JP4591370B2 - Silencer - Google Patents

Description

  The present invention relates to a silencer that is installed in the middle of an intake passage or exhaust passage of an engine in a vehicle, for example, and reduces intake noise or exhaust noise.

  Conventionally, as this type of silencer, there is one described in Patent Document 1, for example. In the silencer shown in the patent document 1, as shown in FIGS. 12A and 12B, the resonance chamber 53 in the resonance box 52 is provided at the tip of the branch pipe 51 connected to the intake passage 50. In addition to being provided, an adjustment body 55 is rotatably supported around the shaft 54 in the resonance chamber 53. The adjusting body 55 includes a pair of sector plates 56a supported by the shaft 54, and an arc-shaped plate 56b provided between the outer peripheral edges of the sector plates 56a. The arcuate plate 56b is rotated about the shaft 54, whereby the actual flow path length in the branch pipe 51 and the opening degree of the opening 51a of the branch pipe 51 are adjusted.

In another silencer shown in the patent document 1, as shown in FIGS. 13A and 13B, the peripheral portion of the opening 51a of the branch pipe 51 is used instead of the adjusting body 55. An arcuate plate 58 is provided which is guided along a pair of guide-like groove portions 57 having an arcuate shape provided on the inner walls on both sides. The arc-shaped plate 58 has the same shape as the arc-shaped plate 56 b of the adjusting body 55, and is driven by a pinion gear 60 that is provided in the resonance chamber 53 and meshes with a rack 59 provided on the inner peripheral surface of the arc-shaped plate 58. . The degree of opening of the opening 51 a is adjusted by moving the arcuate plate 56 b along the guide groove 57.
Japanese Patent Laying-Open No. 2005-30308 (pages 4-6, FIGS. 1-4, FIG. 8)

  By the way, in the muffler shown in FIGS. 12A and 12B of the above-mentioned Patent Document 1, there are parts between the inner side surfaces of the branch pipe 51 and both side surfaces of the sector plate 56a of the adjusting body 55. The gap S for absorbing the dimensional variation and the dimensional change of the component due to thermal expansion is secured along the circumferential direction of the arc-shaped plate 56b, and the operation of the adjusting body 55 is guaranteed by the gap S. If the gap S is too wide, the amount of sound leakage from the branch pipe 51 to the resonance chamber 53 increases, and it becomes difficult to accurately set a desired resonance frequency with respect to the rotation position of the adjusting body 55. As a result, noise in a desired frequency range cannot be sufficiently reduced. On the other hand, if the gap S is reduced, the tolerance of parts must be reduced in order to prevent the arc-shaped plate 58 from coming into contact with both inner side surfaces of the branch pipe 51 at the time of thermal expansion, and the part cost increases.

  In another silencer shown in the above-mentioned patent document 1, since the inner wall of the guide groove 57 and the arc plate 58 are in contact with each other, the branch is made between the guide groove 57 and the arc plate 58. There is little sound leaking from the tube 51 to the resonance chamber 53. However, in this silencer, an extra pinion gear 60 for driving the arc-shaped plate 58 is required, and a rack 59 must be formed on the arc-shaped plate 58, which increases the number of parts, assembly man-hours, and processing man-hours. . Further, in order to operate the arc-shaped plate 58 smoothly, the rack 59 and the pinion gear 60 need to be involute teeth, which increases the processing cost. Further, since the friction between the arc-shaped plate 58 and the guide-shaped groove portion 57 is large, a large torque is required to drive the arc-shaped plate 58, and a drive motor having a large torque is required. In addition, the coefficient of friction between the guide-shaped groove 57 and the arc-shaped plate 58 becomes excessively large due to thermal expansion, and the arc-shaped plate 58 may not move smoothly or abnormal noise may occur. Further, if the sliding portion is worn, the arc-shaped plate 58 becomes easy to move, but a new rattling sound is generated.

  Furthermore, in the other silencer of the above-mentioned Patent Document 1, it is necessary to form the guide-like groove portions 57 on both inner wall surfaces of the branch pipe 51, and a complicated structure is required as a molding die. Further, at the time of assembly, the arc-shaped plate 58 must be inserted into the guide-shaped groove portion 57 from an open portion (not shown) provided in the resonance box 52. Further, after the arc-shaped plate 58 is inserted into the guide-shaped groove portion 57, Since it must be assembled so as to mesh with 59, the work is troublesome.

  The present invention has been made paying attention to such problems existing in the prior art, and the object of the present invention is to increase the number of parts, and to be easily manufactured and have high reliability. Another object is to provide a silencer that can effectively reduce noise in a desired frequency range.

