JPH0639487A - Device for recovering molding sand of shell mold - Google Patents

Abstract

PURPOSE:To provide a device for recovering molding sand of a shell mold having long service life and capable of greatly simply and inexpensively preventing the blocking of a sieve opening. CONSTITUTION:In the molding sand recovering device 20 for shell mold by which the molding sand S broken, separated and discharged by a breaker 12 for shell mold provided in a vibration recovering device and filling material 2 are recovered by further classifying them into the molding sand and the filling material by a prescribed sieve 22. The sieve 22 is provided with a woven wire net 23 having the prescribed mesh size and a supporting plate 24 having the larger sieve opening than the mesh of the woven wire net and supporting this woven wire net.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell mold sand sand recovery apparatus for recovering sand from a shell mold after casting in precision casting by the shell mold method.

[0002]

2. Description of the Related Art In the shell mold method, a sand mold is solidified with a binder of a phenolic resin to form a thin shell-shaped mold, and a filler 2 such as alumina oxide balls is provided around the mold 1 as shown in FIG. By arranging and fixing the mold 1, a molten metal is poured into the mold from the sprue 3 to make a cast product, and the mold 1 is usually 4 to 8 by a large number of fillers 2 in a casting box (not shown).
Individually fixed.

The shell mold method is characterized in that it is easy to remove sand, has a beautiful casting surface, and can cast with a high dimensional accuracy even in a complicated shape. Here, the alumina oxide balls and the like arranged around the mold are pellet-like and spherical fillers fired to about 10 to 30 mm, and are intended for reinforcing the shell mold and degassing.

After the casting, as shown in FIG. 6, the shell mold and the like are integrally disassembled by a vibration recovery device 10 including a casting box reversing machine 11, a dismantling machine 12, a shell sand casting sand recovery device 12 and the like. Then, the product, casting sand, sprue, filler, shell mold pieces (cast metal), etc. are individually separated and collected. Here, the casting box reversing machine 11 lifts the casting box 5 having wheels to above the dismantling machine 12, inverts the casting box 5 in the vertical direction and discharges the contents on the dismantling machine 12, as shown in the figure. It has a lifter 11a for dropping to. Further, the cast box 5 which has been emptied by discharging the contents is moved to the lower part of a hopper (not shown) provided at the carrying end of the conveyor 7 described later so as to receive the filler collected by the vibration collecting device 10. Be transported.

The dismantling machine 12 integrally dismantles the shell mold and the like discharged from the casting box 5, and a large lump of the shell mold 1a having a small thermal effect by the product M and the molten metal and the other casting sand S. And the filler 2 are separated. The product M thus separated is conveyed to the next step and processed, and the large lump shell mold 1a is crushed by a sand crusher in another step,
Re-processing such as replenishment with fresh sand (silica sand having a particle size of # 80 to # 100 (0.25 to 0.32 mm)) is performed and recycled as cast sand S.

On the other hand, the casting sand recovery device 13 separates the casting sand S and the filler 2 separated by the dismantling machine 12 with the first sieve 13a while applying vibration. The separated filler 2 is conveyed to the hopper by the conveyor 7 for reuse, and the contents are dropped by the casting box reversing machine 11 into the dismantling machine 12 and thrown into the empty casting box 5. The casting sand S, after being classified by the second sieve 13b having fine meshes, is conveyed to another treatment step by the carry-out bucket conveyor 14 having a large number of buckets 14a and adheres to the surface thereof. After the sand is prepared by baking the resin, it is recycled by supplying new sand.

[0007]

By the way, the casting sand separated from the filler in the shell sand casting sand recovery device is very fine as compared with the filler, but the casting sand separated by the dismantling machine is used. Due to the strong impact force received from the product or the like during the dismantling of the mold or the like, the fragments of the filler crushed into a flat and sharp shape are mixed.

The fragments of the filler are wedge-shaped clogged in the sieve mesh and come into surface contact with the inner wall surface due to the vibration applied by the casting sand collecting device and the weight of the casting sand stacked on the second sieve, It will block all sieve meshes in a short time. As a result, sieving of the casting sand is significantly hindered. In this case, the casting sand can be removed by removing the second sieve from the casting sand recovery device, but since the fragments of the filler are in surface contact with the inner wall surface of the sieve mesh and are clogged in a wedge shape, it is easy. However, when the second sieve was hit with a hammer or the like, the sieve was deformed and could not be used.

[0009] Therefore, in the conventional casting mold sand recovery apparatus for shell molds, there is a problem that continuous classification and recovery of the casting sand is difficult due to the clogging of the sieve mesh, and the casting does not cause such clogging. It was desired to provide a sand recovery device.
The present invention has been made in view of the above points, and it is possible to extremely easily and inexpensively achieve prevention of clogging of sieve meshes, and an object thereof is to provide a casting sand recovery device for a long-life shell mold. To do.

[0010]

According to the present invention, in order to achieve the above object, the sand and the filler, which are disassembled by a shell mold disassembling machine provided in a vibration recovery device and are separated and discharged, are specified. In the shell sand casting sand collecting apparatus for further classifying and collecting the casting sand and the filler with the sieve, the sieve has a woven wire mesh of a predetermined mesh size, and a sieve mesh larger than the mesh of the woven wire mesh. And a support plate that supports the woven wire mesh.

[0011]

The woven wire mesh captures the filler and its fragments and prevents the fragments of the filler from clogging the sieve mesh of the support plate. Therefore, the casting sand smoothly drops from the woven wire mesh through the sieve mesh of the support plate, and the filler and the casting sand are continuously and efficiently separated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. The shell sand casting sand collecting apparatus 20 of the present invention is an improvement of the shell sand casting sand collecting apparatus 13 in the conventional vibration collecting apparatus 10 described above.
Since other configurations are substantially the same, the same components will be denoted by the same reference numerals.

