PEXA pipe thermal aging test box

Abstract

The invention relates to the technical field of pipe thermal aging, in particular to a PEXA pipe thermal aging test box which comprises a pull-out frame body arranged in a test cavity, the pull-out frame body comprises a rotating section, and a clamping piece and a bottom supporting piece are arranged on the rotating section; the cone frustum rotates by 180 degrees, the elastic clamp suspends and clamps the dumbbell-shaped sample, and at the moment, the circular ring limits the movement range of the lower end of the dumbbell-shaped sample; when the elastic clamp rotates by 180 degrees, the conical structure is inverted and is matched with the cone frustum to fix the straight pipe type sample without stress, and the straight pipe type sample is still through up and down. According to the invention, a multifunctional integrated clamping structure is formed by adopting T-shaped plugging high-stability locking, counterweight self-stabilization and double-position limiting modes, so that a sample is free from clamping deformation in a thermal aging test, is exposed to the maximum extent and is resistant to interference; the core problems of stress concentration, non-uniform heat exchange and low position stability of a sample fixing mode in a traditional thermal aging test are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe thermal aging, in particular to a PEXA pipe thermal aging test box. BACKGROUND

[0002] Thermal aging test is a key means to evaluate the performance stability and service life of high polymer materials (such as PEXA pipes) in long-term high-temperature environment. By simulating the thermal stress conditions that the materials may experience in actual use, the mechanical property degradation, color change, surface cracking and other aging phenomena of the materials can be effectively detected.

[0003] In actual operation, the shapes of the samples to be tested mainly include two types: one is dumbbell type, which is used to evaluate the mechanical properties such as tensile strength and elongation at break of the materials; the other is straight pipe type, which is used to evaluate the durability and structural stability of the pipes in thermal oxygen environment. The existing thermal aging test boxes generally use tray placement or single-end suspension clamping to place the samples, and a forced air circulation system is usually provided in the test chamber to ensure temperature uniformity.

[0004] When the straight pipe type sample is placed in the tray, the horizontal placement may cause the straight pipe type sample to deform due to its own weight during the test, and the airflow impact may cause the straight pipe type sample to displace or even rotate on the tray, thereby affecting the positional stability of the sample, causing surface deformation of the sample, and affecting the test results. When the single-end suspension clamping method is used, the end of the straight pipe type sample may be deformed due to the clamping force, and local stress concentration may be caused at high temperature. In addition, the end of the straight pipe type sample may be closed due to clamping, which may hinder the circulation of hot air in the inner cavity of the straight pipe type sample, resulting in different aging rates of the inner and outer walls of the straight pipe type sample, and making it difficult to truly reflect the aging behavior of the material in actual application.

[0005] When the dumbbell type sample is placed in the tray, it may be unevenly aged on both sides, and it may also be displaced or overturned due to airflow impact. When the single-end suspension clamping method is used, some devices may also have a rotating function to further improve the uniformity of heat exchange. When the airflow and centrifugal force act together, or the airflow speed and centrifugal force are large, the dumbbell type sample may swing due to its thin sheet shape, small gravity and suspended state, especially when the number of samples is large, which may cause collision or contact between the samples. SUMMARY

[0006] In order to solve the above problems, the application provides a PEXA pipe hot aging test box, which is provided with a test cavity; a pull-out type frame body is arranged in the test cavity; the pull-out type frame body comprises a rotating section; clamping pieces and a bottom support piece are arranged on the rotating section; the clamping piece comprises: a hanging body, which is distributed in a circumferential equidistant manner and comprises a T-shaped column and a rectangular frame arranged on the lower side of the T-shaped column; an elastic clamp, which is correspondingly arranged with the hanging body and is rotatably arranged in the rectangular frame; a counterweight ball, which is symmetrically arranged on the outer side of the elastic clamp and is rotatably arranged for keeping the elastic clamp vertical; a T-shaped groove is arranged on the rotating section and is matched with the T-shaped column; the outer side of the T-shaped groove is arranged in an open manner; the bottom support piece comprises: a conical table arranged on the rotating section, which is arranged below the elastic clamp and is correspondingly arranged with the elastic clamp and is vertically penetrated; symmetrically arranged upper insertion plates are arranged on the inner side of the non-clamping end of the elastic clamp, and the symmetrically arranged upper insertion plates are spaced apart and form a conical structure; a circular ring is arranged on the lower side of the large-diameter end of the conical table; a counterweight strip is symmetrically arranged on the outer side of the conical table and is rotatably arranged for keeping the conical table vertical; the conical table is rotated by 180 degrees, the elastic clamp suspends and clamps a dumbbell-shaped sample, at this time, the circular ring limits the movement range of the lower end of the dumbbell-shaped sample; the elastic clamp is rotated by 180 degrees, at this time, the conical structure is inverted and is matched with the conical table to stress-free fix a straight pipe-shaped sample, and the straight pipe-shaped sample is still vertically penetrated.

