A metal material bending testing machine suitable for bars

Abstract

A metal material bending testing machine suitable for bars. It includes a base, a linear rail arranged on the base, and a first slider and a second slider slidably arranged on the linear rail, a first chuck is rotatably arranged on the first slider, a second chuck is rotatably arranged on the second slider, and a bidirectional pressure head is arranged in the middle of the first chuck and the second chuck on the base, and the bidirectional pressure head is used to press down the sample or pull up the middle of the sample under the action of a driving device distributed in the vertical direction to implement a forward or reverse bending test; it also includes a bending angle control device, and the bending angle control device has a plurality of limiters, so as to limit the sliding stroke of the first slider and the second slider along the linear rail through different limiters, so as to fix the bending angle of the sample. The present invention is not only easy to operate and is conducive to the rapid conduct of the test, but also the bending angle is easy to control, so that its performance can be accurately characterized through a bending test.

Description

Technical Field

[0001] The invention relates to the field of metal material detection and testing equipment, in particular to a metal material bending testing machine suitable for bars. Background Art

[0002] In the performance test of metal materials, in addition to the test of the metal material itself, the performance test of rod-shaped metal materials also includes at least forward bending test, reverse bending test and bending fatigue strength test. The forward bending test is to bend the metal rod-shaped material to a specific angle through a pressure head mechanism, and observe the shape of the metal rod-shaped material in the bent state. The reverse bending test is to bend the metal rod-shaped material forward to a specific angle, then reverse bend it to a specific angle, and then observe its shape. The bending fatigue strength test is to repeatedly bend the metal rod-shaped material forward and reversely at a specific angle for a certain number of times, and finally observe its shape.

[0003] In the prior art, there are various bending testing machines for the above-mentioned forward bending test, reverse bending test and bending fatigue strength test of metal rod-type materials. However, on the one hand, after the sample is forward bent, the operator needs to remove it and then install it on the testing machine in reverse, and then perform reverse bending through the pressure head of the testing machine. As a result, the operator needs to repeatedly adjust the position of the sample during the reverse bending test and fatigue strength test of the sample, which is extremely inconvenient to use. On the other hand, in the implementation process of the bending test through the existing bending testing machine, the operator needs to measure the bending angle of the sample through a measuring tool, and then turn off the power mechanism of the testing machine after confirming that the bending angle meets the test requirements. As a result, due to the delay of manual operation, the bending angle of the sample cannot accurately meet the test design requirements, and thus the performance of the metal rod-type material cannot be correctly characterized through the bending test. Summary of the invention

[0004] The present invention aims to provide a metal material bending testing machine suitable for bars, which is not only easy to operate and convenient for rapid testing, but also easy to control the bending angle, making it convenient to accurately characterize its performance through bending tests.

[0005] In order to solve the above technical problems, the specific scheme adopted by the present invention is: a metal material bending testing machine suitable for bars, comprising a base, a linear rail arranged on the base, and a first slider and a second slider slidably arranged on the linear rail, a first chuck is rotatably provided on the first slider, a second chuck is rotatably provided on the second slider, the first chuck and the second chuck are respectively used to clamp and fix the two ends of the sample, a bidirectional pressure head is provided on the base in the middle of the first chuck and the second chuck, the bidirectional pressure head is used to press down the sample or pull up the middle of the sample under the action of a driving device distributed in the vertical direction to implement a forward or reverse bending test, and the sample can drive the first slider and the second slider to slide synchronously along the linear rail through the first chuck and the second chuck in the bending test;

[0006] It also includes a bending angle control device, which has a plurality of limiting members, so as to limit the sliding stroke of the first slider and the second slider along the linear rail through different limiting members, thereby fixing the bending angle of the sample.

[0007] Preferably, the limit member includes a first limit block, a second limit block and a third limit block, and the bottoms of the first limit block, the second limit block and the third limit block are all provided with pin shafts, and a plurality of pin holes for the pin shafts to be installed are provided at intervals along the length direction of the linear rail on the base; the pin shaft on the first limit block is installed in the pin hole located between the first slider and the second slider, and the two sides of the first limit block are respectively provided for the inner side of the first slider and the inner side of the second slider to limit, the pin shaft on the second limit block is installed in the pin hole on the outer side of the first slider, and the inner side of the second limit block is provided for the outer side of the first slider to limit, the pin shaft on the third limit block is installed in the pin hole on the outer side of the second slider, and the inner side of the third limit block is provided for the outer side of the second slider to limit.

[0008] Preferably, the pin shaft and the pin hole are in corresponding rectangular shapes.

[0009] Preferably, the bending angle control device further comprises a first horizontal push rod fixed at an inner position of the first slider, a second horizontal push rod fixed at an inner position of the second slider, and a slide column arranged on the base between the first slider and the second slider, the inner end of the first horizontal push rod is provided with a first flange, the outer end of the first horizontal push rod is eccentrically fixed on a round table rotatably arranged on the first slider, the inner end of the second horizontal push rod is provided with a second flange, the second horizontal push rod is a hollow rod, and a through hole is arranged on the slide column;

[0010] The limiting member comprises a fourth limiting block, a first limiting plate, a second limiting plate and a fifth limiting block. There are multiple fourth limiting blocks and multiple fifth limiting blocks. A sliding hole for cooperating with a sliding column is provided in the middle of any fourth limiting block. A seat plate for supporting the fourth limiting block is also provided on the sliding column above the through hole. Both sides of the fourth limiting block are respectively provided for the inner side of the first flange and the inner side of the second flange in a small-angle positive bending test of the specimen to limit and cooperate. Multiple fifth limiting blocks are spirally and fixedly distributed on the inner wall of the second horizontal push rod along the axial direction of the second horizontal push rod. The inner side of any fifth limiting block is provided for the inner side of the first flange in a large-angle positive bending test of the specimen to limit and cooperate, and the first flange can overlap with multiple fifth limiting blocks one by one in the horizontal direction as the truncated table rotates.

