Constant-pressure winding device for lithium battery diaphragm

Abstract

The utility model discloses a constant-pressure winding device for a lithium battery diaphragm. The constant-pressure winding device comprises a winding shaft, the pressing roller is located below the winding shaft and is parallel to the winding shaft, and the plane where the axis of the pressing roller and the axis of the winding shaft are located is perpendicular to the horizontal plane; the displacement compensation mechanism is connected with the pressing roller and used for enabling the pressing roller to move in the vertical direction; and the force applying mechanism is connected with the pressing roller and used for applying upward acting force to the pressing roller, and the acting force is larger than the gravity of the pressing roller and used for keeping the contact state of the pressing roller and the wound diaphragm. According to the constant-pressure winding device for the lithium battery diaphragm, constant pressure can be applied to the diaphragm on the winding shaft all the time through the pressing roller, air in the winding process is effectively exhausted, and the problem of diaphragm surface bubbling in the winding process is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to diaphragm production technical field further relates to lithium battery diaphragm constant voltage winding device. BACKGROUND

[0002] In the lithium battery diaphragm winding process, due to the winding shaft diameter is small and the winding layer is more, lithium battery diaphragm internal stress distribution is uneven, easy to cause local plastic deformation, thereby leading to product yield decline. At present, the pressure of the pressing roller on the winding shaft is adjusted to change, but the stability of the pressure of the pressing roller on the winding shaft is difficult to guarantee, and the pressure of the pressing roller is too large, which can cause the deformation of the lithium battery diaphragm thickness difference place film surface to be more serious, and the pressure of the pressing roller is too small, which cannot effectively remove the interlayer air in the winding process, and further leads to the film surface to appear bubble defect, which seriously affects the surface quality and overall performance of the lithium battery diaphragm. SUMMARY

[0003] In view of the above technical problems, the utility model aims at providing a lithium battery diaphragm constant voltage winding device to solve the problem of film surface bubble in the diaphragm winding process.

[0004] In order to achieve the above purpose, the lithium battery diaphragm constant voltage winding device provided by the utility model comprises:

[0005] Winding shaft;

[0006] Pressing roller, located below the winding shaft, arranged in parallel with the winding shaft, and the axis of the pressing roller is perpendicular to the horizontal plane of the plane where the axis of the winding shaft is located;

[0007] Displacement compensation mechanism, connected with the pressing roller, for enabling the pressing roller to displace along the vertical direction;

[0008] Force applying mechanism, connected with the pressing roller, for applying upward force to the pressing roller, the force being greater than the gravity of the pressing roller, for maintaining the contact state of the pressing roller and the wound diaphragm.

[0009] In some embodiments, the displacement compensation mechanism comprises a guide rail and a sliding block, the guide rail extends along the vertical direction, the sliding block is slidingly connected to the guide rail, and the pressing roller is rotationally connected to the sliding block.

[0010] In some embodiments, it further comprises a limiting block, and the limiting block is located on the movement stroke of the sliding block.

[0011] In some embodiments, the displacement compensation mechanism comprises a roller, the roller shaft of the pressing roller is rotationally connected to the inner shaft of the roller, the roller is rollingly connected to the strip-shaped groove opened in the rack, and the strip-shaped groove extends along the vertical direction.

[0012] In some embodiments, the force applying mechanism comprises a deflection wheel, a wire rope and a counterweight, one end of the wire rope is connected to the counterweight and the other end is connected to the sliding block after winding around the deflection wheel.

[0013] In some embodiments, the pressing roller is a hollow structure.

[0014] In some embodiments, the pressing roller is a rubber-coated roller.

[0015] In some embodiments, the counterweight is slidingly connected to a sliding groove formed in the rack, and the sliding groove extends in the vertical direction.

[0016] In some embodiments, the pressing roller is a hollow structure.

[0017] In some embodiments, a guide roller is further included, and the diaphragm passes between the guide roller and the pressing roller.

[0018] Compared with the prior art, the lithium battery diaphragm constant pressure winding device has the following beneficial effects:

[0019] The lithium battery diaphragm constant pressure winding device provided by the present application can always apply a constant pressure to the diaphragm on the winding shaft through the pressing roller, effectively expels air during winding, and eliminates the problem of film surface bubble stringing during winding. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above features, technical characteristics, advantages and implementation modes of the present application will be further described in a clear and understandable manner in combination with the preferred embodiments and the accompanying drawings.

[0021] Fig. 1 is a structure schematic diagram of the lithium battery diaphragm constant pressure winding device in a winding state in the preferred embodiment of the present application.

[0022] Fig. 2 is a structure schematic diagram of the part where the winding shaft and the pressing roller are located in the preferred embodiment of the present application.

