JPS61169132A - Manufacture of mold - Google Patents

Abstract

PURPOSE:To save the cost of a pattern for a product of simple shape, such as a circular or a square pillar shape, by using only a temporary pattern provided with a cut at one location or plural divided faces without using a pattern for a mold core in manufacturing a main mold and a mold core. CONSTITUTION:A temporary pattern 1 having a straight inner-diam. shape is provided with a cut 1, at its one location, and a temporary pattern 1 having a recessed part at its inner diam. is divided into plural sections, which are fixed together by joggling and another means. Further, the pattern 1 is formed by using resin material such as expanded polystylene, and is coated with surface hardening material so as to use it repeatedly. The inner-diam. side of pattern 1 is filled with molding sand 6, and matching joggles 7 are attached to the end face of a mold after molding. Next, molding sand 3 is charged into a molding flask 2 for a lower mold to mold a lower mold, which is turned upside down to set the temporary pattern 1, a molding flask 4 for an upper mold and a gate rod thereon, then molding sand 5 is charged into the upper flask 4 to mold an upper mold. Next, the upper and lower molds are separated from each other, and the mold core 6 is taken out after extracting the pattern 1 from the lower mold to register the upper and lower molds and the mold core.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a mold using a simple model. More specifically, the present invention relates to a method of manufacturing a mold using only a simple model for the main mold without using a model for the core.

[Conventional technology] Wooden molds are generally used as model materials for casting.

Molds, resin molds, etc. are used. Molds and resin molds are
It is applied to relatively mass-produced products that require dimensional accuracy, and wooden molds are used for single-item or small-volume products. However, these models are very expensive in terms of both material costs and processing costs.

In recent years, in order to reduce the proportion of model costs in casting costs,
Foamed polystyrene and other materials are used for model materials.

As a method of using foamed polystyrene etc. as a model material,
(1) The so-called “full mold method J” used as a vanishing model
(2) Used as a substitute for a wooden model, and after molding, remove foamed polystyrene etc. from the mold. (3) Used as a substitute for a wooden model and applied to one to several moldings. Three types of simple models can be considered.In the first two methods, the model loses its original shape after one use, while in the second method, the model loses its original shape after one use.
Can be used repeatedly up to several times.

When making a model of a simple round shape such as a bearing or bushing, if there is no draft in the hole, if there are some protrusions, or if the model is large, the external model and the hole are equivalent. Usually, a core box is made and a mold is made.

FIG. 5 is a sectional view of a conventional simple mold, and FIG. 6 is a flowchart showing the molding process of the mold.

The numerals in FIGS. 5 and 6 indicate the same thing.

First, in FIG. 6(A), the simple model 1 is placed on the surface plate 9.
Place the lower mold 1' and the flask 2 for the lower mold in the space shown in Fig. 6 (
As shown in B), hook mold sand 6 is filled and the lower mold of the mold is formed. After the lower mold has been formed, the mold is inverted as shown in FIG. 6(0), and the upper mold 1' of the simple model 1, the upper mold casting flask 4, and the sprue rod are removed as shown in FIG. 6(D). 10 is installed, and the space is filled with molding sand 5 to form a mold. After the molding of the upper and lower molds is completed, as shown in FIG.
'.

1') and sprue rod 10 are removed, a separately produced core 11 is inserted as shown in FIG. 6(F), and a mold is placed as shown in FIG. 6(G). FIG. 5 shows a state in which the upper and lower molds are matched without setting the core 11.

(Problems to be Solved by the Invention) The above conventional method requires the production of a core model (δ phase) (not shown) and the separate molding of the core 11, so the model cost and core production cost are reduced. It will be expensive.

The present invention takes advantage of the shrinkability of the simple model material and the fact that it does not deform over time like the wooden pattern material, and without using a core model.
The present invention provides a mold manufacturing method in which a main mold and a core (hole mold) are manufactured using only a model for the main mold (external mold), thereby reducing the number of man-hours required for manufacturing the model and mold.

[Means for solving problems]

The present invention relates to a mold manufacturing method characterized in that a main mold and a core are manufactured using only a simple model provided with one or more dividing surfaces or cuts, and without using a core model. .

