EP2604362A2

EP2604362A2 - Mold molding device and mold molding method

Info

Publication number: EP2604362A2
Application number: EP11715147.2A
Authority: EP
Inventors: Masahide Noguchi; Tsuyoshi Sakai; Kazunori Ogura
Original assignee: Sintokogio Ltd
Current assignee: Sintokogio Ltd
Priority date: 2010-08-09
Filing date: 2011-02-08
Publication date: 2013-06-19
Also published as: CN102834200B; CN102834200A; JP2012055968A; WO2011049249A2; WO2011049249A3; TW201210716A; JP5626639B2; EP2604362A4

Abstract

The purpose of the present invention is to provide an apparatus for molding a mold and a method for molding a mold which can prevent foundry sand from becoming attached to an inner surface of a sand hopper and to make the structure of the apparatus simple. The apparatus supplies foundry sand into a molding space formed by a pattern plate, a flask, and a filling frame that are placed on a pattern carrier by means of a sand-filling device. Then the apparatus squeezes the foundry sand in the molding space by means of a squeezing device to mold a mold. The apparatus comprises a sand hopper that stores foundry sand in its inside. The sand hopper is disposed above the flask and the filling frame. The apparatus further comprises an openable louver gate disposed in the sand hopper. The apparatus further comprises an opening and closing device for opening and closing a sand-feeding opening. The sand-feeding opening is an opening for supplying the foundry sand into the sand hopper. The opening and closing device is disposed above the sand hopper. The apparatus further comprises an air-blowing chamber attached to the inner surface of the sand hopper.

Description

Technical Field

The present invention relates to an apparatus and a method for squeezing foundry sand filled in a flask to mold a mold.

Background of the Invention

For example, Patent document 1 discloses a conventional apparatus for molding a mold. The apparatus comprises a sand hopper and a squeezing device. The sand hopper is open at its upper end and has an openable louver at a lower position. The squeezing device comprises many segmented squeezing feet. The sand hopper and squeezing device are disposed to be connected to each other. The sand hopper and the squeezing device are in turn conveyed to a position above a flask and a filling frame.

Patent document 1: JP7-185740A

Disclosure of Invention

However, the apparatus of Patent document 1 has a problem in that sand can adhere to the surface of the inner wall of the sand hopper. Also, a mechanism for conveying the sand hopper and the squeezing device is required, because both must be in turn conveyed to a position above the flask and the filling frame. This causes a problem in that the configuration of the apparatus cannot help but be complicated.
The present invention has been made in light of these problems. The purpose of the present invention is to simplify the configurations of the apparatus and method for molding a mold while preventing sand from adhering to a surface of an inner wall of a sand hopper.
To achieve that purpose, provided in the present invention is an apparatus for molding a mold, wherein a sand-filling device fills foundry sand into a molding space formed by a pattern plate, a flask, and a filling frame that are placed on a pattern carrier, and then a squeezing device squeezes the foundry sand filled in the molding space to mold a mold. The sand-filling device comprises the following: a sand hopper that is disposed at a position above the flask and the filling frame and that stores foundry sand inside it; an openable louver gate disposed in the sand hopper; an opening and closing device for opening and closing a sand-feeding opening that is disposed in an upper position of the sand hopper and that serves as an opening for supplying foundry sand into the sand hopper; and an air-blowing chamber attached to an inner surface of the sand hopper.
The apparatus for molding a mold of the present invention comprises the following: a raising and lowering cylinder that is attached to a base; a table connected to the raising and lowering cylinder; a pattern carrier that carries a pattern plate and comprises a surrounding frame that can rise and fall while the frame surrounds the outer circumference of the pattern plate, wherein the pattern carrier can be conveyed to and from a position above the table; a mechanism for conveying the flask to and from a position above the pattern carrier; a squeezing device disposed inside the mechanism for conveying the flask; a filling frame disposed at a position above the flask such that the frame can rise and fall; and a sand-filling device for filling foundry sand into a molding space that is formed by the pattern plate, the flask, and the filling frame that have been conveyed from a position above the table to a position outside the base, wherein the sand-filling device is disposed at a position outside the base.
Further, the apparatus of the present invention comprises an air supply valve that communicates with the sand-filling device.
To achieve the above purpose, also provided in the present invention is a method for molding a mold, wherein a sand-filling device fills foundry sand into a molding space formed by a pattern plate, a flask, and a filling frame that are placed on a pattern carrier, and then a squeezing device squeezes the foundry sand filled in the molding space to mold a mold. The method comprises the following: a step for filling foundry sand into the molding space by means of the sand-filling device; a step for closing an opening and closing device for the sand-feeding opening in the sand-filling device; a step for blowing air from an air-blowing chamber attached to an inner surface of a sand hopper in the sand-filling device; and a step for opening an openable louver gate in the sand-filling device.
Also, the method for molding a mold of the present invention is carried out by using an apparatus comprising two pattern carriers on which a pattern plate is placed, each pattern carrier having a surrounding frame that can rise and fall while the frame surrounds an outer circumference of the pattern plate. The first pattern carrier is disposed in a position above a table. The second pattern carrier is disposed in a position outside a base. Also, an empty flask and a filling frame are placed on the first pattern carrier. A flask that is filled with foundry sand and a filling frame are placed on the second pattern carrier. The method comprises a step for conveying the first pattern carrier, the empty flask, and the filling frame to a position outside the base and for conveying the second pattern carrier, the flask that is filled with foundry sand, and the filling frame, to a position above the table; a step for raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame; a step for causing the upper surface of the surrounding frame of the second pattern carrier to protrude above a parting plane of the pattern plate; a step for contacting the lower surface of the sand hopper with the upper surface of the filling frame that has been conveyed to a position outside the base to form a molding space by the pattern plate, the empty flask, and the filling frame that are placed on the first pattern carrier; a step for lowering the squeeze member in the squeezing device to carry out a first squeeze of the foundry sand; a step for closing a mechanism for conveying the flask; a step for carrying out a second squeeze of the foundry sand by lowering the squeeze member while raising the pattern plate until the height of the upper surface of the surrounding frame in the second pattern carrier and the height of the parting plane of the pattern plate become the same; a step for filling foundry sand into the molding space by means of the sand-filling device; a step for further lowering the squeeze member to carry out a third squeeze of the foundry sand after the pattern plate is raised in the second squeeze; a step for lowering the pattern plate in the second pattern carrier to separate the pattern plate from the foundry sand; a step for separating the sand hopper from the filling frame that has been conveyed to a position outside the base; a step for lowering the second pattern carrier; a step for closing the openable louver gate in the sand-filling device; a step for opening an opening and closing device for a sand-feeding opening in the sand-filling device to feed foundry sand into the sand hopper through the sand-feeding opening; a step for conveying an empty flask to a position between the filling frame that is disposed above the second pattern carrier and the second pattern carrier; a step for placing the empty flask and the filling frame on the second pattern carrier; and a step for opening the mechanism for conveying the flask.
Further, the method for molding a mold of the present invention is carried out by using an apparatus comprising two pattern carriers on which a pattern plate is placed, each pattern carrier having a surrounding frame that can rise and fall while the frame surrounds an outer circumference of the pattern plate. The first pattern carrier is disposed in a position above a table. The second pattern carrier is disposed in a position outside a base. Also, an empty flask and a filling frame are placed on the first pattern carrier. A flask that is filled with foundry sand and a filling frame are placed on the second pattern carrier. The method comprises the following: a step for conveying the first pattern carrier, the empty flask, and the filling frame to a position outside the base and for conveying the second pattern carrier, the flask that is filled with foundry sand, and the filling frame to a position above the table; a step for raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame; a step for causing the upper surface of the surrounding frame in the second pattern carrier to protrude above the parting plane of the pattern plate; a step for contacting the lower surface of the sand hopper with the upper surface of the filling frame that has been conveyed to a position outside the base to form a molding space by the pattern plate, the empty flask, and the filling frame that are placed on the first pattern carrier; a step for further raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame to carry out a first squeeze of the foundry sand; a step for closing a mechanism for conveying the flask; a step for raising the pattern plate until the height of the upper surface of the surrounding frame in the second pattern carrier and the height of the parting plane of the pattern plate become the same so as to carry out a second squeeze of the foundry sand; a step for filling foundry sand into the molding space by means of the sand-filling device; a step for further raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame to carry out a third squeeze of the foundry sand after the pattern plate is raised in the second squeeze; a step for lowering the pattern plate in the second pattern carrier to separate the pattern carrier from the foundry sand; a step for separating the sand hopper from the filling frame that has been conveyed to a position outside the base; a step for lowering the second pattern carrier; a step for closing the openable louver gate in the sand-filling device; a step for opening an opening and closing device for a sand-feeding opening in the sand-filling device to feed foundry sand into the sand hopper through the sand-feeding opening; a step for conveying an empty flask to a position between the filling frame that is disposed above the second pattern carrier and the second pattern carrier; a step for placing the empty flask and the filling frame on the second pattern carrier; and a step for opening the mechanism for conveying the flask.
Also, the method for molding a mold of the present invention further comprises a step for opening the air supply valve that communicates with the sand-filling device after carrying out the step for filling foundry sand into the molding space by means of the sand-filling device such that the foundry sand in the molding space is preliminarily compressed by compressed air flowing through the foundry sand.
The present invention provides an apparatus for molding a mold, wherein a sand-filling device fills foundry sand into a molding space formed by a pattern plate, a flask, and a filling frame that are placed on the pattern carrier, and then a squeezing device squeezes the foundry sand filled in the molding space to mold a mold, and wherein the sand-filling device comprises the following: a sand hopper that is disposed at a position above the flask and the filling frame and stores foundry sand inside; an openable louver gate disposed in the sand hopper; an opening and closing device for opening and closing a sand-feeding opening that is disposed in an upper position of the sand hopper and serves as an opening for supplying foundry sand into the sand hopper; and an air-blowing chamber attached to an inner surface of the sand hopper. So, the apparatus has various effects such as preventing sand from adhering to the inner wall of the sand hopper.

