CA1320031C - Casting method and apparatus therefor - Google Patents
Casting method and apparatus thereforInfo
- Publication number
- CA1320031C CA1320031C CA000578910A CA578910A CA1320031C CA 1320031 C CA1320031 C CA 1320031C CA 000578910 A CA000578910 A CA 000578910A CA 578910 A CA578910 A CA 578910A CA 1320031 C CA1320031 C CA 1320031C
- Authority
- CA
- Canada
- Prior art keywords
- filling material
- gas
- flask
- burner
- manner
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
- B22C9/04—Use of lost patterns
- B22C9/046—Use of patterns which are eliminated by the liquid metal in the mould
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D47/00—Casting plants
- B22D47/02—Casting plants for both moulding and casting
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Casting Devices For Molds (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Feeding And Controlling Fuel (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A flask has obtuse-angled or arcuate portions at its inner periphery. It is provided in such a manner as to be movable by a moving device. A filling material such as sand is filled in this flask. Embedded in the filling material is a melting pattern which is decomposed while generating combustile gas when it is heated. A runner is connected to the melting pattern, and a hollow combustion suction is provided in such a manner that it is in contact with the layer of filling material. The combustion suction device has vent holes on its side wall which forms a gas collecting chamber, as well as a burner at its upper portion. The flask is vibrated by a vibrating device so as to pack the filling material densely and substantially uniformly by the action of the bent portions. Thereafter, a molten metal is poured from a sprue to manufacture a product, and the generated gas is ignited and burned at the burner of the combustion suction device by an ignition device provided in such a manner as to face the burner, by which suction of the gas is conducted.
The flask is then moved so as to provide its burner with another ignition device and thereby maintain suction.
A flask has obtuse-angled or arcuate portions at its inner periphery. It is provided in such a manner as to be movable by a moving device. A filling material such as sand is filled in this flask. Embedded in the filling material is a melting pattern which is decomposed while generating combustile gas when it is heated. A runner is connected to the melting pattern, and a hollow combustion suction is provided in such a manner that it is in contact with the layer of filling material. The combustion suction device has vent holes on its side wall which forms a gas collecting chamber, as well as a burner at its upper portion. The flask is vibrated by a vibrating device so as to pack the filling material densely and substantially uniformly by the action of the bent portions. Thereafter, a molten metal is poured from a sprue to manufacture a product, and the generated gas is ignited and burned at the burner of the combustion suction device by an ignition device provided in such a manner as to face the burner, by which suction of the gas is conducted.
The flask is then moved so as to provide its burner with another ignition device and thereby maintain suction.
Description
~3~Q~
TITLE OF THE INVENTION
CASTING METHOD AND APPARATUS THEREFOR
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a method of manufacturing castings and an apparatus therefor~ More specifically, it pertains to a casting method which employs a melting pattern and a casting apparatus for carrying out this method.
TITLE OF THE INVENTION
CASTING METHOD AND APPARATUS THEREFOR
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to a method of manufacturing castings and an apparatus therefor~ More specifically, it pertains to a casting method which employs a melting pattern and a casting apparatus for carrying out this method.
2. Description of the Prior Art-The present inventor has made a patent application ofthe method and apparatus of the same type in Japan under Japanese Application No. 56272/1986. In these method and apparatus, a large number oE flasks which are made of metal and have a box-like shape are movable provided~ and each of the flasks is filled with noncombustile Eilling material such as sand. Embedded in the filling mat:erial is a melting pattern which is made of polystyrene foam and which is coated with a layer formed oE mineral particles and a binder. A
runner which has a sprue is connected to the melting pattern, and a hollow combustion suction device which has vent holes on its side wall forming a gas collecting chamber and a burner at the upper portion thereof is provided in such a manner that it is in contact with the layer of filling material. The flasks are vibrated by a vibrating device so ~32~3~
as to closely pack the filling material. Thereafter, a molten metal is poured from the sprue. The molten metal gasifies the melting pattern and fills the cavity which has been formed by the melting o~ the melting pattern. The generated gas flows through the interstices of the particles of the filling material, and enters the combustion suction device from the vent holes. It fills the gas collecting chamber, and moves upward to the burner, at which it is ignited by an ignition device provided in such a manner as to face the burner, and is burned. Thereafter, the flask where the above-described operation is conducted is moved away for another process. Upward movement of the burned gas decreases the pressure within the combustion suction device, by which suction of the gas through the vent holes is conducted.
