CN113390587A

CN113390587A - Method and system for detecting sealing performance of box body

Info

Publication number: CN113390587A
Application number: CN202010165289.8A
Authority: CN
Inventors: 熊小川; 吴恒刚
Original assignee: Shenzhen Meimeimeichuangyi Medical Technology Co ltd
Current assignee: Shenzhen Meimeimeichuangyi Medical Technology Co ltd; Mehow Innovative Ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2021-09-14

Abstract

The invention relates to a method and a system for detecting the sealing performance of a box body. The detection method comprises the following steps: providing a box body to be tested, wherein the box body to be tested is provided with a first leakage hole and a second leakage hole which are spaced and have the same aperture; adjusting the pressure in the box body to be tested to a preset pressure, simultaneously opening the first leakage hole and the second leakage hole to restore the pressure in the box body to be tested to the normal pressure, and measuring the first time when the pressure in the box body to be tested is restored to the normal pressure from the preset pressure; adjusting the pressure in the box body to be detected to a preset pressure, opening the first leakage hole and sealing the second leakage hole so as to restore the pressure in the box body to be detected to the normal pressure, and measuring a second time for the pressure in the box body to be detected to be restored to the normal pressure from the preset pressure; and calculating the flow coefficient to be measured of the box body to be measured according to a formula of the flow coefficient to be measured, wherein if the flow coefficient to be measured is larger than 0, the box body to be measured is leaked. The detection method can detect the sealing performance of the large-volume box body and determine the leakage coefficient.

Description

Method and system for detecting sealing performance of box body

Technical Field

The invention relates to the technical field of airtightness detection, in particular to a method and a system for detecting the airtightness of a box body.

Background

Some cases, especially large-volume cases, are mainly made of a plurality of plates and sealed according to contact sealing, glue joint sealing, welding sealing and other ways. The box body obtained in the mode can be used only after the tightness of the box body is detected, otherwise, the normal use of the box body is influenced by the problem of tightness. Some studies have been made to determine the sealing property of the tank by making the inside of the tank be negative pressure, then immersing the tank in water, and observing whether or not liquid has permeated into the tank. This arrangement does not allow the leak coefficient of the tank to be determined and is not suitable for the detection of the sealing performance of a large-volume tank.

Disclosure of Invention

In view of this, it is necessary to provide a method for detecting the sealing property of a tank, which can detect the sealing property of a large-volume tank and can determine the leakage coefficient of the tank.

In addition, a detection system for the sealing performance of the box body is further provided.

A method for detecting the sealing performance of a box body is characterized by comprising the following steps:

providing a box body to be tested, wherein the box body to be tested is provided with a first leakage hole and a second leakage hole which are spaced and have the same aperture;

adjusting the pressure in the box body to be tested to a preset pressure, then opening the first leakage hole and the second leakage hole simultaneously to restore the pressure in the box body to be tested to the normal pressure, and measuring the first time when the pressure in the box body to be tested is restored to the normal pressure from the preset pressure;

adjusting the pressure in the box body to be detected to the preset pressure, then opening the first leakage hole and sealing the second leakage hole to recover the pressure in the box body to be detected to the normal pressure, and measuring the second time for recovering the pressure in the box body to be detected from the preset pressure to the normal pressure; and

according to the formula: calculating the flow coefficient to be measured of the box body to be measured, and if the flow coefficient to be measured is larger than 0, leaking the box body to be measured, wherein the flow coefficient to be measured is larger than 0kIs 0.1~0.25, standard flow coefficient is the flow coefficient of standard box, standard time is pressure in the standard box is followed the time that preset pressure recovered to ordinary pressure, the volume of standard box with the volume of the box that awaits measuring is the same, standard box does not have the leakage, standard box is equipped with standard hole, instituteThe first leakage hole has the same diameter as the standard hole.

In the method for detecting the sealing performance of the box body, the box body to be detected with a first leakage hole and a second leakage hole which are spaced and have the same aperture is provided; adjusting the pressure in the box body to be tested to a preset pressure, then opening the first leakage hole and the second leakage hole simultaneously to restore the pressure in the box body to be tested to the normal pressure, and measuring the first time when the pressure in the box body to be tested is restored to the normal pressure from the preset pressure; adjusting the pressure in the box body to be tested to a preset pressure, then opening the first leakage hole and sealing the second leakage hole to restore the pressure in the box body to be tested to the normal pressure, and measuring a second time for the pressure in the box body to be tested to restore from the preset pressure to the normal pressure; constructing a formula: and calculating the flow coefficient to be measured of the box body to be measured according to the formula, if the flow coefficient to be measured is more than 0, the box body to be measured has leakage, wherein,kthe flow coefficient of the standard box body is 0.1-0.25, the standard flow coefficient is the flow coefficient of the standard box body, the standard time is the time for the pressure in the standard box body to recover to the normal pressure from the preset pressure, the volume of the standard box body is the same as that of the box body to be detected, the standard box body is free of leakage, the standard box body is provided with a standard hole, and the aperture of the first leakage hole is the same as that of the standard hole. By the method for detecting the sealing performance of the box body, whether the box body to be detected leaks can be determined without immersing the box body to be detected into liquid, the leakage coefficient of the box body to be detected can be determined, and the method is suitable for detecting the sealing performance of the large-volume box body.