[0011] The cam is an assembly made of a plurality of first and second cam elements, each of which is adapted to engage the first and second cam elements and to engage with the second cam elements in a manner that allows the cam elements to engage with the first and second cam elements in a manner that is compatible with the first and second cam elements. The apertures decrease from the inside to the outside, the aperture of the small hole in the step hole corresponds to the outer diameter profile of the corresponding first flange or second flange, the first one-way rotating plate and the second one-way rotating plate are spaced apart in the large hole of the step hole and respectively cover part of the small holes, the gap between the first one-way rotating plate and the second one-way rotating plate corresponds to the outer diameter profile of the corresponding first horizontal push rod or the second horizontal push rod and is smaller than the outer diameter profile of the first flange or the second flange, the ends of the first one-way rotating plate and the second one-way rotating plate away from each other are respectively hinged at the outer edge position of the large hole of the step hole, and a torsion spring is also provided at the hinge between the first one-way rotating plate and the second one-way rotating plate and the large hole to maintain the closed state of the first one-way rotating plate and the second one-way rotating plate through the torsion spring, and the inner sides of the first one-way rotating plate and the second one-way rotating plate are used for the outer limit cooperation of the corresponding first flange or the second flange.

[0012] Preferably, the slide column is slidably inserted into a socket provided on the base, a compression spring is provided at the bottom of the socket, and a retractable pin is provided on the side of the socket, the pin cooperates with a pin groove provided on the slide column to maintain the compressed state of the compression spring and make the two sides of the fourth limit block correspond to the first flange and the second flange respectively, and a large and small positive bending angle switching mechanism is also provided between the round table and the slide column, and the large and small positive bending angle switching mechanism is used to pull the pin out of the pin groove when the round table is rotated to perform a large-angle positive bending test of the specimen, so that the slide column rises under the action of the compression spring until the perforation corresponds to the first flange and the second flange;

[0013] The large and small positive bending angle switching mechanism includes an adjusting sleeve rotatably arranged in a base and sleeved on the outer periphery of a latch and a driving gear used to drive the adjusting sleeve to rotate; the outer periphery of the adjusting sleeve is sleeved with driven teeth, the inner periphery is sleeved with a radial plug shaft, and the radial plug shaft is plugged into a slide groove opened at the outer periphery of the latch, and the slide groove is distributed in a spiral shape along the axial direction of the latch, so that the latch is driven to extend or retract by the positive and negative rotation of the adjusting sleeve; the driving gear is sleeved on the round table at the end position in the inner cavity of the first slider and is transmission-connected to the driven gear, the number of teeth of the driving gear is greater than that of the driven gear, and the rack width of the driven gear is greater than that of the driving gear.

[0014] Preferably, the driving gear and the driven gear are meshed through a plurality of intermediate gears, and the number of teeth of the plurality of intermediate gears decreases in sequence from the driving gear to the driven gear.

[0015] Preferably, the table is rotatably arranged in a circular hole opened on the first slider, and a rotation angle positioning mechanism is provided between the circular hole and the table. The rotation angle positioning mechanism includes a radial hole opened at the outer periphery of the table, a positioning shaft slidably installed in the radial hole, a positioning spring for pushing the positioning shaft out of the radial hole, and a positioning groove arranged on the inner wall of the circular hole for the positioning shaft to be plugged in and engaged with. The positioning grooves are semicircular and there are multiple positioning grooves, which are distributed along the circumference of the circular hole.

[0016] Preferably, the driving device is a cylinder, and two chambers located on both sides of the piston plate in the cylinder body of the cylinder are respectively connected to safety valves.

[0017] Preferably, the bidirectional pressure head comprises an upper pressure head body and a lower pressure head body fixed on the output end of the driving device, and the upper pressure head body and the lower pressure head body are both arc-shaped and spaced apart in the vertical direction.

[0018] Preferably, two parallel linear rails are provided on the base, and a first slider and a second slider are slidably provided on any linear rail. The two sides of the first chuck are rotatably set on the opposite sides of the two first sliders, and the two sides of the second chuck are rotatably set on the opposite sides of the two second sliders.

[0019] In the present invention, the two ends of the sample are respectively fixed on the first chuck and the second chuck, and the pressure head is a bidirectional pressure head, so that on the basis of fixing the two ends of the sample, the forward extrusion bending and reverse extrusion bending of the sample can be achieved by lifting and lowering the bidirectional pressure head in the vertical direction. The operator does not need to repeatedly disassemble and assemble the sample and adjust the direction of its bending part during the process, thereby speeding up the test speed, and making the present invention suitable for forward bending test, reverse bending test and bending fatigue strength test, and has strong applicability.

[0020] The first chuck in the present invention is rotatably connected to the first slider, and the second chuck is rotatably connected to the second slider, so that when the bidirectional pressure head performs forward or reverse bending and extrusion on the middle part of the sample, the first slider and the second slider can synchronously slide along the linear rail on the base under the action of positive and reverse pressure, so that the relative positions of the first slider and the second slider are associated with the bending angle of the sample, and then the limiter used to limit the sliding position of the first slider and the second slider in the present invention can be associated with the limited bending angle of the sample, avoiding the error caused by manually measuring the bending angle and then controlling the power mechanism, thereby greatly improving the accuracy of the bending angle of the sample in the bending test compared with the prior art, which is conducive to truly reflecting the performance of the sample through the bending test. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the top view of the structure of the initial state of the embodiment 1 of the present invention;

[0022] Figure 2 for Figure 1 Schematic diagram of the structure under the bending test state;

[0023] Figure 3 A schematic diagram of the structure of the first limiting block, the second limiting block or the third limiting block in Example 1;

[0024] Figure 4 is a schematic diagram of a top view of the structure of Example 2 of the present invention in an initial state;

[0025] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure in the middle BB direction;

[0026] Figure 6 for Figure 5 A schematic diagram of the local enlarged structure of part E in the middle;

[0027] Figure 7 for Figure 6 A schematic diagram of the state of the first horizontal push rod in the process of passing through the first limit plate;

[0028] Figure 8 for Figure 6 A schematic diagram of the state after the first horizontal push rod passes through the first limit plate;

[0029] Fig. 9 for Figure 5 A schematic diagram of the local enlarged structure of part D in the middle;

