Patent Publication Number: US-2023142000-A1

Title: Welding Jig Micro-Cleaning Apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2022/000081, filed on Jan. 4, 2022, which claims priority from Korean Patent Application No. 10-2021-0004088 filed on Jan. 12, 2021, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a welding jig micro-cleaning apparatus. More particularly, the present invention relates to a welding jig micro-cleaning apparatus capable of cleaning a laser welding jig using a micro-blaster. 
     BACKGROUND ART 
     Demand for secondary batteries as energy sources for electronic devices, such as mobile phones, laptop computers, and wearable devices, or electric vehicles has increased. Based on the type of electrode, secondary batteries are classified into a nickel-cadmium secondary battery, a nickel-hydride secondary battery, and a lithium secondary battery, and research and development on the lithium secondary battery, which has advantages of high operating voltage and high energy density per unit weight, has been actively conducted. 
     Based on the shape of a battery case, the lithium secondary battery is classified as a prismatic secondary battery or a cylindrical secondary battery having an electrode assembly mounted in a metal can or a pouch-shaped secondary battery having an electrode assembly mounted in a pouch case made of an aluminum laminate sheet. 
     For a secondary battery cell, an electrode assembly, obtained by stacking or winding a negative electrode and a positive electrode in the state in which a separator is interposed therebetween, is received in a case, and an electrode tab protruding from the electrode assembly is connected to an electrode lead. The electrode tab and the electrode lead are connected to each other by laser welding or ultrasonic welding. In general, the electrode tab and the electrode lead are fixed to a welding jig, and welding is performed on a welding portion therebetween. When the electrode tab and the electrode lead are welded by ultrasonic welding, however, foreign matter, such as spatter, is generated from the welding portion, and the foreign matter may attached to the welding jig, whereby welding quality between the electrode tab and the electrode lead is lowered. 
     Meanwhile, Korean Registered Patent Publication No. 10-1988335 discloses a welding nozzle cleaning apparatus including a main body frame unit, an air supply unit coupled to the main body frame unit, a hose unit configured to allow air supplied from the air supply unit to move therethrough, and a collection unit coupled to the main body frame unit, the collection unit being provided at one side thereof with an opening, through which a nozzle is introduced, the hose unit being inserted into the collection unit so as to be coupled thereto; however, the construction of a micro-blaster for cleaning a welding jig is not disclosed. 
     DISCLOSURE 
     Technical Problem 
     The present invention has been made in view of the above problems, and it is an object of the present invention to remove pollutants, such as spatter, from a welding jig using a micro-blaster, thereby improving welding quality. 
     It is another object of the present invention to provide a welding jig micro-cleaning apparatus capable of simplifying a welding jig cleaning operation through a novel welding jig mounting structure, thereby improving cleaning efficiency. 
     Technical Solution 
     In order to accomplish the above objects, a welding jig micro-cleaning apparatus according to the present invention includes a housing ( 100 ), a sandbox ( 200 ) connected to the housing, an air supply unit ( 300 ) connected to the sandbox through a hose, a blasting gun ( 500 ) located in the housing, a jig fixing portion ( 600 ) located at a lower end of the blasting gun ( 500 ), and a controller ( 400 ), wherein the jig fixing portion ( 600 ) includes a magnetic unit ( 640 ) configured to fix a welding jig ( 700 ). 
     In the welding jig micro-cleaning apparatus according to the present invention, the jig fixing portion ( 600 ) may include a sliding unit ( 620 ) movable horizontally at the lower end of the blasting gun ( 500 ). 
     Also, in the welding jig micro-cleaning apparatus according to the present invention, the sliding unit ( 620 ) may be rotatable by a predetermined angle in a horizontal direction. 
     In the welding jig micro-cleaning apparatus according to the present invention, the blasting gun may include a blasting gun inlet ( 510 ) provided at a tip end of the blasting gun ( 500 ), wherein the blasting gun inlet ( 510 ) may include a discharge port ( 511 ) and a suction port ( 512 ). 
     In the welding jig micro-cleaning apparatus according to the present invention, the blasting gun inlet ( 510 ) may include a sealing portion ( 560 ). 
