Detection tool for structural adhesive for heliostat

Abstract

The utility model relates to an inspection tool for a structural adhesive for a heliostat, which comprises a lower connecting column, a middle fixing plate, a purline pressing block, a bolt pair and an upper connecting column, and is characterized in that the middle fixing plate is connected with the purline pressing block through the bolt pair; and a structural adhesive is clamped between the middle fixing plate and the purline pressing block to connect and bond a sample. According to the utility model, the blank that the structural adhesive connection strength of the heliostat cannot be effectively inspected is filled, and meanwhile, the inspection tool provided by the utility model has the advantages of light weight, simple structure, simplicity and convenience in clamping operation and high sample positioning precision, and can improve the accuracy of the structural adhesive connection strength test of the heliostat and the convenience in the inspection process.

Description

Technical Field

[0001] This utility model belongs to the field of heliostat technology, and more specifically, it relates to an inspection tool for structural adhesive used in heliostats. Background Technology

[0002] The selection of the connection method between the heliostat mirror and the heliostat frame must consider both the connection strength and rigidity of the heliostat mirror under external loads, and the simplicity of the surface shape adjustment process during the heliostat mirror assembly. Compared with the traditional nut fastening method, structural adhesive connection has the following advantages in addition to ensuring connection strength and durability: 1. It can automate the assembly process and improve production efficiency. Structural adhesive connection can achieve integrated injection of all sub-mirrors and the frame through automatic adhesive application equipment, avoiding the tedious steps of adjusting the relative height of each sub-mirror screw individually as with nut fastening. 2. It can improve the accuracy and consistency of surface shape control. Sub-mirrors connected by structural adhesive are placed on the same fixed platform, and the relative surface shape angles between each sub-mirror station on this platform can be adjusted to a high degree of precision. 3. It can reduce the internal stress caused by sub-mirror assembly. The surface shape requirements of the heliostat may result in the phenomenon that the intermediate axis of each screw is not perpendicular to the assembly surface of the frame purlin before the sub-mirror is installed. The nut-tightening method can cause internal stress at each support point of the sub-mirror when pre-tightening force is applied to the nut, while the flexible installation process of the structural adhesive connection method avoids this problem.

[0003] Structural adhesive bonding offers significant advantages over traditional nut fastening in the assembly of heliostat frames and sub-mirrors, and is currently widely used in heliostat assembly production. However, structural adhesive bonding has limitations in quality control during heliostat assembly. Nut fastening allows for control of connection strength and assembly quality through torque tools to ensure and inspect the tightening torque. The basic principle of structural adhesive bonding is that two components mixed in a specific ratio react chemically to form a high-strength solid polyurethane, which then effectively chemically bonds and encapsulates the metal connectors. Due to the aforementioned unique process, there is currently no effective means to determine whether the structural adhesive bonding strength of the assembled heliostat meets requirements. Utility Model Content

[0004] To address the shortcomings of the existing technology, this utility model provides a testing fixture for structural adhesives used in heliostats. By clamping and bonding the sample with the fixture, and connecting it to the upper and lower clamps of a tensile testing machine, the problem of testing the bonding strength of structural adhesives for heliostats can be solved.

[0005] To achieve the above objectives, the present invention provides the following technical solution.

[0006] A testing fixture for structural adhesive used in heliostats, the fixture comprising a lower connecting column, an intermediate fixing plate, a purlin clamping block, a bolt pair and an upper connecting column, wherein the intermediate fixing plate is connected to the purlin clamping block via the bolt pair, and a structural adhesive bonding sample is sandwiched between the intermediate fixing plate and the purlin clamping block.

[0007] Furthermore, the bottom of the lower connecting post is a cylinder 1, the cylinder 1 is provided with a radial through hole, the top of the lower connecting post is a stud, and the middle part of the lower connecting post is a cylinder 2.

[0008] Furthermore, the diameter of the cylinder 2 is larger than the diameter of the cylinder 1 and the stud, and the stud, the cylinder 1 and the cylinder 2 form a coaxial pin.

[0009] Furthermore, the top end face of the stud has a mounting hole for axial positioning of the lower end screw in the structural adhesive bonding sample.

