Method for leak testing of containers and leak testing station and method for filling and filling line for such containers

Abstract

A leak test station (50) for containers (C) housed in respective transport carriers (3), characterized in that it comprises a test carousel (51) which can rotate in continuous motion about a central axis (L) and comprises a plurality of test devices (5), each of which comprises: a movable bell (53) adapted to directly engage a carrier (3) so as to form a chamber (67) which houses said container (C); an opening (38) which is in fluid communication with the inside of said carrier (3), a vacuum generating mechanism (54) and a detection mechanism (55); a tracer gas injection mechanism (59) inside said bell (53) adapted to engage, in a gas-tight manner, a feed inlet (30) of a container (C) in the chamber (67).

Description

[0001] This invention relates to a method and station for testing the sealing properties of containers, particularly for battery packs filled with electrolytes, such as those filled with viscous liquids, semi-liquids (gels), or any fluid. The invention also relates to a method and line for filling such containers, particularly a method and line for filling such containers with electrolytes, the method and line comprising this testing method and this testing station, respectively.

[0002] In the field of filling containers with liquids, semi-liquids, or gases, it may be necessary to test the container's tightness before the filling operation.

[0003] Given the potential risks of electrolyte spillage, this test is crucial for battery containers that are to be filled with electrolyte.

[0004] In fact, the electrolyte used in battery packs (which can be in liquid or gel form) is so corrosive that accidental leakage of this electrolyte can cause harm to people in the surrounding environment and a decrease in battery performance. Furthermore, the electrolyte is highly flammable in non-dry environments.

[0005] The objective of this invention is to design a testing method and provide a testing station capable of identifying defective containers that cannot guarantee complete airtightness.

[0006] Within this objective, the purpose of the present invention is to design a testing method and provide a testing station capable of operating independently and / or as part of a filling production line.

[0007] In particular, the purpose of this invention is to conduct sealing tests on production lines used for continuous production of battery packs without stopping the containers or slowing down the production speed.

[0008] A specific object of the present invention is to perform the above-described tests while keeping the test station relatively small, for example by using a continuously rotating turntable having the diameter and number of devices typically used in filling work lines using turntables.

[0009] Furthermore, the present invention aims to overcome the shortcomings of the prior art in a way that replaces any existing solutions.

[0010] Another object of the present invention is to provide a highly reliable, easy-to-implement, and low-cost testing method and testing station.

[0011] This objective and these purposes, as well as other purposes that will become more apparent below, are achieved by the method according to claim 1, which may optionally have one or more features of the dependent claims.

[0012] The objectives and purposes of the present invention are also achieved by the test station according to claim 9, which optionally has one or more features of the dependent claims.

[0013] The objectives and goals of the present invention are also achieved by the methods and filling lines according to claims 6 and 11, respectively.

[0014] Further features and advantages of the invention will become more apparent from the description of preferred, but not exclusive, embodiments of the invention shown by way of non-limiting example in the accompanying drawings, characterized in that: Figure 1 This is a top view of the test station according to the present invention; Figure 2 yes Figure 1 A perspective view of the test station shown; Figure 3 It is intercepted along line III-III. Figure 1 A cross-sectional view of a portion of the test station shown; Figure 4 A filling operation line equipped with a test station according to the present invention is shown; Figures 5a-5b They are shown respectively Figure 4 The paths of containers and filling units in the production line; Figure 6 This is a perspective view of a fill kit that can be used in the fill work lines shown in the previous figures; Figure 7 yes Figure 6 Axial section view of the kit in the image; Figure 8 Corresponding to the previous figure, but the filling unit is fixed to the carrier (puck) that contains the container. Figure 9 Corresponding to the previous figure, the fixing mechanism is actuated to form an integral component; Figure 10 This is a perspective view of the overall components at the end of filling the container with electrolyte.

[0015] Referring to the accompanying drawings, the leak test station for container C, generally indicated by reference numeral 50, is preferably constructed for a closed container having an inlet 30, particularly an upper inlet 30, as the sole point of entry into the container's interior. Through the corresponding inlet 30, container C can be filled with fluid (specifically, electrolyte) in the filling line 1. When the inlet 30 is sealed, the interior of container C should be completely airtight unless a defect exists.

[0016] Container C is preferably a container for electrochemical batteries or battery packs, particularly for secondary batteries (e.g., lithium-ion batteries or battery packs). The battery can be, for example, a cylindrical or prismatic battery.

[0017] The container C arriving at the test station 50 is contained in a corresponding transfer carrier 3, which is preferably a beaker-shaped tray that exposes the inlet 30 upwards.

[0018] Containers C arrive at test station 50 one after another, each container within its own carrier 3. The arriving containers C preferably contain electrodes for an electrochemical cell, such as a so-called "jelly roll".

[0019] Test station 50 extends along a predetermined path for vehicle 3, and thus along a predetermined path for container C, which follows a circumferential transport drawn by test turntable 51 inserted between two transfer star wheels 52 and 106.

[0020] More specifically, the test turntable 51 is designed as a circular array so that it can simultaneously handle multiple vehicles 3 continuously supplied by the first transfer star wheel 52 and removed by the second transfer star wheel 106.

[0021] In this way, the entire process of testing a single container C is performed during the continuous rotation of the test turntable 51.

