Leak detection device and leak detection method

Abstract

The invention provides a leak detection device and a leak detection method. The leak detection device comprises a box body, a pressure detection mechanism, a first air pump and a controller, a detection cavity is formed in the box body, the pressure detection mechanism comprises a pressure sensor and a detection port, one end of the first air pump is inserted into the detection cavity through a first connecting port of the box body, and the controller determines whether the workpiece has a large leak condition according to the change condition of a pressure value. The leak detection method comprises the steps of placing the workpiece in the detection cavity, connecting the detection port to the detection hole of the workpiece, controlling the first air pump to work to increase the pressure difference between the inside and the outside of the workpiece, detecting the pressure value inside the workpiece, and determining whether the workpiece has large leak according to the change condition of the pressure value. According to the leak detection device, the pressure difference between the inside and outside of the workpiece is increased so that the pressure sensor can detect the internal pressure value of the workpiece, large leak detection is performed according to the detected pressure value change, the accuracy of the detection result is improved, and the production cost is reduced.

Description

Technical Field

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

[0002] At present, with the development of science and technology, the demand for battery cells is gradually increasing, and testing the sealing of battery cells is an indispensable step. The existing commonly used method for battery cell leak detection is helium detection, which requires flushing helium into the battery cell and detecting the molecular weight of helium in the detection chamber and pipeline to determine whether the sealing state of the battery cell is a major leak. This helium detection method allows a large number of helium molecules to enter the detection system. Long-term use will affect the life of the leak detector and increase production costs. In addition, helium is a rare gas, and filling helium during major leak detection will increase the cost of gas use. Summary of the invention

[0003] The embodiments of the present application provide a leak detection device and a leak detection method, which can solve at least part of the above-mentioned technical problems.

[0004] In a first aspect, the present application provides a leak detection device, comprising:

[0005] A box body, wherein a detection cavity is arranged in the box body, and the detection cavity is used to place a workpiece;

[0006] A pressure detection mechanism, the pressure detection mechanism comprising a pressure sensor and a detection port, the detection port being located in the detection cavity, the pressure sensor being connected to the detection port, the detection port being used to connect to a detection hole of a workpiece, and the pressure sensor being used to detect a pressure value inside the workpiece;

[0007] A first air pump, the box body includes a first connection port, one end of the first air pump is inserted into the detection cavity through the first connection port, and the first air pump is used to increase the pressure difference between the inside and the outside of the workpiece;

[0008] A controller, the controller being used to obtain a change in the pressure value inside the workpiece detected by the pressure sensor during and / or after the operation of the first air pump is completed;

[0009] The controller is also used to determine whether there is a large leak in the workpiece according to the change of the pressure value.

[0010] In a second aspect, the present application provides a leak detection method, which is applied to a leak detection device, wherein the leak detection device includes a box, a pressure detection mechanism, and a first air pump, wherein a detection cavity is arranged in the box, the pressure detection mechanism includes a pressure sensor and a detection port, the detection port is located in the detection cavity, the pressure sensor is connected to the detection port, the box includes a first connection port, and one end of the first air pump is inserted into the detection cavity through the first connection port, wherein the leak detection method includes:

[0011] Place the workpiece in the detection chamber;

[0012] Connect the detection port to the detection hole of the workpiece;

[0013] Controlling the first air pump to increase the pressure difference between the inside and outside of the workpiece;

[0014] Detect the pressure value inside the workpiece;

[0015] Acquire the change of the pressure value inside the workpiece detected by the pressure sensor during and / or after the first air pump is operated;

[0016] Determine whether the workpiece has a major leak based on changes in the pressure value.

[0017] The present application provides a leak detection device and a leak detection method. The leak detection device includes a housing, a pressure detection mechanism, a first air pump and a controller. The housing is provided with a detection chamber. The pressure detection mechanism includes a pressure sensor and a detection port. One end of the first air pump is inserted into the detection chamber through the first connection port of the housing. The controller determines whether the workpiece has a large leak according to the change in pressure value. The leak detection method includes placing the workpiece in the detection chamber, connecting the detection port to the detection hole of the workpiece, controlling the first air pump to increase the pressure difference between the inside and outside of the workpiece, detecting the pressure value inside the workpiece, and determining whether the workpiece has a large leak according to the change in pressure value. The leak detection device of the present application increases the pressure difference between the inside and outside of the workpiece so that the pressure sensor can detect the pressure value inside the workpiece, performs large leak detection according to the change in the detected pressure value, improves the accuracy of the detection result, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is an overall schematic diagram of the leak detection device in the embodiment of the present application.

[0020] Figure 2 for Figure 1 The overall schematic diagram of the seal in the sealing connection workpiece.

[0021] Figure 3 Flow chart of the leak detection method in an embodiment of the present application.

[0022] Figure 4 for Figure 3 Flow chart of step S33 in and specific steps of determining whether there is a major leak.

[0023] Figure 5 In the embodiment of this application Figure 4 Flowchart after step S374 in .

[0024] Figure 6 In the embodiment of this application Figure 5 Flowchart before step S41 in .

