DE102010024352A1 - Improved tie rod made of fiber-reinforced plastic - Google Patents

Abstract

The invention relates to a tie rod (1), in particular a rock anchor, made of fiber-reinforced plastic, comprising an anchor rod (2) made of fiber-reinforced plastic, which has an anchor thread (6) at least in a partial area, an anchor plate (5) made of fiber-reinforced plastic with a Anchor hole (15) through which the anchor rod (2) is passed, and an anchor nut (3) made of fiber-reinforced plastic with an internal thread, which can be screwed onto the anchor thread (6) of the anchor rod (2) and supported against the anchor plate (5) is, wherein the anchor plate (5) is provided with a curved contact surface (14) which cooperates with a complementary contact surface (12) assigned to the anchor nut (3) in such a way that the anchor rod (2) in at least one direction by an angle (α ) is tiltable at an angle to the anchor plate (5), the anchor nut (3) in a through hole (21) of a preferably made of fiber-reinforced plastic Seat ring (4) engages, the anchor nut (3) having a conical area (8) on the outside, with which it rests against a complementary inner cone (11) of the seat ring (4), the anchor nut (3) in the conical area (8) ) at least one slot (9), preferably running parallel to the axis, is provided which interrupts the mother wall at least over a partial area of the conical area (8), and wherein the complementary contact surface (12) cooperating with the curved contact surface (14) of the anchor plate (5) the seat ring (4) is formed.

Description

The present invention relates to a fiber reinforced plastic, in particular fiberglass-reinforced plastic (GRP) existing tie rods according to the preamble of claim 1.

The application of such tie rods is predominantly as rock anchors in the underground tunnels of mining, z. B. in hard coal mines. Due to the space there usually very cramped conditions rock anchors are offset as adhesive anchors in rotary drilling boreholes. These are mainly used during the tunneling work for the temporary securing of working face, parts of the ridges and in particular for securing the joints and there in the area of the mineral / coal seam, so as not to hinder the subsequent, mechanical propulsion or dismantling, in which the anchors pass through Routing away gradually. Furthermore, such tie rods can also be used as the final anchorage on rebars for concrete applications to minimize composite lengths.

Such tie rods are for example from the DE 198 28 371 A1 to which reference is made for further details, in particular also for use and for the manufacture of tie rods.

A high-tensile and corrosion-resistant tie rods of the type mentioned is from the DE 299 00 172 U1 known. The anchor nut lies by means of a curved end face against a curved support surface of the anchor plate which is adapted to it, so that an angle compensation of the anchor axis to the rock surface can take place.

Although relatively strong tie-bolt connections can already be achieved with such systems, the strength values are still lower than those of comparable steel armature systems with identical stress cross-sections. In particular, when settling phenomena occur in the near-surface rock body due to convergence, a further increase in the strength of the tie rod is desirable in order to ensure a sufficiently high and at the same time early-wearing expansion resistance.

Object of the present invention is to provide an inexpensive to manufacture and easy to handle tie rods of the type mentioned in fiber-reinforced plastic, which achieves increased load capacity and higher strength values even when subsidence of the subsurface.

This object is achieved by a tie rod according to claim 1. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

It is essential in the inventive solution that the anchor nut engages in a through hole of a preferably made of fiber reinforced plastic seat ring, wherein the anchor nut has on the outside a conical region with which it bears against a complementary inner cone of the seat ring, and wherein in the cone-shaped portion of Anchor nut at least one preferably axially parallel slot is provided which interrupts the nut wall in the circumferential direction over at least a portion of the cone-shaped portion, and that the cooperating with the curved contact surface of the anchor plate complementary contact surface is formed on the seat ring.

The main advantage lies in the fact that, due to the slotted design of the anchor nut and the resulting compression of the female thread in the seat ring during insertion of the female thread, a substantially stronger hold of the anchor nut on the anchor thread of the anchor rod is achieved. Even when it is in the near-surface mountain body settling phenomena, the present invention of anchor nut, seat ring and anchor plate existing anchor head is further compressed and the seat ring slides on the cone of the mother. The load capacity of the entire anchor head construction increases so significantly that workloads are achieved that are comparable to those of steel anchor system with identical voltage cross-section.

