MUFFLER

Abstract

The present disclosure provides a muffler with a simple structure and a low cost. The muffler is formed by an exhaust pipe. The exhaust pipe has an extension direction and a radial direction, an exhaust gas is discharged through the exhaust pipe. At least a partial region of an interior of the exhaust pipe is divided into a muffling chamber and an exhaust passage portion by a partition plate arranged along the extension direction. A cross-sectional area of the exhaust passage portion is larger than that of the muffling chamber. At a downstream end portion of the muffling chamber in a flow direction of the exhaust gas, a peripheral wall of the exhaust pipe on the muffler chamber side is engaged with the partition plate, thereby closing a downstream opening of the muffling chamber in the flow direction of the exhaust gas.

Description

TECHNICAL FIELD

The present disclosure relates to a muffler, in particular to a muffler of an internal combustion engine.

BACKGROUND

An existing muffler is configured such that a partition wall provided inside an exhaust pipe along an extension direction of the exhaust pipe divides the interior of the exhaust pipe into two parts, and valves which can be freely opened and closed are provided at front and rear opening portions of one exhaust passage to form a muffling chamber, and the muffler is formed with a resonance region without holes in the partition wall of the muffling chamber and an expansion region with a hole to communicate with the adjacent exhaust passage. The muffler is provided with a sensor for detecting a rotational speed of the engine, and the muffler is further provided with a controller for controlling the valves to open when the rotational speed of the engine is above a predetermined rotational speed and the throttle opening is above a predetermined opening.

In addition, there also exists a muffler which uses a seal plate instead of a valve to seal a downstream side of an exhaust passage to form a muffling chamber.

SUMMARY

However, in the case of a muffler using valves to form a muffling chamber, the structure is complicated and the cost is high. In addition, in the case of a muffler using a seal plate to form a muffling chamber, the requirement for machining accuracy is high, which causes inconvenience to the operation of the workers, and a number of parts are required, which drives up the cost.

Therefore, an object of the present disclosure is to provide a muffler with a simple structure and low cost.

The present disclosure provides a muffler which is formed by an exhaust pipe for discharging an exhaust gas. The exhaust pipe has an extension direction and a radial direction, at least a partial region of an interior of the exhaust pipe is divided into a muffling chamber and an exhaust passage portion by a partition plate arranged along the extension direction. A cross-sectional area of the exhaust passage portion is larger than that of the muffling chamber. At a downstream end portion of the muffling chamber in a flow direction of the exhaust gas, a peripheral wall of the exhaust pipe on the muffler chamber side is deformed toward the partition plate to engage with the partition plate, thereby closing a downstream opening of the muffling chamber in the flow direction of the exhaust gas.

As an option, the exhaust pipe is a straight pipe.

As an option, the exhaust pipe is a bent pipe with at least one bent portion.

As an option, the muffling chamber is located at least at the bent portion.

As an option, when viewed from the downstream side in the flow direction of the exhaust gas, the peripheral wall of the exhaust pipe on the muffling chamber side is engaged with the partition plate to form a T-shaped engagement portion.

As an option, at the downstream end portion of the muffling chamber, the peripheral wall of the exhaust pipe on the muffling chamber side and the partition plate are welded to each other by melt inert-gas welding.

As an option, at the downstream end portion of the muffling chamber, the peripheral wall of the exhaust pipe on the muffling chamber side is crimped inward in a radial direction to engage with the partition plate.

As an option, at the downstream end portion of the muffling chamber, the partition plate is bent outward in the radial direction to engage with the peripheral wall of the exhaust pipe on the muffling chamber side.

As an option, a cover is provided at the downstream end portion of the muffling chamber to cover the downstream end portion.

As an option, the partition plate has bent portions at both end sides in a width direction perpendicular to the extension direction, wherein the bent portions are welded to the exhaust pipe by laser welding.

