CN111137687A

CN111137687A - Stacking device and stacking method for concrete rectangular groove

Info

Publication number: CN111137687A
Application number: CN202010073902.3A
Authority: CN
Inventors: 张伟; 陈仁山
Original assignee: Shandong Jiaotong University
Current assignee: Shandong Jiaotong University
Priority date: 2020-01-22
Filing date: 2020-01-22
Publication date: 2020-05-12
Anticipated expiration: 2040-01-22
Also published as: CN111137687B

Abstract

The invention discloses a stacking device and a stacking method for a concrete rectangular groove. The material piling method adopts the material piling device. The main beam arranged in the invention can be lifted and rotated, so that the direction and the height of the notch of the concrete rectangular groove can be adjusted after the concrete rectangular groove is clamped, and the concrete rectangular groove can be conveniently clamped and conveyed to a specified position.

Description

Stacking device and stacking method for concrete rectangular groove

Technical Field

The invention relates to a stacking device and a stacking method for a concrete rectangular groove.

Background

The basin construction of flowing water generally adopts prefabricated concrete rectangular channel among hydraulic engineering, and the storehouse of need stacking earlier after the concrete rectangular channel is prefabricated in mill is kept in, generally needs artifical transport pile up neatly from production line ejection of compact platform to the storehouse, needs the workman to pay out great physical power to it is higher to cause this production link cost of labor, has restricted the development of mill.

Disclosure of Invention

The purpose of the invention is as follows: the piling device of the concrete rectangular groove can clamp the concrete rectangular groove and change the direction of the groove opening, so that the piling is compact, and the piling method of the concrete rectangular groove can compact the piling of the concrete rectangular groove.

In order to solve the technical problem, the stacking device for the concrete rectangular groove comprises a trolley, a stand column, a cross beam and a clamping device, wherein the lower end of the stand column is fixed on the trolley, the cross beam comprises an end sleeve and a main beam, the end sleeve is arranged on the stand column in a vertically sliding mode, a through groove penetrating through two sides is formed in the middle of the stand column, one end of the main beam penetrates through the pipe wall of the end sleeve and the through groove of the stand column, and the main beam is connected with the end sleeve in a rotating mode.

In order to control the opening and closing of the clamping device and control the lifting of the cross beam, an oil cylinder for driving the clamping device to slide on the main beam is connected between the main beam and the clamping device, a driving motor is arranged on the end sleeve, a gear rack mechanism matched with the driving motor is arranged between the upright post and the end sleeve, a rack is fixed on the upright post, a gear is rotatably arranged on the end sleeve, the gear is connected with an output shaft of the driving motor, a roller wheel is arranged on one side, deviating from the gear, of the end sleeve, and the roller wheel is in rolling contact with the upright post.

In order to facilitate taking and placing of the rectangular concrete groove, the material clamping device comprises a groove plate and a clamping plate, the section of the groove plate is U-shaped, the groove plate is connected to a main beam in a sliding and buckling mode, an oil cylinder for driving the groove plate to slide on the main beam is connected between the groove plate and the main beam, one end, far away from an end sleeve, of the main beam is transversely provided with a bidirectional synchronous telescopic oil cylinder, the axis of the bidirectional synchronous telescopic oil cylinder is perpendicular to the axis of the main beam, one end, near an upright post, of the clamping plate is rotatably connected with the opening of the groove plate through a rotating shaft, one end, far away from the upright post, of the clamping plate is free, the included angle between the clamping plate and the surface, adjacent to the main beam, of the clamping plate in the rotating process relative to the groove plate is in the range of 0-n degrees, n is not less than or equal to 30, a first, the breach of locating piece is slided and is pegged graft and is had the extrusion piece, be connected with the second spring between extrusion piece adjacent end sheathed tube one end and the girder, when the extrusion piece is not extrudeed, extrusion piece one end is stretched out the locating piece and is kept away from end sheathed tube one side certain distance, and the extrusion piece is located the pivot completely and keeps away from end sheathed tube one side, splint and girder are in the biggest contained angle state, when the extrusion piece is extruded to and the locating piece parallel and level, the both ends of extrusion piece are located the both sides of pivot respectively, the contained angle of splint and girder is zero.

