Linear Thermal Expansion Coefficient Detection Device and Method

Abstract

The invention discloses a linear expansion coefficient detection device and method, which are used to detect the linear expansion coefficient of a plastic sheet material. The plastic sheet material has a fixed end and a telescopic end relative to each other. The linear expansion coefficient detection device includes a mounting base, a clamping and positioning device, and an expansion conversion device. The mounting base is formed with a heat-conducting groove that is opened upward to contain heat-conducting liquid and accommodate the plastic sheet material. The clamping and positioning device includes a fixing member and a push member arranged in the heat-conducting groove, the fixing member abuts against the fixed end, and the push member abuts against the telescopic end. The expansion conversion device includes a rotating rod, a linear light source, and an arc scale plate. The rotating rod is rotated in the up-down direction and arranged on the mounting base and is transmission-connected to the push member. The linear light source is irradiated in the radial direction and arranged on the rotating rod. The arc scale plate is arranged around the rotating rod relative to the linear light source. The elongation of the plastic sheet material is read from the arc scale plate to accurately calculate the expansion coefficient of the plastic sheet material. The device is simple and the detection cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of material linear expansion coefficient determination, and in particular to a linear expansion coefficient detection device and method. Background Art

[0002] Thermal expansion and contraction is a well-known natural physical phenomenon. The degree of change of raw materials in thermal expansion and contraction is expressed by the "linear expansion coefficient" (linear expansion coefficient: the ratio of the change in length of a solid substance to its length at the original temperature when its temperature changes by 1 degree Celsius). In general, factories need to entrust professional testing agencies to use professional testing equipment to determine the linear expansion coefficient of materials, which will cause additional production costs and is extremely inconvenient. Summary of the invention

[0003] The main purpose of the present invention is to provide a linear expansion coefficient detection device and method, aiming to solve the problem that the detection cost of material expansion coefficient in existing factories is high and extremely inconvenient.

[0004] To achieve the above object, the linear expansion coefficient detection device proposed in the present invention is used to detect the linear expansion coefficient of a plastic sheet material, wherein the plastic sheet material has a fixed end and a telescopic end opposite to each other along the length direction, and the linear expansion coefficient detection device comprises:

[0005] A mounting base is formed with a heat-conducting groove which is opened upward, and the heat-conducting groove is used to contain heat-conducting liquid and the plastic sheet;

[0006] A clamping and positioning device, comprising a fixing member and a pushing member provided in the heat-conducting groove, wherein the fixing member is used to abut against the fixing end, the pushing member is used to abut against the telescopic end, and the pushing member can be pushed by the plastic sheet material to move after the plastic sheet material is thermally deformed; and

[0007] The expansion conversion device includes a rotating rod, a linear light source and an arc-shaped scale plate. The rotating rod is rotatably arranged on the mounting base along an axis in the up-down direction, and the pushing member is transmission-connected to the rotating rod to convert the linear movement of the pushing member into the rotational movement of the rotating rod. The linear light source is arranged on the rotating rod and irradiates along the radial direction of the rotating rod. The arc-shaped scale plate is arranged on the circumferential side of the rotating rod relative to the linear light source.

[0008] Optionally, the expansion conversion device also includes a reflective lens, which is arranged on the side wall of the heat conduction groove relative to the rotating rod, the line light source is arranged toward the reflective lens, and the arc scale plate is arranged on the reflective lens, wherein the rotation axis of the rotating rod and the center line of the arc where the arc scale plate is located are symmetrically arranged relative to the reflective lens.

[0009] Optionally, the inner diameter of the arc-shaped scale plate is r1, where r1 = 180 / π mm; and / or,

[0010] The radius of the rotating rod is r2, where r2 = 9 / (2π) mm.

[0011] Optionally, the clamping and positioning device further includes a fixed side splint and a movable side splint that are spaced apart and arranged on the fixed side of the heat conduction groove. The fixed side splint and the movable side splint are used to respectively press against both sides of the plastic sheet in the thickness direction, and the distance between the movable side splint and the fixed side splint is adjustable.

