JP2003062818A - Brick molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brick molding method capable of homogenously molding a brick having a large thickness like a refractory brick with high accuracy at a low cost. SOLUTION: The brick molding method includes a performing process for press-molding a bat (14) not collapsed even if fed under pressure 5-20% of that applied in a main molding process using the cavity having an area 80-95% of that of the cavity used in the main molding process of a performing machine (B), the main molding process for molding the preformed bat (14) under predetermined pressure using the predetermined cavity area of a main molding machine (A) and a weighing process for weighing the bat (14) between the performing process and the main molding process to feed back the measured value to the control means of the performing process and enhancing the accuracy of the bat (14).

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thick brick such as a refractory brick. 2. Description of the Related Art Conventional refractory bricks are molded by using FIGS.
A molding machine shown in FIGS. 8 and 9 (a double-piston press in which the upper and lower plungers 5B and 11B are movable) and a molding machine shown in FIGS. The compounding raw material filled in the mold cavity C is solidified by being pressurized by upper and lower plungers. In this case, the ratio between the filling depth and the thickness of the molded product is called a compression ratio. For example, in the case of raw materials such as raw stone, chamotte, or magnesia, alumina, and zircon, the compression ratio is about 1.5 to 1.
8th place. [0003] Recently, graphite raw materials have been widely used. In particular, molding of magnesia carbon brick (magnesia graphite brick) and alumina carbon brick (alumina graphite brick) has a large amount of fine powder and a high compression ratio. Is larger than 2.0 to 2.
Molding conditions such as No. 2 have come. [0004] Such a condition is a severe function requirement for a forming press. For example, in the case of so-called clay brick molding with a thickness of 150 mm, the compounding material filling depth is about 2
20 mm. If this is a graphite-containing magnesia carbon brick, it will have a compounding material filling depth of about 320 mm when molded into a 150 mm thickness. When the brick thickness is 250 mm, 375 mm is used for clay bricks and 5 mm for magnesia carbon bricks.
Requires a filling depth of 25 mm. Heretofore, bricks having a thickness of 250 mm have rarely been used as practical ones. The reason is that the pressure from above and below cannot exert an effect up to the center portion during molding, and the cavity depth of the mold becomes extremely large, which is almost impossible in terms of cost. [0006] Further, as a major problem, as the filling depth becomes larger, the daylight of the molding machine needs to be extended several times. The specification must be expanded. That is, the overall height of the molding machine becomes significantly larger as the thickness of the brick increases, and the cost becomes remarkably large.
And, if the filling depth becomes large, the amount of air contained in the mixture naturally increases, so it is necessary to remove air by vacuum degassing before molding. In addition, regarding the mold liner, if the compression stroke increases, an extra liner space is naturally required in a state where the pressing force is low, so that the thickness of the mold and the liner are also increased, and unnecessary mold cost is required. . [0008] Unlike molding of tiles and powder metallurgy, molding of refractory bricks requires a large pressurizing force because the shape is large and the thickness is large, and the apparatus requires a strong press frame and mold. Strength is required. As a result of various studies, the present applicant has found that the final molding density of the brick is determined by the applied pressure and stroke up to the final dimension of 10 to 20 mm. For example, in the case of a mag carbon brick, assuming that the compression ratio is 2.0, the pressing depth of 10% is tightened to 46% of the filling depth, the remaining 4% requires high pressure, and pressure is applied to the mold side wall. Range. From the above, the first stage preforming and the second stage
In the first stage, using a mold with a cavity having an area 10% smaller than the regular size, pressurizing at approximately 1/10 of the final pressing force to reduce the so-called angle. In the second stage, the preformed angle is put into a full-sized cavity, and is formed by full-scale pressing. in this case,
The preforming mold may be a very simple raw steel plate. In this molding, the pressing stroke is about 4% of the filling depth, and the stroke is short, so the daylight required for the press is extremely low. It is. The mold also requires a heat treated liner, but a shallow one is sufficient. This concept will be further described with reference to FIGS. First, FIG. 10 shows a case where a compounding material having a compression ratio of 2.0 is pressurized by a conventional method. For example, 30
When molding bricks of 0 mm x 300 mm x 250 (thickness) mm, a minimum effective mold depth of 500 mm is required (see Fig. 10a). And, 1/1 of the final pressure P
At a pressure of 0, the upper punch is inserted into the mold to 54% of the filling depth (see FIG. 10b). Assuming that the filling volume in FIG. 10 is V0, the filling depth of the mold having a cavity of 290 mm × 290 mm shown in FIG. 11 is 535 mm (FIG. 1).
