A steel bar high temperature tensile relaxation testing machine

Abstract

The present application relates to a kind of steel bar high temperature tension relaxation testing machine, applied in steel bar tension relaxation rate test technical field, including workbench and analysis processing equipment, workbench is provided with fixed clamp, sliding clamp, stretching device and displacement detection device;It further includes heating device, thermal expansion deformation measurement component and tension sensor respectively connected with the analysis processing equipment, the heating device includes the heating box for heating the partial structure of steel bar and temperature sensor for detecting the temperature change of steel bar, the thermal expansion deformation measurement component is fixed on the steel bar in the heating box by connecting piece, the tension sensor is arranged on the fixed clamp;With the tension relaxation rate of steel bar under high temperature at detection position can be simulated, and the temperature change and the temperature change curve of generation temperature when steel bar is tested can be automatically and accurately plotted, the whole operation process is simple, convenient, and the effect of higher degree of automation.

Description

TECHNICAL FIELD

[0001] The application applies to the technical field of steel bar tension relaxation rate test, and particularly relates to a steel bar high-temperature tension relaxation testing machine. BACKGROUND

[0002] The existing patent with the patent number "CN209927630U" discloses a stress relaxation test equipment, which is characterized in that a hydraulic stretching device, a sliding clamp and a fixed clamp are sequentially and spacedly arranged in the length direction within a rectangular frame, the test component is detachably installed between the sliding clamp and the fixed clamp, the hydraulic stretching device is connected with the stretching end of the test component through the sliding clamp to stretch the test component, and the analysis processing equipment is connected with the displacement detection device on the test component and the hydraulic stretching device to adjust the tension of the hydraulic stretching device according to the data detected by the displacement detection device to keep the deformation of the test component constant, and the stress relaxation coefficient of the test component is calculated according to the change of the tension with time, so that the stress relaxation performance of the full cross section of the test component can be measured.

[0003] The above description has the following problems: according to the actual work requirement, the steel bar is applied in a high-temperature environment, so the steel bar is subjected to the tension relaxation rate test in the high-temperature environment, the existing stress relaxation test equipment can only detect the stress relaxation rate of the steel bar under normal temperature, and cannot meet the detection of the tension relaxation rate of the steel bar under the high-temperature environment.

[0004] Therefore, it is necessary to provide a device for testing the tension relaxation rate of the steel bar under the high-temperature environment. SUMMARY

[0005] The application aims to provide a steel bar high-temperature tension relaxation testing machine, which solves the problem that the existing stress relaxation test equipment can only detect the stress relaxation rate of the steel bar under normal temperature and cannot test under the high-temperature condition.

[0006] To achieve the above objective, the technical scheme adopted by the application is as follows:

[0007] The application provides a steel bar high-temperature tension relaxation testing machine, which comprises a working machine table and an analysis processing device, the working machine table is provided with a fixed clamp, a sliding clamp, a stretching device and a displacement detection device, the sliding clamp is connected to the driving end of the stretching device, the stretching device drives the sliding clamp to move along the length direction of the working machine table to stretch the steel bar, the displacement detection device is used for detecting the elongation of the steel bar, and the analysis processing device is connected with the displacement detection device and the stretching device respectively; the heating device, the thermal expansion deformation measuring assembly and the tension sensor connected with the analysis processing device are further included, the heating device comprises a heating box used for heating part of the structure of the steel bar and a temperature sensor used for detecting the temperature change of the steel bar, the thermal expansion deformation measuring assembly is fixed on the steel bar in the heating box through a connecting piece, and the tension sensor is arranged on the fixed clamp.

[0008] Further, the thermal expansion deformation measuring assembly comprises test bars I and II, the test bars I and II are connected to the steel bar in the heating box through the connecting pieces respectively, the connecting pieces are arranged at intervals, and the test bars I and II extend out of the heating box at the end close to the stretching device, and the end of the test bars I and II extending out of the heating box is provided with a displacement detector.

