Vent hole structure on a relay housing

Abstract

The application discloses a structure of a ventilation hole on a relay shell, which comprises a base hole formed on the relay shell and capable of communicating the inside and outside of the shell, and a plug assembled in the base hole on the relay shell and capable of shielding the outer end of the base hole, wherein the plug is matched with the base hole to form a ventilation hole with a non-straight air passage on the relay shell. The application can effectively prevent pollutants from directly invading the inside of the relay shell through the ventilation hole, is not easy to block the air passage, and can be manufactured in a simple, easy and economical way.

Description

Technical Field

[0001] This invention relates to a component of a relay—the housing—specifically, to a vent structure on the relay housing. Background Technology

[0002] In order to maintain the balance of air pressure inside and outside the relay housing during application, vent holes that connect the inside and outside of the housing are formed on the relay housing. This is especially common in flux-type relays used in high-temperature environments.

[0003] Due to their small size and stringent technical requirements for electrical performance, the vent holes formed on the relay housing are typically around 1mm in diameter. This is most evident in small or ultra-small flux-treated relays used in household appliances. These fine vent holes are usually formed as straight holes during the casting process on the relay housing.

[0004] However, due to the presence of the straight hole structure vent on the relay housing, various contaminants (such as conformal coating during PCB molding and dust during subsequent applications) can directly enter the relay housing through the straight hole structure vent and / or directly block the outer end of the straight hole structure vent. These technical problems directly affect the electrical performance of the relay.

[0005] In the industry, in order to effectively prevent contaminants from directly entering the interior of the relay housing through the straight-hole structure vent, the vents formed on the relay housing are designed as non-straight-hole structures—that is, the vent channels on the relay housing are designed as bent structures. Examples include "Electromagnetic Relay with a Breathable Shell" (Publication No. CN 104576210, Publication Date April 29, 2015), "A Breathable Hole Structure of a Rainproof Relay" (Publication No. CN 107946140, Publication Date April 20, 2018), and "An Electromagnetic Relay That Can Reduce Foreign Matter Contamination" (Publication No. CN 102983042, Publication Date March 20, 2013), etc. While these technical measures are relatively effective in addressing the issue of contaminants directly invading the relay housing through the vent holes, they fail to effectively solve the problem of vent hole blockage, especially during the application of conformal coating during PCB board molding. Furthermore, the vent holes with their bent air passage structure on the relay housing, created by these technical measures, present significant challenges in molding and cost. This is because designing a relay housing with such a vent hole structure is extremely difficult, if not impossible. Even if the mold design is successful, achieving efficient and high-yield production control of such delicate vent holes during the later stages of casting is extremely challenging. Summary of the Invention

[0006] The technical objective of this invention is to provide a vent structure that effectively prevents contaminants from directly entering the relay housing through the vent, avoids clogging the air passage, and can be manufactured in a simple, easy, and economical manner, addressing the special characteristics of the vent holes on the relay housing and the shortcomings of the prior art.

[0007] The technical objective of this invention is achieved through the following technical solution: a vent structure on a relay housing, comprising a base hole formed on the relay housing that connects the interior and exterior of the housing, wherein a plug is assembled within the base hole on the relay housing to block the outer end of the base hole, and the plug, in conjunction with the base hole, forms a vent on the relay housing with a non-straight-channel structure. This technical measure alters the vent structure of the vent by using a plug assembled within the base hole on the relay housing, making the vent channel a non-straight-channel structure, thus bringing the following main technical advantages: Firstly, the plug provides shielding protection to the outer end of the base hole formed on the relay housing, which serves as a vent hole. Under the protection of the plug, it can effectively prevent contaminants from directly entering the interior of the relay housing through the base hole, thus effectively preventing the relay body assembled inside the relay housing from being contaminated. Secondly, the plug's shielding and protection of the outer end of the base hole makes the outer end of the entire vent hole radially arranged relative to the base hole, and the outer port of the vent is not specifically formed at a certain point, so it is not easy to block the vent. Even when spraying conformal coating during the PCB board forming process, it is not easy to block the vent hole's vent. Third, the vent structure is composed of a base hole formed on the relay housing and a plug assembled on the base hole. This combined structure not only ensures the reliable forming of the vent on the relay housing, but also greatly reduces the technical difficulty of its manufacturing. The entire manufacturing process is simple, easy and convenient, and at the same time, the manufacturing efficiency and the forming qualification rate are both high, resulting in good economic benefits.

