JP2866725B2 - Oil strainer manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a synthetic resin oil strainer using a low melting point alloy core.

[Problems to be solved by conventional technology and invention]

The oil strainer, which is one of the engine components, is usually manufactured from a steel plate. However, the oil strainer can be reduced in weight by being formed by injection molding of a synthetic resin. In this case, since a normal injection molding method using a mold cannot be used, a manufacturing method using a core formed of a low melting point alloy made of Zn, Sn, Sb, Bi, or the like is employed.

According to this method, a core made of a low-melting-point alloy is loaded into a molding die, and a synthetic resin is filled into a cavity formed by the core made of the low-melting-point alloy and the molding die by injection molding. By melting only the core made of a low melting point alloy from the synthetic resin oil strainer with core after curing, a desired synthetic resin oil strainer can be obtained. In this case, a method is used in which a core made of a low-melting-point alloy is immersed in a bathtub, and a heating medium in the bathtub is heated to melt the core. However, this method has a problem that a great deal of time is required to melt and remove the core made of the low melting point alloy.

For this reason, as a method for producing a synthetic resin hollow molded article such as an oil strainer, there has been reported a method in which a core made of a low melting point alloy is self-heated by electromagnetic induction to be melted and removed (Japanese Patent Publication No. 63-227310). issue). However, in order to prevent the performance deterioration of the heating medium and the surface deterioration of the synthetic resin hollow molded article, it is necessary to lower the melting temperature as much as possible. In this case, even if the above method is used, there is a problem that the melting time becomes long. .

By the way, in the above-mentioned method of melting and removing the core made of low melting point alloy by the heating medium in the bathtub, the heating medium used includes mineral oil, synthetic oil and the like. However, when these heating media are used, it is difficult to recover the low-melting-point alloy melted in the heating medium, and the performance of the heating medium after the recovery of the low-melting-point alloy is severely deteriorated. There is a problem that must be. Mineral oil is not practical because of its low heat resistance.In addition, synthetic oil is expensive and raises production costs.In addition, wastewater treatment methods for mineral oil and synthetic oil are complicated from the viewpoint of preventing pollution problems. There is a problem that is.

In addition, when a mineral oil or a synthetic oil is used as the heating medium, it is necessary to wash the synthetic resin hollow molded article after melting the low melting point alloy core. However, for the purpose of cleaning the synthetic resin hollow molded product after the melting of the low melting point alloy core,
When a solvent is used, there is a problem that the surface of a synthetic resin hollow molded article is deteriorated, and the commercial value is reduced.

Accordingly, an object of the present invention is to shorten the time required for melting and removing a core made of a low-melting alloy, to facilitate the recovery of a low-melting alloy melted in a heating medium, and to perform heating after the recovery of a low-melting alloy. By providing a method for manufacturing an oil strainer that is easy to treat waste liquid, and in particular, a method for manufacturing an oil strainer in which a filter is integrally provided, with less deterioration of the medium, low cost, and without lowering the commercial value. is there.

[Means for solving the problem]

As a result of intensive research in view of the above problems, the present inventors, when manufacturing an oil strainer using a low melting point alloy core,
An oil strainer with a core is injection-molded with a synthetic resin using a core made of a low-melting-point alloy in which the filter is integrally cast, and when the core made of the low-melting-point alloy is melted and removed, After immersing the oil strainer in the heating medium, self-heating is generated in the low melting point alloy core by electromagnetic induction, and further, ultrasonic vibration is applied to the cored oil strainer via the heating medium, thereby reducing the oil strainer. The melting time of the core made of the melting point alloy can be reduced, and the use of polyolefin glycol as the heating medium facilitates the recovery of the low melting point alloy that has been melted in the heating medium. The present invention has been found to provide a method for producing an oil strainer that is less likely to deteriorate the performance of the heating medium afterwards, is low in cost, and can easily treat the waste liquid without lowering the commercial value. It was.

That is, the method of manufacturing an oil strainer in which the filter of the present invention is integrally provided includes the steps of: (a) using a low-melting alloy to integrally cast a screen provided with a ring-shaped wire mesh on the outer periphery of the filter; Forming a core by wrapping the wire, in which case the wire mesh of the screen is projected from the surface of the core, (b) forming an oil strainer by injection molding of a synthetic resin using the core, (c) The obtained oil strainer with a core is immersed in a heating medium, and (d)
The core is heated and melted by electromagnetic induction, and the core is removed by applying ultrasonic vibration. It is preferable to use a polyolefin-based glycol as the heating medium.

