A kind of top rod type displacement measuring device and system

Abstract

The present application provides a mandrel type displacement measuring device and system, wherein the measuring device includes a mandrel, a first sleeve, a preload, an elastic member and a displacement sensor; the mandrel is a high temperature resistant mandrel, one end of which is a conical structure, configured to contact a point to be measured in a high temperature furnace, and the other end passes through the first sleeve or is located in the first sleeve, and is connected to the displacement sensor; the preload is located in the first sleeve and can be fixed relative to the mandrel; the elastic member is sleeved on the periphery of the mandrel and is located between the preload and the inner bottom wall of the first sleeve, and the mandrel and the preload are configured to be able to move along the axis of the first sleeve and compress the elastic member. The present application can measure the displacement of an object in a test under a high temperature environment, and by performing point displacement measurement on the point to be measured, the influence of the uneven surface of the object to be measured on the measurement result is reduced, thereby improving the measurement accuracy.

Description

Technical Field

[0001] The present application relates to the technical field of equipment measurement and monitoring, and in particular to a push rod type displacement measurement device and system. Background Art

[0002] With the rapid development of weapons and equipment, the requirements for metrology and testing technology are becoming higher and higher. Many measurement environments in aerospace, aviation, military and other industries need to be carried out in harsh environments such as high temperature. Traditional measurement devices cannot adapt to harsh environments such as high temperature. Therefore, it is necessary to conduct research on high-temperature displacement measurement devices.

[0003] At present, in large-scale static thermal tests, static thermal tests of the whole bomb or compartment level need to be carried out in a high temperature environment (usually in a high temperature furnace). Displacement measurement generally uses high temperature resistant displacement sensors to directly perform contact measurement on the measurement points, but there are also two problems:

[0004] 1) Since the surface of the cabin is curved, it is difficult to fix the sensor, the measurement accuracy is low, and the sensor is easy to damage the surface of the cabin;

[0005] 2) The upper temperature limit of the current high-temperature resistant displacement sensor is around 500°C, and the temperature condition of the static thermal test reaches up to 1000°C. Under ultra-high temperature conditions, the displacement sensor cannot be used normally. Summary of the invention

[0006] In view of this, the purpose of the present application is to provide a push rod type displacement measurement device and system to solve the above problems.

[0007] Based on the above purpose, the present application provides a push rod type displacement measuring device, including a push rod, a first sleeve, a preload member, an elastic member and a displacement sensor;

[0008] The ejector rod is a high temperature resistant ejector rod, one end of which is a conical structure and is configured to contact the point to be measured in the high temperature furnace, and the other end passes through the first sleeve or is located in the first sleeve and is connected to the displacement sensor;

[0009] The pre-tightening member is located in the first sleeve and can be fixed relative to the ejector rod;

[0010] The elastic member is sleeved on the outer periphery of the push rod and is located between the pre-tightening member and the inner bottom wall of the first sleeve, and the push rod and the pre-tightening member are configured to move along the axis of the first sleeve and compress the elastic member;

[0011] The upper limit temperature of the high temperature resistant ejector pin is greater than 1000°C.

[0012] Furthermore, the measuring device also includes a second sleeve, one end of the push rod having a conical structure passes through the second sleeve, the second sleeve is fixedly connected to the first sleeve, and the bottom wall of the second sleeve is abutted against or arranged away from the preload member.

[0013] Furthermore, the preload member includes a third sleeve, which is sleeved on the periphery of the push rod. The inner end of the third sleeve is a bell-mouth structure, and its end is a flared end, and the outer diameter of the contracted end is the same as the outer diameter of the push rod.

[0014] Furthermore, the preload member further comprises a locking nut and an O-ring, the locking nut comprises a threaded section and a limiting section, the threaded section is sleeved on the periphery of the third sleeve and is threadedly connected, the limiting section abuts against the bell mouth structure and is provided with a through hole for the push rod to pass through;

[0015] The O-type gasket is sleeved on the periphery of the push rod and is at least partially located in the bell-mouth structure of the third sleeve, and the limiting section of the locking nut abuts against the O-type gasket so that the inner ring of the O-type gasket is in close contact with the push rod.

