CN109406065A - A kind of side's shell lithium battery casing air-tightness detection device - Google Patents

Abstract

The invention provides an air tightness detection device of a square shell lithium battery casing, comprising: a bracket structure component, a lifting structure component, a lower cavity structure component and an upper cavity structure component; the bracket structure component includes a bottom plate, a top plate and a a plurality of uprights; the lower cavity structure assembly is arranged between the bottom plates for fixing the battery case; the lifting structure assembly is movably hoisted on the top plate for driving the upper cavity structure The component reciprocates up and down; the upper cavity structure component is fixed on the bottom of the lifting structure component, and is used for driving movement through the lifting structure component, and is closed or separated from the lower cavity structure component. In the present invention, the lithium battery case is completely sealed when the upper and lower cavity structural components are fastened together, and the helium content is detected through the processes of evacuation, helium filling, detection, vacuum breaking, and helium exhaustion, which can quickly Detect leak rates with high accuracy.

Description

A kind of square shell lithium battery shell air tightness detection device

technical field

The invention relates to a sealing detection technology of a lithium battery shell, in particular to a device for detecting the air tightness of a square shell lithium battery shell.

Background technique

Lithium batteries are one of the most commonly used types of batteries in electric vehicles. Due to their high energy density and long cycle life, they quickly occupy most of the electric vehicle battery market. Therefore, the performance of lithium batteries affects electric vehicles. the overall performance of the car.

In the lithium battery industry, if the product is poorly sealed, it will lead to serious consequences such as serious battery performance degradation, electrolyte leakage, battery bulging or even explosion, which will seriously affect the service life and safety of lithium ion batteries. Therefore, the advantages and disadvantages of lithium battery sealing critical.

Lithium-ion batteries are mainly divided into three types: plastic case, metal case lithium, and aluminum-plastic film flexible packaging lithium-ion batteries according to the difference of the case. The tightness detection method relies on the human eye, which is difficult to see, the data is not quantified, and the reliability is low. In addition, this detection method easily leads to the deformation of the battery casing that is difficult to recover, especially for metal casings and aluminum-plastic film flexible packaging Li-ion is not applicable , coupled with the low detection efficiency and accuracy, it is urgent to find a suitable leak detection method as soon as possible.

SUMMARY OF THE INVENTION

The invention provides an air tightness detection device of a square shell lithium battery shell, which aims to solve the problems that the traditional lithium battery shell air tightness detection is easy to cause deformation of the shell, low detection efficiency and precision, and complicated detection operations. .

In order to achieve the above purpose, an embodiment of the present invention provides a device for detecting the air tightness of a square shell lithium battery casing, including:

A bracket structure assembly, a lifting structure assembly, a lower cavity structure assembly and an upper cavity structure assembly; wherein,

The support structure assembly includes a bottom plate, a top plate and a plurality of uprights, and a plurality of the uprights are installed between the bottom plate and the top plate;

The lower cavity structure assembly is arranged between the bottom plates and is on the same level as the bottom plate, and is used for fixing the battery case;

The lifting structure assembly is movably hoisted on the top plate for driving the upper cavity structure assembly to reciprocate up and down;

The upper cavity structure assembly is fixed on the bottom of the lifting structure assembly, and is used for being driven by the lifting structure assembly to be closed or separated from the lower cavity structure assembly.

Wherein, the lower cavity structure assembly includes:

a lower cavity plate, a sealing groove is formed on the lower cavity plate, a first sealing ring is sheathed in the sealing groove, and the part enclosed by the first sealing ring on the lower cavity plate is a sealing area ;

a lower casing fixing seat, the lower casing fixing seat is arranged in the sealing area;

A first bellows connection joint, the first bellows connection joint is installed under the lower cavity plate, the first end of the first bellows is communicated with the sealing area through a first air hole, and the first bellows is connected to the sealing area. An air hole is arranged on the outer side of the lower housing fixing seat, and the second end of the first bellows connecting joint is connected with a first vacuum pump through a bellows, the bellows is a first air flow pipeline, and the first A helium mass spectrometer leak detector and a first solenoid valve are installed on a gas flow pipeline;

There are two oil pressure buffers, which are relatively fixed at the midpoint of the side of the lower cavity plate.