[0023] Drawing reference: rack 1, winding shaft 2, diaphragm 3, pressing roller 4, counterweight 5, sliding groove 6, sliding block 7, wire rope 8, deflection wheel 9, guide rail 10, limiting block 11, guide roller 12. DETAILED DESCRIPTION

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, specific implementation manners of the present application will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0025] As shown in Figs. 1-2 The lithium battery diaphragm constant pressure winding device according to a preferred embodiment of the present application comprises a winding shaft 2 and a pressing roller 4. The winding shaft 2 is used for winding the diaphragm 3. The pressing roller 4 is located below the winding shaft 2 and is arranged in parallel with the winding shaft 2. The plane in which the two shafts of the pressing roller 4 and the winding shaft 2 are located is perpendicular to the horizontal plane. During the continuous winding operation of the diaphragm 3 material, the driving motor drives the winding shaft 2 to rotate at a constant speed around its geometric center axis. At this time, the outer surface of the pressing roller 4 and the surface of the winding shaft 2 form a continuous contact interface with the diaphragm 3 material being wound. The specific position of the contact interface is set in the tangent point area of the diaphragm winding path. The pressing roller 4 applies a constant normal pressure to the surface of the diaphragm 3 through an accurately designed mechanical transmission system. This pressure control method effectively suppresses the stretching deformation and string bubble of the diaphragm 3 in the traditional winding process, and improves the product quality. It should be noted that during the winding process, the pressure applied by the pressing roller 4 to the diaphragm 3 on the winding shaft 2 changes within a relatively small range. For actual production, it can be regarded as a constant pressure, rather than an absolute constant for any precision in the mathematical sense.

[0026] In view of the dynamic change of the diameter of the diaphragm roll during the continuous rolling process, the device is configured with a displacement compensation mechanism, which can ensure that the pressing roller 4 always abuts against the diaphragm roll. The structure of the displacement compensation mechanism is not limited in this embodiment. As an example, the displacement compensation mechanism includes a pair of guide rail slider assemblies arranged on the rack 1, and the guide rail slider assemblies are respectively located on the two sides of the shaft of the pressing roller 4 in the axial direction. The guide rail slider assembly includes a guide rail 10 and a slider 7, the guide rail 10 extends in the vertical direction, the slider 7 is slidingly connected to the guide rail 10, and the two ends of the shaft of the pressing roller 4 are respectively rotatably connected to the two sliders 7. As another example, the displacement compensation mechanism includes a pair of rollers (not shown), which are rotatably connected to the two ends of the roller shaft of the pressing roller 4, and the rollers are rollingly connected to the strip-shaped groove of the rack 1, which extends in the vertical direction and is used to define the linear movement direction of the pressing roller 4, so that the pressing roller 4 can only displace along the extension direction of the strip-shaped groove. The pressing roller 4 is connected to the rack 1 through the rollers, so that the pressing roller 4 moves along the strip-shaped groove without sliding, so as to reduce the friction coefficient between the pressing roller 4 and the rack 1 and the frictional resistance required when moving the pressing roller 4. In this way, when the diameter of the diaphragm roll gradually increases with the rolling process, the pressing roller 4 can produce adaptive displacement under the pushing of the contact reaction force of the diaphragm 3 on the surface of the pressing roller 4. The pressing roller 4 will maintain contact with the diaphragm 3, and the actual pressing force will always maintain at the preset value.

[0027] In this embodiment, the rack 1 is also rotatably connected with a guide roller 12, and the diaphragm passes between the guide roller 12 and the pressing roller 4 and is rolled on the rolling shaft. The guide roller 12 can define that the continuous contact interface formed by the pressing roller 4 and the diaphragm 3 being rolled is always located at the tangent point area of the diaphragm winding path, which helps to stabilize the rolling quality of the diaphragm 3.

[0028] In this embodiment, the pressing roller 4 can adopt a hollow structure, and the material is selected from low-density materials such as nylon and polytetrafluoroethylene. The composite material can also be selected, such as a low-density material for the inner layer and a mirror-finished stainless steel material for the outer layer. The weight is lighter, and the requirement for the force applied by the force applying mechanism to the pressing roller 4 can be reduced.

[0029] In the embodiment, the device is configured with a force applying mechanism, through which a vertical upward pulling force can be applied to the pressing roller 4, which is greater than the gravity of the pressing roller, for maintaining the contact state of the pressing roller with the rolled membrane. As an example, the force applying mechanism includes a deflection wheel 9 connected to the rack 1, a wire rope 8, one end of which is connected to the counterweight 5, and the other end of which is connected to the sliding block 7 after passing through the deflection wheel 9. In this way, the weight of the pressing roller 4 can be completely counteracted by the counterweight 5, and the pressing roller 4 is driven to abut against the membrane roll on the winding shaft 2. The weight of the counterweight 5 can be adjusted according to the requirements to ensure that the applied pressure is appropriate. In order to make the movement of the counterweight 5 more stable and thus reduce the pressure fluctuation applied by the pressing roller 4 to the membrane, a sliding groove 6 is formed in the rack 1, which extends in the vertical direction, and the counterweight 5 is slidingly connected in the sliding groove 6 for limiting the movement direction of the counterweight 5.