[0012] Optionally, the movable side splint includes a plurality of abutting blocks that are spaced apart along the length direction of the plastic sheet. The plurality of abutting blocks are used to abut against the plastic sheet; and / or,

[0013] The fixing member is arranged on the fixed side splint, and the position of the fixing member along the length direction of the plastic sheet is adjustable; and / or,

[0014] The pushing member is formed with a slider. The expansion conversion device further includes a mounting slide seat. The mounting slide seat is formed with a chute that penetrates along the length direction of the plastic sheet. The slider is adaptively arranged in the chute, and the telescopic end of the plastic sheet extends into the chute to at least abut against the slider.

[0015] Optionally, the expansion conversion device further includes:

[0016] A support column, which is arranged in the heat conduction groove and on the same side of the plastic sheet relative to the pushing member; and,

[0017] A flexible traction rope, which passes around the support column to have a first traction section and a second traction section. The first traction section is wound around the rotating rod, and the second traction section extends along the length direction of the plastic sheet and is arranged on the pushing member.

[0018] Optionally, the expansion conversion device further includes an elastic tensioning rope. One end of the elastic tensioning rope is wound around the rotating rod, and the other end is arranged on the side wall of the heat conduction groove.

[0019] The present invention also provides a linear expansion coefficient detection method for the above linear expansion coefficient detection device. The linear expansion coefficient detection method includes the following steps:

[0020] Install the plastic sheet to the clamping and positioning device so that the fixing member abuts against the fixed end and the pushing member abuts against the telescopic end;

[0021] Place the plastic sheet statically in the heat conduction liquid at the initial temperature and maintain it for a first set duration;

[0022] Detect the initial length of the plastic sheet material and read the initial angle value of the arc scale plate;

[0023] Heat the heat-conducting liquid to the target temperature and maintain it for a second set duration;

[0024] Read the final angle value of the arc scale plate, calculate the angle change amount based on the initial angle value and the final angle value, and calculate the length change amount of the plastic sheet material based on the angle change amount;

[0025] Calculate the temperature difference based on the initial temperature and the target temperature, and calculate the linear expansion coefficient of the plastic sheet material based on the temperature difference, the length change amount, and the initial length.

[0026] Optionally, the initial temperature is T1, and the target temperature is T2, where T2 - T1 = 50 °C.

[0027] Optionally, the first set duration is t1, where t1 = 30 min; and / or,

[0028] The second set duration is t2, where t2 = 30 min.

[0029] In the technical solution provided by the present invention, one end of the plastic sheet material in the length direction is fixedly abutted through the fixing member. After the plastic sheet material absorbs the heat transferred by the heat-conducting liquid, it heats up and expands, and then the telescopic end pushes the pushing member to move. Then, through the transmission connection between the pushing member and the rotating rod, the length expansion amount of the plastic sheet material is converted into the rotation angle change amount of the rotating rod. Then, as the rotating rod rotates, the linear light source is used to read the rotation angle change amount on the arc scale plate. Then, through the radius of the rotating rod and the radius of the arc scale plate, the expansion amount of the plastic sheet material can be accurately converted, and finally the linear expansion coefficient of the plastic sheet material is calculated. With such a setting, the structure of the device is simple, the manufacturing cost is low, and at the same time, the detection is convenient, saving the outsourcing detection cost; moreover, only by setting the length of the plastic sheet material to be longer, the radius of the arc scale plate to be larger, and the radius of the rotating rod to be smaller, a more accurate linear expansion coefficient can be obtained through conversion. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0031] Figure 1 Schematic structural diagram of the linear expansion coefficient detection device provided by the present invention;

[0032] Figure 2 is Figure 1 Truncated structural diagram of the linear expansion coefficient detection device in

[0033] Figure 3 Flowchart of the steps of the linear expansion coefficient detection method provided by the invention.