That is, the present invention breaks away from the current situation where there is a problem with the repeated use of the simple model itself, and uses the simple model to realize the actual production of the hole mold (core). The unique feature is that the corresponding part of the core can be made using only the main mold model without using a model.

FIG. 1 is a diagram showing an example of an embodiment of a simple model according to the method of the present invention.

The simple model 1 with a straight inner diameter shown in Fig. 1 (A) is
A simple model 1 with a cut 11 at one place and a concave part on the inner diameter as shown in Fig. 1 (B) is divided into two parts and fastened with dowels (a model with an uneven surface so that the divided molds can fit together). )
Then, fix it using a separate means and make a model.

The simple model according to the method of the present invention is made of a resin material such as expanded polystyrene that can be used for molding once or twice as described above, but it is coated with a surface hardening material so that it can be used repeatedly. and the lack of hardness.

An embodiment of the mold manufacturing method according to the present invention will be described in detail with reference to FIG. 2.5. In Fig. 2.6, the same reference numerals as in Fig. 5.6 indicate the same functional parts (components) as in Fig. 5.6.

First, as shown in FIG. 3(A), after placing the simple model 1 according to the present invention and the lower casting flask 2 on the surface plate 9, the hanging ring 8 is installed on the inner diameter side of the simple model 1. - place. Figure 3 (B)
As shown in FIG. 2, after filling the inner diameter side of the simple model 1 with molding sand 6 and forming the model, a parting fern bore is placed on the end face thereof. After the molding sand 6 is hardened, the molding sand 3 is put into the flask 2 for the lower mold to form a lower mold, as shown in FIG. 3(0).

After the lower molding is completed, it is turned over as shown in FIG. 3(D), and as shown in FIG. 3(B), the simple model 1, the upper mold casting flask 4, and the sprue rod 10 are installed, and the Molding sand 5 is poured into the mold to form a mold for the upper mold. After completing the molding of the upper and lower molds, Figure 5 (
As shown in I'), the upper mold (a) and the lower mold (1)) are separated, and the simple model 1 is extracted from the lower mold (1)). At this time, the molding sand 6 on the inner diameter side of the simple model 1 is attached to the simple model 1 and separated from the parting surface. After that, Figure 3 (G)
As shown in the figure, the simple model 1 is divided into parts, and the core 6 is pulled out using a hanger 12.

Details at this time are shown in FIG. That is, Fig. 1 (A
) In the case of the simple model, attach a jig to the small monkey 8 and pull it out, and the mold 6, which corresponds to the buffer and core at the cut 11, can be easily removed as shown in Figure 4 (A). You can get it out. In addition, in the case of the simple model in Figure 1 (B), the third
By dividing the simple model 1 as shown in Figure (G) and Figure 4 (B), it can be easily taken out. In addition, simple model 1 is 2
If the mold cannot be removed locally, the core model can be omitted by further dividing only the axillary part.

Set the core 6 in the lower mold molded as above,
FIG. 2 shows the state in which the upper mold is covered.

In addition, when the above-mentioned hanging ring 8 has a large core 6,
It is used to hang a hanging tool (hook) 12 during movement such as storing the core, and is set on the center side so that the core is balanced when inked. Further, the dowel 7 is provided for positioning when inserting the core 6 into the mold after removing it from the simple model 1.

〔Effect of the invention〕

The present invention has the effect of reducing model costs for cylindrical products such as bearings and bushings, and products with simple rectangular tube shapes, which require models for main molds and cores, as well as the man-hours required for manufacturing cores, in conventional methods. be. In addition, the product dimensions to which the present invention can be applied and which have a large saving effect are, for example, a cylindrical product having an outer diameter of 500 mm or more and a wall thickness of 40 knots or more.

[Brief explanation of the drawing]

1(A) and 1(B) are perspective views showing an embodiment of a simple model according to the method of the present invention, and FIG. 2 is a sectional view of a mold manufactured by the method of the present invention. , FIG. 3 is a flowchart showing an embodiment of the method of the present invention, FIG. 4(A) and FIG.
Figure (B) is a perspective view showing the state of the core being cut out. FIG. 5 is a cross-sectional view for explaining a conventional mold, and FIG. 6 is a flowchart showing a conventional mold manufacturing method. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] A mold manufacturing method characterized by manufacturing a main mold and a core using only a simple model provided with one or more dividing surfaces or cuts, without using a core model.