Wherein, two sides of the short side of the lower housing fixing seat are provided with positioning fixture structural components, the positioning fixture structural components are fixed on the lower cavity plate through a base, and the positioning fixture structural components include:

A guide rail box, the guide rail box is divided into an upper box body and a lower box body;

Clamping device, the clamping device includes a guide post group, a guide post block, a first spring group and a linear bearing, the guide post block is fixed on the upper case panel and is connected with the first end of the guide post group , the guide post group penetrates into the upper case body, in the upper case body, the linear bearing is sleeved on the guide post group, and the second end of the guide post group passes through the upper case body , connected with a buffer assembly, the second end of the guide post group is sheathed with a first spring group;

a limit bar stopper, the limit bar stopper is arranged below the first spring group and fixed on the front edge of the base;

A guide rail limit rod group, the guide rail limit rod group passes through the lower box, the second end of the guide rail limit rod group is fixed on the limit rod block, and the guide rail limit rod group is The second end is sheathed with a second spring group;

A transmission device, the transmission device includes a guide rail, a sliding block and a cam follower, the sliding block is relatively fixed on both sides of the bottom surface of the lower box, and is slidably clamped on the guide rail, and the guide rail is relatively fixed On the two sides of the base, the cam follower is fixed on the side walls of the upper box.

Wherein, the guide column group includes: a first guide column, a second guide column, a third guide column and a fourth guide column, and the buffer assembly includes: a fixing block, a first shell outer block and a second shell outer block The second end of the first guide post and the second end of the second guide post are jointly connected on the first end surface of the fixing block, and the first shell is mounted on the second end surface of the fixing block An external stopper, the second end of the third guide post and the second end of the fourth guide post are jointly connected on the first end surface of the second housing external stopper, and the first end surface of the second housing external stopper is Gaskets are installed on both end faces.

Wherein, the lifting structure assembly includes a cylinder, a lifting plate, a guide shaft, a tank chain, a floating joint and a floating joint connecting block, the cylinder body of the cylinder is installed at the center of the top plate, and the piston rod of the cylinder The floating joint is connected, the floating joint is clamped on the floating joint connecting block, and the floating joint connecting block is fixed at the center position of the lifting plate, and the lifting plate is movably hoisted to the lifting plate through four guide shafts. Below the top plate, the upper towline sheet metal is fixed above the top plate, the lower towline sheet metal is fixed above the lifting plate, and the two ends of the tank chain are respectively connected with the upper towline sheet metal and the lower towline. Chain sheet metal connection.

Wherein, the upper cavity structure assembly includes:

an upper cavity block, the bottom surface of the upper cavity block is fixed below the lifting plate, a groove is arranged in the upper cavity block, and a second air hole and a third air hole are opened in the groove;

an ear plate, which is relatively fixed at the midpoint of the side of the bottom surface of the upper cavity block;

the upper casing fixing seat, the upper casing fixing seat is installed at the center of the groove, the seat opening of the upper casing fixing seat is fixed with a second sealing ring through a sealing gasket baffle, the upper casing The short side baffle of the upper shell of the body fixing seat is provided with a second clamping groove, and a second buffer block is fixed in the second clamping groove;

wedges, the wedges are mounted on the four corners of the upper housing fixing seat;

A filling block, the filling block is fixed in the fixing seat of the upper case and used for filling the lithium battery case.

Wherein, a first flapper valve, a second bellows connection joint, a third bellows connection joint, a second solenoid valve and a third solenoid valve are installed on the lifting plate, and the first flapper valve of the second bellows connection joint The end is connected with the first flapper valve, the second end of the second bellows connecting joint is communicated with the groove in the upper cavity block through the second air hole, and the third bellows is connected The first end of the joint is connected with the second solenoid valve and the third solenoid valve respectively, and the second end of the third bellows connecting joint is connected with the groove in the upper cavity block through the third air hole The second solenoid valve is connected with a second vacuum pump.

Wherein, a fixing plate is installed on the top plate, the first surface of the fixing plate is connected with a second flapper valve, a first three-way joint is installed on the second flapper valve, and the second flapper valve is mounted on the second flapper valve. A second three-way joint is connected to the surface, the first end of the second three-way joint is communicated with the second flapper valve, and the second end of the second three-way joint is connected with the first stopper valve through a bellows The plate valve is connected, the third end of the second three-way joint is connected with a pressure gauge, and the pressure gauge is installed on the top plate.

The above-mentioned scheme of the present invention has the following beneficial effects:

In the present invention, the lithium battery case is fixed in the lower cavity structure component, and the upper cavity structure component is driven to reciprocate up and down by the lifting structure component, and is buckled or separated from the lower cavity structure component. When the upper and lower cavity structure components are buckled When the lithium battery is completely sealed, the helium content can be detected through the process of vacuuming, filling with helium, testing, breaking the vacuum, and exhausting helium, combined with a pressure gauge and a high-precision helium mass spectrometer leak detector. , it can quickly detect the leak rate with high accuracy, and will not cause damage such as extrusion deformation to the lithium battery case.

Description of drawings

1 is a schematic structural diagram of a device for detecting the air tightness of a square shell lithium battery casing according to the present invention;

2 is a schematic diagram of a lower cavity structural assembly of a device for detecting air tightness of a square shell lithium battery case according to the present invention;

3 is a schematic diagram of a positioning fixture structural assembly of a square shell lithium battery case air tightness detection device of the present invention;

4 is a schematic diagram of a lifting structure assembly of a square shell lithium battery casing air tightness detection device of the present invention;

FIG. 5 is a schematic diagram of an upper cavity structure assembly of a device for detecting air tightness of a square shell lithium battery case according to the present invention.