In order to facilitate the material clamping device to move to a specified position, the wheels of the trolley are all universal wheels.

For better balance, the upright post is fixed on the side of the trolley away from the clamping plate.

In order to facilitate the rotation of the main beam, the main beam body is a square column body, the parts of the main beam, which are positioned in the upright post and the end sleeve, are cylinders, one end of the main beam, which is far away from the material clamping device, is provided with two handles which are positioned on the same straight line and are perpendicular to the axis of the main beam, the two handles are provided with radial pin holes, the end sleeve is provided with pin holes, and each pin hole which rotates to the upward handle is connected with the pin hole of the end sleeve through a pluggable positioning pin.

The invention discloses a concrete rectangular groove stacking method, which comprises the following steps: (1) placing a concrete rectangular groove with an upward notch, and buckling a concrete rectangular groove with a downward notch on the placed concrete rectangular groove to form a combined concrete rectangular groove; (2) sequentially stacking a row of combined concrete rectangular grooves according to the step (1) to form a layer of concrete rectangular grooves; (3) stacking concrete rectangular grooves layer by layer from top to bottom according to the step (2) to form a concrete rectangular groove; (4) adhering a pile of stacked concrete rectangular grooves according to the step (3) to finish stacking of the concrete rectangular grooves; when the concrete rectangular groove is stacked, the concrete rectangular groove is picked and placed by adopting the stacking device of the concrete rectangular groove, and the picking and placing method of the concrete rectangular groove with the upward stacking notch comprises the following steps: a, adjusting a clamping plate to a free end to upwarp, adjusting a main beam to a proper height and aligning the main beam to a groove cavity of a concrete rectangular groove, inserting the main beam into the concrete rectangular groove until the concrete rectangular groove is jacked to a positioning block, flatting the clamping plate under the action of an extrusion block, pushing the groove plate to the positioning block through an oil cylinder to clamp the concrete rectangular groove between the clamping plate and the main beam, enabling two ends of a bidirectional synchronous telescopic oil cylinder to extend out to tightly support the inner walls of two sides of the concrete rectangular groove, b, adjusting the main beam to enable a notch of the concrete rectangular groove to face upwards, c, moving a trolley to a position where the concrete rectangular groove is to be stacked, retracting the bidirectional synchronous telescopic oil cylinder, adjusting the height of a cross beam to enable the concrete rectangular groove to enter a stacking position, keeping the trolley and the main beam stationary, driving the groove plate to slide to an upright column on the main beam, moving the clamping plate along with the groove plate, and enabling the concrete rectangular, moving the trolley in the direction far away from the concrete rectangular groove until the main beam leaves the concrete rectangular groove; the difference between the method for taking and placing the concrete rectangular groove with the downward notch after stacking and the method for taking and placing the concrete rectangular groove with the upward notch after stacking is that in the step b, the main beam is adjusted so that the notch of the concrete rectangular groove faces downward.

The invention has the beneficial effects that: the main beam arranged in the invention can be lifted and rotated, so that the direction and the height of the notch of the concrete rectangular groove can be adjusted after the concrete rectangular groove is clamped, and the concrete rectangular groove can be conveniently clamped and conveyed to a specified position. Under the condition that sets up special clamping device, splint can be transferred to upwarping before getting the material, make the feed inlet great, be convenient for the bottom plate of concrete rectangular channel get into between splint and the girder, and utilize the promotion of concrete rectangular channel to the stripper block, the concrete rectangular channel extrudees the stripper block earlier with the locating piece parallel and level, promote frid to the locating plate again in the effect of hydro-cylinder, make the splint promote the level and paste the concrete rectangular channel by the stripper block, utilize two-way synchronous flexible hydro-cylinder to strengthen fixed concrete rectangular channel again simultaneously, make the centre gripping more reliable when adjusting the notch direction, can retract two-way synchronous flexible hydro-cylinder earlier when back-off the concrete rectangular channel toward another ascending concrete rectangular channel, make and leave the space that the cell wall that is detained the rectangular channel got into between cell wall and the girder. The invention can pile up a block of rectangular groove walls which are arranged closely, and every two rectangular grooves are buckled together, so that the stacking is compact.

