Diaphragm defect detection device
By designing a diaphragm defect detection device including a visual detection module and a material transfer module, using the unique settings of the detection camera and light source to generate bright and dark field images, the problems of accuracy and efficiency in traditional detection methods are solved, and efficient and accurate multiple defect detection is achieved.
Patent Information
- Application Number
- CN202420783602.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-16
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-04-16
AI Technical Summary
Traditional manual detection of lithium battery separator defects has problems such as low accuracy, poor real-time, low efficiency and high labor intensity. Due to the wide variety of defects of machine vision detection methods, single equipment detection is prone to miss other types of defects.
A diaphragm defect detection device is designed, including a visual detection module and a material transfer module. By detecting the unique position and angle settings of the camera, the first light source and the second light source, and the time-sharing strobe of the light source alternately illuminating, a bright field image and a dark field image are generated, and the contrast of the defect is enhanced by the comprehensive contrast of the two images.
It realizes the detection of various types of defects in the appearance of the battery diaphragm in a single station, improves detection efficiency and accuracy, and avoids the omission or misjudgment of defects.
Smart Images
Figure CN222636078U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of visual detection, and in particular relates to a diaphragm defect detection device. Background Art
[0002] Lithium battery separator is an important component for isolating the anode and cathode of lithium-ion batteries. Its special structure and physical and chemical properties can prevent short circuits and fires inside the battery. The separator material is usually made of polyolefin film, which has high tensile strength and chemical stability, and can effectively isolate the anode and cathode and avoid direct contact between them.
[0003] Due to the influence of various factors, defects such as holes, pinholes, black spots, scratches, etc. are prone to appear on the surface of lithium battery diaphragms. Severe defects will greatly affect the quality of lithium battery diaphragms. Among them, holes and pinholes are absolutely not allowed, so the detection of diaphragms is very important. The traditional detection method is manual detection of diaphragm surface defects. This method is mostly random inspection, and has low accuracy, poor real-time performance, low efficiency, high labor intensity, and is greatly affected by manual experience and subjective factors. The detection method based on machine vision can overcome the above disadvantages to a large extent, but due to the wide variety of defects in the appearance of the diaphragm, a single device detection is prone to miss other types of defects. Therefore, different structural equipment is used for detection of different defects, which makes the entire detection process cumbersome, time-consuming and costly. Utility Model Content
[0004] In view of the above, the utility model provides a diaphragm defect detection device, which can meet the needs of detecting various types of defects on the appearance of battery diaphragms with one device through optimized structural design, greatly improving the detection efficiency. The specific technical solution is as follows.
[0005] A diaphragm defect detection device comprises a visual detection module and a material conveying module, the material conveying module comprises a unwinding roller, a conveying roller and a winding roller, the visual detection module comprises a detection camera, a first light source and a second light source, the detection camera and the first light source are located above a detection plane of a detection station, the second light source is located below the detection plane of the detection station, and the second light source is located directly below the detection camera, the central axis of the detection camera coincides with the normal of the detection plane, the first light source is inclined with respect to the detection plane, and the first light source and the normal of the detection plane form a detection angle.
[0006] Furthermore, the detection camera is a stroboscopic line scan camera, the first light source is a cross line light, and the second light source is a highlight line light.
[0007] Furthermore, the visual detection module also includes a light source strobe controller, and the light source strobe controller is connected to the first light source and the second light source.
[0008] Furthermore, a vertical distance between the detection camera and the detection plane is greater than a vertical distance between the first light source and the detection plane.
[0009] Furthermore, there are several conveying rollers, which are divided into first conveying rollers and second conveying rollers. There are two first conveying rollers, which are horizontally arranged at the detection station.
[0010] Furthermore, the material conveying module also includes a pressure roller module, which is located at a station after the detection station and includes an active pressure roller mechanism and a passive pressure roller mechanism. The diaphragm conveyed from the detection station passes between the active pressure roller mechanism and the passive pressure roller mechanism.
[0011] Furthermore, the active pressing roller mechanism includes a driving motor, a rolling shaft and a tension roller. The rolling shaft is connected to the rotating shaft of the driving motor and is driven to rotate thereby. The tension roller is arranged on the rolling shaft and rotates therewith.
[0012] Furthermore, the driven pressure roller includes a lifting cylinder and a pressure roller, and the pressure roller is driven by the lifting cylinder to perform lifting motion.
[0013] Furthermore, it also includes a deviation correction control module, which is arranged on the transmission path of the diaphragm.