[0007] Preferably, the side wall of the conical table and the side wall of the upper insertion plate are both provided with uniformly distributed air permeable holes.

[0008] Preferably, the opening width of the outer side of the T-shaped groove is equal to the diameter of the vertical section of the T-shaped column, the vertical section of the T-shaped column is automatically moved downward under the action of gravity after entering the T-shaped groove from the opening, the horizontal section of the T-shaped column is inserted into the horizontal section of the T-shaped groove, and at this time, the horizontal degree of freedom of the T-shaped column is limited.

[0009] Preferably, when the conical structure is inverted and matched with the conical table to limit the position of the straight pipe-shaped sample, the small-diameter ends of the conical structure and the conical table are respectively inserted into two end portions of the straight pipe-shaped sample, the straight pipe-shaped sample is fully limited, and the conical structure does not give extrusion force to the straight pipe-shaped sample.

[0010] Preferably, the inner diameter of the circular ring is greater than the size of the lower end of the dumbbell-shaped sample; during the rotation of the dumbbell-shaped sample driven by the rotating section through the clamping piece and the conveying of air into the test cavity, the circular ring limits the movement range of the lower end of the dumbbell-shaped sample, and at this time, the lower end of the dumbbell-shaped sample does not contact the end face of the conical table.

[0011] Preferably, grid plates are arranged at the left and right ends and the lower end of the test cavity, air is conveyed into the test cavity from three directions during the hot aging test, and the air from top to bottom penetrates the straight pipe-shaped sample.

[0012] Preferably, the counterweight ball is rotatably arranged on the outer side of the non-clamping end of the elastic clamp through a pull rope, and the rotation axis of the pull rope is parallel to the rotation axis of the elastic clamp.

[0013] Preferably, the PEXA pipe material heat aging test box is also provided with a rotary driving member; the pull-out frame body is controlled to be connected with the rotary driving member by the locking member, and after the connection, the rotary driving member drives the rotary section of the pull-out frame body to rotate.

[0014] Preferably, the locking member comprises symmetrical guide rails fixedly installed in the test cavity, and the pull-out frame body further comprises a fixed section linearly slidably connected with the guide rails; under the limitation of the guide rails, the pull-out frame body stably horizontally enters and exits the test cavity, and when the pull-out frame body is located outside the test cavity, sample placement operation is performed.

[0015] Preferably, the clamping member and the bottom support member are arranged away from the grid plates on the left and right sides and the inner wall at the rear side of the test cavity.

[0016] The beneficial effects of the present application are as follows: Firstly, the T-shaped plug-in high-stability locking, weight self-stability and double-position limiting mode adopted by the present application form a multifunctional integrated clamping structure, realize non-clamping deformation of the sample in the heat aging test, maximum exposure and anti-interference, and solve the core problems of stress concentration, uneven heat exchange and low position stability in the traditional heat aging test.

[0017] Secondly, the same set of clamping structures of the present application has two sample position limiting modes, which only need to be turned over by 180 degrees, and can be automatically reset vertically after turning over, without the need for additional manual or mechanical structure correction, thereby ensuring the placement state of the sample; the position limitation for the dumbbell-shaped sample adopts the mode of suspension clamping + non-contact dynamic limiting, and the position limitation for the straight pipe-shaped sample adopts the mode of stress-free double-end plug-in fixing + guaranteeing up-down through, which not only ensures that the sample is effectively fixed and does not deform under the action of additional force, but also maximizes the exposure of the sample and helps the sample to maintain its original physical properties without being affected.

