (for example, see Non-Patent Document 1).
“What is Die Casting?-Die Casting-” Die Casting Association August 2003, page 27

In the case of die-casting a squirrel-cage rotor, recently, a mold containing a rotor core is set in a cavity on a supply device containing molten aluminum, and the plunger of the supply device is driven to supply molten aluminum. A vertical die casting manufacturing apparatus is used which is extruded and supplied into the cavity through a gate. When the PF method is employed in such a manufacturing apparatus, when oxygen is injected into the cavity of the mold, oxygen and molten aluminum immediately react before filling the cavity with a sufficient amount of oxygen, There arises a problem that the inside of the cavity does not reach the desired reduced pressure state.

  The present invention has been made in view of the above circumstances, and a purpose thereof is a method of manufacturing a cage rotor capable of bringing the inside of a mold cavity into a target reduced pressure state even in the case of vertical die casting, and the manufacturing thereof. To provide an apparatus.

In the method for manufacturing a cage rotor according to the present invention, a mold containing a rotor core is set in a cavity on a supply device that stores molten metal, and the mold contacts with the molten metal in the cavity of the mold to oxidize. In the method of manufacturing a cage rotor in which molten metal is supplied from the supply device into the cavity after supplying the reactive gas to react, when supplying the active gas into the cavity of the mold, the shielding means the cut off communication between the supply device and the cavity, when supplying the molten metal into the mold cavity, the structure in which the said supply device and the cavity to release the blocking by the blocking means so as to communicate with the The shielding means is a part of the mold, and when the molten metal is supplied into the cavity of the mold, the part of the mold is moved to a normal position. Characterized in that so as to establish communication between the supply device and the cavity by.

The squirrel-cage rotor manufacturing apparatus of the present invention includes a supply device including a plunger for extruding stored molten metal, and a set of the supply device on the supply device. A mold for blocking communication between the supply device and the cavity, a gas supply means for supplying an active gas that contacts the molten metal into the cavity of the mold and undergoes an oxidation reaction, and after the gas supply by the gas supply means is completed A mold driving means for communicating the cavity with the supply device by moving a part of the mold to a normal position, and a plunger drive means for driving the plunger of the supply device to supply molten metal into the cavity. It has the characteristics in comprising.

  According to the present invention, since an active gas such as oxygen is supplied into the cavity of the mold in a state where communication with the supply device for storing the molten metal is interrupted, a sufficient amount of active gas is supplied into the cavity. The gas can be filled, and the molten metal can be supplied with the inside of the cavity in a desired reduced pressure state.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 4 shows a cage rotor 1 of an induction machine such as an induction motor. The squirrel-cage rotor 1 includes a rotor core 2 formed by laminating a large number of annular cores made of silicon steel plates. A plurality of slots 3 extending in the axial direction are formed in the outer circumferential portion of the rotor core 2 at a predetermined interval, for example, a predetermined interval in the circumferential direction. The formed conductor 4 is inserted.

  The both ends of the rotor core 2 in the axial direction are provided with aluminum short-circuit rings 5 and 5, and the axial ends of the plurality of conductors 4 are short-circuited to each other. . A plurality of aluminum cooling fins 6 projecting outward in the axial direction are integrally formed on the end face portions of the short-circuit rings 5 and 5. A shaft hole 7 is formed at the center of the rotor core 2, and a rotating shaft 8 is inserted and fixed in the shaft hole 7.

  In the cage rotor 1 having such a configuration, the aluminum conductor 4, the short-circuit rings 5, 5 and the cooling fin 6 are integrally formed by aluminum die-casting. The apparatus 9 will be described with reference to FIGS.

  The supply device 10 is configured such that a cylinder portion 12 is provided in a suspended state on a bed 11 and a plunger 13 is fitted to the cylinder portion 12 so as to be slidable in the vertical direction. The plunger 13 is driven up and down by a plunger driving device 14 such as a hydraulic cylinder as a plunger driving means.

