JPH08117924A - Backup mold device for casting mold and its production - Google Patents

Abstract

PURPOSE: To easily and surely back up a shell-like casting mold by constituting a recess corresponding to the height of the shell-like casting mold in a frame member and providing the shell-like casting mold with a cured packing material having a cavity surface of nearly the same shape as the shape of the rear surface side of the mold and a sand supply hole. CONSTITUTION: The frame member 4 is placed on a drag 1 by positioning a cavity molding member 2 on the inner side and a pattern 5 for forming the sand supply hole is erected atop this cavity molding member 2. Slurry cement 6 or the like as the self-curing heat resistant packing material is packed into the space delineated by the cavity molding member 2 and the frame member 4. The frame member 4, the cavity molding member 2, a pattern 5 for forming the sand supply hole and the cement 6 are separated from the drag 1 when the cement 6 cures. The cavity molding member 2 and the pattern 5 for forming the sand supply hole are removed from the frame member 4, the cavity molding member 2, the pattern 5 for forming the sand supply hole and the cement 6 in the state of allowing the cement 6 to remain in the frame member 4. The backup mold device 8 having the sand supply hole 7 is thus obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold apparatus for backing up a shell-shaped mold on its back side and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in order to reduce the use amount of useless molding sand, a mold forming method in which a mold is made into a shell shape has been developed and applied for a patent.
In this mold making method, the model is placed on the mold frame having the minimum required space between the model shape and the cavity created between them is filled with molding sand by utilizing vibration and decompression force. The amount of foundry sand used is kept to a minimum.

[0003]

By the way, when two casting molds formed as described above are combined to define a casting cavity, and when a molten metal is injected into this casting cavity to produce a casting, these are It is necessary to back up the mold from the outside, but conventionally, this backup is done by burying the mold that constitutes the casting cavity in the sand placed on the floor surface, and therefore the productivity is poor. There were problems such as worsening the work environment. Therefore, it has been proposed to cut metal or wood as a material to manufacture a backup mold having a recess having the same shape as the outer shape of the shell-shaped mold, but it has not been put into practical use because of high manufacturing cost. The present invention has been made in view of the above circumstances. The first invention is a mold device for backing up a shell-shaped mold, and the second invention is a backup mold device which is inexpensive and can be easily manufactured. The purpose is to provide a possible method.

[0004]

In order to achieve the above object, the first invention is a mold device for backing up a shell-shaped mold on the back side thereof, which is a frame member and a frame built in the frame member. A cavity surface which forms a recess having a depth corresponding to the height of the shell-shaped mold with the member and has a shape substantially the same as the back side shape of the shell-shaped mold, and a sand supply hole communicating with the cavity surface. And a hardened heat-resistant filling material having the same.

A second aspect of the present invention is a method for manufacturing a mold device for backing up a shell-shaped mold on the back side thereof, which comprises a model part constituting a model surface for molding a casting cavity surface and the model part as an upper surface. And a mold body having a plurality of through-holes communicating with a vacuum source at the outer peripheral position of the model part, on the upper surface of the lower mold, the thickness and flexibility required to be substantially the same as the thickness of the shell mold. A first step of adsorbing a non-air-permeable cavity molding member having a size, and placing a frame member with the cavity molding member positioned inside on the lower mold, and supplying sand to the upper surface of the cavity molding member Second step of standing up the hole forming model, and filling a self-hardening heat-resistant filler in the space defined by the cavity molding member and the frame member, and after the filler is cured, the frame member and The cavity molding member and the front Third step of separating the sand supply hole molding model and the filling from the lower mold; the frame member, the cavity molding member, and the sand separated while the filling remains in the frame member. A fourth step of removing the cavity molding member and the sand supply hole forming model from the supply hole forming model and the filling material.

[0006]

Next, a method of adhering a predetermined shell-shaped mold to the backup mold apparatus of the first invention will be described. After the mounting surface of the shell-shaped mold in the backup mold apparatus is coated with an appropriate mold release material, the lower mold A backup mold device is mounted on the mold to define a mold cavity, and subsequently, a discharge port of a hopper that stores self-hardening or gas-hardening molding sand is connected to a sand supply hole of the backup mold device. Next, a suction action is exerted on the upper surface of the lower die main body to reduce the pressure in the mold cavity, whereby the molding sand in the hopper is suction-filled in the mold cavity. After the filled molding sand has hardened with the passage of time or through the flow of hardening gas, the backup mold device containing the hardened molding sand is lifted and separated from the lower mold to obtain the desired shell mold for the backup mold device. Can be attached. This mold has a cavity surface for casting on the lower mold side.

Here, as the filler used in the method of manufacturing the backup type device of the second invention, there are cement, self-hardening molding sand, and the like. Further, the separation of the shell-shaped mold from the pack-up mold device is performed by a method in which a release material is interposed between the backup mold device and the shell-shaped mold.
Alternatively, a plurality of through holes may be provided in the backup mold device, and a rod may be passed through the through holes to push out the shell mold from the backup mold device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a method for manufacturing a backup type device of the present invention will be described in detail with reference to FIGS. As shown in Figure 1,
A model portion 1a forming a model surface for molding a casting cavity surface, and a mold body 1b having the model portion 1a mounted on the upper surface.
After mounting a non-air-permeable cavity molding member 2 having a required thickness and flexibility on the upper surface of the lower mold 1 consisting of, the lower mold is suctioned and decompressed in the hollow chamber 3 below the mold body 1b. The cavity molding member 2 is adsorbed to the upper surface of the cavity molding die 1, and then the peripheral edge portion of the cavity molding member 2 is cut and removed to make the cavity molding member 2 a required size.