[0034] Explanation of the reference numerals in the drawings:

[0035] Label Name Label Name 100 Linear expansion coefficient detection device 31 Rotating rod 1 Installation base 32 Linear light source 11 Heat conduction groove 33 Arc scale plate 2 Clamping and positioning device 34 Reflection lens 21 Fixing piece 35 Support column 22 Pushing piece 36 Flexible traction rope 23 Fixed side splint 361 First traction section 24 Movable side splint 362 Second traction section 241 Abutting block 37 Tensioning rope 25 Installation sliding seat 38 Tensioning column 3 Expansion conversion device 200 Plastic sheet material

[0036] The realization of the object of the present invention, functional characteristics and advantages will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that if there are directional indications involved in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0039] In addition, if there are descriptions such as "first" and "second" involved in the embodiments of the present invention, the descriptions of "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0040] Thermal expansion and contraction is a well-known natural physical phenomenon. The degree of change of raw materials in thermal expansion and contraction is expressed by the "linear expansion coefficient" (linear expansion coefficient: the ratio of the change in length of a solid substance to its length at the original temperature when its temperature changes by 1 degree Celsius). In general, factories need to entrust professional testing agencies to use professional testing equipment to determine the linear expansion coefficient of materials, which will cause additional production costs and is extremely inconvenient.

[0041] In view of this, the present invention proposes a linear expansion coefficient detection device and method, aiming to solve the problem that the existing factory has high cost and is extremely inconvenient in detecting the material expansion coefficient, wherein Figures 1 to 2 A schematic structural diagram of an embodiment of a linear expansion coefficient detection device provided by the present invention, Figure 3 This is a flow chart of the steps of the linear expansion coefficient detection method provided by the present invention.

[0042] See also Figures 1 to 2 The linear expansion coefficient detection device 100 is used to detect the linear expansion coefficient of the plastic sheet 200. The plastic sheet 200 has a fixed end and a telescopic end opposite to each other along the length direction. The linear expansion coefficient detection device 100 includes a mounting base 1, a clamping and positioning device 2, and an expansion conversion device 3. The mounting base 1 is formed with a heat-conducting groove 11 which is opened upward. The heat-conducting groove 11 is used to contain heat-conducting liquid and accommodate the plastic sheet 200. The clamping and positioning device 2 includes a fixing member 21 and a pushing member 22 provided in the heat-conducting groove 11. The fixing member 21 is used to abut the fixed end, and the pushing member 22 is used to abut the telescopic end. end, and the pushing member 22 can be pushed and moved by the plastic sheet 200 after the plastic sheet 200 is thermally deformed, the expansion conversion device 3 includes a rotating rod 31, a linear light source 32 and an arc scale plate 33, the rotating rod 31 is rotatably arranged on the mounting base 1 along the axis of the up and down directions, and the pushing member 22 is transmission-connected to the rotating rod 31, so as to convert the linear movement of the pushing member 22 into the rotational movement of the rotating rod 31, the linear light source 32 is arranged on the rotating rod 31, and irradiates along the radial direction of the rotating rod 31, and the arc scale plate 33 is arranged around the rotating rod 31 relative to the linear light source 32.

[0043] In the technical solution provided by the present invention, one end of the plastic sheet 200 in the length direction is fixedly abutted by the fixing member 21. After absorbing the heat transferred by the heat-conducting liquid, the plastic sheet 200 expands and elongates due to temperature rise, and the telescopic end is used to push the pushing member 22 to move. Then, through the transmission connection between the pushing member 22 and the rotating rod 31, the length telescopic amount of the plastic sheet 200 is converted into the rotation angle change amount of the rotating rod 31. Then, as the rotating rod 31 rotates, the linear light source 32 is used to read the rotation angle change amount on the arc-shaped scale plate 33. Then, through the radius of the rotating rod 31 and the radius of the arc-shaped scale plate 33, the telescopic amount of the plastic sheet 200 can be accurately converted, and finally the linear expansion coefficient of the plastic sheet 200 is calculated. With such a setting, the structure of the device is simple, the manufacturing cost is low, and at the same time, the detection is convenient, saving the outsourcing detection cost. Moreover, only by setting the length of the plastic sheet 200 to be longer, the radius of the arc-shaped scale plate 33 to be larger, and the radius of the rotating rod 31 to be smaller, a more accurate linear expansion coefficient can be obtained through conversion.