[0025] Figure 7 In the embodiment of this application Figure 5 Flowchart after step S44 in .

[0026] Figure 8 In the embodiment of this application Figure 4 S373 in Figure 5 S45 or Figure 7 The flowchart after S62 in FIG.

[0027] Figure Number:

[0028] Leak detection device-1;

[0029] Box body-11; detection chamber-111; first connection port-112; second connection port-113; first box body-114; second box body-115; first detection chamber-116; second detection chamber-117;

[0030] Pressure detection mechanism-12; detection port-121; driving member-1211; sealing member-1212; pressure sensor-122; control valve-123; helium supply member-124; second air pump-125; workpiece nitrogen supply member-126;

[0031] first air pump-13; controller-14; leak detector-15; valve-16; chamber nitrogen supply-17;

[0032] Workpiece-2; Inspection hole-21. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings. The term "connection" in this application, unless otherwise specified, mainly refers to a physical structural connection, and may also include meanings such as direct connection or indirect connection when specified. The terms "first" and "second" in the specification and claims of this application and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the term "includes" and any variations thereof are intended to cover non-exclusive inclusions.

[0035] Please also read Figure 1 and Figure 2 , Figure 1 is an overall schematic diagram of the leak detection device 1 in the embodiment of the present application, Figure 2 for Figure 1 The seal 1212 in the figure is a schematic diagram showing the overall connection of the workpiece 2. The leak detection device 1 includes a box body 11, a pressure detection mechanism 12, a first air pump 13 and a controller 14. The box body 11 is provided with a detection chamber 111, and the detection chamber 111 is used to place the workpiece 2. The pressure detection mechanism 12 includes a pressure sensor 122 and a detection port 121. The detection port 121 is located in the detection chamber 111. The pressure sensor 122 is connected to the detection port 121, and the detection port 121 is used to connect to the detection hole 21 of the workpiece 2. The pressure sensor 122 is used to detect the pressure value inside the workpiece 2. The box body 11 includes a first connecting port 112, and one end of the first air pump 13 is inserted into the detection chamber 111 through the first connecting port 112. The operation of the first air pump 13 is used to increase the pressure difference between the inside and outside of the workpiece 2. The controller 14 is used to obtain the change of the pressure value inside the workpiece 2 detected by the pressure sensor 122 during and / or after the operation of the first air pump 13 is completed. The controller 14 is also used to determine whether there is a large leak in the workpiece 2 according to the change of the pressure value.

[0036] Thus, the leak detection device 1 increases the pressure difference between the inside and the outside of the workpiece 2 through the first air pump 13, so that the pressure sensor 122 can detect the internal pressure value of the workpiece 2, and the controller 14 can determine whether the workpiece 2 has a large leak according to the obtained change in the pressure value, thereby improving the accuracy of the detection result and reducing the production cost; and, the present application does not inject a large amount of helium into the workpiece 2 during large leak detection, thereby reducing the impact of a large amount of helium on the leak detection device 1, increasing the service life of the leak detection device 1, and reducing the use of helium, thereby reducing procurement costs.

[0037] In some embodiments, Figure 1 and Figure 2As shown, the box body 11 includes a first box body 114 and a second box body 115. The first box body 114 is provided with a first detection cavity 116, and the second box body 115 is provided with a second detection cavity 117. The first detection cavity 116 is used to accommodate the detection port 121, and the second detection cavity 117 is used to place the workpiece 2. The first box body 114 and the second box body 115 can be matched and connected during leak detection, so that the first detection cavity 116 and the second detection cavity 117 are combined into a sealed detection cavity 111.

[0038] It is understandable that the workpiece 2 may be, but is not limited to, a battery cell. The workpiece 2 may also be a battery, which is not limited here.

[0039] In some embodiments, the controller 14 may further output a control signal to control the operation of the first air pump 13 .

[0040] In some embodiments, the first air pump 13 is used to draw gas from the detection chamber 111 to increase the pressure difference between the inside and outside of the workpiece 2. The controller 14 is also used to determine that there is a large leak in the workpiece 2 when the pressure value changes by more than a preset threshold value. The controller 14 is also used to determine that there is no large leak in the workpiece 2 when the pressure value changes by less than or equal to a preset threshold value.

[0041] Thus, the first air pump 13 sucks the gas in the detection chamber 111, and the internal pressure of the detection chamber 111 gradually decreases. If the workpiece 2 has a large leak, due to the pressure difference between the inside and outside of the workpiece 2 and the suction operation of the first air pump 13, the gas inside the workpiece 2 is gradually sucked into the detection chamber 111 through the large leak, and the internal pressure of the workpiece 2 also gradually decreases, so that the inside of the workpiece 2 is in a low-pressure state. At this time, the pressure sensor 122 detects the pressure value inside the workpiece 2, so that the controller 14 can more easily obtain the pressure value change to determine whether the workpiece 2 has a large leak, and compare the pressure value change with the preset threshold to perform large leak detection on the workpiece 2, thereby improving the accuracy of the large leak detection result.

