A stress relaxation testing machine

Abstract

The utility model provides a stress relaxation testing machine, including bearing frame, bearing frame includes main girder, be provided with driving element, transmission wheel group and ball screw on main girder, driving element passes transmission wheel group transmission connection ball screw, transmission wheel group includes slewing bearing, the inner ring of slewing bearing is installed in main girder, the outer ring of slewing bearing is connected with ball screw, the one side of ball screw length direction is fixed with anti -rotation guide plate, install a plurality of calibration bearing cross -beam along the ball screw length direction on main girder. This stress relaxation testing machine, this stress relaxation testing machine adopts slewing bearing to transmit the driving force on ball screw, can realize transmission ball screw's big torque, can also bear bigger test compression force, and compared with bearing sleeve structure, slewing bearing and ball screw are more compact.

Description

Technical Field

[0001] This utility model relates to the field of stress relaxation testing technology, and in particular to a stress relaxation testing machine that can provide 28.6 low-relaxation prestressed steel strands that meet the standard of "GB / T 5224-2023 Steel Strands for Prestressed Concrete". Background Technology

[0002] Existing relaxation testing machines are generally available in models with a capacity of 500kN or less, suitable for steel strand samples with a nominal diameter of 17.8 or less. The research and application of 28.6 low-relaxation prestressed steel strands are gradually expanding. In order to meet the requirements of relevant industry users for the test force value of relaxation testing machines, it is also urgent to test the mechanical properties of such large-diameter steel strands.

[0003] However, the existing 500kN microcomputer-controlled tensile stress relaxation testing machine has the following drawbacks:

[0004] The loading system of the stress relaxation testing machine adopts a bearing sleeve structure, which is large in size and difficult to withstand large test compressive forces.

[0005] The selected spring guide rod type achieves hard limit on the ball screw through the limit block. Since the limit block can be adjusted arbitrarily on the guide rod, if the operation is not standardized, it is easy to cause the limit position to be set incorrectly, resulting in the ball screw running over the travel, which in turn leads to the damage of the ball screw.

[0006] The guide key anti-rotation design of ball screws is prone to key wear, which increases the cost of use.

[0007] Therefore, in order to solve the above problems, this utility model proposes a stress relaxation testing machine that can withstand large test compression force, avoids damage to the ball screw caused by a single hard limit, and avoids key wear that is prone to occur in the guide key anti-rotation form. Utility Model Content

[0008] To address the problems existing in the prior art, this utility model provides a stress relaxation testing machine.

[0009] According to one objective of this utility model, this utility model provides a stress relaxation testing machine, including a load-bearing frame, wherein the load-bearing frame includes a main beam;

[0010] The main beam is equipped with a driving component, a transmission wheel set and a ball screw. The driving component is connected to the ball screw through the transmission wheel set. The transmission wheel set includes a slewing bearing. The inner ring of the slewing bearing is installed on the main beam and the outer ring of the slewing bearing is connected to the ball screw.

[0011] An anti-rotation guide plate is fixed on one side of the ball screw along its length. Several calibration load-bearing crossbars are installed on the main beam along the length of the ball screw. The calibration load-bearing crossbars are spaced apart in the circumferential direction of the ball screw. The anti-rotation guide plate is slidably connected to the calibration load-bearing crossbars along the length of the ball screw.

[0012] A proximity switch is provided on the other side of the ball screw along its length. The proximity switch is electrically connected to the drive unit and is configured to provide a limit on the stroke of the ball screw.

[0013] Preferably, the transmission wheel set includes:

[0014] A speed reducer, a drive wheel, and a transition gear are mounted on the main beam. The servo motor drives and connects to the speed reducer. The speed reducer is connected to the drive wheel via a key. The drive wheel, the transition gear, and the tooth surfaces on the outer ring of the slewing bearing are sequentially connected in a transmission manner.

