JPH0128659B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a blow molding apparatus for molding sand and the like.

For example, in a conventional molding sand blow molding device, the first
As shown in the side view, hopper 01, gate 0
2. Constant supply tank 03, introduction pipe 04, kneading machine 0
6. Consists of sandblad hose 08, etc. When performing spray molding, use gate 02 from hopper 01.
After putting a certain amount of sand into quantitative supply tank 03 through Kneading machine 0
6, and the sand mixed by the mixer 06 is sent to the booster.
Booster air blows out from 0B and blows through sandblasting hose 08.

Therefore, the quantitative supply tank 03 has a strong structure to withstand internal pressure, and its manufacture and use must be certified as a Class 2 pressure vessel designated by the regulatory authority. Since the gate 02 is kept closed when this device is in operation, sand cannot be supplied to the constant supply tank 03 during that time.
The operation is intermittent in batches, and a nozzle 04 is attached below the quantitative supply tank 03 to continuously and quantitatively supply sand.
The amount of sand supplied due to No. 4 fluctuates and is not stable.

The present invention has been proposed in view of the above circumstances, and eliminates the need for a quantitative supply tank, has a supply capacity greater than the flow capacity of the introduction pipe that introduces the powder and granules into the hopper, and utilizes gravity. The purpose of this project is to provide a spray molding device that can stably and continuously supply powder and granular materials.
An airtight metering feeder that quantitatively and continuously supplies powder and granules, an airtight kneader airtightly connected below the discharge port of the airtight metering feeder, and an airtight kneader attached to the airtight kneader. The invention is characterized by comprising a curing agent injection nozzle, a binder injection nozzle, a compressed air blowing nozzle, and a hose connected to the outlet of the airtight kneader via a booster.

An embodiment in which the present invention is applied to a molding sand blow molding apparatus will be explained with reference to the drawings. FIG. 2 is a side view thereof, FIG. 3 is an enlarged sectional view showing the rotary valve in FIG. 2, and FIG. 3 is a vertical sectional view taken along - in FIG. 3, FIGS. 5 and 6 are partially enlarged views of FIGS. 3 and 4, respectively, and FIG. 7 is a partially enlarged sectional view showing the kneading machine of FIG. 2. .

In the above figure, 1 is a hopper, 2 is a rotary valve with an airtight structure, 4 is a kneading machine airtightly connected to the rotary valve 2 via a connecting pipe 3, 5 is a kneading machine driving motor, 6 is a stand, and 7 is a kneading machine. A chute 8 for discharging the kneaded sand from the kneader 4 is attached to the bend pipe 10, and a sandblasting hose 9 is attached to the bend pipe 10 to blast the kneaded sand with compressed air.
11 is the casing of the rotary valve 2, 12 is an airtight impeller pivotally supported on the casing 11, 13 is an impeller shaft, 14 is a side plate that closes both sides of the casing 11, and 15 is a side plate. 14 is an attached bearing for pivotally supporting the impeller shaft 13; 16 is an introduction pipe with a rectangular cross section provided at the inlet of the rotary valve 2; 17 is an inlet pipe with a rectangular cross section;
18 is a sealing material attached to the edge of the impeller 12 facing the casing 11; 18 is a trough of the kneading machine 4;
19 is a shaft 20 which is pivotally supported on the trough 18 and has a large number of twisted stirring blades 22 protruding in the radial direction;
21 is a side plate that closes both ends of the trough 18, 21 is a bearing that is attached to the side plate 20 and pivotally supports both ends of the shaft 19, 23 is a side plate that closes both ends of the trough 18;
and 24 are a curing agent injection nozzle and a binder injection nozzle attached near the entrance of the trough 18, respectively, 25 is an outlet of the kneading machine 4, and 26 is a chute 4
A nozzle box 28 is provided at the top of the nozzle box 28 for blowing compressed air into the chute 4 through a plurality of nozzle holes, and is a joint fitting that connects the sandblasting hose 9 to the bend pipe 10.

In such a device, the impeller shaft 13 of the rotary valve 2 is rotated by a motor (not shown) via a chain wheel, so that the foundry sand introduced into the hopper 1 passes through the introduction pipe 16 and flows between the blades of the impeller 12. The sand that has flowed into the fan-shaped space b that is formed is discharged from the lower discharge port C of the casing 11 as the impeller 12 rotates.

At this time, since the impeller 12 rotates at a constant rotation speed, the sand is continuously supplied and discharged to the kneading machine 4. The passage capacity of the introduction pipe 16 is made smaller than the sand feeding capacity.

In addition, in this device, nozzle boxes 26 are attached to the chute 7 and the bend pipe 10 of the kneading machine 4, respectively.
And since compressed air is introduced from booster 8,
A part of the compressed air flows back to the rotary valve 2 through the kneader 4, and this backflow air pressure is generally 0.8~
Reaching 1.5Kg/ ^cm2 .

