JP4847749B2 - Air introduction duct - Google Patents

Description

  The present invention relates to an air introduction duct for introducing air into an internal combustion engine.

  In Patent Document 1, a partition wall is provided separately from the case body of the air cleaner, and a sound absorbing material is attached between the partition wall and the back plate, or a sound absorbing material is disposed between the case body and the cover. And a connection protrusion provided on each of the covers are connected and fixed by a small screw to reduce the intake noise.

Further, in Patent Document 2, a sound absorbing material made of a sponge having a cross-shaped cross section is held in contact with an inner peripheral surface of an intake hose bellows in an intake hose connecting an air cleaner and an engine. A technique for absorbing flow vibration and preventing intake noise is disclosed.
Japanese Utility Model Publication No. 3-1207077 JP-A-7-293374

  However, in Patent Document 1, in order to provide the partition wall separately from the case main body, the mold structure of the case main body is complicated, and the complicated structure makes it difficult to fill the sound absorbing material in a predetermined position. There is a possibility that the sound absorption performance of the period cannot be secured.

  Further, in Patent Document 2, in order to fix and hold the sound absorbing material in the intake hose, it is necessary to apply the adhesive after fixing the outer peripheral surface of the sound absorbing material in contact with the hose, or to fix the sound absorbing material by attaching a double-sided tape. Further, since it is difficult to keep the fixed holding position constant, variations are likely to occur, and there is a possibility that the sound absorption performance is deteriorated.

In an air introduction duct for introducing air into an internal combustion engine, the air introduction duct has a cylindrical duct main body portion whose tip is a rectangular air intake opening that is open to the atmosphere, and a silencer unit that is inserted into the air intake opening. The silencing unit includes an L-shaped plate member that can be inserted into the air intake port, and a sound absorbing material that is held and fixed to the plate member, and the plate member includes the silencing unit. A first wall portion that closes a part of the air intake port serving as an insertion port, and a second wall portion that is orthogonal to the first wall portion and extends from the air intake port into the duct body portion. and, wherein the sound absorbing material is always fixed on the second wall portion, wherein the silencer unit is inserted into the air intakes, unevenness formed between the duct body portion and the second wall portion The shape parts are By engaging the is characterized in that it is held by the duct body portion. Thereby, the silencing unit is only inserted into the air introduction duct, and the concave or convex portion formed in the air introducing duct is engaged with the concave or convex portion formed in the silencing unit with one touch. Further, the intake sound generated in the air introduction duct is absorbed by the sound absorbing material, so that the sound quality is improved.

  According to the present invention, the muffler unit can be attached to the existing air introduction duct without making a significant design change by forming the muffler unit according to the air intake port of the air introduction duct. The sound absorbing material can be easily and reliably attached to a predetermined position with respect to the air introduction duct.

  An embodiment of the present invention will be described in detail with reference to the drawings.

  1 to 5 show an air introduction duct 1 according to the present invention. FIG. 1 is an explanatory view schematically showing the air duct, and FIG. 2 shows an air introduction duct 1 according to the present invention. 3 is an exploded perspective view, FIG. 3 is a perspective view of the air introduction duct 1 according to the present invention, FIG. 4 is a cross-sectional view of the main part of the air introduction duct 1 according to the present invention, and FIG. The perspective view of the air introduction duct 1 concerning the present invention seen from a different angle is shown.

  The air introduction duct 1 has a substantially cylindrical duct main body portion 2 made of a resin material, and a sound deadening unit 4 that is inserted into the air intake port 3 of the air introduction duct 1 and fixed to the duct main body portion 2. is doing. The silencer unit 4 includes a sound absorbing material 5 made of porous urethane foam and a plate member 6 made of a resin material.

  The duct main body 2 is manufactured by blow molding, and as shown in FIGS. 1, 2, 3 and 5, one end opens to the atmosphere as an air intake 3 and the other end is an air cleaner 13. It is connected to the. The duct body 2 is formed such that the passage cross-sectional area of one end 7 where the air intake 3 is formed is larger than the cross-sectional area of the other end 8 connected to the air cleaner 13.

  In the present embodiment, the air intake 3 that opens at one end 7 of the duct body 2 is divided into two by reinforcing ribs 9 provided near one end of the duct body 2. That is, in the one end portion 7 of the duct main body 2, the air intake 3 is partitioned into the first air intake 3 a and the second air intake 3 b by the reinforcing rib 9. The second air intake port 3b of the air intake port 3 is provided with a sound absorbing material 5 and a plate member 6 that serve as the sound deadening unit 4. A part of the passage cross-sectional area of the air introduction duct 1 is provided by the sound deadening unit 4. It is blocked. In other words, in the intake passage formed in the air introduction duct 1 by the silencer unit 4, a part of the passage cross-sectional area is blocked in a partial section adjacent to the air intake 3. Note that the silencer unit 4 may be disposed in the first air intake port 3a.