[0018] Thirdly, the present application suspends and clamps the dumbbell-shaped sample at the upper end by using an elastic clamp, and the lower end of the dumbbell-shaped sample is freely suspended, thereby avoiding stress concentration; at the same time, a dynamic ring-shaped protection structure is formed by using a circular ring, which allows the dumbbell-shaped sample to swing slightly but avoids collision, and allows air to flow around the dumbbell-shaped sample, thereby ensuring uniform heat aging.

[0019] Fourthly, the present application only naturally inserts the end of the straight pipe-shaped sample by using the cooperation of the circular conical platform and the inverted conical structure, but does not squeeze the straight pipe-shaped sample, thereby realizing non-pressing positioning, avoiding local stress concentration, and making the straight pipe-shaped sample maintain its original shape; at the same time, the circular conical platform is up-down through, and the upper plug-in plate is symmetrically arranged at a certain distance, thereby making the straight pipe-shaped sample keep up-down through, avoiding the formation of local thermal resistance, promoting the circulation of air in the straight pipe-shaped sample, and making the inner and outer walls of the straight pipe-shaped sample age synchronously.

[0020] Five, the cooperation of the T-shaped column and the T-shaped groove in the application has double locking ability of transverse tensile and longitudinal shear, compared with the weak connection of the traditional thin hook hanging hole relying on the top suspension, can more firmly fix the clamp assembly on the rotating section, without additional tightening bolts or using tools, even when the air flow speed and the centrifugal force are larger, the clamping piece and the bottom support piece cannot move, ensuring the structural stability of the whole clamping system, thereby avoiding the instability of the clamping structure aggravating the instability of the sample state. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the overall structure schematic diagram of the application.

[0022] Figure 2 is the structure schematic diagram of the clamping piece, the bottom support piece, the locking piece and the rotating driving piece in the application.

[0023] Figure 3 is the structure schematic diagram of the clamping piece and the pull-out type frame body in the application.

[0024] Figure 4 is the structure schematic diagram of the clamping piece and the T-shaped groove in the application.

[0025] Figure 5 is the structure schematic diagram of the bottom support piece and the locking piece in the application.

[0026] Figure 6 is the structure schematic diagram of the bottom support piece in the application.

[0027] Figure 7 is the structure schematic diagram of the elastic clip and the circular ring cooperation to limit the dumbbell type sample in the application.

[0028] Figure 8 is the structure schematic diagram of the upper insertion plate and the circular cone cooperation to limit the straight pipe type sample in the application.

[0029] In the figure: 1, pull-out type frame body; 2, clamping piece; 3, bottom support piece; 4, grid plate; 5, rotating driving piece; 6, locking piece; 10, rotating section; 100, T-shaped groove; 11, fixed section; 20, hanging body; 21, elastic clip; 22, counterweight ball; 200, T-shaped column; 201, rectangular frame; 30, circular cone; 31, upper insertion plate; 32, circular ring; 33, counterweight strip; 60, guide rail; 61, push strip; 62, extension plate; 63, arc-shaped plate. DETAILED DESCRIPTION

[0030] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described below, and those skilled in the art can make similar improvements without departing from the concept of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] Referring to Figure 1 and Figure 2 , a PEXA pipe hot aging test box is provided with a heating system, an air circulation system, a control and monitoring system, a test cavity and other components, all of which are prior art and their specific structures will not be described in detail in the present application. In addition, the test box is also provided with a rotary driving member 5 and a pull-out frame 1. The rotary driving member 5 includes a driving shaft rotatably installed at the bottom wall of the test cavity. The driving shaft is fixedly connected with the output shaft of an internal motor (not shown in the figure). A rectangular block is slidably installed on the upper end of the driving shaft. Grid plates 4 are arranged at the left and right ends and the lower end of the test cavity. During the hot aging test, air is supplied into the test cavity from three directions, and the driving shaft rotates through the corresponding grid plate 4.

