A testing device and method for the sealing force of a metal shell cover button battery

Abstract

The present invention provides a device and method for testing the sealing force of a metal case cover button battery. The device is applied to the battery case of the metal case cover button battery to be tested. The sealing force testing device includes two inner nuts, two screw rods and two limit members. The two inner nuts are stacked along the axial direction inside the battery case; on the outer edges of the positive and negative electrodes of the battery case, a screw rod is respectively provided corresponding to the axial direction of the case. Through holes for only the screw rods to pass through are respectively opened at the center positions of the bottoms of the positive electrode metal case cover and the negative electrode metal case cover. The screw rod located at the positive electrode passes through the through hole on the positive electrode metal case cover and is threadedly engaged with only the inner nut close to the positive electrode. The screw rod located at the negative electrode passes through the through hole on the negative electrode metal case cover and is threadedly engaged with only the inner nut close to the negative electrode. And limit members are respectively provided at the outer ends of the two screw rods. The two limit members are connected to a tensile force measuring device, and an outward reverse tensile force is applied to the two limit members through the tensile force measuring device.

Description

Technical Field

[0001] The present invention relates to the field of battery testing devices, and in particular to a device and method for testing the sealing force of a metal shell and button-type battery. Background Art

[0002] The battery safety testing standards GB / T 31241, UL1642, and IEC62133 stipulate that the thermal abuse test must be conducted at a rate of 5°C ± 2°C / min from room temperature to 130°C ± 2°C, then held constant for 30 minutes. The battery must not catch fire or explode. Furthermore, the heating and spraying tests in the UL1642 standard also require that the battery not catch fire or explode under specific heating conditions. However, since heating vaporizes the electrolyte within the battery, increasing internal pressure, the positive and negative electrode shells often pop open.

[0003] The incidence of the positive and negative shells of the battery popping open is generally determined by the sealing force of the battery. The Chinese patent with the authorization announcement number CN210221363U discloses a lithium battery shell sealing plate fitting force measurement device, but the device applies an external force on the outer bottom surface of the shell to move the sealing body, and measures the maximum external force value when the shell and the sealing plate are relatively displaced, which is the sealing force of the lithium battery. For metal shell button batteries, the opening edge of the positive shell and the opening edge of the negative shell are in conflict with each other. When an external force is applied on the outer bottom surface of either pole shell to move the other pole shell, it is impossible for the two to have relative displacement. Therefore, the device cannot detect the sealing force of metal shell button batteries.

[0004] For metal-cased button batteries, there's currently no method for quantitatively testing the sealing force. Consequently, the selection and design of the positive and negative electrode casings, as well as the sealing mold design, rely on empirical data, derived from safety testing of numerous battery batches. Furthermore, these empirical data must adapt to changes in the positive and negative electrode casings and sealing molds, severely impacting production efficiency and testing stability. This also hinders the innovative development and advancement of these materials. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a metal shell cover button type battery sealing force testing device. By testing the sealing force of the metal shell cover button type battery, the stability and production efficiency of the metal shell cover button type battery sealing force detection can be improved. At the same time, it can also provide a clear and quantifiable basis for the impact of changes in the positive and negative metal shell covers and sealing molds on the battery sealing force, thereby improving the efficiency of equipment process improvement and metal shell cover button type battery product development.

[0006] A metal shell button battery sealing force testing device is applied to the battery shell of the metal shell button battery to be tested. The battery shell is mainly composed of a positive metal shell cover, a negative metal shell cover and a sealing ring, which are packaged using the existing metal shell button battery packaging structure; the sealing force testing device includes two inner nuts, two screws and two limiters. The two inner nuts are located in the battery shell and are stacked along the axial direction. When working, the outer circumferences of the two inner nuts do not contact the inner circumference of the battery shell; the positive and negative A screw is respectively arranged along the axial direction of the outer pole of the shell, and a through hole for only the screw to pass through is respectively opened at the center position of the bottom circle of the positive metal shell cover and the negative metal shell cover. The screw at the positive pole passes through the through hole on the positive metal shell cover and cooperates with the internal nut thread only close to the positive pole. The screw at the negative pole passes through the through hole on the negative metal shell cover and cooperates with the internal nut thread only close to the negative pole. A limit piece is provided at the outer end of each screw, and the two limit pieces are connected to the tension metering device and the tension metering device applies an outward reverse pulling force to the two limit pieces.