Unlike the known casting apparat:us which employs a pump to suck the gas, the disclosed methocl and apparatus can omit the use of pump. Further, suction force can be varied to a suitable value as a series of operations are carried out including starting of generation of the gas, increase and decrease in the amount of gas generated, and completion of generation of the gas. Also, generation of gas can be automatically started and completed. These enable manufacture of a sound casting which cannot be obtained by an apparatus employing a pump.
However, such apparatus and method have following ~3~ 3~
disadvantages: in the above-described method, -the flasks are vibrated by the vibrating device so as to closely pack the filling material accommodated in each of the flasks and to thereby hold the melting pattern firmly during casting and prevent collasping of the filling material into a cavity formed by the dissipation of the melting pattern. However, if the flask has four right-angled corners, i.e., the flask has four square cornersl the ~illing material cannot be closely packed uniformly when it is vibrated. Further, after the burner has been ignited, that flask is moved away from the ignition device to a position at which another process is carried out so as to enable casting operation to be conducted continuously. This makes flow of the gas filling in the filling material into the combustion suction device discontinuous, and the burning at the burner and hence the suctlon are interrupted~
SUMMARY OF THE INVENTION
The present invention is directed to obviate the above-described problems of the prior art, and its object is to provide a casting method and~ an apparatus therefor which enable a filling meterial to be easily and substantially uniformly packed in the overall flask when the flask is vibrated, and which enables suction to be conducted substantially continuously even when the flask is moved away from an ignition device a~ter ignition and flow o~ the gas ~3~3~
into the combustion suction device thereby becomes discontinuous.
To this end, the present invention provides a casting method which comprises the steps of: filling a noncombustible filling material in a flask having obtuse-angled or arcuate portions at its inner periphery, the Elask being provided in such a manner as to be movable by a moving device embedding in the filling material a melting pattern coated with a gas permeable layer formed of mineral particles and a binder, the melting pattern being decomposed while generating combustile gas when heated; providing a runner having a sprue in such a manner that it is in contact with th~ melting pattern;
providing a hollow combustion suction device having vent holes on its side wall forming a gas collecting chamber as well as a burner at its upper portion in such a manner that it is in contact with the layer of filling material and that the burner projects rom the upper surface of the layer of ~illing material: vibrating the flask by a vibrating device 50 as to pack the filling material densely; pouring a molten metal from a ~urnace through the sprue so as to gasify the melting pattern by the molten metal and replace the pattern with a product; igniting and burning at the burner by an ignition device the gas which enters the gas collecting chamber of the combustion suction device through the vent holes ater it has passed through the interstices in the ~320~3 ~
Eilling materi.al so as to cause it to rise; decreasing the pressure in the gas collecting chamber by th~ upward movement of the gas so as to enable suction of the gas through the vent holes to be conducted; and moving the flask and then providing the burner with another ignition device after the movement of the flask has taken place.
The present invention also provides a casting manufacturing apparatus which comprises: a large number of flasks provided in such a manner as to be movable by a moving device, each of the flasks having obtuse-angled or arcuate bent portions at i.ts inner periphery; a noncombustible filling material filled in each of the flasks; a vibrating device for packing the Eilling material densely; a melting pattern embedded in the filling material for generating combustible gas when heated; a gas pe.rmeable coating formed on the outside oE the pattern, -the coating being ~ormed of mineral particles and a binder, a runner having a sprue, the runner being provided in such a manner that it is in contact with the pattern; a hollow combustion suction device provided in such a manner that it is in contact with the layer of filling material, the combustion suction device having vent holes on its side wall forming a gas collecting chamber and a burner at its upper portion; a plural.ity of ignition devices for igniting each of the burners; and a furnace for supplying a molten metal to the sprue.
~ 3 ~
The present invention also provides a casting manufacturing apparatus which is characterized in that the combustion suction device has a protector on the outside thereof which runs in the axial direction thereof.