[0008] As a key preferred solution, the plug is an expandable plug, which mainly consists of a plug cap and at least two elastically deformable claws formed on the bottom side of the plug cap. These claws form a mating gap. The outer diameter of the plug cap is larger than the diameter of the base hole on the relay housing. In the free state, the diameter of the largest circle formed by the ends of the claws is larger than the diameter of the base hole on the relay housing. This technical measure effectively ensures the formation of the vent passage structure and ensures the plug is stably assembled into the base hole on the relay housing, facilitating automated operation.

[0009] Furthermore, the bottom side of the cap of the expansion plug has at least two outwardly protruding height-limiting bosses. When the expansion plug is assembled into the base hole on the relay housing, the cap forms an air passage on the outer surface of the relay housing that communicates with the base hole through the height-limiting bosses on the bottom side. Alternatively, the bottom side of the cap of the expansion plug has at least one inwardly recessed air guide groove. When the expansion plug is assembled into the base hole on the relay housing, the cap forms an air passage on the outer surface of the relay housing that communicates with the base hole through the air guide groove on the bottom side. This technical measure can effectively prevent the outer end of the air passage of the vent from being blocked, and the anti-blocking technology has a prominent effect, which is especially evident in the height-limiting boss structure.

[0010] Furthermore, each claw of the expansion plug has a radially protruding barb at its end. In its free state, the diameter of the largest circle formed by the barbs at the ends of all the claws is larger than the diameter of the base hole on the relay housing. This technical measure ensures that the expansion plug is stably and reliably assembled within the base hole on the relay housing, eliminating the risk of it falling off.

[0011] Furthermore, each claw of the expansion plug has a guide bevel at its end. This technical feature facilitates the smooth insertion of the expansion plug into the base hole on the relay housing, making the insertion process easy, convenient, and efficient.

[0012] As a key preferred embodiment, a concave groove is formed on the outer surface of the relay housing around the base hole. When the concave groove mates with a plug assembled inside the base hole, it lies within the orthographic projection coverage of the plug's cap. This technique, building upon the protective effect of the plug, reliably collects small amounts of contaminants that tend to intrude into the relay housing through the concave groove, preventing their entry into the housing. Simultaneously, the contaminants collected in the groove do not interfere with the normal ventilation of the air passage, thus further reliably enhancing the anti-intrusion and anti-clogging effects.

[0013] As a key preferred solution, the outer end of the base hole on the relay housing has a housing-side guide slope. This technical measure facilitates the smooth insertion of the plug into the base hole on the relay housing, making the insertion process easy, convenient, and efficient.

[0014] As a key preferred embodiment, the outer edge of the outer surface of the relay housing has a cavity for forming the base hole. At least one outer peripheral wall of the cavity is open, and the outer edge of the plug cap assembled in the base hole forms a clearance fit with the outer peripheral wall of the cavity. This technical measure can effectively prevent the plug assembled in the base hole of the relay housing from protruding too much on the outer surface of the relay housing, ensuring a compact overall structure of the relay, and can also effectively enhance the anti-clogging effect.

[0015] The base hole on the relay housing is a straight hole structure, and the diameter of the base hole is less than 5mm.

[0016] The beneficial technical effect of this invention is that the above-mentioned technical measures change the air passage structure of the vent by using a plug assembled in the base hole on the relay housing, so that the air passage of the vent is a non-straight passage structure, thus bringing the following main technical advantages: Firstly, the plug provides shielding protection to the outer end of the base hole formed on the relay housing, which serves as a vent hole. Under the protection of the plug, it can effectively prevent contaminants from directly entering the interior of the relay housing through the base hole, thus effectively preventing the relay body assembled inside the relay housing from being contaminated. Secondly, the plug's shielding and protection of the outer end of the base hole makes the outer end of the entire vent hole radially shaped relative to the base hole, and the outer port of the vent is not specifically shaped at a certain point, thus making it less likely to block the vent. Even when spraying conformal coating during the PCB board forming process, it is not easy to block the vent hole's vent. Third, the vent structure is composed of a base hole formed on the relay housing and a plug assembled on the base hole. This combined structure not only ensures the reliable forming of the vent on the relay housing, but also greatly reduces the technical difficulty of its manufacturing. The entire manufacturing process is simple, easy and convenient, and at the same time, the manufacturing efficiency and the forming qualification rate are both high, resulting in good economic benefits. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of one structure of the present invention.

