Vent pipe end part structure

Abstract

To provide a vent pipe end part structure capable of introducing air from the atmosphere to a structure side of a vehicle with small air resistance.SOLUTION: In a vent pipe end part structure in which a pipe end vent part is provided at an end part of a vent pipe provided in a structure of a vehicle to prevent intrusion of foreign matter, the pipe end vent part is formed in a three-dimensional shape, and a slit-shaped vent hole is formed radially from the end part side to a base part side on at least a curved surface of the three-dimensional shape formed in the pipe end vent part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a ventilation pipe end structure. [Background technology]

[0002] Vehicles such as automobiles are equipped with canisters that prevent fuel vapor (evaporative gas) generated in the fuel tank from being released into the atmosphere. The canister is filled with an adsorbent (activated carbon) that adsorbs and desorbs evaporative gas. When the internal pressure of the fuel tank increases, the evaporative gas is adsorbed and captured by the adsorbent due to the pressure difference. In contrast, the air in the adsorbent is released into the atmosphere through a vent pipe. The evaporative gas adsorbed in the adsorbent is also released (purged) in response to the engine's intake negative pressure and reburned with fresh air. When the evaporative gas is released from the adsorbent, outside air flows into the canister through a vent pipe installed in the vehicle's structure, regenerating the adsorbent.

[0003] In addition, ventilation slits or mesh are provided at the open end of the ventilation pipe. These ventilation slits or mesh are primarily intended to prevent the open end from being blocked by small insects such as spiders. However, while the vehicle is running, flat foreign objects such as leaves may be caught up in the open end and cause a blockage. Furthermore, if sand and dust accumulate on the mesh, the dust may grow and cause clogging.

[0004] For example, Patent Document 1 (JP 2015-90094 A) discloses a technique in which a cover is attached to the opening of a ventilation pipe. In this document, a first ventilation slit is formed on the side surface of the open end of the ventilation pipe, a second ventilation slit that intersects with the first ventilation slit is formed on the side surface of the cover, and a ventilation hole is formed on the front surface of the cover.

[0005] With the technology disclosed in this document, even if the ventilation hole on the front of the cover portion is blocked by the accumulation of flat foreign matter or dust, air can be introduced into the canister through the second ventilation slit formed on the side of the tip portion and the first ventilation slit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-90094 Summary of the Invention [Problem to be solved by the invention]

[0007] The technology disclosed in Patent Document 1 has a two-layer structure in which a first ventilation slit is formed on the side of the open end of the ventilation pipe, and a second ventilation slit is formed in the cover part attached to this open end, resulting in a complex structure.

[0008] Furthermore, the technology disclosed in Patent Document 1 has a labyrinth structure in which the first and second ventilation slits intersect, which increases air resistance when introducing air from the atmosphere into the filter, making it difficult to fully remove the evaporated gas.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide a simple vent pipe end structure that is capable of introducing air from the atmospheric side into the vehicle structure side with little air resistance. [Means for solving the problem]

[0010] The present invention relates to a ventilation pipe end structure in which a pipe end ventilation section that prevents foreign matter from entering is provided at the end of a ventilation pipe installed in a vehicle structure, and the pipe end ventilation section is formed in a three-dimensional shape, and slit-shaped ventilation holes are formed radially from the end side to the base side on at least the curved surface of the three-dimensional shape formed in the pipe end ventilation section. [Effects of the Invention]

[0011] According to the present invention, the pipe end ventilation section is formed in a three-dimensional shape, and slit-shaped ventilation holes are formed radially on at least the curved surface from the end side to the base side. This not only simplifies the structure, but also makes it possible to introduce air from the atmosphere side into the structure side with little air resistance. [Brief explanation of the drawings]

[0012] [Figure 1] Schematic diagram of a canister and a filter according to the first embodiment. [Figure 2] FIG. 10 is a side view showing the state in which the ventilation cap is attached to the ventilation pipe of the filter case. [Figure 3] The right side view of Figure 2 [Figure 4A] The same, front view of arrow IV in Figure 2 [Figure 4B] FIG. 1 is a front view of the ventilation pipe. [Figure 5] 4A, VV cross section [Figure 6A] 6, a cross-sectional view of FIG. 4A taken along line VI-VI. [Figure 6B] 6B is a cross-sectional view showing the state in which the ventilation cap is removed from FIG. 6A. [Figure 7] FIG. 10 is a side view showing a state in which a flat foreign object is attached to the ventilation cap of the same. [Figure 8] 6A according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] 1 to 7 show a first embodiment of the present invention. A canister 1 shown in Fig. 1 is connected to the downstream side of a fuel evaporation (evaporation) passage 2 and the upstream side of a purge passage 3. The upstream side of the evaporation passage 2 is connected to the upper space of the fuel tank. The downstream side of the purge passage 3 is connected to the intake system downstream of the throttle valve.