[0022] According to the present invention, the test turntable 51 includes a plurality of individual test devices 5 along its periphery, each test device 5 being temporarily associated with a corresponding carrier 3 conveyed by the test turntable 51. The test devices 5, rotating integrally with the turntable 51, are equidistant from the central axis of rotation L of the test turntable 51 and are arranged at regular intervals along the circumference of the turntable. Each test device 5 preferably includes: - A bell-shaped element 53, which can be hermetically associated with the carrier 3, to define a chamber 67 between the bell-shaped element 53 and the carrier 3. The chamber 67 can be associated with a vacuum generating mechanism 54 and is also functionally connected to a tracer gas detection mechanism 55 for detecting any presence of the tracer gas within the chamber 67; - An injection mechanism 56, which can be associated with the upper inlet 30 of container C in an airtight manner, and is configured to inject tracer gas (e.g., helium) specifically into container C for a preset time or until a preset pressure is reached inside container C.

[0023] Each bell-shaped element 53 can move toward or away from its corresponding support base 37 (which supports the carrier 3) in a direction substantially parallel to the axis of rotation L of the test turntable 51, which is integral with the turntable 51 during rotation. By moving toward the base 37, the lower part of the bell-shaped element 53 is airtightly connected to the upper edge 31 of the carrier 3, which may advantageously have an annular washer that engages the base of the bell-shaped element 53, such as... Figure 3 As shown.

[0024] In a preferred embodiment, the bell-shaped element 53 can be coupled to the carrier 3 by an actuator that moves the bell-shaped element 53 toward the carrier 3 after the carrier is conveyed to the test turntable 51 until the bell-shaped element 53 engages with the carrier.

[0025] The vacuum generating mechanism 54 includes a suction device or vacuum pump (not shown) that communicates with a support base 37 and is connected to the internal volume of a chamber 67 via a vacuum valve 57, which communicates with a through hole 34 defined in the base 33 of the carrier 3.

[0026] At the base 33 of the carrier 3, within the support base 37, an opening 38 is provided. This opening 38 is positioned to communicate fluidly with the hole 34 in the carrier 3 (when the carrier is transported by the turntable 51), with the vacuum valve 57, and with the detection mechanism 55. The opening 38 may include a hollow plunger 58 coaxial with it, the shape of which allows it to be attached to the through hole 34 and to position the carrier 3 in communication with the vacuum valve 57 and / or the detection mechanism 55.

[0027] Similarly, the injection mechanism 56 includes an injection plunger 59 housed within a bell-shaped member 53 and movable coaxially with respect to the bell-shaped member 53 between a position detached from container C and a position engaged with container C. In the detached position, the upper inlet 30 is unobstructed and thus communicates with the internal volume of the chamber 67. In the engaged position, the upper inlet 30 communicates with an injection channel 60 defined within the injection plunger 59 (in an airtight manner relative to the outside of container C).

[0028] The injection channel 60 extends toward the support base 37 to the inlet 30. The injection channel 60 is surrounded by a sealing mechanism 39 (e.g., an axial sealing ring), which is adapted to engage the container C around the inlet 30 to prevent tracer gas from leaking from the injection channel 60 and the inlet 30 into the chamber 67. The injection channel 60 is also connected to a circuit for supplying tracer gas via an inlet valve 61.

[0029] A radial washer 66 is provided between the inside of the bell-shaped member 53 and the outside of the injection plunger 59. The radial washer 66 is adapted to prevent gas from leaking from the chamber 67.

[0030] Conveniently, the injection mechanism 56 also includes a first discharge valve 63, which is adapted to discharge the tracer gas from the chamber 67 after the test method is completed.

[0031] Advantageously, the testing unit 55 includes a detector or "sniffer" located on the discharge pipe 64 of the carrier 3 and between the through hole 34 and a second discharge valve 65 adapted to restore the internal pressure of the chamber 67 after the test method is completed.

[0032] As previously described, the test turntable 51 includes a plurality of the aforementioned test devices 5 to process containers C arriving from the first transfer star wheel 52 continuously and sequentially.

[0033] Conveniently, in order to remove the defective container 3, a bypass and / or pickup mechanism can be provided, which is configured to cause the vehicle 3 containing the defective container C to fall out of the path.

[0034] Referring to what has been described so far, the test method according to the present invention typically requires the following steps: 1. The vehicles 3 are fed sequentially to the test turntable, so that each arriving vehicle is received on the support base 37 surrounding the turntable 51; 2. Furthermore, during the continuous rotation of turntable 51: - Each bell-shaped component 53 is connected to a carrier 3 arranged on a corresponding support base in an airtight manner, such that the container C in the carrier 3 is contained in a corresponding chamber 67 that is closed between the bell-shaped component 53 and the carrier 3. In this case, the upper inlet 30 of the container C is in fluid communication with the chamber 67; - A vacuum is generated in chamber 67 by vacuum generating mechanism 54 in order to remove air and / or other gases present in chamber 67 and therefore also in container C; - After the vacuum generation step, the plunger 59 is lowered toward the support base 37 and the tracer gas is injected into the corresponding container C through the upper feed port 30. - While the inlet 30 of container C is kept sealed to the outside by the sealing mechanism 39, the detection mechanism 55 is used to detect any trace of tracer gas in the discharge pipe 64. - Discharge container C and move bell 53 away from support base 37 so that container C can then be handed over to star wheel 106.

[0035] In this way, given that the single inlet 30 is sealed relative to chamber 67 by the engagement between the plunger 59 and the inlet, any tracer gas detected by the sniffer 55 must have leaked from another part of the container or from a defect in the inlet 30. Therefore, container C has a manufacturing defect and will thus be discarded downstream as a defective container.

