A method for online detection of residual stress in aluminum-plastic film punching

Abstract

The present invention provides an online detection method for residual stress of aluminum-plastic film shell punching, comprising the following steps: step 1: aluminum-plastic film shell punching, the aluminum-plastic film is made to complete the shell punching through a shell punching mechanism; step 2: CCD photography, using a camera to take photos of the side edge seal and the top edge seal of the aluminum-plastic film after the shell punching is completed; step 3: curling area calculation, according to the photos of the side edge seal and the top edge seal taken, the curling area S1 of the side edge seal and the curling area S2 of the top edge seal are obtained by integral calculation; step 4: curling degree calculation, according to the formula R=K1S1+K2S2+b, the curling degree R of the aluminum-plastic film shell punching is calculated, wherein K1 is a coefficient related to S1, K2 is a coefficient related to S2, b is a formula correction number, and before calculating the curling degree R, the values ​​of K1, K2 and b are obtained by normalization of data simulation graphics. The present invention can realize online detection and accurate evaluation of the residual stress after the aluminum-plastic film shell punching, and can timely discover when bad curling occurs, thereby avoiding the generation of batch defective products.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum-plastic film production equipment, and in particular to an online detection method for residual stress of aluminum-plastic film punching. Background Art

[0002] The aluminum-plastic film is mainly composed of a nylon layer, an aluminum foil layer and a CPP layer. Due to the different stresses of the raw material nylon layer and the CPP layer, and the tension on the equipment during the composite process of the nylon layer, the aluminum foil layer and the CPP layer, the aluminum-plastic film will be subjected to certain tensile deformation and produce residual stress. The residual stress will be released when the aluminum-plastic film is punched into a shell, resulting in different degrees of curling. The residual stress is proportional to the degree of curling, that is, the greater the residual stress, the greater the degree of curling.

[0003] The existing residual stress detection method is an offline detection and evaluation method, which is evaluated by measuring the angles of the side and top sealing edges. However, when curling occurs, it is impossible to accurately evaluate the residual stress after the aluminum-plastic film is punched into the shell. At the same time, soft-pack lithium batteries are currently produced in a highly automated continuous manner, with no personnel inspection process in the middle. When curling occurs, it is impossible to detect it in time, resulting in the production of batch defective products. Summary of the invention

[0004] The present invention aims at the deficiencies in the prior art and provides an online detection method for residual stress of aluminum-plastic film shell punching, which can realize online detection and accurately evaluate the residual stress of the aluminum-plastic film after shell punching, and can timely discover the occurrence of curling defects to avoid the production of batch defective products.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An online detection method for residual stress of aluminum-plastic film punching shells comprises the following steps:

[0007] Step 1: Punching the aluminum-plastic film into a shell, and passing the aluminum-plastic film through a shell punching mechanism to complete the shell punching;

[0008] Step 2: CCD camera is used to take photos of the side sealing and top sealing of the aluminum-plastic film after the shell is punched;

[0009] Step 3: Calculate the curling area. According to the photos of the side and top seals, the curling area S of the side seals is calculated by integration. 1 and the curling area S of the top edge 2 ;

[0010] Step 4: Calculate the curl degree according to the formula R = K 1 S 1 +K 2 S 2 +b, calculate the curling degree R of the aluminum-plastic film punching shell, where K 1 For S1 The correlation coefficient, K 2 For S 2 The relevant coefficient, b is the formula correction number.

[0011] As a preferred solution, in step 4, when calculating the curling degree, the curling area of ​​the edge seal curling toward the nylon layer side of the aluminum-plastic film is set as a positive value, and the curling area of ​​the edge seal curling toward the CPP layer side of the aluminum-plastic film is set as a negative value.

[0012] As a preferred solution, in step 4, before calculating the curling degree R, K is obtained by normalizing the data simulation graph. 1 , K 2 and the value of b.

[0013] As a preferred solution, during normalization, 20 grades of aluminum-plastic films with curling degrees R between -10 and 10 are selected to obtain the curling areas S of the side sealing edges corresponding to the 20 grades of aluminum-plastic films. 1 and the curling area S of the top edge 2 The value of R = K 1 S 1 +K 2 S 2 +b K is obtained by normalizing the data simulation graph 1 , K 2 and the value of b.

[0014] As a preferred solution, the camera includes a side edge sealing camera and a top edge sealing camera arranged outside the shell punching mechanism.

[0015] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, by implementing CCD photography, curling area calculation and curling degree calculation, the side edge sealing and top edge sealing of the aluminum-plastic film after shell punching are photographed by a camera, and the curling area S of the side edge sealing is calculated. 1 and the curling area S of the top edge 2 , and then according to the formula R = K 1 S 1 +K 2 S 2 +b, the curling degree R of the aluminum-plastic film shell is calculated, and then the magnitude of the residual stress is determined, so that online detection can be realized and the residual stress of the aluminum-plastic film after shell punching can be accurately evaluated. When curling is poor, it can be discovered in time to avoid the production of batch defective products.

