JP2005082125A - Breather structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the breather structure capable of surely preventing leakage of the liquid housed in a housing space outside and being easily manufactured with a small number of man-hours. <P>SOLUTION: The breather structure is formed of a base, a port part integrally formed with the base, and a baffle member separately formed from the base. An air flow passage inside the port part is divided to be bent by a projecting wall of the baffle member, and a ventilation hole for communicating with housing space with inside the port part is provided between an outer edge of a lower end of the port part and a bottom plate of the baffle member. The bottom plate shields intrusion of the liquid housed in the housing space into the port part, and the projecting wall shields flow-out of the liquid intruding into the port part outside to prevent leakage of the liquid outside. The breather structure can be easily manufactured with a small number of man-hour by separately forming the baffle member from the base and assembling it in the base for integration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a breather structure that discharges air from the inside of a storage space to the outside, and more particularly to a breather structure that discharges air while preventing leakage of liquid from the inside of the storage space to the outside.

  A liquid storage container such as an oil tank disposed in a vehicle is provided with a ventilation channel for discharging air in a storage space for storing liquid to the outside and maintaining the internal pressure of the container at atmospheric pressure. However, since not only air but also liquid in the accommodation space may leak to the outside through this ventilation channel, various breather structures for preventing liquid leakage have been developed (for example, patent documents). 1).

  A schematic cross-sectional view showing a conventional breather structure disclosed in Patent Document 1 is shown in FIG. The breather structure shown in FIG. 6 discharges the air in the storage space of the oil tank disposed in the vehicle to the outside.

  In the breather structure 100 shown in FIG. 6, the upper wall surface 102 of the oil tank 101 is provided with an opening 103 that communicates the inside and outside of the oil tank 101. Further, the inside of the oil tank 101 of the opening 103 is covered with a cylindrical body 105, and the inside of the cylindrical body 105 and the accommodation space 104 provided inside the oil tank 101 are partitioned by a partition plate 106.

  The partition plate 106 is further provided with a communication hole 107 that allows the accommodation space 104 to communicate with the inside of the cylindrical body 105. The air in the accommodation space 104 enters the inside of the cylindrical body 105 through the communication hole 107 and is discharged to the outside of the breather structure 100 through the opening 103.

  In the breather structure 100, the communication hole 107 and the opening 103 are arranged at positions shifted from each other in the vertical direction, that is, offset from each other. For this reason, for example, even when the liquid stored in the storage space 104 flows toward the inside of the cylindrical body 105 due to the tank internal pressure or the like, the liquid that has passed through the communication hole 107 does not directly contact the opening 103. The leakage of the liquid through the opening 103 to the outside is reduced.

  However, in the breather structure 100 as shown in Patent Document 1, the liquid that has entered the cylindrical body 105 vibrates with the vibration of the vehicle and the like, resulting in liquid droplets that reach the opening 103. In some cases, the oil tank 101 leaks outside.

The breather structure 100 is manufactured by welding a tubular body 105 and a partition plate 106 to an oil tank 101. For this reason, there is a problem that the manufacturing process for welding a complicated structure including the cylindrical body 105 and the partition plate 106 inside the large oil tank 100 is very complicated and increases the number of manufacturing steps.
Japanese Utility Model Publication No. 62-93402

  The present invention has been made in view of the above circumstances, and provides a breather structure that can more reliably prevent leakage of liquid stored in a storage space to the outside and can be easily manufactured with less man-hours. Objective.

  The breather structure of the present invention includes a container-like base body having an accommodation space inside and having an opening communicating with the upper wall surface inside and outside, and formed integrally with the base body, constitutes an outer edge of the opening and extends upward of the base body. A substantially cylindrical port part whose inside is a flow path of air from the accommodation space to the outside, and a base body are formed separately, and protrudes upward from the upper surface of the bottom plate and the bottom plate having a larger diameter than the lower edge of the port part. And a baffle member assembled to the base so that the top wall of the bottom plate is in contact with the lower edge of the lower end of the port. A vent hole is provided between the lower end outer edge of the part and the bottom plate so as to communicate the housing space and the inside of the port part, and the air flow path inside the port part is partitioned by a protruding wall.

  It is preferable that the projecting wall partitions the air flow path into a maze.

  It is preferable that the bottom plate is at least outside the portion that contacts the lower edge of the lower end of the port portion, and the upper surface adjacent to the vent hole is inclined downward toward the housing space.

