RU1790492C - Rotary press for molding earthenware articles - Google Patents

Abstract

Usage: molding products from ceramic materials. Summary of the invention: a rotary press consists of a lower and an upper bed connected by a central and side columns. A rotor is mounted on the central column. In the grooves of the rotor, the upper and lower pillows with punches fixed in them are coaxially located. The molds are aligned with the pillows in the rotor. The mold-filled mold is closed by the upper punch as it approaches the first pre-compression step. In the section of the first pressing step, the elevation angles of the upper and lower fists are equal, so bilateral pressing occurs. Then begins the section of internal stress relieving and air removal, then the second stage of preliminary pressing, followed by stress relieving and air removal. The third stage of final pressing has a pressing section and a relaxation section in which the angle of elevation of the fists is zero. Then the upper punch is lifted and the product is removed from the press. 3 ill.

Description

The invention relates to the molding of articles made of ceramic materials, and more specifically to rotary presses for semi-dry pressing of articles.

A device for molding ceramic products is known. The apparatus for forming a particulate mixture product comprises a table mounted on a bed, which is rotated around the center column by a drive. The articles are formed by double-pressing by upper and lower punches. The device is made with fixed upper and lower spiral guides. Thrust rods, rigidly connected to the lower heads of the upper punches, are supported on the upper fixed spiral guide. A slit is formed in the lower fixed guide along its axis, in which the pressure heads of the lower punches are placed. The lower punches, together with the upper punches, compress the rigid dispersed mixture fed into the matrix and push the molded product onto the table surface, the pressure heads of the lower punches sliding along the lower fixed spiral guide, the profile of which provides the required axial displacement of them. The dimensions of the products along the perimeter are determined by the dimensions of the matrix, and the dimensions by thickness are determined by measuring the position of the lower fixed guide.

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The disadvantages of this design include:

1) the lack of automatic adjustment of the filling of the molds with the mixture during the operation of the device depending on the pressure in the process. Each mass has its own maximum press excess, which causes cracking in the product. The pressure developed during the pressing process determines the resistance of the finished product to compression;

2) it is not possible to completely remove air from the mass being pressed during the pressing process, since preliminary pressing occurs continuously in the process of moving the rods along spiral guides, and the final pressing occurs continuously in one revolution of the eccentric. The presence of one gap between the pressing steps (preliminary and final) is not. provides complete removal of air from the pressed mass. Air residues reduce the quality of products,

Of the known rotary presses, the closest in technical essence is a rotary press for pressing ceramic products (1), which contains the lower and upper beds connected by columns, a rotor with pillows and punches mounted on a central column, molds, upper and lower fists variable profile, means for holding the upper pads, rotor rotation drive, metering mechanism for adjusting the filling of the molds with the mixture. ,

A disadvantage of the known press design is that it is not possible to adjust the filling of the mold with the mixture during operation of the press, since the composition of the mixture and humidity can change during operation. Each mass has its own maximum pressure pressure, the excess of which causes cracking in the brick, a decrease in pressure reduces the quality and strength of the product.

In addition, to remove air from the pressed mass, there is one time interval between the two stages of pressing, which is not sufficient to completely remove air from the mass.

An object of the present invention is to improve product quality.

The goal is achieved in that a rotary press for molding ceramic products, comprising lower and upper beds connected by columns,

rotor with pillows and punches mounted on the central column, molds, upper and lower fists of variable profile, means for holding the upper

The 5 pillows, the rotor rotation drive and the metering mechanism for adjusting the filling of the molds with the mixture according to the invention are equipped with traverses kinematically connected with the means for holding the upper pillows and rods connecting said traverses with a metering mechanism made in the form of a housing located in bearings on a central column of a press coaxially with

5 by a rotor, of a drive mounted on the upper bed and connected to the housing of the metering mechanism through a nut and screw, and the metering mechanism is equipped with a hydraulic cylinder electrically connected to it

0 drive, while in the zone of all pressing steps the variable profile of the lower fist has a constant angle of elevation, and the profile of the upper fist is made with a variable angle of elevation. In addition, after the last pressing step, the profile of the upper and lower fists has horizontal sections, and at the last pressing step, the profile of the upper fist is pivotally in contact with the upper cushions and the metering cylinder. Such a constructive implementation of the rotary press will provide improved quality molded products.

35 This is achieved by automatically adjusting the pressing pressure during the operation of the press in the last stage of pressing by changing the level of filling of the molds with the mixture. The level of filling 40 of the molds is controlled by changing the position of the lower pillows with punches fixed on them, which are in constant contact with the traverses of the metering mechanism, the drive of which

45 receives a switch-on from the pressure transducer depending on the pressure change in the hydraulic cylinder of the last pressing stage, adjusted to the nominal pressing pressure, Increase

50 and the reduction in compression pressure depends on the amount of filling of the molds with the mixture.

The required amount of product is achieved by repeated removal

55 residual air from the pressed mass and the redistribution (removal) of internal stresses in the product by moving the pressed mass in the mold between the stages of pressing. This is due to an increase in the number of pressing steps (three or more) and a change in the design of the upper and lower fists in such a way that in the spaces between the pressing steps the product is forced to move relative to the molds without pressure, pressing, creating favorable conditions for removing air from pressed mass.

And also thanks to the introduction on the fists of the last pressing stage of the relaxation section, where the product is under constant nominal pressure without deformation, which creates the condition for the complete disappearance of residual deformation of the product. This is achieved by creating a horizontal section on the upper and lower fists behind the last pressing step.