[0036] Advantageously, test station 50 can be inserted into filling operation line 1, such as Figure 4 , Figure 5a and Figure 5b As shown.

[0037] More specifically, as will be better described below, test station 50 can be inserted upstream of filling station 13 along a portion of the first path P1 between inlet 10 and connecting station 14.

[0038] The filling line 1 includes a first path P1 for conveying a series of containers C to be filled. The containers C are preferably conveyed in continuous motion from inlet 10 to outlet 11. The containers C to be filled enter the filling line 1 at inlet 10, and containers C (also referred to here as C') filled with a predetermined volume of fluid exit the filling line 1 from outlet 11. Inlet 10 and outlet 11 are respectively traversed by linear conveyors 10a and 11a (e.g., belt conveyors, chain conveyors, or screw feeders) known per se.

[0039] The filling fluid can be any liquid or semi-liquid, and can be viscous and / or sticky. However, the present invention is particularly suitable for filling fluids that are slowly introduced into container C, due to the fluid’s specific density / viscosity or due to the presence of obstacles and / or voids within the container that slow down its filling.

[0040] Container C can be any type, but in particular it can be a type that includes multiple barriers, compartments and / or gaps inside, which slow down the filling of the container with fluid.

[0041] In a preferred embodiment of the invention, the fluid is an electrolyte for the battery, such as an electrolytic gel, while the container C supplied at inlet 10 is a container for the battery (e.g., for a cylindrical, prismatic, or pouch battery), containing an anode plate and a cathode plate, as well as other materials and components that optionally occupy the interior space of container C (which hinder the rapid introduction of the original electrolyte). Container C may have a cylindrical shape with a circular base, as shown in the figures, or a prismatic or pouch shape, wherein the anode plate, cathode plate, and other materials (e.g., insulators) (not shown) are rolled up to form a single multi-layer roll inside container C.

[0042] Each container C along the first path P1 is housed in a corresponding transfer carrier 3, which is a beaker-shaped body opening upward at its edge 31 to allow the container C to slide (automatically) into the carrier through the edge 31, exposing the upper inlet 30 of the container C, and stabilizing the container C during various operations along the entire first transport path P1. The carrier 3 is preferably adapted to remain integral with the container C along the entire first path P1 by an interference fit and / or form fit connection with the outer surface of the container C, but preferably leaves at least one lateral gap 36 to allow a vacuum to be created in the container C before filling and / or to allow rinsing of the container C before and / or after filling with fluid. For example, the carrier 3 may also have a generally cylindrical shape, and the container C is preferably housed in the carrier 3 such that the container C does not protrude above the edge 31.

[0043] The carrier 3 may have a fixing surface on its lateral surface, for example in the form of at least one depression 32, which, in the illustrated embodiment, is coaxial with the central axis of the carrier and is advantageously annular. The fixing surface 32 is preferably arranged near the upper edge 31 of the carrier 3.

[0044] At the end opposite edge 31 in the axial direction, the carrier 3 has a base 33, which is adapted to provide internal support for the container C and / or, in any case, an outward resting surface for conveying the carrier and thus the container C along at least a first conveying path P1 or some sections of the first conveying path P1. The base 33 is provided, for example, with a through hole 34 at its center.

[0045] The lateral surface of the vehicle 3 may have an enlarged radial portion 35, which essentially serves as a radial spacer when the vehicles are arranged side by side, particularly in the buffer station 110 described below.

[0046] The filling line 1 also includes a second conveying path P2 for a series of filling units 2.

[0047] The filling unit 2 is essentially a tap that can move continuously along a second path P2, which is preferably a closed path and in any case at least partially superimposed on the first conveying path P1, such that in the superimposed section, the filling unit 2 and the corresponding container C are superimposed on each other in the axial direction, i.e., parallel to the (vertical) direction that is substantially perpendicular to the floor of the installation work line 1.

[0048] Each filling unit 2 essentially comprises an injector-like body provided with a reservoir 21 adapted to contain a predetermined volume of fluid (e.g., electrolyte) to be transferred to a corresponding container C within its internal first chamber 21a. For this purpose, the reservoir 21 includes a bottom opening 20 for the passage of fluid, which may (but not necessarily) have a diameter of approximately a few millimeters (e.g., 2-3 mm), and the bottom opening 20 may advantageously be connected to the upper inlet 30 of the corresponding container C, for example by having the opening 20 have a nozzle 20a protruding outward from the reservoir 21.

[0049] In the illustrated embodiment, a reservoir 21 is associated with a plunger 22, which is axially movable relative to the reservoir 21 by means of a guide 24, which is fixed to the reservoir 21, for example, using a flange connector as shown in the illustrated embodiment. Specifically, the guide 24 of the plunger 22 is provided with a tubular guide 242, which is coaxial with the reservoir 21 but external to the reservoir 21, and the plunger 22 is associated in the tubular guide 242 so that the plunger 22 can slide.

[0050] The plunger 22 includes a piston 23 fixed to or integral with the reservoir 21, which is hermetically slidable along the inner wall of the reservoir 21 and divides the internal space of the reservoir into a first chamber 21a for containing fluid to be transferred to container C and a second chamber 21b for containing pressurized gas (e.g., air), which is adapted to cause the piston 23 to move in a direction that expands the volume of the second chamber 21b while reducing the volume of the first chamber 21a of the reservoir 21 by its expansion, thereby allowing the fluid to exit from the opening 20. For this purpose, the plunger 22 includes an internal coaxial passage 25 connected to the second chamber 21b, which is closed at the other end along the axis of the plunger 22 by a one-way valve (not shown), which can only be mechanically opened to introduce or expel gas from the second chamber 21b of the reservoir 21.

