Precise calibration clamp for prestressed reinforcement tensioning

Abstract

The utility model discloses an accurate calibration clamp for prestressed reinforcement tensioning, which relates to the technical field of reinforcement tension testing, and adopts the technical scheme that the accurate calibration clamp for prestressed reinforcement tensioning comprises a rack, a sliding frame and a rotary driving component are fixed at the bottom of an upper frame of the rack, and the rotary driving component is arranged at one end of the top of a lower frame of the rack; the rotation driving assembly comprises a first fixing frame, the two ends of the axis of the first fixing frame are rotationally connected with a first rotating arm and a second rotating arm which are symmetrically arranged correspondingly, and the first rotating arm and the second rotating arm can synchronously and relatively rotate. According to the utility model, the two groups of tension testing assemblies are synchronously driven by the rotary driving assembly to rotate to a certain angle in a face-to-face or back-to-back manner, the tension testing assemblies are extended until the U-shaped clamp is clamped outside the extension arm of the section to be tested, and the tension testing assemblies are driven to continuously extend, so that the tension of different sections of reinforcing steel bars with the same pipe diameter can be continuously and independently detected; the detection efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of steel bar tension testing technology, and more specifically, it relates to a precision calibration fixture for prestressed steel bar tensioning. Background Technology

[0002] Prestressing of steel bars involves applying pressure to structural members before they bear external loads, causing compressive stress to be generated in the tensile zone of the concrete under external loads. This compressive stress is used to counteract or reduce the tensile stress generated by the external loads, thereby improving the crack resistance and stiffness of the structural members. Before the steel bars undergo elastic elongation by tensioning the prestressed steel bars, the strength of the steel bar material needs to be measured using a tensile testing machine. During the use of the tensile testing machine, the steel bars to be tested need to be clamped with fixtures.

[0003] Tensile testing machine fixtures are devices used to fix and clamp specimens to ensure that the specimens are subjected to uniform force and their mechanical properties are accurately measured during tensile testing. These include wedge clamps, flat-push clamps, and U-shaped clamps. The U-shaped clamp mainly consists of a U-shaped clamp body and a fastening device. The U-shaped body is usually made of metal materials, such as carbon steel or stainless steel, which have certain strength and toughness and can withstand the load during tensile testing. The U-shaped clamp is tightened by common fastening devices, which can clamp steel bars of a suitable pipe diameter. Common fastening devices include bolt and nut combinations or snap-fit ​​structures. Bolt and nut combinations tighten the U-shaped clamp by tightening the nut, thereby fixing the specimen. Snap-fit ​​structures achieve clamp fastening through quick snap-fit, which is more convenient to operate.

[0004] Existing prestressed steel bar tensioning precision calibration fixtures, after clamping the steel bars, are generally used in conjunction with machines to test the tension of a single segment of steel bars of the same pipe diameter. However, testing the tension of multiple segments of steel bars of the same pipe diameter requires manual intervention. The functionality of mechanized continuous testing of multiple segments of steel bars of the same pipe diameter is not ideal. Therefore, in order to solve the above technical problems, this application proposes a prestressed steel bar tensioning precision calibration fixture. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a prestressed steel bar tensioning precision calibration fixture, thereby solving the technical problem that the existing prestressed steel bar tensioning precision calibration fixtures are not functionally adequate for mechanized continuous coordination with machine detection of multi-segment tension of steel bars.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a prestressed steel bar tensioning precision calibration fixture, including a frame, wherein a sliding frame is fixed at the bottom of the upper frame;

[0007] A rotary drive assembly is disposed at one end of the top of the lower frame of the machine frame. The rotary drive assembly includes a first fixed frame. A first rotating arm and a second rotating arm are symmetrically connected to both ends of the first fixed frame at the axis. The first rotating arm and the second rotating arm can rotate synchronously relative to each other. Two sets of arc grooves are symmetrically arranged on the machine frame. The arc grooves are located on a circumference with the axis of the first fixed frame as the center.

[0008] A tensile testing assembly, comprising two sets of tensile testing assemblies, both slidably connected within an arc groove, with the two sets of tensile testing assemblies respectively fixed to the outer ends of the first and second rotating arms;

[0009] The fixture has a fixing base at the bottom and is fixed to the lower frame of the machine frame by the fixing base;

[0010] The movable fixtures are in several groups and have the same structure as the fixed fixtures. They are slidably connected to the other end of the frame via a sliding frame. Each group of movable fixtures has an extension arm symmetrically installed at its bottom, and the extension arms of each group are staggered.