BRIBF DESCRIPTION OF THE DRAWINGS
-Fig. 1 is a cross--sectional view of an apparatus embodying this invention, showing one of the steps of a method embodying this invention;
Fig. 2 is a cross-sectional view of the apparatus of Fig. 1, showing another step of the method of the present nvention;
Fig. 3 is a schematic perspective view of the casting manufacturing apparatus;
Fig. 4 is a plan view of a flask;
Fig. 5 is a plan view of another example of the flask;
Fig. 6 is a plan view of the Elask employed in the apparatus of the same type which has been disclosed by the present inventor;
Fig. 7 is a side elevational views o~ part of the casting manufacturing apparatus according to the present invention;
Fig. 8 is a perspective cross-sectional view of part o the casting manufacturing apparatus of the present invention;
FigO 9 is a plan view of part of the apparatus of the present invention; and ~32,~3~
Fig. 10 is a plan view of part of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figs. 4 and 5, a flask 3 has obtuse-angled or arcwise portions 1 at its inner periphery. In this case, the obtuse~angled portion means a portion made up of straight lines, as the corner portion 1 shown in Fig. 5, or a portion made up of a straight line and a curve, as shown in Fig. 40 In Figs. 1 to 3, a moving device 2 includes rollers 24, shafts 25, bearings 26, a base 27 for supporting the bearings 26, and urging members 28 which are hydraulic cylinders. As shown in Fig. 3, a plurality of flasks 3 can be continuously pivoted in an endless Eashion by the our urging members 28 of the moving device 2. A vertically moving roller 29 shown in Figs. 3 and 7 whose detailed description is omitted moves the flasks 3 up and down, by which the flasks 3 are located above,a vibrating device 15 having a spring 30 and are loaded on the vibrating device. Each of t~e flasks 3 is made of iron or other metal which is in the form of a container. The flask 3 is filled with a noncombustible filling material 4 such as molding sand. A melting pattern 6 which generates combustible gas when heated is embedded in the filling material 4. The pattern may be formed from a polystyrene foam. Although it may also be formed from other synthetic resin foams, polystyrene foam is preEerable. A gas permeable ~32~31 layer 5 mainly made of mineral particles is provided on the pattern 6. The coated layer 5 may be formed by coating on the pattern 6 a liquid which contains silica or other mineral particles dissolved in a binder such as molasses, and then by drying it. A known coated layer 5 including an imported product may be employed. A sprue 7 may be a ceramic molded product, and a runner 8 may be a shell molded product. The sprue 7 and the runner a may also be made of the same material as that from which the pattern 6 is formed.
combustion suction device 13 may be of a cylindrical shape and made o metal. The device 13 has vent holes 11 on a side wall 10 thereof. The vent holes 11 are so small as to inhibit entrance of the sand. As shown in Fig. 8, the combustion suction device 13 may comprise a spiral pipe filter 32 and a pipe 33 having the same diameter as that of the spiral pipe filter 32, -the pipe 33 being welded to the spiral pipe filter 32. The spiral pi~pe Eilter 32 may be formed of steel having the continuously formed vent holes 11.
~herefore, it can withstand a high external pressure. The vent holes 11 have a width which is largest at the inner surface and which gradually decreases as it approaches the outer surface. In consequence, the vent holes 11 are prevented from being clogged with the filling material 4, that is, cleaning o the vent holes is easy. The combustlon suction device 13 also includes a reinforcing materisl 34, ~32~3:L
and a protector 22 made of a bar steel. The protector prevents damage to the vent holes 11 which would be caused by the contact of a product 18 shown in Fig. 2 with the vent holes 11 which would occur when the product 18 is taken out.
The protector 22 also makes the fixing of the filter 32 to the pipe 33 firm~
The combustioon suction device 13 may be fixed to a bottom of the flask 3 by bolts 36. Alternatively, it may be fixed to a guide rail (not shown) provided on the bottom 35 of the flask 3 at any desired position. In this wayl the combustion suction device 13 can be moved to a suitable position, depending on the size and length o~ the melting pattern 6. The combustion suction device 13 may also be mad0 o any of various kinds of material having a multiplicity oE
openings, such as a wire net, a punched metal or steel wool.
An ignition device 19 may be of any type which is capable of igniting the combustible gas, such as a burner which is fired with town or propane gas. As shown in Figs. 3 and 10, a plurality of ignition devices 19 are provided along a passage 20 of the flasks 3 as an ignition device set 21.
Since a plurality of iginition devices 19 are provided, even if the ~low of gas into the combustion suction device 13 becomes irregular or discontinuous, the gas is kept burning, thereby keeping the suction substantially continuous and constant~ The reference numeral 37 denotes a valve.
g ~32~
Next, the corner portions 1 of the flask 3 are reshaped in an obtuse angled or arcwise form, as shown in Figs. 4 and 5. They are 50 formed because it was found out in the experiments that, when the corner portions 1 were formed at a right angle, as shown in Fig. 6, the filling material 4 was packed in a region 38 at a different density from that at which it was packed in any of regions 39. More specifically, the filling material was packed at a high density in the region 38, whereas the packing density of the material at the regions 39 was low. This occurs when the filling material 4 is shaken by the vibrating device shown in Fig. 7 and 3 so that it is densely packed. If this happens, it is difficult for the filling material 4 to hold the melting pattern 6 stationarily. Further, there is a possibility of the filling material collapsing into a cavity formed by the meltin~ of the melting pattern 6. These problems can be prevented if the bent portions 1 are shaped in an obtuse angled or an arcuate form. With the bent portions thus shaped, the filling material 4 could be packed substantially uniformly over the entirety o~ the ~lask when it was shaken in experiments conducted by us, and the above-described problems were therefore solved. This phenomenon can be surely reproduced in an experiment.