1a). Next, as shown in FIG. 11, the filling volume is made uniform as shown in FIG.
An elementary angle of 90 mm × 290 mm × 290 mm = V1 can be formed (see FIG. 11B). In this case, the pressure stroke of the upper plunger is 245 mm, which is about 46% of the filling depth. Here, if the final pressure is applied, 2 more
Although the target thickness is obtained at 2.5 mm, compression to the end is not performed here. Then, as shown in FIG.
= 290mm x 290mm x 290mm elementary angle is 3
Place in a 00 mm x 300 mm cavity (Fig. 12
a)). This is pressed with the final pressing force P to obtain a target molded product of 300 mm × 300 mm × 250 mm (see FIG. 12C). The pressure stroke in this case is 40m
m. The inventor has found that the final pressing force can be obtained by the two-stage molding and the target molded product can be achieved with a stroke of 40 mm. The density of the two-stage molded product is higher than that of the conventional one-stage molded product. In other words, once the elementary angle is lightly molded, the air, distortion, etc., which are interposed during molding, are once discharged out of the mold, so that it is in equilibrium with the outside air until it is put into the molding machine. Keep. In addition, air, distortion, etc. are released again at the stage of being inserted into a cavity that is 10% wider and further pressurized, so that a complicated pressurizing effect can be obtained for uniaxial molding. The inventor of the present invention discloses a forming method for breaking the element angles in Japanese Utility Model Laid-Open No. 54-116262. However, this technology is to perform pre-compression for the purpose of deaeration, and it is possible to produce homogeneous and high-precision molded products at low cost with molding equipment with low overall height using raw materials that require a large compression ratio. is not. SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems, and enables a brick having a large thickness, such as a refractory brick, to be formed in a molding machine having a low overall height with uniform high accuracy and low cost. It is an object of the present invention to provide a method for forming a moldable brick. According to the present invention, there is provided a method for forming a brick, comprising: a preforming machine for performing a preforming step; and a main forming machine for performing a main forming step. Pressure molding is performed by using a cavity having an area of 80 to 95% of a predetermined cavity area and molding the element so as not to lose even when conveyed by a pressing force of 5 to 20% of a predetermined pressing force in the main forming step. A preforming step to perform, a main forming step of forming the preformed element angle with a predetermined pressing force in a predetermined cavity area, and performing a measurement of the element angle between the preforming step and the main forming step. And a weighing step of feeding back the measured value to control means for controlling the preforming step to improve the accuracy of the element angle. Therefore, according to the present invention, since the compounded raw material having a high compression ratio is preformed at a pressure of about 1/10 of the final pressure, the molding stroke in the main molding step can be greatly reduced. Therefore, the overall height of the molding device can be reduced. Further, since the stroke in the high pressure region is reduced, the cost of the mold, the hydraulic device, and the like can be reduced. Then, between the preforming step and the main forming step, the weight of the preformed element angle is measured, and the measured value is fed back to the control means of the preforming step.
For example, by precisely controlling the filling depth of the compounding material to be filled into the cavity, the product weight is controlled with an accuracy comparable to an accurate weighing. In addition, since the element angles are exposed to the outside air after the preforming step, and are formed while losing the shape in the main forming step, distortion between the upper, lower, and lower parts of the conventional forming method is small, and the degassing effect is large. . Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a molding apparatus for carrying out the brick molding method of the present invention. A main molding machine A is provided on the left side of the figure, and a preforming machine B is provided on the right side of the figure. . With respect to the preforming machine B, the upper frame 1 is supported by four pressing bars 2, and both rod pistons 3 are provided below the pressing bar 2 in the lower frame 12. And is vertically operated by hydraulic oil from a supply port and a discharge port (not shown). An upper plunger 5 protrudes from the lower surface of the upper frame 1. Below the upper frame 1, a mold holder 6 including a metal frame 7 is provided with its lower part supported by a support bar 8.
Is connected to both rod pistons 9 inserted into a cylinder 10 in a lower frame 12, and the mold holder 6
Are configured to be operable in the vertical direction. The lower plunger 11 is provided with a metal frame 7 at a position facing the upper plunger 5.
