JP2002254422A - Method for forming molded body of green material and shape modifying apparatus using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a molding cycle and to perform modification of the shape of a molded body of a green material while contact with the surface of the molded body of the green material is kept at a minimum by performing simultaneously perforation and modification of the shape of the molded body of the green material after demolding. SOLUTION: A method for forming the molded body of the green material with a specified shape by carrying a wet molded body of the green material removed from a mold for cast molding under a condition where it is placed on a member for carrying to a perforating process in which a hole is made at a specified position of the molded body of the green material, a surface finishing process in which the surface of the molded body of the green material is finished and a drying process is provided and both the perforation and the modification of the shape are performed in the perforation process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming method for forming a green body of sanitary ware into a predetermined shape and a shape correcting device used for the method.

[0002]

2. Description of the Related Art A conventional process for forming a green body of sanitary ware will be described by taking a toilet bowl washing tank as an example. First, a green body molded body (hereinafter, referred to as a molded body) of a toilet washing tank formed in a casting mold (hereinafter, referred to as a mold) is removed from a pallet. Here, since the mold release water generated at the time of mold release may accumulate in the concave portion of the molded product that has been removed, the mold release puddle may be removed if necessary. Work is performed. Next, after chamfering a required portion such as an end portion of the molded body, a drain hole having a predetermined dimension, a cleaning water discharge lever mounting hole, and the like are formed at predetermined positions. Thereafter, a surface finishing treatment such as a treatment of casting burrs remaining at the drilled portion and unevenness of a joint portion of the chamfer and a process of wiping traces of water dripping on the surface of the molded body are performed. After these series of operations are completed, they are transported to the drying chamber.

[0003] Generally, the amount of shrinkage deformation of a molded body generated in a drying step or a baking step is reflected in advance in the shape of a mold when the mold is manufactured, and for example, the above-mentioned toilet washing tank (hereinafter referred to as a tank). Special shrinkage deformation may occur. That is, this is a case where the upper end opening of the tank is deformed outward in the horizontal direction, and the center portion of the side surface of the tank is deformed inward in the horizontal direction. On the other hand, in some cases, the shape of the tank is required to have a shape in which the upper end opening is narrow and the side center is swelled from the viewpoint of the design in appearance. However, the molded body of the tank is generally molded by a molding die composed of a middle die and an outer die. When the green body is released from the middle and outer molds after the molding, it cannot be released with the above-mentioned shape in which the center of the side surface is swollen. Therefore, in order to obtain a shape in which the center of the side surface is swollen, it is necessary to perform an operation of processing the molded body after demolding and correcting the shape.

As a method of correcting the shape of the molded body of the tank after the above-mentioned demolding, a technique disclosed in Japanese Patent Application Laid-Open No. Hei 7-16822 has been proposed. The technology of this publication includes a movable pressing plate for pressing the inner surface of the molded body from the inside of the molded body to a molded body transfer device, and a suction pad for suction-holding and transferring the inner surface of the molded body, After the completion of the drilling, the formed body is conveyed from the drilling step to a shape correcting step which is the next step, in order to correct the shape while being suction-held by the suction pad. In the shape correction step, a correction mold for correcting the side surface of the molded body into a predetermined shape is movably provided. When the molded body is conveyed to the shape correction process, a correction mold is set on the outer surface of the molded body, and the movable correction plate moves forward and presses the inner surface of the molded body to correct the shape according to the correction mold. I do.

[0005]

However, in the technique disclosed in the above publication, the shape correcting device is attached to the molded body transfer device, so that the molded body itself is caused by vibrations when the molded body is transferred. May be deformed, scratched or cracked. Further, the contact of the modified mold with the outer surface of the molded body may directly lead to the attachment or flaw of the foreign matter, which may cause a deterioration in the appearance quality of the molded body, and the contact area between the modified mold and the molded body surface is large. There is a problem that the possibility is higher as the above-mentioned ratio increases.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention aims to shorten the molding cycle by correcting the shape at the same time as drilling the green body after demolding, and to minimize the contact with the surface of the molded body. An object of the present invention is to provide a method for forming a green body and a shape correction device used for the green body, which can correct the shape of the green body while being fixed.

[0007]

In order to solve the above-mentioned problems, a method of forming a green body molded article according to the present invention comprises placing a wet green body molded article removed from a casting mold on a conveying member. In a state in which the green body is formed, a hole is formed at a predetermined position of the green body, a surface finishing step of finishing the surface of the green body, and a drying step is performed to form a green body having a predetermined shape. In addition, in the drilling step, drilling and shape correction are performed. By doing so, it is possible to correct the target shape without performing a transfer operation that causes deformation, scratches and cracks of the green body compact, and it is possible to shorten the cycle of forming the green body body.