[0016] Furthermore, a groove for the displacement sensor to pass through is provided on the bottom side wall of the first sleeve, and the displacement sensor moves away from or passes through the groove as the push rod moves.

[0017] Furthermore, the port of the first sleeve is sleeved on the outer periphery of the second sleeve, and the two are threadedly connected.

[0018] Furthermore, the top rod is a glass rod.

[0019] A mandrel type displacement measurement system comprises a fixed bracket and the above-mentioned measuring device, wherein the fixed bracket is fixedly connected to the measuring device.

[0020] Furthermore, the measurement system also includes a base, and the fixed bracket is located on the base and connected to the base.

[0021] Furthermore, a gap is provided on the side wall of the high-temperature furnace for the ejector rod to pass through.

[0022] From the above, it can be seen that the present application provides a push rod type displacement measuring device and system, in which the push rod is set to be a high temperature resistant push rod, and the displacement is measured by contacting the push rod with the point to be measured, so that the measuring device can perform displacement measurement in a high temperature environment. In addition, the contact end of the push rod and the point to be measured is set to a conical structure, so that the push rod and the point to be measured are contacted and measured point-to-point, which improves the measurement accuracy while reducing the damage to the outer surface of the object to be measured. In addition, the preload member and the elastic member are set to apply a certain preload force to the push rod, which can ensure that the push rod changes with the change of the displacement of the point to be measured, thereby further ensuring the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of the structure of the ejector-type displacement measuring device according to an embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of the installation process of the ejector-type displacement measuring device according to an embodiment of the present application;

[0026] Figure 3 It is a cross-sectional structural schematic diagram of the positional relationship between the third sleeve and the O-ring in the embodiment of the present application;

[0027] Figure 4 This is a three-dimensional schematic diagram of a push rod type displacement measuring device according to an embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the structure of the ejector-type displacement measurement system according to an embodiment of the present application.

[0029] In the figure: 1, push rod; 2, first sleeve; 3, preload member; 31, third sleeve; 32, locking nut; 33, O-ring; 4, elastic member; 5, displacement sensor; 6, second sleeve; 7, fixing bracket; 8, base; 9, bell-mouth structure; 91, flared end; 92, contracted end. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0031] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] As described in the background technology section, in the related art, in order to achieve the purpose of displacement measurement in a static thermal experiment in a high temperature environment, a high temperature resistant displacement sensor is generally used to directly perform contact measurement on the measurement object.

[0033] However, the applicant has found through research that the above method has corresponding problems: the upper limit temperature of the high-temperature resistant displacement sensor is about 500°C, and the high-temperature resistant displacement sensor cannot adapt to the temperature in the static heat experiment. In addition, the measured object is a curved surface, and the displacement sensor is directly used to contact the measured object to measure the displacement. The result obtained is of low accuracy, and the displacement sensor is easy to damage the contact surface of the measured object. This not only increases the measurement cost, but also the measurement results are inaccurate, which is not conducive to subsequent experimental research.

[0034] like Figure 1 As shown, in view of this, this embodiment provides a push rod type displacement measuring device, including a push rod 1, a first sleeve 2, a preload member 3, an elastic member 4 and a displacement sensor 5;

[0035] The push rod 1 is a high temperature resistant push rod with an upper limit temperature greater than 1000°C. One end of the push rod 1 is a conical structure, which is configured to contact the point to be measured in the high temperature furnace. The other end passes through the first sleeve 2 or is located in the first sleeve 2 and is connected to the displacement sensor 5. The displacement sensor 5 can slide through the bottom wall of the first sleeve 2 or slide in the first sleeve 2 under the drive of the push rod 1. The displacement sensor 5 and the push rod 1 slide smoothly in the first sleeve 2. One end of the conical structure of the push rod 1 contacts the point to be measured and moves with the movement of the point to be measured. Correspondingly, the displacement sensor 5 moves with the movement of the push rod 1. The displacement sensor 5 can measure the displacement of the point to be measured in the high temperature furnace in a non-high temperature environment. In addition, one end of the conical structure of the push rod 1 contacts the point to be measured, so that the push rod 1 contacts the point to be measured point-to-point, which reduces the damage to the outer surface of the object to be measured during the measurement process.