As shown in FIG. 1, the shell sand casting sand recovery apparatus 20 is provided with a hopper 12a provided on the discharge side of the dismantling machine 12.
It is located at the bottom of. The casting sand collecting apparatus 20 includes a housing 21 that is vibrated by a vibration motor (not shown).
A sieve 22 for classifying the casting sand S and the filler 2 which are separated and discharged from the dismantling machine 12 into the casting sand S and the filler 2 is arranged therein, and the sieve 22 is shown in FIG. Thus, the woven wire mesh 23 and the support plate 24 are provided. Also, the housing 2
A bucket conveyor 14 that conveys the sand S separated and collected by the sieve 22 to another processing step is disposed in the inside 1.

The woven wire net 23 is made of metal wire 23a having a wire diameter of 0.8 to 1.0 mm and mesh sizes # 0.8 to # 1.0 (1).
A wire mesh with a side of 2.0 mm) is laid in close contact with the support plate 24 so as not to create a substantial gap with the support plate 24, and is filled with the casting sand S separated and discharged from the dismantling machine 12. Material 2
And separate. The support plate 24 is a metal plate in which sieve holes 24a having a predetermined diameter are provided at a predetermined pitch, and a central portion is projected upward in a mountain shape by about 5 to 10 mm. For example, a metal plate having a thickness of 4 mm and a sieve hole having a diameter of 5 mm are used. 24a is formed with a pitch of 4 mm, and a commercially available punching metal is used.

In the casting sand collecting apparatus 20 of the present invention, since the sieve 22 is composed of the woven wire net 23 and the supporting plate 24 as described above,
The casting sand S and the filler 2 separated by the dismantling machine 12 are separated as follows without clogging. The casting sand S and the filler 2 which are dismantled by the disassembling machine 12 and are discharged from the hopper 12a to the casting sand recovery device 20 are cast when the sieve 22 vibrates with the vibration of the housing 21 vibrated by the vibration motor. The sand S passes through the sieve 22 and falls, and the sieved filler 2 is sent from the shooter 25 to the conveyor 7.

At this time, since the mesh size of the woven wire mesh 23 of the sieve 22 is as fine as # 0.8 to # 1.0, not only the filler 2 but also the fragments F of the filler 2 as shown in FIG. Since the fragments F are also captured, the fragments F are not captured by the sieve holes 24a of the support plate 24 and are not clogged. Moreover, the woven wire net 23
Because the metal wire 23a is woven, the surrounding metal wire 23a forming the mesh is not on the same plane, and the metal wire 23a has a circular cross-sectional shape, so that it is in point contact with the fragment F of the filler 2. Therefore, the captured fragments F are free to move in response to the vibration of the housing 21.

Therefore, the casting sand S passes through the mesh of the woven wire mesh 23 in accordance with the vibration of the sieve 22, and the sieve hole 2 of the support plate 24.
4A, the casting sand S and the filler 2 are continuously and efficiently separated. Here, when a gap is created between the woven wire net 23 and the support plate 24, the fragments F of the filler 2 that have passed through the mesh of the woven wire net 23 pass through the gap and the sieve holes 2 of the support plate 24.
4a, the classification efficiency of the casting sand S decreases, and in some cases, the weight of the casting sand S supplied to the casting sand recovery device 20 and the filler 2 may cause damage.

Needless to say, the casting sand recovery apparatus is not limited to the above-mentioned shape, and for example, as shown in FIG. 4, a woven wire net 33 and a support plate 34 forming a sieve 32 are formed in a planar shape. And the sieve 32 is tilted from the horizontal by about 6 to 10 ° and vibrated by a vibration motor (not shown), the filler 2 is discharged to the carry-out conveyor 35, and the casting sand S is discharged from the hopper 36 to the housing 31. You may make it fall inward and it may convey to another process process by the bucket conveyor 14 arrange | positioned inside.

[0019]

As is apparent from the above description, according to the present invention, there is provided a sand casting sand recovery apparatus for a shell mold which can prevent clogging of sieve meshes extremely easily and inexpensively. It

[Brief description of drawings]

FIG. 1 is a front view showing a cross section of a shell sand casting sand recovery apparatus of the present invention.

FIG. 2 is an enlarged cross-sectional view of a screen including a woven wire mesh and a support plate used in the foundry sand recovery apparatus of FIG.

FIG. 3 is a plan view of the screen shown in FIG.

FIG. 4 is a front view showing a modified example of the shell sand casting sand recovery device in section.

FIG. 5 is a cross-sectional view illustrating the arrangement of a mold and a filler for explaining casting by the shell mold method.

FIG. 6 is a schematic configuration diagram showing a vibration recovery device equipped with a sand molding recovery device for a shell mold.

[Explanation of symbols]

 1 Mold 2 Filling Material 20 Shell Mold Recovery Device 21 Housing 22 Sieve 23 Woven Wire Mesh 23a Metal Wire 24 Support Plate 24a Sieve Hole 32 Sieve 33 Woven Wire Mesh 34 Support Plate S Cast Sand F Filler Fragment

Claims (1)

[Claims] 1. A casting sand and a filler, which are disassembled by a shell mold disassembling machine provided in a vibration recovery device and separated and discharged,
In a shell sand casting sand collecting apparatus for further classifying and collecting the casting sand and the filler with a predetermined sieve, the sieve has a woven wire mesh of a predetermined mesh size and a sieve mesh larger than the mesh of the woven wire mesh. And a support plate for supporting the woven wire mesh, the casting sand collecting device for a shell mold.