JP2002361387A - Die casting device for motor rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diecasting device provided with a die construction capable of enlarging the clearance of a suction path formed on the opposing face to the die for sucking air and gas remaining in a cavity by a vacuum source and communicating with an annular groove, in the case of casting a body part and an end ring of a motor rotor by a diecasting machine. SOLUTION: In first and second dies in contact with both ends of a laminated iron core held by a core metal, a plurality of pin gates linked with the annular groove for forming the end ring is formed, and by making the cross-sectional area of the gate part adequately large for sucking/exhausting the gas and air in the cavity, the cross-sectional area, that is the clearance, of the suction path formed on the opposing surface of the second die and a stationary die is formed large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor rotor die casting apparatus, and more particularly to a vacuum die casting apparatus suitable for a motor rotor which performs die casting by sucking gas or air in a cavity using a vacuum source.

[0002]

2. Description of the Related Art A conductor in a rotor of a rotating electric machine is formed by casting a molten aluminum by a vertical or horizontal die casting machine.

FIG. 3 shows a conventional apparatus (actually disclosed in Japanese Unexamined Utility Model Publication No.
No. 9254).

In FIG. 3, molten aluminum 2
A plunger 23 is provided in a sleeve 22 for injecting a plunger. On the sleeve 22, a mold receiver 26 to which a gate plate 24 is attached on the lower surface side and a gate part mold 25 which can be divided into plural parts is attached on the upper surface side. The gate plate 24 has a plurality of gates 24.
a is formed, and an end ring constituting a part of the rotor conductor and a cavity 25a also serving as a gate for forming a plurality of blades are formed in the gate side mold 25,
A recess 25b is formed at the center of the upper surface.

On the other hand, the rotor blank 27 is inserted into and laminated on a cored bar 28 having a flange 28a at the lower end, and a plurality of rotor blanks 27 are provided on the outer periphery of the rotor blank 27. An open slot 27a is provided. And
The peripheral side surface of the rotor blank 27 inserted and held in the cored bar 28 in a stacked state is surrounded by, for example, a three-part cylindrical mold 29. Then, on the upper part of the rotor blank 27 that is inserted into the cored bar 28 and surrounded by the cylindrical mold 29,
A counter gate 30 having a circular hole 30a at the center is placed, and a cavity 30b for forming an end ring and a blade of a rotor conductor is formed in the counter gate 30. Have been. The side gate 30 is vertically movably connected to a holder 31 stacked on the upper surface thereof. A guide hole 30c is formed in the gate 30 in order to connect the gate 30 to the holder 31 so as to be able to move up and down, and a guide pin longer than the thickness of the gate 30 by 10 mm is also used. Is screwed to the holder 31 through the guide hole 30c.

The holder 31 has a circular hole 3 at the center.
The mounting plate 33 is fixed by screws 34 so as to close the circular hole 31a. And
On the inner peripheral side of the lower surface of the holder 31, there is formed a gas vent groove 35 which produces a clearance of 0.05 to 0.15 mm when overlapped with the sluice side mold 30. An annular groove 36 communicating with the outer peripheral side of the outer peripheral groove 35 is formed. Incidentally, the annular groove 36 may be formed on the inner peripheral side of the gas vent groove 35. Further, this 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 of the gas vent passage 37, and a hose 39 connected to the joint 38 is connected to an intake device 40. Although not shown, the suction device 40 is a vacuum pump,
It consists of a vacuum tank and a solenoid on-off valve.

Next, the operation of the above configuration will be described.

First, a predetermined number of rotor blanks 27 are inserted into a core 28 and laminated to a predetermined thickness, and a flange 28 a of the core 28 is fitted into a recess 25 b of the sprue side mold 25. Next, the outer peripheral side surface of the rotor blank 27 is surrounded by a 30% cylindrical mold 29. Subsequently, the counter gate 30 connected to the holder 31 is placed on the upper end of the rotor blank 27, and the holder 31 is overlaid on the counter mold 30. As described above, a casting preparation 41 in which the periphery of the rotor punching plate 27 is surrounded by the gate side mold 25, the cylindrical mold 29, the counter gate side mold 30 and the holder 31.
Is configured.

