JP2001300691A - Molding method for mold with flask and apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding method for mold with a flask with which the generation of spill sand and cut sand is drastically reduced and also, the compression of molding sand is uniformly performed to the whole mold at a low cost, and an apparatus thereof. SOLUTION: This molding method for mold with the flask is peculiarly provided with an aeration process after charging the molding sand into a sand hopper, a process for filling with air in the aerated molding sand into a molding space, a process for primarily squeezing the molding sand by lowering and inserting squeeze-foot, a process for secondarily squeezing the molding sand by lowering the squeeze-foot, an upper auxiliary flask and a molding flask toward a pattern plate while lowering a snupflask and a process for removing the flask by raising together with the squeeze-foot, the upper auxiliary flask and the molding flask while raising the snupflask, and this apparatus is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a framed sand mold for alternately molding upper and lower sand molds into and out of an empty cast frame that is carried in.

[0002]

2. Description of the Related Art Conventionally, when a sand mold is formed in a casting flask, molding sand is charged and filled into a space in which a casting frame and a filling frame are overlapped on a pattern plate. A method is generally employed in which casting sand is flattened and then compressed using a flat squeeze plate or a segment type squeeze foot.

[0003]

However, as described above, there is a problem that a large amount of spill sand is generated when the casting sand is charged and filled into the casting flask and leveled. Further, in the compression of molding sand using a flat squeeze plate, there is a problem that the compression becomes uneven at the high portion and the low portion of the pattern plate model, and the compression is particularly insufficient at the low portion of the model. In the case where the molding sand is compressed by the squeeze foot of the segment type, the upper surface of the molded sand mold is not flattened, and an operation of shaving the uneven surface after the molding is required. The present invention has been made in view of the above problems, and significantly reduces the occurrence of spill sand and cutting sand, and the molding sand is uniformly compressed throughout the mold, and a frame with a low cost can be provided. An object of the present invention is to provide a method for molding a sand mold and an apparatus therefor.

[0004]

In order to achieve the above object, a method of forming a sand mold with a frame according to the present invention is provided. The method comprises the steps of: introducing casting sand into a sand hopper; A step of forming an air jet for ejecting air from the inside to float and fluidize the molding sand, and forming a pattern plate, a cutting frame,
A step of filling the molding space defined by the squeeze foot of the segment type in which the irregularities corresponding to the irregularities of the casting frame, the filling frame and the pattern plate are formed with the air through the sand filling nozzle by the air. A step of lowering and inserting the segment type squeeze foot to primary squeeze the molding sand; and a step of lowering the punching frame to integrally pattern the segment type squeeze foot, fill frame and casting frame. A step of lowering the molding sand toward the secondary squeezing to perform secondary squeezing, and a step of integrally moving the segment type squeeze foot, filling frame and casting frame while removing the molding frame to remove the mold. , Are provided.

Further, the apparatus for molding a sand mold with a frame according to the present invention comprises an elevating support frame erected between upper ends of frame set cylinders erected on both right and left sides of a molding base; Rotatably supported by one of the
A pattern carrier in which pattern carriers on which pattern plates are placed can be alternately carried into and out of the upper center of the molding base.
And an air-ejecting chamber suspended from and supported by the lifting and lowering support frame, and forming an air-earing chamber for emitting air to the lower peripheral side and / or the lower inner part to float and fluidize the molding sand. Sand hopper, a segment-type squeeze foot disposed at the lower end of the sand hopper so as to be capable of ascending and descending stop control, a sand filling nozzle disposed around the segment-type squeeze foot, A squeeze foot and a sand filling nozzle which surrounds the outside of the group of sand filling nozzles so as to be able to move up and down and which is provided with a vent hole on the upper side and which is connected to a filling frame cylinder; And a conveyor for loading and unloading the flask, which is suspended via a frame extending to a position below the segment type squeeze foot on the outside. It is an.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. In FIG. 1, frame set cylinders 2 and 2 are set upright on both right and left sides of a molding base 1, and an elevating support frame is provided between the ends of the piston rods 2A and 2A of the frame set cylinders 2 and 2. 3 are installed. The center of the turntable 4 is rotatably supported below one of the frame set cylinders 2 (left side in FIG. 1), and at both ends of the turntable 4 Is set in a state where the pattern carriers 6, 6A on which the pattern plates 5, 5A (upper and lower pattern plates) are placed are lifted by about 5 mm by a spring (not shown), and the pattern plates are set. 5, 5A are alternately carried into and out of the upper center of the molding base 1.