The sound absorbing material 5 is set to have a volume that can absorb a resonance level of a low frequency due to the shape and structure of the duct main body 2, for example, a low frequency of about 150 Hz. The air introduction duct 1 in the present embodiment is formed so that the resonance frequency at the P portion, which is a portion surrounded by a dotted line in FIG. 1, is 150 Hz . Their to sound absorbing material 5 is pre-fixed by the plate member 6, for example, an adhesive or the like, becomes integral with the plate member 6, and at least part of the outer surface is exposed to air flowing in the air introducing duct It is attached to the duct main body 2 in a state.

  As shown in FIGS. 2, 4, 6, and 7, the plate member 6 includes a first wall portion 6a that closes the air intake port 3b substantially perpendicular to the air flow direction in the air intake port 3b. The second wall portion 6b is substantially orthogonal to the first wall portion 6a and extends along the air flow direction, and is formed in a substantially L shape as a whole.

  The second wall portion 6b of the plate member 6 has a pair of through holes 10 and 10 and a pair of convex portions 11 and 11 provided outside the through hole and provided on the bottom surface side of the second wall portion 6b. And are formed. Further, corresponding to the through holes 10 and 10 and the projections 11 and 11 of the plate member 6, four duct side penetrations are made on the bottom wall surface of the duct main body 2 so that the central axis is along the direction perpendicular to the air flow. A hole 12 is formed. In other words, the pair of through holes 10 and 10 are set so as to overlap at predetermined positions with respect to the inner two of the four duct side through holes 12 formed through the bottom wall surface of the duct main body portion 2. A pair of convex parts 11 and 11 are set so that it may engage with two outside on four duct side through holes 12 in a predetermined position.

  That is, when the plate member 6 is inserted into the second air intake port 3b, the convex portions 11, 11 engage with the duct side through holes 12, 12 corresponding to the convex portions 11, 11, and the air introduction duct 2 is engaged. Positioning and holding is performed. In other words, the convex and concave portions are formed between the duct main body 2 and the plate member 6 by the convex portions 11 and 11 and the duct side through holes 12 and 12. At this time, the through holes 10 and 10 of the plate member 6 and the duct side through holes 12 and 12 corresponding to the through holes 10 and 10 are in a state of overlapping each other. The overlapped through hole 10 and duct side through hole 12 prevent mechanical dropout due to external factors such as large external vibration when the air introduction duct 1 is attached to the actual vehicle. Therefore, each of the plug-in plastic pins (not shown) is inserted to fasten the plate member 6 and the duct main body 2.

  FIG. 8 shows an air introduction duct 41 of the first comparative example, and FIG. 9 shows an air introduction duct 51 of the second comparative example.

  The air introduction duct 41 of the first comparative example shown in FIG. 8 has a configuration in which the silencer unit 4 is removed from the air introduction duct 1 in the above-described embodiment of the present invention, and the other configurations are substantially the same. Yes.

That is, the air introduction duct 41 of the first comparative example shown in FIG. 8 has one end opened to the atmosphere as an air intake 42 and the other end connected to the air cleaner 43. The air introduced into the air cleaner is supplied to an engine (not shown) located on the downstream side of the air cleaner 43. In the air introduction duct 41 in the first comparative example, the passage sectional area of the one end portion 44 where the air intake port 42 is formed is relatively larger than the passage sectional area of the other end portion 45 connected to the air cleaner 43. The passage cross-sectional area is formed so as to gradually change between the one end portion 44 and the other end portion 45 . Their to air inlet duct 41 in the first comparative example, the resonance frequency in the P portion is a portion enclosed by a dotted line in the middle lower side of the end portion 44 of FIG. 8 are formed so as to be 150 Hz. In addition, 46 in FIG. 8 is a reinforcing rib provided near the air intake 42 of the one end 44.

  Here, about the 2nd comparative example mentioned later, about the part which has the same structure as the 1st comparative example mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 9 shows an air introduction duct 51 of the second comparative example. Fig.9 (a) is explanatory drawing which showed typically the air introduction duct 51 in a 2nd comparative example, FIG.9 (b) is sectional drawing along the AA line of Fig.9 (a). .

  The air introduction duct 51 of the second comparative example has substantially the same configuration as the air introduction duct 41 of the first comparative example described above. However, in this second comparative example, the one end 44 is separated from the reinforcing rib 46. The rib 52 is separately provided at the P portion. In other words, the air introduction duct 51 of the second comparative example is separately provided with a rib 52 at a position of a P portion that is a portion surrounded by a dotted line on the lower center side of the one end portion 44. And the air introduction duct 51 in the 2nd comparative example is formed so that the resonant frequency in P section may be 150 Hz like the 1st comparative example mentioned above.