[Description of reference numerals]

1-Bracket structure component; 2-Lower cavity structure component; 3-Positioning fixture structure component; 4-Lifting structure component; 5-Upper cavity structure component; 6-Lithium battery shell; 7-Second bellows connection joint ; 8-the third bellows connection joint; 9-the first flapper valve; 10-the second solenoid valve; 11-the third solenoid valve; 12-the second flapper valve; 13-fixed plate; 14-the first three 15-second tee joint; 16-pressure gauge; 101-top plate; 102-column; 103-bottom plate; 201-lower chamber plate; 202-lower housing fixing seat; 203-oil pressure buffer; 204- the first bellows connection joint; 205- the first sealing ring; 206- the first air hole; 2021- the receiving plate; 2022- the lower casing block; 301-base; 302-upper box; 303-lower box; 304-guide column group; 305-linear bearing; 306-guide column block; 307-first spring group; 308-second spring group; 309- Guide rail limit rod group; 310-cam follower; 311-slider; 312-guide rail; 313-second shell outer block; 314-fixed block; 315-first shell outer block; 316-washer; 317 -Limiting rod stop; 401-Lifting plate; 402-Guide shaft; 403-Cylinder; 404-Tank chain; 405-Upper drag chain sheet metal; 406-Lower drag chain sheet metal; Joint connection block; 501-upper cavity block; 502-ear plate; 503-upper shell fixing seat; 504-seal gasket baffle; 505-second sealing ring; 506-second buffer block; 507-filling block ; 508 - wedge; 509 - second air hole; 510 - third air hole.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1 , an embodiment of the present invention provides an air tightness detection device for a square shell lithium battery case 6 , including: a bracket structure component 1 , a lifting structure component 4 , a lower cavity structure component 2 and an upper cavity Structural assembly 5; wherein, the support structure assembly 1 includes a bottom plate 103, a top plate 101 and a plurality of uprights 102, and a plurality of the uprights 102 are installed between the bottom plate 103 and the top plate 101; the lower cavity structure The component 2 is arranged between the bottom plates 103 and is at the same level as the bottom plate 103, and is used for fixing the battery case; the lifting structure component 4 is movably hoisted on the top plate 101 for driving the The upper cavity structure assembly 5 reciprocates up and down; the upper cavity structure assembly 5 is fixed on the bottom of the lifting structure assembly 4, and is used to drive the movement through the lifting structure assembly 4, and is connected with the lower cavity structure assembly. 2 closed or separated.

The air tightness detection device of the square shell lithium battery case 6 according to the above-mentioned embodiment of the present invention, by fixing the lithium battery case 6 in the lower cavity structure assembly 2, starts the lifting structure assembly 4 to drive the upper cavity structure assembly 5 Move downward until it is closed with the lower cavity structure assembly 2 to form a sealed cavity, completely seal the lithium battery case 6, and turn on the first vacuum pump to extract air from the space between the lithium battery case 6 and the sealed cavity. When the space environment between the lithium battery case 6 and the sealed cavity reaches a vacuum state, helium gas is filled into the lithium battery case 6, and a helium mass spectrometer leak detector is used to detect the leakage in the sealed cavity outside the lithium battery case 6. Then, the second vacuum pump is turned on to exhaust the helium in the lithium battery case 6, and then the first vacuum pump and the second vacuum pump are stopped at the same time, and then the sealed cavity is The body and the lithium battery casing 6 are respectively connected to the external environment, so that the air pressure between the sealed cavity and the lithium battery casing 6 is balanced with the external air pressure, the lifting structure assembly 4 is activated again to drive the upper cavity structure assembly 5 to move upward, and the above steps are repeated The air tightness of the square shell lithium battery case 6 can be quickly and accurately detected.

As shown in FIG. 2 , the lower cavity structure assembly 2 includes: a lower cavity plate 201 , a sealing groove is formed on the lower cavity plate 201 , and a first sealing ring 205 is sheathed in the sealing groove. The part enclosed by the first sealing ring 205 on the lower cavity plate 201 is the sealing area; the lower casing fixing seat 202 is arranged in the sealing area; the first bellows is connected A joint 204, the first bellows connection joint 204 is installed under the lower cavity plate 201, the first end of the first bellows communicates with the sealing area through a first air hole 206, the first The air hole 206 is arranged on the outer side of the lower casing fixing seat 202, and the second end of the first bellows connecting joint 204 is connected with a first vacuum pump through a bellows, and the bellows is a first air flow pipeline, so A helium mass spectrometer leak detector and a first solenoid valve are installed on the first gas flow pipeline; oil pressure buffers 203, two oil pressure buffers 203 are arranged, and are relatively fixed on the side of the lower cavity plate 201 the midpoint position of .