Reference numeral 40 denotes a hook. The apparatus of this embodiment is mo~ed a distance equivalent to one ~32~
flask 3 in the direction indicated by the arrows A28 by the urging members 28. While it is being pivoted on the plane, a series of casting operations, including pou~ing o~ the molten metal t ignition of the generated gas, combustion of the gas, continuation of ignition, cooling of a molded product, removal of the molded product, supply of the filling material 4, embedding of the pattern 4, and shaking of the filling material by the vibrating device 15, are carried out in that order. When the gas is burned at a burner portion 12, it rises from the lower portion of the combustion suction device, making the pressure in that portion lower and thereby making suction of the gas possible.
In the present invention arranged in the above-described manner, suction of the gas is conducted by the combustion suction device. Therefore, timing of the suction operation including generation of the gas, increases and decreases in the amount of gas generated and completion of the generation, as well as the suction force, can be automatically adjusted, unlike the case in which a pump is employed for suction, and well-molded products can thereby be easily manufactured.
When the flasks are moved after the gas has been burned, the burner oE each of the flasks is provided with another ignition device. In consequence, even if the flow of gas into the combustion suction device becomes irregular and discontinuous, the gas is ignited every time burning of the ~32~31L
gas is interrupted, and the suction can be thereby conducted continuously.
Further, since the bent portions of the flask have an obtuse-angled or arcuate shape, the filling material in the flask can be closely packed substantially uniformly ove.r the entirety of the flask. In consequence, the melting pattern can be held firmly, and the possibility of the filling material collapsing into the cavity formed by the decomposition of the pattern can be eliminated. In addition, the provision of protectors in the combustion suction device enables damage to the vent holes thereof which would be otherwise caused by the product to be prevented~
runner which has a sprue is connected to the melting pattern, and a hollow combustion suction device which has vent holes on its side wall forming a gas collecting chamber and a burner at the upper portion thereof is provided in such a manner that it is in contact with the layer of filling material. The flasks are vibrated by a vibrating device so ~32~3~
as to closely pack the filling material. Thereafter, a molten metal is poured from the sprue. The molten metal gasifies the melting pattern and fills the cavity which has been formed by the melting o~ the melting pattern. The generated gas flows through the interstices of the particles of the filling material, and enters the combustion suction device from the vent holes. It fills the gas collecting chamber, and moves upward to the burner, at which it is ignited by an ignition device provided in such a manner as to face the burner, and is burned. Thereafter, the flask where the above-described operation is conducted is moved away for another process. Upward movement of the burned gas decreases the pressure within the combustion suction device, by which suction of the gas through the vent holes is conducted.
Unlike the known casting apparat:us which employs a pump to suck the gas, the disclosed methocl and apparatus can omit the use of pump. Further, suction force can be varied to a suitable value as a series of operations are carried out including starting of generation of the gas, increase and decrease in the amount of gas generated, and completion of generation of the gas. Also, generation of gas can be automatically started and completed. These enable manufacture of a sound casting which cannot be obtained by an apparatus employing a pump.
However, such apparatus and method have following ~3~ 3~
disadvantages: in the above-described method, -the flasks are vibrated by the vibrating device so as to closely pack the filling material accommodated in each of the flasks and to thereby hold the melting pattern firmly during casting and prevent collasping of the filling material into a cavity formed by the dissipation of the melting pattern. However, if the flask has four right-angled corners, i.e., the flask has four square cornersl the ~illing material cannot be closely packed uniformly when it is vibrated. Further, after the burner has been ignited, that flask is moved away from the ignition device to a position at which another process is carried out so as to enable casting operation to be conducted continuously. This makes flow of the gas filling in the filling material into the combustion suction device discontinuous, and the burning at the burner and hence the suctlon are interrupted~
SUMMARY OF THE INVENTION
The present invention is directed to obviate the above-described problems of the prior art, and its object is to provide a casting method and~ an apparatus therefor which enable a filling meterial to be easily and substantially uniformly packed in the overall flask when the flask is vibrated, and which enables suction to be conducted substantially continuously even when the flask is moved away from an ignition device a~ter ignition and flow o~ the gas ~3~3~
into the combustion suction device thereby becomes discontinuous.
