阅读说明：本技术 一种利用手持红外设备标定压力的方法 (Method for calibrating pressure by using handheld infrared equipment ) 是由 蒋忠亮 许志峰 于 2020-07-03 设计创作，主要内容包括：本发明公开了一种利用手持红外设备标定压力的方法,将抽真空开关(4)顺时针旋转并拧紧,直至抽真空开关(4)的第四上端圆平面与抽真空内腔(2)的第二下端向上同心圆环面齐平；本发明可以精确控制吸出或挤入气体的体积,进而可以对封闭空间内部气体压力精确控制。与原方案相比,降低了气体压力值的误差,对内应力释放装置参数的标定更加准确,获得的数据更加可靠。从而,内应力释放装置在薄壁壳体上使用时,能更可靠的发挥效果。(The invention discloses a method for calibrating pressure by using handheld infrared equipment, which comprises the steps of clockwise rotating and screwing a vacuum-pumping switch (4) until a fourth upper end circular plane of the vacuum-pumping switch (4) is flush with a second lower end upward concentric circular ring surface of a vacuum-pumping inner cavity (2); the invention can accurately control the volume of the sucked or squeezed gas, thereby accurately controlling the pressure of the gas in the closed space. Compared with the original scheme, the method reduces the error of the gas pressure value, more accurately calibrates the parameters of the internal stress release device, and more reliably obtains data. Therefore, when the internal stress releasing device is used on the thin-wall shell, the effect can be exerted more reliably.)

1. A method for calibrating pressure by using handheld infrared equipment comprises a vacuum-pumping hose (3) and a pressure gauge (5), and is characterized by further comprising a power piston (1), a vacuum-pumping inner cavity (2), a vacuum-pumping switch (4) and an exhaust switch (6);

the power piston (1) is a first cylinder, the first cylinder of the power piston (1) is a rotary body, the lower surface of the first cylinder of the power piston (1) is a first lower end circular plane, the side surface of the first cylinder of the power piston (1) is a first outer cylindrical surface, the upper surface of the first cylinder of the power piston (1) is a first upper end circular plane, a first cylindrical boss is arranged at the center of the first upper end circular plane of the power piston (1), the rotary body axis of the first cylindrical boss of the power piston (1) is superposed with the rotary body axis of the first cylinder of the power piston (1), and a first external thread is arranged on the side surface of the first cylindrical boss of the power piston (1);

the axis of the revolving body of the power piston (1) is vertical to the ground;

the vacuumizing inner cavity (2) is a second cylinder body, the second cylinder body of the vacuumizing inner cavity (2) is a revolving body, the inner side surface of the second cylinder body of the vacuumizing inner cavity (2) is a second inner cylindrical surface, the upper end of the second inner cylindrical surface of the vacuumizing inner cavity (2) is provided with a second upper end inner flange, the inner side surface of the second upper end inner flange of the vacuumizing inner cavity (2) is provided with a second upper end internal thread, the lower end surface of the second upper end inner flange of the vacuumizing inner cavity (2) is a second upper end downward concentric circular ring surface, the lower end surface of the second inner cylindrical surface of the vacuumizing inner cavity (2) is provided with a second lower end inner flange, the upper end surface of the second lower end inner flange of the vacuumizing inner cavity (2) is a second lower end upward concentric circular ring surface, the lower end surface of the second lower end inner flange of the vacuumizing inner cavity (2) is a second lower end downward concentric circular ring surface, the inner side surface of the second lower end inner flange of the vacuumizing inner cavity (, the lower end of the inner cylindrical surface of the second lower end of the vacuumizing inner cavity (2) is provided with a second lower end internal thread, the middle part of the inner cylindrical surface of the second lower end of the vacuumizing inner cavity (2) is provided with a second annular groove, the left end of the lower surface of the second annular groove of the vacuumizing inner cavity (2) is provided with a second left end circular through hole, the axis of the second left end circular through hole of the vacuumizing inner cavity (2) is parallel to the axis of the revolving body of the vacuumizing inner cavity (2), the second left end circular through hole of the vacuumizing inner cavity (2) is communicated with the second annular groove of the vacuumizing inner cavity (2) and the lower part of the downward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2), the right end of the lower surface of the second annular groove of the vacuumizing inner cavity (2) is provided with a second right end circular through hole, the axis of the second right end circular through hole of the vacuumizing inner cavity (2) is parallel to the axis of the revolving body of the vacuumizing inner cavity (2), and the lower part of a second lower end downward concentric circular ring surface of the inner cavity (2), the right end edge of the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2) is provided with a second right end edge circular through hole, the axis of the second right end edge circular through hole of the vacuumizing inner cavity (2) is parallel to the axis of the revolution body of the vacuumizing inner cavity (2), the second right end edge circular through hole of the vacuumizing inner cavity (2) is communicated with the upper part of the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2) and the lower part of the downward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2), the inner side surface of the second right end edge circular through hole of the vacuumizing inner cavity (2) is a second right end inner circular cylindrical surface, and the lower end of the second right end inner cylindrical surface;