In another aspect, the present disclosure provides a muffler which is formed by an exhaust pipe for discharging an exhaust gas. The exhaust pipe has an extension direction and a radial direction, at least a partial region of an interior of the exhaust pipe is divided into a muffling chamber and an exhaust passage portion by a partition plate arranged along the extension direction. A cross-sectional area of the exhaust passage portion is larger than that of the muffling chamber. A cover is provided at a downstream end portion of the exhaust pipe in a flow direction of the exhaust gas to cover the downstream end portion, and a part of the cover is in close contact with or engaged with the partition plate to close a downstream opening of the muffling chamber in the flow direction of the exhaust gas.

According to the present disclosure, a muffler with a reduced number of parts, a simple structure, and a reduced cost can be provided. Moreover, for workers, the manufacture of the muffler becomes simple.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a muffler according to a first embodiment of the present disclosure.

FIG. 2 is a schematic diagram for explaining the flow of exhaust gas of the muffler according to the first embodiment of the present disclosure.

FIG. 3 is a cross-sectional view of the muffler according to the first embodiment of the present disclosure along a line A-A in FIG. 1.

FIG. 4 is a schematic diagram of a downstream end portion of a muffling chamber of the muffler according to the first embodiment of the present disclosure.

FIG. 5 is a schematic diagram of a muffler according to a second embodiment of the present disclosure.

FIG. 6 is a schematic diagram for explaining the flow of exhaust gas of the muffler according to the second embodiment of the present disclosure.

FIG. 7 is a schematic diagram showing a modified example of a partition plate of the muffler according to the present disclosure.

FIG. 8 is a schematic diagram showing another modified example of the muffler according the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the drawings. In the drawings, the same reference numerals denote elements with the same or similar functions. Although various aspects of the embodiments are shown in the drawings, unless otherwise specified, the drawings are not necessarily drawn to scale.

In addition, to better explain the present disclosure, numerous specific details are given in the following specific embodiments. It is to be understood by those skilled in the art that the present disclosure may also be implemented without some specific details. In some examples, the methods and means well known to those skilled in the art are not described in detail, so as to highlight the gist of the present disclosure.

First Embodiment

FIG. 1 is a schematic diagram of a muffler 10 according to a first embodiment of the present disclosure. FIG. 2 is a schematic diagram for explaining the flow of exhaust gas of the muffler 10 according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view of the muffler 10 according to the first embodiment of the present disclosure along a line A-A in FIG. 1. FIG. 4 is a schematic diagram of a downstream end portion 16a of a muffling chamber 16 of the muffler 10 according to the first embodiment of the present disclosure.

As shown in FIG. 1, an exhaust pipe 11 forming the muffler 10 is a straight pipe which may be made of metal, but the exhaust pipe 11 is not limited to this, that is, the exhaust pipe 11 may not be a straight pipe, or may be made of other materials than metal. The exhaust pipe 11 has an extension direction L and a radial direction R. Exhaust gas is discharged through the exhaust pipe 11. The extension direction L refers to a direction in which the exhaust pipe 11 extends, which may be a straight extension direction or a curved extension direction. Flange portions for connecting with other members are provided at both ends of the exhaust pipe 11 in the extension direction L.

As shown in FIGS. 2 and 3, the exhaust pipe 11 is formed in a substantially cylindrical shape, and has a small-diameter portion 12, an enlarged-diameter portion 13, and a large-diameter portion 14 in this order from an upstream side of a flow direction of exhaust gas G. An interior of the exhaust pipe 11 is divided into a muffling chamber 16 and an exhaust passage portion 17 by a partition plate 15 extending along the extension direction L. An upstream end portion of the partition plate 15 is more to the downstream side than a downstream end portion of the enlarged-diameter portion 13. Thus, the flow of the exhaust gas in the small-diameter portion 12 and the enlarged-diameter portion 13 is not affected, and the exhaust gas may be smoothly divided in the enlarged-diameter portion 13.

Furthermore, a cross-sectional area of the exhaust passage portion 17 is larger than that of the muffling chamber 16. As shown in FIG. 2, a diameter of the large-diameter portion 14 is larger than that of the small-diameter portion 12. Therefore, the cross-sectional area of the exhaust passage portion 17 can be made equal to the cross-sectional area of the small-diameter portion 12, and the discharge of the exhaust gas will not be affected. However, the present disclosure is not limited to this, that is, the cross-sectional area of the exhaust passage portion 17 may not be equal to the cross-sectional area of the small-diameter portion 12.