  It is preferable that the baffle member is assembled to the base body by engaging an engagement portion provided on the bottom plate with an engaged portion provided on the base body.

  The shape of the baffle member is preferably formed in a symmetrical shape with respect to the port portion and the engaged portion.

  In the breather structure of the present invention, the air in the housing space of the base body enters the inside of the port portion through a vent hole provided between the outer edge of the lower end of the port portion and the bottom plate of the baffle member. This air passes through the air flow path inside the port portion and is discharged outside the port portion, that is, outside the breather structure. In the breather structure of the present invention, since the air flow path is partitioned by the protruding wall, the liquid flow from the vent hole to the outside of the port portion is interfered by the protruding wall, and the liquid leaks to the outside. Is prevented. In addition, even when an external force such as vibration is applied to the liquid that has entered the inside of the port part and the liquid splashes, the splashing of the splashes to the outside of the port part is blocked by the protruding wall, so the liquid leaks to the outside. Is more reliably prevented.

  Further, since the vent hole is provided between the lower edge of the port portion and the bottom plate, when the liquid inside the accommodation space enters the port portion, the liquid first comes into contact with the bottom plate. Therefore, the flow of the liquid into the port portion is interfered by the bottom plate, and the liquid does not easily enter the port portion, so that the leakage of the liquid to the outside is further reliably prevented. As a result, according to the breather structure of the present invention, it is possible to discharge the air in the storage space to the outside and more reliably prevent the liquid in the storage space from leaking to the outside.

  In the breather structure of the present invention, the port portion is formed integrally with the base body, and the baffle member is assembled and integrated after being formed separately from the base body. For this reason, the baffle member having a complicated structure is formed separately in advance, and then assembled to the base body and integrated with the base body. Therefore, the baffle member can be easily manufactured with a small number of manufacturing steps.

  The breather structure of the present invention includes a base, a port portion, and a baffle member.

  The base body is a container having an accommodation space inside and having an opening communicating with the upper wall surface inside and outside. The accommodation space of the base body is a space for containing a liquid such as oil or water, and the opening is inside the accommodation space. It becomes the outlet of the air from the outside. In the breather structure of the present invention, various bases that store liquid in the storage space can be used as a base, and for example, a power steering oil or an oil tank for brake oil mounted on a vehicle can be used as a base. .

  The port portion is a portion that is formed integrally with the base, has a substantially cylindrical shape, is a portion that constitutes the outer edge of the opening and extends upward of the base. The inside of the port portion becomes an air flow path, and the air that flows out from the opening of the base body is discharged to the outside through the port portion.

  The baffle member is a part formed separately from the base body, and has a bottom plate and a protruding wall. The bottom plate is a portion having a larger diameter than the outer edge of the lower end of the port portion, and the protruding wall is a portion protruding upward from the upper surface of the bottom plate.

  The baffle member is assembled to the base so that the protruding wall is inserted into the port portion from the inside of the base and the upper surface of the bottom plate is in contact with the lower edge of the lower end of the port portion. That is, in the state assembled to the base body, the bottom plate of the baffle member is disposed in the housing space of the base body, and the projecting wall projects from the opening above the base body and is disposed inside the port portion. The assembly of the baffle member to the base body can be performed by various known methods such as adhesion, welding, screwing and engagement.

  In the breather structure of the present invention, only one protruding wall can be provided, or a plurality of two or more protruding walls can be provided. Moreover, the protrusion wall should just be a shape which can be divided so that an air flow path may be bent, and a substantially flat shape may be sufficient as it, and the curved shape may be sufficient as it. For example, the protruding wall itself can be bent. Such a protruding wall preferably partitions the air flow path into a maze shape so that the air flow path bends a plurality of times. This is because the greater the number of times the air flow path is bent, the greater the number of times the liquid flow interferes with the protruding wall, thereby more reliably preventing the liquid from leaking out.

  The breather structure of the present invention has a vent hole that allows the accommodation space and the inside of the port portion to communicate with each other between the lower end outer edge of the port portion and the bottom plate. That is, as described above, when the baffle member is assembled to the base body, the outer edge of the lower end of the port portion and the upper surface of the bottom plate come into contact with each other. Vents are provided.