To this end, the present invention provides a casting method which comprises the steps of: filling a noncombustible filling material in a flask having obtuse-angled or arcuate portions at its inner periphery, the Elask being provided in such a manner as to be movable by a moving device embedding in the filling material a melting pattern coated with a gas permeable layer formed of mineral particles and a binder, the melting pattern being decomposed while generating combustile gas when heated; providing a runner having a sprue in such a manner that it is in contact with th~ melting pattern;
providing a hollow combustion suction device having vent holes on its side wall forming a gas collecting chamber as well as a burner at its upper portion in such a manner that it is in contact with the layer of filling material and that the burner projects rom the upper surface of the layer of ~illing material: vibrating the flask by a vibrating device 50 as to pack the filling material densely; pouring a molten metal from a ~urnace through the sprue so as to gasify the melting pattern by the molten metal and replace the pattern with a product; igniting and burning at the burner by an ignition device the gas which enters the gas collecting chamber of the combustion suction device through the vent holes ater it has passed through the interstices in the ~320~3 ~
Eilling materi.al so as to cause it to rise; decreasing the pressure in the gas collecting chamber by th~ upward movement of the gas so as to enable suction of the gas through the vent holes to be conducted; and moving the flask and then providing the burner with another ignition device after the movement of the flask has taken place.
The present invention also provides a casting manufacturing apparatus which comprises: a large number of flasks provided in such a manner as to be movable by a moving device, each of the flasks having obtuse-angled or arcuate bent portions at i.ts inner periphery; a noncombustible filling material filled in each of the flasks; a vibrating device for packing the Eilling material densely; a melting pattern embedded in the filling material for generating combustible gas when heated; a gas pe.rmeable coating formed on the outside oE the pattern, -the coating being ~ormed of mineral particles and a binder, a runner having a sprue, the runner being provided in such a manner that it is in contact with the pattern; a hollow combustion suction device provided in such a manner that it is in contact with the layer of filling material, the combustion suction device having vent holes on its side wall forming a gas collecting chamber and a burner at its upper portion; a plural.ity of ignition devices for igniting each of the burners; and a furnace for supplying a molten metal to the sprue.
~ 3 ~
The present invention also provides a casting manufacturing apparatus which is characterized in that the combustion suction device has a protector on the outside thereof which runs in the axial direction thereof.
BRIBF DESCRIPTION OF THE DRAWINGS
-Fig. 1 is a cross--sectional view of an apparatus embodying this invention, showing one of the steps of a method embodying this invention;
Fig. 2 is a cross-sectional view of the apparatus of Fig. 1, showing another step of the method of the present nvention;
Fig. 3 is a schematic perspective view of the casting manufacturing apparatus;
Fig. 4 is a plan view of a flask;
Fig. 5 is a plan view of another example of the flask;
Fig. 6 is a plan view of the Elask employed in the apparatus of the same type which has been disclosed by the present inventor;
Fig. 7 is a side elevational views o~ part of the casting manufacturing apparatus according to the present invention;
Fig. 8 is a perspective cross-sectional view of part o the casting manufacturing apparatus of the present invention;
FigO 9 is a plan view of part of the apparatus of the present invention; and ~32,~3~
Fig. 10 is a plan view of part of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figs. 4 and 5, a flask 3 has obtuse-angled or arcwise portions 1 at its inner periphery. In this case, the obtuse~angled portion means a portion made up of straight lines, as the corner portion 1 shown in Fig. 5, or a portion made up of a straight line and a curve, as shown in Fig. 40 In Figs. 1 to 3, a moving device 2 includes rollers 24, shafts 25, bearings 26, a base 27 for supporting the bearings 26, and urging members 28 which are hydraulic cylinders. As shown in Fig. 3, a plurality of flasks 3 can be continuously pivoted in an endless Eashion by the our urging members 28 of the moving device 2. A vertically moving roller 29 shown in Figs. 3 and 7 whose detailed description is omitted moves the flasks 3 up and down, by which the flasks 3 are located above,a vibrating device 15 having a spring 30 and are loaded on the vibrating device. Each of t~e flasks 3 is made of iron or other metal which is in the form of a container. The flask 3 is filled with a noncombustible filling material 4 such as molding sand. A melting pattern 6 which generates combustible gas when heated is embedded in the filling material 4. The pattern may be formed from a polystyrene foam. Although it may also be formed from other synthetic resin foams, polystyrene foam is preEerable. A gas permeable ~32~31 layer 5 mainly made of mineral particles is provided on the pattern 6. The coated layer 5 may be formed by coating on the pattern 6 a liquid which contains silica or other mineral particles dissolved in a binder such as molasses, and then by drying it. A known coated layer 5 including an imported product may be employed. A sprue 7 may be a ceramic molded product, and a runner 8 may be a shell molded product. The sprue 7 and the runner a may also be made of the same material as that from which the pattern 6 is formed.