[0030] Fig.10 for Figure 5 A schematic diagram of the local enlarged structure of part F in the middle;

[0031] Fig.11 It is a structural schematic diagram of the first sliding block and the second sliding block in the embodiment 1 in a state of being limited by the fourth limiting block;

[0032] Fig.12 It is a schematic diagram of the structure in which the first sliding block and the second sliding block in Embodiment 1 are limited by the first limiting plate and the second limiting plate;

[0033] Fig.13 for Figure 5 Schematic diagram of the structure after the sliding column posture is adjusted;

[0034] Fig.14 for Fig.13 A schematic diagram of the structure in which the first slider and the second slider are in a state of being limited by a fifth limit block;

[0035] Fig.15 It is a schematic diagram of the state of the sample in the present invention under the main viewing angle;

[0036] Fig.16 for Fig.15 Schematic diagram of the state of the sample after being forward bent 90°;

[0037] Fig.17 for Fig.16 Schematic diagram of the state of the sample after reverse bending 20°;

[0038] Fig.18 for Fig.15 Schematic diagram of the state of the sample after being forward bent 180°;

[0039] Markings in the figure: 1, base, 2, linear rail, 3, first slider, 4, pin hole, 5, first limit block, 6, second slider, 7, second chuck, 8, driving device, 9, sample, 10, rotating shaft, 11, first chuck, 12, second limit block, 13, third limit block, 14, pin shaft, 15, first horizontal push rod, 16, L-shaped cover plate, 17, slide column, 18, second horizontal push rod, 19, intermediate gear, 20, driving gear, 21, round table, 22, first flange, 23, first limit plate, 24, fourth limit block, 25, limit Position hole, 26, seat plate, 27, second limit plate, 28, second flange, 29, slot, 30, fifth limit block, 31, jack, 32, compression spring, 33, latch, 34, slide groove, 35, adjustment sleeve, 36, torsion spring, 37, first one-way rotating plate, 38, second one-way rotating plate, 39, positioning groove, 40, radial hole, 41, positioning spring, 42, positioning shaft, 43, radial plug shaft, 44, pin groove, 45, through hole, 46, safety valve, 47, air pipe connection port, 48, upper pressure head body, 49, lower pressure head body. DETAILED DESCRIPTION

[0040] like Figure 1 and Figure 4 As shown, the metal material bending testing machine suitable for bars of the present invention comprises two bases 1 which are spaced and arranged in parallel, and two horizontal and parallel linear rails 2 are arranged on the upper horizontal planes of the two bases 1. A first slider 3 is arranged on the left side of any linear rail 2, and a second slider 6 is arranged on the right side, and both the first slider 3 and the second slider 6 can slide flexibly on the corresponding linear rail 2. A first chuck 11 is arranged between the two first sliders 3, and a second chuck 7 is arranged between the two second sliders 6. The first chuck 11 and the second chuck 7 are respectively used to clamp and fix the two end positions of the sample 9. Rotating shafts 10 are respectively arranged on both sides of the first chuck 11 and the second chuck 7, and the rotating shaft 10 is rotatably arranged in an axial hole opened on the side wall of the corresponding first slider 3 or the second slider 6 facing the gap between the two bases 1.

[0041] A driving device 8 is provided on the base 1, located directly above the middle of the sample 9. The driving device 8 has a push-pull function output in the vertical direction, and a bidirectional pressure head is provided on the push-pull output end of the driving device 8. The bidirectional pressure head is used to press down the sample 9 or pull up the middle of the sample 9 under the action of the driving device 8 to implement a forward or reverse bending test. Since the two ends of the sample 9 are respectively fixed by the first chuck 11 and the second chuck 7, the sample 9 can drive the first slider 3 and the second slider 6 to slide synchronously along the linear track 2 through the first chuck 11 and the second chuck 7 during the bending test, so that the distance or relative position between the first slider 3 and the second slider 6 is associated with the bending angle of the test. The present invention utilizes the association between the bending angle of the sample 9 and the distance between the first slider 3 and the second slider 6, and achieves the effect of accurately controlling the bending angle of the sample 9 through the bending angle control device.

[0042] The bending angle control device in the present invention has multiple limit members with different specifications and sizes. The corresponding limit members can be selectively detachably connected to the base 1, so that the sliding stroke of the first slider 3 and the second slider 6 along the linear rail 2 can be limited by different limit members, thereby fixing the bending angle of the sample 9.

[0043] like Figure 15-18 As shown, the driving device 8 in the present invention is a cylinder, and a bidirectional pressure head is arranged on the piston rod of the cylinder, so that the cylinder applies a positive or reverse extrusion force to the sample 9 through the push stroke and return stroke of its piston rod. The bidirectional pressure head includes an upper pressure head body 48 and a lower pressure head body 49, and the upper pressure head body 48 and the lower pressure head body 49 are both arc-shaped and are arranged on the piston rod of the cylinder at intervals in the vertical direction. The cylinder body of the cylinder is divided into two upper and lower chambers by a piston plate, and air pipe connecting ports 47 are respectively connected to the right sides of the two chambers. The air pipe connecting port 47 is used to be connected to the air pipe. When one of the air pipes is ventilated to the corresponding chamber, the other chamber is exhausted through the corresponding air pipe, that is, the piston plate is pushed to link the piston rod to move, so as to realize the output of the thrust or pull of the cylinder. Safety valves 46 are connected to the left sides of the two chambers. The purpose of setting the safety valves 46 is that when the first slider 3 and the second slider 6 are fixed in position by the stopper, the position of the cylinder piston rod and the piston plate are locked in linkage. At this time, the high-pressure air continuously input from the air pipe connection port 47 of the air intake chamber in the cylinder can be discharged through the corresponding safety valve 46, thereby preventing the pressure increased by the continuous air intake of the air intake chamber from damaging the first slider 3, the second slider 6, the stopper or the cylinder itself. In the specific implementation of the present invention, an oil cylinder or other existing push-pull device with similar functions can also be used as the driving device 8.

