FR2653809A1 - Installation for producing concrete reinforcement bars - Google Patents

Abstract

The invention relates to an installation which is used for producing concrete reinforcement bars and is intended in particular for preparing concrete reinforcement bars for use in a mechanical connection in which two concrete reinforcement bars are joined substantially coaxially by way of a tapped connecting sleeve. The installation comprises in particular means (1) for cold-upsetting of the end or ends (2) of the concrete reinforcement bar, and means for prestressing the upset end after its threading.

Description

 The invention relates to an installation for producing concrete rods, in particular allowing their preparation in order to effect a mechanical connection of such concrete rods. It will find its application in particular in the field of construction of buildings or concrete buildings.

 In this area, to tie the concrete rods, it is common to make junctions whose role is to ensure the transmission of the tensile force. In addition. to be interesting, such links must be easy to implement and nevertheless remain economical.

 Different solutions are proposed by the manufacturers.

This is particularly the case with overlay systems, in which a length of concrete reinforcing bars is left on standby so that the joint can then be made. There is also known a connection system which uses a coupling sleeve with thread into which are screwed the ends of the concrete rods then provided for this purpose.

 In particular, a mechanical connection has recently been developed in which two concrete rods are joined substantially coaxially by means of a tapped connection sleeve. In addition. to obtain perfect resistance and efficiency, the ends of the concrete rods to be bonded have a backflow at the level of the threaded part. then are subjected, after the threading, and prior to the assembly of the connection on the site, to a prestressing with a force close to the elastic limit of the concrete rod.

 Such a solution is advantageous because it makes it possible to obtain a very high resistance of the connection for the same diameter of concrete reinforcing rod and on the other hand makes it possible to comply with the very severe criteria of deformations imposed by certain standards or certain regulations imposing tests. up to 80 Z of elastic resistance.

 The purpose of the present invention is to provide an installation for producing concrete rods which can be used in a threaded mechanical connection as mentioned above.

 In addition, it should be noted that the preparation of concrete reinforcing bars can, in certain cases, be carried out beforehand in the factory, but in other cases, to avoid excessive transport costs, it is advantageous to carry out the preparation of the rounds concrete at the site of use.

 In this regard, one of the aims of the present invention is to propose an installation for producing concrete rods which is compact and easily transportable and also using traditional means.

 Other objects and advantages of the present invention will appear during the following description which is however only given as an indication and which is not intended to limit it.

 According to the invention, the installation for producing concrete rounds, in particular intended for preparing concrete rounds with a view to their implementation in a mechanical connection in which two concrete rounds are joined substantially coaxially by means of a tapped connection sleeve, is characterized in that it has means for cold pressing the end or ends of the concrete ring.

 This reinforcement being carried out, the installation also comprises means for threading the driven end (s).

 Finally, to test the manufacture and to allow the mechanical connection which will be carried out to comply with the deformation criteria of certain standards, the installation will also present means for prestressing the driven end after the threading.

 The present invention will be better understood on reading the following description accompanied by the drawings which form an integral part thereof.

 FIG. 1 shows the installation for producing concrete rods of the present invention and particularly an embodiment of the means for cold pressing the ends of the concrete rods.

 Figure 2 shows a left view of the installation shown in Figure 1.

 FIG. 3 shows a sectional view along axis III-III of the installation shown in FIG. 1.

 Figure 4 shows a top view of a detail of the means shown in Figure 1 and in particular shows the shape of 1 discharge imprint.

 FIG. 5 shows another detail of the installation of the present invention and in particular an embodiment of the means for pre-stressing the repressed and threaded end of the concrete rods.

 Figure 6 shows a left view of the installation illustrated in Figure 5.

 Figure 7 shows a right view of the installation illustrated in Figure 5.

 Figure 8 shows a top view of a detail of the means shown in Figure 5 and in particular shows the shape of the imprint of the matrix.

 FIG. 9 shows another embodiment of the present invention and in particular means for pre-stressing 1 threaded driven end.

 FIGS. 10a to 10c schematically show the different stages of operation of the installation illustrated in FIG. 9.

 The invention relates to an installation for producing concrete rods in particular intended to be used in a mechanical connection of concrete rods in which two concrete rods are joined by means of a tapped connecting sleeve.

 As recalled in the preamble to the application, there is known a process for producing mechanical connection of concrete rods by which the connection of concrete rods is made substantially coaxially using tapped connection sleeves.

