Defective engine block recycling method in continuous casting line

Abstract

A defective engine block recycling method in a continuous casting line includes inserting a bore pin into an engine block mold, fitting a real liner to an outer circumferential surface of the bore pin, and injecting molten aluminum into the engine block mold to cast an engine block body. If an abnormality is generated in the engine block mold or the molten aluminum and if a defect is expected to generate in the engine block body, a defective engine block unit is produced by fitting a dummy liner, which is made of a material identical with or similar to a material of the engine block body, to the bore pin. The defective engine block unit thus produced is directly melted and recycled.

Claims

1. A defective engine block processing method in a continuous casting line comprising inserting a bore in into an engine block mold, detecting whether or not an abnormality exists in the engine block mold or in molten aluminum used to cast an aluminum engine block body that will result in a defect in the aluminum engine block body, wherein when no abnormality is detected, the method comprises: fitting a real liner to an outer circumferential surface of the bore pin; and injecting the molten aluminum into the engine block mold to cast the aluminum engine block body, the improvement comprising: wherein when the abnormality is detected, the method comprises: fitting an aluminum dummy liner to the outer circumferential surface of the bore pin, injecting the molten aluminum into the engine block mold to cast a defective engine block unit, and recycling the defective engine block unit without removing the aluminum dummy liner, wherein a diameter of the aluminum dummy liner increases along a length of the aluminum dummy liner.

2. The method of claim 1, wherein the aluminum dummy liner is formed by an extrusion process.

3. The method of claim 1, further comprising: using a die casting machine to cast the defective engine block unit.

4. The method of claim 3, further comprising: detecting, via a temperature sensor of the die casting machine, a temperature of the engine block mold; and triggering an alarm when the temperature of the engine block mold falls outside a predetermined temperature range.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments, given in conjunction with the accompanying drawings.

(2) FIG. 1 is a perspective view of an aluminum engine block manufactured by the prior art.

(3) FIG. 2 is a plan view of the aluminum, engine block illustrated in FIG. 1.

(4) FIGS. 3A to 3D are sectional views illustrating how to mount a cast iron liner to a mold in the prior art.

(5) FIG. 4 is an enlarged sectional view illustrating how to fit a cast iron liner to a bore pin in the prior art.

(6) FIG. 5 is an enlarged sectional view illustrating how to fit a dummy liner to a bore pin according to the present invention.

(7) FIG. 6 is a flowchart illustrating a process of producing an engine block unit according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(8) One preferred embodiment of a defective engine block recycling method in a continuous casting line according to the present invention will now be described with reference to FIGS. 5 and 6.

(9) For the sake of convenience, descriptions will be made on a case where an engine block unit including an aluminum engine block body 10 and a cast iron liner 20 is produced by a die casting method.

(10) Since the die casting method has been described in the background art, no duplicate description will be made thereon. The following descriptions will be centered on the features of the present invention.

(11) A defective engine block recycling method in a continuous casting line according to the present invention includes; inserting a bore pin 40 into an engine block mold M; fitting a real liner 20 to an outer circumferential surface of the bore pin 40; and injecting molten aluminum into the engine block mold M to cast an engine block body 10.

(12) If an abnormality is generated in the engine block mold M or the molten aluminum and if a defect is expected to generate in the engine block body 10, a defective engine block unit is produced by fitting a dummy liner 20a, which is made of a material identical with or similar to a material of the engine block body 10, to the bore pin 40, and the defective engine block unit thus produced is directly melted and recycled.

(13) The dummy liner 20a is melted together with the defective engine block unit without removing the dummy liner 20a from the defective engine block unit and is recycled into an aluminum ingot.

(14) The dummy liner 20a is not used as a real cylinder liner. In the case where a defect is expected to generate in the engine block body 10, the dummy liner 20a is used in place of the cast iron real liner 20 in order to avoid stoppage of an operation in a continuous casting line.

(15) Conventionally, a defective engine block unit is recycled by breaking and removing a cast iron liner from an engine block body, or melting and removing a cast iron liner from an engine block body, or cutting and removing a cast iron liner from an engine block body using a cutting device. For that reason, a great deal of time and cost is required in recycling the defective engine block unit.

(16) In the present invention, the dummy liner 20a is made of a material identical with or similar to a material of the engine block body 10, specifically a material which does not reduce the quality of an aluminum ingot obtained by melting a defective engine block unit. Thus, there is no need to stop a continuous casting line even when a defect is expected to generate in the engine block body 10.

(17) It is preferred that the dummy liner 20a has a diameter which grows larger upward. The dummy liner 20a is preferably formed by expanding or contracting an aluminum pipe produced through an extruding process. However, the method of manufacturing the dummy liner 20a is not limited thereto.

(18) The engine block body 10 is cast by a die casting machine (not illustrated). The die casting machine preferably includes a temperature sensor configured to detect a temperature of the engine block mold M and an alarming device configured to issue an alarm when the temperature of the engine block mold M fails outside a predetermined temperature range.