  The bottom plate may have a diameter larger than that of the lower edge of the port portion, and the shape thereof is not particularly limited. However, at least the upper surface adjacent to the vent hole and the upper surface of the bottom plate faces the housing space. It is preferable to incline downward. This is because the liquid that has entered the gap between the upper surface of the bottom plate and the outer edge of the lower end of the port portion is discharged into the accommodation space along the inclination of the bottom plate, so that the entry of the liquid into the vent hole is suppressed.

  As described above, the baffle member can be attached to the base body by various methods, but it is preferable that the baffle member is attached by engagement between the baffle member and the base body. This is because the assembly process can be easily performed with fewer man-hours. At this time, it is more preferable to provide an engaged portion on the base and to provide an engaging portion that engages with the engaged portion on the bottom plate of the baffle member. Since the assembly of the baffle member to the base is performed from the lower side to the upper side of the upper wall surface of the base, when the engagement portion is provided on the bottom plate of the baffle member, the direction of the assembly of the baffle member and the base Since the direction matches, assembly can be performed more easily.

  Moreover, it is preferable that the shape of the baffle member is formed in an assembly symmetrical shape with respect to the port portion and the engaged portion. The assembly symmetrical shape is a shape having a portion that can be assembled by changing the arrangement position and changing the orientation. When the shape of the baffle member is not symmetrical with respect to the port portion and the engaged portion, the direction of the baffle member when assembling the baffle member to the base is limited to one direction. Sometimes it is necessary to check the orientation of the baffle member, and the assembly work is complicated. On the other hand, when the shape of the baffle member is formed symmetrically with respect to the port portion and the engaged portion, the baffle member is assembled with the opposite symmetrical sides of the baffle member facing the base. Since the work of confirming the orientation of the baffle member during assembly is reduced, the assembly work can be performed more easily.

The breather structure of the present invention will be described below with reference to the drawings.

(Example 1)
The breather structure of the first embodiment is an example in which an oil tank for power steering oil disposed in a vehicle is used as a base. FIG. 1 shows a schematic exploded perspective view of the breather structure of the first embodiment, and FIG. 2 shows a schematic sectional view taken along line AA ′ in FIG. 1 of the breather structure of the first embodiment. Furthermore, the model perspective view showing a baffle part among the breather structures of the present Example 1 is shown in FIG. Further, hereinafter, the upper, lower, left, and right of the breather structure in this specification refer to the upper, lower, left, and right shown in FIG.

  The breather structure 1 according to the first embodiment includes a base body 2, a port portion 3, and a baffle member 5. The substrate 2 is made of a composite resin material in which glass is blended with 6-nylon, and is formed by injection press molding. The base body 2 has a hollow container shape, and the hollow interior is a housing space 6 in which power steering oil, which is a liquid, is housed. The base body 2 is formed in a state of being divided into two parts, an upper part 7 and a lower part (not shown), which are joined and integrated later. On the right end side of the upper wall surface 8 of the upper split body 7, a substantially rectangular opening 10 that communicates inside and outside is provided. The opening 10 serves as an air flow path from the accommodation space 6 to the outside. Further, a second opening (not shown) is further provided on the upper wall surface 8 of the upper split body 7 in the base body 2, and the second opening is covered with a lid (not shown). The second opening serves as an inlet for injecting oil into the accommodation space 6.

  The outer edge of the opening 10 is constituted by a substantially cylindrical port portion 3 extending upward from the base 2. A portion on the right side of the port portion 3 projects and opens toward the right side so as to be substantially perpendicular to the extending direction of the port portion 3, thereby forming a discharge port 11 that communicates the inside and outside of the port portion 3. Further, the outer edge of the lower end of the port portion 3 extends in a substantially ring shape in the direction of the accommodation space 6 and forms a ring wall 12. In the ring wall 12, a portion located on the side opposite to the discharge port 11 is formed with a notch-shaped vent hole 13 that allows the accommodation space 6 and the port portion 3 to communicate with each other. Further, at two locations on the outer periphery side of the ring wall 12 in the base body 2, tapered engaging projections 15 are provided so as to project in the direction of the accommodation space 6. The engaging protrusion 15 becomes an engaged portion when the baffle member 5 is assembled to the base 2.

  The baffle member 5 is formed by injection molding using 66-nylon as a material, and includes a bottom plate 16 and a pair of protruding walls 17 protruding upward from the center of the upper surface of the bottom plate 16. As shown in FIG. 3, the outer shape of the baffle member 5 is formed so as to be symmetrical with respect to the plane 18 including the central axis of the port portion 3.

