Patent Publication Number: US-2023150073-A1

Title: Snap-fit structure and method of assembling snap-fit structure

Description:
BACKGROUND 
     Field of the Invention 
     The present disclosure relates to a snap-fit structure and a method of assembling the snap-fit structure. 
     Description of the Related Art 
     Japanese Patent Laid-Open No. 2004-332762 discloses a technique of providing a dimension-maintaining member for maintaining a dimension between opposing snap-fit portions (engaging portions) in a mounting hole. 
     However, in the technique disclosed in Japanese Patent Laid-Open No. 2004-332762, since the dimension-maintaining member is arranged on a side where an engaging portion elastically deforms, space on the side where the engaging portion elastically deforms cannot be effectively utilized. 
     An object of the present disclosure is to provide a snap-fit structure in which the space on the side where the engaging portion elastically deforms can be effectively utilized. 
     SUMMARY 
     In order to achieve the object, a snap-fit structure of the present disclosure comprises a mounting component with a first engaging portion and a second engaging portion and a mounted component formed with an engaged portion for engaging the first engaging portion and the second engaging portion, wherein the second engaging portion is arranged in a position not aligned on the same line in a direction in which the first engaging portion elastically deforms. 
     Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of a common snap-fit structure; 
         FIG.  2    is a schematic diagram of the common snap-fit structure viewed from above; 
         FIGS.  3 A and  3 B  are schematic diagrams showing how disengagement occurs in the common snap-fit structure; 
         FIG.  4    is a schematic diagram of a snap-fit structure according to the present embodiment; 
         FIG.  5    is a schematic diagram of the snap-fit structure according to the present embodiment as viewed from above; 
         FIG.  6    is a schematic diagram of the snap-fit structure according to the present embodiment as viewed from above; 
         FIG.  7    is a schematic diagram of a first mounted component viewed from above; 
         FIG.  8    is a schematic diagram of the first mounted component viewed from above; 
         FIG.  9    is a schematic cross-sectional view taken along line IX-IX shown in  FIG.  5   ; 
         FIGS.  10 A,  10 B, and  10 C  are schematic diagrams showing a method of assembling the snap-fit structure according to the present embodiment; 
         FIG.  11    is a schematic diagram of the first mounted component according to the present embodiment as viewed from above; 
         FIG.  12    is a schematic diagram of the first mounted component according to the present embodiment as viewed from above; 
         FIG.  13    is a schematic diagram of the snap-fit structure according to the present embodiment as viewed from above; 
         FIGS.  14 A and  14 B  are schematic diagrams of the snap-fit structure according to the present embodiment as viewed from above; 
         FIGS.  15 A,  15 B, and  15 C  are schematic diagrams showing a method of assembling the snap-fit structure according to the present embodiment; 
         FIG.  16    is a diagram schematically showing a component using the snap-fit structure of the present disclosure; and 
         FIG.  17    is an enlarged view schematically showing the vicinity of an opening of a sub tank. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     A common snap-fit structure will be described below to facilitate understanding of a snap-fit structure of the present disclosure. 
       FIG.  1    is a schematic diagram of a common snap-fit structure. The common snap-fit structure includes a mounting member  10  and a mounted member  20  on which the mounting member  10  is mounted. The mounting member  10  includes an engaging portion  11  having elasticity. The mounted member  20  includes a hole portion  21 . In a case where the mounting member  10  is mounted on the mounted member  20 , the engaging portion  11  is pressed into the hole portion  21  while being elastically deformed and reduced in diameter. Then, after the engaging portion  11  passes through the hole portion  21 , the engaging portion  11  returns to an original shape due to an elastic restoring force. As a result, the engaging portion  11  can be engaged with the hole portion  21 . That is, the snap-fit structure makes it possible to easily mount the mounting member  10  on the mounted member  20  only by pressing the engaging portion  11  into the hole portion  21 . 
       FIG.  2    is a schematic diagram of the common snap-fit structure viewed from above. Above means a +Z direction shown in  FIG.  1   . As shown by a two-dot chain line in  FIG.  2   , the two engaging portions  11  are arranged so that surfaces on a side in a direction of elastic deformation are aligned on the same line inside the hole portion  21 . That is, inside the hole portion  21 , the two engaging portions  11  are back to back on the same line in the direction of elastic deformation (X-axis direction). Hereinafter, a plane on the side in the direction in which the engaging portion  11  elastically deforms will be referred to as a “back side” as appropriate. The two engaging portions  11  being aligned so that their back sides face each other is appropriately referred to as “back to back.” 
