Patent Publication Number: US-2023140262-A1

Title: Anti-loosening fastener for fuel cell stacks

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. § 119(a) to Korean patent application number 10-2021-0148607 filed on Nov. 2, 2021, the entire disclosure of which is incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to an anti-loosening fastener for fuel cell stacks, and more particularly, to an anti-loosening fastener for fuel cell stacks, which is capable of maintaining performance of a fuel cell stack and prolonging a life of a fuel cell by preventing the fastener for coupling unit cells of the fuel cell stack from loosening due to vibration generated during driving. 
     2. Related Art 
     In general, a fuel cell stack is formed by stacking a plurality of unit cells. In the fuel cell stack, the cathode of one unit cell is electrically connected to the anode of an adjacent unit cell, and the unit cells are fastened to each other at the same pressure as a whole when they are stacked in order to prevent leakage, bending, and the like. 
     The fuel cell stack includes a separator, a gasket, a gas diffusion layer, a membrane electrode assembly (MEA), a compression plate, a current collector, etc., and these components are included in each unit cell. The fuel cell stack is manufactured by stacking unit cells according to the desired output and finally fastening them using full threaded bolts. 
     In a fuel cell stack manufactured by fastening unit cells using a plurality of full threaded bolts and nuts to maintain the unit cells at the same interval and pressure, the nuts may be pushed back due to vibration generated during driving. 
     This may cause damage or the like to the fuel cell stack. In this case, various methods such as use of double nuts, washer insertion, and coupling using bonds have been applied in order to prevent the loosening of the nuts fastened to the full threaded bolts as described above. However, these methods also do not prevent completely the loosening of the nuts. 
     Conventionally, Korean Patent No. 10-179060 (Sep. 11, 2017) discloses a bolt assembly having an anti-loosening nut, but there is a problem in that the nut is loosened when excessive vibration occurs. In addition, Korean Patent No. 10-1103171 (Dec. 29, 2011) discloses an insert anti-loosening nut, but there is a problem in that the nut is loosened when nylon rings or synthetic resin molded articles deteriorate over time. 
     Patent Document 
     Korean Patent No. 10-179060 (Sep. 11, 2017) 
     Korean Patent No. 10-1103171 (Dec. 29, 2011) 
     SUMMARY 
     Various embodiments are directed to an anti-loosening fastener for fuel cell stacks, which is capable of having a simple structure to ensure productivity or reliability of operation and prevent a fastening force of the fastener from decreasing due to vibration generated during driving, thereby maintaining performance of a fuel cell stack and prolonging a life of a fuel cell. 
     In accordance with an aspect of the present disclosure, there is provided an anti-loosening fastener for fuel cell stacks, including:
     a full threaded bolt ( 100 ) exposed through a fuel cell stack and provided with a threadless part ( 110 ) having a predetermined length;   a positioner ( 200 ) screwed to a male threaded part ( 120 ) of the full threaded bolt ( 100 ) and having a coupling hole ( 241 ) coupled to a stopper ( 300 ); and   the stopper ( 300 ) slidably fitted to the threadless part ( 110 ) of the full threaded bolt ( 100 ) while having a stopper protrusion ( 330 ) coupled to the coupling hole ( 241 ). Accordingly, it is possible to prevent a fastening force of the fastener from decreasing due to vibration generated during driving, to maintain the performance of the fuel cell stack and prolong the life of the fuel cell, and to ensure reliability of operation.   