  Of the baffle member 5, the bottom plate 16 has a larger diameter than the lower end outer edge 20 of the port portion 3, and has a long and substantially flat plate shape with left and right end portions inclined downward toward the accommodation space 6. In addition, substantially circular engagement holes 21 are formed in left and right end portions of the bottom plate 16 which are inclined. The engagement hole 21 is an engagement portion that engages with the engagement protrusion 15 described above.

  The two projecting walls 17 are spaced apart from each other. Each of the protruding walls 17 has an outer wall 23 having a substantially U-shaped cross section and a U-shaped interior 22 disposed so as to face each other, and the direction of the outer wall 23 from the U-shaped inner 22 side toward the other outer wall 23. And an inner wall 25 protruding to Each outer wall 23 extends in the longitudinal direction of the bottom plate 16. The inner wall 25 extends in the short direction of the bottom plate 16. Further, the inner wall 25 has a bottom surface 26 integrated with the bottom plate 16, and a side surface 27 integrated with the outer wall 23 in the entire length in the protruding direction of the outer wall 23. It extends to the U-shaped interior 22 of the protruding wall 17.

  When the baffle member 5 is assembled to the base body 2, the protruding wall 17 of the baffle member 5 is inserted into the port portion 3, and the air flow path 28 inside the port portion 3 is defined by the outer wall 23 and the inner wall 25 of the protruding wall 17. The port portion 3 is partitioned so as to be bent in a maze shape from the left side to the right side. When the baffle member 5 is assembled to the base body 2, the bottom plate 16 of the baffle member 5 is disposed in the accommodation space 6, and the upper surface 30 of the bottom plate 16 abuts on the ring wall 12 that is the lower edge of the port portion 3. When the upper surface 30 of the bottom plate 16 abuts on the ring wall 12, the inside of the port portion 3 and the accommodation space 6 are partitioned by the ring wall 12 and the bottom surface 26.

  The assembly of the baffle member 5 to the base 2 is performed by inserting the engaging protrusion 15 of the base 2 into the engaging hole 21 of the bottom plate 16 and engaging the engaging protrusion 15 with the engaging hole 21. Yes. Further, a ring-shaped retaining ring 31 having an outer shape larger than that of the engaging hole 21 is further inserted into the insertion end of the engaging protrusion 15 inserted into the engaging hole 21, and the retaining protrusion 31 causes the engaging protrusion to be engaged. 15 and the engagement hole 21 are not disengaged.

  When the internal pressure of the storage space 6 increases, the air in the storage space 6 enters the port portion 3 through the vent hole 13 that connects the storage space 6 and the port portion 3. The air that has entered the port portion 3 enters the air flow path 28 through a gap between the two opposing outer walls 23. Since the air flow path 28 is sectioned and bent by the outer wall 23 and the inner wall 25, the air flows while bending from the left side to the right side along the air flow path 28, and the right side of the port portion 3. It is discharged to the outside through a discharge port 11 provided above.

  On the other hand, when an external force such as vibration is applied to the accommodation space 6, the liquid splash may be directed toward the vent hole 13. Here, since the liquid is heavier than air, it is difficult for the liquid to flow from below to above, and the flow of the liquid in the direction of the vent hole 13 is interfered by the bottom plate 16 disposed below the vent hole 13. Therefore, most of the liquid flowing in the direction of the vent hole 13 is returned to the lower part of the accommodation space 6. When a part of the liquid enters the gap between the upper surface 30 of the bottom plate 16 and the upper wall surface 8 of the base body 2, the left and right end portions of the bottom plate 16 are lowered toward the accommodation space 6 in the breather structure 1 of this embodiment. Therefore, most of the liquid that has entered the gap between the upper surface 30 of the bottom plate 16 and the upper wall surface 8 of the base 2 is returned to the lower portion of the accommodating space 6 along the inclination. However, a part of the liquid remaining in the gap between the upper surface 30 of the bottom plate 16 and the upper wall surface 8 of the base 2 enters the port portion 3 through the vent hole 13 and passes through the gap between the outer walls 23 to form the air flow path. 28 may be entered.