[0014] The utility model of the diaphragm defect detection device for lithium batteries can obtain multiple detection presentation effects at a single station, with high detection efficiency and accuracy, and is applicable to many types of defect detection. Through the unique position and angle settings of the detection camera, the first light source and the second light source, and the time-sharing strobing and alternating lighting of the first light source and the second light source, the detection camera will generate a bright field image and a dark field image at the same position of the diaphragm. The contrast of the defects is enhanced by the comprehensive comparison of the two images. Compared with the product appearance image obtained under a single light source, it can effectively detect or distinguish more types of defects and avoid omissions or misjudgments of defects. For the bright field formed when the first light source is lit, the detection effect is more obvious mainly for defects such as dirt, scratches, spots, stripes, and light spots on the diaphragm. For the dark field formed when the second light source is lit, the detection effect is more obvious mainly for defects such as pinholes and holes.
[0015] Additional aspects and advantages of the present invention will be further described in the following description, and some will become apparent from the following description or be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic diagram of the visual detection module of the utility model;
[0017] Figure 2 It is a structural schematic diagram of a diaphragm defect detection device of Example 1;
[0018] Figure 3 It is a structural schematic diagram of a diaphragm defect detection device of Example 2;
[0019] Figure 4 This is a schematic diagram of the structure of the diaphragm defect detection device of Example 3. DETAILED DESCRIPTION
[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.
[0021] In the description of the present invention, it should be understood that the terms "upper" and "lower" etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0022] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "setting", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1
[0023] like Figure 2 , a membrane defect detection device of this embodiment includes a visual detection module and a material conveying module, the material conveying module includes an unwinding roller 1, a conveying roller and a winding roller 2, the visual detection module includes a detection camera 3, a first light source 4 and a second light source 5, the detection camera 3 and the first light source 4 are located above the detection plane of the detection station 100, the second light source 5 is located below the detection plane of the detection station 100, and the second light source 5 is located directly below the detection camera 3, the central axis of the detection camera 3 coincides with the normal of the detection plane corresponding to the detection camera 3 below, the first light source 4 is inclined with the detection plane, and the first light source 4 forms a detection angle a with the normal of the detection plane, and in this embodiment, the detection angle a=45°±10°. The unwinding roller and the winding roller are both connected to a drive motor to drive the unwinding and winding of the material.
[0024] In this embodiment, the detection camera 3 is a stroboscopic line scan camera, which is arranged on the frame 200 of the device through an anti-shake bracket. The field of view of the detection camera 3 is larger than the width of the diaphragm 300. Taking a diaphragm product with a width of 100㎜ as an example for testing, a set of 4k stroboscopic line scan cameras is used, and the horizontal field of view of a single station is 160mm. If the width of the diaphragm 300 exceeds the field of view of a single camera, multiple detection cameras can be arranged side by side as needed to meet the requirement that the field of view of the detection camera 3 is larger than the width of the diaphragm 300. The first light source 4 is a cross-line light source, and the second light source 5 is a highlight line light source. The vertical distance between the first light source 4 and the detection plane is equal to the vertical distance between the second light source 5 and the detection plane. The vertical distance between the detection camera 3 and the detection plane is greater than the vertical distance between the first light source 4 and the detection plane, which is 150-350㎜. Figure 1 The vertical distance WD between the detection camera 1 and the detection plane is adjustable from 200 to 300 mm, the vertical distance LWD2 between the first light source 4 and the detection plane is adjustable from 0 to 45 mm, the vertical height LWD1 of the second light source 5 and the detection plane is LWD2, and the horizontal distance LWD3 between the first light source 4 and the detection camera 3 is adjustable from 40 to 110 mm.
[0025] In addition, the visual inspection module also includes a light source strobe controller, which is connected to the first light source 4 and the second light source 5, and is also connected to the inspection camera 3. The light source strobe controller receives and responds to the signal of the inspection camera to control the alternating lighting of the first light source 4 and the second light source 5.
[0026] There are several conveying rollers 6, which are divided into a first conveying roller 61 and a second conveying roller 62. There are two first conveying rollers 61, which are horizontally arranged at the detection station 100 to flatten the diaphragm of the detection station 100 to facilitate detection at the detection station.