[0009] Further, the stretching device comprises a rotating piece arranged on the working machine table, a lead screw slidingly connected in the rotating piece and a driving motor driving the rotating piece to work, and one end of the lead screw is connected with the sliding clamp through a shaft coupling.

[0010] Further, the upper end faces of the two side walls of the heating box in the width direction are provided with embedding grooves corresponding to the positions of the steel bar, the test bar I and the test bar II, and the steel bar, the test bar I and the test bar II are slidingly connected in the corresponding embedding grooves.

[0011] Further, the connecting piece comprises a lower connecting block, an upper connecting block and a locking bolt fastening the upper connecting block and the lower connecting block.

[0012] Further, the opposite end faces of the lower connecting block and the upper connecting block are provided with a lower semicircular groove for placing the steel bar, the diameter of the lower semicircular groove is smaller than the diameter of the steel bar, and the upper connecting block is provided with an upper semicircular groove matched with the lower semicircular groove.

[0013] Compared with the prior art, the application has the following advantages due to the above technical scheme:

[0014] The steel bar high-temperature tension relaxation testing machine can simulate the tension relaxation rate of the steel bar at high temperature, and can automatically and accurately draw the tension change curve, the temperature change of the steel bar during testing and the change curve of the generated temperature, and can automatically generate a detection report, display the detection result, and export experimental raw data for analysis. In addition, the entire operation process is simple and convenient, and no manual operation is required except for clamping the steel bar, and the degree of automation is high.

[0015] The thermal expansion deformation measuring assembly is arranged to detect the thermal expansion deformation elongation of the steel bar during high-temperature heating and transmit the thermal expansion deformation elongation to the analysis processing device. The analysis processing device calculates the thermal expansion deformation elongation detected by the thermal expansion deformation measuring assembly in real time according to the automatic control program, so that the tensile deformation elongation of the steel bar is not affected by thermal expansion. Thus, the tension relaxation rate of the steel bar at high temperature can be simulated and calculated, the quality of the steel bar is improved, and the processed steel bar meets the actual needs of customers. BRIEF DESCRIPTION OF DRAWINGS

[0016] Some specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. The same reference signs in the drawings denote the same or similar components or parts. Those skilled in the art should understand that the drawings are not necessarily drawn to scale. In the drawings:

[0017] Figure 1 is the overall structure front view in the preferred embodiment of the present application;

[0018] Figure 2 is the overall structure top view in the preferred embodiment of the present application;

[0019] Figure 3 is a schematic view of the cooperation relationship between the heating device and the thermal expansion deformation measuring assembly in the preferred embodiment of the present application;

[0020] Figure 4 is a schematic view of the connection in the embodiment of the present application;

[0021] Figure 5 is a schematic view of the tensile deformation of the steel bar after high-temperature heating in the embodiment of the present application;

[0022] Figure 6 is a curve graph of the detection result in the embodiment of the present application.

[0023] In the drawings, the reference signs are explained as follows:

