JP4738638B2 - Geikast device for motor rotor - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a die casting apparatus for a motor rotor, and more particularly to a vacuum die casting apparatus suitable for a motor rotor that performs die casting by sucking gas or air in a cavity using a vacuum source.
[0002]
[Prior art]
The conductor in the rotor of the rotating electrical machine is formed by casting molten aluminum using a vertical or horizontal die casting machine.
[0003]
FIG. 3 shows a main part of a conventional apparatus (Japanese Utility Model Laid-Open No. 3-9254) applied when casting a rotor conductor using a vertical die casting machine.
[0004]
In FIG. 3, a plunger 23 is provided in a sleeve 22 for injecting molten aluminum 21. On the sleeve 22, a mold receiver 26 is mounted with a gate plate 24 attached on the lower surface side and a gate side mold 25 that can be divided into a plurality of pieces on the upper surface side. The gate plate 24 is formed with a plurality of gates 24a, and the gate side mold 25 is formed with an end ring constituting a part of the rotor conductor and a gate 25a for forming a plurality of blades. In addition, a recess 25b is formed at the center of the upper surface.
[0005]
On the other hand, the rotor blank 27 is inserted into a cored bar 28 having a flange 28a at the lower end and stacked. The rotor blank 27 has a plurality of open-type outer peripheral portions. A slot 27a is provided. The peripheral side surface of the rotor blank 27 inserted and held on the core metal 28 in a stacked state is surrounded by, for example, a three-divided cylindrical mold 29. An anti-pouring side mold 30 having a circular hole 30a at the center is placed on the upper portion of the rotor punch 27 inserted in the core 28 and surrounded by the cylindrical mold 29. In addition, the anti-gate side mold 30 is formed with a cavity 30b for forming rotor conductor end rings and blades. The anti-pouring gate mold 30 is connected to a holder 31 that is stacked on the upper surface thereof so as to be movable up and down. In order to connect the anti-pouring side mold 30 to the holder 31 so as to be movable up and down, a guide hole 30c is formed in the anti-pouring side mold 30 and also serves as a guide pin that is longer than the thickness dimension of the anti-pouring side mold 30 by several tens of millimeters. The stepped bolt 32 is threaded into the holder 31 through the guide hole 30c.
[0006]
The holder 31 has a circular hole 31a at the center, and the mounting plate 33 is fixed by screws 34 so as to close the circular hole 31a. A gas vent groove 35 is formed on the inner peripheral side of the lower surface of the holder 31 to generate a clearance of 0.05 to 0.15 mm when the holder 31 is overlaid on the anti-pouring side mold 30. An annular groove 36 communicating with the punched groove 35 on the outer peripheral side is formed. The annular groove 36 may be formed on the inner peripheral side of the gas vent groove 35. Further, the holder 31 is formed with a gas vent passage 37 that communicates the circular hole 31a and the annular groove 36 to the outside. A joint 38 is attached to an outlet portion of the gas vent passage 37, and a hose 39 coupled to the joint 38 is connected to the intake device 40. Although not shown, the intake device 40 includes a vacuum pump, a vacuum tank, and an electromagnetic on-off valve.
[0007]
Next, the operation of the above configuration will be described.
[0008]
First, a predetermined number of rotor blanks 27 are inserted into the metal core 28 and laminated to a predetermined thickness, and then the flange 28a of the metal core 28 is fitted into the recess 25b of the gate side mold 25. Then surrounding the outer peripheral side of the rotor blank 27 by a three-minute split cylindrical mold 29. Subsequently, the anti-pouring gate side mold 30 connected to the holder 31 is placed on the upper end portion of the rotor punching plate 27, and the holder 31 is overlaid on the anti-pouring gate side mold 30. Thus, the casting preparation product 41 is configured in which the periphery of the rotor blank 27 is surrounded by the gate side mold 25, the cylindrical mold 29, the anti-gate side mold 30, and the holder 31.
