JPS5832833Y2 - Diaphragm mold making equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a diaphragm type mold making device that can be applied to making flan molds, green molds, CO2 molds, and various self-hardening molds.

FIGS. 1 and 2 are longitudinal sectional side views of a conventional diaphragm type mold making device, showing the housing and part of the molding process.

FIG. 3 is a longitudinal cross-sectional side view of the formed mold.

The conventional apparatus will be described with reference to FIGS. 1 to 3. In FIG. 1, 01 is foundry sand that is shaped and hardened to become a mold.

02 is integrated with molding sand 01 to form the mold (0 in Fig. 3).
30), and has a rectangular horizontal cross section.

03 is a wooden model to be molded, 04 is a molding table for a metal structure, and 05a and 05b are columns fixed on the molding table 04, and screw parts 05a' and 05b' are provided at the upper ends, respectively. be.

Nuts 06a and 06b are fitted into the threaded portions 05a' and 05b', and 07 is a diaphragm, which is usually made of highly elastic natural rubber.

08 is a pressurized steel container, which is approximately square in plan view.

The flange portion (lower portion) of the pressurized container 08 is provided with a holding frame 09 and a plurality of stud bolts 010a that approximately correspond to the entire circumference of the flange portion.

010b, the diaphragm 07 is airtightly attached.

Furthermore, an air connecting pipe 0 is provided on a part of the side surface of the pressurized container 08.
11 are provided.

Further, a connecting portion 08a is provided at the center of the upper surface of the pressurized container 08, and is connected to a support arm 012 by a pin 013.

Both ends of the support arm 0120 are connected to the screw portions 053' and 0.
5b' and tightened by nuts 06a and 06b.

Note that the air connection pipe 011 has an air source (not shown).
(e.g. compressor) and pneumatic piping systems (e.g. valves, leak valves, rubber hose connectors, etc.).

The above-mentioned conventional device is manufactured in the following process order (7) to (on-site).

(7) First, the oak t (16a and 06b and pressure parts 07 to 0
13 is removed by a crane (not shown), the model 03 and the flask 02 are placed on the molding table 04, and the molding sand 01 is poured in, making sure that the upper surface of the molding sand 01 is not much higher than the upper end of the flask 02. Adjust the amount of foundry sand 01.

(a) The pressurizing parts 07 to 013 are placed on the casting flask 02 by a crane (not shown), and both ends of the support arm 0120 are tightened with screws 06 a t 06 b, respectively.

This state is shown in FIG. (Next, by means of an air source and an air piping system (not shown), through the air connecting pipe 011,
When air is introduced into the pressurized container 08, the diaphragm 07 swells as the pressure increases, and as a result, the molding sand 01
FIG. 2 shows this state in which the data will be compressed.

(→ In the case of furan sand, after the specified time has passed, pressurized container 0
By removing the air in the mold 8 and removing the pressurizing part OT~013 and the imitation 03, a mold 030 as shown in FIG. 3 is completed.

When molding is performed using conventional equipment as shown in FIGS. 1 and 2, the molding sand 01 above the model 03 has a high degree of filling, but
The molding sand surrounding the model 03 has a major drawback in that the degree of filling is low because the air pressure is not sufficiently transmitted.

The reason for this is that when the molding sand 01 is pressed evenly from the top, the filling degree of the molding sand 01 gradually increases from the top, but the molding sand 01 above the model 03 is higher than the molding sand 01 in the peripheral area. Since the air pressure is low, once it contracts to a certain extent, it cannot contract any further, so most of the pressure due to air pressure is transmitted to the upper surface of the model 03.

On the other hand, when the molding sand 01 in contact with the flask 02 is pushed down, a large amount of friction is generated between the molding sand 01 and the flask 02, which prevents the molding sand 01 from descending due to compression.

Due to this condition, the molding sand 01 in the upper part of the peripheral area
When being pushed down, the molding sand 01 above the model 03, which has become hard due to compression, and the friction between the inner surface of the flask 02 prevents its descent.