[0018] Figure 2 for Figure 1 A schematic diagram of a partial structure of the relay housing.

[0019] Figure 3 for Figure 1 A schematic diagram of the expansion plug structure in the image.

[0020] The symbols in the diagram have the following meanings: 1—Relay housing; 11—Cavity; 12—Base hole; 13—Dirty collection trough; 14—Housing side guide slope; 2—Expansion plug; 21—Plug cap; 22—Height limiting boss; 23—Claw; 24—Barb; 25—Plug side guide slope. Detailed Implementation

[0021] This invention relates to a component of a relay—the housing—specifically, to a vent structure on the relay housing. This vent structure is applicable to any relay requiring a vent in the housing, particularly flux-resistant relays. The main technical content of this invention is described in detail below with several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings—that is… Figure 1 , Figure 2 and Figure 3 The technical solution of the present invention is clearly and in detail explained; although other embodiments are not shown in separate drawings, their main structure can still be referred to the drawings of Embodiment 1.

[0022] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified in order to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art.

[0023] Example 1 See Figure 1 , Figure 2 and Figure 3 As shown, the present invention is a vent structure on a relay housing, which includes a base hole 12 formed on the relay housing 1 that can connect the inside and outside of the housing, and an expansion plug 2 that can be assembled in the base hole 12.

[0024] Specifically, a corner of the relay housing 1 serves as the forming area for the base hole 12. The outer surface of this area has a concave cavity 11 used to form the base hole 12. The depth of the cavity 11 should be approximately flush with or slightly lower than the top of the assembled expansion plug 2. The area of ​​the cavity 11 should be larger than the area of ​​the plug cap 21 of the expansion plug 2. Since the cavity 11 is formed at a corner of the relay housing 1, the outer peripheral walls at both sides of the cavity 11 are open structures, that is, the corner of the current plate of the relay housing 1 has a stepped surface structure. This is beneficial for the air passage of the following vent structure to remain unobstructed for a longer period of time.

[0025] The base hole 12 is formed at the center of the aforementioned cavity 11 on the relay housing 1. The base hole 12 has a straight hole structure, connecting the interior and exterior of the relay housing 1. The diameter of the base hole 12 is determined according to the performance requirements of the corresponding relay product, and is usually around 2 mm, generally not exceeding 5 mm. Under normal circumstances, the diameter of the base hole in this invention should be slightly larger than the diameter of the vent hole on a typical relay housing, so that the air passage formed after assembling the expansion plug 2 will not be too small. To facilitate the assembly of the expansion plug 2 within the base hole 12, the outer end of the base hole 12 is designed as an open-shaped inclined guide structure, that is, the outer end of the base hole 12 has a housing-side guide inclined surface 14.

[0026] In order to effectively prevent contaminants such as conformal paint and dust from entering the base hole 12 and the interior of the relay housing 1 in conjunction with the expansion plug 2, an annular dirt collection groove 13 is formed in the cavity 11 on the relay housing 1 with an inward concave structure. The dirt collection groove 13 is formed on the outer periphery of the base hole 12 with the base hole 12 as the center, that is, the dirt collection groove 13 is formed on the outer periphery of the housing side guide slope 14 at the outer end of the base hole 12.

[0027] The expansion plug 2 mainly consists of a plug cap 21 and two elastically deformable claws 23 formed on the bottom side of the plug cap 21.

[0028] The cap portion 21 of the expansion plug 2 is a closed, non-porous structure in the axial direction. The outer diameter of the cap portion 21 of the expansion plug 2 is larger than the diameter of the aforementioned base hole 12 on the relay housing 1, and is also substantially larger than the outer diameter of the aforementioned dirt collection groove 13 on the relay housing 1. When the expansion plug 2 is assembled into the base hole 12 on the relay housing 1, the orthogonal projection of the cap portion 21 of the expansion plug 2 in the axial direction (or vertical direction) can cover the dirt collection groove 13, and will undoubtedly block the outer end of the base hole 12. This ensures that contaminants that have entered the bottom side of the cap portion 21 are effectively collected in the dirt collection groove 13, preventing further intrusion.