[0042] Among them, the large leakage situation is that the workpiece 2 has an obvious leakage defect, such as a relatively obvious leakage hole or gap. When the first air pump 13 sucks the gas in the detection chamber 111, the gas inside the workpiece 2 can be further sucked through the obvious leakage defect to cause the internal pressure of the workpiece 2 to change, thereby detecting whether the workpiece 2 has a large leakage.

[0043] In some other embodiments, the first air pump 13 is used to blow gas into the detection chamber 111 to increase the pressure difference between the inside and the outside of the workpiece 2, and the controller 14 is also used to determine that the workpiece 2 has a large leak when the pressure value changes by more than a preset threshold value, and the controller 14 is also used to determine that the workpiece 2 does not have a large leak when the pressure value changes by less than or equal to a preset threshold value.

[0044] Thus, the first air pump 13 blows gas into the detection chamber 111, and the internal pressure of the detection chamber 111 gradually increases. If the workpiece 2 has a large leak, due to the pressure difference between the inside and outside of the workpiece 2 and the blowing operation of the first air pump 13, the gas blown by the first air pump 13 can enter the workpiece 2 from the large leak, so that the internal pressure of the workpiece 2 also gradually increases. At this time, the pressure sensor 122 detects the pressure value inside the workpiece 2, so that the controller 14 can more easily obtain the pressure value change to determine whether the workpiece 2 has a large leak, thereby improving the accuracy of the large leak detection result.

[0045] In other embodiments, the first air pump 13 is used to blow gas into the workpiece 2 to increase the pressure difference between the inside and outside of the workpiece 2, and the controller 14 is also used to determine that the workpiece 2 has a large leak when the pressure value changes less than or equal to a preset threshold value, and the controller 14 is also used to determine that the workpiece 2 does not have a large leak when the pressure value changes more than a preset threshold value.

[0046] Thus, the first air pump 13 blows gas into the workpiece 2, and the internal pressure of the workpiece 2 gradually increases. If there is a large leak in the workpiece 2, due to the pressure difference between the inside and outside of the workpiece 2 and the blowing operation of the first air pump 13, the gas blown by the first air pump 13 can overflow from the large leak into the detection chamber 111, so that the internal pressure of the workpiece 2 does not change significantly. At this time, the pressure sensor 122 detects the pressure value inside the workpiece 2, so that the controller 14 can more easily obtain the pressure value change to determine whether there is a large leak in the workpiece 2, thereby improving the accuracy of the large leak detection result.

[0047] Among them, the connection of blowing gas or sucking gas in the present application is a pipeline connection, so that the pressure sensor 122 can detect the pressure value inside the workpiece 2, and it is also easy to detect large leaks.

[0048] In some embodiments, Figure 1 and Figure 2As shown, the pressure detection mechanism 12 also includes a control valve 123 and a helium supply component 124, one end of the control valve 123 is connected to the controller 14, and the other end is connected to the helium supply component 124, the controller 14 is used to control the control valve 123 to open when there is no large leak in the workpiece 2 so that the helium supply component 124 supplies and injects helium into the interior of the workpiece 2 through the detection hole 21, the leak detection device 1 also includes a leak detector 15, the leak detector 15 is connected between the first connecting port 112 and the first air pump 13, the leak detector 15 is used to detect the helium concentration in the detection chamber 111, so as to determine whether there is a micro-leakage in the workpiece 2 according to the helium concentration.

[0049] Thus, the opening and closing of the control valve 123 can be controlled according to the needs of the leak detection operation, making the leak detection device 1 intelligent; and, after the large leak detection, helium is injected into the workpiece 2 for micro-leak detection. At this time, the first air pump 13 is still in the suction state. If there is a micro-leak in the workpiece 2, the first air pump 13 will accelerate the diffusion of helium from the micro-leak of the workpiece 2 to the detection chamber 111, and the helium will be sucked into the pipeline connected to the leak detector 15 together with the gas in the detection chamber 111, so that the leak detector 15 can detect the helium concentration in the detection chamber 111, thereby speeding up the micro-leak detection.

[0050] Since the content of helium in the ambient air is very small and it diffuses quickly, the time for the leak detector 15 to perform micro-leak detection on the workpiece 2 can be shortened. In addition, helium is easy to obtain, non-toxic and has a high safety factor. Therefore, helium is selected to perform micro-leak detection.

[0051] It is understandable that the helium supply element 124 may be, but is not limited to, a helium cylinder, which may be selected according to actual needs and is not limited here.

[0052] Among them, the micro-leakage situation is that there is an inconspicuous leakage defect in the workpiece 2, such as a tiny leakage pore. When the first air pump 13 sucks the gas in the detection cavity 111, it is unable to suck the gas inside the workpiece 2 through the inconspicuous leakage defect. Therefore, it is judged that there is no large leakage in the workpiece 2, and then helium is injected into the workpiece 2, so that the helium is squeezed by the gas inside the workpiece 2 and leaks into the detection cavity 111 from the inconspicuous leakage defect.

[0053] In some embodiments, the controller 14 may send a control signal to control the operation of the leak detector 15 .