[0036] The preload member 3 is located in the first sleeve 2 and can be fixed relative to the push rod 1;

[0037] The elastic member 4 is sleeved on the outer periphery of the push rod 1 and is located between the preload member 3 and the inner bottom wall of the first sleeve 2. The push rod 1 and the preload member 3 are configured to move along the axis of the first sleeve 2 and compress the elastic member 4. The preload member 3 can apply a certain preload force to the push rod 1 under the action of the elastic force of the elastic member 4, so that the push rod 1 moves with the movement of the point to be measured. The preload force ensures that the push rod 1 is in stable contact with the point to be measured, thereby ensuring the accuracy of the measurement result.

[0038] In some embodiments, both ends of the elastic member 4 are ground and contact the preload member 3 and the inner bottom wall of the first sleeve 2 respectively, which can ensure that the elastic member 4 is stably subjected to the compression force and further ensure the stability of the measuring device.

[0039] In some embodiments, one end of the elastic member 4 is fixedly connected to the preload member 3, and the other end is abutted against the inner bottom wall of the first sleeve 2. The fixed connection between the elastic member 4 and the preload member 3 can further ensure the contact between the preload member 3 and the elastic member 4, so that the preload member 3 can stably apply compression force to the elastic member 4, and when the elastic member 4 rebounds, the elastic member 4 can apply a stable rebound force to the preload member 3, and correspondingly apply a stable rebound force to the push rod 1, thereby ensuring that the push rod 1 applies a stable force to the point to be measured, thereby ensuring the stability of the measurement process of the measuring device and the accuracy of the measurement results during the measurement process.

[0040] In addition, the displacement sensor 5 is connected to a data acquisition device and a data analysis device, which can collect and analyze the displacement data obtained by the displacement sensor 5, and perform force and displacement analysis on the measurement results of the measuring device, which is beneficial to the result analysis of the static thermal experiment.

[0041] Figure 4 When using the measuring device, align the conical structure end of the push rod 1 with the point to be measured, then fix the measuring device, compress the push rod 1 so that the conical structure end of the push rod 1 contacts the point to be measured, release the compression force on the push rod 1, debug the displacement sensor 5 and the data acquisition equipment and data analysis equipment connected thereto, and start the measurement. The preload member 3 moves the push rod 1 with the displacement change of the point to be measured under the rebound force of the elastic member 4. Correspondingly, the displacement sensor 5 connected to the push rod 1 also moves with the displacement change of the point to be measured, and then the measurement result of the displacement sensor 5 is the displacement measurement result of the point to be measured. The measuring device allows the push rod 1 to measure point-to-point with the object to be measured, which not only causes less damage to the surface of the object to be measured, but also improves the displacement measurement accuracy.

[0042] In addition, the measuring device can perform displacement measurement not only in a high temperature environment, but also in a low temperature environment. The measuring device can also set the push rod 1 and the elastic member 4 of different lengths according to the specific characteristics of the object to be measured to meet the displacement measurement requirements, making the measuring device extremely applicable.

[0043] In some embodiments, the measuring device also includes a second sleeve 6, and one end of the push rod 1 with a conical structure passes through the second sleeve 6. The second sleeve 6 is fixedly connected to the first sleeve 2, and the bottom wall of the second sleeve 6 is abutted against or separated from the preload member 3. The second sleeve 6 is fixedly connected to the opening of the first sleeve 2, which can not only seal the preload member 3 and the elastic member 4 to avoid damage by external force, but also limit the preload member 3 and the elastic member 4. Accordingly, the moving range of the push rod 1 is limited, so that the displacement measurement of the measuring device is within a certain range to avoid exceeding the range, which will reduce the rebound force exerted by the elastic member 4 and affect the measurement accuracy of the measuring device.