[0011] Preferably, the rotary drive assembly further includes a second bevel gear rotatably mounted in the first fixed frame. The power input end of the second bevel gear is connected to a stepper motor. The outer ends of the second bevel gear are respectively meshed with a first bevel gear and a third bevel gear. The shafts of the first and third bevel gears are hollow and respectively fixed with a first hollow tube and a second hollow tube. The opposite ends of the first and second hollow tubes are respectively fixed with a second rotating arm and a first rotating arm. The first hollow tube is rotatably connected to the inner sidewall of the second hollow tube.

[0012] Preferably, the tensile testing assembly includes a hydraulic rod, with a tensile / compression sensor and a universal rotating assembly mounted on one end of the hydraulic rod facing the fixed clamp, and a U-shaped clamp rotatably connected to the universal rotating assembly.

[0013] Preferably, the sliding frame includes a second fixed frame fixed to the bottom of the upper frame, and a plurality of sliding rods are fixed to the inner side wall of the second fixed frame.

[0014] Preferably, the movable clamp includes a first arc clamping block that slides outside the slide rod. A U-shaped rod is fixed inside the first arc clamping block. Several first buckle strips are installed in a straight, equidistant array on the straight part of the U-shaped rod. The cross-section of the first buckle strip is triangular and the inclined surface faces the opening of the U-shaped rod. A second buckle strip that can cooperate with the first buckle strip is buckled to the outside of the first buckle strip. An arc strip is fixed on the outer wall of the second buckle strip. The arc strip is elastically connected to the through hole of the top strip by a spring. A slider is fixed at both ends of the arc strip. A groove is opened at the corresponding position of the top strip. The arc strip slides on the top strip through the slider and the groove. A second arc clamping block that can cooperate with the first arc clamping block is fixed at the bottom end of the top strip.

[0015] Preferably, the extendable arm includes a first extendable rod, a second extendable rod, and a third extendable rod that are symmetrically distributed at different angles along the axis of the clamping hole of the movable clamp. The first extendable rod, the second extendable rod, and the third extendable rod are respectively installed on the lower part of the three sets of movable clamps and can all cooperate with the U-shaped clamp.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention uses a rotary drive assembly to synchronously drive two sets of tensile testing components to rotate towards or away from each other to a certain angle, extending the tensile testing components until the U-shaped clamp is locked outside the arm of the section to be tested. By driving the tensile testing components to continue extending, the tension force of different sections of steel bars of the same pipe diameter can be continuously and independently tested, improving testing efficiency and solving the problem that the existing prestressed steel bar tensioning precision calibration fixtures are not functionally good for mechanized continuous testing of multiple sections of steel bars of the same pipe diameter. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0019] Figure 1 The diagram on the right shows the overall structure of this utility model;

[0020] Figure 2 for Figure 1 Schematic diagram of the structure at point A;

[0021] Figure 3 This is a schematic diagram of the overall structure of this utility model from the left side.

[0022] Figure 4 This is a cross-sectional structural diagram of the present invention to illustrate the structure of the rotary drive assembly;

[0023] Figure 5 for Figure 4 Schematic diagram of the structure at point B;

[0024] Figure 6 This is a cross-sectional structural diagram of the present invention to illustrate the structure of the movable clamp;

[0025] Figure 7 for Figure 6 A schematic diagram of the structure at point C.

[0026] 1. Frame; 2. Rotary drive assembly; 3. Tensile testing assembly; 4. Fixed fixture; 5. Sliding frame; 6. Movable fixture; 7. Extending arm; 8. Fixed base;

[0027] 201. First fixed frame; 202. First bevel gear; 203. Second bevel gear; 204. Third bevel gear; 205. Arc groove; 206. First rotating arm; 207. Second rotating arm; 208. Stepper motor; 209. First hollow tube; 210. Second hollow tube;

[0028] 301. Hydraulic rod; 302. Tension / compression sensor; 303. Universal rotating assembly; 304. U-shaped clamp;

[0029] 501. Second fixing frame; 502. Slide rod;

[0030] 601. First arc clamping block; 602. U-shaped rod; 603. First latching strip; 604. Second latching strip; 605. Arc strip; 606. Spring; 607. Top strip; 608. Slider; 609. Slide groove; 610. Second arc clamping block;

[0031] 701. First extension rod; 702. Second extension rod; 703. Third extension rod. Detailed Implementation