Then, a predetermined amount of molten aluminum 21 is poured into a sleeve 22 of a die casting machine, and a mold receiver 26 of a casting preparation 41 is fitted into a circular hole formed in a base of a press (not shown). The gate plate 24 is placed on the sleeve 22 in such a manner as to match. Then, pressure is applied from above the mounting plate 33 by a press, and in this state, the electromagnetic on-off valve of the intake device 40 is opened. Then, gas (air) inside the mold is sucked through the gas vent groove 35, and the inside of the mold is depressurized. When the pressure is reduced, the plunger 23 is pushed up at a high pressure, and the molten aluminum 21 is injected under pressure from the gate 24a of the gate plate 24, whereby the rotor conductor is formed. In addition, the suction in the mold by the suction device 40 ends when a few seconds have passed after the aluminum 21 was injected into the mold. After the formation of 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 gate side mold 30. Therefore, the aluminum residue and impurities adhering to the gas vent groove 35 are blown off by compressed air to be cleaned. Next, the cylindrical mold 2
9 and the sprue side mold 25 are disassembled to take out the rotor blank 27 (rotor core).

According to such a conventional embodiment, before the molten aluminum 21 is injected into the mold under pressure, the gas in the mold is sucked by the suction device 40 to reduce the pressure. This eliminates the risk of entraining gas in the process of filling the molten aluminum 21 into the mold, thereby making it possible to more reliably prevent the occurrence of nests.

Further, at least before the molten aluminum is press-fitted into the mold, the gas in the mold is sucked by the suction device, so that the molten aluminum does not entrain the gas. By separating, the gas vent groove can be cleaned each time, so that the occurrence of nests can be prevented more reliably.

[0012]

However, in the structure shown in FIG. 3, the cross-sectional area of the suction path of the gas vent groove 35 formed on the contact surface between the holder 31 and the mold on the side of the sprue is usually made of molten aluminum. It is necessary that the gap is not inserted, and according to the knowledge of the present inventor, the gap of the cross section is 0.0
Very small, about 5 to 0.1 mm.

On the other hand, as described in the above-mentioned conventional example, the time for performing suction by the vacuum source must be terminated before the molten aluminum is press-fitted into the cavity. The demand for shortening the casting cycle and the demand for high quality by degassing, that is, removal of residual air in the cavity, have inconsistent aspects.

As the demand for high-speed rotation of the motor increases, it is crucial to realize a high vacuum by removing residual air in the cavity, which is a prerequisite for higher quality.

However, the gas vent groove 35 shown in FIG.
It is disclosed that the gap of the cross section of the suction path is about 0.05 to 0.15 mm.
0b, the suction operation by the suction device 40 should be performed at least by the plunger 23.
Has to be terminated before it rises from the sleeve 22 to reach the gate 24a.

Therefore, the time during which the suction can be performed is determined by the suction device 40.
Due to the variation in the time required to turn on and off the solenoid valves inside, it must be determined on the premise that the molten aluminum does not reach the cavity 30b on the side of the sprue on the safe side, that is, even if there is a delay. Was.

The above-mentioned point has a problem in that when the time required for the casting cycle of the motor rotor is fixed, the cross-sectional area of the gas vent groove 35 is small in making the inside of the cavity a sufficiently high vacuum state during the evacuation time. That is.

The present invention has been made to solve the above-mentioned problem, and the cross-sectional area of the suction passage from the side of the sprue is made much larger than in the prior art so that the cross-section of the passage does not hinder the performance of the suction device. At the same time, the molten metal is supplied through pin gates formed at both ends of the motor rotor, so that the molten metal does not immediately enter the suction passage even when it reaches the end ring portion. An object of the present invention is to provide a die casting device for a motor rotor, which simplifies a discharge sequence of the motor rotor from inside a mold.

[0019]

In order to achieve the above-mentioned object, the invention according to claim 1 is directed to a multi-core iron core formed of a multiplicity of thin steel sheets held in a laminated state on a cored bar. In a motor rotor die casting apparatus for casting and molding a thin rod-shaped conductor portion in a slot portion and annular end rings which are formed at both ends of the iron core and short-circuit the respective conductor portions, the core iron core is provided in an inner peripheral portion. An iron core holding mold for storing and holding, an injection sleeve for receiving the molten metal formed as the rod-shaped conductor portion and the end ring, a fixed die plate for holding and holding the injection sleeve, and being attached and fixed to the fixed die plate. A fixed mold for forming a runner portion of the molten metal in the vicinity of the injection-side end of the injection sleeve; and a motor rotor having an opening at the center and having been formed through the opening. A movable die plate equipped with an extrusion rod for ejecting and ejecting the core from the core holding mold, a movable mold attached to and fixed to the movable die plate, and one end side of the movable die plate is in contact with the fixed mold and the movable mold. , The other end face side is arranged to be in contact with each end face side of the iron core and the iron core holding mold, and inside each of them, an annular groove for forming the end ring and a plurality of pin gates following the top of the end ring are formed. And a second mold provided with a cone-shaped molten metal passage for connecting the fixed mold and the second metal mold, one end of which is in communication with the cone-shaped molten metal passage and the other end of which is a vacuum source. And a suction passage formed so as to communicate with the motor.

