JPH0428680Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a blowhead structure for a molding machine that molds a shell mold.

(Prior Art) Conventionally, a blow head for blowing and supplying shell sand to a mold for making shell molds has been detachably attached to the lower surface of a blow tank that moves up and down. When blowing shell sand, the blow head is pressed against the mold, and the shell sand fed inside is filled into the cavity in the mold through the blow port. (For example, Utsukai 57-
(See Publication No. 122747) The above-mentioned mold is heated to an elevated temperature, and the blow-filled shell sand is hardened by the heat of the mold, and the shell mold after molding is taken out by opening the mold.

Since the blow head for making the shell mold has a blow port arrangement corresponding to the sand inlet of the mold, the blow head is also replaced together with the mold when the mold is replaced.

(Problem to be Solved by the Invention) However, when replacing the blow head with the mold, it is convenient to handle the mold and the blow head together, but it is difficult to handle the blow head in close contact with the mold immediately after use. If left unattended, the shell sand in the blowhead will receive the heat of the mold and harden, which will become an obstacle when the mold is used again.
For this reason, the shell sand in the blow head is removed to avoid heat hardening of the shell sand, but this operation is complicated.

In addition, the blow head is handled separately from the mold,
Although it is conceivable to prevent the blow head from being affected by the heat of the mold, it is not preferable because it would complicate the management of the storage position of the blow head corresponding to the mold.

Therefore, in view of the above-mentioned circumstances, the present invention provides a blowhead structure for making shell molds that prevents the remaining shell sand from being thermally hardened even when the blowhead is placed on the mold and the mold is replaced. The purpose is to

(Means for solving the problem) The blow head structure of the present invention is provided with extendable support legs on the blow head, and when the blow head is placed on a mold, the support legs extend to form a gap between the two. On the other hand, it is characterized in that it is provided with a spring that compresses when the blow tank is pressed and presses the blow head against the mold.

(Function) In the blowhead structure as described above, when the blowhead is attached to the underside of the blow tank and a shell mold is formed, when the blow tank is pressed against the mold, the supporting legs of the blow head are moved by the contraction of the spring. The blow head then presses against the mold and blows the shell sand into the mold.

On the other hand, when replacing the mold, the blow head is separated from the blow tank and replaced with the mold while the blow head is placed on the mold. It is in an extended state due to the biasing force of the spring. Therefore, a gap is formed between the blowhead and the mold, and the heat from the mold, which is in a state of rising temperature, is insulated by the gap, thereby blocking the transmission of heat from the mold to the blowhead. The shell sand remaining in the blow head can be handled as one while preventing the shell sand remaining in the blow head from being hardened by heat, resulting in excellent workability and easy mold replacement.

(Example) Hereinafter, an example of the present invention will be described along with the drawings. FIG. 1 is a sectional view of the main part of the shell mold in a state of being made.

A blow head 1 is detachably attached to the lower surface of a blow tank 2, and is pressed onto a mold 3 to fill and supply shell sand S supplied from the blow tank 2 into the mold 3. The mold 3 is movably divided into upper and lower parts, and has a cavity 4 for molding the shell inside.
and a sand inlet 4 communicating with this cavity 4.
An opening a is formed at a predetermined position on the upper surface of the mold 3 corresponding to the shape of the cavity 4. Also, this mold 3
is heated to a predetermined temperature by a heating means (not shown).

The blow head 1 is formed into a box shape with an open upper surface, and has a flange portion 1a for connection with a blow tank 2 on the outer periphery of the upper portion. Further, a blow port 5 for supplying shell sand S is arranged on the bottom plate 1b at a position corresponding to the sand introduction port 4a opened on the upper surface of the mold 3. This blow port 5 is connected to the bottom plate 1
A sleeve 6 is fitted into the opening formed in b, and the lower end of the sleeve 6 slightly protrudes from the lower surface of the bottom plate 1b, and a packing 7 higher than the protrusion is installed on the outer periphery of the protrusion. Further, above the opening of the blow port 5, a baffle plate 8 is disposed by a pin 8a at a predetermined distance from the upper surface of the bottom plate 1b. This baffle plate 8 prevents the shell sand S from flowing out from the blow port 5 by keeping the angle of the shell sand S with respect to the blow port 5 smaller than the angle of repose except during blowing.