[0032] like Figure 1-7 As shown, this utility model provides a prestressed steel bar tensioning precision calibration fixture, including a frame 1, and a sliding frame 5 fixed at the bottom of the upper frame 1;

[0033] The rotary drive assembly 2 is located at one end of the top of the lower frame of the frame 1. The rotary drive assembly 2 includes a first fixed frame 201. A first rotating arm 206 and a second rotating arm 207 are symmetrically connected to both ends of the first fixed frame 201 at its axis. The first rotating arm 206 and the second rotating arm 207 can rotate synchronously relative to each other. Two sets of arc grooves 205 are symmetrically arranged on the frame 1, located on a circumference centered at the axis of the first fixed frame 201. The rotary drive assembly 2 also includes a second bevel gear 203 rotatably mounted within the first fixed frame 201. The second bevel gear 203 is powered by… The input end is connected to a stepper motor 208. The outer ends of the second bevel gear 203 are respectively meshed with the first bevel gear 202 and the third bevel gear 204. The shafts of the first bevel gear 202 and the third bevel gear 204 are hollow and respectively fixed with a first hollow tube 209 and a second hollow tube 210. The opposite ends of the first hollow tube 209 and the second hollow tube 210 are respectively fixed with a second rotating arm 207 and a first rotating arm 206. The first hollow tube 209 is rotatably connected to the inner side wall of the second hollow tube 210. The rotation drive assembly 2 can synchronously drive the two sets of tensile test assemblies 3 to rotate towards or away from each other to a certain angle.

[0034] Tensile testing component 3, there are two sets of tensile testing component 3 and both are slidably connected in the arc groove 205. The two sets of tensile testing component 3 are respectively fixed to the outer ends of the first rotating arm 206 and the second rotating arm 207, so that the tensile testing component 3 can slide along the arc groove 205, that is, it is convenient to match the extension arm 7.

[0035] Fixed clamp 4 has a fixed base 8 at its bottom and is fixed to the lower frame of machine frame 1 by the fixed base 8. Several sets of movable clamps 6 have the same structure as fixed clamp 4 and are slidably connected to the other end of machine frame 1 via sliding frame 5. Each set of movable clamps 6 has an extension arm 7 symmetrically installed at its bottom, with each set of extension arms 7 staggered. The sliding frame 5 includes a second fixed frame 501 fixed to the bottom of the upper frame of machine frame 1. Several sliding rods 502 are fixed to the inner wall of the second fixed frame 501. The extension arms 7 include a first extension rod 701, a second extension rod 702, and a third extension rod 703 symmetrically distributed at different angles along the axis of the clamping hole of the movable clamp 6. The first extension rod 701, the second extension rod... 702 and the third extension rod 703 are respectively installed on the lower part of the three sets of movable clamps 6 and can be matched with the U-shaped clamp 304. The tensile test assembly 3 includes a hydraulic rod 301. The end of the hydraulic rod 301 facing the fixed clamp 4 is equipped with a tensile and compressive sensor 302 and a universal rotating assembly 303, and is rotatably connected to the U-shaped clamp 304 through the universal rotating assembly 303. When the tensile test assembly 3 rotates to a certain angle in opposite directions, the tensile test assembly 3 is extended until the U-shaped clamp 304 is clamped outside the extension arm 7 of the section to be tested, so as to detect the tensile force of the steel bar in the section to be tested. The universal rotating assembly 303 can make the U-shaped clamp 304 rotate to fit with the extension arm 7 and clamp the extension arm 7 more tightly.

[0036] Furthermore, the movable clamp 6 includes a first arc-shaped clamping block 601 that slides outside the slide rod 502. A U-shaped rod 602 is fixed inside the first arc-shaped clamping block 601. Several first locking strips 603 are installed in a straight, equidistant array on the straight part of the U-shaped rod 602. The cross-section of the first locking strip 603 is triangular, and the inclined surface faces the opening of the U-shaped rod 602. A second locking strip 604 that can cooperate with the first locking strip 603 is locked to the outside of the first locking strip 603. The outer wall of the second locking strip 604 is fixed. An arc strip 605 is fixed, and the arc strip 605 is elastically connected to the through hole of the top strip 607 by a spring 606. A slider 608 is fixed at both ends of the arc strip 605, and a groove 609 is opened at the corresponding position of the top strip 607. The arc strip 605 slides on the top strip 607 through the slider 608 and the groove 609. A second arc clamp 610 that can cooperate with the first arc clamp 601 is fixed at the bottom end of the top strip 607. The steel bar can be quickly clamped or disassembled by a snap-on U-shaped clamp.