       FIGS.  3 A and  3 B  are schematic diagrams showing how the common snap-fit structure is disengaged. As shown in  FIG.  3 A , it is assumed that after the mounting member  10  is mounted on the mounted member  20 , a force is applied in a direction in which the engaging portion  11  is elastically deformed (an arrow P 1  direction). This causes the engaging portion  11  to be elastically deformed and reduced in diameter. As shown in  FIG.  3 B , in a case where the engaging portion  11  is reduced in diameter, the engaging portion  11  cannot engage the mounted member  20 . Then, a force is applied in a gravity direction (an arrow P 2  direction) and the mounting member  10  is disengaged from the mounted member  20 . Up to this point the common snap-fit structure has been described. 
     First Embodiment 
       FIG.  4    is a schematic diagram of a snap-fit structure according to the present embodiment. As shown in  FIG.  4   , the snap-fit structure according to the present embodiment includes a first mounting component  40  and a first mounted component  50 . The first mounting component  40  includes a snap-fit portion  41  as an engaging portion that engages the first mounted component  50 . On the other hand, the first mounted component  50  includes an opening  51  as an engaged portion engaged by the snap-fit portion  41 . In the present embodiment, the snap-fit portion  41  engages an opening  51  formed in the first mounted component  50 . As a result, the first mounting component  40  can be mounted on the first mounted component  50 . 
       FIG.  5    is a schematic view of the snap-fit structure according to the present embodiment as viewed from above. As shown in  FIG.  5   , the snap-fit portion  41  includes an elastically deformable first engaging portion  41   a  and an elastically deformable second engaging portion  41   b . The first engaging portion  41   a  and the second engaging portion  41   b  are arranged so as not to be aligned with each other on the same line in the direction of elastic deformation (X-axis direction). That is, the first engaging portion  41   a  and the second engaging portion  41   b  are arranged so as not to be back to back. 
     The configuration enables space on the back side of the first engaging portion  41   a  or space on the back side of the second engaging portion  41   b  to be larger than in a case where the first engaging portion  41   a  and the second engaging portion  41   b  are arranged back to back. That is, this configuration makes it possible to effectively utilize at least one of the space on the back side of the first engaging portion  41   a  and the space on the back side of the second engaging portion  41   b . For example, the second engaging portion  41   b  is not arranged on the back side of the first engaging portion  41   a . Thus, another component (not shown) can be arranged on the back side of the first engaging portion  41   a . Accordingly, the snap-fit structure according to the present embodiment makes it possible to effectively utilize the space on the side where the snap-fit portion  41  elastically deforms. 
     Second Embodiment 
       FIG.  6    is a schematic view of the snap-fit structure according to the present embodiment as viewed from above. An object of the present embodiment is to provide a snap-fit structure in which disengagement is less likely to occur. The snap-fit structure according to the present embodiment is different from the snap-fit structure according to the first embodiment in the arrangement of the opening  51  and in that the snap-fit structure according to the present embodiment includes a film  60 . In the following description, the same reference numeral will be given to the same or corresponding constituent as in the first embodiment, the description thereof will be omitted, and a difference will be mainly described. 
     Entire Configuration 
     As shown in  FIG.  6   , the opening  51  according to the present embodiment includes a first opening  51   a  for engaging the first engaging portion  41   a  and a second opening  51   b  for engaging the second engaging portion  41   b . That is, the first engaging portion  41   a  engages the first opening  51   a . On the other hand, the second engaging portion  41   b  engages the second opening  51   b . The first mounted component  50  according to the present embodiment includes a first column portion  52  as a base to which the film  60  is adhered (thermal-sealed, for example). The first column portion  52  protrudes toward an insertion direction (to be described later) of the snap-fit portion  41 . Further, the first mounted component  50  according to the present embodiment includes the film  60  as a suppressing portion that suppresses elastic deformation of the snap-fit portion  41 . 
     First Mounted Component  50   
       FIG.  7    is a schematic diagram of the first mounted component  50  viewed from above. For convenience of description,  FIG.  7    does not illustrate the film  60 . A material for the first mounted component  50  is not limited as long as the first mounted component  40  can be mounted. For example, resin, metal, ceramic, or a combination thereof can be used as a material for the first mounted component  50 . In the present embodiment, polypropylene is used as a material for the first mounted component  50  and the first column portion  52 . This is to strengthen adhesion between the first column portion  52  and the film  60 . Incidentally, adhesion of the film  60  will be described later. 