As a result, the pressure applied around the flask 02 and the model 0
3, the pressure transmitted downward is reduced.

Therefore, the degree of filling of the molding sand 01 around the model 03 becomes low.

These phenomena are caused by the fact that the fluidity of the foundry sand 01 is very poor, unlike that of a liquid, and is generally well known.

If the molding sand 01 is hardened with a poor filling degree, this can be easily detected because the resisting pressure of the mold in that area decreases.

Therefore, if a mold with a low filling degree of foundry sand 01 is used for casting, the mold 030 may be damaged during casting, or so-called penetrating sintering may occur, where molten metal drips between the sand grains. This results in disadvantages in that the yield in manufacturing castings decreases and that surface finishing work on the castings requires a great deal of time and effort.

The present invention was proposed with the aim of eliminating the drawbacks of the above-mentioned conventional devices, and by supplying pressurized air into a pressurized container body equipped with a diaphragm installed fluid-tightly on the lower surface, the diaphragm In a diaphragm type mold making device configured to compress molding sand in a flask to form a mold, the molding sand is compressed by fluid pressure at a suitable location in the pressurized container body, and the molding sand is compressed through the diaphragm. At least one molding sand tamping means for compacting the molding sand is disposed, and a vibration means for applying transverse vibration to the molding sand in the flask from the outside direction is disposed at an appropriate position of the flask. This relates to a diaphragm type mold making device.

The present invention will be specifically explained below with reference to embodiments shown in FIGS. 4 to 8.

Components numbered 1 to 7, 9a to 10b in FIGS.
Since the name, structure and function are the same as those of the member b, the explanation thereof will be omitted.

8 is the unique pressurized container main body of the present invention, and 7 at the bottom thereof
As in the case of the conventional device, there is a holding frame 9° 9a in the runno section.
The diaphragm 7 is airtightly attached by a plurality of stud bolts lOa and 10b.

Further, as shown in the figure, an air connection pipe 11 is provided on a part of the side surface.

Furthermore, a means for tamping the foundry sand 1 through the diaphragm 7, such as a plunger mechanism 21a, is provided at a suitable location of the pressurized container main body 8, for example, on the upper surface plate as shown in the figure.
25b are arranged at two locations in this example.

The number and position of the plunger mechanisms 21a to 25b are determined according to the shape of the model 3, and if the molding sand 1 is not likely to clog the center of the model 3, the plunger mechanisms 21a to 25b are arranged in the center of the flask 2. The plunger mechanisms 21a to 25b
may be provided.

Here, 21a and 21b are cylinders whose lower parts are fixed at two places on the pressurized container main body 8, and upper air connectors 23a and 23b are arranged at the upper part of the side wall, and lower air connectors 24a and 24b are arranged at the lower part. It is set up.

A piston 25at is provided in the cylinders 21a and 21b.
25b and the upper parts of plungers 22a and 22b are inserted.

A connecting plate 21 c is provided at the upper end of the cylinders 21 a and 21 b.
, 21 d, and by pins 13a and 13b,
Each is connected to an upper support arm 12.

Further, as in the case of the conventional device, the support arm 12 has both ends fitted into the threaded portions 5a' and 5b' of the supports 5a and sb.
oak) 6 a t 6 b.

Alternatively, such a plunger mechanism can be moved vertically or vibrated using hydraulic pressure or electric power.

Further, the tips of the plungers 22a and 22b can be appropriately set to be long in the horizontal direction (horizontal cross section is rectangular) or arcuate, depending on the shape of the model 3.

Further, 31 is an electric vibrator, and its details will be explained with reference to FIGS. 7 and 8. This electric vibrator 31 can be replaced with an air vibrator or a small internal combustion engine vibrator. You can also do it.

7 and 8, 31a and 31b are electric wires for supplying power, 32at32b are support shafts installed on both sides of the electric vibrator, and 33a and 33b are the electric vibrator 3.
Connectors 10 are provided on both sides to move the electric vibrator 31, and there are holes at both ends, and the hole at the lower end is an elongated hole.

