JPH11207440A - Method for molding mold and apparatus therefor and electric servo actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the height of an apparatus by vertically driving each of plural squeeze foots constituting a segment squeeze head with an electric servo motor and executing the stamping of molding sand in a molding flask. SOLUTION: After charging the molding sand S into the molding flask 11 on a pattern plate 1, pushing force and descending speed of the squeeze foots 3, 3 are beforehand selected and the squeeze foots 3, 3 are vertically driven through a control unit 6, in which the torque and the rotating angle of the motors in the electric servo actuators 4, 4 are stored according to this selected items, and the molding sand S is stamped. Successively, after squeezing, the molding flask 11 is descended with a cylinder 10 and the molding flask 11 is separated from the pattern plate 1. The electric actuator 4 to be used, is the one, in which the rotation of the output shaft is transformed into the linear movement of an extension rod with a screw mechanism and then, the squeeze foot 3 is vertically driven with this extension/contraction and the actuator 4 has the double motive structure with two sets of coils and rotors of the motor arranged in series in the vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of moving a plurality of squeeze feet constituting a segment squeeze head up and down by a plurality of electric servo actuators.
TECHNICAL FIELD The present invention relates to a mold molding method for molding a mold by squeezing at least molding sand charged in a molding frame on a model plate to form a mold, an apparatus therefor, and an electric servo actuator.

[0002]

2. Description of the Related Art Conventionally, as a mold making apparatus of this kind, a plurality of squeeze feet constituting a segment squeeze head are disclosed in Japanese Patent Application Laid-Open No. Hei. The servo cylinder is moved up and down by an electric servo actuator, and the plurality of squeeze feet and the plurality of electric servo actuators are moved up and down by one hydraulic cylinder. The hydraulic cylinder is disposed at the center position of the ceiling of the portal frame. There is something.

[0003]

However, in the conventional mold making apparatus configured as described above, the ceiling of the portal frame must be made strong to support the reaction force applied to the hydraulic cylinder during the mold making. However, the mold making apparatus is large and expensive, and the mold making apparatus is generally high in height.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a mold molding apparatus that can be made relatively low as a whole, and a mold molding apparatus. It is an object of the present invention to provide a mold molding method, an apparatus thereof, and an electric servoactuator at a low cost.

[0005]

Means for Solving the Problems In order to achieve the above object, a method for molding a mold according to the present invention comprises the steps of: loading a molding sand for a green mold into a casting frame on a model plate; By moving the squeeze feet up and down by a plurality of electric servo actuators, at least the molding sand in the casting flask is squeezed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to FIGS. As shown in FIG. 1 which is a partial cross-sectional front view, the present mold making apparatus includes an elevating table 2 for elevating and lowering a model plate 1 mounted on an upper surface, and a cubic member arranged above and below the elevating table 2 so as to be able to move up and down. A plurality of squeeze feet 3.3, a plurality of electric servo actuators 4, 4 for vertically moving the plurality of squeeze feet 3, 3 to squeeze molding sand, and a plurality of electric servo actuators 4, And a control device 6 for controlling the operation of the electric servo actuators 4.

The gate-shaped frame 5 comprises four pillars 8.8 erected at the four corners of the upper surface of a base 7 having a platen shape, and a ceiling erected between the upper ends of the four pillars 8.8. Frame 9
It consists of An upward cylinder 10 is provided at the center of the upper surface of the base 7, and the elevating table 2 is fixed to a tip of a piston rod of the cylinder 10. A casting frame 11 is placed on the model plate 1.

The electric servo actuator 4.
4, as shown in FIG. 2 which is a partial cross-sectional front view, two coils 12.
At the lower end of a special electric motor 16 having a double power structure having three and two rotors 14 and 15, a cylindrical bearing case 1 is provided.
A cylindrical cylinder 18 extending downward is mounted on the lower surface of the bearing case 17 at the upper end. The lower end of the output shaft 16a of the special electric motor 16 is connected at the upper end with a screw shaft 19 having a screw cut on the surface, and an upper portion of the screw shaft 19 is provided with a bearing mounted in the bearing case 17. 20 is fitted to the inner cylinder part. Further, a special nut 21 is screwed to the screw shaft 19 so as to be vertically slidable, and a sliding member 22 fitted to the cylinder 18 so as to be vertically slidable is fitted to the special nut 21. . A hollow telescopic rod 23 concentric with the screw shaft 19 and extending downward is fixed to the lower surface of the sliding member 22 at the upper end. The telescopic rod 23 is attached to a front lid 24 attached to the lower end of the cylinder 18. It is slidably inserted through a cylindrical bush 25. At the lower end of the screw shaft 19, a support member 26 fitted to the telescopic rod 23 so as to be vertically slidable is fixed. As a result, the telescopic rod 2
Reference numeral 3 is adapted to expand and contract by the forward and reverse driving of the special motor 16.