[0029] The two claws 23 of the expansion plug 2 have basically the same monolithic structure.

[0030] Each claw 23 has its root integrally formed on the cap portion 21 of the expansion plug 2, with its end extending downwards. During the extension process, it slightly opens outwards relative to the axial center of the entire expansion plug 1, and the downward extension length of the claw 23 is greater than the height of the aforementioned base hole 12. The end of the claw 23 has a radially protruding barb 24, that is, a stepped structure is formed on the outer side of the end of the claw 23. The forming position of the barb 24 at the end of the claw 23 should ensure that the claw 23 can hook into the inner end of the base hole 12 when it is inserted into the aforementioned base hole 12. In other words, the distance from the barb 24 to the root of the claw 23 should be slightly greater than the height of the aforementioned base hole 12. In order to facilitate the smooth entry of the claw into the aforementioned base hole 12 during assembly, the end of the claw 23 has a plug-side guide slope 25, which is an arrow-shaped structure that contracts at the front and expands at the rear.

[0031] As described above, the two claws 23 are formed in a circumferentially distributed manner on the bottom side of the cap portion 21 of the expansion plug 2. It is best if they are formed symmetrically from left to right, so that a fitting gap is formed between the two claws 23. This fitting gap is not only the fitting gap between the two claws 23 in the circumferential direction, but also the fitting gap in the radial direction (i.e., their fitting width direction). This way, the expansion plug 2 can be assembled in the base hole 12 without affecting the air passage in the base hole 12.

[0032] In the free state (i.e., the untightened state), the diameter of the largest circle formed by the outer sides of the roots of the expansion plug 2 is basically equal to the diameter of the aforementioned base hole 12. The diameter of the largest circle formed by the outermost sides of their ends—especially the barbs 24—must be larger than the diameter of the aforementioned base hole 12 (however, in the tightened state, the diameter of the largest circle formed by their ends—especially the barbs 24—must be slightly smaller than the diameter of the aforementioned base hole 12), so that the claws 23 can effectively penetrate the base hole 12 and hook at the inner end of the base hole 12 during assembly.

[0033] When the expansion plug 2 with the above-described structure is assembled into the base hole 12, an air passage should be formed between the bottom surface of the plug cap 21 and the surface of the cavity 11. Therefore, two downwardly protruding height-limiting protrusions 22 are formed on the bottom side of the plug cap 21 of the expansion plug 2. Each height-limiting protrusion 22 basically corresponds to one claw 23, so that the corresponding height-limiting protrusions 22 are formed on the outside of the claws 23, which effectively avoids the height-limiting protrusions 22 occupying the space between the two claws 23. From the aforementioned structure, it can also be concluded that the distance between the barb 24 and the height-limiting protrusion 22 must be greater than the height of the base hole 12. The outer end of the aforementioned height-limiting protrusion 22 is preferably located in the inner region of the aforementioned sludge collection tank 13, so as to avoid covering the sludge collection tank 13 during assembly.

[0034] The expansion plug 2 of the above-described structure extends into the base hole 12 on the relay housing 1 through two claws 23. The barbs 24 of the elastically expanded claws 23 hook from the inner end of the base hole 12, and the expansion plug 2 is firmly assembled on the relay housing 1 without falling off. The plug cap 21 of the expansion plug 2 sits on the surface of the cavity 11 on the relay housing 1 through the height limiting boss 22 on the bottom side. The plug cap 21 is located in the area of ​​the cavity 11, and the outer edge of the plug cap 21 forms a clearance fit with the outer peripheral wall of the cavity 11. Of course, it should not extend beyond the open edge of the cavity 11. The cap 21 of the expansion plug 2 forms a shield around the outer end of the base hole 12. This shield is not a seal, but rather a way to redirect the air passage in conjunction with the base hole 12. This is because the cap 21 forms a mating gap between the bottom surface and the surface of the cavity 11 through the height limiting boss 22. This mating gap actually constitutes an air passage that can communicate with the base hole 12. In other words, the expansion plug 2, in conjunction with the base hole 12, forms a vent hole on the relay housing 1 with a non-straight structure (i.e., a bent structure) for the air passage.