     Opening  51   
     The first opening  51   a  and the second opening  51   b  are formed in positions where the first opening  51   a  and the second opening  51   b  are not arranged on the same line in the direction (X-axis direction) in which the snap-fit portion  41  elastically deforms, that is, in different positions on a Y-axis. For example, the second opening  51   b  is not arranged on the same line in a direction in which the first engaging portion  41   a  elastically deforms. 
     First Column Portion  52   
     The first mounted component  50  according to the present embodiment includes a first column portion  52  on an upper surface (+Z direction side surface). The first column portion  52  extends from the first mounted component  50  in the insertion direction (in a Z-axis direction) of the snap-fit portion  41  by about 0.5 mm to about 1.0 mm. That is, the height of the first column portion  52  is about 0.5 mm to about 1.0 mm. The first column portion  52  is arranged in a position where the elastic deformation of the snap-fit portion  41  is not inhibited. For example, the two first column portions  52  are formed in positions sandwiching the first opening  51   a  along the direction in which the first engaging portion  41   a  elastically deforms. 
     It should be noted that the film  60  can be thermally welded directly to the first mounted component  50  without the first column portion  52 . However, it is preferable to bond the film  60  via the first column portion  52 . For example, it is assumed that the film  60  is welded directly to the first mounted component  50  without the first column portion  52  interposed therebetween. In this case, it is assumed that the first mounted component  50  is warped. This is because in this case, the distortion of the first mounted component  50  cannot be released and there is possibility that the film  60  may be peeled off from the first mounted component  50 . 
     Further, in a case where the molding accuracy of the upper surface of the first mounted component  50  is low, the upper surface of the first mounted component  50  has more concavities and convexities than the upper surface of the first mounted component  50  having good molding accuracy. Thus, in a case where the film  60  is thermally welded to the first mounted component  50 , there is a possibility that air accumulating in a concave portion may thermally expand. In a case where the air accumulating in the concave portion thermally expands, the film  60  is peeled off from the first mounted component  50 . 
     On the other hand, in a case where the first column portion  52  and the film  60  are thermal-welded, the thermal expansion described above can be suppressed at least in a case where the top surface of the first column portion  52  is smooth. That is, intentionally providing the first column portion  52  makes it possible to lessen a region requiring high molding accuracy. Thus, providing the first column portion  52  makes it easier to mold the first mounted component  50 . 
     Film  60   
       FIG.  8    is a schematic diagram of the first mounted component  50  viewed from above. It should be noted that  FIG.  8    illustrates the film  60 . A material for the film  60  is not limited as long as the member can suppress the elastic deformation of the snap-fit portion  41  by using flexibility. For example, a resin film can be used as a material for the film  60 . Specifically, the film  60  may be formed of two upper and lower film layers, the upper layer being a PET film layer, the lower layer being a CPP layer. 
     In the present embodiment, the film  60  has the function of holding the snap-fit portion  41  from above. In the present embodiment, in a case where the first mounting component  40  is mounted on the first mounted component  50 , a leading end  92  (to be described later) of the snap-fit portion  41  contacts the film  60 . As a result, the elastic deformation of the snap-fit portion  41  is suppressed and the snap-fit portion  41  is less likely to be reduced in diameter. That is, the film  60  holds the snap-fit portion  41  from above, so that the first mounting component  40  is less likely to be disengaged from the first mounted component  50 . Accordingly, considering strength at the time of holding the snap-fit portion  41  with the film  60 , the film  60  preferably includes a resin film (e.g., a PET film layer) having strength. 
     The film  60  also preferably includes a CPP layer underneath the PET film. As described above, a material for the first column portion  52  is polypropylene. Thus, the CPP layer included in the film  60  becomes a compatible layer during thermal welding. As a result, the film  60  and the first column portion  52  can be adhered more tightly. Further, using a resin film as a material for the film  60  facilitates the process of cutting the film  60  (described later). 