As shown in FIG. 3, the partition plate 15 has a substantially rectangular plate shape, and arc-shaped bent portions 15a, 15a on both end sides of the partition plate 15 in a width direction are fixed to the large-diameter portion 14. The fixing may be achieved by laser welding or other known engaging methods. The width direction of the partition plate 15 is perpendicular to the extension direction L. In addition, the partition plate 15 may also be formed as a bent plate with radian.

As shown in FIG. 4, at the downstream end portion 16a of the muffling chamber 16 in the flow direction of the exhaust gas G, a peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side is deformed toward the partition plate 15 to engage with the partition plate 15 to form an engagement portion 19, thereby closing the downstream opening of the muffling chamber 16. This engagement may be achieved by melt inert-gas welding (MIG welding) or other known engaging methods. Therefore, there is no need to additionally provide a member for closing the downstream opening of the muffling chamber 16.

The downstream end portion 16a of the muffling chamber 16 comprises a portion with a reduced cross section on the downstream side of the muffling chamber 16.

As shown in FIG. 2, a part of the exhaust gas G flowing into the exhaust pipe 11 flows into the muffling chamber 16 and collides with the closed downstream end portion 16a to flow backward, such that resonance occurs and muffling is performed. The remaining exhaust gas G flows into the exhaust passage portion 17, and is discharged out of the exhaust pipe 11.

In addition, as shown in FIG. 1, a cover 18 for covering the downstream end portion of the muffling chamber 16 may be provided at the downstream end portion 16a of the muffling chamber 16, and the exhaust pipe 11 can be connected to another member by this cover 18. As shown in FIG. 1, the cover 18 is formed in a cylindrical shape, and its inner diameter is the same as the outer diameter of the large-diameter portion 14 of the exhaust pipe 11, such that it can cover the downstream end portion 16a of the muffling chamber 16. The cover 18 may function as a connector between the muffler 11 and another member.

Second Embodiment

FIG. 5 is a schematic diagram of a muffler 20 according to a second embodiment of the present disclosure. FIG. 6 is a schematic diagram for explaining the flow of exhaust gas of the muffler 20 according to the second embodiment of the present disclosure.

The second embodiment is different from the first embodiment mainly in the exhaust pipe and the partition plate. Hereinafter, only the portions different from those of the first embodiment will be described, and the same portions will be denoted by the same reference numerals and the description thereof will be omitted appropriately.

As shown in FIG. 5, the muffler 20 in the second embodiment is formed by an exhaust pipe 21 which is a bent pipe with a bent portion 21a. Only one bent portion is shown in FIG. 5, but the present disclosure is not limited to this, that is, there may be a plurality of bent portions. As shown in FIG. 6, the exhaust pipe 21 has a small-diameter portion 12, an enlarged-diameter portion 13, and a large-diameter portion 14 in this order from an upstream side in the flow direction of the exhaust gas G. The bent portion 21a is provided in the large-diameter portion 14.

As in the first embodiment, an interior of the exhaust pipe 21 is divided into a muffling chamber 26 and an exhaust passage portion 27 by a partition plate 25 extending along the extension direction L. An upstream end portion of the partition plate 25 is more to the downstream side than the downstream end portion of the enlarged-diameter portion 13. Thus, the dividing of the flow of the exhaust gas at the enlarged-diameter portion 13 is not affected. Here, the extension direction L of the exhaust pipe 21 is a direction in which the exhaust pipe 21 extends by following the bending thereof.

As shown in FIG. 6, the partition plate 25 is provided at least at the bent portion 21a. As in the first embodiment, arc-shaped bent portions on both end sides of the partition plate 25 in a width direction are fixed to the large-diameter portion 14. The fixing may be achieved by laser welding or other known engaging methods.

As in the first embodiment, at the downstream end portion 26a of the muffling chamber 26, the peripheral wall of the exhaust pipe 21 on the muffling chamber 26 side is engaged with the partition plate 25 to close the downstream opening of the muffling chamber 26. Therefore, there is no need to additionally provide a member for closing the downstream opening of the muffling chamber 26.