In one embodiment, the second leakage holes are multiple, and the second leakage holes are arranged at intervals; the step of then simultaneously opening the first and second leakage holes includes: then simultaneously opening the first leakage holes and one of the second leakage holes and sealing the other second leakage holes; the step of then opening the first leakage hole and sealing the second leakage hole comprises: the first leakage holes are then opened and each of the second leakage holes is sealed.

In one embodiment, the first leakage hole is located in the middle of one surface of the box to be tested, one second leakage hole is arranged at each corner of the box to be tested, and if the box to be tested leaks, the step of calculating the flow coefficient to be tested of the box to be tested according to the formula further includes the step of determining the leakage position of the box to be tested:

opening the first leakage holes and sealing each second leakage hole, and then adjusting the pressure in the box body to be tested so that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in a preset period to obtain a standard waveform of the pressure in the box body to be tested and the test time;

the test waveform for each of the corners was determined as follows: opening the second leakage hole at one corner and sealing other second leakage holes, and then adjusting the pressure in the box body to be tested so that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in the preset period, so as to obtain a change curve of the pressure in the box body to be tested and the test time, and obtain a test waveform corresponding to the corner; and

and comparing the phase difference between the test waveform and the standard waveform corresponding to each corner, wherein the corner corresponding to the minimum phase difference has leakage.

In one embodiment, the negative value of the second pressure is equal to the first pressure.

In one embodiment, the second pressure is a relative pressure, and the second pressure is 1.0Pa to 30.0 Pa.

In one embodiment, the preset period is 10 s-50 s.

In one embodiment, the preset pressure is a relative pressure, and the preset pressure is 1.0 Pa-30.0 Pa;

and/or the aperture of the standard hole is 2.0 mm-3.0 mm;

and/or the standard flow coefficient is 0.38[ mL/(s × Pa) ] to 0.87[ mL/(s × Pa) ], and the standard time is 10s to 50 s.

A system for detecting the leak tightness of a tank, comprising:

the pressure regulating device can be arranged on the box body to be measured and can regulate the pressure in the box body to be measured to a preset pressure, and the box body to be measured is provided with a first leakage hole and a second leakage hole which are spaced and have the same aperture;

a seal capable of sealing the second leakage hole;

a timing device capable of measuring a first time when the first leakage hole and the second leakage hole are simultaneously opened to restore the pressure in the tank to be tested from the preset pressure to the normal pressure, and measuring a second time when the first leakage hole is opened and the second leakage hole is sealed to restore the pressure in the tank to be tested from the preset pressure to the normal pressure; and

the detection device can be connected with the timing device and receives the time signal transmitted by the timing device, and then according to the formula: calculating the flow coefficient to be measured of the box body to be measured, and if the flow coefficient to be measured is larger than 0, the box body to be measured is leaked, wherein the flow coefficient to be measured is calculatedkBe 0.1~0.25, standard flow coefficient is the flow coefficient of standard box, standard time is pressure in the standard box is followed the time of preset pressure recovery to ordinary pressure, the volume of standard box with the volume of the box that awaits measuring is the same, standard box does not have and reveals, standard box is equipped with the standard hole, the aperture of first exposure hole with the aperture of standard hole is the same.

In one embodiment, the first leakage hole is located in the middle of one surface of the box body to be tested, the second leakage holes are arranged in a plurality of numbers, one second leakage hole is arranged at each corner of the box body to be tested, the pressure regulating device can also regulate the pressure in the box body to be tested, so that the pressure in the tank to be measured is alternately changed between the first pressure and the second pressure at a preset period, the detection device can also be connected with the pressure regulating device to receive the pressure signal transmitted by the pressure regulating device, then measuring a standard waveform corresponding to the first leakage hole and a test waveform corresponding to each corner, the phase difference of the test waveform and the standard waveform corresponding to each corner can then be compared, the position of the corner corresponding to the minimum phase difference can be determined to determine the leakage position of the box body to be tested; the standard waveform is a change curve of the pressure in the box body to be tested and the test time in the process that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in the preset period when the first leakage holes are opened and each second leakage hole is sealed; when the second leakage hole at one corner is opened and other second leakage holes are sealed, the pressure in the box body to be tested is in the process of alternating change between the first pressure and the second pressure in the preset period, and the change curve of the pressure in the box body to be tested and the test time is obtained.

Drawings

Fig. 1 is a schematic structural diagram of a detection system for tightness of a box body and a box body to be detected according to an embodiment;

FIG. 2 is a schematic view of the tightness detection system of the box shown in FIG. 1 and another angle of the box to be tested;

FIG. 3 is a schematic view of the tightness detection system of the box shown in FIG. 1 and another angle of the box to be tested;

fig. 4 is a graph showing a change curve of the pressure in the tank to be measured and the time in the process of recovering the pressure in the tank from the preset pressure to the normal pressure in embodiment 1;

FIG. 5 is a graph comparing the standard waveform and the test waveform in example 1.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In the following, the relative pressure is a pressure expressed with reference to the atmospheric pressure, and is equal to the true pressure minus the atmospheric pressure, unless otherwise specified. The normal pressure is a standard atmospheric pressure, and the standard atmospheric pressure is 101325 Pa. The corner is a joint formed by the joint of at least three surfaces.

According to the method for detecting the sealing performance of the box body, the sealing performance of the box body with large volume can be detected, and the leakage coefficient of the box body can be determined. The method for detecting the sealing performance of the box body comprises the following steps of S110-S140:

s110, providing a box body to be detected, wherein the box body to be detected is provided with a first leakage hole and a second leakage hole which are spaced and have the same aperture.