[0054] In some embodiments, Figure 1 and Figure 2As shown, the pressure detection mechanism 12 also includes a second air pump 125, which is connected to the control valve 123. The controller 14 is used to control the control valve 123 to open so that the second air pump 125 draws the internal gas of the workpiece 2 to a vacuum state when there is no large leakage in the workpiece 2 and before the helium supply part 124 supplies and injects helium into the interior of the workpiece 2 through the detection hole 21.

[0055] Thus, the control valve 123 can integrate multiple connecting pipes and can be used as a multi-way valve to connect to the interior of the workpiece 2 as needed, making the leak detection operation more convenient and reducing the leak detection cost; and, when there is no large leak in the workpiece 2 and before the helium supply part 124 supplies and injects helium into the interior of the workpiece 2 through the detection hole 21, the second air pump 125 draws the gas inside the workpiece 2 to a vacuum state, which can avoid air interfering with the detection of helium concentration by the leak detector 15, and also allows the helium to diffuse quickly after being injected into the workpiece 2, so as to overflow from the micro-leak of the workpiece 2 more quickly, thereby facilitating micro-leak detection of the workpiece 2, accelerating the detection speed, and improving the accuracy of micro-leak detection.

[0056] In some embodiments, the controller 14 may send a control signal to control the operation of the second air pump 125 .

[0057] In some embodiments, Figure 1 and Figure 2 As shown, the leak detection device 1 also includes a valve 16 and a chamber nitrogen supply component 17, the housing 11 also includes a second connecting port 113, the chamber nitrogen supply component 17 is connected to the second connecting port 113 to communicate with the detection chamber 111, the valve 16 is connected between the chamber nitrogen supply component 17 and the second connecting port 113, and the valve 16 is used to connect the chamber nitrogen supply component 17 and the detection chamber 111 when there is a slight leak in the workpiece 2, so that the chamber nitrogen supply component 17 fills nitrogen into the detection chamber 111 to clear the helium in the detection chamber 111.

[0058] Thus, when there is a slight leak in the workpiece 2, the valve 16 is opened to allow the chamber nitrogen supply part 17 to fill the detection chamber 111 with nitrogen, and the nitrogen will squeeze the helium in the detection chamber 111 to make it enter the first connecting port 112 connected to the first air pump 13. At this time, the first air pump 13 sucks the gas in the detection chamber 111, so that the helium can be sucked to the outside by the first air pump 13 from the pipeline connected to the first connecting port 112, thereby preventing the remaining helium in the detection chamber 111 from affecting the detection result of the next round of workpiece 2; the second air pump 125 can also simultaneously suck the helium inside the workpiece 2 to remove the helium inside the workpiece 2, thereby preventing the helium from overflowing from the slight leak of the workpiece 2 and remaining in the detection chamber 111.

[0059] In some embodiments, the controller 14 may send a control signal to control the operation of the valve 16 .

[0060] It is understandable that the chamber nitrogen supply member 17 may be, but is not limited to, a nitrogen bottle, which may be selected according to actual needs and is not limited here.

[0061] Among them, nitrogen is chosen to be filled to remove helium because it is easily available, cheap and safe.

[0062] In some embodiments, Figure 1 and Figure 2 As shown, the pressure detection mechanism 12 also includes a workpiece nitrogen supply component 126, which is connected to the control valve 123. The controller 14 is also used to control the control valve 123 to open so that the workpiece nitrogen supply component 126 supplies and injects nitrogen into the interior of the workpiece 2 through the detection hole 21 to balance the air pressure inside and outside the workpiece 2.

[0063] Therefore, the workpiece nitrogen supply component 126 can fill nitrogen into the workpiece 2 when the workpiece 2 is in a low pressure or vacuum state, so as to break the vacuum inside the workpiece 2, avoid damage to the workpiece 2, and reduce production costs.

[0064] It is understandable that the workpiece nitrogen supply component 126 can be, but is not limited to, a nitrogen bottle, which can be selected according to actual needs and is not limited here.

[0065] In some embodiments, Figure 1 and Figure 2 As shown, the detection port 121 includes a driving member 1211 and a sealing member 1212, wherein the sealing member 1212 is used to seal and connect the detection hole 21, the sealing member 1212 is connected to the driving member 1211, and the driving member 1211 is used to drive the sealing member 1212 to perform lifting movement to seal the detection hole 21 or open the detection hole 21.

[0066] Thus, the sealing member 1212 can seal the detection hole 21 to make the detection result more accurate; and the driving member 1211 drives the sealing member 1212 to move up and down to align and seal the detection hole 21 as needed.

[0067] In some embodiments, the controller 14 may send a control signal to control the operation of the driving member 1211 .

[0068] It is understandable that the driving member 1211 may be, but is not limited to, a cylinder, and may be selected according to actual needs.

[0069] Among them, the connections for blowing in gas and sucking out gas are both pipeline connections, so that the gas enters the interior of the workpiece 2 and the detection chamber 111 through the pipeline, and the gas is sucked from the detection chamber 111 and the workpiece 2 through the first air pump 13 and the second air pump 125 to be discharged to the outside.

