Central needle

Abstract

The utility model belongs to the technical field of lithium battery manufacturing, and particularly relates to a center pin which comprises a hollow annular body, the annular body comprises an outer ring formed by a plurality of supporting arcs distributed at intervals, and the adjacent supporting arcs are connected through contraction arcs protruding towards the circle center. When the outer wall of the annular body is subjected to radial acting force, the two ends of each contraction arc are closed at the corresponding notch, the middle section of each contraction arc deforms and then enters the hollow position of the annular body, and when the radial acting force borne by the outer wall of the annular body is cancelled, the middle section of each contraction arc deforms and then enters the hollow position of the annular body. And the annular body is reset. The technical problem that in the prior art, a central needle can only ensure that a roll core does not collapse but cannot shrink in the radial direction, so that a battery swells is solved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to lithium battery manufacturing technical field especially relates to a center needle. BACKGROUND

[0002] The center needle is arranged in the middle of the winding core of the lithium battery, and plays the roles of supporting, heat conduction, exhaust and protecting the winding core in the battery. The center needle in the prior art mostly adopts a steel pipe, which can avoid the collapse of the winding core. However, in the normal operation of the battery, the winding core cannot be contracted inward in the radial direction, but can only expand outward. The expansion of the winding core to the inner wall of the battery shell exerts force on the battery shell, which is easy to cause the battery to bulge. SUMMARY

[0003] In order to solve the technical problem that the center needle in the prior art can only prevent the collapse of the winding core, but cannot be contracted in the radial direction to cause the battery to bulge, the application provides a center needle, which solves the above technical problem.

[0004] The technical scheme adopted by the utility model to solve its technical problem is:

[0005] The utility model provides a kind of center needle, including hollow annular body, the annular body includes the outer ring formed by the support arc of multiple interval distribution, adjacent the support arc is connected by the contraction arc protruding to the center of circle, to form the gap for the outer ring contraction between adjacent the support arc, when the outer wall of the annular body is subjected to radial force, the both ends of the contraction arc converge at the gap, the middle segment of the contraction arc is deformed and enters the hollow of the annular body, when the radial force of the outer wall of the annular body is cancelled, the annular body resets.

[0006] Further, the outer ring includes three support arcs.

[0007] Further, the thickness of the support arc is greater than the thickness of the contraction arc.

[0008] Further, the annular body is made of hard plastic resistant to high temperature.

[0009] Based on the above technical scheme, the utility model can achieve the following technical effects:

[0010] The center needle of the utility model, the support arc of the annular body has rigidity, so that the annular body cannot be bent or shrink in the axial direction, can support the roll core, avoid the deformation and collapse of the roll core in the battery cycle process, affect the battery performance, in particular, the hollow design of the annular body and the gap design between the support arcs, when the center needle is subjected to the force of the roll core in the radial direction, the shrink arc connected between the support arcs will deform, the specific deformation process is that the two ends of the shrink arc converge at the gap, the middle section of the shrink arc further protrudes to the hollow of the annular body, so that the center needle can be retracted, when the force of the roll core is cancelled, the annular body resets, that is, in the normal work of the battery, the roll core can be retracted inward, greatly reducing the outward expansion action of the roll core, thereby reducing the force of the roll core on the inner wall of the battery steel shell, reducing the occurrence of the 'bulge' phenomenon, greatly prolonging the service life of the lithium battery, at the same time, the hollow of the annular body and the gap between the support arcs can be used for exhaust and liquid permeation, when the battery is out of control, the battery explosion caused by the pressure accumulation in the battery is avoided, so that the safety is improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Fig. 1 It is the overall structure schematic view of the center needle of the utility model before retraction;

[0012] Fig. 2 It is the schematic view of the center needle of the utility model retracted to the limit position;

[0013] Fig. 3 It is the schematic view of the center needle of the utility model after being cut along the upper and lower two quadrant points.

