Sealing detection method and sealing detection device

Abstract

The invention provides a sealing test method and a sealing test device, and belongs to the field of batteries. The sealing test method comprises the following steps: inflating a to-be-tested product until the pressure in the to-be-tested product reaches a preset pressure; communicating the interior of the to-be-tested product with a standard pressure source, and maintaining for a preset duration; the standard pressure source has preset output pressure; and determining the sealing performance of the to-be-tested product according to the pressure in the to-be-tested product and the preset output pressure.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a sealing detection method and a sealing detection device. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] More and more battery systems are using liquid cooling systems with higher thermal management efficiency. The internal circuit of the liquid cooling system is complex, and its water inlet and outlet are connected to the outside using adapters. The liquid cooling system has strict requirements on sealing performance, which has a direct impact on the performance and safety of the battery. How to accurately detect the density performance of the battery's liquid cooling system has become an important issue that needs to be solved urgently. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the background technology. To this end, one object of the present application is to provide a sealing detection method and a sealing detection device to improve the accuracy of sealing performance detection of a battery liquid cooling system.

[0005] An embodiment of the first aspect of the present application provides a sealing test method, which includes: inflating air into the product to be tested until the pressure inside the product to be tested reaches a preset pressure; connecting the interior of the product to be tested to a standard pressure source and maintaining the connection for a preset period of time; the standard pressure source has a preset output pressure; and determining the sealing performance of the product to be tested based on the pressure inside the product to be tested and the preset output pressure.

[0006] In the technical solution of the embodiment of the present application, by connecting the inflated product to be tested with a standard pressure source, the pressure fluctuations within the product to be tested during the pre-test preparation stage can be effectively suppressed, so that the internal pressure of the product to be tested can enter a stable state more quickly after inflation, which is beneficial to improving the accuracy of subsequent leakage rate detection.

[0007] In some embodiments, after inflating the product to be tested until the pressure inside the product to be tested reaches a preset pressure, the process further includes: inflating the product to be tested in a manner that maintains the pressure inside the product to be tested at the preset pressure, detecting the inflation flow rate, and stopping inflation until the inflation flow rate is less than or equal to a preset flow rate threshold. By adding a volume deformation supplementary inflation step in the inflation process, the pressure change caused by the volume expansion after inflation can be compensated, so that the volume and pressure of the product to be tested after inflation are in a relatively stable state, which is conducive to improving the accuracy of subsequent leakage rate detection results.

[0008] In some embodiments, determining the sealing performance of the product to be tested based on the pressure of the product to be tested and the preset output pressure includes: obtaining the volume of the product to be tested, determining the leakage threshold according to the preset volume and leakage threshold mapping relationship and the volume of the product to be tested; determining the leakage rate of the product to be tested according to the pressure of the product to be tested and the preset output pressure, and determining the sealing performance of the product to be tested according to the leakage rate and leakage threshold of the product to be tested. By selecting the leakage threshold corresponding to the current volume of the product to be tested through the mapping relationship between the volume and the leakage threshold determined in advance, the sealing performance of the product to be tested with volume changes can be detected more accurately, reducing the risk of overkilling.

[0009] In some embodiments, obtaining the volume of the product to be tested further includes: connecting the product to be tested to a standard leak hole, the standard leak hole having a set leakage amount, obtaining a pressure drop value in the product to be tested when the gas in the product to be tested leaks out from the set leak hole, and determining the volume of the product to be tested according to the pressure drop value and the set leakage amount of the set leak hole. By connecting the product to be tested to the standard leak hole, the volume calculated by detecting the pressure drop value and the leakage rate can more accurately characterize the volume of the product to be tested after inflation, thereby being able to obtain a more accurate judgment threshold and make a judgment on the sealing performance, thereby improving the accuracy of the sealing performance detection.

[0010] In some embodiments, inflating the product to be tested until the pressure in the product to be tested reaches a preset pressure includes: controlling the gas source to inflate the product to be tested with a first inflation pressure until the pressure in the product to be tested reaches a first threshold pressure; controlling the gas source to inflate the product to be tested with a second inflation pressure until the pressure in the product to be tested reaches a preset pressure; wherein the second inflation pressure is less than the first inflation pressure, and the first threshold pressure is less than the preset pressure. The pressure in the product to be tested can be quickly increased to a first threshold pressure close to the preset pressure by the first inflation pressure with a larger pressure, and then the pressure in the product to be tested can be continued to be inflated to reach the preset pressure by the second inflation pressure with a smaller pressure. This can shorten the inflation time on the one hand, and prevent overcharging to a certain extent on the other hand, thereby improving the stability of the entire inflation process.

[0011] In some embodiments, inflating the product to be tested until the pressure in the product to be tested reaches a preset pressure includes: controlling the gas source to inflate the product to be tested at a third inflation pressure until the pressure in the product to be tested reaches a second threshold pressure; controlling the product to be tested to exhaust air to the outside until the pressure in the product to be tested reaches a preset pressure; wherein the second threshold pressure is greater than the preset pressure. By overfilling the product to be tested in advance and then exhausting and reducing the pressure to the preset pressure, the deformation speed of the product to be tested can be accelerated, so that the volume and preset pressure of the product to be tested have stabilized after inflation is completed, thereby eliminating the pressure fluctuation caused by the inconsistency of inflation and deformation to a certain extent, which is beneficial to the accuracy of subsequent leakage rate detection.

