The invention covers manufacture of building products, mainly building blocks with a split surface, that are used for creation of different structures, in particular, constructions of a small perimeter, namely enclosures, including fences, posts for gates and wickets, ornamental posts, walls and other constructions and structures.

The method of manufacturing building blocks by means of pressing and the mold for its implementation are known from the technical level. They are disclosed in the information source RU 2087307 A 1, 1997.

The known method is as follows: semidry molding compound is prepared by mixing mineral binder (cement), fine aggregate (ground stabilized with supplements) and water; loading of the molding compound in a mold is performed whilst being influenced with vibratory impulses during the loading process; pressing is performed by means of opposite pressure direction at the molding compound: from the bottom to the top from the side of the driven die pallet during its displacement and reaction thrust from the top to the bottom from the side of the mold cover rigidly fixed, meanwhile the compression is performed with the pallet speed change (at 3 phases). If necessary in the process of pressing there are hollows formed in products with the help of a vertical hollow- forming machine, after which the product is removed from the mold. The removal is done through pressing-out during lift of the bottom die up and further the product is displaced in accordance with the manufacturing route which includes the operation of product removing after pressing-out as well as its transportation if necessary, for example, at the position of heat treatment, stacking. The method implements the variant of manufacturing various building products from compounds different in composition, in particular of bricks of the size (290x140x90) mm by the method of hyper pressing (20 - 30 MPa) during one cycle that has three phases by the speed of bottom die pallet displacement.

The following can by assigned to weaknesses of the described method: unilateral compression of the molding compound by means of insertion in it only the bottom die leads to the density uneven in the product depth that decreases in the direction of the mold cover, which has an adverse effect on the strength, freeze resistance and other characteristics of a building product.

The task, to which solution the invention is directed, is possibility enhancement of creating building constructions of a small perimeter, simplifying building block construction and its manufacturing technology, simplifying assembly of building constructions of a small perimeter and increasing their strength.

The set task is solved in the following order: according to the first variant of manufacturing building blocks with split surface finish of, at least, side faces the molding compound is prepared on the basis of cement and aggregate with the lifted array containing, at least, one section for manufacturing a twin pulley block, an interchangeable pallet is installed on the table of vibropress, chamfer formers are installed on the surface of the interchangeable pallet, the array is lowered on the pallet and loading of the molding compound in the array section is performed, the punch is lowered on the molding compound, vibratory impulse is set and forming of a twin pulley block is performed, then chamfer formers are removed from the array, lift of the array and a punch is performed, the twin pulley block with a pallet is removed from the press and laid on a rack for strength gain, then the twin pulley block is cut into separate blocks and side faces are cut.

According to the second variant of manufacturing building blocks with split surface finish of, at least, side faces the molding compound is prepared on the basis of cement and aggregate with the lifted array containing, at least, one section for manufacturing a twin pulley block, a skid board with chamfer formers mounted on it is installed on the table of vibropress, the array is lowered on the skid board and loading of the molding compound in the array section is performed, the punch is lowered on the molding compound, vibratory impulse is set and forming of a twin pulley block is performed, then lift of the punch and the array with the as-formed twin pulley block is performed, an interchangeable pallet is installed on the table of vibropress and the twin pulley block is extruded on it from the array with the help of the punch, the interchangeable pallet with the twin pulley block is removed from the press and laid on a rack for strength gain, then the twin pulley block is cut into separate blocks and side faces are cut.

Moreover if necessary end faces of building blocks can be cut, the molding compound may contain plasticizers and a dye.

Row building blocks are manufactured in a mold that contains an array flexible- installed in a vertical plane. This array includes, at least, one section for manufacturing a twin pulley block. Section internal cavity is formed with walls closed on perimeter. Their counter includes flat side areas and symmetrically located lugs and dents that have a trapezoidal form for formation of fixing grooves and corresponding dents on the end faces of the formable row building blocks with the possibility of joining row building blocks in the dovetail attachment. There is one chamfer former that contains three linear elements for every formable building block. Meanwhile one of the elements serves for forming a fixing groove on the formable row building block and two other elements - for forming a cut line. There is a punch installed opposite to the array section with the possibility of vertical displacement that contains a form-generating plate with a profiled surface that corresponds to internal configuration of the array section. Meanwhile the array is manufactured with the possibility of support on an interchangeable pallet or a sheet pallet.

The mold for manufacturing corner building blocks contains an array flexible- installed in a vertical plane. This array includes, at least, one section for manufacturing a twin pulley block. The section includes a case which internal configuration has a construction closed on perimeter and which is equipped with a bridge in the upper part and two, installed in the case, symmetric to the bridge, inserts for hollow formation. Meanwhile the case internal configuration includes symmetrically allocated lugs and dents for formation of the corresponding grooves and lugs on the side faces as well as symmetrically allocated lugs and dents that have a trapezoidal form for formation of the corresponding grooves and lugs on the end faces of the formable corner building blocks with the possibility of joining corner building blocks in the dovetail attachment. There are two chamfer formers installed perpendicular to each other for each formable corner building block. One chamfer former is made in the form of a linear element for creation of a spalling line in the end part of the formable corner building block and the other includes three linear elements, one of which serves for forming a cut line and two others serve for creating grooves on the formable corner building block. There is a punch installed opposite to the array section with the possibility of vertical displacement that contains a form-generating plate with a profiled surface that corresponds to internal configuration of the array section case including cavities for passing of the bridge and inserts. Meanwhile the array is manufactured with the possibility of support on an interchangeable pallet or a sheet pallet.