Further, support legs 10 are provided at the corners of the blow head 1 and project downward through the bottom plate 1b. The support leg 10 is fitted into a bush 11 of the bottom plate 1b and is provided so as to be slidable in the vertical direction. Support leg 1 is installed between the upper end of 10a and the cover 12.
A spring 13 is compressed to bias 0 in the projecting direction, that is, downward. Further, the upper flange 10a contacts the upper surface of the bottom plate 1b to restrict the maximum amount of protrusion of the support leg 10 (see FIG. 2). Further, the lower end engaging portion 10b of the support leg 10 is formed into a conical shape, and the engaging portion 10b is inserted into the support hole 14 of the mold 3 to support the blow head 1.

On the other hand, the blow tank 2 connected to the upper surface of the blow head 1 has a flange part 2a on the lower outer periphery that connects with the flange part 1a on the upper outer periphery of the blow head 1, and a sand supply cylinder 16 is provided in the center of the upper part. Shell sand S is supplied from above, and the lower opening 16a of this sand supply cylinder 16 is opened and closed by a sand opening/closing valve 17. In addition, sand supply cylinder 1
In the upper part of the blow tank 2 at the outer circumference of 6,
A blow air pipe 18 is connected and opened, and pressurized air is supplied during blowing.

Furthermore, a plate 19 is disposed on the lower surface of the blow tank 2 to cover the lower surface, and a sand feeding port 20 is opened at a predetermined position in the plate 19. Baffle plates 21 are arranged by pins 21a at intervals of , and prevent the shell sand S from flowing out when not being fed. The blow tank 2 is supported so as to be slidable vertically by a support mechanism (not shown), and is provided so that the blow head 1 can be pressed against the mold 3 by being driven by a driving means.

Next, the operation of the above structure will be explained. 1st
The figure shows a state in which the shell mold is made by the mold 3, and as the blow tank 2 moves downward, the blow head 1
In this case, the support leg 10 is retracted against the spring 13, and the gasket 7 on the lower surface is pressed against the sand inlet 4a on the upper surface of the mold 3. By introducing pressurized air from the blow air pipe 18, the shell sand S fed into the blow head 1 from the blow tank 2 is filled into the cavity 4 of the mold 3 from the blow port 5 together with the blow air. Subsequently, the blow tank 2 moves upward, and after a predetermined period of time, the mold 3
When the shell sand S filled inside is hardened by the heat of the mold 3, the mold 3 is opened to take out the molded shell mold. Then, after closing the mold 3 again, blow the blow head 1 against the top surface of the mold 3.
is crimped and filled with shell sand S.
Modeling is performed continuously by repeating the above operations.

On the other hand, when replacing the mold 3, the connection between the blow tank 2 and the blow head 1 is released, and the blow head 1 is placed on the mold 3. At this time, as shown in FIG.
is in a protruding state due to the biasing force of the spring 13, and the blow head 1 is lifted to form a gap A between the lower surface of the blow head 1 and the upper surface of the mold 3, so that the heat of the mold 3 is directly transferred to the blow head 1. I try not to communicate it. Therefore, even if thermosetting shell sand S is contained in the blow head 1, this shell sand S will not be hardened by the heat of the mold 3, and there is no need to remove the shell sand S. The mold 3 and blow head 1 are taken out of the molding apparatus as a unit, and the next mold 3 is brought in together with the corresponding blow head 1.

(Effect of the invention) According to the invention as described above, when the blow head is separated from the blow tank and placed on the mold when replacing the mold, etc., the support legs provided on the blow head are Therefore, by forming a gap between the blow head and the mold, this gap can block the heat transfer from the mold to the blow head, which is in a heated state, and harden the thermosetting shell sand. It can be stored in the blow head without any problems, has excellent handling workability, and can improve the efficiency of mold replacement work.

Furthermore, when making a shell mold with a blow head attached to a blow tank, the supporting legs of the blow head are recessed as the blow tank moves downward, and do not affect the shell sand blowing operation, unlike conventional sand molds. It can be handled in the same way.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of essential parts showing the state of molding a shell mold using a blow head in an embodiment of the present invention;
FIG. 2 is a sectional view of the main part when replacing the mold. 1...Blow head, 2...Blow tank, 3
...Mold, S...Ciel sand, 5...Blow mouth, 7
...Putskin, 8...Baffle plate, 10...Support leg,
10a... Upper flange, 10b... Engaging portion, 1
3...Spring, 14...Support hole, A...Gap.

Claims (1)

[Scope of utility model registration request] The blow head attached to the underside of the blow tank is provided with extensible support legs, which extend when the blow head is placed on the mold to form a gap between both sides, and contract when the blow tank is pressed to prevent the blow head from collapsing. A blowhead structure for making a shell mold, characterized in that the blowhead structure is provided via a spring that presses the blowhead to the mold.