     Even in a case where a rigid component (e.g., a block or the like) is used instead of the film  60  as an elastic-deformation-suppressing member arranged on the back side of the snap-fit portion  41 , a disengagement-suppressing effect can be obtained. However, there is also a case where it is necessary to arrange a different component on the back side of the snap-fit portion  41 . In a case where the film  60  is used to hold the snap-fit portion  41  from above, there is no need to install the rigid component as an elastic-deformation-suppressing member on the back side of the snap-fit portion  41 . Thus, a different component can be arranged on the back side of the snap-fit portion  41 . 
     No matter what kind of shape the leading end  92  of the snap-fit portion  41  has, the snap-fit portion  41  can be held so as to be wrapped by using the film  60  having flexibility. The snap-fit portion  41  can also be held so as to be wrapped by using the film  60  with flexibility no matter what portion of the snap-fit portion  41  the film  60  contacts. 
     Snap-Fit Portion  41   
       FIG.  9    is a schematic cross-sectional view taken along line IX-IX shown in  FIG.  5   . As shown in  FIG.  9   , the first engaging portion  41   a  includes a back side portion  91 , which is a surface on a side in a direction of elastic deformation and diameter reduction, and the leading end  92  that extends from the back side portion  91  and is located most distally in the insertion direction of the snap-fit portion  41  (in a Z-axis direction). The first engaging portion  41   a  also includes a slope portion  93  extending from the leading end  92  in the direction in which the first engaging portion  41   a  engages the first mounted component  50  and downward (that is, the −X direction and −Z direction in the drawing). Further, the first engaging portion  41   a  includes an engaging surface  94  extending from the lower end of the slope portion  93  in the direction of elastic deformation and diameter reduction. In a case where the first engaging portion  41   a  engages the first opening  51   a , the engaging surface  94  comes into contact with and runs on an end of the first opening  51   a . This stabilizes the engagement of the first opening  51   a.    
     In this embodiment, the snap-fit portion  41  has a shape such that the width gradually becomes greater downward from the leading end  92  in order to facilitate insertion into the opening  51 . The width from the back side portion  91  to the lower end of the slope portion  93  is represented as a width W. The width (the length in the X direction in the drawing) of the lower end of the snap-fit portion  41  is smaller than the width W. This facilitates the elastic deformation of the snap-fit portion  41 . 
     The first engaging portion  41   a  also has the back side portion  91 . As described above, the back side portions  91  of the two snap-fit portions  41  are arranged so as not to be aligned opposite to each other on the same line. A material for the first mounting component  40  is not limited as long as the component can be mounted on the mounted component  50 . For example, resin, metal, or a combination thereof is preferably used as a material for the first mounting component  40  in order to facilitate the elastic deformation of the snap-fit portion  41 . In the present embodiment, polypropylene is used for molding at low cost. 
     Method of Assembling the Snap-Fit Structure 
       FIGS.  10 A,  10 B, and  10 C  are schematic diagrams showing a method of assembling the snap-fit structure according to the present embodiment. The method of assembling the snap-fit structure according to the present embodiment includes the following steps. 
     First, in the case of mounting the first mounting component  40  on the first mounted component  50 , a user presses the first mounting component  40  in a mounting direction (insertion direction) into the first mounted component  50  while keeping the slope portion  93  into contact with the lower end of the opening  51 . Then, as the insertion proceeds, the snap-fit portion  41  is elastically deformed and reduced in diameter while being rubbed against the lower end of the opening  51  ( FIG.  10 A ). 
     Next, the user further presses the first mounting component  40  in the mounting direction into the first mounted component  50  while keeping the lower end of the slope portion  93  into contact with an inner peripheral surface of the opening  51 . Then, the leading end  92  comes into contact with the film  60 . The user further presses in the first mounting component  40  while keeping the leading end  92  in contact with the film  60 . Then, the film  60  flexes in a direction intersecting a direction in which the snap-fit portion  41  is reduced in diameter. In other words, the film  60  stretches (deforms) according to a force with which the user presses in (inserts) the first mounting component  40  ( FIG.  10 B ). At this time, a force to return to its original shape is generated in the stretched film  60 . Thus, the user may feel a repulsive force from the film  60  and find it difficult to press in the first mounting component  40 . However, as described above, a material for the film  60  is a resin film having a certain strength. Accordingly, the user can further presses in the first mounting component  40  with a force which is not enough to damage the film  60 . 
