JPH01317656A - Ceramic pattern for forming attaching projected part in casting - Google Patents

Abstract

PURPOSE:To reduce man-hour of molding work for forming a projected part for hanging up, etc., by forming a hollow state, having opening part leading to a casting body part at one end side and having inner surface corresponding to the shape of this attaching projected part. CONSTITUTION:A pottery-made pattern 10 is used to casting of the projected part for hanging up the casting body with crane, etc., and it is desirable to be the unglazed ceramic and it is formed to hollow-state. The opening part 11 is arranged at the lower end, and a flat spherical shaped top part 13 is arranged at the upper part of the cylindrical barrel part 12. An opening end edge 15 of the ceramic pattern 10 is pushed to the prescribed position in the main body pattern 20 and molding sand 30 is packed in outer circumferential part of the main body pattern 20 and the ceramic pattern 10. The main body pattern 20 is taken off, but the ceramic pattern 10 is remained in the mold as it is. At the time of supplying molten metal, the attaching projected part with the pottery-made pattern 10 is cast together with the casting body part. Small holes 14 for air vent are formed at the top part. By this method, the attaching projected part is easily formed, and casting defect and poisonous gas are not generated and as the ceramic pattern can be easily broken with a hammer, removal of it after casting is easily executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a ceramic mold for forming an accessory projection provided on a casting body.

(Prior technology) There are many types of parts on the main body of the casting, such as a hanging protrusion (suspension tengu) used to lift the cast iron with a crane, etc., and a blind riser to prevent cavities during casting. In order to cast the protruding accessory protrusion, the following molding method was adopted.

■ A method in which the casting body and the casting body are formed using foundry sand using a wooden mold or metal mold.

■ A method in which a resin foam molded product such as Styrofoam is used, and the foam is removed from the mold after molding, or melted and removed by pouring molten metal into the mold without cutting the foam.

(Problem to be solved by the invention) The above method (■) requires cutting after molding, and
Coating work on the mold surface is required, which takes a lot of man-hours.

The former method (2) has the same problem as (2) because it requires operations such as removing the foam from the mold after molding. The latter method (2) requires fewer man-hours, but has problems such as generating toxic gas when the resin foam melts and easily causing casting defects.

Therefore, an object of the present invention is to solve the above-mentioned problems,
To provide a mold capable of casting an attached protrusion of a desired shape at low cost, with a small number of man-hours, and without causing casting defects.

C Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a ceramic mold for casting an attached protrusion of a cast product, which is hollow and has a cast part on one end. Provided is a ceramic mold for molding an accessory protrusion, which has an opening communicating with the main body and an inner surface corresponding to the shape of the accessory protrusion.

This mold is preferably unglazed and has a thickness of, for example, 1 to several mm.

(Function) The ceramic mold having the above structure is attached to the main body for molding the casting main body and is buried together with the main body in foundry sand. After filling the outer periphery of this ceramic mold with foundry sand, the main body is removed from the mold, but the ceramic mold remains in the foundry sand. Thereafter, casting is performed by supplying hot water into the casting body and the inside of the ceramic mold, and when the mold is taken apart after casting, the ceramic mold is broken and removed with a hammer or the like.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3. The ceramic mold 10 of this embodiment is used to cast a lifting protrusion for lifting the cast body with a crane or the like.

The ceramic mold 10 is preferably made of unglazed ceramic and has a hollow shape as shown in FIG. The thickness t of the mold wall is 1 to several 1. Preferably, it is 2 to 3 mm, and as shown in FIG. 2, an opening 11 is provided at the lower end in the figure. An oblate spherical head 13 is provided on the upper side of the cylindrical body 12 in the drawing. A small hole 14 for venting gas is provided in the center of the head 13.

An end edge 15 of the body portion 12 on the opening 11 side is formed into a flared shape that spreads outward. The inner surface 16 of the ceramic mold 10 is
This corresponds to the shape of the attached protrusion to be cast.

Next, how to use this ceramic mold 10 will be explained. As shown in FIG. 3, the opening edge 15 of the ceramic mold 10 is pressed against a predetermined position of the main body 20 such as a wooden mold for molding the casting main body, that is, the position where the attached protrusion is to be provided.
Then, the outer periphery of the ceramic mold 10 is filled with molding sand 30. Thereafter, the main body mold 20 is demolded in the same manner as in a normal molding operation, but the ceramic mold 10 is left as it is in the mold made of foundry sand 30.

A mold coating agent is applied to the mold surface 30a made of foundry sand 30 formed by the main body 20, but the mold coating agent is not applied to the inner surface of the ceramic mold 10 and is left as it is. When a mold is thus created using the ceramic mold 10 and foundry sand 30 and hot water is supplied, the molten metal flows into the inside of the ceramic mold 10 at the same time as the inside of the mold formed by the main body 20, and flows together with the casting body. An attached protrusion is cast using a ceramic mold 10.

The ceramic mold 10 has a small hole 14 (shown in the figure) located at the top of the head 13 and a maximum diameter part of the head 13 in order to facilitate degassing during hot water supply and to more completely fill the molten metal. It is desirable to provide a plurality of small holes (not shown) horizontally so that the ceramic mold 10 can be used either vertically or horizontally. Note that when used horizontally, there is a large opening 11 communicating with the cast body, so the small hole 14 is not necessarily necessary.

Furthermore, if the ceramic mold 10 is used, there is no risk of problems such as seizure even if no mold coating agent is applied to the inner surface of the mold, and moreover, it can be easily removed by hitting it with a tool such as a hammer when removing the mold. I can do it. This ceramic mold 10 does not generate toxic gases, hardly any other gases, and does not have any adverse effects such as causing casting defects on not only the attached protrusions but also the casting body.

FIG. 4 shows a second embodiment of the present invention, in which a ceramic mold 10a for a blind feeder is shown in a molded state. This ceramic mold 10a has a generally oval spherical shape, and has an opening 11a communicating with the casting body at one end, and a convex portion 18 projecting toward the inner surface at the other end. The material, wall thickness, etc. of this ceramic mold 10a may be the same as those of the ceramic mold 10 of the above-described embodiment.

The method of use is also as described above. 20a is a wooden mold for molding the casting body.

[Effects of the Invention] As described above, according to the present invention, the number of man-hours required for molding work for molding an accessory projection such as a lifting projection or a blind feeder is reduced. Furthermore, if the shape of the attached protrusion can be standardized (standardized), ceramic molds can be obtained at low cost even if the shape is relatively complex, so casting costs can be reduced, and the attached protrusion and the cast body No casting defects or harmful gases are generated. Furthermore, since the ceramic mold can be easily broken with a hammer or the like, the mold can be easily removed after casting.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a ceramic mold showing one embodiment of the present invention;
The figure is a partially cutaway perspective view of the ceramic mold shown in FIG. FIG. 7 is a partial sectional view showing a molded state of a ceramic mold showing another example. 10.10a... Ceramic mold, 11. lla...opening,
20.20a...Main body type for molding, 30...Casting sand (mold). Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 nl

Claims (2)

[Claims] (1) A ceramic mold for casting an attached protrusion of a casting, which is hollow and has an opening communicating with the main body of the casting at one end, and an inner surface corresponding to the shape of the attached protrusion. A ceramic mold for forming an accessory protrusion of a casting, characterized by having the following features: (2) A ceramic mold for forming an attached protrusion of a casting according to claim 1, which has a small hole for degassing at a position different from the opening.