At the outer sides of the four corners of the pattern plates 5, 5A of the pattern carriers 6, 6A, extraction cylinders 7, 7A are buried facing upward, and the leading ends of the pattern cylinders 7, 7A are embedded in the pattern carriers 5, 6A. The frame-shaped release frames 8, 8A that slide up and down around the outer circumferences of the ports 5, 5A are connected and supported. The release frames 8, 8A project slightly upward from the parting surfaces of the pattern plates 5, 5A at the extended ends of the lifting cylinders 7, 7A (see FIG. 1), and at the retracted ends, the pattern presses, 8A. 5 and 5A are substantially flush with the parting surface (FIG. 5).
See).

The lifting support frame 3 is provided at its upper end with a sand inlet 10 which is opened and closed by a slide gate 9, and has a lower pressure air (for example, 0.05 to 0.05) through a switching valve (not shown) on the upper side. 0.18 MPa), and a number of air ejection chambers 11, 11 communicating with a compressed air source (not shown) through one switching valve (not shown) on the lower peripheral side and the lower inside through a switching valve (not shown).
Is suspended from the sand hopper 12. It should be noted that low pressure air (for example, 0.05 to 0.18 MPa) is blown into the sand hopper 12 from the plurality of air blowing chambers 11 and 11 so as to form an air suspension for floating the casting sand S. Is configured. Further, at the lower end of the sand hopper 12, segment type squeeze feet 13, 13 and a sand filling nozzle 1 around the squeeze feet 13, 13 are provided.
4 and 14 are provided.

Also, the outside of the group of the segment type squeeze feet 13, 13 and the sand filling nozzles 14, 14 is vertically movable so as to surround and surround the vent holes 15, 15 communicating with an exhaust control chamber (not shown). Is pierced, and is arranged in connection with the bottom frame cylinders 17, 17 provided downward on the lower side of the sand hopper 12. Further, at the left and right outer positions of the sand hopper 12 in the lifting support frame 3, the conveyors 19 for loading and unloading the casting flask 20 via the frames 18, 18 extending to positions below the squeeze feet 13, 13 of the segment type. Is suspended.

Next, the operation of the above-described apparatus will be described in detail. In the state of FIG. 1, the casting sand S is put into the sand hopper 12, and the segment type squeeze foot 13,
The entire surface 13 forms irregularities in opposition to the irregularities of the lower pattern plate 5, and the empty casting frame 20
Has been carried in. The pattern carrier 6 is set on the turntable 4 while being lifted up by about 5 mm by a spring (not shown), and has a gap of about 5 mm between the pattern carrier 6 and the molding base 1. The release frame 8 is projected upward from the parting surface of the pattern plate 5 by the lifting cylinders 7,7.

In this state, the slide gate 9 is operated to close the sand inlet 10, and then the filling cylinders 17, 17 are extended to lower the filling frame 16 and press it tightly against the upper surface of the casting flask 20. At the same time, the frame setting cylinders 2 and 2 are contracted and the cast frame 20 is pressed onto the die-cut frame 8 projecting upward at the outer periphery of the pattern plate 5 to form the pattern.
The carrier 6 is pressed down against a spring (not shown), and is pressed on the molding base 1 to obtain the state shown in FIG. At this time, the molding space defined by the pattern plate 5, the punching frame 8, the casting frame 20, the filling frame 16, and the squeeze feet 13, 13 is such that the squeeze feet 13, 13 are irregularities of the pattern plate 5. Is formed in a concavo-convex shape corresponding to.

Next, a number of air ejection chambers 11, 1
1 to supply air 2 through a switching valve (not shown) while causing low-pressure air to be blown out into the sand hopper 12 to cause air to float and float the molding sand S in the sand hopper 12.
1 to supply sand to the sand hopper 12 to supply molding sand S to the molding space by means of the low-pressure air.
Then, as shown in FIG. At this time, the low-pressure air at the time of filling the air hole is exhausted from a vent hole (not shown) of the vent hole 15 and / or the pattern plate 5. The amount of exhaust from the vent plate 15 (not shown) of the pattern plate 5 can be controlled by controlling the amount of exhaust from the vent hole 15 in an exhaust control chamber (not shown). This makes it possible to partially adjust the filling density of the molding sand in the complicated shape portion of the pattern plate 5 in the molding space.

