JPH0320028Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is used in the technical field of casting using shell molds, and is particularly applicable to casting boxes (back-up boxes) for holding and housing shell molds with back-up materials. ).

(Prior art) Generally, when casting products of the same shape, a plurality of shell molds are housed in a casting box of an appropriate size, and a metal backup material such as a steel shot is tightly wrapped around the shell molds. The molten metal is poured while the molten metal is filled and held.

(Problem to be solved by the invention) However, since the metal back-up material has a slippery grain shape, the wider the distance between the shell molds and the distance between the shell mold and the wall of the casting box, the easier it will be after filling. The degree of freedom (movement) of the metal increases, making it easier to flow, and the rise in temperature after pouring causes abnormal force to act on the shell mold, causing the shell mold to bend, leading to casting defects. .

As an example of a conventional casting box, a single casting box is provided with a floor in which granular refractory material is accommodated in a flowable manner.
A method in which a plurality of shell molds are held by this bed (for example, see Japanese Patent Application Laid-Open No. 56-41044) has been disclosed, but this method is difficult to prevent the unburned metal remaining in the shell mold from remaining in the shell mold after pouring into the shell mold. regeneration of the foundry sand by burning the resin binder with air introduced into the bed, and then heat treatment of the cast product at a predetermined temperature and time controlled by the flammable mixed gas introduced into the bed. However, no measures have been taken to prevent the shell mold from bending during pouring as described above.

In view of the above-mentioned conventional problems, the present invention prevents deformation such as bending of the shell mold by restricting the degree of freedom of the backup material for holding the shell mold in the casting box and reducing fluidity. In addition, it is an object of the present invention to provide a casting box for shell molds which increases the degree of freedom regarding the size of shell molds to be accommodated.

(Means for Solving the Problems) In order to achieve the above object, the solution of the present invention is to create a shell in which a plurality of shell molds are held and housed in a single casting box by a metal back up shot. A casting box for molds is assumed. A rigid wall member that partitions adjacent shell molds in the casting box is removably provided between both side walls of the casting box. Flange portions are formed on both sides of the shell mold in the direction of partition by the wall member, each extending substantially parallel to the wall member and close to the side wall of the casting box.

(Function) As a result, in the present invention, the degree of freedom of the back up shot in the casting box is restricted by the wall member, so the shell mold can be backed up without any abnormal force acting on it during pouring. .

In particular, since the wall member and the flange part of the shell mold are arranged in the same direction, that is, they are arranged in parallel, the distance between the wall member and the shell mold can be narrowed, and the movement of the back up shot can be ensured. It can be restrained, and the deformation of the shell mold can be more reliably prevented.

In addition, since the above wall members are removable, in the case of casting a different shell mold with a larger size, some of the wall members can be removed and placed in the same casting box for casting. .

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

Figures 1 and 2 show a single casting box 1 that is applied to vertical casting in an endless conveyor line (not shown) equipped with a back-up station and a pouring station. There is.
A plurality of (four in the figure) shell molds 2, 2, . A core body 3 made of a heat insulating material such as ceramic fiber is covered with an outer cover body 4 made of a rigid material such as an iron plate to increase rigidity so as to partition the molds 2, 2, . . .
Wall members 5, 5... are removably provided.
Each shell mold 2 is held by a metal back-up shot 6 whose periphery is densely packed. The shell mold 2 has flange portions on both sides of the wall member 5 in the partitioning direction, that is, on both sides of the sprue 7 and on both sides and lower side of the main body 8, extending substantially parallel to the wall member 5 and up to the vicinity of the side wall 1a of the casting box 1. 9 are integrally formed. The wall member 5 may be inserted into the casting box 1 in a tight fit, or may be inserted into the casting box 1 using a guide pin (not shown) provided on the side wall 1a of the casting box 1.
Alternatively, it is provided in a removable manner by being held in a guide groove (not shown).

Next, the operation of this embodiment will be explained.

First, in an empty casting box 1, a plurality of wall members 5, 5,
5 are arranged at appropriate intervals, and spaces 10, 10, .
After each shell mold 2 is charged into the shell mold 2, the back up shot 6 is filled on the circumferential surface of the shell mold 2. Here, the back up shot 6 is used to determine the distance between the shell mold 2 and the wall member 5, and the distance between the shell mold 2 and the front wall 1b.
Otherwise, it will be in a state similar to that of a box housed in a small volume box with a narrow distance from the rear wall 1c, so its degree of freedom (movement amount) is restricted and an abnormal force is applied to the outer peripheral surface of the shell mold 2. is maintained without acting, and the distortion of the shell mold 2 is reduced.

(Test Results) A casting test was conducted in which the casting box 1 to which the wall member 5 of the present invention was applied was moved in the direction of the arrow A in FIG. 2 and the metal was sequentially poured into each shell mold 2. As a result, the shell mold numbers 2, 2, ... shown in FIG. The amount of bending b of the product 11 was measured. The product 11 cast by the shell mold is curved to the plus side shown by the broken line in FIG. 3 and to the minus side shown by the chain line, and the amount of bending b is as shown in FIG. On the negative side, all others were curved on the positive side. Wall member 5
As shown in the figure, the results are different depending on the presence or absence of the wall member 5, and a favorable result was obtained in which the amount of bending b was reduced by half in the case where the wall member 5 was present (shown on the right side) compared to the case where it was not present (shown on the left side).

(Effects of the invention) Since the present invention is configured as described above, a rigid wall member is provided between each shell mold, and the wall member and the flange portion of the shell mold are arranged in parallel. The distance between the wall member and the shell mold can be narrowed, and the degree of freedom (movement) of the back-up material is reliably regulated, which prevents deformation of the shell mold without applying abnormal force due to movement of the back-up shot. It can definitely be prevented.
In addition, since the wall members are removable, even if the number of shell molds is large, by removing some of the wall members, it can be set and cast in the same casting box, increasing the degree of freedom. This has an excellent effect.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention; Fig. 1 is an external perspective view of a casting box in which a plurality of shell molds for vertical casting are held in a back up shot, and Fig. 2 is a central longitudinal section of the casting box for shell molds. 3 is a schematic diagram of the cast product (camshaft) taken out from the shell mold, and a side view showing the curved state when the longitudinal direction is vertical; FIG. 4 is a diagram showing the measurement results of the amount of curvature of the cast product. It is. 1...casting box, 1a...side wall, 1b...front wall, 1
c... Back wall, 2... Shell mold, 3... Core body, 4
... Outer cover, 5 ... Wall member, 6 ... Backup site, 7 ... Sprue, 8 ... Main body, 9 ... Flange section, 10 ... Space section.

Claims (1)

[Scope of Claim for Utility Model Registration] In a casting box for shell molds in which a plurality of shell molds are held and housed in a single casting box by a metal back up shot, there is a space between both side walls of the casting box, A rigid wall member that partitions adjacent shell molds in the casting box is removably provided, and on both sides of the shell mold in the partitioning direction by the wall member, there are molded walls approximately parallel to the wall member. A casting box for a shell mold, characterized in that a flange portion extending to near the side wall of the box is formed.