The first sealing ring 205 on the lower cavity plate 201 according to the above-mentioned embodiment of the present invention can completely fit and compact with the edge of the upper cavity block 501 when the upper and lower cavity structural components are closed, so as to ensure the first sealing ring 205 on the lower cavity plate 201. The sealing area inside a sealing ring 205 is isolated from the external environment, the lower case fixing seat 202 is arranged in the sealing area, and the bottom of the lithium battery case 6 is fixed, and the sealing area outside the lower case fixing seat 202 has a first air hole 206 , the first air hole 206 is connected with the first bellows connection joint 204, the first bellows connection joint 204 is arranged below the lower cavity plate 201, and is connected with the first vacuum pump through the bellows to form a first airflow pipeline, the first electromagnetic The valve and the helium mass spectrometer leak detector are respectively installed on the first gas flow pipeline. When the first vacuum pump is turned on, the first solenoid valve is in a closed state, and the gas between the sealed cavity and the lithium battery case 6 passes through the first air hole 206 from the first air hole 206 . A bellows connection joint 204 is pulled out; when the lithium battery case 6 is filled with helium gas, if helium molecules overflow from the lithium battery case 6, they enter the sealed cavity and are extracted by the first vacuum pump. The gas molecules flow out from the first air hole 206 and reach the vicinity of the helium mass spectrometer leak detector along the first gas flow pipeline. The helium mass spectrometer leak detector can sensitively detect the overflow of helium gas, thereby accurately judging the leak rate of the lithium battery case 6; When the detection is completed, the first vacuum pump is turned off, the first solenoid valve is turned on, and the outside gas enters the sealed cavity from the first air hole 206 through the first bellows connection joint 204 along the first air flow pipeline, so that the pressure of the gas inside and outside the sealed cavity is increased. Achieve balance.

Further, when the upper and lower cavity structural assemblies are closed, in order to prevent the upper cavity structural assembly 5 from moving downward too fast, the oil pressure buffer 203 disposed on the side of the lower cavity plate 201 When it approaches the lower cavity structure assembly 2 , the speed becomes slower, preventing the lithium battery case 6 from being crushed by the excessive downward force.

Wherein, the lower casing fixing seat 202 includes a receiving plate 2021, a lower casing block 2022, a lower casing long-side baffle 2023 and a first buffer block 2024, and the receiving plate 2021 is fixed at the center of the sealing area , the lower casing block 2022 is fixed on the four corners of the receiving plate 2021, the lower casing long-side baffle 2023 is relatively fixed on the long side of the casing receiving plate 2021, and the long side of the lower casing The inner side of the baffle plate 2023 is provided with a first card slot, and the first buffer block 2024 is embedded in the first card slot.

The shape of the receiving plate 2021 described in the above-mentioned embodiment of the present invention is the same as that of the bottom of the lithium battery case 6 , and the baffles of the lower case are fixed to the four corners of the receiving plate 2021 , which can just clamp and fix the bottom of the lithium battery case 6 . The fixed position of the lower case baffles at the four corners of the receiving plate 2021 can also be adjusted to adapt to different sizes of lithium battery cases 6, the lower case long side baffles 2023 installed on the long sides of the receiving plate 2021, and the lower case long side baffles 2023 can be used to fix the long side wall of the lithium battery case 6, at the same time, the first buffer block 2024 is embedded in the first slot inside the long side baffle of the lower case, which can prevent the long side of the lithium battery case 6. When the side wall is fixed, it is pressed and deformed by pressure.

As shown in FIG. 3 , two sides of the short side of the lower housing fixing seat 202 are provided with positioning fixture structural components 3 , and the positioning fixture structural components 3 are fixed on the lower cavity plate 201 through a base 301 . The clamp structure assembly 3 includes: a guide rail box, the guide rail box is divided into an upper box body 302 and a lower box body 303; a clamping device, the clamping device includes a guide column group 304, a guide column block 306, and a first spring group 307 and the linear bearing 305, the guide post block 306 is fixed on the panel of the upper case 302, and is connected with the first end of the guide post group 304, the guide post group 304 penetrates the upper case 302, and at the In the upper box body 302, the linear bearing 305 is sleeved on the guide column group 304, and the second end of the guide column group 304 passes through the upper box body 302 and is connected with a buffer assembly. The second end of the column group 304 is sheathed with a first spring group 307 ; a limit rod block 317 is arranged below the first spring group 307 and fixed to the front end of the base 301 edge; guide rail limit rod group 309, the guide rail limit rod group 309 passes through the lower box 303, the second end of the guide rail limit rod group 309 is fixed on the limit rod block 317 , the second end of the guide rail limit rod group 309 is sheathed with a second spring group 308; a transmission device, the transmission device includes a guide rail 312, a slider 311 and a cam follower 310, the slider 311 is relatively fixed to the Both sides of the bottom surface of the lower case 303 are slidably clamped on the guide rails 312 , the guide rails 312 are relatively fixed on two sides of the base 301 , and the cam follower 310 is fixed on the upper on the side wall of the box 302 .