     In the welding jig micro-cleaning apparatus according to the present invention, the sealing portion ( 560 ) may be brought into tight contact with a die ( 610 ) of the jig fixing portion ( 600 ) such that the welding jig ( 700 ) is located in an inner space of the sealing portion. 
     In the welding jig micro-cleaning apparatus according to the present invention, the sealing portion ( 560 ) may be made of an elastic material. 
     In the welding jig micro-cleaning apparatus according to the present invention, the blasting gun ( 500 ) may be connected to a moving unit so as to be movable upwards and downwards. 
     In the welding jig micro-cleaning apparatus according to the present invention, the sandbox ( 200 ) and the air supply unit ( 300 ) may adjust supply amounts of air and sand under control of the controller ( 400 ). 
     In the welding jig micro-cleaning apparatus according to the present invention, the housing ( 100 ) may include a housing door ( 110 ), and the housing door ( 110 ) may include an observation window ( 120 ). 
     In the present invention, one or more constructions that do not conflict with each other may be selected and combined from among the above constructions. 
     Advantageous Effects 
     A welding jig micro-cleaning apparatus according to the present invention is capable of removing pollutants, such as spatter, from a welding jig during a laser welding process, thereby improving laser welding quality. 
     The present invention has an advantage in that a welding jig cleaning effect is improved through horizontal movement and upward-downward rotation of a jig fixing portion. 
     The welding jig micro-cleaning apparatus according to the present invention is located in a hermetically sealed housing, whereby it is possible to prevent secondary pollution due to cleaning. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a schematic view of a battery cell according to an embodiment of the present invention. 
         FIG.  2    is a perspective view showing the external appearance of a welding jig micro-cleaning apparatus according to an embodiment of the present invention. 
         FIG.  3    is a schematic view of the micro-cleaning apparatus according to the embodiment of the present invention located in a housing of  FIG.  2   . 
         FIG.  4    is a schematic view of a blasting gun according to an embodiment of the present invention. 
     
    
    
     BEST MODE 
     In the present application, it should be understood that the terms “comprises,” “has,” “includes,” etc. specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof. 
     In addition, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. In the case in which one part is said to be connected to another part in the specification, not only may the one part be directly connected to the other part, but also, the one part may be indirectly connected to the other part via a further part. In addition, that a certain element is included does not mean that other elements are excluded, but means that such elements may be further included unless mentioned otherwise. 
     Hereinafter, a micro-cleaning apparatus according to the present invention will be described with reference to the accompanying drawings. 
       FIG.  1    is a schematic view of a battery cell according to an embodiment of the present invention. 
     Referring to  FIG.  1   , the battery cell  1  according to the embodiment of the present invention is a pouch-shaped secondary battery. The battery cell  1  may include a battery case  10 , an electrode assembly  20 , an electrode lead  30 , an insulating tape  40 , and an electrode tab  50 . 
     The battery case  10  may define the external appearance of the battery cell  1 , and may receive the electrode assembly  20 , the electrode lead  30 , and the electrode tab  50 , a description of which will follow, therein. The battery case  10  may be configured in the form of an aluminum pouch, and an aluminum thin film may be interposed between an insulating layer made of a polymer material and an adhesive layer made of a polymer material of the aluminum pouch. 
     The electrode assembly  20  may be received in the battery case  10 , and may include a positive electrode plate, a negative electrode plate, and a separator. Each of the electrode plates (positive electrode plates and negative electrode plates) of the electrode assembly  20  may be configured to have a structure in which an active material slurry is applied to an electrode current collector. The active material slurry may generally be formed by stirring active material particles, an auxiliary conductor, a binder, and a plasticizer in the state in which a solvent is added thereto. Each electrode plate may have an uncoated portion to which the active material slurry is not applied, and an electrode tab  50 , a description of which will follow, corresponding to each electrode plate may be formed at the uncoated portion. 
     The electrode lead  30  may be electrically connected to the electrode assembly  20 , and may protrude outwards from the battery case  10 . A pair of electrode leads  30  may be provided, and the pair of electrode leads  30  may include a positive electrode lead and a negative electrode lead. 
     The pair of electrode leads  30  may be connected to the electrode assembly  20 , and may protrude outwards from the battery case  10  in the same direction or in opposite directions. 