[0012] In some embodiments, determining the sealing performance of the product to be tested based on the pressure inside the product to be tested and the preset output pressure includes: obtaining the pressure difference between the pressure inside the product to be tested and the preset output pressure of the standard pressure source, and determining the leakage rate of the product to be tested based on the pressure difference. Determining the change in the pressure difference between the pressure inside the product to be tested and the preset output pressure of the standard pressure source as the leakage rate of the product to be tested can more accurately characterize the pressure change inside the product to be tested, thereby improving the precision and accuracy of the sealing detection.

[0013] In some embodiments, determining the sealing performance of the product to be tested based on the pressure inside the product to be tested and the preset output pressure further includes: in response to the leakage rate being less than the preset leakage threshold, determining the sealing performance of the product to be tested as "OK". This can improve the efficiency of the test and facilitate subsequent integration with other production lines to perform processing procedures after the determination, thereby improving production efficiency.

[0014] An embodiment of the second aspect of the present application provides a sealing detection device, which includes an air source, a pressure sensor and a balance detection unit. The air source is connected to the product to be tested to inflate the interior of the product to be tested; the pressure sensor is connected to the product to be tested to detect the pressure inside the product to be tested; the balance detection unit includes a standard pressure source and a leakage detection unit. The standard pressure source has a preset output pressure, and the standard pressure source is used to communicate with the interior of the product to be tested to balance the pressure inside the product to be tested; the leakage detection unit is used to connect to the product to be tested to detect the leakage rate of the product to be tested.

[0015] In some embodiments, the leakage detection unit is a differential pressure gauge, and the two ends of the differential pressure gauge are respectively connected to the standard pressure source and the product to be tested to detect the pressure difference between the inside of the product to be tested and the standard pressure source. The differential pressure gauge can directly read the pressure difference between the pressure inside the product to be tested and the standard pressure source, and then the change in the pressure difference per unit time (i.e., pressure drop) can be determined as the leakage rate of the product to be tested.

[0016] In some embodiments, the sealing detection device further includes a flow sensor, which is connected to the gas source and the product to be tested respectively to detect the inflation flow rate provided by the gas source to the product to be tested. By detecting the inflation flow rate and judging the deformation completion of the product to be tested from the change of the inflation flow rate, it is possible to determine the cut-off time of inflation and improve the accuracy of the detection.

[0017] In some embodiments, the sealing detection device further includes a standard leak hole, which is used to connect to the product to be tested and has a preset leakage rate. The standard leak hole can be used to calculate the volume of the product to be tested after inflation, and then calibrate the volume of the product to be tested after inflation and the corresponding leakage threshold, thereby improving the accuracy of sealing performance detection.

[0018] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0020] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application;

[0021] Figure 2 A schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0022] Figure 3 A flow chart of a sealing detection method according to some embodiments of the present application;

[0023] Figure 4 A flow chart of a sealing detection method according to some other embodiments of the present application;

[0024] Figure 5 Schematic diagram of a sealing detection device according to some embodiments of the present application.

[0025] Description of reference numerals:

[0026] Vehicles 1000;

[0027] Battery 100, controller 200, motor 300; sealing detection device 400;

[0028] Box body 10, battery cell 20, liquid cooling assembly 30;

[0029] A first mounting hole 101, a second mounting hole 102, an accommodating space 103, a current collector 301, a connecting pipe 302, and a water cooling plate 303;

[0030] Gas source 401, pressure sensor 402, balance detection unit 403, standard pressure source 4031, leakage detection unit 4032, flow sensor 404, standard leak hole 405, pressure control valve 406, first switch K-1, second switch K-2, third switch K-3, fourth switch K-4. DETAILED DESCRIPTION

[0031] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0037] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0040] In order to control the temperature of the battery to maintain battery performance, a thermal management component, such as a liquid cooling component, can be set inside the battery box to achieve thermal management of the battery through heat exchange. The liquid cooling component can include a water cooling plate set between battery cells and a connecting pipe and adapter that connects the water cooling plate to the outside. The sealing performance of the liquid cooling system is directly related to the liquid cooling effect and battery performance, and even the safety of the battery.

[0041] In the related art, the sealing performance test of the liquid cooling system is usually carried out by measuring the pressure change per unit time caused by leakage or detecting the leakage flow per unit time. However, since the leakage amount of the liquid cooling component is usually not small, especially for the water cooling plate in the liquid cooling component, the testing of its sealing performance is easily affected by various factors, such as the switching of the control switch in the pipeline, the change of volume and pressure due to structural deformation, etc. These will cause deviations in the test results, and then cause the test results to be missed or over-killed.

[0042] The embodiment of the present application proposes a sealing test method, including the following steps: inflating the product to be tested until the pressure inside the product to be tested reaches a preset pressure; connecting the inside of the product to be tested to a standard pressure source and maintaining it for a preset time; the standard pressure source has a preset output pressure; obtaining the leakage rate of the product to be tested, and determining the sealing performance of the product to be tested based on the leakage rate. By setting up a standard pressure source and connecting it to the product to be tested, the pressure inside the product to be tested can be balanced before testing, reducing the pressure fluctuations caused by the operation during the test and the distortion of the test results caused by the deformation of the product to be tested itself, and improving the accuracy of the sealing performance test.

