A drop test device applicable to small battery packs and its test method

Abstract

The present invention discloses a drop test device applicable to a small battery pack and a test method thereof. The drop test device includes a test platform, a support frame fixedly mounted on the test platform at the bottom, a suspension mechanism mounted on the support frame, a drop mechanism, and a connecting rope. The drop mechanism is connected to the lifting end of the suspension mechanism through the connecting rope. The drop test device of the present invention has a simple structure and convenient test operation, can stably clamp a small battery pack, and can meet different requirements for drop tests on the bottom plane, edges or corners of the small battery pack.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery testing, and specifically to a drop test device and a test method applicable to small battery packs. Background Art

[0002] In modern society, with the development of the economy, the global environment has inevitably been affected. In recent years, the concept of sustainable development has become more and more deeply rooted in people's hearts, and the concept of environmental protection has also been accepted by everyone. In order to implement sustainable development and environmental protection, more and more new technologies have been proposed and developed. Among them, the new energy industry has developed rapidly in recent years. In the new energy industry, the battery is a device for energy storage and release, and its safety and reliability have attracted people's attention. Therefore, in the process of battery design and manufacturing, various aspects of safety and reliability testing of the battery are essential and one of the most important links. In the battery testing link, the battery is subjected to a drop test to test the anti-drop ability of the battery pack.

[0003] Some invention patents in the field of battery technology are disclosed in the prior art. Among them, the invention patent with the application number CN113670553A discloses a battery drop test machine, belonging to the technical field of battery detection. It includes a drop test machine body. An impact plate is provided at the bottom end of the drop test machine body. A mounting plate is fixed to the end face of the impact plate facing the drop test machine body. A mounting groove for inserting the mounting plate is opened at the bottom end of the drop test machine body; between the impact plate and the drop test machine body, there are several groups of connecting mechanisms (4) for fixing the mounting plate in the mounting groove; a protective frame is provided on the upper surface of the impact plate. Several mutually parallel sliding grooves are opened on the upper surface of the impact plate. Several sliders are fixed to the lower end face of the protective frame. The sliders slide in the sliding grooves. Between the impact plate and the protective frame, there are several groups of fixing mechanisms for fixing the sliders in the sliding grooves. This application has the effect of improving the accuracy of test data.

[0004] However, during the existing drop test, except that the flat drop test of the battery bottom is relatively simple, when performing a targeted drop test on the bottom edge or corner of the battery pack, because the fixing devices such as jigs are relatively simple, the operation difficulty is relatively high, the proficiency requirements for the test personnel are relatively high, and the labor intensity is relatively large, resulting in a relatively long time for a single drop, it is difficult to perform multiple repeated tests, and at the same time, the interval time between two adjacent drops is relatively long and not fixed, leading to a decrease in the accuracy of test data. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a drop test device and a test method applicable to small battery packs, which have a simple structure, convenient test operation, can realize stable clamping of small battery packs, and can meet the different requirements of flat drop test, edge drop test or corner drop test on the bottom of small battery packs.

[0006] The technical solution of the present invention is as follows:

[0007] A drop test device applicable to a small battery pack, comprising a test platform, a support frame fixedly mounted at the bottom on the test platform, a suspension mechanism mounted on the support frame, a drop mechanism, and a connecting rope. The drop mechanism is connected to the lifting end of the suspension mechanism through the connecting rope.

[0008] The drop mechanism includes a cross-shaped fixing plate, a clamping mechanism, two groups of opening and closing rods, and four tightening mechanisms. The clamping mechanism is connected to the vertical portion of the cross-shaped fixing plate. The two groups of opening and closing rods are both horizontally arranged. The hinged ends of the two groups of opening and closing rods are slidably connected to the horizontal portion of the cross-shaped fixing plate and are respectively located on both sides of the vertical portion of the cross-shaped fixing plate. Corresponding lifting lugs and tightening mechanisms are connected to the four movable ends of the two groups of opening and closing rods. The lifting lugs on the drop mechanism are connected to the suspension mechanism through the connecting rope; the four tightening mechanisms each include a vertically arranged rotating shaft and an L-shaped tightening clamp plate. The top end of the L-shaped tightening clamp plate is fixedly connected to the bottom end of the rotating shaft. The rotating shafts of every two tightening mechanisms are rotatably connected to the two movable ends of a corresponding group of opening and closing rods. The L-shaped tightening clamp plates of every two tightening mechanisms are located directly below the two movable ends of a corresponding group of opening and closing rods.