[0014] The canister 1 is filled with activated carbon 1a as an adsorbent. This activated carbon 1a adsorbs and desorbs the evaporated gas generated in the fuel tank. The passages 2 and 3 communicate with the base side of the drain passage 4 across the activated carbon 1a of the canister 1. A filter unit 5 is provided at the tip end of the drain passage 4.

[0015] As shown in Figures 2 and 3, the filter unit 5 has a filter case 6. An air filter 7 is mounted in the filter case 6. A communication pipe 8 is formed in the filter case 6. The communication pipe 8 is connected to the tip of the drain passage 4. The canister 1 and the filter unit 5 function as structural components of the vehicle.

[0016] Furthermore, a ventilation pipe 9 is formed on the opposite side of the air filter 7 from the communication pipe 8 of the filter case 6. A pipe end ventilation part 10 is provided at the open end of the ventilation pipe 9. This pipe end ventilation part 10 is formed in the shape of a cap that can be attached and detached to the open end of the ventilation pipe 9. Hereinafter, in this embodiment, this pipe end ventilation part 10 will be referred to as a ventilation cap 10 for convenience.

[0017] Here, we will briefly explain the function of the canister 1. When the internal pressure of the fuel tank increases, the evaporation gas flows into the canister 1 through the evaporation passage 2 due to the pressure difference, and is adsorbed and captured by the activated carbon 1a. At that time, the air in the activated carbon 1a passes through the drain passage 4 and filter unit 5, and is released into the atmosphere.

[0018] Meanwhile, the evaporative gas adsorbed and captured by the activated carbon 1a is purged in response to the engine's intake negative pressure and supplied to the intake system downstream of the throttle valve via the purge passage 3. The evaporative gas supplied downstream of the throttle valve is re-burned together with fresh air. At this time, the pressure difference within the canister 1 causes outside air to be introduced into the canister 1 via the vent pipe 9, regenerating the activated carbon 1a.

[0019] As shown in Figures 4B and 6B, a step 9a is formed on the inner periphery of the open end of the ventilation pipe 9. A pair of protrusions 9b are formed diagonally on the corners of this step 9a. The upper part of the main body 10' of the ventilation cap 10 is formed in a three-dimensional curved shape, which is an example of a deep dish-shaped three-dimensional shape. The upper part of this main body 10' may also have a three-dimensional curved shape that is approximately dome-shaped.

[0020] Furthermore, the lower part of the main body 10' is formed in a circular ring shape that continues to the upper part. The circular ring-shaped part of the main body 10' is formed to be the same size as or slightly smaller than the inner circumference of the ventilation pipe 9.

[0021] Furthermore, a flange portion 10a is formed near the boundary between the deep dish-shaped portion of the main body portion 10' and the annular portion. This flange portion 10a is attached to the step portion 9a of the ventilation pipe 9. The outer periphery of the flange portion 10a is formed to be approximately the same size as or slightly smaller than the inner periphery of the step portion 9a. The bottom surface of the flange portion 10a is hooked onto the step portion 9a, and the attachment / detachment direction is positioned.

[0022] A lever portion 10b extends downward from the lower end of the main body portion 10'. A pair of lever portions 10b are formed diagonally on the main body portion 10'. A hook 10c is formed at the bottom of the lever portion 10b. The hook 10c is formed on the outer periphery of the lever portion 10b. Furthermore, a notch 10d is formed in the flange portion 10a located on an extension of the center of the width of the lever portion 10b. The notch 10d is formed in the same position as the protrusion 9b. The notch 10d is shaped to fit into the protrusion 9b.

[0023] As shown in Figure 4A, when attaching the ventilation cap 10 to the ventilation pipe 9, the positions of the notch 10d and the protrusion 9b are aligned. As a result, the notch 10d and the protrusion 9b of the ventilation cap 10 fit together, restricting movement in the rotational direction. The notch 10d and the protrusion 9b correspond to the positioning portion of the present invention.

[0024] 5 and 6A, when the ventilation cap 10 is attached to the ventilation pipe 9, the lower end of the flange portion 10a abuts against the step portion 9a, and the attachment / detachment direction is determined. At the same time, the hook 10c is hooked onto the inner surface of the filter case 6, which is the base of the ventilation pipe 9. This restricts movement of the ventilation cap 10 relative to the ventilation pipe 9 in the attachment / detachment direction.