This effect according to the invention, in which the full anchor head effect of the rock bolt system can be achieved in two stages, namely on the one hand by active setting of the tie rod and on the other hand, by passive self-tensioning due to convergence in settlement phenomena of the mountains under almost any installation situation, allows a simple, fast and thus inexpensive anchorage. These advantages can be achieved in both temporary and permanent anchors, since depending on the choice of fiber material and the matrix resin and long-term stability is given immediately and high service loads are provided.

One advantage is that in case of overload (comparable to the material properties in the high plasticizing range of comparable steel anchor systems), the anchor head does not abruptly break off due to the lower moduli of elasticity of the composite and the resulting elasticities, but is slowly stripped off.

The construction is relatively simple, so that the tie rod according to the invention is inexpensive to produce.

It is particularly advantageous if the outer cone of the anchor nut is designed to be self-clamping in the inner cone of the seat ring. As a result, the high load capacity remain permanently secured.

It is also particularly advantageous if the slotted cone segment of the anchor nut is compressed during the tension of the tie rod by penetrating into the inner cone of the seat ring inwardly so that the radial thread play between the anchor rod and the anchor nut is reduced. In this way, increased strength values of the armature shaft are also achieved at the anchor head.

Preferably, the slotted cone segment of the anchor nut when tightening the tie rod by the inner cone of the seat ring are thereby compressed so far inward that the radial thread clearance between the anchor rod and the anchor nut is at least almost completely eliminated.

It is particularly advantageous if the slotted cone segment of the anchor nut can be compressed inwardly by the inner cone of the seat ring so that not only the radial thread clearance but also the axial thread play between the anchor rod and the anchor nut is completely eliminated. As a result, on the one hand maximum load capacities and strength values of the anchor system and on the other hand slip-free specifications z. B. also be achieved by reinforcing bars in concrete applications.

A structurally particularly simple and axially small-sized embodiment can be achieved in that the contact surface of the anchor plate is concave, while the complementary contact surface of the seat ring is convex. In principle, the possibility for angular compensation of the armature axis to the rock surface but also given in a reverse embodiment in which the contact surface of the anchor plate is convex and the complementary contact surface of the seat ring is concave.

According to a particularly preferred embodiment of the invention it is provided that the contact surface of the anchor plate and the complementary contact surface of the seat ring are curved spherical or spherical surface. In this way, the angle compensation between the anchor axis and the rock surface can be done particularly easily in all directions.

It is advantageous if the anchor hole bore of the anchor plate is extended on the side facing away from the anchor nut side truncated cone to facilitate the inclination of the anchor rod to the anchor plate at the angle compensation.

The strength of the anchor plate can be increased by the fact that the anchor hole bore of the anchor plate is enlarged slot-like in a radial direction on the side facing away from the anchor nut side. In this direction, then a greater inclination of the anchor rod is possible than in the other direction, where instead of more material is available at the anchor plate. By twisting the anchor plate, the direction of the greatest inclination can be adjusted.

The subject of the present invention is also an anchor set comprising at least one anchor rod, at least one anchor nut, at least one anchor plate and at least one seat ring of the type described above, wherein these components of the tie rod set each consist of fiber-reinforced plastic.

Further advantages and features of the invention will become apparent from the following description and the embodiments illustrated in the drawings. Show it:

1 : Cross section through a tie rod according to the invention in a deflected angular position;

2 : Tie rod out 1 in set condition;

3 : Cross section through a tie rod according to the invention in a non-deflected position;

4 : Tie rod out 3 in set condition;

5 : Cross section through the seat ring of the tie rods from the 1 - 4 ;

6 : Side view of the anchor nut of the tie rods from the 1 - 4 ; and

7 : Front view of anchor nut off 6 ,

1 shows an embodiment of a rock anchor according to the invention 1 which consists entirely of fiber composite material. It consists of the following four elements: anchor rod 2 , Anchor nut 3 , Seat ring 4 and anchor plate 5 ,

The anchor rod 2 consists here of at least 75% by volume of glass fibers (rovings) with high strength and high chemical resistance and at most 25% by volume of matrix resin, which may be depending on the application polyester, vinyl ester or epoxy. The anchor rod 2 is manufactured in a modified pultrusion process, in which the outer fibers are reoriented in the process and before curing of the matrix resin from unidirectional arrangement to wave segment-like course, whereby without fiber interruption a coarse rib profile is formed, which by its special geometry a durable hochtragfähiges thread 6 forms.

