JP2008082306A - Resonator of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resonator capable of providing a plurality of volume chambers while restraining ventilation resistance. <P>SOLUTION: A first tubular member 5 has a small-diameter part 8 with a plurality of first through-holes 7a formed thereon, and a large-diameter part 9 continued to the small-diameter part 8; a second tubular member 6 has a barrel part 18 with a plurality of through-holes 17a formed thereon, and a flange part 19 extending from a base end 18a of the barrel part 18 toward the circumferential side. The first tubular part 5 and the second tubular part 6 are coaxially connected to each other and attached to an expansion part 3 so as not to generate a step in a connection part 21 between a tip 18b and one end 8a and to tightly fit an opening end 9a to the flange part 19. The connection part 21 is composed of a first adhesion surface 22 being a plane along the radial direction of the barrel part 18, and a second adhesion surface 23 increasing the diameter toward the base end 19a side of the barrel part 18; and the opening end 9a of the large-diameter part 9 comes into linear contact with a tapered surface 28 of the flange part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resonator provided in an intake passage of an internal combustion engine.

  In recent vehicles, the intake system has become complicated, and it is necessary to mute a plurality of frequency components.

For example, FIG. 6 shows an example of a conventional resonator. The resonator 50 includes a body 51 and a cover 52 that are divided into left and right at the center portion, and a connecting pipe 53 having a flange portion 53b at the center. The body 51 and the pipe portions 51b and 52b of the cover 52 have resonance. Communication holes 61 and 62 are formed at positions corresponding to the tubes 59 and 60. Further, in the circular tubular portion 53a of the connecting tube 53, resonance tubes 59 and 60 are provided on both sides of the flange portion 53b as a boundary, and the butting portion is interposed so that the flange portion 53b is sandwiched between the body 51 and the cover 52. A resonator having two resonance chambers welded by vibration is disclosed (see Patent Document 1).
Japanese Utility Model Publication No. 64-41663

  However, in the case of providing a plurality of resonance chambers in the conventional resonator, the connection pipe 53 having the flange portion 53b is sandwiched between the body 51 and the cover 52 so that airtightness between the plurality of resonance chambers is obtained by vibration welding or the like. It is necessary to ensure the mold cost due to seal leakage at that time, increase of air resistance due to assembly misalignment between parts at the time of welding, securing jigs such as vibration welding, increase of man-hours, change of required specifications There is a risk of increase.

  Accordingly, claim 1 of the present invention is constituted by an expansion portion provided in the intake passage, and a first tubular member and a second tubular member assembled in a state of being connected to each other inside the expansion portion. A resonator for an internal combustion engine, wherein the first tubular member has a cylindrical small-diameter portion in which a plurality of first through holes are formed, and a cylindrical shape larger in diameter than the small-diameter portion continuous with one end of the small-diameter portion. And the second tubular member extends from the base end of the body portion toward the outer peripheral side of the body portion, with a plurality of second through holes formed therein. A flange portion, and is connected so that the tip of the trunk portion and one end of the small diameter portion are in close contact so that no step is generated at the connecting portion between the tip of the trunk portion and one end of the small diameter portion, and The open end of the large-diameter portion is in close contact with the flange portion, and the first tubular member and the second tubular member are A first volume chamber is defined between the small diameter portion and the inner wall surface of the expansion portion, and is attached to the inside of the expansion portion in a state of being connected on a shaft. A second volume chamber is defined therebetween, a first resonator is constituted by the small diameter portion and the first volume chamber, and a second resonator is constituted by the body portion and the second volume chamber. A connecting portion between the tip of the small diameter portion and one end of the small diameter portion is continuous with the first contact surface defined by a plane along the radial direction of the body portion and the small diameter portion, and is continuous with the first contact surface. A second contact surface defined by a tapered surface having a larger diameter toward the base end side of the portion, and the opening end of the large diameter portion is lined with a flange portion tapered surface provided in the flange portion. It is characterized in that it is in close contact with the flange by contactingThereby, the axial direction and radial direction positioning of the second tubular member with respect to the first tubular member are performed by the first close contact surface and the second close contact surface. And a level | step difference does not arise in the connection part of the front-end | tip of the said trunk | drum, and the end of the said small diameter part, and deterioration of ventilation resistance is prevented. Moreover, the open end of the large diameter portion is in close contact with the flange portion, and a plurality of volume chambers are formed.