[0025] In addition, slit-shaped ventilation holes 10e are formed radially in the main body 10' from the top side (end side) to the flange portion 10a on the base side. Furthermore, two ventilation holes 10f formed at positions corresponding to the notched portions 10d of the main body 10' are formed only at the lower positions at the same intervals as the other ventilation holes 10e, and are formed in a roughly trapezoidal shape with a short height to the top. Note that the symbol F in Figure 7 represents a flat foreign object such as paper or a leaf.

[0026] Next, the operation of this embodiment with such a configuration will be described.

[0027] When attaching the ventilation cap 10 to the open end of the ventilation pipe 9, the worker visually checks the position of the notch 10d formed in the ventilation cap 10. The ventilation hole 10f corresponding to the position of this notch 10d is shorter in height than the other ventilation holes 10e. Therefore, by visually checking this ventilation hole 10f, the position of the notch 10d can be easily recognized.

[0028] Then, the worker inserts the lever portion 10b of the ventilation cap 10 along the inner periphery of the ventilation pipe 9. At that time, the worker attaches the ventilation cap 10 to the ventilation pipe 9 with the notch portion 10d aligned with the protrusion 9b formed on the step portion 9a of the ventilation pipe 9.

[0029] Then, when the lower end of the flange portion 10a formed on the ventilation cap 10 abuts against the step portion 9a formed on the ventilation pipe 9, the notch portion 10d fits into the protrusion 9b. This restricts movement of the ventilation cap 10 in the rotational direction. Furthermore, when the lower end of the flange portion 10a abuts against the step portion 9a, the hook 10c formed on the lever portion 10b of the ventilation cap 10 is hooked onto the inner surface of the filter case 6. This restricts movement of the ventilation cap 10 in the attachment / detachment direction. As a result, the ventilation cap 10 is fixed to the open end of the ventilation pipe 9, as shown in FIGS. 2, 5, and 6A.

[0030] When the evaporated gas adsorbed on the activated carbon 1a in the canister 1 is purged into the intake system, air equivalent to the purged evaporated gas flows into the canister 1. This air passes through the vent holes 10e and 10f formed in the main body 10' of the ventilation cap 10 and the air filter 7 mounted in the filter case 6 before flowing in.

[0031] Dust and other particles mixed in the air that passes through the air vents 10e and 10f and flows into the canister 1 are removed by the air filter 7. Furthermore, planar foreign objects F, such as paper or leaves, that are kicked up while the vehicle is traveling do not pass through the air vents 10e and 10f but instead adhere to the surface of the main body 10' as shown in Figure 7. Therefore, these planar foreign objects F do not enter the filter case 6.

[0032] 7, the ventilation holes 10e, 10f are formed in a three-dimensional radial pattern along the side surface from the top of the main body 10'. Therefore, even if a planar foreign object F adheres to the surface of the main body 10', all of the ventilation holes 10e, 10f will not be blocked. Therefore, the ventilation of the ventilation cap 10 can be ensured at all times.

[0033] Furthermore, the ventilation holes 10e, 10f are formed as three-dimensional curved slits that conform to the shape of the main body 10'. Therefore, the opening area of the ventilation holes 10e, 10f is relatively large, making it difficult for dust to accumulate in the ventilation holes 10e, 10f. Therefore, the ventilation holes 10e, 10f do not become clogged with accumulated dust.

[0034] As described above, according to this embodiment, the ventilation hole 10e is formed in a slit shape from the top side of the main body 10' to the flange portion 10a on the base side. Furthermore, the ventilation holes 10e, 10f are formed radially on the main body 10'. Therefore, the opening area of each ventilation hole 10e, 10f is relatively large, allowing outside air to be introduced into the filter case 6 with little air resistance.

[0035] Furthermore, the ventilation holes 10e, 10f are formed as slits with three-dimensional curves that conform to the shape of the main body 10'. Therefore, even if a planar foreign object F is kicked up while the vehicle is traveling and adheres to the main body 10', all of the ventilation holes 10e, 10f will not be blocked, and ventilation can be maintained at all times.

[0036] Furthermore, each ventilation hole 10e is formed in a slit shape from the top to the base. Therefore, the opening area of each ventilation hole 10e, 10f is relatively large, making it difficult for dust to accumulate. Therefore, each ventilation hole 10e, 10f does not become clogged with dust, and high reliability can be achieved.