Brief Description of the Drawings

[Fig. 1] Fig. 1 illustrates a sectional side view of the apparatus in the first embodiment of the present invention. The apparatus is in a state in which an empty flask and a filling frame are placed on a pattern carrier that is located above the table, and in which another flask, which is filled with foundry sand, and another filling frame, are placed on a pattern carrier that is located outside the base.
[Fig. 2] Fig. 2 is a sectional side view of the apparatus when it is in a state in which another flask, which is filled with foundry sand, and another filling frame, have been conveyed, by rotating a turntable, to a position above the table, and in which the empty flask and the filling frame have been conveyed, by rotating the turntable, to a position outside the base.
[Fig. 3] Fig. 3 is a sectional side view of the apparatus when it is in a state in which another flask, another filling frame, and the surrounding frame above the table, have all been raised and in which a molding space has been formed outside the base.
[Fig. 4] Fig. 4 is a sectional side view of the apparatus when it is in a state in which the foundry sand above the table is squeezed a first time and in which a conveyor for conveying a flask is closed.
[Fig. 5] Fig. 5 is a sectional side view of the apparatus when it is in a state in which the foundry sand above the table is squeezed a second time and in which the molding space outside the base is filled with foundry sand.
[Fig. 6] Fig. 6 is a sectional side view of the apparatus when it is in a state in which the foundry sand above the table is squeezed a third time.
[Fig. 7] Fig. 7 is a sectional side view of the apparatus when it is in a state in which a pattern plate above the table is separated from the foundry sand and in which the pattern carrier, the flask, and the filling frame outside the base are lowered.
[Fig. 8] Fig. 8 is a sectional side view of the apparatus when it is in a state in which another flask is placed on a roller that is located above the table and in which foundry sand is supplied into the sand hopper outside the base.
[Fig. 9] Fig. 9 is a sectional side view of the apparatus when it is in a state in which another empty flask and another filling frame are placed on the pattern carrier above the table and in which the conveyer for conveying a flask is opened.
[Fig. 10] Fig. 10 is an expanded sectional view of the sand-filling device in Fig. 1.
[Fig. 11] Fig. 11 is a sectional side view of the apparatus in the second embodiment of the present invention. The apparatus is in a state in which an empty flask and a filling frame are placed on the pattern carrier that is located above the table and in which another flask, which is filled with foundry sand, and another filling frame, are placed on another pattern carrier that is located outside the base.
[Fig. 12] Fig. 12 is a sectional side view of the apparatus when it is in a state in which the empty flask and the filling frame have been conveyed, by rotating the turntable, to a position outside the base and in which another flask, which is filled with foundry sand, and another filling frame, have been conveyed, by rotating the turntable, to a position above the table.
[Fig. 13] Fig. 13 is a sectional side view of the apparatus when it is in a state in which the flask, the filling frame, and the surrounding frame outside the base have been raised and in which a molding space has been formed in a position above the table.
[Fig. 14] Fig. 14 is a sectional side view of the apparatus when it is in a state in which the foundry sand is squeezed a first time above the table and in which a conveyor for conveying a flask is closed.
[Fig. 15] Fig. 15 is a sectional side view of the apparatus when it is in a state in which the foundry sand above the table is squeezed a second time and in which the molding space that is in a position outside the base is filled with foundry sand.
[Fig. 16] Fig. 16 is a sectional side view of the apparatus when it is in a state in which the foundry sand is squeezed a third time above the table.
[Fig. 17] Fig. 17 is a sectional side view of the apparatus when it is in a state in which a pattern plate above the table is separated from the foundry sand and the pattern carrier, the flask, and the filling frame outside the base have all been lowered.
[Fig. 18] Fig. 18 is a sectional side view of the apparatus when it is in a state in which another flask is placed on a roller above the table and in which foundry sand has been supplied into the sand hopper outside the base.
[Fig. 19] Fig. 19 is a sectional side view of the apparatus when it is in a state in which the filling frame above the table has been raised and in which many cylinders are being stopped at the an intermediate position.
[Fig. 20] Fig. 20 is a sectional side view of the apparatus when it is in a state in which another empty flask and another filling frame are placed on the pattern carrier above the table.
[Fig. 21] Fig. 21 is an enlarged and detailed sectional figure illustrating the squeezing device in the second embodiment.
[Fig. 22] Fig. 22 is an enlarged and detailed sectional figure explaining an example of an operation of the squeezing device in the second embodiment.