 For this, the ends of the concrete rods are threaded, but prior to the threading, the cold end (s) of the concrete rods to be bonded are cold pressed. In addition, between the threading step of said repressed end and its assembly on site, the repressed end (s) are prestressed in order to test the connection and install the threads in order to avoid elongation during a test.

 Thus, by pushing back the end of the concrete ring, its diameter is increased and one can then thread the end without reducing its resistance because the diameter at the bottom of the thread of the thread is not less than the nominal diameter of the concrete round.

 The diameter of the discharge is essentially dependent on the nominal diameter of the bar, the rate of increase in the diameter of the connected part being in principle equal to or less than 30 / ..

 In addition, this discharge is carried out over the entire length of the thread and good results are obtained for example by carrying out a reinforcement over a length corresponding substantially to the diameter of the concrete rod.

 However, according to the present invention, the installation for producing concrete rods has means 1 for cold pressing the end or ends 2 of the concrete rod 3.

 In the embodiment shown in FIGS. 1 to 3, these means 1 are constituted by a matrix 4 capable on the one hand of immobilizing the concrete rod 3 and on the other hand of authorizing an increase 5 in the diameter of the end of the bar 2, as well as by a punch 6 acting on said end 2 to allow its cold delivery into the die 4.

 The latter consists of a fixed imprint 7 and a movable imprint 8. FIG. 4 shows a view of the internal face of these imprints 7 or 8 which first of all comprise a housing 9 whose diameter is substantially close to that of the concrete rod 3 to be worked and a cavity 10 inside which will be carried out cold delivery and whose diameter corresponds to that sought for said delivery.

 In practice, the imprint of the fixed 7 and mobile 8 matrices are identical, but there will be a set of imprints per diameter of nominal bars.

 As particularly shown in Figures 1 and 3, the first fixed footprint 7 is arranged in a frame 11 advantageously made of a sheet of large thickness, for example 200 mm. This steel sheet is oxidized to define an interior space 12 in which the various necessary elements will be provided.

 In particular, on the frame 11, will be disposed a first cylinder 13 which will be connected to the cavity 8. The cavities 7, 8 and the said first cylinder 13 will be arranged such that the concrete ring 3 is immobilized in translation in the matrix to authorize the refoulement.

 The means for cold pressing 1 also include a second cylinder 14, also arranged in the interior part 12 of the frame 11, and bearing on it.

 This second jack will be able to move the said punch 6 substantially in the longitudinal axis of the said round 3 to cold press the end 2 into the housing 10 of the imprints 7 and 8.

 The cold discharge operation is carried out sequentially and the machine has sensors and limit switches which react with a control unit to authorize the succession of the different stages.

The concrete rod 3 is introduced into the inlet orifice 15 of the means 1, the two cavities 7 and 8 then being separated and the punch 6 in the withdrawn position
When the end 2 of the concrete rod arrives at the punch 6, the indentations 7, 8 of the clamping matrix 4 are then closed. When the clamping is sufficient to immobilize the concrete rod correctly during the pushing of the punch 6, the actuator 14 is then put into action.

 When the delivery is finished, the punch 6 returns to its initial position and the imprints are separated.

 By way of example, hydraulic actuators 13, 14 are used as actuators capable of developing thrusts of the order of 400 tonnes, which makes it possible to work concrete rods up to a diameter of 40 mm for example . These cylinders are naturally controlled by a traditional hydraulic circuit using a pump delivering for example a pressure of the order of 700 bars.

Regarding the quality of the materials used for the die and for the punch, advantageously used
2 high resistance steel treated 160 Kgimm in hardness generally called Z160 CDV12. With regard to the sequential control of the cylinders, the pressure in the circuits will advantageously be countered to verify the correct immobilization of the concrete reinforcing rod or the end of the delivery step.

 At the end of this delivery operation, the operator therefore releases the end of the dies 7, 8 and will then carry out 1 threading operation.

For this, the installation of the present invention further comprises means, not shown, for threading the driven end (s). Any device known to those skilled in the art can allow the threading of bars such as a comb lathe
At the end of these operations, the bars are advantageously tested and it is advantageous to stress the end which has just been threaded to put the threads in place.

 In this regard, the installation of the present invention comprises means 16 for prestressing the driven end 5 after its threading.

A first embodiment of these means is shown in Figures 5 to 7 and essentially comprises
a clamping matrix 17 able to immobilize the concrete ring 3 in translation,
a support sleeve 18, threaded, capable of receiving the threaded driven end 5 of the concrete ring 3,
- A cylinder 19 able to bear on the sleeve 18 to subject the concrete ring 3 and its threaded end driven 5 to a tensile force close to its elastic limit.