Drawings

FIG. 1 is a schematic view of a state of the stacker apparatus to be gripped;

FIG. 2 is a schematic view of a clamping state of the stacking apparatus according to the present invention;

FIG. 3 is a schematic view of the connection structure of the end socket and the upright post according to the present invention;

FIG. 4 is an enlarged view of the structure of the clamping device in a clamping state;

FIG. 5 is an enlarged view of the clamping state of the clamping device according to the present invention;

FIG. 6 is a schematic diagram of the right side view of the structure of FIG. 5;

FIG. 7 is a schematic diagram of the right side view of FIG. 5 after clamping a rectangular concrete trough;

FIG. 8 is a schematic structural view of the concrete rectangular trough to be clamped by the clamping device of the present invention;

FIG. 9 is a schematic structural view of the clamping device of the present invention after clamping a rectangular concrete trough;

FIG. 10 is an enlarged view of a portion A of FIG. 1;

FIG. 11 is a schematic view of a concrete rectangular trough structure;

FIG. 12 is a schematic diagram of the construction of a rectangular concrete tank pile;

in the figure: 1. the device comprises a vertical column, 1-1 parts of a through groove, 2 parts of a rack, 3 parts of an end sleeve, 4 parts of a motor, 5 parts of a main beam, 6 parts of an oil cylinder, 7 parts of a clamping plate, 8 parts of a bidirectional synchronous telescopic oil cylinder, 9 parts of an extrusion block, 10 parts of a positioning block, 11 parts of a groove plate, 11-1 parts of a flanging, 12 parts of a trolley, 13 parts of a gear, 14 parts of a second spring, 15 parts of a first spring, 16 parts of a rotating shaft, 17 parts of a material taking table, 18 parts of a concrete rectangular groove, 19 parts of a handle, 20 parts of a positioning pin, 21 parts of.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The stacking device for the concrete rectangular groove shown in fig. 1-10 comprises a trolley 12, a vertical column 1, a cross beam and a clamping device, wherein the lower end of the vertical column 1 is fixed on one side of the trolley 12, and the clamping device is positioned outside the other side of the trolley 12. The crossbeam comprises an end sleeve 3 and a main beam 5, the end sleeve 3 is arranged on the upright post 1 in a vertically sliding manner, a through groove 1-1 penetrating through two sides is arranged in the middle of the upright post 1, one end of the main beam 5 penetrates through the pipe wall of the end sleeve 3 and the through groove 1-1 of the upright post 1, and the main beam 5 is rotatably connected with the end sleeve 3. The wheels of the trolley 12 are universal wheels, so that the running direction of the trolley 12 can be well adjusted under the condition that the trolley body is not rotated.

An oil cylinder 6 for driving the clamping device to slide on the main beam 5 is connected between the main beam 5 and the clamping device, a driving motor 4 is arranged on the end sleeve 3, a matched gear rack mechanism is arranged between the upright post 1 and the end sleeve 3, the rack 2 is fixed on the upright post 1, a gear 13 is rotatably arranged on the end sleeve 3, and the gear 13 is connected with an output shaft of the driving motor 4. The side of the end sleeve 3 facing away from the gear 13 is provided with a roller 21, and the roller 21 is in rolling contact with the upright 1.

