JP4384933B2 - Silencer for turbocharger - Google Patents

Description

  The present invention relates to a silencer for a supercharger that silences noise generated from an air suction port of the supercharger, and more particularly, to a silencer for a supercharger that can improve a silencing effect.

  In general, a turbocharger is used for large diesel engines in order to improve their performance, but in recent years, a high pressure ratio and high efficiency are also required for turbochargers in order to increase the output of diesel engines. As a result, the supercharger has been driven at a high rotational speed. And the noise level from a supercharger is also high by the high rotation drive of this supercharger.

  The noise from the turbocharger is divided into the noise upstream of the compressor and the noise radiated from the surface of the air passage on the engine side. Both noise components are the order components of the number of blades at the inlet of the compressor. Therefore, the air flow at the compressor inlet affects the noise level.

  For this reason, conventionally, a silencer that silences noise radiated from the air suction port to the outside is provided on the inlet side of the compressor of this type of turbocharger. In general, there are two types: a cylindrical outer periphery suction type and a square front suction type.

  As an example of the conventional cylindrical outer periphery suction type silencer, a circular hole is formed in each central portion, and there are two bent portions between a pair of disks arranged in parallel. A plurality of sound-absorbing splitters that are substantially Z-shaped as a whole by three portions connected to each other are arranged at intervals in the circumferential direction of the two discs.

  Each of the sound absorbing splitters is surrounded by an outer peripheral wall made of a metal such as aluminum and a punching metal in which a large number of through holes are formed. The outer peripheral wall is formed of a first side wall, a second side wall, and both end walls. Further, as described above, two bent portions that are bent in opposite directions are formed on the outer peripheral wall, and each sound-absorbing splitter has a substantially Z shape as a whole.

  Among the outer peripheral walls that are divided into three portions in the longitudinal direction by the respective bent portions, the air resistance is reduced at the ends of the both end walls located on the inner peripheral edge side and the outer peripheral edge side of the both disks. A tip having a substantially triangular shape is formed. The length in the longitudinal direction of the intermediate portion that is connected to the end portion on the inner peripheral edge side in a plan view at an angle of approximately 120 ° is approximately twice the longitudinal length of the end portion on the inner peripheral edge side. Yes. Further, the length in the longitudinal direction of the end on the outer peripheral side connected to the intermediate portion is about 1.5 times the length in the longitudinal direction of the end on the inner peripheral side. In addition, the said through-hole is not formed in each said point.

  In the internal space formed in the outer peripheral wall of each of the sound absorbing splitters, a net-like or non-woven sound absorbing material made of glass wool is housed.

  The convex side of each bent portion is formed on a convex arc surface in order to reduce air resistance.

  With such a configuration, air supplied to the supercharger is provided between each pair of adjacent sound-absorbing splitters arranged in the circumferential direction between the two discs from the outside to the inside of the two discs. Are distributed and introduced from a plurality of air passages. And since the length of the air passage is increased by the two bent portions of each of the sound absorbing splitters, the volume of noise introduced is increased, and further, the two bent portions of the respective sound absorbing splitters A sound wave having a frequency higher than the fundamental frequency collides with each of the bent portions, thereby preventing a sound wave having a frequency higher than the fundamental frequency from passing through.

Japanese Patent No. 2876000

  However, the conventional silencer for a supercharger as described above is based on the force of the air flow that flows on the surface of the sound absorbing splitter when the adhesive that bonds the fibers of the non-woven sound absorbing material such as glass wool deteriorates. In order to prevent the fibers that make up the nonwoven fabric from being scattered, the sound absorbing material is housed in the outer peripheral wall in which many through holes are formed in a metal such as aluminum. There is a problem in that sound waves are reflected at the part of the material and sound absorption by the sound absorbing material is hindered.

  Moreover, since the outer peripheral wall in which many through-holes were formed in order to prevent scattering of the fiber of a sound absorption material, there existed a problem that cost increased.

  Furthermore, the oil contained in the air sucked into the supercharger soaks into the sound absorbing material, the sound absorption level of the sound absorbing material decreases, and the sound absorbing material must be replaced periodically.

  The present invention has been made in view of such problems, and it is not necessary to provide an outer peripheral wall in which a large number of through holes for preventing the scattering of the fibers of the sound absorbing material are provided, and the silencing effect can be improved. An object of the present invention is to provide a silencer for a turbocharger that can reduce costs.