Next, the frame setting cylinders 2 and 2 are further contracted to lower the ascending / descending support frame 3 and the members supported by this while contracting the filling frame cylinders 17 and 17 to obtain segments. Squeeze feet 13, 13
Primary squeezing of the molding sand S is performed until the entire lower surface is flat, and the slide gate 9 is operated in reverse to make the sand inlet 10
Is released to the state shown in FIG. At this time, the contraction operation of the frame set cylinders 2 and 2 is performed when the squeeze pressure reaches the set pressure of the primary squeeze by a pressure sensor (not shown) or the encoder position (not shown) of the frame set cylinders 2 and 2 is set to the primary squeeze. It continues until it reaches the set position.

Next, by switching to the state of relieving the oil of the withdrawal cylinders 7 and 7, the frame setting cylinders 2 and 2 perform the contraction operation at a pressure higher than the primary squeeze, thereby forming the casting frame 20 and the filling frame 16. , And squeeze feet 13, 1
3 descends together to secondary squeeze the entire casting sand S. As a result, the removal frame 8 is removed from the lifting cylinders 7, 7
Is lowered to a level substantially the same as the cut surface of the pattern plate 5, and the state shown in FIG. If the squeeze pressure has not reached the secondary squeeze set pressure when the removal frame 8 reaches the lower end, the frame set cylinders 2, 2 are moved while the filling frame cylinders 17, 17 are contracted. Further squeezing is performed by further contracting.

Next, when the squeeze pressure reaches the set pressure of the secondary squeeze, a squeeze stabilization timer is operated to hold the squeeze for a predetermined time. At this time, in order to cope with the case where the removal frame 8 has not reached the lower end, the filling frame cylinders 17 and 17 are extended to lower the filling frame 16 and the removal frame 8 reaches the lower end. The casting flask 20 is pushed down until it. Thereby, the protrusion dimension of the mold with respect to the lower surface of the flask 20 can be made constant every time.

Next, the pull-out cylinders 7, 7 are extended to press the casting frame 20 against the filling frame 16 via the pull-out frame 8, and the frame setting cylinders 2, 2 operate in reverse to pull out the die. At this time, the filling frame cylinders 17, 17 are raised integrally with the casting flask 20 and the squeeze feet 13, 13. After that, the casting flask 20 in which the mold is formed is pulled up and supported by the pulling-up cylinders 7 and 7 via the pull-out frame 8, while
Fill frame 16 and segment type squeeze feet 13, 1
The casting frame 20 on which the mold is formed is scooped up by the carry-in / out conveyor 19 to be completely separated from the pattern plate 5 and the molding sand S is transferred to the sand hopper 12 on the way. And the state shown in FIG. 6 is obtained. At this time, the molded mold is lifted slightly from the stopped state together with the casting frame 20 to be released, and the piston rods 2A, 2A of the frame set cylinders 2, 2 are removed in the most contracted state, so that the removal accuracy is improved. It is expensive.

Next, the casting flask 20 in which the mold is formed is carried out through the carrying-in / out conveyor 19, and the empty casting flask 20 is carried in, and the turntable 4 is rotated by 180 degrees to form a pattern plate. The pattern plate 5 is replaced with the pattern plate 5A, and the segment type squeeze feet 13, 13 are actuated to form irregularities corresponding to the irregularities of the pattern plate 5A. Is repeated.

In the embodiment of the present invention, the sand hopper 1
A low-pressure air is jetted from the lower peripheral side and the lower inner part of the casting sand 2 to float and fluidize the foundry sand.
A low-pressure air may be ejected from the lower peripheral side or the lower inner side of the molding sand to float and fluidize the molding sand. Further, in the embodiment of the present invention, the preliminary compression of the molding sand by the pressurized air is not performed, but the preliminary compression of the molding sand by the pressurized air is provided by providing a rotating gate, a compressed air inlet, and the like. May be performed. Further, in the embodiment of the present invention, one switching valve (not shown) is communicated with the plurality of air-ejection chambers 11 and 11. However, each air-ejection chamber 11 is provided with each switching valve. Low pressure air
May be partially adjusted.