Detailed Description of the Invention

Below, the first embodiment of the present invention is explained in detail with reference to the drawings. In Fig. 1, the raising and lowering cylinder 2 (an oil hydraulic cylinder in this embodiment) is attached to the top of the center of the base 1. The table 3 is connected to the tip of the raising and lowering cylinder 2. Guiding rods 4 are disposed beside the raising and lowering cylinder 2. The guiding rods 4 penetrate holders 5 that are attached to the base 1 such that the guiding rods 4 can move up and down in the holders 5. Incidentally, the tips of the guiding rods 4 are connected to the table 3.
Posts 6 stand in the right and left positions on the base 1 (see Fig. 1). An upper frame 7 is installed between the upper ends of the posts 6. The center of the turntable 8 is supported by one of the posts 6 (the left one in Fig. 1) at the lower position of the post such that the turntable 8 can rotate horizontally . The left one of the posts 6 in Fig. 1 serves also as the main shaft of the turntable 8. Supporting members (not illustrated) are attached to the turntable 8. The pattern carriers 9, 9A are placed on both ends of the turntable 8 via the supporting members(not illustrated). Incidentally, the turntable 8 can be rotated by means of an actuator (not illustrated). For example, an oil hydraulic cylinder, etc., can be used as an actuator. Also, the pattern carriers 9, 9A are conveyed to and from a position above the table 3 by rotating the turntable 8 while the table 3 is located at the lowest position.
Also, the pattern plates 10, 10A are placed on the pattern carriers 9, 9A, respectively. The pattern carriers 9, 9A each have a surrounding frame 11. Each surrounding frame 11 can move up and down while it surrounds the outer circumference of the pattern plate 10, 10A. Also, the flasks W and the filling frames 17 are placed on the pattern carriers 9, 9A.
Also, a plurality (four in this embodiment) of raising and lowering cylinders 12 (oil hydraulic cylinders in this embodiment) for raising and lowering the surrounding frames are attached to the table 3. Rod heads 13 are connected to the tips of the raising and lowering cylinders 12. Also, a plurality of suspended rods 14 (four rods in this embodiment) are suspended from the lower surface of the surrounding frame 11. Incidentally, the surrounding frame 11 can move up and down by the extension and the retraction of the raising and lowering cylinders 12 via the suspended rods 14. Also, a clamping device that clamps the pattern carriers 9, 9A (not illustrated) is attached to the table 3. Thus, the clamping is released when the table 3 is located at the lowest position. The pattern carriers 9, 9A are clamped by the table 3 when the table 3 rises.
Also, a conveyor 15, for conveying a flask, is disposed inside both posts 6. The conveyor 15 can be opened and closed. The conveyor 15 serves as a mechanism for conveying a flask W to and from a position above the pattern carrier 9 or 9A. The conveyor 15, for conveying a flask, comprises arms 10b, rollers 15c, and members for placing a filling frame 15d. The upper ends of the arms 15b are connected to a frame 15a such that the arms can rotate. The rollers 15c are attached to the respective tips (lower ends) of the arms 10b. The members for placing a filling frame 10d are fixed to the mid position along the vertical direction of the arms 15b.
A plurality (four in this embodiment) of locating pins 16 are fixed to the upper parts of the members 15d. Incidentally, the positions of the members 15d and the position of the filling frame 17 are determined by means of the locating pins 16 when the filling frame 17 is placed on the members 15d.
Also, the conveyor 15 is suspended from a raising and lowering frame 19 via suspending members 18. The raising and lowering frame 19 can be raised and lowered by means of a cylinder for raising and lowering the mechanism for conveying a flask. The cylinder is not illustrated.
Also, a squeezing device 20 is disposed within the area enclosed by the two arms of the conveyor 15. The squeezing device 20 comprises many cylinders 20a (oil hydraulic cylinders in this embodiment), squeezing feet 20b, which serve as a squeezing member connected to the tips of the cylinders 20a, and a support 20c for supporting the cylinders 20a. Incidentally, the support 20c is fixed to the center of the lower part of the upper frame 7.
Also, a device 21 for raising and lowering a pattern carrier is disposed under the pattern carrier 9A, which is located outside the base 1. Below, the device 21 for raising and lowering a pattern carrier is explained in detail. A cylinder 21b (an oil hydraulic cylinder in this embodiment) for raising and lowering a pattern carrier is attached to the top of the center of a stand 21a. A driving-roller conveyor 21c is connected to the tip of the cylinder 21b. Guiding rods 21d are disposed at each side of the cylinder 21b for raising and lowering a pattern carrier. The guiding rods 21d can be raised and lowered through holders 21e that are attached to the stand 21a. Incidentally, the tips of the guiding rods 21d are connected to the driving-roller conveyor 21c. Also, a clamping device for clamping the pattern carriers 9, 9A is attached to the driving-roller conveyor 21c. The clamping device is not illustrated. Thereby the clamping is released when the driving-roller conveyor 21c is located at the lowest position. The pattern carriers 9, 9A are clamped by the driving-roller conveyor 21c when the driving-roller conveyor 21c rises.
Incidentally, the flask W and the filling frame 17, which are both located outside the base 1, are clamped by means of a clamping device that is attached to the sand hopper 22a, discussed below, and that is not illustrated, while one of the pattern carriers 9, 9A is being replaced by the other of them. The cylinder 21b for raising and lowering a pattern carrier is operated to dispose only the pattern carriers 9, 9A at a predetermined height. Then the clamping by means of the clamping device (not illustrated) that clamps the pattern carriers 9 or 9A is released. Then, by operating the driving-roller conveyor 21c, the pattern carrier 9 or 9A, one of which is located on the driving-roller conveyor 21c, is conveyed from a position above the driving-roller conveyor 21c, while another pattern carrier is conveyed to a position above the driving-roller conveyor 21c.
Also, a sand-filling device 22 is disposed above the flask W and the filling frame 17, which are both disposed outside the base 1. The sand-filling device 22 is fixed to a supporting frame 23. Below, the sand-filling device 22 is explained in detail. As in Fig. 10, the openable louver gate 24 is disposed inside the lower part of the sand hopper 22a, which stores foundry sand S inside it. The openable louver gate 24 has a structure in which two or more gating plates 24b are disposed horizontally. One end of each gating plate is fixed to a rotating shaft 24a. Also, a device for spraying a mold-releasing agent is attached to a position between the openable louver gate 24 on the outer surface of the sand hopper 22a and the lower surface of the sand hopper 22a. The device is not illustrated.
Also, a device 25 for opening and closing a sand-feeding opening is disposed in the upper part of the sand hopper 22a. Below, the device 25 for opening and closing a sand-feeding opening is explained in detail. The sand-feeding opening 25b is formed on the ceiling of a casing 25a that communicates with the sand hopper 22a. The sand-feeding opening 25b serves as an opening through which foundry sand S is supplied into the sand hopper 22a. A gating member 25c, which can open and close the sand-feeding opening 25b by moving horizontally, is disposed inside the casing 25a. An opening and closing cylinder 25d for horizontally moving the gating member 25c is attached to one side of the casing 25a. The gating member 25c is connected to the tip of the opening and closing cylinder 25d.
Also, an air-blowing chamber 26 is attached to the entire inner surface of the sand hopper 22a. The air-blowing chamber 26 comprises a hollow chamber 26a and a porous body 26b that is disposed at the tip of the hollow chamber 26a. Incidentally, a switching valve(not illustrated) communicates with the hollow chamber 26a. Compressed air blows out of the porous body 26b through the hollow chamber 26a when the switching valve is opened. Also, in this embodiment, the porous body 26b is produced by sintering a polyethylene having an ultra high molecular weight.
