An internal expansion anchor for prestressed steel strands and steel rod end connections

Abstract

The utility model discloses an internal expansion anchor for connecting prestressed steel strands and steel rod broken ends, comprising a plurality of inner expansion sleeves and an outer anchor pipe, wherein the inner side of the inner expansion sleeve is in a circular arc shape in radial direction, the radial arc surface of the outer side of the circular arc inner expansion sleeve is a jujube-shaped conical surface with a high middle and low ends in the axial direction, the circular arc inner expansion sleeve surrounds the broken end of the steel strand or the broken end of the steel rod and is arranged at intervals in radial direction to embrace each other to form a tight hoop, the outer anchor pipe is two, and the inner hole of the outer anchor pipe is a diameter of The conical inner hole is larger at one end and smaller at the other end, and the axial inclined surface of the conical inner hole is an inclined surface that matches the axial single-sided inclined surface of the jujube-shaped conical surface of the inner expansion sleeve. The aperture of the large-diameter end of the conical inner hole of the outer anchor pipe is smaller than the diameter formed by the highest point in the middle of the jujube-shaped conical surfaces of the multiple inner expansion sleeves that form the tight hoop. When the tight hoop is put on, the two outer anchor pipes are respectively put into the tight hoop from both ends of the tight hoop to press and shrink the tight hoop, so as to press and connect the broken ends of the steel strands or steel rods.

Description

Technical Field

[0001] The utility model relates to an internal expansion anchor used for connecting the broken ends of prestressed steel strands and steel rods. Background Art

[0002] The existing connection methods for broken ends of steel strands or prestressed steel rods generally adopt twisting or capillary sleeve methods. For example, the twisting of steel strands is to first interweave two steel strands together, and then use tools to repeatedly twist until a strong knot is formed. This method requires attention to the strength during twisting to avoid damage to the steel strands due to excessive twisting. The capillary sleeve method is to first expose the steel strand for a certain length, then use a steel capillary to sleeve the two steel strands together, and weld the steel wires at the joint. This method needs to ensure the welding quality, and different specifications of steel strands require corresponding capillaries. The above methods have problems such as complex structure and high construction difficulty. Summary of the invention

[0003] The utility model aims to provide an internal expansion anchor for connecting prestressed steel strands and steel rod ends.

[0004] In order to achieve the above purpose, the solution of the utility model is:

[0005] An internal expansion anchor for prestressed steel strands and steel rods, comprising a plurality of inner expansion sleeves and an outer anchor pipe, wherein the inner side of the inner expansion sleeve is in a circular arc shape, and the radial arc surface of the outer side of the circular arc inner expansion sleeve is a jujube-shaped cone surface with a high middle and low ends in the axial direction, and a plurality of circular arc inner expansion sleeves are arranged radially at intervals around the broken ends of the steel strands or steel rods to form a tight hoop for the broken ends, and the inner circular arc surface of the inner expansion sleeve is a treated anti-slip rough surface; the outer anchor pipe is two, and the inner side of the outer anchor pipe is in a circular arc shape. The hole is a conical inner hole with a larger diameter at one end and a smaller diameter at the other end. The axial inclined surface of the conical inner hole is an inclined surface that matches the axial single-sided inclined surface of the jujube-shaped conical surface of the inner expansion sleeve. The diameter of the large-diameter end of the conical inner hole of the outer anchor pipe is smaller than the diameter formed by the highest point in the middle of the jujube-shaped conical surfaces of the multiple inner expansion sleeves that form the tight hoop. After the tight hoop is put on, the two outer anchor pipes are respectively put into the tight hoop from both ends of the tight hoop, and the tight hoop is contracted by pressing the outer anchor pipe toward the middle of the tight hoop, so that the broken ends of the steel strands or steel rods are pressed and connected.

[0006] A further solution is that the anti-skid rough surface is an axially serrated anti-skid rough surface.

[0007] A further solution is that the clamping sleeve is composed of three or four inner expansion sleeves arranged radially at intervals around the broken ends of the steel strands or steel rods to form a clamping sleeve for connecting the broken ends.

[0008] A further solution is that the angle between the axial single-sided inclined surface of the jujube-shaped cone surface and the axial horizontal direction, that is, the angle between the axial single-sided inclined surface of the inner expansion sleeve and the axial horizontal direction is 3 to 5 degrees.

[0009] A further solution is that flange rings are respectively protruded at the large-diameter end of the inner hole on the outside of the two outer anchor pipes, and through holes are provided on the flange rings. Bolts are passed through the through holes of the two flange rings, and the outer anchor pipes inserted from both ends of the tightening sleeve are pressed and contracted by the bolts to tighten and connect the broken ends of the steel strands or steel rods.

[0010] A further solution is that the anchor also includes a concrete column, and after the broken ends of the steel strands or steel rods are compressed and connected, the clamp sleeve and the outer anchor pipe are fixed in the concrete column by pouring.

[0011] The utility model has the advantages of simple construction, good fastening performance, high efficiency, etc., and has a wide range of applications. It can be used not only for connecting steel strands and prestressed steel rods, but also for other similar structures, and can also be used in the connection and repair projects of load-bearing cables.

[0012] The utility model is described in detail below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the end surface structure of the utility model;

[0015] Figure 3 This is a schematic diagram of the utility model in a use state structure;

[0016] Figure 4 It is a structural schematic diagram of the utility model in which the outer anchor pipe has a flange. DETAILED DESCRIPTION

[0017] An internal expansion anchor for prestressed steel strands and steel rods. Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the anchor comprises multiple inner expansion sleeves 1 and outer anchor pipes 2, the inner side 101 of the inner expansion sleeve 1 is radially arc-shaped, the outer radial arc surface of the arc-shaped inner expansion sleeve 1 is axially a jujube-shaped cone surface with a high middle 102 and low two ends 103, multiple arc-shaped inner expansion sleeves 1 are arranged radially at intervals around the broken ends of the steel strands 4 or the broken ends of the steel rods to form a tight hoop connected with the broken ends, the inner arc surface of the inner expansion sleeve 1 is a treated anti-skid rough surface 104; the anti-skid rough surface 104 of the inner expansion sleeve 1 is pressed on the steel strands 4 or steel rods on both sides of the broken ends, the outer anchor pipes 2 are two, and the inner hole 201 of the outer anchor pipe 2 is a conical inner hole with a larger diameter at one end and a smaller diameter at the other end, The axial inclined surface of the conical inner hole 201 is an inclined surface that matches the axial single-sided inclined surface of the jujube-shaped conical surface of the inner expansion sleeve 1. In order to be able to extrude the inner expansion sleeve 1 of the tight hoop from both ends, the aperture of the large-diameter end of the conical inner hole 201 of the outer anchor pipe 2 is smaller than the diameter formed by the highest point in the middle of the jujube-shaped conical surfaces of the multiple inner expansion sleeves 1 that form the tight hoop. After the tight hoop is put on, the two outer anchor pipes 2 are respectively put into the tight hoop from both ends, and the tight hoop is contracted by pressing the outer anchor pipes 2 toward the middle of the tight hoop, so that the broken ends of the steel strands or steel rods are compressed and connected; pressing the outer anchor pipes 2 toward the middle of the tight hoop can be achieved by clamping the two outer anchor pipes 2 with hydraulic pliers.

[0018] like Figure 3 As shown, in order to prevent the outer anchor pipe 2 from loosening due to environmental influences, the anchor also includes a concrete column 5. After being compressed and connected, the clamp sleeve and the outer anchor pipe are fixed in the concrete column 5 by pouring concrete; this structure is suitable for high humidity and high salt environments.

[0019] Wherein: as the best solution, the anti-skid rough surface 104 is an axially serrated anti-skid rough surface. The tight hoop is a tight hoop connected by three or four inner expansion sleeves 1 arranged radially and spaced around the broken ends of the stranded wire or the broken ends of the steel rod. The angle between the axial single-side inclined surface of the jujube-shaped cone and the axial horizontal is equivalent to the angle between the axial single-side inclined surface of the inner expansion sleeve and the axial horizontal is 3 to 5 degrees.

[0020] In order to prevent the two outer anchor pipes 2 from loosening due to vibration after being pressed and connected, Figure 4As shown: the two outer anchor tubes 2 are respectively provided with flange rings 202 protruding at the large-diameter end of the inner hole on the outside, and the flange rings 202 are provided with through holes, and bolts 6 are provided through the through holes of the two flange rings 202. The outer anchor tubes 2 inserted from both ends of the tightening sleeve can be compressed and contracted by the bolts 6 to tighten the steel strand or steel rod broken ends; of course, it is also possible to maintain the tightening state of the tightening sleeve on the steel strand or steel rod after the two outer anchor tubes 2 are compressed and connected to the middle of the tightening sleeve by the bolts 6 to prevent the outer anchor tubes 2 from loosening due to vibration. Of course, it is also possible to drill holes in the outer anchor tube 2 around the axial direction of the tightening sleeve and penetrate the bolts to lock the two outer anchor tubes 2.

[0021] The structure shown in the above-mentioned internal expansion anchor embodiment for prestressed steel strands and steel rod broken ends connection has the advantages of simple construction, good fastening performance, high efficiency, etc., and at the same time has a wide range of applications. It can not only be used for steel strands and prestressed steel rod connections, but also for other similar structures. It can also be used in the connection and repair projects of load-bearing cables.

Claims

1. An internal expansion anchor for prestressed steel strands and steel rods, characterized in that: The anchor comprises a plurality of inner expansion sleeves and an outer anchor pipe, wherein the inner side of the inner expansion sleeve is in a circular arc shape in the radial direction, and the outer radial arc surface of the circular arc inner expansion sleeve is a jujube-shaped cone surface with a high middle and low ends in the axial direction, and a plurality of circular arc inner expansion sleeves are arranged radially at intervals around the broken ends of the steel strands or steel rods to form a tight hoop sleeve for connecting the broken ends, and the inner circular arc surface of the inner expansion sleeve is a treated anti-slip rough surface; there are two outer anchor pipes, and the inner hole of the outer anchor pipe is a diameter that is larger at one end than at the other end. The small conical inner hole, the axial inclined surface of the conical inner hole is an inclined surface that matches the axial single-sided inclined surface of the jujube-shaped conical surface of the inner expansion sleeve, the aperture of the large-diameter end of the conical inner hole of the outer anchor pipe is smaller than the diameter formed by the highest point in the middle of the jujube-shaped conical surfaces of the multiple inner expansion sleeves that form the tight hoop. After the tight hoop is put on, the two outer anchor pipes are respectively put into the tight hoop from both ends of the tight hoop, and the tight hoop is contracted by pressing the outer anchor pipe toward the middle of the tight hoop, so that the broken ends of the steel strands or steel rods are pressed and connected.

2. The anchor according to claim 1, characterized in that: The anti-skid rough surface is an axially serrated anti-skid rough surface.

3. The anchor according to claim 1, characterized in that: The tight hoop is composed of three or four inner expansion sleeves arranged radially at intervals around the broken ends of the steel strands or steel rods to form a tight hoop for connecting the broken ends.

4. The anchor according to claim 1, characterized in that: The angle between the axial single-side inclined surface of the jujube-shaped cone surface and the axial horizontal plane, that is, the angle between the axial single-side inclined surface of the inner expansion sleeve and the axial horizontal plane is 3 to 5 degrees.

5. The anchor according to claim 1, characterized in that: The outer sides of the two outer anchor pipes are respectively provided with flange rings protruding at the large-diameter end of the inner hole, and the flange rings are provided with through holes. Bolts are passed through the through holes of the two flange rings. The outer anchor pipes inserted from both ends of the tightening sleeve are pressed and contracted by the bolts to tighten and connect the broken ends of the steel strand or the steel rod.

6. The anchor according to claim 1, characterized in that: The anchor also includes a concrete column. After the broken ends of the steel strands or the broken ends of the steel rods are compressed and connected, the tight hoop sleeve and the outer anchor pipe are fixed in the concrete column by pouring.

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