34a and 34b are fixed to the flask 2, and the supporting shaft 32
a, 32b are guide plates for bringing the electric vibrator 31 into contact with the flask 2; 35a, 35b are the fixing fittings 36a;
, 36b.

One embodiment of the device of the present invention is configured as described above,
To explain the tightening action according to FIGS. 4 to 8, the nuts 6a and 6b are removed and the pressurizing parts 7 to 13b and 21a to 25b are
Move the mold to another location, place the model 3 and the flask 2 on the molding table 4, and pour in the molding sand 1, making sure that the top surface of the molding sand 1 is not higher than the top of the flask 2. Adjust the amount of foundry sand 1.

Next, the pressurizing parts 7 to T3bt21a to 25b are placed on the flask 2 by a crane (not shown), and both ends of the support arm 12 are respectively tightened with nuts 6a.

Tighten and secure with 6b.

This state is shown in FIG.

At this point, the electric vibrator 31 is moved to bring it into contact with the outer surface of the flask 2, as shown in FIG.

Next, when electric power is supplied from a power source (not shown) connected to the electric wires 31a and 31b shown in FIG. That will happen.

Next, an air source (e.g. compressor) and air piping system (e.g. valve leak valve, rubber hose) (not shown)
connector), first connect the upper air connector 23a
, 23b respectively.

If air is introduced into the upper part of the cylinders 21a and 21b, the piston 25a will move as the air pressure increases.

25b and plungers 22a, 22b are depressed.

As a result, the lower ends of the plungers 22a and 22b are indirectly connected to the plungers 22a and 22b from the upper surface of the diaphragm 7.
An operation is performed to compact the foundry sand 1 below 22b.

This state is shown in FIG.

This tamping operation by vertically moving the plungers 22a and 22b does not have to be performed only once (although it can be performed several times to further increase the effect).

After this tamping operation is completed, the air above the cylinders 21a, 21b is removed by operating an air piping system (not shown), air is introduced into the lower part of the cylinders 21a, 2Ib through the lower air connectors 24a, 24b, and the piston 2
5a, 25b and plungers 22a, 22b are raised.

Therefore, if air is introduced into the space formed by the pressurized container 8 and the diaphragm 7 through the air connection pipe 11 using an air source and an air piping system (not shown), the diaphragm 7 will swell as the pressure increases. .

The foundry sand 1 is compressed and filled, and the degree of filling is increased.

This state is shown in FIG.

At this point, the vibration of the electric vibrator 31 is stopped.

In the case of furan sand, after the time required for hardening has elapsed, the air in the pressurized container 8 is removed and the pressurized parts 7 to 13b, 21a to 25b are used.
And if the model 3 is removed, a cylindrical shape 030 as shown in FIG.
It is possible to obtain a mold having a shape almost similar to that of the above.

Since the device of the present invention has the above-described configuration and operation, according to the present invention, the molding sand 1 around the model 3, where the degree of filling is most likely to deteriorate, is subjected to lateral vibration while Plungers 22a, 22
The tamping operation in step b first tamps the mold, and then the diaphragm 7 pressurizes the entire mold, so the degree of filling of the molding sand 1 around the mold 3 is greatly improved compared to the conventional device. I will do it.

This is because when the molding sand 1 below the plungers 22a and 22b is compacted, the molding sand 1 above the model 3 has not yet been compressed, so there is less friction between the molding sand 1 and the molding flask. 3, the molding sand 1 below the plungers 22a, 22b is compressed due to the relatively small friction with the inner surface of the plungers 22a, 22b.

This is because it tends to fall downward.

Further, in this case, the transverse vibration by the electric vibrator 31 serves to reduce friction between the foundry sand 1.

As a result, the degree of filling of the molding sand 1 surrounding the model 3 is increased, which has the practical effect of improving mold strength in that area.