The guide post group 304 includes: a first guide post, a second guide post, a third guide post and a fourth guide post, and the buffer assembly includes: a fixing block 314 , a first housing outer stop 315 and a second guide post The outer block 313 of the housing, the second end of the first guide post and the second end of the second guide post are jointly connected on the first end surface of the fixing block 314 , and the second end surface of the fixing block 314 is installed There is the first housing outer stopper 315, the second end of the third guide post and the second end of the fourth guide post are jointly connected on the first end surface of the second housing outer stopper 313, the A washer 316 is installed on the second end surface of the outer block 313 of the second housing.

The positioning fixture structural assembly 3 described in the above-mentioned embodiment of the present invention is disposed on both sides of the short side of the lower casing fixing seat 202 , and can be used for clamping and fixing the short side of the lithium battery casing 6 in the lower cavity structural assembly 2 . When the upper cavity structure assembly 5 is close to the lower cavity structure assembly 2, the wedge 508 of the upper cavity structure assembly 5 moves downward, pushing the cam follower 310 to the short side wall of the lithium battery case 6 The cam follower 310 drives the guide rail box to move along the guide rail 312 toward the short side wall of the lithium battery case 6, and the first case outer block 315 and the second case on the second end face of the guide post group 304 The external stopper 313 contacts the short side wall of the lithium battery case 6, and the first spring group 307 is gradually compressed under the pushing of the guide rail 312. When the upper and lower cavity structural components are completely closed, the first spring group 307 is gradually compressed. 307 is compressed to the maximum extent, and a strong clamping force is applied to the short side wall of the battery case through the first case outer block 315 and the second case outer block 313, so that the lithium battery case 6 is further fixed firmly.

Further, the cam follower 310 is installed on both side walls of the upper box body 302 of the guide rail box. When it drives the guide rail box to move toward the short side wall of the lithium battery case 6, it is sleeved on the guide rail limit rod group 309. The second spring group 308 on the two ends interferes with the limit bar stopper 317 fixed on the front edge of the base 301. When the upper and lower cavity structural assemblies are completely closed, the second spring group 308 is in the lower box 303 and the limit bar block. The blocks 317 are compressed; when the air tightness test is completed, the upper cavity assembly moves upward and begins to gradually separate from the lower cavity structural assembly 2, and the first spring group 307 and the second spring group 308 begin to recover, pushing the guide rail The box moves along the guide rail 312 in the opposite direction to the short side wall of the lithium battery case 6. The guide post group 304 moves away from the lithium battery case 6 along with the guide rail box. The short side wall of the battery case 6 is loosened; when the upper and lower cavity structural components are completely separated, the guide rail box will continue to occur along the guide rail 312 after returning to its position due to the thrust of the first spring group 307 and the second spring group 308 At this time, the limit head at the first end of the guide rail limit rod group 309 will block the guide rail box to prevent the guide rail box from rushing out of the guide rail 312 due to inertia slip.

Further, the fixing block 314 and the first housing outer stopper 315 are superimposed and connected to the second end of the first guide post and the second end of the second guide post, and the second housing outer stopper 313 is directly connected to the third guide post. The second end and the second end of the fourth guide post, the first housing outer stopper 315 and the second housing outer stopper 313 have the same level, and the second end surface of the second housing outer stopper 313 is provided with a washer 316 to keep the When the short side wall of the lithium battery case 6 is clamped, the pressing force is evenly distributed. The gasket 316 is arranged corresponding to the circular pit on the lithium battery case and is used to fill in the circular pit, and all the The gasket 316 also has a buffering effect, which can prevent the deformation of the short side wall of the lithium battery case 6 due to excessive local pressing force.

As shown in FIG. 4 , the lifting structure assembly 4 includes a cylinder 403 , a lifting plate 401 , a guide shaft 402 , a tank chain 404 , a floating joint 407 and a floating joint connecting block 408 , and the cylinder body of the cylinder 403 is installed on the top plate 101, the piston rod of the cylinder 403 is connected to the floating joint 407, the floating joint 407 is clamped on the floating joint connecting block 408, and the floating joint connecting block 408 is fixed to the lifting plate At the center position of 401, the lift plate 401 is movably hoisted under the top plate 101 through four guide shafts 402, an upper drag chain sheet metal 405 is fixed above the top plate 101, and a lower drag chain is fixed above the lift plate 401. Chain sheet metal 406, the two ends of the tank chain 404 are respectively connected with the upper drag chain sheet metal 405 and the lower drag chain sheet metal 406.