  The mold 15 includes a mold body 16 and a gate plate 17. The mold body 16 includes an intermediate mold 18 having a cavity 18 a that houses the rotor core 2 of the cage rotor 1, and an upper mold 19 having a cavity 19 a for molding the short-circuit ring 5 and the cooling fin 6 on one side. And a lower mold 20 having a cavity 20a for molding the short-circuit ring 5 and the cooling fin 6 on the other side. The upper mold 18 and the lower mold 20 are detachably mounted on the upper end portion and the lower end portion of the intermediate mold 18 in a state where the rotor core 2 is housed in the cavity 18a. In this case, the rotor core 2 is placed on the lower mold 20, and the cavity 19 a of the upper mold 19 and the cavity 20 a of the lower mold 20 communicate with the slot 3 of the rotor core 2. Further, a shaft-like fitting member 21 is inserted into the shaft hole portion 7 of the rotor core 2, and the upper die 19 is formed with a recess 19 b that fits with the head portion 21 a of the fitting member 21. The lower mold 20 is formed with a through hole 20b that fits with the lower end of the fitting member 21.

  The gate plate 17 as a shielding means is slidably mounted in the left-right direction at the lower part of the mold body 16 and is detachably attached to the cavity 20a of the lower mold 20 at a normal position as will be described later. A plurality of gates 17a communicating with each other are provided. In addition, the gate plate 17 receives the lower end of the fitting member 21 at the upper surface at the normal position, and a dummy hole 17b penetrating vertically is formed in the receiving portion.

  The mold 15 is set on the bed 11 of the supply device 10, and when the gate plate 17 is in the normal position, the gate 17 a allows the upper opening 12 a of the cylinder part 12 to pass through the cavity 20 a of the lower mold 20. To communicate with. The gate plate 17 that forms a part of the mold 16 is driven in the left-right direction between a regular position and a non-regular position by a mold driving device 22 including an air cylinder as a mold starting means. ing.

The upper mold 19 of the mold 15 is formed with a gas supply path 23 that allows the cavity 19a to communicate with the outer right side, which is the outer side, as a gas supply means for supplying oxygen as an active gas. The hose 24a of the oxygen cylinder 24 is connected.
The manufacturing apparatus 9 includes a slider 25. The slider 25 is driven by a driving device (not shown) so as to be movable in the vertical direction and the horizontal direction while the mold 15 is suspended.

Next, the operation of this embodiment will be described.
The rotor core 2 is formed by laminating a large number of iron core materials, and the iron core material is formed by punching a band-shaped silicon steel plate with a press. In order to improve the punchability at the time of press punching, it is usual that punching oil is applied to the band-shaped silicon steel plate, but this punching oil adheres to the punched iron core material. Therefore, in this embodiment, the rotor core 2 is preheated at a predetermined temperature, for example, 300 ° C., and punching oil is burned (iron core oil firing).

  Next, as shown in FIG. 1, the mold 15 is assembled in a state where the rotor core 2 is housed in the cavity 18 a of the intermediate mold 18, and molten aluminum 26 that is a molten metal is placed in the cylinder portion 12 of the supply device 10. Is supplied and stored, and then the mold 15 is set on the bed 11 of the supply device 10 by the slider 25. In this case, as shown in FIG. 1, the gate plate 17 which is a part of the mold 15 is set at a non-normal position on the left side of the normal position, and the gate 17 a corresponds to the cavity 20 a of the lower mold 20. In other words, the communication between the cavity 20a and the upper surface opening 12a of the cylinder 12 in the supply device 10 is blocked by the gate plate 17 itself. Then, the hose 24a of the oxygen cylinder 24 is connected to the gas supply path 19b of the upper mold 19, and oxygen is transferred from the oxygen cylinder 24 into the cavity 20a of the lower mold 20, the slot 3 of the rotor core 2, and the cavity 19a of the upper mold 19. 27 is supplied and filled.