combustion suction device 13 may be of a cylindrical shape and made o metal. The device 13 has vent holes 11 on a side wall 10 thereof. The vent holes 11 are so small as to inhibit entrance of the sand. As shown in Fig. 8, the combustion suction device 13 may comprise a spiral pipe filter 32 and a pipe 33 having the same diameter as that of the spiral pipe filter 32, -the pipe 33 being welded to the spiral pipe filter 32. The spiral pi~pe Eilter 32 may be formed of steel having the continuously formed vent holes 11.
~herefore, it can withstand a high external pressure. The vent holes 11 have a width which is largest at the inner surface and which gradually decreases as it approaches the outer surface. In consequence, the vent holes 11 are prevented from being clogged with the filling material 4, that is, cleaning o the vent holes is easy. The combustlon suction device 13 also includes a reinforcing materisl 34, ~32~3:L
and a protector 22 made of a bar steel. The protector prevents damage to the vent holes 11 which would be caused by the contact of a product 18 shown in Fig. 2 with the vent holes 11 which would occur when the product 18 is taken out.
The protector 22 also makes the fixing of the filter 32 to the pipe 33 firm~
The combustioon suction device 13 may be fixed to a bottom of the flask 3 by bolts 36. Alternatively, it may be fixed to a guide rail (not shown) provided on the bottom 35 of the flask 3 at any desired position. In this wayl the combustion suction device 13 can be moved to a suitable position, depending on the size and length o~ the melting pattern 6. The combustion suction device 13 may also be mad0 o any of various kinds of material having a multiplicity oE
openings, such as a wire net, a punched metal or steel wool.
An ignition device 19 may be of any type which is capable of igniting the combustible gas, such as a burner which is fired with town or propane gas. As shown in Figs. 3 and 10, a plurality of ignition devices 19 are provided along a passage 20 of the flasks 3 as an ignition device set 21.
Since a plurality of iginition devices 19 are provided, even if the ~low of gas into the combustion suction device 13 becomes irregular or discontinuous, the gas is kept burning, thereby keeping the suction substantially continuous and constant~ The reference numeral 37 denotes a valve.
g ~32~
Next, the corner portions 1 of the flask 3 are reshaped in an obtuse angled or arcwise form, as shown in Figs. 4 and 5. They are 50 formed because it was found out in the experiments that, when the corner portions 1 were formed at a right angle, as shown in Fig. 6, the filling material 4 was packed in a region 38 at a different density from that at which it was packed in any of regions 39. More specifically, the filling material was packed at a high density in the region 38, whereas the packing density of the material at the regions 39 was low. This occurs when the filling material 4 is shaken by the vibrating device shown in Fig. 7 and 3 so that it is densely packed. If this happens, it is difficult for the filling material 4 to hold the melting pattern 6 stationarily. Further, there is a possibility of the filling material collapsing into a cavity formed by the meltin~ of the melting pattern 6. These problems can be prevented if the bent portions 1 are shaped in an obtuse angled or an arcuate form. With the bent portions thus shaped, the filling material 4 could be packed substantially uniformly over the entirety o~ the ~lask when it was shaken in experiments conducted by us, and the above-described problems were therefore solved. This phenomenon can be surely reproduced in an experiment.
Reference numeral 40 denotes a hook. The apparatus of this embodiment is mo~ed a distance equivalent to one ~32~
flask 3 in the direction indicated by the arrows A28 by the urging members 28. While it is being pivoted on the plane, a series of casting operations, including pou~ing o~ the molten metal t ignition of the generated gas, combustion of the gas, continuation of ignition, cooling of a molded product, removal of the molded product, supply of the filling material 4, embedding of the pattern 4, and shaking of the filling material by the vibrating device 15, are carried out in that order. When the gas is burned at a burner portion 12, it rises from the lower portion of the combustion suction device, making the pressure in that portion lower and thereby making suction of the gas possible.