[0009] A middle positioning through hole and two end positioning through holes are formed between the two side walls on the vertical portion of the cross-shaped fixing plate and connected to the horizontal portion of the cross-shaped fixing plate. The middle positioning through hole is located in the middle of the vertical portion of the cross-shaped fixing plate, and the two end positioning through holes are respectively located at the two end portions of the vertical portion of the cross-shaped fixing plate; the clamping mechanism includes two L-shaped clamp plates. The lengths of the two L-shaped clamp plates are the same as the length of the vertical portion of the cross-shaped fixing plate. Horizontally arranged middle positioning guide plates and two end positioning guide plates are fixedly mounted on the inner walls near the top of the vertical portions of the two L-shaped clamp plates. The middle positioning guide plate is located in the middle of the vertical portion of the L-shaped clamp plate, and the two end positioning guide plates are respectively located at the two end portions of the vertical portion of the L-shaped clamp plate; when the two L-shaped clamp plates are connected to the vertical portion of the cross-shaped fixing plate, the two middle positioning guide plates on the two L-shaped clamp plates respectively penetrate into the middle positioning through hole from both ends of the middle positioning through hole of the cross-shaped fixing plate, and the two end positioning guide plates at the same phase end on the two L-shaped clamp plates respectively penetrate into the corresponding middle positioning through hole from both ends of the corresponding end positioning through hole; when the ends of the horizontal portions of the two L-shaped clamp plates are completely in contact and closed, the vertical portion of the cross-shaped fixing plate and the two L-shaped clamp plates form a rectangular ring closed structure.

[0010] On the vertical part of the cross-shaped fixing plate and at both ends, there are bolt holes that penetrate vertically up and down. The two bolt holes respectively penetrate through the two end positioning perforations. Locking bolts are threadedly connected to both bolt holes. On the two end positioning guide plates of each L-shaped clamping plate, there are semi-circular notches. When the ends of the horizontal parts of the two L-shaped clamping plates are completely in contact and closed, the two opposite semi-circular notches on the two L-shaped clamping plates form a circular perforation. The locking bolts sequentially pass through the upper part of the bolt hole, the circular perforation, and the lower part of the bolt hole, thereby closing and locking the two L-shaped clamping plates on the vertical part of the cross-shaped fixing plate.

[0011] On the two horizontal parts of the cross-shaped fixing plate on both sides of its vertical part, there are guide grooves. Limit blocks are slidably arranged in the guide grooves. The hinge shafts of the hinge ends of each group of opening and closing rods are fixed to a corresponding limit block, so that each group of opening and closing rods slides along the corresponding guide groove and is locked and positioned.

[0012] On the two horizontal parts of the cross-shaped fixing plate, there are guide holes. The guide holes penetrate through the bottom of the guide groove. The axis of the guide hole is parallel to the axis of the guide groove. The guide hole is composed of a row of interconnected limit holes. The width of each limit hole is greater than the width of the connecting hole between adjacent limit holes. The screw rod of the locking bolt is threadedly connected to the limit block and passes downward through a corresponding limit hole. The minimum diameter of the screw rod of the locking bolt is greater than the width of the connecting hole between adjacent limit holes, so that the locking bolt is locked and positioned in a limit hole.

[0013] The support frame is a support frame with an inverted U-shaped structure. The two bottom ends of the support frame are fixed on the test platform; the suspension mechanism includes a lifting linear module, a movable pulley, a fixed pulley, and a suspension belt. The lifting linear module is fixed on one of the vertical parts of the support frame. The movable pulley and the fixed pulley are both vertically arranged and the axles of both are perpendicular to the axis of the horizontal part at the top of the support frame. The movable pulley is fixed on the lifting slider of the lifting linear module. The fixed pulley is fixed on the horizontal part at the top of the support frame. The fixed end of the suspension belt is fixed on the horizontal part of the support frame. The lifting end of the suspension belt sequentially passes through the movable pulley and the fixed pulley and then extends vertically downward. The lifting lug on the dropping mechanism is connected to the lifting end of the suspension belt through a connecting rope.