Features of the turbocharger silencer according to the present invention for achieving the above object is the centered portion concentrically with one of the disc circular hole is formed this one disc of the same size other circle Between the pair of disks arranged in parallel with each other, each has two bent portions and is formed in a Z shape as a whole, and the end on the inner peripheral side of the circular hole of the one disk is the two A plurality of sound-absorbing splitters formed at an angle of 0 ° with respect to the center line of the discs are spaced apart in the circumferential direction of both discs so that air is sucked inward from the outside between the discs. A pair of sound-absorbing splitters that are spaced apart and adjacent to each other are arranged in parallel, and a truncated cone that protrudes toward the circular hole side is provided at the center of the other disk , attached to the air intake port, supercharging for performing silencing of turbocharger noise emitted to the outside from the air inlet In use silencer, the sound-absorbing splitter is in that it is formed by heat-sealing polyester fibers.

  In addition, the distance between the air passages between the pair of adjacent sound absorbing splitters is formed so as to gradually decrease from the outside to the inside of the two disks.

  Further, the convex side of each bent portion of each of the sound absorbing splitters is formed on an arc surface.

According to the silencer for a supercharger of the present invention, since the sound absorption splitter is formed by compressing polyester fiber by sintering (heating and pressurization, the same applies hereinafter) , the fibers are heat-sealed, and the surface of the sound absorption splitter is It is possible to prevent the fibers from being scattered by the force of the flowing air, and there is no need to provide an outer peripheral wall in which a large number of through holes are formed to prevent the fibers from scattering. For this reason, while being able to reduce cost, the sound-absorbing effect by the sound-absorbing splitter can be improved without the sound wave being reflected and preventing sound absorption at a portion other than the through hole of the outer peripheral wall.

  Hereinafter, embodiments of a silencer for a supercharger according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing a first embodiment of a silencer for a supercharger according to the present invention, (a) is a front view, (b) is a longitudinal sectional side view, and FIG. 2 is an arrangement of the sound absorbing splitters of FIG. FIG. 3A is a front view, FIG. 3B is a longitudinal sectional side view, FIG. 3 is a front view of the sound absorbing splitter of FIGS. 1 and 2, and FIG. 4 is a frequency and noise amount generated in the turbocharger. FIG. 5 is a comparison diagram of the volume reduction between the sound absorption splitter of the present embodiment and the conventional sound absorption splitter, FIG. 6 is a schematic diagram showing a second embodiment of the silencer for a supercharger according to the present invention, FIG. 7A is a front view, FIG. 7B is a longitudinal sectional side view, and FIG. 7 is a perspective view showing a part of the sound absorbing splitter of FIG.

  As shown in FIG. 1, the turbocharger silencer 1 according to the first embodiment has a pair of discs 2 and 3 made of steel plates arranged in parallel with each other at intervals. The outer diameters of these discs 2 and 3 are equal to each other. A relatively large diameter circular hole 4 for air circulation is formed concentrically at the center of the disc 3 located on the supercharger side end (not shown) of these discs 2 and 3. Has been.

  At the center of the disc 2, a truncated cone 5 having a tapered truncated cone shape projecting toward the circular hole 4 of the disc 3 facing the disc 2 is projected. In order to guide the air introduced into the turbocharger silencer 1 toward the supercharger (not shown) without resistance, the outer peripheral surface is formed in a conical shape.

  In addition, sound absorbing material 6 formed by compressing and compressing polyester fibers is accommodated in the circular disks 2 and 3 and the truncated cone 5, and the opposing surfaces of the circular disks 2 and 3 A large number of through holes 7 are formed on the surface of the truncated cone 5.

  Further, as shown in FIG. 2, a plurality of sound absorbing splitters 8, 8... Are arranged between the disks 2 and 3 so as to be fixed to the disks 2 and 3. In FIG. 2, a large number of sound absorbing splitters 8 are described by a single line for convenience, but in reality, each of the sound absorbing splitters 8 has the same shape.

  Each of the sound absorbing splitters 8 is formed by compressing and compressing polyester fibers in the same manner as the sound absorbing material 6, and the sound absorbing splitters 8 are bent in opposite directions as shown in detail in FIG. Two bent portions 8a and 8b are formed, and each sound absorbing splitter 8 has a substantially Z shape as a whole.