[0035] The number of claws 23 of the aforementioned expansion plug 2 should not be too many, usually two to four are sufficient. Too few - that is, one is not enough to make the expansion plug stably assembled in the base hole and form an air passage. Too many - that is, more than five can easily affect the formation of the air passage in the base hole. It is best to have three claws evenly arranged in the circumference.

[0036] The number of height-limiting protrusions 24 on the aforementioned expansion plug 2 should not be excessive, usually two to four are sufficient. Too few—that is, one is not enough to ensure that the plug cap sits stably, and too many—that is, more than five—can easily affect the air passage formation. Moreover, it is best to form each limiting protrusion corresponding to the root of each claw.

[0037] Example 2 The present invention relates to a vent structure on a relay housing, comprising a base hole formed on the relay housing that connects the interior and exterior of the housing, and an expansion plug that can be assembled into the base hole.

[0038] Specifically, a corner of the relay housing serves as the forming area for the base hole. The outer surface of this area has a concave cavity used to form the base hole. The depth of the cavity should be approximately flush with or slightly lower than the top of the assembled expansion plug, corresponding to the current outer surface of the relay housing plate. The area of ​​the cavity should be larger than the area of ​​the expansion plug cap. Since the cavity is formed at a corner of the relay housing, the outer peripheral walls at both sides of the cavity are open, meaning that the corner of the current plate of the relay housing has a stepped surface structure. This facilitates the long-term unobstructed flow of the air passages in the following vent structure.

[0039] The base hole is formed at the center of the aforementioned cavity on the relay housing. The base hole has a straight hole structure, connecting the interior and exterior of the relay housing. The diameter of the base hole is determined according to the performance requirements of the corresponding relay product, usually around 2mm, and generally not exceeding 5mm. Under normal circumstances, the diameter of the base hole in this invention should be slightly larger than the diameter of the vent hole on a typical relay housing, so that the air passage formed after assembling the expansion plug will not be too small. To facilitate the assembly of the expansion plug in the base hole, the outer end of the base hole is designed as an open-shaped inclined guide structure, that is, the outer end of the base hole has a housing-side guide inclined surface.

[0040] In order to effectively prevent contaminants such as conformal paint and dust from entering the base hole and then the relay housing, an annular dirt collection groove is formed in the aforementioned cavity on the relay housing in an inward concave structure. The dirt collection groove is formed on the outer periphery of the base hole with the base hole as the center, that is, the dirt collection groove is formed on the outer periphery of the housing side guide slope at the outer end of the aforementioned base hole.

[0041] The expansion plug mainly consists of a plug cap and two elastically deformable claws formed on the bottom side of the plug cap.

[0042] The expansion plug's cap portion has a closed, non-porous structure in the axial direction. The outer diameter of the expansion plug's cap portion is larger than the diameter of the aforementioned base hole on the relay housing, and is also substantially larger than the outer diameter of the aforementioned dirt collection groove on the relay housing. When the expansion plug is assembled into the base hole on the relay housing, the orthogonal projection of the expansion plug's cap portion in the axial direction (or vertical direction) can cover the dirt collection groove, and will undoubtedly block the outer end of the base hole. This ensures that contaminants that have entered the bottom side of the cap portion are effectively collected in the dirt collection groove, preventing further intrusion.

[0043] The bottom surface of the plug cap has multiple air guide grooves with a concave structure, which are arranged basically evenly along the circumferential direction of the plug cap. The inner end of each air guide groove extends to the center area of ​​the bottom surface of the plug cap, and the outer end extends to the outer edge of the plug cap, forming an opening at the outer edge. When the expansion plug is assembled in the aforementioned hole, the inner ends of these air guide grooves on the bottom side of the plug cap should be within the orthographic projection coverage of the aforementioned hole.

[0044] The two claws of the expansion plug have essentially the same monolithic structure.

[0045] Each claw's root is integrally molded onto the cap of the expansion plug, with its end extending downwards. During this extension, it slightly opens outwards relative to the axial center of the entire expansion plug, and the downward extension length of the claw is greater than the height of the aforementioned base hole. The end of the claw has a radially protruding barb, forming a stepped structure on the outer side. The position of this barb at the claw end should ensure that the claw can hook into the inner end of the base hole when inserted; that is, the distance from the barb to the claw root should be slightly greater than the height of the base hole. To facilitate smooth insertion of the claw into the base hole during assembly, the end of the claw has a plug-side guide ramp, which is an arrow-shaped structure that contracts at the front and expands at the rear.

