Manufacturing and installation method of mobile crossbeam and strength support device for universal testing machine

Abstract

The utility model discloses a mobile crossbeam for universal testing machine belongs to universal testing machine technical field, mobile crossbeam section is square, hollow inside, and the middle part of mobile crossbeam is equipped with the through -hole for the installation of clamp, and the inside of mobile crossbeam is equipped with two strength support device symmetrical in the through -hole left and right sides, and strength support device includes the resin concrete column of supporting the inside surface of mobile crossbeam up and down and is located in the resin concrete column several longitudinal distribution's prestressed steel, and the both ends of prestressed steel are curved to the outside of mobile crossbeam, and resin concrete column is with mobile crossbeam interference fit. In addition, the utility model still provides the manufacturing and installation method of above -mentioned strength support device. The utility model improves mobile crossbeam rigidity through the structure improvement, avoids the micro deformation of mobile crossbeam in the test process because of the clamp pressure through the inside strength support device, improves mobile crossbeam service life and test accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of universal testing machine, in particular to a mobile beam with high rigidity for a universal testing machine and a manufacturing method thereof. BACKGROUND

[0002] The universal testing machine is mainly composed of a driving system, a control system and a measuring system. After the driving system is connected to the power supply, the microcomputer sends a mobile beam moving instruction according to the preset value before the test. The instruction controls the rotation of the servo motor inside the main machine through the servo control system, drives the left and right lead screws to rotate through the belt and gear deceleration mechanism, and drives the mobile beam to rise or fall through the nut inside the mobile beam and the tooth. With the rising or falling of the mobile beam, the clamp is moved to realize the tensile or bending test of the test piece. During the overall movement of the mobile beam, with the application of the test force, the installation structure of the clamp always exerts pressure on the mobile beam during the test. Long-term load test can cause the mobile beam to produce micro-deformation in the middle compression area. Although the deformation is very small, it still has an impact on the precise test, resulting in inaccurate test results. SUMMARY

[0003] In order to overcome the above-mentioned defects of the prior art, the present application aims to provide a mobile beam for a universal testing machine, which has high rigidity and can effectively prevent the deformation of the compression area of the mobile beam.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0005] The mobile beam for the universal testing machine has a square cross section and is hollow inside. A through hole is arranged in the middle of the mobile beam for mounting the clamp. Two strength support devices are symmetrically arranged on the left and right sides of the through hole inside the mobile beam. The strength support device comprises a resin concrete column supporting the inner side surface of the mobile beam and a plurality of longitudinal prestressed steel bars arranged in the resin concrete column. The two ends of the prestressed steel bars are bent outwardly from the mobile beam. The resin concrete column is in interference fit with the mobile beam.

[0006] Preferably, the opposite surfaces of the two strength support devices are attached to each other to form the peripheral structure of the through hole.

[0007] Preferably, a top plate is arranged on the upper part of the resin concrete column. The top plate is made of a shape memory alloy material and has a height higher than that of the resin concrete column. A thermal insulation layer is arranged between the top plate and the resin concrete column.

[0008] Preferably, the top plate has the same shape as the surface of the resin concrete column and has an area smaller than that of the resin concrete column.

[0009] In addition, the present application also provides a manufacturing and installation method of the strength support device in the above-mentioned mobile beam for the universal testing machine, which comprises the following steps:

[0010] S1. Strength support device manufacturing:

[0011] S1.1. Mould preparation: install resin concrete column bottom film, clean the table top, and brush isolating agent;

[0012] S1.2. Pre-stressed steel bar manufacturing: install steel bar framework, pre-stressed steel bar is first tensioned and then bent;

[0013] S1.3. Install resin concrete column side mould;

[0014] S1.4. First time pouring resin concrete, pour to the lower surface of the thermal insulation layer, maintain and take the same condition maintenance test block;

[0015] S1.5. When the same condition maintenance test block strength reaches 65% of the standard maintenance strength, release the thermal insulation layer and the top plate, second time pour resin concrete, and maintain;

[0016] S1.6. Remove the mould;

[0017] S1.7. Release tension, cut the steel bar, and surface maintenance treatment;

[0018] S2. Strength support device installation: heat the top plate to make its temperature rise to the high temperature phase change temperature, at the high temperature phase change temperature, the height of the top plate is reduced; drive the strength support device from the both sides to the middle of the moving cross beam respectively, adjust the position by observing from the middle through hole, until they are symmetrically and closely attached to each other; naturally or artificially cool the top plate, when the temperature drops back to the low temperature phase change area, the height of the top plate restores to the initial height, and tightly presses the inner side surface of the moving cross beam.