[0024] 1, workbench; 2, analysis and processing device; 3, fixed clamp; 4, sliding clamp; 5, stretching device; 51, rotating part; 52, screw rod; 53, driving motor; 54, coupling; 55, speed reducer; 6, displacement detection device; 7, steel bar; 8, heating device; 81, heating box; 82, temperature sensor; 9, thermal expansion deformation measurement assembly; 91, test bar I; 92, test bar II; 93, displacement detector; 10, tension sensor; 11, connecting piece; 111, lower connecting block; 112, upper connecting block; 113, locking bolt; 13, embedded groove; 14, lower semicircular groove. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0028] Reference Figure 1 , Figure 2 and Figure 3The application provides a steel bar high-temperature tension relaxation testing machine, which comprises a working machine table 1 and an analysis processing device 2, and the analysis processing device 2 is a computer terminal; the working machine table 1 is provided with a fixed clamp 3, a sliding clamp 4, a stretching device 5 and a displacement detection device 6, and the analysis processing device 2 is connected with the displacement detection device 6 and the stretching device 5, that is, the data detected by the displacement detection device 6 and the stretching device 5 is transmitted to the analysis processing device 2 in real time, and the analysis processing device 2 is used for analysis and calculation; the fixed clamp 3 and the sliding clamp 4 are oppositely arranged along the length direction of the working machine table 1, and the sliding clamp 4 can reciprocate along the length direction of the working machine table 1; the steel bar 7 is detachably connected between the fixed clamp 3 and the sliding clamp 4, the sliding clamp 4 is connected to the driving end of the stretching device 5, the stretching device 5 drives the sliding clamp 4 to move along the length direction of the working machine table 1 to stretch the steel bar 7, the signal emission end of the displacement detection device 6 is arranged on the working machine table 1, the signal receiving end matched with the signal emission end of the displacement detection device 6 is arranged on the sliding clamp 4, the displacement detection device 6 is used for detecting the stretching elongation of the steel bar 7 when the steel bar 7 is stretched by the stretching device 5, the analysis processing device 2 adjusts the tension of the stretching device 5 in real time according to the data detected by the displacement detection device 6 so that the deformation of the steel bar 7 is within the set range, and the stress relaxation coefficient of the steel bar 7 is calculated according to the change of the tension with time. The displacement detection device 6 is a displacement sensor, a grating ruler, a laser range finder or an ultrasonic range finder.

[0029] Reference Figure 1 , Figure 2 and Figure 3The heating device 8, the thermal expansion deformation measuring assembly 9 and the tension sensor 10 are respectively connected with the analysis processing device. The heating device 8 comprises a heating box 81 for heating part of the structure of the steel bar 7 and a temperature sensor 82 for detecting the temperature change of the steel bar. The heating box 81 is arranged on the working table 1 and located between the fixed clamp 3 and the sliding clamp 4. The thermal expansion deformation measuring assembly 9 is fixed on the steel bar 7 in the heating box 81 through a connecting piece 11. The thermal expansion deformation measuring assembly 9 comprises a test bar I 91 and a test bar II 92. The material and diameter of the test bar I 91 and the test bar II 92 are the same as those of the steel bar 7. The test bar I 91 and the test bar II 92 are respectively connected with the steel bar 7 in the heating box 81 through the connecting piece 11. The connecting pieces 11 are arranged at intervals. The test bar I 91 and the test bar II 92 extend out of the heating box 81 at one end close to the stretching device 5. The end of the test bar I 91 and the test bar II 92 extending out of the heating box 81 is provided with a displacement detector 93. The displacement detector 93 is a high-precision marshall digital display millionth table 1086R-HR12.5 / 0.0001mm. The detection end of the displacement detector 93 abuts against the end of the corresponding test bar I 91 and test bar II 92. The length of the test bar I 91 and the test bar II 92 moving along with the deformation elongation of the steel bar 7 is detected by the displacement detector 93. The tension sensor 10 is arranged on the fixed clamp 3. The tension sensor 10 is used for detecting the tension applied by the stretching device 5 to the steel bar 7.

[0030] Reference Figure 2 , Figure 3 and Figure 5 When the steel bar 7 is heated at high temperature and thermal expansion occurs, the thermal expansion deformation elongation of the steel bar will affect the detection result of the high-temperature stress relaxation rate of the steel bar. Therefore, the thermal expansion deformation measuring assembly 9 is arranged to detect the thermal expansion deformation elongation of the steel bar 7 when heated at high temperature and transmit the detection result to the analysis processing device 2. The analysis processing device 2 calculates the thermal expansion deformation elongation of the steel bar 7 in real time according to the following formula, so that the thermal expansion deformation elongation of the steel bar 7 is not affected by the thermal expansion.

[0031] α·T·L1=(α·T·L2)+(α·T·L0)

[0032]

[0033] L1=(L2+L0)

[0034] Wherein, T is the test temperature;

[0035] α is the thermal expansion coefficient;

[0036] LI is the length of the test bar I;

[0037] L2 is the length of the test bar II;

[0038] L0 is the length of the steel bar between the two connectors;

[0039] The steel bar has the same material and diameter as the test bar I and the test bar II.