[0043] The sealing detection method and sealing detection device disclosed in the embodiments of the present application can be used, but are not limited to, to detect the sealing performance of a liquid cooling system in a battery. The liquid cooling system can be a liquid cooling system that has been arranged in a battery case, or a liquid cooling system that has not yet been assembled, or a component in the liquid cooling system that requires sealing detection, such as a heat exchange plate.

[0044] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft.

[0045] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0046] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0047] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. Vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0048] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0049] Please refer to Figure 2 , Figure 2 The schematic diagram of the exploded structure of the battery provided in some embodiments of the present application. The battery 100 includes a box body 10 and a battery cell 20, and the battery cell 20 is accommodated in the box body 10. The box body 10 is used to provide a accommodating space 103 for the battery cell 20, and the box body 10 can adopt a variety of structures.

[0050] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the accommodation space 103 of the box 10; of course, the battery 100 may also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and then accommodated in the box 10.

[0051] The battery 100 may further include other structures. For example, the battery 100 may further include a liquid cooling assembly 30 for implementing thermal management of the plurality of battery cells 20 .

[0052] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0053] The liquid cooling assembly 30 may include a current collector 301, a connecting pipe 302 and a water cooling plate 303. The water cooling plate 303 may be arranged in a plurality in parallel, and each water cooling plate 303 is located between two rows of battery cells 20 to exchange heat with the battery cells 20 to achieve battery thermal management. The current collector 301 is located at the end of the water cooling plate 303, and the connecting pipe 302 is connected to the current collector 301. The cooling liquid can flow into and out of the water cooling plate 303 through the connecting pipe 302 and the current collector 301. In some embodiments, the liquid cooling assembly 30 may also include an adapter, and the connecting pipe 302 may be connected to the adapter through the mounting plate on the housing 10, so that the cooling liquid can be connected to the outside (e.g., the cooling system of the vehicle) through the adapter.

[0054] See also Figure 3 , Figure 3 This is a flow chart of a sealing detection method according to some embodiments of the present application.

[0055] The present application provides a sealing test method, which includes:

[0056] Step S101: Inflate the product to be tested until the pressure inside the product to be tested reaches a preset pressure;

[0057] Step S102: connecting the interior of the product to be tested to a standard pressure source and maintaining the connection for a preset time; the standard pressure source has a preset output pressure;

[0058] Step S103: determining the sealing performance of the product to be tested according to the pressure inside the product to be tested and the preset output pressure.

[0059] The product to be tested may be a liquid cooling system 30, or a component of the liquid cooling system, such as a water cooling plate 303, or a battery 100 with a liquid cooling system. In some embodiments, the product to be tested is a water cooling plate 303. A flow channel for liquid flow is provided inside the product to be tested, and the interior of the product to be tested is connected to a gas source to fill the space inside the product to be tested with gas until the pressure inside the product to be tested reaches a preset pressure. The preset pressure can be set in advance according to the type and specification of the product to be tested.

[0060] The standard pressure source is a device that uses components such as pressure sensors and pressure-stabilizing valves to precisely control the flow and pressure of the gas, thereby outputting gas with a set pressure to the outside. Since the inflation stage in step S101 will control the on-off of the gas circuit through some switch elements in some cases, this will cause the pressure inside the product to be tested to fluctuate, and some gas may even escape from related control elements or pipelines, causing unexpected changes in the pressure inside the product to be tested. The standard pressure source has a preset output pressure, which is the external output pressure of the standard pressure source that can be set in advance according to the actual detection needs. In some embodiments, the preset output pressure of the standard pressure source can be adjusted to be equal to the preset pressure, and the inside of the product to be tested can be connected to the standard pressure source, and the stable output pressure of the standard pressure source can be used to stabilize the air pressure fluctuation inside the product to be tested, so that the pressure inside the product to be tested can enter a stable state faster, shortening the time required for equilibrium, which is beneficial to the accuracy of subsequent leakage rate detection. The length of time that the inside of the product to be tested is connected to the standard pressure source can be determined according to the corresponding product type.

[0061] The detection of sealing performance can be determined by the pressure drop method or the flow method. The leakage rate of the product to be tested can be characterized by the pressure drop value per unit time or the leakage flow rate per unit time. Theoretically, the worse the sealing performance of the product to be tested, the more gas leaks per unit time, that is, the larger the leakage flow rate, and gas leakage will cause the internal pressure to decrease, and vice versa. In some embodiments, the pressure drop value of the pressure (air pressure) inside the product to be tested per unit time or the gas leakage per unit time can be detected as the leakage rate of the product to be tested, and the pressure drop value or the leakage amount can be compared with the corresponding judgment threshold to determine whether the sealing performance of the product to be tested meets the requirements. In some embodiments, the sealing performance of the product to be tested can be determined based on the change in the pressure difference between the pressure inside the product to be tested and the preset output pressure.

[0062] In this embodiment, by connecting the inflated product to be tested with a standard pressure source, the pressure fluctuation within the product to be tested during the pre-test preparation stage can be effectively suppressed, so that the internal pressure of the product to be tested can enter a stable state more quickly after inflation, which is beneficial to improving the accuracy of subsequent leakage rate detection.

[0063] See also Figure 4 , Figure 4 This is a flow chart of a sealing detection method according to some other embodiments of the present application.