[0032] Referring to Figure 1 , Figure 2 , Figure 3 , the pull-out frame 1 includes a rotating section 10 composed of a vertical cylinder and a ring section fixedly installed on the outer side of the upper end of the cylinder by a plurality of support rods. The ring section is coaxial with the cylinder. A rectangular groove is formed in the lower end surface of the cylinder for abutting with the rectangular block. The cylinder is controlled by a locking member 6 to abut with the rotary driving member 5. After abutting, the rotating section 10 of the pull-out frame 1 is driven to rotate by the rotary driving member 5. The rotating section 10 is provided with a clamping member 2 and a bottom support member 3, which are arranged away from the grid plates 4 on the left and right sides and the inner wall at the rear side of the test cavity.

[0033] Referring to Figure 3 , Figure 4 , Figure 7 and Figure 8 , the clamping member 2 includes an elastic clamp 21 and a counterweight ball 22. The elastic clamp 21 is circumferentially equidistantly distributed and rotatably arranged. The clamping end of the elastic clamp 21 is rounded, and the rotation axis of the elastic clamp 21 extends radially along the cylinder. The counterweight balls 22 are symmetrically arranged and rotatably installed on the outer side of the non-clamping end of the elastic clamp 21 by a pull rope. The rotation axis of the pull rope is parallel to the rotation axis of the elastic clamp 21. The counterweight ball 22 is used to keep the elastic clamp 21 vertical.

[0034] Referring to Figure 4 , Figure 5 , Figure 6 and Figure 7, the bottom support 3 includes a conical table 30, an upper insertion plate 31, a circular ring 32 and a counterweight strip 33; the conical table 30 is located below the elastic clamp 21 and corresponds to the elastic clamp 21 one by one, the conical table 30 is through from top to bottom, the conical table 30 is fixedly installed at the end of the sleeve pipe, the sleeve pipe is rotatably installed at one end of the fixed rod, the other end of the fixed rod is fixedly connected with the outer wall of the same ring seat, the ring seat is fixed on the rotating section 10 through bolts, and the bolts are symmetrically arranged on both sides of the rotating section 10 and the number of the bolts is at least two. The upper insertion plate 31 is symmetrically arranged on the inner side of the non-clamping end of the elastic clamp 21, and the symmetric upper insertion plate 31 forms a conical structure; it should be noted that the distance between the symmetric upper insertion plate 31 is enough to pinch the elastic clamp 21 to make the clamping end of the elastic clamp 21 open, so as to complete the operation of clamping the dumbbell-shaped sample. The circular ring 32 is fixedly connected with the lower end face of the large diameter end of the conical table 30 through the connecting rib plate. The counterweight strip 33 is symmetrically and rotatably installed on the outer side of the conical table 30, and the counterweight strip 33 is used for keeping the conical table 30 vertical; as shown in Figure 6 , the counterweight strip 33 is rotatably installed on one end of the pin shaft, the other end of the pin shaft is fixedly connected with the outer side wall of the conical table 30, and the pin shaft is located at the end of the counterweight strip 33. The outer side wall of the conical table 30 and the upper insertion plate 31 are both provided with uniformly distributed air holes, so as to ensure the stability of the position limitation of the straight pipe type sample while increasing the contact area of air and the inner wall of the straight pipe type sample.

[0035] Please refer to Figure 2 and Figure 6 In addition, the rotating section 10 is provided with mounting holes (not shown in the figure) matched with the bolts and distributed equidistantly from top to bottom, the position adjustment of the ring seat is realized by cooperation of the bolts and the mounting holes with different heights, and then the distance between the clamping part 2 and the bottom support 3 is adjusted to meet the needs of adapting to samples with different lengths.

[0036] Please refer to Figures 1 to 8 , the specific working process: before the test, the sample is placed at 23±2℃, 50±5% humidity for at least 24 hours, and the initial performance of the sample (such as tensile strength, elongation at break, etc.) is measured, the sample color and surface state are photographed and kept as baseline data; the test chamber also needs to be preheated to the target temperature before placing the sample, so as to reduce the temperature fluctuation. After the test chamber is preheated to the target temperature, the door of the test chamber is opened, and the operator uses tools or wears heatproof gloves to first release the connection between the pull-out frame 1 and the rotary driving part 5 through the locking part 6, then moves the pull-out frame 1 outward, and finally the pull-out frame 1 is located outside the test chamber, the purpose of the pull-out design is to avoid the operation of placing the sample in a limited space, improve the convenience and efficiency of placing the sample, and also help to ensure the consistency of placing the sample.