the axis of a revolving body of the vacuumizing inner cavity (2) coincides with the axis of a revolving body of the power piston (1), a first cylinder of the power piston (1) is positioned inside a second cylinder of the vacuumizing inner cavity (2), a first upper end circular plane of the power piston (1) is positioned at the lower end of a downward concentric circular ring surface at the second upper end of the vacuumizing inner cavity (2), a first lower end circular plane of the power piston (1) is positioned at the upper end of an upward concentric circular ring surface at the second lower end of the vacuumizing inner cavity (2), a first external thread of the power piston (1) is matched with an internal thread at the second upper end of the vacuumizing inner cavity (2), and a first external cylindrical surface of the power piston (1) is in sliding fit contact with an internal cylindrical surface at the second inner end of the vacuumizing inner cavity (2);

the vacuum-pumping hose (3) is a third round pipe, and the third round pipe of the vacuum-pumping hose (3) is a revolving body;

the vacuum-pumping hose (3) is positioned at the lower end of the vacuum-pumping inner cavity (2), the right end of a third circular pipe of the vacuum-pumping hose (3) is connected with a second left-end circular through hole of the vacuum-pumping inner cavity (2), and the left end of the third circular pipe of the vacuum-pumping hose (3) is connected with a closed space of which the gas pressure needs to be changed;

the vacuumizing switch (4) is a fourth cylinder, the fourth cylinder of the vacuumizing switch (4) is a revolving body, the upper surface of the fourth cylinder of the vacuumizing switch (4) is a fourth upper end circular plane, the side surface of the fourth cylinder of the vacuumizing switch (4) is a fourth outer cylindrical surface, and the lower end of the fourth outer cylindrical surface of the vacuumizing switch (4) is provided with a fourth outer thread;

the axis of a revolving body of the vacuumizing switch (4) is superposed with the axis of a revolving body of the power piston (1), a fourth outer cylindrical surface of the vacuumizing switch (4) is in sliding fit contact with an inner cylindrical surface at the second lower end of the vacuumizing inner cavity (2), a fourth outer thread of the vacuumizing switch (4) is in internal thread fit with the second lower end of the vacuumizing inner cavity (2), and a fourth upper end circular plane of the vacuumizing switch (4) is flush with an upward concentric circular ring surface at the second lower end of the vacuumizing inner cavity (2);

the pressure gauge (5) is used for detecting the pressure of gas, the upper end of the pressure gauge (5) is provided with a fifth outer cylindrical surface, the lower end of the pressure gauge (5) is provided with a fifth dial plate, and the fifth dial plate of the pressure gauge (5) displays the pressure value of the detected gas;

a fifth outer cylindrical surface of the pressure gauge (5) is connected with a second right-end circular through hole of the vacuumizing inner cavity (2), the pressure gauge (5) is communicated with a second annular groove of the vacuumizing inner cavity (2), and the pressure gauge (5) detects and displays a gas pressure value in the second annular groove of the vacuumizing inner cavity (2);