[0037] Working principle: This utility model uses a rotary drive component 2 to synchronously drive two sets of tensile testing components 3 to rotate towards or away from each other to a certain angle, extending the tensile testing components 3 until the U-shaped clamp 304 is locked outside the extension arm 7 of the section to be tested. By driving the tensile testing components 3 to continue to extend, the tensile force of different sections of the same diameter steel bar can be continuously and independently tested, improving testing efficiency. First, the top bar 607 and the second arc clamp 610 at the top of the fixed clamp 4 and the movable clamp 6 are disassembled as a whole. The arc bar 605 is pressed against the inner wall of the through hole of the top bar 607, causing the arc bar 605 and the second locking bar 604 to slide away from the first locking bar 603. The spring 606 is compressed and shortened, causing the second locking bar 604 to separate from the first locking bar 603 and release the locking state. Remove the top bar 607 and the second arc clamp 610 from the opening of the U-shaped rod 602. Hold the movable clamp 6 and slide it on the slide rod 502. Adjust the position of the multiple sets of movable clamps 6 to fit the section of the rebar to be tested. Secure one end of the rebar to be tested in the fixed clamp 4 and the other end in the multiple sets of movable clamps 6. Snap the top bar 607 and the second arc clamp 610 back onto the fixed clamp 4 and the movable clamp 6. Align the two through holes of the top bar 607 with the two vertical bars of the U-shaped rod 602, so that the top bar 607 fits over the two vertical bars of the U-shaped rod 602 through the through holes. The first snap-fit ​​bar 603 has a triangular cross-section with its inclined surface facing the opening of the U-shaped rod 602. When the top bar 607 is pressed into the U-shaped rod 602, the second snap-fit ​​bar 610 in the through hole... 04 can slide quickly down the slope of the first clamping bar 603. Due to the limiting spring 606, the upper end of the second clamping bar 604 is limited by the right-angle side of the first clamping bar 603 and cannot slide upwards. The second arc clamping block 610 can quickly cooperate with the first arc clamping block 601 to clamp the rebar. When the second arc clamping block 610 and the first arc clamping block 601 cooperate to clamp the rebar, there is a gap between the second arc clamping block 610 and the first arc clamping block 601, which can clamp the rebar more tightly. After clamping the rebar, the external power supply turns on the stepper motor 208 through the external switch, controlling the stepper motor 208 to rotate forward or backward. The stepper motor 208 drives the second bevel gear 203 to rotate. Since the first bevel gear 202 and the third bevel gear 204 are respectively meshed at the outer ends of the second bevel gear 203, the first bevel gear 202 rotates. Gear 202 and the third bevel gear 204 rotate synchronously in opposite directions relative to each other. The first hollow tube 209 and the second hollow tube 210 also rotate synchronously in opposite directions relative to each other. The opposite ends of the first hollow tube 209 and the second hollow tube 210 are respectively fixed with a second rotating arm 207 and a first rotating arm 206. The second rotating arm 207 and the first rotating arm 206 rotate synchronously about the common axis of the first hollow tube 209 and the second hollow tube 210 as the center, and rotate relative to or opposite to each other along the arc groove 205, so that the two sets of tensile test components 3 open or close at a certain angle to match the extension arm 7 of the end to be tested. When the two sets of tensile test components 3 are opened to match the third extension rod 703, the hydraulic rod 301 is driven to extend to the U-shaped clamp 304 and lock outside the first extension rod 701.The universal rotating assembly 303 allows the U-shaped clamp 304 to rotate to fit with the third extension rod 703, more tightly locking the third extension rod 703. This continues to drive the hydraulic rod 301 to extend, causing the movable clamp 6 at the top of the third extension rod 703 to slide along the slide rod 502 to the other end. The tension / compression sensor 302 detects the tension force of this section of the rebar. When this section is tested, the hydraulic rod 301 is first driven to shorten, causing the U-shaped clamp 304 to disengage from the third extension rod 703. The rotating drive assembly 2 then drives the two sets of tension testing assemblies 3 until they are adjusted to fit the second extension rod 702. The tension testing assemblies 3 are then driven to extend and continue testing the tension force of the other section of the rebar. The principle is the same, and this process repeats continuously (the stepper motor 208, hydraulic rod 301, and tension / compression sensor 302 are all existing products and are connected to an external power supply and external switch).