  FIG. 10 shows the inertance level according to frequency in the P part of the air introduction duct 1 in the embodiment of the present invention and the P parts of the air introduction ducts 41 and 51 in the first and second comparative examples. Here, the inertance level is an index expressed by A / F when the acceleration at the response point of the object to be measured is A with respect to the input F by hammer vibration to the object to be measured. . In other words, the inertance level is the surface rigidity level, and the higher the surface rigidity level, the higher the rigidity.

  As in the first comparative example, in the air introduction duct 41 in which no sound absorbing material is arranged, a resonance frequency exists at 150 Hz and a peak also exists near 400 Hz.

Further, when the rib 52 other than the reinforcing rib 46 is provided at the one end portion 44 as in the second comparative example, the resonance frequency level (inertance level) of 150 Hz is slightly reduced, but it is so-called in the vicinity of 400 Hz. It can be seen that the resonance frequency level (inertance level) increases due to rebounding. On the other hand, like the air introduction duct 1 in the embodiment of the present invention, the sound absorbing material 5 made of urethane foam is placed in the air introduction duct 1. As can be seen from FIG. 10, the resonance frequency level (inertance level) of 150 Hz can be reduced and rebounding in the vicinity of 400 Hz can also be suppressed.

  Therefore, FIG. 11 shows the results of evaluating the noise of the vehicle interior mounted on an actual vehicle with respect to the air introduction duct 1 in the present embodiment and the air introduction duct 41 in the first comparative example. As shown in FIG. 11, the air introduction duct 1 in which the sound absorbing material 5 made of urethane foam is disposed has improved the overall quietness of the vehicle interior as compared with the air introduction duct 41 of the first comparative example. I understand that.

  In this way, instead of shifting the resonance frequency to shift the peak to another resonance frequency, the sound absorbing material 5 made of urethane foam is disposed inside, thereby reducing the resonance frequency level and further suppressing the rebound. It can be seen that an air introduction duct capable of performing

  As described above, the air intake duct 1 according to the present invention forms the muffler unit 4 including the sound absorbing material 5 in accordance with the shape of the air intake 3 of the air intake duct 1, so that the existing air introduction duct is formed. 1, the silencing unit 4 can be mounted by adding only the duct side through hole 12 to the air introduction duct 1 without making a significant design change.

  Further, when the silencer unit 4 is attached to the duct main body 2, the projecting portion 11 of the plate member 6 is engaged with the through hole 12 of the duct main body 2. The duct 1 can be easily and reliably attached to a predetermined position.

  Further, since the sound absorbing material 5 is fixed to the duct main body 2 just by inserting it into the duct main body 2 as the sound deadening unit 4 for fixing the plate member 6 integrally, the partition wall is separated from the duct main body 2 separately. There is no need to provide it, and the mold shape of the duct main body 2 can be kept in a simple shape, and the fixing and holding position of the sound absorbing material 5 can be surely determined at a predetermined position.

In the above-described embodiment, the projection 11 is provided on the plate member 6, and the duct side through hole 12 that engages the projection 11 is provided on the duct body 2, but the recess provided on the plate member 6 side is also provided. Alternatively, it is possible to engage the through hole with a convex portion provided on the duct main body side.

Explanatory drawing which showed typically the air introduction duct which concerns on this invention. The disassembled perspective view of the air introduction duct which concerns on this invention. The perspective view of the air introduction duct which concerns on this invention. The principal part sectional drawing of the air introduction duct which concerns on this invention. The perspective view of a duct main-body part. The perspective view of a plate member. The perspective view which looked at the plate member from the bottom face. Explanatory drawing which showed typically the air introduction duct of the 1st comparative example. (A) is explanatory drawing which showed typically the air introduction duct of the 2nd comparative example, (b) is sectional drawing along the AA line of Fig.9 (a). The characteristic diagram which shows the inertance level according to frequency in P part of the air introduction duct in embodiment of this invention, and P part of each air introduction duct in a 1st and 2nd comparative example. Explanatory drawing which shows the result of having evaluated the muffled sound of the air introduction duct in embodiment of this invention, and the air introduction duct in a 1st comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air introduction duct 2 ... Duct main-body part 3 ... Air intake 4 ... Silencer unit 5 ... Sound absorption material 6 ... Plate member 10 ... Through-hole 11 ... Convex part 12 ... Duct side through-hole

Claims (1)

In an air introduction duct for introducing air into an internal combustion engine,
The air introduction duct has a cylindrical duct main body portion that is open into the atmosphere as a long and narrow rectangular air intake port, and a muffler unit inserted into the air intake port,
The silencing unit includes an L-shaped plate member that can be inserted into the air intake port, and a sound absorbing material that is held and fixed to the plate member,
The plate member is a first wall portion that covers a part of the air intake port serving as an insertion port of the silencer unit, and is orthogonal to the first wall portion and extends from the air intake port into the duct main body portion. A second wall,
The sound absorbing material is always fixed on the second wall portion,
The silencing unit inserted into the air intake port is held by the duct main body portion by engaging the concave and convex shape portions formed between the duct main body portion and the second wall portion. An air introduction duct characterized by that.

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