JP4697743B2 - Multi-room resonator - Google Patents

Description

  The present invention relates to a multi-chamber resonator having a plurality of resonance chambers therein.

  A resonator is known that is connected to a flow pipe through which gas can flow and reduces or silences sound during the flow of gas. For example, a resonator is used in an intake duct of a vehicle engine to reduce or mute the intake sound. The resonator is composed of a hollow container having a communication pipe portion connected to a circulation pipe, and has a resonance chamber inside. In the resonator, the frequency at which the sound can be reduced or silenced is determined by the relationship between the volume of the resonance chamber and the cross-sectional area and length of the communication pipe portion.

  In addition, since the sound generated when passing through the circulation pipe such as the duct is composed of sounds having different frequencies, a plurality of volumes having different volumes are provided so that a plurality of sounds having different frequencies can be reduced or silenced. A multi-chamber resonator divided into resonance chambers has been proposed (see Patent Document 1).

  As a conventional multi-chamber resonator, for example, as shown in FIG. 9, container halves 61 and 64 whose interiors are partitioned by partition walls 62 and 65 are injection-molded, and then both container halves 61 and 64 are partitioned into partition walls 62. , 65 are joined together with an adhesive or the like at the same joining position. One container half 61 is formed with a communication pipe portion 63 on the outer surface that communicates with the space on both sides of the partition wall 62.

  Further, as shown in FIG. 10, container half bodies 71 and 74 having communication pipe portions 72 and 75 communicating with the outside and having joint surfaces 73 and 76 are formed by blow molding, respectively, and the communication pipe portions 72, There is also a multi-chamber resonator in which the container halves 71 and 74 are joined at the joining surfaces 73 and 76 at the same position.

  However, the multi-chamber resonator in which the container halves 61 and 64 made of injection-molded products are joined has a communicating pipe portion 63 depending on the positions of the partition walls 62 and 65, that is, the volumes of the plurality of resonance chambers partitioned by the partition walls 62 and 65. The position of will be determined. For this reason, when the position of the communication pipe portion 63 is limited depending on the installation location of the resonator, the positions of the partition walls 62 and 65 may not be set so as to obtain an optimum capacity corresponding to the target frequency. Further, when the two container halves 61 and 64 are joined, the positions of the joining ends of the partition walls 62 and 65 are shifted from each other, thereby impairing the airtightness due to the partition walls and reducing the sound reduction and silencing effects.

  On the other hand, in the multi-chamber resonator in which the container halves 71 and 74 made of blow-molded products are joined, an airtight failure due to poor adhesion occurs at the joint surfaces of the communication pipe portions 72 and 75, thereby reducing sound reduction. In addition, the sound deadening property may be inferior, and furthermore, it may not be used on a part where airtightness is required, for example, on a clean side downstream of an air cleaner of an intake system component.

  Another multi-chamber resonator has been proposed in which a partition body is arranged in a parison to form a plurality of resonance chambers during blow molding (see Patent Document 2). However, in this case, adhesion failure may occur between the partition wall and the inner surface of the parison, and the airtightness due to the partition wall may be impaired, and the sound reduction and silencing effects may be reduced.

JP-A-5-240120 JP-A-9-14066

  The present invention has been made in view of the above points, and has a high degree of freedom in the position of the communication pipe part, and is excellent in air tightness, and can be divided into a plurality of resonance chambers having a volume suitable for the target frequency. The purpose is to provide a room type resonator.

The invention according to claim 1, connected to the flow pipe can flow of gas, in a plurality-chamber resonator having a plurality of resonance chambers inside a hollow having a communication pipe portion of the tubular to be connected to the circulation pipe The main body case includes a main body case and a small hollow case having a small communication pipe portion with a semicircular cross section having an outer diameter smaller than the inner diameter of the communication pipe portion and formed smaller than the main body case The small case is housed therein, and the main body case is divided into a small case resonance chamber formed in the small case and a main body resonance chamber formed in the remaining portion, and the small communication pipe is provided in the communication pipe portion. The communication pipe part is divided into the small communication pipe part that communicates the flow pipe and the small case resonance chamber, and the remaining part that communicates the communication pipe and the main body resonance chamber. The main body case The small case is made of a blow-molded product which is blow-molded by housing the small case in a molding parison, and the small case is engaged with both inner edges of the flat surface of the small communication pipe portion on the inner surface of the communication pipe portion. The positioning engaging portion for preventing the rotation of the communicating tube portion is formed along the axial direction of the communicating tube portion .