In the above-mentioned embodiment of the present invention, the piston rod is connected with the floating joint 407, the floating joint 407 is clamped on the floating joint connecting block 408, and the floating joint connecting block 408 is fixed at the central position of the lifting plate 401. When the cylinder 403 drives the piston rod During the telescopic movement, the lifting plate 401 is driven to reciprocate up and down, and the four corners of the lifting plate 401 are connected with guide shafts 402, which can ensure that the lifting plate 401 will not shift when moving up and down, and the lifting plate 401 and the top plate 101 also pass through the tank chain. 404 is connected, when the lifting plate 401 moves up and down, the tank chain 404 also rises and shrinks, which plays an auxiliary role in lifting the lifting plate 401.

As shown in FIG. 5 , the upper cavity structure assembly 5 includes: an upper cavity block 501 , the bottom surface of the upper cavity block 501 is fixed under the lifting plate 401 , and the upper cavity block 501 A groove is provided in the groove, and the second air hole 509 and the third air hole 510 are opened in the groove; the ear plate 502 is relatively fixed at the midpoint position of the side of the bottom surface of the upper cavity block 501 ; The upper housing fixing seat 503, the upper housing fixing seat 503 is installed at the center of the groove, and the seat opening of the upper housing fixing seat 503 is fixed with a second sealing ring through the sealing gasket 504 505, the upper shell short side baffle plate of the upper shell fixing seat 503 is provided with a second slot, and a second buffer block 506 is fixed in the second slot; the wedge 508, the wedge 508 is installed in the The four corners of the upper casing fixing seat 503; the filling block 507, the filling block 507 is fixed in the upper casing fixing seat 503, and is used to fill the lithium battery casing 6.

The upper cavity block 501 according to the above-mentioned embodiment of the present invention is fixed under the lifting plate 401 . When the upper and lower cavity structural assemblies are closed, the edge of the upper cavity block 501 and the first cavity on the lower cavity plate 201 The sealing ring 205 is compacted, the grooves in the upper cavity block 501 completely cover the sealing area, the seat opening of the upper case fixing seat 503 is buckled with the upper port of the lithium battery case 6, and at the same time the upper case fixing seat 503 The second sealing ring 505 at the seat mouth of the upper case is in close contact with the upper port of the lithium battery case 6 to ensure that the lithium battery case 6 is completely sealed. The upper port of the lithium battery case 6 plays a protective role when it is buckled to prevent the short side wall of the lithium battery case 6 from being squeezed and deformed by pressure during fixing; the wedge 508 is installed on the case fixing seat 503 At the four corners, when the upper and lower cavity structural components are gradually closed, the hypotenuse of the wedge block 508 squeezes and pushes the cam follower 310 to move toward the short side wall of the lithium battery case 6; the ear plate 502 is relatively fixed on the upper The midpoint of the side of the bottom surface of the cavity block 501 corresponds to the oil pressure buffer 203 on the side of the lower cavity plate 201. When the upper and lower cavity structural components are closed, the lug plate 502 presses the oil pressure buffer 203 , resulting in a buffer effect; the second air hole 509 and the third air hole 510 opened in the groove are both located at the bottom of the upper casing holder 503, the second air hole 509 is used for filling helium into the lithium battery case 6, and the third air hole 510 is used to discharge the helium gas in the lithium battery case 6; the upper case fixing seat 503 is buckled with the upper port of the lithium battery case 6, and the filling block 507 is embedded in the lithium battery case 6, which can reduce the air in the case capacity, increase the helium filling speed and save the helium filling volume.

The lift plate 401 is also provided with a first flapper valve 9 , a second bellows connection joint 7 , a third bellows connection joint 8 , a second solenoid valve 10 and a third solenoid valve 11 . The first end of the bellows connecting joint 7 is connected to the first flapper valve 9 , and the second end of the second bellows connecting joint 7 is connected to the valve in the upper cavity block 501 through the second air hole 509 . The grooves are connected, the first end of the third bellows connection joint 8 is connected to the second solenoid valve 10 and the third solenoid valve 11 respectively, and the second end of the third bellows connection joint 8 The third air hole 510 communicates with the groove in the upper cavity block 501, and the second solenoid valve 10 is connected with a second vacuum pump.

Wherein, a fixing plate 13 is installed on the top plate 101, the first surface of the fixing plate 13 is connected with a second flapper valve 12, and the second flapper valve 12 is mounted with a first three-way joint 14, so The second surface of the fixing plate 13 is connected with a second three-way joint 15, the first end of the second three-way joint 15 is communicated with the second flapper valve 12, and the third The two ends are connected to the first flapper valve 9 through bellows, and the third end of the second three-way joint 15 is connected to a pressure gauge 16 installed on the top plate 101 .