[0008] In a preferred embodiment of the method for forming a green body molded article of the present invention, the outer surface of the upper end of the green body formed body is held in a predetermined shape, and the inner surface of the green body formed body is pressed until it has a predetermined shape. To correct the shape. By doing so, it is possible to minimize adhesion and flaws of foreign matter due to contact with the outer surface of the green body molded body, and to plastically deform the green body into a desired shape.

In a preferred embodiment of the method for forming a green body molded article according to the present invention, the green body formed body is a tank for storing washing water whose upper part is open and whose central part on the side bulges outward. The upper end outer surface of the tank is pressed from the outside and the upper end inner surface opposed to the upper end outer surface is subjected to pressure to press the center of the side surface inside the tank to the outside. By doing so, it is possible to efficiently form a tank in which the center of the side surface of the tank bulges outward.

[0010] Further, the shape correcting device for a green body molded article of the present invention is a shape correcting apparatus for a green body formed body that corrects a shape of a green body formed after removal from a casting mold to a desired shape. Further, the shape correcting apparatus is provided with an integrated boring means. By doing so, it will be possible to commercialize the method of forming a green body as an automatic machine, maintain high productivity and reliability, share the drilling means and equipment components, and reduce the number of parts. Become.

In a preferred aspect of the shape correcting device for a green body molded article according to the present invention, the shape correcting device presses an inner side surface of the green body formed body to correct the shape; An upper end outer surface holding means having a predetermined shape for holding the upper end outer surface of the body is provided. By doing so, the method of forming the green body can be put to practical use as an automatic machine, high productivity and reliability can be maintained, and adhesion and damage of foreign matters due to contact with the outer surface of the green body can be maintained. The shape can be corrected by plastically deforming to the target shape while minimizing the pressure.

In a preferred aspect of the shape correcting device for a green body molded article of the present invention, the upper end outer surface holding means presses the upper outer surface and the upper end of the green body facing the upper upper surface. Pressure receiving means for receiving the inner surface. By so doing, the upper end of the green body is securely held in a predetermined shape, so that the shape of the upper end is not deformed when modifying the shape of the other part of the green body.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a green body of sanitary ware is conveyed by a conveyor and a drying cart while being placed on the same pallet from demolding to completion of drying. The transfer of the green body is itself a factor that can cause deformation, scratches, and cracks and should be avoided as much as possible in the production process. Are transported on the same pallet.

In the shape correction performed by the shape correction device, it is desirable to consider the return deformation due to the elasticity of the green body. In general, under the condition that cracks and breakage do not occur due to excessive stress, the green body is subjected to elastic stress that tends to return to the shape before deformation with respect to shape deformation.
Even for intentional shape correction as in the present invention, including a short pressing time, return deformation due to elasticity similarly acts, so as to eventually secure a desired correction amount Need to make some slight corrections. However, the amount of the return deformation due to the elasticity is largely determined experimentally or empirically because it largely depends on a plurality of factors such as the shape and thickness of the correction portion and the properties of the cast base slurry. For example, the center of the tank is 1
In order to inflate 0 mm, a shape correction of 12 to 30 mm is required. Also, if the guide surface of the guide for correcting the shape is small, it will not be a gently swollen shape as a whole, it will be a partly protruding unsightly shape, and if it is too large, cracks will form from the corners Therefore, various precautions are required to determine the amount of correction because a defect such as an error occurs.

Next, the configuration of an embodiment of the shape correcting apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a shape correcting device for forming a hole and correcting the shape of the green compact 5 formed on a transport pallet 10 and having an open upper portion and a substantially rectangular cross section in a horizontal direction. The shape correcting apparatus A includes an elevating frame 1 which is vertically moved up and down by an elevating means such as a cylinder with a brake (not shown), a drilling cylinder 2 vertically arranged on the elevating frame 1, and a vertical movement of the drilling cylinder 2. And a drilling cutter 6 attached to the tip of the cylinder rod to be drilled. Further, a guide ram 3 fixed to the lifting frame 1 and disposed below, a shape correcting cylinder 4a,
4b, shape correction guides 7a, 7b, upper holding cylinders 8a, 8b fixed to the lower part of the lifting frame 1 via a fixed frame, and upper holding guides 9a, 9b attached to the tip end of the cylinder rod of the upper holding cylinders 8a, 8b.
It has.

The guide ram 3 has a shape substantially conforming to the internal shape of the tank green body molded body 5 and has a shape and size capable of entering and retracting inside the tank green body green body 5, and positions and drills the tank green body green body 5. It supports the entire green body formed body 5 during processing and shape correction processing.