Therefore, in order to block this backflow air with the rotary valve 2, a wear-resistant elastic sealing material 17 is attached to the tip and outer circumference of the blades of the impeller 12, as shown in FIGS. By sliding in contact with the inner surface of the casing 11, leakage of backflow air is prevented.

Therefore, the supply of molding sand by the rotary valve 2 is performed stably, quantitatively and continuously, and there is no air leakage, so the pressurized tank conventionally provided for pressure feeding of molding sand can be used. No installation is required, and it also solves the problem of sand supply fluctuations caused by fluctuations in tank internal pressure and the amount of sand in the tank.

In this way, a constant amount of sand that is continuously and stably supplied from the rotary valve 2 flows into the kneading machine 4, where it is stirred and kneaded by the stirring blade 22, fed, and injected from the curing agent injection nozzle 23. The curing agent and sand are stirred and kneaded, and then further stirred and kneaded with the binder injected from the binder injection nozzle 24, and then the sand reaches the discharge port 25.

The mixed sand that has reached the discharge port 25 falls into the chute 7, is fluidized and accelerated by the compressed air injected from the nozzle box 26, and is forced into the bend pipe 10, and is further compressed by the compressed air injected by the booster 8. After being accelerated to the speed required for spray molding, it is fed under pressure to the sandblasting hose 9.

The booster 8 includes one that has a plurality of nozzle holes on the inner wall surface and injects compressed air in a spiral along the inner wall surface, one that injects compressed air in the direction of movement of the mixed sand, and one that has a ring-shaped nozzle on the inner wall surface. A type having an opening and spraying it onto the entire inner wall surface is used.

Although the mixed sand falls into the bend pipe 10 even if the nozzle box 26 attached to the chute 7 is not used, the nozzle box is used to ensure a smooth and stable flow of the mixed sand in the bend pipe 10 and the booster 8. No. 26 is effective, and in order to prevent adhesion of the mixed sand to the inner wall surface of the chute 7, one having a nozzle hole similar to that of the booster is used.

As mentioned earlier, the kneading machine 4 has a nozzle box 2.
6 and the booster 8, O-rings, dust seals, It has an airtight structure using V-ring elastic sealing material, etc.

In this example, a rotary valve was used as the airtight continuous metering feeder, but slide gate valves, double flap valves, ball valves, etc. may also be used as long as they maintain continuous sand metering and the airtightness of the metering feeder. good.

In short, according to the present invention, the airtight quantification system has a supply capacity that is greater than the flow capacity of the introduction pipe that drops and introduces the powder and granules into the hopper, and uses gravity to quantitatively and continuously supply the powder and granules. A feeder, an airtight kneader airtightly connected below the discharge port of the airtight quantitative feeder, a curing agent injection nozzle, a binder injection nozzle, and a compressed air blower attached to the airtight kneader. The present invention is industrially extremely useful because it provides a high-performance and low-cost spray molding device by providing a jetting nozzle and a hose connected to the discharge port of the airtight kneading machine via a booster. It is.

[Brief explanation of drawings]

FIG. 1 is a side view showing a conventional molding sand blow molding device, FIG. 2 is a side view showing an embodiment in which the present invention is applied to a molding sand blow molding device, and FIG. 4 is a vertical sectional view taken along - in FIG. 3, FIGS. 5 and 6 are partially enlarged views of FIGS. 3 and 4, respectively, and FIG. FIG. 2 is a partially enlarged sectional view showing the kneading machine shown in the figure. 1...Hopper, 2...Rotary valve, 3...
...Connecting pipe, 4...Kneading machine, 5...Motor, 6...
Frame, 7... Shoot, 8... Booster, 9...
Sandblasting hose, 10...Bend pipe, 11
...Casing, 12... Impeller, 13... Impeller shaft, 14... Side plate, 15... Bearing,
16...Introduction pipe, 17...Sealing material, 18...Trough, 19...Shaft, 20...Side plate, 21...Bearing, 22...Stirring blade, 23
... Hardening agent injection nozzle, 24 ... Binder injection nozzle, 25 ... Discharge port, 26 ... Nozzle box, 28 ...
...Joint fittings.

Claims (1)

[Claims] 1. A rotary valve type airtight metering feeder that has a supply capacity greater than the flow capacity of the introduction pipe that introduces the powder and granules into the hopper, and uses gravity to quantitatively and continuously supply the powder and granules. , an airtight kneader airtightly connected below the discharge port of the airtight quantitative feeder, and a curing agent injection nozzle, a binder injection nozzle, and a compressed air blowing nozzle attached to the airtight kneader. and a hose connected to the outlet of the airtight kneader.