the exhaust switch (6) is a sixth cylinder, the sixth cylinder of the exhaust switch (6) is a revolving body, the upper surface of the sixth cylinder of the exhaust switch (6) is a sixth upper end circular plane, the side surface of the sixth cylinder of the exhaust switch (6) is a sixth outer cylindrical surface, and the lower end of the sixth outer cylindrical surface of the exhaust switch (6) is provided with a sixth external thread;

the axis of a revolving body of the exhaust switch (6) is parallel to the axis of a revolving body of the power piston (1), a sixth outer cylindrical surface of the exhaust switch (6) is in sliding fit contact with the inner cylindrical surface of the second right end of the vacuumizing inner cavity (2), a sixth outer thread of the exhaust switch (6) is in inner thread fit with the second right end of the vacuumizing inner cavity (2), and a sixth upper end circular plane of the exhaust switch (6) is flush with the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2).

The ratio of the diameter of the first cylindrical boss of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 3-4;

the ratio of the axial length of the first outer cylindrical surface of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 5-6;

a handheld infrared tester is arranged outside the device, the handheld infrared tester is used for testing the gas pressure inside the vacuumizing inner cavity (2), and pressure data are obtained in a digital display mode;

the method for calibrating the pressure by utilizing the handheld infrared device comprises the following steps:

step 1: placing the vacuumizing inner cavity (2) on a horizontal table;

step 2: assembling a power piston (1) with a vacuumizing inner cavity (2);

and step 3: assembling the vacuum-pumping hose (3) with the vacuum-pumping inner cavity (2);

and 4, step 4: assembling a vacuum-pumping switch (4) with a vacuum-pumping inner cavity (2);

and 5: assembling a pressure gauge (5) with the vacuumizing inner cavity (2);

step 6: assembling an exhaust switch (6) with the vacuumizing inner cavity (2);

and 7: when the gas pressure of the closed space needs to be reduced: the vacuumizing switch (4) is rotated clockwise and screwed until the fourth upper end circular plane of the vacuumizing switch (4) is flush with the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2); the exhaust switch (6) rotates anticlockwise until being dismounted; the power piston (1) rotates clockwise to the lowest position until the first lower end circular plane of the power piston (1) contacts with the second lower end upward concentric circular ring surface of the vacuum-pumping inner cavity (2); then the exhaust switch (6) is rotated clockwise and screwed until the sixth upper end circular plane of the exhaust switch (6) is flush with the upward concentric circular ring surface of the second lower end of the vacuum-pumping inner cavity (2); the vacuumizing switch (4) rotates anticlockwise and is loosened until a fourth upper end circular plane of the vacuumizing switch (4) is flush with the lower surface of a second annular groove of the vacuumizing inner cavity (2); then the power piston (1) is rotated anticlockwise to the uppermost position until the first upper end circular plane of the power piston (1) is contacted with the downward concentric circular ring surface of the second upper end of the vacuum-pumping inner cavity (2); thus, the closed space is exhausted once, so that the gas pressure of the closed space is reduced;

and 8: repeating the step 7, gradually pumping the closed space to gradually reduce the gas pressure of the closed space, waiting for 3-5 minutes after the step 7 is completed each time, and then performing the next step 7 until the gas pressure of the closed space reaches a preset value, wherein the gas pressure value of the closed space is P, and the value of P is as follows:

p is the gas pressure value of the closed space, unit: pa; v is the enclosed space volume, unit: l; c is the volume of the inner cavity of the device, unit: l; t is the air pressure value in units: pa; n is the number of times of pumping the closed space by the device; a is an empirical coefficient, and the value range of a is 0.85-0.91;

and step 9: when it is desired to increase the gas pressure in the enclosed space: the vacuumizing switch (4) is rotated clockwise and screwed until the fourth upper end circular plane of the vacuumizing switch (4) is flush with the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2); the exhaust switch (6) rotates anticlockwise until being dismounted; rotating the power piston (1) to the uppermost position anticlockwise until a first upper end circular plane of the power piston (1) is contacted with a downward concentric circular ring surface of a second upper end of the vacuumizing inner cavity (2); then the exhaust switch (6) is rotated clockwise and screwed until the sixth upper end circular plane of the exhaust switch (6) is flush with the upward concentric circular ring surface of the second lower end of the vacuum-pumping inner cavity (2); the vacuumizing switch (4) rotates anticlockwise and is loosened until a fourth upper end circular plane of the vacuumizing switch (4) is flush with the lower surface of a second annular groove of the vacuumizing inner cavity (2); then the power piston (1) is rotated clockwise to the lowest position until the first lower end circular plane of the power piston (1) is contacted with the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity (2); thus, the gas filling of the closed space is completed once, so that the gas pressure of the closed space is increased;