In the present invention arranged in the above-described manner, suction of the gas is conducted by the combustion suction device. Therefore, timing of the suction operation including generation of the gas, increases and decreases in the amount of gas generated and completion of the generation, as well as the suction force, can be automatically adjusted, unlike the case in which a pump is employed for suction, and well-molded products can thereby be easily manufactured.
When the flasks are moved after the gas has been burned, the burner oE each of the flasks is provided with another ignition device. In consequence, even if the flow of gas into the combustion suction device becomes irregular and discontinuous, the gas is ignited every time burning of the ~32~31L
gas is interrupted, and the suction can be thereby conducted continuously.
Further, since the bent portions of the flask have an obtuse-angled or arcuate shape, the filling material in the flask can be closely packed substantially uniformly ove.r the entirety of the flask. In consequence, the melting pattern can be held firmly, and the possibility of the filling material collapsing into the cavity formed by the decomposition of the pattern can be eliminated. In addition, the provision of protectors in the combustion suction device enables damage to the vent holes thereof which would be otherwise caused by the product to be prevented~
Claims (3)
1. A casting method comprising the steps of:
filling a noncombustible filling material in a flask having obtuse-angled or arcuate portions at its inner periphery, said flask being provided in such a manner as to be movable by a moving device;
embedding in said filling material a melting pattern coated with a gas permeable layer formed of mineral particles and a binder, said melting pattern being decomposed while generating combustile gas when heated;
providing a runner having a sprue in such a manner that it is in contact with said melting pattern;
providing a hollow combustion suction device having vent holes on its side wall forming a gas collecting chamber as well as a burner at its upper portion in such a manner that it is in contact with said layer of filling material and that said burner projects from the upper surface of said layer of filling material;
vibrating said flask by a vibrating device so as to pack said filling material densely;
pouring a molten metal from a furnace through said sprue so as to gasify said melting pattern by said molten metal and replace said pattern with a product;
igniting and burning at said burner by an ignition device the gas which enters said gas collecting chamber of said combustion suction device through said vent holes after it has passed through the interstices in said filling material so as to cause it to rise;
decreasing the pressure in said gas collecting chamber by the upward movement of said gas so as to enable suction of the gas through said vent holes to be conducted; and moving said flask and then providing said burner with another ignition device after the movement of said flask has taken place.
filling a noncombustible filling material in a flask having obtuse-angled or arcuate portions at its inner periphery, said flask being provided in such a manner as to be movable by a moving device;
embedding in said filling material a melting pattern coated with a gas permeable layer formed of mineral particles and a binder, said melting pattern being decomposed while generating combustile gas when heated;
providing a runner having a sprue in such a manner that it is in contact with said melting pattern;
providing a hollow combustion suction device having vent holes on its side wall forming a gas collecting chamber as well as a burner at its upper portion in such a manner that it is in contact with said layer of filling material and that said burner projects from the upper surface of said layer of filling material;
vibrating said flask by a vibrating device so as to pack said filling material densely;
pouring a molten metal from a furnace through said sprue so as to gasify said melting pattern by said molten metal and replace said pattern with a product;
igniting and burning at said burner by an ignition device the gas which enters said gas collecting chamber of said combustion suction device through said vent holes after it has passed through the interstices in said filling material so as to cause it to rise;
decreasing the pressure in said gas collecting chamber by the upward movement of said gas so as to enable suction of the gas through said vent holes to be conducted; and moving said flask and then providing said burner with another ignition device after the movement of said flask has taken place.
2. A casting manufacturing apparatus comprising:
a large number of flasks provided in such a manner as to be movable by a moving device, each of said flasks having obtuse-angled or arcuate bent portions at its inner periphery;
a noncombustible filling material filled in each of said flasks;
a vibrating device for packing said filling material densely;
a melting pattern embedded in said filling material for generating combustible gas when heated;
a gas permeable coating formed on the outside of said pattern, said coating being formed of mineral particles and a binder;
a runner having a sprue, said runner being provided in such a manner that it is in contact with said pattern;
a hollow combustion suction device provided in such a manner that it is in contact with said layer of filling material, said combustion suction device having vent holes on its side wall forming a gas collecting chamber and a burner at its upper portion;
a plurality of ignition devices for igniting each of said burners; and a furnace for supplying a molten metal to said sprue.
a large number of flasks provided in such a manner as to be movable by a moving device, each of said flasks having obtuse-angled or arcuate bent portions at its inner periphery;
a noncombustible filling material filled in each of said flasks;
a vibrating device for packing said filling material densely;
a melting pattern embedded in said filling material for generating combustible gas when heated;
a gas permeable coating formed on the outside of said pattern, said coating being formed of mineral particles and a binder;
a runner having a sprue, said runner being provided in such a manner that it is in contact with said pattern;
a hollow combustion suction device provided in such a manner that it is in contact with said layer of filling material, said combustion suction device having vent holes on its side wall forming a gas collecting chamber and a burner at its upper portion;
a plurality of ignition devices for igniting each of said burners; and a furnace for supplying a molten metal to said sprue.