[0044] It should be noted that there are various specific forms of the transmission connection between the rotating rod 31 and the pushing member 22. The rack can be arranged along the length direction of the plastic sheet 200 on the pushing member 22 in the form of gear-rack meshing transmission, and then the gear is coaxially arranged on the rotating rod 31, so as to realize the conversion of the linear movement of the pushing member 22 into the rotation of the rotating rod 31. The specific form is not limited in this embodiment.

[0045] The arc-shaped scale plate 33 is disposed around the rotating rod 31. The light of the linear light source can directly irradiate the irradiation surface of the arc-shaped scale plate 33. At this time, the center line of the arc where the arc-shaped scale plate 33 is located coincides with the rotation axis of the rotating rod 31. However, in this setting method, the irradiation radius required by the arc-shaped scale plate 33 will cause the overall volume of the device to be relatively large. Based on this, in this embodiment, the expansion conversion device 3 further includes a reflecting lens 34. The reflecting lens 34 is disposed on the side wall of the heat conduction groove 11 relative to the rotating rod 31. The linear light source 32 is arranged facing the reflecting lens 34, and the arc-shaped scale plate 33 is disposed on the reflecting lens 34. Among them, the rotation axis of the rotating rod 31 and the center line of the arc where the arc-shaped scale plate 33 is located are symmetrically arranged relative to the reflecting lens 34. Through the reasonable setting of the arc-shaped scale plate 33 and the rotating rod 31, the rotation axis of the rotating rod 31 and the center line of the arc where the arc-shaped scale plate 33 is located are symmetrically arranged relative to the reflecting lens 34, so that the linear light source 32 can irradiate the mirror image of the arc-shaped scale plate 33, and then be symmetrically irradiated to the arc-shaped scale plate 33 through the specular reflection of the reflecting lens 34. This setting method can reduce the radial distance between the arc-shaped scale plate 33 and the linear light source 32, and only part of the arc segment of the arc-shaped scale plate 33 needs to be used, thereby reducing the overall volume of the device. It is worth mentioning that the length expansion amount of the plastic sheet 200 is generally small, and the converted rotation angle change amount of the rotating rod 31 is also small. By reasonably setting the initial irradiation position of the linear light source 32, the rotation stroke of the rotating rod 31 corresponding to the reflecting lens 34 is sufficient, and the situation where the linear light source 32 rotates with the rotating rod 31 to directly irradiate the arc-shaped scale plate 33 will not occur.

[0046] By reasonably setting the radius of the rotating rod 31 and the radius of the arc-shaped scale plate 33, the expansion and contraction change amount of the plastic sheet 200 can be simply and clearly read on the arc-shaped scale surface. Specifically, in this embodiment, the inner diameter of the arc-shaped scale plate 33 is r1, where r1 = 180 / π mm. Such a setting can make the scale surface circumference of the arc-shaped scale plate 33 be 360 mm, which is convenient for subsequent conversion.

[0047] In another embodiment, the radius of the rotating rod 31 is r2, where r2 = 9 / (2π) mm. With such a setting, when the rotating rod 31 rotates one week, the linear movement amount of the pushing member 22 is 9 mm, which is convenient for subsequent conversion.