Specifically, the step of providing a box to be tested comprises: a first leakage hole and a second leakage hole which are spaced and have the same aperture are formed in the box body to be detected. It should be noted that, if the first leakage hole and the second leakage hole are already formed in the box body to be tested, the step of forming the first leakage hole and the second leakage hole with the same interval and aperture on the box body to be tested may be omitted.

Wherein the volume of the box body to be measured is 500L-1000L. The aperture of the first leakage hole is 2.0 mm-3.0 mm. In one embodiment, the volume of the box to be measured is 500L, and the aperture of the first leakage hole is 2.0 mm. In one embodiment, the volume of the box to be measured is 800L, and the aperture of the first leakage hole is 2.0 mm. In one embodiment, the volume of the box to be measured is 1000L, and the aperture of the first leakage hole is 2.5 mm.

The volume of the chamber to be tested is not limited to the above-mentioned range, and the sealing performance of the chamber to be tested having other volumes can be tested by the method for testing the sealing performance of the chamber according to the present invention, and can be selected as needed. The aperture of the first leakage hole is not limited to the above-mentioned range, and may be set as needed.

In one embodiment, the box to be tested is made of a plurality of plates through sealing connection. At this time, the corner formed by the joint of at least three plates is very easy to leak.

S120, adjusting the pressure in the box body to be tested to a preset pressure, and then opening the first leakage hole and the second leakage hole simultaneously to enable the pressure in the box body to be tested to be recovered to the normal pressure, and determining the first time when the pressure in the box body to be tested is recovered to the normal pressure from the preset pressure.

Wherein, the step of adjusting the pressure in the box body to be measured to preset pressure includes: the first vent hole and the second vent hole are sealed, the first vent hole is formed in the box body to be tested, the first pressure regulator is installed on the box body to be tested, the first vent hole is blocked, the first pressure regulator is connected with the box body to be tested in a sealing mode, gas is introduced into the box body to be tested through the first vent hole through the first pressure regulator, and the ventilation is stopped until the pressure in the box body to be tested rises to the preset pressure. Further, the gas is air. The first pressure regulator may be, for example, an inflator or a vacuum pump. The first and second leakage holes are sealed with a seal. Further, the seal may be, for example, a gas plug.

The preset pressure is relative pressure and is 1-30 Pa. The preset pressure is not limited to the above-mentioned range, and may be set as needed.

In one embodiment, the second leakage holes are multiple, and the multiple second leakage holes are arranged at intervals; then the step of simultaneously opening the first and second leakage holes includes: then, the first leakage hole and one of the second leakage holes are simultaneously opened, and the other second leakage holes are sealed.

S130, adjusting the pressure in the box body to be tested to the preset pressure, then opening the first leakage hole and sealing the second leakage hole to enable the pressure in the box body to be tested to be recovered to the normal pressure, and determining the second time for the pressure in the box body to be tested to be recovered to the normal pressure from the preset pressure.

The step of adjusting the pressure in the tank to be tested to the preset pressure in S130 is the same as the step of adjusting the pressure in the tank to be tested to the preset pressure in S120, which is specifically referred to above and is not described herein again.

In one embodiment, the second leakage holes are multiple, and the multiple second leakage holes are arranged at intervals; the step of then opening the first leakage hole and sealing the second leakage hole comprises: the first leakage holes are then opened and each second leakage hole is sealed.

The steps of S120 and S130 are not limited, and the operation of S120 may be performed first and then the operation of S130 may be performed, or the operation of S130 may be performed first and then the operation of S120 may be performed.

S140, according to a formula: and calculating the flow coefficient to be measured of the box body to be measured, wherein if the flow coefficient to be measured is larger than 0, the box body to be measured is leaked.

Wherein, kthe flow coefficient of the standard box body is 0.1-0.25, the standard flow coefficient is the flow coefficient of the standard box body, the standard time is the time for the pressure in the standard box body to recover to the normal pressure from the preset pressure, the volume of the standard box body is the same as that of the box body to be detected, the standard box body is free of leakage, the standard box body is provided with a standard hole, and the aperture of the first leakage hole is the same as that of the standard hole.

It should be noted that the standard case has no leakage, which means that the standard case has no other leakage position except the standard hole.

Wherein the volume of the standard box body is 500L-1000L. The aperture of the standard hole is 1.0 mm-3.2 mm. The standard flow coefficient is 0.38mL/(s Pa) to 0.87mL/(s Pa), and the standard time is 10s to 50 s.

In one embodiment, the standard case has a volume of 500L. The standard hole has a diameter of 2.0 mm. The standard flow coefficient was 0.38mL/(s × Pa). The standard time was 12 s.

In one embodiment, the standard box has a volume of 800L. The standard hole has a diameter of 2.0 mm. The standard flow coefficient is 0.38mL/(s × Pa), i.e. the standard orifice of the standard tank has a flow of 0.38mL/s at a pressure of 1 Pa. The standard time was 18 s.

In one embodiment, the standard case has a volume of 1000L. The standard hole had a diameter of 2.5 mm. The standard flow coefficient was 0.6mL/(s × Pa). The standard time was 16S.