[0014] Among them: 1-annular body, 11-support arc, 12-shrink arc, 13-gap. DETAILED DESCRIPTION

[0015] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. The description of at least one exemplary embodiment is actually only illustrative, not as any limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0016] As Figs. 1-3The utility model provides a center needle, including hollow annular body 1, annular body 1 includes the outer ring that is formed by a plurality of interval distribution's support arc 11, and the support arc 11 between adjacent is connected through the contraction arc 12 that protrudes to the center of circle, to form the gap 13 that supplies the outer ring contraction between adjacent support arc 11, when the outer wall of annular body 1 is subjected to radial force, the both ends of contraction arc 12 converge at gap 13, and the middle segment of contraction arc 12 enters hollow of annular body 1 after deformation, when the radial force of the outer wall of annular body 1 is cancelled, annular body 1 resets.

[0017] The utility model discloses a center needle, the support arc 11 of annular body 1 has rigidity, so that annular body 1 will not be bent, or shrink in the axial direction, can play the support roll core, avoid the deformation collapse of roll core in the battery cycle process, influence battery performance, especially, the hollow design of annular body 1 and the gap 13 design between support arc 11, when the center needle is subjected to the force of roll core in the radial direction, the contraction arc 12 connected between support arc 11 will deform, and the specific deformation process is that the both ends of contraction arc 12 converge at gap 13, and the middle segment of contraction arc 12 further protrudes to the hollow of annular body 1, so that the center needle can be retracted, when the force of roll core is cancelled, annular body 1 resets, that is, in the normal operation of battery, let roll core can be retracted inward, greatly reduce the outward expansion action of roll core, thereby reduce the force that roll core exerts on the inner wall of battery steel shell, reduce the occurrence of " bulge " phenomenon, greatly prolong the service life of lithium battery, simultaneously, the hollow of annular body 1 and the gap 13 between support arc 11 can be used for exhaust and liquid permeation, when battery heat runaway occurs, avoid the battery explosion caused by the pressure accumulation in battery, thereby improve safety.

[0018] In a preferred embodiment of the utility model, the outer ring includes three support arcs 11.

[0019] In a specific embodiment of the utility model, the thickness of support arc 11 is greater than the thickness of contraction arc 12, support arc 11 is thick, guaranteeing the rigidity of center needle, so that the center needle can play a supporting role, contraction arc 12 is thin, guaranteeing that when the center needle is subjected to the radial force of roll core, contraction arc 12 can deform, so that the center needle retracts, guaranteeing that roll core can also retract inward.

[0020] In one preferred embodiment of the utility model, annular body 1 is made of hard plastic which is resistant to high temperature. In the prior art, the center needle is made of steel pipe, the center needle head gap is wide, the center needle is easy to be embedded together, which leads to the machine card machine of the machine which inserts the center needle on the production line, even the push head of the machine is broken, the machine is easy to be damaged, in the utility model, the center needle is made of hard plastic which is resistant to high temperature, the risk of scalding the diaphragm of the center of the roll core when spot welding the negative lug is reduced, the risk of the steel center needle production machine being easy to be damaged is also avoided, at the same time, since the plastic has certain elasticity, after the battery is extruded by the roll core under high temperature, it still has a certain degree of rebound, which prolongs the service life of the battery.

[0021] It should be understood that the specific embodiments described above are only used to explain the utility model and are not used to limit the utility model. The obvious changes or changes derived from the spirit of the utility model are still within the protection scope of the utility model.

Claims

1. A central needle, characterized in that The invention relates to a hollow ring-shaped body (1) comprising an outer ring composed of a plurality of spaced-apart support arcs (11), adjacent support arcs (11) being connected by a contraction arc (12) projecting towards the center of the circle to form a gap (13) between adjacent support arcs (11) for the contraction of the outer ring, the ends of the contraction arc (12) converging at the gap (13) when the outer wall of the ring-shaped body (1) is subjected to a radial force, the middle section of the contraction arc (12) deforming to enter the hollow of the ring-shaped body (1), the ring-shaped body (1) returning when the radial force acting on the outer wall of the ring-shaped body (1) is removed.

2. The centering needle of claim 1, wherein, The outer ring comprises three support arcs (11).

3. The centering needle of claim 1, wherein, The thickness of the support arcs (11) is greater than the thickness of the contraction arc (12).

4. The centering needle of claim 1, wherein, The ring-shaped body (1) is made of a hard plastic resistant to high temperatures.

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