Air cleaner

Abstract

An air cleaner (1) has an auxiliary casing (8) provided with a third volume chamber (24) that is continuous with a first volume chamber (14) on the upstream side in the air flow direction relative to a filter element (6). The auxiliary casing (8) has an air introduction part (26) for introducing air passing through the filter element (6). The air introduction part (26) is formed in the auxiliary casing (8) so that the air flow reaching the filter element (6) via the auxiliary casing (8) becomes a U-shaped path without directly directing the filter element (6).

Description

air cleaner

[0001] The present invention relates to an air cleaner to be installed in an intake passage of an internal combustion engine.

[0002] For example, Patent Document 1 discloses an air cleaner in which a precleaner is provided upstream of a filter element that filters air in a case in which the filter element is arranged, to remove foreign matter (dust) contained in the air.

[0003] The precleaner has wings that generate a swirling flow, and a dust cup that collects foreign matter that has been centrifuged by the swirling flow generated by the wings.

[0004] The air cleaner of Patent Document 1 facilitates maintenance of the filter element by removing relatively large foreign matter with the precleaner.

[0005] However, the air cleaner of Patent Document 1 may have a risk of increasing pressure loss due to the provision of the wings.Furthermore, the air cleaner of Patent Document 1 needs to have a structure for guiding the foreign matter centrifuged by the swirling flow of the wings to the dust cup, which may increase costs.

[0006] In other words, there is room for further improvement in air cleaners in order to improve the maintainability of the filter element.

[0007] Japanese Patent Application Laid-Open No. 2005-330826

[0008] The air cleaner has an auxiliary casing with an auxiliary volume chamber that is continuous with a space upstream of the filter element in the air flow direction. The auxiliary casing has an air inlet that introduces air that passes through the filter element. The air inlet is formed in the auxiliary casing so that the air flow that reaches the filter element through the auxiliary casing follows a U-shaped path without being directed directly at the filter element.

[0009] The air cleaner of the present invention can improve the maintainability of the filter element by suppressing localized clogging of the filter element.

[0010] The present invention will be described in detail below with reference to the accompanying drawings, in which: Fig. 1 is a perspective view showing a schematic configuration of an air cleaner according to the present invention; Fig. 2 is a cross-sectional view taken along line AA in Fig. 1; and Fig. 3 is an explanatory diagram showing a schematic view of air flowing inside the air cleaner according to the present invention.

[0011] An embodiment of the present invention will be described in detail below with reference to Figures 1 to 3. Figure 1 is a perspective view showing the general configuration of an air cleaner 1 according to the present invention. Figure 2 is a cross-sectional view taken along line A-A in Figure 1. Figure 3 is an explanatory diagram showing a schematic view of air flowing inside the air cleaner 1 according to the present invention.

[0012] As shown in Figure 1, an inlet duct 3 is connected to an air cleaner 1 via a bellows-shaped hose 2. One end of the inlet duct 3 serves as an intake port 4 for taking in outside air. In addition, an outlet duct 5 is connected to the air cleaner 1, which supplies air that has passed through the air cleaner 1 and been filtered to an internal combustion engine (not shown). In other words, the air cleaner 1 is disposed in the intake passage of the internal combustion engine.

[0013] As shown in FIGS. 1 and 2, the air cleaner 1 has a filter element 6, a main casing 7 made of a resin material, and an auxiliary casing 8 made of a resin material.

[0014] The filter element 6 has a rectangular flat plate shape and is disposed inside the main casing 7 .

[0015] The resin main casing 7 is a hollow member having an approximately rectangular parallelepiped outer shape, and includes a deep dish-shaped first casing 9 and a deep dish-shaped second casing 10. The main casing 7 is obtained by butting together the opening of the first casing 9 and the opening of the second casing 10 with a seal material 11 interposed between them.

[0016] The first casing 9 has a flat opposing wall 12 that faces the filter element 6 at a distance, and a cylindrical side wall 13 that surrounds the opposing wall 12. The opposing wall 12 and the side wall 13 define a first volume chamber 14 inside the first casing 9.

[0017] The opposing wall 12 has a wall surface that faces the filter element 6 and is spaced apart from the filter element 6, among the wall surfaces of the first casing 9 that form the first volume chamber 14. A filter holding portion 15 that holds the filter element 6 is formed in the upper end portion of the side wall 13 of the first casing 9, which is the opening side of the first casing 9. The filter holding portion 15 is formed by causing the upper end portion of the side wall 13 to protrude toward the outer periphery of the first casing 9. A first air opening 16 that serves as an inlet for air introduced via the auxiliary casing 8 is formed in the side wall 13 of the first casing 9.

[0018] The first chamber 14 is a space located upstream of the filter element 6 in the air flow direction, and serves as the so-called dust side within the main casing 7 .