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view illustrating an anti-loosening fastener for fuel cell stacks according to an embodiment of the present disclosure. 
         FIG.  2    is an exploded perspective view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure. 
         FIG.  3    is an exploded bottom perspective view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure. 
         FIG.  4    is a longitudinal cross-sectional view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure. 
         FIG.  5    is an exploded perspective view illustrating an anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure. 
         FIG.  6    is an exploded bottom perspective view illustrating the anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure. 
         FIG.  7    is a longitudinal cross-sectional view illustrating the anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, specific embodiments will be described with reference to the accompanying drawings since the present disclosure may be subjected to various modifications and have various examples. It should be understood, however, that the present disclosure is not intended to be limited to the specific embodiments, but the present disclosure includes all modifications, equivalents or replacements that fall within the spirit and scope of the disclosure as defined in the following claims. 
     These embodiments are provided to explain the present disclosure in more detail to those skilled in the art to which the present disclosure pertains. The drawings are not necessarily to scale and in some instances, proportions may have been exaggerated in order to clearly illustrate features of the embodiments. In certain embodiments, a detailed description of configurations well known in the art may be omitted to avoid obscuring appreciation of the disclosure by those skilled in the art. 
     Terms such as “first” and/or “second” may be used herein to describe various elements of the present disclosure, but these elements should not be construed as being limited by the terms. These terms will be used only for the purpose of differentiating one element from other elements of the present disclosure. 
     The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     In the disclosure, terms such as “comprises/includes” and/or “have/has” should be construed as designating that there are such features, integers, steps, operations, components, parts, and/or combinations thereof, not to exclude the presence or possibility of adding of one or more of other features, integers, steps, operations, components, parts, and/or combinations thereof. 
     First, the present disclosure may include one of a full threaded bolt  100 , a positioner  200 , and a stopper  300 . 
     Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. 
       FIG.  1    is a perspective view illustrating an anti-loosening fastener for fuel cell stacks according to an embodiment of the present disclosure.  FIG.  2    is an exploded perspective view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure.  FIG.  3    is an exploded bottom perspective view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure.  FIG.  4    is a longitudinal cross-sectional view illustrating the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure. 
     Referring to  FIGS.  1  to  4   , the anti-loosening fastener for fuel cell stacks according to the embodiment of the present disclosure includes a full threaded bolt  100  exposed through a fuel cell stack and provided with a threadless part  110  having a predetermined length, a positioner  200  screwed to a male threaded part  120  of the full threaded bolt  100  and having a coupling hole  241  coupled to a stopper protrusion  330 , and a stopper  300  slidably fitted to the threadless part  110  of the full threaded bolt  100  while having the stopper protrusion  330  coupled to the coupling hole  241 . 
     The full threaded bolt  100  is provided with a male thread having a predetermined pitch and formed over the entire length thereof on the outer periphery thereof having a predetermined diameter. The threadless part  110  is formed to have a D-shape by planing the outer periphery of the full threaded bolt  100  by a predetermined length, so that the threadless part  110  is slidably fitted into a guide hole  320  of a stopper body  310 , which will be described later, thereby preventing the stopper  300  from rotating. 
     The positioner  200  is screwed to the male threaded part  120  of the full threaded bolt  100  to laterally apply a pressing or tightening force thereto. The positioner  200  includes a female threaded part  220  formed on the inner periphery thereof and screwed to the male threaded part  120  of the full threaded bolt  100 , and a positioner body  230  having a polygonal tool latching part formed on the outer periphery thereof. 
     The stopper protrusion  330  is coupled to the coupling hole  241  formed in the positioner body  230 , thereby completely preventing the positioner  200  from loosening or being decoupled from the full threaded bolt  100  due to vibration. The coupling hole  241  has a predetermined diameter and depth and may consist of one or more coupling holes provided at equal intervals between the female threaded part  220  and the positioner body  230 . Such multiple coupling holes  241  enables the positioner  200  to remain fixed at an optimal position by increasing or decreasing a tightening force. 
     The stopper  300  serves to fundamentally prevent the positioner  200  screwed to the full threaded bolt  100  from rotating. The guide hole  320  is formed in the stopper body  310  having the same shape as the positioner body  230  in external appearance, and has a D-shape so that it is slidably fitted to the threadless part  110  of the full threaded bolt  100 . 
     To this end, each of the coupling holes  241  is formed in the positioner body  230 , and the stopper protrusion  330  is fitted into the coupling hole  241 . Here, the stopper protrusion  330  may have a cylindrical shape for easy manufacture and assembly. 
       FIG.  5    is an exploded perspective view illustrating an anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure.  FIG.  6    is an exploded bottom perspective view illustrating the anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure.  FIG.  7    is a longitudinal cross-sectional view illustrating the anti-loosening fastener for fuel cell stacks according to another embodiment of the present disclosure. 
     In the anti-loosening fastener for fuel cell stacks according to the previous embodiment, the male threaded part  120  of the full threaded bolt  100  is screwed to the female threaded part  220  of the positioner  200 , and the stopper  300  is slidably fitted to the threadless part  110  provided in the full threaded bolt  100  while the stopper protrusion  330   provided on the stopper body  310  is fitted into the coupling hole  241  in order to prevent loosening of them. In addition to such a configuration, as illustrated in  FIGS.  5  to  7   , the anti-loosening fastener for fuel cell stacks according to the present embodiment includes a full threaded bolt  100 , a positioner  200 , and a stopper  300 . The positioner  200  includes a female threaded part  220  formed on the inner periphery thereof and screwed to a male threaded part  120  of the full threaded bolt  100 , a positioner body  230  having a polygonal latching part  250  formed on the outer periphery thereof, and an inner female threaded part  251  through which a set screw  260  is screwed to the polygonal latching part  250 . 
     The stopper  300  has a guide hole  320  having a D-shape and formed on the top of a stopper body  310  having a positioner insertion space  311  which is open at the bottom thereof. The stopper  300  has an outer female threaded part  313  through which each set screw  260  is screwed to the outer portion of the stopper body  310  when the positioner body  230  is coupled to the positioner insertion space  311  of the stopper  300  and the stopper  300  is slidably fitted to the threadless part  110 , provided in the full threaded bolt  100 , through the D-shaped guide hole  320  formed on the top of the stopper body  310 . The set screw  260  screwed to the outer female threaded part  313  is pressed against the male threaded part  120  of the full threaded bolt  100  by passing through the inner female threaded part  251  of the positioner body  230 . 
     As is apparent from the above description, the anti-loosening fastener according to the present disclosure can have a simple structure to ensure productivity or reliability of operation. 
     In addition, this enables the fastening force of the fastener to be prevented from decreasing due to vibration generated during driving. 
     Moreover, it is possible to maintain the performance of the fuel cell stack and prolong the life of the fuel cell. 
     While the present disclosure has been described with respect to the embodiments illustrated in the drawings, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Therefore, it will be understood by those skilled in the art that various substitutions, modifications, and variations may be made without departing from the spirit and scope of the disclosure as defined in the following claims.