[0009]
Then, a predetermined amount of molten aluminum 21 is injected into the sleeve 22 of the die casting machine, and the mold receiver 26 of the casting preparation 41 is fitted into a circular hole formed in the base of a press (not shown). Then, the gate plate 24 is placed on the sleeve 22. Then, pressure is applied from above the mounting plate 33 by a press, and the electromagnetic on-off valve of the intake device 40 is opened in this state. Then, the gas (air) inside the mold is sucked through the gas vent groove 35, and the inside of the mold is decompressed. When the pressure is reduced, the plunger 23 is pushed up at a high pressure to inject molten aluminum 21 under pressure from the gate 24a of the gate plate 24, thereby forming a rotor conductor. The intake of the mold by the intake device 40 ends when 2-3 seconds have elapsed after the injection of the aluminum 21 into the mold. Then, after forming the rotor conductor, the pressing force of a press (not shown) is removed, the mounting plate 33 is pulled up, and the holder 31 is separated from the anti-gate side mold 30. Therefore, the aluminum debris and impurities adhering to the degassing groove 35 are blown off with compressed air to obtain a clean state. Next, the cylindrical mold 29 and the gate side mold 25 are disassembled, and the rotor blank 27 (rotor core) is taken out.
[0010]
According to such a conventional embodiment, before the molten aluminum 21 is pressurized and injected into the mold, the gas in the mold is sucked by the intake device 40 to reduce the pressure, so the molten aluminum pressure-injected into the mold is injected. There is no risk of entraining gas in the process of filling the mold with the mold 21, and the formation of nests can be prevented more reliably.
[0011]
Further, at least before the molten aluminum is press-fitted into the mold, the gas in the mold is sucked by the intake device so that the molten aluminum does not entrain the gas, and the anti-pouring side mold and the holder are separated. Thus, the gas vent groove can be cleaned each time, so that the formation of nests can be prevented more reliably.
[0012]
[Problems to be solved by the invention]
However, in the configuration shown in FIG. 3, the suction channel cross-sectional area of the gas vent groove 35 formed on the contact surface between the holder 31 and the anti-spout side mold needs to be such that normally molten aluminum cannot be inserted. According to the knowledge of the present inventor, the gap in the cross section is as small as about 0.05 to 0.1 mm.
[0013]
On the other hand, the time for performing suction by the vacuum source must be terminated before the molten aluminum is press-fitted into the cavity as described in the above-described conventional example, and the casting cycle of the motor rotor (electric rotor) is completed. There is a contradictory aspect between the requirement for shortening and the requirement for quality improvement by degassing, that is, removal of residual air in the cavity.
[0014]
As the demand for high-speed rotation for electric motors becomes stronger, the realization of high vacuum by removing residual air in the cavity, which is the premise of the latter, is crucial.
[0015]
However, there is a disclosure that the gap of the suction path cross section of the gas vent groove 35 shown in FIG. 3 is about 0.05 to 0.15 mm, and the molten aluminum reaches the cavity 30b leading to the gas vent groove 35. In view of this, the suction operation by the suction device 40 must be terminated at least before the molten aluminum 21 by the plunger 23 rises from the sleeve 22 and reaches the gate 24a.
[0016]
Therefore, the time that can be sucked also varies depending on the time required to turn on and off the electromagnetic valve in the suction device 40, so that the molten aluminum reaches the cavity 30b on the anti-pouring side on the safe side, that is, even if there is a delay. It had to be decided on the premise of not.
[0017]
In short, if the time required for the casting cycle of the motor rotor is constant, there is a problem in that the cross-sectional area of the degassing groove 35 is small in order to obtain a sufficiently high vacuum in the cavity within the evacuation time. It is.