     The insulating tape  40  may be provided so as to correspond in number to the electrode lead  30 . In this embodiment, therefore, a pair of insulating tapes  40  may be provided. 
     The pair of insulating tapes  40  may prevent the occurrence of short circuiting between the battery case  10  and the electrode lead  30  and may increase sealing force of the battery case  10 . 
     The electrode tabs  50  may protrude from the electrode assembly  20  in order to connect the electrode lead  30  and the electrode assembly  20  to each other. Here, the electrode tab  50  may include a positive electrode tab and a negative electrode tab, each of which may be formed so as to protrude from the electrode assembly  20 . That is, the positive electrode tab may be formed so as to protrude from the positive electrode plate of the electrode assembly  20 , and the negative electrode tab may be formed so as to protrude from the negative electrode plate of the electrode assembly  20 . 
     The electrode tab  50  may include a plurality of positive electrode tabs and a plurality of negative electrode tabs. In this case, the plurality of positive electrode tabs may be connected to the positive electrode lead, which is one of the electrode leads  30 , and the plurality of negative electrode tabs may be connected to the negative electrode lead, which is the other of the electrode leads  30 . 
     The electrode tab  50  may be coupled to the electrode lead  30  by laser welding. Laser welding exhibits higher welding strength than ultrasonic welding, i.e. conventional main ultrasonic welding, and does not require a considerable welding width, which is required by the main ultrasonic welding. In addition, for laser welding, problems, such as wear or bending of equipment and burning of the electrode tab  50 , do not occur when welding is performed, unlike the conventional main ultrasonic welding. 
     In addition, for laser welding, the electrode lead  30  and the electrode tab  50  may be fixed and supported by a welding jig. Pollutants, such as spatter, generated during laser welding may attach to the welding jig, which leads to poor welding between the electrode lead  30  and the electrode tab  50 . 
       FIG.  2    is a perspective view showing the external appearance of a welding jig micro-cleaning apparatus according to an embodiment of the present invention,  FIG.  3    is a schematic view of the micro-cleaning apparatus according to the embodiment of the present invention located in a housing of  FIG.  2   , and  FIG.  4    is a schematic view of a blasting gun according to an embodiment of the present invention. 
     Referring to  FIGS.  2  to  4   , the welding jig micro-cleaning apparatus according to the embodiment of the present invention may include a housing  100 , a sandbox  200 , an air supply unit  300 , a controller  400 , a jig fixing portion  600 , and a blasting gun  500 . The jig fixing portion and the blasting gun may be located in the housing  100 . 
     First, when describing the housing  100  in detail, the housing is a portion that defines the external appearance of the welding jig micro-cleaning apparatus. The housing  100  may be formed in a hexahedral shape having an empty inner space. A housing door  110  may be located at an upper part of a front end of the housing  100 . The housing door  110  may be configured to open and close a part of a front surface of the housing  100  and a part of an upper end of the housing. After the housing door  110  is opened, a welding jig  700 , a description of which will follow, may be mounted to the jig fixing portion  600  located in the housing or may be separated from the jig fixing portion  600  and taken out to the outside. The housing door  110  may be manually opened and closed, and may be connected to an automatic control system so as to be automatically opened and closed as needed. A sealing means may be provided at a portion at which an edge of the housing door  110  and the housing  100  are connected to each other in tight contact with each other in order to hermetically seal the interior of the housing, whereby it is possible to prevent polluted sand or other pollutants dispersed during cleaning from being discharged to the outside. 
     An observation window  120  may be provided in a front surface (x-z plane) of the housing door  110 . Cleaning of the welding jig  700  in the housing  100  may be observed through the observation window  120 . 
     Next, the sandbox  200  and the air supply unit  300  will be described in detail. 
     The sandbox  200  may be located above the housing  100 , and the air supply unit  300  may be connected to the sandbox  200 . The sandbox  200  may be formed in an approximately cylindrical shape or an approximately hexahedral shape. However, the shape of the sandbox is not particularly restricted as long as sand and other necessary members can be received in an inner space thereof. 