Also, an air-supplying valve 28 communicates, through a pipe 27, with the casing 25a of the device 25 for opening and closing the sand-feeding opening. The air-supplying valve 28 communicates with the source of compressed air. The source is not illustrated. Incidentally, the number 29 denotes a sand-charging chute attached to the ceiling of the casing 25a.
Below, the operation of the apparatus that is configured in this way is explained. Fig. 1 illustrates the apparatus in a state in which one pattern carrier 9 of the two pattern carriers 9, 9A (hereafter, this pattern carrier is referred to as a pattern carrier for a lower flask) is disposed above the table 3, and in which the other pattern carrier 9A (hereafter, this pattern carrier is referred to as a pattern carrier for an upper flask) is disposed outside the base 1. In Fig. 1, the empty flask W and the filling frame 17 are placed on the pattern carrier 9 for a lower flask. Also, another flask W, which is filled with foundry sand S, and another filling frame 17, are placed on the pattern carrier 9A for an upper flask. Incidentally, in the present invention, for example, green sand, artificial sand that is made from ceramics, etc., may be used as the foundry sand S.
The pattern carrier 9 for a lower flask, the empty flask W, and the filling frame 17, are conveyed to a position outside the base 1, and the other pattern carrier 9A for an upper flask, another flask W, which is filled with foundry sand S, and another filling frame 17, are conveyed to a position above the table 3 by rotating the turntable 8 when the apparatus is in the state shown in Fig. 1. The rotated state is shown in Fig. 2. Next, the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frame 17, are raised along with the table 3 by extending the raising and lowering cylinder 2. Then the upper surface of the surrounding frame 11 in the pattern carrier 9A for an upper flask is caused to protrude (30 mm in this embodiment) above the parting plane of the pattern plate 10A by extending the cylinder 12 for raising and lowering a surrounding frame.
Also, outside the base 1, the pattern carrier 9 for a lower flask, the empty flask W, and the filling frame 17, are raised by extending the cylinder 21b for raising and lowering the pattern carrier. Thereby the lower surface of the sand hopper 22a contacts the upper surface of the filling frame 17 that is conveyed to a position outside the base 1. Thereby a molding space is formed by the pattern plate 10, the empty flask W, and the filling frame 17, which are placed on the pattern carrier 9 for a lower flask. This state is shown in Fig. 3. Then a mold-releasing agent is sprayed in the molding space by means of the device for spraying a mold-releasing agent. The device is not illustrated. Incidentally, a stopper for preventing the filling frame 17 from rising is attached to the lower surface of the upper frame 7. The stopper is not illustrated. In Fig. 3, the upper surface of the filling frame 17, which is located above the base 1, contacts the lower surface of the stopper.
Next, the foundry sand S is squeezed a first time by extending the many cylinders 20a to lower the squeezing feet 20b. Then the conveyor 15 for conveying a flask is closed by means of an opening and closing device (for example, a cylinder) that is not illustrated. This state is shown in Fig. 4.
Next, the foundry sand S is squeezed a second time by further lowering the squeezing feed 20b while the pattern plate 10A is raised by extending the raising and lowering cylinder 2 until the upper surface of the surrounding frame 11 and the parting plane of the pattern plate 10A in the pattern carrier 9A for an upper flask are located at the same height. During this period, the flask W and the filling frame 17 are kept pinched between the stopper (not illustrated) and the surrounding frame 11. Namely, the surrounding frame 11, the flask W, and the filling frame 17, do not move vertically.
Also, outside the base 1, the foundry sand S is supplied into the molding space by means of the sand-filling device 22. Now, the details of this point are explained. First, the opening and closing cylinder 25d in the device 25 for opening and closing the sand-feeding opening is extended. Thereby the sand-feeding opening 25b is closed by the gating member 25c. Then compressed air blows out of the porous body 26b through the hollow chamber 26a when the switching valve (not illustrated) is opened. The plurality of rotating shafts 24a of the openable louver gates 24 are forwardly rotated by means of the cylinders for opening and closing the gates. The cylinders are not illustrated. Thereby the plurality of gating plates 24b are changed to be vertical from a horizontally-disposed state (it means that the louver gates 24 are opened). By doing so, the foundry sand S in the sand hopper 22a is supplied into the molding space. This state is shown in Fig. 5. Incidentally, the compressed air is made to continuously flow out of the porous body 26b while the foundry sand S is being supplied into the molding space. The compressed air is discharged through a vent hole that is formed on the pattern plate 10 and that is not illustrated or through a vent hole that is formed on the side of the filling frame 17 and that is also not illustrated.
Next, the foundry sand S is squeezed a third time by further lowering the squeezing feet 20b after the elevation of the pattern plate 10A in the second squeeze is finished. This state is shown in Fig. 6. Also, outside the base 1, the foundry sand S in the molding space is preliminarily compressed by opening the air-supplying valve 28 to cause compressed air to flow through the foundry sand S in the molding space (the foundry sand S is preliminarily compressed by so-called air pressure). Then an exhaust valve that communicates with the casing 25a and that is not illustrated is opened to exhaust the compressed air that remains in the sand hopper 22a.
Next, the pattern plate 10A in the pattern carrier 9A for an upper flask is lowered. Thereby the pattern plate 10A is separated from the foundry sand. During this period, the flask W and the filling frame 17 are kept pinched between the stopper (that is not illustrated) and the surrounding frame 11. Namely, the surrounding frame 11, the flask W, and the filling frame 17, do not move vertically. So, the pattern plate is separated by lowering the pattern plate 10A by just a predetermined distance (30 mm in this embodiment).
Also, outside the base 1, the pattern carrier 9 for a lower flask, the flask W, and the filling frame 17 are lowered by retracting the cylinder 21b for raising and lowering a pattern carrier. Thereby the upper surface of the filling frame 17 is separated from the lower surface of the sand hopper 22a. This state is shown in Fig. 7.
Next, the pattern carrier 9A for an upper flask, the flask W, and the filling frame 17 are lowered by retracting the raising and lowering cylinder 2. By doing so, the flask W is placed on the rollers 15c. Also, the filling frame 17 is placed on the members 15d for placing a filling frame. The positions of the filling frame 17 and the members 15d are determined by means of the locating pins 16. Then the lower surface of the stopper (not illustrated) is separated from the upper surface of the filling frame 17 while the filling frame 17 descends.
Next, the many cylinders 20a are retracted to raise the squeezing feet 20b. Then the surrounding frame 11 is lowered by retracting the cylinder 12 for raising and lowering a surrounding frame when the table 3 is located at the lowest position.
Also, outside the base 1, a plurality of rotating shafts 24a in the openable louver gates 24 are reversely rotated by means of the cylinders for opening and closing the gates. Incidentally, the cylinders are not illustrated. Thereby a plurality of gating plates 24b are changed from a vertical state to a horizontal state (the louver gates 24 are closed). Then the sand-feeding opening 25b is opened by retracting the opening and closing cylinder 25d in the device 25 for opening and closing the sand-feeding opening. Then the foundry sand S is supplied into the sand hopper 22a through the sand-feeding opening 25b by means of a device for feeding foundry sand (for example, a belt feeder). The device is not illustrated. This state is shown in Fig. 8.