  Here, since the discharge port 11 that connects the port portion 3 and the outside is located above the vent hole 13, the liquid that has entered the port portion 3 is unlikely to reach the discharge port 11, and the liquid is not exposed to the outside. It is difficult to leak. Since the air flow path 28 from the vent hole 13 to the discharge port 11 is bent and bent in a maze shape by the protruding wall 17, the liquid flow is interfered by the protruding wall 17, and the liquid passes through the protruding wall 17. It does not reach the discharge port 11 arranged on the side opposite to the pores 13, and this also prevents the liquid from leaking out. Further, even when an external force such as vibration is applied to the liquid entering the port portion 3 and the liquid splashes and the splashes scatter toward the discharge port 11, the splashes are blocked by the protruding wall 17. It is difficult to reach the discharge port 11, and even in this case, leakage of the liquid to the outside is prevented.

  Thus, according to the breather structure 1 of the present embodiment, the liquid in the accommodation space 6 is difficult to enter the air flow path 28 of the port portion 3, and the liquid that has entered the port portion 3 reaches the outside. Therefore, leakage of the liquid to the outside is remarkably reduced.

  Further, in the breather structure 1 of the first embodiment, since the assembly of the baffle member 5 to the base body 2 is performed by the engagement of the engagement protrusion 15 and the engagement hole 21, the assembly of the baffle member 5 to the base body 2 is performed. Attaching is easily performed with a small number of steps. Further, since the baffle member 5 is symmetrical with respect to the plane 18 in the left-right direction and has an assembly symmetrical shape, the direction of the baffle member 5 toward the base body 2 can be reversed left and right. The work of confirming the orientation of the baffle member is reduced, and the assembly of the baffle member 5 to the base body 2 is further facilitated. Further, since the baffle member 5 having a complicated structure is formed separately from the base body 2 by injection molding, the breather structure 1 can be easily manufactured with fewer man-hours.

  In the present embodiment, the protruding wall 17 is composed of the outer wall 23 and the inner wall 25. However, the projecting wall 17 can be composed of only the outer wall 23 or only the inner wall 25, for example. Furthermore, a plurality of inner walls 25 can be provided on each protruding wall 17. In any case, since the air channel 28 is partitioned by the protruding wall 17, leakage of the liquid to the outside is prevented.

  Moreover, the shape of the baffle member 5 may be an assembling symmetrical shape that can be assembled so that the direction to the base body is reversed left and right, and the shape of the baffle member 5 is not necessarily symmetrical with respect to the plane 18. There is no.

(Example 2)
The breather structure of the second embodiment of the present invention has the same base as that of the first embodiment, and is the same as the first embodiment except that the ring wall is a part of the bottom plate and the shape of the protruding wall. FIG. 4 shows a schematic cross-sectional view of the breather structure of the second embodiment, and FIG. 5 shows a schematic perspective view of a baffle portion in the breather structure of the second embodiment.

  The breather structure 32 of the second embodiment has the same base 33 as that of the first embodiment. The port portion 35 is formed in the same shape as that of the first embodiment except that the lower end outer edge 36 is substantially flush with the upper wall surface 37 of the base body 33.

  The baffle member 38 includes a bottom plate 40 and two protruding walls 41 protruding upward from the center of the upper surface of the bottom plate 40. The bottom plate 40 has a substantially flat shape in which the left and right end portions are inclined downward toward the accommodation space 42 as in the first embodiment, and the inclined left and right end portions are the same as those in the first embodiment. The same engagement hole 43 is drilled.

  The upper surface 45 of the bottom plate 40 protrudes toward the lower end outer edge 36 at a position facing the lower end outer edge 36 of the port portion 35 to form a ring wall 46. A portion of the ring wall 46 that is located on the opposite side of the port portion 35 from the outlet 47 is provided with a vent hole 48 that allows the accommodation space 42 and the port portion 35 to communicate with each other. When the baffle member 38 is assembled to the base body 33, the protruding end of the ring wall 46 comes into contact with the lower end outer edge 36 of the port portion 35.

  Each protruding wall 41 includes an outer wall 50 extending in the short direction of the bottom plate 40 and two inner walls 51 protruding from one outer wall 50 toward the other outer wall 50. Each outer wall 50 is provided with one through hole 52 on the upper and lower end sides. This through hole 52 serves as an entry path to the air flow path 56 of the air that has entered the gap between the port portion 35 and the outer wall 50. Further, the inner walls 51 protruding from the same outer wall 50 are arranged in the protruding direction of the outer wall 50 while being separated from each other. The bottom surface 53 of the inner wall 51 is separated from the bottom plate 40, and the side surface 55 is integrated with the outer wall 50 in the entire length in the extending direction of the outer wall 50. The inner walls 51 protruding from different outer walls 50 extend so as to alternately mesh with each other while being separated from each other.