(Examples and actions)

FIG. 1 shows an example of an oil strainer produced by the method of the present invention, FIG. 2 shows an example of a low melting point alloy core used in the method of producing an oil strainer of the present invention, and FIG. Screen 20 to be attached to low melting point alloy core shown in
(Comprising a wire mesh 23 and a filter 24),
The figure shows another example of the screen 20 (comprising a wire mesh 23 and a filter 24 and having a core metal 22 on the outer peripheral portion) mounted on the core made of a low melting point alloy shown in FIG.

In the example shown in FIGS. 1 to 4, the core 2 made of a low melting point alloy shown in FIG. 2 is formed by integrally casting the screen 20 shown in FIG. 3 or FIG. . Further, an outer peripheral portion 21 of the screen 20 protrudes outward from the low melting point alloy core 2.

First, the core 2 made of a low melting point alloy shown in FIG. 2 is formed of a Bi-Sn alloy or the like. Then, the low melting point alloy core is loaded into an injection mold having the same shape as the outer shape of the synthetic resin oil strainer 1 shown in FIG. The core 2 made of a melting point alloy is fixed. A thermoplastic resin such as polyamide is injected into a cavity formed by an injection molding die and a core made of a low melting point alloy to form an oil strainer made of a synthetic resin with a core.

Next, after the molded synthetic resin oil strainer with core is immersed in a heating medium made of polyolefin-based glycol, self-heating is generated in the low melting point alloy core 2 by electromagnetic induction using a high frequency induction furnace or the like. Then, a low melting point alloy core is melted and removed by applying ultrasonic vibration to the synthetic resin oil strainer with the core.

Thus, the core made of the low melting point alloy can be melted in a short time, and the low melting point alloy melted in the heating medium can be easily recovered. Furthermore, without causing significant performance degradation in the heating medium after recovery of the low melting point alloy,
In addition, the synthetic resin oil strainer can be formed without deteriorating the surface of the synthetic resin oil strainer.

The first embodiment of the present invention is characterized in that ultrasonic vibration is applied in order to promote the melting and removal of a core made of a low melting point alloy. The energy of the ultrasonic vibration can be variously changed depending on the material and size of the core, etc., but generally it is sufficient to be about 20 KHz to 40 KHz. By applying ultrasonic vibration, the core removal time can be reduced by about 30 to 35%.

The second embodiment of the present invention is characterized in that a polyolefin-based glycol is used as a heating medium for removing a core made of a low melting point alloy. The use of the polyolefin-based glycol not only facilitates the removal of the core by melting, but also facilitates the cleaning of the hollow molded article due to its water solubility.

Furthermore, by using a polyolefin-based glycol as a heating medium and applying ultrasonic vibration during electromagnetic induction heating, the low-melting-point alloy core can be more easily and quickly removed by melting. Since the low melting point alloy melted in polyolefin glycol sinks to the bottom,
Can be easily separated.

The synthetic resin oil strainer 1 molded by the above method is integrated with the screen 20 after melting the low melting point alloy core as shown in FIG. There is an advantage that a necessary joining process such as welding of a screen is not required.

The heating medium is preferably a polyolefin-based glycol which is easily treated for waste liquid, and particularly preferably a polyethylene glycol.

 The present invention will be described in detail by the following specific examples.

Example 1 A core made of a low melting point alloy shown in FIG. 2 was formed from a Bi-Sn alloy, and the core made of a low melting point alloy was loaded into an injection mold.
Inject 6-nylon as a thermoplastic resin into the cavity formed by the injection mold and the low melting point alloy core,
An oil strainer made of a synthetic resin with a core was molded.

Then, after immersing the synthetic resin oil strainer including the molded core in a heating medium made of polyethylene glycol, in a 15 kw vacuum tube high-frequency induction furnace, the pressure was 0.1 mm.
Under the condition of 7A / 8kv, self-heating was generated in the low melting point alloy core by electromagnetic induction, and ultrasonic vibration was further applied.

