JPS62176631A - Production of die - Google Patents

Abstract

PURPOSE:To improve the accuracy of a die and to reduce the cost thereof by fixing a mold for a joint surface having a pouring port to a casting mold, supplying a molten metal through the pouring port into a cavity and forming a die body having the joint surface. CONSTITUTION:A pattern is preliminarily imposed on a molding board and a molding flask is disposed around the pattern. Molding sand is packed into the flask to form the casting mold 44. The mold 44 is then rolled over and the mold 46 for the joint surface having the pouring port 48 is disposed atop the same and is pressed and fixed by a weight 52. The molten metal is there after poured through the pouring port 48 into the cavity 50 so that the molten metal spreads to the top end of the pouring port 48. Gas is thereby discharged from the mold 46 and the pouring port 48 to the outside; at the same time, the flat joint surface 56 is formed on the bottom surface of the mold 46. The need for grinding the same is eliminated. The accuracy of the die such as punch 62 having the die body 54 is thus improved and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mold, and more specifically, to simplify the manufacturing process of a mold used in various molding devices such as a press molding device, a plastic molding device, or a casting device. The present invention also relates to a method of manufacturing a mold that can be manufactured at low cost.

There are various methods for molding the molding material into a predetermined shape, such as press molding in which the material is deformed by pressing force, plastic molding or casting in which molten metal is supplied into a molded product cavity and the molten metal is solidified. There is a molding method.

In plastic molding and casting, a mold is used to define a cavity, while in press molding, a mold consisting of a male mold and a female mold is used, and a plastic material is placed in the mold. Bending processing or deep drawing processing is generally performed so as to follow the material. FIG. 1 shows an example of a molding apparatus according to the prior art.

That is, the press forming apparatus 2 is an apparatus for press-working a plate material 4 made of a planar material into the shape shown in the figure, and includes a male die 6 and a female die 8 that press the plate material 4 in a sandwiching manner. The male mold 6 essentially consists of a mold holding member 10 and a convex mold body 12 mounted on the mounting surface 1) of the mold holding member 10. Further, a plurality of holes 14 are bored near the outer edge of the mold holding member 10, and the plurality of holes 1
A rod 16 is inserted through each of the rods 1 and 4.
Holder I8 is supported by.

On the other hand, the female mold 8 consists of a mold holding member 24 made up of a plate 20 and a holder 22, and a concave mold body 26 attached to this mold holding member 24.

When press forming is carried out using the press forming apparatus 2 having such a configuration, first, the male die 6 and the female die 8 are separated by a predetermined distance, and the plate material 4 having an undesired shape is placed at the spaced apart portion. Then, by displacing either the male mold 6 or the female mold 8 with a predetermined pressing force so as to fit into the other, the plate material 4 is molded into a shape along the mold bodies 12 and 26.

Therefore, when constructing the press molding apparatus 2, normal press working cannot be performed unless the mold bodies I2 and 26 of a predetermined shape are accurately attached to the mold holding member 10.24.

Therefore, the manufacturing operation of the male mold 6 including the casting and attachment process of the mold body 12 will be explained next.

As shown in FIG. 2a, a spacer 30 is disposed on the lower surface of the model 28 for casting the mold body 12, taking into account the grinding part of the crack generation part, which will be described later.
The model 28 is placed on the surface plate 32 so that 0 is interposed therebetween. Further, a formwork 34 surrounding the model 28 and the spacer 30 is placed on the surface plate 32. Thereafter, a mold 36 is formed by filling molding sand into the space defined by the model 28, spacer 30, surface plate 32, and mold 34.

Next, as shown in FIG. 2, the mold 36 is inverted to open the concave cavity 38 defined in the mold 36.
Molten metal, that is, molten metal, is poured into the container. in this case,
The molten metal is poured until the surface reaches the upper end of the cavity 38, but as shown in FIG. A corresponding shrinkage occurs, and a shrinkage portion 12a is formed.

Therefore, as shown in FIG. 2d, the cut portion 12a of the mold body 12 is ground using a grinding machine 40. That is, after casting the mold body 12, the part corresponding to the spacer 30 is scraped off, thereby obtaining the mold body 12 having the same shape as the model 28. Then, the male mold 6 is constructed by joining the processed surface 42 of the mold body 12 formed by the grinding process to the mounting surface 1) of the mold holding member 10.