[0048] It should be noted that the above two parallel technical features, "the inner diameter of the arc-shaped scale plate 33 is r1, where r1 = 180 / π mm" and "the radius of the rotating rod 31 is r2, where r2 = 9 / (2π) mm", can be set alternatively or simultaneously. Obviously, the effect of setting them simultaneously is better. When setting them simultaneously, when the pushing member 22 drives the rotating rod 31 to rotate one full circle, that is, 360°, the irradiation light of the linear light source 32 can just sweep across 360 mm on the scale surface of the arc-shaped scale plate 33. That is, when the linear light source 32 rotates 40°, the plastic sheet 200 expands or contracts by 1 mm. That is, the expansion and contraction amount of the plastic sheet 200 is magnified by 40 times without additional conversion. It should be noted that for every 1 mm interval on the scale surface of the arc-shaped scale plate 33, there is a 1° change amount.

[0049] The international unit of the linear expansion coefficient is 10 -6 *1 / °C. Based on this, in this embodiment, the length of the plastic sheet 200 is 500 mm. In this way, it is equivalent to magnifying the length change amount of the plastic sheet 200 by 500 times. By controlling the temperature change amount of the plastic sheet 200 within 50°C, it is equivalent to magnifying the temperature change amount of the plastic sheet 200 by 50 times. Combining with the arc-shaped scale plate 33 and the rotating rod 31 to magnify the expansion and contraction amount of the plastic sheet 200 by 40 times, finally obtaining 10 +6 times, corresponding to the international unit 10 -6 *1 / °C, completing the conversion of the elongation amount of the plastic sheet 200 to the angle scale.

[0050] When the plastic sheet 200 is set to be longer in order to obtain a more obvious expansion and contraction amount, the plastic sheet 200 may bend after being heated. To avoid this situation, in this embodiment, the clamping and positioning device 2 further includes a fixed side clamp plate 23 and a movable side clamp plate 24 that are arranged at intervals on the fixed side of the heat conduction groove 11. The fixed side clamp plate 23 and the movable side clamp plate 24 are used to respectively press against both sides in the thickness direction of the plastic sheet 200, and the interval between the movable side clamp plate 24 and the fixed side clamp plate 23 is adjustable. Through the setting of the fixed side clamp plate 23 and the movable side clamp plate 24, the plastic sheet 200 can be clamped from the thickness direction, thereby preventing the plastic sheet 200 from bending during the heating process and ensuring the accuracy of the detection result of the linear expansion coefficient.

[0051] Further, in this embodiment, the movable side clamping plate 24 includes a plurality of abutting blocks 241 arranged at intervals along the length direction of the plastic sheet 200, and the plurality of abutting blocks 241 are used to abut against the plastic sheet 200. With this arrangement, while ensuring that the plastic sheet 200 does not bend, the heat exchange area between the plastic sheet 200 and the heat-conducting liquid is increased, thereby reducing the time for the plastic sheet 200 to reach the temperature of the heat-conducting liquid and improving the detection efficiency.

[0052] In another embodiment, the fixing member 21 is arranged on the fixed side clamping plate 23, and the position of the fixing member 21 along the length direction of the plastic sheet 200 is adjustable. With this arrangement, the linear expansion coefficient detection device 100 can be adapted to measure and detect samples with different thicknesses, improving the general performance. It is worth mentioning that there are various ways to adjust the position of the fixing member 21 along the length direction of the plastic sheet 200. The fixing member 21 can be tightened to the fixed side clamping plate 23 by a tightening stud, or other methods. This embodiment does not limit this.

[0053] In another embodiment, the pushing member 22 is formed with a slider, and the expansion conversion device 3 further includes an installation sliding seat 25. The installation sliding seat 25 is formed with a chute penetrating along the length direction of the plastic sheet 200, and the slider is adaptively arranged in the chute. The telescopic end of the plastic sheet 200 extends into the chute to at least abut against the slider. With this arrangement, the slider can be stably connected through the chute, preventing the pushing member 22 from shifting to ensure the accuracy of the detection. Moreover, since the telescopic end of the plastic sheet 200 extends into the chute, the chute can also play a certain positioning role for the plastic sheet 200, further ensuring the accuracy of the detection result.