[0019] In the step S3, the heating mode of the top plate adopts electromagnetic heating.

[0020] In the step S3, the strength support device moving to the middle of the moving cross beam adopts air pressure driving mode.

[0021] In the step S3, the bottom plate inner side surface of the moving cross beam is provided with a limiting plate at the through hole, and the resin concrete column is provided with a positioning groove matched with the shape of the limiting plate.

[0022] The present application greatly improves the rigidity of the middle part of the moving cross beam by the self structure design of the moving cross beam and the design of the strength support device, effectively avoids the micro deformation caused by long-term bearing load, and improves the accuracy of the test result and the service life of the moving cross beam. The specific performance is as follows: first, the square cross section and the internal hollow structure of the moving cross beam. The square cross section provides sufficient stress surface for the upper and lower load, so that the stress is uniform. According to the hollow section criterion of mechanical design: under the condition of the same material cross section area, the hollow structure has better strength and rigidity. In the case of the same material consumption, the square cross section and the internal hollow structure can improve the maximum rigidity with the minimum increment of the overall cross section area. Second, the strength support device adopts resin concrete column and longitudinal prestressed steel bar distributed in the resin concrete column. The prestressed steel bar is processed by the pretension method or the post-tension method (the present application adopts the pretension method) and is poured in the resin concrete column. Since the two ends of the prestressed steel bar are bent to the outside of the moving cross beam, under the condition of the recovered prestress, the internal stress of the resin concrete column is respectively to the outside (the upper side and the lower side) of the moving cross beam. Since the resin concrete column is interference fit with the moving cross beam, when the moving cross beam is compressed on the top surface or the ground and is about to be deformed, the internal stress of the resin concrete column offsets the external pressure to prevent deformation (in the case of the existence of the top plate, the deformation is transmitted by the top plate).

[0023] In addition, the present application has the following advantages compared with the prior art:

[0024] 1. Since the compression area of the moving cross beam is very small compared with the overall area, the hollow area of the moving cross beam is also small, and the resin concrete does not use cement at all, so the resin concrete column in the present application will not be as heavy as the concrete as imagined, and will not burden the moving cross beam. The main role in the present application is to fix the position of the prestressed steel bar and the force transmission effect.

[0025] 2. The installation of the strength support device is made easier by the top plate of the shape memory alloy. Since the length of the moving cross beam is longer than that of the resin concrete column, the resin concrete column is interference fit with the moving cross beam, and it is easy to cause scratches inside the moving cross beam when directly pushed from both sides. The moving cross beam is a force transmission piece, and when the shape or weight of both sides is not the same, it will directly affect the test result. The present application uses the memory characteristics of the shape memory alloy, adopts the shape contraction at high temperature and the shape recovery at low temperature, installs to the appropriate position when contracting, and naturally tightens to achieve interference fit when recovering. The heating mode of the top plate adopts electromagnetic heating, so that it can quickly deform in the high temperature phase, and the air pressure drives the installation of the moving cross beam to improve the safety of the installation of the moving cross beam and avoid the contact between the installer and the high temperature top plate.

[0026] 3. The top plate and the concrete column are integrated by the pouring process, which can greatly improve the integrity and structural strength compared with other processes (laser welding, bonding, etc.). BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Figure 3 is a schematic view of the middle structure of the moving cross beam;

[0028] Figure 2 Figure 4 is an enlarged view of the resin concrete column;

[0029] Figure 3 Figure 5 is a schematic view of the three-dimensional structure of the outer shape of the moving cross beam;

[0030] Figure 4 Figure 6 is a schematic view of the three-dimensional structure of the resin concrete column;

[0031] Figure 5 Figure 7 is a side view of the outer shell of the moving cross beam;

[0032] Figure 6 Figure 8 is a schematic view of the overall structure of the universal testing machine.

[0033] In the figure: 10, moving cross beam; 11, through hole; 12, limiting plate; 20, resin concrete column; 21, prestressed steel bar; 22, top plate; 23, temperature insulation layer; 24, positioning groove. DETAILED DESCRIPTION

[0034] The specific structure and principle of the moving cross beam provided by the present application will be fully described in combination with specific embodiments, so that those skilled in the art can fully understand and implement it.