It should be noted that the flow coefficient and the standard time of the standard tank can be found from the product specification of the standard tank, or can be measured according to the conventional measurement method in the art. For example: the method for measuring the flow coefficient of the standard box comprises the following steps: the flow meter and the differential pressure sensor are arranged in the box body and close to the standard hole, gas with certain pressure is introduced into the standard box body from the standard hole, the flow of the gas in the box body and close to the standard hole is measured by the flow meter, the differential pressure sensor is used for detecting the pressure difference between the inside and the outside of the box body at the standard hole, and then the flow coefficient of the standard gas is obtained by dividing the pressure difference by the flow. The method for measuring the standard time of the standard box comprises the following steps: introducing gas into the standard box body to enable the pressure in the standard box body to be the preset pressure, opening the standard hole to enable the pressure in the standard box body to be recovered to the normal pressure, and detecting the time for the pressure in the standard box body to be recovered to the normal pressure to obtain standard time; and the preset pressure in the standard time measurement of the standard box body is equal to the preset pressure in the first time and the second time measurement of the box body to be measured.

In one embodiment, the first leakage holes are located in the middle of one surface of the box body to be tested, the second leakage holes are multiple, and the second leakage holes are arranged at intervals. And each corner of the box body to be tested is provided with a second leakage hole, and if the box body to be tested has leakage, the step of measuring the leakage position of the box body to be tested is also included after the step of calculating the flow coefficient to be tested of the box body to be tested according to the formula. Specifically, the step of determining the leakage position of the box body to be detected comprises S151-S153:

s151, opening the first leakage holes and sealing each second leakage hole, and then adjusting the pressure in the box body to be tested to enable the pressure in the box body to be tested to be changed alternately between the first pressure and the second pressure in a preset period, so that a standard waveform of the pressure in the box body to be tested and the test time is obtained.

Wherein, then, the step of the internal pressure of pressure in the regulation box includes: and a second vent hole is formed in the box body to be tested, a second pressure regulator is arranged on the box body to be tested and covers the second vent hole and is in sealed connection with the box body to be tested, and the second pressure regulator regulates the pressure in the box body to be tested. Further, the second pressure regulator is a reciprocating pump. The second voltage regulator can be installed on the box body to be tested. Further, the second pressure regulator is a piston pump. Specifically, air is injected into the box body to be tested through a second pressure regulator, so that the pressure in the box body to be tested is a second pressure; and then, pumping out air from the box body to be tested through a second pressure regulator so as to enable the pressure in the box body to be tested to be the first pressure. More specifically, 20-40 mL of air is injected into the box body to be tested through the second pressure regulator, so that the pressure in the box body to be tested is the second pressure. 20-40 mL of air is pumped out of the box body to be detected through the second pressure regulator, so that the pressure in the box body to be detected is the first pressure.

Wherein the negative value of the second pressure is equal to the first pressure. Further, the second pressure is relative pressure, and the second pressure is 1.0 Pa-30 Pa. Correspondingly, the first pressure is also relative pressure, and the first pressure is-1 Pa to-30 Pa. Further, the second pressure is 5 Pa. The first pressure is-5 Pa. The first pressure and the second pressure are not limited to the above-described settings, and may be set as needed.

Wherein the preset period is 10 s-50 s. Further, the preset period is 30 s. It should be noted that the preset period is not limited to the above setting, and may be set as needed.

S152, measuring a test waveform corresponding to each corner according to the following steps: and opening a second leakage hole at one corner, sealing other second leakage holes, and then adjusting the pressure in the box body to be tested so that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in the preset period to obtain a change curve of the pressure in the box body to be tested and the test time, thereby obtaining a test waveform corresponding to one corner.

The step of adjusting the pressure in the tank to be tested in S152 is the same as the step of adjusting the pressure in the tank to be tested in S151, and is not described herein again for details.

It should be noted that the measurement method for measuring the test waveform corresponding to each corner is basically the same, except that it is necessary to measure which corner corresponds to the test waveform, and then the second leakage hole at the corner needs to be opened and the other second leakage holes need to be closed. It should be noted that, when measuring the test waveform corresponding to each corner, the open/close state of the first leakage hole is not limited, and the first leakage hole may be in an open state or a sealed state.

The order of S151 and S152 is not limited, and S151 and S152 may be performed first, or S152 and S151 may be performed first.

And S153, comparing the phase difference between the test waveform corresponding to each corner and the standard waveform, wherein the corner corresponding to the minimum phase difference has leakage.

When there are a plurality of corners corresponding to the minimum phase difference, there is leakage at each corner corresponding to the minimum phase difference. Note that, if the phase differences corresponding to the corners are equal, there is leakage at each corner.

It should be noted that, if it is only necessary to determine whether the box body to be tested has a leak, the step of determining the leak position of the box body to be tested may be omitted.

In one specific example, the box to be tested is in a cube shape and is made of eight plates which are hermetically connected. The first leakage hole is positioned in the middle of one surface of the box body to be tested. There are nine second leakage holes. One of the second leakage holes and the first leakage hole are located on the same surface and are arranged close to the first leakage hole. The other eight second leakage holes are respectively positioned at eight corners of the box body to be tested. Wherein, the corner is the junction of three surfaces in the box body to be measured. In this case, in the method for detecting the sealing property of the case, S120 includes: adjusting the pressure in the box body to be tested to a preset pressure, simultaneously opening the first leakage hole and a second leakage hole which is positioned on the same surface as the first leakage hole, sealing other second leakage holes to restore the pressure in the box body to be tested to normal pressure, and measuring the first time when the pressure in the box body to be tested is restored to normal pressure from the preset pressure; s130 includes: adjusting the pressure in the box to be tested to the preset pressure, then opening the first leakage holes and sealing each second leakage hole so as to restore the pressure in the box to be tested to the normal pressure, and determining the second time for the pressure in the box to be tested to be restored to the normal pressure from the preset pressure.

