JP3468625B2 - Sand core drying apparatus and casting method using the same. - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sand core drying device and a sand core drying device.
And a casting method using the same .

[0002]

2. Description of the Related Art In the gravity casting method, the gas generated from the shell core or the mold release agent disturbs the molten metal during pouring or immediately after pouring, and forms oxides inside the casting or on the surface of the casting surface. Or, blowholes may be generated.
As a countermeasure, the casting method is optimized so that the molten metal flow in the casting does not become turbulent.

Further, it is known that the generation of gas is caused by the evaporation of water contained between the particles of the sand core. Therefore, it is also known that the generation of blowholes can be suppressed by heating and drying the core in advance.

As a method and apparatus for drying the core, a method of blowing dry air to the core, or a method of storing the core in a drying box and sending hot air into the drying box to raise the ambient temperature, There is a device for drying.

[0005]

However, in the method of blowing dry air to the core, as shown in FIG. 6, the weight ratio of dry water is low, and for example, 75% of water remains in the core.

Further, in the method of storing the cores in the drying box and drying the cores, a large amount of cores can be dried at a time, but after the cores are taken out from the drying box, the cores are put in a waiting state at the pouring site. However, there is a drawback that the core absorbs moisture in the air.

The present invention has been made in consideration of the above circumstances, and has a large amount of water vaporized from the core, a short drying time of the core, and a standby state at the casting pouring site. It is an object of the present invention to provide a core drying device capable of reliably preventing the occurrence of blowholes inside a casting by suppressing moisture absorption in the casting as much as possible.

[0008]

SUMMARY OF THE INVENTION claims 1 invention, the internal cavity is formed in the sand core drying apparatus for drying the sand core of the lidded cylindrical communicating with said cavity open at one end The sand core drying device supplies hot air to generate hot air.
Machine and the open end of the sand core down,
It is formed in an area where it can be erected, and
A table provided with an opening for guiding hot air, and the hot air generator
From the cavity of the sand core through the hole in the table
A duct for supplying the hot air into the section,
Supply the sand core until just before use, and remove the water inside the sand core.
By allowing the sand core to dry,
The sand core in the dry state is used for casting equipment using the sand core.
Can be set in the mold and can be installed near the casting equipment
It is a Noh play .

The invention of claim 2 is the same as the invention of claim 1.
Furthermore, the sand core drying device is installed on the base and the base.
Stake and the horizontal arrangement at the top of the stake and the front at the top
The table on which the hollow pipe is erected and the hot air generator and
And a sand core drying stand with a duct
It was done.

The invention of claim 3 is the invention of claim 1 or 2.
In addition, it is installed on the table in the above-mentioned standing state.
A hollow pipe that can be extended to the hollow portion of the core,
A plurality of opening holes are formed around the hollow pipe.
Of.

According to a fourth aspect of the invention, one end is open.
Dry the covered cylindrical sand core with the cavity inside.
It is a casting method that uses a sand core dryer to remove hot air.
The hot air generator to be supplied and the open end of the sand core are placed downward.
And is formed in an area where this sand core can be erected.
A table provided with an opening hole for guiding the hot air to the cavity
And from the hot air generator, through the opening hole of the table
And a duct for supplying the hot air into the cavity of the sand core
It can be installed near a casting facility that uses the sand core
Drying sand core by using a different sand core dryer
On the table of the device, with the open end of the sand core facing down,
Place it so that the opening hole is located in the cavity of the sand core.
Then, through the duct, through the opening hole, empty the sand core.
Hot air is supplied into the cave until just before the sand core is used,
By evaporating the water inside the child to the outside, the sand core is
After drying, the sand core in the dry state is treated with the above-mentioned casting equipment.
It is set in a mold and cast.

The invention of claim 5 is the same as the invention of claim 4.
Furthermore, the sand core drying device is installed on the base and the base.
Stake and the horizontal arrangement at the top of the stake and the front at the top
The table on which the hollow pipe is erected and the hot air generator and
And a sand core drying stand with a duct
It was done.

The invention of claim 6 is the invention of claim 4 or 5.
In addition, it is installed on the table in the above-mentioned standing state.
A hollow pipe that can be extended to the hollow portion of the core,
A plurality of opening holes are formed around the hollow pipe.
Of.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a core drying stand showing an embodiment of a core drying device according to the present invention together with casting equipment. FIG. 2 is a front view showing the core drying stand of FIG. FIG. 3 is a sectional view showing a partially enlarged view of FIG. 2 in a sectional state. FIG. 4 shows IV of FIG.
FIG. FIG. 5 is an enlarged view showing a part of FIG. 4 in an enlarged manner. FIG. 6 is a graph showing the dry state of the core in the core drying stand shown in FIG. 1 and the conventional core drying method and apparatus.