[0070] See also Figure 3 , Figure 3 This is a flow chart of the leak detection method in the embodiment of the present application. The leak detection method is applied to a leak detection device, which includes a box, a pressure detection mechanism and a first air pump. The box is provided with a detection cavity, the pressure detection mechanism includes a pressure sensor and a detection port, the detection port is located in the detection cavity, the pressure sensor is connected to the detection port, the box includes a first connection port, one end of the first air pump is inserted into the detection cavity through the first connection port, and the leak detection method includes:

[0071] S31: placing the workpiece in the detection chamber;

[0072] S32: Connecting the detection port to the detection hole of the workpiece;

[0073] S33: controlling the first air pump to work so as to increase the pressure difference between the inside and outside of the workpiece;

[0074] S34: Detecting the pressure value inside the workpiece;

[0075] S35: Acquiring a change in the pressure value inside the workpiece detected by the pressure sensor during and / or after the first air pump is operated;

[0076] S36: Determine whether the workpiece has a large leak according to the change in the pressure value.

[0077] Therefore, by increasing the pressure difference between the inside and outside of the workpiece so as to detect the internal pressure value of the workpiece, it is determined whether the workpiece has a large leak based on the obtained change in the pressure value, thereby improving the accuracy of the detection result and reducing the production cost.

[0078] The specific operations are as follows:

[0079] The workpiece is placed in the detection cavity of the box, the box is controlled to move to the detection station, the detection cavity is controlled to close as a sealed cavity, the detection port is controlled to descend to connect to the detection hole of the workpiece, so that the connecting pipeline of the pressure detection mechanism is connected to the inside of the workpiece, the first air pump increases the pressure difference between the inside and outside of the workpiece, and the pressure sensor repeatedly detects the pressure value inside the workpiece. When the change of the pressure value inside the workpiece is between the resolution range of the pressure sensor, the pressure sensor can detect the changed pressure value, and the pressure value change is obtained according to the pressure value inside the workpiece detected by the pressure sensor, and whether there is a large leak in the workpiece is determined according to the pressure value change.

[0080] In some embodiments, the resolution of the pressure sensor is 10-1000 Pa (Pa).

[0081] For some examples, see Figure 4 , Figure 4 for Figure 3 Step S33 in the flowchart and the specific steps of determining whether there is a large leak, the increasing the pressure difference between the inside and outside of the workpiece includes:

[0082] S371: Sucking the gas in the detection chamber to increase the pressure difference between the inside and outside of the workpiece;

[0083] S372: Determine whether the pressure value change is greater than a preset threshold;

[0084] S373: If the pressure value change is greater than a preset threshold, it is determined that the workpiece has a large leak;

[0085] S374: If the pressure value change is less than or equal to a preset threshold, it is determined that there is no major leakage in the workpiece.

[0086] Thus, the gas in the detection chamber is sucked to increase the pressure difference between the inside and outside of the workpiece. At this time, the pressure value inside the workpiece is detected, which makes it easier to obtain the pressure value change to determine whether there is a large leak in the workpiece, improve the accuracy of the large leak detection result, and set the large leak detection standard according to the pressure value change.

[0087] The specific operations are as follows:

[0088] The gas in the detection chamber is sucked by the first air pump, and the internal pressure of the detection chamber gradually decreases. If the workpiece has a large leak, the internal pressure of the workpiece also gradually decreases due to the pressure difference between the inside and outside of the workpiece and the suction operation of the first air pump, so that the inside of the workpiece is in a low-pressure state, causing the internal pressure value of the workpiece to change. If the workpiece does not have a large leak, the internal pressure value of the workpiece does not change or changes very little.

[0089] In some other embodiments, increasing the pressure difference between the inside and outside of the workpiece includes:

[0090] Gas is blown into the detection cavity to increase the pressure difference between the inside and outside of the workpiece.

[0091] Gas is blown into the detection chamber, and the internal pressure of the detection chamber gradually increases. If the workpiece has a large leak, due to the pressure difference between the inside and outside of the workpiece and the blowing operation of the first air pump, the gas blown by the first air pump can enter the inside of the workpiece from the large leak, so that the internal pressure of the workpiece gradually increases, and the change in the internal pressure value of the workpiece is greater than the preset threshold. If the workpiece does not have a large leak, the internal pressure value of the workpiece does not change or changes less than the preset threshold. This method step is another specific implementation method of S33.

[0092] In some other embodiments, increasing the pressure difference between the inside and outside of the workpiece includes:

[0093] Blowing gas into the workpiece to increase the pressure difference between the inside and outside of the workpiece;

[0094] Determining whether the pressure value change is greater than a preset threshold;

[0095] If the pressure value change is less than or equal to a preset threshold, it is determined that a large leak exists in the workpiece;

[0096] If the pressure value change is greater than a preset threshold, it is determined that there is no major leakage in the workpiece.