[0054] It should be noted that the above three parallel technical solutions can be set selectively, can be set in pairs, or can be set simultaneously. Obviously, the effect of setting simultaneously is better.

[0055] In another embodiment, a plurality of heat-conducting through holes are provided through the thickness direction of the plastic sheet 200 on both the movable side clamping plate 24 and the fixed side clamping plate 23. Through the arrangement of the plurality of heat-conducting through holes, while ensuring that the plastic sheet 200 is tightly clamped, the plastic sheet 200 can fully exchange heat with the heat-conducting liquid, reducing the time for the plastic sheet 200 to reach the temperature of the heat-conducting liquid and improving the detection efficiency.

[0056] In another embodiment, the thickness direction of the plastic sheet 200 is the front-back direction, and the length direction of the plastic sheet 200 is the left-right direction; the expansion conversion device 3 further includes a driving and adjusting device, and the driving and adjusting device includes two driving components and a linkage component. The driving component includes an adjusting rod, a transmission sleeve, and a driving gear ring. The adjusting rod extends along the front-back direction and is arranged on the movable side clamping plate 24. The transmission sleeve is rotatably arranged in the heat conduction groove 11 along the front-back axis. The transmission sleeve is connected to the adjusting rod through a threaded connection pair. The driving gear ring is coaxially sleeved on the periphery of the transmission sleeve. The two driving components are respectively arranged at the left and right ends of the movable side clamping plate 24. The linkage component includes a transmission belt. The inner side of the transmission belt is formed with transmission teeth. The transmission belt is engaged with the corresponding two driving gear rings through the transmission teeth. The outer side of the transmission belt is further formed with a holding convex part. Through the holding convex part, the tester can drive the transmission belt to rotate, so as to drive the two driving gear rings to rotate simultaneously, and then drive the corresponding adjusting rods to move back and forth through the threaded pairs of the two transmission sleeves, that is, drive the distance between the movable side clamping plate 24 and the fixed side clamping plate 23 to be adjusted to adapt to plastic sheets 200 with different thicknesses.

[0057] There are various specific forms of the transmission connection between the rotating rod 31 and the pushing member 22. Specifically, in this embodiment, the expansion conversion device 3 further includes a support column 35 and a flexible traction rope 36. The support column 35 is arranged in the heat conduction groove 11 and on the same side of the plastic sheet 200 relative to the pushing member 22. The flexible traction rope 36 passes around the support column 35 to have a first traction section 361 and a second traction section 362. The first traction section 361 is wound around the rotating rod 31. The second traction section 362 extends along the length direction of the plastic sheet 200 and is arranged on the pushing member 22. By arranging the second traction section 362 to extend along the length direction of the plastic sheet 200, the telescopic change amount of the plastic sheet 200 can be accurately converted into the linear movement amount of the second traction section 362, so as to drive the rotating rod 31 to rotate a corresponding angle through the winding of the first traction section 361, ensuring the accuracy of the detection; moreover, through the arrangement of the support column 35 and the flexible traction rope 36 passing around the support column 35, the rotating rod 31 and the arc-shaped scale plate 33 can be arranged on one side of the elongation direction of the plastic sheet 200, thereby reducing the width of the linear expansion coefficient detection device 100 and reducing the use of the flexible traction rope 36, that is, reducing the telescopic change amount generated during the self-traction process of the flexible traction rope 36 and ensuring the accuracy of the detection. It should be noted that the flexible traction rope 36 is a non-elastic rope.

[0058] Further, in this embodiment, the expansion conversion device 3 further includes a tension column 38, which is disposed between the support column 35 and the rotating rod 31 and is located on the side of the support column 35 away from the pushing member 22. A part of the first traction section 361 is tensioned around the tension column 38, thereby preventing the first traction section 361 from interfering with the movement stroke of the pushing member 22.