[0044] In some embodiments, the elastic member 4 is a spring. Optionally, the spring wire diameter of the spring is 0.8 mm, the pitch is 2.89 mm, the effective number of turns is 16, the number of supporting turns is 3, and the free length is 40-50 mm. The lengths of the first sleeve 2 and the second sleeve 6 and the moving range of the displacement sensor 5 are set according to the performance parameters of the spring, which can effectively ensure the accuracy of the measurement results of the measuring device.

[0045] In addition, the length and diameter of the push rod 1 are set according to the performance parameters of the elastic member 4 to ensure that the measuring device can stably perform the displacement measurement function.

[0046] In some embodiments, Figure 3 As shown, the preload member 3 includes a third sleeve 31, and the third sleeve 31 is sleeved on the periphery of the push rod 1. The inner end of the third sleeve 31 is a bell-mouth structure 9, and its end is a flared end 91. The diameter of the contracted end 92 is slightly larger than the outer diameter of the push rod 1. The middle inner diameter of the third sleeve 31 is the same as the diameter of the contracted end 92. The corresponding minimum inner diameter of the third sleeve 31 is slightly larger than the outer diameter of the push rod 1, so that the third sleeve 31 can be sleeved on the periphery of the push rod 1 and fixed relative to the push rod 1, thereby making the preload member 3 fixed relative to the push rod 1.

[0047] In some embodiments, the preload member 3 further includes a locking nut 32 and an O-ring 33, the locking nut 32 includes a threaded section and a limiting section, the threaded section is sleeved on the periphery of the third sleeve 31 and is threadedly connected, the limiting section is arranged opposite to the bell mouth structure 9, and is provided with a through hole for the push rod 1 to pass through;

[0048] The O-ring 33 is sleeved on the periphery of the push rod 1 and is at least partially located in the bell-mouth structure 9 of the third sleeve 31. The limiting section of the locking nut 32 presses the O-ring toward the tapered end 92 so that the inner ring of the O-ring 33 is in close contact with the push rod 1.

[0049] The push rod 1 passes through the locking nut 32, and the locking nut 32 is threadedly connected to the outer periphery of the third sleeve 31. By rotating the locking nut 32, the limiting section gradually approaches the end of the third sleeve 31. The O-ring 33 is located in the bell-mouth structure 9 of the third sleeve 31 and is sleeved on the outer periphery of the push rod 1. The inner diameter of the O-ring 33 is slightly larger than the outer diameter of the push rod 1. When the limiting section abuts against the end of the third sleeve 31, the limiting section applies a force to the O-ring 33 directed to the shrinking end 92, that is, the O-ring further moves toward the shrinking end 92, and the corresponding The inner wall of the bell-mouth structure 9 with a gradually decreasing inner diameter applies a pressure perpendicular to its inner wall to the O-ring 33, and the separation of the pressure in the direction perpendicular to the axis of the push rod 1 will press the O-ring 33 into close contact with the periphery of the push rod 1 and the inner wall of the third sleeve 31, thereby increasing the friction between the O-ring 33 and the push rod 1 and the third sleeve 31, and increasing the fixing force between the third sleeve 31 and the push rod 1, so that the third sleeve 31 is more stable on the push rod 1, and the preload member 3 is more stable on the push rod 1, so that the measuring device can more stably perform the displacement measurement function.

[0050] Optionally, two of the locking nut 32 and the O-ring 33 are provided, respectively located at the two ends of the third sleeve 31 , and their combined effect makes the fixing effect between the third sleeve 31 and the push rod 1 stronger.