[0035] As shown in Figures 1-6 , the moving cross beam of the universal testing machine, the moving cross beam 10 is square in cross section and hollow inside, and the moving cross beam 10 is provided with a through hole 11 for installing a clamp in the middle; two strength support devices are symmetrically arranged on the left and right sides of the through hole 11 inside the moving cross beam 10, and the opposite faces of the two strength support devices are in close contact to form the peripheral structure of the through hole 11; the strength support device includes a resin concrete column 20 supporting the inner side faces of the moving cross beam 10 upward and downward, and a plurality of prestressed steel bars 21 longitudinally distributed inside the resin concrete column 20; the two ends of the prestressed steel bars 21 are bent outward of the moving cross beam 10; the resin concrete column 20 is in interference fit with the moving cross beam 10.

[0036] Further provided: the resin concrete column 20 is provided with a top plate 22, the top plate 22 is made of shape memory alloy material; the height of the top plate 22 is higher than that of the resin concrete column 20 (the height of the top surface is not the net height), the top plate 22 is consistent with the surface shape of the resin concrete column 20, and the area is smaller than that of the resin concrete column 20; the top plate 22 is in interference fit with the moving cross beam 10 through the top plate 22 on the upper side of the resin concrete column 20, and a temperature insulation layer 23 is arranged between the top plate 22 and the resin concrete column 20.

[0037] The embodiment improves the structure of the moving beam 10 to greatly improve the rigidity of the moving beam 10, and avoids micro deformation of the upper and lower outer surfaces of the moving beam 10 under compression (tension / bending test) through the strength support device, so that the test result is more accurate, and the service life of the moving beam 10 is improved.

[0038] As shown in Figure 2 When the upper surface of the moving beam 10 is about to be micro-deformed under compression, the tensile stress in the prestressed steel bar 21 (after being tensioned) and the bending elastic force promote the outer elastic force of the two ends of the prestressed steel bar 21, and a compressive stress A is generated in the resin concrete column 20. The branch B of the compressive stress A upwardly transmits the moving beam 10 through the top plate 22 to offset the external pressure received by the moving beam 10.

[0039] The manufacturing and installation method of the strength support device in the moving beam of the universal testing machine comprises the following steps:

[0040] S1. Strength support device manufacturing:

[0041] S1.1. Mould preparation: install the bottom film of the resin concrete column 20, clean the table top, and brush the release agent;

[0042] S1.2. Manufacturing of the prestressed steel bar 21: install the steel reinforcement cage, and first tension and then bend the prestressed steel bar 21;

[0043] S1.3. Install the side mould of the resin concrete column 20;

[0044] S1.4. First pouring of resin concrete, pouring to the lower surface of the thermal insulation layer 23, curing and taking the same condition curing test block;

[0045] S1.5. When the strength of the same condition curing test block reaches 65% of the standard curing strength, release the thermal insulation layer 23 and the top plate 22, and secondly pour the resin concrete, and cure;

[0046] S1.6. Remove the mould;

[0047] S1.7. Release tension, cut the reinforcement, and perform surface curing treatment;

[0048] S2. Strength support device installation: heat the top plate 22 to increase the temperature to the high-temperature phase change temperature, and the height of the top plate 22 is reduced at the high-temperature phase change temperature; drive the strength support device from both sides to the middle of the moving beam 10, respectively, and observe and adjust the position through the middle through hole 11 until they are symmetrically fitted; naturally or artificially cool the top plate 22, and when the temperature decreases to the low-temperature phase change zone, the height of the top plate 22 restores to the initial height, and tightly presses the inner surface of the moving beam 10.

[0049] Further arrangement: the heating mode of the top plate 22 in step S3 adopts electromagnetic heating. Electromagnetic heating can make the shape memory alloy quickly heat to the high temperature phase change point, and accurately grasp the heating and heating position.

[0050] Further arrangement: the strength support device moves to the middle part of the moving cross beam 10 in step S3 adopts a gas pressure driving mode. The gas pressure driving mode pushes the strength support device to move by applying gas pressure on both sides of the moving cross beam 10, avoids the installer from contacting the high-temperature shape memory alloy, and improves safety.

[0051] Further arrangement: the inner side surface of the bottom plate of the moving cross beam 10 is provided with a limiting plate 12 at the through hole 11, and the resin concrete column 20 is provided with a positioning groove 24 matched with the shape thereof. The limiting plate 12 and the positioning groove 24 make the installation more quick and convenient, without the need to check from the outside of the through hole 11, and only need to push the strength support device to the limiting plate 12 to complete the installation.