The clamping device comprises a groove plate 11 and a clamping plate 7, the section of the groove plate 11 is U-shaped, the groove plate 11 is connected to the main beam 5 in a sliding and buckling mode, and a flanging 11-1 buckled on the main beam 5 is arranged at the notch of the groove plate 11, so that the groove plate 11 is not prone to falling off from the main beam 5. An oil cylinder 6 for driving the groove plate 11 to slide on the main beam 5 is connected between the groove plate 11 and the main beam 5, a cylinder body of the oil cylinder 6 is fixed on the main beam 5, a piston rod of the oil cylinder 6 is connected with the groove plate 11, one end of the main beam 5, far away from the end sleeve 3, is transversely provided with a bidirectional synchronous telescopic oil cylinder 8, the bidirectional synchronous telescopic oil cylinders 8 can be coaxially arranged, and piston rods of the two oil cylinders point to two sides respectively. The bidirectional synchronous telescopic oil cylinder 8 can also be provided with two pistons in the cylinder body, the two pistons are connected with a piston rod, the two piston rods extend out from two sides of the cylinder body, and oil inlet and outlet pipelines are arranged between the two pistons and at two ends of the cylinder body. The axis of the bidirectional synchronous telescopic oil cylinder 8 and the axis vertical line of the main beam 5 enable the bidirectional synchronous telescopic oil cylinder to tightly support the inner walls of two sides of a concrete rectangular groove 18, one end, close to the upright post 1, of the clamping plate 7 is rotatably connected with the opening part of the groove plate 11 through a rotating shaft 16, one end, far away from the upright post 1, of the clamping plate 7 is free, the included angle between the clamping plate 7 and the surface, adjacent to the main beam 5, of the clamping plate 7 in the rotating process of the clamping plate 7 relative to the groove plate 11 ranges from 0 degree to n degrees, n is more than or equal to 10 degrees and less than or equal to 30 degrees, when the included angle is n, the other end, far away from the. Aforementioned contained angle restriction can be realized through setting up limit structure on the frid, for example set up two spacing bumps, and when splint 7 rotated spacing bump of contact, the contained angle of splint 7 and the adjacent face of girder 5 was 0, and when splint 7 rotated another spacing bump of contact, the contained angle of splint 7 and the adjacent face of girder 5 was n. A first spring 15 is arranged between the clamping plate 7 and the groove plate 11, a positioning block 10 is fixed on the main beam 5, one side of the positioning block 10 is used for positioning the concrete rectangular groove, and the other side of the positioning block is used for positioning the groove plate 11. Locating piece 10 is located the one side that girder 5 is close to splint 7, the trapezoidal breach that is provided with in the middle of the locating piece 10, the base that trapezoidal breach is close to girder 5 one side is less than the base of opposite side, it has extrusion block 9 to slide in the breach of locating piece 10 to peg graft, be connected with second spring 14 between extrusion block 9 the one end that is close to end sleeve 3 and the girder 5, when extrusion block 9 is not extrudeed, extrusion block 9 one end stretches out locating piece 10 and keeps away from one side certain distance of end sleeve 3, and extrusion block 9 is located the one side that end sleeve 3 was kept away from to pivot 16 completely, splint 7 and girder 5 are in the biggest contained angle state, when extrusion block 9 is extruded to and locating piece 10 parallel and level, the both ends of extrusion block 9 are located the both sides of pivot 16 respectively, splint 7 and girder 5's. In this patent, material clamping device, girder, hydro-cylinder 6 constitute a material clamping structure.

The main body of the main beam 5 is a square column body, the parts of the main beam 5, which are positioned in the upright post 1 and the end sleeve 3, are cylinders, one end of the main beam 5, which is far away from the material clamping device, is provided with two handles 19 which are positioned on the same straight line and are perpendicular to the axis of the main beam 5, the two handles 19 are all provided with radial pin holes, the end sleeve 3 is provided with pin holes, and each pin hole which rotates to the upward handle 19 is connected with the pin hole of the end sleeve 3 through a pluggable positioning pin 20.