Example 2 An oil strainer made of a synthetic resin with a core molded in the same manner as in Example 1 was immersed in a heating medium made of polyethylene glycol, and heated by electromagnetic induction without applying ultrasonic vibration.

Comparative Example 1 Mineral oil was used as a heating medium, and the core was melted and removed as in Example 1 by simply heating.

FIG. 5 is a graph showing the relationship between the temperature of the heating medium and the melting time of the core made of a low-melting alloy. Examples 1 (indicated by A in FIG. 5) and Example 2 (indicated by B in FIG. 5). And the method shown in Comparative Example 1 (indicated by C in FIG. 5).

As is clear from the graph shown in FIG. 5, when the method of Comparative Example 1 was used, the temperature of the heating medium was as large as about 200 ° C., the melting time was as large as about 20 minutes, and the temperature of the heating medium was set at 170 ° C.
When the temperature was lowered below ℃, the melting time increased to more than 40 minutes.
At 200 ° C. or higher, deterioration of the synthetic resin oil strainer was observed, and fumes were generated from the heating medium.

When the method of Example 2 was used, the temperature of the heating medium was
At around 200 ° C, the melting time is as short as 10 minutes or less, and even when the temperature of the heating medium is 150 ° C or less, the melting time is within 15 minutes. Compared with Comparative Example 1, it can be melted in about 1/4 of the time. Was. In addition, since polyethylene glycol is used as the heating medium, it is possible to easily recover the molten low-melting-point alloy, and there is no significant deterioration in the performance of polyethylene glycol recovered from the low-melting-point alloy. No effect on the surface was observed.

Further, in the first embodiment, by applying the ultrasonic vibration, the melting and removing time of the core at the same heating temperature is:
It was able to be reduced to about 1 / 1.5 of Example 2. Further, since polyethylene glycol was used as the heating medium, the molten low melting point alloy could be easily recovered as in Example 2. Also, no significant performance degradation of polyethylene glycol after recovery of the low melting point alloy was observed,
No effect on the surface of the synthetic resin oil strainer was observed.

In this embodiment, an example in which polyethylene glycol is used as the heating medium has been described. However, in the present invention, it is needless to say that other polyolefin-based glycols can be used.

〔The invention's effect〕

As described in detail above, the method for manufacturing an oil strainer of the present invention comprises forming an oil strainer using a low-melting alloy core obtained by casting a filter, and immersing the oil strainer with the core in a heating medium. Then, self-heating is generated in the low melting point alloy core by electromagnetic induction, and ultrasonic vibration is further applied. As a result, the time required for melting and removing the core made of the low melting point alloy can be shortened, and a joining step such as conventional screen welding is not required.

In addition, by using a polyolefin-based glycol as the heating medium, it is easy to recover the low-melting-point alloy that has been melted in the heating medium. Waste liquid treatment can be easily performed without lowering the commercial value due to deterioration or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an oil strainer manufactured by the method of the present invention, and FIG. 2 is a perspective view showing an example of a low melting point alloy core used in the method of manufacturing an oil strainer of the present invention. FIG. 3 is a plan view showing an example of a screen mounted on the low melting point alloy core shown in FIG. 2, and FIG. 4 is a view showing another example of the screen mounted on the low melting point alloy core shown in FIG. FIG. 5 is a graph showing the relationship between the temperature of the heating medium and the melting time of the low-melting alloy core. 1. Oil strainer 2. Low melting point alloy core 20. Screen 21. Outer peripheral part 22. Core 23. Wire mesh 24. Filter 30, 31, 32.

Claims (2)

(57) [Claims] 1. A method of manufacturing an oil strainer in which a filter is integrally provided, comprising: (a) using a low melting point alloy to integrally integrate a screen provided with a ring-shaped wire mesh around an outer periphery of the filter. Forming a core by casting, wherein the wire mesh of the screen is projected from the surface of the core, (b) forming an oil strainer by injection molding of a synthetic resin using the core, (c) ) Immerse the obtained oil strainer with core in the heating medium,
(D) A method for producing an oil strainer, wherein the core is heated and melted by electromagnetic induction, and the core is removed by applying ultrasonic vibration. 2. The method for producing an oil strainer according to claim 1, wherein a polyolefin-based glycol is used as the heating medium.