  According to a second aspect of the present invention, in the resonator of the internal combustion engine according to the first aspect, a plurality of engagement pieces are formed at predetermined positions on the outer peripheral edge of the flange portion, and the plurality of engagement pieces are the expansion parts. The first and second tubular members are respectively inserted into a plurality of engagement holes formed at predetermined positions of the portion, and are fixed at predetermined positions of the expansion portion.

  According to the present invention, it is possible to easily form a resonator having a plurality of resonance frequencies in which sealability is ensured only by assembling a plurality of tubular members coaxially. Further, there is no need for vibration welding or the like when forming a plurality of volume chambers.

  And since the opening end of the said large diameter part of the said 1st tubular member is stuck to the said flange part taper surface, the dispersion | variation in the axial direction length of the said 1st tubular member and the said 2nd tubular member is this flange. It can be absorbed at the contact portion between the tapered portion and the open end of the large diameter portion. In addition, the tip of the body portion and one end of the small diameter portion are in close contact with each other, and the opening end of the large diameter portion and the flange portion taper surface of the flange portion are in close contact with each other. The secrecy of the second volume chamber configured as described above can be ensured.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  The intake air flows through the inside of the flow path formed by connecting a plurality of members. FIG. 1 is a cross-sectional view showing a schematic configuration of a resonator 1 according to the present invention, and shows one of the connection portions of the flow path. In the intake passage 2 that constitutes one of the connection portions, the terminal on the connection portion side is the expansion portion 3 and has a larger diameter than the general portion 4. Spaces each having a substantially circular cross section are formed inside the general portion 4 and the extended portion 3 of the intake passage 2.

  And the 1st tubular member 5 and the 2nd tubular member 6 are assembled | attached to this expansion part 3. As shown in FIG. In the present embodiment, the intake passage 2 is formed integrally with an air cleaner (not shown), and the expansion portion 3 is connected to an intake duct (not shown) communicating with the intake intake.

  The first tubular member 5 has a cylindrical small diameter portion 8 in which the inner diameter is substantially the same as the inner diameter of the general portion 4 of the intake passage 2 and a plurality of first through hole groups 7 are formed, and one end of the small diameter portion 8. The cylindrical large-diameter portion 9 that is larger in diameter than the small-diameter portion 8 continuous to 8a (the right end in FIG. 1) and concentric with the small-diameter portion 8 is roughly configured. More specifically, a substantially bowl-shaped wall 10 extending toward the outer peripheral side of the small-diameter portion 8, that is, radially outward of the small-diameter portion 8, protrudes from the entire circumference of the one end 8a of the small-diameter portion 8. The small diameter portion 8 and one end of the large diameter portion 9 are continuous through 10. That is, the first tubular member 5 has a substantially stepped cylindrical shape as a whole. In addition, the protrusion amount of the wall part 10 in this embodiment is not uniform along the circumferential direction of the small diameter part 8, and the protrusion amount is relatively larger toward the wall part 10 at the upper side position in FIG. 1. . An annular seal member 11 is disposed on the outer peripheral edge of the wall portion 10, and the seal member 11 seals the space between the inner wall surface 3 a of the extension portion 3 and the wall portion 10 over the entire circumference. Yes. The seal member 11 may not be disposed when the dimensional accuracy and surface roughness between the outer peripheral edge of the wall portion 10 and the inner peripheral surface 3a of the expansion portion 3 are good and there is no problem in sealing performance. . In that case, when inserting the 1st tubular member 5 in the expansion part 3, sliding resistance with the internal peripheral surface 3a of the expansion part 3 is reduced.