The anchor nut 3 , the seat ring 4 as well as the anchor plate 5 consist here in each case at least 60% by volume of glass fibers with high strength and high chemical resistance and at most 40% by volume of matrix resin, which may be depending on the application conditions polyester, vinyl ester or epoxy resin. This will be the anchor nut 3 , the seat ring 4 as well as the anchor plate 5 each manufactured in a modified molding process, in which the fibers are used as scrim / fabric in combination with short and long fibers and rovings.

The anchor nut 3 has an external hexagon at the front end 7 for mounting and preloading, and at the rear end via an outer cone 8th , which is designed self-clamping and a paraxial aligned slot here 9 having. Instead of the embodiment shown here with only one slot, the conical region 8th also be divided by several slots, for example by parallel slots or double slots into several segments. About a wavy special thread profile 6 of the anchor rod 2 adapted internal thread 10 can the anchor nut 3 initially slightly screwed onto the anchor rod with little play, whereas later in radial compression or clamping the internal thread 10 the anchor nut 3 play and slip-free on the thread 6 of the anchor rod 2 is determined.

The seat ring 4 eroded via a through hole 21 whose wall has an inner cone 11 for receiving the outer cone 8th and thus for biasing the anchor nut 3 forms. At the anchor plate 5 facing the seat ring 4 a dome-shaped "seat", which has a convex, spherical contact surface 12 forms, by means of an angle compensation of the longitudinal axis 20 of the rock anchor 1 to the rock surface 19 is possible.

The anchor plate 5 has on the outside, so on the side facing away from the rock, a centric, here truncated conical elevation 13 , in which a (dome-shaped) recess is introduced, which has a concave, spherically curved contact surface 14 forms, which at the contact surface 12 is adjusted. This recess has centered the bore 15 for the anchor rod 2 on. At the back, so on the side facing the rock, this anchor hole is bore 15 in a truncated cone in the outlet direction so widened that the assortment of anchor nut 3 , Seat ring 4 and anchor plate 5 penetrating anchor rod 2 is applicable under various borehole angles.

When mounting the single rock anchor 1 is the entire three-piece anchor head, made from the anchor nut 3 , the seat ring 4 and the anchor plate 5 exists, on the anchor end 16 pre-assembled and the rock anchor 1 then preferably with adhesive cartridges 17 filled borehole 18 added. This can be the anchor nut 3 After curing of the resin, first conventionally tightened by torque and the rock bolt 1 so over the three-piece anchor head 3 . 4 . 5 be tense. When tightening the anchor nut 3 this runs at the end with the cone 8th in the stacking ring 4 , where both the jacket friction of the nut cone 8th in the stacking ring 4 as well as the friction of the other GRP anchor head components with each other exclude too high a torsional load. Nevertheless, a tensioning on at least 40% of the breaking load of the rock anchor 1 possible. On the other hand, in a variant, the Konuspaarung for a corresponding requirements with a lubricant / lubricant, coating or the like can be significantly reduced if higher active set loads are required.

In this process, the anchor plate 5 and the seat ring 4 through the anchor nut 3 firmly against the rock surface 19 pressed and brought to the plant, without overloading the construction of points, which is why a certain angular adjustment between the anchor axis 20 and mountain surface 19 is required by the convex-concave fit.

The cone segment 8th the anchor nut 3 is due to the slit 9 radially compressed, whereby the radial thread play is already now at least almost completely canceled, resulting in a jamming of the anchor nut 3 in the seat ring 4 leads. The nut thread 10 prevents due to the positive connection an axial movement of the anchor nut 3 ,

Advantageously, the anchor head 3 . 4 . 5 also be retrofitted or exchanged for a conventional anchor head, as long as expected Nachkonvergengenzen allow a subsequent Selbstspannen.

Otherwise, with correspondingly high torques on the part of the Ankerbohr- and Setting device (ABS) the final tension and immediate high load capacity can also be achieved directly.