It is fixed on the upper surface of the lower frame 12 in a state of being inserted therein. As shown in FIG. 2, the charger device 13 is arranged so as to reciprocate in the direction of the arrow X and to charge the compounding material into the metal frame 7. An ultrasonic linear scale (not shown) for measuring the filling depth of the compounding raw material with an accuracy of 0.05 mm is provided, and the predetermined depth is accurately detected and set by the vertical movement of both rod pistons 9. I have. The preforming machine B shown in FIG. 1 shows a state in which the compounding raw material has been supplied before the start of the preforming step. From this state, the upper plunger 5 descends. Also descends at a slower speed than the plunger 5.
And both rod pistons (also known as pre-pressurized pistons) 3
The element angle 14 is formed in a state where the pressing force of the element has reached a predetermined value (see FIG. 3). Further, from this state, the upper plunger 5 is raised, while the mold holder 6 is further lowered, and the preforming step is completed in the state shown in FIG. At one end (right side in the figure) of the mold holder 6,
A picker 28 is provided, and is configured to convey the formed elementary angle 14 onto an automatic weighing machine 17 provided between the main forming machine A and the preforming machine B. At the other end (left side in the figure) of the mold holder 6,
A screen plate 18 is attached, and an automatic weigher 17 is installed below the screen plate 18 as shown in FIG. Before filling the compounding raw material and during molding, the comb-type block 19 of the automatic weighing machine is located below the screen plate 18 and the block 19 extends out of the plate 18 with the mold holder 6 pulled down. , Forming angle 1
Place 4 and weigh. The weighed value is inputted to a control means (not shown) of the preforming machine B, and an OK signal is sent if the weight is a predetermined weight, and a correction signal is sent if the weight is heavy or light to correct the filling depth in the next cycle. The filling amount of the compounding raw material is controlled. Returning to FIG. 4, the molding machine A is provided with a manipulator 20 on one side. The element 21 weighed by the weighing device 17 is grasped by the pad 21 and transported onto the lower plunger 22. In addition, a manipulator 25 is provided on the other side, and its pad 26
Each of the formed elementary angles 24 is configured to be carried out onto a conveyor 29. In the figure, reference numeral 23 is used.
Denotes a mold holder, and 30 denotes a liner. The pressing force of the preforming machine B has a pressing force of 5 to 20% of that of the main molding machine A, and the pressing stroke has a stroke of 5 to 20 times that of the main molding machine A. Further, the area of the cavity C1 of the preforming machine B is configured to have 80 to 95% of the area of the cavity C2 of the main molding machine A. With such a configuration, the compounding material having a predetermined filling depth is filled in the cavity C1 of the preforming machine B, and the element angle 14 is formed in the preforming step to such an extent that the element angle 14 is not distorted even when conveyed. . Then, it is conveyed to the weighing device 19, weighed, and the measured value is fed back to the control means. As described above, since the pressing force in the preforming step is not large and the stroke is long, the weight of the element angle 14 is controlled by the feedback of the weighing device 19 to precisely control the filling depth of the mold. By doing so, it is controlled with an accuracy comparable to an accurate weighing. The element angles 14 thus weighed are further conveyed to the main molding machine A, and the element angles 24 formed by performing the main molding are carried out onto a conveyor 29. In the state of the two molding machines A and B shown in FIG. 4, the lower plunger 1 of the preliminary molding machine B and the main molding machine A
1, 22 have the same upper surface height h, h
4 can easily be put into the cavity of the main molding machine A. The molding machine A shown in FIG. 1 shows a state where the element angle 24 is placed on the upper surface of the lower plunger 22 and the mold holder 23 is pulled up. That is, a state in which the molding machine A is filled with the molding object is shown. With this configuration, the upper surface of the element angle 24 to be inserted and the upper plunger 27 are formed.
Of the upper plunger 27 can be minimized.
If the element angle 24 is to be inserted into the cavity C2 without the mold holder 23 being pulled down, the upper plunger 27 needs to be raised higher by the thickness of the element angle 24, and the stroke of the upper plunger 27 is Must be increased. One object of the present invention is to provide a high pressure, for example, 30
An object of the present invention is to minimize the plunger stroke that can withstand a hydraulic oil pressure of 0 kgf / cm ² and shorten the overall length of the molding machine A. That is, in a conventional press, for example, 70
According to the present invention, it was necessary to make a plunger and a cylinder capable of withstanding 300 kgf / cm ² for an upper plunger stroke of 0 to 800 mm.