Next, the molded flask W is discharged by means of the flask-conveying conveyor 15. Then another empty flask W is conveyed to a position between the filling frame 17 and the pattern carrier 9A for an upper flask. Then the empty flask W and the filling frame 17 are placed on the pattern carrier 9A for an upper flask by lowering the flask-conveying conveyor 15 by means of a cylinder for raising and lowering the mechanism for conveying a flask. Incidentally, the cylinder is not illustrated. Then the flask-conveying conveyor 15 is opened by means of an opening and closing device (not illustrated). This state is shown in Fig. 9. Next, the flask-conveying conveyor 15 is raised by means of the cylinder for raising and lowering the mechanism for conveying a flask. Incidentally, the cylinder is not illustrated. This state is shown in Fig. 1. Then these operations are repeated.
Incidentally, in the present invention, in the sand hopper 22a comprising the openable louver gates 24, compressed air is made to blow out of the air-blowing chamber 26, which is attached to the inner surface of the sand hopper 22a, while the sand hopper 22 is sealed by closing the sand-feeding opening 25b. So, the foundry sand can be prevented from becoming attached to the inner wall of the sand hopper 22a. Also, the consumption of the air that is used can be reduced, because the compressed air is made to blow out of the air-blowing chamber 26 under a state in which the sand hopper 22a is sealed, instead of a state in which the upper end of the sand hopper 22a is opened. Also, the foundry sand S is preliminarily compressed by the compressed air that blows out of the air-blowing chamber 26, after the molding space is filled with the foundry sand S by opening the openable louver gates 24.
Also, in the present invention, neither the sand-filling device 22 nor the squeezing device 20 need to be conveyed. This is because the sand-filling device 22 is disposed outside the base 1, and the squeezing device 20 is disposed above the base 1 (more specifically, inside the mechanism for conveying a flask). So, also, no mechanism for conveying the sand-filling device 22 and the squeezing device 20 is required. Thereby the structure of the apparatus can be made simple.
Incidentally, in this embodiment of the present invention, outside the base 1, the pattern carrier (9A in Fig. 1), the flask W, and the filling frame 17 are raised and lowered by means of the device 21 for raising and lowering a pattern carrier. However, the embodiment is not limited to this configuration. The sand-filling device 22 may be raised and lowered without raising and lowering the pattern carrier, the flask W, and the filling frame 17. In this case, a molding space is formed by lowering the sand-filling device 22 to cause the lower surface of the sand hopper 22a to contact the upper surface of the filling frame 17 that is conveyed to a position outside the base 1. Incidentally, for example, a raising and lowering cylinder may be connected to the sand-filling device 22 to raise and lower it.
Incidentally, the many squeezing feet 20b were used as the squeezing member. However, the squeezing member is not limited to the many squeezing feet. In this embodiment of the present invention, one plate-like squeezing board may be used as the squeeze member. Incidentally, in this case, the cylinder for raising and lowering the squeezing board may consist of one or more cylinders.
In this embodiment of the present invention, a body produced by sintering a polyethylene having an ultra high molecular weight was exemplified as the porous body 26b. However, the porous body 26 is not limited to this. The porous body 26b may be a plate-like material having many holes (for example, round holes each having a diameter of from 1 mm to 2 mm).
Further, in this embodiment of the present invention, the openable flask-conveying conveyor 15 is configured such that the conveyor can be raised and lowered. However, the conveyor is not limited to this configuration. The flask-conveying conveyor 15 may be fixed to the upper frame 7 instead of being raised and lowered. However, when a configuration in which the flask-conveying conveyor 15 can be raised and lowered as in the above embodiment is used, the empty flask W and the filling frame 17 can be immediately placed on the pattern carrier 9, 9A by lowering the flask-conveying conveyor 15 after the empty flask W is conveyed to a position above the rollers 15c of the flask-conveying conveyor 15. Thereby the cycle time of the apparatus for molding a mold can be shortened. This is desirable.
In this embodiment of the present invention, the foundry sand S is preliminarily compressed by air pressure by opening the air-supplying valve 28, which communicates with the sand-filling device 22, after the step for filling the molding space with the foundry sand S by means of the sand-filling device 22 is carried out. However, the preliminary compression of the foundry sand S by air pressure is not indispensable. So, the compression may be omitted. However, the preliminary compression of the foundry sand S by air pressure is preferable, because then the density of the foundry sand S packed near the pattern plate 10, 10A is increased.
Next, the second embodiment, which is an embodiment different from the first embodiment, is explained below. First, the differences between the first and the second embodiments are explained below. In the second embodiment, as in Fig. 11, a plurality of cylinders 101b for raising and lowering a filling frame are attached to the lower parts of arms 101a of an openable flask-conveying conveyor 101 that serves as a mechanism for conveying a flask. Also, members 101c for placing a filling frame are connected to the tips of the cylinders 101b for raising and lowering a filling frame. A plurality of locating pins 101d (four pins in this embodiment) are fixed to the upper parts of the members 101c for placing a filling frame. Incidentally, the position of the members 101c for placing a filling frame and the position of the filling frame 102 are determined by means of the locating pins 101d when the filling frame 102 is placed on the members 101c for placing a filling frame. Also, the upper ends of the arms 101a are connected to the lower end of the upper frame 7 such that the arms 101a can rotate. In the second embodiment, the flask-conveying conveyor 101 neither rises nor falls.
Also, a plurality of downwardly facing cylinders 103 are disposed above both ends of the filling frame 102. The downwardly facing cylinders 103 are attached to the upper frame 7. Heads 104 are connected to the tips of the downwardly facing cylinders 103.
Also, a squeezing device 105 is disposed inside the flask-conveying conveyor 101. The squeezing device 105 comprises many double-rod cylinders 105a (they are oil hydraulic cylinders in this embodiment), squeezing feet 105b, which serve as a squeezing member connected to the tips of the cylinders 105a, and a support 105c for supporting the cylinders 105a. Incidentally, the support 105c is fixed to the upper frame 7. As in Fig. 21, in the many double-rod cylinders 105a, upper oil-pressure chambers 105d communicate with each other through upper communicating paths 105e. Also, lower oil-pressure chambers 105f communicate with each other through lower communicating paths 105g.
Also, a rod-height-determining device 106 that determines the heights of the piston rods 105h of the many cylinders 105a is disposed above the squeezing device 105. The rod-height-determining device 106 comprises a plate-like positioning member 106b and a cylinder 106a for raising and lowering the positioning member. The cylinder 106a is attached to the upper end of the upper frame 7. The positioning member 106b is connected to the tip of the cylinder 106a. Incidentally, the positioning member 106b and the piston rods 105h are not connected.