[0059] In this embodiment, the expansion conversion device 3 further includes an elastic tension rope 37. One end of the elastic tension rope 37 is wound around the rotating rod 31, and the other end is disposed on the side wall of the heat conduction groove 11. By providing the elastic tension rope 37, a reverse torque can be constantly provided to the rotating rod 31, thereby preventing the rotating rod 31 from rotating excessively under the driving of the pushing member 22 and ensuring the accuracy of the reading of the arc scale plate 33.

[0060] Moreover, please refer to Figure 3 , the present invention also provides a linear expansion coefficient detection method for the above linear expansion coefficient detection device 100. The linear expansion coefficient detection method includes the following steps:

[0061] S100: Install the plastic sheet 200 on the clamping and positioning device 2 so that the fixing member 21 abuts against the fixed end and the pushing member 22 abuts against the telescopic end;

[0062] S200: Place the plastic sheet 200 statically in a heat-conducting liquid at an initial temperature and maintain it for a first set time;

[0063] S300: Detect the initial length of the plastic sheet 200 and read the initial angle value of the arc scale plate 33;

[0064] S400: Heat the heat-conducting liquid to a target temperature and maintain it for a second set time;

[0065] S500: Read the final angle value of the arc scale plate 33, calculate the angle change amount according to the initial angle value and the final angle value, and calculate the length change amount of the plastic sheet 200 according to the angle change amount;

[0066] S600: Calculate the temperature difference according to the initial temperature and the target temperature, and calculate the linear expansion coefficient of the plastic sheet 200 according to the temperature difference, the length change amount and the initial length;

[0067] By heating and insulating the plastic sheet 200 at different temperatures, measuring the temperature difference while ensuring that the expansion of the plastic sheet 200 reaches stability, and finally calculating the linear expansion coefficient of the plastic sheet 200 based on the temperature difference, the change in length, and the initial length of the plastic sheet 200, the method is simple and effective and easy to operate. Moreover, by reasonably setting the inner diameter of the arc-shaped scale plate 33, the radius of the rotating rod 31, the temperature difference, and the initial length of the plastic sheet 200, the change in length can be directly read from the arc-shaped scale plate 33, eliminating the need for calculation.

[0068] Specifically, in this embodiment, the initial temperature is T1 and the target temperature is T2, where T2 - T1 = 50°C. By setting the temperature difference between the initial temperature and the target temperature to 50°C, and by controlling the temperature change of the plastic sheet 200 within 50°C, it is equivalent to magnifying the temperature change of the plastic sheet 200 by 50 times, which is beneficial to the expansion and elongation of the plastic sheet 200, thereby more accurately detecting the linear expansion coefficient of the plastic sheet 200.

[0069] Specifically, in this embodiment, the first set duration is t1, where t1 = 30 min. By insulating for 30 min, the plastic sheet 200 is fully heat-exchanged with the heat-conducting liquid and stably reaches the initial temperature.

[0070] In another embodiment, the second set duration is t2, where t2 = 30 min. By insulating for 30 min, the plastic sheet 200 is fully heat-exchanged with the heat-conducting liquid and stably reaches the target temperature.

[0071] It should be noted that the above two parallel embodiments, "the first set duration is t1, where t1 = 30 min" and "the second set duration is t2, where t2 = 30 min", can be set alternatively or simultaneously. Obviously, the effect of setting them simultaneously is better.