[0064] According to some embodiments of the present application, the sealing test method includes:

[0065] Step S201: Inflate the product to be tested until the pressure inside the product to be tested reaches a preset pressure;

[0066] Step S202: inflating the product to be tested in such a manner as to maintain the pressure in the product to be tested at a preset pressure, detecting the inflation flow rate, and stopping inflation until the inflation flow rate is less than or equal to a preset flow rate threshold;

[0067] Step S203: connecting the interior of the product to be tested to a standard pressure source and maintaining the connection for a preset time; the standard pressure source has a preset output pressure;

[0068] Step S204: determining the sealing performance of the product to be tested according to the pressure inside the product to be tested and the preset output pressure.

[0069] Step S201 may be the same as step S101 in the above embodiment, and step S203 and step S204 may be the same as step S102 and step S103 in the above embodiment.

[0070] The inflation in step S202 is constant pressure inflation, and the pressure in the product to be tested is maintained at a preset pressure during the inflation process. It is understandable that in the actual inflation process, due to the limited accuracy of various control valves, the pressure in the product to be tested usually fluctuates within a small range around the preset pressure. This situation also falls within the scope of the method of maintaining the pressure in the product to be tested at the preset pressure described in step S202 of this embodiment. The inflation flow rate can be detected by setting a flow sensor between the gas source and the product to be tested to detect the inflation flow rate during the inflation process.

[0071] Since the pressure inside the product to be tested will increase significantly after inflation, the pressure difference between the inside and outside may cause the product to be tested to deform, which in turn causes the volume inside the product to be tested to change. Since the size of the volume is directly related to the pressure, the pressure will also change. In some examples, the product to be tested is a water-cooled plate, which is a thin-walled structure with a flow channel or a flow cavity inside. After inflation, it will expand and cause the volume to increase. Since the expansion of the product to be tested is not completely synchronized with the inflation process in S201, that is, after the pressure inside the product to be tested reaches the preset pressure and inflation is stopped, the deformation of the product to be tested is not necessarily over at this time. As the deformation continues, in the absence of external gas supplementation, the pressure inside the product to be tested can also decrease due to volume expansion and deformation. That is to say, at this stage, the pressure drop inside the product to be tested includes not only the pressure drop caused by leakage, but also the pressure drop caused by volume change. For some products to be tested with large deformation, the pressure drop caused by volume change may be significantly greater than the pressure drop caused by leakage, which will obviously affect the accuracy of the detection of the leakage rate of the product to be tested.

[0072] In this embodiment, a compensating inflation step S202 is added. The inflation in this step is to compensate for the fluctuation of the internal pressure caused by the volume change of the product to be tested. The product to be tested is inflated with constant pressure and the pressure inside the product to be tested is maintained at a preset pressure. When the product to be tested is deformed and the volume tends to be stable, the pressure drop caused by the volume change inside the product will gradually decrease until it is close to or even equal to 0. The inflation flow rate at this stage will also gradually decrease until it tends to be stable or even equal to 0. Considering that there is a leak inside the product to be tested, in step S202, the gas source will continue to inflate the product to be tested in order to maintain the pressure inside the product to be tested at the preset pressure. Therefore, an inflation flow rate less than or equal to a preset flow rate threshold is selected as the inflation cutoff condition in step S202. The preset flow rate threshold can be greater than 0, for example, it can be determined according to the average leakage level of the product to be tested.

[0073] It should be noted that after the supplementary inflation in step S202 and the step S203, the volume and pressure in the product to be tested are basically stable. At this time, executing step S204 can basically and truly reflect the leakage of the product to be tested.

[0074] By adding a volume deformation supplementary inflation step in the inflation process, the pressure change caused by the volume expansion after inflation can be compensated, so that the volume and pressure of the product to be tested after inflation are in a relatively stable state, which is conducive to improving the accuracy of subsequent leakage rate detection results.

[0075] According to some embodiments of the present application, step S103 further includes:

[0076] Obtain the volume of the product to be tested;

[0077] Determine the leakage threshold value according to the preset volume and leakage threshold mapping relationship and the volume of the product to be tested;

[0078] Determine the leakage rate of the product to be tested according to the pressure of the product to be tested and the preset output pressure;

[0079] The sealing performance of the product to be tested is determined based on the leakage rate and leakage threshold of the product to be tested.

[0080] After the product to be tested is inflated, the internal pressure increases, which may cause its volume to expand and change, and the change in volume will cause the pressure to change. For example, after the volume increases, the pressure inside the product to be tested will decrease. At this time, the pressure drop of the product to be tested includes not only the pressure drop caused by leakage, but also the pressure drop caused by volume change. Therefore, characterizing the leakage rate by simply detecting the pressure drop value inside the product to be tested after inflation cannot accurately reflect the true sealing performance of the product to be tested. On the other hand, the leakage threshold used to judge the sealing performance is simply set for the leakage level of the product to be tested. In this way, the pressure drop value obtained during the test is often significantly greater than the leakage threshold, resulting in over-killing.

[0081] Since the deformation ability and deformation amplitude of the products to be tested of different specifications are different during the sealing performance test, the products to be tested of different specifications can be tested in advance to obtain the mapping relationship between the volume and leakage threshold of the products to be tested. In some examples, the products to be tested of different specifications are tested according to the following operations: the volume of the product to be tested after the inflation value is preset, and then the leakage rate of the product to be tested in this state is detected, for example, the leakage rate of the product to be tested is determined according to the change in the difference between the pressure of the product to be tested and the preset output pressure, and further according to the actual leakage degree of the product to be tested, the leakage threshold corresponding to the volume of the product to be tested is determined to determine the sealing performance of the product to be tested. In this way, multiple sets of mapping relationships between volume and leakage threshold can be obtained, which can be used to select the corresponding leakage threshold according to the volume size to determine the sealing performance.