[0010] Furthermore, an internal threaded through hole is provided at the center of the intermediate fixing plate, and the thickness of the intermediate fixing plate is greater than or equal to the height of the stud at the top of the lower connecting column.

[0011] Furthermore, the intermediate fixing plate has four U-shaped holes on both sides of the width direction, and the four U-shaped holes are symmetrically arranged with respect to the internal threaded holes of the intermediate fixing plate.

[0012] Furthermore, there are two purlin clamping blocks, each with a bolt pair connection hole. The installation position of the purlin clamping block is determined by the position of the U-shaped hole on the intermediate fixing plate.

[0013] Furthermore, the purlin pressing block consists of two parts: a clamping plate and a pressing block. The clamping plate has a screw mounting hole in the middle, and the clamping plate and the pressing block are connected by screws.

[0014] Furthermore, the bolt assembly 12 consists of one bolt, two flat washers, and one wing nut.

[0015] Furthermore, a radial through hole is provided at the top of the upper connecting post, and a threaded blind hole is provided at the bottom end face of the upper connecting post.

[0016] The beneficial effects of this invention are as follows: The inspection fixture for structural adhesives used in heliostats proposed in this invention fills the gap in the lack of effective testing for the bond strength of structural adhesives in heliostats. It can also measure the test data of the bond strength of structural adhesives during the production and assembly process of heliostats, and provide a reference for tracing the quality of incoming structural adhesives, optimizing process parameters, and adjusting the production cycle. The inspection fixture for structural adhesives used in heliostats proposed in this invention has the advantages of being lightweight, simple in structure, easy to clamp and operate, and having high sample positioning accuracy, which can improve the accuracy of testing the bond strength of structural adhesives in heliostats and the convenience of the inspection process. Attached Figure Description

[0017] Figure 1 Schematic diagram of the heliostat frame structure.

[0018] Figure 2 Schematic diagram of the structure of a heliostat.

[0019] Figure 3 Schematic diagram of structural adhesive connection method.

[0020] Figure 4 This utility model presents a schematic diagram of the adhesive sample clamping fixture structure.

[0021] Figure 5 Schematic diagram of the lower connecting column structure.

[0022] Figure 6 Schematic diagram of the intermediate fixing plate structure.

[0023] Figure 7 Schematic diagram of purlin pressing block structure.

[0024] Figure 8 Schematic diagram of bolt pair structure.

[0025] Figure 9 Schematic diagram of the upper connecting column structure.

[0026] Among them: 1-torque beam, 2-truss, 3-purlin, 4-reflector, 5-support mirror holder, 6-connecting screw, 7-glue block, 8-glue plug, 9-lower connecting column, 9.1-cylinder 1, 9.2-stud, 9.3-cylinder 2, 10-intermediate fixing plate, 10.1-internal threaded through hole, 10.2-U-shaped hole, 11-purlin pressure block, 11.1-clamping plate, 11.2-pressure block, 12-bolt pair, 12.1-bolt, 12.2-flat washer, 12.3-wing nut, 13-upper connecting column, 13.1-radial through hole, 13.2-threaded blind hole. Detailed Implementation

[0027] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of this utility model.

[0028] The terms used in this application, such as top, bottom, left, right, inner, outer, front, rear, head, and tail, are based on the orientations or positional relationships shown in the accompanying drawings. Different drawings may result in different positional relationships, therefore they should not be construed as limiting the scope of protection.

[0029] In this utility model, the terms "installation," "connection," "interlocking," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a connection that allows communication, a direct connection, or an indirect connection through an intermediate medium. They can also refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0030] To further clarify the technical solution of this application, the technical terms involved are defined as follows.

[0031] Heliostat: A heliostat is an optical device that reflects sunlight in a fixed direction. Its main function is to track the sun's position by rotating a mirror, causing sunlight to be reflected and emitted in a specific direction, thus concentrating solar energy and overcoming the low density of solar radiation. Heliostats are primarily used in solar tower thermal power generation. Through the reflection and focusing effect of the heliostat, solar energy can be effectively collected and converted into heat energy, which then drives a generator to produce electricity.

[0032] Heliostat surface shape: The surface of a heliostat is typically composed of small-area reflecting mirror units arranged in a parabolic or elliptical shape so that incident parallel rays can be focused at the focal point. The arrangement and combination of the positions and angles of the reflecting mirror units to ensure the reflection effect of the heliostat is called the surface shape of the heliostat.

