JP4203839B2 - Mold making method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold making method and an apparatus therefor, and more specifically, a sand filling space is defined by a model plate, a casting frame, a filling frame, a sand tank, and a plurality of squeeze feet that are raised and lowered by an air cylinder, The present invention relates to a method and an apparatus for molding a mold so that the density of the mold molded in the frame is substantially uniform and the surface corresponding to the back surface of the cavity surface of the mold is substantially the same as the surface of the casting frame.
[0002]
[Prior art]
The present applicant has previously described a method for filling casting sand so that the density of the mold in the casting mold is substantially uniform, and the surface corresponding to the back of the cavity surface of the casting mold is substantially the same as the surface of the casting mold. The present invention provides a mold making method and apparatus using the casting sand filling method.
[0003]
[Problems to be solved by the invention]
However, in the mold molding method configured in this way, the blown foundry sand enters between a plurality of squeeze feet, or the foundry sand is solidified during pre-compression, so that the foundry sand moves appropriately during the main compression. As a result, the molded mold has a problem that the desired characteristics of having a substantially uniform density cannot be obtained.
[0004]
The present invention has been made in view of the above-mentioned circumstances, and its purpose is to reserve, in particular, the upper sand of the foundry sand filled in the sand filling space defined by the model plate, the casting frame, the plurality of squeeze feet, etc. It is an object of the present invention to provide a mold making method and apparatus capable of moving when the main compression is performed after the compression.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the mold making method of the present invention defines a sand filling space by a model plate, a casting frame, a filling frame, a sand tank, and a plurality of squeeze feet that are lifted and lowered by an air cylinder. A method for molding a mold so that the density of the mold molded in the casting frame is made substantially uniform by compression of the molding sand in the space, and the surface corresponding to the back of the cavity surface in the casting mold is substantially the same as the surface of the casting frame A sand filling space is defined by the model plate, the casting frame, the fill frame, the sand tank, and the plurality of squeeze feet, and the plurality of squeeze feet are formed by a model portion of the model plate. so as to form the required interval in, i.e., the plurality of intervals form between model part of the model plate that faces the plurality of squeezing feet and interact with these prior compression of molding sand a, and B When these are a and b after compression, these ratios a / A and a step of ascending or descending the plurality of squeeze feet so that b / B substantially satisfies the relationship of a / A = b / B, and after filling the sand-filling space with foundry sand, the plurality of squeeze feet The sand tank and the plurality of squeeze feet are brought close to each other while maintaining the relative positional relationship of the results of each of the ascending and descending to form a required interval, and the foundry sand is made to approach Pre-compressing, detecting reaction force to the squeeze foot , and exceeding a set value, raising the lowered squeeze foot so that all squeeze feet are not lowered, and A step of bringing the sand tank and the plurality of squeeze feet closer to each other with respect to the model plate and finally compressing the foundry sand in the sand-filled space. And wherein the door.
[0006]
[Example 1]
Hereinafter, an embodiment of a mold making machine to which the present invention is applied will be described in detail with reference to FIG. 1 and FIG. As shown in FIG. 1, the mold making machine includes a model plate 2 attached on a platen-shaped conveying member 1, a casting frame 3 disposed on the model plate 2, and a casting frame. 3, a filling frame 4 disposed above and below the casting frame 3, a sand tank 5 disposed above the casting frame 3 and having a lower portion slidably fitted to the filling frame 4, A plurality of squeeze feet 7, 7 mounted on the lower part of the sand tank 5 so as to be movable up and down by an air cylinder 6.
[0007]
Two conveying members 1 are provided so that they can enter and exit directly below the filling frame 4 via horizontal rotating arms 8 and 8, and an extension operation of a positioning cylinder 9 mounted on a machine base 14 to be described later. As a result, the piston rod of the positioning cylinder 9 enters the recess of the conveying member 1 and is positioned . Also, the on the pattern plate 2 to each of the conveying members 1, 1 vertically slidably mounted around by a frame-shaped cutting die frame - arm 10 Yes wearing possible increase, cutting die frame - arm 10 - 10 is raised by the extension operation of the upward cylinders 11 and 11 mounted on the machine base 14 described later.
[0008]
Further, the casting frame 3 is configured to enter and exit directly above the model plate 2 through a roller conveyor 12 with a collar, and to move up and down through the roller conveyor 12 with a collar. The conveyor 12 is suspended from the lower surface of the lifting frame 13. The elevating frame 13 is constructed between the upper ends of the piston rods of two upward cylinders 15, 15 erected on the left and right of the machine base 14, and is moved up and down by the expansion and contraction operation of the cylinders 15, 15. Yes. The hydraulic circuit 19 of the cylinders 15 and 15 is equipped with a pressure sensor 20 as a detecting means for detecting the reaction force to the squeeze foot 7, and the force applied to the squeeze foot 7 is larger than a set value. Accordingly, the air cylinders 6 and 6 that are operating to expand are contracted by a signal from the pressure sensor 20.
[0009]
The filling frame 4 is disposed so as to be movable up and down via a plurality of cylinders 16 and 16 mounted on the left and right outer surfaces of the sand tank 5, and the filling control is not shown in the filling frame 4. Vent holes 17 and 17 leading to the chamber are formed. The sand tank 5 is mounted on the elevating frame 13 so as to penetrate vertically. The sand tank 5 has a bifurcated lower portion and two sand outlets 18 and 18 on the left and right.
[0010]
Next, the operation of the above configuration will be described. First, as shown in FIG. 2A, the positioning cylinder 9 is extended to position the conveying member 1 on the machine base 14, the upward cylinders 11 and 11 are extended to raise the die frame 10, and the cylinder 15 15 is contracted to place the casting frame 3 on the die-cutting frame 10, the cylinders 15 and 15 are extended to place the filling frame 4 on the casting frame 3, and the central air cylinder 6 is extended. The squeeze foot 7 is actuated to lower the squeeze foot 7 , whereby the model board 2, the die frame 10, the casting frame 3, the fill frame 4, the sand tank 5, and the plurality of squeeze feet 7, 7 are filled with sand And the plurality of squeeze feet 7 and 7 form a required interval with the model portion of the model plate 2. That is, when a plurality of intervals formed by the squeeze feet 7 and 7 before compression of the molding sand and the model portion of the model plate 2 facing each other are A and B, and a and b after compression, these percentages a / a and b / B is set to be in a relationship of approximately a / a = b / B.
[0011]
Next, as shown in FIG. 2B, the sand filling space H is filled with the foundry sand from the sand tank 5 , and then the cylinders 15 and 15 are contracted as shown in FIG. 5. The squeeze feet 7, 7 and the like are lowered to pre-compress the foundry sand in the sand filling space H. Next, when the cylinders 15 and 15 are further contracted to lower the sand tank 5 and the squeeze feet 7 and 7 and the like, and the pre-compressed foundry sand is then solidified within a movable range when it is subsequently compressed. The air cylinder 6 in which the squeeze foot 7 is lowered by the extension operation is contracted to raise the squeeze foot 7. Thereby, a dent is formed near the upper center of the pre-compressed foundry sand. It is detected by a pressure sensor 20 mounted on the hydraulic circuit 19 that the pre-compressed foundry sand has been solidified within a movable range when it is subsequently compressed.
[0012]
Next, as shown in FIG. 2D, the cylinders 11 and 11 are contracted to lower the die frame 10 and the cylinders 15 and 15 are further contracted to operate the sand tank 5, squeeze feet 7 and 7 and the like. Further down, the foundry sand in the sand filling space H is fully compressed. In this case, during the main compression, a part of the upper foundry sand easily moves into the recess, and as a result, the foundry sand in the sand filling space is almost uniformly solidified to a required density. It will be.
[0013]
After that, the cylinders 15 and 15 are extended to raise the casting frame 3 and the like to perform die cutting, and the cylinders 16 and 16 are extended to return the filling frame 4 to the original state. The casting frame 3 with a built-in mold is unloaded through 12 and an empty casting frame 3 is loaded to complete one cycle.
[0014]
In the above-described embodiment, the pressure sensor 20 is mounted on the hydraulic circuit 19 as detection means for detecting the reaction force to the squeeze foot 7, but the present invention is not limited to this. For example, the pressure sensor is mounted on the air cylinder 6. A squeeze foot 7 may be provided with a load cell.
[0015]
【The invention's effect】
As is clear from the above description, according to the present invention, the sand in the sand filling space defined by the model plate, the casting frame, the plurality of squeeze feet, etc., in particular, the upper sand is the one after the pre-compression. Excellent practical effects such as being movable when compressed.
[Brief description of the drawings]
FIG. 1 is a partial sectional front view of an embodiment of the present invention.
FIG. 2 is an operation explanatory diagram in FIG. 1;
[Explanation of symbols]
2 Model plate 3 Cast frame 4 Fill frame 7 Squeeze foot 20 Pressure sensor

