JP4358045B2 - Silencer - Google Patents

Description

  The present invention relates to a silencer connected to an exhaust system of an engine.

Conventionally, in a silencer connected to an exhaust system of a vehicle engine such as an automobile, the silencer chamber in the silencer is divided into a plurality of partition walls, and the exhaust gas flowing into the silencer chamber is silenced by this partition wall. It is known that an outlet pipe is supported to discharge to the atmosphere, and the inlet end of the outlet pipe is expanded to increase the amount of exhaust gas flowing into the outlet pipe. (For example, refer to Patent Document 1).
JP 2002-97922 A

  By the way, in what is indicated by the said patent document 1, as shown in FIG. 9, in order to expand the opening end of an outlet pipe to flare shape, after supporting an outlet pipe to a partition wall, Since the diameter expansion jig is inserted into the opening end and the end of the outlet pipe is expanded, it is necessary to clamp the outlet pipe with the clamp member in order to fix the outlet pipe during the expansion process. . Therefore, a predetermined interval for receiving the clamp member is required between the partition walls (the interval between the partition walls cannot be reduced), and there is a problem that the design freedom of the silencer is reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a novel silencer that solves the above-described problem and easily forms a flare portion at the opening end of the outlet pipe. To do.

In order to achieve the above object, the invention according to claim 1 divides the silencing chamber in the shell by the partition wall, and provides an outlet pipe for silencing the exhaust gas flowing into the silencing chamber and discharging it to the outside. In the silencer
A flare pipe having an enlarged opening formed separately from the outlet pipe is connected to the opening end of the silencer chamber of the outlet pipe, and the partition wall, the outlet pipe and the flare pipe are welded simultaneously. The outlet pipe and the flare pipe are supported by the partition wall.

  According to the present invention, a flare pipe having an enlarged opening formed separately from the outlet pipe is connected to the opening end of the silencer chamber of the outlet pipe, and the partition wall, the outlet pipe, and the flare pipe. Since the outlet pipe and the flare pipe were supported by the partition wall at the same time, the flare part was formed integrally at the opening end of the outlet pipe without impairing the design freedom of the silencer. The inflow amount of the exhaust gas can be increased, and the support rigidity of the outlet pipe having the flare pipe can be increased.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on examples of the present invention shown in the accompanying drawings.

  First, an embodiment of the present invention will be described with reference to FIGS. 1 to 7. This embodiment is a case where the silencer of the present invention is applied to an exhaust system of an automobile engine. FIG. 2 is a schematic plan view of an exhaust system of an engine equipped with a silencer, FIG. 2 is a perspective view of the silencer shown in the arrow 2 of FIG. 1, and FIG. 3 is a plan view of the silencer shown in the arrow 3 of FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4, FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. FIG. 7 is an enlarged view of a portion surrounded by an imaginary line 7 in FIG. 3.

  In FIG. 1, an exhaust system Ex for exhausting exhaust gas exhausted by its operation to the atmosphere is connected to an automobile engine generally indicated by E, and this exhaust system Ex is connected to the engine E. The exhaust pipe 1 connected to the exhaust port includes a catalyst C, a pre-chamber P, and a silencer M that are sequentially connected from the upstream side to the downstream side.

  When the exhaust system Ex is connected to the engine E, as shown in FIG. 4, the shell 2 constituting the casing of the silencer M is inclined at an inclination angle θ with respect to the horizontal plane so as to take a slightly forward inclined posture. The residual water accumulated in the shell 2 is collected at the front part.

  Then, the exhaust gas discharged from the engine E is purified by the catalyst C, the primary component is silenced by the pre-chamber P, the secondary noise is silenced by the silencer M, and the exhaust gas is discharged to the atmosphere.

  Next, the structure of the silencer M according to the present invention will be described in detail with reference to FIGS.

  The shell 2 constituting the casing of the silencer M is formed by winding a plate material made of stainless steel into an elliptic cylinder, and joining both ends of the shell body 2a integrally with each other, and the front and rear opening ends thereof, Before being airtightly caulked and fixed, the rear end plates 2b and 2c are formed in a sealed hollow oval shape. The elliptical shell 2 is connected to the downstream portion of the exhaust pipe 1 with its short axis side facing up and down. An exhaust pipe 1 communicating with the pre-chamber P is connected to the front end plate 2b of the shell 2, and a tail pipe 9 opening to the atmosphere is connected to the rear end plate 2c in an airtight manner. .