[0037] Then, according to the shape of the sample, the corresponding placing and fixing mode is selected, when the sample is dumbbell-shaped (as shown in Figure 7As shown), first rotate the truncated cone 30 180 degrees. The inverted truncated cone 30 will remain vertical under the action of the counterweight 33. At this time, the ring 32 is located above the inverted truncated cone 30. Then, the upper end of the dumbbell-shaped sample is clamped and fixed by the clamping end of the elastic clamp 21 (at this time, the clamping end of the elastic clamp 21 is naturally facing downwards). Then, lift the elastic clamp 21 slightly upwards so that the lower end of the dumbbell-shaped sample is located inside the ring 32. Then, release the elastic clamp 21. The elastic clamp 21 will automatically move down and reset under the action of gravity. However, it should be noted that at this time, the dumbbell-shaped sample does not contact the truncated cone 30 and the ring 32 (the inner diameter of the ring 32 is much larger than the size of the lower end of the dumbbell-shaped sample), ensuring that the airflow flows around the dumbbell-shaped sample; the ring 32 is used to limit the range of motion of the lower end of the dumbbell-shaped sample. During the subsequent rotation of the clamping part 2 driven by the cylinder and the three-way input of air into the test chamber, the ring 32 forms a circumferential protective structure to prevent the dumbbell-shaped sample from contacting the side wall of the test chamber under the action of centrifugal force and gas blowing.

[0038] When the sample is a straight tube type (e.g.) Figure 8 As shown), first rotate the elastic clamp 21 180 degrees. The elastic clamp 21 will remain vertical under the action of the counterweight ball 22. At this time, the conical structure is inverted and directly opposite the truncated cone 30. Then, first lift the elastic clamp 21 upwards and place the straight tube sample on the truncated cone 30 (at this time, the truncated cone 30 is naturally upright). The small diameter end of the truncated cone 30 is naturally inserted into the end of the straight tube sample, achieving the purpose of both limiting and not applying stress. The end of the straight tube sample does not deform or only deforms slightly. Then, move the elastic clamp 21 downwards so that the small diameter end of the inverted conical structure is also naturally inserted into the end of the straight tube sample, but the conical structure does not... Applying clamping force to the straight tubular sample and fixing it through a non-compression conical insertion method ensures that the straight tubular sample does not undergo axial deformation and remains vertically continuous, while also helping to maintain the original physical properties of the straight tubular sample without affecting them. This avoids the deformation of the straight tubular sample caused by traditional clamping, which would affect the accuracy of the aging data. Furthermore, because the truncated cone 30 is vertically continuous, there is a gap between the two upper insert plates 31 that make up the conical structure, and air vents are provided on both the upper insert plates 31 and the truncated cone 30, the straight tubular sample, even in a position-limited state, remains vertically continuous, allowing air to pass through it, resulting in uniform thermal aging inside and outside the straight tubular sample.

[0039] Switching between the two fixed sample modes requires only a 180-degree flip, while the automatic reset function of the counterweight ball 22 and counterweight bar 33 ensures that no manual angle calibration is needed after operation, transforming complex attitude control into a simple physical self-balancing mechanism. Furthermore, the design of the two fixed sample modes ensures that all types of samples can undergo thermal aging tests with maximum area exposure, thereby improving the accuracy and reliability of the test results.

[0040] It should be noted that even if the sample is fixed between the clamping pieces 2 and the bottom support pieces 3, there is still an effective spacing between the circumferentially distributed samples, rather than being arranged closely; when placing the sample, the cylinder can drive the clamping pieces 2 and the bottom support pieces 3 to rotate freely under the control of the operator, so as to place the sample circumferentially.