[0072] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A linear expansion coefficient detection device for detecting the linear expansion coefficient of a plastic sheet. The plastic sheet has a fixed end and a telescopic end opposite to each other in the length direction, and is characterized in that The linear expansion coefficient detection device comprises: A mounting base is formed with a heat-conducting groove which is opened upward, and the heat-conducting groove is used to contain heat-conducting liquid and the plastic sheet; A clamping and positioning device, comprising a fixing member and a pushing member provided in the heat-conducting groove, wherein the fixing member is used to abut against the fixing end, the pushing member is used to abut against the telescopic end, and the pushing member can be pushed by the plastic sheet material to move after the plastic sheet material is thermally deformed; and The expansion conversion device comprises a rotating rod, a linear light source and an arc scale plate, wherein the rotating rod is rotatably arranged on the mounting base along an axis in the up-down direction, and the push member is transmission-connected to the rotating rod to convert the linear motion of the push member into the rotational motion of the rotating rod, the linear light source is arranged on the rotating rod and irradiates in the radial direction of the rotating rod, and the arc scale plate is arranged around the rotating rod relative to the linear light source; The expansion conversion device further comprises a reflective lens, which is arranged on the side wall of the heat conduction groove relative to the rotating rod, the line light source is arranged toward the reflective lens, and the arc scale plate is arranged on the reflective lens, wherein the rotation axis of the rotating rod and the center line of the arc where the arc scale plate is located are symmetrically arranged relative to the reflective lens; The expansion conversion device also includes: a support column, disposed in the heat-conducting groove and located on the same side of the plastic sheet relative to the pushing member; and A flexible traction rope is wound around the support column to have a first traction section and a second traction section, wherein the first traction section is wound around the rotating rod, and the second traction section extends along the length direction of the plastic sheet and is arranged on the pushing member; The expansion conversion device also includes an elastic tension rope, one end of which is wound around the rotating rod, and the other end of which is arranged on the side wall of the heat conduction groove.

2. The linear expansion coefficient detection device according to claim 1, characterized in that, The inner diameter of the arc-shaped scale plate is r1, wherein r1=180 / πmm; and / or, The radius of the rotating rod is r2, where r2=9 / (2π) mm.

3. The linear expansion coefficient detection device according to claim 1, characterized in that, The clamping and positioning device also includes a fixed side clamp and a movable side clamp arranged at intervals in the heat conducting groove, the fixed side clamp and the movable side clamp are used to respectively press against the two sides of the thickness direction of the plastic sheet, and the interval between the movable side clamp and the fixed side clamp is adjustable.

4. The linear expansion coefficient detecting device according to claim 3, wherein The movable side clamping plate comprises a plurality of abutment blocks arranged at intervals along the length direction of the plastic sheet material, and the plurality of abutment blocks are used to abut against the plastic sheet material; and / or, The fixing member is arranged on the fixed side clamping plate, and the position of the fixing member along the length direction of the plastic sheet is adjustable; and / or, The push member is formed with a slider, and the expansion conversion device also includes a mounting slide seat, the mounting slide seat is formed with a slide groove that penetrates along the length direction of the plastic sheet, the slider is adapted to be arranged in the slide groove, and the telescopic end of the plastic sheet extends into the slide groove to at least abut against the slider.

5. A linear expansion coefficient detection method, which is used for the linear expansion coefficient detection device described in any one of claims 1 to 4, and is characterized in that, The linear expansion coefficient detection method comprises the following steps: Installing the plastic sheet to the clamping and positioning device so that the fixing member abuts against the fixing end and the pushing member abuts against the telescopic end; Place the plastic sheet statically in the heat-conducting liquid at the initial temperature and maintain for the first set duration; Detect the initial length of the plastic sheet and read the initial angle value of the arc scale plate; Heat the heat-conducting liquid to the target temperature and maintain for the second set duration; Read the final angle value of the arc scale plate, calculate the angle change amount based on the initial angle value and the final angle value, and calculate the length change amount of the plastic sheet according to the angle change amount; Calculate the temperature difference based on the initial temperature and the target temperature, and calculate the linear expansion coefficient of the plastic sheet according to the temperature difference, the length change amount and the initial length; 6. The linear expansion coefficient detection method according to claim 5, wherein, The initial temperature is T1, and the target temperature is T2, where T2 - T1 = 50 °C; 7. The linear expansion coefficient detection method according to claim 5, characterized in that The first set duration is t1, where t1 = 30 min; and / or The second set duration is t2, where t2 = 30 min.

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