In the above arrangement, the first leakage hole is formed in the middle of one surface of the box body to be tested, the second leakage hole and the first leakage hole are formed in the same surface and are close to the first leakage hole, and therefore the sealing performance of the box body to be tested can be conveniently operated. It should be noted that the second leak hole located on the same surface as the first leak hole and adjacent to the first leak hole may be omitted. When a second leakage hole, which is located on the same surface as the first leakage hole and is disposed close to the first leakage hole, is omitted, in the method for detecting the sealing property of the box body, S120 includes: the pressure in the box body to be tested is adjusted to a preset pressure, then the first leakage hole and one of the second leakage holes are opened simultaneously, and other second leakage holes are sealed, so that the pressure in the box body to be tested is recovered to the normal pressure, and the first time when the pressure in the box body to be tested is recovered to the normal pressure from the preset pressure is measured.

In the method for detecting the sealing performance of the box body, the box body to be detected with a first leakage hole and a second leakage hole which are spaced and have the same aperture is provided; adjusting the pressure in the box body to be tested to a preset pressure, then opening the first leakage hole and the second leakage hole simultaneously to restore the pressure in the box body to be tested to the normal pressure, and measuring the first time when the pressure in the box body to be tested is restored to the normal pressure from the preset pressure; adjusting the pressure in the box body to be tested to a preset pressure, then opening the first leakage hole and sealing the second leakage hole to restore the pressure in the box body to be tested to the normal pressure, and measuring a second time for the pressure in the box body to be tested to restore from the preset pressure to the normal pressure; constructing the formula and calculating the flow coefficient to be measured of the box body to be measured according to the formula, if the flow coefficient to be measured is more than 0, the box body to be measured has leakage, wherein,kthe flow coefficient of the standard box body is 0.1-0.25, the standard flow coefficient is the flow coefficient of the standard box body, the standard time is the time for the pressure in the standard box body to recover to the normal pressure from the preset pressure, the volume of the standard box body is the same as that of the box body to be detected, the standard box body is free of leakage, the standard box body is provided with a standard hole, and the aperture of the first leakage hole is the same as that of the standard hole. By the method for detecting the sealing property of the box body, whether the box body to be detected leaks or not can be detected without immersing the box body to be detected into liquid, and the box body to be detected can be determinedAnd the leakage coefficient is suitable for the tightness detection of the large-volume box body.

Furthermore, in the method for detecting the sealing performance of the box body, the first leakage hole is located in the middle of one surface of the box body to be detected, the number of the second leakage holes is multiple, each corner of the box body to be detected is provided with one second leakage hole, the first leakage hole is opened and each second leakage hole is sealed, then the pressure in the box body to be detected is adjusted, so that the pressure in the box body to be detected is changed alternately between the first pressure and the second pressure in a preset period, a standard waveform of the pressure and the test time in the box body to be detected is obtained, a test waveform corresponding to the second leakage hole in each corner is measured, the phase difference between the test waveform corresponding to the second leakage hole in each corner and the standard waveform of the first leakage hole is compared, and the leakage position of the box body to be detected is detected by the corner corresponding to the minimum phase difference.

At present, the sealing performance of a box body is mainly detected in a mode of observing a bubble point in liquid by permeating or filling positive pressure gas into the liquid under negative pressure, the leakage amount of the box body cannot be accurately quantified, the sealing performance of a large box body cannot be detected, the detection of the large box body needs a larger sealing box body and equipment for loading, unloading and the like, the detection mode is complicated, the detection period is long, the quantification of the leakage amount and the long position confirmation period are long, and the mass production and the quick delivery of products are not facilitated; the sealing coefficient for a particular test sealed housing cannot be quickly determined. The method for detecting the tightness of the box body is simple to operate, can determine the leakage coefficient and the leakage position of the box body, is short in detection time, and can detect the leakage coefficient and the leakage position in real time, wherein the detection time of the leakage amount is about 5 minutes, and the detection time of the leakage position is about 20 minutes.

It can be understood that, when determining whether the box body to be tested leaks, the first leakage hole is not limited to be located in the middle of one surface of the box body to be tested, and may be located in other positions.

It is understood that the box to be tested is not limited to be cubic, but may be other shapes, such as pyramid, prism, sphere or cone, and may be selected according to the needs. When the box body to be tested is in a shape without corners, such as a sphere or a cone, the method for detecting the sealing performance of the box body can be used for detecting whether the box body to be tested leaks or not, and the leakage position at the joint of the box body to be tested cannot be accurately detected.

It can be understood that the quantity of second leakage hole is not limited to be eight or nine, if only need survey the box that awaits measuring and whether leak, then the second leakage hole can have one, if still need survey the position of leaking of box that awaits measuring, then can set up according to the quantity at the corner of the box that awaits measuring to it can all to guarantee that every corner has a second leakage hole.

In addition, the detection system of the sealing performance of the box body of the embodiment is provided, and the sealing performance of the large-volume box body can be detected according to the detection method of the sealing performance of the box body of the embodiment, and the leakage coefficient of the box body can be determined.

Referring to fig. 1, the system for detecting the sealing performance of the box specifically includes a pressure regulating device 110, a sealing member 120, a timing device (not shown), and a detecting device (not shown).