[0046] As described above, the two claws are formed in a circumferentially distributed manner on the bottom side of the cap of the expansion plug. It is best if they are formed symmetrically from left to right, so that a fitting gap is formed between the two claws. This fitting gap is not only the fitting gap between the two claws in the circumferential direction, but also the fitting gap in the radial direction (i.e., their fitting width direction). This way, the expansion plug can be assembled in the above-mentioned base hole without affecting the air passage in the base hole.

[0047] In the free state (i.e., the untightened state), the diameter of the largest circle formed by the outer sides of the roots of the expansion plug is basically equal to the diameter of the aforementioned base hole. The diameter of the largest circle formed by the outermost sides of their ends—especially the outermost sides of the barbs—must be larger than the diameter of the aforementioned base hole (however, in the tightened state, the diameter of the largest circle formed by their ends—especially the outermost sides of the barbs—must be slightly smaller than the diameter of the aforementioned base hole). This is so that the claws can effectively penetrate the base hole and hook at the inner end of the base hole during assembly.

[0048] The expansion plug of the above structure extends into the base hole on the relay housing through two claws. The barbs of the two elastically expanded claws hook from the inner end of the base hole, and the expansion plug is firmly assembled to the relay housing without falling off. The plug cap of the expansion plug rests on the concave surface of the relay housing through its bottom surface. The plug cap is located within the concave area, and a clearance fit is formed between the outer edge of the plug cap and the outer peripheral wall of the concave cavity. Of course, it should not extend beyond the open edge of the concave cavity. The plug cap of the expansion plug forms a shield at the outer end of the base hole. This shield is not a seal, but rather a way to redirect the air passage with the base hole. This is because the plug cap, through the air guide grooves formed in the concave shape of its bottom surface, creates a fitting clearance channel between the bottom surface and the concave surface. These fitting clearance channels actually constitute an air passage that can communicate with the base hole. In other words, the expansion plug, in conjunction with the base hole, creates a vent hole on the relay housing with a non-straight structure (i.e., a bent structure).

[0049] The number of claws on the expansion plug should not be too many, usually two to four are sufficient. Too few - that is, one is not enough to make the expansion plug stably assembled in the base hole and form an air passage. Too many - that is, more than five can easily affect the formation of the air passage in the base hole. It is best to have three claws evenly arranged in the circumference.

[0050] The more air channels the expansion plug has, the better. Too many air channels will create a large number of height-limiting protrusions as in Example 1. Of course, each individual air channel formed by this structure is small and easy to block. However, a large number of air channels will form a redundant configuration structure that is not easy to block.

[0051] Example 3 The other contents of this embodiment are the same as those of embodiment 1 or embodiment 2, except that there is no dirt collection groove structure on the relay housing.

[0052] Under this technical measure, in order to effectively prevent contaminants from entering, it is best to design the cap of the expansion plug to be large enough, so that the air passage at the outer end of the base hole (i.e. the air passage formed between the bottom surface of the cap and the surface of the relay housing) is long enough to counteract the movement force when contaminants enter.

[0053] Example 4 The other contents of this embodiment are the same as those of Embodiment 1, Embodiment 2 or Embodiment 3, except that: there is no cavity structure on the relay housing, and the base hole is directly formed on the current plate of the relay housing.

[0054] Under this technical measure, the cap of the expansion plug will always protrude from the current plate surface of the relay housing.

[0055] Example 5 The other contents of this embodiment are the same as those of Embodiment 1, Embodiment 2 or Embodiment 3, except that the cavity structure on the relay housing is formed at the edge of the current plate of the relay housing.

[0056] Under this technical measure, one side edge of the cavity is an open structure.

[0057] Example 6 The other contents of this embodiment are the same as those of Embodiment 1, Embodiment 2 or Embodiment 3, except that the cavity structure on the relay housing is formed in the non-edge area of ​​the current plate of the relay housing.

[0058] Under this technical measure, the cavity has vertical peripheral walls on all four sides, which has lower ventilation or anti-clogging performance compared to structures with open sides or one side. It is best to maximize the difference between the cavity area and the area of ​​the plug cap of the expansion plug.