According to a second aspect of the present invention, in the first aspect, the small communication pipe portion is formed with a positioning engagement portion formed of a protrusion at the tip and base of the arc-shaped outer peripheral surface, and is provided at the tip of the small communication pipe portion. The positioning engaging portion including the protruding portion is engaged with a concave groove-shaped positioning engaging portion formed on the inner surface of the distal end of the communication tube portion, and from the protrusion provided at the base portion of the small communication tube portion. The positioning engaging portion is engaged with the positioning engaging portion formed of the corner portion of the inner surface of the base portion of the communication pipe portion to prevent the small case from being displaced along the axial direction of the communication pipe portion. and said that you are.

  According to the present invention, by the small case housed in the main body case, the main body case is divided into a small case resonance chamber consisting of the inside of the small case and a main body resonance chamber consisting of the remaining portion, A small communication pipe portion that houses the small communication pipe portion of the small case in the communication pipe portion of the main body case, and communicates the flow pipe through which the gas can flow and the small case resonance chamber in the communication pipe portion, and the communication pipe And the remaining part that allows the main body resonance chamber to communicate with each other, the position of the communication pipe portion is the position of the partition wall, i.e., a plurality of internal portions, like a multi-chamber resonator made of a conventional injection molded product. It is difficult to be influenced by the size of the resonance chamber, and the degree of freedom such as the position of the communication pipe portion and the volume of the plurality of resonance chambers is high. In addition, unlike the case where the container halves made of injection-molded products and blow-molded products are joined, a small case is housed in the main body case and divided into a plurality of resonance chambers. Further, by adjusting the volume of the main body case and the volume of the small case, it is possible to obtain good sound reduction and noise reduction suitable for the target frequency.

Furthermore, according to the invention of claim 1, the small case can be prevented from rotating, and according to the invention of claim 2, the small case can be displaced along the axial direction of the communication pipe portion. Can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail. 1 is a sectional view of a multi-chamber resonator according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, FIG. 3 is a sectional view taken along the line 3-3 in FIG. 5 is a perspective view of the small case, FIG. 5 is a cross-sectional view of the molding die showing the placement of the small case on the molding die when the multi-chamber resonator is blow molded, and FIG. 6 is a drawing of the molding die showing the blow molding state of the main body case. FIG. 7 is a perspective view showing a part of the mandrel.

  The multi-chamber resonator 10 shown in FIGS. 1 to 3 is made of a plastic blow molded product, and is connected to a gas flow pipe 50 such as an intake duct of an engine in a vehicle, and the gas passes through the flow pipe 50. This is to reduce or mute the sound that is generated during the operation.

  The multi-chamber resonator 10 includes a hollow main case 21 and a small hollow case 31 accommodated in the main case 21, and the small case resonance is formed in the main case 21. It is divided into a chamber 31A and a main body resonance chamber 21A comprising the remaining portion.

  The main body case 21 includes a hollow main body portion 27 and a communication pipe portion 23 formed to protrude from the outer surface of the main body portion 27. The hollow main body 27 has a required volume according to the frequency to be reduced or silenced. The volume of the main body resonance chamber 21A and the small case resonance chamber 31A suitable for the frequency to be reduced or silenced, the dimensions of the communication pipe portion 23 and the small communication pipe portion 33 to be described later, etc. It can be obtained from the equations (1) to (4), etc. of Patent Document 1, but the volume of the resonance chamber and the dimensions of the communication pipe portion 23 and the small communication pipe portion 33 are variously created to reduce the sound. It can also be obtained by examining the effect.

  The communication pipe portion 23 has a cylindrical shape formed by communicating the inside and outside of the main body portion 27, and is connected to the gas flow pipe 50 to communicate between the flow pipe 50 and the main body case 21. A positioning engagement portion 29 that engages with a small communication tube portion 33 of a small case 31 described later is formed on the inner surface of the communication tube portion 23. As can be understood from FIGS. 1 and 3, the positioning engaging portion 29 is formed on the inner surface of the communication pipe portion 23, in a substantially target position in this embodiment, and in the axial direction L ( 1) and is engaged with the outer edges 34a, 34a of the flat surface portion 34 of the small communication tube portion 33 formed in a substantially semicircular cross section in the small case 31. Then, the small case 21 is prevented from rotating.