3. A casting manufacturing apparatus according to claim 2, wherein said combustion suction device has a protector on the outside thereof which runns in the axial direction thereof.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23579/1988 | 1988-02-03 | ||
| JP63023579A JPH01202339A (en) | 1988-02-03 | 1988-02-03 | Method for pouring casting and apparatus for using to same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1320031C true CA1320031C (en) | 1993-07-13 |
Family
ID=12114471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000578910A Expired - Fee Related CA1320031C (en) | 1988-02-03 | 1988-09-28 | Casting method and apparatus therefor |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPH01202339A (en) |
| AU (1) | AU612663B2 (en) |
| CA (1) | CA1320031C (en) |
| CH (1) | CH678604A5 (en) |
| ES (1) | ES2011136A6 (en) |
| FR (1) | FR2627713B1 (en) |
| GB (1) | GB2214848B (en) |
| MY (1) | MY103679A (en) |
| NZ (1) | NZ226328A (en) |
| PT (1) | PT88660B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4514995B2 (en) * | 2001-06-22 | 2010-07-28 | 花王株式会社 | Vanishing model casting method |
| CN103406501B (en) * | 2013-07-21 | 2016-07-13 | 河南广瑞汽车部件股份有限公司 | Casting machine electronic pulse ignition method and device |
| CN113664189A (en) * | 2021-08-12 | 2021-11-19 | 天津昌昊实业有限公司 | Efficient casting production line |
| DE102022129733A1 (en) * | 2022-11-10 | 2024-05-16 | Man Truck & Bus Se | Method and device for igniting casting gases |
| CN118729297A (en) * | 2024-06-14 | 2024-10-01 | 广东金志利科技股份有限公司 | Automatic ignition and air entrainment system and method for sand casting large castings |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1177221A (en) * | 1980-12-04 | 1984-11-06 | General Kinematics Corporation | Vibratory method for packing foundry sand into a pattern prior to the pouring of molten metal |
| DE3423199C1 (en) * | 1984-06-22 | 1985-02-21 | Grünzweig + Hartmann und Glasfaser AG, 6700 Ludwigshafen | Device for the implementation of the full molding process |
| GB2188267B (en) * | 1986-03-14 | 1989-11-15 | Morikawa Sangyo | Casting method and apparatus |
| JPS62214848A (en) * | 1986-03-14 | 1987-09-21 | Morikawa Sangyo Kk | Casting method |
-
1988
- 1988-02-03 JP JP63023579A patent/JPH01202339A/en active Pending
- 1988-07-05 AU AU18705/88A patent/AU612663B2/en not_active Ceased
- 1988-07-12 FR FR8809457A patent/FR2627713B1/en not_active Expired - Fee Related
- 1988-09-26 NZ NZ226328A patent/NZ226328A/en unknown
- 1988-09-28 CA CA000578910A patent/CA1320031C/en not_active Expired - Fee Related
- 1988-09-29 GB GB8822891A patent/GB2214848B/en not_active Expired - Fee Related
- 1988-10-04 PT PT88660A patent/PT88660B/en not_active IP Right Cessation
- 1988-10-07 ES ES8803053A patent/ES2011136A6/en not_active Expired
- 1988-12-28 MY MYPI88001558A patent/MY103679A/en unknown
-
1989
- 1989-04-04 CH CH1234/89A patent/CH678604A5/fr not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| MY103679A (en) | 1993-08-28 |
| GB8822891D0 (en) | 1988-11-02 |
| GB2214848B (en) | 1991-06-26 |
| ES2011136A6 (en) | 1989-12-16 |
| AU612663B2 (en) | 1991-07-18 |
| JPH01202339A (en) | 1989-08-15 |
| CH678604A5 (en) | 1991-10-15 |
| FR2627713A1 (en) | 1989-09-01 |
| FR2627713B1 (en) | 1993-09-24 |
| GB2214848A (en) | 1989-09-13 |
| NZ226328A (en) | 1990-03-27 |
| AU1870588A (en) | 1989-08-03 |
| PT88660A (en) | 1989-10-04 |
| PT88660B (en) | 1994-01-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |