Quincunx limiting tensioning head based on reverse pulling method

Abstract

The utility model provides a kind of plum blossom shape limit tensioning head based on anti-pulling method, it is related to the field of auxiliary tool of anchor withdrawal, including cylinder, the one end of cylinder is recessed with multiple circular-arc notches along outer circumferential direction and forms plum blossom shape limit block, one end inside of cylinder with plum blossom shape limit block is recessed ladder-shaped, the symmetrical distribution of plum blossom shape notches provides uniform radial constraint for clamping piece, prevent clamping piece from tilting or deviating when detecting, recessed ladder structure ensures that clamping piece and limit block are in surface contact, reduce local stress concentration, improve structural stability.

Description

Technical Field

[0001] This utility model relates to the field of anchor unwinding auxiliary tools, and in particular to a plum blossom-shaped limiting tensioning head based on the reverse tensioning method. Background Technology

[0002] Prestressed anchor cable technology has been widely used in civil engineering (such as bridge engineering and slope engineering). For prestressed structural engineering, effective prestress directly affects the deformation and cracking of the structure, influencing its service performance and safety performance. It is the core of its quality control and the long-term lifeline of the project. Therefore, for prestressed concrete bridge structures, it is necessary to use effective means to detect and evaluate the quality of prestressing construction. This can largely avoid the problem of insufficient load-bearing capacity in prestressed structures and ensure the safe operation of the structure.

[0003] The exposed steel strands can be tensioned as a whole or individually, with simultaneous testing of tension force and strand elongation. Alternatively, the anchor head itself can be pulled. When the pull-out force is less than the original effective prestress, the wedges secure the steel strands, and the freely elongating strands are the exposed free length. When the pull-out force exceeds the original effective prestress, the anchor head detaches from the wedges. In addition to the exposed free length, a portion of the strands located under the anchor also participates in the tensioning process, resulting in a significant increase in the freely elongated strand length. Furthermore, the wedges themselves will also displace outwards as the steel strands elongate.

[0004] The existing announcement number CN217481317U discloses an anchor removal auxiliary tool, including a circular tube. Rectangular clamping openings are provided on opposite side walls of the circular tube. The clamping openings are connected to the anchor removal holes formed by the tube holes of the circular tube. The circular tube has multiple arc-shaped notches recessed along the outer circumference of one end face to form a limiting block. The structure is simple, practical, and low in cost, ensuring the reliable operation of anchor removal, facilitating the removal of clamps, and saving time and effort.

[0005] However, when the above-mentioned anchor removal auxiliary tool is used, the inside of the round tube is straight. When the inner wall of the straight tube comes into contact with the clamping plate, the friction force is easily concentrated in a local area, which makes the clamping plate easy to get stuck during the reverse pulling process.

[0006] Therefore, it is necessary to provide a new plum blossom-shaped limiting tensioning head based on the reverse tensioning method to solve the above-mentioned technical problems. Utility Model Content

[0007] To address the technical problem that frictional force tends to concentrate in localized areas when the cylindrical inner wall contacts the clamping plate, causing the clamping plate to easily get stuck during the reverse tensioning process, this utility model provides a plum blossom-shaped limiting tensioning head based on the reverse tensioning method.

[0008] The plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model includes a cylindrical body. One end of the cylindrical body is recessed with multiple arc-shaped notches along the outer circumference to form a plum blossom-shaped limiting block. The inner side of the end of the cylindrical body with the plum blossom-shaped limiting block is concave and stepped. The concave and stepped inner side is integrally formed with the cylindrical body to avoid eccentric force when in contact with the clamping plate. When the tensioning head is sleeved on the exposed end of the steel strand, the plum blossom-shaped limiting block of the cylindrical body is not affected by the position of the adjacent clamping plate.

[0009] Furthermore, the concave stepped portion of the plum blossom-shaped limiting block is threadedly connected to an adjustable block.

[0010] Furthermore, a step is provided at the end of the cylinder away from the plum blossom-shaped limiting block.

[0011] Furthermore, the outer side of the cylinder is provided with a through hole that communicates with its inner cavity.

[0012] Furthermore, the cylinder body and the plum blossom-shaped limiting block are integrally connected.

[0013] Furthermore, the adjustable block has a through groove on its inner side, and two opposing protrusions are integrally connected to the inner side of the through groove.

[0014] Compared with related technologies, the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model has the following beneficial effects:

[0015] This invention provides a plum blossom-shaped limiting tensioning head based on the reverse tensioning method. In specific implementation, the symmetrical distribution of the plum blossom-shaped notches provides uniform radial constraint for the clamping pieces, preventing them from tilting or shifting during testing. The concave stepped structure ensures surface contact between the clamping pieces and the limiting block, reducing local stress concentration and improving structural stability. Attached Figure Description

[0016] Figure 1 A schematic diagram of the overall structure of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model;

[0017] Figure 2 A cross-sectional view of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model;

[0018] Figure 3 This is a schematic diagram of the disassembled structure of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model.

