JP2000127178A - Method for removing metal core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for removing a metal core capable of effectively removing a core metal of the core even in the case of complicated shape of a molding. SOLUTION: In the method for removing a metal core comprising the steps of dipping a molding M enclosing the core C made of a low melting point metal in heated oil 12 in a heated oil tank 11, heating the core C by the oil 12 to melt to remove the core, a work W obtained by integrating the molding M with the core C is grasped by a hand 17a of a robot 17, the work W is dipped in the oil 12 in this state, and the core C is melted to be removed while shaking the work W in the oil 12 by the hand 17a.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a method for removing a metal core, and more particularly, to plastic molding by injection molding using a metal core made of a low melting point metal. It is useful when applied after removing the core from the molded article after molding. 2. Description of the Related Art When molding a molded article such as plastic, a metal core may be used. In this case, the metal core is made of a low-melting metal. For example, a plastic molded product is molded in a state in which the metal core is wrapped by injection molding and then melted and removed from the molded product. In this case, the metal core is melted and removed by immersing the low-melting metal core integrated with the molded article in a liquid heating medium and heating and melting the liquid core and the induction heating means. I have. A conventional apparatus for removing a metal core used for such heating and melting will be described with reference to FIG. 2 together with a removing method using the same. As shown in FIG. 3A, the molded article M before the metal core C is melted and removed is injection-molded so as to enclose the metal core C forming the hollow portion. It is immersed in the heating oil 2 in the heating oil tank 1 shown in b). Here, the heating oil tank 1 shown in FIG. 2 (a) is provided with a heating means (not shown) on the outer wall and has a heat retaining property, and has a metal core inside the heating oil tank 1 from the heating means on the outer wall. A heating oil 2 such as polyethylene glycol, which is a liquid heating medium adjusted to a temperature slightly higher than the melting point of C, is contained therein, and an induction heating coil 4 connected to a high frequency power supply 3 outside the tank is provided as induction heating means. . The induction heating coil 4 is fixed by a holder (not shown) with the central axis being in the vertical direction. In the vicinity of the bottom of the side wall of the heating oil tank 1, a pipe 5 penetrates watertightly. The pipe 5 has an obliquely upward nozzle 6 at a tip extending below the induction heating coil 4 and is connected to a gas supply source (not shown) such as air or nitrogen gas installed outside the tank. I have. In FIG. 2B, reference symbol A denotes a core metal that has melted and has accumulated at the bottom of the heating oil tank 1. [0004] In removing the metal core C from the molded product M, the molded product M is heated inside the induction heating coil 4 so that one opening end faces the nozzle 6 at a predetermined interval. 2 immersion. At this time, the nozzle 6
Is located off from immediately below the opening end so that the falling core metal does not fall. And heating oil 2
The metal core C is heated by the heat of (1) and the electromagnetic induction effect due to energization of the induction heating coil 4, and the metal core C is melted out of the molded product M. Next, when most of the metal core C is melted and removed, a gas is injected from the nozzle 6 to the molded article M while performing the above-described heating. [0005] This gas becomes bubbles and passes through the inside of the molded article M and floats. Thereby, in the heating oil tank 1, the heating oil 2 goes upward in the molded article M, and around the heating oil 2, a downward circulating flow is generated. Create a flow. Thus, since the heat conduction is promoted by the flowing heating oil 2, the core metal a remaining on the inner surface of the molded article M is efficiently heated and melted, and is quickly removed by the flow. . [0006] In the above-described method of removing the metal core C according to the prior art, the metal core C (work) integrated with the molded product M is heated in the heating oil tank 1. Is fixed, so that when the shape of the workpiece is complicated, even if the flow of the heating oil 2 is forcibly generated in the molded product M, the molten core metal is May remain inside. SUMMARY OF THE INVENTION In view of the above prior art, the present invention provides a method of removing a metal core and an apparatus used for the same, which can reliably remove a metal core even when the shape of a molded product is complicated. And so on. The structure of the present invention that achieves the above object has the following features. 1) A molded product enclosing a metal core made of a low melting point metal is immersed in a liquid heating medium, and the metal core is heated and melted and removed by the liquid heating medium. In the removal method, the work in which the molded product and the metal core are integrated is gripped by a hand such as a robot, and the work is immersed in the liquid metal in this state, and the work is shaken in the liquid metal through the hand. While melting the metal core. 2) In the metal core removing method described in 1) above, when the workpiece is gripped by a hand such as a robot and shaken, the workpiece is directed toward the core metal to be removed via a nozzle. To inject gas. 3) A molded product enclosing a metal core made of a low melting point metal is immersed in a liquid heating medium, and the metal core is heated and melted and removed by the liquid heating medium. In the removal device, a heating oil tank containing a liquid heating medium and a work in which the molded product and the metal core are integrated are gripped via a hand, and the work is immersed in the liquid metal in this state, and the hand is A gripping / vibrating means such as a robot for melting and removing the metal core while shaking the workpiece through 4) In the metal core removing device described in 3) above, the gripping / vibrating means has a nozzle for injecting gas toward the core metal to be removed. 5) A nozzle that can be attached to the gripping / vibrating means of the metal core removing device described in 4) above, and that integrates a nozzle for injecting gas toward the core metal to be removed. Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, the apparatus for removing a metal core according to the present embodiment is obtained by adding a robot 17 to the apparatus according to the prior art shown in FIG.