  Each of the sound absorbing splitters 8 is divided into three portions in the longitudinal direction by the two bent portions 8a and 8b, and is located inside the discs 2 and 3 on the left side in FIG. A tip 8d having a substantially triangular shape is formed at the tip of the inner end 8c to reduce air resistance, and each inner end 8c of each sound absorbing splitter 8 is connected to the center line of both the disks 2 and 3, respectively. Is formed at an angle of 0 °. The longitudinal length of the intermediate portion 8e connected to the inner end portion 8c obliquely to the right in plan view with an angle of approximately 160 degrees with the inner end portion 8c is about the longitudinal length of the inner end portion 8c. 2.5 times. In addition, the longitudinal length of the outer end portion 8f connected to the intermediate portion 8e obliquely to the right of the intermediate portion 8e in plan view with an angle of approximately 100 degrees is equal to the longitudinal length of the inner end portion 8c. The tip of the outer end portion 8f is formed with a substantially triangular tip 8g to reduce air resistance.

  Further, a nonwoven fabric 11 made of polyester fiber having good air permeability and waterproofness and oilproofness is attached to the surface of each sound absorbing splitter 8 to cover each sound absorbing splitter 8.

  Here, regarding the silencing effect of the sound-absorbing splitter formed by sintering and compressing the polyester fiber of the present embodiment, in the outer peripheral wall made of punching metal in which a large number of through holes are formed, A description will be given in comparison with a conventional sound-absorbing splitter in which a non-woven sound-absorbing material is accommodated.

  In general, the noise generated from the suction port of the turbocharger is mainly composed of the fundamental frequency and the overtone generated by the rotation of the turbo compressor of the turbocharger, and is greatly superior to other frequencies. This fundamental frequency is determined by multiplying the rotation speed of the turbo compressor and the number of blades. For example, when the rotational speed of the turbo compressor is 43500 rpm and the number of blades is 11, 43500 (rpm) × 11 (sheets) / 60 (seconds) = 7975 (approximately 8.0 K) (Hz).

  And although the noise which generate | occur | produces in the suction port of a supercharger changes also with impeller diameters, as shown in FIG. 4, when the fundamental frequency is 8.0K (Hz), the noise in a supercharger is 133 dB (A). Then, 132 dB (A) is the main component at 16.0 K (Hz), which is a harmonic of the fundamental frequency. The noise generated from the engine using the turbocharger is about 100 dB (A), and the noise generated from the turbocharger after the silencer is attached must be reduced to the same extent, so about 30 dB (A). Mute is required.

  Therefore, when comparing the noise reduction volume of the sound absorption splitter of this embodiment and the conventional sound absorption splitter, as shown in FIG. 5, when the frequency is 8.0 K (Hz), the noise reduction volume of the conventional sound absorption splitter is 20 dB. (A), and the noise reduction volume of the sound absorbing splitter of this embodiment is 27 dB (A). Furthermore, as shown in FIG. 5, when the frequency exceeds 8.0 K (Hz), the noise reduction level of the conventional sound absorption splitter is reduced, but the noise reduction level of the sound absorption splitter of the present embodiment may not be reduced. I understand.

  Therefore, it can be seen that the sound absorbing effect of the sound absorbing splitter of the present embodiment is improved over the conventional sound absorbing splitter.

  As shown in FIG. 2, the plurality of sound absorbing splitters 8 having the above-described configuration are substantially parallel between the disks 2 and 3, so that each of them extends in the radial direction of the disks 2 and 3. Although arranged in parallel, the sound absorbing splitters 8 are arranged so that the distance between each pair of adjacent sound absorbing splitters 8 and 8 is equal on the inner peripheral edge 12 and the outer peripheral edge 13 of both discs 2 and 3. The discs 2 and 3 are fixed in the same direction. Accordingly, the interval between the air passages 14 formed between the pair of adjacent sound absorbing splitters 8 and 8 is gradually reduced from the outside of the discs 2 and 3 toward the inside.

  A wire mesh 9 is wound on the outer side between the outer peripheral edges of the discs 2 and 3, and a filter 10 for removing dust in the air is wound on the outer side of the wire mesh 9 so as to be excessive. A silencer 1 for a feeder is configured.