[0014] The suspension mechanism further includes an electric telescopic rod and a suspension locking block. The fixed end of the electric telescopic rod is fixed on the horizontal part of the support frame. The telescopic end of the electric telescopic rod faces the suspension belt on the fixed pulley. The suspension locking block is fixed on the telescopic end of the electric telescopic rod.

[0015] The connecting rope described above consists of a middle sling, two suspension ropes, and two end hooks. Each end hook is fixedly connected to the middle sling through a corresponding suspension rope. A middle hook is provided on the descending end of the suspension mechanism extending vertically downward. The middle sling of the connecting rope is connected to the middle hook of the suspension mechanism, and the two end hooks of the connecting rope are respectively connected to two lugs.

[0016] A drop test method applicable to small battery packs specifically includes the following steps:

[0017] (1) Place the small battery pack to be subjected to the drop test on the test platform and directly below the descending end of the suspension mechanism. Then move the drop mechanism in the open state to directly above the top grip of the small battery pack. The drop mechanism moves downward until the top grip of the small battery pack is located within the clamping mechanism. Then operate the clamping mechanism to close, thereby clamping and fixing the grip of the small battery pack.

[0018] (2) Slide the two sets of opening and closing rods relative to the horizontal part of the cross-shaped fixing plate. Then adjust the distance between the two movable ends of each set of opening and closing rods. Finally, rotate and adjust the four tightening mechanisms until the L-shaped clamping plates of the four tightening mechanisms respectively clamp the four corners at the top of the small battery pack. Finally, lock and position the hinged ends of the two sets of opening and closing rods, that is, complete the clamping connection of the small battery pack.

[0019] (3) Before conducting the drop test on the bottom plane of the small battery pack, lower the descending end of the suspension mechanism extending vertically downward. Then connect the lugs on the four movable ends of the two sets of opening and closing rods to the descending end of the suspension mechanism through connecting ropes. Then raise the descending end of the suspension mechanism, that is, vertically lift the small battery pack. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly to achieve the drop test of the bottom plane of the small battery pack.

[0020] (4) Before conducting the drop test on any edge at the bottom of the small battery pack, connect two of the lugs to the descending end of the suspension mechanism through a connecting rope, so that the small battery pack is in an inclined state, and the edge of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly to achieve the drop test of any edge at the bottom of the small battery pack.

[0021] (5) Before conducting the drop test on any corner at the bottom of the small battery pack, directly connect one of the lugs to the descending end of the suspension mechanism, so that the small battery pack is in an inclined state, and the corner of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly to achieve the drop test of any corner at the bottom of the small battery pack. A drop test method applicable to small battery packs specifically includes the following steps:

[0022] (1) Place the small battery pack to be subjected to the drop test on the test platform and directly below the lifting end of the suspension mechanism. Then, move the drop mechanism in the open state to directly above the grip at the top of the small battery pack. Lower the drop mechanism until the grip at the top of the small battery pack is located within the clamping mechanism, and then control the clamping mechanism to close, thereby clamping and fixing the grip of the small battery pack.

[0023] (2) Slide the two sets of opening and closing rods relative to the horizontal part of the cross-shaped fixing plate, then adjust the distance between the two movable ends of each set of opening and closing rods. Finally, rotate and adjust the four tightening mechanisms until the L-shaped clamping plates of the four tightening mechanisms respectively clamp the four corners at the top of the small battery pack. Finally, lock and position the hinged ends of the two sets of opening and closing rods, that is, complete the clamping connection of the small battery pack.

[0024] (3) Before performing the drop test on the bottom plane of the small battery pack, lower the lifting end of the suspension mechanism that extends vertically downward. Then, connect the lugs on the four movable ends of the two sets of opening and closing rods to the lifting end of the suspension mechanism through connecting ropes. Then, raise the lifting end of the suspension mechanism, that is, vertically lift the small battery pack. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly, realizing the drop test of the bottom plane of the small battery pack.