[0097] The first air pump blows gas into the workpiece, and the internal pressure of the workpiece gradually increases. If the workpiece has a large leak, due to the pressure difference between the inside and outside of the workpiece and the blowing operation of the first air pump, the gas blown by the first air pump can overflow from the large leak into the detection chamber, so that the internal pressure of the workpiece does not change significantly, and the internal pressure value of the workpiece does not change or changes less than a preset threshold. If the workpiece does not have a large leak, the internal pressure value of the workpiece changes more than the preset threshold. The method steps are step S33 and another specific implementation method for determining whether there is a large leak.

[0098] See also Figure 5 , Figure 5In the embodiment of this application Figure 4 The pressure detection mechanism further includes a control valve and a helium supply component, one end of the control valve is connected to the controller, and the other end is connected to the helium supply component, the leak detection device further includes a leak detector, and the leak detector is connected between the first connection port and the first air pump, and the leak detection method further includes:

[0099] S41: when there is no large leakage in the workpiece, the control valve is controlled to open, and the helium supply component supplies and injects helium into the workpiece through the detection hole;

[0100] S42: Detecting the helium concentration in the detection chamber;

[0101] S43: Determine whether there is a micro-leakage in the workpiece according to the helium concentration;

[0102] S44: When the molecular weight of helium in the detection chamber is greater than the leak rate threshold, it is determined that the workpiece has a micro-leakage;

[0103] S45: When the molecular weight of helium in the detection chamber is less than the leakage rate threshold, it is determined that there is no micro-leakage in the workpiece.

[0104] Therefore, the control valve is controlled to open according to the needs of the leak detection operation, and helium is injected into the workpiece for micro-leak detection after the large leak detection. If the workpiece has a micro-leak, it can be judged whether the workpiece has a micro-leak by detecting the helium concentration in the detection chamber.

[0105] S41-S45 are the method steps after S374. The specific operations are as follows:

[0106] After determining that there is no major leakage in the workpiece, the leak detection device performs micro-leak detection on the workpiece, controls the control valve to open, so as to connect the connecting pipe between the helium supply part and the inside of the workpiece, and the helium supply part supplies and injects helium into the inside of the workpiece through the detection hole. At this time, the first air pump performs a suction operation on the gas in the detection chamber, and the leak detector can determine whether there is a micro-leak in the workpiece according to the concentration of helium. Helium will overflow into the detection chamber due to the extrusion caused by the continuous injection of helium into the inside of the workpiece and the suction of the first air pump. The first air pump suctions the gas in the detection chamber so that the gas in the detection chamber enters the pipe connected to the detector. When the detector detects that the molecular weight of helium is greater than the leak rate threshold, it means that helium overflows from the micro-leak of the workpiece, and it is determined that there is a micro-leak in the workpiece. When the molecular weight of helium in the detection chamber is less than the leak rate threshold, it means that there is no helium overflow, and it is determined that there is no micro-leak in the workpiece.

[0107] See also Figure 6 , Figure 6 In the embodiment of this application Figure 5 The pressure detection mechanism further includes a second air pump, the second air pump is connected to the control valve, the control valve is controlled to open when there is no large leak in the workpiece, and before the helium supply component supplies and injects helium into the workpiece through the detection hole, the leak detection method further includes:

[0108] S51: controlling the control valve to open when there is no large leakage in the workpiece;

[0109] S52: Pumping the gas inside the workpiece into a vacuum state.

[0110] Thus, the control valve can integrate a plurality of connecting pipes to connect the interior of the workpiece as needed, making the leak detection operation more convenient; and, when there is no large leak in the workpiece and before the helium supply component supplies and injects helium into the interior of the workpiece through the detection hole, the second air pump draws the gas inside the workpiece into a vacuum state, which can avoid air interfering with the leak detector's detection of helium concentration and also allows the helium to diffuse quickly after being injected into the workpiece, so as to overflow from the micro-leak of the workpiece more quickly, thereby facilitating micro-leak detection of the workpiece, accelerating the detection speed, and improving the accuracy of micro-leak detection.

[0111] The specific operations are as follows:

[0112] When S374 is executed to determine that there is no major leakage in the workpiece, the control valve is controlled to open to connect the second air pump and the interior of the workpiece. After the second air pump draws the gas inside the workpiece to a vacuum state, S41 is executed.

[0113] See also Figure 7 , Figure 7 In the embodiment of this application Figure 5 The leak detection device further includes a valve and a chamber nitrogen supply, the housing further includes a second connection port, the chamber nitrogen supply is connected to the second connection port to communicate with the detection chamber, the valve is connected between the chamber nitrogen supply and the second connection port, and the leak detection method further includes:

[0114] S61: Open the valve to connect the chamber nitrogen supply part and the detection chamber when there is a slight leak in the workpiece;

[0115] S62: Filling nitrogen into the detection chamber to remove the helium in the detection chamber.

[0116] Therefore, when there is a micro-leak in the workpiece, the valve is opened to allow the chamber nitrogen supply part to fill the detection chamber with nitrogen to clear the residual helium in the detection chamber and the pipeline during micro-leak detection, thereby preventing the residual helium in the detection chamber from affecting the detection results of the next round of workpieces.