[0015] The drive wheel is mounted on the main beam via a support frame, and a pair of first deep groove ball bearings are supported and connected between the drive wheel and the support frame, and between the drive wheel and the main beam.

[0016] Preferably, the transition gear is installed in the centering pin hole on the main beam. The number of teeth of the transition gear is the same as the number of teeth of the driving gear. The shaft of the transition gear and the gear are supported and connected by a pair of second deep groove ball bearings.

[0017] Preferably, the inner ring of the slewing bearing is fixed to the main beam, the tooth surface on the outer ring of the slewing bearing meshes with the transition gear, and a liner is provided between the outer ring of the slewing bearing and the ball screw.

[0018] Preferably, the liner is connected to the ball screw by screws, and the ball screw is provided with a nut sleeve that matches the screws.

[0019] Preferably, a sensor seat is connected to the first end of the ball screw along its length, a spoke-type sensor is mounted on the sensor seat, and the anti-rotation guide plate is disposed between the ball screw and the spoke-type sensor.

[0020] Preferably, a limit plate is provided at the second end of the ball screw along its length, and the limit plate is matched with the proximity switch.

[0021] Preferably, the load-bearing frame further includes a fixed end beam, and the fixed end beam and the main beam are arranged at intervals along the length of the ball screw;

[0022] A lower crossbar group and an upper crossbar group are provided between the fixed end beam and the main beam. The lower crossbar group and the upper crossbar group are arranged alternately from bottom to top. The lower crossbar group and the upper crossbar group are both supported and connected between the fixed end beam and the main beam along the length direction of the ball screw.

[0023] Both the lower horizontal bar group and the upper horizontal bar group include two horizontal bars. The ends of the horizontal bars in the upper horizontal bar group are respectively connected to a calibration load-bearing horizontal bar. The calibration load-bearing horizontal bar and the horizontal bars in the upper horizontal bar group are coaxially arranged.

[0024] Preferably, the load-bearing frame further includes an intermediate support beam. In the length direction of the ball screw, the intermediate support beam is spaced between the fixed end beam and the main beam, and the intermediate support beam supports and connects the lower crossbar group and the upper crossbar group.

[0025] A worktable is installed at the bottom of the load-bearing frame along the length of the ball screw, and the proximity switch is installed on the worktable.

[0026] Preferably, the stress relaxation testing machine further includes: a calibration beam, which is supported and connected between the calibration load-bearing crossbars.

[0027] Compared with the prior art, the beneficial effects of this utility model are:

[0028] This stress relaxation testing machine uses a slewing bearing to transmit the driving force on the ball screw, which can transmit the large torque of the ball screw and withstand a large test compression force. At the same time, the slewing bearing and ball screw are more compact than the bearing sleeve structure.

[0029] A proximity switch is installed to limit the travel of the ball screw, making the limiting of the ball screw more reliable and avoiding damage to the ball screw caused by manual assembly errors during the process of using a single hard limit block.

[0030] By connecting the ball screw to the anti-rotation guide plate, the ball screw can slide on the calibrated load-bearing crossbar through the anti-rotation guide plate, making the anti-rotation effect more reliable and avoiding the key wear that is prone to occur with the guide key anti-rotation method.

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the loading system in the stress relaxation testing machine described in this utility model;

[0033] Figure 2 This is a schematic diagram of the load-bearing system in the stress relaxation testing machine described in this utility model;

[0034] Figure 3 This is a schematic diagram of the calibration system in the stress relaxation testing machine described in this utility model. Detailed Implementation

[0035] The following description is intended to provide a detailed account of the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0036] Please see Figure 1-2 This utility model provides a technical solution: a stress relaxation testing machine, comprising: a load-bearing frame, wherein the load-bearing frame includes a main beam 2;

[0037] The main beam 2 is provided with a driving component, a transmission wheel set and a ball screw 10. The driving component is connected to the ball screw 10 through the transmission wheel set. The transmission wheel set includes a slewing bearing 8. The inner ring of the slewing bearing 8 is installed on the main beam 2 and the outer ring of the slewing bearing 8 is connected to the ball screw 10.