  When a predetermined amount of oxygen 27 is filled in the mold 15, the supply of oxygen from the oxygen cylinder 24 is stopped. After that, the gate plate 17 of the mold 15 is moved rightward from the non-regular position in FIG. 1 by the mold driving device 22 and driven to the regular position shown in FIG. Thereby, the gate 17 a of the gate plate 17 communicates with the upper surface opening 12 a of the cylinder portion 12 in the supply device 10 corresponding to the cavity 20 a of the lower mold 20. As a result of the communication between the cavity 20a and the opening 12a of the cylinder portion 12, as shown in FIG. 1, the oxygen 27 filled in the mold 15 comes into contact with the molten aluminum 26 stored in the supply device 10. Oxidation reaction occurs, and the cavity 20a, the slot 3, and the cavity 19a are decompressed. In this case, the punched oil remains in the rotor core 2, but the remaining punched oil also burns during the oxidation reaction between the oxygen 27 and the molten aluminum 26. When the gate plate 17 is in the normal position, the dummy hole 17 b corresponds to the lower end of the fitting member 21, and the upper end opening is closed at the lower end of the fitting member 21.

  After that, as shown in FIG. 3, the plunger 13 is driven by the plunger driving device 14 of the supply device 10 so that the plunger 13 moves upward, and the molten aluminum 26 is pushed out from the upper surface opening 12a by the plunger 13 through the gate 17a. The cavity 20a, the slot 3 and the cavity 19a are sequentially supplied and filled. At this time, the molten aluminum 26 is also filled in the dummy holes 17b of the gate plate 17. In this way, after filling the mold 15 with the molten aluminum 26, the mold 15 is cooled, the mold 15 is removed from the supply apparatus 10, and then the mold 20 is disassembled and the car is disassembled. The semi-finished product of the mold rotor 1 is taken out. In this case, the gate 17a and the dummy hole 17b of the gate plate 17 are filled with the molten aluminum 26 and hardened, but the hardened aluminum remains in the gate plate 17 by inserting a knock bar into the upper part of the dummy hole 17b. Objects can be taken out and removed.

  Here, the semi-finished product of the squirrel-cage rotor 1 means a state in which there is no rotating shaft 8 in the squirrel-cage rotor 1 shown in FIG. Fins 6 are integrally formed. Then, the rotary shaft 8 is inserted and fixed in the shaft hole portion 7 of the rotor core 2 to complete the cage rotor 1 (completed product).

  Thus, according to the present embodiment, when oxygen is supplied from the oxygen cylinder 24 into the mold 15, the gate plate 17, which is a part of the mold 15, is placed in a non-regular position, and the supply device 10 is provided by the gate plate 17. Since the communication between the upper surface opening 12a of the cylinder part 12 and the cavity 20a of the lower mold 20 is cut off, the oxygen injected into the mold 15 immediately comes into contact with the molten aluminum and oxidizes. There is no reaction, and oxygen can be supplied and filled in the mold 15 by a sufficient theoretical amount.

  Therefore, after that, the gate plate 17 is moved to a normal position, and the upper surface opening 12a of the cylinder portion 12 and the cavity 20a of the lower mold 20 in the supply device 10 are communicated with each other through the gate 17a. 26 is subjected to an oxidation reaction, the inside of the mold 15 can be brought to a desired reduced pressure state, and then a molten aluminum 26 is supplied into the mold 15 so that a non-porous high-quality vertical die casting can be obtained. Can be obtained.

  According to the present embodiment, the gate plate 17 which is a part of the mold 15 is moved, so that the cavity 20a of the lower mold 20 and the upper surface opening 12a of the cylinder portion 12 in the supply device 10 are communicated and blocked ( Therefore, there is no need to provide a special dedicated opening / closing device.

  By the way, conventionally, before the rotor core is housed in the mold, the rotor core is heated at a high temperature of 400 ° C. or higher to completely burn and remove the attached punching oil. If the rotor core heated to a high temperature is housed in the mold, the temperature is too high, so that it is necessary to cool the molten aluminum before supplying molten aluminum into the mold, resulting in poor workability. In contrast, in this embodiment, the rotor core 2 is preheated at a relatively low temperature of 300 ° C. to burn most of the punched oil, and the remaining punched oil is oxidized between the oxygen 27 and the molten aluminum 26. Since it is made to burn at the time of reaction, it is not necessary to perform special cooling, and the punched oil can be completely burned and removed.