The concrete rectangular groove stacking method adopting the stacking device of the embodiment comprises the following steps: as shown in fig. 11 and 12, (1) placing a concrete rectangular groove 18 with an upward notch, and buckling a concrete rectangular groove with a downward notch on the placed concrete rectangular groove to form a combined concrete rectangular groove; (2) sequentially stacking a row of combined concrete rectangular grooves according to the step (1) to form a layer of concrete rectangular grooves; (3) stacking concrete rectangular grooves layer by layer from top to bottom according to the step (2) to form a concrete rectangular groove; (4) adhering a pile of stacked concrete rectangular grooves according to the step (3) to finish stacking of the concrete rectangular grooves; when the concrete rectangular groove is stacked, the method for taking and placing the concrete rectangular groove with the upward opening after stacking comprises the following steps: a, adjusting the clamping plate 7 to a state that the free end is upwarped, as shown in the states of fig. 1, 4 and 8, adjusting the main beam 5 to a proper height and aligning with a groove cavity of the concrete rectangular groove, wherein the height of the main beam 5 needs to be adjusted according to different material taking platforms 17 as the concrete rectangular groove 18 is placed on the material taking platform 17, such as a discharging platform after production and molding. And then the main beam 5 is inserted into the concrete rectangular groove until the concrete rectangular groove is pushed to the positioning block 10, therefore, the extrusion block 9 is extruded to be level with the positioning block 10, the clamping plate 7 is laid flat under the action of the extrusion block 9, the oil cylinder 6 pushes the groove plate to be pushed to the positioning block 10, the concrete rectangular groove is clamped between the clamping plate 7 and the main beam 5, and then two ends of the bidirectional synchronous telescopic oil cylinder extend out to tightly support the inner walls of two sides of the concrete rectangular groove 18. The clamping plate and the main beam do not clamp the concrete rectangular groove completely, the clamping plate and the main beam are also required to be matched with the bidirectional synchronous telescopic oil cylinder completely, the main beam can be adjusted to be centered by the bidirectional synchronous telescopic oil cylinder when being inserted into the concrete rectangular groove and not centered, the concrete rectangular groove is controlled to enter a designated position more accurately, and the oil cylinder 6 can not push the concrete rectangular groove away from the positioning block when pushing the groove plate. The concrete rectangular groove b is completely adjusted to enable the notch of the concrete rectangular groove to face upwards, the lower positioning pin 20 can be detached, the main beam 5 is rotated by 180 degrees, and then the upper positioning pin 20 is installed. c, moving the trolley 12 to a position where the concrete rectangular groove is to be stacked, retracting the bidirectional synchronous telescopic oil cylinder 8, adjusting the height of the cross beam to enable the concrete rectangular groove to enter the stacking position, keeping the trolley 12 and the main beam 5 stationary, driving the groove plate 11 to slide on the main beam 5 towards the upright post 1, and realizing through the control oil cylinder 6, wherein the clamping plate 7 moves along with the groove plate 11, the concrete rectangular groove does not move along with the clamping plate 7 under the positioning of the positioning block 10 until the clamping plate 7 completely leaves the concrete rectangular groove 18, and moving the trolley 12 in the direction far away from the concrete rectangular groove until the main beam 5 leaves the concrete rectangular groove. The difference between the method for taking and placing the concrete rectangular groove with the notch facing downwards after stacking and the method for taking and placing the concrete rectangular groove with the notch facing upwards after stacking is that in the step b, the main beam 5 is adjusted so that the notch of the concrete rectangular groove faces downwards, and the notch faces downwards when clamping is carried out, namely, the main beam 5 does not need to be rotated.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a windrow device of concrete rectangular channel which characterized in that: including dolly, stand, crossbeam and clamp material device, the stand lower extreme is fixed on the dolly, and the crossbeam includes end sleeve pipe and girder, and gliding setting is on the stand from top to bottom in the end sleeve pipe, and the centre of stand is provided with the logical groove that runs through both sides, and the logical groove of end sheathed tube pipe wall and stand is run through to the one end of girder, and the girder rotates with the end sleeve pipe to be connected.

2. A stacking device for concrete rectangular grooves according to claim 1, characterized in that: the main beam and the clamping device are connected with each other to drive the clamping device to slide on the main beam, the end sleeve is provided with a driving motor, a matched gear rack mechanism is arranged between the stand column and the end sleeve, the rack is fixed on the stand column, the gear is rotatably arranged on the end sleeve, the gear is connected with an output shaft of the driving motor, one side of the end sleeve, which is far away from the gear, is provided with a roller, and the roller is in rolling contact with the stand column.