[0033] Heliostat mirrors: Considering various aspects of mirror production, transportation, and installation, the overall reflective area of ​​a heliostat is typically composed of several mirror units with different surface designs. Each mirror unit is defined as a sub-mirror. Sub-mirrors are usually assembled by bonding a single-sided mirror and a mirror support using silicone adhesive. Depending on the form of the sub-mirror support, heliostat mirrors can be divided into backplate-bonded sub-mirrors and mirror holder-bonded sub-mirrors. The assembly of the mirror involves fixing the mirror supports of each sub-mirror to the heliostat's support structure using mirror connectors, according to the surface design.

[0034] Structural Adhesive for Heliostats: Structural adhesive for heliostats is the core material used to bond heliostat lenses and frames together. It is a two-component polyurethane adhesive that combines the properties of structural adhesives and potting compounds, while also exhibiting weather resistance suitable for harsh outdoor environments. When using heliostat structural adhesive, components A and B are mixed according to the specified ratio. It exhibits good leveling properties within the workable time and has excellent workability. After reaching its initial curing time, the adhesive cures to achieve high structural strength and strong adhesion to the metal contact surfaces. The workable time and initial curing time of the heliostat structural adhesive can be adjusted by changing the catalyst ratio to meet production cycle control requirements under different ambient temperatures.

[0035] like Figure 1 The diagram shows the structure of the heliostat frame, which is mainly assembled from torque beam 1, truss 2 and purlin 3 by bolting or riveting. Its main function is to connect and support the reflector and to transmit the movement of the transmission components to the reflector in a stable and high-precision manner.

[0036] like Figure 2 The diagram shows a schematic of a heliostat. The sub-mirror is a mirror-supported sub-mirror, mainly composed of a reflector 4, a supporting mirror 5, and a connecting screw 6. Its main function is to reflect sunlight and focus it on a designated position. The sub-mirror has requirements for surface shape and tracking stability.

[0037] The heliostat frame and sub-mirrors need to be securely connected, and the sub-mirrors must maintain precise facial angles. Currently, the connection methods between the sub-mirrors and the frame of a heliostat include nut fastening and structural adhesive bonding.

[0038] Structural adhesive bonding is suitable for assemblies where the frame is fixed to the surface platform from top to bottom, with each sub-mirror attached as such. The connection method between the sub-mirrors and the frame is as follows: Figure 3 As shown. The mounting holes of the purlins 3 of the heliostat frame pass through the heliostat mirror mounting screws 6. The lower end of the purlin is sealed by the glue plug 8, and the two sides along the length of the purlin are sealed by glue blocks 7. An automated glue application device is used to apply glue from the upper end of the purlin into the sealed space of each sub-mirror screw. Finally, the device is left to stand for the structural glue to cure and bond firmly.

[0039] This invention provides a testing fixture for inspecting the bonding strength of structural adhesive used in heliostats. The function of this fixture is to clamp the bonded specimen and connect it to the upper and lower clamps of a tensile testing machine, thus solving the problem of testing the bonding strength of structural adhesive used in heliostats.

[0040] The structural adhesive bonding test specimens for heliostats, or simply bonding specimens, are assembled with the same parts, fit between parts, and adhesive application method as the heliostat frame and sub-mirrors during assembly. This serves to indirectly verify the bonding strength of the structural adhesive in the heliostat. A bonding specimen preparation station is set up near the heliostat lens bonding station. After applying structural adhesive to all the connection points of the entire frame using a glue gun, the bonding specimen at the preparation station is immediately injected with structural adhesive. Once the required curing time for the structural adhesive has been reached, the bonding specimen is clamped and measured on a tensile testing machine using specialized fixtures. The bonding failure force value on the mechanical test curve is used as the indicator of bonding strength.

[0041] The bonding strength of bonded specimens is measured using a tensile testing machine. The purlin of the bonded specimen is fixed to a fixed shaft at the bottom of the machine, while the connecting screw of the bonded specimen is connected to a movable shaft at the top of the machine. The control unit of the tensile testing machine is equipped with tensile load, displacement velocity, and fracture force determination functions. Tensile force is slowly applied to the bonded specimen using the tensile testing machine, and the tensile force value recorded by the machine is the maximum load that the screw and purlin of the bonded specimen can withstand in the bonded state, thus characterizing the bonding strength of the specimen. By comparing the bonding strength value of the structural adhesive bonded specimen with the design requirement value, the bonding strength of the structural adhesive to the heliostat mirror and frame can be tested and determined.