     The user then further presses in the first mounting component  40  in the insertion direction (in a Z-axis direction) until after the engaging surface  94  passes through the opening  51 . After the engaging surface  94  passes through the opening  51 , the elastically deformed snap-fit portion  41  returns to its original shape due to an elastic restoring force ( FIG.  10 C ). At this time, the presence of the first column portion  52  facilitates the insertion of the slope portion  93  into a gap between the upper surface of the first mounted component  50  and the film  60 . This is because in a case where there is no first column portion  52 , the user cannot create the gap between the upper surface of the first mounted component  50  and the film  60  without pressing in the first mounting component  40  with a stronger force. 
     Further, the snap-fit portion  41  can be reliably held using the film  60  by forming the first column portion  52  having the height of the first column portion  52  lower than a height from the engaging surface  94  to the leading end  92 . At this time, the film  60  contacts the slope portion  93  of the snap-fit portion  41  (in a Z-axis direction), the leading end  92 , and the tip side of the back side portion  91 . That is, in a case where the first mounting component  40  is mounted on the first mounted component  50 , at least a portion on the tip side in the back side portion  91  of the snap-fit portion  41  (in a Z-axis direction) is held by the film  60 . This suppresses elastic deformation of the back side of the snap-fit portion  41 . 
     Conclusion 
     In the snap-fit structure according to the present embodiment, there is no other snap-fit portion  41  on the same line in the direction (in the X-axis direction) in which the snap-fit portion  41  elastically deforms. As a result, even in a case where it is necessary to arrange a different component on the back side of the snap-fit portion  41 , the first mounting component  40  can be mounted on the first mounted component  50  in a space-saving manner. Further, in the snap-fit structure according to the present embodiment, a portion of the back side of the snap-fit portion  41  is held by the film  60 . This makes it possible to suppress the disengagement of the first mounting component  40  from the first mounted component  50  due to elastic deformation (due to diameter reduction) of the snap-fit portion  41 . 
     Third Embodiment 
     An object of the present embodiment is to provide a snap-fit structure in which the film  60  is less likely to peel off. A difference between the snap-fit structure according to the second embodiment and the snap-fit structure according to the present embodiment is the shape of a column portion. In the following description, the same reference numeral will be given to the same or corresponding constituent as in the second embodiment, the description thereof will be omitted, and a difference will be mainly described. 
       FIG.  11    is a schematic diagram of the first mounted component  50  according to the present embodiment as viewed from above. For convenience of description, the film  60  is not shown. As shown in  FIG.  11   , a second column portion  110  according to the present embodiment has a cylindrical shape smaller than the first column portion  52 . It should be noted that the shape of the second column portion  110  is not limited to a cylindrical shape. As described in the second embodiment, in bonding the film  60 , high molding accuracy is required so that an adhesion surface becomes flatter in order to reduce concavities and convexities on the adhesion surface. As the area of the adhesion surface is smaller as in the case of the second columnar portion  110 , the area of a portion requiring high molding accuracy can be reduced. 
     As a result, it is possible to reduce the area of a portion where adhesion to the film  60  may be weak. Further, since the second column portion  110  is smaller than the first column portion  52 , more space for arranging a different component can be made. Thus, using the second column portion  110  according to the present embodiment can provide a space-saving snap-fit structure in which the film  60  is less likely to peel off. 
     Fourth Embodiment 
     An object of the present embodiment is to provide a snap-fit structure which is formed more easily. A difference between the snap-fit structure according to the third embodiment and the snap-fit structure according to the present embodiment is that an already existing member is used instead of the column portion to adhere the film  60 . In the following description, the same reference numeral will be given to the same or corresponding constituent as in the third embodiment, the description thereof will be omitted, and a difference will be mainly described. 
       FIG.  12    is a schematic diagram of the first mounted component  50  according to the present embodiment as viewed from above (i.e., the +Z direction). For convenience of description, the film  60  is not shown. As shown in  FIG.  12   , the first mounted component  50  according to the present embodiment includes a flow path  120 . The flow path  120  according to the present embodiment is surrounded by a wall whose outer periphery is higher than the surroundings by about 0.5 mm to 1.0 mm. That is, the height of the wall around the flow path  120  is approximately the same as the height of the second column portion  110 . 
     The flow path  120  in  FIG.  12    passes through from the back toward the front in the drawing. Thus, the flow path  120  is not completed at this stage. By adhering the film  60  to the upper surface of the wall around the flow path  120 , the upper portion of the wall is blocked. As a result, the flow path  120  is completed. 