(Second embodiment)
FIG. 5 shows a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below.
In this second embodiment, instead of the gate plate 17, a mold body 16 which is a part of the mold 15 is used as a shielding means. That is, the mold body 16 is provided so as to be movable in the left-right direction between the normal position and the non-normal position with respect to the gate plate 17 and the slider 25, and is driven by the mold driving device 22. When the mold body 16 is in an irregular position as shown in FIG. 5, the cavity 20a of the lower mold 20 does not correspond to the gate 17a of the gate plate 17, and the lower mold 20 is connected to the cavity 20a and the supply device. 10, the communication with the upper surface opening 12a of the cylinder portion 12 is blocked.

  Thereafter, when the mold main body 16 is moved to the normal position by the mold driving device 22, the mold main body 16 is in the same state as in FIG. 2, and the oxidation reaction between the oxygen 27 and the molten aluminum 26 is performed. Therefore, the same effect as the first embodiment can be obtained by the second embodiment.

(Third embodiment)
6 and 7 show a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below.
In this third embodiment, the gas supply path 23 is formed in the gate plate 17, and when the gate plate 17 is in the non-regular position, as shown in FIG. It communicates with 20a. Therefore, as described above, when the gate plate 17 is in the irregular position, the gate plate 17 itself blocks communication between the cavity 20a of the lower mold 20 and the upper surface opening 12a of the cylinder portion 12 in the supply device 10. Therefore, sufficient oxygen 27 is supplied and filled in the mold 15.

When the gate plate 17 is moved to the normal position by the mold driving device 22, as shown in FIG. 7, the gas supply path 23 is disconnected from the cavity 20a of the lower mold 20 by the gate plate 17 itself. Thus, when the molten aluminum 26 is supplied into the mold 15 by driving the plunger 13, the molten aluminum 26 does not enter the gas supply path 23.
Therefore, also according to the third embodiment, the same effect as that of the first embodiment can be obtained, and the effect that the aluminum cured product does not remain in the gas supply path 23 is also achieved.

(Fourth embodiment)
8 and 9 show a fourth embodiment of the present invention. The same parts as those in the second embodiment are denoted by the same reference numerals, and different parts will be described below.
In the fourth embodiment, the gas supply path 23 is formed in the slider 25, and when the mold body 16 is in the irregular position, the cavity of the upper mold 19 in the mold 15 is shown in FIG. It communicates with 19a. Therefore, as described above, when the mold body 16 is in the non-standard position, the lower mold 20 itself blocks communication between the cavity 20a of the lower mold 20 and the upper surface opening 12a of the cylinder section 12 in the supply device 10. Therefore, sufficient oxygen 27 is supplied and filled in the mold 15.

When the mold body 16 is moved to the normal position by the mold driving device 22, the gas supply path 23 is disconnected from the cavity 19a by the upper mold 19 itself of the mold 16 as shown in FIG. Thus, when the molten aluminum 26 is supplied into the mold 15 by driving the plunger 13, the molten aluminum 26 does not enter the gas supply path 23.
Therefore, the fourth embodiment can provide the same effects as those of the first and third embodiments.

(Fifth embodiment)
FIG. 10 shows a fifth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below.
In the above embodiment, a part of the mold 15 is used as the shielding means. However, in the fifth embodiment, the shielding body 28 is used as the shielding means. The shield 28 has a flat plate shape, and is interposed between the supply device 10 and the mold 15 so as to be movable in the left-right direction between the closed position and the open position. It is driven by the driving device 29. The shield 28 has through holes 28 a and 28 b that allow the gate 17 a and the dummy hole 17 b of the gate plate 17 to communicate with the upper surface opening 12 a of the cylinder portion 12 in the supply device 10 when in the open position.

  Thus, when the shield 28 is in the closed position, the through hole 28a of the shield 28 does not correspond to the gate 17a of the gate plate 17 as shown in FIG. The communication between the cavity 20a and the upper surface opening 12a of the cylinder portion 12 in the supply device 10 is blocked. Therefore, sufficient oxygen 27 is supplied and filled from the oxygen cylinder 24 into the mold 15.