[0025] (4) Before performing the drop test on any edge at the bottom of the small battery pack, connect two of the lugs to the lifting end of the suspension mechanism through connecting ropes, so that the small battery pack is in an inclined state, and the edge of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly, realizing the drop test of any edge at the bottom of the small battery pack.

[0026] (5) Before performing the drop test on any corner at the bottom of the small battery pack, directly connect one of the lugs to the lifting end of the suspension mechanism, so that the small battery pack is in an inclined state, and the corner of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the drop mechanism to move downward rapidly, realizing the drop test of any corner at the bottom of the small battery pack.

[0027] Advantages of the present invention:

[0028] (1) The clamping mechanism of the drop mechanism of the present invention can clamp and fix the grip at the top of the small battery pack, avoiding the problem of the small battery pack falling during the test. Furthermore, the four tightening mechanisms are used to further clamp and fix the four corners at the top of the small battery pack. Through the connection method of connecting the lugs on the connecting telescopic and drop mechanisms, different requirements for the drop test of the bottom plane, edge or corner of the small battery pack are realized. The operation is simple and convenient, omitting the repetitive, cumbersome and difficult clamping operations, and the drop interval is controllable, making the test data more credible and reliable.

[0029] (2) The suspension mechanism provided by the present invention eliminates the need for operators to manually pull the suspension strap to lift the small battery pack for drop testing, reducing the labor intensity of the operators. It also avoids the problem of inconsistent lifting heights caused by physical exhaustion during multiple drop tests by operators. At the same time, when releasing the suspension strap, the released suspension strap is in a relaxed state, avoiding the influence caused by the frictional force generated when the suspension strap contacts the operator's hand during manual release, thereby improving the accuracy and precision of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of the drop testing device of the present invention.

[0031] Figure 2 is a schematic structural diagram of the suspension mechanism of the present invention.

[0032] Figure 3 is a schematic structural diagram of the drop mechanism in the open state of the present invention.

[0033] Figure 4 is Figure 3 the enlarged view of part A in

[0034] Figure 5 is Figure 3 the enlarged view of part B in

[0035] Figure 6 is a partial schematic structural diagram of the opening and closing rod connected to the cross-shaped fixing plate of the present invention.

[0036] Figure 7 is a schematic structural diagram of the connecting rope of the present invention.

[0037] Reference numerals: 1 - test platform, 2 - support frame, 3 - suspension mechanism, 4 - drop mechanism, 5 - connecting rope, 31 - lifting linear module, 32 - movable pulley, 33 - fixed pulley, 34 - suspension strap, 35 - middle hook, 36 - electric telescopic rod, 37 - suspension locking block, 41 - cross-shaped fixing plate, 42 - L-shaped clamping plate, 43 - opening and closing rod, 44 - lifting lug, 45 - rotating shaft, 46 - L-shaped tightening clamping plate, 411 - middle positioning perforation, 412 - end positioning perforation, 413 - bolt hole, 414 - locking bolt, 415 - guide groove, 416 - limiting block 416, 417 - guide hole, 418 - locking bolt, 421 - middle positioning guide plate, 422 - end positioning guide plate, 423 - semi-circular notch, 51 - middle hanging ring, 52 - suspension rope, 53 - end hook. DETAILED DESCRIPTION OF THE INVENTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] See Figure 1 , a drop test device applicable to a small battery pack, comprising a test platform 1, a support frame 2 fixed at the bottom on the test platform 1 and having an inverted U-shaped structure, a suspension mechanism 3 installed on the support frame 2, a drop mechanism 4 connected to the suspension mechanism 3, and a connecting rope 5;

[0040] See Figure 2 , the suspension mechanism 3 comprises a lifting linear module 31, a movable pulley 32, a fixed pulley 33, a suspension belt 34, a middle hook 35, an electric telescopic rod 36 and a suspension locking block 37. The lifting linear module 3 is fixed on the vertical part on the left side of the support frame 2. The movable pulley 32 and the fixed pulley 33 are both vertically arranged and the wheel axles of both are perpendicular to the axis of the horizontal part at the top of the support frame 2. The movable pulley 32 is fixed on the lifting slider of the lifting linear module 31. The fixed pulley 33 is fixed at the middle of the horizontal part at the top of the support frame 2. The fixed end of the suspension belt 34 is fixed at the left end of the horizontal part of the support frame. The lifting end of the suspension belt 34 extends vertically downward after passing through the movable pulley 32 and the fixed pulley 33 in sequence. A middle hook 35 is fixed on the lifting end of the suspension belt 34. The fixed end of the electric telescopic rod 36 is fixed on the horizontal part of the support frame 2. The telescopic end of the electric telescopic rod 36 faces the suspension belt 34 on the fixed pulley 33. The suspension locking block 37 is fixed on the telescopic end of the electric telescopic rod 36;