step 10: and (5) repeating the step (9), gradually filling gas into the closed space to gradually increase the gas pressure of the closed space, waiting for 3-5 minutes after the step (9) is finished each time, and then performing the step (9) again until the gas pressure of the closed space reaches a preset value.

2. A method for calibrating pressure using a hand-held infrared device according to claim 1, characterized in that the ratio of the diameter of the first cylindrical projection of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 3;

the ratio of the axial length of the first outer cylindrical surface of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 5.

3. a method for calibrating pressure using a hand-held infrared device according to claim 1, characterized in that the ratio of the diameter of the first cylindrical projection of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 4;

the ratio of the axial length of the first outer cylindrical surface of the power piston (1) to the diameter of the first outer cylindrical surface of the power piston (1) is 1: 6.

Technical Field

The invention belongs to the technical field of calibration, relates to a method for calibrating pressure, and particularly relates to a method for calibrating pressure by using handheld infrared equipment.

Background

The liquid-phase fire extinguishing agent is filled in the fire extinguishing bomb, and is scattered into the air through the scattering mechanism, so that wide-range fire extinguishing agent cloud mist is formed, and burning flames are extinguished. In order not to affect the spreading range of the liquid-phase fire extinguishing agent, the shell of the fire extinguishing bomb is usually of a thin-wall structure, and therefore, the fire extinguishing bomb is of a typical thin-wall shell structure filled with liquid-phase materials.

For a thin-wall shell structure filled with liquid-phase materials, the expansion coefficient of the liquid materials is much higher than that of solid materials, the liquid materials are incompressible materials, the internal stress of the shell caused by the expansion of the liquid-phase materials is very high after the temperature rises, and the shell is damaged at a weak position due to overhigh internal stress, so that the leakage of the liquid-phase materials is caused, and major accidents are caused. The patent "an internal stress release device for liquid-phase loading warhead" (china, 6 months 2015, application number: 201510304454.2) discloses an internal stress release device (hereinafter referred to as internal stress release device) suitable for filling a liquid-phase material thin-wall shell structure, when the internal stress of the liquid-phase material thin-wall shell structure (hereinafter referred to as thin-wall shell) is too large due to expansion of a liquid-phase material, an annular disc spring of the device is subjected to compression deformation, the space occupied by the liquid-phase material is increased, the expansion stress of the liquid-phase material is relieved, and the internal stress of the thin-wall shell is reduced; when the temperature is reduced and the liquid phase material shrinks to cause overlarge negative pressure in the thin-wall shell, the annular disc spring of the device generates tensile deformation, so that the space occupied by the liquid phase material is reduced, and the shrinkage stress of the liquid phase material is relieved, thereby reducing the internal stress of the thin-wall shell and solving the problem of the damage of the thin-wall shell caused by overlarge internal stress caused by the expansion with heat and contraction with cold of the liquid phase material.

The internal stress release devices have various specifications from small to large in size, each internal stress release device needs performance detection and calibration, the adjustable volume of each internal stress release device under different internal stresses is researched, and the internal stress release devices are calibrated after the parameters are detected. Then, according to the requirements of the thin-wall shell in the actual use process, namely according to the environment temperature of the thin-wall shell in the actual use process, the volume of the liquid-phase material for expansion and contraction and the corresponding internal stress are obtained, and then an internal stress release device matched with the actual requirements is installed in the thin-wall shell, so that the safety and the reliability of the thin-wall shell in the actual use process can be ensured, and the redundant design can be avoided.