[0018]
The present invention is intended to solve the above problems, and the cross-sectional area of the suction passage from the anti-pouring side is made much larger than before so that this passage cross-section does not hinder the ability of the suction device, The molten metal is supplied via the pin gates formed at both ends of the motor rotor so that even if the molten metal reaches the end ring part, it is not immediately inserted into the suction passage. Therefore, the suction time can be made longer than before, and from the inside of the mold. An object of the present invention is to provide a die casting apparatus for a motor rotor in which the discharge sequence of the motor rotor is simplified.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that a thin bar-shaped conductor portion is formed in a large number of slot portions formed in a core core made of a large number of thin steel plates held in a laminated state on a core metal. In a die casting apparatus for a motor rotor that is molded at both ends of an iron core and casts an annular end ring that short-circuits each of the conductor portions, an iron core holding mold that stores and holds the core iron core in an inner peripheral portion, An injection sleeve for receiving the molten metal formed as the rod-shaped conductor portion and the end ring, a fixed die plate for fixing and holding the injection sleeve, and a portion near the injection side of the injection sleeve that is fixedly attached to the fixed die plate at a fixed die for forming the runner portion of the molten metal, a motor rotor of a movable die plate after casting through the aperture to have a hole in the center It said movable die plate formed by mounting a push rod which allowed to extrusion discharged from the serial core holding dies, the movable die made fixedly attached to the movable die plate, to each one end face the fixed mold and the moving mold The other end surface side is arranged so as to be in contact with each end surface side of the iron core and the iron core holding mold, and an annular groove for forming the end ring and a plurality of pin gates following the top of the end ring are formed in each inside A first mold on the right side surface of the laminated iron core provided with a cone-shaped molten metal passage and a second mold on the left side surface of the laminated iron core, the moving mold, and the second mold The motor rotor die casting apparatus is characterized in that a suction passage is formed on the contact surface so that one end communicates with the cone-shaped molten metal passage and the other end communicates with a vacuum source.
[0020]
According to the second aspect of the present invention, an annular groove communicating with the pin gate is formed as a molten metal supply path in the fixed mold and the movable mold, and the end face of the annular molded portion formed in the annular groove is pressed. And the extrusion pin for discharging | emitting from the said annular groove was provided so that advance / retreat was possible.
[0021]
Furthermore, the invention described in claim 3 is characterized in that means for restricting the separation of the first mold from the fixed mold to a predetermined amount is provided.
[0022]
The invention according to claim 4 is characterized in that the tip portion of the extrusion pin that presses the end surface of the annular molding portion is formed in an undercut shape with the tip downward, and the die casting device for motor rotor according to claim 2 is characterized. To do.
[0023]
[Action]
In the first aspect of the present invention, the molten metal supplied from the gate side enters the laminated iron core through the pin gate and the annular groove formed in the first mold in contact with the fixed mold and the end ring annular groove. To the annular groove formed in the moving mold via the pin gate and end ring annular groove formed in the second mold on the anti-pouring side. Even if the suction passage cross-sectional area formed on the contact surface between the mold and the second mold, that is, the gap between the contact surfaces is increased, the molten metal is not inserted into the suction passage. By providing a plurality of these pin gates by securing a cross-sectional area of about 1 to several millimeters in diameter, the resistance to suction at each pin gate portion is reduced, and a plurality of pin gates are provided, so that the cavities can be reduced in a short time overall. The inner is to a high vacuum.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a mechanism of a casting mold in a horizontal type gold chamber die casting machine, and details of its injection mechanism and mold clamping mechanism are omitted. In FIG. 1, an injection sleeve 102 is attached and fixed to a fixed die plate 101 on the right end side, and an inlet 103 for molten metal M is formed. A plunger rod 104 connected to an injection cylinder rod (not shown) via a coupling and a plunger tip 105 fixed to the left end of the injection sleeve 102 are slidably fitted. Reference numeral 107 denotes a fixed die fixed on the fixed die plate 101, and a runner portion 120 communicating with the left end opening of the injection sleeve 102 is formed in the lower portion thereof. The fixed mold 107 is further formed with an annular groove 118, which is in the first mold 108 adjacent to the fixed mold 107 and has a plurality of circumferences on the circumference having the same diameter as the annular groove 118. It communicates with a cone-shaped molten metal passage 117 formed at a location. Reference numeral 111 is an extrusion pin for discharging the aluminum member solidified in the annular groove 118 together with the aluminum member solidified in the cone-shaped molten metal passage 117 to the outside of the mold, and is fixedly attached to the extrusion plate 112. The pushing plate 112 is always urged to the right in the drawing by a spring 113, and when ejected, the pushing plate 111 is urged to the left by a piston rod 106 protruding from a cylinder provided in the fixed die plate 101. It is designed to move to the left. The distal end portion of the push pin 111 has an undercut portion. FIG. Such an undercut 111A is also formed at the tip of an extrusion pin 154 described later.
