JPS5823180B2 - Sand blowing device in automatic molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sand blowing device for an automatic molding machine, and more particularly to a sand blowing device for an automatic molding machine using compressed air.

Conventional mold forming methods include (1) manually putting raw sand into the flask with a shovel or the like and pounding it to harden it; (2) letting the raw sand flow into the flask via a conveyor or opening and closing the mouth of a hopper. (3) Filling the mold into a flask and compressing and solidifying it using a jolt squeeze molding machine.
A method of rotating an impeller such as a slinger to scatter the green sand, forcing it into the flask, and pounding it to harden it. (4) A method of blowing sand into the flask with compressed air and squeezing it to harden it.・There is a squeeze type device.

In the sand blowing device of the automatic molding machine described in (4) above, a mold of the desired shape is placed, and the green sand is moistened appropriately with water into the upper and lower casting flasks, which are integrated through matte plates. The raw sand is blown into the mold using compressed air, and the sand in the flask is shaken up and down to harden the raw sand and form the mold.

However, even if wet sand is pressed in at a fairly high pressure, the force of gravity will cause the sand to reach the back side of the mold's sand inlet in the casting flask and into every corner of the complex-shaped mold. It is not filled and becomes a bottleneck in the molding work.

On the other hand, if the pressure of compressed air is increased in order to prevent a gap from forming between the mold and the sand in the flask, there is a drawback that the flask and mold will wear out.

Therefore, in molds with complex shapes, corners, or holes on the opposite side of the blowing port, a uniform sand mold with sufficient hardness cannot be obtained, resulting in defects such as leakage of hot water, cracks, or dimensional differences in the product.

For this reason, this type of molding machine is limited to applications where the mold is relatively thin and has a simple shape, which is a major drawback.

In order to eliminate these drawbacks, we can install new vent holes in areas where it is difficult for sand to enter to allow air to escape and allow sand to enter easily, or raise the casting flask to compensate by squeezing, or use a combination of these methods. method is implemented.

However, even these methods are not sufficient and have the biggest drawback of requiring extra sand.

The following are thought to be the causes of these shortcomings.

In other words, the sand blown into the flask from the blowing port flows in with the flow of air, and at this time, the sand particles are unaffected by the air flow and are filled into the flask, but they are heavier than air. Therefore, the force to move straight due to inertia becomes strong, and the surface opposite to the blowing port is filled with debris that has hit the side of the flask or the piled up sand and bounced back, and sand passes over the holes etc. As a result, even with assistance with vent holes, etc., it is difficult for sand to enter and the hardness is insufficient.

This is thought to be due to the fact that the filling speed of sand is extremely fast.

This invention was made by focusing on the above-mentioned problems with sand blowing devices in automatic molding machines that use compressed air. A compressed air injection nozzle is installed at the top, bottom, or side of the casting flask, and when blowing, compressed air with controlled pressure and time is blown into the flask to change the flow of incoming sand. Let enough sand flow into the
To provide a sand blowing device which can easily and quickly create a sand mold having no defects and having uniform hardness.

A detailed description of the invention will be given with reference to the drawings.

In FIG. 1.2, a mold 10 of a desired shape is placed in the upper and lower flasks 12 and 13 via a match plate 11, and a blowing port 14 is formed in one side of the upper flask 12. Sand and compressed air supply pipes 15 are connected to the upper flask, and vent holes 1 are formed in the through holes 16 drilled in the side or top plate of the upper flask.
6, and tightly fit the nozzle 18 into the through hole 17 that is bored on the back side of the sand blowing port 14 of the mold 10 or in a hole or a place where sand is difficult to flow in, and connect the compressed air supply pipe to the nozzle. Connect 19.

Sand blowing port 20 bored on one side of the lower flask 13
A compressed air and sand supply pipe 21 is connected to the mold 10, and a vent hole 23 is fitted into the through hole 22 formed in the side or bottom plate of the lower flask, and the sand injection port 20 of the mold 10 is connected to the vent hole 23. A nozzle 25 is tightly fitted into a through hole 24 made on the back side, a corner, a hole, or a place where sand cannot easily enter, and a compressed air supply pipe 26 is connected to the nozzle.

Furthermore, squeeze cylinders 27 and 27 are compressed at the top and bottom of the upper and lower flasks 12 and 13, respectively, so that they can be suppressed in the vertical direction.

In the above-mentioned embodiment, in addition to sand and compressed air blowing ports 14 and 20 in the upper and lower flasks 12 and 13, compressed air injection nozzles 18 are provided at the top and bottom or on the sides of these flasks.
, 25 are provided respectively, and these nozzles are connected to the blowing ports 14, 2.
Directly direct the sand through the compressed air from these blowing ports to the back side, corners, holes, corners, etc. of the mold with the compressed air from the nozzle 18°25. By directing the flow path of sand and compressed air to areas where it is difficult for sand to flow in, the metal bodies in the upper and lower flasks are filled with sand of uniform hardness, making it possible to instantaneously create a perfect sand mold.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of a sand blowing port according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of another embodiment thereof. 10...Mold, 11...Match plate, 12...Upper flask, 13...Lower flask, 14, 20...・Sand blowing port, 15
, 21... Sand and compressed air supply pipe, 16...
...Vent hole, 17,24...Through hole, 1
8, 25... Nozzle, 19, 26...
Compressed air supply pipe.

Claims (1)

[Claims] 1. A mold of the desired shape is placed inside through a match plate, and compressed almost in front of the hole or corner where sand is difficult to enter, on the back side of the core mold blowing port of the upper F casting flask. An automatic manufacturing machine that is equipped with a low pressure injection nozzle and changes the flow of sand and compressed air that flow in from the air inlet via compressed air so that sand flows into these locations with uniform hardness. Sand blowing equipment.