If array leans against the interchangeable pallet, the linear elements of the chamfer former can be done with the possibility of horizontal displacement and fixed on the common holder, which can be manufactured in the form of a flat strip. If the array leans against the sheet pallet, the linear elements of the chamfer former can be done with the possibility of rigid fixing on the sheet pallet and has the form of triangle at the section view.

Enclosures, including fences and ornamental hedges, different in size and length, closed and open in perimeter are made from row and corner building blocks, manufactured by a variant of the method.

On fig. 1 the mold for manufacture according to p. 9of a twin pulley row building block is represented.

On fig. 2 a variant of the mold for manufacture according to p. 12of a row building block is represented.

On fig. 3 the general view of a row building block is represented.

On fig. 4 the mold for manufacture according to p. 15 of a twin pulley corner building block is represented.

On fig. 5 the array for manufacture of a twin pulley corner building block is represented.

On fig. 6 the punch for manufacture of a twin pulley corner building block is represented.

On fig. 7 a variant of the mold for manufacture according to p. 18 of a twin pulley corner building block is represented. On fig. 8 the general view of a corner building block is represented.

On fig. 9 the general view of an enclosure from row and corner building blocks is represented.

Manufacture of building blocks is performed by the method of semidry vibration pressing of cement-sand mixture with the equipment that includes a vibropress (not shown on drawings) and a mold.

The mold contains array 1 that is a construction closed on perimeter which is flexible-installed in a vertical plane and has a possibility to lean against interchangeable pallet 2 or skid board 3. Array 1 contains one or a few sections; each section is meant for manufacturing a twin pulley block. Internal cavity of array 1 section for manufacturing a row building block (fig. 1 and 2) is created with walls closed on perimeter. Their counter includes flat side areas and symmetrically located lugs and dents that have a trapezoidal form for formation of fixing grooves and corresponding dents on the end faces of the formable row building blocks with the possibility of joining row building blocks in the dovetail attachment. Internal cavity of array 1 section for manufacturing a corner building block (fig. 5) is a case 4 that has a construction closed on perimeter and is equipped with a bridge 5 in the upper part and two, installed in the case, symmetric to the bridge, inserts 6 for hollow formation if necessary. Meanwhile the case internal configuration includes symmetrically allocated lugs and dents for formation of the corresponding grooves and lugs on the side faces as well as symmetrically allocated lugs and dents that have a trapezoidal form for formation of the corresponding grooves and lugs on the end faces of the formable comer building blocks with the possibility of joining corner building blocks in the dovetail attachment.

Besides the mold for manufacture of a row building block includes chamfer formers 7, which quantity depends on the quantity of sections in the array. The chamfer formers 7 are installed on the interchangeable pallet 3 or skid board 4. There is one for each formable row building block. Each chamfer former contains three linear elements 8, which can be fixed on a common holder 9. Meanwhile one of the elements serves for creation of a fixing groove on a formable row building block and two other elements - for creation of a cut line.

In order to manufacture a corner building block, two chamfer formers 7 and 10 (fig. 4 and 7), installed perpendicular to each other, are used. One chamfer former is made in the form of a linear element 10 and serves for creation of a spalling line in the end part of the formable building block. The other chamfer former 7 includes three aligned linear elements 8. Meanwhile the central element serves for forming a cut line and two extreme ones serve for creating grooves on the formable corner building block. Three linear elements can be fixed on the common holder 9.

The chamfer formers can have a form of triangle at section and be rigidly fixed on the skid board 3 (fig. 7).

The punch 1 1 (fig. 6) is made with the possibility of vertical displacement and installed opposite to each section of the array 1. It contains a flange 12 for fixing in a press ram, a form-generating plate 13 with a profiled surface that corresponds to internal configuration of a section of the array 1. While a corner building block is manufactured, it includes cavities for passing of a bridge 5 and inserts 6.

The mold construction provides an interchangeable pallet 2 or a skid board 3 which are limiters for molding sand. Besides the interchangeable pallet serves also as a tray for a twin pulley block on which the as-formed twin pulley block is laid on a rack for strength gain.

The stated method is performed in the following manner.

One prepares the molding sand in the form of cement-sand mixture which includes cement PC 500 D 0; sand of the top grade, 2.5 fineness modulus (washed); granite macadam of the cuboidal form (5-20 mm fraction); dyes; plasticizers; armature 12-20 mm diameter.

The prepared molding compound gets into a batch meter.

If the array 1 is lifted, the interchangeable pallet 2 is installed on the vibropress table. The chamfer formers 7 are installed on the surface of the interchangeable pallet 2. The array 1 is lowered on the pallet 2 and loading of the molding compound in the array section is performed.

The punch 11 is lowered on the molding compound, top and bottom vibrators are switched on and formation of a twin pulley block is performed.

Upon finish of formation process the chamfer formers 7 are removed from the array, lift of the array 1 and the punch 11 is performed, the twin pulley block with the pallet 2 is removed from the press and laid on a rack for strength gain, then the twin pulley block is cut into separate blocks and side faces are cut. If necessary end faces are cut.

Plasticizers can be added into the molding sand in order to give it special characteristics, such as damp-proof features, freeze resistance, extra strength, good shrinkage, heightened flowability etc.

In order to get multi-colored building blocks, dyes are added into the molding sand.

If the skid board 3 is used during manufacture of building blocks, the chamfer formers 7 are rigidly fixed on it, then the skid board 3 with the chamfer formers 7 is installed on the vibropress table. Upon finish of formation operation the lift of the punch 1 1 and array 1 together with a formed twin pulley block is performed. The skid board 3 with the chamfer formers 11 is removed from the vibropress table and the interchangeable pallet 2 is installed on the vibropress table. Then the twin pulley block is extruded on this pallet from the array with the help of the punch.