[0019] The first casing 9 is fixed to the second casing 10 using a plurality of clips (not shown), for example made of metal.

[0020] The second casing 10 has a flat second opposing wall 17 that faces the filter element 6 at a distance, and a cylindrical second side wall 18 that surrounds the second opposing wall 17. A second volume chamber 19 is formed inside the second casing 10 by the second opposing wall 17 and the second side wall 18. The outlet duct 5 is connected to the second side wall 18 of the second casing 10.

[0021] The second chamber 19 is a space located downstream of the filter element 6 in the air flow direction, and serves as the so-called clean side within the main casing 7 .

[0022] The resin auxiliary casing 8 is located to the side of the main casing 7 and has a flat horizontal wall 21 adjacent to and continuous with the opposing wall 12 of the first casing 9, a ceiling wall 22 facing the horizontal wall 21, and a vertical wall 23 located between the horizontal wall 21 and the ceiling wall 22 and connecting the horizontal wall 21 and the ceiling wall 22. The auxiliary casing 8 has a third volume chamber 24 formed therein by the horizontal wall 21, the ceiling wall 22, and the vertical wall 23. The vertical wall 23 of the auxiliary casing 8 has an air outlet opening 25 formed therein, which serves as an outlet for introducing air from the third volume chamber 24 into the first volume chamber 14. The ceiling wall 22 of the auxiliary casing 8 has a cylindrical air inlet 26 formed therein to introduce air that has passed through the filter element 6.

[0023] The auxiliary casing 8 is connected to the first casing 9 by vibration welding so that the air outlet opening 25 overlaps the first air opening 16 of the first casing 9. In other words, the auxiliary casing 8 is a separate part from the main casing 7.

[0024] The third chamber 24 communicates with the first chamber 14 via the first air opening 16 of the first casing 9 and the air outlet opening 25 of the auxiliary casing 8 .

[0025] The ceiling wall 22 of the auxiliary casing 8 has a flat first wall portion 27 inclined relative to the side wall 21, a flat second wall portion 28 not inclined relative to the side wall 21, and a flat intermediate wall portion 29 connecting the first wall portion 27 and the second wall portion 28. More specifically, the second wall portion 28 is formed so as to be substantially parallel to the side wall 21.

[0026] The first wall portion 27 and the second wall portion 28 are formed so that they protrude the same amount from the side wall 13 of the first casing 9. In other words, the first wall portion 27 and the second wall portion 28 are formed so that they protrude the same amount to the side of the main casing 7. The second wall portion 28 is positioned further outward from the side wall 21 than the first wall portion 27 when viewed from the side wall 21.

[0027] The auxiliary casing 8 is formed so that the volume of the portion sandwiched between the second wall portion 28 and the side wall 21 is larger than the volume of the portion sandwiched between the first wall portion 27 and the side wall 21 .

[0028] The air introduction section 26 is formed in the first wall section 27 and connected to the hose 2. The air introduction section 26 is formed so as not to point directly toward the filter element 6, but rather to point toward the opposing wall 12 of the first casing 9. In other words, the air introduction section 26 is formed so that the central axis of the air introduction section 26 is not perpendicular to the lateral wall 21 but is inclined at an angle.

[0029] Figure 3 is an explanatory diagram that schematically shows the air flow within the air cleaner 1. The arrow L shown by a thick dashed line in Figure 3 indicates the center of the air flow that flows into the air cleaner 1 from the air inlet portion 26. The truncated cone shape S shown by a thin dashed line in Figure 3 indicates how the cross-sectional area of ​​the flow path of the air that bounces off the opposing wall 12 increases as the flow velocity decreases.

[0030] 3, the air introduction section 26 is formed in the auxiliary casing 8 so as to be directed within the range in which the filter element 6 is projected on the opposing wall 12. In other words, as shown in FIG. 3, the air introduction section 26 is formed in the auxiliary casing 8 so that the air flow that reaches the filter element 6 through the auxiliary casing 8 follows a U-shaped path without being directed directly toward the filter element 6.

[0031] Furthermore, the air inlet section 26 is formed in the auxiliary casing 8 so that the center position of the flow path cross section (effective cross section) of the air flow when it reaches the filter element 6 overlaps with the center position of one end face 6 a of the filter element 6 that faces the first chamber 14, which is a space upstream of the filter element 6 in the air flow direction. In other words, the air inlet section 26 is formed so that the center position of the flow path cross section (effective cross section) of the air flow when it passes through the filter element 6 overlaps with the center position of one end face 6 a of the filter element 6 that faces the first chamber 14. In other words, the air inlet section 26 is formed in the auxiliary casing 8 so that the air flow is directed toward the center of the filter element 6 after bouncing off the opposing wall 12.