[0044] The angle bending control device of the present invention is described in detail below through two embodiments:

[0045] Example 1

[0046] like Figure 1 and Figure 2 As shown, the limiting member in the angle bending control device in this embodiment includes a first limiting block 5, a second limiting block 12 and a third limiting block 13. The first limiting block 5, the second limiting block 12 and the third limiting block 13 are all rectangular, wherein the first limiting block 5 is installed on the base 1 between the first slider 3 and the second slider 6, and the two sides of the first limiting block 5 are respectively provided for the inner side of the first slider 3 and the inner side of the second slider 6 (the inner side is the side facing the middle of the base 1, and the outer side is the side opposite to the middle of the base 1, the same below). The second limiting block 12 is installed on the base 1 on the left side of the first slider 3, and the inner side of the second limiting block 12 is provided for the outer side of the first slider 3. The third limiting block 13 is installed on the right side of the second slider 6, and the inner side of the third limiting block 13 is provided for the outer side of the second slider 6.

[0047] like Figure 3 As shown, the bottoms of the first limit block 5, the second limit block 12 and the third limit block 13 are all provided with a pin shaft 14. Correspondingly, a plurality of pin holes 4 for the pin shaft 14 to be installed are provided at intervals along the length direction of the linear rail 2 on the base 1, so as to realize the quick disassembly and assembly between the first limit block 5, the second limit block 12 and the third limit block 13 and the base 1. The pin shaft 14 and the pin hole 4 in this embodiment are in the shape of corresponding rectangles, so as to define the direction of the first limit block 5, the second limit block 12 and the third limit block 13 after installation by the specific shape of the pin shaft 14 and the pin hole 4, so as to avoid the first limit block 5, the second limit block 12 and the third limit block 13 failing to produce the limiting effect on the first slider 3 and the second slider 6 according to the design requirements due to the wrong installation direction.

[0048] Taking the reverse bending test of sample 9 as an example, the specific implementation process of this embodiment is as follows:

[0049] First, Figure 1 and 15 As shown, the sample 9 is passed through the first chuck 11, the bidirectional pressure head and the second chuck 7 in the horizontal direction, and the two ends of the sample 9 are fixed by the first chuck 11 and the second chuck 7 respectively, and the middle part of the sample 9 is exactly overlapped with the bidirectional pressure head in the vertical direction.

[0050] Then, the first stopper 5 corresponding to the positive bending of the sample 9 by 90° is installed at the middle position of the first slider 3 and the second slider 6 through the pin 14; the cylinder is started to move the bidirectional pressure head vertically downward until it reaches the position shown in FIG. Figure 2 In the state shown, the inner sides of the first slider 3 and the second slider 6 respectively touch the positions on both sides of the first limit block 5, and the sample 9 is as shown in FIG. Fig.16 As shown, the upper pressing head body 48 is pressed and bent to a forward bending state of 90°.

[0051] Finally, still Figure 2 As shown, the second limit block 12 and the third limit block 13 are respectively installed on the base 1, and the cylinder is started to move the bidirectional pressure head upward, and the lower pressure head body 49 generates an upward squeezing force on the curved part of the sample 9 to achieve the following Fig.17 The reverse bending test of sample 9 is completed in the state of reverse bending by 20° as shown.

[0052] In addition to the reverse bending test of the sample 9 listed above, the number of the first limit block 5, the second limit block 12 and the third limit block 13 in this embodiment are all multiple, and the shape is rectangular. By selecting different lengths of the first limit block 5, the second limit block 12 and the third limit block 13, the first slider 3 and the second slider 6 can be limited to different sliding stroke displacements, thereby realizing accurate limitation of various bending angles of the sample 9, so that this embodiment can meet the bending tests with various bending angle requirements. For example Fig.18 As shown, using Figure 1 The shorter first stopper 5 shown in FIG. 1 realizes the 180° positive bending test of the sample 9. Figure 1 The longer first stopper 5 shown in the figure realizes the positive bending test of the sample 9 less than 90°. A person skilled in the art can obtain the linear relationship between the stopper length and the bending angle through experiments based on the above angle control principle, which will not be described in detail in this embodiment.

[0053] Example 2

[0054] In the above-mentioned embodiment 1, when the reverse bending test of the sample 9 is performed, due to the obstruction of the first slider 3 and the second slider 6, it is necessary to install the second limit block 12 and the third limit block 13 after the first slider 3 and the second slider 6 are blocked and limited by the first limit block 5. Although the reverse bending test of the sample 9 can be completed completely and accurately, the installation of the limit block and the process of the driving mechanism squeezing the sample 9 through the bidirectional pressure head are intertwined, and the whole test process is slightly cumbersome and leads to certain dangers. In order to solve the problems existing in embodiment 1, different bending angle control devices are set in this embodiment.

[0055] like Figure 4 and Figure 5 As shown, the bending angle control device in this embodiment also includes a first horizontal push rod 15 fixed at the inner side of the first slider 3, a second horizontal push rod 18 fixed at the inner side of the second slider 6, and a slide column 17 arranged on the base 1 between the first slider 3 and the second slider 6. The first horizontal push rod 15 is a solid structure, and a first flange 22 is arranged at its inner end, and an outer end thereof is eccentrically fixed on a round table 21 rotatably arranged on the first slider 3. The second horizontal push rod 18 is a hollow rod, and a second flange 28 is arranged at its inner end. A through hole 45 is arranged on the slide column 17.