     In the present embodiment, the second column portion  110  may or may not exist. In a case where the first mounted component  50  according to the present embodiment includes the second column portion  110 , the height of the second column portion  110  is preferably equal to the height of the wall around the flow path  120 . This is because in a case where the height of the second column portion  110  and the height of the wall around the flow path  120  are not equal, the film  60  cannot be applied evenly and thereby may be peeled off. 
       FIG.  13    is a schematic diagram of the snap-fit structure according to the present embodiment as viewed from above (i.e., the +Z direction).  FIG.  13    illustrates the film  60 . That is, in  FIG.  13   , the flow path  120  described above is completed. The flow path  120  is formed using the inner surface of the wall and the back surface of the film  60  (a surface on a depth side in the drawing) by attaching the film  60  to the upper surface of the wall around the flow path  120 . It should be noted that the film  60  can be adhered to the first mounted component  50  without the wall around the flow path  120 . However, the existence of the wall around the flow path  120  allows more liquid to flow by the height of the wall as compared to a case where there is no wall around the flow path  120 . 
     As shown in  FIG.  13   , in the snap-fit structure according to the present embodiment, the film  60  is adhered to the upper surface of the wall around the flow path  120 . As a result, even in a case where there is no second column portion  110 , the film  60  can be adhered using the wall around the flow path  120  in place of a column. Accordingly, the film  60  can be adhered to the first mounted component  50  by using the already existing wall around the flow path  120  in place of a column instead of forming the second column portion  110 . Consequently, since the trouble of forming the second column portion  110  can be saved, the snap-fit structure can be easily formed. The completed flow path  120  is connected to a different flow path (not shown) existing in the depth direction in the drawing. 
     As a result, for example, it is possible to flow liquid through a different flow path (not shown) via the flow path  120 . Thus, the configuration can provide a snap-fit structure which is formed more easily. 
     Fifth Embodiment 
     An object of the present embodiment is to provide a snap-fit structure in which insertion can be performed more easily. In the present embodiment, the area of a portion for holding the snap-fit portion  41  using the film  60  is smaller than that in the fourth embodiment. In the following description, the same reference numeral will be given to the same or corresponding constituent as in the fourth embodiment, the description thereof will be omitted, and a difference will be mainly described. 
       FIGS.  14 A and  14 B  are schematic diagrams of a snap-fit structure according to the present embodiment as viewed from above.  FIG.  14 A  is a schematic diagram showing a state before the first mounting component  40  is mounted on the first mounted component  50 . As shown in  FIG.  14 A , the second film  140  according to the present embodiment has a smaller area than that of the fourth embodiment. The film  60  according to the fourth embodiment covers the entire upper portion of the opening  51  (see  FIG.  13   ). On the other hand, in the second film  140  according to the present embodiment, the area of a portion covering the upper portion of the opening  51  is about half that of the fourth embodiment. Specifically, two corners of the second film  140  are adhered to the second column portion  110 . Additionally, the remaining corners of the second film  140  are adhered along the top surface of the wall around the flow path  120 . 
       FIG.  14 B  is a schematic diagram showing a state after the first mounting component  40  is mounted on the first mounted component  50 . The film  60  according to the fourth embodiment holds the entire upper portion of the snap-fit portion  41  (see  FIG.  13   ). On the other hand, in the second film  140  according to the present embodiment, the area (width) of a portion holding the snap-fit portion  41  is about half that of the first embodiment. That is, in the second embodiment, a portion corresponding to the entire width W (see  FIG.  9   ) is held by the film  60 . In the snap-fit portion  41  according to the present embodiment, the area (width) of a portion held by the second film  140  is ½W (see  FIG.  14 A ). 
     As shown in  FIGS.  14 A and  14 B , a surplus portion of the second film  140  is cut off. A method of cutting the second film  140  is not limited as long as the second film  140  can be cut. For example, a metal blade (such as scissors or a cutter) can be used to cut the second film  140 . In the present embodiment, a laser is used to cut the second film  140 . It is preferable to cut a region in the second film  140  around the second column portion  110  or the flow path  120  to which the film  60  is adhered along the shape of the second column portion  110  or the flow path  120 . 
     In the second film  140 , the region covering the upper portion of the opening  51  is preferably cut so that a portion corresponding to half (½W) of the width W of the snap-fit portion  41  can be seen. This is because the repulsive force of the second film  140  during insertion is reduced by reducing by approximately half the area of a portion for holding the snap-fit portion  41 . 