  The first through hole group 7 formed in the small diameter portion 8 is constituted by two first through holes 7a and 7a adjacent to each other along the circumferential direction of the small diameter portion 8 and is arranged in two rows in the axial direction of the small diameter portion 8. Is formed. Each row is composed of four first through-hole groups 7, and these four first through-hole groups 7 are arranged at equal intervals along the circumferential direction of the small diameter portion 8. That is, when viewed from the direction indicated by the arrow A in FIG. 1, the first through-hole group 7 in each row has four first through-hole groups 7 in the circumferential direction of the small-diameter portion 8 around the small-diameter portion 8 axis. Are arranged at intervals of 90 °.

  In addition, a protruding wall 12 having a substantially L-shaped cross section is formed at the other end 8b (left end in FIG. 1) of the small diameter portion 8 and is continuous over the entire circumference in the circumferential direction of the small diameter portion 8.

  The protruding wall 12 has a bowl-shaped bottom portion 13 protruding toward the radially outer peripheral side of the small diameter portion 8 and gradually from the outer peripheral edge of the bottom portion 13 toward the other end 8b side of the small diameter portion 8 (left direction in FIG. 1). A taper wall portion 14 formed so that its inner diameter is enlarged, and a taper-like inner peripheral surface 14a of the taper wall portion 14 projects from the end wall 3b of the expansion portion 3 of the intake passage 2. The inclined surface 15 a of the mating protrusion 15 is in close contact, and the space between the inner wall surface 3 a of the extension portion 3 and the protruding wall 12 is sealed over the entire circumference of the protruding wall 12.

  That is, the inner peripheral surface 14a of the tapered wall portion 14 and the inclined surface 15a of the engaging protrusion 15 are in close contact with each other, and the seal member 11 seals between the outer peripheral edge of the wall portion 10 and the inner wall surface 3a of the extension portion 3. Therefore, the confidentiality of the 1st volume chamber 16 (it mentions later for details) comprised on the outer peripheral side of the small diameter part 8 is securable.

  Note that the amount of protrusion of the bottom portion 13 in this embodiment is not uniform along the circumferential direction of the small diameter portion 8, and the amount of protrusion is relatively larger toward the bottom portion 13 in the upper position in FIG. 1.

  The second tubular member 6 includes a cylindrical trunk portion 18 in which a plurality of second through-hole groups 17 are formed, and an outer periphery of the trunk portion 18 from the entire circumference of a base end 18a (right end in FIG. 1) of the trunk portion 18. It is generally constituted by a flange-like flange portion 19 projecting toward the side, that is, radially outward.

  The body portion 18 is formed so that the inner diameter of the tip end 18b is equal to the inner diameter of the one end 8a of the small diameter portion 8, and no step is produced when the tip end 18b of the body portion 18 and the one end 8a of the small diameter portion 8 are connected. It is configured as follows. In addition, the protrusion amount of the flange part 19 in this embodiment is not uniform along the circumferential direction of the trunk | drum 18, and the protrusion amount is comparatively large as the flange part 19 of the upper position in FIG. . Further, a seal member 20 is disposed on the outer peripheral edge of the flange portion 19, and the seal member 20 seals between the inner wall surface 3 a of the extension portion 3 and the flange portion 19 over the entire circumference of the flange portion 19. Has been. The sealing member 20 may not be disposed when the dimensional accuracy and surface roughness between the outer peripheral edge of the flange portion 19 and the inner wall surface 3a of the expansion portion 3 are good and there is no problem in sealing performance. In that case, when inserting the 2nd tubular member 5 in the expansion part 3, sliding resistance with the internal peripheral surface 3a of the expansion part 3 is reduced.