  The protruding wall 41 of the baffle member 38 is inserted into the port portion 35, and the air flow path 56 inside the port portion 35 is a labyrinth from the lower side to the upper side of the port portion 35 by the outer wall 50 and the inner wall 51 of the protruding wall 41. It is divided so that it may be bent.

  As in the first embodiment, the baffle member 38 is assembled to the base 33 by engaging the engagement protrusions 57 provided on the base 33 and the engagement holes 43 provided on the bottom plate 40.

  In the breather structure 32 of the second embodiment, the air in the accommodation space 42 enters the air flow path 56 defined by the two protruding walls 41 through the vent hole 48 and the through hole 52. The air that has entered the air flow path 56 flows along the air flow path 56 while being bent from the lower side to the upper side of the port part 35, and passes through the discharge port 47 provided on the upper right side of the port part 35 to the outside. Discharged.

  On the other hand, when the liquid in the storage space 42 is directed toward the vent hole 48, the flow is inhibited by the bottom plate 40 as in the first embodiment. When a part of the liquid enters the gap between the upper surface 45 of the bottom plate 40 and the upper wall surface 37 of the base body 33, a part of the entered liquid passes through the vent hole 48 and further out of the through holes 52 of the outer wall 50. The air flow path 56 may enter through the lower through hole 58. However, also in the breather structure 32 of the second embodiment, the liquid flow that has entered the air flow path 56 is interfered by the protruding wall 41, so that leakage of the liquid to the outside is prevented. Further, even when an external force is applied to the liquid entering the port portion 35 and the liquid splash is generated, the splash is blocked by the protruding wall 41, so that leakage of the liquid to the outside is prevented.

  As described above, according to the breather mechanism of the second embodiment, it is difficult for the liquid in the accommodation space 42 to enter the air flow path 56 of the port portion 35 and the liquid that has entered the port portion 35 reaches the outside. Therefore, like the breather structure 32 of the first embodiment, the leakage of the liquid to the outside is remarkably reduced.

1 is a schematic exploded perspective view of a breather structure according to Embodiment 1. FIG. It is a figure which represents typically the cross section in the same position as A-A 'in FIG. 1 of the breather structure of Example 1. FIG. It is a model perspective view showing a baffle part among breather structures of Example 1. FIG. 6 is a schematic cross-sectional view of a breather structure in Example 2. FIG. It is a model perspective view showing a baffle part among breather structures of Example 2. It is a schematic cross section showing the conventional breather structure.

Explanation of symbols

1: Breather structure 2: Base body 3: Port portion 5: Baffle member 6: Storage space 10: Opening 13: Vent 16: Bottom plate 17: Protruding wall 32: Breather structure 33: Base body 35: Port portion 38: Baffle member 40: Bottom plate 41: protruding wall 42: accommodation space 48: vent hole

Claims (5)

A container-shaped base body having an accommodating space inside and having an opening communicating with the inside and outside of the upper wall surface;
A substantially cylindrical port portion which is formed integrally with the base body, constitutes the outer edge of the opening and extends upward of the base body, and the inside of which forms a flow path of air from the housing space to the outside;
A bottom plate formed separately from the base and having a diameter larger than the outer edge of the lower end of the port portion and a protruding wall protruding upward from the upper surface of the bottom plate, the protruding wall extending from the inside of the base to the port portion And a baffle member assembled to the base so that the upper surface of the bottom plate is in contact with the lower edge of the port portion.
A vent hole is provided between the lower end outer edge of the port portion and the bottom plate so as to communicate the accommodating space and the inside of the port portion, and is partitioned by the protruding wall so that the air flow path inside the port portion is bent. Breather structure characterized by having   The breather structure according to claim 1, wherein the protruding wall divides the air flow path in a maze shape.   2. The breather structure according to claim 1, wherein the bottom plate is outside of at least a portion in contact with the outer edge of the lower end of the port portion, and an upper surface adjacent to the vent hole is inclined downward toward the accommodation space.   The breather structure according to claim 1, wherein the baffle member is assembled to the base body by engaging an engaging portion provided on the bottom plate with an engaged portion provided on the base body.   The breather structure according to claim 4, wherein a shape of the baffle member is formed symmetrically with respect to the port portion and the engaged portion.

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