JPS626895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the field of metallurgy, and in particular to making molds and cores by forcing free foundry sand or plastic sand into sand molds or core molds using compressed air. The present invention relates to a sand sump device. More specifically, the present invention relates to a sand sump device for a mold or core suction molding machine or a sand supply device. This device is useful in powder metallurgy for filling and pre-compressing molds with powdered materials for casting, and for producing abrasives and refractories from free-flowing materials.
The present invention can also be applied to applications other than those described above, such as increasing the charging speed and compression speed of casting sand in order to improve the manufacturing efficiency of products.

The device for blow-molding molds or cores or the device for dropping foundry sand has a sand sump device, and this sand sump device is a dish-shaped device that is excited by a hopper-type container or jig located above the device. It is used to receive molding sand sent from. This sand sump device is connected via an air valve to an air reservoir, which is supplied with compressed air from the factory's air system. This sand sump device has a nozzle provided with a vent plate, which is attached to the sand mold or core mold which is pressurized during the production of the mold or core.

The blow molding machine or the sand feeder also incorporates a device for final compression hardening of the molding sand or a device for extracting the horizontal mold from the compressed mold.

A core blow molding machine or a sand supply device for cores is also equipped with a device for hardening the core and a device for taking out the core from the core mold.

The main operating part of a mold or core blow molding machine or sand feeding device is a sand sump device.

A sand sump device built into a mold or core blow molding machine, comprising a housing and a cylindrical air-permeable shell installed concentrically within the housing, with holes in the housing and shell. It is known that molding sand is fed into the shell through a hole, which hole is closed with a gate. Furthermore, the sand sump device includes an air chamber equipped with an air valve. The air chamber is formed between the housing and the shell and is connected to an air valve, which is mounted below the weir.
A nozzle is provided in the lower part of the housing and the shell, and the nozzle is provided with a plate-like member with a ventilation hole, through which casting sand is blown into the sand mold or core mold, This sand mold or core mold is pushed towards the nozzle by a table.

When the device is started to operate, the weir is in a position to open a hole in both the housing and shell for the sand. The foundry sand is gravity fed into the permeable shell to fill the shell. The weir then closes the sand-loading hole. The table presses the sand mold or core mold against the vent plate.

In order to fill and compress the sand mold or core mold with foundry sand, an air valve sends compressed air into the air chamber of the sand sump device, and this air is passed through the air-permeable wall of the shell. Pass through and enter this Ciel. By the action of this compressed air, the sand is blown from the sand sump device through the blowing hole of the nozzle into the sand mold or neutral mold, and the blown sand is compacted in the sand mold or core mold. On the other hand,
The blown air escapes to the atmosphere through the vent. The table is then lowered, the compacted casting or core is pulled or removed from the core mold, the weir is returned to its initial position, and the cycle of operation is repeated.

A disadvantage of the sand sump device for mold or core forming machines described above is that the pressure of the compressed air blowing in is relatively high and the density of the product produced is insufficient. The reason for this is the cylindrical space of the housing, the ventilated shell that combines an air chamber with a conical nozzle, and the air valve installed on the surface of this shell that includes the vertical axis, making sure that the energy of the compressed air is not sufficiently absorbed. This is because it is not available. Because the axis of this air valve is in a plane that includes the vertical axis of the sump device and the permeable shell, and because the air intake space of this sump device is narrow, the air flow between the shell and the sump device housing is The compressed air, which must enter the space quickly and unobstructed, is blocked by impinging on the vertical walls of the ventilated shell, so that part of its energy is lost.

Moreover, since the housing and shell of the sand sump device are cylindrical, various spaces, i.e., cavities and recesses, are created in the casting sand that enters the shell.
This cavity or recess prevents the casting sand from filling properly and evenly when the next blowing is carried out. Due to these drawbacks, it is not possible to guarantee that the casting sand will stably fill the casting equipment, and it is not possible to use sand with low fluidity.

The object of the present invention is to provide a sand sump device for a blow molding machine for molds or cores, the shape of its housing and shell being designed to suitably reduce the amount of compressed air blown into it and improve the overall efficiency of the device. Our aim is to provide what we have created.

The purpose is to provide a sand sump device used in a blow molding machine or sand supply device for molds or cores, and to provide a housing containing a breathable shell, and to provide a hole in the housing and the shell, through which the casting According to the present invention, there is provided an apparatus in which sand is fed into the shell, the hole is closed with a weir, an air chamber is provided between the housing and the shell, and an air valve is connected to the air chamber. This can be realized by making the inner surface of the housing and the breathable shell spherical, and by providing a weir having a spherical concave part to compensate for the missing part of the spherical shape of the housing and make it completely spherical. .

This device reduces the amount of compressed air blown to manufacture molds or cores, improves the quality of the molds or cores, and also improves the quality of molds or cores used for this purpose. The operational reliability of the sand supply device can be improved.