[0040] Reference Figure 1 and Figure 2 , the stretching device 5 includes a rotating part 51 arranged on the workbench 1, a lead screw 52 slidingly connected in the rotating part 51, and a driving motor 53 driving the rotating part 51 to work. The driving motor is provided with a speed reducer 55, and one end of the lead screw 52 is connected with the sliding clamp 4 through a shaft coupling 54. When the driving motor 53 drives the rotating part 51 to rotate, the lead screw 52 slidingly connected in the rotating part 51 moves along the length direction of the workbench 1 at this time, so as to stretch the steel bar 7.

[0041] Reference Figure 2 and Figure 3 , the heating box 81 includes a box body and a box cover hinged to the box body. The upper end surface of the two side walls of the box body in the width direction is provided with an embedded groove 13 corresponding to the position of the steel bar 7, the test bar I 91 and the test bar II 92. During the test, the steel bar 7, the test bar I 91 and the test bar II 92 are all slidingly connected in the corresponding embedded groove 13, which can reduce the gap between the box cover and the box body of the heating box 81, and improve the heating and insulation performance.

[0042] Reference Figure 2 , Figure 3 and Figure 4 , the connector 11 includes a lower connecting block 111, an upper connecting block 112 and a locking bolt 113 fastening the lower connecting block 111 and the upper connecting block 112. The opposite end surfaces of the lower connecting block 111 and the upper connecting block 112 are provided with a lower semicircular groove 14 for placing the steel bar 7. The diameter of the lower semicircular groove 14 is smaller than the diameter of the steel bar 7. The upper connecting block 112 is provided with an upper semicircular groove matched with the lower semicircular groove 14. The connector 11 with this structure facilitates the connection and disassembly of the test bar I 91 and the test bar II 92 on the steel bar 7.

[0043] Reference Figure 1 , Figure 2 and Figure 3 , specifically, the test steps of the steel bar high temperature tensile relaxation tester in this example are as follows:

[0044] Step S1, the steel bar 7 to be detected is placed horizontally, and the two ends of the steel bar 7 to be detected are clamped and fixed by the fixed clamp 3 and the sliding clamp 4. At this time, part of the structure of the steel bar 7 to be detected is located in the box body of the heating box 81, and the temperature sensor 82 is installed on the steel bar 7 located in the heating box 81. Finally, the box cover of the heating box 81 is covered on the box body of the heating box 81;

[0045] Step S2, the steel bar 7 is tensioned by the tensioning device 5 to the stress state corresponding to the stress relaxation coefficient to be measured (i.e. the pre-tightening force is applied to the steel bar by the tensioning device to make it reach the stress state level required by the test), and the steel bar 7 is heated by the heating box 81;

[0046] Step S4, the elongation of the tensile deformation of the steel bar 7 is measured by the displacement detection device 6 (or a laser range finder, etc.), and the expansion deformation of the steel bar 7 after high-temperature heating is measured by the thermal expansion deformation measurement assembly 9, and the data detected by the displacement detection device 6 and the data detected by the thermal expansion deformation measurement assembly 9 are transmitted to the analysis processing equipment 2 in real time, and the rotation speed of the driving motor 53 of the tensioning device 5 is adjusted in real time by the analysis processing equipment 2 to adjust the tension of the tensioning device 5 to the steel bar 7, so as to ensure the elongation of the tensile deformation of the steel bar 7.

[0047] Step S5, the tension of the tensioning device 5 is fed back to the analysis processing equipment 2 in real time, and the analysis processing equipment 2 processes the curve of the force change with time, calculates the force change curve of the pre-stressed steel bar 7 within the set tensile deformation range, and according to the force change curve (deformation within a certain range), the analysis processing equipment 2 calculates the stress relaxation coefficient of the steel bar (for reference Figure 6 )。

[0048] In summary: the steel bar high-temperature tension relaxation tester can simulate the tension relaxation rate of the steel bar 7 at high temperature, and can automatically and accurately draw the tension change curve, the temperature change of the steel bar during the test and the temperature change curve, and can automatically generate a detection report, display the test results, and export the experimental raw data for analysis. In addition, the whole operation process is simple and convenient, and no manual operation is required except for clamping the steel bar, and the degree of automation is high.