[0056] The limiting member in this embodiment includes a fourth limiting block 24, a first limiting plate 23, a second limiting plate 27 and a fifth limiting block 29. There are multiple fourth limiting blocks 24 and fifth limiting blocks 29, wherein the two sides of the fourth limiting block 24 are respectively provided for limiting the inner side of the first flange 22 and the inner side of the second flange 28 in the small-angle positive bending test of the specimen 9. A sliding hole for matching with the slide column 17 is provided in the middle of any fourth limiting block 24, so that the first limiting plate 23 can be matched with the slide column 17 through the sliding hole and supported by the seat plate 26 arranged on the slide column 17 above the through hole 45. A plurality of fifth stoppers 29 are fixedly distributed on the inner wall of the second horizontal push rod 18 in a spiral shape along the axial direction of the second horizontal push rod 18. The inner side of any fifth stopper 29 is provided for the inner side stopper of the first flange 22 in the large-angle positive bending test of the sample 9, and the first flange 22 can overlap with the plurality of fifth stoppers 29 one by one in the horizontal direction as the truncated table 21 rotates. The small-angle positive bending test and the large-angle positive bending test described in this embodiment are divided by 120°. In the small-angle positive bending test, the angle control is achieved by replacing different fourth stoppers 24; in the large-angle positive bending test, the angle control is achieved by rotating the truncated table 21 so that the specific fifth stopper 29 cooperates with the first flange 22. In other embodiments of the present invention, the critical angles of the small-angle positive bending test and the large-angle positive bending test, the number of the fifth stoppers 30, and the arrangement angle and spacing between the fifth stoppers 30 can be set separately according to the size of each component and the commonly used bending angle requirements.

[0057] The first limit plate 23 is inserted on the base 1 between the first slider 3 and the slide post 17, and the second limit plate 27 is inserted on the base 1 between the second slider 6 and the slide post 17, and is used to limit and block the outer sides of the first flange 22 and the second flange 28 in the reverse bending test. In order to achieve the limit in multiple reverse bending states, a plurality of slots 29 for the first limit plate 23 and the second limit plate 27 to be inserted and matched are provided on the base 1 along the length direction of the linear rail 2. After the first limit plate 23 and the second limit plate 27 are inserted in different slots 29, they correspond to the control of different reverse bending angles. In order to improve the stability of the limiting effect of the first limit plate 23 and the second limit plate 27 on the first flange 22 and the second flange 28, as shown in FIG. Figure 4 and 5As shown, an L-shaped cover plate 16 is also provided on the base 1. The vertical plate of the L-shaped cover plate 16 is fixed on the base 1, and the horizontal plate on its upper edge extends toward the gap between the two bases 1. A slide groove 34 is also provided on the lower edge of the horizontal plate of the L-shaped cover plate 16, and the slide groove 34 on the lower edge of the horizontal plate of the L-shaped cover plate 16 corresponds to the slide groove 34 on the base 1 in a one-to-one group, respectively, for the upper and lower ends of the first limit plate 23 or the second limit plate 27 to cooperate with and install (a notch is also provided on the vertical plate of the L-shaped cover plate 16 for the first limit plate 23 or the second limit plate 27 to start inserting into the slot 29). The slide groove 34 and the upper and lower ends of the first limit plate 23 and the second limit plate 27 are all dovetail-shaped to further increase the stability of the limit fit.

[0058] The first limiting plate 23 and the second limiting plate 27 are provided with limiting holes 25 respectively. The limiting holes 25 are only for the corresponding first flange 22 or second flange 28 to move through in the direction toward the sliding column 17, and block the corresponding first flange 22 or second flange 28 from moving through in the direction opposite to the sliding column 17. Since the position of the second horizontal push rod 18 is fixed, the number of limiting holes 25 on the second limiting plate 27 is one; and since the first horizontal push rod 15 needs to cooperate with different fifth limiting blocks 29 for limiting, and thus needs to rotate to different positions with the round table 21, the number of limiting holes 25 on the first limiting plate 23 is multiple, and the multiple limiting holes 25 on the first limiting plate 23 overlap and correspond to the multiple fifth limiting blocks 29 in the horizontal direction, so that after the round table 21 is rotated to make the first flange 22 correspond to any fifth limiting block 29, both can pass through the limiting holes 25 in one direction, and the limiting holes 25 form a blocking limit to the outer side of the first flange 22.

[0059] Combination Figure 5 and 6 As shown, the limiting hole 25 on the first limiting plate 23 includes a stepped hole opened on the first limiting plate 23 and a first one-way rotating plate 37 and a second one-way rotating plate 38 arranged in the stepped hole. The stepped hole is a two-stage hole, and the apertures are reduced from the inside to the outside. The aperture of the small hole corresponds to the outer diameter profile of the corresponding first flange 22, so that the first flange 22 can pass through. The first one-way rotating plate 37 and the second one-way rotating plate 38 are distributed in the large hole of the stepped hole at intervals and cover part of the small holes respectively. The gap between the first one-way rotating plate 37 and the second one-way rotating plate 38 corresponds to the outer diameter profile of the corresponding first horizontal push rod 15 or the second horizontal push rod 18 and is smaller than the outer diameter profile of the first flange 22 or the second flange 28. The ends of the first one-way rotating plate 37 and the second one-way rotating plate 38 that are far away from each other are respectively hinged at the outer edge position of the large hole of the stepped hole. Figure 6 In the embodiment, after the first flange 22 moves to the right, Figure 7 As shown, the first one-way rotating plate 37 and the second one-way rotating plate 38 are pushed open until Figure 8As shown, after the first flange 22 passes over, the first one-way rotating plate 37 and the second one-way rotating plate 38 are reset under the action of the torsion spring 36, and the right side of the first one-way rotating plate 37 and the second one-way rotating plate 38 form a one-way limit on the left side of the first flange 22. The structure of the limiting hole 25 on the second limiting plate 27 is the same as that of the limiting hole 25 on the first limiting plate 23, and will not be repeated.