Then, as shown in FIG. 2, the frame molding member 2 is placed on the lower mold 1 with the cavity molding member 2 positioned inside, and the sand molding hole molding model is mounted on the upper surface of the cavity molding member 2. 5 is erected, and subsequently, the space defined by the cavity molding member 2 and the frame member 4 is filled with slurry-like cement 6 as a self-hardening heat-resistant filler.

After the filled cement 6 hardens, the frame member 4, the cavity molding member 2, the sand supply hole molding model 5 and the cement 6 are separated from the lower mold 1, and then the cement is cemented. 6 left in the frame member 4, the separated frame member 4, the cavity molding member 2, the sand supply hole molding model 5, and the cement 6
Then, the cavity molding member 2 and the sand supply hole molding model 5 are removed. Thereby, the backup type device 8 having the sand supply hole 7 can be obtained.

Next, the operation of adhering a shell mold to the backup mold device 8 using the above-mentioned backup mold device 8 and the lower mold 1 will be described with reference to FIG. 3 which is a longitudinal sectional view. First, the backup mold device 8 is placed on the lower mold 1 to define the mold cavity C, and then the lid member 9 is placed on the backup mold device 8. Then, the blow head 10 containing the self-hardening molding sand S is placed on the lid member 9 with the sand discharge port aligned with the sand supply hole 7. Next, compressed air is supplied to the blow head 10 to blow and fill the self-hardening molding sand S into the mold cavity C. After the filled self-hardening molding sand S is hardened, the backup mold device 8 is lifted and separated from the lower mold 1, so that the backup mold device 8 can be equipped with a desired shell mold. That is, the shell-shaped mold can be backed up on the back side by the backup device 8. The gate can be formed by drilling a hole in the sand supply hole 7 of the mold.

In the above-mentioned embodiment, the self-hardening molding sand S is filled in the mold cavity C by a so-called blowing method. It may be performed by. Further, in the above example, the self-hardening molding sand was used as the molding sand for molding, but gas-hardening molding sand may be used, and in this case, the molding gas filled in the mold cavity C is flowed with the hardening gas. Need to let. Also,
Two or more sand supply holes 7 may be provided. Further, the lid member 9
May be omitted.

[0013]

As is apparent from the above description, the first aspect of the present invention is a mold apparatus that backs up a shell-shaped mold on the back side thereof, and includes a frame member and a frame member incorporated in the frame member. A hardened material having a cavity surface having a recess having a depth corresponding to the height of the shell-shaped mold and having a shape substantially the same as the shape of the back side of the shell-shaped mold and a sand supply hole communicating with the cavity surface. Since the above-mentioned filling material is included, by molding the shell-shaped mold in this backup mold device, the shell-shaped mold can be easily and surely packed up, which is an excellent effect. A second aspect of the present invention is a method of manufacturing a mold device that backs up a shell-shaped mold on the back side thereof, which comprises a model part constituting a model surface for molding a casting cavity surface and the model part mounted on the top surface. On the upper surface of the lower mold, which is composed of a mold body having a plurality of through holes communicating with the vacuum source at the outer peripheral position of the model portion, and the thickness and flexibility and required size substantially the same as the thickness of the shell mold. A first step of adsorbing a non-air-permeable cavity molding member having: and placing a frame member with the cavity molding member positioned inside on the lower mold, and forming a sand supply hole on the upper surface of the cavity molding member. The second step of standing up the model for
A self-hardening filling is filled in a space defined by the cavity molding member and the frame member, and after the filling is cured, the frame member, the cavity molding member, the sand supply hole forming model, and the filling A third step of separating the object from the lower mold; the frame member, the cavity molding member, the sand supply hole forming model, and the filler, which are separated while the filler remains in the frame member. From the fourth step of removing the cavity molding member and the sand supply hole molding model from the above, there is an excellent effect that a backup mold device can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view for explaining a manufacturing process according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view for explaining a manufacturing process according to an embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing an embodiment in which a shell-shaped mold is attached and molded to a backup mold device of the present invention.

[Explanation of symbols]

 4 Frame member, 6 Filling material 7 Sand supply hole

Claims (2)

[Claims] 1. A mold device for backing up a shell-shaped mold on the back side thereof, which comprises a frame member 4 and a depth corresponding to the height of the shell-shaped mold, which is built in the frame member 4 and corresponds to the height of the shell-shaped mold. A hardened heat-resistant filling 6 having a cavity surface which forms a recess having a height and has a shape substantially the same as the shape of the back surface of the shell-shaped mold, and a sand supply hole 7 communicating with the cavity surface. A backup mold apparatus for molds characterized by the above. 2. A method for manufacturing a mold apparatus for backing up a shell-shaped mold on the back side thereof, which comprises a model part constituting a model surface for molding a casting cavity surface and a model part mounted on the top surface of the model part. A mold having a plurality of through-holes communicating with the vacuum source at the outer peripheral position of the lower mold, and having a thickness substantially the same as that of the shell mold, flexibility and a required size. A first step of adsorbing a breathable cavity molding member, placing a frame member with the cavity molding member positioned inside on the lower mold, and mounting a sand supply hole molding model on the upper surface of the cavity molding member. Second to stand
Step, filling a space defined by the cavity molding member and the frame member with a self-hardening heat-resistant filling material, and after the filling material is cured, the frame member, the cavity molding member, and the sand supply hole forming A third step of separating the model and the filling from the lower mold; the frame member, the cavity molding member, and the sand supply hole forming which are separated while the filling remains in the frame member. A fourth step of removing the cavity molding member and the sand supply hole molding model from the model and the filling, a method of manufacturing a backup mold device.