  In this embodiment, positioning engagement portions 28 a and 28 b different from the positioning engagement portion 29 are formed in order to make the engagement with the small communication pipe portion 33 more reliable. The positioning engagement portion 28 a has a concave groove shape formed on the inner surface of the distal end of the communication tube portion 23, and engages with a positioning engagement portion 38 a formed on the small communication tube portion 33. On the other hand, the positioning engaging portion 28 b is configured by a corner portion on the inner surface of the base portion of the communication pipe portion 23, and engages with a positioning engagement portion 38 b formed in the small communication pipe portion 33. The positioning engaging portions 28 a and 28 b prevent the small case 31 from shifting along the axial direction L of the communication pipe portion 23 in the main body case 21. Specifically, the small case 31 is prevented from being displaced inward of the main body case 21, and conversely, being displaced toward the distal end side of the communication pipe portion 23 of the main body case 21.

  The small case 31 is formed to be smaller than the main body case 21, and is accommodated in the main body case 21 so that the main body case 21 has a small case resonance chamber 31 </ b> A composed of the small case 31 and the rest. It is divided into a main body resonance chamber 21A consisting of parts.

  As shown in FIG. 4, the small case 31 includes a hollow small main body portion 37 and a small communication pipe portion 33 formed to protrude from the outer surface of the small main body portion 37. The small main body portion 37 of the small case 31 is formed smaller than the main body portion 27 so as to be housed in the main body portion 27 of the main body case 21. Further, the small communication pipe portion 33 of the small case 31 is formed to have an outer diameter smaller than the inner diameter of the communication pipe portion 23 of the main body case 21 and is housed in the communication pipe portion 23, whereby the communication pipe The inside of the section 23 is divided into the small communication pipe portion 33 for communicating the flow pipe 50 and the small case resonance chamber 31A, and the remaining portion 23A for communicating the communication pipe 50 and the main body resonance chamber 21A. The small communication pipe portion 33 in the present embodiment has a cylindrical shape with a substantially semicircular cross section. The positioning engaging portions 38a and 38b are formed at the tip and the base of the arc-shaped outer peripheral surface 35 in the small communication pipe portion 33. The positioning engagement portion 38a at the tip of the small communication pipe portion 33 is engaged with the positioning engagement portion 28a at the tip of the communication tube portion 23 of the main body case 21, and is constituted by a protrusion. . On the other hand, the positioning engaging portion 38b of the base portion of the small communication pipe portion 33 is engaged with the positioning engaging portion 28b formed of the corner portion of the base inner surface of the communication pipe portion 23 of the main body case 21, It consists of protrusions.

  In the multi-chamber resonator 10, the small case 31 formed in advance by blow molding is placed in a blow mold 51 as shown in FIG. 5, and the small case 31 is placed in a known blow molding parison 53. The main body case 21 is housed and blow molded as shown in FIG. At that time, the small case 31 is set on the mandrel 55 and disposed in the blow mold 51. As shown in FIG. 7, the mandrel 55 has a gap 56 in the center where the flat portion 34 of the small communication pipe portion 33 of the small case 31 can be inserted, and is formed on one side portion 57 divided by the gap 56. A small communication pipe portion 33 of the small case 31 is attached. Further, when the small communication pipe portion 33 is attached to the lower part of the one side portion 57, the small communication pipe portion 33 collides with the tip (opening end) of the small communication pipe portion 33 to hold the small communication pipe portion 33 in a predetermined position. A stepped portion K is formed. Further, on the other side portion 58 of the gap 56, that is, the side where the small communication pipe portion 33 of the small case 31 is not mounted, the corner portion of the side portion is a positioning engagement in the communication pipe portion 23 of the main body portion 21. Cutout portions 59 and 59 for forming the portions 29 and 29 are formed. The blow molding parison 53 is formed by extruding molten or softened plastic into a cylindrical shape. The blow molding is performed by placing the blow molding parison 53 in the molding die 51 and inflating the parison 53 by blowing air or the like into the parison 53 so as to adhere to the inner shape of the molding die 51. It is the method of making it shape and is a well-known shaping | molding method.

  By blow molding of the main body case 21, the small case 31 is accommodated in the main body case 21 and the small communication pipe portion 33 is accommodated in the communication pipe portion 23. The multi-chamber resonator 10 to which the case 31 is joined is obtained. In addition, after the mold 51 is opened, when an unnecessary portion exists on the periphery of the multi-chamber resonator 10, the unnecessary portion is appropriately removed by trimming.