[0041] See Figures 3 - 5, the dropping mechanism 4 includes a cross-shaped fixing plate 41, a clamping mechanism, two sets of opening and closing rods 43 and four tightening mechanisms. A middle positioning through hole 411 and two end positioning through holes 412 are formed between the two side walls on the vertical part of the cross-shaped fixing plate 41 and connected to the horizontal part of the cross-shaped fixing plate 41. The middle positioning through hole 411 is located in the middle of the vertical part of the cross-shaped fixing plate 41, and the two end positioning through holes 412 are respectively located at both ends of the vertical part of the cross-shaped fixing plate 41; the clamping mechanism includes two L-shaped clamping plates 42. The lengths of the two L-shaped clamping plates 41 are the same as the length of the vertical part of the cross-shaped fixing plate 41. Horizontally arranged middle positioning guide plates 421 and two end positioning guide plates 422 are fixed on the inner walls near the top of the vertical parts of the two L-shaped clamping plates 42. The middle positioning guide plate 421 is located in the middle of the vertical part of the L-shaped clamping plate 42, and the two end positioning guide plates 422 are respectively located at both ends of the vertical part of the L-shaped clamping plate 42; when the two L-shaped clamping plates 42 are connected to the vertical part of the cross-shaped fixing plate 41, the two middle positioning guide plates 421 on the two L-shaped clamping plates 42 respectively penetrate into the middle positioning through hole 411 from both ends of the middle positioning through hole 411 of the cross-shaped fixing plate, and the two end positioning guide plates 422 at the same phase end on the two L-shaped clamping plates 42 respectively penetrate into the corresponding middle positioning through hole 412 from both ends of the corresponding end positioning through hole 412; when the ends of the horizontal parts of the two L-shaped clamping plates 42 are completely in contact and closed, the vertical part of the cross-shaped fixing plate 41 and the two L-shaped clamping plates 42 form a rectangular ring closed structure; bolt holes 413 that penetrate up and down are provided at both ends on the vertical part of the cross-shaped fixing plate 41. The two bolt holes 413 respectively penetrate the two end positioning through holes 412. Locking bolts 414 are threadedly connected to the two bolt holes 413. Semi-circular notches 423 are provided on the two end positioning guide plates 422 of each L-shaped clamping plate 42. When the ends of the horizontal parts of the two L-shaped clamping plates 42 are completely in contact and closed, the two opposite semi-circular notches 423 on the two L-shaped clamping plates form a circular through hole. The locking bolts 414 sequentially pass through the upper part of the bolt hole 413, the circular through hole and the lower part of the bolt hole 413, so as to close and lock the two L-shaped clamping plates 42 on the vertical part of the cross-shaped fixing plate 41;

[0042] See Figure 6, the two sets of opening and closing rods 43 are both horizontally arranged. Guide grooves 415 are provided on both horizontal parts of the cruciform fixing plate 41 on both sides of its vertical part. Limit blocks 416 are slidably arranged in the guide grooves 415. The hinge shafts at the hinge ends of each set of opening and closing rods 43 are fixed to a corresponding limit block 416, so that each set of opening and closing rods 43 slides along the corresponding guide groove 415. Guide holes 417 are provided on both horizontal parts of the cruciform fixing plate 41. The guide holes 417 penetrate the bottom of the guide grooves 415. The axis of the guide holes 417 is parallel to the axis of the guide grooves 415. The guide holes 417 are composed of a row of interconnected limit holes. The width of each limit hole is greater than the width of the communication hole between adjacent limit holes. The screw of the locking bolt 418 is threadedly connected to the limit block 416 and passes downward through a corresponding limit hole. The minimum diameter of the screw of the locking bolt 418 is greater than the width of the communication hole between adjacent limit holes, so that the locking bolt 418 is locked and positioned in a limit hole;