[0019] The following are labeled in the diagram: 1. Cylinder body; 2. Plum blossom-shaped limiting block; 3. Adjustable block; 4. Step; 5. Through hole; 6. Protrusion. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Please refer to the following: Figure 1 , Figure 2 as well as Figure 3 ,in, Figure 1 A schematic diagram of the overall structure of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model; Figure 2 A cross-sectional view of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model; Figure 3 This is a schematic diagram of the disassembled structure of the plum blossom-shaped limiting tensioning head based on the reverse tensioning method provided by this utility model.

[0022] In the specific implementation process, such as Figures 1-3 As shown, the plum blossom-shaped limiting tensioning head based on the reverse tensioning method includes a cylinder 1. One end of the cylinder 1 has multiple arc-shaped notches recessed along the outer circumference to form a plum blossom-shaped limiting block 2. The inner side of the end of the cylinder 1 with the plum blossom-shaped limiting block 2 is concave and stepped. The cylinder 1 and the plum blossom-shaped limiting block 2 are integrally connected. The concave and stepped inner side is integrally formed with the cylinder 1 to avoid eccentric force when in contact with the clamping plate. When the tensioning head is sleeved on the exposed end of the steel strand, the plum blossom-shaped limiting block 2 contacts the clamping plate. The arrangement of the plum blossom-shaped limiting block 2 in the cylinder 1 is not affected by the position of the adjacent clamping plate.

[0023] It should be noted that the concave stepped part of the plum blossom-shaped limiting block 2 is threadedly connected to an adjustable block 3. The inner side of the adjustable block 3 is provided with a through groove, and the inner side of the through groove is integrally connected to two opposing protrusions 6. The adjustable block 3 is used to adjust its position in the concave stepped part by means of threads, limit the displacement of the clamping piece, overcome the frictional resistance of the clamping piece, control the initial gap between the protrusions 6 and the clamping piece, thereby setting the maximum allowable displacement of the clamping piece (e.g., 1.5mm). When the clamping piece touches the protrusions 6, the adjustable block 3 prevents further displacement, and at this time the counter-tension reaches the original prestress value.

[0024] It should be noted that a step 4 is provided at the end of the cylinder 1 away from the plum blossom-shaped limiting block 2. The step 4 at the end of the cylinder 1 away from the plum blossom-shaped limiting block 2 is connected to the force measuring ring to ensure that the force measuring ring does not slip and move synchronously. A through hole 5 is also provided on the outside of the cylinder 1, which is connected to its inner cavity. The through hole 5 on the outside of the cylinder 1 facilitates the bonding of strain gauges to the steel strands inside the structure and the laying of lead wires.

[0025] The working principle of this utility model is as follows: During the reverse tensioning process, the tensioning head is placed on the exposed end of the steel strand. The step 4 block at the end of the cylinder 1 away from the plum blossom-shaped limiting block 2 is connected to the force measuring ring. The plum blossom-shaped limiting block 2 is in contact with the clamping plate. The adjustable block 3 is preset to the initial displacement limiting position. When the reverse tension force on the clamping plate exceeds the original prestress, the clamping plate begins to move. By rotating the adjustable block 3, its position in the concave step is adjusted, and the initial gap between the protrusion 6 and the clamping plate is controlled, thereby setting the maximum allowable displacement of the clamping plate. When the clamping plate touches the protrusion 6, the adjustable block 3 prevents further displacement. At this time, the reverse tension force reaches the original prestress value. The effective prestress can be determined by combining the data of the force measuring ring.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A plum blossom-shaped limiting tensioning head based on the reverse tensioning method, characterized in that, The cylinder (1) includes a cylindrical body (1), one end of which is recessed along the outer circumference to form a plum blossom-shaped limiting block (2), and the inner side of the end of the cylindrical body (1) with the plum blossom-shaped limiting block (2) is concave and stepped.

2. The plum blossom-shaped limiting tensioning head based on the reverse tensioning method according to claim 1, characterized in that, The concave stepped portion of the plum blossom-shaped limiting block (2) is threadedly connected to an adjustable block (3).

3. The plum blossom-shaped limiting tensioning head based on the reverse tensioning method according to claim 1, characterized in that, The end of the cylinder (1) away from the plum blossom-shaped limiting block (2) is provided with a step (4).

4. The plum blossom-shaped limiting tensioning head based on the reverse tensioning method according to claim 1, characterized in that, The outer side of the cylinder (1) is also provided with a through hole (5) that communicates with its inner cavity.

5. The plum blossom-shaped limiting tensioning head based on the reverse tensioning method according to claim 1, characterized in that, The cylinder (1) and the plum blossom-shaped limiting block (2) are integrally connected.

6. The plum blossom-shaped limiting tensioning head based on the reverse tensioning method according to claim 2, characterized in that, The adjustable block (3) has a through groove on its inner side, and two opposing protrusions (6) are integrally connected to the inner side of the through groove.

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