[0051] In some embodiments, a groove for the displacement sensor 5 to pass through is provided on the bottom side wall of the first sleeve 2. The displacement sensor 5 moves away from or through the groove as the push rod 1 moves. The displacement sensor 5 moves with the movement of the push rod 1. In order to prevent the bottom side wall of the first sleeve 2 from limiting the displacement sensor 5, a groove for the displacement sensor 5 to pass through is provided on the bottom side wall of the first sleeve 2. The displacement sensor 5 can pass smoothly through the groove, thereby preventing the groove from generating a reaction force on the displacement of the displacement sensor 5 and affecting the measurement accuracy of the measuring device.

[0052] Accordingly, the push rod 1 passes smoothly through the first sleeve 2 and the second sleeve 6, thereby preventing the first sleeve 2 and the second sleeve 6 from generating reaction force on the push rod 1 and affecting the displacement of the push rod 1, thereby affecting the measurement accuracy of the measuring device.

[0053] In some embodiments, the port of the first sleeve 2 is sleeved on the periphery of the second sleeve 6, and the two are threadedly connected. The threaded connection between the first sleeve 2 and the second sleeve 6 can not only meet the needs of fixed connection, but also facilitate the installation and disassembly of the measuring device, which meets the actual needs. In addition, the first sleeve 2 is sleeved on the periphery of the second sleeve 6, and the position of the second sleeve 6 can be adjusted according to the position of the preload 3, so that the second sleeve 6 can flexibly limit the preload 3, so that the measuring device can flexibly adjust the position of the second sleeve 6 during use to flexibly limit the preload 3, thereby meeting the needs of displacement measurement.

[0054] In some embodiments, the top rod 1 is a glass rod, and the glass used to make the glass rod has a melting point greater than 1000°C, so that the glass rod can stably perform the function of displacement measurement in a high temperature environment of 1000°C in a static thermal experiment without affecting the measurement accuracy.

[0055] In addition, the push rod 1 can be made of any material with a melting point greater than the temperature of the static thermal experiment environment. The higher the melting point, the less the push rod 1 is affected by the elastic force of the elastic member 4, and the displacement measurement accuracy is not affected.

[0056] like Figure 2 As shown, the installation process of the measuring device is as follows: the first step is to install the third sleeve 31 and the O-ring 33 with the push rod 1, and the third sleeve 31 and the O-ring 33 are both sleeved on the outer periphery of the push rod 1; the second step is to install the locking nut 32 and rotate the locking nut 32 to press the O-ring 33 into the third sleeve 31 and make the O-ring 33 pressed against the third sleeve 31 and the push rod 1; the third step is to pass the elastic member 4 through the end of the push rod 1 away from the conical structure and contact / connect with the locking nut 32; the fourth step is to put the installed structure into the first sleeve 2, and the end of the push rod 1 close to the elastic member 4 passes through the bottom wall of the first sleeve 2 and is connected to the displacement sensor 5; the fifth step is to connect and fix the second sleeve 6 to the first sleeve 2. The installed measuring device is shown in FIG. Figure 4 shown.

[0057] like Figure 5 As shown, this embodiment provides a top rod type displacement measurement system, including a fixed bracket 7 and the above-mentioned measuring device, the fixed bracket 7 is fixedly connected to the measuring device, the measuring device is installed on the fixed bracket 7 and fixed, which meets the displacement measurement work needs of the measuring device, and there is no need to manually hold the measuring device during the measurement process.

[0058] In some embodiments, the measuring device is fixedly connected to the fixing bracket 7 by bolts, so as to facilitate the installation of the measuring device.

[0059] In some embodiments, the measuring system also includes a base 8, the fixed bracket 7 is located on the base 8 and connected to the base 8, and the fixed bracket 7 is fixed relative to the base 8, so that the fixed bracket 7 can more stably support the measuring device. In addition, the fixed bracket 7 can adjust its position on the support to facilitate the displacement measurement of the measured point, thereby improving the applicability of the measuring system.