[0117] S61-S62 are the method steps after executing S44. The specific operations are as follows:

[0118] After executing S44 to determine that there is a slight leak in the workpiece, the valve is opened to connect the chamber nitrogen supply component and the detection chamber, and the chamber nitrogen supply component fills nitrogen into the detection chamber. The filled nitrogen will squeeze the helium in the detection chamber to make it enter the first connection port connected to the first air pump, and the first air pump sucks the gas in the detection chamber, and the helium can also be sucked to the first connection port by the first air pump. The leak detector detects the molecular weight of helium again. If there is no helium molecular weight in the detection chamber, it means that the helium in the detection chamber has been completely removed, and the first air pump stops working. If there is still helium molecular weight in the detection chamber, the first air pump and the chamber nitrogen supply component continue to work, and the method steps are repeated to remove the helium in the detection chamber and the pipeline. The second air pump also simultaneously sucks the helium inside the workpiece to remove the helium inside the workpiece.

[0119] After executing S45 to determine that there is no micro-leakage in the workpiece, the control valve is controlled to open to connect the connecting pipe between the second air pump and the inside of the workpiece, and the second air pump sucks helium inside the workpiece and discharges it.

[0120] See also Figure 8 , Figure 8 In the embodiment of this application Figure 4 S373 in Figure 5 S45 or Figure 7 The pressure detection mechanism further includes a workpiece nitrogen supply component, the workpiece nitrogen supply component is connected to the control valve, and the leak detection method further includes:

[0121] S71: Control the control valve to open;

[0122] S72: Nitrogen is supplied and injected into the interior of the workpiece through the detection hole to balance the air pressure inside and outside the workpiece.

[0123] Therefore, the workpiece nitrogen supply component can fill nitrogen into the workpiece when the interior of the workpiece is in a low-pressure state, so as to break the vacuum inside the workpiece, avoid damage to the workpiece, and reduce production costs.

[0124] The specific operations are as follows:

[0125] After executing S373 to determine that there is a large leak in the workpiece, executing S62 to clear the helium in the detection chamber, or executing S45 to determine that there is no micro-leak in the workpiece and discharge the helium, the control valve is controlled to open to connect the workpiece nitrogen supply part and the interior of the workpiece. The workpiece nitrogen supply part supplies and injects nitrogen into the interior of the workpiece through the detection hole to balance the air pressure inside and outside the workpiece.

[0126] In some embodiments, the detection port includes a driving member and a sealing member, the sealing member is connected to the driving member, and the leak detection method further includes:

[0127] Driving the sealing member to perform lifting motion;

[0128] The sealing member seals and connects the detection hole or opens the detection hole.

[0129] Thus, the sealing member can seal the detection hole and connect the inside of the workpiece, so that the detection result is more accurate; and the driving member drives the sealing member to move up and down to align and seal the detection hole as needed.

[0130] The specific operations are as follows:

[0131] When S32 is executed, the driving member drives the seal to descend so that the seal can seal the detection hole. After S72 is executed, the driving member drives the seal to ascend so that the seal can open the detection hole and the detection cavity. The box moves to the unloading position to unload the workpiece.

[0132] In some embodiments, the leak detection method can be applied to the aforementioned leak detection device 1, and the steps in the leak detection method can be functional operations controlled and executed by the controller 14 in the aforementioned leak detection device 1. The contents of the leak detection method and the aforementioned leak detection device 1 can be referenced to each other.

[0133] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application; in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A leak detection device, characterized in that: include: A box body, wherein a detection cavity is arranged in the box body, and the detection cavity is used to place a workpiece; A pressure detection mechanism, the pressure detection mechanism comprising a pressure sensor and a detection port, the detection port being located in the detection cavity, the pressure sensor being connected to the detection port, the detection port being used to connect to a detection hole of a workpiece, and the pressure sensor being used to detect a pressure value inside the workpiece; A first air pump, the box body includes a first connection port, one end of the first air pump is inserted into the detection cavity through the first connection port, and the first air pump is used to increase the pressure difference between the inside and the outside of the workpiece; A controller, the controller being used to obtain a change in the pressure value inside the workpiece detected by the pressure sensor during and / or after the operation of the first air pump is completed; The controller is also used to determine whether there is a large leak in the workpiece according to the change of the pressure value.

2. The leak detection device according to claim 1, characterized in that: The first air pump is used to pump gas in the detection chamber to increase the pressure difference between the inside and outside of the workpiece, and the controller is also used to determine that there is a large leak in the workpiece when the pressure value changes by more than a preset threshold value; The controller is also used to determine that there is no major leakage in the workpiece when the pressure value change is less than or equal to a preset threshold.

3. The leak detection device according to claim 1, characterized in that: The pressure detection mechanism also includes a control valve and a helium supply component, one end of the control valve is connected to the controller, and the other end is connected to the helium supply component, the controller is used to control the control valve to open when there is no large leak in the workpiece so that the helium supply component supplies and injects helium into the interior of the workpiece through the detection hole, and the leak detection device also includes a leak detector, the leak detector is connected between the first connecting port and the first air pump, and the leak detector is used to detect the helium concentration in the detection chamber to determine whether there is a micro-leakage in the workpiece according to the helium concentration.