The pressure adjusting device 110 can adjust the pressure inside the tank 200 to be measured to a preset pressure. The chamber 200 has a first leakage hole 210 and a second leakage hole 220 spaced apart from each other and having the same diameter. For the detailed description of the box 200 to be tested, the first leakage hole 210 and the second leakage hole 220, please refer to the above, which is not described herein again.

In one embodiment, the system for detecting the tightness of the box further comprises a tapping device (not shown). The hole forming device can form a first leakage hole 210 and a second leakage hole 220 on the box 200 to be tested. It should be noted that, if the box 200 has the first leakage hole 210 and the second leakage hole 220 with the same aperture and spacing, the hole opening device may be omitted.

In one embodiment, the first leakage hole 210 is located in the middle of one surface of the to-be-tested case 200, the number of the second leakage holes 220 is multiple, one second leakage hole 220 is disposed at each corner of the to-be-tested case 200, and the pressure adjusting device 110 can adjust the pressure inside the to-be-tested case 200, so that the pressure inside the to-be-tested case 200 is changed between the first pressure and the second pressure alternately in a preset period. For the specific description of the preset period, the first pressure and the second pressure, please refer to the above, and the detailed description is omitted here.

Referring to fig. 2 to 3, the voltage regulating device 110 further includes a first voltage regulator 112 and a second voltage regulator 114.

The first pressure regulator 112 is capable of regulating the pressure within the tank 200 to be measured to a predetermined pressure. Further, the first pressure regulator 112 can be installed on the box 200 to be tested, so as to introduce gas into the box 200 to be tested, so as to regulate the pressure in the box 200 to be tested to a preset pressure. Furthermore, the box body 200 to be tested is provided with a first vent hole, the first pressure regulator 112 can be installed on the box body 200 to be tested and cover the first vent hole and is hermetically connected with the box body 200 to be tested, and the first pressure regulator 112 can introduce gas into the box body 200 to be tested through the first vent hole so as to regulate the pressure in the box body 200 to be tested. Specifically, the first pressure regulator 112 is an inflator or a vacuum pump.

The second pressure regulator 114 is capable of regulating the pressure inside the tank 200 to be tested so that the pressure inside the tank 200 to be tested alternates between the first pressure and the second pressure at a preset cycle. Further, the box 200 to be tested is provided with a second vent hole, and the second voltage regulator 114 can be installed on the box 200 to be tested and cover the second vent hole and be connected with the box 200 to be tested in a sealing manner. Further, the second pressure regulator 114 is a reciprocating pump. Specifically, the second pressure regulator 114 is a piston pump.

The seal 120 can seal the second leakage hole 220. Further, the seal 120 can also seal the second leakage hole 220. Specifically, the seal 120 is a gas plug. The seal 120 is not limited to the air lock, and may be another seal 120 as long as it can seal the hole.

In one embodiment, the system for detecting the tightness of the tank further comprises a pressure detector (not shown). The pressure detector is plural, and each pressure detector can be disposed in the case 200 to be tested, so that one pressure detector is disposed at each of the first leakage hole 210 and the second leakage hole 220. Further, the pressure detector is a pressure sensor.

The timing device can measure a first time when the first and second leakage holes 210 and 220 are simultaneously opened to restore the pressure in the chamber 200 to be measured from a preset pressure to a normal pressure. The timing device is also capable of measuring a second time when the first leakage hole 210 is opened and the second leakage hole 220 is sealed to restore the pressure in the chamber 200 to be measured from the preset pressure to the normal pressure. The timing test is also capable of recording the test time during which the pressure inside the tank 200 to be tested alternates between the first pressure and the second pressure at a preset cycle.

The detection device can be connected with the timing device and receives the time signal transmitted by the timing device, then the flow coefficient to be detected of the box body 200 to be detected is calculated according to the formula, and if the flow coefficient to be detected is larger than 0, the box body 200 to be detected leaks.

Further, the detection device can also determine the leakage condition of the box body 200 to be detected according to the flow coefficient to be detected. In particular, the detection device can also have a display or alarm function. If the detection device determines that the box body 200 to be detected has leakage, the detection device can prompt the box body 200 to be detected to have the leakage detection result in a display or alarm manner.

In one embodiment, the detection device can be further connected to the pressure regulating device 110 to receive the pressure signal transmitted by the pressure regulating device 110, then measure the standard waveform corresponding to the first leakage hole 210 and the test waveform corresponding to each corner, then compare the phase difference between the test waveform corresponding to each corner and the standard waveform, and determine the leakage position of the box 200 to be tested by determining the position of the corner corresponding to the minimum phase difference. The standard waveform is a variation curve of the pressure in the case 200 to be tested and the test time during the process of alternating the pressure in the case 200 to be tested between the first pressure and the second pressure in a preset period when the first leakage hole 210 is opened and each second leakage hole 220 is sealed. The test waveform is a change curve of the pressure in the case 200 to be tested and the test time during the process of alternating the pressure in the case 200 to be tested between the first pressure and the second pressure in a preset period when the second leakage hole 220 at one corner is opened and other second leakage holes 220 are sealed.

The operation of the above-described detection system for tightness of a case 200 to be tested for tightness is as follows:

1. the operation process for determining whether the box 200 to be tested has leakage is as follows:

(1) the first leakage holes 210 and each of the second leakage holes 220 are sealed by the sealing member 120, and the first pressure regulator 112 is mounted on the case 200 to be tested and shields the first vent hole and is hermetically connected to the case 200 to be tested. The detection device is connected with the timing device. The detection device is connected with the pressure detector.