Regarding the performance detection and calibration of the internal stress release device, if a real state experiment is carried out, the internal stress release device is installed in a thin-wall shell, a liquid-phase material is filled in the thin-wall shell, the temperature is changed, the internal stress data of the liquid-phase material is obtained, then the volume adjustment amount of the internal stress release device in the internal stress environment is measured, and the performance parameters of the internal stress release device are calibrated. The scientific research method is to adopt simulation experiment research, install the internal stress release device in the enclosed space, add high-pressure gas or vacuumize in the enclosed space, make the internal pressure value close to the real state of the thin-walled shell inside, investigate the adjustable volume of the internal stress release device under the effect of internal pressure, thus obtain the performance parameter of the internal stress release device. Vacuumizing and pressurizing are needed in a closed space of a simulation experiment so as to achieve the purpose of changing the internal gas pressure. Usually, the evacuation is performed by a vacuum pump, and the pressurization is performed by an air compressor. However, the vacuum pump and the air compressor have an advantage in changing the speed of the gas pressure, and cannot be precisely controlled in changing the volume of the gas, and at the same temperature, the pressure of the gas is uniquely determined by the volume, and the gas pressure cannot be precisely controlled due to the inaccuracy of the gas volume, so that the specific value of the internal gas pressure cannot be precisely controlled by the vacuum pump and the air compressor. Inside gas pressure value generally acquires through the manometer reading, and gas is at the enclosure space in-process that flows, and gas pressure value is different everywhere, and from inside to oral area gas pressure be certain gradient, and the manometer reading can only represent the pressure value of manometer position this moment, and can not represent inside average pressure value, along with inside pressure gradient recovery balance, the numerical value of manometer also can the corresponding change. Therefore, the error of controlling the internal pressure of the closed space through the vacuum pump and the air compressor is large, the performance of the internal stress release device is calibrated, and the most critical parameter is the pressure value. If the pressure value is inaccurate, the calibration error is too large, and the actual use effect of the product is influenced.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention provides a method for calibrating pressure by using a handheld infrared device, which can accurately control the volume of sucked or squeezed gas and further can accurately control the pressure of the gas in a closed space. Compared with the original scheme, the method reduces the error of the gas pressure value, more accurately calibrates the parameters of the internal stress release device, and more reliably obtains data. Therefore, when the internal stress releasing device is used on the thin-wall shell, the effect can be exerted more reliably.

The invention provides a method for calibrating pressure by using handheld infrared equipment, which comprises a vacuum-pumping hose 3 and a pressure gauge 5, and is characterized by also comprising a power piston 1, a vacuum-pumping inner cavity 2, a vacuum-pumping switch 4 and an exhaust switch 6;

the power piston 1 is a first cylinder, the first cylinder of the power piston 1 is a revolving body, the lower surface of the first cylinder of the power piston 1 is a first lower end circular plane, the side surface of the first cylinder of the power piston 1 is a first outer cylindrical surface, the upper surface of the first cylinder of the power piston 1 is a first upper end circular plane, the center of the first upper end circular plane of the power piston 1 is provided with a first cylindrical boss, the axis of the revolving body of the first cylindrical boss of the power piston 1 is superposed with the axis of the revolving body of the first cylinder of the power piston 1, and the side surface of the first cylindrical boss of the power piston 1 is provided with a first external thread;

the axis of the revolving body of the power piston 1 is vertical to the ground;