(19) According to this configuration, if a defect is expected to generate in the engine block body 10, for example, if the temperature of the engine block mold M falls outside a predetermined temperature range or if the molten aluminum is determined to be poor, a worker may use the aluminum-made dummy liner 20a instead of the cast iron real liner 20.

(20) Since the dummy liner 20a does not affect the quality of an aluminum ingot produced by melting the engine block unit, the defective engine block unit may be directly recycled by melting the dummy liner 20a together with the engine block body 10.

(21) A process of manufacturing an engine block unit according to the present invention will now be described with reference to FIG. 6.

(22) First, the engine block mold M is mounted to the die casting machine, and the bore pin 40 is inserted into the engine block mold M. The cast iron real liner 20 and the dummy liner 20a are disposed side by side on the continuous casting line. This enables a robot arm 50, which will be described later, to selectively pick up the cast iron real liner 20 or the dummy liner 20a and fit the same to the bore pin 40.

(23) The bore pin 40 is a member which serves as a core in the casting process. The bore pin 40 is configured to support the cast iron liner 20 when injecting the molten aluminum into the engine block mold M.

(24) Then, the robot arm 50 is operated so as to pick up the cast iron real liner 20 or the aluminum-made dummy liner 20a and fit the same to the bore pin 40. In the case where the engine block body 10 is of a four-cylinder type, the robot arm 50 picks up four cast iron liners 20 or four dummy liners 20a at a time and fits the same to the bore pin 40.

(25) When automatically casting engine block units in a continuous casting line, a defect may be generated in a specific section. Particularly, if molten aluminum is injected toward a cast iron real liner, a casting defect is often generated in a boundary region between the molten aluminum and the cast iron real liner.

(26) In order to cast an engine block unit with a high quality, it is necessary to preheat the engine block mold M to a predetermined temperature and to keep the temperature constant. In the case where a casting work is initially started or restarted after pause, the temperature of the engine block mold M may fail, outside a suitable temperature range. In this case, the temperature sensor (not illustrated) of the die casting machine detects the temperature of the engine block mold M which fails outside the suitable temperature range. Then, the alarming device notifies a worker of the situation by issuing an alarm. Furthermore, there may be a case where the state of molten aluminum is poor and a defect is expected to generate in the engine block body 10.

(27) In these cases, the worker does not stop the continuous casting line but takes a measure so that the robot arm 50 picks up the dummy liner 20a in place of the cast iron real liner 20 and fits the dummy liner 20a to the bore pin 40 of the engine block mold M.

(28) In other words, if the continuous casting line is normally operated, the east iron real liner 20 is fitted to the bore pin 40 of the engine block mold M. If an abnormality is detected in the continuous casting line, the dummy liner 20a is fitted to the bore pin 40 of the engine block mold M.

(29) The dummy liner 20a is not used as a real cylinder liner because the dummy liner 20a made of aluminum is weak in wear resistance and is unsuitable for use as a real cylinder liner. The dummy liner 20a is used to manufacture a defective engine block unit without stopping the continuous casting line even in the case where a defect is expected to generate in the engine block body 10.

(30) In the prior art, if a defect is generated in an engine block body 10 in a certain section of a continuous casting line, the operation of the continuous casting line is stopped to take a necessary measure. Thereafter, the operation of the continuous casting line is resumed. This leads to a problem in that the productivity in the continuous casting line is reduced.

(31) In an effort to prevent reduction of the productivity, the continuous casting line may be continuously operated even when a defect is generated in an engine block body. In this case, however, there is manufactured a defective product in which a cast iron real liner is integrally formed with an aluminum engine block body. Thus, a great deal of time and cost is required in recycling the defective product. Furthermore, it is quite difficult to completely remove the cast iron real liner from the aluminum engine block. This may reduce the quality of a recycled aluminum ingot.

(32) In contrast, according to the present invention, if an abnormality is generated in the engine block mold M or if a defect is expected to generate in the engine block body 10, the aluminum-made dummy liner 20a is used in place of the cast iron real liner 20. This makes it possible to continuously perform a casting work in the continuous casting line.

(33) That is to say, there is no need to stop the operation of the continuous casting line. It is therefore possible to prevent reduction of productivity. Since the engine block body 10 and the dummy liner 20a are made of an identical or similar material, it is possible to directly melt the defective engine block unit and to recycle the defective engine block unit into an aluminum ingot.

(34) Inasmuch as it is not necessary to perform a work of removing the cast iron real liner 20 from the aluminum-made engine block body 10, it is possible to significantly reduce the cost required in recycling the defective engine block unit.

(35) In addition, since the engine block body 10 and the dummy liner 20a are made of an identical or similar material, it is possible to prevent deterioration of physical properties of a recycled aluminum ingot otherwise caused by the mixture of impurities and to improve the quality of a recycled aluminum ingot.

(36) While one preferred embodiment of the invention has been described above, the present invention is not limited to these embodiments. It is to be understood that various changes and modifications may be made without departing from the scope of the invention defined in the claims.