[0037] This ventilation cap 10 can be attached and detached to the ventilation pipe 9 of the filter case 6. Therefore, this ventilation cap 10 can be replaced with an existing ventilation cap, providing high versatility. Furthermore, since the ventilation cap 10 can be easily replaced, good maintainability can be achieved.

[0038] Furthermore, a notch 10d is formed in the flange 10a of the main body 10', and a protrusion 9b that fits into this notch 10d is formed on the ventilation pipe 9. Therefore, by fitting this notch 10d into the protrusion 9b, movement of the ventilation cap 10 in the rotational direction can be restricted with a single touch.

[0039] Furthermore, the vent hole 10f corresponding to the position of the notch 10d is formed at a height shorter than the other vent holes 10e, so that the worker can easily determine the position of the notch 10d by visually checking the position of the vent hole 10f.

[0040] Furthermore, the position of the hook 10c formed on the lever portion 10b of the ventilation cap 10 coincides with the position of the notch portion 10d in the axial direction. Therefore, for example, when removing the ventilation cap 10 from the ventilation pipe 9, the worker can easily estimate the position of the hook 10c by recognizing the position of the notch portion 10d or the ventilation hole 10f. As a result, the worker can easily attach and detach the ventilation cap 10, improving workability.

[0041] Furthermore, the simple structure of the main body 10' with the vent holes 10e, 10f formed radially and the flange 10a formed facilitates manufacturing. Furthermore, the vent holes 10e, 10f are formed as slits that follow the three-dimensional curved surface of the main body 10', so that the mold only needs to be removed in both directions, facilitating molding.

[0042] [Second embodiment] A second embodiment of the present invention is shown in Fig. 8. In this embodiment, a pipe end ventilation part 10 is formed integrally with a ventilation pipe 9 of a filter case 6.

[0043] Therefore, the pipe end vent part 10 of this embodiment does not require the flange part 10a and lever part 10b of the vent cap 10 of the first embodiment. Furthermore, the main body part 10' of the pipe end vent part 10 does not require the part below the position corresponding to the flange part 10a of the first embodiment, and this part is formed integrally with the vent pipe 9.

[0044] According to this embodiment, the pipe end ventilation part 10 is formed integrally with the ventilation pipe 9, so the step of assembling the pipe end ventilation part 10 can be omitted.

[0045] The following statements may be added to the claims: <Appendix> The vent pipe end structure according to claim 1, which has as vehicle structures a filter case and a canister that adsorbs and desorbs fuel evaporative gas generated in a fuel tank, and the canister is connected to the opposite side of the vent pipe across the air filter of the filter case.

[0046] The present invention is not limited to the above-described embodiments, and for example, the main body 10' may be formed in a three-dimensional cylindrical or conical shape. [Explanation of symbols]

[0047] 1...canister, 1a...Activated carbon, 2...evaporative passage, 3...Purge passage, 4...Drain passage, 5...filter unit, 6...Filter case, 7...Air filter, 8...Communication pipe, 9...vent pipe, 9a...Dan section, 9b...convex part, 10...Pipe end ventilation part (ventilation cap), 10'...main body, 10a...flange portion, 10b...lever part, 10c...hook, 10d...notch, 10e, 10f...ventilation holes, F…Flat foreign object

Claims

1. In a ventilation pipe end structure, a pipe end ventilation part that prevents foreign matter from entering is provided at the end of a ventilation pipe provided in a vehicle structure, The pipe end ventilation portion is formed in a three-dimensional shape, Slit-like ventilation holes are formed radially from the end side to the base side on at least the curved surface of the three-dimensional shape formed in the pipe end ventilation portion. A ventilation pipe end structure characterized by the above.

2. The three-dimensional shape is a three-dimensional curved surface shape.

2. The ventilation pipe end structure according to claim 1.

3. the pipe end ventilation part is detachably attached to the end of the ventilation pipe, A hook is formed on the base side of the pipe end ventilation part to be inserted into the ventilation pipe and hooked onto the structure.

2. The ventilation pipe end structure according to claim 1.

4. A step is formed on the inner periphery of the ventilation pipe, a flange portion attached to the step portion is provided on the outer periphery of the pipe end ventilation portion; The step portion and the flange portion are formed with positioning portions that fit together to restrict movement in the rotational direction.

4. The ventilation pipe end structure according to claim 3.

5. The pipe end ventilation portion is integrally formed at the end of the ventilation pipe.

2. The ventilation pipe end structure according to claim 1.

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