In order to achieve the above-mentioned object, the invention according to claim 1 includes a housing in which a resonance chamber communicated with an intake passage or an exhaust passage of an engine via a communication pipe is formed , and the resonance chamber. And an adjustment body having an arc-shaped adjustment wall along an arc surface centered on the axis, and depending on the rotation position of the adjustment body, In the silencer, wherein the resonance frequency is adjusted by changing the opening degree of the opening on the resonance chamber side in the communication pipe, an opening is formed on one side wall of the housing, and the opening is a lid while closed by, is opened toward the opening in the opening, the inner surface of the opening side of the housing is formed in a circular arc shape along the arcuate surface of the regulating member, the opening Both sides of the part A pair of projecting wall is formed, the outer peripheral surfaces of both width ends of the axial direction of the adjusting wall faces via the inner peripheral surface and the first gap of the housing on both sides of the opening together, both width ends of the axial direction of the adjusting member is opposed through the inner surface and the second gap of the adjusting side of the pair of projecting wall, said first gap and said second gap , is formed at an section bent shape, space between the pair of protruding walls is characterized in that it is open toward the opening.

  In addition to the invention described in claim 1, the invention described in claim 2 is formed with a plurality of the projecting walls, and the adjusting body is formed with a protrusion that forms a labyrinth passage together with the projecting walls. It is characterized by.

According to a third aspect of the present invention, there is provided a housing in which a resonance chamber communicating with an intake passage or an exhaust passage of an engine via a communication pipe is formed , and is rotatable about an axis in the resonance chamber. And an adjusting body having an arc-shaped adjusting wall along an arc surface centered on the axis of the adjusting body, and depending on the rotation position of the adjusting body, the adjusting wall opens the resonance chamber side in the communication pipe. In the silencer in which the opening degree of the part is changed and the resonance frequency is adjusted, an opening is formed on one side wall of the housing, the opening is closed by a lid, and the opening is A pair of stepped portions are formed on both sides of the opening in the opening-side wall of the housing, and the outer peripheral surface of the both end portions in the axial direction of the adjustment wall. , said pair of stepped With face each other through the inner peripheral surface of the first gap, both width ends of the shaft direction in adjusting member is opposed through the inner surface and the second gap of the pair of stepped portions, said first gap and said second gap is formed at an section bent shape, the space portion between the pair of stepped portions is characterized in that it is open toward the opening.

(Function)
According to the first aspect of the present invention, the opening degree of the arc-shaped opening in the communication pipe that opens into the resonance chamber by the adjustment wall of the adjustment body that is supported rotatably about the axis in the resonance chamber; The actual flow path length in the communication pipe is changed. As a result, the resonance frequency determined by the actual opening area of the opening, the actual flow path length of the communication pipe, and the volume of the resonance chamber is adjusted. Further, both width end portions of the outer peripheral surface of the adjustment wall are opposed to the inner side surface of the resonance chamber on both sides of the opening portion through a gap, and the inner side surface of the resonance chamber is opposed to both width ends of the adjustment wall. Thus, projecting walls that face each other through a gap are formed. For this reason, a gap is formed between the adjustment wall that moves relative to each other with the rotation of the adjustment body and the inner surface of the resonance chamber. ing. For this reason, noise that tries to leak from the communication pipe to the resonance chamber through the gap is effectively attenuated by the gap having a bent cross section. Therefore, the actual resonance frequency for an opening degree with an opening portion is closer to the resonance frequency obtained from the actual opening area of the opening portion, the actual flow path length in the communication pipe, and the volume of the resonance chamber. In addition, since the opening is opened toward the opening provided on one side wall of the housing, and the space between the projecting walls opens toward the opening, the opening is directed toward the opening inside the housing. The adjustment body can be assembled by a simple operation of inserting the adjustment body from the opening portion. For this reason, unlike the one disclosed in Patent Document 1, the manufacture is facilitated. Furthermore, extra parts such as pinion gears, racks and pinion gears are difficult and no extra processing is required. Therefore, it is possible to provide a silencer that does not increase the number of parts, is easy to manufacture, has high reliability, and can effectively reduce noise in a desired frequency range.

  According to the invention described in claim 2, in addition to the operation of the invention described in claim 1, the communication pipe is formed by a labyrinth passage formed by a plurality of projecting walls and a projecting portion provided in the adjusting body. The noise leaking from the resonance chamber to the resonance chamber is further effectively reduced. For this reason, the actual resonance frequency is closer to the resonance frequency determined by the actual flow path length in the communication pipe, the actual opening area of the opening, and the volume of the resonance chamber. Therefore, noise in a desired frequency range can be further effectively reduced.