7a is provided with a nozzle 16 and the hand 17a
Thus, a workpiece W in which a molded product M and a metal core C are integrated is gripped. A gas (air or nitrogen gas) supplied from a gas supply source 18 is injected from the nozzle 16. Other configurations are the same as those of the device according to the related art shown in FIG. 2B, and include a heating oil tank 11, a heating oil 12, a high-frequency power supply 13, an induction heating coil 14, and the like corresponding to the components of the device. are doing. In the removing method using the removing device, the work W is first immersed in the heating oil 12 inside the induction heating coil 14 in the same manner as in the prior art.
To the work W
Heat is supplied from the heating oil 12 to the heater and induction heating is performed at the same time.
As a result, the metal core C melts and falls downward from the inside of the molded product M, and accumulates at the bottom of the heating oil tank 1. In this step, the metal core C cannot be completely removed. In the present embodiment, the work W is heated by the heating oil 12 and simultaneously by the induction heating coil 14, but it is not essential to use the induction heating together. Conventionally, high-frequency induction heating is usually used together to shorten the melting time. However, in consideration of the melting time, the high-frequency induction heating is omitted, and only the heating oil 12 is heated to make the metal core C.
Can be removed by melting. As described above, after removing the metal core C by heating with the heating oil 12 and high-frequency induction heating, the work W is gripped by the hand 17a of the robot 17, and the work W is immersed in the heating oil 12 in this state. I do. Then, Robot 1
The work M is heated with the heating oil 12 while the work W is being shaken by operating the 7. At this time, the posture of the work W is controlled by the operation of the robot 17 so that the molten core metal C is easily discharged from below the hollow portion of the work W. At the same time, the gas is injected from the nozzle 16 toward the metal core C, and the operation is performed so that the molten metal can be more effectively removed. At this time, the gas is injected toward a portion where the molten metal is likely to adhere and remain, such as a bent portion of the molded article M. Thus, even if the shape of the molded article M is complicated, the metal core C including the one that adheres to and remains as a thin film on the inner surface of the molded article M to the end can be completely removed. In the above embodiment, the nozzle 16 is 1
Although a book was used, the number is not limited to this. It can be increased as needed. Although the direction of gas injection by the nozzle 16 is fixed, the tip of the nozzle 16 may be swung about its base end. In this case, gas can be injected over a wide range. Further, the removal efficiency of the metal core C can be further improved. Also,
The hand 17a does not need to be limited to a robot.
As long as the work W can be shaken in the same manner as in the above-described embodiment, another device, generally a gripping / vibrating means, may be used. As described in detail with the above embodiments, according to the present invention, the work is shaken in a state of being immersed in the liquid metal, so that even if the shape of the work is complicated, it can be ensured. The molten core metal can be removed. Such a removing action becomes more reliable by injecting a gas toward the core metal through the nozzle, and in this case, the core metal can be more favorably removed. Further, it is not necessary to limit the hand 17a to the robot 17. There is no particular limitation as long as the workpiece W can be swung similarly to the robot 17.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view conceptually showing an apparatus for removing a metal core according to an embodiment of the present invention. FIGS. 2A and 2B are an explanatory diagram showing a work of a metal core removing device and an explanatory diagram conceptually showing a metal core removing device according to a conventional technique. [Description of Signs] W Work C Metal core 11 Heating oil tank 12 Heating oil 16 Nozzle 17 Robot 17a Hand 18 Gas supply source

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[Procedure amendment] [Date of submission] December 8, 1998 (1998.12.