According to a second aspect of the present invention, there is provided a fixed mold and a movable mold each having an annular groove connected to the pin gate as a supply path of the molten metal, and an annular forming portion formed in the annular groove. An extrusion pin for pressing an end face and discharging the same from the annular groove is provided so as to be able to advance and retreat.

Further, the invention according to claim 3 is characterized in that a means is provided for regulating the distance of the first mold from the fixed mold to a predetermined amount.

The invention according to claim 4 is characterized in that the tip of the push pin for pressing the end face of the annular formed portion is formed in an undercut shape.

[0023]

According to the first aspect of the present invention, the molten metal supplied from the sprue side is laminated via the pin gate, the annular groove, and the end ring annular groove formed in the first mold in contact with the fixed mold. It reaches the iron core, and further reaches the annular groove formed in the movable mold via the pin gate and the end ring annular groove formed in the second mold on the side of the sprue. Even if the cross-sectional area of the suction passage formed in the contact surface between the fixed die and the second die, that is, the gap between the contact surfaces is enlarged, the molten metal is prevented from being inserted into this suction passage. The cross-sectional area of one pin gate is 1 to
By providing a plurality of these pin gates by securing several millimeters, the resistance to suction at each pin gate portion is reduced, and by providing a plurality of pin gates, the inside of the cavity is made to have a high vacuum in a short time as a whole.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 an injection mechanism and a 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 the molten metal M is formed. Inside the injection sleeve 102, 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 thereof are slidably fitted. 107 is a fixed die plate 10
A fixed mold is fixed on the upper part 1 and a lower part thereof is formed with a runner part 120 communicating with the left end opening of the injection sleeve 102. The stationary mold 107 further includes an annular groove 11.
8 are formed, and this annular groove 118 is
7 in the first mold 108 and the annular groove 118
And is communicated with cone-shaped molten metal passages 117 formed at a plurality of locations on the circumference having the same diameter as. Reference numeral 111 denotes an extrusion pin for discharging the aluminum member solidified in the annular groove 118 to the outside of the mold together with the aluminum member solidified in the cone-shaped molten metal passage 117, and is attached and fixed to an extrusion plate 112. The pushing plate 112 is constantly urged rightward in the figure by a spring 113, and the fixed die plate 10
The push pin 111 is urged to the left by a piston rod 106 projecting from a cylinder provided in the cylinder 1 to move the push pin 111 to the left. The distal end of the push pin 111 has an undercut, and FIG. Such an undercut 11
1A is also formed at the tip of an extrusion pin 154 described later.

FIG. 2A shows a state in which an undercut portion 111A is formed at the tip end of the extrusion pin 111, and the molten metal M goes around and is solidified.

FIG. 2B is an axial cross-sectional view of the push-out pin 111, as viewed from the tip end side of the pin. As can be seen from these figures, the undercut 111A is
Of the extrusion pin 11
By extruding 1 to the left, the solidified molded portion including the undercut portion is discharged downward by gravity. or,
As long as the extrusion pin 111 is not moved, the solidified molded portion is prevented from moving leftward by the undercut portion even if it is pulled leftward.

Returning to FIG. 1, reference numerals 109 and 110 indicate the core 1
Laminated iron core 11 for motor rotor held by 15A
5 is an iron core holding mold for housing 5 inside.
9 and 110 may be constituted by a single member.

The first die 108 is disposed on the right end face of the laminated iron core 115, and the second die 143 is disposed on the left end face thereof in contact therewith. Core holding mold 1
10 are fixed to each other by bolts 143A.
The first mold 108 has 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 molding a conductor portion. It is connected to the distal end of the molten metal passage 117, and the connection part constitutes a pin gate PG. That is, the cross section of this pin gate PG has a diameter of 1
The pin gate PG is cut along with the mold opening operation after molding.

The cone-shaped molten metal passage 117, the pin gate PG, the annular groove 1 for the end ring in the first mold 108
A configuration similar to 16 is also formed in the second mold 143, shown as 117A, PG, and annular groove 116A, respectively. Reference numerals 141 and 142 denote moving dies attached to and fixed to the moving die plate 140. The die 142 has an annular groove 118A formed therein, and the cone-shaped molten metal passage 117A is formed at a plurality of locations concentric with the annular groove 118A. It communicates with the bottom.

The extruding plate 1 is provided on the movable dies 141 and 142.
An extruding pin 154 attached to 51 is provided, and the rod end of the piston cylinder 153 urges the extruding plate 151 rightward against the spring 152.