  The second through hole group 17 formed in the body portion 18 is configured by two second through holes 17 a and 17 a that are adjacent to each other along the circumferential direction of the body portion 18. In the present embodiment, four second through-hole groups 17 formed at equal intervals along the circumferential direction of the body portion 18 are formed in the body portion 18. That is, when viewed from the direction indicated by the arrow A in FIG. 1, the four second through hole groups 17 are arranged at 90 ° intervals along the circumferential direction of the trunk portion 18 with the trunk portion 18 as the center. .

  As shown in FIGS. 2 and 3, the second tubular member 6 has the body portion 18 inserted into the large-diameter portion 9 of the first tubular member 5, and the distal end 18 b of the body portion 18 is inserted into one end 8 a of the small-diameter portion 8. Thus, the first tubular member 5 is coaxially connected. The first tubular member 5 and the second tubular member 6 that are coaxially connected are inserted into the expansion portion 3 of the intake passage 2, and the other end 8 b of the small diameter portion 8 is an end portion of the general portion 4 of the intake passage 2. It is assembled in the expansion chamber 3 in a state of being in close contact with.

  At this time, the engagement pieces 32, 32 formed at two predetermined positions on the outer peripheral edge of the flange portion 19 of the second tubular member 6 are formed at two predetermined positions at the other end of the expansion portion 3. The second tubular member 6 is assembled to the inner side of the extended portion 3 by a snap fit structure inserted into the holes 3c and 3c. Thereby, it fixes to a predetermined position only by inserting the 2nd tubular member 6 in the general part 4 side, without using a fastening member or a special tool. In addition, since no step is generated in the connecting portion 21 between the tip 18b of the body portion 18 and the one end 8a of the small diameter portion 8, it is possible to prevent deterioration in ventilation resistance. Further, since the inner diameter of the small diameter portion 8 is substantially the same as the inner diameter of the general portion 4 of the intake passage 2, the other end 8b of the small diameter portion 8 and the end portion of the general portion 4 are continuous without causing a step.

  Here, as shown in FIGS. 1 and 4, the connecting portion 21 between the distal end 18 b of the body portion 18 and the one end 8 a of the small diameter portion 8 is parallel to a plane orthogonal to the central axes of the body portion 18 and the small diameter portion 8. A first contact surface 22 defined by a flat surface, and a second contact surface 23 defined by a tapered surface that is continuous with the first contact surface 22 and gradually increases in diameter toward the base end 18a side of the body portion 18. And is composed of.

  More specifically, a housing groove 24 is formed on the inner peripheral side of the one end 8 a of the small diameter portion 8 of the first tubular member 5 to be fitted to the tip 18 b of the body portion 18 of the second tubular member 6. As shown in FIG. 4, the housing groove 24 is parallel to a plane perpendicular to the axis of the small diameter portion 8, in other words, a bottom wall 25 along the radial direction of the small diameter portion 8, and is continuous with the bottom wall 25. The small-diameter portion 8 includes a tapered wall 26 whose inner diameter gradually increases toward the one end 8 a side (the right side in FIGS. 1 and 4), and a cylindrical wall 27 continuous with the tapered wall 26. On the other hand, the front end 18b of the body portion 18 of the second tubular member 6 is formed in a tapered truncated cone shape. The first tubular member 5 and the second tubular member are fitted with the bottom wall 25 and the tapered wall 26 of the housing groove 24 fitted into the truncated cone-shaped tip 18b of the trunk portion 18 so that they are in close contact with each other without a gap. 6 are connected.

  On the surface of the flange portion 19 of the second tubular member 6 on the body portion 18 side (left side in FIGS. 1 and 4), a flange portion taper surface 28 that is tapered toward the tip end 18 b side of the body portion 18 is formed. Yes. When the first tubular member 5 and the second tubular member 6 are connected to each other, the tapered flange portion tapered surface 28 has an inner peripheral edge of the open end 9a of the large-diameter portion 9 of the first tubular member 5 on the entire circumference. It is formed at a position where it comes into line contact.