[0030] In the embodiment, in order to prevent the movement direction of the membrane 3 from deviating and affecting the subsequent winding effect, the pressing roller 4 needs to provide friction to the membrane 3 to achieve better compression effect. For example, the pressing roller 4 has a friction surface, for example, the pressing roller 4 can be a rubber-coated roller, which provides friction to the membrane 3 to compress the membrane 3.

[0031] In the embodiment, when the membrane roll with a predetermined outer diameter is wound on the winding shaft 2, the winding shaft 2 needs to be timely removed. Due to the loss of the blocking of the winding shaft 2 and the membrane roll thereon, the pressing roller 2 will move upward under the pulling force of the counterweight 5 and occupy the position of another to-be-installed winding shaft 2. In order to avoid this phenomenon, a limiting block 11 is also installed on the rack 1, which is located in the movement stroke of the sliding block 7 or the roller shaft of the pressing roller 4. In this way, the installation position of the winding shaft 2 is exposed, which is convenient for the disassembly and assembly of the winding shaft 2.

[0032] The working principle of the lithium battery membrane constant pressure winding device of the embodiment will be described below.

[0033] Before winding the membrane 3, the pressing roller 4 is moved to a suitable position to expose the gap between the pressing roller 4 and the winding shaft 2. After fixing one end of the membrane 3 to the winding shaft 2, the force acting on the pressing roller 4 is removed, and the pressing roller 4 is abutted against the winding shaft 2 under the pulling force of the counterweight 5. The driving motor drives the winding shaft 2 to rotate at a constant speed around its geometric center axis, and the outer surface of the pressing roller 4 forms a continuous contact interface with the membrane 3 material being wound on the winding shaft surface. When the diameter of the membrane roll gradually increases with the winding process, the pressing roller 4 produces adaptive displacement under the pushing of the contact reaction force of the membrane 3 surface, and the pressing roller 4 will maintain contact with the membrane 3, and the actual pressing force will always maintain at a preset value.

[0034] In conclusion, the lithium battery diaphragm constant pressure winding device provided by the utility model, the pressing roller 4 always applies constant pressure to the diaphragm 3 on the winding shaft 2, effectively discharges the air in the winding process, and there is no problem of bubble stringing on the film surface in the winding process.

[0035] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the utility model, and it should be pointed out that, for ordinary skilled persons in the art, several improvements and refinements can be made without departing from the principles of the utility model, and these improvements and refinements should also be considered within the protection scope of the utility model.

Claims

1. A constant pressure winding device for lithium battery separators, characterized by, The device comprises: a winding shaft; a pressing roller, which is arranged below the winding shaft in parallel with the winding shaft, and the axis of the pressing roller is perpendicular to the horizontal plane in which the axis of the winding shaft lies; a displacement compensation mechanism, which is connected with the pressing roller and is used to displace the pressing roller in the vertical direction; a force applying mechanism, which is connected with the pressing roller and is used to apply an upward force to the pressing roller, the force being greater than the gravity of the pressing roller, so as to maintain the contact state of the pressing roller with the winding separator.

2. The device according to claim 1, wherein: the displacement compensation mechanism comprises a guide rail and a sliding block, the guide rail extends in the vertical direction, the sliding block is slidingly connected to the guide rail, and the pressing roller is rotationally connected to the sliding block.

3. The device according to claim 2, wherein: the device further comprises a limiting block, which is located on the movement stroke of the sliding block.

4. The device according to claim 1, wherein: the displacement compensation mechanism comprises a roller, the roller shaft of the pressing roller is rotationally connected to the inner shaft of the roller, and the roller is rollingly connected to a strip-shaped slot which is formed in the rack and extends in the vertical direction.

5. The device according to claim 2, wherein: the force applying mechanism comprises a deflection wheel, a wire rope and a counterweight, one end of the wire rope is connected to the counterweight, and the other end of the wire rope is connected to the sliding block after winding around the deflection wheel.

6. The device according to claim 1, wherein: the pressing roller is of a hollow structure.

7. The device according to claim 1, wherein: the pressing roller is a rubber-coated roller.

8. The device according to claim 5, wherein: the counterweight is slidingly connected to a sliding slot which is formed in the rack and extends in the vertical direction.

9. The device according to claim 1, wherein: the peripheral wall of the pressing roller is close to the winding position on the winding shaft at the position where the peripheral wall abuts against the separator on the winding shaft.

10. The device according to claim 9, wherein: the device further comprises a guide roller, and the separator passes between the guide roller and the pressing roller.

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