  Further, when air supplied to a supercharger (not shown in FIG. 1) is sucked inward from the outer peripheral side of the turbocharger silencer 1, a pair of sound absorbing splitters between the discs 2 and 3. The plurality of air passages 14 between 8 and 8 are distributed and introduced. At this time, noise generated from the supercharger is introduced into the air passages 14 and is silenced by the sound absorbing splitters 8, and the sound absorbing material 6 is obtained from the through holes 7 formed in the opposing surfaces of the discs 2 and 3. To mute. Furthermore, since the length of each air passage 14 is formed long by the two bent portions 8a and 8b of each sound absorbing splitter 8, the volume of silence by each sound absorbing splitter 8 can be increased.

  In each air passage 14, the two bent portions 8a and 8b of each sound absorbing splitter 8 cause a sound wave having a frequency higher than the fundamental frequency in the air to collide with the bent portions 8a and 8b, which is higher than the fundamental frequency. It is possible to prevent sound waves having a frequency from passing through.

  Therefore, sound waves of various frequencies are removed from the noise that has passed through each air passage 14. Moreover, the noise that has passed through each air passage 14 is also silenced by the sound absorbing material 6 from each through hole 7 formed on the surface of the truncated cone 5.

  Moreover, since the nonwoven fabric 11 which consists of polyester fiber which has air permeability and water resistance and oil proof property is affixed on the surface of each sound absorption splitter 8, and coat | covers each sound absorption splitter 8, a silencer for superchargers Therefore, it is possible to prevent the oil contained in the air sucked into 1 from permeating the sound absorbing splitters 8 and to prolong the service life of the sound absorbing splitters 8. Therefore, it is possible to reduce the cost of periodically replacing each sound absorbing splitter 8.

Next, as shown in FIG. 6, in the turbocharger silencer 21 of the reference embodiment, two disks 22 and 23 formed with the same outer diameter are arranged in parallel with a distance therebetween, and a plurality of ( It is connected by a plate-shaped support plate 24 of four) in this reference embodiment. At the center of both discs 22 and 23, cylindrical portions 22a and 23a having relatively large diameters are formed concentrically so as to protrude inward and outward of the opposing discs 22 and 23, respectively. ing. Note that the outside of the cylindrical portion 22a is closed.

  Further, a disk-like sound absorbing material 25 formed by compressing and sintering polyester fibers is accommodated in the cylindrical portion 22a of the disk 22. The surface of the sound absorbing material 25 has air permeability. Well, a nonwoven fabric 26 made of polyester fiber having waterproof and oilproof properties is affixed to cover the sound absorbing material 25. Further, a cover member 27 having a large number of through holes 27a is fixed to the surface of the nonwoven fabric 26 by fastening members (not shown), and the sound absorbing material 25 is fixed.

  As shown in FIG. 6, the end portions in the circumferential direction are supported between the discs 22 and 23 by the support plates 24 that connect the discs 22 and 23. A plurality of sound absorbing splitters 28, 28... Are arranged in parallel and at equal intervals, and air sucked into the turbocharger silencer 21 flows between a pair of adjacent sound absorbing splitters 28, 28. An air passage 30 is formed.

Each of the sound absorbing splitters 28 is formed by compressing and compressing a polyester fiber, and a circular hole having substantially the same diameter as the circular plates 22 and 23 and having the same diameter as the cylindrical portions 22a and 23a is formed. formed in a donut shape sound absorbing material (in the present reference embodiment) is divided into four. The inner peripheral edge 28a of each sound absorbing splitter 28 on the disk 22 side directs the air flow sucked into the turbocharger silencer 21 to direct the disk 23 to the disk 23. It is formed so as to incline in the direction.

Further, as shown in FIG. 7, a nonwoven fabric 29 made of polyester fiber having good air permeability and waterproofness and oilproofness is attached to the surface of each sound absorbing splitter 28 to cover each sound absorbing splitter 28. ing. A plurality of sound-absorbing splitters 28 arranged in parallel and at equal intervals to both the disks 22 and 23 are held by the partition plate 31 at each end in the circumferential direction. Incidentally, sound-absorbing splitter 28 of this preferred embodiment also, as described in the first embodiment, the outer peripheral wall in which a large number of through holes made of formed punching metal, a material such as glass wool mesh or nonwoven The silencing effect is improved over the conventional sound-absorbing splitter in which the sound-absorbing material is stored.

  A wire mesh 32 is wound on the outer side between the outer peripheral edges of the circular plates 22 and 23, and a filter 33 for removing dust in the air is wound on the outer side of the wire mesh 32. .