[0051] The kit formed by the filling unit 2 and the corresponding carrier 3 also includes a mechanism 27 for removable fixing, which is adapted to temporarily integrate the filling unit 2 and the carrier 3 to form an integral component 4, for example, as Figures 9-10 The components shown.

[0052] As in the illustrated embodiment, the mechanism 27 for removable fixation is preferably associated with each filling unit 2, but alternatively, the mechanism 27 for removable fixation may be provided on the carrier 3 (if any).

[0053] The mechanism 27 for removable fixation may be provided with one or more claws 271, for example, a gripper formed by a plurality of said claws 271, which can move closer to / away from each other around the central axis of the filling unit 2.

[0054] In other embodiments not shown, the mechanism for removable fastening may use other snap-acting coupling mechanisms to perform fastening by interference fit or by friction (e.g., using threaded connections).

[0055] In the illustrated embodiment, each claw 271 is a rocker arm with a fulcrum 276, for example, provided on a corresponding pair of lugs 26a-26b protruding from the reservoir, so as to swing relative to a horizontal axis. Each claw 271 may have a hook-like portion 272 at one end, the hook-like portion 272 being adapted to grip a recess 32 of the carrier 3.

[0056] Each claw 271 can also be pivotally connected relative to a corresponding link 273 at the opposite end of the arm relative to the fulcrum 276. The link 273 is in turn hinged to a corresponding hinge hole 277 of a drive slider 274, which can advantageously move in a direction coaxial with the filling unit 2. For example, in an embodiment, the drive slider 274 is fitted onto a tubular guide 242 so that it can slide axially toward / away from the reservoir 21, i.e., slide relative to the flange of the guide 24 fixed to the reservoir 21.

[0057] The mutual approach and separation between the drive slider 274 and the guide body 24 along the axial direction respectively result in the separation and fixation between the filling unit 2 and the carrier 3, that is, the hook-shaped portions 272 of the claw 271 are separated and approach each other along the corresponding axial plane.

[0058] Furthermore, a resilient return mechanism is preferably provided to hold the resiliently loaded fixing mechanism 27 in a locked state relative to the carrier 3. This allows the filling unit 2 to be coupled to the carrier 3 (if present) or to the container C by a snap-fit ​​action, simply by bringing them together in the axial direction and thus obtaining the integral assembly 4.

[0059] In a preferred but non-exclusive embodiment of the invention, the fixing mechanism 27 is implemented using a clamp, the locked state is the state in which the hooks 272 are at their minimum mutual distance relative to the central axis of the filling unit 2, and the elastic return mechanism is essentially composed of a compression spring 275 inserted between the drive slider 274 and the guide 24 to prevent the drive slider 274 and the guide 24 from approaching each other.

[0060] The drive slider 274 is advantageously implemented using a multi-bladed plate, such that a compression spring 275 is inserted between the corresponding blade of the slider 274 and the guide 24. Furthermore, the blades of the drive slider 274 are optionally offset relative to the eyelet 277 for hinged link 273, such that the area between one blade and the next does not impede the movement of link 273 and the pivot point of the corresponding pawl 271 away from the guide 24.

[0061] According to a particular aspect of the invention, transport paths P1 and P2 pass through component 100 and buffer station 110 for producing filling container C (filled with a predetermined volume of fluid).

[0062] Production assembly 100 includes a separation station 12, a filling station 13 downstream of the separation station (indicated by the arrow of the second path P2 relative to the transport direction of the filling unit 2), and a connecting station 14 downstream of the filling station 13. Stations 12-14 each include at least one separation turntable 120, at least one filling turntable 130, and at least one connecting turntable 140, each turntable being capable of rotating about a central axis of rotation 121, 131, 141, respectively, preferably in continuous motion.

[0063] Each turntable 120, 130, 140 is provided with a plurality of clamping mechanisms 122, 132, 142, which are arranged along a peripheral area and adapted to hold at least one corresponding filling unit 2 during rotation of the respective turntable (based on the embodiment considered). The clamping mechanisms 122, 132, 142 are angularly equidistant from each other about their respective central rotation axes 121, 131, 141 to form a circumference. The pitch of the clamping mechanisms 122, 132, 142 about their respective central rotation axes 121, 131, 141 is preferably equal for all turntables.

[0064] Turntables with clamping mechanisms along their circumference are well-known in the bottling industry.

[0065] Advantageously, conveyor wheels 101-106 are also positioned upstream and downstream of each of the turntables 120, 130, and 140 (relative to the transmission direction of paths P1 and / or P2). Conveyor wheels 101-106 also rotate, preferably in continuous motion, about respective axes of rotation 121, 131, and 141 parallel to the central axes of rotation of the turntables 120, 130, and 140. Conveyor wheels 101-106 may be of the type having slots arranged at a constant pitch around the axis of rotation of the respective wheel to catch objects received from the upstream turntable or conveyor and supply them to the downstream turntable or conveyor.

[0066] Intermediate conveyor star wheels 102 and 103 are inserted between turntables 120 and 130 and between turntables 130 and 140, respectively, so as to convey at least filling unit 2 between one turntable and the next.