[0060] The truncated table 21 in this embodiment is rotatably arranged in a circular hole provided on the first slider 3. In order to prevent the truncated table 21 and the first horizontal push rod 15 from moving in the circumferential direction during the test and to ensure that the truncated table 21 can rotate, a set of thrust bearings is provided between the truncated table 21 and the circular hole. In order to facilitate the first horizontal push rod 15 to accurately point to the target fifth limit block 29 during the rotation of the truncated table 21, a scale line corresponding to the first horizontal push rod 15 and the specific fifth limit block 29 can be provided on the truncated table 21, and the truncated table 21 can be positioned at the position corresponding to the specific fifth limit block 29 through the rotation angle positioning mechanism. Figure 5 and Fig. 9 As shown, the rotation angle positioning mechanism in this embodiment includes a radial hole 40 opened at the outer peripheral position of the truncated table 21, a positioning shaft 42 slidably installed in the radial hole 40, a positioning spring 41 for pushing the positioning shaft 42 out of the radial hole 40, and a positioning groove 39 provided on the inner wall of the circular hole for the positioning shaft 42 to be inserted and matched. The positioning groove 39 is semicircular and there are multiple positioning grooves 39, which are distributed along the circumference of the circular hole. When the truncated table 21 rotates under the action of an external force, the ball head of the positioning shaft 42 is slidably matched with the smooth inner wall of the circular hole. After rotating to any positioning groove 39, the ball head of the positioning shaft 42 automatically slides into the positioning groove 39 under the action of the positioning spring 41, so as to maintain the first horizontal push rod 15 on the truncated table 21 and the specific fifth limit block 29 in an accurate corresponding state. In this embodiment, a positioning mechanism similar to the above is also provided between the first slider 3, the second slider 6 and the linear rail 2, so that after the first slider 3 and the second slider 6 are positioned on the linear rail 2 by the positioning mechanism, the sample 9 is installed on the first chuck 11 and the second chuck 7, so that the middle of the sample 9 is located just below the bidirectional pressure head, eliminating the tedious operation of manually measuring and adjusting the positions of the first slider 3 and the second slider 6.

[0061] The process for implementing the small angle reverse bending test of sample 9 in this embodiment is as follows:

[0062] First, Figure 5As shown, a fourth limit block 24 having a length corresponding to the length of the positive bending of the sample 9 of 90° is installed on the seat plate 26 of the slide post 17 (the fourth limit block 24 can be set to be U-shaped, and is inserted into the slide post 17 along the horizontal direction through a groove opened on the vertical plate of the L-shaped cover plate 16. The slide post 17 in this embodiment facilitates the positioning and installation of the fourth limit block 24), and the first limit plate 23 and the second limit plate 27 are respectively plugged and installed at the position of the slot 29 corresponding to the bending of 20° in the direction of the sample 9.

[0063] Then the cylinder piston rod can be started to extend, and the middle of the sample 9 can be pressed down through the upper pressure head body 48 to achieve the following Fig.11 and 16 The positive bending state of 90° as shown in the figure is then controlled to retract the cylinder piston rod, and the middle of the sample 9 is pushed up by the lower pressure head body 49 to achieve the following Fig.12 and 17 The reverse bending state of 20° shown is a complete set of reverse bending tests of 9 specimens at a specific angle.

[0064] The process for implementing the large-angle positive bending test of sample 9 in this embodiment is as follows:

[0065] First, pull up the slide column 17 and fix its position, and make the through hole 45 completely correspond to the second horizontal push rod 18; rotate the round table 21, and position the second horizontal push rod 18 to point to a fifth limit block 30 corresponding to a specific bending angle (180°) through the rotation angle positioning mechanism. Then start the cylinder to press down the middle of the sample 9 through the upper pressure head body 48 until it reaches the position shown in the figure. Fig.18 The experiment is completed when the status shown is shown.

[0066] The switching of the above-mentioned large and small angle bending tests requires the operator to rotate the round table 21 and adjust the lifting and lowering of the slide column 17. In order to further facilitate the operation, the operation of rotating the round table 21 is also linked with the lifting process of the slide column 17 in this embodiment to further improve the test efficiency. Specifically:

[0067] like Figure 5As shown, the slide post 17 in this embodiment is slidably inserted into the insertion hole 31 provided on the base 1, and a compression spring 32 is provided at the bottom of the insertion hole 31. A retractable pin 33 is provided on the base 1 at a position on the left side of the insertion hole 31 and close to the upper edge of the base 1. The pin 33 cooperates with the pin groove 44 provided on the left side of the slide post 17 to maintain the compression state of the compression spring 32, so that the two sides of the fourth limit block 24 correspond to the first flange 22 and the second flange 28 respectively (applicable to small angle bending test). A large and small positive bending angle switching mechanism is also provided between the truncated table 21 and the slide post 17. The large and small positive bending angle switching mechanism is used to pull the pin 33 out of the pin groove 44 when the truncated table 21 is rotated to perform a large angle positive bending test of the sample 9, so that the slide post 17 is raised to the through hole 45 under the action of the compression spring 32 and corresponds to the first flange 22 and the second flange 28 (applicable to large angle bending test).

[0068] The large and small positive bending angle switching mechanism includes an adjustment sleeve 35 that is rotatably arranged in the base 1 and sleeved on the outer periphery of the latch 33, and a driving gear 20 for driving the adjustment sleeve 35 to rotate. The adjustment sleeve 35 is arranged in a strip groove opened in the base 1 near the upper edge position, and the adjustment sleeve 35 can only rotate under the action of external force, and cannot produce axial displacement. The axial bearings that are respectively arranged on both sides of the strip groove and matched with the ends of the adjustment sleeve 35 prevent its rotation. The outer periphery of the adjustment sleeve 35 is sleeved with a driven tooth (not shown in the figure), and the driven tooth is connected by the middle gear 19 that is rotatably arranged in the inner cavity of the first slider 3 and meshes with the driving gear 20, and the lower part of the driven tooth is meshed with the driven tooth through the top notch position of the strip groove. Therefore, the rotation of the round table 21 can drive the adjustment sleeve 35 to rotate through the driving gear 20, the middle gear 19 and the driven tooth. The wheel diameters of the driving gear 20, the intermediate gear 19 and the driven gear are reduced successively, and the number of teeth is reduced successively, so that the effect of driving the adjustment sleeve 35 to rotate multiple circles is achieved when the truncated table 21 is rotated at a small angle. The rack of the driven gear is longer and covers the length direction of the adjustment sleeve 35, so that the intermediate gear 19 can always maintain a meshing state with the driven gear during the sliding process with the first slider 3 to avoid tooth disengagement. The inner circumference of the adjustment sleeve 35 is provided with a radial insertion shaft 43, such as Fig.10 As shown, the radial plug shaft 43 is plugged into the slide groove 34 provided at the outer peripheral position of the latch pin 33, and the slide groove 34 is spirally distributed along the axial direction of the latch pin 33, and the slide groove 34 and the radial plug shaft 43 are smoothly matched, so that the latch pin 33 can be driven to move along its own axial direction by the rotation of the adjustment sleeve 35 through the sliding fit between the radial plug shaft 43 and the slide groove 34, and the moving direction of the latch pin 33 can be controlled by the forward and reverse rotation of the adjustment sleeve 35 to realize the extension or retraction of the latch pin 33.