  In the multi-chamber resonator 10 having the above structure, the small case 31 is housed in the main body case 21 and the main body case 21 is divided into a plurality of resonance chambers. Further, by adjusting the volume of the main body case 21 and the volume of the small case 31, it is possible to obtain good sound reduction and muffling properties suitable for the target frequency. Further, unlike dividing the inside of the main body case 21 into a resonance chamber having a required volume by a partition wall, the main body case 21 is divided into a plurality of resonance chambers by housing the small case 31 in the main body case 21. The position of the communication pipe portion 23 is hardly affected by the position of the partition wall, that is, the size of the plurality of resonance chambers inside, and the degree of freedom of the position of the communication pipe portion and the volume of the plurality of resonance chambers is high.

  In the present invention, the number of small cases housed in the main body case is not limited to one, and may be plural. For example, the small case is composed of two small cases, and as shown in FIG. 8, the small communication pipe portions 33A and 33B of the two small cases are accommodated in the communication pipe portion 23 of the main body case. The interior may be divided into three resonance chambers.

  In this embodiment, the communication pipe portion 23 of the main body case is provided with other positioning engagement portions 28a and 28b in addition to the positioning engagement portion 29, but only one of the positioning engagement portions is provided. May be provided. Furthermore, the structure of the positioning engaging portion is not limited to the above.

It is sectional drawing of the multiple chamber type resonator which concerns on one Example of this invention. It is 2-2 sectional drawing of FIG. FIG. 3 is a 3-3 cross-sectional view of FIG. 1. It is a perspective view of the small case in the Example. It is sectional drawing of the shaping | molding die which shows the time of arrangement | positioning of a small case. It is sectional drawing of the shaping | molding die which shows the blow molding state of a main body case. It is a perspective view which shows a part of mandrel. It is sectional drawing of the communicating pipe part which shows an example in case a plurality of small cases are made. It is a disassembled perspective view of the conventional multiple chamber resonator which consists of injection-molded articles. It is a disassembled perspective view of the conventional multiple chamber resonator consisting of a blow molded product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Multiple chamber resonator 21 Main body case 21A Main body resonance chamber 23 Communication pipe part 23A The remaining part which connects a flow pipe and a main body resonance chamber in a communication pipe part 27 Main body part 28a, 28b, 29 Positioning engagement part 31 Small case 31A Small Case resonance chamber 33 Small communication pipe portion 37 Small body portion 38a, 38b Positioning engagement portion 51 Blow molding die 53 Blow molding parison 55 Mandrel

Claims (2)

In a multi-chamber resonator connected to a flow pipe through which gas can flow and having a plurality of resonance chambers inside,
A hollow body case (21) having a cylindrical communication pipe portion (23) connected to the flow pipe;
A hollow small case (31) having a small communication pipe portion (33) having a semicircular cross section whose outer diameter is smaller than the inner diameter of the communication pipe portion (23) and smaller than the main body case (21). )
The small case (31) is accommodated in the main body case (21), and the main case (21) includes a small case resonance chamber (31A) including the inside of the small case and a main body resonance chamber including the remaining portion. (21A),
The small communication pipe part (33) is accommodated in the communication pipe part (23), and the communication pipe part (23) communicates the flow pipe with the small case resonance chamber (31A). The communication pipe part (33) is divided into the remaining part (23A) for communicating the communication pipe and the main body resonance chamber (21A) ,
The main body case (21) is made of a blow molded product that is blow molded by housing the small case (31) in a blow molding parison (51).
The inner surface of the communication pipe part (23) is engaged with both outer edges (34a, 34a) of the flat surface part (34) of the small communication pipe part (33) to prevent the rotation of the small case (31). The multi-chamber resonator, wherein the positioning engaging portion (29) is formed along the axial direction of the communicating pipe portion (23) . The small communication pipe portion (33) is formed with positioning engaging portions (38a, 38b) including protrusions at the tip and base of the arc-shaped outer peripheral surface (35),
The positioning engaging portion (38a) formed of a protrusion provided at the tip of the small communication tube portion (33) is a concave groove-shaped positioning engagement portion formed on the inner surface of the tip of the communication tube portion (23). (28a)
The positioning engaging portion (38b) formed by a protrusion provided at the base portion of the small communication pipe portion (33) is a positioning engagement portion (28b) formed by a corner portion of the inner surface of the base portion of the communication pipe portion (23). The multi-chamber resonator according to claim 1, wherein the small case (31) is prevented from being displaced along the axial direction (L) of the communication pipe portion (23) by engaging with the horn. .

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