[0067] The first inlet star wheel 101 (in the direction of transport relative to the second path P2) is located upstream of the separation turntable 120 and downstream of the unloading conveyor 108 for the integral assembly 4, which connects the outlet of the buffer station 110 to the production assembly 100 so that the integral assembly 4 can be returned after the corresponding container C has been filled.

[0068] The second inlet star wheel 106 is alternatively arranged downstream of the linear conveyor 10a and preferably upstream of the connecting turntable 140 (relative to the transport direction of the first path P1) to feed the container C to be filled (which is contained in the corresponding carrier 3) to the connecting turntable 140. Alternatively, the second inlet star wheel 106 may be located upstream of the filling turntable 130 (relative to the transport direction of the first path P1).

[0069] This second entry star wheel 106 corresponds to the second transfer star wheel of the test station 50.

[0070] The first unloading star wheel 105 (in the transmission direction relative to the second path P2) is located downstream of the connecting turntable 140 and upstream of the feed conveyor 107 for feeding the overall assembly 4 to the buffer station 110.

[0071] The second unloading star wheel 104 is alternatively arranged downstream of the separation turntable 120 (relative to the transmission direction of the first path P1) and upstream of the unloading conveyor 11a, which is used to unload the filled container C' optionally contained in the corresponding carrier 3.

[0072] The first conveying path P1 and the second conveying path P2 comprise circular arcs ideally drawn by the clamping mechanisms 122, 142 and the clamping mechanism 132 for P2 through their rotation about their respective central rotation axes 121, 141 and 131. The circular arcs of the first path P1 and the second path P2 are preferably superimposed along the circumferences ideally drawn by the clamping mechanisms 122 and 142 of the separating turntable 120 and the connecting turntable 140, respectively.

[0073] Other overlapping sections between the first path P1 and the second path P2 are provided along the buffer station 110 and along the feed conveyor 107 and the unloading conveyor 108, the feed conveyor 107 for feeding the integral assembly 4 into the buffer station 110 and the unloading conveyor 108 for unloading the integral assembly 4 from the buffer station 110.

[0074] The clamping mechanism can be, for example, in the form of grippers. In the separating turntable 120, the clamping mechanism 122 can be formed by two pairs of grippers stacked in a direction parallel to the axis of rotation 121, so as to clamp the filling unit 2 and the container C (or carrier 3, if any) of the integral assembly 4 respectively. Such pairs of grippers can move relative to each other in the axial direction (e.g., using jacks associated with each pair of stacked grippers) so as to space the filling unit 2 and the container C apart from each other, or keep them separated from each other.

[0075] Advantageously, the clamping mechanism 122 or a suitable tilting cam fixed around the central axis 121 of the separating turntable 120 may include a thrust surface adapted to push the drive slider 274 toward the guide 24, thereby opening the pawl 271 and allowing the filling unit 2 to be separated from the rest of the integral assembly 4 during rotation about axis 121.

[0076] Similarly, in the connecting turntable 140, the clamping mechanism 142 can be formed by two pairs of clamps stacked in a direction parallel to the rotation axis 141 to clamp the filling unit 2 and the carrier 3 (or container C) respectively, and such pairs of clamps can move relative to each other parallel to the rotation axis 141 (e.g., using corresponding jacks) so that the filling unit 2 and the corresponding container C are brought closer together in the axial direction to form an integral assembly 4 in which the filling unit 2 and the corresponding container C are in fluid communication. If the fixing mechanism 27 is a snap-fit ​​type, as in the example of the clamps shown, the integral assembly 4 is obtained by simply moving them closer to each other as described above.

[0077] The connection station 14 may also include a mechanism for pressurizing the filling unit 2, which is adapted to open a one-way valve of the internal channel 25 and inject pressurized gas (e.g., air) into a second chamber 21b, which gradually expands by translating the plunger 23 toward the bottom of the reservoir 21.

[0078] When the filling unit 2 is released from the coupling station 14, the one-way valve will close, thereby trapping the pressurized gas in the second chamber 21b.

[0079] In an alternative embodiment, a mechanism for pressurizing the buffer station 110 can be provided by providing multiple pressure taps on the buffer station 110, which are automatically connected to the plunger 22 of the integral assembly 4 transported at the accumulator 110. The pressure taps are then automatically removed before the integral assembly leaves the accumulator 110.

[0080] In other alternative embodiments of the invention, the plunger 22 may be electrically actuated (e.g., using a linear motor) or mechanically actuated (e.g., using a spring or using an inclined cam surface that interacts with the plunger 22 to move the plunger 22 axially as the overall assembly moves forward in the buffer station 110), rather than using pneumatic actuation obtained by gas expansion.

[0081] The filling station 13 includes mechanisms at each clamping mechanism 132 for introducing a predetermined volume of fluid into the filling unit, specifically including a tap and a filling nozzle for each clamping mechanism 132, the tap and nozzle being connected to the main reservoir of the production line 1, which contains fluid for filling container C. The tap and nozzle are mounted along the outer peripheral region of the filling turntable 130 so as to rotate integrally with the turntable about its own central axis of rotation 131. The filling nozzle can be mounted below the clamping mechanism 132 and oriented upward so as to engage with the bottom opening 20 of the filling unit 2 held by the corresponding clamping mechanism 132.

[0082] When a predetermined volume of fluid is delivered from the filling nozzle to the filling unit 2, its first chamber 21a is gradually filled with fluid, thereby causing the plunger 23 to move in the direction of reducing the volume of the second chamber 21b.