Alternatively, a cover 18 may be provided at the downstream end portion 26a of the muffling chamber 26 to cover the downstream end portion 26a, and the inner diameter of the cover 18 may be substantially the same as the outer diameter of the large-diameter portion 14.

Downstream End Portion of Muffling Chamber

The structure of the downstream end portion 26a of the muffling chamber 26 in the second embodiment of the present disclosure is the same as that of the downstream end portion 16a of the muffling chamber 16 in the first embodiment. Therefore, the first embodiment of the present disclosure will be taken as an example to explain the downstream end portion of the muffling chamber, without describing the downstream end portion 26a of the muffling chamber 26 in the second embodiment.

In the first embodiment of the present disclosure, the downstream opening of the muffling chamber 16 is closed by engaging the peripheral wall of the exhaust pipe 11 on the muffling chamber side with the partition plate 15 at the downstream end portion 16a of the muffling chamber 16 in the flow direction of the exhaust gas G.

As shown in FIG. 4, at the downstream end portion 16a of the muffling chamber 16, the peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side is crimped inward in the radial direction to engage with the partition plate 15. However, the present disclosure is not limited to this, that is, the partition plate 15 may be bent outward in the radial direction to engage with the peripheral wall of the exhaust pipe 11 on the muffling chamber side, at the downstream end portion 16a of the muffling chamber 16. Alternatively, at the downstream end portion 16a of the muffling chamber 16, the peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side is crimped inward in the radial direction, and the partition plate 15 is bent outward in the radial direction, thereby engaging the peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side with the partition plate 15.

As an option, when viewed from the downstream side in the flow direction of the exhaust gas G, the peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side is engaged with the partition plate 15 to form a T-shaped engagement portion 19. As an option, as shown in FIG. 4, the engagement portion is formed in a symmetrical T shape, that is, the plane where the protruding part in the center of the T shape is located is coplanar with a central axis of the exhaust pipe 11. In this way, the protruding part may function as a reinforcing rib to enhance the strength.

In addition, in the example shown in FIG. 4, when viewed from the downstream side in the flow direction of the exhaust gas G, the engagement portion 19 has the shape of an inverted letter T. In the case where the engagements at the bent portions 15a, 15a on both sides of the partition plate 15 in the width direction are included, it can be regarded that the engagement portion 19 has the shape of an inverted letter Y Furthermore, based on the actual application situation, when viewed from the downstream side in the flow direction of the exhaust gas G, the engagement portion 19 may take the shape of the letter T or Y in any orientation, such as a rightly-placed letter T or Y.

In addition, the engagement between the peripheral wall of the exhaust pipe 11 on the muffling chamber 16 side and the partition plate 15 may be achieved by a known engaging method such as laser welding and MIG welding.

Modified Examples

As described above, the bent portions at both end sides of the partition plates 15, 25 in the width direction are fixed to the peripheral walls of the exhaust pipes 11, 21. The positions where the bent portions at both end sides of the partition plates 15, 25 in the width direction are fixed to the exhaust pipes 11, 21 may be arbitrarily selected as required.

For example, FIG. 7 is a schematic diagram showing a modified example of the partition plate of the muffler according to the present disclosure, corresponding to a cross-sectional view taken along the line A-A in FIG. 1. As shown in FIG. 7, when viewed along the flow direction of the exhaust gas, a rectangular coordinate system with its origin on the central axis of the exhaust pipe is set. The case where the partition plate is orthogonal to the positive direction of the X-axis and the case where the partition plate is orthogonal to the negative direction of the X-axis are described as that “the partition plate is provided at 90 degrees” (portion (e) of FIG. 7) and that “the partition plate is provided at −90 degrees” (portion (a) of FIG. 7), respectively. The case where the partition plate is parallel to the X-axis is described as that “the partition plate is provided at 0 degrees” (portion (c) of FIG. 7). The case where the partition plate is inclined at 45 degrees to the positive direction of the X-axis and the case where the partition plate is inclined at 45 degrees to the negative direction of the X axis are described as that “the partition plate is provided at 45 degrees” (portion (d) of FIG. 7) and that “the partition plate is provided at −45 degrees” (portion (b) of FIG. 7), respectively.

