Tab connector and connection method for battery testing

Abstract

The application discloses a tab connector for battery test, which comprises a bolt, a ratchet gear nut and a fixing assembly matched with the ratchet gear nut, the lower part of the ratchet gear nut is a ratchet, the fixing assembly is provided with a containing part, the containing part is provided with a limiting valve for preventing the ratchet from being loosened, the limiting valve is rotatable in the containing part, the head of the bolt and the fixing assembly are provided with a current voltage collection terminal and a tab, the screw rod of the bolt is provided with an anti-rotation boss near the head, and the fixing assembly is provided with an anti-rotation groove at the corresponding position. The limiting valve is abutted against the ratchet, the anti-rotation boss and the anti-rotation groove are matched, the bolt is relatively fixed with the fixing assembly, and the pressure of the bolt and the nut on the current voltage collection terminal and the tab is kept near the initial pressure in the long-time charge-discharge test.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery detection, and in particular relates to a tab connector and a connection method thereof for preventing tab connections from loosening during power battery testing during long-cycle verification. Background Art

[0002] A power battery is a power source that provides power for electric tools, and mostly refers to a storage battery that provides power for electric vehicles, electric trains, electric bicycles, etc. The tab is a metal conductor welded to the positive or negative current collector, protruding from the outside of the power battery, and is used for electrical connection between the battery current collector and the outside. Its specifications and dimensions and overcurrent capacity are relatively large. In order to detect the quality of the power battery, it is necessary to perform a charge and discharge cycle test on the power battery. For example, a "tooling fixture for battery testing" disclosed in a Chinese patent document, with the announcement number CN204964561U, includes a tab clamping assembly, which is used to clamp the battery tab and electrically connect to the battery tab; and a wire nose connector, which is used to install the wire nose and electrically connect to the wire nose, wherein: the tab clamping assembly is electrically connected to the wire nose connector, and a battery test fixture is set between the battery tab and the wire nose. The battery tabs are clamped by the tab clamping assembly in the battery testing fixture, and the wire noses are connected and installed by the wire nose connector in the battery testing fixture, so that the battery tabs and the wire noses are conveniently connected through the bridge effect of the battery testing fixture, and the wire noses can be connected to thicker wires, thereby overcoming the defect of inconvenient installation and connection between the wire noses and the battery tabs and improving the detection efficiency. However, the connection efficiency of this method is not high enough, and as the number of interfaces increases, the stable contact of the interfaces cannot be guaranteed.

[0003] Another solution is: use a hole opener to open holes in the positive and negative tabs of the battery respectively, and then use bolts to fix the current and voltage output ends of the charging and discharging equipment with the terminals of the charging and discharging equipment. This connection method often causes the nuts to loosen due to mechanical vibrations such as the equipment compressor when the temperature box is running. Especially during long-term testing and verification, mechanical vibrations or temperature changes inside the connectors lead to poor contact between the positive and negative tabs of the battery cell and the copper terminals or the upper and lower pressure plates, and large contact internal resistance, which affects the analysis of verification results; the battery tabs are pressed by splints and connected by alligator clips. The pressure required to press the tabs is high, and the pressure at each battery tab is uneven, making it difficult to unify and measure the pressing force; the pressing method with special-shaped threaded metal rods is not universally applicable to tabs of different thicknesses, and the contact surface of the metal rod pressing and the contact surface of the tab are easy to slide. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem that the existing tab connectors for battery testing are easy to loosen, and to propose a tab connector and a connection method thereof that can prevent the tab connection from loosening during power battery testing during long-cycle verification.

[0005] The present invention is achieved through the following technical solutions:

[0006] A tab connector for battery testing includes a bolt, a ratchet gear nut, and a fixing assembly that cooperates with the ratchet gear nut. The upper part of the ratchet gear nut is a rotating part, and the lower part is a ratchet. The fixing assembly is recessed downward to form an accommodating portion that can accommodate the ratchet gear nut. The accommodating portion is also provided with a limiting valve to prevent the ratchet from being loosened. The limiting valve is rotatable within the accommodating portion. A current and voltage collection terminal and a tab are provided between the head of the bolt and the fixing assembly. A bolt hole is provided at the bottom of the accommodating portion. The screw rod of the bolt is provided with an anti-rotation protrusion near the head, and an anti-rotation groove is provided at the corresponding position of the fixing assembly. The current and voltage collection terminal and the tab are provided with a through hole that can be passed through by the screw rod of the bolt.