[0083] Buffer station 110 is arranged along the overlapping sections of paths P1 and P2 from connection station 140 to separation station 120, and is associated with feed conveyor 107 and unloading conveyor 108 of integral component 4, which feed integral component 4 to buffer station 110 and unload it from buffer station 110 at the production speed of production line 1, respectively.

[0084] Buffer station 110 is a FIFO (First-In, First-Out) type accumulator and may be a component of an accumulator platform or accumulator conveyor. The FIFO accumulator may have one or more moving pads, conveyor belts, electric roller conveyors, or sliding surfaces, which may optionally be arranged to form a serpentine route, and in any case are suitable for storing (large quantities) of integral components 4 (specifically N*t integral components, where N is the production rate of line 1 in units of containers per minute, and t is the time in minutes for filling a single container C with a predetermined volume of fluid) by distributing the integral components on sufficient surfaces or by allowing the integral components to travel along tortuous and / or extended paths, so that the integral components remain in buffer station 110 for the period of time necessary for filling the container C of the integral component with the corresponding predetermined volume of fluid.

[0085] The accumulator platform or accumulator conveyor itself is known, for example, from patent US 5,282,525 or from patent EP1144285.

[0086] The integral components 4 preferably arrive at the buffer station 110 in a continuous, neat row, and optionally are spaced apart from each other at the same pitch as the clamping mechanisms 122, 132, 142 of the turntable and the sockets of the transfer star wheels 101-106.

[0087] Buffer station 110 is adapted to advance integral components 4 from feed conveyor 107 toward unloading conveyor 108 at a speed and path length defined by the time (t) required to fill a single container C with a predetermined volume of fluid. Each of these incoming integral components 4 includes a filling unit 2 substantially filled with a predetermined volume of fluid and a container C not yet filled with that volume.

[0088] Using the pressure exerted by the gas in the second chamber 21b, a certain volume of fluid is slowly transferred to the container C of the integral assembly 4, which can remain on the accumulator stage for the entire time required to complete the transfer of the certain volume of fluid from the filling unit 2 to the container C of the integral assembly 4.

[0089] With the aid of buffer station 110, production assembly 100 can operate at high production rates N (e.g., between 100 and 600 containers C per minute) by rapidly filling filling units 2 with a turntable 13 having a limited number of clamping mechanisms 132 and filling nozzles (e.g., on the order of several times 10). At buffer station 110, each filling unit 2 then autonomously fills the corresponding container C of the overall assembly 4 by transferring a predetermined volume of fluid received from filling station 13 of production assembly 100 to container C in a much shorter time (e.g., 5 seconds) within a time t (e.g., 10 minutes), while autonomously filling the corresponding container C of the overall assembly 4 within a (longer) time t required by the internal characteristics of container C and / or the properties of the fluid. Thus, filling station 13 can have a relatively small number of filling nozzles and taps (e.g., between 30 and 60 on turntable 130).

[0090] The operation of the present invention can be clearly seen from the foregoing description.

[0091] Container C moves continuously within the corresponding carrier 3 along a first conveying path P1 between the inlet 10 and outlet 11 of production assembly 100 and is continuously conveyed at a certain desired (high) production speed N corresponding to the speed of the production line into which the filling operation line 1 is inserted. For example, the speed N at which filled containers C' leave the outlet 11 of production assembly 100 is several hundred containers per minute (e.g., between 100 and 600 containers per minute).

[0092] Immediately following the entrance 10, the carrier 3 follows a predetermined path to the test station 50. The carrier 3 may have barcodes or other (optical) identifiers to identify containers C that are detected as defective in the test station 50 and to discard these defective containers C immediately or at the exit 11, preferably without associating these defective containers C with the filling unit 2.

[0093] Along their transport path P1, the carrier 3 is fixed to the corresponding "moving tap" represented by the filling unit 2, which was previously filled at a speed N in the filling station 13 with the required fluid volume of the filling container C, and the filling unit 2 is pressurized in the coupling station 14.

[0094] Specifically, in filling station 13, filling unit 2 is held by a corresponding clamping mechanism 132 of filling turntable 130 and brought to a corresponding filling nozzle 135, which is connected to the opening 20 of reservoir 21.

[0095] During the rotation of the filling turntable 130, fluid injected into the reservoir 21 via the opening of the nozzle 135's tap 134 lifts the plunger 23 to a height determined by the amount of fluid injected, which is based on a predetermined amount required to fill the container C. In the example shown in the figures, the fluid amount is the maximum permissible value, and the first volume 21a of the reservoir 21 is thus filled, lifting the plunger 23 upward to its stroke limit.

[0096] Subsequently, each filling unit 2 (via intermediate star wheel 103) is conveyed to the coupling turntable 140, where each filling unit 2 is coupled to a corresponding carrier 3 to form an integral assembly 4, and is conveyed to a corresponding pressurizing needle, which injects pressurized gas (air) into the second chamber 21b. The pressurized gas begins to cause the plunger 23 to descend and transfer fluid to the container C.

[0097] Then, container C continues along path P1, again traveling at the production speed N of component 100, while the filling unit 2 connected to container C completely fills container C with fluid through the expansion of pressurized gas in the second chamber 21b. Container C is held at buffer station 110 for a predetermined time required to be filled, for example, at least 2 minutes. Optionally, in addition to the time container C is held in buffer station 110, the filling time t of container C may also include the time for conveying the integral component 4 along sections of conveyors 107 and 108, along which filling may begin and continue respectively.