[0025]
FIG. 2 (A) shows a state where an undercut portion 111A is formed at the tip of the extrusion pin 111, and the molten metal M turns around and solidifies there.
[0026]
FIG. 2B is an axial cross-sectional view of the push pin 111 and is a view seen from the tip side of the pin. As can be seen from these drawings, the undercut 111A is formed toward the lower end of the end of the extrusion pin 111, and the solidified molded part including the undercut portion is pushed downward by gravity by pushing the extrusion pin 111 to the left. Is discharged. Further, as long as the push pin 111 is not moved, the solidified molded portion is prevented from moving leftward by the undercut portion even if it is pulled leftward.
[0027]
Referring back to FIG. 1, reference numerals 109 and 110 denote iron core holding dies for housing the laminated iron core 115 for the motor rotor held by the core metal 115A. These 109 and 110 are constituted by a single member. May be.
[0028]
The first metal mold 108 is disposed on the right end surface of the laminated iron core 115 and the second metal mold 143 is disposed on the left end surface. The second metal mold 143 and the iron core holding metal are disposed. The molds 110 are fixed to each other by bolts 143A. The first mold 108 is formed with an annular groove 116 for forming an end ring, which is formed in the laminated iron core 115 and communicates with a slot 114 for forming a conductor portion. The top of the annular groove 116 is the cone. It connects with the front-end | tip part of the molten metal channel | path 117, The connection part comprises pin gate PG. That is, the cross section of the pin gate PG is formed with a diameter of about 1 to several mm, and the pin gate PG portion is cut along with the mold opening operation after molding.
[0029]
The same configuration as the cone-shaped molten metal passage 117, the pin gate PG, and the ring groove 116 for the end ring in the first mold 108 is also formed in the second mold 143, and 117A, PG, and the annular groove 116A, respectively. Indicated. Reference numerals 141 and 142 denote movable molds attached to and fixed to the movable die plate 140. The mold 142 is formed with an annular groove 118A, and a conical molten metal passage 117A at a plurality of locations on the circumference concentric with the annular groove 118A. It communicates with the bottom of the.
[0030]
Further, the movable molds 141 and 142 are provided with push pins 154 attached to the push plate 151 so that the rod tip of the piston cylinder 153 biases the push plate 151 against the spring 152 to the right. It has become.
[0031]
Reference numeral 138 denotes a suction passage formed on the opposing surfaces of the second mold 143 and the moving mold 142, and the lower end of the passage 138 is communicated with the cone-shaped molten metal passage 117A via the annular groove 118A. The upper end portion opens to a switching valve device 131 for turning on and off the suction operation via the vacuum source 130 and the pipe line 137.
[0032]
The switching valve device 131 includes two members 132A and 132B. The member 132A is fixed to the upper surface of the second mold 143, and the member 132B is fixed to the upper surface of the moving mold 142.
[0033]
A small cylinder mechanism 133 is attached to the left end of the member 132B, and a valve element 135 is attached to the right end of the rod 134 that is connected to the piston 134A. Therefore, the valve body 135 is configured to turn ON / OFF the communication between the suction passage 138 and the suction port 136 of the switching valve device 131 by the movement of the rod 134.
[0034]
The illustrated state corresponds to OFF.
[0035]
The cylinder mechanism may be either oil or pneumatic. Although not shown, as another method, instead of the cylinder system, the rod 134 is configured to be directly moved by an electromagnetic coil such as a moving coil, so that the operation of the valve body 135 is made more responsive than a general electromagnetic switching valve. The valve body 135 can be closed precisely in time with the movement stroke position of the plunger tip 105 in the injection sleeve 102, which is useful for extending the suction time. .
[0036]
Members having pins 144 and 145 attached thereto are fixed to the lower portions of the second mold 143 and the moving mold 142, respectively, and long holes are engaged with the pins 144 and 145 on the inner peripheral side thereof. A member 146 is provided. The length l corresponds to the maximum separation length when the second mold 143 and the moving mold 142 are separated from the contact state shown in FIG. Is to prevent. Furthermore, a member 121 having a pin 122 attached is fixedly attached to the lower end portion of the first mold 108 provided on the fixed side, while the piston rod 123 in the cylinder device 124 attached to the fixed die plate. Is connected to the pin 122. Therefore, the first mold 108 can be separated from the fixed mold 107 to its stroke limit by supplying pressure oil to the rod side or head side oil chamber of the cylinder 124. Further, instead of the cylinder 124, it is possible to use a long hole member 146 or the like used for regulating the separation length between the second mold 143 and the movable mold 142.