(2) Gas is introduced into the tank 200 to be tested through the first pressure regulator 112, so that the pressure in the tank 200 to be tested is adjusted to a preset pressure, and then the gas introduction is stopped. Simultaneously opening the first leakage hole 210 and the second leakage hole 220 to restore the pressure in the chamber 200 to normal pressure; and the timing device detects a first time from the preset pressure to the normal pressure and transmits the first time to the detection device.

(3) Gas is introduced into the tank 200 to be tested through the first pressure regulator 112, so that the pressure in the tank 200 to be tested is adjusted to a preset pressure, and then the gas introduction is stopped. Opening the first leakage hole 210 to restore the pressure in the box 200 to normal pressure; and the timing device detects a second time from the preset pressure to the normal pressure and transmits the second time to the detection device.

(4) The detection device receives the first time and the second time and adopts the formula: and calculating the flow coefficient to be measured of the tank body 200 to be measured. If the flow coefficient to be measured is greater than 0, the box body 200 to be measured has leakage.

2. After determining that the box body 200 to be tested has leakage, the operation process for detecting the leakage position of the box body 200 to be tested is as follows:

(1) the first leakage holes 210 and each of the second leakage holes 220 are sealed with a sealing member 120. The second voltage regulator 114 is installed on the case 200 to be tested and covers the second vent hole and is hermetically connected with the case 200 to be tested.

(2) The first leakage hole 210 is opened and the pressure in the tank 200 to be tested is adjusted by the second pressure regulator 114 so that the pressure in the tank 200 to be tested is alternately changed between the first pressure and the second pressure at a preset period. The pressure detector records the pressure change of the box body 200 to be detected and transmits a pressure signal to the detection device. The timing device measures a test time in which the pressure in the case 200 to be tested is alternately changed between the first pressure and the second pressure at a preset period, and transmits the test time to the detection device. The detection device determines a standard waveform from the pressure signal and the test detection, and determines a phase of the standard waveform.

(3) The second leakage hole 220 at one corner is opened, the first leakage hole 210 is sealed and the remaining second leakage holes 220 are sealed. The pressure in the tank 200 to be tested is adjusted by the second pressure regulator 114 so that the pressure in the tank 200 to be tested alternates between the first pressure and the second pressure at a preset cycle. The pressure detector records the pressure change of the box body 200 to be detected and transmits a pressure signal to the detection device. The timing device measures a test time in which the pressure in the case 200 to be tested is alternately changed between the first pressure and the second pressure at a preset period, and transmits the test time to the detection device. The detection device determines a test waveform according to the pressure signal and the test detection, and determines the phase of the test waveform. The test waveform for each corner was determined in the same operation.

(4) The detection device compares the phase difference between the test waveform corresponding to each corner and the standard waveform, and determines the leakage position of the box body 200 to be tested by determining the position of the corner corresponding to the minimum phase difference.

Through the detection system for the sealing performance of the box body, whether the box body 200 to be detected leaks can be determined without immersing the box body 200 to be detected into liquid, the leakage coefficient of the box body 200 to be detected can be determined, and the detection system is suitable for sealing performance detection of large-volume box bodies.

The following are specific examples:

example 1

The box body is filled with gas with certain air pressure, the whole box body is placed into water, and whether continuous bubbles exist at the joint of the box body or not is observed so as to judge the gas leakage position of the box body and not obtain the leakage amount.

1. The process of determining whether the box body to be detected has leakage is as follows:

(1) and providing a box body to be tested. The box body to be tested is cubic and is made by sealing and connecting eight plates, and the volume of the box body to be tested is 500L. The first leakage hole is positioned in the middle of one surface of the box body to be tested. There are nine second leakage holes. One of the second leakage holes and the first leakage hole are located on the same surface and are arranged close to the first leakage hole. The other eight second leakage holes are respectively positioned at eight corners of the box body to be tested. It is known that there is a leak in one corner of the tank under test.

(2) The pressure in the box body to be tested is adjusted to a preset pressure, then the first leakage hole and the second leakage hole which is located on the same surface with the first leakage hole are opened simultaneously, and other second leakage holes are sealed, so that the pressure in the box body to be tested is recovered to the normal pressure, and the first time for recovering the pressure in the box body to be tested to the normal pressure from the preset pressure is measured. The preset pressure is 3 Pa. The first time is 18 s. The change curve of the pressure in the tank to be measured and the time in the process of recovering the pressure in the tank to be measured from the preset pressure to the normal pressure is shown in figure 4 in detail. T1 in FIG. 4 is the first time, and P is the preset pressure.

(3) Adjusting the pressure in the box to be tested to the preset pressure, then opening the first leakage holes and sealing each second leakage hole so as to restore the pressure in the box to be tested to the normal pressure, and determining the second time for the pressure in the box to be tested to be restored to the normal pressure from the preset pressure. The preset pressure is 3 Pa. The first time is 18 s. The change curve of the pressure in the tank to be measured and the time in the process of recovering the pressure in the tank to be measured from the preset pressure to the normal pressure is shown in figure 4 in detail. In fig. 4, t2 is the second time, and P is the preset pressure.