[0098] When the integral component 4 reaches the outlet of the buffer station 110, for example, when the integral component 4 is on the unloading conveyor 108, the corresponding container C is completely filled with a predetermined volume of fluid. The unloading conveyor 108 propels the integral component 4 at the high production speed required to produce component 100. At the separation station 12, after optionally venting gas, the drive slider 274 is mechanically activated to separate the emptied filling unit 2 from the filled container C, and each filled container is carried by a corresponding clamping mechanism 122 (e.g., lower clamping mechanism 122) of the separation turntable 120 to the second unloading star wheel 104, which conveys the container C to the unloading conveyor 11a.

[0099] Then, the filling unit 2 is continuously recirculated along the closed path P2 in the filling line 1, along a section of the closed path P2, where the filling unit 2 is temporarily integrated with the corresponding carrier 3 again (thus forming the corresponding independent integral component 4), so that the corresponding container C can be filled mainly at the buffer station 110 within a time t (which can be very long), which is longer than the time required to fill the filling unit with the same volume of fluid, to ensure that the filled container C is output from the line 1 at a preset production rate N.

[0100] Therefore, it has been found that the present invention fully achieves the intended goals and objectives.

[0101] This invention is thus conceived to accommodate many modifications and variations, all of which are within the scope of the appended claims. Furthermore, all details can be replaced by other, technically equivalent elements.

[0102] In practice, the materials used, as well as the possible shapes and sizes, can be arbitrary, depending on the needs and the state of existing technology.

[0103] The disclosure of Italian patent application No. 102023000026895, which claims priority to this application, is incorporated herein by reference.

[0104] Where a technical feature mentioned in any claim is followed by a reference numeral, such reference numerals are inserted for the sole purpose of increasing the comprehensibility of the claim, and therefore these reference numerals have no limiting effect on the interpretation of each element represented by these reference numerals by way of example.

Claims

1. A method for leak testing of a container (C), said container (C) being particularly a container for a battery or battery pack to be filled with electrolyte, characterized in that, The container (C) has an inlet (30) through which the container (C) can be filled with fluid, particularly electrolyte, in a filling operation line, characterized in that the method includes the following steps: - The container (C) is conveyed along a predetermined path, preferably in a continuous motion. - Each of the containers (C) is enclosed in a corresponding chamber (67) such that the container (C) continues to be transported along a portion of the predetermined path together with the chamber (67); And characterized in that, during the transport of the container (C) enclosed in the respective chamber (67) along the predetermined path, the method includes the following steps: - A vacuum is created in each of the containers (C) by evacuating air from the chamber (67); - After the vacuum generation step, tracer gas is injected into each of the containers (C) through the feed port (30); - After the tracer gas injection step, detect any presence of the tracer gas that has leaked into the corresponding chamber (67).

2. The method according to claim 1, characterized in that, Each of the containers (C) contained in the respective carrier (3) is transported along the predetermined path; and is characterized in that, in the closing step, the container (C) is closed between the respective carrier (3) and the bell-shaped member (53), the bell-shaped member moving along a closed path including the portion of the predetermined path, the bell-shaped member engaging the carrier (3) in an airtight manner to form the chamber (67) along the portion of the predetermined path.

3. The method according to the preceding claim, characterized in that, The carrier (3) includes a through hole (34), and is characterized in that, during the vacuum generation step, air is drawn out from the outside of the carrier toward the chamber (67) through the through hole (34).

4. The method according to the preceding claim, characterized in that, In the detection step, the through hole (34) is connected to the detection mechanism (55).

5. The method according to one or more of claims 2 to 4, characterized in that, The bell-shaped member includes a plunger (59) for injecting the tracer gas, the injection plunger being coaxially movable with the bell-shaped member (53), and is characterized in that the injection step includes engaging the plunger (59) with the feed port (30) in an airtight manner.

6. A method for filling a container (C) with fluid in a filling operation line, wherein, The container (C) is continuously conveyed within a corresponding carrier (3) along a first conveying path (P1) between an inlet (10) for an empty container (C) and an outlet (11) for a container (C) filled with the fluid, characterized in that the method comprises the following steps: - A series of filling units (2) are conveyed along the second conveying path (P2), wherein the first path (P1) and the second path (P2) are partially superimposed on each other; - Along a portion of the second path (P2), each filling unit (2) is filled with the predetermined volume of fluid; - Along the overlapping sections of the first conveying path (P1) and the second conveying path (P2), each filling unit (2) is temporarily integrated with a corresponding one of the carriers (3) to form an integral assembly (4) in which the filling unit (2) and the corresponding container (C) contained in the carrier (3) are in fluid communication. - The overall component (4) is assembled in a buffer station (110), in which the filling unit (2) transfers the volume of fluid to the container (C). - When the fluid of the volume is transferred, the carrier (3) containing the container (C) filled in this way is separated from the filling unit (2) that is emptied in this way, and the carrier (3) is transported toward the outlet (11); Furthermore, the method is characterized in that it includes a leakage test method according to one or more of the preceding claims, wherein the predetermined path is a portion of the first path (P1) upstream of the overlay segment.

7. The filling method according to the preceding claim, characterized in that, The second delivery path (P2) is a closed path, and the filling unit (2) that is filled with the volume of fluid in the filling step is the filling unit that was previously separated from the integral component (4) in the separation step.

8. The filling method according to one or more of claims 6-7, characterized in that, The time to fill each filling unit (2) with the fluid of the specified volume is shorter than the time (t) to transfer the fluid of the specified volume from the filling unit (2) to the container (C).