Reference numeral 138 denotes a suction passage formed on the opposite surface of the second mold 143 and the movable mold 142, and the lower end of the passage 138 has a conical molten metal passage 117A through the annular groove 118A. And the upper end is a vacuum source 13
It is open to a switching valve device 131 for turning ON and OFF the suction operation via a line 0 and a pipe 137.

The switching valve device 131 includes two members 13
2A and 132B, the member 132A is fixed to the upper surface of the second mold 143, and the member 132B is
It is fixed to the upper surface of.

A small cylinder mechanism 133 is mounted on the left end of the member 132B, and a valve body 135 is mounted on the right end of the rod 134 connected to the piston 134A inside the cylinder mechanism 133. . Therefore, the rod 13
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 valve body 4.

The state shown corresponds to OFF.

The cylinder mechanism may be either oil or pneumatic. Although not shown, as another method, the valve body 1 is configured so that the rod 134 is directly moved by an electromagnetic coil such as a moving coil instead of the cylinder method.
It is possible to make the response of the operation of the valve 35 faster and more accurate than that of a general electromagnetic switching valve, and to close the valve body 135 in exact timing with the movement stroke position of the plunger tip 105 in the injection sleeve 102. This is useful for prolonging the suction time.

A member to which pins 144 and 145 are attached is fixed to the lower part of the second mold 143 and the movable mold 142, respectively, and these pins 144 and 145 are engaged with the inner peripheral side thereof. A long hole member 146 is provided.
Note that the length 1 corresponds to the maximum separation length when the second mold 143 and the movable mold 142 are separated from the contact state shown in FIG. It is to prevent. Furthermore, the first mold 1 provided on the fixed side
A member 121 to which a pin 122 is attached is fixedly attached to a lower end portion of the cylinder 08, while a tip of a piston rod 123 in a cylinder device 124 attached to a fixed die plate is connected to the pin 122. Therefore, cylinder 12
By supplying the pressure oil to the rod-side or head-side oil chamber of No. 4, the first mold 108 can be separated from the fixed mold 107 to the stroke limit. Also, instead of the cylinder 124, the second mold 143 and the movable mold 14
It is also possible to use a long hole member 146 or the like used for regulating the length of separation from the second member.

Reference numeral 150 denotes the laminated iron core 11 after molding.
5 and an extruding rod for ejecting the core metal 115A from the core holding dies 109 and 110.
40 is connected to a piston rod 155A of a cylinder mechanism 155 attached and fixed to the left end of the center part.

Next, the filling operation of the mold and the opening sequence of each mold after molding will be described.

With the mold opened in advance, the laminated core 115 held by the core 115A is inserted into the inner peripheral portions of the core holding dies 109 and 110 shown in FIG. 1, and then the arrangement of the die shown in FIG. 1 is obtained. To do. Then, the injection filling process is waited.
Next, when the molten metal M is injected into the injection sleeve 102, the plunger tip 105 slowly moves to the left, and when the left end of the plunger tip 105 passes through the insertion port 103, the inside of the cavity can be sucked to be in a suckable state. Then, by moving the valve body 135 to the right in FIG. 1, suction in the cavity for communicating the suction passage 138 with the vacuum source 130 is started. When the plunger tip 105 further moves to the left and reaches a predetermined position, the high-speed injection operation is started, and the molten metal M is moved from the runner section 120 to the annular groove 118,
The conical molten metal passage 117A passes through the conical molten metal passage 117, the pin gate PG, reaches the annular groove 116 for the end ring, and further from the groove 116 to the inside of each slot 114. It reaches the annular groove 118A. The timing to end 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 movable die plate 140 starts moving in the direction of arrow (a) in FIG. At this time, if the piston rod 123 of the cylinder device 124 is kept free (without supplying pressure oil), the movable dies 141 and 142, the second die 143, and the iron core holding dies 109 and 110 together with the movable die plate 140 are provided. Then, the formed motor rotor and the first mold 108 move to the left. At this time, the annular groove 11
8. The molding portion occupying the cone-shaped molten metal passage 117 is fixed by the undercut portion at the tip of the extrusion pin 111.
7, the first mold 108 eventually moves to the left after the pin gate PG at the tip of the cone-shaped molding portion is cut, leaving the cone-shaped molding portion in the fixed mold 107. It will be.