[0043] See Figure 3 and Figure 6 , lifting lugs 44 are connected to the four movable ends of the two sets of opening and closing rods 43. The lifting lugs 44 on the dropping mechanism are connected to the middle hook 35 of the suspension mechanism through the connecting rope 5; Each tightening mechanism includes a vertically arranged rotating shaft 45 and an L-shaped tightening clamp 46. The top end of the L-shaped tightening clamp 46 is fixedly connected to the bottom end of the rotating shaft 45. The rotating shafts 45 of every two tightening mechanisms are rotatably connected to the two movable ends of a corresponding set of opening and closing rods 43. The L-shaped tightening clamps 46 of every two tightening mechanisms are located directly below the two movable ends of a corresponding set of opening and closing rods 43;

[0044] See Figure 7 , the connecting rope 5 includes a middle sling 51, two suspension ropes 52 and two end hooks 53. Each end hook 53 is fixedly connected to the middle sling 51 through a corresponding suspension rope 52. The middle sling 51 of the connecting rope is connected to the middle hook 35 of the suspension mechanism. The two end hooks 53 of the connecting rope are respectively connected to the two lifting lugs 44.

[0045] A dropping test method applicable to a small battery pack specifically includes the following steps:

[0046] (1). Place the small battery pack to be subjected to the dropping test on the test platform 1 and directly below the lifting end of the suspension mechanism 3. Then move the dropping mechanism in the open state to directly above the grip at the top of the small battery pack. The dropping mechanism moves downward until the grip at the top of the small battery pack is located between the vertical parts of the two L-shaped clamping plates 42 of the clamping mechanism. Then the two L-shaped clamping plates 42 move relative to each other until the ends of the horizontal parts of the two L-shaped clamping plates 42 are in full contact and closed. At this time, the grip at the top of the small battery pack is limited within the rectangular ring closing structure, thereby clamping and fixing the grip of the small battery pack;

[0047] (2) Slide the two sets of opening and closing rods 43 relative to the horizontal part of the cross-shaped fixing plate 41, then adjust the distance between the two movable ends of each set of opening and closing rods 43, and finally rotate the rotating shafts 45 of the four tightening mechanisms until the L-shaped clamping plates 49 of the four tightening mechanisms respectively clamp the four corners at the top of the small battery pack. Finally, lock and position the hinged ends of the two sets of opening and closing rods 43 through the locking bolts 418, thus completing the clamping connection of the small battery pack;

[0048] (3) Before conducting the drop test on the bottom plane of the small battery pack, lower the middle hook 35 of the suspension mechanism, then connect the lugs 44 on the four movable ends of the two sets of opening and closing rods 43 to the middle hook 35 through two connecting ropes 5, and then the middle hook 35 drives the small battery pack clamped on the dropping mechanism to move upward, so as to vertically lift the small battery pack. During the test, control the suspension mechanism 3 to drive the dropping mechanism 4 to move downward rapidly, realizing the drop test of the bottom plane of the small battery pack;

[0049] (4) Before conducting the drop test on any edge at the bottom of the small battery pack, connect two of the lugs 44 to the middle hook 35 of the suspension mechanism through the connecting rope 5, so that the small battery pack is in an inclined state, and the edge of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism 3 to drive the dropping mechanism 4 to move downward rapidly, realizing the drop test of any edge at the bottom of the small battery pack;

[0050] (5) Before conducting the drop test on any corner at the bottom of the small battery pack, directly connect one of the lugs 44 to the middle hook 35 of the suspension mechanism, so that the small battery pack is in an inclined state, and the corner of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism 3 to drive the dropping mechanism 4 to move downward rapidly, realizing the drop test of any corner at the bottom of the small battery pack.