[0082] It should be noted that the volume here refers to the volume after inflation to a preset pressure, and the corresponding leakage threshold is also determined based on the leakage rate under the corresponding volume state. At this time, the leakage rate includes not only the actual leakage rate caused by leakage, but also the leakage rate increased by the volume change. In some embodiments, the leakage threshold is greater than the actual leakage rate. This can reduce the overkill in the sealing performance judgment to a certain extent and improve the accuracy of the sealing performance detection.

[0083] By selecting the leakage threshold corresponding to the volume of the current product to be tested based on the mapping relationship between the volume and the leakage threshold determined in advance, the sealing performance of the product to be tested with volume changes can be tested more accurately, reducing the risk of over-killing.

[0084] According to some embodiments of the present application, obtaining the volume of the product to be tested further includes:

[0085] Connect the product to be tested to a standard leak hole with a set leakage volume;

[0086] Obtain the pressure drop value in the product to be tested when the gas in the product to be tested leaks out from the set leak hole;

[0087] The volume of the product to be tested is determined based on the pressure drop value and the set leakage volume of the set leak hole.

[0088] In this embodiment, the volume of the product to be tested is the volume after inflation. At this time, the product to be tested may have undergone a certain degree of expansion and deformation. Different materials, different structural forms, different preset pressures, and different product rules to be tested may affect the volume of the product to be tested after inflation.

[0089] A standard leak is a standard leak that produces an accurate leak rate (simulating the gas leakage of a leak) under a specific gas pressure. The standard leak has a set leakage volume Q SAssume that the actual leakage of the product to be tested is Q0, the volume of the product to be tested is V, the pressure drop caused by the leakage of the product itself is P0, and the pressure drop caused by the standard leak is P S According to the gas state equation, the same product to be tested satisfies the following formula under the same working conditions:

[0090] P×V=K×Q,

[0091] Where P is the voltage drop of the product to be tested, and satisfies P=P0+P S ,

[0092] V is the volume of the product to be tested,

[0093] R is a constant,

[0094] Q is the leakage of the product to be tested, and satisfies Q=Q0+Q S .

[0095] Due to the leakage of the standard leak Q S is much larger than Q0, and the pressure drop is positively correlated with the corresponding leakage, so P S Much larger than P0, the relationship between the internal pressure and flow rate of the product (P S +P0)V=K(Q S +Q0) can be simplified to P S ×V≈K×Q S , Q S It is known that the pressure drop value △P at this stage can be accurately characterized by collecting the high-frequency pressure signal of the pressure sensor and integrating the collected pressure value relative to time. According to the equation V=Q S The corresponding volume V can be calculated from K / △P.

[0096] In some embodiments, the above volume detection and calculation method can also be used to determine the mapping relationship between volume and leakage threshold, which can keep the determination method the same, reduce errors, and improve the accuracy of the detection result.

[0097] In this embodiment, the product to be tested is connected to a standard leak hole, and the volume V calculated by detecting the pressure drop value and the leakage rate can more accurately characterize the volume of the product to be tested after inflation, so that a more accurate judgment threshold can be obtained and the sealing performance can be determined, thereby improving the accuracy of sealing performance detection.

[0098] According to some embodiments of the present application, step S101 includes:

[0099] Controlling the gas source to inflate the product to be tested with a first inflation pressure until the pressure in the product to be tested reaches a first threshold pressure;

[0100] Controlling the gas source to inflate the product to be tested with a second inflation pressure until the pressure in the product to be tested reaches a preset pressure;

[0101] The second inflation pressure is lower than the first inflation pressure, and the first threshold pressure is lower than a preset pressure.

[0102] In this embodiment, the inflation stage of step S101 is divided into two stages, the first inflation pressure of the first stage is greater than the second inflation pressure used in the second stage, and the first threshold pressure is a pressure value less than the preset pressure. In some embodiments, the first threshold pressure can be between 60% and 95% of the preset pressure, for example, 60%, 70%, 80%, 90% or 95%.

[0103] The pressure in the product to be tested can be quickly increased to a first threshold pressure close to the preset pressure through the first inflation pressure with a higher pressure, and then the pressure in the product to be tested can be continued to reach the preset pressure through the second inflation pressure with a lower pressure. This can shorten the inflation time on the one hand, and prevent overcharging to a certain extent on the other hand, thereby improving the stability of the entire inflation process.

[0104] According to some embodiments of the present application, step S101 includes:

[0105] Controlling the gas source to inflate the product to be tested at a third inflation pressure until the pressure in the product to be tested reaches a second threshold pressure;

[0106] Control the exhaust of the product to be tested until the pressure inside the product to be tested reaches the preset pressure;

[0107] The second threshold pressure is greater than the preset pressure.