On the other hand, the female mold 8 is also manufactured by the same method as the male mold 6.

That is, after casting the mold body 26, the mold body 2
The joint portion with the plate 20 at 6 will be ground.

However, in order to press the plate material 4 into a predetermined shape, it is necessary to attach the mold body 12.26 to the mold holding member 10.24 with high precision. Therefore, the above-mentioned grinding process requires precision and is inconvenient in that the work is complicated. Moreover, since such a grinding process is required, the male die 6 and the female die 8 require an amount of molten metal corresponding to the grinding allowance in advance, and the grinding process takes time, resulting in high manufacturing costs. It also exposes the shortcomings of being forced to do so.

The present invention has been made in order to overcome the above-mentioned disadvantages, and when casting a mold body, the joint surface of the mold body with the mold holding member is molded by a mold for the joint surface having a feeder port, while A hole for inserting a protrusion formed along the feeder opening is formed in the mounting surface of the mold holding member, and the protrusion is inserted into the hole for positioning, and the mold body is By bringing the bonding surface of the mold into close contact with the mounting surface of the mold holding member, there is no need for grinding after the casting process, which shortens manufacturing time and reduces manufacturing costs. The purpose is to provide a method for manufacturing molds.

In order to achieve the above object, the present invention provides a method for manufacturing a mold including a mold body in contact with the molding material for molding a molding material and a mold holding member holding the mold body, the method comprising: A first step of molding a mold having a cavity based on a model of the main body, and fixing to the mold a mold for a joint surface provided with a pouring port and for molding a joint surface of the mold main body to the mold holding member. a second step, and a third step of supplying the molten metal into the cavity through the pouring port, solidifying the molten metal to form a mold body that corresponds to the shape of the cavity and has the joint surface; and a fifth step of joining the mold body and the mold holding member so that the joint surface is brought into close contact with the mold holding member after the mold body is completely cast by performing mold disassembly. It is characterized by consisting of.

Next, preferred embodiments of the mold manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings.

In addition, in the following explanation, the same reference numerals as the reference numerals indicating the above-mentioned prior art indicate the same components,
A detailed explanation thereof will be omitted.

3a to 3d show the manufacturing process of the male mold in the molding apparatus 2. FIG.

First, as shown in FIG. 3A, the model 28 is placed on the upper surface of the surface plate 32, and then the formwork 34 surrounding the model 28 is placed on the surface plate 32. Thereafter, a mold 44 is formed by filling molding sand into the space defined by the model 28, surface plate 32, and mold 34.

Next, the mold 44 is inverted as shown in FIG. 3, and a mold 46 for the bonding surface is placed on the upper surface thereof. The bonding surface mold 46 is made of a plate material with good air permeability, and a pouring port 48 is formed approximately in the center thereof. That is, mold 4
A cavity 50 is defined by the joint surface mold 46 and the joint surface mold 46, and in this case, a weight 52 is provided near the outer edge of the joint surface mold 46.
By placing the bonding surface mold 46 on the mold 44 side, the joint surface mold 46 is pressed and fixed.

Next, molten metal is poured into the cavity 50 through the pouring port 48 . In this case, the molten metal is poured until the molten metal reaches the upper end of the pouring port 48, and the molten metal is completely spread within the cavity 50.

Thereafter, the temperature of the molten metal decreases over time, and finally, as shown in FIG. 3C, the molten metal solidifies into a mold body 54. When the molten metal is cooled and solidified to form the mold body 54, the gas generated from the molten metal flows through the mold 46 for the joint surface with good air permeability and the pouring port 48 formed in the mold 46 for the joint surface. is discharged outside. Therefore, there is no possibility that bubbles or recesses caused by residual gas will appear in the mold body 54. Moreover, since the molten metal remaining in the pouring port 48 provides a feeder effect, the occurrence of shrinkage in the portion that affects the mold body 54 due to solidification and contraction of the molten metal is suitably prevented.

Therefore, a mold body 54 that exactly corresponds to the shape of the cavity 50 is cast. In this case, the joint surface 56 is formed by the flat lower surface of the joint surface mold 46, and a protrusion 5 corresponding to the shape of the spout 48 is formed at the center of the joint surface 56.
8 is molded.