[0051] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A drop test device applicable to a small battery pack, characterized in that: It includes a test platform, a support frame with its bottom fixed on the test platform, a suspension mechanism installed on the support frame, a dropping mechanism, and a connecting rope. The dropping mechanism is connected to the lifting end of the suspension mechanism through the connecting rope; the dropping mechanism includes a cross-shaped fixing plate, a clamping mechanism, two groups of opening and closing rods, and four tightening mechanisms. The clamping mechanism is connected to the vertical part of the cross-shaped fixing plate. The two groups of opening and closing rods are both horizontally arranged. The hinged ends of the two groups of opening and closing rods are slidably connected to the horizontal part of the cross-shaped fixing plate and are respectively located on both sides of the vertical part of the cross-shaped fixing plate. Corresponding lifting lugs and tightening mechanisms are connected to the four movable ends of the two groups of opening and closing rods. The lifting lugs on the dropping mechanism are connected to the suspension mechanism through the connecting rope. The four tightening mechanisms all include a vertically arranged rotating shaft and an L-shaped tightening clamp plate. The top end of the L-shaped tightening clamp plate is fixedly connected to the bottom end of the rotating shaft. The rotating shafts of every two tightening mechanisms are rotatably connected to the two movable ends of the corresponding group of opening and closing rods. The L-shaped tightening clamp plates of every two tightening mechanisms are located directly below the two movable ends of the corresponding group of opening and closing rods.

2. The drop test device for a small battery pack according to claim 1, wherein: There are a middle positioning through hole and two end positioning through holes formed between the two side walls connected to the horizontal part of the cross-shaped fixing plate on the vertical part of the cross-shaped fixing plate. The middle positioning through hole is located in the middle of the vertical part of the cross-shaped fixing plate, and the two end positioning through holes are respectively located at both ends of the vertical part of the cross-shaped fixing plate; the clamping mechanism includes two L-shaped clamp plates. The lengths of the two L-shaped clamp plates are the same as the length of the vertical part of the cross-shaped fixing plate. Horizontally arranged middle positioning guide plates and two end positioning guide plates are fixedly installed on the inner walls near the top of the vertical parts of the two L-shaped clamp plates. The middle positioning guide plate is located in the middle of the vertical part of the L-shaped clamp plate, and the two end positioning guide plates are respectively located at both ends of the vertical part of the L-shaped clamp plate; when the two L-shaped clamp plates are connected to the vertical part of the cross-shaped fixing plate, the two middle positioning guide plates on the two L-shaped clamp plates respectively penetrate into the middle positioning through hole from both ends of the middle positioning through hole of the cross-shaped fixing plate, and the two end positioning guide plates in the same direction on the two L-shaped clamp plates respectively penetrate into the corresponding middle positioning through hole from both ends of the corresponding end positioning through hole; when the ends of the horizontal parts of the two L-shaped clamp plates are completely in contact and closed, the vertical part of the cross-shaped fixing plate and the two L-shaped clamp plates form a rectangular ring closed structure.

3. The drop test device for a small battery pack according to claim 2, wherein: There are vertically through bolt holes arranged at both ends on the vertical part of the cross-shaped fixing plate. The two bolt holes respectively penetrate the two end positioning through holes. Locking bolts are threadedly connected to the two bolt holes. Semi-circular notches are arranged on the two end positioning guide plates of each L-shaped clamp plate. When the ends of the horizontal parts of the two L-shaped clamp plates are completely in contact and closed, the two opposite semi-circular notches on the two L-shaped clamp plates combine into a circular through hole. The locking bolts sequentially pass through the upper part of the bolt hole, the circular through hole, and the lower part of the bolt hole, thereby closing and locking the two L-shaped clamp plates on the vertical part of the cross-shaped fixing plate.

4. A drop test device for a small battery pack according to claim 1, characterized in that: The cross-shaped fixing plate is provided with guide grooves on two horizontal portions on both sides of its vertical portion. A limiting block is slidably arranged in the guide groove, and the hinge shaft of the hinge end of each set of opening and closing rods is fixed to a corresponding limiting block, so that each set of opening and closing rods slides along the corresponding guide groove and is locked and positioned.

5. The drop test device for a small battery pack according to claim 4, wherein: The two horizontal portions of the cross-shaped fixing plate are both provided with guide holes. The guide holes penetrate through the bottom of the guide groove, and the axis of the guide hole is parallel to the axis of the guide groove. The guide hole is composed of a row of interconnected limiting holes. The width of each limiting hole is greater than the width of the connecting hole between adjacent limiting holes. The screw rod of the locking bolt is threadedly connected to the limiting block and passes downward through a corresponding limiting hole. The minimum diameter of the screw rod of the locking bolt is greater than the width of the connecting hole between adjacent limiting holes, so that the locking bolt is locked and positioned in a limiting hole.