the vacuumizing inner cavity 2 is a second cylinder body, the second cylinder body of the vacuumizing inner cavity 2 is a revolving body, the inner side surface of the second cylinder body of the vacuumizing inner cavity 2 is a second inner cylindrical surface, the upper end of the second inner cylindrical surface of the vacuumizing inner cavity 2 is provided with a second upper end inner flange, the inner side surface of the second upper end inner flange of the vacuumizing inner cavity 2 is provided with a second upper end internal thread, the lower end surface of the second upper end inner flange of the vacuumizing inner cavity 2 is a second upper end downward concentric circular ring surface, the lower end of the second inner cylindrical surface of the vacuumizing inner cavity 2 is provided with a second lower end inner flange, the upper end surface of the second lower end inner flange of the vacuumizing inner cavity 2 is a second lower end upward concentric circular ring surface, the lower end surface of the second lower end inner flange of the vacuumizing inner cavity 2 is a second lower end downward concentric circular ring surface, the inner side surface of the second lower end inner flange of the vacuumizing inner cavity 2 is a second lower end inner cylindrical surface, the second lower end of the second, the middle part of the inner cylindrical surface of the second lower end of the vacuumizing inner cavity 2 is provided with a second annular groove, the left end of the lower surface of the second annular groove of the vacuumizing inner cavity 2 is provided with a second left-end circular through hole, the axis of the second left-end circular through hole of the vacuumizing inner cavity 2 is parallel to the axis of the revolution body of the vacuumizing inner cavity 2, the second left-end circular through hole of the vacuumizing inner cavity 2 is communicated with the second annular groove of the vacuumizing inner cavity 2 and the lower part of the second lower end downward concentric circular ring surface of the vacuumizing inner cavity 2, the right end of the lower surface of the second annular groove of the vacuumizing inner cavity 2 is provided with a second right-end circular through hole, the axis of the second right-end circular through hole of the vacuumizing inner cavity 2 is parallel to the axis of the revolution body of the vacuumizing inner cavity 2, the second circular through hole of the second right-end of the vacuumizing inner cavity 2 is communicated with the lower part of the second lower end downward concentric circular ring surface of the vacuumizing inner, the second right end of the vacuumizing inner cavity 2 is parallel to the axis of the revolving body of the vacuumizing inner cavity 2 along the axis of the circular through hole, the second right end of the vacuumizing inner cavity 2 is communicated with the upper part of the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity 2 and the lower part of the downward concentric circular ring surface of the second lower end of the vacuumizing inner cavity 2 along the circular through hole, the inner side surface of the second right end of the vacuumizing inner cavity 2 along the circular through hole is a second right end inner circular cylindrical surface, and the lower end of the second right end inner circular cylindrical surface of the vacuumizing inner cavity 2 is provided with a;

the axis of a revolving body of the vacuumizing inner cavity 2 coincides with the axis of a revolving body of the power piston 1, a first cylinder of the power piston 1 is positioned inside a second cylinder of the vacuumizing inner cavity 2, a first upper end circular plane of the power piston 1 is positioned at the lower end of a downward concentric circular ring surface at the second upper end of the vacuumizing inner cavity 2, a first lower end circular plane of the power piston 1 is positioned at the upper end of an upward concentric circular ring surface at the second lower end of the vacuumizing inner cavity 2, a first external thread of the power piston 1 is matched with an internal thread at the second upper end of the vacuumizing inner cavity 2, and a first external cylindrical surface of the power piston 1 is in sliding fit contact with a second internal cylindrical surface of the vacuumizing inner cavity 2;

the vacuumizing hose 3 is a third round pipe, and the third round pipe of the vacuumizing hose 3 is a revolving body;

the vacuum-pumping hose 3 is positioned at the lower end of the vacuum-pumping inner cavity 2, the right end of a third circular pipe of the vacuum-pumping hose 3 is connected with a second left-end circular through hole of the vacuum-pumping inner cavity 2, and the left end of the third circular pipe of the vacuum-pumping hose 3 is connected with a closed space in which gas pressure needs to be changed;

the vacuumizing switch 4 is a fourth cylinder, the fourth cylinder of the vacuumizing switch 4 is a revolving body, the upper surface of the fourth cylinder of the vacuumizing switch 4 is a fourth upper end circular plane, the side surface of the fourth cylinder of the vacuumizing switch 4 is a fourth outer cylindrical surface, and the lower end of the fourth outer cylindrical surface of the vacuumizing switch 4 is provided with a fourth outer thread;

the axis of the revolving body of the vacuum switch 4 coincides with the axis of the revolving body of the power piston 1, the fourth outer cylindrical surface of the vacuum switch 4 is in sliding fit contact with the inner cylindrical surface of the second lower end of the vacuum cavity 2, the fourth outer thread of the vacuum switch 4 is in internal thread fit with the second lower end of the vacuum cavity 2, and the fourth upper end circular plane of the vacuum switch 4 is flush with the upward concentric circular ring surface of the second lower end of the vacuum cavity 2;