[0038] An anti-rotation guide plate 14 is fixed on one side of the ball screw 10 along its length. Several calibration load-bearing crossbars 15 are installed on the main beam 2 along the length of the ball screw 10. The calibration load-bearing crossbars 15 are arranged at intervals in the circumferential direction of the ball screw 10. The anti-rotation guide plate 14 is slidably connected to the calibration load-bearing crossbars 15 along the length of the ball screw 10.

[0039] A proximity switch 17 is provided on the other side of the ball screw 10 along its length. The proximity switch 17 is electrically connected to the drive unit and is configured to provide a limit on the stroke of the ball screw 10.

[0040] The stress relaxation testing machine uses a slewing bearing 8 to transmit the driving force on the ball screw 10, which can transmit the large torque of the ball screw 10 and withstand the large test compression force. At the same time, the slewing bearing 8 and the ball screw 10 are more compact than the bearing sleeve structure.

[0041] A proximity switch 17 is provided to limit the travel of the ball screw 10, making the limiting of the ball screw 10 more reliable and avoiding damage to the ball screw 10 caused by manual assembly errors during the process of single hard limiting through the limiting block.

[0042] By connecting the ball screw 10 to the anti-rotation guide plate 14, the ball screw 10 can slide on the calibrated load-bearing crossbar 15 through the anti-rotation guide plate 14, making the anti-rotation effect more reliable and avoiding the key wear that is prone to occur in the guide key anti-rotation form.

[0043] In this embodiment, the stress relaxation testing machine as a whole includes: a loading system, a load-bearing system, and a calibration system;

[0044] like Figure 1 As shown, the loading system includes a main beam 2 of the load-bearing frame, a support frame 4, a first deep groove ball bearing 5, a transmission wheel set, a second deep groove ball bearing 7, a slewing bearing 8, a liner 9, a ball screw 10, a nut sleeve 11, a sensor seat 12, a 1000kN spoke-type sensor 13, an anti-rotation guide plate 14, a calibration load-bearing crossbar 15, a limit plate 16, and a proximity switch 17. The transmission wheel set includes a reducer set 1, a drive wheel 3, and a transition gear 6.

[0045] The speed reducer 1 is installed on the main beam 2 of the load-bearing frame and is connected to the drive wheel 3 by a key. The drive wheel 3 is fixed on the main beam 2 of the load-bearing frame by a support frame 4. Since the span between the output shaft of the speed reducer 1 and the drive wheel 3 is too long, a pair of first deep groove ball bearings 5 ​​are configured on the support frame 4 and the main beam 2 of the load-bearing frame to support the shaft assembly.

[0046] The transition gear 6 is also mounted on the main beam 2 of the load-bearing frame. The main beam 2 has a centering pin hole. The number of teeth of the transition gear 6 is the same as that of the drive gear 3. The shaft and gear of the transition gear 6 are both supported by a pair of second deep groove ball bearings 7. The number of teeth of the transition gear 6 is much smaller than the number of teeth on the tooth surface of the outer ring of the slewing bearing.

[0047] The inner ring of the slewing bearing 8 is fixed to the main beam 2 of the load-bearing frame by 10 M16 hex socket screws. Its toothed outer ring meshes with the transition gear 6. The outer ring is fixed to the liner plate 9 by 10 M16 hex socket screws. The liner plate 9 is connected to the ball screw 10 by 8 M20 hex socket screws. Since the liner plate 9 only has a partial mating length with the nut of the ball screw 10, a nut sleeve 11 is configured to optimize the force distribution. Its inner hole matches the outer diameter of the nut and is fixed to the liner plate 9 by screws.

[0048] The left end of the ball screw 10 is fixed to the sensor base 12 by four M12 hex socket screws, and the 1000kN spoke-type sensor 13 is fixed to the sensor base 12 by eight M20 hex socket screws.