6. The drop test device for a small battery pack according to claim 1, characterized in that: The support frame is a support frame with an inverted U-shaped structure, and the two bottom ends of the support frame are fixed on the test platform; the suspension mechanism includes a lifting linear module, a movable pulley, a fixed pulley and a suspension belt. The lifting linear module is fixed on one of the vertical portions of the support frame. The movable pulley and the fixed pulley are both vertically arranged, and the axles of both of them are perpendicular to the axis of the horizontal portion at the top end of the support frame. The movable pulley is fixed on the lifting slider of the lifting linear module, and the fixed pulley is fixed on the horizontal portion at the top end of the support frame. The fixed end of the suspension belt is fixed on the horizontal portion of the support frame. The lifting end of the suspension belt sequentially passes through the movable pulley and the fixed pulley and then extends vertically downward. The lifting eye on the dropping mechanism is connected to the lifting end of the suspension belt through a connecting rope.

7. The drop test device for a small battery pack according to claim 6, characterized in that: The suspension mechanism further includes an electric telescopic rod and a suspension locking block. The fixed end of the electric telescopic rod is fixed on the horizontal portion of the support frame, the telescopic end of the electric telescopic rod faces the suspension belt on the fixed pulley, and the suspension locking block is fixed on the telescopic end of the electric telescopic rod.

8. The drop test device for a small battery pack according to claim 1, characterized in that: The connecting rope includes a middle sling, two suspension ropes and two end hooks. Each end hook is fixedly connected to the middle sling through a corresponding suspension rope. A middle hook is arranged on the vertically downward extending lifting end of the suspension mechanism. The middle sling of the connecting rope is connected to the middle hook of the suspension mechanism, and the two end hooks of the connecting rope are respectively connected to the two lifting eyes.

9. The test method of a drop test device for a small battery pack according to claim 1, characterized in that: Specifically, it includes the following steps: (1). Place the small battery pack to be subjected to the dropping test on the test platform and directly below the lifting end of the suspension mechanism. Then move the dropping mechanism in the open state to directly above the grip at the top of the small battery pack. The dropping mechanism moves downward until the grip at the top of the small battery pack is located within the clamping mechanism. Then control the clamping mechanism to close, so as to clamp and fix the grip of the small battery pack. (2). Slide the two sets of opening and closing rods relatively along the horizontal portion of the cross-shaped fixing plate. Then adjust the distance between the two movable ends of each set of opening and closing rods. Finally, rotate and adjust the four tightening mechanisms until the L-shaped clamping plates of the four tightening mechanisms respectively clamp the four corners at the top of the small battery pack. Finally, lock and position the hinge ends of the two sets of opening and closing rods, that is, complete the clamping connection of the small battery pack. Before conducting the drop test on the bottom plane of the small battery pack, lower the lifting end of the suspension mechanism that extends vertically downward, and then connect the lugs on the four movable ends of the two sets of opening and closing rods to the lifting end of the suspension mechanism through connecting ropes. Then, raise the lifting end of the suspension mechanism to vertically lift the small battery pack. During the test, control the suspension mechanism to drive the dropping mechanism to quickly move downward to achieve the drop test on the bottom plane of the small battery pack; Before conducting the drop test on any edge of the bottom of the small battery pack, connect two of the lugs to the lifting end of the suspension mechanism through connecting ropes, so that the small battery pack is in an inclined state, and the edge of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the dropping mechanism to quickly move downward to achieve the drop test on any edge of the bottom of the small battery pack; Before conducting the drop test on any corner of the bottom of the small battery pack, directly connect one of the lugs to the lifting end of the suspension mechanism, so that the small battery pack is in an inclined state, and the corner of the small battery pack to be tested is at the lowest horizontal height. During the test, control the suspension mechanism to drive the dropping mechanism to quickly move downward to achieve the drop test on any corner of the bottom of the small battery pack.

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