the pressure gauge 5 is used for detecting the pressure of gas, the upper end of the pressure gauge 5 is provided with a fifth outer cylindrical surface, the lower end of the pressure gauge 5 is provided with a fifth dial plate, and the fifth dial plate of the pressure gauge 5 displays the pressure value of the detected gas;

a fifth outer cylindrical surface of the pressure gauge 5 is connected with a second right-end circular through hole of the vacuumizing inner cavity 2, the pressure gauge 5 is communicated with a second annular groove of the vacuumizing inner cavity 2, and the pressure gauge 5 detects and displays a gas pressure value in the second annular groove of the vacuumizing inner cavity 2;

the exhaust switch 6 is a sixth cylinder, the sixth cylinder of the exhaust switch 6 is a revolving body, the upper surface of the sixth cylinder of the exhaust switch 6 is a sixth upper end circular plane, the side surface of the sixth cylinder of the exhaust switch 6 is a sixth outer cylindrical surface, and the lower end of the sixth outer cylindrical surface of the exhaust switch 6 is provided with a sixth external thread;

the axis of a revolving body of the exhaust switch 6 is parallel to the axis of a revolving body of the power piston 1, the sixth outer cylindrical surface of the exhaust switch 6 is in sliding fit contact with the inner cylindrical surface of the second right end of the vacuumizing inner cavity 2, the sixth outer thread of the exhaust switch 6 is in inner thread fit with the second right end of the vacuumizing inner cavity 2, and the sixth upper end circular plane of the exhaust switch 6 is flush with the upward concentric circular ring surface of the second lower end of the vacuumizing inner cavity 2.

The ratio of the diameter of the first cylindrical boss of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 3-4;

the ratio of the axial length of the first outer cylindrical surface of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 5-6;

a handheld infrared tester is arranged outside the device, the handheld infrared tester is used for testing the gas pressure inside the vacuumizing inner cavity 2, pressure data are obtained in a digital display mode, and the data are only used as the reference of the method;

the method for calibrating the pressure by utilizing the handheld infrared device comprises the following steps:

step 1: placing the vacuumizing inner cavity 2 on a horizontal table;

step 2: assembling a power piston 1 with a vacuumizing inner cavity 2;

and step 3: assembling a vacuum-pumping hose 3 with a vacuum-pumping inner cavity 2;

and 4, step 4: assembling a vacuumizing switch 4 with a vacuumizing inner cavity 2;

and 5: assembling a pressure gauge 5 with the vacuumizing inner cavity 2;

step 6: assembling an exhaust switch 6 with the vacuumizing inner cavity 2;

and 7: when the gas pressure of the closed space needs to be reduced: rotating and screwing the vacuum switch 4 clockwise until a fourth upper end circular plane of the vacuum switch 4 is flush with a second lower end upward concentric circular ring surface of the vacuum cavity 2; the exhaust switch 6 rotates anticlockwise until being dismounted; the power piston 1 rotates clockwise to the lowest position until the first lower end circular plane of the power piston 1 contacts with the second lower end upward concentric circular ring surface of the vacuum pumping inner cavity 2; then the exhaust switch 6 is rotated clockwise and screwed until the sixth upper end circular plane of the exhaust switch 6 is flush with the second lower end upward concentric circular ring surface of the vacuum-pumping inner cavity 2; the vacuumizing switch 4 rotates anticlockwise and is loosened until a fourth upper end circular plane of the vacuumizing switch 4 is flush with the lower surface of a second annular groove of the vacuumizing inner cavity 2; then the power piston 1 is rotated anticlockwise to the uppermost position until the first upper end circular plane of the power piston 1 is contacted with the downward concentric circular ring surface of the second upper end of the vacuum-pumping inner cavity 2; thus, the closed space is exhausted once, so that the gas pressure of the closed space is reduced;