  According to the third aspect of the present invention, the “inner peripheral surface and inner side surface of the step portion” instead of the “inner side surface and protruding wall” of the resonance chamber according to the first aspect, The effect can be obtained similarly.

  According to the present invention, it is possible to provide a silencer that does not increase the number of components, is easy to manufacture, has high reliability, and can effectively reduce noise in a desired frequency range.

(First embodiment)
Next, a first embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the silencer 10 includes a housing 12 that is formed in a box shape and in which a resonance chamber 11 is formed. The resonance chamber 11 includes an intake pipe (not shown) of an engine (not shown). The intake passage) 13 communicates with the housing 12 through a communication pipe 14 integral with the housing 12. As shown in FIG. 3, the housing 12 includes a box body 15 having a side wall portion 15 a and a ceiling wall portion 15 b, and a lid body 16 that closes the open portion 15 c on the opposite side of the communication tube 14 of the box body 15. Has been. The communication pipe 14 is provided on the ceiling wall 15b side of the box 15 with respect to the resonance chamber 11, and the opening 17 in the resonance chamber 11 is formed in a side arc shape as shown in FIGS. And open toward the opening 15c. Further, as shown in FIG. 3, on the inner side surface of the ceiling wall portion 15b of the box body 15, the ridge portions 18 projecting toward the open portion 15c along both peripheral edges of the opening portion 17 are integrally formed. ing. And the space part between both the protrusion parts 18 is opened toward the open part 15c. In this embodiment, both the protrusions 18 correspond to protrusion walls.

  As shown in FIGS. 1 and 2, the adjusting body 20 is rotatably supported in the resonance chamber 11 via a shaft 19 inserted through a pair of support holes 15d provided in the side wall portion 15a. Has been. The adjusting body 20 includes a base portion 20a fixed to the shaft 19, and an arc-shaped adjusting wall 20c is supported by a plurality of arm portions 20b extending from the base portion 20a. The adjusting wall 20c is located on a circular arc surface centered on the shaft 19, and the degree of opening of the opening 17 can be adjusted. The protrusion 18 is located on a plane orthogonal to the shaft 19.

  Both width end portions of the outer peripheral surface of the adjustment wall 20c are opposed to the inner side surface of the ceiling wall portion 15b on both sides of the opening portion 17 via a gap Q1. Further, the inner side surfaces of the projecting ridge portions 18 are opposed to both width ends of the adjusting wall 20c via a gap Q2. Accordingly, the gap Q including the gap Q1 and the gap Q2 has a cross-sectional shape bent at a right angle. The gap Q is provided in order to absorb the dimensional variation of the housing 12 and the adjusting body 20 and the dimensional change of these parts due to thermal expansion, and guarantee the operation of the adjusting body 20. .5mm is set. The adjusting body 20 is rotated by rotating the shaft 19 by the drive motor 21 mounted on the outer surface of the housing 12, and adjusts the degree of opening of the opening 17. The rotating position of the adjusting body 20 at this time is detected by the rotating position sensor 22, and the adjusting motor 20 is arranged at a desired rotating position by controlling the drive motor 21 based on this detection.

Now, the muffler configured as described above is assembled as follows.
First, the adjusting body 20 is arranged at a predetermined position in the box 15 from the opening portion 15c, and the adjusting body 20 is supported by the shaft 19 inserted through the support hole 15d from the outside of the box 15 in this state. . At this time, both width end portions of the outer peripheral surface of the adjustment wall 20c are opposed to the inner wall surface of the ceiling wall portion 15b on both sides of the opening portion 17 through the gap Q, and the width ends of the adjustment wall 20c The inner side surfaces of both protrusions 18 provided on the inner side surface of the wall portion 15b face each other with a gap Q therebetween. As a result, a gap Q is formed between the inner side surface of the housing 12 and the adjusting wall 20c. The gap Q has a bent cross-sectional shape on the surface orthogonal to the circumferential direction of the adjusting body 20.

  Next, the drive motor 21 and the rotational position sensor 22 are attached to the outer surface of the side wall 15 a of the box 15, and are connected to the respective ends of the shaft 19 extending to the outside of the box 15. Finally, the lid 16 is fixed to the opening 15c of the box 15 by vibration welding, and the opening 15c is closed.