After the upper and lower cavity structural assemblies described in the above-mentioned embodiments of the present invention are closed, the first vacuum pump is activated to start pumping out from the first bellows connection joint 204. At this time, the first flapper valve 9 and the second flapper The valve 12, the first solenoid valve, the second solenoid valve 10 and the third solenoid valve 11 are all in the closed state. When the gas in the sealed cavity is exhausted, the first flapper valve 9 and the second flapper valve 12 are opened, and the helium gas is discharged from the valve. The first three-way joint 14 is filled and enters the second three-way joint 15 through the second flapper valve 12. The second end of the second three-way joint 15 is connected to the first flapper valve 9 through a bellows, and the second three-way joint The third end of the through joint 15 is connected to the pressure gauge 16, and the helium gas is connected to the joint 7 from the first flapper valve 9 through the second bellows, and is charged into the lithium battery case 6 through the second air hole 509. At the same time, the pressure Table 16 shows the helium pressure in the lithium battery case 6. Keep the first vacuum pump running. If helium molecules overflow from the lithium battery case 6 and enter the sealed cavity, the helium molecules can be extracted from the first air hole 206 to be evacuated. Detected by helium mass spectrometer leak detector;

When the detection is completed, the first flapper valve 9 and the second flapper valve 12 are closed, and the helium gas will no longer be charged into the lithium battery case 6. At this time, the second solenoid valve 10 is opened, and the second solenoid valve 10 and the The two vacuum pumps are connected, and the second vacuum pump is started to extract the residual helium gas in the lithium battery casing 6 from the third air hole 510, and the residual helium gas then passes through the third bellows connection joint 8 and is discharged in the direction of the second vacuum pump, waiting for the lithium battery The helium gas in the casing 6 is exhausted, and the second solenoid valve 10 is closed, so that the residual helium gas can be prevented from interfering with the accuracy of the air tightness detection of the next lithium battery casing 6;

Next, stop the operation of the first vacuum pump and the second vacuum pump, open the first solenoid valve, and the external air flows from the first solenoid valve along the first airflow pipeline through the first bellows connection joint 204, and enters the sealed cavity from the first air hole 206. , so that the air pressure in the sealed cavity is balanced with the external air pressure; at the same time, the third solenoid valve 11 is opened, and the external gas enters from the third solenoid valve 11, and then passes through the third bellows connection joint 8, and enters the lithium battery from the third air hole 510. Inside the casing 6, the air pressure inside the lithium battery casing 6 is balanced with the outside air pressure, thereby facilitating the separation of the upper and lower cavity structural components.

The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (9)