  The silencing chamber CA in the shell 2 is divided into three chambers, namely, first and second expansion chambers 5 and 6 and a resonance chamber 7 by first and second partition walls 3 and 4. Specifically, the first partition wall 3 and the second partition wall 4 are fixed in the shell 2 substantially in parallel with the front and rear end plates 2b and 2c with an interval in the longitudinal direction thereof. The first expansion chamber 5 is partitioned by the first partition wall 3 and the second partition wall 4 in the middle portion of the shell 2 in the longitudinal direction, and on the front side of the first expansion chamber 5, A second expansion chamber 6 is defined by the front end plate 2b and the first partition wall 3, and further, a second partition wall 4 and a rear end plate 2c are provided on the rear side of the first expansion chamber 5. And the resonance chamber 7 is partitioned.

  As shown in FIG. 5, two communication holes 15 and 16 are opened on the left and right sides of the first partition wall 3 with a space therebetween, and a plurality of interference holes 17 are opened at the lower part thereof. The first expansion chamber 5 and the second expansion chamber 6 are communicated with each other through the communication holes 15 and 16 and the interference hole 17. As shown in FIG. 6, a plurality of small interference holes 18 are opened in the second partition wall 4 over the entire region, and the first expansion chamber 5 and the resonance chamber 7 are interposed through these interference holes 18. Are in communication with each other.

  As shown most clearly in FIG. 3, the front end (upstream end) of the inlet pipe 10 disposed in the shell 2 is connected to and connected to the rear end (downstream end) of the exhaust pipe 1. The inlet pipe 10 is formed in a straight shape over the entire length thereof, and is penetrated and supported by the front end plate 2b, the first partition wall 3 and the second partition wall 4, and extends in the shell 2 in the longitudinal direction. . The rear half 10r located in the resonance chamber 7 has a smaller diameter than the front half 10f located in the first and second expansion chambers 5 and 6. The rear end (downstream end) of the inlet pipe 10 is closed by a plug body 11. A portion of the inlet pipe 1 corresponding to the first expansion chamber 5 is provided with a discharge hole 12 made up of a plurality of small holes, and the inside of the inlet pipe 10 passes through these discharge holes 12 to form the first expansion chamber 5. Communicated within. A discharge hole 13 made up of a large number of small holes is also opened in a portion of the inlet pipe 10 corresponding to the second expansion chamber 6, and the inside of the inlet pipe 10 passes through these discharge holes 13 to form the second expansion chamber 6. Communicated within. Further, a discharge hole 14 made up of a large number of small holes is opened in a portion of the inlet pipe 10 corresponding to the resonance chamber 7, and the inside of the inlet pipe 10 is communicated with the resonance chamber 7 through these discharge holes 14.

  Therefore, the exhaust gas that has flowed into the inlet pipe 10 from the exhaust pipe 1 passes through the discharge holes 12 and 13, enters the first and second expansion chambers 5 and 6, and further flows into the inlet pipe 10. The part also enters the resonance chamber 7 through the discharge hole 14, and the exhaust sound is attenuated by the expansion and resonance action of the exhaust gas. And the exhaust gas discharged | emitted from the inlet pipe 10 joins the 2nd expansion chamber 6, Then, it enters into the outlet pipe 20 mentioned later, and here, secondary silencing of an exhaust sound is performed effectively.

  An outlet pipe 20 is disposed in the shell 2 in parallel with the inlet pipe 10. As a whole, the outlet pipe 20 is bent and extended in an S-shape from the top to the bottom in the shell 2, and has a U-shaped exhaust gas inlet pipe portion 21 and a straight exhaust gas discharge. It consists of a pipe part 23 and an arcuate direction changing pipe part 22 that connects the pipe parts 20 and 23 together, and is bent twice.

  The exhaust gas entry pipe portion 21 is located on the upper side (right side in FIGS. 5 and 6), deviated to one side from the central portion in the shell 2, and is curved in a U-shape in the front-rear direction while being inclined downward. It is provided across the first expansion chamber 5 and the resonance chamber 7, and an intermediate portion thereof is penetrated and supported by the second partition wall 4, and its upstream end and downstream end penetrate through the first partition wall 3. It is supported.