[0007] The metal shell cover button battery sealing force testing device of the present invention can test the battery sealing force, which can improve the stability and production efficiency of the metal shell cover button battery sealing force detection. At the same time, it also provides a clear and quantifiable basis for the impact of changes in the positive and negative metal shell covers and sealing molds on the battery sealing force. The quality of the positive and negative metal shell covers and sealing molds can be judged by the size of the battery sealing force, which facilitates the rapid screening and optimization design of the positive and negative metal shell covers and sealing molds of the battery. Moreover, by only using the testing device of the present invention to detect the sealing force of the button battery, and based on whether the sealing force can meet the requirements, it can be predicted whether the metal shell cover button battery assembled using the battery shell structure meets the battery safety test standards specified in GB / T 31241, UL1642, and IEC62133, thereby avoiding waste. Therefore, the use of the present invention can greatly improve the efficiency of equipment process improvement and product development of metal shell cover button batteries.

[0008] Preferably, the tensile force measurement device is an electronic tensile testing machine. During operation, the battery housing is placed vertically, and the two stoppers are clamped in the upper and lower tensile gauge fixtures of the tensile testing machine. The electronic tensile testing machine is an existing device that generates a tensile force change curve based on the change in tensile force value, facilitating more intuitive and accurate observation of tensile force changes.

[0009] In a specific implementation process, the limiting member is a nut structure, or the limiting member and the corresponding screw rod are an integrally formed bolt structure.

[0010] Preferably, the sum of the axial thicknesses of the two inner nuts is slightly smaller than the axial height of the inner cavity of the battery housing to prevent the screw from axially moving and affecting the measurement.

[0011] Preferably, the outer diameter of the inner nut is slightly smaller than the inner diameter of the battery housing, which can ensure that there is no contact between the outer peripheral surface of the two inner nuts and the inner peripheral surface of the battery housing during the process of pulling the two tension measuring devices. At the same time, the battery housing plays a certain limiting role on the screw rod and the inner nut, avoiding the shaking of the screw rod and the inner nut, and is more conducive to the matching installation between the screw rod and the inner nut.

[0012] Preferably, the through hole is a threaded hole that can cooperate with the screw rod.

[0013] Preferably, the inner nut is made of A3 steel material nut, which has high hardness, will not slip the thread, and is more durable.

[0014] Preferably, a circular groove is provided on the surface of the inner nut that contacts the metal shell cover, and the center of the circular groove coincides with the central axis of the inner nut, which is beneficial to the uniform distribution of the tension. Further, the radial distance between the inner edge and the outer edge of the circular groove is 2-3 mm.

[0015] The second object of the present invention is to provide a method for testing the sealing force of a metal shell cover button cell, which is carried out by using the above-mentioned metal shell cover button cell sealing force testing device, and includes the following steps: first, prepare the positive metal shell cover and the negative metal shell cover of the metal shell cover button cell to be tested, and respectively open through holes only for the screw rod to pass through at the center of the bottom of the positive metal shell cover and the negative metal shell cover; then, coaxially embed an inner nut in the positive metal shell cover and the negative metal shell cover of the button cell respectively, and use the existing metal shell cover button cell packaging structure to package the positive metal shell cover, the negative metal shell cover and the sealing ring to form a button cell housing, and axially stack and package the two inner nuts in the battery housing; then, respectively set a screw rod on the axial outer edges of the positive and negative electrodes of the battery housing, the screw rod at the positive electrode passes through the through hole on the positive metal shell cover and is threadedly engaged with only the inner nut close to the positive electrode, the screw rod at the negative electrode passes through the through hole on the negative metal shell cover and is threadedly engaged with only the inner nut close to the negative electrode, and a limiting member is provided at the outer ends of the two screw rods, and there is no contact between the outer peripheral surfaces of the two inner nuts and the inner peripheral surface of the battery housing; finally, connect the two limiting members to the tension measuring device and apply an outward reverse tension to the two limiting members simultaneously through the tension measuring device, and the peak value of the tension displayed on the tension measuring device is the sealing force of the metal shell cover button cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an axial sectional view structure diagram of the battery housing of the present invention;