3. A stacking device for concrete rectangular grooves according to claim 1, characterized in that: the clamping device comprises a groove plate and a clamp plate, the section of the groove plate is U-shaped, the groove plate is buckled on a main beam in a sliding manner, an oil cylinder for driving the groove plate to slide on the main beam is connected between the groove plate and the main beam, a bidirectional synchronous telescopic oil cylinder is transversely arranged at one end, far away from an end sleeve, of the main beam, the axis of the bidirectional synchronous telescopic oil cylinder is perpendicular to the axis of the main beam, one end, close to an upright post, of the clamp plate is rotatably connected with the opening of the groove plate through a rotating shaft, one end, far away from the upright post, of the clamp plate is free, the included angle between the clamp plate and the adjacent surface of the main beam in the rotating process of the clamp plate relative to the groove plate is in the range of 0-n degrees, n is not less than 10 and not more than 30, a first spring is arranged between the clamp plate and the groove plate, a positioning block is fixed on, the second spring is connected between one end of the extrusion block adjacent to the end sleeve and the main beam, when the extrusion block is not extruded, one end of the extrusion block extends to a certain distance from one side of the positioning block away from the end sleeve, the extrusion block is completely positioned on one side of the rotating shaft away from the end sleeve, the clamping plate and the main beam are in a maximum included angle state, when the extrusion block is extruded to be parallel and level with the positioning block, two ends of the extrusion block are respectively positioned on two sides of the rotating shaft, and the included angle between the clamping plate and the main beam is zero.

4. A stacking device for rectangular concrete troughs according to claim 1 or 2, characterized in that: the wheels of the trolley are all universal wheels.

5. A stacking device for rectangular concrete troughs according to claim 1 or 2, characterized in that: the upright post is fixed on one side of the trolley far away from the clamping plate.

6. A stacking device for rectangular concrete troughs according to claim 1 or 2, characterized in that: the main beam body is a square column body, the parts of the main beam, which are positioned in the stand column and the end sleeve, are cylinders, one end of the main beam, which is far away from the material clamping device, is provided with two handles which are positioned on the same straight line and are perpendicular to the axis of the main beam, the two handles are provided with radial pin holes, the end sleeve is provided with pin holes, and each pin hole which rotates to the upward handle is connected with the pin hole of the end sleeve through a pluggable positioning pin.

7. A stacking method of a concrete rectangular groove is characterized in that: the stacking method comprises the following steps: (1) placing a concrete rectangular groove with an upward notch, and buckling a concrete rectangular groove with a downward notch on the placed concrete rectangular groove to form a combined concrete rectangular groove; (2) sequentially stacking a row of combined concrete rectangular grooves according to the step (1) to form a layer of concrete rectangular grooves; (3) stacking concrete rectangular grooves layer by layer from top to bottom according to the step (2) to form a concrete rectangular groove; (4) adhering a pile of stacked concrete rectangular grooves according to the step (3) to finish stacking of the concrete rectangular grooves; when the concrete rectangular groove is stacked, the concrete rectangular groove is picked and placed by the stacking device of the concrete rectangular groove according to claim 3, and the picking and placing method of the concrete rectangular groove with the upward notch after stacking comprises the following steps: a, adjusting a clamping plate to a free end to upwarp, adjusting a main beam to a proper height and aligning the main beam to a groove cavity of a concrete rectangular groove, inserting the main beam into the concrete rectangular groove until the concrete rectangular groove is jacked to a positioning block, flatting the clamping plate under the action of an extrusion block, pushing the groove plate to the positioning block through an oil cylinder to clamp the concrete rectangular groove between the clamping plate and the main beam, enabling two ends of a bidirectional synchronous telescopic oil cylinder to extend out to tightly support the inner walls of two sides of the concrete rectangular groove, b, adjusting the main beam to enable a notch of the concrete rectangular groove to face upwards, c, moving a trolley to a position where the concrete rectangular groove is to be stacked, retracting the bidirectional synchronous telescopic oil cylinder, adjusting the height of a cross beam to enable the concrete rectangular groove to enter a stacking position, keeping the trolley and the main beam stationary, driving the groove plate to slide to an upright column on the main beam, moving the clamping plate along with the groove plate, and enabling the concrete rectangular, moving the trolley in the direction far away from the concrete rectangular groove until the main beam leaves the concrete rectangular groove; the difference between the method for taking and placing the concrete rectangular groove with the downward notch after stacking and the method for taking and placing the concrete rectangular groove with the upward notch after stacking is that in the step b, the main beam is adjusted so that the notch of the concrete rectangular groove faces downward.