     Schematic Diagram Showing a Method of Assembling a Snap-Fit Structure According to the Present Embodiment 
       FIGS.  15 A,  15 B, and  15 C  are schematic diagrams showing a method of assembling the snap-fit structure according to the present embodiment. 
     First, in mounting the first mounting component  40  on the first mounted component  50 , the user presses the first mounting component  40  in the mounting direction into the first mounted component  50  while keeping the slope portion  93  into contact with the lower end of the opening  51 . Then, the snap-fit portion  41  is elastically deformed and reduced in diameter ( FIG.  15 A ). 
     Next, the user further presses the first mounting component  40  in the mounting direction into the first mounted component  50  while keeping the lower end of the slope portion  93  into contact with the inner peripheral surface of the opening  51 . Then, the leading end  92  comes into contact with the film  60 . The user further presses in the first mounting component  40  while keeping the leading end  92  in contact with the second film  140 . Then, the second film  140  stretches according to a force with which the user presses in the first mounting component  40  ( FIG.  15 B ). At this time, a force to return to its original shape is generated in the stretched film  60 . Thus, the user may feel a repulsive force from the film  60 . However, in the present embodiment, the area of a portion of the second film  140  for holding the snap-fit portion  41  is about half (½W width) of that of the first embodiment (width W). Accordingly, a repulsive force from the second film  140  is weaker than in the first embodiment. Therefore, the user can easily press in the first mounting component  40 . 
     The user then further presses the first mounting component  40  into the first mounted component  50  until after the engaging surface  94  passes through the opening  51 . After the engaging surface  94  has passed through the opening  51 , the elastically deformed snap-fit portion  41  returns to its original shape due to an elastic restoring force ( FIG.  15 C ). In the present embodiment, in returning to its original shape, the snap-fit portion  41  passes through a gap between the cut second film  140  and the end portion of the opening  51  and returns to its original shape. As a result, the snap-fit portion  41  can be engaged with the opening  51 . 
     At this time, the second film  140  contacts only the leading end  92  of the snap-fit portion  41  (in a X-axis direction) and the tip side of the back side portion  91 . That is, the second film  140  does not contact a slope portion  93  side. 
     In the present embodiment, since the second film  140  is cut, the entire upper portion of the snap-fit portion  41  is not held. However, the second film  140  holds the snap-fit portion  41  from a portion of the leading end  92  to the tip side of the back side portion  91  (i.e., an elastically deformable side). Thus, it is possible to suppress the snap-fit portion  41  from being elastically deformed and reduced in diameter. As a result, it is possible to provide a snap-fit structure in which insertion is performed more easily and disengagement is less likely to occur. 
     Specific Examples 
       FIG.  16    is a diagram schematically showing a component using the snap-fit structure of the present disclosure. For example, the snap-fit structure according to the fourth embodiment can be used for a print head  160  provided in a printing apparatus (e.g., a printer). As shown in  FIG.  16   , a main tank  162  provided in the print head  160  has a plurality of sub tanks  161  smaller than the main tank  162 . For convenience of description, the film  60  is not shown. Each of the sub tanks  161  stores ink to be supplied to the main tank  162 . For example, the ink inside the sub-tank  161  is supplied to the main tank  162  via the flow path  120 . In the illustrated example, the snap-fit portion  41  (not shown) is inserted into the opening  51  from the back toward the front in the drawing. As a result, the first mounting component  40  can be mounted on the sub tank  161  as the first mounted component  50 . 
       FIG.  17    is an enlarged view schematically showing the vicinity of the opening  51  provided in the sub tank  161 . As shown in  FIG.  17   , the sub-tank  161  is formed with two openings  51  so that the two snap-fit portions  41  are not back-to-back in a case where the first mounting component  40  is attached. This is because the sub tank  161  is smaller than the main tank  162  and it is difficult to secure space for arranging a block-shaped elastic-deformation-suppressing member. Specifically, this is because the flow path  120  is formed on the back side of the second opening  51   b  and there is no space for arranging the elastic-deformation-suppressing member. 
     The illustrated print head  160  is attached to a printer (not shown). In a case where the printer performs a print operation, the print head  160  scans left and right. Thus, in a case where the print head  160  scans, there is a possibility that scanning vibration may be transmitted to the sub tank  161 . Accordingly, in the sub tank  161  without the film  60 , there is a case where the vibration causes the snap-fit portion  41  to deform elastically and be disengaged. However, in the illustrated sub tank  161 , the film  60  can be used to wrap and hold the snap-fit portion  41 , so that the elastic deformation of the snap-fit portion  41  is suppressed. 