[0017] Figure 2This is a front view of the metal shell button battery sealing force testing device of the present invention, wherein the battery shell is an axial cross-sectional structure diagram, and the directions indicated by the arrows are the respective tensile directions of the two tensile force measuring devices. DETAILED DESCRIPTION

[0018] The embodiments of the present invention are described in detail with reference to the accompanying drawings:

[0019] Take the 1254 metal shell button battery as an example, combined with Figure 1 and Figure 2 The sealing force testing device is applied to the battery shell of the metal shell button battery to be tested. The battery shell is mainly composed of a positive metal shell cover 1, a negative metal shell cover 2 and a sealing ring 3, which are packaged using the existing metal shell button battery packaging structure; the sealing force testing device includes two inner nuts 4, two screws 5 and two limiters 6. The two inner nuts 4 are located in the battery shell and are stacked along the axial direction thereof. When working, the outer circumference 40 of the two inner nuts 4 does not contact the inner circumference 20 of the battery shell; the positive and negative outer surfaces of the battery shell are respectively arranged along the axial direction of the shell. A screw rod 5 is provided, and a through hole (11, 21) for only the screw rod 5 to pass through is respectively opened at the center position of the bottom circle of the positive metal shell cover 1 and the negative metal shell cover 2. The screw rod 5 located at the positive electrode passes through the through hole 11 on the positive metal shell cover 1 and is threadedly engaged with, and only with, the internal nut 4 close to the positive electrode. The screw rod 5 located at the negative electrode passes through the through hole 21 on the negative metal shell cover 2 and is threadedly engaged with, and only with the internal nut 4 close to the negative electrode. A limit piece 6 is provided at the outer end of each of the two screw rods 5. The two limit pieces 6 are connected to a tension metering device 7, and an outward reverse tension is applied to the two limit pieces 6 by the tension metering device 7.

[0020] When measuring the battery sealing force, the tension metering device 7 applies an outward reverse tension to the two limit members 6 at the same time, and gradually increases the tension until the tension on the tension metering device 7 reaches a maximum peak value. The maximum peak value of the tension is the critical value of the tension that can cause the positive and negative metal shell covers (1, 2) to move relative to each other, and the sealing force of the metal shell cover button type battery is obtained.

[0021] When the test device of the present invention is working, the outer peripheral surfaces 40 of the two inner nuts 4 do not contact the inner peripheral surface 10 of the battery case, so as to avoid friction between the inner nut and the battery case, and the existence of frictional force causes the test data of the battery sealing force to be distorted. Since the test device for the sealing force of the metal shell cover button cell of the present invention can test the sealing force of the battery, it can improve the stability and production efficiency of the detection of the sealing force of the metal shell cover button cell. At the same time, it also provides a clear and quantifiable basis for the influence of the changes of the positive and negative metal shell covers (1, 2) and the sealing die on the battery sealing force. By judging the size of the battery sealing force, the advantages and disadvantages of the positive and negative metal shell covers (1, 2) and the sealing die can be judged, which is convenient for quickly screening and optimizing the design of the positive and negative metal shell covers (1, 2) and the sealing die of the battery. Moreover, only by using the test device of the present invention to detect the sealing force of the snap-down battery and judging whether the sealing force can meet the requirements, it can be predicted whether the metal shell cover button cell assembled with this battery case structure can meet the battery safety test standards specified in GB / T 31241, UL1642, and IEC62133, so as to avoid waste. Therefore, the use of the present invention can greatly improve the efficiency of the equipment process improvement and product development of the metal shell cover button cell.