[0032] In the air cleaner 1 of the above-described embodiment, the air introduced from the auxiliary casing 8 does not directly reach the filter element 6 but follows a U-shaped path to reach the filter element 6 .

[0033] That is, the air cleaner 1 can make the path length of the air introduced into the auxiliary casing 8 until it reaches the filter element 6 longer than when the air introduced into the auxiliary casing 8 is directed directly toward the filter element 6. Therefore, the air cleaner 1 can suppress (slow) the flow velocity of the air as it passes through the filter element 6, and can reduce the pressure loss when the air passes through the filter element 6.

[0034] Furthermore, the air cleaner 1 can suppress and slow the flow rate of air as it passes through the filter element 6, thereby increasing the flow path cross-sectional area (effective cross-sectional area) of the air flow as it passes through the filter element 6, thereby improving the dust capture performance in the passing air and suppressing localized (partial) clogging of the filter element 6.

[0035] Furthermore, the air cleaner 1 can improve the maintainability of the filter element 6 by suppressing local clogging of the filter element 6.

[0036] In the air cleaner 1, the air inlet section 26 is formed so that the center position of the flow path cross section (effective cross section) of the air flow as it passes through the filter element 6 coincides with the center position of one end face 6a of the filter element 6 facing the first volume chamber 14, allowing the filter element 6 to be used (utilized) efficiently.

[0037] The air cleaner 1 is formed so that the volume of the portion sandwiched between the second wall portion 28 of the auxiliary casing 8 and the side wall 21 is larger than the volume of the portion sandwiched between the first wall portion 27 of the auxiliary casing 8 and the side wall 21, thereby providing an advantageous configuration for increasing the capacity of the third volume chamber 24.

[0038] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the invention.

[0039] For example, the outer shape of the auxiliary casing 8 is not limited to the shape in the above-described embodiment, and can be modified as appropriate depending on the shapes of the components arranged around the air cleaner 1. That is, as long as the auxiliary casing 8 does not interfere with the components arranged around the air cleaner 1, the first wall portion 27 may be formed to be approximately parallel to the side wall 21, similar to the second wall portion 28, and the first wall portion 27 and the second wall portion 28 may be formed so that they are the same distance from the side wall 21. In this case, the intermediate wall portion 29 is omitted, and the first wall portion 27 and the second wall portion 28 are directly continuous with each other.

[0040] For example, the air introduction portion 26 may be formed on the vertical wall 23 or may be formed across the ceiling wall 22 and the vertical wall 23 as long as it does not interfere with components arranged around the air cleaner 1.

[0041] For example, the auxiliary casing 8 may have recesses appropriately formed in the vertical walls 23 etc. so as not to interfere with components arranged around it.

Claims

1. An air cleaner comprising: a filter element for purifying air; a main casing in which the filter element is arranged; and an auxiliary casing located to the side of the main casing and equipped with an auxiliary volume chamber that is continuous with a space in the main casing upstream of the filter element in the air flow direction, wherein the auxiliary casing has an air inlet section for introducing air passing through the filter element, and the air inlet section is formed in the auxiliary casing so that the air flow reaching the filter element through the auxiliary casing follows a U-shaped path without being directed directly at the filter element.

2. An air cleaner as described in claim 1, wherein the air introduction portion is formed in the auxiliary casing so as to be oriented toward an opposing wall having a wall surface facing the filter element among the wall surfaces that form a space that is upstream of the filter element of the main casing in the air flow direction.

3. An air cleaner according to claim 1, wherein said air introduction section is formed so that the center position of the cross section of the flow passage of the air when it reaches said filter element coincides with the center position of said filter element.

4. An air cleaner according to claim 2, wherein said air introduction portion is formed in said auxiliary casing so that the air flow, after bouncing off said opposing wall, is directed toward the center of said filter element.

5. An air cleaner as described in claim 2, wherein the auxiliary casing is located to the side of the main casing and has a side wall continuous with the opposing wall, a ceiling wall facing the side wall, and a vertical wall located between the side wall and the ceiling wall and connecting the side wall and the ceiling wall, the ceiling wall has a first wall portion inclined with respect to the side wall, a second wall portion not inclined with respect to the side wall, and an intermediate wall portion connecting the first wall portion and the second wall portion, and the air introduction portion is formed in the first wall portion of the ceiling wall.

6. An air cleaner as described in claim 5, wherein the second wall portion is located outside the side wall more than the first wall portion, and the auxiliary casing is formed so that the volume of the portion sandwiched between the second wall portion and the side wall is larger than the volume of the portion sandwiched between the first wall portion and the side wall.

7. An air cleaner according to claim 1, wherein said main casing and said auxiliary casing are separate parts made of resin material, and are connected to each other by welding.

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