[0041] Please refer to Figure 2 、 Figure 3 and Figure 5 , the locking piece 6 includes a guide rail 60 symmetrically and fixedly installed on the bottom wall in the test cavity, and a push strip 61 linearly slidably connected with the guide rail 60, and the pull-out frame body 1 further includes a fixed section 11 linearly slidably connected with the guide rail 60 through a long strip, the fixed section 11 is an inverted U-shaped plate, the long strip is fixedly installed at the lower end of the vertical section of the inverted U-shaped plate, and the long strip is horizontally arranged, and under the limitation of the guide rail 60, the pull-out frame body 1 stably horizontally enters and exits the test cavity; the end of the push strip 61 close to the rear side wall of the test cavity is a wedge-shaped structure, the moving area of the push strip 61 and the corresponding long strip are independent of each other and will not interfere with each other; the guide rail 60 is slidably installed on the opposite sides of the test cavity, and the upper push plate matched with the slope of the wedge-shaped structure is slidably installed on the opposite sides of the test cavity, the rectangular block is symmetrically installed on the left and right ends of the rectangular block, and the extension plate 62 in contact with the upper end surface of the corresponding upper push plate is symmetrically installed on the left and right ends of the rectangular block; at the same time, the arc-shaped plates 63 are symmetrically arranged on the front and rear sides of the rectangular block, the lower ends of the arc-shaped plates 63 are fixedly connected with the corresponding grid plates 4 through the fixed columns, and the distance between the two arc-shaped plates 63 is slightly greater than the width of the extension plate 62; in order to improve the structural strength of the upper push plate, a guide column is slidably installed between the lower side of the end of the upper push plate close to the rectangular block and the bottom wall of the test cavity, and the guide column slidably penetrates the corresponding grid plate 4. In addition, a plurality of through holes are formed in the horizontal section of the fixed section 11, the upper push plate and the extension plate 62, so as to reduce the obstruction to the air from below.

[0042] After the sample is placed, the drawer 1 is pushed into the test chamber, and the long strip cannot be moved any further when the cylinder is located directly above the rectangular block. At this time, the operator pushes the push bar 61 inward, and the wedge-shaped structure of the push bar 61 moves the upper push plate upward. The upper push plate then pushes the rectangular block upward through the extension plate 62 until the rectangular block is fully inserted into the rectangular slot. At this time, the upper end surface of the upper push plate is flush with the upper end surface of the arc-shaped plate 63, and the opposite ends of the two upper push plates and the two arc-shaped plates 63 form a complete annular support surface. Then the door is closed, the heat aging test is started, and the start time is recorded. During the test, the drive shaft, rectangular block, and cylinder rotate together through the built-in motor control, and the cylinder rotates with the clamping piece 2, bottom support piece 3, and fixed sample. This enhances the uniformity of sample surface heat exchange, and the extension plate 62 rotates along the annular support surface, which continuously and effectively supports the extension plate 62. The rotation speed, wind speed, and temperature are automatically monitored and controlled in real time according to experimental requirements. The total test time is set in advance, and after the set time is reached, the test chamber is closed, the sample is removed, and the sample is cooled for 1-2 hours in a 23°C environment. Then observe the color change, surface condition, and take photos for record. Subsequently, perform tests such as tensile strength and elongation at break and record the data. Compare the data before and after heat aging to obtain the heat aging results.

[0043] It should be noted that after the push bar 61 is moved inward to the position, the position of the push bar 61 can be limited by conventional structures such as pins, and then the door is closed, and the inner wall of the door abuts against the end of the push bar 61 and the end of the long strip. Alternatively, the extension plate 62 can be rotated with the rectangular block by the rotary drive 5 to a small angle, and the extension plate 62 is moved to the arc-shaped plate 63 without contacting the upper push plate. At this time, the upper push plate is stopped at the current position, and then the door is closed to limit the position of the push bar 61 by abutting the end of the push bar 61 and the end of the long strip against the inner wall of the door. The specific setting method is selected according to the actual situation.

[0044] Please refer to Figure 3 , Figure 4 , Figure 7 and Figure 8The clamping piece 2 further comprises circumferentially equidistantly distributed hanging bodies 20, the hanging body 20 comprising a T-shaped column 200, a V-shaped mounting plate and a rectangular frame 201, the rectangular frame 201 being fixedly installed at one end of the V-shaped mounting plate, the other end of the V-shaped mounting plate being fixedly connected with the lower end of the vertical section of the T-shaped column 200, the rectangular frame 201 being located directly below the T-shaped column 200, a T-shaped groove 100 being provided on the ring section of the rotating section 10 and being matched with the T-shaped column 200, the T-shaped groove 100 extending vertically, the T-shaped groove 100 being provided with an opening at the outer side (i.e. the side away from the axis of the rotating section 10), and the opening width of the T-shaped groove 100 at the outer side being equal to the diameter of the vertical section of the T-shaped column 200, the T-shaped column 200 and the T-shaped groove 100 being insertedly matched to keep the position stable, the elastic clamp 21 being correspondingly rotatably installed in the rectangular frame 201, and the distance between the inner space of the rectangular frame 201 and the lower end surface of the vertical section of the T-shaped column 200 being sufficient for the rotation of the elastic clamp 21.