4. The leak detection device according to claim 3, characterized in that: The pressure detection mechanism also includes a second air pump, which is connected to the control valve. The controller is used to control the control valve to open so that the second air pump sucks the gas inside the workpiece to a vacuum state when there is no large leakage in the workpiece and before the helium supply component supplies and injects helium into the workpiece through the detection hole.

5. The leak detection device according to claim 3, characterized in that: The leak detection device also includes a valve and a chamber nitrogen supply component, the housing also includes a second connection port, the chamber nitrogen supply component is connected to the second connection port to communicate with the detection chamber, the valve is connected between the chamber nitrogen supply component and the second connection port, and the valve is used to connect the chamber nitrogen supply component and the detection chamber when there is a slight leak in the workpiece, so that the chamber nitrogen supply component fills nitrogen into the detection chamber to remove the helium in the detection chamber.

6. The leak detection device according to claim 3, characterized in that: The pressure detection mechanism also includes a workpiece nitrogen supply component, which is connected to the control valve. The controller is also used to control the control valve to open so that the workpiece nitrogen supply component supplies and injects nitrogen into the interior of the workpiece through the detection hole to balance the air pressure inside and outside the workpiece.

7. The leak detection device according to claim 1, characterized in that: The detection port includes a driving member and a sealing member, wherein the sealing member is used for sealingly connecting the detection hole, the sealing member is connected to the driving member, and the driving member is used for driving the sealing member to perform lifting motion to seal the detection hole or open the detection hole.

8. A leak detection method, applied to a leak detection device, the leak detection device comprising a box, a pressure detection mechanism and a first air pump, the box is provided with a detection cavity, the pressure detection mechanism comprises a pressure sensor and a detection port, the detection port is located in the detection cavity, the pressure sensor is connected to the detection port, the box comprises a first connection port, one end of the first air pump is inserted into the detection cavity through the first connection port, characterized in that: The leak detection method comprises: Place the workpiece in the inspection chamber; Connect the detection port to the detection hole of the workpiece; Controlling the first air pump to increase the pressure difference between the inside and outside of the workpiece; Detect the pressure value inside the workpiece; Acquire the change of the pressure value inside the workpiece detected by the pressure sensor during and / or after the first air pump is operated; Determine whether the workpiece has a major leak based on changes in the pressure value.

9. The leak detection method according to claim 8, characterized in that: Increasing the pressure difference between the inside and outside of the workpiece comprises: Sucking the gas in the detection cavity to increase the pressure difference between the inside and outside of the workpiece; Determining whether the pressure value change is greater than a preset threshold; If the pressure value change is greater than a preset threshold, it is determined that a large leak exists in the workpiece; If the pressure value change is less than or equal to a preset threshold, it is determined that there is no major leakage in the workpiece.

10. The leak detection method according to claim 8, characterized in that: The pressure detection mechanism further includes a control valve and a helium supply component, one end of the control valve is connected to the controller, and the other end is connected to the helium supply component, the leak detection device further includes a leak detector, and the leak detector is connected between the first connection port and the first air pump, and the leak detection method further includes: When there is no large leakage in the workpiece, the control valve is controlled to open, and the helium supply component supplies and injects helium into the workpiece through the detection hole; detecting the helium concentration in the detection chamber; Determine whether the workpiece has a micro-leakage according to the helium concentration; When the molecular weight of helium in the detection chamber is greater than the leak rate threshold, it is determined that the workpiece has a micro-leak; When the molecular weight of helium in the detection chamber is less than the leak rate threshold, it is determined that there is no micro-leakage in the workpiece.

11. The leak detection method according to claim 10, characterized in that: The pressure detection mechanism further includes a second air pump, which is connected to the control valve. When there is no large leak in the workpiece, the control valve is controlled to open. Before the helium supply component supplies and injects helium into the workpiece through the detection hole, the leak detection method further includes: Controlling the control valve to open when there is no major leakage in the workpiece; The gas inside the workpiece is sucked into a vacuum state.

12. The leak detection method according to claim 10, characterized in that: The leak detection device further includes a valve and a chamber nitrogen supply, the box further includes a second connection port, the chamber nitrogen supply is connected to the second connection port to communicate with the detection chamber, the valve is connected between the chamber nitrogen supply and the second connection port, and the leak detection method further includes: Open the valve to connect the chamber nitrogen supply part and the detection chamber when there is a slight leak in the workpiece; Nitrogen is filled into the detection cavity to remove the helium in the detection cavity.

13. The leak detection method according to claim 10, characterized in that: The pressure detection mechanism further includes a workpiece nitrogen supply component, wherein the workpiece nitrogen supply component is connected to the control valve, and the leak detection method further includes: Controlling the control valve to open; Nitrogen is supplied and injected into the interior of the workpiece through the detection hole to balance the gas pressure inside and outside the workpiece.

14. The leak detection method according to claim 8, characterized in that: The detection port includes a driving member and a sealing member, wherein the sealing member is connected to the driving member, and the leak detection method further includes: Driving the sealing member to perform lifting motion; The sealing member seals and connects the detection hole or opens the detection hole.

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