  FIG. 4 shows a state in which the degree of opening of the opening 17 of the communication pipe is minimized by the adjusting wall 20c of the adjusting body 20. In this state, the actual flow path length in the communication pipe 14 extending from the intake pipe 13 to the resonance chamber 11 is maximized. FIG. 5 shows a state in which the opening degree of the opening portion 17 of the communication pipe is maximized by the adjusting wall 20c of the adjusting body 20. In this state, the actual flow path length in the communication pipe from the intake pipe 13 to the resonance chamber 11 is minimized. The resonance frequency is determined by the actual opening area of the opening 17, the actual flow path length in the communication pipe 14, and the volume of the resonance chamber 11, and noise at the resonance frequency is reduced in the resonance chamber 11.

The embodiment configured as described above has the following effects.
(1) A gap Q between the adjustment wall 20c that moves relative to each other as the adjustment body 20 rotates and the inner surface of the resonance chamber 11 is formed in a bent cross-sectional shape. For this reason, the noise from the communication pipe 14 is unlikely to pass through the gap Q. For this reason, the resonance frequency characteristic determined by the actual flow path length in the communication pipe 14, the actual opening area of the opening 17, and the volume of the resonance chamber 11 is hardly impaired. Therefore, noise in a desired frequency range can be effectively reduced. Further, unlike the above-mentioned Patent Document 1, the gap Q can be widened, so that contact between the housing 12 and the adjusting body 20 due to thermal expansion can be prevented even if the tolerance of the parts is increased. Parts costs can be reduced.

  (2) The opening 17 opens toward the opening 15 c of the box 15, and the space between the two protrusions 18 opens toward the opening 15 c of the box 15. For this reason, since there is no complicated molding part like the guide-shaped groove part of the said patent document 1, the shaping | molding die of a complicated structure becomes unnecessary. Further, the adjusting body 20 can be assembled by a simple operation of simply inserting the adjusting body 20 from the opening 15 c toward the opening 17 inside the box 15. In this case, both protrusions 18 serve as guides for the adjusting body 20. Therefore, unlike the above-mentioned Patent Document 1 shown in FIG. 13, it is not necessary to perform a difficult operation such as mounting an arc-shaped plate along a curved guide-shaped groove, so that assembly is facilitated. Furthermore, parts such as pinion gears and difficult machining of racks and pinion gears are not required. In addition, since the gap Q is provided between the housing 12 and the adjustment body 20, the operation of the adjustment body 20 is not affected by thermal expansion, and the reliability is improved. Therefore, the number of parts is not increased, and the manufacture is easy and has high reliability.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, only differences from the first embodiment will be described.

  As shown in FIGS. 6 to 8, the housing 12 of the silencer 10 of this embodiment is not provided with the protrusion 18 in the first embodiment, and instead, an opening in the communication pipe 14 is provided. The step portions 30 are formed along the 17 arcuate peripheral edges. The step portion 30 has an inner peripheral surface 30a on the opening 17 side and an arc-shaped inner side surface 30b orthogonal to the inner peripheral surface 30a.

  Both width end portions of the outer peripheral surface of the adjustment wall 20 c in the adjustment body 20 face the inner peripheral surface 30 a of the step portion 30 via the gap Q 1, and both width ends of the adjustment wall 20 c are inside the step portion 30. It faces the side surface 30b via the gap Q2. Accordingly, the gap Q formed by the gaps Q1 and Q2 has a bent cross-sectional shape in a plane orthogonal to the circumferential direction of the adjusting body 20.

The second embodiment configured as described above also has the same effect as that of the first embodiment.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. In this embodiment, only differences from the first embodiment will be described.

  As shown in FIGS. 9 to 11, in the housing 12 of this embodiment, the inner surface of the ceiling wall portion 15 b of the box body 15 is directed toward the open portion 15 c along the arc-shaped side edges of the opening 17. A plurality of protruding ridges 40a to 40c are integrally formed. Each of the protrusions 40 a to 40 c is located on a plane orthogonal to the shaft 19. In this embodiment, each protruding portion 40a to 40c corresponds to a protruding wall portion.

  On the other hand, an end wall portion 20d is provided at both width ends of the adjustment wall 20c in the adjustment body 20, and the end wall portion 20d faces the protrusion 40a via the gap Q on the inner surface. Further, on both sides of the adjustment wall 20c in the adjustment body 20, protrusions 41a and 41b that protrude to the outer peripheral side of the adjustment wall 20c and extend in the circumferential direction are integrally formed, respectively. Each of the protrusions 41 a and 41 b is located on a plane orthogonal to the shaft 19. And each protrusion part 41a, 41b is each arrange | positioned between the said protrusion part 40a, 40b, 40c at the front end side, and the outer peripheral surface is the inside of the ceiling wall part 15b of the box 15 via the gap | interval Q. While facing each side surface, both side surfaces thereof face the side surfaces of the protrusions 40a, 40b, 40b, and 40c via the gap Q, respectively. Therefore, a labyrinth passage is formed by the gap Q.