[0045] When the sample is dumbbell-shaped, the operator needs to pinch the effective position of the elastic clamp 21 to open the clamping end of the elastic clamp 21, and the operator's requirement for the operation space will be increased, and the time consumed for fixing the dumbbell-shaped sample will be increased compared with fixing the same number of straight pipe-shaped samples, so in order to facilitate the operation of the operator, shorten the opening time of the box door when placing the sample, reduce heat loss and temperature fluctuation, the elastic clamp 21 can be used to clamp the dumbbell-shaped sample outside the test box, at this time the space available for the operator to operate is basically not affected, which is beneficial to the fast clamping and fixing efficiency of the dumbbell-shaped sample. After the dumbbell-shaped sample is clamped and fixed, the box door is opened and the pull-out frame body 1 is pulled out, then the conical table 30 is turned over, and then the vertical section of the T-shaped column 200 is inserted into the vertical section of the T-shaped groove 100, at this time the lower end of the dumbbell-shaped sample is basically aligned with the middle of the circular ring 32, then the operator only needs to release the hand, and the T-shaped column 200, the rectangular frame 201 and other components automatically move downward under the action of gravity, and finally the horizontal section of the T-shaped column 200 is inserted into the horizontal section of the T-shaped groove 100, and the T-shaped column 200 and the T-shaped groove 100 are insertedly matched to keep the position stable, at this time the T-shaped column 200 cannot be horizontally moved out of the T-shaped groove 100, and the lower end of the dumbbell-shaped sample is located in the circular ring 32. Compared with the traditional method of aligning the small-size hanging hole with the slender hook to realize the suspension of the clamp and the sample, the operation is time-consuming and prone to misalignment. The wide inlet guide design of the T-shaped groove 100 allows the T-shaped column 200 to enter quickly, and after the horizontal section of the T-shaped column 200 is inserted into the T-shaped groove 100, it is naturally locked under the action of gravity, forming a mechanical lock against tension and shear, and even if it is rotated at a high speed, it will not be pulled out, and the elastic clamp 21 will not cause large amplitude multi-directional deviation of the sample, and the structure is simple but reliable, easy to use and durable.

[0046] It needs to be said that all components placed in the test cavity are made of high-temperature-resistant, low-heat-conducting and anti-sticking materials or are coated with high-temperature-resistant, low-heat-conducting and anti-sticking coatings on the surface to avoid metal catalysis. The clamping end of the elastic clamp 21, the outer side wall of the upper insertion plate 31 and the outer side wall of the conical platform 30 can be provided with a high-temperature-resistant, low-heat-conducting and anti-sticking elastic silica gel layer to prevent slipping and avoid indentation.

[0047] The application is not simply solving two independent problems: dumbbell type fixing + straight pipe type fixing, but proposes a unified optimization scheme for the common problem of "systematic defects of sample fixing method in heat aging test". The innovation lies in: structural reusability, the same component adapts to two kinds of samples; core consistency, no stress, maximum exposure, high stability.