Therefore, when a mold made by this apparatus is used for casting, the mold may be damaged or the molten metal may penetrate between the sand grains.

Since so-called penetrating sintering does not occur, the yield in manufacturing castings is improved, and the time and labor required for surface finishing of castings can be reduced.

This greatly contributes to reducing the cost of castings and is therefore very useful industrially.

Molding tests and casting tests were conducted using the device of the present invention. First, the test conditions are as follows.

In other words, casting flask dimensions: 600 mm width x 600 mm width x 325 mm
Height, model dimensions: 300 x 300 x 2001
711 height, foundry sand; No. 5, furan sand mixed with furan resin (0.75 wt% based on the sand) and catalyst (57 wt% paratoluene sulfonic acid based on the resin).

Air pressure introduced into the cylinders 21a, 21b and the pressurized container 8 with an inner diameter of 801i1ri; 50kgAm2; the electric vibrator 31 outputs; 100W (voltage; 220V current;
0.6A) A vibrator with a vibration motor set having a frequency of 3450 c/m was disposed on each side of the plungers 22a and 22b.

Further, the tamping operation using the plungers 22a and 22b was performed three times.

FIG. 9 is a plan view of the flask 2 and model 3 used in this experiment.

A and A' are plungers 22a. This is the direct F position of 22b.

Under the above conditions, a molding test was carried out using the conventional device and the device of the present invention, and a molding test was carried out to form A shown in FIG.

The anti-pressure test piece (
A specimen (φ50 mm x 50 mm height) was sampled and subjected to an anti-pressure test.

As a result, as shown in (■) and H in the following table, the anti-pressure of the castings molded by the device of the present invention was improved by about 30% compared to those molded by the conventional device.

It was confirmed in other experiments that the smaller the distance between the model 3 and the mold 2, the greater the effect of the device of the present invention.

In addition, a casting test was conducted using molds produced under similar conditions (a mold produced using a conventional device and a mold produced using the device of the present invention).

After molding (and hardening of the furan sand), the inner surface of the cylinder is coated with coating materials (base material: zircon flour, binder: phenolic resin, solvent: methyl,
Alcohol) was applied and dried.

In addition, molten ordinary steel at 1560° C. was cast in combination with a separately manufactured upper mold.

As a result, in the mold made with the conventional device, penetrative burning occurred partially, but in the mold made with the device of the present invention, there was no penetrative burning, and a sound casting could be made.

[Brief explanation of drawings]

FIGS. 1 and 2 are vertical side views of a conventional diaphragm type mold making device, showing a part of the molding process. FIG. 3 is a longitudinal sectional side view of a mold made using a conventional device. FIGS. 4, 5, 1 and 6 are longitudinal sectional side views schematically illustrating an embodiment of the present invention, and are diagrams briefly illustrating the molding process. 7 and 8 are schematic explanatory diagrams of an example of an electric vibrator that is a part of the device of the present invention, FIG. 7 is a view taken along the line ■-■ in FIG. 5, and FIG. Fig. 9 is a plan view of the flask and model used in the experiment of the device of the present invention. In FIGS. 4 to 8, 1.. Even sand, 2.. Casting flask, 3.. Model, 7.. Diaphragm, 8.. Pressurized container body, 21a, 21b to 25a? : 2sb - Casting tamping means (plunger mechanism) operated by fluid pressure, 31... Transverse vibration means for the flask 2 (electric vibrator).

Claims (1)

[Scope of utility model registration request] The diaphragm is configured to compress the molding sand in the flask and form a mold by supplying compressive air into a separate container body having a diaphragm installed in a fluid-tight manner on the lower surface thereof. In the diaphragm type mold making device, at least one molding sand tamping means is disposed at a suitable position in the diaphragm container body and is operated by fluid pressure to compact the foundry sand through the diaphragm, and at least one molding sand tamping means is disposed at a suitable position in the casting flask. A diaphragm type mold making device characterized in that a vibration means for applying lateral vibration to the molding sand in the flask from the outside thereof is disposed.