[0016] In order to more clearly explain the structural features, technical means and specific purposes and functions achieved by the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the shell punching process of an embodiment of the present invention;

[0018] Figure 2 It is a schematic diagram of aluminum-plastic film punching and shell forming according to an embodiment of the present invention.

[0019] Description of the accompanying drawings:

[0020] 10-aluminum-plastic film unwinding shaft; 11-shell punching mechanism; 12-side edge sealing camera; 13-top edge sealing camera; 14-aluminum-plastic film; 141-side edge sealing; 142-top edge sealing. DETAILED DESCRIPTION

[0021] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the positions or elements referred to must have specific directions, be constructed and operated in specific directions. Therefore, they should not be understood as limitations on the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1-2 As shown, an online detection method for residual stress of aluminum-plastic film punching shells comprises the following steps:

[0024] Step 1: The aluminum-plastic film 14 is punched into shells. The aluminum-plastic film unwinding shaft 10 outputs the aluminum-plastic film 14 to the shell punching mechanism 11, so that the aluminum-plastic film 14 passes through the shell punching mechanism 11 to complete the shell punching;

[0025] Step 2: CCD photography, using a camera to take photos of the side sealing edge 141 and the top sealing edge 142 of the aluminum-plastic film 14 after the shell punching is completed, the camera includes a side sealing edge camera 12 and a top sealing edge camera 13 arranged outside the shell punching mechanism 11;

[0026] Step 3: Calculate the curling area. The curling area S of the side edge seal 141 is calculated by integral calculation based on the photographs of the side edge seal 141 and the top edge seal 142. 1 and the curling area S of the top sealing edge 142 2 , the curling area S of the side edge 141 in the photo can be calculated using the principle of calculus1 and the curling area S of the top sealing edge 142 2 The value of

[0027] Step 4: Calculate the curl degree according to the formula R = K 1 S 1 +K 2 S 2 + b, calculate the curling degree R of the aluminum-plastic film 14 punch shell, where K 1 For S 1 The correlation coefficient, K 2 For S 2 The relevant coefficient, b is the formula correction number, the side edge 141 and the top edge 142 will curl towards the same side when curling, when calculating the curling degree, the curling area of ​​the edge curling towards the nylon layer side of the aluminum-plastic film 14 is set as a positive value, and the curling area of ​​the edge curling towards the CPP layer side of the aluminum-plastic film 14 is set as a negative value, and the R value is set to 0 when the edge is flat. Before calculating the curling degree R, K is obtained by normalizing the data simulation graph. 1 , K 2 When the values ​​of and b are normalized, 20 grades of aluminum-plastic films 14 with curling degrees R between -10 and 10 are selected to obtain the curling areas S of the side sealing edges 141 corresponding to the 20 grades of aluminum-plastic films 14. 1 and the curling area S of the top sealing edge 142 2 The value of R = K 1 S 1 +K 2 S 2 +b K is obtained by normalizing the data simulation graph 1 , K 2 and the value of b.

[0028] After obtaining the R value, if the R value reaches a certain value, an alarm will be sounded through the alarm device to remind the operator, thereby reducing the occurrence of defective products.

[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Therefore, any modification, equivalent replacement, improvement, etc. made to the above embodiment based on the technical practice of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An online detection method for residual stress of aluminum-plastic film punching, characterized in that: The following steps are involved: Step 1: Punching the aluminum-plastic film into a shell, and passing the aluminum-plastic film through a shell punching mechanism to complete the shell punching; Step 2: CCD camera is used to take photos of the side sealing and top sealing of the aluminum-plastic film after the shell is punched; Step 3: Calculate the curling area, and obtain the curling area S1 of the side edge seal and the curling area S2 of the top edge seal by integral calculation based on the photographs of the side edge seal and the top edge seal; Step 4: Calculate the curling degree. According to the formula R=K1S1+K2S2+b, calculate the curling degree R of the aluminum-plastic film punching shell, where K1 is a coefficient related to S1, K2 is a coefficient related to S2, and b is a formula correction number. The curling area of ​​the edge seal facing the nylon layer of the aluminum-plastic film is set to a positive value, and the curling area of ​​the edge seal facing the CPP layer of the aluminum-plastic film is set to a negative value. Before calculating the curling degree R, the values ​​of K1, K2 and b are obtained by normalizing the data simulation graph. During normalization, 20 grades of aluminum-plastic films with curling degrees R between -10 and 10 are selected, and the values ​​of the curling area S1 of the side edge seal and the curling area S2 of the top edge seal corresponding to the 20 grades of aluminum-plastic films are obtained respectively. Then, the values ​​of K1, K2 and b are obtained by normalizing the data simulation graph according to the formula R=K1S1+K2S2+b.

2. The method for online detection of residual stress of aluminum-plastic film punching shell according to claim 1 is characterized in that: The cameras include a side edge sealing camera and a top edge sealing camera which are arranged outside the shell punching mechanism.

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