[0007] By limiting the valve against the ratchet, the ratchet can only rotate in the direction in which the nut is tightened on the bolt, so that the nut and the fixing assembly are relatively fixed. The anti-rotation protrusion on the screw and the fixing assembly prevent the groove from fitting, so that the bolt and the fixing assembly are relatively fixed. Therefore, it can be ensured that during long-term charge and discharge tests, the pressure of the bolt and nut on the current and voltage collection terminals and the tabs is maintained near the initial pressure, preventing the contact internal resistance from increasing and affecting the verification result analysis.

[0008] Preferably, the limiting valve includes a rotating shaft fixed to the bottom surface of the accommodating portion, a limiting bar with a middle portion sleeved on the rotating shaft, and a spring connecting the limiting bar and the side wall of the accommodating groove, and the limiting bar is kept in contact with the ratchet by the spring.

[0009] Preferably, one end of the limiting bar abuts against the ratchet teeth of the ratchet, and the other end is provided with a smooth manual part, and the distance between the manual part and the rotating shaft is greater than the distance between the rotating shaft and the ratchet teeth where the limiting bar abuts. Pressing the manual part can make the limiting bar leave the ratchet, thereby loosening the nut and bolt.

[0010] Preferably, the bolt is a flange bolt, and an annular groove is provided on the flange surface of the flange bolt. The provision of the annular groove can increase the pressing force of the bolt head on the current and voltage collection terminal or the tab contact surface.

[0011] Preferably, the current and voltage acquisition terminal is connected to the flange bolt when connected, and a small deformation hole corresponding to the position of the annular groove is provided on the side of the current and voltage acquisition terminal facing the flange bolt, which plays a role in dissipating heat and accommodating expansion without reducing the contact area between the current and voltage acquisition terminal and the flange plate of the flange bolt.

[0012] Preferably, the accommodating portion is provided with a cover plate above the limiting valve for protecting the limiting valve and making the appearance more beautiful.

[0013] A connecting method using the lug connector for battery test as described above, comprising:

[0014] S1: the screw rod of the flange bolt is sequentially inserted through the lug provided with the screw hole, the current and voltage collection terminal and the fixing assembly, and the anti-rotation protrusion is installed into the anti-rotation groove;

[0015] S2: the current and voltage collection terminal is connected with the charge and discharge equipment;

[0016] S3: the upper part of the ratchet gear nut is rotated clockwise by using the torque wrench, at this time, the ratchet of the ratchet gear nut is rotated and the limiting strip of the limiting valve is pushed;

[0017] S4: when the torque of the torque wrench reaches a specified value, the rotation of the ratchet gear nut is stopped, at this time, the limiting valve pushes against the ratchet to fix it.

[0018] Therefore, the present application has the following beneficial effects:

[0019] By pushing the ratchet with the limiting valve, the ratchet can only rotate in the direction in which the nut is tightened on the bolt, so that the nut is relatively fixed with the fixing assembly, and by the cooperation of the anti-rotation protrusion on the screw rod and the anti-rotation groove of the fixing assembly, the bolt is relatively fixed with the fixing assembly, so that the pressure of the bolt and the nut on the current and voltage collection terminal and the lug can be kept near the initial pressure during long-time charge and discharge test, the contact resistance is prevented from increasing, and the influence on the test result is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is an explosion schematic view of the side view of the embodiment of the present application;

[0021] Figure 2 is a top view schematic view of the embodiment of the present application without the cover plate;

[0022] Figure 3 is a top view of the bolt flange surface and the current and voltage collection terminal of the embodiment of the present application;

[0023] Figure 4 is a data table of the anti-loosening effect comparison of the embodiment of the present application and the comparative example.