  According to this embodiment, since the gap Q is a labyrinth passage, noise from the communication pipe 14 is more difficult to pass through the gap Q. Therefore, it is possible to more effectively reduce the intake sound in the desired frequency range.

In addition, this embodiment can also be changed and embodied as follows.
As shown by a two-dot chain line in FIG. 6, the flow path of the communication pipe 14 is divided into two flow paths having different flow path cross-sectional areas by the partition wall 45 provided inside the communication pipe 14. In this case, since the silencer 10 has two different resonance frequencies, noise of two frequency components corresponding to the two resonance frequencies can be reduced.

  The present invention is embodied in a silencer that is provided in an exhaust passage of an engine and reduces exhaust noise.

The longitudinal cross-sectional view which shows the silencer of 1st Embodiment. The AA line sectional view in Drawing 1 of a silencer. The longitudinal cross-sectional view which shows a housing. The BB line sectional view in Drawing 1 of a silencer. Similarly BB sectional drawing. The longitudinal cross-sectional view which shows the silencer of 2nd Embodiment. CC sectional view taken on the line in FIG. The longitudinal cross-sectional view which shows a housing. The longitudinal cross-sectional view which shows the silencer of 3rd Embodiment. DD sectional view taken on the line in FIG. The longitudinal cross-sectional view which shows a housing. (A) is a longitudinal cross-sectional view which shows the conventional silencer, (b) is the EE sectional view taken on the line in (a). (A) is the longitudinal cross-sectional view which shows the principal part of a silencer similarly, (b) is the FF sectional view taken on the line in (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Silencer, 11 ... Resonance chamber, 12 ... Housing, 13 ... Intake pipe as intake passage, 14 ... Communication pipe, 15 ... Box body which comprises a housing, 15c ... Opening part, 16 ... Similarly lid body, 17 ... Opening portion, 18 ... ridge portion as a protruding wall portion, 19 ... shaft, 20 ... adjusting body, 20c ... adjusting wall, 30 ... stepped portion, 30a ... inner peripheral surface, 30b ... inner side surface, 40a to 40c ... protruding wall Ridges constituting the portion, 41a, 41b ... ridges, Q ... gaps.

Claims (3)

A housing in which a resonance chamber communicated with the intake passage or exhaust passage of the engine via a communication pipe is formed ;
An adjustment body that is supported rotatably about an axis in the resonance chamber and has an arc-shaped adjustment wall along an arc surface centered on the axis;
In the silencer according to which the resonance frequency is adjusted by changing the opening degree of the opening on the resonance chamber side in the communication pipe by the adjusting wall according to the rotation position of the adjusting body.
Forming an opening in one side wall of the housing, the opening as well as closing the lid, is opened toward the opening in the opening,
The inner side surface of the housing on the opening side is formed in an arc shape along the arc surface of the adjusting body, and a pair of projecting walls are formed on both sides of the opening.
The outer peripheral surfaces of both width ends of said axial adjustment wall with opposed through the inner peripheral surface and the first gap of the housing on both sides of the opening, the axial direction of the adjusting member both the width ends of the faces via the inner surface and the second gap of the adjusting side of the pair of projecting walls,
The first gap and the second gap are formed with a cross-sectional bent shape,
The silencer characterized in that a space between the pair of projecting walls is opened toward the opening.   The muffler according to claim 1, wherein a plurality of the protruding walls are formed, and a protrusion that forms a labyrinth passage together with the protruding wall is formed on the adjusting body. A housing in which a resonance chamber communicated with the intake passage or exhaust passage of the engine via a communication pipe is formed ;
An adjustment body that is supported rotatably about an axis in the resonance chamber and has an arc-shaped adjustment wall along an arc surface centered on the axis;
In the silencer according to which the resonance frequency is adjusted by changing the opening degree of the opening on the resonance chamber side in the communication pipe by the adjusting wall according to the rotation position of the adjusting body.
Forming an opening in one side wall of the housing, the opening as well as closing the lid, is opened toward the opening in the opening,
A pair of steps is formed on both sides of the opening in the opening side wall of the housing ,
The outer peripheral surfaces of both width ends of said axial adjustment wall with opposed through the inner peripheral surface and the first gap of the pair of stepped portions, the axial direction of both the width of the adjusting member end faces through the inner surface and the second gap of the pair of stepped portions,
The first gap and the second gap are formed with a cross-sectional bent shape,
The silencer characterized in that a space between the pair of steps is opened toward the opening.

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