This can be reduced to a stroke of 100 mm or less. The present invention is configured as described above,
The following effects are obtained. (1) A conventional press forming apparatus has a total height of 6 to 7 m and a pressure of 300 kgf / cm ^2.
requires an upper pressure piston with a stroke of
In addition, although a considerable amount of hydraulic oil was required, according to the present invention, a total height of 3 m or more is sufficient even with two main and preforming devices. In addition, the amount of hydraulic oil is small, and the amount of power consumption is half or less. (2) The preforming machine may be of a small capacity, and therefore the liner of the required mold may be made of inexpensive material, for example, a steel plate without heat treatment, because it has little wear. It suffices to form an elementary angle and precisely control its weight, and it is sufficient that the press has the lowest level of function. (3) The present molding machine requires a minimum stroke and an actual pressure of, for example, about 50 mm, so that the height of the molding machine can be significantly reduced. Since the working stroke in the high pressure range is short, the hydraulic cylinder is short and an economical one can be selected. Also, since the height of the mold liner can be reduced, the expensive heat treated liner may be relatively short. (4) In the conventional displacement type charger in press molding, the detection of the weight of the brick and the check of the molding dimension could not be performed until the molding was completed. However, in the present invention, since the weight is measured during the molding process, the molding allowance is equivalent. With the remaining thickness control, remarkable size and weight control is possible. (5) In addition, the cycle time can be reduced to about 1/2 of that in the related art, including the angle transport and the weight inspection. (6) The element angles formed in the preforming step are exposed to the outside air, and are formed while losing the shape in the main forming step.
Great degassing effect. Therefore, the conventional vacuum degassing can be performed in a state where the raw material which is difficult to form is unnecessary. (7) According to the present invention, for example, for a 1000 mm long brick or a 300 mm thick block, etc.
Even with a 000-ton press, the stroke required for actual pressurization can be reduced to 100 mm or less, and the preforming machine required for that can be reduced to about 300 ton, which is economical.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing one embodiment of a molding device for carrying out the present invention. FIG. 2 is a plan view of FIG. 1; FIG. 3 is a sectional view showing a state in which molding has been completed by the molding apparatus of FIG. 1; FIG. 4 is a sectional view showing a state where a mold holder of the molding apparatus of FIG. 1 is pulled down. FIG. 5 is an explanatory view of the weighing by the weighing device (a view taken along the arrow aa in FIG. 4). FIG. 6 is a front view showing a conventional molding press (withdrawal press). FIG. 7 is a side view of FIG. 6; FIG. 8 is a front view showing a conventional molding press (double piston press). FIG. 9 is a side view of FIG. 8; FIG. 10 is a view for explaining a filling amount and a molding volume of a conventional compounding raw material. FIG. 11 is a diagram illustrating a filling amount and a molding volume in a preliminary molding step. FIG. 12 is a diagram illustrating a filling amount and a molding volume in a main molding step. [Description of Signs] A: Main molding machine B: Preliminary molding machine 1: Upper frame 2: Pressure bar 3: Both rod pistons 4: Cylinder 5: Plunger 6 mold holder 7 mold frame 8 support bar 9 both rod pistons 10 cylinder 11 lower plunger 12 lower frame 13 charger device 14, 24 ... Molding angles 15, 21, 26 ... Pad 17 ... Automatic weighing device 18 ... Screen plate 19 ... Comb type block 20, 25 ... Manipulator 22 ... Lower plunger 23 Mold holder 27 Upper plunger 28 Picker 29 Conveyor 30 Liner

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[Procedure amendment] [Submission date] March 6, 2002 (2002.3.6) [Procedure amendment 1] [Document name to be amended] Description [Item name to be amended] 0011 [Amendment method] Change [Amendment] The concept will be further described with reference to FIGS. First, FIG. 10 shows a case where a compounding material having a compression ratio of 2.0 is pressurized by a conventional method. For example, 30
When molding bricks of 0 mm x 300 mm x 250 (thickness) mm, a minimum effective mold depth of 500 mm is required (see Fig. 10a). And, 1/1 of the final pressure P
At a pressing force of 0, the upper punch is inserted into the mold to 54% of the filling depth of the compact (see FIG. 10b).

Claims (1)

Claims: 1. A method of forming a brick, comprising a preforming machine for performing a preforming step and a main forming machine for performing a main forming step, wherein a predetermined cavity area of the main forming step is 80 to 80%. 9
A preforming step of press-forming an elementary angle formed by using a cavity having an area of 5% and by a pressing force of 5 to 20% of a predetermined pressing force of the main forming step so as not to be deformed even when conveyed; Controlling the preforming step by performing a preforming step of forming the preformed elementary angle with a predetermined pressing force in a predetermined cavity area and weighing the elementary angle between the preforming step and the main forming step A weighing step of feeding back the measured value to the control means to improve the accuracy of the element angle.