[0024] In the figure: bolt 1, anti-rotation protrusion 11, flange plate 12, annular groove 121, ratchet gear nut 2, rotating part 21, ratchet 22, fixing assembly 3, containing part 31, bolt hole 311, anti-rotation groove 32, limiting valve 4, rotating shaft 41, limiting strip 42, manual part 421, spring 43, current and voltage collection terminal 5, small deformation hole 51, lug 6, through hole 7. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] In the description of the present invention, it should be noted that the terms "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0027] Example 1, as Figure 1-3 As shown, a tab connector for battery testing includes a bolt 1, a ratchet gear nut 2, and a fixing assembly 3 that cooperates with the ratchet gear nut. The bolt is a flange bolt, the upper part of the ratchet gear nut is a rotating part 21, and the lower part is a ratchet 22. The fixing assembly 3 is recessed downward to form a receiving portion 31 that can accommodate the ratchet gear nut 2. The receiving portion is also provided with a limiting valve 4 to prevent the ratchet 22 from being loosened. The limiting valve is located on the side of the ratchet and can rotate a small angle in the receiving portion. A current and voltage collection terminal 5 and a tab 6 are provided between the head of the bolt and the fixing assembly. A bolt hole 311 is provided at the bottom of the receiving portion 31. The screw rod of the bolt is provided with an anti-rotation protrusion 11 near the head, and an anti-rotation groove 32 is provided at the corresponding position of the fixing assembly. The current and voltage collection terminal 5 and the tab 6 are provided with a through hole 7 that can be passed through by the screw rod of the bolt. The limiting valve 4 includes a rotating shaft 41 fixed to the bottom surface of the housing, a limiting bar 42 with a central portion sleeved on the rotating shaft, and a spring 43 connecting the limiting bar and the side wall of the housing. One end of the limiting bar 42 abuts against the ratchet teeth of the ratchet 22. The extension line of the limiting bar 42 does not pass through the ratchet 22, and the limiting bar 42 can rotate within the housing and is restricted by the side wall of the housing. Therefore, it can limit the rotation of the ratchet in the loosening direction, while the limiting bar can be moved when the ratchet or even the ratchet gear nut is tightened. The spring 43 is arranged on the limiting bar between the rotating shaft 41 and the ratchet 22. The spring amplifies the force of the limiting bar against the ratchet through the principle of leverage. The direction of the spring force causes the limiting bar to point towards the ratchet, preventing the limiting bar from moving away from the ratchet when there is no pressure between the ratchet teeth and the limiting bar, thereby failing to prevent the ratchet from rotating in the loosening direction.

[0028] The limiting bar 42 of the limiting valve 4 is pressed against the ratchet 22, so that the ratchet can only rotate in the direction in which the ratchet gear nut 2 is tightened on the bolt 1, so that the ratchet gear nut 2 is relatively fixed to the fixing component 3, and the bolt 1 is relatively fixed to the fixing component 3 through the cooperation of the anti-rotation protrusion 11 on the screw 1 and the anti-rotation groove 32 of the fixing component 3. Therefore, it can be ensured that during long-term charge and discharge tests, the pressure of the bolt 1 and the ratchet gear nut 2 on the current and voltage collection terminal 5 and the pole ear 6 is maintained near the initial pressure, preventing the contact internal resistance from increasing and reducing the impact on the test results.

[0029] One end of the limiting bar 42 abuts against the ratchet teeth of the ratchet 22, and the other end is provided with a smooth manual part 421. The distance between the manual part 421 and the rotating shaft 41 is greater than the distance between the rotating shaft and the ratchet teeth where the limiting bar abuts. Therefore, pressing the manual part can easily make the limiting bar leave the ratchet, thereby loosening the nuts and bolts.

[0030] An annular groove 121 is provided on the flange 12 of the flange bolt. This groove 121 increases the pressure applied by the bolt head against the contact surface of the current and voltage collection terminal 5 or the tab 6, and also serves as a heat dissipation channel. When connected, the current and voltage collection terminal 5 engages the flange bolt. The surface of the current and voltage collection terminal facing the flange bolt is provided with a small, deformable hole 51 corresponding to the position of the annular groove 121. This hole, along with the annular groove 121, dissipates heat and accommodates expansion without reducing the contact area between the current and voltage collection terminal 5 and the flange 12 of the flange bolt.

[0031] In addition, the accommodating portion is provided with a cover plate above the limiting valve for protecting the limiting valve and making the appearance more beautiful.

[0032] The battery charge and discharge test is performed using the above-mentioned battery test tab connector, and the connection method includes:

[0033] S1: The screw of the flange bolt passes through the current and voltage collection terminal with screw holes, the tab and the fixing component in sequence, and the anti-rotation protrusion is installed into the anti-rotation groove;

[0034] S2: The current and voltage acquisition terminals are connected to the charging and discharging equipment;

[0035] S3: Use a torque wrench to rotate the upper part of the ratchet gear nut clockwise. At this time, the ratchet of the ratchet gear nut rotates and moves the limit bar of the limit valve;

[0036] S4: When the torque displayed by the torque wrench reaches the specified value, stop rotating the ratchet gear nut. At this time, the limiting valve presses against the ratchet to fix it.