     The air supply unit  300  may be an air compressor. Compressed air from the air supply unit  300  may be supplied to the sandbox  200  through a compressed air supply hose (not shown). A compressed air distribution means (not shown), a cut-off valve (not shown), a pressure control valve (not shown), and a flow control valve (not shown) may be disposed in the compressed air supply hose. Compressed air from the air supply unit  300  may be supplied to the sandbox  200  and other rear equipment through the compressed air distribution means. 
     First compressed air (not shown), which is some of compressed air from the air supply unit  300 , may be supplied to the sandbox  200  through a connection pipe (not shown) so as to be mixed with sand. 
     A sand and air discharge port (not shown) may be located at a lower end of the sandbox  200 , and a three-way valve (not shown) may be located in the air discharge port. Sand and air mixed in the sandbox  200  may be introduced into a first hole of the three-way valve, and second compressed air (not shown), which is compressed air from the air supply unit  300 , may be introduced into a second hole of the three-way valve. The compressed air introduced into the second hole and the sand and air mixture introduced into the first hole may be discharged together through a third hole of the three-way valve. Here, the third hole may be connected to a supply hose  530  in order to transfer the sand supplied from the sandbox  200  to the blasting gun  500 . The amount and flow speed of sand supplied to the supply hose  530  may be adjusted using the first compressed air and the second compressed air, and a control valve (not shown) may be mounted on a transfer line for the first compressed air and the second compressed air in order to adjust the flow rate of compressed air. 
     Next, the controller  400  will be described. 
     The controller  400  according to the present invention may be connected to a side surface of the housing  100 . The controller  400  may control driving of the air supply unit  300 , operation of the control valve (not shown) configured to adjust flow rate of compressed air, upward and downward movement of a support portion  550  of the blasting gun  500 , a description of which will follow, on and off of a magnetic unit, and horizontal movement and rotation of a sliding unit  620 , a description of which will follow. 
     Next, the blasting gun  500  will be described. 
     In the present invention, a supply hose  530  connected to the third hole of the three-way valve located at the lower end of the sandbox  200  is connected to the blasting gun  500  to supply the sand and the compressed air discharged from the third hole of the three-way valve to the blasting gun  500 . A discharge hose  520  is located spaced apart from the supply hose  530  by a predetermined distance, and the supply hose  530  and the discharge hose  520  extend into a body portion  540  so as to be connected to the body portion  540 . Flow of a fluid in the supply hose  530 , the discharge hose  520 , and the body portion  540  will be described below in detail. The sand and the compressed air introduced into the body portion  540  through the supply hose  530  are sprayed through a blasting gun inlet  510  to remove pollutants from the welding jig  700 , a description of which will follow. The body portion  540 , which is connected to the supply hose  530  and the discharge hose  520 , may be fixed to a side wall of the housing  100  via the support portion  550 . In addition, the support portion  550  may be controlled by the controller so as to be movable upwards and downwards. The support portion  550  may be coupled to a vertical moving cylinder (not shown) so as to be movable upwards and downwards, and the vertical moving cylinder may be controlled by the controller  400 . 
     Referring to  FIG.  4   , the blasting gun inlet  510  may include a discharge port  511  and a suction port  512 . The discharge port  511  may be located at a tip end of an internal flow path (not shown) of the body portion  540  to which the supply hose  530  extending into the body portion  540  is connected. The discharge port  511  may spray the sand and the compressed air supplied from the supply hose  530  to the welding jig  700 , a description of which will follow, disposed thereunder in order to clean the welding jig. The internal flow path of the body portion  540  may be a hose or a stainless steel pipe. A partition wall of the body portion  540  is spaced apart from a partition wall of the internal flow path while wrapping the internal flow path of the body portion  540 , whereby a space functioning as an external flow path (not shown) is formed. The partition wall of the body portion  540  and the partition wall of the internal flow path are spaced apart from each other, whereby the suction port  512  is formed at a tip end of the blasting gun inlet  510 . The suction port  512  is located around the discharge port  511 . The discharge hose  520  is connected to the body portion  540  through the partition wall of the body portion so as to be opposite the suction port  512  in the state in which the external flow path is located therebetween. During a process in which the sand and the compressed air are sprayed through the discharge port  511  to remove pollutants from the welding jig  700  in order to clean the welding jig, the sprayed sand and the pollutants separated from the welding jig  700  are suctioned through the suction port  512 . 