The air chamber is in the shape of a torus surrounding the upper half of the shell, and the air valve is disposed on a surface including the outer diameter of the torus of the air chamber. Preferably, the air valve is spaced from the axis of the torus by a distance less than or equal to a fixed distance, the fixed distance being from the center of the circle defining the torus to the axis of rotation of this circle.

A structure with such an arrangement substantially reduces the energy consumption of the compressed air supplied into the sump device through the air valve.
Moreover, the action of the compressed air on the foundry sand is enhanced by the cumulative effect caused by the spherical inner surface of the permeable shell and housing.

In order to maximize this cumulative effect, the weir shall be provided with a ventilated section whose shape matches the recess of the weir and supplements the shape of the shell to make it perfectly spherical. is preferable. The sand then actively moves between the top of the permeable shell and the underside of the weir.

In order to improve the connection between the air chamber and the spherical recess of the weir, the shell and housing are preferably connected by means of a vent ring device on the working surface of the weir. This bond allows the upper part of the breathable shell to be held in the housing and prevents the casting sand from entering the air chamber between the shell and the housing. be able to.

Embodiments of the present invention will be described below with reference to the drawings.

The sand sump device for a mold or core blow molding machine or sand supply device disclosed in this specification has a housing 1.
(FIG. 1), and this housing 1 has a ventilated shell 2 inside. This housing 1
In the upper part of the shell 2, there is a hole 3 having a diameter D, through which sand for casting is introduced into the shell 2.

There is a nozzle 5 at the bottom of the sand sump device, and this nozzle 5 is provided with a plate-shaped member 6 provided with a vent.

Both the inner surface of the housing 1 and the inner surface of the breathable shell are spherical. This spherical shell 2 may be arranged eccentrically with respect to the spherical inner surface of the housing 1. The outer surface of the housing 1 is suitably spherical to facilitate manufacturing. Air chamber 7
is formed in an annular shape above the housing 1 and the breathable shell so as to surround the shell 2.
This annular air chamber 7 extends into a space 8 defined between the spherical surface of the housing 1 and the spherical shell 2, and an air valve 9 (see FIGS. 1 and 2).
), the air valve 9 is mounted in the air chamber 7 in a plane containing the outer diameter of the torus. The air valve 9 can be spaced a short distance from the torus such that the distance from the horizontal axis of the air valve to the center of the torus is less than the distance "a". This distance "a" is the distance between the center of a circle (radius is r) that specifies this torus and the rotation center axis OO of this circle. In fact, the air valve 9 can be placed at any arbitrary position, for example on the axis O ₁ -O ₁ (FIG. 2) of this sand sump device.
Or it can be located elsewhere within said distance "a". However, in a preferred embodiment,
This air valve 9 has a horizontal axis O ₂ - O ₂ of this air valve 9.
(Fig. 1) is arranged tangent to the axis of the torus, the axis of which is formed by a circle of radius "r" (of this radius "r"). The axis of a circle is the geometric locus defined along the path along which the center of this circle moves during torus formation).

The weir 4 (FIG. 1) has a spherical recess 10,
This spherical recess 10 has a shape that becomes a complete sphere when combined with the spherical shape of the internal space of the housing 1. This weir (FIGS. 3 and 4) is preferably provided with a ventilation section 11, the shape of which complements the shape of the shell to make it perfectly spherical. In this case, this ventilation portion 11 is the ventilation ring 1
2 to the weir 4, while the shell 2
and the housing 1 are connected in the working plane of the weir 4 by a ventilation ring 13 (FIG. 4). The housing 1 (FIGS. 1 and 3) is provided with a hopper-shaped box 14 for feeding casting sand into the shell 2.

The sand sump device according to the invention works as follows.

The weir 4 (FIG. 1) overlaps the sand inlets 3, 3' (diameter D) in the housing 1 and the shell 2. Hopper-shaped box 1 for sand for molds or cores
4 into the spherical space of the breathable shell 2 by gravity fall. Once the shell 2 is filled with this sand, the weir 4 closes the sand inlet 3 in the housing 1 and the shell 2 to form a spherical closure filled with free-flowing foundry sand or foundry sand of the plastic 1. identify what was done. Next, the sand mold or core mold (not shown) is inserted into the vent plate 6 from below.
Pressure is applied by the tapered nozzle 5 toward. When the air valve is opened, the compressed air first enters the annular air chamber 7, the overflowing air flows outside the ventilated shell 2, and this air passes through the ventilated wall of this shell and enters the annular air chamber 7. Enter the spherical internal space of the breathable shell 2. Since the center of this air flow coincides with the center of the spherical housing 1 and shell 2, a cumulative effect occurs,
This cumulative effect increases the vector sum of the airflow that directs the energy of the compressed air toward the tapered nozzle 5. This, in turn, clearly means that the foundry sand should be brought into a dense stream and be fed unhindered into the sand mold or core box with minimal consumption of compressed air.