In addition, the service life of the molds is increased due to the fact that the pressure on the walls of the molds at all stages of pressing is distributed along the height of the side walls.

In FIG. 1 shows a rotary press in section; in FIG. 2 is an enlarged view of a metering mechanism with a drive; in FIG. 3 is a schematic depiction of a rotor with pillows, fists and a metering mechanism.

A rotary press for molding ceramic products, such as bricks, consists of a lower 1 and upper 2 beds connected by a central 3 and side 4 columns. On the central column 3, on the rolling bearings, a rotor 5 with a gear wheel 6 is mounted. In the grooves of the rotor 5 there are coaxially arranged upper 7 and lower 8 pillows with punches 9 and 10 fixed in them and means for holding the upper pillows made in the form of spring-loaded rods 11 bearing at one end a roller 12 in contact with a fist 13 mounted in a lower bed. The alignment of the pillows in the rotor is fixed to the mold 14. On the lower 1 and upper 2 beds are also fixed fists 15.16 variable profiles, which are in contact with the rollers 17, 18 of the upper and lower pillows 7, 8. The upper end fist 16 has a section 19, installed pivotally in the upper bed. In the zone of all pressing steps, the variable profile of the lower fist has a constant angle of elevation, and the profile of the upper fist is made with a variable angle of elevation. Furthermore, behind the last pressing step, the profile of the upper and lower fists has horizontal sections.

The rotor 5 is driven by a drive 20 mounted on an upper bed

through the pinion shaft 21 and the gear 6. On the central column 3 in the bearings coaxially with the rotor 5 there is a metering mechanism for adjusting the filling 5 of the molds with the mixture, made in the form of a housing 22 and a drive 23 mounted on the upper frame and connected to the housing dosing mechanism through nut 24 and screw 25, the dosing mechanism is provided

A 0-cylinder 26 electrically connected to its drive 23. A portion 19 of the upper cam 16 is in contact with the upper cushions 7 and the cylinder 16 of the metering mechanism. To the case 22 of the mechanism

5 dosing rods 27 mounted traverses 28 mounted on the rods 17 holding the upper pillows. On the upper bed 2 there is a mechanism 29 for controlling the filling of the molds, which is connected to the screw

0 26 dosing mechanism.

The device operates as follows.

The mold 14 is filled with the mixture from the hopper at the loading position (zone I, Fig. 3).

5 The operation of the press is carried out with continuous rotation of the rotor. The rotation from the drive 20 through the pinion shaft 21 and the gear 6 is transmitted to the rotor 5. The filled mixture, the mold 14 is closed

0 by the upper punch 9 (zone II) when approaching the first stage of preliminary pressing (zone III). In the section of the first stage of pressing, the angle of elevation of the upper and lower fists is equal, therefore,

5 double-sided pressing. After the first stage of pressing, the section begins to relieve internal stresses and remove air (zone IV). In this section, the upper and lower punches move synchronously upwards. The compression mass without deformation moves upward relative to the mold. The second stage of preliminary pressing (zone V), and the next section for stress and air removal (zone VI), are similar to zones 111 and IV. The third stage of final pressing has a pressing section (zone VII) and a relaxation section (zone VIII), on which the fist lifting angle is a 0.

0 Then the upper punch 9 is lifted, the product is pushed out with the lower punch 10 and the product is removed from the press (zone IX). In the filling area, the lower cushion 8, moving along the fist, goes down, the mixture is sucked in, and leaning on the yoke 28, the dispensing mechanism hangs over the lower fist. The level of the crosshead, and hence the depth of filling, depends on the composition and humidity of the mixture. Lowering or raising the traverse occurs using the drive 23

dosing mechanism through screw 25, nut 21, rod 27.

The signal to turn on the engine is received from the hydraulic cylinder 26 through a measuring transducer (not shown in the drawing), depending on the pressure in the hydraulic cylinder 26 adjusted to the nominal pressing pressure that occurs during compression of the mixture. Each mass has its own maximum pressure. The pressure generated during the pressing process determines the resistance of the finished compression product. An increase or decrease in pressure in the hydraulic cylinder forces

change the signal value of the measurement transducer, respectively reduce or increase the depth of filling of the molds 14 with the mixture. After passing through the filling portion, the pillow roller smoothly makes contact with the lower fist and begins to move upward. At this time, the upper punch 9 advances to close the die. In this position, the mold 14 approaches the first pre-pressing step and the process is repeated. The amount of filling of the molds is controlled by the mechanism 29 for controlling the movement of the traverse 28 on devices installed on

press control panel.

Claims (1)

SUMMARY OF THE INVENTION A rotary press for molding ceramic products, comprising a lower and an upper frame connected by columns, a rotor with pillows and punches mounted on a central column, molds, upper and lower fists of a variable profile, means for holding the upper pillows, rotor rotation drive and a dosing mechanism for adjusting the filling of the molds with the mixture, with the exception that, in order to improve the quality of the products, the press is equipped with traverses kinematically connected with the holding means of the upper pillows and rods connecting the traverse with the metering mechanism, made in the form of a housing located in bearings on the central column of the press coaxially with the rotor, and a drive mounted on the upper bed and connected to the housing of the metering mechanism through a nut and screw, and the metering mechanism equipped with a hydraulic cylinder electrically connected to its drive, while in the zone of all stages of pressing the variable profile of the lower fist has a constant angle of elevation, and the profile of the upper fist is made with a variable angle of elevation, to In addition, the profiles of the upper and lower fists have horizontal sections behind the last pressing step, and at the last pressing step, the profile of the upper fist is hinged and contacts the upper cushions and the metering cylinder.