[0027] During operation, the diaphragm roll is loaded on the unwinding roller 1, and is stretched and flattened by the second conveying roller 62 and the first conveying roller 6 in turn, and is conveyed to the winding roller 2 for winding. The diaphragm 300 at the detection station 100 is stretched and flattened by two horizontally arranged first conveying rollers 61 at a uniform speed, and the surface of the diaphragm 300 product passing at a uniform speed is scanned and photographed by the detection camera 3 above the diaphragm 300 product. The detection camera 3 outputs multiple groups of signals at high speed and cyclically in succession. The light source strobe controller responds to the signal at high speed and switches the two light sources on and off alternately in succession. Due to the setting of the specific light source and the strobe camera, the detection camera 3 will generate a bright field image and a dark field image at the same position of the diaphragm. The contrast of the defects is enhanced by the comprehensive comparison of the two images. Compared with a single field of view, more types of defects can be effectively detected. In the process of the diaphragm passing under the detection camera at a uniform speed, multiple groups of signal receiving images will be continuously obtained. All images are spliced to obtain images of all defects on the diaphragm.
[0028] The first light source 4 is on, and the second light source 5 is off, forming a bright field of view, which is mainly used to detect defects such as dirt, scratches, spots, stripes, and light spots on the diaphragm. The first light source 4 is off, and the second light source 5 is on, forming a dark field of view, which is mainly used to detect defects such as pinholes and holes. If there are dirt and holes at the same position on the diaphragm, the bright field image and dark field image generated by the detection camera can clearly detect both defects at the same time to avoid missing defects. Example 2
[0029] Reference Figure 2-Figure 3 A diaphragm defect detection device of this embodiment, based on Example 1, also includes a roller die set 7, and the roller die set 7 is located at a station after the detection station, and includes an active roller mechanism and a passive roller mechanism. The diaphragm transmitted from the detection station 100 passes between the active roller mechanism and the passive roller mechanism.
[0030] Furthermore, the active pressure roller mechanism includes a driving motor, a rolling shaft 72 and a tension roller 73. The rolling shaft 72 is connected to the rotating shaft of the driving motor and driven to rotate by the rolling shaft. The tension roller 73 is arranged on the rolling shaft 72 and rotates with the rolling shaft. The passive pressure roller includes a lifting cylinder 74 and a pressure roller 75. The pressure roller 75 is driven to move up and down by the lifting cylinder 74. There are two lifting cylinders 74, which are fixed to the frame 200 of the device through a mounting plate 76. The two ends of the pressure roller 75 are respectively connected to the piston end of a lifting cylinder 74. A push block 78 is connected below the piston end of the lifting cylinder 74 through a connecting rod 77. The two ends of the pressure roller 75 are rotatably arranged on the push block 78. The operation of the lifting cylinder 74 drives the pressure roller 75 to move up and down. The pressure roller 75 descends to contact the tension roller 73 in the active pressure roller mechanism. The tension roller 73 drives the diaphragm to be transferred to the next station. The pressure roller 75 presses on the diaphragm to prevent it from running off.
[0031] During operation, the diaphragm is rolled on the unwinding roller for loading, and is successively stretched and flattened by one of the second conveying rollers 62, the first conveying roller 61, the pressure roller module 7, and the remaining second conveying rollers 62 to be rolled up on the winding roller 2. The diaphragm 300 at the inspection station 100 is stretched and flattened by two horizontally arranged first conveying rollers 61 at a uniform speed. The tension roller 73 pulls the diaphragm to move at a uniform speed behind the inspection station 100 and transmits it to the next station. The pressure roller 75 presses on the diaphragm 300 to prevent it from deviating. The inspection camera 3 scans and photographs the surface of the diaphragm 300 product passing at a uniform speed. The detection camera 3 outputs multiple groups of signals at high speed and in a cycle. The light source strobe controller responds to the signals at high speed and switches the two light sources on and off alternately. Due to the settings of the specific light source and the strobe camera, the detection camera will generate a bright field image and a dark field image at the same position of the diaphragm. The contrast of the defects is enhanced through the comprehensive comparison of the two images. Compared with a single field of view, more types of defects can be effectively detected. In the process of the diaphragm passing under the detection camera at a uniform speed, multiple groups of signal receiving images will be continuously obtained. All images are spliced to obtain images of all defects on the diaphragm. Example 3
[0032] Reference Figure 4 The diaphragm defect detection device of this embodiment further includes a correction control module 8 on the basis of the embodiment 2. The correction control module 8 is arranged on the transmission path of the diaphragm 300 and corrects the diaphragm 300 by tension to ensure that the diaphragm 300 is flat and does not deviate during transmission. The correction control module 8 can use an existing correction controller, which is understandable without further elaboration.