[0060] In some embodiments, a slotted structure is provided on the base 8, a slide rail is provided in the slotted structure, the fixed bracket 7 is located in the slotted structure and connected to the slide rail, and can move along the slotted structure to meet the needs of different displacement measurements. When the fixed bracket 7 moves to a suitable position, a limiting fixing member is provided in the slide rail to fix the fixed bracket 7.

[0061] In some embodiments, a gap is provided on the side wall of the high-temperature furnace for the push rod 1 to pass through, and the gap is as small as possible without applying force to the push rod 1. When the point to be measured is located in the high-temperature furnace, the measuring device needs to pass through the side wall of the high-temperature furnace to perform displacement measurement on the point to be measured. The gap provided on the side wall of the high-temperature furnace for the push rod 1 to pass through can not affect the movement of the push rod 1, so that the measurement result of the measurement system is more accurate.

[0062] In addition, the high temperature furnace can also be located on the base 8, so that the measuring system can more conveniently measure the object to be measured located in the high temperature furnace.

[0063] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0064] The various embodiments in the present application are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] The description of the present application is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the present application to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present application, and to enable those of ordinary skill in the art to understand the present application and thus design various embodiments with various modifications suitable for specific purposes.

[0066] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0067] Although the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.

[0068] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A push rod type displacement measuring device, characterized in that: It includes a push rod, a first sleeve, a preload member, an elastic member, a displacement sensor, a second sleeve, a third sleeve, a locking nut and an O-type washer; The ejector rod is a high temperature resistant ejector rod, one end of which is a conical structure and is configured to contact the point to be measured in the high temperature furnace, and the other end passes through the first sleeve or is located in the first sleeve and is connected to the displacement sensor; The pre-tightening member is located in the first sleeve and can be fixed relative to the ejector rod; The elastic member is sleeved on the outer periphery of the push rod and is located between the pre-tightening member and the inner bottom wall of the first sleeve, and the push rod and the pre-tightening member are configured to move along the axis of the first sleeve and compress the elastic member; One end of the push rod having a conical structure passes through the second sleeve, the second sleeve is fixedly connected to the first sleeve, and the bottom wall of the second sleeve is in contact with or away from the preload member; The third sleeve is sleeved on the outer periphery of the push rod, the inner end of the third sleeve is a bell mouth structure, and the end thereof is a flared end, and the outer diameter of the shrunken end is the same as the outer diameter of the push rod; The locking nut comprises a threaded section and a limiting section, the threaded section is sleeved on the periphery of the third sleeve and is threadedly connected, the limiting section abuts against the bell mouth structure and is provided with a through hole for the push rod to pass through; The O-type gasket is sleeved on the outer periphery of the push rod and is at least partially located in the bell mouth structure of the third sleeve, and the limiting section of the locking nut abuts against the O-type gasket so that the inner ring of the O-type gasket is in close contact with the push rod; A groove for the displacement sensor to pass through is provided on the side wall at the bottom of the first sleeve, and the displacement sensor moves away from or passes through the groove as the push rod moves; Wherein, the upper limit temperature of the high temperature resistant ejector rod is greater than 1000°C.

2. A push rod type displacement measuring device according to claim 1, characterized in that: The port of the first sleeve is sleeved on the outer periphery of the second sleeve, and the two are threadedly connected.

3. A push rod type displacement measuring device according to claim 1, characterized in that: The top rod is a glass rod.

4. A mandrel type displacement measurement system, characterized in that: It comprises a fixed bracket and a measuring device as described in any one of claims 1 to 3, wherein the fixed bracket is fixedly connected to the measuring device.

5. A push rod type displacement measurement system according to claim 4, characterized in that: It also includes a base, and the fixing bracket is located on the base and connected to the base.

6. A push rod type displacement measurement system according to claim 4, characterized in that: The side wall of the high-temperature furnace is provided with a gap for the ejector rod to pass through.

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