  As shown in FIGS. 2 to 4, the opening end (upstream end) of the outlet pipe 20, that is, the opening end of the exhaust gas entry pipe portion 21, is expanded toward the second expansion chamber 6. The base portion of the flare pipe 30 having a diameter opening portion is integrally connected, so that the amount of exhaust gas flowing into the outlet pipe 20 is increased. The three ends of the open end of the exhaust gas entry pipe portion 21, the flare pipe 30, and the first partition wall 3 are integrally MIG welded. Specifically, as shown in FIG. 7, the first partition wall 3 is provided with a support hole 3a, and the support hole 3a is directed toward the rear side (first expansion chamber 5 side). A short cylindrical welding allowance 3b is formed. The opening end of the exhaust gas entry pipe portion 21 and the base portion of the flare pipe 30 are overlapped and fitted into the support hole 3a, and they are MIG welded W. At this time, the MIG welding torch can easily enter even in a narrow gap between the first and second partition walls 3 and 4, and the MIG welding W can be performed easily and easily.

  On the other hand, the exhaust gas discharge pipe portion 23 is located lower than the exhaust gas entry pipe portion 21 and is located at a substantially central portion in the left-right direction in the shell 2 and substantially parallel to the axis of the shell 2. It arrange | positions and is penetrated and supported by the 1st, 2nd partition walls 3 and 4 and the rear-part end plate 2c. The front end (upstream end) faces the second expansion chamber 6 and is connected to the direction changing pipe portion 22, and the rear end (downstream end) is opened to the atmosphere and connected to the tail pipe 9. ing.

  As shown in FIG. 4, a sound absorbing means 44 is provided at an intermediate portion of the exhaust gas discharge pipe portion 23. The sound absorbing means 44 includes a large number of sound absorbing holes 45 drilled in the middle of the exhaust gas discharge pipe portion 23, an outer cylinder 46 covering the sound absorbing holes 44, and glass wool 47 filled therebetween. .

  The downstream end of the exhaust gas inlet pipe portion 21 located above the shell 2 and the upstream end of the exhaust gas discharge pipe portion 23 located below the shell 2 are in the second expansion chamber 6. The direction change pipes 22 are connected in communication, and their connection portions are supported by the first partition wall 3. As shown in FIGS. 3 and 4, the direction changing pipe portion 22 is formed into a circular arc shape by joining the two pipe halves 22 h and 22 h so that the exhaust gas flowing through the exhaust gas inlet pipe portion 21 It is led to the exhaust gas discharge pipe part 23 while detouring from the front to the rear and changing the direction.

  As shown in FIGS. 2 to 6, the three pipe parts constituting the outlet pipe 20, that is, the exhaust gas inlet pipe part 21, the direction changing pipe part 22, and the exhaust gas discharge pipe part 23, are directed from above to below. The S-shaped long bend is formed, and the exhaust gas flowing through them is assisted by gravity and promotes its flow with little resistance.

  As shown most clearly in FIG. 4, a water drain hole 50 is provided in the vicinity of the upstream portion of the exhaust gas discharge pipe portion 23. This drain hole 50 sucks the residual water stored in the silencer M, that is, the shell 2 into the pipe 20 by the spray effect by the flow of the exhaust gas flowing in the outlet pipe 20 and discharges it together with the exhaust gas to the outside. Is to do.

  As shown in FIG. 4, water holes 51 and 52 are provided at the lowermost portions of the first partition wall 3 and the second partition wall 4 so that the front and rear thereof communicate with each other. Since the shell 2 is slightly forward tilted as described above, the water is collected in the front portion of the shell 2 through the water passage holes 52 and 51. The collected residual water is discharged from the drain hole 50 through the outlet pipe 20 to the outside as described later.

  Next, the operation of this embodiment will be described.

  Now, the engine E is operated, and the exhaust gas discharged therefrom is guided to the exhaust system Ex. The exhaust gas flowing through the exhaust system Ex enters the silencer M, where main exhaust noise is silenced.

  2 to 4, the exhaust gas that has flowed into the inlet pipe 10 from the exhaust pipe 1 passes through the discharge hole 12 and the discharge hole 13 to the first expansion chamber 5 and the second expansion chamber 6. In addition, a part of the exhaust gas also enters the resonance chamber 7 through the exhaust hole 14, and the exhaust sound energy is effectively attenuated by the combined action of the expansion and resonance of the exhaust gas, and the primary exhaust gas is exhausted. The sound is muted.