8) [Procedure amendment 1] [Document name to be amended] Description [Item name to be amended] Claims [Amendment method] Change [Content of amendment] [Claims] [Claim 1] Made of low melting point metal A method of removing a metal core, in which a molded product enclosing a metal core is immersed in a liquid heating medium, and the metal core is heated and melted and removed by the liquid heating medium, comprising: the work in which the child is integral gripped by the hand of the robot or the like, the work in this state was immersed in a liquid heating medium <br/>, waving his work through the hand with a liquid heating medium liquid metal in the metal A method for removing a metal core, wherein the core is melted and removed. 2. A method of removing the metal core described [Claim 1], in shake this work by gripping the workpiece with the hand, such as robots are to be removed through the nozzle A method for removing a metal core, wherein a gas is injected toward the core metal. 3. A molded product enclosing a metal core made of a low-melting metal is immersed in a liquid heating medium, and the metal core is melted and removed by heating the metal core with the liquid heating medium. In the removal device, a heating oil tank for holding a liquid heating medium, and a work in which the molded product and the metal core are integrated are gripped via a hand, and the work is immersed in the liquid metal in this state, and the hand is An apparatus for removing a metal core, comprising: gripping and vibrating means such as a robot for melting and removing a metal core while shaking a workpiece through the metal core. 4. A metal core removing device according to claim 3, wherein the gripping / vibrating means has a nozzle for injecting a gas toward the core metal to be removed. Core removal device. 5. A metal core removing device according to claim 4, which can be attached to a gripping / vibrating means, and that a nozzle for injecting gas toward the core metal to be removed is integrated. A hand part used for the metal core removal device, which is a feature. [Procedure amendment 2] [Document name to be amended] Description [Item name to be amended] 0009 [Amendment method] Change [Content of amendment] [0009] 1) A molded product enclosing a metal core made of a low melting point metal is liquid In the method for removing a metal core, which is immersed in a heating medium and heats and melts and removes the metal core with the liquid heating medium, a work in which a molded product and a metal core are integrated with a robot or the like is used. The work is immersed in a liquid heating medium in this state, and the metal core is melted and removed while shaking the work in the liquid heating medium through the hand. [Procedure amendment 3] [Document name to be amended] Description [Item name to be amended] 0010 [Amendment method] Change [Content of amendment] 2) In the method for removing a metal core described in 1) above, when shake the workpiece grip the workpiece at the hand of the bot or the like, it was to inject gas toward the core metal to be removed through a nozzle.

Claims (1)

Claims: 1. A molded article enclosing a metal core made of a low-melting metal is immersed in a liquid heating medium, and the liquid core is heated to melt and remove the metal core. In a method of removing a metal core, a work in which a molded product and a metal core are integrated is gripped by a hand such as a robot, and the work is immersed in a liquid metal in this state, and the work is performed through the hand. Wherein the metal core is melted and removed while shaking in a liquid metal. 2. A method for removing a metal core according to claim 1, wherein when the workpiece is gripped by a hand such as a robot and shaken, the core metal to be removed via a nozzle is removed. A method for removing a metal core, characterized by injecting a gas toward the core. 3. A molded product enclosing a metal core made of a low-melting metal is immersed in a liquid heating medium, and the metal core is melted and removed by heating the metal core with the liquid heating medium. In the removal device, a heating oil tank for holding a liquid heating medium, and a work in which the molded product and the metal core are integrated are gripped via a hand, and the work is immersed in the liquid metal in this state, and the hand is An apparatus for removing a metal core, comprising: gripping and vibrating means such as a robot for melting and removing a metal core while shaking a workpiece through the metal core. 4. A metal core removing device according to claim 3, wherein the gripping / vibrating means has a nozzle for injecting a gas toward the core metal to be removed. Core removal device. 5. A metal core removing device according to claim 4, which can be attached to a gripping / vibrating means, and that a nozzle for injecting gas toward the core metal to be removed is integrated. A hand part used for the metal core removal device, which is a feature.