     As described above, the configuration suppresses the disengagement of the first mounting component  40  from the first mounted component  50 . 
     Other Embodiments 
     In the first embodiment, the first engaging portion  41   a  and the second engaging portion  41   b  are arranged so as not to be back to back. Another example is that the first engaging portion  41   a  may be engaged near the center of the end portion of the opening  51 , the second engaging portion  41   b  may be engaged with a corner of the opening  51 , and further the third engaging portion (not shown) may be engaged with a corner of the opening  51  which is not engaged with the second engaging portion  41   b . The configuration enables space on the back side of each engaging portion to be effectively used while reducing the possibility that the first mounting component  40  may be disengaged even in a case where the first mounted component  50  is vibrated. Further, since the second engaging portion  41   b  and the third engaging portion are engaged with at least two corners of the opening  51 , it is possible to suppress the first mounting component  40  from rotating due to vibration or the like (for example, rotating counterclockwise in the example of  FIG.  5   ) and being disengaged from the first mounted component  50 . 
     In the second embodiment, the first engaging portion  41   a  and the second engaging portion  41   b  are arranged so as not to be back to back. However, in the case of holding the snap-fit portion  41  with the film  60 , the first engaging portion  41   a  and the second engaging portion  41   b  may be arranged back to back. 
     The second embodiment has shown the example in which the one film  60  is used to hold the first engaging portion  41   a  and the second engaging portion  41   b . Another example is that the two films  60  are used, the first film  60  is used to hold the first engaging portion  41   a , and the second film  60  is used to hold the second engaging portion  41   b.    
     In the second embodiment, the first mounting component  40  is mounted on the first mounted component  50  to which the film  60  has already been attached. As another mounting method, an example is that the film  60  is attached after engaging the snap-fit portion  41  with the opening  51 . However, the height of the first column portion  52  is less than the length from the engaging surface  94  to the leading end  92 . In this case, accordingly, the leading end  92  is located higher than the upper surface of the first column portion  52 . Thus, in a case where the user applies the film  60  after the snap-fit portion  41  is engaged with the opening  51 , the film  60  must be applied so as not to make an impact on the leading end  92 . That is, in a case where the film  60  is applied after the snap-fit portion  41  is engaged with the opening  51 , the film  60  must be applied so as not to interfere with the leading end  92 . 
     The second embodiment has shown the example in which the number of openings  51  is two (see  FIG.  6   ). However, it is only required that the number of openings  51  be at least one or more and equal to or more than the number of snap-fit portions  41 . 
     The second embodiment has shown the example in which the snap-fit portion  41  includes the first engaging portion  41   a  and the second engaging portion  41   b  (see  FIG.  5   ). However, it is only required that the number of engaging portions having elasticity be at least one or more. For example, the first engaging portion  41   a  has elasticity, but the second engaging portion  42   b  does not have to have elasticity. In this case, the first mounting component  40  can be mounted on the first mounted component  50  by engaging the first engaging portion  41   a  after engaging the second engaging portion  42   b.    
     The fifth embodiment has shown the example in which the film  60  from which the surplus portion is cut out is adhered to the second column portion  110 . Another example is that instead of the film  60 , a rubber plate as an elastic-deformation-suppressing member is adhered to the first mounted component  50  without the second column portion  110  interposed therebetween. In this case, the rubber plate and the first mounted component  50  may be molded as one member made of the same material (e.g., silicone rubber). Of course, as long as the rubber plate can be adhered to the first mounted component  50 , a material for the first mounted component  50  may be a material other than rubber. One example is that polypropylene is used as a material for the first mounted component  50  and silicone rubber is used as a material for the rubber plate. This configuration makes it possible to use the elastic force of the rubber plate to hold a portion from a portion of the leading end  92  to the tip side of the back side portion  91  (i.e., an elastically deformed side) while reducing the repulsive force of the rubber plate at the time of inserting the snap-fit portion  41 . 
     The technique according to the present disclosure can provide a snap-fit structure in which space on a side where a snap-fit portion elastically deforms can be effectively utilized. 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2021-184766, filed Nov. 12, 2021, which is hereby incorporated by reference wherein in its entirety.