As shown in FIG. 1, in a casting facility 10, a sand core 12 is installed in a pair of molds 11, and molten metal is poured from a pouring port 13 of the molds 11 to form a bottom case of a front fork or the like. It is for molding a casting.

The sand core 12 contains water between the sand particles, and this water may cause blowholes inside the casting. Therefore, the sand core 12 is dried by the core drying stand 14 as a core drying device installed near the casting facility 10.

The sand core 12 is, as shown in FIGS.
It is a cylindrical long object with a lid in which a hollow portion 15 is formed and one end is an open end portion 16 communicating with the hollow portion 15.

As shown in FIGS. 1 and 2, the core drying stand 14 is provided with a pillar 18 standing on a base 17, a table 19 is horizontally arranged on the top of the pillar 18, and a hollow pipe 20 and hot air are generated. The machine 21 is provided.

The table 19 is horizontally arranged on the support column 18, and as shown in FIG. 3, the sand core 12 can be placed upright with the open end 16 of the sand core 12 facing downward.

As shown in FIGS. 2 and 3, a plurality of hollow pipes 20, for example, four hollow pipes 20 are erected at appropriate positions on the table 19, and the sand core 1 is placed on the table 19 in an upright state.
It is possible to extend the inside of the hollow portion 15 of FIG. 2 (FIG. 3).

Further, in the table 19, as shown in FIGS. 3 to 5, a plurality of opening holes 22 are formed around the hollow pipe 20.
Is opened. The opening hole 22 is formed at a position facing the hollow portion 15 of the sand core 12 placed on the table 19.

As shown in FIG. 1 and FIG. 2, the hot air generator 21 is mounted on a mounting plate 23 fixed to the support column 18, and is placed in the hollow pipe 20 and the opening hole 22 through the duct 24. For example, hot air of 100 ℃ is supplied. This hot air is guided into the hollow portion 15 of the sand core 12 through the hollow pipe 20 and the opening hole 22, as shown by the arrow in FIG.

Reference numeral 25 in FIG. 2 is a reinforcing plate for reinforcing the mounting plate 23, and reference numeral 2 in FIG.
6 is a mounting screw hole for mounting the duct 24.

Next, the operation will be described. Before using the sand core 12 (for example, 200 seconds before use), the sand core 12 is placed on the table 19 of the core drying stand 14 with the open end 16 facing downward so that the hollow pipe 20 is positioned inside the cavity 15.

Next, the hot air generator 21 is operated to guide the hot air from the hollow pipe 20 and the opening hole 22 into the hollow portion 15 of the sand core 12 through the duct 24. The above-mentioned hot air is supplied until just before the sand core 12 is used, for example, for 200 seconds to dry the sand core 12, and then the dry sand core 12 is installed in the mold 11 of the casting facility 10. , Casting is carried out.

According to the above embodiment, the sand core 12 is planted on the table 19 in the core drying stand 14.
Since the inside of the hollow pipe 20 and the opening hole 22 that can be extended into the hollow portion 15 of the above are used as hot air passages, the hollow pipe 20 and the opening hole 22 can be inserted into the sand core 12 of the elongated object.
The hot air is sent from the inside of the sand core 12, and the evaporated moisture of the sand core 12 is released to the outside. For this reason, the temperature of the outside atmosphere should be raised and the sand core 1
Compared to the conventional drying device that uses a drying box that dries 2,
The amount of water vaporized from the sand core 12 can be increased as shown in FIG. 6, and the time for drying the sand core 12 can be shortened. For example, by only supplying hot air of 100 ° C. from the hot air generator 21 for 200 seconds, as shown in FIG. 6, the water content in the sand core 12 can be reduced to 11.3% of the saturated state.

Further, in the core drying stand 14,
It suffices that the table 19 be formed in an area where the sand core 12 can be erected, so that the installation space of the core drying stand 14 can be reduced. Therefore, the core drying stand 14 can be installed in the vicinity of the casting equipment 10, which is a narrow space. Therefore, the dry sand core 12 dried by the core drying stand 14 is taken out from the core drying stand 14. It can be installed in the mold 11 in a short time. In this way, the waiting time at the pouring site after drying the sand core 12 can be extremely shortened, so that the water absorption of the sand core 12 during the waiting time can be suppressed as much as possible.