  When air supplied to a supercharger (not shown in FIG. 6) is sucked inward from the outer peripheral side of the supercharger silencer 21, a pair of sound absorbing splitters between the disks 22 and 23. In other words, the air is distributed and introduced into a plurality of air passages 30 between 28 and 28. At this time, noise emitted from the supercharger is introduced into each air passage 30 and is silenced by each sound absorbing splitter 28 and is also silenced by the sound absorbing material 25 housed in the cylindrical portion 22a of the disc 22. The air that has passed through each of the sound absorbing splitters 28 is surely introduced into the supercharger side because the inner peripheral edge 28a of each sound absorbing splitter 28 on the disk 22 side is inclined toward the disk 23 side. .

  Further, since the nonwoven fabric 29 made of polyester fiber having good air permeability and waterproofness and oil proofing is attached to the surface of each sound absorbing splitter 28 and covers each sound absorbing splitter 28, the silencer 21 for the supercharger. It is possible to prevent the oil contained in the air sucked into the respective sound absorbing splitters 28 from being infiltrated into the sound absorbing splitters 28 and to prolong the service life of the respective sound absorbing splitters 28. Can be reduced.

Further, in the sound-absorbing splitter 28 of this preferred embodiment is formed in a donut-shaped sound absorbing material is divided, each sound-absorbing splitter 28 disposed parallel to both discs 22 and 23, each end of each circumferential direction Therefore, the attachment / detachment to / from the turbocharger silencer 21 is facilitated, and assembly and replacement of the sound absorption splitter 28 can be simplified.

In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed. Further, in the reference embodiment, a disk-like sound absorbing material 25 formed by compressing and sintering polyester fibers is accommodated in the cylindrical portion 22 a of the disk 22, and a nonwoven fabric 26 and a cover are placed on the surface of the sound absorbing material 25. Although the member 27 is arranged, a truncated cone in which a sound absorbing material is housed inside the cylindrical portion 22a and a large number of through holes are formed on the surface thereof, as in the first embodiment. May be formed.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows 1st Embodiment of the silencer for superchargers which concerns on this invention, (a) is a front view, (b) is a longitudinal cross-sectional side view. It is the schematic which showed the arrangement | sequence of the sound-absorption splitter of FIG. 1, (a) is a front view, (b) is a longitudinal cross-sectional side view. Front view of the sound-absorbing splitter of FIGS. 1 and 2 Relationship diagram between frequency and amount of noise generated in turbocharger Comparison of noise reduction between sound absorbing splitter of this embodiment and conventional sound absorbing splitter BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the reference form of the silencer for superchargers which concerns on this invention, (a) is a front view, (b) is a longitudinal cross-sectional side view. The perspective view which extracted and showed some sound absorption splitters of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silencer for turbochargers 2 Disc 3 Disc 4 Circular hole 5 Frustum 6 Sound absorbing material 7 Through hole 8 Sound absorbing splitter 9 Wire mesh 10 Filter 11 Non-woven fabric 21 Supercharger silencer 22 Disc 23 Disc 24 Support plate 25 Sound absorption Material 26 Non-woven fabric 27 Cover member 28 Sound absorbing splitter 29 Non-woven fabric 31 Partition plate 32 Wire mesh 33 Filter

Claims (3)

Two bent portions are provided between a pair of discs in which one disc having a circular hole concentrically formed in the central portion and the other disc having the same size as the one disc are arranged in parallel. A plurality of sound-absorbing splitters that are formed in a Z shape as a whole and whose end portions on the inner peripheral edge side of the circular hole of the one disk are formed at an angle of 0 ° with respect to the center line of the both disks, A pair of sound-absorbing splitters arranged adjacent to each other are arranged in parallel with a space in the circumferential direction between both the disks so that air is sucked inwardly from the outside between the both disks. In the center of the other disk, a truncated cone projecting toward the circular hole is provided, and is attached to the air intake port of the supercharger, and supercharger noise radiated outward from the air intake port In the silencer for turbocharger to mute
The turbo silencer according to claim 1, wherein the sound absorbing splitter is formed by heat-sealing polyester fibers.   2. The supercharging according to claim 1, wherein an interval of an air passage between the pair of adjacent sound absorbing splitters is formed so as to gradually decrease from the outside to the inside of the two disks. Silencer for machine. 3. The silencer for a supercharger according to claim 1, wherein a convex side of each bent portion of each sound absorbing splitter is formed in a circular arc surface . 4.