Claims (1)

A mold filled with a model plate, a casting frame, a filling frame, a sand tank, and a plurality of squeeze feet that are moved up and down by an air cylinder, and molded into the casting frame by compression of the foundry sand in the sand filling space The mold is formed so that the density of the mold is substantially uniform and the surface corresponding to the back of the cavity surface in the mold is substantially the same as the surface of the casting frame,
A sand filling space is defined by the model plate, the casting frame, the fill frame, the sand tank, and the plurality of squeeze feet, and the plurality of squeeze feet are spaced apart from a model portion of the model plate. In other words, a plurality of intervals formed by a plurality of squeeze feet before compression of the molding sand and a model portion of the model plate facing each other are defined as A and B, and after compression, a and b Where these ratios a / A and raising or lowering each of the plurality of squeeze feet such that b / B substantially satisfies a relationship of a / A = b / B ;
After the sand filling space is filled with foundry sand , each of the plurality of squeeze feet is raised or lowered so as to form a predetermined interval, and the relative position of each of the squeeze feet is maintained with respect to the model plate. Pre-compressing the foundry sand by bringing a tank and a plurality of the squeeze feet close to each other;
Detecting a reaction force to the squeeze foot and, when a set value is exceeded, raising the lowered squeeze foot so that all squeeze feet are not lowered ; and
A step of bringing the sand tank and the plurality of squeeze feet closer to each other with respect to the model plate and finally compressing the foundry sand in the sand filling space;
A mold making method comprising the steps of:

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