[0019]

According to the present invention, as apparent from the above description, casting sand is injected into the sand hopper and then air is ejected from the lower peripheral side and / or lower inside of the sand hopper to float the casting sand. A step of forming an fluidized air sand, and removing the air sand from the molding sand by using a pattern plate, a punching frame, a casting frame, a filling frame, and unevenness corresponding to the unevenness of the pattern plate. A step of filling the molding space defined by the formed segment type squeeze foot with air through a sand filling nozzle by air, and lowering and inserting the segment type squeeze foot to primarily squeeze molding sand. A second squeezing of the molding sand by lowering the die frame and lowering the segment type squeeze foot, the filling frame and the casting frame integrally toward the pattern plate while lowering the mold release frame. A step of the cutting die frame - squeezing of the segment type while raising the arm foot,
A step of integrally raising the casting frame and the casting flask and removing the mold, so that the generation of spill sand and cutting sand can be greatly reduced, and the molding sand can be quantitatively and efficiently filled and the pattern can be removed. Squeezing can be performed on the entire mold in conformity with the irregularities of the template, and there is an effect that a uniform mold can be formed. Further, since the hydraulic power and the air consumption can be reduced, the cost can be reduced by saving energy. Furthermore, the adoption of the punching frame has various effects such as a two-stage (secondary) squeeze and a high precision punching.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state of a device of the present invention before starting.

FIG. 2 is a longitudinal sectional view showing a state where a molding space is defined.

FIG. 3 is a longitudinal sectional view showing a state in which casting sand is charged by air.

FIG. 4 is a longitudinal sectional view showing a primary squeeze state of molding sand.

FIG. 5 is a longitudinal sectional view showing a secondary squeeze state of molding sand.

FIG. 6 is a vertical cross-sectional view showing a state in which a molding die is removed and a molding sand is supplied.

FIG. 7 is a longitudinal sectional view showing a pattern change state.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Molding base 2 Frame set cylinder 4 Turntable 5 5A Pattern plate 6 6A Pattern carrier 7 7A Pull-out cylinder 8 8A Pull-out frame 11 Air ejection chamber 12 Sand hopper 13 Squeeze foot 14 Sand filling nozzle 15 Vent hole 16 Fill frame 17 Fill frame cylinder 19 Carry-in / out conveyor 20 Mold frame S Foundry sand

Claims (3)

[Claims] 1. A step of introducing molding sand into a sand hopper and then jetting air from a lower peripheral side and / or a lower inside of the sand hopper to form an air line for floating and fluidizing the molding sand. Aerating molding sand is used for pattern plate, die-cut frame, casting frame, fill frame and pattern plate.
Filling the molding space defined by the segment type squeeze foot with the unevenness corresponding to the unevenness of the air through the sand filling nozzle by air, and inserting the segment type squeeze foot downward. And primary squeezing of the molding sand,
Moving the segment type squeeze foot, fill frame and casting frame together toward a pattern plate while lowering the casting frame to secondary squeeze molding sand, and raising the die-cut frame. A step of integrally raising the segment type squeeze foot, filling frame, and casting frame while removing the mold, and removing the mold. 2. An elevating support frame 3 erected between upper ends of frame setting cylinders 2 and 2 erected on both right and left sides of a molding base 1 and one of the frame setting cylinders 2 and 2. A pattern table 4 rotatably supported and having pattern carriers 6 and 6A on which pattern plates 5 and 5A are mounted alternately carried into and out of the upper center of the molding base 1.
An air ejection chamber 11 suspended from and supported by the lifting and lowering support frame 3 and configured to emit air toward the lower peripheral side and / or the lower interior to form an air line for floating and fluidizing the molding sand; Sand hopper 12 provided with
2, a segment-type squeeze foot 13, 13 disposed at the lower end of the segment 2 so as to be capable of lifting and lowering control, a sand filling nozzle 14, 14 disposed around the segment-type squeeze foot 13, 13, and the segment. Squeeze feet 13, 13 and sand filling nozzle 14,
14 are vertically movable so as to surround them, and are provided with vent holes 15
A filling frame 16 connected to the lifting frames 7 and 17;
And a conveyor 19 for loading and unloading cast frames suspended via frames 18, 18 extending to positions below the squeeze feet 13, 13 of the segment type on the left and right sides of the sand hopper 12 in the frame 3. A molding apparatus for a sand mold with a frame. 3. The pattern carriers 6, 6A are provided with frame-shaped release frames 8, 8A which surround the outer sides of the pattern plates 5, 5A and slide up and down. The molding device for a sand mold with a frame according to claim 2, wherein