The shape correction guides 7a and 7b are correction guides having an arcuate surface shape for making substantially central portions of both wall surfaces in the long side direction of the tank green body 5 bulge outward.
The shape correction cylinders 4a and 4b push the inner surface of the green compact 5 to plastically deform the shape following the shape correction guides 7a and 7b.

The upper end holding cylinders 8a and 8b and the upper end holding guides 9a and 9b are used to maintain the shape of the upper opening of the tank green body 5 in a predetermined shape. It plays a role in preventing it from being drawn and deformed during the shape correcting operation.

Next, the shape correcting operation will be described with reference to FIGS. FIG. 2 shows a state before drilling and correcting the shape of the tank green body 5, and FIG. 3 shows a state in which the shape correcting device A is lowered and a guide ram, a shape correcting guide, a shape correcting cylinder, FIG. 4 shows a state in which the drilling cutter is inserted, and FIG. 4 shows a state in which the shape is being corrected simultaneously with the drilling.

First, as shown in FIG.
Is placed on a pallet 10 and transported to a piercing step by transport means such as a conveyor and stopped at a predetermined position. Next, as shown in FIG.
The tank green body 5 is positioned with high accuracy while being accommodated in the tank green body 5. continue,
When the lifting frame 1 descends and stops at a predetermined height, FIG.
As described above, the drilling cutter 6 is extruded by the drilling cylinder 2 to form a hole in the bottom surface of the green compact 5. At the same time, the upper end pressing guides 9a and 9b advance by the upper end pressing cylinders 8a and 8b, and press both upper portions in the longitudinal direction of the tank green body molded body 5. At this time, the pressing of the upper end holding guides 9a and 9b is received near the upper end of the ram guide 5, and the upper end holding guides 9a and 9b and the vicinity of the upper end of the ram guide 5 are used to move the upper and lower ends of the green compact 5 in the longitudinal direction. Hold the part. Next, the shape correction guides 7a and 7b are advanced by the shape correction cylinders 4a and 4b to push out the central portion of the tank green body 5 and bulge outward to plastically deform the shape. Finally, the drilling cylinder 2, the shape correction cylinders 4a and 4b, the upper end holding cylinders 8a and 8b,
, The lifting frame 1 rises and stops.
Thereafter, the green compact 5 is transferred to the next step.

[0021]

As described above, according to the method for forming a green body and the shape correcting apparatus used in the same according to the present invention, the factors of deformation, scratches and cracks of the green body are eliminated in parallel with the drilling operation. Thus, the shape of the green body can be easily corrected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire shape correcting apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a state before drilling and shape correction of a green body for tank body 5 by the shape correction device of FIG. 1;

FIG. 3 is a view showing a state in which a guide ram, a shape correction guide, a shape correction cylinder, and a drilling cutter are inserted into the green compact 5; .

FIG. 4 is a diagram showing a state in which shape modification is performed simultaneously with drilling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Elevating frame 2 ... Drilling cylinder 3 ... Guide ram 4a, 4b ... Shape correction cylinder 5 ... Tank green body molded body 6 ... Drilling cutter 7a, 7b ... Shape correction guide 8a, 8b ... Top holding cylinder 9a, 9b ... Top holding Guide 10: Transport pallet

Claims (6)

[Claims] 1. A boring step for drilling a hole in a predetermined position of the green body molded article in a state where the wet green body molded article removed from the casting mold is placed on a conveying member. A method for forming a green body having a predetermined shape by transferring to a surface finishing step for finishing the surface of the object, and a drying step, wherein the green hole forming and the shape correction are performed in the hole forming step. How the body is formed. 2. The shape correction is performed by holding the outer surface of the upper end of the green body in a predetermined shape and pressing the inner surface of the green body to a predetermined shape. 3. The method for forming a green body molded article according to item 1. 3. A tank for storing washing water in which said green body molded body is open at an upper part and a central part of a side surface swells outwardly, and presses an upper end outer surface of said tank from outside and opposes said upper end outer surface. 3. The method for forming a green body according to claim 2, wherein the inner surface of the upper end is subjected to pressure and the center of the side surface inside the tank is pressed outward. 4. An apparatus for correcting the shape of a green body after a mold is removed from a casting mold to a desired shape, wherein the shape correcting apparatus integrally includes a boring means. An apparatus for correcting the shape of a green body made of sanitary ware, comprising: 5. A shape correcting device for correcting a shape by pressing an inner surface of the green body, and holding an upper end outer surface of a predetermined shape for holding an upper outer surface of the green body. The apparatus for correcting the shape of a green body molded body according to claim 4, comprising means. 6. The method according to claim 5, wherein said upper end outer surface holding means comprises a pressing means for pressing said upper end outer surface and a pressure receiving means for receiving an upper end inner surface of said green body formed body facing said upper end outer surface. An apparatus for correcting a shape of a green body according to the above description.