[0048] In the description of the application, it should be noted that unless otherwise specified and limited, the terms "arrangement", "connection", "installation", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, or slidingly connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0049] The embodiments of the specific implementation are the preferred embodiments of the application, and do not limit the protection scope of the application, so: any equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A PEXA pipe heat aging test chamber, configured with a test cavity; characterized in that, The pull-out frame body arranged in the test cavity comprises a rotating section, and a clamping piece and a bottom support piece are arranged on the rotating section; The clamping piece comprises: The hanging bodies are circumferentially equidistantly distributed and comprise T-shaped columns and rectangular frames arranged on the lower sides of the T-shaped columns; The elastic clips are one-to-one corresponding to the hanging bodies and are rotatably installed in the rectangular frames; The counterweight balls are symmetrically and rotatably installed outside the elastic clips and are used for keeping the elastic clips vertical; A T-shaped groove is formed in the rotating section and is matched with the T-shaped column, and the outside of the T-shaped groove is arranged in an open manner; The bottom support piece comprises: A circular conical table is arranged on the rotating section, is located below the elastic clips, is one-to-one corresponding to the elastic clips, and is vertically penetrated; Symmetrical upper insertion plates are arranged on the inner sides of the non-clamping ends of the elastic clips, and the symmetrical upper insertion plates are spaced apart from each other and form a circular conical structure; A circular ring is arranged on the lower side of the large-diameter end of the circular conical table; Counterweight strips are symmetrically and rotatably installed outside the circular conical table and are used for keeping the circular conical table vertical; When the circular conical table is rotated by 180 degrees, the elastic clips suspend and clamp the dumbbell-shaped sample, and at this time, the circular ring limits the movement range of the lower end of the dumbbell-shaped sample; When the elastic clips are rotated by 180 degrees, the circular conical structure is inverted and is matched with the circular conical table to stress-free fix the straight pipe-shaped sample, and the straight pipe-shaped sample is still vertically penetrated.

2. The PEXA pipe heat aging test chamber according to claim 1, characterized in that: Ventilation holes are formed in the side walls of the circular conical table and the side walls of the upper insertion plates.

3. The PEXA pipe heat aging test chamber according to claim 1, wherein: The opening width of the outside of the T-shaped groove is equal to the diameter of the vertical section of the T-shaped column, the vertical section of the T-shaped column automatically moves downward under the action of gravity after entering the T-shaped groove from the opening, the horizontal section of the T-shaped column is inserted into the horizontal section of the T-shaped groove, and at this time, the horizontal degree of freedom of the T-shaped column is limited.

4. The PEXA pipe heat aging test chamber according to claim 1, wherein: When the circular conical structure is inverted and matched with the circular conical table to limit the position of the straight pipe-shaped sample, the small-diameter ends of the circular conical structure and the circular conical table are respectively inserted into two end portions of the straight pipe-shaped sample, the straight pipe-shaped sample is fully positioned, and the circular conical structure does not give the straight pipe-shaped sample extrusion force.

5. The PEXA pipe heat aging test chamber according to claim 1, wherein: The inner diameter of the circular ring is greater than the size of the lower end of the dumbbell-shaped sample; during rotation of the dumbbell-shaped sample driven by the rotating section through the clamping piece and conveying of air into the test cavity, the circular ring limits the movement range of the lower end of the dumbbell-shaped sample, and at this time, the lower end of the dumbbell-shaped sample does not contact the end face of the circular conical table.

6. The PEXA pipe heat aging test chamber according to claim 1, wherein: Grid plates are arranged at the left end, the right end and the lower end of the test cavity, air is conveyed into the test cavity from three directions during the heat aging test, and the air penetrates the straight pipe-shaped sample from top to bottom.

7. The PEXA pipe heat aging test chamber according to claim 1, wherein: The counterweight balls are rotatably installed outside the non-clamping ends of the elastic clips through pull ropes, and the rotation axes of the pull ropes are parallel to the rotation axes of the elastic clips.

8. The PEXA pipe heat aging test chamber according to claim 1, wherein: The PEXA pipe heat aging test box is further provided with a rotary driving member; the pull-out frame body is controlled to be connected to the rotary driving member through a locking member, after the connection, the rotary driving member drives the rotating section of the pull-out frame body to rotate.

9. The PEXA pipe heat aging test chamber according to claim 7, wherein: The locking member comprises guide rails that are symmetrically and fixedly installed in the test cavity, and the pull-out frame body further comprises a fixed section that is linearly and slidably connected to the guide rails; under the limitation of the guide rails, the pull-out frame body stably horizontally enters and exits the test cavity, and when the pull-out frame body is located outside the test cavity, sample placement operation is performed.

10. The PEXA pipe heat aging test chamber according to claim 1, wherein: The clamping piece and the bottom support piece are arranged away from the grid plates on the left side and the right side and the inner wall on the rear side of the test cavity.

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