[0059] The above embodiments are merely illustrative of the present invention and not intended to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features. For example, the expansion plug can be replaced by a plug with a hollow structure plug segment (i.e., the part inserted into the base hole) or a plug cap with a radially shaped air guide groove structure; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A vent structure on a relay housing, comprising a base hole (12) formed on the relay housing (1) and capable of communicating between the inside and outside of the housing. Its features are: A plug capable of blocking the outer end of the base hole (12) is assembled in the base hole (12) on the relay housing (1), and the plug has a plug cap and at least two claws formed on the bottom side of the plug cap. These claws are formed on the bottom side of the plug cap in a circumferentially distributed manner, and a mating gap is formed between these claws. This mating gap is not only the mating gap of these claws in the circumferential direction, but also the mating gap in the radial direction. The bottom surface of the cap is formed with multiple height limiting protrusions in a downwardly convex structure, or the bottom surface of the cap is provided with multiple air guide grooves in an inwardly concave structure. The plug extends into the base hole (12) of the relay housing (1) with its claws, so that the mating gap between each claw and the base hole (12) are mated to form an air passage. The plug cap of the plug covers the base hole (12) at the outer end. Each height limiting boss / each air guide groove on the bottom surface of the plug cap forms a mating gap that can communicate with the base hole (12) between it and the outer end surface of the base hole (12). The plug cap works with the base hole (12) to turn the air passage, so that a vent hole with a non-straight passage structure is formed on the relay housing (1).

2. The vent structure on the relay housing according to claim 1, characterized in that: The plug is an expansion plug (2), which mainly consists of a plug cap (21) and at least two elastically deformable claws (23) formed on the bottom side of the plug cap (21). These claws (23) form a fitting gap. The outer diameter of the plug cap (21) is larger than the diameter of the base hole (12) on the relay housing (1). In the free state, the diameter of the largest circle formed by the ends of each claw (23) of the expansion plug (2) is larger than the diameter of the base hole (12) on the relay housing (1).

3. The vent structure on the relay housing according to claim 2, characterized in that: The expansion plug (2) has at least two outwardly protruding height limiting bosses (22) on the bottom side of the plug cap (21). When the expansion plug (2) is assembled into the base hole (12) on the relay housing (1), the plug cap (21) forms an air passage that can communicate with the base hole (12) on the outer surface of the relay housing (1) through the height limiting bosses (22) on the bottom side.

4. The vent structure on the relay housing according to claim 2, characterized in that: The expansion plug (2) has at least one concave air guide groove on the bottom side of the plug cap (21). When the expansion plug (2) is assembled into the base hole (12) on the relay housing (1), the plug cap (21) forms an air passage that can communicate with the base hole (12) on the outer surface of the relay housing (1) through the air guide groove on the bottom side.

5. The vent structure on the relay housing according to claim 2, 3 or 4, characterized in that: Each claw (23) of the expansion plug (2) has a radially protruding barb (24) at its end. In the free state, the diameter of the largest circle formed by the barbs (24) at the ends of each claw (23) is greater than the diameter of the base hole (12) on the relay housing (1).

6. The vent structure on the relay housing according to claim 2, 3 or 4, characterized in that: Each claw (23) of the expansion plug (2) has a plug-side guide ramp (25) at its end.

7. The vent structure on the relay housing according to claim 1 or 2, characterized in that: The outer surface of the relay housing (1) is formed with a concave structure to form a dirt collection groove (13) on the outer periphery of the base hole (12). When the dirt collection groove (13) is engaged with the plug assembled in the base hole (12), the dirt collection groove (13) is within the orthographic projection coverage of the plug cap of the plug.

8. The vent structure on the relay housing according to claim 1 or 2, characterized in that: The relay housing (1) has a housing-side guide slope (14) at the outer end of the base hole (12).

9. The vent structure on the relay housing according to claim 1, characterized in that: The outer edge of the outer surface of the relay housing (1) has a cavity (11) for forming the base hole (12). At least one outer peripheral wall of the cavity (11) is an open structure. The outer edge of the plug cap of the plug assembled in the base hole (12) forms a clearance fit with the outer peripheral wall of the cavity (11).

10. The vent structure on the relay housing according to claim 1 or 9, characterized in that: The base hole (12) on the relay housing (1) is a straight hole structure, and the diameter of the base hole (12) is less than 5mm.

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