9. A leak test station (50) for a container (C), said leak test station (50) being used to perform the method according to one or more of claims 1 to 5, said container (C) having an inlet (30) and being housed in a corresponding carrier (3), characterized in that, The leak test station (50) includes a vacuum generating mechanism (54), a tracer gas supply mechanism, a tracer gas detection mechanism (55), and a test turntable (51). The test turntable (51) is rotatable around a central axis (L), preferably rotating continuously. The test turntable (51) includes multiple test devices (5), which rotate integrally with the test turntable (51). Each of the test devices (5) includes: - A bell-shaped member (53) adapted to directly engage the carrier (3) to form a chamber (67) for accommodating the container (C), the bell-shaped member being movable relative to a support base (37) for the carrier (3), the support base (37) rotating integrally with the test turntable (51); - An opening (38) in the support base (37) is in fluid communication with the vacuum generating mechanism (54) and the detection mechanism (55); - A tracer gas injection mechanism (59) inside the bell-shaped member (53) is adapted to engage the feed port (30) of the container (C) in the chamber (67) in an airtight manner.

10. The leakage test station (1) according to the preceding claim, characterized in that, The tracer gas injection mechanism includes an injection plunger (59) movable within the bell-shaped member (53), the bell-shaped member (53) and the injection plunger (59) being movable in a direction substantially parallel to the axis of rotation (L), the injection plunger (59) including an internal injection channel (60) leading to the support base (37), and the injection plunger (59) including a sealing mechanism (39) adapted to engage around the inlet (30) of the container (C).

11. A filling line (1) for performing the method according to one or more of claims 6-8, comprising: - Inlet (10), the inlet (10) is used for a vehicle (3) containing an empty container (C); - Outlet (11), said outlet (11) for said carrier (3) having a filled container (C); - First transport path (P1), the first transport path (P1) is used to transport the vehicle (3) between the inlet (10) and the outlet (11); The filling operation line (1) is characterized in that it includes: - A second conveying path (P2) for a series of filling units (2), wherein the first path (P1) and the second path (P2) are partially overlapped; - A separation station (12), a filling station (13) for filling the filling unit (2) downstream of the separation station, a connecting station (14) downstream of the filling station (13), and a buffer station (110) between the connecting station and the separation station, the station being traversed by at least a second conveying path (P2), the first conveying path (P1) and the second conveying path (P2) being superimposed on each other at least at the connecting station (14) and the buffer station (110); - At the filling station (13), a mechanism (135) for introducing a predetermined volume of fluid to be injected into the container (C) into each filling unit (2). - The coupling station (14) is adapted to connect each of the vehicles (3) to a corresponding one of the filling units (2) that are reached from the filling station (13) in order to form an integral assembly (4) in which the filling unit (2) and the corresponding container (C) are in fluid communication. - Actuation mechanism (23) for actuating the filled filling unit (2) of the integral assembly (4) to transfer the volume of fluid from the filling unit (2) to the container (C) of the corresponding integral assembly (4) at the buffer station (110), the integral assembly (4) being composed of the emptied filling unit (2) and the filled container (C) at the end of the transfer; The separation station (12) is adapted to disassemble the integral component (4) that has left the buffer station (110) and separate the emptied filling unit (2) from the corresponding filled container (C) of each integral component (4); The filling operation line is further characterized in that it includes a leak test station (50) according to one or more of claims 9-10, the leak test station (50) being arranged between the inlet (10) and the connection station (14) along a portion of the first path (P1).

12. The filling line according to the preceding claim, characterized in that, The second transport path (P2) is a closed path, such that the filling unit (2) filled with the volume of fluid in the filling station (13) is a filling unit that is reached from the buffer station (110) through the separation station (12).

13. The filling production line according to any one of claims 11-12, characterized in that, The separation station, the filling station, and the connecting station each respectively include at least one separation turntable (120), at least one filling turntable (130), and at least one connecting turntable (140). Each of the turntables (120, 130, 140) is rotatable about a corresponding central axis of rotation (121, 131, 141), preferably rotating continuously about the corresponding central axis of rotation (121, 131, 141), and is provided with a plurality of clamping mechanisms (122, 132, 142). The clamping mechanisms (122, 132, 142) are angularly separated from each other about the central axis of rotation. The first conveying path (P1) and the second conveying path (P2) include arcs drawn by the rotation of the clamping mechanisms (122, 142) of at least the separation turntable (120) and the connecting turntable (140) about the corresponding central axis of rotation (121, 141) of the turntable.

14. The filling production line according to one or more of claims 11-13, characterized in that, One or both of the filling unit (2) and the carrier (3) include a mechanism (27) for removable fixing, which can be actuated upon command, and the coupling station (14) is adapted to activate the mechanism (27) for removable fixing, so that the carrier (3) and the corresponding filling unit (2) become one unit, thereby forming the integral component (4).

15. The filling production line according to one or more of claims 11-14, characterized in that, Each of the filling units (2) includes an injector-like body comprising a reservoir (21) and at least one first plunger (23), the reservoir (21) being provided with an opening (20) for fluid passage, the first plunger (23) being movable within the reservoir (21) and dividing the reservoir into a first chamber (21a) and a second chamber (21b), the first chamber (21a) being adapted to contain a predetermined volume of fluid, and the second chamber (21b) being adapted to contain pressurized gas, the pressurized gas being adapted to move the first plunger (23) toward the opening (20) of the reservoir (21) by means of gas expansion.

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