[0022] The method for testing the sealing force of the 1254 model metal shell cover button cell includes the following steps: First, prepare the positive metal shell cover 1 and the negative metal shell cover 2 of the metal shell cover button cell to be tested, and respectively open through holes (11, 21) only for the screw 5 to pass through at the center positions of the bottoms of the positive metal shell cover 1 and the negative metal shell cover 2; then, coaxially embed an inner nut 4 in each of the positive metal shell cover 1 and the negative metal shell cover 2 of the button cell, and use the existing metal shell cover button cell packaging structure to package the positive metal shell cover 1, the negative metal shell cover 2 and the sealing ring 3 to form a button cell case, and axially stack and package the two inner nuts 4 in the battery case; then, respectively set a screw 5 on the axial outer edges of the positive and negative poles of the battery case. The screw 5 at the positive pole passes through the through hole 11 on the positive metal shell cover 1 and is threadedly engaged with and only with the inner nut 4 close to the positive pole. The screw 5 at the negative pole passes through the through hole 21 on the negative metal shell cover 2 and is threadedly engaged with and only with the inner nut 4 close to the negative pole, and a limiting member 6 is provided at the outer ends of both screws 5, and the outer peripheral surfaces 40 of the two inner nuts 4 do not contact the inner peripheral surface 10 of the battery case; finally, connect the two limiting members 6 to the tensile force measuring device 7 and apply an outward reverse tensile force to the two limiting members 6 simultaneously through the tensile force measuring device 7, and the peak tensile force displayed on the tensile force measuring device 7 is the sealing force of the metal shell cover button cell.

[0023] Preferably, as Figure 2As shown, the tensile force measuring device 7 is an electronic tensile testing machine. During operation, the battery housing is placed vertically, and the two limit members 6 are respectively clamped in the upper and lower tensile gauge clamps (71, 72) of the tensile testing machine. The electronic tensile testing machine is an existing device, which forms a tensile force change curve according to the change of the tensile force value, facilitating a more intuitive and accurate observation of the tensile force change.

[0024] In the specific implementation process, the limit member 6 is a nut structure, or the limit member 6 and the corresponding screw 5 together form an integrally molded bolt structure.

[0025] Preferably, as Figure 1 、 Figure 2 shown, the sum of the axial thicknesses of the two inner nuts 4 is slightly less than the axial height of the inner cavity of the battery housing, avoiding axial movement of the screw 5 and affecting the measurement.

[0026] Preferably, as Figure 1 shown, the outer diameter of the inner nut 4 is slightly less than the inner diameter of the battery housing, which can ensure that there is no contact between the outer peripheral surface of the two inner nuts 4 and the inner peripheral surface of the battery housing during the process of pulling the two tensile force measuring devices. At the same time, the battery housing plays a certain limiting role on the screw 5 and the inner nut 4, avoiding shaking of the screw 5 and the inner nut 4, and being more conducive to the matching installation between the screw 5 and the inner nut 4.

[0027] Preferably, the through holes (11, 21) are threaded holes that can cooperate with the screw 5.

[0028] Preferably, the inner nut 4 is a nut made of A3 steel, which has high hardness, will not slip, and is more durable.

[0029] Preferably, as Figure 1 shown, a circular groove 41 is provided on the surface of the inner nut 4 that contacts the metal shell covers (1, 2). The center of the circular groove 41 coincides with the central axis of the inner nut 4, which is beneficial to the uniform distribution of the tensile force. Further, as Figure 1 shown, the radial distance L between the inner edge and the outer edge of the circular groove 41 is 2 - 3 mm.

[0030] Of course, the metal shell cover button cell sealing force testing device and method of the present invention are not only applicable to the 1254 model metal shell cover button cell, but also applicable to all models of metal shell cover button cells.