and 8: repeating the step 7, gradually pumping the closed space to gradually reduce the gas pressure of the closed space, waiting for 3-5 minutes after the step 7 is completed each time, and then performing the next step 7 until the gas pressure of the closed space reaches a preset value, wherein the gas pressure value of the closed space is P, and the value of P is as follows:

p is the gas pressure value of the closed space, unit: pa; v is the enclosed space volume, unit: l; c is the volume of the inner cavity of the device, unit: l; t is the air pressure value in units: pa; n is the number of times of pumping the closed space by the device; a is an empirical coefficient, and the value range of a is 0.85-0.91;

and step 9: when it is desired to increase the gas pressure in the enclosed space: rotating and screwing the vacuum switch 4 clockwise until a fourth upper end circular plane of the vacuum switch 4 is flush with a second lower end upward concentric circular ring surface of the vacuum cavity 2; the exhaust switch 6 rotates anticlockwise until being dismounted; rotating the power piston 1 to the uppermost position anticlockwise until a first upper end circular plane of the power piston 1 is contacted with a second upper end downward concentric circular ring surface of the vacuumizing inner cavity 2; then the exhaust switch 6 is rotated clockwise and screwed until the sixth upper end circular plane of the exhaust switch 6 is flush with the second lower end upward concentric circular ring surface of the vacuum-pumping inner cavity 2; the vacuumizing switch 4 rotates anticlockwise and is loosened until a fourth upper end circular plane of the vacuumizing switch 4 is flush with the lower surface of a second annular groove of the vacuumizing inner cavity 2; then the power piston 1 is rotated clockwise to the lowest position until the first lower end circular plane of the power piston 1 contacts with the second lower end upward concentric circular ring surface of the vacuum-pumping inner cavity 2; thus, the gas filling of the closed space is completed once, so that the gas pressure of the closed space is increased;

step 10: and (3) repeating the step (9), gradually filling gas into the closed space, so that the gas pressure of the closed space is gradually increased, waiting for 3-5 minutes after the step (9) is completed each time, and then performing the next step (9) until the gas pressure of the closed space reaches a preset value, wherein the gas pressure value of the closed space is Q, and the value of Q is as follows:

q is the closed space gas pressure value, unit: pa; v is the enclosed space volume, unit: l; c is the volume of the inner cavity of the device, unit: l; m is the air-entrapping frequency of the closed space through the device; b is an empirical coefficient, and the value range of b is 0.81-0.86.

With respect to the ratio of the first cylindrical boss diameter of power piston 1 to the first outer cylindrical surface diameter of power piston 1, and the ratio of the first outer cylindrical surface axial length of power piston 1 to the first outer cylindrical surface diameter of power piston 1, any of the following 2 ways may be adopted:

implementation mode 1: the ratio of the diameter of the first cylindrical boss of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 3;

the ratio of the axial length of the first outer cylindrical surface of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 5.

implementation mode 2: the ratio of the diameter of the first cylindrical boss of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 4;

the ratio of the axial length of the first outer cylindrical surface of power piston 1 to the diameter of the first outer cylindrical surface of power piston 1 is 1: 6.

the method for calibrating the pressure by using the handheld infrared equipment has the following technical effects:

the invention can accurately control the volume of the sucked or squeezed gas in relation to the change of the gas pressure in the closed space, and thus can accurately control the gas pressure inside the closed space. Compared with the original scheme, the method reduces the error of the gas pressure value, more accurately calibrates the parameters of the internal stress release device, and more reliably obtains data. Therefore, when the internal stress releasing device is used on the thin-wall shell, the effect can be exerted more reliably.

Drawings

Fig. 1 is a schematic diagram of a method for calibrating pressure using a hand-held infrared device. 1. The device comprises a power piston, 2, a vacuumizing inner cavity, 3, a vacuumizing hose, 4, a vacuumizing switch, 5, a pressure gauge, 6 and an exhaust switch.

Detailed Description

The present invention is further described in detail with reference to the drawings and examples, it should be noted that the present invention is not limited to the following examples, and equivalent changes based on the technical scheme of the present invention are within the scope of the present invention.