  That is, the first contact surface 22 and the second contact surface 23 position the second tubular member 6 in the axial direction and the radial direction with respect to the first tubular member 5 (the axial direction of the first tubular member 5 with respect to the second tubular member 6). And radial positioning). And since the opening end 9a of the large diameter part 9 of the 1st tubular member 5 is stuck to the flange part taper surface 28, the variation of the axial direction length of the 1st tubular member 5 and the 2nd tubular member 6 is this. It can be absorbed at the contact portion between the flange taper surface 28 and the open end 9a of the large diameter portion 9. Further, the front end 18b of the body portion 18 and the one end 8a of the small diameter portion 8 are in close contact with each other, and the opening end 9a of the large diameter portion 9 and the flange portion tapered surface 28 of the flange portion 19 are in close contact with each other. It is possible to ensure the confidentiality of the second volume chamber 29 (details will be described later).

  The first volume chamber 16 configured on the outer peripheral side of the small diameter portion 8 is defined by the small diameter portion 8, the wall portion 10, and the expansion portion 3. The second volume chamber 29 configured between the trunk portion 18 and the large diameter portion 9 is defined by the wall portion 10, the large diameter portion 9, the trunk portion 18 and the flange portion 19.

  The first resonator 30 that reduces the intake sound in the first frequency range is configured by the small diameter portion 8 and the first volume chamber 16, and the body portion 18 and the second volume chamber 29 generate the intake sound in the second frequency range. A second resonator 31 to be reduced is configured. That is, as the number of the first through holes 7a is larger in the first resonator 30, and as the number of the second through holes 17a is larger in the second resonator 31, the intake noise of each target frequency is reduced. The effect is increased.

  That is, the number of the first through holes 7a provided in the small diameter portion 8 and the number of the second through holes 17a provided in the trunk portion 18 are not limited to the number of the above-described embodiments. In the above-described embodiment, the first through hole group 7 is formed in two rows in the small-diameter portion 8 axial direction, but the first through-hole group 7 is arranged in only one row in the small-diameter portion 8 axial direction. Alternatively, it is possible to form three or more rows. Similarly, it is possible to form the second through hole group 17 in the trunk portion 18 in two or more rows in the axial direction of the trunk portion 18. However, the first through hole groups 7 having the same position along the axial direction of the small diameter portion 8 are formed at equal intervals along the circumferential direction of the small diameter portion 8. Similarly, the second through hole group 17 having the same position along the axial direction of the trunk portion 18 is formed at equal intervals along the circumferential direction of the trunk portion 18.

  The first resonator 30 includes a volume of the first volume chamber 16, a hole diameter of the first through hole 7 a, a length of the first through hole 7 a (thickness of the small diameter portion 8), and 2 in the first through hole group 7. The frequency of the intake noise to be silenced is set by appropriately adjusting the distance between the first through holes 7a and 7a. The second resonator 31 has a volume of the second volume chamber 29, a hole diameter of the second through hole 17 a, a length of the second through hole 17 a (thickness of the body portion 18), and 2 in the second through hole group 17. The frequency of the intake noise to be silenced is set by appropriately adjusting the distance between the second through holes 17a and 17a.

  In the present embodiment, the first resonator 30 is set to mute the intake noise having a frequency of 2350 Hz, and the second resonator 31 is set to mute the intake noise having a frequency of 2650 Hz. Therefore, the intake noise can be effectively reduced as shown in FIG. That is, by tuning each of the first resonator 30 and the second resonator 31, it is possible to intensively reduce intake sounds in two high frequency regions having particularly high sound pressure levels (peaks).

  The broken line in FIG. 5 indicates the intake noise level of the intake system serving as the base, and the solid line in FIG. 5 indicates the intake noise level when the above-described resonator 1 of the present embodiment is applied to the intake system serving as the base. Show.