     A sealing portion  560  may be located at an external partition wall around the blasting gun inlet  510 . The sealing portion  560  may be coupled to the circumference of the blasting gun inlet  510  so as to extend outwards from the body portion  540 , or may be configured to receive the welding jig  700  mounted to the jig fixing portion  600 , a description of which will follow, therein. 
     A tip end surface of the sealing portion  560  may be brought into tight contact with an upper end surface of a die  610 , a description of which will follow, and specifically may be made of an elastic material, such as silicone or synthetic rubber. The reason for this is that, when the jig fixing portion  600  is moved leftwards and rightwards or upwards and downwards, the jig fixing portion comes into contact with the sealing portion  560 , whereby damage, such as scratch, to the welding jig  700  mounted to the jig fixing portion  600  is prevented. In addition, the sealing portion  560  may be permanently fixed to the circumference of the blasting gun inlet  510  by adhesion, or may be detachably attached thereto through an attachment and detachment means. Here, the tip end surface of the sealing portion  560 , which is brought into tight contact with the die  610 , a description of which will follow, may be coated with a metal material. In this case, the extent of tight contact between the sealing portion and the die  610  is improved by a magnetic unit  640 , a description of which will follow, which is advantageous in suctioning the removed pollutant, such as spatter. 
     Next, the jig fixing portion  600  will be described in detail. 
     The jig fixing portion  600  may be located under the blasting gun  500 , and may include a die  610 , a sliding unit  620 , a sliding slit  630 , and a magnetic unit  640 . The welding jig  700  is located at an upper end of the die  610  so as to be cleaned by the sand and the compressed air sprayed from the discharge port  511  of the blasting gun  500 . The die  610  may have a plate shape. The magnetic unit  640  may be located at the die  610  in order to fix the welding jig  700 , whereby it is possible to prevent separation or displacement of the welding jig  700  during a cleaning process. The magnetic unit  640  may be constituted by a permanent magnet or an electromagnet. In the case in which the magnetic unit is constituted by an electromagnet, an on-off lever (not shown) may be provided. The magnetic unit  640  may be magnetized or demagnetized by manipulation of the on-off lever. In addition, magnetic force of the magnetic unit may be controlled. In the present invention, therefore, it is preferable for the magnetic unit  640  to be constituted by an electromagnet. 
     The die  610  may be connected to the sliding unit  620 , and the sliding unit  620  may be connected to a rear sliding driving portion (not shown) through the sliding slit  630 , which is formed in the partition wall of the housing  100 . The sliding unit  620  may be moved leftwards and rightwards in a horizontal direction by manipulation of the sliding driving portion. After the welding jig  700  is mounted to the upper end of the die  610 , the welding jig  700  may be moved under the blasting gun inlet  510  through operation of the sliding unit  620 , and cleaning may be performed. 
     In addition, a hinge coupling portion (not shown) provided at the sliding unit  620  to allow the die  610  to be rotated by a predetermined angle may be included. As a result, a disposition angle of the welding jig  700  may be adjusted, which is advantageous in effectively removing pollutants from a bent portion of the welding jig  700  through cleaning. 
     Although the specific details of the present invention have been described in detail, those skilled in the art will appreciate that the detailed description thereof discloses only preferred embodiments of the present invention and thus does not limit the scope of the present invention. Accordingly, those skilled in the art will appreciate that various changes and modifications are possible, without departing from the category and technical idea of the present invention, and it will be obvious that such changes and modifications fall within the scope of the appended claims. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           1 : Battery cell 
           10 : Battery case 
           20 : Electrode assembly 
           30 : Electrode lead 
           40 : Insulating tape 
           50 : Electrode tab 
           100 : Housing 
           110 : Housing door 
           120 : Observation window 
           200 : Sandbox 
           300 : Air supply unit 
           400 : Controller 
           500 : Blasting gun 
           510 : Blasting gun inlet 
           511 : Discharge port 
           512 : Suction port 
           520 : Discharge hose 
           530 : Supply hose 
           540 : Body portion 
           550 : Support portion 
           560 : Sealing portion 
           600 : Jig fixing portion 
           610 : Die 
           620 : Sliding unit 
           630 : Sliding slit 
           640 : Magnetic unit 
           700 : Welding jig