JPS5849166Y2 - Core molding equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a core molding device using a blow type vertically split mold.

Core molding for round items and bilaterally symmetrical items is often done using a blow-in shell mold. Conventionally, as shown in Figure 2, vertically split molds a and b1 and a mandrel C are assembled and fixed, and then Blow play) d is connected to blow shell sand into the molding cavity in the mold, and the air in this cavity is transferred to the pendo plug e.
The shell sand is discharged to the outside through the air vent f and the opening g of the mount, filling the molding space with shell sand, and is sintered and molded by heating the mold.

Thereafter, the molds a and b are released leaving the core i on the molding side, and the core i is ejected from the mold by an ejector j and taken out.

When the core has a symmetrical shape, the core i may remain on the side of the mold a, resulting in poor work efficiency for removing the core.

The present invention was developed in view of these drawbacks, and is designed to cause air to flow backward through the air vent to ensure that the core remains on the side of the mold where the ejector is attached when the mold is released. .

That is, a chamber that communicates with the air vent is attached to the outside of the mold, and a valve provided at the sand discharge port below the chamber is opened and closed by moving the blow plate back and forth, and when shell sand is being blown in, the shell powder leaking from the vent plug is removed from the sand discharge port. To provide a core molding device in which compressed air is discharged to the outside together with exhaust air from the mold, and when a mold is released, a sand discharge port is closed, compressed air is introduced into a chamber, and the core is always left on the ejector side by causing the inside of the air vent to flow backwards. The purpose is to

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, 1 is a core molding apparatus for molding a core 2 such as a water jacket for a cylinder block.

3 and 4 are vertically divided molds, each of which has molding surfaces 5 and 6 having the same external shape as the core 2 and facing each other, and has a cavity surrounded by the molding surfaces. A mandrel 8 is inserted into the center of the space 7 so as to leave a gap t comparable to the wall thickness of the core 2.

One of the molds 3 is provided with an air vent 10.10 which passes through the mold body 9 of the molding surface 5 of the mold and opens to the outside.
A vent plug 11.11 with raised pores is fitted onto the molding surface 5 side of the air vent.

A chamber 12 communicating with air vents 10, 10 is connected to the outside of the mold 3, and a truncated conical sand discharge port 13 is bored in the lower part of the chamber, and a truncated conical valve is connected to the sand discharge port. 14 is provided so as to be openable and closable.

A valve shaft 15 is connected to the valve, and the valve shaft passes through the chamber 12 and is connected to a chamber body 16 that contacts the mold 3.
A washer 18 extending upward and fixed at its upper end with a split pin 17 is provided, a spring 19 is interposed between the washer and the chamber body 16, and the spring 19 springs the valve 14. It is formed to close when biased and open when a blow plate 22 that contacts the upper end surface 20 of the valve shaft via a protrusion 21 descends.

Further, in the other mold 4, an ejector 24° 24, which has an end face of a collar portion 23 flush with the molding surface 6 of the mold, is attached to the mold body 2.
5 to the outer force, and has a split pin 2 at its outer end.
A washer 27 held at 6 is attached, a spring 28 is interposed between the washer and the mold 4, and the ejector 24.2
4 is biased outwardly by the spring 28.

29 is a compressed air port provided above the chamber 12;
0 and 31 are orifices and nozzles of the flow plate 22, 32 is a shell sand inlet of the mold, 33, 34 is a mounting base, and 35 is a backing.

It is also possible to provide a sand reservoir (not shown) below the sand discharge port 13 and connect the two with a communicating pipe, so that the sand can be reused.

In the above structure, when blowing shell sand, if the blow plate 22 from the standby position (the chain line position in FIG. 1) is lowered to the solid line position and the nozzle 31 is connected to the shell sand inlet 32, the valve shaft 15 is By the protrusion 21 of
The spring 190 moves downward against the elastic force, and the valve 14 is fully opened.

The shell sand whose flow rate is adjusted by the orifice part 30 of the blow plate flows into the cavity 7 through the nozzle 31 and the shell sand inlet 32, and the air in the cavity and the vent plug 11 leak out with this air. The sand is also completely discharged to the outside through the air vent 11 and the chamber 12 through the sand discharge port 13.

At the time of demolding, the spring 19 expands as the blow plate 22 rises (C) and retreats) to close the valve 14, and then
Compressed air is introduced from the compressed air port 29 into the chamber 12,
Air vent No. 10 is caused to flow backwards, and a gap is created between the core 2 and one mold 3. When the mating surfaces of both molds are opened, the core 2 comes off from one mold and falls into the other mold. After that, the core 2 is pushed out from the other mold 4 by the ejector 24, 24 and taken out.

With the above configuration, the present invention allows the compressed air to flow back through the air vent, so that the core can be reliably left in the required mold.

Furthermore, in this invention, the chamber is opened and closed in conjunction with the vertical movement of the blow plate, so the chamber is constantly cleaned and obstructions to the flow of compressed air are eliminated, making the molding work stable and increasing production efficiency. In addition to this, it has the excellent effect of making effective use of shell sand and improving the working environment.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, and FIG. 1 is a central vertical cross-sectional view of a core molding device, and FIG. 2 is a central vertical cross-sectional view illustrating a conventional example of the core molding device. 2... Core, 3... One mold, 4...
...The other mold, 10...Air vent,
11...Vent plug, 12...Chamber, 13...Sand discharge port, 14...Valve, 15...Valve shaft, 22 ...Blow plate, 24...Ejector, 29...
...Compressed air port.

Claims (1)

[Scope of utility model registration request] An air vent provided on the molding surface of the single-force mold of the vertically divided mold, a chamber provided on the external force of the mold so as to communicate with the air vent, and a sand discharge port provided below the chamber, It consists of a valve that is biased by a spring to close, and a valve shaft that is connected to the valve and extends above the mold so that the valve is opened by a blow plate, and is brought into the chamber from the air vent during sand blowing. sand,
The core is discharged from the sand discharge port, and when the core is released from the mold, compressed air is introduced into the chamber to cause a reverse flow inside the air vent, and the core is removed from the mold and left in the mold of external force. Core molding equipment.