[0069] Based on the above technical solution, when switching from a small-angle bending test to a large-angle bending test, Figure 5In the state shown, the truncated table 21 is rotated to align the first flange 22 with a fifth stopper 29, and the adjustment sleeve 35 is driven to rotate by the truncated table 21-driving gear 20-intermediate gear 19-driven gear. The latch 33 moves leftward under the rotation of the spiral sleeve, and the slide column 17 rises under the action of the compression spring 32, passing through the top of the fourth stopper 24 and the lower edge of the horizontal plate in the L-shaped cover plate 16 to reach the position shown in FIG. Fig.13 Then the cylinder can drive the bidirectional pressure head to press the sample 9 down to the state shown. Fig.14 The state shown is to complete the large angle bending test.

[0070] In this embodiment, in order to prevent the latch 33 from rotating synchronously with the adjustment sleeve 35, the portion of the latch 33 located in the adjustment sleeve 35 is circular corresponding to the shape of the inner cavity of the adjustment sleeve 35, while the portion of the latch 33 located at the left end of the adjustment sleeve 35 is a non-circular rectangle or other shape. Correspondingly, an anti-rotation hole having a shape corresponding to the left end of the latch 33 is provided at the left end of the strip groove on the base 1. The anti-rotation hole is for the left end of the latch 33 to be inserted and has a certain length to allow the latch 33 to move.

[0071] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0072] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A metal material bending testing machine suitable for bars, characterized by: The invention comprises a base (1), a linear rail (2) arranged on the base (1), and a first slider (3) and a second slider (6) slidably arranged on the linear rail (2); a first chuck (11) is rotatably arranged on the first slider (3), and a second chuck (7) is rotatably arranged on the second slider (6); the first chuck (11) and the second chuck (7) are respectively used to clamp and fix two ends of a sample (9); a bidirectional pressure head is provided on the base (1) at the middle of the first chuck (11) and the second chuck (7); the bidirectional pressure head is used to press down the sample (9) or pull up the middle of the sample (9) under the action of a driving device (8) distributed in a vertical direction to implement a forward or reverse bending test; and during the bending test, the sample (9) can drive the first slider (3) and the second slider (6) to slide synchronously along the linear rail (2) through the first chuck (11) and the second chuck (7); It also includes a bending angle control device, which has a plurality of limiting members, so as to limit the sliding stroke of the first slider (3) and the second slider (6) along the linear track (2) through different limiting members, thereby fixing the bending angle of the sample (9); The bending angle control device also includes a first horizontal push rod (15) fixed at an inner position of the first slider (3), a second horizontal push rod (18) fixed at an inner position of the second slider (6), and a slide column (17) arranged on the base (1) between the first slider (3) and the second slider (6); the inner end of the first horizontal push rod (15) is provided with a first flange (22); the outer end of the first horizontal push rod (15) is eccentrically fixed on a round table (21) rotatably arranged on the first slider (3); the inner end of the second horizontal push rod (18) is provided with a second flange (28); the second horizontal push rod (18) is a hollow rod; and a through hole (45) is provided on the slide column (17); the limiting member includes a fourth limiting block (24), a first limiting plate (23), a second limiting plate (27) and a fifth limiting block (30); the fourth limiting block (24) and the fifth limiting block (30) The number of the fourth limit blocks (24) is multiple, and a sliding hole for mounting with the slide column (17) is opened in the middle of each of the fourth limit blocks (24). A seat plate (26) for supporting the fourth limit block (24) is also provided above the through hole (45) on the slide column (17). The two sides of the fourth limit block (24) are respectively provided for the inner side of the first flange (22) and the inner side of the second flange (28) in the small-angle positive bending test of the sample (9) to limit the cooperation; a plurality of fifth limit blocks (30) are fixedly distributed on the inner wall of the second horizontal push rod (18) in a spiral shape along the axial direction of the second horizontal push rod (18). The inner side of each of the fifth limit blocks (30) is provided for the inner side of the first flange (22) in the large-angle positive bending test of the sample (9) to limit the cooperation, and the first flange (22) can overlap with the plurality of fifth limit blocks (30) one by one in the horizontal direction as the truncated table (21) rotates; The first limiting plate (23) is inserted on the base (1) and is located between the first slider (3) and the slide column (17); the second limiting plate (27) is inserted on the base (1) and is located between the second slider (6) and the slide column (17); a plurality of slots (29) for the first limiting plate (23) and the second limiting plate (27) to be inserted and matched are arranged on the base (1) at intervals; limiting holes (25) are respectively arranged on the first limiting plate (23) and the second limiting plate (27); the limiting holes (25) are only for the corresponding first flange (22) or the second flange (28) to move in the direction toward the slide column (17) The first limit plate (23) and the second limit plate (25) are connected to the first limit plate (23) and the second limit plate (27) respectively, and the first limit plate (23) and the second limit plate (28) are connected to the first limit plate (23) and the second limit plate (27) respectively, so as to prevent the corresponding first flange (22) or second flange (28) from moving in the direction opposite to the sliding column (17) and passing through. The number of the limiting hole (25) on the second limit plate (27) is one, the number of the limiting holes (25) on the first limit plate (23) and the number of the fifth limit blocks (30) are multiple, and the multiple limiting holes (25) on the first limit plate (23) and the multiple fifth limit blocks (30) are overlapped one by one in the horizontal direction; any limiting hole (25) includes a step hole opened on the first limit plate (23) or the second limit plate (27) and a first unidirectional rotation hole arranged in the step hole. The first one-way rotating plate (37) and the second one-way rotating plate (38) have apertures that decrease from the inside to the outside, and the apertures of the small holes in the step holes correspond to the outer diameter profiles of the corresponding first flange (22) or the second flange (28). The first one-way rotating plate (37) and the second one-way rotating plate (38) are spaced apart in the large hole of the step holes and cover a part of the small holes respectively. The gap between the first one-way rotating plate (37) and the second one-way rotating plate (38) corresponds to the outer diameter profiles of the corresponding first horizontal push rod (15) or the second horizontal push rod (18) and is smaller than the first flange (22) or the second flange. The outer diameter profile of the edge (28) is formed by the first one-way rotating plate (37) and the second one-way rotating plate (38), and the ends of the first one-way rotating plate (37) and the second one-way rotating plate (38) that are away from each other are respectively hinged at the outer edge position of the large hole of the step hole. A torsion spring (36) is also provided at the hinge between the first one-way rotating plate (37) and the second one-way rotating plate (38) and the large hole to maintain the first one-way rotating plate (37) and the second one-way rotating plate (38) in a closed state through the torsion spring (36). The inner sides of the first one-way rotating plate (37) and the second one-way rotating plate (38) are used for the corresponding outer side of the first flange (22) or the second flange (28) to limit the cooperation.