The cumulative effect is caused by the fact that the inner surface of the housing 1 is completely spherical by being supplemented by the spherical recess 10 of the sand inlet 3 closed by the weir 4, and that the shell 2 is spherical. be.

Ventilation part 11 (Fig. 3) and ventilation rings 12, 13
By providing this, air flows from the annular air chamber 7 into the spherical shell 2 having ventilation, and also from the recess of the weir 4 through the ventilation rings 12, 13 and the ventilation portion 11. Enter into 2.

Subsequently, the ventilation portion 11, which compensates for the shape of the shell 2 to become a perfect sphere, further increases the cumulative effect of compressed air while blowing with the weir 4 in the closed position. Reduce wear and tear.

By forming the inner surfaces of the housing 1 and the shell 2 of the sand sump device into a spherical structure that takes advantage of the cumulative effect, the formation of cavities or recesses in the sand blown into the shell 2 is avoided. be able to. This makes it possible to pack the foundry sand uniformly into the sand sump and to ensure that the sand properly fills the sand mold or core mold.

The sand basin device of the present invention can use a compressed air device to uniformly pack and compress sand into a sand mold or core mold to a desired density, which has a cumulative effect due to the structure based on the present invention. It depends on what you can do.

The device can be used to make casting molds or cores using techniques that involve or do not involve hardening and drying of foundry sand, and hardening and drying of this sand can be performed using high-temperature casting. It is carried out inside or outside a sand mold or core box to suit low-temperature casting, or carbon dioxide casting.

The present invention, as constructed as described above, not only reduces compressed air consumption and provides considerable compressed air savings, but also allows the sand to be removed at lower pressures than would normally be possible under the given conditions. can be sent out. Furthermore, when molds and cores are made using the same pressure as in the past, the same level of filling as in the past can be achieved with a smaller amount of sand than in the past.

Furthermore, the sand sump device according to the present invention is capable of replacing the sand sump device of any type of conventional mold or core molding machine, and is capable of reducing the suction amount of compressed air for making molds or cores. In addition to reducing the amount of mold or core produced, the quality of the mold or core made is improved, and by further increasing the casting accuracy, metal materials are significantly saved, and the overall performance and reliability of the mold or core forming machine is improved. It also has various effects, such as being useful for health management within the factory.

[Brief explanation of the drawing]

Figure 1 is an elevational sectional view of a sand sump device for a core or mold blow molding machine, Figure 2 is a horizontal sectional view of a sand sump device for a core or mold blow molding machine, and Figure 3 is a middle view. FIG. 4 is an elevational cross-sectional view of the upper part of a sand sump device for a secondary blow molding machine or a mold blow molding machine, and FIG. 4 is an enlarged view of the section A assembly in FIG. 3. DESCRIPTION OF SYMBOLS 1... Housing, 2... Ventilation shell, 3... Holes of housing 1 and shell 2, 4... Weir, 5... Tapered nozzle, 6... Vent holding plate, 7... Air chamber, 8... Spherical shape of housing 1 Space between the inner surface and the spherical shell, 9... Air valve, 10... Spherical recess of the weir 4, 11... Ventilation part of the weir, 12... Ventilation ring of the weir,
13... A ventilation ring that connects the housing 1 and the shell 2, 14... A hopper-shaped box.

Claims (1)

[Claims] 1. A sand sump device used in a mold or core molding machine, comprising a housing 1 containing an air permeable shell 2, the housing 1 and the shell 2 having an opening 3. The opening 3 is used for charging sand for casting into the shell 2 and is closed by a weir 4. An air chamber 7 is formed between the housing 1 and the shell 2, and this air In a sand sump device in which an air valve 9 is connected to the chamber 7,
The inner surface of the housing 1 and the breathable shell 2 are spherical, and a space 8 is formed between the housing 1 and the shell 2, and the weir 4 is connected to the housing 1.
A sand basin device characterized by having a concave portion 10 having a shape that complements the spherical shape of the spherical shape so that it becomes a perfect spherical shape. 2. The air chamber 7 has a toroidal shape surrounding the upper half of the shell 2, and the air valve 9 is attached to the air chamber 7, and the attachment position is such that the air valve 9 is in the annular shape. The air valve 9 is mounted on a plane that includes the outer diameter of the body, and is mounted so that it is separated from the air chamber 7 within a distance a from the center of a circle that specifies the torus to the rotation axis of this circle. A sand sump device according to claim 1, characterized in that: 3. The weir 4 has a ventilation portion 11, and the ventilation portion 11 has a shape that matches the recess 10 of the weir and complements the shape of the shell to make it a perfect sphere. A sand sump device according to claim 1 or 2. 4. The shell 2 and the housing 1 are connected within the operating plane of the weir 4 by a device including a ventilation ring 13, according to any one of claims 1 to 3. Sand storage device.