Claims

1. A metal shell button battery sealing force tester, characterized by: The invention is applied to the battery shell of the metal shell button battery to be tested, wherein the battery shell is mainly composed of the positive metal shell cover, the negative metal shell cover and the sealing ring, which are packaged in the existing metal shell button battery packaging structure; the sealing force testing device comprises two inner nuts, two screws and two limiters, wherein the two inner nuts are arranged in an axial direction in the battery shell and stacked together. When working, the outer circumferences of the two inner nuts do not contact the inner circumference of the battery shell; the outer circumferences of the positive and negative electrodes of the battery shell are respectively arranged along the axial direction of the shell. A corresponding screw is set, and a through hole for only the screw to pass through is opened at the center position of the bottom circle of the positive metal shell cover and the negative metal shell cover respectively. The screw located at the positive pole passes through the through hole on the positive metal shell cover and cooperates with the internal nut thread close to the positive pole, and the screw located at the negative pole passes through the through hole on the negative metal shell cover and cooperates with the internal nut thread close to the negative pole, and a limit piece is provided at the outer end of each screw. The two limit pieces are connected to the tension metering device and the tension metering device applies an outward reverse pulling force to the two limit pieces.

2. The metal shell button type battery sealing force testing device according to claim 1, characterized in that: A circular groove is provided on the surface of the inner nut that contacts the metal shell cover, and the center of the circular groove coincides with the central axis of the inner nut.

3. The metal shell button type battery sealing force testing device according to claim 2, characterized in that: The radial distance between the inner edge of the circular groove and the outer edge of the inner nut is 2 to 3 mm.

4. The metal shell and button type battery sealing force testing device according to claim 1, characterized in that: The tensile force measuring device adopts an electronic tensile testing machine. When working, the battery shell is placed vertically, and the two limit members are clamped in the upper and lower tensile gauge fixtures of the tensile testing machine respectively.

5. The metal shell button type battery sealing force testing device according to claim 1, characterized in that: The limiting member is a nut structure.

6. The metal shell button type battery sealing force testing device according to claim 1, characterized in that: The limiting member and the corresponding screw rod form an integrally formed bolt structure.

7. The metal shell and button type battery sealing force testing device according to claim 1, characterized in that: The sum of the axial thicknesses of the two inner nuts is equal to the axial height of the inner cavity of the battery shell.

8. The metal shell and button type battery sealing force testing device according to claim 1, characterized in that: The outer diameter of the inner nut is slightly smaller than the inner diameter of the battery casing.

9. The metal shell and button type battery sealing force testing device according to claim 1, characterized in that: The through hole is a threaded hole capable of cooperating with a screw rod.

10. A method for testing the sealing force of a metal shell and button-type battery, using the metal shell and button-type battery sealing force testing device according to any one of claims 1 to 9, comprising the following steps: First, prepare the positive metal shell cover and negative metal shell cover of the metal shell cover button battery to be tested, and open a through hole for the screw to pass through at the center position of the bottom circle of the positive metal shell cover and the negative metal shell cover respectively; then, coaxially embed an inner nut in the positive metal shell cover and the negative metal shell cover of the button battery respectively, and use the existing metal shell cover button battery packaging structure to package the positive metal shell cover, the negative metal shell cover and the sealing ring to form a button battery shell, and axially stack the two inner nuts and package them in the battery shell; then, set the positive and negative poles of the battery shell along the axial direction of the shell respectively. A screw, the screw located at the positive electrode passes through the through hole on the positive electrode metal shell cover and cooperates with the internal nut thread close to the positive electrode, and the screw located at the negative electrode passes through the through hole on the negative electrode metal shell cover and cooperates with the internal nut thread close to the negative electrode, and the outer ends of the two screws are equipped with a limit piece, and the outer circumferences of the two internal nuts do not contact the inner circumference of the battery shell; finally, the two limit pieces are connected to a tension metering device and the tension metering device is used to simultaneously apply an outward reverse tension to the two limit pieces. The tension peak value displayed on the tension metering device is the sealing force of the metal shell cover button battery.

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