1. A square shell lithium battery shell air tightness detection device, characterized in that, comprising: a bracket structure assembly, a lifting structure assembly, a lower cavity structure assembly and an upper cavity structure assembly; wherein, The support structure assembly includes a bottom plate, a top plate and a plurality of uprights, and a plurality of the uprights are installed between the bottom plate and the top plate; The lower cavity structure assembly is arranged between the bottom plates and is on the same level as the bottom plate, and is used for fixing the battery case; The lifting structure assembly is movably hoisted on the top plate for driving the upper cavity structure assembly to reciprocate up and down; The upper cavity structure assembly is fixed on the bottom of the lifting structure assembly, and is used for being driven by the lifting structure assembly to be closed or separated from the lower cavity structure assembly. 2 . The device for detecting air tightness of a square shell lithium battery case according to claim 1 , wherein the lower cavity structure assembly comprises: a lower cavity plate, a sealing groove is formed on the lower cavity plate, a first sealing ring is sheathed in the sealing groove, and the part enclosed by the first sealing ring on the lower cavity plate is a sealing area ; a lower casing fixing seat, the lower casing fixing seat is arranged in the sealing area; A first bellows connection joint, the first bellows connection joint is installed under the lower cavity plate, the first end of the first bellows is communicated with the sealing area through a first air hole, and the first bellows is connected to the sealing area. An air hole is arranged on the outer side of the lower housing fixing seat, and the second end of the first bellows connecting joint is connected with a first vacuum pump through a bellows, the bellows is a first air flow pipeline, and the first A helium mass spectrometer leak detector and a first solenoid valve are installed on a gas flow pipeline; There are two oil pressure buffers, which are relatively fixed at the midpoint of the side of the lower cavity plate. 3. The device for detecting air tightness of a square shell lithium battery shell according to claim 2, wherein the lower shell fixing seat comprises a receiving plate, a lower shell block, a lower shell long-side baffle and a first A buffer block, the receiving plate is fixed at the center of the sealing area, the lower casing block is fixed on the four corners of the receiving plate, and the long side baffles of the lower casing are relatively fixed to the casing On the long side of the receiving plate, the inner side of the long side baffle plate of the lower shell is provided with a first clamping groove, and the first buffer block is embedded in the first clamping groove. 4 . The air tightness detection device of the square shell lithium battery case according to claim 2 , wherein the air tightness detection device of the square shell lithium battery case further comprises a positioning fixture structure component, and the positioning fixture structure The components are respectively arranged on both sides of the lower housing fixing seat, and the positioning fixture structural component is fixed on the lower cavity plate through a base, and the positioning fixture structural component includes: A guide rail box, the guide rail box is divided into an upper box body and a lower box body; Clamping device, the clamping device includes a guide post group, a guide post block, a first spring group and a linear bearing, the guide post block is fixed on the upper case panel and is connected with the first end of the guide post group , the guide post group penetrates into the upper case body, in the upper case body, the linear bearing is sleeved on the guide post group, and the second end of the guide post group passes through the upper case body , connected with a buffer assembly, the second end of the guide post group is sheathed with a first spring group; a limit bar stopper, the limit bar stopper is arranged below the first spring group and fixed on the front edge of the base; A guide rail limit rod group, the guide rail limit rod group passes through the lower box, the second end of the guide rail limit rod group is fixed on the limit rod block, and the guide rail limit rod group is The second end is sheathed with a second spring group; A transmission device, the transmission device includes a guide rail, a sliding block and a cam follower, the sliding block is relatively fixed on both sides of the bottom surface of the lower box, and is slidably clamped on the guide rail, and the guide rail is relatively fixed On the two sides of the base, the cam follower is fixed on the side walls of the upper box. 5 . The device for detecting airtightness of a square shell lithium battery case according to claim 4 , wherein the guide post group comprises: a first guide post, a second guide post, a third guide post and a fourth guide post. 6 . The buffer assembly includes: a fixing block, a first housing outer stop and a second housing outer stop, the second end of the first guide post and the second end of the second guide post are jointly connected to the fixing block On the first end face of the block, the second end face of the fixing block is provided with the first housing outer stopper, and the second end of the third guide post and the second end of the fourth guide post are jointly connected to each other. A washer is installed on the second end surface of the outer stopper of the second housing, and the second end surface of the outer stopper of the second housing is provided with a gasket. 6. The device for detecting air tightness of a square shell lithium battery shell according to claim 1, wherein the lifting structure assembly comprises a cylinder, a lifting plate, a guide shaft, a tank chain, a floating joint and a floating joint connecting block, The cylinder body of the air cylinder is installed at the central position of the top plate, the piston rod of the air cylinder is connected with the floating joint, the floating joint is clamped on the floating joint connecting block, and the floating joint connecting block is fixed At the central position of the lifting plate, the lifting plate is movably hoisted under the top plate through four guide shafts, the upper towline sheet metal is fixed above the top plate, and the lower towline sheet metal is fixed above the lifting plate. The two ends of the tank chain are respectively connected with the upper towline sheet metal and the lower towline sheet metal. 7. The device for detecting the air tightness of a square shell lithium battery case according to claim 6, wherein the upper cavity structure assembly comprises: an upper cavity block, the bottom surface of the upper cavity block is fixed below the lifting plate, a groove is arranged in the upper cavity block, and a second air hole and a third air hole are opened in the groove; an ear plate, which is relatively fixed at the midpoint of the side of the bottom surface of the upper cavity block; the upper casing fixing seat, the upper casing fixing seat is installed at the center of the groove, the seat opening of the upper casing fixing seat is fixed with a second sealing ring through the sealing gasket baffle, the upper casing The short side baffle of the upper shell of the body fixing seat is provided with a second clamping groove, and a second buffer block is fixed in the second clamping groove; wedges, the wedges are mounted on the four corners of the upper housing fixing seat; A filling block, the filling block is fixed in the fixing seat of the upper case and used for filling the lithium battery case. 8 . The air-tightness detection device of a square shell lithium battery case according to claim 7 , wherein a first flapper valve, a second bellows connection joint, and a third bellows connection are installed on the lift plate. 9 . A joint, a second solenoid valve and a third solenoid valve, the first end of the second bellows connection joint is connected with the first flapper valve, and the second end of the second bellows connection joint passes through the first Two air holes are communicated with the grooves in the upper cavity block, the first ends of the third bellows connecting joint are respectively connected with the second solenoid valve and the third solenoid valve, the third bellows The second end of the pipe connecting joint is communicated with the groove in the upper cavity block through the third air hole, and the second electromagnetic valve is connected with a second vacuum pump. 9 . The airtightness detection device of a square shell lithium battery case according to claim 8 , wherein a fixing plate is installed on the top plate, and a second flapper valve is connected to the first surface of the fixing plate, 10 . A first three-way joint is installed on the second flapper valve, a second three-way joint is connected to the second surface of the fixing plate, and the first end of the second three-way joint is connected to the second flapper valve is connected, the second end of the second three-way joint is connected with the first flapper valve through a bellows, the third end of the second three-way joint is connected with a pressure gauge, and the pressure gauge is installed on the top plate.