Also, contacting members 102a that can contact the heads 104, which are connected to the tips of the downwardly facing cylinders 103, are attached to both ends of the filling frame 102. Also, in the first embodiment, the air-blowing chamber 26, which is attached to the inner surface of the sand hopper 22a, is disposed only in the area above the openable louver gates 24. In contrast, in the second embodiment, the air-blowing chamber 26 is disposed not only in that area, but also in the area below the openable louver gates 24.
The points discussed above explain the configurations that differ in the first and the second embodiments. Except for them, the second embodiment has the same configurations as in the first embodiment. Incidentally, the components that are used in the second embodiment and that are the same as those used in the first embodiment are not explained below, but are denoted by the same numerals.
The operation of the second embodiment configured in this way is explained below. Fig. 11 illustrates a state in which a first pattern carrier 9 (hereafter, it is referred to as a pattern carrier for a lower flask), which is one of the two pattern carriers 9, 9A, is disposed above a table 3, and in which a second pattern carrier 9A (hereafter, it is referred to as the pattern carrier for an upper flask) is disposed outside the base 1, and in which an empty flask W and a filling frame 102 are placed on the pattern carrier 9 for a lower flask, and in which another flask W that is filled with foundry sand S and another filling frame 102 are placed on the pattern carrier 9A for an upper flask.
Incidentally, in Fig. 11, all the many cylinders 105a of the squeezing device 105 are stopped in a position corresponding to half of the distance of the entire stroke, i.e., an intermediate position. Now, the details about this point are explained. First, the positioning member 106b is lowered to the lowest position by means of the cylinder 106a of the rod-height-determining device 106. Then the many cylinders 105a are raised until the upper surfaces of the piston rods 105h contact the lower surface of the positioning member 106b. Thus, all of the many cylinders 105a are stopped in the intermediate position.
By rotating the turntable 8 in this state, the pattern carrier 9 for a lower flask, the empty flask W, and the filling frame 102, are conveyed to a position outside the base 1, and the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frame 102, are conveyed to a position above the table 3. This state is shown in Fig. 12. Next, the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frame 102, are raised along with the table 3 by extending the raising and lowering cylinder 2. Then the upper surface of the surrounding frame 11 in the pattern carrier 9A for an upper flask is caused to protrude (30 mm in this embodiment) above the parting plane of the pattern plate 10A, by extending the cylinders 12 for raising and lowering a surrounding frame. Then the positioning member 106b is raised by retracting the cylinder 106a for raising and lowering a positioning member. Thereby the lower surface of the positioning member 106b is separated from the upper surfaces of the piston rods 105h.
Also, outside the base 1, the pattern carrier 9 for a lower flask, the empty flask W, and the filling frame 102, are raised by extending the cylinder 21b for raising and lowering a pattern carrier. Thereby the lower surface of the sand hopper 22a is made to contact the upper surface of the filling frame 102 that is conveyed to a position outside the base 1. Thereby a molding space is formed by the pattern plate 10, the empty flask W, and the filling frame 102 that are placed in the pattern carrier 9 for a lower flask. This state is shown in Fig. 13. Then a mold-releasing agent is sprayed in the molding space by means of a device for spraying such a mold-releasing agent. The device is not illustrated. Incidentally, in the state shown in Fig. 13, the upper surfaces of the contacting members 102a disposed at both ends of the filling frame 102 that is located above the base 1 contact the lower surfaces of the heads 104 at the tips of the downwardly facing cylinders 103.
Next, the foundry sand S is squeezed a first time by extending the raising and lowering cylinder 2 to further raise the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frame 102, along with the table 3. The flask-conveying conveyor 101 is closed by means of an opening and closing device that is not illustrated (for example, a cylinder). This state is shown in Fig. 14.
Next, the foundry sand S is squeezed a second time by extending the raising and lowering cylinder 2 to raise the pattern plate 10A until the upper surface of the surrounding frame 11 and the parting plane of the pattern plate 10A in the pattern carrier 9A for an upper flask are located at the same height. During this period, the flask W and the filling frame 102 are kept pinched by the surrounding frame 11 and the heads 104.
Also, outside the base 1, the foundry sand S is supplied into the molding space by means of the sand-filling device 22. Now, the details of this point are explained. First, the opening and closing cylinder 25d of the device 25 for opening and closing the sand-feeding opening is extended to close the sand-feeding opening 25b by the gating member 25c. When a switching valve (not illustrated) is opened, compressed air blows out of the porous body 26b through the hollow chamber 26a. Then a plurality of rotating shafts 24a of the openable louver gates 24 are forwardly rotated by means of the cylinders for opening and closing a gate (the louver gates 24 are opened). Incidentally, the cylinders are not illustrated. The plurality of gating plates 24b are changed from a horizontal state to a vertical state. By doing so, the foundry sand S in the sand hopper 22a is supplied into the molding space. This state is shown in Fig. 15. Incidentally, the blowout of the compressed air out of the porous body 26b is continued while the foundry sand S is supplied into the molding space. Then the compressed air is discharged through a vent hole that is provided on the pattern plate 10 and that is not illustrated or through a vent hole that is provided on the side of the filling frame 102 and that is also not illustrated.
Next, the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frame 102, are further raised along with the table 3 by further extending the raising and lowering cylinder 2 after the elevation of the pattern plate 10A in the second squeeze is finished. Thereby the foundry sand S is squeezed a third time. The state is shown in Fig. 16. Also, outside the base 1, the foundry sand S in the molding space is preliminarily compressed by opening the air-supplying valve 28 to cause compressed air to flow through the foundry sand S in the molding space (the foundry sand S is preliminarily compressed by so-called air pressure). Then the compressed air that remains in the sand hopper 22a is discharged by opening an exhaust valve that communicates with the casing 25a (not illustrated).
Next, the pattern plate 10A in the pattern carrier 9A for an upper flask is lowered. Thereby the pattern plate 10A is separated from the foundry sand. During this period, the state in which the flask W and the filling frame 102 are pinched by the surrounding frame 11 and the heads 104 is maintained. So, the surrounding frame 11, the flask W, and the filling frame 102, do not move vertically. For this reason, the pattern plate is separated by lowering the pattern plate 10A by only a predetermined distance (30 mm in this embodiment).
Also, outside the base 1, the pattern carrier 9 for a lower flask, the flask W, and the filling frame 102, are lowered by retracting the cylinder 21b for raising and lowering a pattern carrier. Thereby, the upper surface of the filling frame 102 is separated from the lower surface of the sand hopper 22a. This state is shown in Fig. 17.
Next, the pattern carrier 9A for an upper flask, the flask W, and the filling frame 102 are lowered by retracting the raising and lowering cylinder 2. By doing so, the flask W is placed on the rollers 101e. At the same time, the downwardly facing cylinders 103 are extended along with the descent of the filling frame 102. Then the surrounding frame 11 is lowered by retracting the cylinder 12 for raising and lowering a surrounding frame when the table 3 is located at the lowest position.