Further, an electromagnetic brake 27 for braking the rotation of the output shaft 16a is mounted on the upper end of the special motor 16 of the electric servo actuator 4, and the special motor 16 is mounted on the upper surface of the electromagnetic brake 27. Output shaft 16
A rotary encoder 28 for detecting the rotation angle of a, that is, the length of expansion / contraction of the expansion / contraction rod 4a of the electric servo actuator 4, is mounted. The squeeze hood 3 is mounted on the lower end of the telescopic rod 4a of each electric servo actuator 4. The special motor 16
The control device 6 is electrically connected to the electromagnetic brakes 27 and the rotary encoders 28 and 28, and the microcomputer (not shown) of the control device 6 has the shape of the model plate 1. Corresponding torques and rotation angles of the special electric motors 16, 16 of the electric servo actuators 4, 4, that is, pressing forces and expansion / contraction speeds of the expansion / contraction rods 4a, 4a can be stored.

Next, the operation of forming a mold using the thus-configured mold forming apparatus will be described. The magnitude of the pressing force of the squeeze hood 3.3, the descending speed, etc. are selected in advance in accordance with the shape of the model of the model plate 1, and the special electric motor 1 of the electric servo actuators 4, 4 corresponding thereto is selected.
The torque and the rotation angle of 6.16 are stored in the microcomputer of the control device 6, respectively.

In this state, after the casting sand S is put into the casting flask 11, the present mold making apparatus is started via the control device 6. First, the special electric motors 16, 16 of the electric servo actuators 4, 4 are started. In each of the above, the output shaft 16a and the screw shaft 19 are positively rotated at high speed by the coil 13 and the rotor 15 to extend the telescopic rods 23 of the electric servo actuators 4 at a high speed, and the squeeze hoods 3.3 Descends at a high speed to squeeze the foundry sand S. Subsequently, in each of the special motors 16, the output shaft 16a and the screw shaft 19 are reversely rotated by the coil 16 and the rotor 14, respectively. The telescopic rods 23 of 4 are contracted, and the squeeze hoods 3.3 are raised. Such a tamping step is performed an appropriate number of times according to the shape of the model plate 1.

After completion of the compacting process, the special motor 16
In each of 16, the output shaft 16 a and the screw shaft 19 are rotated forward by the coils 12 and 13 and the rotors 14 and 15, and the telescopic rods 23 of the electric servo actuators 4 and 4 are extended, and the squeeze hoods 3 and 3 are extended. Descends to squeeze the foundry sand S. After the squeeze of the molding sand S is completed, in each of the special electric motors 16, the coil 12 and the rotor 1 are rotated in the same manner as in the step of compacting the molding sand S.
4, the output shaft 16a and the screw shaft 19 are rotated in the reverse direction, and the telescopic rods 23.2 of the electric servo actuators 4
3 contracts, and the squeeze hood 3.3 rises. Thereby, the foundry sand in the flask 11 is solidified. Next, the cylinder 10 is contracted to lower the elevating table 2, the cast frame 11 with solidified foundry sand, and the like. Subsequently, the cast frame 11 is separated and raised from the model plate 1 by conventional means (not shown) to release the mold. Do. Thereby, a required mold can be obtained.

Although the squeeze hood 3 has a cubic shape in the above embodiment, it may have a cylindrical shape. Further, in the above-described embodiment, the squeeze hood 3 is used to squeeze the casting sand S in the casting flask 11 and then squeeze the squeeze hood 3, but the squeeze may be omitted depending on the type of the model plate 1. You may.

[0014]

As is apparent from the above description, according to the present invention, a plurality of squeeze feet constituting a segment squeezing head are formed by charging a molding sand for a green mold into a casting frame on a model plate. By moving up and down with an electric servo actuator, at least the molding sand in the casting flask is squeezed, so that a so-called distributed load is applied to the ceiling frame at the time of mold molding. The bending of the ceiling frame is reduced to about half compared to that of the conventional equipment, and accordingly, the device may be small and inexpensive. Since a hydraulic cylinder to be used is not required, an excellent effect such as a reduction in the overall height of the mold making apparatus as compared with a conventional one is achieved.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view of an electric servo actuator which is a main part of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Model board 2 Elevating table 3 Squeeze foot 4 Electric servo actuator 5 Portal frame 6 Control device

Claims (3)

[Claims] 1. A method according to claim 1, wherein after the casting sand for the green mold is charged into the casting frame on the model plate, a plurality of squeeze feet constituting the segment squeeze head are vertically moved by a plurality of electric servo actuators. A mold molding method characterized by at least squeezing molding sand in a frame. 2. A mold making apparatus for moving a plurality of squeeze feet constituting a segment squeeze head up and down so as to squeeze at least the green molding sand loaded in a casting frame on a model plate. A lifting table 2 for raising and lowering the model plate 1, a plurality of squeeze feet 3.3 arranged vertically above and below the lifting table 2, and each of the plurality of squeeze feet 3.3. A plurality of electric servo actuators 4 that move up and down so as to squeeze molding sand at least, and a portal frame 5 that supports the plurality of electric servo actuators 4
And a control device 6 for controlling the operation of the electric servo actuator 4. 3. When a plurality of squeeze feet constituting a segment squeeze head are moved up and down to at least squeeze molding sand and form a mold, the rotation of the output shaft of the electric motor is converted into linear motion of a telescopic rod by a screw mechanism. An electric servoactuator that moves the squeeze foot up and down by expansion and contraction of the telescopic rod has a dual power structure in which two sets of coils and a rotor of the electric motor are vertically arranged in series. Features electric servo actuator.