[0049] An anti-rotation guide plate 14 is provided between the ball screw 10 and the 1000kN spoke-type sensor 13, which cooperates with two calibrated load-bearing crossbars 15. A limit plate 16 is provided at the right end of the ball screw 10, which is used in conjunction with the proximity switch 17 as a hard limit for the screw travel.

[0050] See Figure 1 and 2 The load-bearing system includes a lower crossbar assembly 18, an upper crossbar assembly 19, a calibrated load-bearing crossbar 15, an intermediate support beam 20, a fixed end beam 21, and a workbench 22.

[0051] The fixed end beam 21 and the main beam 2 are arranged at intervals along the length of the ball screw 10. A lower crossbar group 18 and an upper crossbar group 19 are provided between the fixed end beam 21 and the main beam 2. The lower crossbar group 18 and the upper crossbar group 19 are arranged at intervals from bottom to top. The lower crossbar group 18 and the upper crossbar group 19 are both supported and connected between the fixed end beam 21 and the main beam 2 along the length of the ball screw 10.

[0052] Both the lower horizontal bar group 18 and the upper horizontal bar group 19 include two horizontal bars. The ends of the horizontal bars in the upper horizontal bar group 19 are connected to a calibration load-bearing horizontal bar 15. The calibration load-bearing horizontal bar 15 and the horizontal bars in the upper horizontal bar group 19 are coaxially arranged.

[0053] Specifically, the crossbars in the lower crossbar group 18 are fastened to the main beam 2 with two hexagonal screws, and the two crossbars in the lower crossbar group 18 are diagonally distributed.

[0054] The two horizontal bars in the upper horizontal bar group 19 have screw holes at their ends connected to the screws of the two calibration load-bearing horizontal bars 154, thus realizing the series connection of the load-bearing system and the calibration system.

[0055] Since the load-bearing frame has a certain length, in order to ensure the stability of the load-bearing frame under long-term stress, an intermediate support beam 20 is set in the middle section of the main beam 2 and the fixed end beam 21. The right ends of the four crossbars are fastened to the fixed end beam 21 with hexagonal screws. The bottom of the intermediate support beam 20 and the fixed end beam 21 are fastened to the workbench 22 with hexagonal screws. The workbench 22 is provided with two fixing holes at the front and rear for mounting the proximity switch 17. The proximity switch 17, which serves as the travel limit of the ball screw 10, is installed on the workbench 22.

[0056] See Figure 3 The calibration system includes a calibration beam 23 and a calibration nut 24. The calibration system can directly calibrate the sensor on the equipment. While calibrating the sensor, it also reflects the force accuracy of the whole machine, improving the accuracy of the calibration data. The two calibration load-bearing crossbars 15 are passed through the two holes set on the calibration beam 23 and tightened with the calibration nut 24 to complete the assembly.

[0057] The embodiments described above are only used to illustrate the technical ideas and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. The scope of patent application of this utility model should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in this utility model still fall within the patent scope of this utility model.

Claims

1. A stress relaxation testing machine, characterized in that, Includes a load-bearing frame, wherein the load-bearing frame includes a main beam (2); The main beam (2) is provided with a driving component, a transmission wheel set and a ball screw (10). The driving component is connected to the ball screw (10) through the transmission wheel set. The transmission wheel set includes a slewing bearing (8). The inner ring of the slewing bearing (8) is installed on the main beam (2), and the outer ring of the slewing bearing (8) is connected to the ball screw (10). An anti-rotation guide plate (14) is fixed on one side of the ball screw (10) along its length. Several calibration load-bearing crossbars (15) are installed on the main beam (2) along the length of the ball screw (10). The calibration load-bearing crossbars (15) are arranged at intervals in the circumferential direction of the ball screw (10). The anti-rotation guide plate (14) is slidably connected to the calibration load-bearing crossbars (15) along the length of the ball screw (10). A proximity switch (17) is provided on the other side of the ball screw (10) along its length. The proximity switch (17) is electrically connected to the drive unit. The proximity switch (17) is configured to provide a limit for the stroke of the ball screw (10).