[0037] After the connection is completed, the charge and discharge cycle can be carried out. The steps of the charge and discharge cycle are:

[0038] SS1: The battery is discharged at 1C to 2.5V and left to stand until the battery surface temperature is ≤27℃;

[0039] SS2: Charge at 1C constant current to 4.2V. Stop charging when the current is ≤0.05C and let it stand until the battery surface temperature is ≤27℃.

[0040] SS3: Repeat the charge and discharge cycles of SS1 to SS2 500 times, and perform a SOH (battery capacity, health, and performance status) check every 100 times.

[0041] Figure 4 This is the comparative data of the bolt torque change between the comparative example and the present embodiment. The difference between the comparative example and the present embodiment is that ordinary bolts and nuts are used, among which 1#, 2#, and 3# are connected using the first embodiment, and 4#, 5#, and 6# are comparative examples.

[0042] Therefore, the present invention has the following beneficial effects:

[0043] By limiting the valve against the ratchet, the ratchet can only rotate in the direction in which the nut is tightened on the bolt, so that the nut and the fixing assembly are relatively fixed, and the bolt 1 and the fixing assembly are relatively fixed through the cooperation of the anti-rotation protrusion on the screw and the anti-rotation groove of the fixing assembly. Therefore, it can be ensured that during long-term charge and discharge tests, the pressure of the bolt and nut on the current and voltage collection terminal and the tab is maintained near the initial pressure, preventing the increase of contact internal resistance and reducing the impact on the test results; the setting of the annular groove can increase the pressing force of the bolt head on the contact surface of the current and voltage collection terminal or the tab; the setting of the small deformation hole can play a role in heat dissipation and accommodating expansion without reducing the contact area between the current and voltage collection terminal and the flange plate of the flange bolt.

Claims

1. A tab connector for battery testing, comprising a bolt and a ratchet nut, characterized in that: A fixing assembly is provided between the ratchet nut and the bolt, the upper part of the ratchet nut is a rotating part, and the lower part is a ratchet. A limiting valve is provided on the side of the fixing assembly near the nut to prevent the ratchet from being loosened, a current and voltage collection terminal and a pole ear are provided between the head of the bolt and the fixing assembly, the fixing assembly is provided with a bolt hole, the screw rod of the bolt is provided with an anti-rotation protrusion near the head, and an anti-rotation groove is provided at the corresponding position of the bolt hole, the current and voltage collection terminal and the pole ear are provided with a through hole that can be passed by the screw rod of the bolt; the bolt is a flange bolt; the fixing assembly is recessed downward to form an accommodating portion that can accommodate the ratchet nut, and the accommodating portion is provided with a cover plate above the limiting valve.

2. The tab connector for battery testing according to claim 1, wherein: The restricting valve is rotatably disposed in the accommodation portion.

3. The tab connector for battery testing according to claim 2, wherein: The limiting valve comprises a rotating shaft fixed on the bottom surface of the accommodating portion, a limiting strip with a middle portion sleeved on the rotating shaft, and a spring connecting the limiting strip and the side wall of the accommodating portion.

4. The tab connector for battery testing according to claim 3, characterized in that: One end of the limiting bar abuts against the ratchet teeth of the ratchet wheel, and the other end is provided with a smooth manual part, and the distance between the manual part and the rotating shaft is greater than the distance between the rotating shaft and the position where the limiting bar abuts against the ratchet teeth.

5. The tab connector for battery testing according to claim 1, 2, 3 or 4, characterized in that: The flange surface of the flange bolt is provided with an annular groove.

6. The tab connector for battery testing according to claim 5, characterized in that: The current and voltage collection terminal is connected to the flange when connected, and a small deformation hole corresponding to the position of the annular groove is provided on the side of the current and voltage collection terminal facing the flange bolt.

7. A connection method using the tab connector for battery testing according to any one of claims 1 to 6, comprising: S1: The screw of the flange bolt passes through the lug with screw holes, the current and voltage collection terminal, and the fixing component in sequence, and the anti-rotation protrusion is installed into the anti-rotation groove; S2: The current and voltage acquisition terminals are connected to the charging and discharging equipment; S3: Use a torque wrench to rotate the upper part of the ratchet gear nut clockwise. At this time, the ratchet of the ratchet gear nut rotates and turns the limiting valve; S4: When the torque displayed by the torque wrench reaches the specified value, stop rotating the ratchet gear nut. At this time, the limiting valve presses against the ratchet to fix it.

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