In addition to the positions shown in portions (a) to (e) of FIG. 7, the positions where the bent portions at both end sides of the partition plate in the width direction are fixed to the exhaust pipe may also be located somewhere else, that is, the above positions may be arbitrarily selected as required.

Moreover, as described above, a cover 18 may be provided at the downstream end portion 16a of the muffling chamber 16 to cover the downstream end portion of the muffling chamber as shown in FIG. 1, and the exhaust pipe 11 may be connected to another member by the cover 18.

However, the present disclosure is not limited to the above structure. Alternatively, as shown in the modified example of FIG. 8, the cover 18 may be provided at the downstream end portion of the exhaust pipe in the flow direction of the exhaust gas to cover the downstream end portion, and the cover 18 may be formed to have a first portion 18a which has an inner diameter same as the outer diameter of the large-diameter portion of the exhaust pipe 11 and which covers the downstream end portion of the exhaust pipe 11 in the flow direction of the exhaust gas; a second portion 18b which is connected to the first portion 18a at the downstream side of the first portion 18a in the flow direction of the exhaust gas and which has an inner diameter decreasing toward the downstream side; and a third portion 18c which is connected to the second portion 18b at the downstream side of the second portion 18b in the flow direction of the exhaust gas and of which the downstream end portion may be connected to another member.

According to the modified example shown in FIG. 8, the downstream end portion of the partition plate 15 in the flow direction of the exhaust gas protrudes from the exhaust pipe 11, and at the boundary between the second portion 18b and the third portion 18c of the cover 18, the cover 18 is in close contact with the partition plate 15 or is engaged with the partition plate 15 by welding or the like, thereby closing the muffling chamber.

It is appreciated that although the cover 18 closes the downstream opening of the muffling chamber in the flow direction of the exhaust gas, the cover 18 does not close the exhaust passage portion 17 but opens the exhaust passage portion 17 to the downstream side.

Therefore, as is clear from FIG. 8, the cover 18 not only can execute the function of connecting the muffler with other members but also can execute the function of closing the downstream opening of the muffling chamber, thereby reducing the number of parts and reducing the cost.

Functions and Effects

As mentioned above, according to the present disclosure, at the downstream end portion of the muffling chamber in the flow direction of the exhaust gas, the peripheral wall of the exhaust pipe on the muffling chamber side is engaged with the partition plate, thereby closing the downstream opening of the muffling chamber in the flow direction of the exhaust gas. Thus, there is no need to additionally provide a member for closing the downstream opening of the muffling chamber, so that the number of parts can be reduced and the cost can be reduced.

In addition, welding can be carried out simply by crimping the peripheral wall of the exhaust pipe on the muffling chamber side or bending the downstream end portion of the partition plate. Therefore, the requirement for machining accuracy is low, so the process of manufacturing the muffler becomes simple for workers and the cost is further reduced.

In addition, according to the present disclosure, the exhaust pipe forming the muffler can be either a straight pipe or a bent pipe, so the present disclosure has a high versatility.

In the case where the exhaust pipe is a bent pipe, the straight partition plate 15 may be first inserted into the straight exhaust pipe 11, the exhaust pipe 11 is filled with an elastic filling medium, then the exhaust pipe 11 is bent, and then the partition plate 15 and the exhaust pipe 11 are welded. In this way, it can be ensured that the partition plate 15 can be easily inserted into the exhaust pipe 11, and the bending will not affect the welding quality. Undoubtedly, this operation is only exemplary and is not intended to limit the present disclosure.

Furthermore, when viewed from the downstream side in the flow direction of the exhaust gas, the engagement portion formed by engaging the peripheral wall of the exhaust pipe on the muffling chamber side with the partition plate is formed by crimping, and has a symmetrical T shape. Therefore, there is no need for an additional deburring process, and the protruding part in the center of the T shape can function as a reinforcing rib to enhance the strength of the engagement portion.