2. A metal material bending testing machine suitable for bars according to claim 1, characterized in that: The limiting member comprises a first limiting block (5), a second limiting block (12) and a third limiting block (13); the bottoms of the first limiting block (5), the second limiting block (12) and the third limiting block (13) are all provided with a pin shaft (14); a plurality of pin holes (4) for the pin shaft (14) to be mounted in cooperation are provided on the base (1) along the length direction of the linear rail (2); the pin shaft (14) on the first limiting block (5) is mounted in cooperation with the pin hole (4) located between the first slider (3) and the second slider (6); The two sides of the positioning block (5) are respectively provided for the inner side of the first slider (3) and the inner side of the second slider (6) to limit the fit, the pin shaft (14) on the second positioning block (12) is installed in the pin hole (4) on the outer side of the first slider (3), the inner side of the second positioning block (12) is provided for the outer side of the first slider (3) to limit the fit, the pin shaft (14) on the third positioning block (13) is installed in the pin hole (4) on the outer side of the second slider (6), the inner side of the third positioning block (13) is provided for the outer side of the second slider (6) to limit the fit.

3. A metal material bending testing machine suitable for bars according to claim 2, characterized in that: The pin shaft (14) and the pin hole (4) are in the shape of corresponding rectangles.

4. The metal material bending testing machine suitable for bars according to claim 1, characterized in that: The slide column (17) is slidably inserted into a socket (31) provided on the base (1), a compression spring (32) is provided at the bottom of the socket (31), and a retractable pin (33) is provided on the side of the socket (31). The pin (33) cooperates with a pin groove (44) provided on the slide column (17) to maintain the compression state of the compression spring (32) and to make the two sides of the fourth limit block (24) correspond to the first flange (22) and the second flange (28) respectively. A large and small positive bending angle switching mechanism is also provided between the truncated table (21) and the slide column (17). The large and small positive bending angle switching mechanism is used to remove the pin (33) from the pin groove (44) when the truncated table (21) is rotated to perform a large-angle positive bending test on the sample (9), so that the slide column (17) is lifted up to the through hole (45) corresponding to the first flange (22) and the second flange (28) under the action of the compression spring (32); The large and small positive bending angle switching mechanism comprises an adjusting sleeve (35) rotatably arranged in a base (1) and sleeved on the outer periphery of a latch pin (33) and a driving gear (20) for driving the adjusting sleeve (35) to rotate; the outer periphery of the adjusting sleeve (35) is sleeved with driven teeth, the inner periphery is provided with a radial insertion shaft (43), and the radial insertion shaft (43) is inserted and matched in a slide groove (34) provided at the outer periphery of the latch pin (33), and the slide groove (34) is distributed in a spiral shape along the axial direction of the latch pin (33), so that the latch pin (33) is driven to extend or retract by the positive and negative rotation of the adjusting sleeve (35); the driving gear (20) is sleeved on the truncated table (21) at an end position in the inner cavity of the first slider (3) and is transmission-connected with the driven gear, the number of teeth of the driving gear (20) is greater than that of the driven gear, and the rack width of the driven gear is greater than that of the driving gear (20).

5. The metal material bending testing machine suitable for bars according to claim 4, characterized in that: The driving gear (20) and the driven gear are meshed through a plurality of intermediate gears (19), and the number of teeth of the plurality of intermediate gears (19) decreases in sequence from the driving gear (20) to the driven gear.

6. The metal material bending testing machine suitable for bars according to claim 1, characterized in that: The truncated table (21) is rotatably arranged in a circular hole formed on the first sliding block (3); a rotation angle positioning mechanism is arranged between the circular hole and the truncated table (21); the rotation angle positioning mechanism comprises a radial hole (40) formed at an outer peripheral position of the truncated table (21); a positioning shaft (42) slidably mounted in the radial hole (40); a positioning spring (41) for pushing the positioning shaft (42) out of the radial hole (40); and a positioning groove (39) arranged on the inner wall of the circular hole and for the positioning shaft (42) to be plugged in and fitted into. The positioning groove (39) is semicircular and has a plurality of them. The plurality of positioning grooves (39) are distributed along the circumference of the circular hole.

7. The metal material bending testing machine suitable for bars according to claim 1, characterized in that: The driving device (8) is a cylinder, and two chambers located on both sides of the piston plate in the cylinder body of the cylinder are respectively connected to safety valves (46).

8. The metal material bending testing machine suitable for bars according to claim 1, characterized in that: The bidirectional pressure head comprises an upper pressure head body (47) and a lower pressure head body (48) fixed on the output end of the driving device (8); the upper pressure head body (47) and the lower pressure head body (48) are both arc-shaped and spaced apart in the vertical direction.

9. The metal material bending testing machine suitable for bars according to claim 1, characterized in that: Two parallel linear rails (2) are provided on a base (1), a first slider (3) and a second slider (6) are slidably provided on any linear rail (2), two sides of a first chuck (11) are rotatably provided on opposite sides of the two first sliders (3), and two sides of a second chuck (7) are rotatably provided on opposite sides of the two second sliders (6).

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