JP2001062845A - Manufacture of hollow resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for carrying out the positive eluation and removal of a molten core in a rapid and low cost manner in the eluation process of a lost core method which is a method for manufacturing a hollow resin molding. SOLUTION: In the eluation process of a lost core method for manufacturing a hollow resin molding 4 using a molten core 5 made up of a low melt point alloy such as Bi-Sn with process hardware such as an eluation tank 1 filled with an eluate oil 2, a heater 3 for heating up and holding the temperature of the eluate oil 2 at a heated-up level, a pump 8 for sucking the eluate oil 2 and a jet nozzle 9 arranged at a desired spot of the molding 4, a jet stream is directly applied to the hollow part of the molten core 5 in an oil bath tank when the eluation of the hollow molten core 5 is performed. Consequently, the interior of the molten core 5 is forcibly fluidized to realize the rapid eluation of the core 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow resin molded article, and more particularly to a method for molding a three-dimensionally complicated resin shape such as an automobile intake manifold using a lost core method. Regarding the required elution technology.

[0002]

2. Description of the Related Art Conventionally, as a dissolution apparatus for a molten core, an apparatus having a structure shown in FIG. 2 is generally used. In this apparatus, an oil bath 1 is filled with eluting oil 2, and the temperature of the eluting oil 2 is raised and maintained by a heater 3 so as to be equal to or higher than a melting core melting point and equal to or lower than a molded product deformation temperature. In this method, the molded product 4 with the molten core 5 is immersed in the oil bath for a predetermined time, and the molten core 5 is eluted to take out only the molded product 4. The eluted molten core 5 a accumulates at the bottom of the oil bath 1.

[0003]

In the prior art as described above, the elution time becomes long, and in order to improve the productivity, the elution tank 1 needs to be a large pool-like one in which a plurality of molded articles can be stored. In addition, there is a possibility that the molten core remains inside the molded article, and a step of removing the molten core is required. As another example, there has been introduced a method of manufacturing a coil in which a molded article can be inserted and performing induction heating by high frequency to elute at a high speed and injecting a jet nozzle toward the interior of the molded article as disclosed in Japanese Patent Application Laid-Open No. 3-247429. However, it is very expensive and the structure is complicated. The present invention provides a method for significantly shortening the elution time and preventing residual molten core.

[0004]

According to the present invention, a molded article is immersed in an oil bath, and a jet nozzle is installed at an appropriate location of the molded article with a hollow molten core to force the inside of the molten core to flow. ,
It is characterized by improving heat transfer and shortening elution time.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention has a structure shown in FIG. In this apparatus, an oil bath 1 is filled with eluting oil 2, and the temperature of the eluting oil 2 is raised and maintained by a heater 3 so as to be equal to or higher than a melting core melting point and equal to or lower than a molded product deformation temperature. Here, the eluting oil 2 in the elution tank 1 is sucked by the pump 8 through the filter 6 and the suction pipe 7, and from the jet nozzle 9 arranged to flow inside the molded article with the hollow molten core. The dissolution oil 2 is arranged to be discharged.

[0006] In the core elution apparatus thus constructed, the molded article 4 with the molten core 5 is immersed in the oil bath 1 for a predetermined time, as in the prior art. Here, the eluting oil 2 sucked by the pump 8 causes the jet nozzle 9 to generate forced flow inside the molded article with the hollow molten core, and the molten core 5 is accelerated by the effect of heat transfer by the forced flow. This is a method in which only the molded article 4 is eluted and taken out. The eluted molten core 5 a accumulates at the bottom of the oil bath 1.

According to this structure, elution can be performed at high speed simply by adding a filter 6, a suction pipe 7, and a jet nozzle 9 to a pump 8 for generating a jet in the same equipment as the conventional one. In addition, a shear force is generated between the jet flow and the inner surface of the molded article, and the molten core is not left at all. Thus, the step of removing the residual molten core can be achieved at the same time.

[0008]

As described above, according to the present invention, a jet equipment is added to the conventional elution tank, and the jet nozzle is arranged toward the inside of the molded article, so that the core elution time can be greatly increased as compared with the conventional one. And the remaining of the molten core inside the molded article is prevented.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of the present invention.

FIG. 2 is a diagram showing an example of a conventional core elution device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Elution tank, 2 ... Elution oil, 3 ... Heater, 4 ... Resin molding, 5 ... Hollow melting core, 5a ... Melt, 6 ... Filter,
7 ... suction pipe, 8 ... pump, 9 ... jet nozzle.

Claims (1)

[Claims] Claims 1. An elution tank containing an elution oil and an eluate oil,
Hollow resin molding using a molten core consisting of a low melting point alloy such as Bi-Sn, which has a heater for holding, a pump that discharges the eluting oil, and a jet nozzle installed at the desired location of the molded product In the elution method in the lost core method for manufacturing products, when the hollow core is eluted, a jet is directly applied to the hollow of the molten core in an oil bath to force the inside of the molten core to flow at high speed. A method for eluting a hollow core, comprising eluting.