Next, when the movement limit of the cylinder 124, that is, the piston head comes into contact with the left end of the cylinder 124, the first die is prevented from moving leftward thereafter, so that the end ring formed in the annular groove 116 is closed. First mold 108
And moves with the moving die plate 140 to the left. Thus, the left end face of the first mold 108 and the annular groove 11
The moving die plate 140 moves to the left and stops until the distance from the top surface of No. 6 to the length required for discharging is reached. Next, the cylinder 155 is urged, and the right end of the push rod 150 pushes the core bar 115A to the right, so that the push pin 1
54, the second die 14
3 is cut off, and then the core bar 115A
The laminated core 115 having the end ring and the conductor portion formed therein by casting is discharged from the core holding dies 109 and 110 to the outside of the die. At this time, the second mold 143, the bolt 1
43A, the length l of the elongated hole member 146 moves rightward due to the sliding resistance of the outer peripheral surface of the laminated core 115 (a constant resistance is generated due to thermal expansion) because it is fixed to the core holding mold 110 by 43A. During this time, the cone-shaped molten metal passage 117A
The cone-shaped molded part formed in the second mold 143
You will get out of When the second mold 143 and the movable mold 142 are separated by a length l, the pin 145 abuts on the inner periphery of the left end of the elongated hole member 146, and further separation is prevented. Next, the piston rods 106 and 153 are biased,
The extruding pin 11 is pushed through the extruding plates 112 and 151, respectively.
1, 154 respectively press the end faces of the formed portions formed in the annular grooves 118, 118A, and these formed portions are formed so that the undercut portions are directed downward, and are discharged downward by their own weight. It will be.

[0041]

As described above, according to the present invention,
First, which is in contact with both ends of the laminated core held by the metal core,
A plurality of pin gates are formed in the second mold following the annular groove for forming the end ring, and the cross-sectional area of the gate portion is made large enough to suck and discharge gas and air in the cavity. As a result, the cross-sectional area of the suction passage formed on the opposing surface of the second mold and the fixed mold, that is, the gap can be increased by one digit or more compared to the conventional case, and a high vacuum in the cavity can be realized in a short time. It became so. In the above description, an example is shown in which the pin gate PG in the second mold is cut during the movement of the push rod 150 to the right. The cutting may be performed substantially simultaneously with the cutting of the pin gate PG in the first mold.

[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 view of an undercut portion of a Z portion shown in FIG.

FIG. 3 is a detailed sectional view of a main part of a conventional mold structure for casting a motor rotor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Fixed die plate 102 Injection sleeve 103 Injection port 104 Plunger rod 105 Plunger tip 106 Piston rod 107 Fixed die 108 First die 109, 110 Iron core holding die 111, 154 Extruded pin 112, 151 Extruded plate 113 Spring 114 Slot 115 laminated iron core 116 annular groove 117 cone-shaped 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 150 Push rod PG Pin gate

Claims (4)

[Claims] 1. A thin rod-shaped conductor portion formed in a number of slots formed in a core iron made of a number of thin steel sheets held in a laminated state on a cored bar, and formed at both ends of the core, and the respective conductor portions are formed. A die casting apparatus for a motor rotor for casting and forming an annular end ring that short-circuits a core, a core holding die that stores and holds the core iron in an inner peripheral portion, and a molten metal that is formed as the rod-shaped conductor portion and the end ring. An injection sleeve for receiving the injection sleeve, a fixed die plate for fixing and holding the injection sleeve, and a fixed mold attached to and fixed to the fixed die plate and forming a runner portion of the molten metal near an injection end of the injection sleeve. Movement by mounting an extrusion rod having an opening at the center and allowing the motor rotor after casting to be ejected from the core holding die through the opening. A die plate, a movable die attached and fixed to the movable die plate, one end surface side is in contact with the fixed die and the movable die, and the other end surface is in contact with each end surface side of the iron core and the core holding die. First and second molds each having an annular groove for forming the end ring and a cone-shaped molten metal passage for forming a plurality of pin gates continuing to the top of the end ring. And a suction passage formed on the contact surface between the fixed mold and the second mold, one end communicating with the cone-shaped molten metal passage and the other end communicating with a vacuum source. Die casting device for motor rotor. 2. A fixed metal mold and a movable metal mold each having an annular groove connected to the pin gate as a supply path of a molten metal and pressing an annular molding end face formed in the annular groove to form the annular groove. 2. A die casting apparatus for a motor rotor according to claim 1, wherein an extrusion pin for discharging the fluid from the motor is provided so as to be able to move forward and backward. 3. The motor rotor die-casting device according to claim 1, further comprising means for restricting a separation of the first mold from the fixed mold to a predetermined amount. 4. The die casting apparatus for a motor rotor according to claim 2, wherein the tip of the push pin for pressing the end face of the annular forming portion is formed in an undercut shape.