Furthermore, a cover is provided at the downstream end portion of the muffling chamber to cover the downstream end portion, so that the exhaust pipe can be connected to another member by the cover.

The above embodiments are merely exemplary, and are not intended to limit the present disclosure. Those skilled in the art can make various changes and modifications based on the technical concept of the present disclosure, which of course are also within the protection scope of the present disclosure.

For example, instead of providing a cover at the downstream end portion of the muffling chamber, another member to be connected may directly sleeve the outer periphery of the large-diameter portion of the exhaust pipe to cover the downstream end portion of the muffling chamber.

In addition, in the above embodiment, the partition plate is formed in a rectangular plate shape, but the partition plate may also be a curved plate with a curvature, for example.

INDUSTRIAL AVAILABILITY

The present disclosure can provide a muffler with a simple structure and a low cost.

DESCRIPTION OF REFERENCE NUMERALS

• • 10, 20 muffler
  • 11, 21 exhaust pipe
  • 12 small-diameter portion
  • 13 enlarged-diameter portion
  • 14 large-diameter portion
  • 15, 25 partition plate
  • 16, 26 muffling chamber
  • 17, 27 exhaust passage portion
  • 18 cover
  • 19 engagement portion

Claims

1. A muffler, wherein, the muffler is formed by an exhaust pipe for discharging an exhaust gas,

the exhaust pipe having an extension direction and a radial direction, at least a partial region of an interior of the exhaust pipe being divided into a muffling chamber and an exhaust passage portion by a partition plate arranged along the extension direction,

at a downstream end portion of the muffling chamber in a flow direction of the exhaust gas, a peripheral wall of the exhaust pipe on the muffler chamber side being crimped and deformed toward the partition plate to engage with the partition plate, thereby closing a downstream opening of the muffling chamber in the flow direction of the exhaust gas, wherein the crimped and deformed peripheral wall forms a protruding part.

2. The muffler according to claim 1, wherein the exhaust pipe is a straight pipe.

3. The muffler according to claim 1, wherein the exhaust pipe is a bent pipe with at least one bent portion.

4. The muffler according to claim 3, wherein the muffling chamber is located at least at the bent portion.

5. The muffler according to claim 1, wherein when viewed from a downstream side in the flow direction of the exhaust gas, the peripheral wall of the exhaust pipe on the muffling chamber side is engaged with the partition plate to form a T-shaped engagement portion.

6. The muffler according to claim 1, wherein at the downstream end portion of the muffling chamber, the peripheral wall of the exhaust pipe on the muffling chamber side and the partition plate are welded to each other by melt inert-gas welding.

7. The muffler according to claim 1, wherein at the downstream end portion of the muffling chamber, the peripheral wall of the exhaust pipe on the muffling chamber side is crimped inward in the radial direction to engage with the partition plate.

8. The muffler according to claim 1, wherein at the downstream end portion of the muffling chamber, the partition plate is bent outward in the radial direction to engage with the peripheral wall of the exhaust pipe on the muffling chamber side.

9. The muffler according to claim 1, wherein a cover is provided at the downstream end portion of the muffling chamber to cover the downstream end portion.

10. The muffler according to claim 1, wherein the partition plate has bent portions at both end sides in a width direction perpendicular to the extension direction, wherein the bent portions are welded to the exhaust pipe by laser welding.

11. A muffler, wherein the muffler is formed by an exhaust pipe for discharging an exhaust gas,

the exhaust pipe having an extension direction and a radial direction, at least a partial region of an interior of the exhaust pipe being divided into a muffling chamber and an exhaust passage portion by a partition plate arranged along the extension direction,

a cross-sectional area of the exhaust passage portion being larger than a cross-sectional area of the muffling chamber, and

a cover being provided at a downstream end portion of the exhaust pipe in a flow direction of the exhaust gas to cover the downstream end portion, and a part of the cover being in close contact with or engaged with the partition plate to close a downstream opening of the muffling chamber in the flow direction of the exhaust gas.

12. The muffler according to claim 1, wherein a cross-sectional area of the exhaust passage portion is larger than a cross-sectional area of the muffling chamber.