 These various elements are in particular arranged in a frame 19 which can also be produced by oxycutting in a very thick steel sheet to withstand the forces generated.

 The matrix 17 consists of a first fixed imprint 20 relative to the frame and a second movable imprint 21, these two imprints being able to be brought closer to one another to allow the tightening of the concrete ring 3.

 In this regard, Figure 8 shows a view of the internal face of the dies 20 or 21 which, in this case, have only one cavity 22 because the matrix has only a clamping function. The diameter of the cavity 22 is determined as a function of the nominal diameter of the concrete rod to be tested.

 The movable footprint 21 is controlled by a first cylinder 23 which allows the approximation of the two footprints 20, 21 and consequently the immobilization in translation of the concrete ring, this according to the same principle as described above.

 The means 16 further comprise a second hollow cylinder 24 capable of being freely traversed by the said round 3 to be tested and capable of acting on the said threaded sleeve 18 to generate the prestress.

 Here again, a control device associated with sensors or detectors makes it possible to ensure the succession of the steps sequentially.

 The operator introduces the concrete rod 3 into the installation through the inlet orifice 41, passes it through the cavities 20, 21 of the hollow jack 24 so that the threaded ends 5 are protruding.

 it then comes to screw the support sleeve 18 on the end 5, then places the sleeve in the active part 25 of the jack provided for this purpose.

 The prestressing cycle is then launched, the jaws 20, 21 approach each other, enclose the body of the concrete rod, then when the controlled clamping force is sufficient, the end 25 of the second jack acts on the sleeve 18 and generates the prestressing .

 it should be noted that, in order to carry out a correct test and authorize the fitting of the threads in order to meet the most stringent standards, the threaded end is subjected to a prestressing force of between 70 and 95% of the elastic limit concrete reinforcing bar.

 FIGS. 9 and 10 show a second embodiment of the means for prestressing the threaded driven end of the concrete ring, means generally marked with 26.

 The essential difference with the embodiment described above in Figures 5 to 7 lies in the mode of immobilization of the concrete rod 3 to be tested.

 Indeed, there is a threaded support sleeve 27, capable of receiving the threaded end 5 of the rebound 3 as well as a jack 28 capable of bearing on the sleeve 27 to subject the concrete rod 3 and its threaded end 5 at a tensile force close to its elastic limit.

 However, the immobilization of the latter is achieved thanks to the presence of a jaw-tightening mandrel 29 adapted on the one hand, in one position, to be crossed by the concrete ring 3 then on the other hand, in another position to enclose the body of said concrete rod 3.

 These various elements are arranged on a fixed frame 30, 31, 32, substantially constituted by flanges joined by means of spacers 33 as shown for example in FIG. 9.

 More specifically, the body 34 of the mandrel 29 is disposed on the flange 31. A set of movable jaws 35 are provided for sliding in the body of the mandrel, capable of gripping the body of the concrete rod 3.

 Finally, an elastic mechanism 36, based on the fixed frame, and more precisely on the flange 30, acts on the set of movable jaws 35 to allow the jaws to approach the body of the concrete ring.

 Furthermore, the body 34 of the mandrel 29 and the movable jaws 35 are advantageously conical and act in the manner of a wedge box under the action of the traction generated in the concrete ring 3.

 The operation is illustrated in FIGS. 10a to 10c schematically showing the various elements which have just been described.

 FIG. 10a shows the initial position in which the jack 28 is in the rest position and the clamping mandrel 29 is in the open position.

 it should be noted the presence of a non-deformable mechanical connection 37 which makes it possible to position relatively between them the end of the jack 28 and the elastic mechanism 36 resting on all of the movable jaws 35.

 As shown particularly in Figure 9, this link is adjustable in length and allows to determine the maximum opening of the clamping mandrel 29 to allow the introduction of the concrete rod in the machine.

 In the position shown in FIG. 10a, the operator can then introduce the concrete ring 3 and pass right through the installation so that its end 5 is through.

 The sleeve 27 is then screwed on this end 5 and then has in the end part 38 of the rod of the hollow cylinder 28 as shown precisely in Figure 10b.

 it should be noted that such an arrangement allows correct centering of the different elements together which will promote the prestressing of the different elements.

 Then, as shown in FIG. 10, the jack 28 is put into action and this rod, which is freely crossed by the said concrete ring, pushes the sleeve 27.

 Such displacement also allows displacement of the connecting rod 37 which will gradually control the action of the elastic mechanism 36 on all of the jaws 35.