[0049] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A high-temperature tensile relaxation testing machine for steel bars, comprising a worktable (1) and an analysis and processing device (2), wherein the worktable (1) is provided with a fixed clamp (3), a sliding clamp (4), a tensile device (5), and a displacement detection device (6), the sliding clamp (4) being connected to the drive end of the tensile device (5), the tensile device (5) driving the sliding clamp (4) to move along the length direction of the worktable (1) to stretch the steel bar (7), the displacement detection device (6) being used to detect the tensile elongation of the steel bar (7), and the analysis and processing device (2) being connected to the displacement detection device (6) and the tensile device (5) respectively; characterized in that, It also includes a heating device (8), a thermal expansion deformation measurement component (9), and a tensile sensor (10) connected to the analysis and processing equipment (2). The heating device (8) includes a heating box (81) for heating a portion of the steel bar (7) and a temperature sensor (82) for detecting temperature changes in the steel bar (7). The thermal expansion deformation measurement component (9) is fixed to the steel bar (7) located inside the heating box (81) by a connector (11). The tensile sensor (10) is mounted on the fixing clamp (3). The thermal expansion deformation measurement component (9) includes test rod I (91) and test rod II (92). Test rod I (91) and test rod II (92) are respectively connected to the steel rod (7) located in the heating box (81) through the connector (11). The connector (11) is spaced apart. One end of test rod I (91) and test rod II (92) near the tensile device (5) extends out of the heating box (81). The other end of test rod I (91) and test rod II (92) is located in the heating box (81). Displacement detectors (93) are provided at the ends of test rod I (91) and test rod II (92) extending out of the heating box (81). The analysis and processing equipment (2) calculates the data detected by the thermal expansion deformation measurement component (9) in real time according to the following formula, so that the tensile deformation elongation of the steel bar (7) is not affected by thermal expansion; the calculation formula is as follows: α·T·L1=(α·T·L2)+(α·T·L0) (L2 + L0) L1 = (L2 + L0) Where T is the test temperature; α is the coefficient of thermal expansion; LI is the length of test rod I; L2 is the length of test bar II; L0 is the length of the steel bar between the two connectors; The steel bar is made of the same material and has the same diameter as test bar I and test bar II.

2. The high-temperature tensile relaxation testing machine for steel bars according to claim 1, characterized in that, The stretching device (5) includes a rotating part (51) mounted on the workbench (1), a lead screw (52) slidably connected in the rotating part (51), and a drive motor (53) that drives the rotating part (51) to work. One end of the lead screw (52) is connected to the sliding clamp (4) through a coupling.

3. The high-temperature tensile relaxation testing machine for steel bars according to claim 1, characterized in that, The upper surfaces of the two side walls of the heating box (81) in the width direction are provided with embedding grooves (13) at positions corresponding to the steel rod (7), the test rod I (91) and the test rod II (92). The steel rod (7), the test rod I (91) and the test rod II (92) are all slidably connected in the corresponding embedding grooves (13).

4. The high-temperature tensile relaxation testing machine for steel bars according to claim 1, characterized in that, The connector (11) includes a lower connector (111), an upper connector (112), and a locking bolt (113) for fastening the upper connector (112) and the lower connector (111).

5. The high-temperature tensile relaxation testing machine for steel bars according to claim 4, characterized in that, The lower connecting block (111) and the upper connecting block (112) have a lower semi-circular groove (14) on their opposite end faces for placing the steel rod (7). The diameter of the lower semi-circular groove (14) is smaller than the diameter of the steel rod (7). The upper connecting block (112) has an upper semi-circular groove that mates with the lower semi-circular groove (14).

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