[0108] The second threshold pressure is a pressure value greater than the preset pressure. Since the greater the pressure, the greater the volume deformation of the product to be tested, directly inflating the product to be tested to the second threshold pressure greater than the preset pressure through the air source can accelerate the speed of volume deformation of the product to be tested and intensify the degree of deformation. The air is then exhausted to reduce the pressure in the product to be tested to the preset pressure. At this time, the volume of the product to be tested will shrink as the pressure decreases during the exhaust process. In this way, after the inflation is completed, the volume of the product to be tested has actually completed expansion deformation and contraction deformation. The volume at this time can be adapted to the preset pressure, and the degree of subsequent deformation is much smaller, thereby reducing the pressure fluctuation caused by volume change.

[0109] By overfilling the product to be tested in advance and then exhausting and reducing the pressure to the preset pressure, the deformation speed of the product to be tested can be accelerated, so that after the inflation is completed, the volume and the preset pressure of the product to be tested have become stable, thereby eliminating the pressure fluctuation caused by the inconsistency of inflation and deformation to a certain extent, which is beneficial to the accuracy of subsequent leakage rate detection.

[0110] According to some embodiments of the present application, step S103 includes:

[0111] Obtain the pressure difference between the pressure inside the product to be tested and the preset output pressure of the standard pressure source,

[0112] The leakage rate of the product to be tested is determined based on the pressure difference.

[0113] In some embodiments, a differential pressure gauge can be set between the product to be tested and the standard pressure source. The differential pressure gauge can directly read the pressure difference between the pressure inside the product to be tested and the pressure source of the standard pressure source, and then the change in the pressure difference per unit time (i.e., pressure drop) can be determined as the leakage rate of the product to be tested.

[0114] Since the preset output pressure of the standard pressure source is highly stable, it can provide a high-precision judgment basis for pressure changes. Determining the change in the pressure difference between the pressure inside the product to be tested and the pressure source of the standard pressure source as the leakage rate of the product to be tested can more accurately characterize the pressure changes inside the product to be tested, thereby improving the precision and accuracy of seal detection.

[0115] According to some embodiments of the present application, step S103 further includes:

[0116] In response to the leakage rate being less than the preset leakage threshold, the sealing performance of the product to be tested is determined to be "OK".

[0117] In some embodiments, a corresponding determination unit may be provided to determine the sealing performance of the product to be tested by comparing the determined leakage rate with a preset leakage threshold. When the leakage rate is less than the preset leakage threshold, the sealing performance of the product to be tested is determined to be "OK", otherwise the sealing performance of the product to be tested is determined to be "NG". It is understood that the above determination steps may be implemented by a computer or other automated device with a preset corresponding program.

[0118] In some embodiments, the leakage threshold may be a threshold determined based on an actual leakage value of the product to be tested, or may be obtained through a mapping relationship between volume and leakage threshold in the embodiments described above. For example, the mapping relationship between volume and leakage threshold acquired or determined in advance may be stored in a storage unit of a computer, and the corresponding leakage threshold may be directly retrieved for determination during determination, thereby obtaining a determination result.

[0119] By comparing the leakage rate with the preset leakage threshold, the sealing performance of the product to be tested can be quickly determined, which can improve the efficiency of detection and facilitate subsequent integration with other production lines to execute the processing procedures after the determination, thereby improving production efficiency.

[0120] See also Figure 5 , Figure 5 Schematic diagram of a sealing detection device according to some embodiments of the present application.

[0121] The embodiment of the present application provides a sealing detection device, which includes a gas source 401, a pressure sensor 402, and a balance detection unit 403. The gas source 401 is connected to a product to be tested 410 to inflate the interior of the product to be tested 410; the pressure sensor 402 is connected to the product to be tested 410 to detect the pressure inside the product to be tested 410; the balance detection unit 403 includes a standard pressure source 4031 and a leakage detection unit 4032. The standard pressure source 4031 has a preset output pressure, and the standard pressure source 4031 is used to communicate with the interior of the product to be tested to balance the pressure inside the product to be tested; the leakage detection unit 4032 is used to connect to the product to be tested 410 to detect the leakage rate of the product to be tested 410.

[0122] like Figure 5 As shown, in some embodiments, the gas source 401 is connected to the product to be tested 410 through the first switch K-1, the pressure valve 406 and the balance detection unit 403, and the pressure sensor 402 is connected to the product to be tested 410 alone to detect the gas pressure inside the product to be tested 410. The gas source 401 can be a tracer gas, such as helium. The pressure valve 406 can adjust the gas pressure delivered by the gas source to the product to be tested 410. When the pressure sensor 402 detects that the internal pressure of the product to be tested 410 reaches a preset pressure, the first switch K-1 is disconnected to stop the inflation. The standard pressure source 4031 in the balance detection unit 403 can be inflated to a preset pressure together with the product to be tested 410 during inflation, and the output pressure of the standard pressure source 4031 can always be maintained at the preset output pressure. In some embodiments, the preset output pressure can be equal to the preset pressure. The first switch K-1 can be any fluid on-off control valve, such as a ball valve.

[0123] In some embodiments, the sealing detection device 400 can be used to implement the sealing detection method described in any of the above embodiments, thereby improving the accuracy of the sealing performance detection of the product to be tested.

[0124] According to some embodiments of the present application, the leakage detection unit 4032 is a differential pressure gauge, and both ends of the differential pressure gauge are respectively connected to the standard pressure source 4031 and the product to be tested 410 to detect the pressure difference between the inside of the product to be tested 410 and the standard pressure source 4031.