[0037]
Reference numeral 150 is an extrusion rod for discharging the formed laminated iron core 115 and the core metal 115A from the iron core holding dies 109, 110, and through an opening 149 in the center of the moving die plate 140. It is connected to a piston rod 155A of a cylinder mechanism 155 attached and fixed to the left end of the central portion of the moving die plate 140.
[0038]
Next, the mold opening operation / order of each mold after filling with the molten metal and molding will be described.
[0039]
The laminated core 115 held by the core metal 115A is inserted into the inner peripheral portions of the core holding molds 109 and 110 shown in FIG. 1 in a state where the mold is opened in advance, and then the arrangement of the mold shown in FIG. 1 is obtained. . Then wait for the injection filling process. Next, when the molten metal M is introduced into the injection sleeve 102, the plunger tip 105 moves slowly to the left, and when the left end of the plunger tip 105 passes through the insertion port 103, the cavity is made suckable, thereby enabling suction. Then, by moving the valve body 135 to the right in FIG. 1, suction in the cavity that causes the suction passage 138 to communicate with the vacuum source 130 is started. When the plunger tip 105 moves further left and reaches a predetermined position, the high-speed injection operation is started and the molten metal M reaches the annular groove 116 for the end ring from the runner portion 120 through the annular groove 118, the cone-shaped molten metal passage 117, and the pin gate PG. Further, it advances from the groove 116 into each slot 114 and reaches the cone-shaped molten metal passage 117A and the annular groove 118A from the left annular groove 116A through the pin gate PG. Note that the timing of ending the suction operation by moving the valve body 135 to the left is set at an appropriate time before and after the start of the high-speed injection operation. Next, when the molten metal M is solidified, the moving die plate 140 starts moving in the direction of the arrow (A) in FIG. At this time, if the piston rod 123 of the cylinder device 124 is left free (without supplying pressure oil), the moving molds 141 and 142, the second mold 143, and the iron core holding molds 109 and 110 are moved together with the moving die plate 140. And the molded motor rotor and the first mold 108 move to the left. At this time, the molded portion occupying the annular groove 118 and the cone-shaped molten metal passage 117 is fixed to the fixed mold 107 side by the undercut portion at the tip of the extrusion pin 111, so the first mold 108 is eventually formed into this cone-shaped portion. After the pin gate PG at the tip of the molded part is cut, the cone-shaped molded part is moved to the left while remaining in the fixed mold 107.
[0040]
Next, when the movement limit of the cylinder 124, that is, when the piston head comes into contact with the left end of the cylinder 124, the first mold is prevented from moving to the left thereafter, so the end ring formed in the annular groove 116 has the first ring. It moves out of the mold 108 and moves with the moving die plate 140 to the left. In this way, the moving die plate 140 moves to the left and stops until the distance between the left end surface of the first mold 108 and the top end surface of the annular groove 116 becomes a length necessary for discharging. Next, the cylinder 155 is energized and the right end of the push rod 150 protrudes the metal core 115A to the right, whereby the pin gate PG in the second mold 143 is cut by the action of the undercut at the tip of the push pin 154, and then the core. The laminated core 115 which is held by the metal 115A and in which the end ring and the conductor part are cast is discharged from the core holding molds 109 and 110 to the outside of the mold. At that time, since the second mold 143 and the bolt 143A are fixed to the iron core holding mold 110, the elongated hole member is caused by the sliding resistance of the outer peripheral surface of the laminated core 115 (a constant resistance is generated by thermal expansion). Only the length l of 146 moves to the right, and during this time, the cone-shaped molded portion molded in the cone-shaped molten metal passage 117A comes out of the second mold 143. When the second mold 143 and the moving mold 142 are separated by a length l, the pin 145 comes into contact with the inner periphery of the left end of the long hole member 146, and further separation is prevented. Next, the piston rods 106 and 153 are energized, and the extrusion pins 111 and 154 press the formed portion end surfaces formed in the annular grooves 118 and 118A through the extrusion plates 112 and 151, respectively. Since the undercut portion is formed so as to face downward, the undercut portion is discharged downward by its own weight.