Also, outside the base 1, a plurality of rotating shafts 24a of the openable louver gates 24 are reversely rotated by means of a cylinder for opening and closing the gate. Incidentally, the cylinder is not illustrated. Thereby a plurality of gating plates 24b are changed from a vertical state to a horizontal state (the louver gates 24 are closed). Then the sand-feeding opening 25b is opened by retracting the opening and closing cylinder 25d of the device 25 for opening and closing the sand-feeding opening. Then the foundry sand S is supplied into the sand hopper 22a through the sand-feeding opening 25b by means of a device for supplying foundry sand (for example, a belt feeder). Incidentally, the device is not illustrated. This state is shown in Fig. 18.
Next, the filling frame 102 is raised along with the members 101c for placing a filling frame and the locating pins 101d by extending the cylinder 101b for raising and lowering a filling frame. During this period, the downwardly facing cylinders 103 are retracted along with the elevation of the filling frame 102.
Next, all of the many cylinders 105a are operated such that the piston rods 105h are lowered to lower all the squeezing feet 105b to their lowest positions. Then the positioning member 106b is lowered to its lowest position by extending the cylinder 106a for raising and lowering a positioning member. Then, all of the many cylinders 105a are operated to raise the piston rods 105h such that the upper surfaces of all the piston rods 105h contact the lower surface of the positioning member 106b. Thus, all of the many cylinders 105a are stopped in a position corresponding to half of the entire stroke, i.e., in an intermediate position. The state is shown in Fig. 19.
Next, the molded flask W is conveyed off by the flask-conveying conveyor 101. Then another empty flask W is conveyed to a position between the filling frame 102 and the pattern carriers 9A for an upper flask. Then, another empty flask W is placed on the pattern carrier 9A for an upper flask by extending the raising and lowering cylinder 2. Then the flask W is raised a little above the rollers 101e. Then the filling frame 102 is lowered to place it on the empty flask W by retracting the cylinder 101b for raising and lowering a filling frame. This state is shown in Fig. 20. At this time, the downwardly facing cylinders 103 are extended along with the descent of the filling frame 102. The positions of the members 101c for placing a filling frame and the position of the filling frame 102 are no longer determined by means of the locating pins 101d.
Next, the flask-conveying conveyor 101 is opened by means of an opening and closing device (not illustrated). Then the empty flask W and the filling frame 102 are lowered by retracting the raising and lowering cylinder 2. This state is shown in Fig. 11. Then these operations are repeated.
Incidentally, in the first squeeze, in the second squeeze, and in the third squeeze, in the second embodiment, the squeezing device 105 operates as follows. As in Fig. 22, the oil in an upper oil-pressure chamber 105d of a cylinder 105a in which a squeezing foot 105b is quickly raised flows into another upper oil-pressure chamber 105d of another cylinder 105a that is located near the former cylinder. Thereby a squeezing foot 105b of the latter cylinder 105a near the former cylinder is lowered. The back side of a mold can be squeezed by a uniform pressure, because the squeezing device operates in such a way.
In the second embodiment, either after or while the third squeeze is being carried out, oil may be supplied into the upper oil-pressure chambers 105d of all the cylinders 105a to squeeze the back side of a mold by the squeezing feet 105b of all the cylinders 105a.
The rod-height-determining device 106 in the second embodiment is configured such that the plate-like positioning member 106b is raised and lowered by means of the cylinder 106a for raising and lowering the positioning member. However, the device is not limited to that configuration. The plate-like positioning member may be moved horizontally by means of an actuator (for example, a traversing cylinder). In this case, for example, the positioning member should have respective holes through which the piston rods 105h can pass. The positioning member is connected to the tip of the traversing cylinder to allow the positioning member to move horizontally. In this case, each of the centers of the piston rods 105h coincide with the centers of the holes when the traversing cylinder is extended to its end. So, the piston rods 105h can pass through the holes unrestrictedly. Also, the surfaces of the piston rods 105h do not coincide with the holes when the traversing cylinder is fully retracted. So, the upper surfaces of all the piston rods 105h contact the lower surface of the positioning member (a position in which no hole is formed) when all the piston rods 105h are raised after they are lowered and then the traversing cylinder is fully retracted. In this way, as in the second embodiment, all of the many cylinders 105a can be stopped in the position corresponding to half of the distance of the entire stroke, i.e., in the intermediate position.
In the second embodiment of the present invention, outside the base 1, the pattern carrier (9A in Fig. 11), the flask W, and the filling frame 102, are raised and lowered by means of the device 21 for raising and lowering a pattern carrier. However, the apparatus is not limited to this configuration. The sand-filling device 22 may be raised and lowered instead of raising and lowering the pattern carrier, the flask W, and the filling frame 102. In this case, a molding space is formed by lowering the sand-filling device 22 to cause the lower surface of the sand hopper 22a to contact the upper surface of the filling frame 102 that is conveyed to a position outside the base 1. Incidentally, for example, a raising and lowering cylinder may be connected to the sand-filling device 22, to raise and lower the sand-filling device 22.
Further, in the second embodiment of the present invention, a body produced by sintering a polyethylene having an ultra high molecular weight was exemplified as the porous body 26b. However, the porous body 26 is not limited to such a body. The porous body 26b may be a plate-like material having many holes (for example, round holes each having a diameter of from 1 mm to 2 mm).
Further, in the second embodiment of the present invention, the flask-conveying conveyor 101 can be neither raised nor lowered. However, the conveyer is not limited to this. The flask-conveying conveyor 101 may be raised and lowered.
Further, in the second embodiment of the present invention, the foundry sand S is preliminarily compressed by air pressure by opening the air-supplying valve 28, which communicates with the sand-filling device 22, after the step for filling the molding space with the foundry sand S by means of the sand-filling device 22 is carried out. However, the preliminary compression of the foundry sand S by air pressure is not indispensable. So, the preliminary compression may be omitted. However, the preliminary compression of the foundry sand S by air pressure is preferably carried out, because the density of the foundry sand S packed near the pattern plate 10, 10A is thereby increased.
In the first and the second embodiment of the present invention, in the step carried out before the step of the first squeeze above the base 1, the upper surface of the surrounding frame 11 in the pattern carrier 9A for an upper flask is caused to protrude above the parting plane of the pattern plate 10A, after the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frames 17, 102, are raised. However, the order can be changed. The pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frames 17, 102, may be raised, after the upper surface of the surrounding frame 11 in the pattern carrier 9A for an upper flask is caused to protrude above the parting plane of the pattern plate 10A. Further, the step for raising the pattern carrier 9A for an upper flask, the flask W that is filled with foundry sand S, and the filling frames 17, 102, and the step for causing the upper surface of the surrounding frame 11 in the pattern carrier 9A for an upper flask to protrude above the parting plane of the pattern plate 10A, may be carried out at the same time.