As described above, in the core drying stand 14, the amount of evaporated water in the sand core 12 can be extremely increased and the absorption of water into the sand core 12 can be suppressed, so that the generation of blowholes inside the casting is prevented. It can be surely prevented.

In particular, in the core drying stand 14, an opening hole 22 is formed around the hollow pipe 20 in the table 19, and the opening hole 22 allows the hot air from the hot air generator 21 to be fed in the same manner as the hollow pipe 20. Since it is guided into the cavity 15 of the sand core 12, hot air can be sent to the entire cavity 15 of the sand core 12. Therefore, the drying effect of the sand core 12 can be further improved, and the generation of blow holes inside the casting can be prevented more reliably.

[0031]

As described above, according to the core drying apparatus of the present invention, the amount of water vaporized from the core is large, and the core drying time is short. It is possible to suppress the absorption of water as much as possible during the stand-by state as much as possible and reliably prevent the formation of blowholes inside the casting.

[Brief description of drawings]

FIG. 1 is a perspective view showing a core drying stand showing one embodiment of a core drying device according to the present invention together with casting equipment.

FIG. 2 is a front view showing the core drying stand of FIG.

FIG. 3 is a sectional view showing a part of FIG. 2 in an enlarged manner in a sectional state.

FIG. 4 is a view on arrow IV of FIG.

FIG. 5 is an enlarged view showing a part of FIG. 4 in an enlarged manner.

FIG. 6 is a graph showing a core drying state in the core drying stand shown in FIG. 1 and a conventional core drying method and apparatus.

[Explanation of symbols]

12 sand core 14 Core drying stand 15 Sand core cavity 16 Open end of sand core 19 table 20 hollow pipe 21 hot air generator 22 Open hole

Claims (2)

(57) [Claims] 1. A hollow portion therein is formed, one end opened to dry the sand core of the lidded cylindrical communicating with said cavity
A sand core drying apparatus, the sand core drying apparatus, a hot-air generator for supplying hot air, the open end portion of the sand core in the lower, erected the sand core
It is formed in the area to obtain the hot air to the cavity.
From the table provided with the opening hole for leading and the hot air generator, through the opening hole of the table
A duct for supplying the hot air into the cavity of the sand core , and supplying the hot air until just before the sand core is used,
The sand core is dried by evaporating the water of
To enable the dry sand core to be used in a casting facility using the sand core.
Can be set in the mold and can be installed near the casting equipment
Sand core drying device, characterized in that at capacity ones. 2. The sand core drying device includes a base and the base.
The pillars that are erected on the
A table on which the hollow pipe is erected at
The sand core drying apparatus according to claim 1, which is a sand core drying stand including a raw machine and the duct . 3. The table is installed on the table and is in the standing state.
A hollow pipe that can be extended to the hollow portion of the core,
A contract in which a plurality of the opening holes are formed around the hollow pipe.
The sand core drying device according to claim 1 or 2. 4. A cavity having one end open is formed inside.
Uses a sand core dryer to dry a cylindrical sand core with a lid.
A casting method for a hot-air generator for supplying hot air, and beneath the open end of the sand core, erected the sand core obtained
Of the hot air to the cavity.
From the table provided with the open hole and the hot air generator through the open hole of the table.
It has a duct that supplies the hot air into the cavity of the sand core.
And, installable sand core in the vicinity of the casting equipment using sand cores
By using a dryer , the sand core dryer's table is placed on the open end of the sand core.
Down, the opening hole is located in the cavity of the sand core.
So that the sand core is hollow from the opening through the duct.
By supplying hot air into the sand core until just before use, and evaporating the moisture in the sand core to the outside,
After drying the core, the dry sand core is set in the mold of the casting equipment.
And use a sand core drying device characterized by casting
Casting method. Wherein said sand core drying apparatus, base and, base plate
The pillars that are erected on the
A table on which the hollow pipe is erected at
It is a sand core drying stand equipped with a raw machine and the duct.
A casting method using the sand core drying device according to claim 4. 6. installed on the table, the stand state
A hollow pipe that can be extended to the hollow portion of the core,
A contract in which a plurality of the opening holes are formed around the hollow pipe.
Casting method using the sand core dryer according to claim 4 or 5.
Law.