(4) According to the formula: and calculating the flow coefficient to be measured of the box body to be measured.kIs 0.15. The volume of the standard box is 800L. The standard hole has a diameter of 2.0 mm. The standard flow coefficient was 0.38mL/(s × Pa). The standard time was 18 s.

Through calculation, the flow coefficient to be measured is 0.12 mL/(s × Pa), and the box body to be measured has leakage.

2. The detection process of the leakage position of the box body to be detected is as follows:

(1) and opening the first leakage holes and sealing each second leakage hole, and then adjusting the pressure in the box body to be tested so that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in a preset period to obtain a standard waveform of the pressure in the box body to be tested and the test time. The second pressure is 1 bar. The first pressure was-1 bar. The preset period is 30 s. The standard waveform is shown in fig. 5. The curve at t1 in fig. 5 is a standard waveform.

(2) The test waveform for each corner was determined as follows: and opening a second leakage hole at one corner, sealing other second leakage holes, and then adjusting the pressure in the box body to be tested so that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in the preset period to obtain a change curve of the pressure in the box body to be tested and the test time, thereby obtaining a test waveform corresponding to one corner. And measuring the test waveforms corresponding to the other corners according to the same operation, and opening the second leakage holes at the corners and sealing the other second leakage holes. The test waveform for one of the corners is shown in fig. 5. The curve at t2 in fig. 5 is a test waveform.

(3) And comparing the phase difference between the test waveform and the standard waveform corresponding to each corner. The phase difference between the corresponding test waveform and the standard waveform at each corner is shown in table 1. Positions 1-8 in table 1 correspond to 8 corners of the box to be tested.

As can be seen from table 1, position 6, which has a phase difference of 22 ms, has a leak in the corner.

Position of	∆t（ms）
		1	11
2	15
		3	12
4	19
		5	12
6	22
		7	18
8	16

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for detecting the sealing performance of a box body is characterized by comprising the following steps:

according to the formula: calculating the flow coefficient to be measured of the box body to be measured, and if the flow coefficient to be measured is larger than 0, leaking the box body to be measured, wherein the flow coefficient to be measured is larger than 0kBe 0.1~0.25, standard flow coefficient is the flow coefficient of standard box, standard time is pressure in the standard box is followed the time of preset pressure recovery to ordinary pressure, the volume of standard box with the volume of the box that awaits measuring is the same, standard box does not have and reveals, standard box is equipped with the standard hole, the aperture of first exposure hole with the aperture of standard hole is the same.

2. The method for detecting the sealing performance of the box body according to claim 1, wherein the second leakage hole is provided in plurality, and the plurality of second leakage holes are arranged at intervals; the step of then simultaneously opening the first and second leakage holes includes: then simultaneously opening the first leakage holes and one of the second leakage holes and sealing the other second leakage holes; the step of then opening the first leakage hole and sealing the second leakage hole comprises: the first leakage holes are then opened and each of the second leakage holes is sealed.

3. The method for detecting the sealing performance of the tank body according to claim 2, wherein the first leakage hole is located in a middle portion of one surface of the tank body to be tested, one second leakage hole is provided at each corner of the tank body to be tested, and if the tank body to be tested has a leakage, the method further comprises a step of determining a leakage position of the tank body to be tested after the step of calculating the flow coefficient to be tested of the tank body to be tested according to the formula:

4. The method of detecting the sealability of a tank according to claim 3, wherein the negative value of the second pressure is equal to the first pressure.

5. The method for detecting the sealing performance of the box according to claim 4, wherein the second pressure is a relative pressure, and the second pressure is 1.0Pa to 30.0 Pa.

6. The method for detecting the sealing performance of the box body according to any one of claims 3 to 5, wherein the preset period is 10s to 50 s.

7. The method for detecting the sealing performance of the box body according to any one of claims 1 to 5, wherein the preset pressure is a relative pressure, and the preset pressure is 1.0Pa to 30.0 Pa;

and/or the aperture of the standard hole is 2.0 mm-3.0 mm;

and/or the standard flow coefficient is 0.38mL/(s Pa) to 0.87mL/(s Pa), and the standard time is 10s to 50 s.

8. A detection system of the leakproofness of box, characterized by including:

a seal capable of sealing the second leakage hole;

9. The system for testing the sealing performance of a tank body according to claim 8, wherein the first leakage hole is formed at a central portion of one surface of the tank body to be tested, the second leakage holes are arranged in a plurality of numbers, one second leakage hole is arranged at each corner of the box body to be tested, the pressure regulating device can also regulate the pressure in the box body to be tested, so that the pressure in the tank to be measured is alternately changed between the first pressure and the second pressure at a preset period, the detection device can also be connected with the pressure regulating device to receive the pressure signal transmitted by the pressure regulating device, then measuring a standard waveform corresponding to the first leakage hole and a test waveform corresponding to each corner, the phase difference of the test waveform and the standard waveform corresponding to each corner can then be compared, the position of the corner corresponding to the minimum phase difference can be determined to determine the leakage position of the box body to be tested; the standard waveform is a change curve of the pressure in the box body to be tested and the test time in the process that the pressure in the box body to be tested is changed alternately between the first pressure and the second pressure in the preset period when the first leakage holes are opened and each second leakage hole is sealed; when the second leakage hole at one corner is opened and other second leakage holes are sealed, the pressure in the box body to be tested is in the process of alternating change between the first pressure and the second pressure in the preset period, and the change curve of the pressure in the box body to be tested and the test time is obtained.