After the mold body 54 is molded in this manner, the mold 44 is demolded and casting of the mold body 54 is completed.

Next, a case will be described in which the press molding apparatus 2 is constructed using the mold body 54 molded in this manner. Third
As shown in Figure d, the mounting surface 1) of the mold holding member 10 is prepared in advance.
A hole 60 having a larger diameter than the protrusion 58 of the mold body 54 is bored approximately in the center of the mold body 54 . Therefore, the mold body 54 is fixed to the mounting surface 1).

That is, the protrusion 58 is inserted into the hole 6o, the joint surface 56 of the mold body 54 is brought into close contact with the mounting surface 1), and the male mold 62 as a mold is positioned and fixed.

When manufacturing the male mold 62 in this manner, there is no need to perform grinding as in the conventional method, and there is no need to use the spacer 30 (see FIG. 2a) when molding the mold 44. That is, since the conventional grinding process can be omitted, the press molding device 2 can be manufactured easily and the manufacturing time can be shortened. Moreover, since the joint surface 56 of the mold body 54 is formed into a flat shape by the joint surface mold 46, the joint surface 56
and the mounting surface 1) of the mold holding member 10 can be suitably joined, and as a result, a male mold 62 with excellent dimensional accuracy can be easily obtained. Furthermore, by configuring the projection 58 of the mold body 54 to fit appropriately into the hole 60 of the mold holding member 10, positioning of the mold body 54 on the mold holding member 10 can be easily performed. becomes possible.

In this embodiment, a method for manufacturing a male mold in a press molding apparatus has been described, but a female mold corresponding to the m-type can be constructed by a manufacturing method similar to this. Furthermore, it is not limited to press molding equipment, for example,
It will be easily understood that the present invention can also be applied to the production of molds for various molding devices such as injection molding devices or casting devices.

According to the present invention, as described above, when manufacturing a mold consisting of a mold holding member and a mold body, the conventional grinding process of the mold body is unnecessary, so the manufacturing process of the molding device is simplified. As a result, the molding apparatus can be provided at a low cost. Moreover, since the joint surface of the mold body with the mold holding member is molded into a predetermined shape and size in the casting process, it is possible to manufacture a mold with excellent dimensional accuracy.

Furthermore, since it is possible to easily change only the mold body, it is possible to achieve the effect of reducing the manufacturing cost of the product even in the trial production stage of the product or in the case of high-mix low-volume production.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical sectional view of a press molding apparatus according to the prior art, Fig. 2a to 2e are explanatory diagrams of the manufacturing process of a mold according to the prior art, and Fig. 3a to 3d are FIG. 3 is an explanatory diagram of a manufacturing process of a mold according to the present invention. 2...Press molding device 6...Male mold 8...
Female mold lO...mold holding member 12...
・Mold body 24...Mold holding member 26・
...Mold body 28...Model 44...
Mold 46...Mold 54 for joint surface...
・Mold body 62...Male mold patent applicant
Honda Motor Co., Ltd. FIG, 3a FIG, 3c FIG, 3d

Claims (3)

[Claims] (1) A method for manufacturing a mold including a mold body in contact with the molding material and a mold holding member holding the mold body for molding the molding material, the mold having a cavity based on a model of the mold body. a first step of molding a mold; a second step of fixing to the mold a joint surface mold provided with a pouring port and for forming a joint surface of the mold body to the mold holding member; and a second step of fixing a mold for a joint surface to the mold; a third step of supplying molten metal into the cavity through a fourth step of solidifying the molten metal to form a mold body that corresponds to the shape of the cavity and has the joint surface; and mold disassembly. After completing the casting of the mold body, a fifth step of joining the mold body and the mold holding member so that the joint surface is brought into close contact with the mold holding member. Mold manufacturing method. (2) In the method according to claim 1, when the molten metal solidifies to form a mold body, a protrusion corresponding to the pouring port is formed on the joint surface side of the mold body, while a mold holding part is formed. A method for manufacturing a mold, in which the joint surface and the mold holding member are brought into close contact by inserting the protrusion into a hole provided in the member. (3) A method for manufacturing a mold according to claim 1, in which the joint surface mold is made of a plate material having air permeability through which gas generated from the molten metal can pass.