[0042] Testing the connection failure force of structural adhesive bonded specimens requires a tensile testing machine. This invention, based on the unique structure of structural adhesive bonded specimens, proposes a specialized testing fixture for verifying the bond strength of structural adhesives used in heliostats. For example... Figure 4 As shown, this testing fixture consists of a lower connecting column 9, an intermediate fixing plate 10, a purlin clamping block 11, a bolt pair 12, and an upper connecting column 13. The intermediate fixing plate 10, the purlin clamping block 11, and the bolt pair 12 are combined to connect and fix the structural adhesive bonded specimen at the bottom fixed end of the tensile testing machine.

[0043] like Figure 5As shown, the lower connecting column 9 is used to connect the intermediate fixing plate and the bottom clamping shaft of the tensile testing machine. The bottom of the lower connecting column is designed as a cylinder 1 (9.1), the diameter and height of which depend on the size and depth of the mounting hole of the bottom clamping shaft of the tensile testing machine; a radial through hole is provided on the cylinder 1, the position and diameter of which depend on the size of the connecting pin of the tensile testing machine. The top of the lower connecting column is designed as a stud (9.2) for mounting and fitting with the intermediate fixing plate; a mounting hole is opened on the top end face of the stud for axial positioning of the lower end screw in the structural adhesive connection sample; a relief groove is opened at the root of the thread of the stud to ensure that the stud is fully screwed into the intermediate fixing plate. The middle part of the lower connecting column is a cylinder 2 (9.3), the diameter of which is required to be larger than the diameter of cylinder 1 and the stud, and the three parts form a coaxial pin. When installing the lower connecting column, the bottom cylinder is inserted into the mounting hole of the bottom clamping shaft of the tensile testing machine, and after aligning the pin holes of the two, the connecting pin of the tensile testing machine is inserted.

[0044] like Figure 6 As shown, the function of the intermediate fixing plate 10 is to contact and support the lower outer end face of the purlin of the structural adhesive-bonded sample, and to provide a lower connecting hole for the bolt pair. An internally threaded through hole (10.1) is provided at the center of the intermediate fixing plate, and its thread specification matches the external thread at the top of the lower connecting column. The thickness of the intermediate fixing plate is greater than or equal to the height of the cylindrical top of the lower connecting column, ensuring that after the intermediate fixing plate and the lower connecting column are threadedly connected, the top surface of the lower connecting column does not exceed the upper end face of the intermediate fixing plate. The length of the intermediate fixing plate is required to be greater than the length of the structural adhesive-bonded sample. The width of the intermediate fixing plate is required to be greater than the width of the structural adhesive-bonded sample. Four U-shaped holes (10.2) are provided on both sides of the intermediate fixing plate in the width direction, symmetrically arranged with respect to the central internally threaded hole in the length and width directions of the intermediate fixing plate. The planar arrangement of the four U-shaped holes requires that the width direction be greater than the purlin width of the sample, and the length direction be greater than the sum of the widths of the sample adhesive block and the pressure block. The design of the U-shaped holes facilitates the removal of the fixture from the outside and the replacement of the sample during the testing process.

[0045] like Figure 7As shown, the purlin pressure block 11 is used to contact and apply pressure to the lower inner end face of the purlin of the structural adhesive bonded sample, and provides a connecting hole on the bolt pair. There are two purlin pressure blocks, symmetrically installed on the left and right sides of the adhesive block of the structural adhesive bonded sample. The installation position is determined by the longitudinal spacing of the U-shaped holes on the intermediate fixing plate. The purlin pressure block consists of a clamping plate (11.1) and a pressure block (11.2). The clamping plate is used to install the bolt pair and connect the pressure block. The pressure block applies pressure to the lower end face of the purlin within the purlin groove of the structural adhesive bonded sample to fix the purlin part. The clamping plate has U-shaped holes at both ends along its longitudinal direction, with the spacing matching the width of the U-shaped holes on the intermediate fixing plate; a screw mounting hole is provided in the middle, aligned with the center of the upper end face of the pressure block. The top of the pressure block is provided with a threaded blind hole for the threaded connection between the clamping plate and the pressure block; the height of the pressure block is required to be greater than the height of the purlin, the length is less than the width of the inner groove of the purlin, and the width is required to be greater than the width of the rubber block in the sample after the two purlin pressure blocks are installed with bolt pairs.