[0033] During operation, the diaphragm is rolled on the unwinding roller 1 for loading, and is successively stretched and flattened by the second conveying roller 62, the first conveying roller 61, the pressure roller module 7, the remaining second conveying rollers 62, and the deviation correction control module 8, and is conveyed to the winding roller 2 for winding. The diaphragm 300 at the detection station 100 is stretched and flattened at a uniform speed by two horizontally arranged first conveying rollers 61. The tension roller 73 pulls the diaphragm to move at a uniform speed behind the detection station 100 and transmits it to the next station. The pressure roller 75 presses on the diaphragm 300 to prevent it from deviating. The detection camera 3 is above the diaphragm 300 product passing at a uniform speed to monitor its surface. Scan and take photos, the detection camera 3 outputs multiple groups of signals at high speed and in a cycle. The light source strobe controller responds to the signal at high speed and switches the two light sources alternately. Due to the setting of the specific light source and the strobe camera, the detection camera will generate a bright field image and a dark field image at the same position of the diaphragm. The contrast of the defects is enhanced by the comprehensive comparison of the two images. Compared with a single field of view, more types of defects can be effectively detected. In the process of the diaphragm passing under the detection camera at a uniform speed, multiple groups of signal receiving images will be continuously obtained. All images are spliced to obtain all defect images on the diaphragm. After the inspection, the reeled diaphragm is further ensured by the correction control module 8 that the diaphragm 300 product does not deviate when it is reeled.
[0034] Although the specific implementation of the utility model has been described in detail with reference to the illustrative embodiments of the utility model, it must be understood that a variety of other improvements and embodiments can be designed by those skilled in the art, and these improvements and embodiments will fall within the spirit and scope of the principles of the present invention. Specifically, within the scope of the aforementioned disclosure, drawings and claims, reasonable variations and improvements can be made in the arrangement of parts and / or subordinate combination layouts without departing from the spirit of the present invention. Except for variations and improvements in parts and / or layouts, the scope is defined by the attached claims and their equivalents.
Claims
1. A diaphragm defect detection device, characterized in that: It includes a visual inspection module and a material conveying module, the material conveying module includes a unwinding roller, a conveying roller and a winding roller, the visual inspection module includes a detection camera, a first light source and a second light source, the detection camera and the first light source are located above the detection plane of the detection station, the second light source is located below the detection plane of the detection station, and the second light source is located directly below the detection camera, the central axis of the detection camera coincides with the normal of the detection plane, the first light source is inclined with respect to the detection plane, and the first light source and the normal of the detection plane form a detection angle.
2. The diaphragm defect detection device according to claim 1, characterized in that: The detection camera is a stroboscopic line scan camera, the first light source is a cross line light, and the second light source is a highlight line light.
3. The diaphragm defect detection device according to claim 1 or 2, characterized in that: The visual detection module also includes a light source strobe controller, which is connected to the first light source and the second light source.
4. The diaphragm defect detection device according to claim 1, characterized in that: The vertical distance between the detection camera and the detection plane is greater than the vertical distance between the first light source and the detection plane.
5. The diaphragm defect detection device according to claim 1, characterized in that: There are multiple conveying rollers, which are divided into first conveying rollers and second conveying rollers. There are two first conveying rollers, which are horizontally arranged at the detection station.
6. The diaphragm defect detection device according to claim 1, characterized in that: The material conveying module also includes a pressure roller module, which is located at a station after the detection station and includes an active pressure roller mechanism and a passive pressure roller mechanism. The diaphragm conveyed from the detection station passes between the active pressure roller mechanism and the passive pressure roller mechanism.
7. The diaphragm defect detection device according to claim 6, characterized in that: The active pressing roller mechanism comprises a driving motor, a rolling shaft and a tension roller. The rolling shaft is connected to the rotating shaft of the driving motor and is driven to rotate by the rolling shaft. The tension roller is arranged on the rolling shaft and rotates together with the rolling shaft.
8. The diaphragm defect detection device according to claim 6, characterized in that: The driven pressure roller comprises a lifting cylinder and a pressure roller, and the pressure roller is driven by the lifting cylinder to perform lifting motion.
9. The diaphragm defect detection device according to claim 1, characterized in that: It also includes a deviation correction control module, which is arranged on the transmission path of the diaphragm.