[0125] After the inflation is stopped, the first switch K-1 is disconnected, and the two ends of the leakage detection unit 4032 are respectively connected to the standard pressure source 4031 and the product to be tested 410, so that the pressure difference between the two can be directly displayed.

[0126] The pressure difference between the pressure inside the product to be tested 410 and the pressure source 4031 can be directly read by the differential pressure gauge, and the change in the pressure difference per unit time (ie, pressure drop) can be determined as the leakage rate of the product to be tested 410 .

[0127] According to some embodiments of the present application, the sealing detection device 400 further includes a flow sensor 404 , which is respectively connected to the gas source 401 and the product to be tested 410 to detect the inflation flow provided by the gas source 401 to the product to be tested 410 .

[0128] The flow sensor 404 can be connected to the product to be tested through the second switch K-2, so as to detect the gas flow passing through the flow sensor per unit time.

[0129] By detecting the inflation flow rate and judging the deformation completion of the product 410 to be tested from the change of the inflation flow rate, it is possible to determine the inflation cut-off time and improve the accuracy of the test.

[0130] According to some embodiments of the present application, the sealing detection device 400 further includes a standard leak hole 405 , which is used to be connected to a product to be tested 410 , and the standard leak hole 405 has a preset leakage rate.

[0131] The standard leak hole 405 can be connected to the product to be tested 410 through a fourth switch K-4.

[0132] The standard leak hole 405 can be used to calculate the volume of the product to be tested after being inflated, and then calibrate the volume of the product to be tested after being inflated and the corresponding leakage threshold, thereby improving the accuracy of sealing performance detection.

[0133] The sealing detection method and sealing detection device of the present application are described below in conjunction with specific embodiments.

[0134] like Figure 1-Figure 5 As shown, in some embodiments, the sealing detection device 400 includes an air source 401, a pressure sensor 402 and a balance detection unit 403. The air source 401 is connected to the product to be tested 410 to inflate the interior of the product to be tested 410; the pressure sensor 402 is connected to the product to be tested 410 to detect the pressure inside the product to be tested 410; the balance detection unit 403 includes a standard pressure source 4031 and a leakage detection unit 4032. The standard pressure source 4031 has a preset output pressure, which may be equal to the preset pressure. The standard pressure source 4031 is used to communicate with the interior of the product to be tested to balance the pressure inside the product to be tested; the leakage detection unit 4032 is used to connect to the product to be tested 410 to detect the leakage rate of the product to be tested 410.

[0135] The sealing detection device 400 further includes a flow sensor 404 , which is connected to the gas source 401 and the product to be tested 410 respectively through a second switch K- 2 to detect the inflation flow provided by the gas source 401 to the product to be tested 410 .

[0136] The balance detection unit 403 may be connected to the product to be tested 410 through the flow sensor 404 and the second switch K- 2 , or may be directly connected to the product to be tested 410 through the third switch K- 3 .

[0137] The sealing detection device 400 further includes a standard leak hole 405 , which is connected to the product to be tested 410 via a fourth switch K- 4 , and has a preset leakage rate.

[0138] The sealing detection device 400 further includes a pressure control valve 406 , which is disposed between the gas source 401 and the balance detection unit 403 .

[0139] Seal testing methods include:

[0140] Step S101: Inflate the product 410 to be tested until the pressure in the product 410 to be tested reaches a preset pressure.

[0141] Close the first switch K-1 and the third switch K-3, disconnect the second switch K-2 and the fourth switch K-4, connect the gas source 401 to the product to be tested 410, control the pressure control valve 406 to control the gas pressure output by the gas source 401, and the pressure sensor 402 detects the pressure in the product to be tested 410. When the pressure in the product to be tested 410 reaches the preset pressure, disconnect the first switch K-1 and stop inflation.

[0142] Step S102: Connect the interior of the product to be tested 410 to the standard pressure source 4031 and maintain the connection for a preset time; the preset output pressure of the standard pressure source is equal to the preset pressure.

[0143] The third switch K-3 is closed, and the first switch K-1, the second switch K-2 and the fourth switch K-4 are opened, so that the interior of the product to be tested 410 is connected to the standard pressure source 4031.

[0144] Step S103: Obtain the leakage rate of the product to be tested 410, and determine the sealing performance of the product to be tested 410 according to the leakage rate.

[0145] The pressure difference value displayed by the leakage detection unit 4032 within a period of time is read and the pressure drop value per unit time is calculated, the pressure drop value is used as the leakage rate of the product to be tested, and the pressure drop value is compared with the preset leakage threshold to determine the sealing performance of the product to be tested.

[0146] In some embodiments, between step S101 and step S02, the following may also be included:

[0147] Inflate the product 410 to be tested in such a way that the pressure in the product 410 is maintained at a preset pressure, detect the inflation flow rate, and stop inflating until the inflation flow rate is less than or equal to a preset flow rate threshold.

[0148] The first switch K-1 and the second switch K-2 are closed, and the third switch K-3 and the fourth switch K-4 are opened. The pressure control valve 406 is adjusted so that the pressure sensor 402 shows that the pressure in the product to be tested 410 is maintained at a preset pressure during the inflation process, and the flow sensor 404 detects the inflation flow value in real time until the inflation flow is less than or equal to the preset flow threshold, and the first switch K-1 is opened.