[0046] like Figure 8 As shown, the bolt assembly 12 connects the intermediate fixing plate and the two purlin clamping blocks, and adjusts the tightness between them via threads. The bolt assembly includes one bolt (12.1), two flat washers (12.2), and one wing nut (12.3). The bolt assembly is used by laterally installing the bolt into the corresponding U-shaped holes in the intermediate fixing plate and the purlin clamping plate. The two flat washers are located on the lower end face of the intermediate fixing plate and the upper end face of the purlin clamping plate, respectively. Tightening the wing nut causes the purlin clamping blocks to press down and fix the purlins of the sample.

[0047] like Figure 9 As shown, the function of the upper connecting post 13 is to connect the top clamping shaft of the tensile testing machine to the upper screw of the specimen. The upper connecting post is cylindrical in shape, and its diameter matches the mounting hole of the top clamping shaft of the tensile testing machine and is required to be smaller than the width of the specimen's rubber block. A radial through hole (13.1) is provided at its top, and its position and diameter depend on the size of the connecting pin of the tensile testing machine. A threaded blind hole (13.2) is designed on its bottom end face, and the thread specification corresponds to the external thread specification of the connecting screw for bonding the specimen, with a thread depth of not less than 6 times the pitch dimension.

[0048] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this innovative technical solution.

Claims

1. A testing tool for a structural adhesive for heliostats, characterized by, The fixture consists of a lower connecting column, an intermediate fixing plate, a purlin clamping block, a bolt pair, and an upper connecting column. The intermediate fixing plate is connected to the purlin clamping block through the bolt pair. A structural adhesive bonding sample is sandwiched between the intermediate fixing plate and the purlin clamping block.

2. The inspection tool for structural adhesive of heliostat according to claim 1, characterized in that, The bottom of the lower connecting post is a cylinder 1, and the cylinder 1 is provided with a radial through hole. The top of the lower connecting post is a stud. The middle part of the lower connecting post is a cylinder 2.

3. The inspection tool for structural adhesive of heliostat according to claim 2, characterized in that, The diameter of cylinder 2 is larger than the diameter of cylinder 1 and stud, and the stud, cylinder 1 and cylinder 2 form a coaxial pin.

4. The inspection tool for structural adhesive of heliostat according to claim 3, characterized in that, The stud has a mounting hole on its top end face for axial positioning of the lower end screw in the structural adhesive bonding sample.

5. The inspection tool for structural adhesive of heliostat according to claim 1 or 4, characterized in that, The intermediate fixing plate has an internal threaded through hole at its center, and the thickness of the intermediate fixing plate is greater than or equal to the height of the stud at the top of the lower connecting column.

6. The inspection tool for structural adhesive of heliostat according to claim 5, characterized in that, The intermediate fixing plate has four U-shaped holes on both sides of the width direction, and the four U-shaped holes are symmetrically arranged with respect to the internal threaded holes of the intermediate fixing plate.

7. The inspection tool for structural adhesive of heliostat according to claim 1 or 6, characterized in that, The purlin clamping block consists of two pieces. Each purlin clamping block has a bolt pair connection hole. The installation position of the purlin clamping block is determined by the position of the U-shaped hole on the intermediate fixing plate.

8. The inspection tool for structural adhesive of a heliostat according to claim 7, characterized in that, The purlin clamping block consists of two parts: a clamping plate and a clamping block. The clamping plate has a screw mounting hole in the middle, and the clamping plate and the clamping block are connected by screws.

9. The inspection tool for structural adhesive of heliostat according to claim 1 or 8, characterized in that, The bolt assembly consists of one bolt, two flat washers, and one wing nut.

10. The inspection tool for structural adhesive of a heliostat according to claim 9, wherein, The upper connecting post has a radial through hole at its top and a threaded blind hole at its bottom.

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