Due to these variants, the anchor system can also be used as an effective extension in tunnel structures outside of mining applications according to NÖT / NATM (New Austrian Tunneling Method / New Austrian Tunneling Method) and at the same time as temporary and final expansion, for example in single-shell structures.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19828371 A1 [0003]
• DE 29900172 U1 [0004]

Claims (11)

Tie rods ( 1 ), in particular rock anchors, of fiber-reinforced plastic, comprising - an anchor rod made of fiber-reinforced plastic ( 2 ), at least on a portion of an anchor thread ( 6 ), - an anchor plate made of fiber-reinforced plastic ( 5 ) with an anchor hole ( 15 ), through which the anchor rod ( 2 ), and - an anchor nut made of fiber-reinforced plastic ( 3 ) with an internal thread, which on the anchor thread ( 6 ) of the anchor rod ( 2 ) and against the anchor plate ( 5 ) is supportable, wherein the anchor plate ( 5 ) with a curved contact surface ( 14 ) fitted with one of the anchor nuts ( 3 ) associated complementary contact surface ( 12 ) cooperates such that the anchor rod ( 2 ) in at least one direction at an angle (α) obliquely to the anchor plate ( 5 ) is tiltable, characterized in that the anchor nut ( 3 ) in a through hole ( 21 ) of a preferably made of fiber-reinforced plastic seat ring ( 4 ), wherein the anchor nut ( 3 ) on the outside a cone-shaped area ( 8th ), with which they on a complementary inner cone ( 11 ) of the seat ring ( 4 ), and wherein in the cone-shaped region ( 8th ) the anchor nut ( 3 ) at least one preferably axially parallel slot ( 9 ) is provided, the at least over a partial region of the cone-shaped area ( 8th ), and that with the curved contact surface ( 14 ) of the anchor plate ( 5 ) cooperating complementary contact surface ( 12 ) on the seat ring ( 4 ) is trained. Tie rods ( 1 ) according to claim 1, characterized in that the outer cone ( 8th ) the anchor nut ( 3 ) in the inner cone ( 11 ) of the seat ring ( 4 ) is self-clamping. Tie rods ( 1 ) according to claim 2, characterized in that the slotted cone segment ( 8th ) the anchor nut ( 3 ) when tensioning the tie rod ( 1 ) by penetration into the inner cone ( 11 ) of the seat ring ( 4 ) is compressed inwardly such that the radial thread clearance between the tie rod ( 2 ) and the anchor nut ( 3 ) is reduced. Tie rods ( 1 ) according to claim 3, characterized in that the slotted cone segment ( 8th ) the anchor nut ( 3 ) when tensioning the tie rod ( 1 ) through the inner cone ( 11 ) of the seat ring ( 4 ) is compressible to the extent that the radial thread clearance between the anchor rod ( 2 ) and the anchor nut ( 3 ) is at least almost completely eliminated. Tie rods ( 1 ) according to claim 3 or 4, characterized in that the slotted cone segment ( 8th ) the anchor nut ( 3 ) through the inner cone ( 11 ) of the seat ring ( 4 ) is compressible to the extent that the radial thread clearance and the axial thread play between the anchor rod ( 2 ) and the anchor nut ( 3 ) is completely removed. Tie rods ( 1 ) according to one of the preceding claims, characterized in that at least one of the contact surfaces of Konuspaarung ( 8th . 11 ) between the anchor nut ( 3 ) and the seat ring ( 4 ) is provided with a friction-reducing coating. Tie rods ( 1 ) according to one of the preceding claims, characterized in that the contact surface ( 14 ) of the anchor plate ( 5 ) concave and the complementary contact surface ( 12 ) of the seat ring ( 4 ) is convexly curved. Tie rods ( 1 ) according to one of the preceding claims, characterized in that the contact surface ( 14 ) of the anchor plate ( 5 ) and the complementary contact surface ( 12 ) of the seat ring ( 4 ) are spherically curved. Tie rods ( 1 ) according to claim 8, characterized in that the anchor hole bore ( 15 ) of the anchor plate ( 5 ) on that of the anchor nut ( 3 ) facing away from the side is truncated cone-like. Tie rods ( 1 ) according to claim 9, characterized in that the anchor hole bore ( 15 ) of the anchor plate ( 5 ) on that of the anchor nut ( 3 ) facing away from the side in a radial direction is enlarged slot-like. Tie rod set comprising at least one anchor rod ( 2 ), at least one anchor nut ( 3 ), at least one anchor plate ( 5 ) and at least one seat ring ( 4 ) according to one of claims 1 to 10, wherein these components of the tie rod set each consist of fiber-reinforced plastic.

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