When the shield 28 is moved to the open position by the shield-type drive device 29, the through hole 28a of the shield 28 communicates the cavity 20a of the lower mold 20 and the upper surface opening 12a of the cylinder portion 12 in the supply device 10. It has become. Therefore, due to the communication between the cavity 20a and the opening 12a of the cylinder part 12, the oxygen 27 filled in the mold 15 comes into contact with the molten aluminum 26 stored in the supply device 10 and undergoes an oxidation reaction, thereby causing the cavity 20a, The slot 3 and the cavity 19a are decompressed.
Also according to the fifth embodiment, the same operational effects as those of the first embodiment can be obtained.

  The present invention is not limited to the embodiments described above and shown in the drawings. For example, the present invention can be applied to a squirrel-cage rotor for induction machines in general and can be modified as appropriate without departing from the scope of the invention. Of course, it can be implemented.

The longitudinal cross-sectional view of the manufacturing apparatus which shows 1st Example of this invention FIG. 1 equivalent diagram for explaining the operation Figure 2 equivalent figure in different states Perspective view of cage rotor FIG. 1 equivalent view showing a second embodiment of the present invention. FIG. 1 equivalent view showing a third embodiment of the present invention. 3 equivalent figure FIG. 1 equivalent view showing a fourth embodiment of the present invention. 3 equivalent figure FIG. 1 equivalent view showing a fifth embodiment of the present invention.

Explanation of symbols

  In the drawings, 1 is a squirrel-cage rotor, 2 is a rotor core, 3 is a slot, 4 is a conductor, 5 is a short ring, 6 is a cooling fin, 7 is a shaft hole, 8 is a rotating shaft, 9 is a manufacturing device, 10 is a supply device, 13 is a plunger, 14 is a plunger drive device (plunger drive means), 15 is a mold, 16 is a mold body (part of the mold, shielding means), and 17 is a gate plate (one mold). 17a is a gate, 18 is an intermediate mold, 18a is a cavity, 19 is an upper mold, 19a is a cavity, 20 is a lower mold, 20a is a cavity, 22 is a mold driving device (mold driving means), Reference numeral 23 is a gas supply path, 24 is an oxygen cylinder (gas supply means), 26 is molten aluminum, 27 is oxygen (active gas), 28 is a shield (shielding means), and 29 is a shield drive device.

Claims (7)

Set the mold containing the rotor core in the cavity on the supply device that stores the molten metal, supply the active gas that contacts the molten metal and oxidizes in the cavity of the mold, and then inside the cavity In the manufacturing method of the cage rotor in which the molten metal is supplied from the supply device to
When supplying the active gas into the cavity of the mold, the communication between the supply device and the cavity is blocked by shielding means, and when the molten metal is supplied into the cavity of the mold, the blocking by the shielding means is blocked. In the configuration in which the supply device and the cavity are communicated with each other,
The shielding means is a part of the mold, and when supplying the molten metal into the cavity of the mold, the supply device and the cavity communicate with each other by moving a part of the mold to a normal position. A method of manufacturing a squirrel-cage rotor, wherein The mold is composed of a gate plate set on a supply device and a mold body set on the gate plate, and a part of the mold is the gate plate. A method for producing a cage rotor according to 1. The mold is composed of a gate plate set on a supply device and a mold body set on the gate plate, and a part of the mold is the mold body. Item 2. A method for manufacturing a cage rotor according to Item 1 . Shielding means, the production method of the cage rotor according to claim 1, characterized in that the movably interposed a shield between the supply device and the mold. The gas supply path for supplying an active gas into the cavity of the mold is configured to block communication with the cavity when supplying molten metal into the cavity of the mold. Item 5. A method for manufacturing a cage rotor according to any one of Items 1 to 4 . The method for manufacturing a cage rotor according to any one of claims 1 to 5, wherein the rotor core stored in the cavity of the mold is preheated before storage . A supply device having a plunger for extruding the stored molten metal;
A mold that is set on the supply device, the rotor core is housed in the cavity, and partly blocks communication between the supply device and the cavity;
A gas supply means for supplying an active gas that contacts the molten metal and oxidizes in the cavity of the mold;
Mold drive means for communicating the cavity with the supply device by moving a part of the mold to a normal position after the gas supply by the gas supply means is completed;
An apparatus for manufacturing a squirrel-cage rotor comprising plunger driving means for driving a plunger of the supply device to supply molten metal into the cavity.

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