  Further, in the resonator 1 according to the present embodiment, the first tubular member 5 and the second tubular member 6 can be divided with respect to the expanded portion 3 of the intake passage 2, and therefore the first penetration of the first tubular member 5. Changes in the specifications of the hole group 7 (changes in the diameter of the first through hole 7a and the distance between the first through holes 7a, 7a), and changes in the specification of the second through hole group 17 in the second tubular member 6 (second penetration) By changing the first tubular member 5 and the second tubular member 6 by appropriately changing the diameter of the hole 17a and the distance between the second through holes 17a and 17a), the configuration of the peripheral part shape and layout The resonator 1 according to the desired specification can be easily configured without changing the frequency, and tuning of the frequency of the intake noise to be silenced can be easily set.

  The resonator 1 according to the above-described embodiment is mainly composed of the two tubular members 5 and 6 that are assembled on the same axis. However, if the number of the tubular members that are assembled on the same axis is three, the intake air can be silenced. A resonator having three noise frequencies can be formed, and if the number of tubular members assembled on the same axis is four, a resonator having four intake noise frequencies to be silenced can be formed.

Sectional drawing which shows schematic structure of the resonator which concerns on this invention. The perspective view of the 1st tubular member and the 2nd tubular member. The perspective view of the 1st tubular member and the 2nd tubular member. 1 is an enlarged view of the main part The characteristic diagram which shows the intake noise reduction effect of the intake system to which the resonator of this embodiment was applied. Explanatory drawing which shows an example of the conventional resonator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resonator 5 ... 1st tubular member 6 ... 2nd tubular member 7 ... 1st through-hole group 7a ... 1st through-hole 8 ... Small diameter part 9 ... Large diameter part 16 ... 1st volume chamber 17 ... 2nd through-hole group 17a ... 2nd through-hole 18 ... trunk | drum 19 ... flange part 29 ... 2nd volume chamber 30 ... 1st resonator 31 ... 2nd resonator

Claims (2)

A resonator for an internal combustion engine comprising: an expansion portion provided in an intake passage; and a first tubular member and a second tubular member assembled in a state of being connected to each other inside the expansion portion,
The first tubular member has a cylindrical small-diameter portion in which a plurality of first through holes are formed, and a cylindrical large-diameter portion having a larger diameter than the small-diameter portion continuous with one end of the small-diameter portion. ,
The second tubular member has a cylindrical body portion in which a plurality of second through holes are formed, and a flange portion extending from the base end of the body portion toward the outer peripheral side of the body portion,
The front end of the body portion and the one end of the small diameter portion are connected so that there is no step at the connection portion between the front end of the body portion and one end of the small diameter portion, and the open end of the large diameter portion is Closely attached to the flange portion, the first tubular member and the second tubular member are coaxially connected and attached to the inside of the extension portion,
A first volume chamber is defined between the small diameter portion and the inner wall surface of the expansion portion, and a second volume chamber is defined between the trunk portion and the large diameter portion,
A first resonator is constituted by the small diameter portion and the first volume chamber, and a second resonator is constituted by the body portion and the second volume chamber,
The connecting portion between the front end of the body portion and one end of the small diameter portion is continuous with the first contact surface defined by a plane along the radial direction of the body portion and the small diameter portion, and the first contact surface, And a second contact surface defined by a tapered surface having a large diameter toward the base end side of the body portion,
A resonator for an internal combustion engine, wherein the open end of the large-diameter portion is in close contact with the flange portion by making line contact with a flange tapered surface provided on the flange portion.   A plurality of engagement pieces are formed at predetermined positions on the outer peripheral edge of the flange portion, and the plurality of engagement pieces are respectively inserted into a plurality of engagement holes formed at predetermined positions of the extension portion, and the first and first 2. A resonator for an internal combustion engine according to claim 1, wherein two tubular members are fixed to a predetermined position of the expansion portion.

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