Explanations of letters and numerals

1	Base
2	Raising and Lowering Cylinder
3	Table
9 9A	Pattern Carrier
10 10A	Pattern Plate
11	Surrounding Frame
15, 101	Mechanism for conveying the Flask on and off
17, 102	Filling Frame
20, 105	Squeezing Device
20b,105b	Squeezing Member
22	Sand-filling Device
22a	Sand Hopper
24	Openable Louver Gate
25	Opening and Closing Device for the Sand-feeding Opening
25b	Sand-feeding Opening
26	Air-blowing Chamber
28	Air-Supply Valve
S	Foundry Sand
W	Flask

Claims

An apparatus for molding a mold by filling foundry sand into a molding space that is defined by a pattern plate placed on a pattern carrier, a flask, and a filling frame by means of a sand-filling device, and then by squeezing the foundry sand in the molding space to mold a mold by means of a squeezing device,
wherein the sand-filling device comprises the following: a sand hopper that stores foundry sand in its inside and that is disposed above the flask and the filling frame; an openable louver gate disposed inside the sand hopper; an opening and closing device that is disposed above the sand hopper and that can open and close a sand-feeding opening that serves as an opening for supplying the foundry sand into the sand hopper; and an air-blowing chamber attached to an inner surface of the sand hopper.
The apparatus of claim 1, wherein the apparatus further comprises the following:
a raising and lowering cylinder attached to a base;

a table connected to the raising and lowering cylinder; and

a mechanism for conveying the flask to and from a position above the pattern carrier;

wherein the pattern carrier that carries the pattern plate and comprises a surrounding frame that can move up and down while the surrounding frame surrounds an outer circumference of the pattern plate,

wherein the pattern carrier is conveyed to and from a position above the table,

wherein the squeezing device is disposed inside the mechanism for conveying the flask,

wherein the filling frame is disposed above the flask such that it can rise and fall, and

wherein the sand-filling device is disposed outside the base and supplies the foundry sand in the molding space that is defined by the pattern plate, the flask, and the filling frame that are conveyed from a position above the table to a position outside the base.
The apparatus of claim 1 or 2, wherein an air-supplying valve is connected to the sand-filling device.
A method for molding a mold by filling foundry sand into a molding space that is defined by a pattern plate placed on a pattern carrier, a flask, and a filling frame by means of a sand-filling device and then by squeezing the foundry sand in the molding space to mold a mold by means of a squeezing device,
wherein the method comprises the following:
a step for filling the molding space with the foundry sand by means of the sand-filling device,

a step for closing a device for opening and closing a sand-feeding opening in the sand-filling device,

a step for blowing out air from an air-blowing chamber attached to an inner surface of a sand hopper in the sand-filling device, and

a step for opening an openable louver gate in the sand-filling device.
The method of claim 4, wherein the method comprises the following:
a step for conveying a first pattern carrier, an empty flask, and a filling frame to a position outside a base and for conveying a second pattern carrier, a flask that is filled with foundry sand, and a filling frame to a position above a table,

wherein the two pattern carriers on which the pattern plate is placed each comprise a surrounding frame that can move up and down while the surrounding frame surrounds an outer circumference of the pattern plate,

wherein the step for conveying the two pattern carriers is carried out in a state in which the first pattern carrier is disposed at a position above the table, and in which the second pattern carrier is disposed at a position outside the base, and in which the empty flask and the filling frame are placed on the first pattern carrier, and in which the flask that is filled with foundry sand and the filling frame are placed on the second pattern carrier,

a step for raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame,

a step for causing the upper surface of the surrounding frame in the second pattern carrier to protrude above a parting plane of the pattern plate,

a step for causing a lower surface of the sand hopper to contact the upper surface of the filling frame that has been conveyed to a position outside the base to form a molding space by the pattern plate that is placed on the first pattern carrier, the empty flask, and filling frame,

a step for lowering the squeeze member in the squeezing device to squeeze the foundry sand a first time,

a step for closing a mechanism for conveying a flask,

a step for squeezing the foundry sand a second time by lowering the squeeze member while the pattern plate is being raised until the upper surface of the surrounding frame in the second pattern carrier and the parting plane of the pattern plate are placed at the same height,

a step for filling the foundry sand into the molding space by means of the sand-filling device,

a step for further lowering the squeeze member to squeeze the foundry sand a third time after the pattern plate is raised in the second squeeze,

a step for lowering the pattern plate in the second pattern carrier to separate the pattern plate from the foundry sand,

a step for separating the sand hopper from the filling frame that has been conveyed to a position outside the base,

a step for lowering the second pattern carrier,

a step for closing the openable louver gate in the sand-filling device,

a step for opening the device for opening and closing the sand-feeding opening in the sand-filling device and for supplying the foundry sand from the sand-feeding opening to the sand hopper,

a step for conveying an empty flask to a position between the filling frame that is disposed above the second pattern carrier and the second pattern carrier,

a step for placing the empty flask and the filling frame on the second pattern carrier, and

a step for opening the mechanism for conveying the flask.
The method of claim 4, wherein the method comprises the following:
a step for conveying a first pattern carrier, an empty flask, and a filling frame to a position outside the base and for conveying a second pattern carrier, a flask that is filled with foundry sand, and a filling frame, to a position above the table,

wherein the two pattern carriers on which the pattern plate is placed each comprise a surrounding frame that can move up and down while the surrounding frame surrounds an outer circumference of the pattern plate,

wherein the step for conveying the two pattern carriers is carried out in a state in which the first pattern carrier is disposed at a position above the table, and in which the second pattern carrier is disposed at a position outside the base, and in which the empty flask and the filling frame are placed on the first pattern carrier, and in which the flask that is filled with foundry sand and the filling frame are placed on the second pattern carrier,

a step for raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame,

a step for causing the upper surface of the surrounding frame in the second pattern carrier to protrude above the parting plane of the pattern plate,

a step for causing the lower surface of the sand hopper to contact the upper surface of the filling frame that has been conveyed to a position outside the base to form a molding space by the pattern plate that is placed on the first pattern carrier, the empty flask, and the filling frame,

a step for further raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame, to squeeze the foundry sand a first time,

a step for closing a mechanism for conveying a flask,

a step for raising the pattern plate to squeeze the foundry sand a second time until the upper surface of the surrounding frame and the parting plane of the pattern plate in the second pattern carrier are located at the same height,

a step for filling the molding space with the foundry sand by means of the sand-filling device,

a step for further raising the second pattern carrier, the flask that is filled with foundry sand, and the filling frame, to squeeze the foundry sand a third time after the pattern plate is raised in the second squeeze,

a step for lowering the pattern plate in the second pattern carrier to separate the pattern plate from the foundry sand,

a step for separating the sand hopper from the filling frame that has been conveyed to a position outside the base,

a step for lowering the second pattern carrier,

a step for closing the openable louver gate in the sand-filling device,

a step for opening the device for opening and closing the sand-feeding opening in the sand-filling device and for supplying the foundry sand from the sand-feeding opening to the sand hopper,

a step for conveying an empty flask to a position between the second pattern carrier and the filling frame that is disposed at a position above the second pattern carrier ,

a step for placing the empty flask and the filling frame on the second pattern carrier, and

a step for opening the mechanism for conveying the flask.
The method of claim 4, 5, or 6, wherein the foundry sand in the molding space is preliminarily compressed by blowing compressed air through the foundry sand by opening an air-supplying valve that communicates with the sand-filling device after the step for filling the molding space with the foundry sand by means of the sand-filling device.