2. The stress relaxation testing machine according to claim 1, characterized in that, The transmission wheel set includes: A reducer unit (1), a drive wheel (3), and a transition gear (6) are installed on the main beam (2). A servo motor drives and connects the reducer unit (1). The reducer unit (1) is connected to the drive wheel (3) via a key. The drive wheel (3), the transition gear (6), and the tooth surfaces on the outer ring of the slewing bearing are sequentially connected for transmission. The drive wheel (3) is mounted on the main beam (2) via a support frame (4). A pair of first deep groove ball bearings (5) are supported and connected between the drive wheel (3) and the support frame (4), and between the drive wheel (3) and the main beam (2).

3. A stress relaxation testing machine according to claim 2, characterized in that, The transition gear (6) is installed on the main beam (2) with a centering pin hole. The number of teeth of the transition gear (6) is the same as the number of teeth of the driving wheel (3). The shaft of the transition gear (6) and the gear are supported and connected by a pair of second deep groove ball bearings (7).

4. A stress relaxation testing machine according to claim 2, characterized in that, The inner ring of the slewing bearing (8) is fixed to the main beam (2), the tooth surface on the outer ring of the slewing bearing (8) meshes with the transition gear (6), and a liner (9) is provided between the outer ring of the slewing bearing (8) and the ball screw (10).

5. A stress relaxation testing machine according to claim 4, characterized in that, The liner (9) is connected to the ball screw (10) by screws, and the ball screw (10) is provided with a nut sleeve (11) that matches the screw.

6. A stress relaxation testing machine according to claim 1, characterized in that, The first end of the ball screw (10) along its length is connected to a sensor seat (12), and a spoke-type sensor (13) is installed on the sensor seat (12). The anti-rotation guide plate (14) is disposed between the ball screw (10) and the spoke-type sensor (13).

7. A stress relaxation testing machine according to claim 1, characterized in that, The second end of the ball screw (10) in the length direction is provided with a limiting plate (16), and the limiting plate (16) is matched with the proximity switch (17).

8. A stress relaxation testing machine according to claim 1, characterized in that, The load-bearing frame also includes a fixed end beam (21), and the fixed end beam (21) and the main beam (2) are arranged at intervals along the length of the ball screw (10); A lower crossbar group (18) and an upper crossbar group (19) are provided between the fixed end beam (21) and the main beam (2). The lower crossbar group (18) and the upper crossbar group (19) are arranged alternately from bottom to top. The lower crossbar group (18) and the upper crossbar group (19) are both supported and connected between the fixed end beam (21) and the main beam (2) along the length direction of the ball screw (10). Both the lower horizontal bar group (18) and the upper horizontal bar group (19) include two horizontal bars. The ends of the horizontal bars in the upper horizontal bar group (19) are respectively connected to a calibration load-bearing horizontal bar (15). The calibration load-bearing horizontal bar (15) and the horizontal bars in the upper horizontal bar group (19) are coaxially arranged.

9. A stress relaxation testing machine according to claim 8, characterized in that, The load-bearing frame also includes an intermediate support beam (20). In the length direction of the ball screw (10), the intermediate support beam (20) is spaced between the fixed end beam (21) and the main beam (2). The intermediate support beam (20) supports and connects the lower crossbar group (18) and the upper crossbar group (19). The bottom of the load-bearing frame is equipped with a worktable (22) arranged along the length of the ball screw (10), and the proximity switch (17) is installed on the worktable (22).

10. A stress relaxation testing machine according to claim 1, characterized in that, Also includes: A calibration beam (23) is supported and connected between the calibration load-bearing crossbars (15).

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