[0041]
【The invention's effect】
As described above, according to the present invention, a plurality of pin gates are formed in the first and second molds in contact with both end portions of the laminated core held by the core metal, following the annular groove for forming the end ring. The cross-sectional area of the gate portion is made large enough to suck and discharge the gas and air in the cavity, thereby cutting off the suction passage formed on the facing surface of the second mold and the fixed mold. The area, that is, the gap can be increased by one digit or more than before, and high vacuum in the cavity can be realized in a short time. In the above description, the pin gate PG in the second mold is cut in the middle of the movement of the push rod 150 to the right. The pin gate PG in the first mold may be cut substantially simultaneously with the cutting.
[Brief description of the drawings]
FIG. 1 is a detailed sectional view of a main part of a mold structure for casting a motor rotor in an embodiment of the present invention.
FIG. 2 is a detailed explanatory diagram of an undercut portion of a Z portion shown in FIG.
FIG. 3 is a detailed cross-sectional view of a main part of a conventional mold structure for casting a motor rotor.
[Explanation of symbols]
101 Fixed die plate 102 Injection sleeve 103 Insertion port 104 Plunger rod 105 Plunger tip 106 Piston rod 107 Fixed mold 108 First mold 109, 110 Iron core holding mold 111, 154 Extrusion pin 112, 151 Extrusion plate 113 Spring 114 Slot 115 Laminated iron core 116 Annular groove 117 Conical molten metal passage 118 Annular groove 123 Piston rod 131 Switching valve device 134 Rod 135 Valve body 140 Moving die plate 141, 142 Moving mold 143 Second mold 144, 145 Pin 146 Long hole member
149 Opening 150 Extrusion Rod PG Pin Gate

Claims (4)

A thin rod-shaped conductor portion formed in a large number of slot portions formed in a core iron core made of a large number of thin steel plates held in a laminated state on a cored bar, and an annular ring that short-circuits each conductor portion. In a die casting apparatus for a motor rotor for casting an end ring, an iron core holding mold for accommodating and holding the core iron core in an inner peripheral portion, and an injection sleeve for receiving the rod-shaped conductor portion and the molten metal formed as the end ring A fixed die plate that fixes and holds the injection sleeve, a fixed die that is fixedly attached to the fixed die plate and forms a runner portion of the molten metal near the injection side end of the injection sleeve, and a central portion the extruded rods allowed to extrusion discharged from the core holding dies of a movable platen motor rotor after casting through the aperture to have a hole instrumentation Wherein the movable die plate formed by the movable die made fixedly attached to the movable die plate, each one end face is in contact with the fixed mold and the moving mold, the other end surface side of the iron core and iron core holding dies A laminated iron core that is arranged in contact with each end face side, and is provided with a cone-shaped molten metal passage for forming a plurality of pin gates following the annular groove for forming the end ring and the top of the end ring in each inside One end of the first mold on the right side and the second mold on the left side of the laminated core and the contact surface between the moving mold and the second mold communicate with the cone-shaped molten metal passage. A die casting apparatus for a motor rotor, wherein the other end side includes a suction passage formed to communicate with a vacuum source.   An annular groove communicating with the pin gate is formed as a molten metal supply path in the fixed mold and the movable mold, respectively, and an end of the annular molded portion formed in the annular groove is pressed and discharged from the annular groove. 2. The die casting apparatus for a motor rotor according to claim 1, wherein the extrusion pin is provided so as to be able to advance and retract.   3. The die casting apparatus for a motor rotor according to claim 1, further comprising means for restricting the separation of the first mold from the fixed mold to a predetermined amount. 3. The die casting apparatus for a motor rotor according to claim 2, wherein the tip end portion of the extrusion pin that presses the end surface of the annular molded portion is formed in an undercut shape with the tip downward .

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