[0052] After the above-mentioned strength support device is installed, the both ends of the moving cross beam 10 are sealed with a sealing plate, and the sealing plate is welded with the moving cross beam 10 in an integrated manner by laser welding.

[0053] The present application improves the rigidity by changing the structure of the moving cross beam 10, and avoids the possible micro-deformation of the moving cross beam 10 during use by the internal strength support device, thereby improving the service life of the moving cross beam 10 and the accuracy of the test results.

[0054] The above-mentioned embodiments are only preferred embodiments of the present application, and do not limit the present application in any form. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application by using the above-mentioned disclosed methods, or modify equivalent embodiments with equivalent changes. Therefore, any combination, modification or replacement of the disclosed technical features of the present application according to the technical essence of the present application shall belong to the protection scope of the technical solutions of the present application.

Claims

1. A moving crosshead for a universal testing machine, characterized in that, The mobile crossbeam (10) is square in section and hollow inside, and a through hole (11) for mounting a clamp is arranged in the middle of the mobile crossbeam (10); two strength support devices are symmetrically arranged on the left and right sides of the through hole (11) inside the mobile crossbeam (10); the strength support device comprises a resin concrete column (20) supporting the inner side surface of the mobile crossbeam (10) and a plurality of longitudinal prestressed steel bars (21) arranged in the resin concrete column (20); the two ends of the prestressed steel bar (21) are bent towards the outside of the mobile crossbeam (10); the resin concrete column (20) is in interference fit with the mobile crossbeam (10).

2. The moving crosshead for a universal testing machine of claim 1 wherein, The opposite faces of the two strength support devices are in close contact with each other to form the peripheral structure of the through hole (11).

3. The moving crosshead for a universal testing machine of claim 2, wherein, A top plate (22) is arranged on the upper part of the resin concrete column (20), the top plate (22) is made of shape memory alloy material, the top surface of the top plate (22) is higher than that of the resin concrete column (20), the upper side of the resin concrete column (20) is in interference fit with the mobile crossbeam (10) through the top plate (22), and a temperature insulation layer (23) is arranged between the top plate (22) and the resin concrete column (20).

4. The moving crosshead for a universal testing machine of claim 3 wherein, The top plate (22) and the resin concrete column (20) have the same surface shape and the area of the top plate (22) is smaller than that of the resin concrete column (20).

5. A method of manufacturing and installing the strong support means for the moving crosshead of a universal testing machine as claimed in claim 4, characterized in that, The method comprises the following steps: S1. Strength support device manufacturing: S1.

1. Mould preparation: installing resin concrete column (20) bottom film, cleaning table surface, and brushing separating agent; S1.

2. Prestressed steel bar (21) manufacturing: installing steel bar framework, prestressed steel bar (21) is first tensioned and then bent; S1.

3. Installing resin concrete column (20) side mould; S1.

4. First time pouring resin concrete, pouring to the lower surface of the temperature insulation layer (23), curing and taking the same condition curing test block; S1.

5. When the strength of the same condition curing test block reaches 65% of the standard curing strength, placing the temperature insulation layer (23) and the top plate (22), second time pouring resin concrete, and curing; S1.

6. Removing the mould; S1.

7. Strain releasing, cutting, and surface curing treatment; S2. Strength support device installation: heating the top plate (22) to increase the temperature to the high temperature phase change temperature, the height of the top plate (22) is reduced at the high temperature phase change temperature; driving the strength support devices from the two sides to the middle of the mobile crossbeam (10), observing and adjusting the position from the middle through hole (11), until the mutual symmetry is close to each other; naturally or artificially cooling the top plate (22), when the temperature decreases to the low temperature phase change area, the height of the top plate (22) restores to the initial height, and tightly presses against the inner side surface of the mobile crossbeam (10).

6. The manufacturing and installation method of the strength support device for the moving crossbeam of the universal testing machine as described in claim 5, characterized in that, The heating mode of the top plate (22) in step S3 adopts electromagnetic heating.

7. The manufacturing and installation method of the strength support device for the moving crossbeam of the universal testing machine as described in claim 5, characterized in that, The moving of the strength support device to the middle of the mobile crossbeam (10) in step S3 adopts a pneumatic driving mode.

8. The method of manufacturing and installing a strong support for a moving crosshead of a universal testing machine according to any one of claims 5-7, characterized in that, A limiting plate (12) is arranged on the inner side surface of the bottom plate of the mobile crossbeam (10) at the through hole (11), and the resin concrete column (20) is provided with a positioning groove (24) matching the shape thereof.

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