[0038] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any way. Those skilled in the art can readily implement this utility model based on the accompanying drawings and the above description. However, any modifications, alterations, or equivalent variations made by those skilled in the art without departing from the scope of the utility model's technical solution, utilizing the disclosed technical content, are considered equivalent embodiments of this utility model. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of this utility model's technical solution.

Claims

1. A precision calibration fixture for prestressed steel bar tensioning, characterized in that, Includes a frame (1), and a sliding frame (5) is fixed to the bottom of the frame (1); A rotary drive assembly (2) is set at one end of the lower frame of the frame (1). The rotary drive assembly (2) includes a first fixed frame (201). The first fixed frame (201) has a first rotating arm (206) and a second rotating arm (207) symmetrically connected at both ends of the axis of the first fixed frame (201). The first rotating arm (206) and the second rotating arm (207) can rotate synchronously relative to each other. Two sets of arc grooves (205) are symmetrically arranged on the frame (1). The arc grooves (205) are located on the circumference line with the axis of the first fixed frame (201) as the center. Tensile testing assembly (3), there are two sets of tensile testing assembly (3) and both are slidably connected in the arc groove (205). The two sets of tensile testing assembly (3) are respectively fixed to the outer ends of the first rotating arm (206) and the second rotating arm (207); The fixing fixture (4) has a fixing seat (8) at the bottom and is fixed to the lower frame of the machine frame (1) by the fixing seat (8); The movable clamps (6) are in several groups and have the same structure as the fixed clamps (4). They are slidably connected to the other end of the frame (1) via a sliding frame (5). The bottom of each of the movable clamps (6) is symmetrically equipped with an extension arm (7) and the extension arms (7) of each group are staggered.

2. The prestressed steel bar tensioning precision calibration fixture according to claim 1, characterized in that: The rotary drive assembly (2) further includes a second bevel gear (203) rotatably mounted in the first fixed frame (201). The power input end of the second bevel gear (203) is connected to a stepper motor (208). The outer ends of the second bevel gear (203) are respectively meshed with a first bevel gear (202) and a third bevel gear (204). The shafts of the first bevel gear (202) and the third bevel gear (204) are hollow and respectively fixed with a first hollow tube (209) and a second hollow tube (210). The opposite ends of the first hollow tube (209) and the second hollow tube (210) are respectively fixed with a second rotating arm (207) and a first rotating arm (206). The first hollow tube (209) is rotatably connected to the inner wall of the second hollow tube (210).

3. The prestressed steel bar tensioning precision calibration fixture according to claim 2, characterized in that: The tensile testing assembly (3) includes a hydraulic rod (301), and a tensile / compression sensor (302) and a universal rotating assembly (303) are installed on one end of the hydraulic rod (301) facing the fixed clamp (4), and a U-shaped clamp (304) is rotatably connected through the universal rotating assembly (303).

4. The prestressed steel bar tensioning precision calibration fixture according to claim 3, characterized in that: The sliding frame (5) includes a second fixed frame (501) fixed to the bottom of the frame (1), and a number of sliding rods (502) are fixed on the inner side wall of the second fixed frame (501).

5. A precision calibration fixture for prestressed steel bar tensioning according to claim 4, characterized in that: The movable clamp (6) includes a first arc clamping block (601) that slides outside the slide rod (502). A U-shaped rod (602) is fixed inside the first arc clamping block (601). A plurality of first latching strips (603) are installed in a straight, equidistant array on the straight part of the U-shaped rod (602). The cross-section of the first latching strip (603) is triangular and the inclined surface faces the opening of the U-shaped rod (602). A second latching strip (604) that can cooperate with the first latching strip (603) is snapped to the outside of the first latching strip (603). 604) An arc strip (605) is fixed on the outer wall. The arc strip (605) is elastically connected to the through hole of the top strip (607) by a spring (606). A slider (608) is fixed at both ends of the arc strip (605). A groove (609) is opened at the corresponding position of the top strip (607). The arc strip (605) slides on the top strip (607) through the slider (608) and the groove (609). A second arc clamp (610) that can cooperate with the first arc clamp (601) is fixed at the bottom end of the top strip (607).

6. A precision calibration fixture for prestressed steel bar tensioning according to claim 5, characterized in that: The extension arm (7) includes a first extension rod (701), a second extension rod (702) and a third extension rod (703) symmetrically distributed at different angles along the axis of the clamping hole of the movable clamp (6). The first extension rod (701), the second extension rod (702) and the third extension rod (703) are respectively installed on the lower part of the three sets of movable clamps (6) and can all cooperate with the U-shaped clamp (304).

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