 Indeed, the springs 39 which bear on the flange 30 of the frame are gradually decompressed and generate a force on the plate 40 which transmits it to the jaws 35 to cause them to move in the direction of approximation towards the body of the concrete ring .

When the jaws come into contact with the concrete ring, a sufficient tightening is obtained which will allow, during the rear displacement of the rod of the jack to move the conical jaws 35 in the internal part 34 of the clamping mandrel 29, in the manner of a corner box.

 In other words, the more the rod of the jack comes out, the more effective the clamping of the mandrel, like a wedge box, will be important.

 Such a solution is advantageous because there is somehow a self-tightening system which avoids the use of a second cylinder specifically intended to immobilize the bar. Only a relatively small clamping pressure is required to bring the jaws closer to the body of the concrete reinforcing bar.

 However, in the case where it is necessary to prepare the concrete reinforcing bars on the site, the installation of the present invention is advantageously arranged in a container of standard type and provided as a traveling workshop, an installation is thus produced. compact and easily transportable.

 Naturally, other implementations of the present invention, within the reach of those skilled in the art, could have been envisaged without departing from the scope of the present application.

Claims (10)

 1. Installation for making concrete rods, in particular intended for preparing concrete rods for their implementation in a mechanical connection in which two concrete rods are joined substantially coaxially by means of a threaded connecting sleeve , characterized in that it has means (1) for cold pressing the end (s) (2) of the concrete reinforcing bar (3).  2. Installation according to claim 1, characterized in that it further has means for threading the driven end (s) (5).  3. Installation according to claim 1, characterized in that it further comprises means (16; 26) for prestressing the driven end (5) after its threading.  4. Installation according to claim 1, characterized in that the means (1) for cold delivery consist of a matrix (4) adapted on the one hand to immobilize the concrete reinforcing rod (3) and on the other hand to allow an increase (5) in the diameter of the end (2) of the bar (3) as well as by a punch (6) acting on said end (2) to allow it to be pushed back into the die (4).  5. Installation according to claim 4, characterized in that it comprises  - a matrix (4) consisting of a fixed imprint (7), and a movable imprint (8) controlled by a first cylinder (13), the imprints (7 and 8) and the first cylinder (13) being such that the concrete ring (3) can be at least immobilized in translation,  - A second cylinder (14) able to move said punch (6) substantially in the longitudinal axis of said round (3) immobilized in the cavities (7, 8).  6. Installation according to claim 3, characterized in that the means (16) for prestressing the threaded driven end (5) consist of:  - a clamping matrix (17) capable of immobilizing the concrete rod (3) in translation,  - a threaded support sleeve (18) capable of receiving 1 threaded end (5) of the concrete rod,  - A jack (19) able to bear on the sleeve (18) to subject the concrete ring (3) and its threaded end (5) to a tensile force close to its elastic limit.  7. Installation according to claim 6, characterized in that it comprises  - a fixed cavity (20) and a movable cavity (21) controlled by a first cylinder (23), the cavities (20, 21) and the first cylinder (23) being such that the concrete ring can be immobilized in translation ,  - A second hollow jack (24) capable of being freely traversed by the said round (3) and capable of acting on the said threaded sleeve (18) to generate the prestress.  8. Installation according to claim 3, characterized in that the means (26) for prestressing the driven end (5) are constituted by  - A jaw chuck (29) adapted on the one hand, in one position, to be crossed by the concrete ring (3) then on the other hand, in another position, to grip the body of said round to concrete (3),  - a threaded support sleeve (27) capable of receiving the threaded end of the concrete ring (3) thus blocked in the mandrel,  - A jack (28) able to bear on the sleeve (27) to subject the concrete ring (3) and its threaded end (5) to a tensile force close to its elastic limit.  9. Installation according to claim 8, characterized in that it comprises  - a body (34) of mandrel (29), disposed on a fixed frame (30-33),  - a set of movable jaws (35), disposed in the body of the mandrel (34), capable of gripping the body of the concrete rod (3),  - an elastic mechanism (36) resting on the fixed frame (30) and acting on the set of movable jaws (35) to allow the jaws to be brought closer to the body of the concrete reinforcing rod (3),  - A hollow cylinder (28), integral with the frame (3), capable of being freely traversed by said round and having a rod (38) capable of bearing on said sleeve (27), and on the other hand capable of gradually control the action of the elastic mechanism (36) on all of the jaws (35).  10. Installation according to claim 9, characterized in that the body (34) of the mandrel (29) and the movable jaws (35) are conical and act in the manner of a wedge box under the action of traction generated in the concrete ring (3).