[0149] In some embodiments, step S103 may further include:

[0150] Connect the product to be tested 410 to the standard leak hole 405;

[0151] Obtaining a pressure drop value ΔP in the product to be tested 410 when the gas in the product to be tested 410 leaks out from a set leak hole;

[0152] According to the pressure drop value △P and the set leakage amount Q of the set leakage hole S Determine the volume V of the product 410 to be tested;

[0153] Determine the leakage threshold value according to the preset volume and leakage threshold mapping relationship and the volume of the product to be tested;

[0154] The sealing performance of the product to be tested is determined based on the leakage rate and leakage threshold of the product to be tested.

[0155] The third switch K-3 and the fourth switch 404 are closed, and the first switch K-1 and the second switch K-2 are opened. The product to be tested 410 is connected to the standard leak hole 405, and the pressure drop value △P per unit time is calculated by the pressure difference value displayed by the leakage detection unit 4032, so as to obtain the value of V=Q S The volume V of the product 410 to be tested is obtained by calculating K / ΔP.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A sealing test method, characterized in that: include: Inflate the product to be tested until the pressure in the product to be tested reaches a preset pressure; Connecting the interior of the product to be tested to a standard pressure source and maintaining the pressure for a preset period of time; The standard pressure source has a preset output pressure; The sealing performance of the product to be tested is determined according to the pressure in the product to be tested and the preset output pressure.

2. The method according to claim 1, characterized in that The step of inflating the product to be tested until the pressure in the product to be tested reaches a preset pressure further includes: The pressure in the product to be tested is maintained at the preset pressure by inflating the product to be tested, and the inflation flow rate is detected until the inflation flow rate is less than or equal to a preset flow rate threshold, and then the inflation is stopped.

3. The method according to claim 1, characterized in that The determining the sealing performance of the product to be tested according to the pressure in the product to be tested and the preset output pressure also includes: Obtaining the volume of the product to be tested, Determine the corresponding leakage threshold according to the preset volume and leakage threshold mapping relationship and the volume of the product to be tested; Determining the leakage rate of the product to be tested according to the pressure of the product to be tested and the preset output pressure; The sealing performance of the product to be tested is determined according to the leakage rate of the product to be tested and the leakage threshold.

4. The method according to claim 3, characterized in that The obtaining the volume of the product to be tested further comprises: Connect the product to be tested to a standard leak hole, wherein the standard leak hole has a set leakage volume. obtaining a pressure drop value in the product to be tested when the gas in the product to be tested leaks out from the set leak hole, The volume of the product to be tested is determined according to the pressure drop value and the set leakage amount of the set leak hole.

5. The method according to any one of claims 1 to 4, characterized in that The step of inflating the product to be tested until the pressure in the product to be tested reaches a preset pressure comprises: Controlling the gas source to inflate the product to be tested with a first inflation pressure until the pressure in the product to be tested reaches a first threshold pressure; Controlling the gas source to inflate the product to be tested with a second inflation pressure until the pressure in the product to be tested reaches the preset pressure; The second inflation pressure is lower than the first inflation pressure, and the first threshold pressure is lower than the preset pressure.

6. The method according to any one of claims 1 to 4, characterized in that The step of inflating the product to be tested until the pressure in the product to be tested reaches a preset pressure comprises: Controlling the gas source to inflate the product to be tested with a third inflation pressure until the pressure in the product to be tested reaches a second threshold pressure; Controlling the product to be tested to exhaust air to the outside until the pressure inside the product to be tested reaches the preset pressure; Wherein, the second threshold pressure is greater than the preset pressure.

7. The method according to any one of claims 1 to 6, characterized in that Determining the sealing performance of the product to be tested according to the pressure in the product to be tested and the preset output pressure includes: Obtaining the pressure difference between the pressure in the product to be tested and the preset output pressure of the standard pressure source, The leakage rate of the product to be tested is determined according to the pressure difference.

8. The method according to claim 7, characterized in that The determining the sealing performance of the product to be tested according to the pressure in the product to be tested and the preset output pressure also includes: In response to the leakage rate being less than a preset leakage threshold, the sealing performance of the product to be tested is determined to be "OK".

9. A sealing detection device, characterized in that: Used to perform a sealing test on a product to be tested according to the sealing test method according to any one of claims 1 to 8, the sealing detection device comprises: An air source, connected to the product to be tested, for inflating air into the interior of the product to be tested; a pressure sensor connected to the product to be tested to detect the pressure inside the product to be tested; and The balance detection unit includes a standard pressure source and a leakage detection unit. The standard pressure source has a preset output pressure and is used to communicate with the inside of the product to be tested to balance the pressure inside the product to be tested; the leakage detection unit is used to connect with the product to be tested to detect the leakage rate of the product to be tested.

10. The device according to claim 9, characterized in that The leakage detection unit is a differential pressure gauge, and two ends of the differential pressure gauge are respectively connected to the standard pressure source and the product to be tested to detect the pressure difference between the inside of the product to be tested and the preset output pressure of the standard pressure source.

11. The device according to claim 9 or 10, characterized in that The sealing detection device also includes: A flow sensor is connected to the gas source and the product to be tested respectively to detect the inflation flow provided by the gas source to the product to be tested.

12. The device according to any one of claims 9 to 11, characterized in that The sealing detection device also includes: The standard leak hole is used to be connected to the product to be tested, and the standard leak hole has a preset leakage rate.

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