JPS624373Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a blow head in a so-called blow molding machine such as a shell machine or a cold box molding machine.

As shown in FIGS. 1 and 2, the blowhead currently in common use consists of an upper cylinder 1 and a lower box 2, with side walls of the cylinder 1 having
An opening 6 communicating with a compressed air tank 5 via a conduit 3 and an intake/exhaust switching valve 4 is bored, and
A slit tube 7 having a large number of vertical slits is fitted inside the cylindrical body 1 with a slight gap maintained between it and the inner wall of the cylindrical body 1.

Note that the contact areas between the upper and lower ends of the slit tube 7 and the cylindrical body 1 are covered with sealing materials 12, 12a, 13,
13a makes it airtight. The upper end of the cylindrical body 1 is connected to the supply port 9 of the molding sand supply hopper 8, and the bottom surface of the box body 2 is provided with a plurality of blow nozzles 10 that match the blowing ports of the mold (not shown). It is provided. A mold is brought into close contact with the lower surface of such a blow head, and a predetermined amount of molding sand 11 is supplied from the hopper 8 into the blow head,
When compressed air is blown into the opening 6 in the side wall of the cylindrical body 1 after the supply port 9 is sealed, the compressed air flows downward through the gap between the inner wall of the cylindrical body 1 and the slit tube 7, and also flows through the slit. The molding sand 11 inside is pressed through the slit of the cylinder 7. As a result, the molding sand 11 passes through the blow nozzle 10 and is filled into the cavity portion of the mold (not shown).

By the way, a part of the compressed air blown into the blowhead as described above flows into the mold together with the molding sand 11 and is released into the atmosphere from the exhaust port provided in the mold, but the rest is Most of it remains in the blowhead. When the mold is separated from the blow head, the residual compressed air causes the molding sand 11 remaining in the blow head to be ejected from the blow nozzle 10, so it must be discharged from the blow head before separating the mold. Must be. Conventionally,
The residual compressed air was discharged into the atmosphere through the conduit 3 and the intake/exhaust switching valve 4 from the same opening 6 in the side wall of the blowhead as when blowing.

However, in this method, the molding sand 11 in the blow head is also attracted to the inner wall surface of the slit tube 7 along with the exhaust air, causing clogging of the slit.
Subsequent blowing performance of compressed air will deteriorate, causing defective molds to be produced. For this reason, the operator had to clean the slit tube 7 almost every day.

The present invention was developed in view of the above-mentioned circumstances, and it is an object of the present invention to provide a blowhead that can discharge residual compressed air within the blowhead into the atmosphere without clogging the slit tube.

Hereinafter, the present invention will be explained in detail based on an embodiment. Fig. 3 shows a cross section of a main part of a blow head according to the present invention, and the blow head includes a box body 22 equipped with a blow nozzle 20 on the lower surface, and a box body 22 provided with a blow nozzle 20 on the lower surface. It consists of a stepped cylindrical body 21 that communicates with the central part of the upper surface of the cylinder. The stepped cylindrical body 21 further comprises an upper narrow diameter portion and a lower thick diameter portion, and an exhaust port 23 is provided in the side wall of the narrow diameter portion, and the exhaust port 23 is connected to the exhaust port 23 through a conduit 24. It communicates with a cut valve 25 exclusively for exhaust (Fig. 4). Note that the exhaust port 23 and the conduit 2
A filter 26 is loaded in the connection portion with 4. The configuration of the large diameter portion of the stepped cylindrical body 21 is similar to that of the conventional device, in which a slit tube 27 is provided inside, and an air inlet 28 connected to a conduit 33 is bored in the side wall. However, the other end of the conduit 33 is connected to a cut valve 29 exclusively for blowing.
The exhaust port 3 is located on the top surface of the box body 22 at the bottom of the blowhead.
0,30a are provided, and the exhaust ports 30,3
0a communicates with the exhaust exclusive cut valve 25 via conduits 31 and 31a. The exhaust port 3
Filters 32, 32a are also installed at the connection portions between 0, 30a and conduits 31, 31a. Further, the valve 25 is connected to an exhaust pipe 35 having an exhaust throttle valve 34 attached therebetween. In the blowhead configured as described above, after adjusting the exhaust throttle valve 34 appropriately in advance and bringing the upper surface of the mold (not shown) into close contact with the lower surface of the blowhead, the blow-only cut valve 29 is opened to open the cut valve 29 of the mold. Fill the cavity with molding sand using the same method as before. After a predetermined period of time has elapsed, when the cut valve 29 for blowing is closed and the cut valve 25 for exhaust is opened, the compressed air remaining in the blow head is discharged from the exhaust port 2.
3, 30, 30a to conduits 24, 31, 31a,
It is released into the atmosphere through the valve 25 and exhaust pipe 35. During exhaust, the foundry sand remaining in the blow head is captured by the filters 26, 32, 32a attached to the exhaust ports 23, 30, 30a, and does not escape to the outside.

As is clear from the above description, the present invention is to provide an exhaust port in the blowhead separately from the blowing port, and to discharge residual compressed air in the blowhead through the exhaust port. Therefore, during evacuation, the molding sand in the blowhead will not be attracted to the inner wall surface of the slit tube and clog the slit, so that subsequent blowing of compressed air will not be hindered. In other words, the blowing performance is stable and good molding is guaranteed. Also, cleaning of the slit tube becomes unnecessary.

The present invention, which has the above-mentioned excellent features, will greatly contribute to the development of the industry.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of a conventional blowhead, FIG. 2 is a piping system diagram thereof, FIG. 3 is a sectional view of the main part of the blowhead according to the present invention, and FIG. 4 is a diagram of the piping system. 21...Stepped cylindrical body, 22...Box body, 23,3
0,30a...Exhaust port, 28...Suction port, 25...
...Cut valve only for exhaust, 29...Cut valve only for blowing, 26, 32, 32a...Filter, 2
7...Slit tube.

Claims (1)

[Scope of utility model registration request] A large diameter part of a stepped cylindrical body 21 consisting of a large diameter part and a small diameter part is connected to the center part of the upper surface of a box body 22 equipped with a blow nozzle 20 on the lower surface, and the stepped cylindrical body 21
A slit tube 27 is fitted into the large diameter portion of the cylindrical body 21, and an inlet 28 is provided on the side wall of the large diameter portion of the cylindrical body 21 to communicate with the compressed air tank 5 via a conduit 33 and a cut valve 29 exclusively for blowing. 21 and the upper surface of the box body 22 are provided with conduits 24, 3.
1, 31a and exhaust ports 23, 30, 30a communicating with the atmosphere through an exhaust-only cut valve 25.