  Exhaust gas in the resonance chamber 7 enters the first expansion chamber 5 through a small communication hole 18 (see FIG. 6), and the exhaust gas in the first expansion chamber 5 further passes through the first partition wall. The exhaust gas that has entered the second expansion chamber 6 through the three communication holes 15 and 16 and the interference hole 17 (see FIG. 5) and merged in the chamber 6 is indicated by an arrow B in FIGS. Then, it flows into the outlet pipe 20 from the flare pipe 30 of the exhaust gas entry pipe portion 21. At this time, since the flare pipe 30 whose diameter increases toward the second expansion chamber 6 is connected to the open end (upstream end) of the outlet pipe 20, the outlet pipe 20 for the exhaust gas in the second expansion chamber 6. It is possible to increase the amount of inflow into the water and to reduce the inflow resistance.

  Thus, the flare pipe 30 having the enlarged diameter opening can be formed at the opening end of the outlet pipe 20 by MIG welding W, so that the conventional one can be used for manufacturing the silencer. There is no restriction such as (disclosed in Patent Document 1). Further, since the outlet pipe 20 and the flare pipe 30 are simultaneously MIG welded W together with the first partition wall 30, their supporting rigidity is enhanced.

  In addition, as described above, the outlet pipe 20 is bent in a S-shape and is extended to be long, so that the exhaust gas in the outlet pipe 20 is further attenuated while flowing through the pipe 20. Therefore, the mute is effectively performed. The exhaust gas that has been sufficiently silenced is discharged from the rear end of the exhaust gas discharge pipe portion 23 to the atmosphere through the tail pipe 9 as indicated by an arrow C in FIGS.

  In the exhaust gas silencing process, the high-temperature exhaust gas is cooled in the shell 2 and the water contained therein is dewed and condensed, or the water that has entered the shell 2 from the outlet pipe 20 during car washing is residual water. It is stored.

  As described above, the exhaust gas flowing through the outlet pipe 20 is accelerated by the gravity while being assisted by gravity, and the whistling effect of the gas flow causes the residual water to flow through the drain hole 50. It can be sucked into the pipe 20 and reliably discharged to the outside together with the exhaust gas. In particular, even when the exhaust pressure is low, such as when the engine is idling, residual water stored at the bottom of the shell 2 can be sufficiently discharged.

  Next, a modified example of the embodiment will be described with reference to FIG.

  FIG. 8 is a diagram corresponding to FIG. 7, and the same reference numerals are given to the same elements as those in the embodiment.

  In this modified example, the structure of the simultaneous MIG welding W portion of the outlet pipe 20 (exhaust gas inflow pipe portion 21) and the flare pipe 30 with respect to the first partition wall 3 is different from that of the above embodiment. The first partition wall 2 is provided with a support hole 3a ', and a short cylindrical welding allowance 3b' standing up toward the front side (the second expansion chamber 6 side) is provided in the support hole 3a '. It is formed. The opening end of the exhaust gas entry pipe portion 21 and the base portion of the flare pipe 30 are overlapped and fitted into the support hole 3a ′, and MIG welding W is performed.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the Example, A various Example is possible within the scope of the present invention. For example, in the above embodiment, the outlet pipe 20 and the flare pipe 30 are supported by the first partition wall 3, but they may be supported by the second partition wall 4. Further, instead of the MIG welding W of the above embodiment, other effective welding means may be used.

Schematic plan view of an exhaust system of an engine equipped with the silencer of the present invention FIG. 1 is a perspective view of the silencer shown in the arrow 2 in FIG. Plan view of the silencer shown in the arrow 3 of FIG. Sectional view along line 4-4 in FIG. Sectional view along line 5-5 in FIG. Sectional drawing which follows the 6-6 line of FIG. Enlarged view of the phantom line encircled portion in FIG. Corresponding diagram of FIG. 7 (variation example) Partial schematic view of a conventional silencer with an outlet pipe having a flare portion

Explanation of symbols

2 ... Shell 3 ..... Partition wall (first partition wall)
6 ... Expansion chamber (second expansion chamber)
10 ············ Inlet pipe 20 ··················································································

Claims (1)

The silencer chamber (CA) in the shell (2) is divided by the partition wall (3), and the exhaust pipe flowing into the silencer chamber (CA) is silenced and discharged to the partition wall (3). In the silencer provided with (20),
A flare pipe (30) having an enlarged opening formed separately from the outlet pipe (20) is connected to an opening end in the silencer chamber (CA) of the outlet pipe (20), and a partition wall ( 3) The three features of the outlet pipe (20) and the flare pipe (30) are welded simultaneously to support the outlet pipe (20) and the flare pipe (30) on the partition wall (3). A silencer to do.

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