muffler

Abstract

The objective is to suppress the generation of airflow noise. [Solution] The silencer 10 comprises a silencer body 20, a sixth baffle plate 50 as a baffle plate that partitions the inside of the silencer body 20, and a connecting pipe 82 extending from the sixth baffle plate 50. The sixth baffle plate 50 comprises a partition surface 100 that partitions the inside of the silencer body 20 into one side I and the other side T, and an opening 104 formed in the partition surface 100 for allowing exhaust gas G to flow into the seventh space 72, which is the one-side space of the one-side I. The sixth baffle plate 50 has a funnel shape with the partition surface 100 recessed toward the other side T, and has a guide portion 106 that guides the exhaust gas G from the seventh space 72, which is the one-side space, to the connecting pipe 82 that protrudes toward the other side T.

Description

Technical Field

[0001] The present invention relates to a muffler.

Background Art

[0002] Patent Document 1 discloses a muffler. The muffler includes a lid portion that closes an exhaust inlet opening at the exhaust inflow side end of an outlet pipe. An exhaust inlet having a valve body is formed in the lid portion, and the exhaust inlet is opened and closed according to the engine rotation speed.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the muffler of Patent Document 1, when the exhaust gas flowing into the outlet pipe passes through the exhaust inlet of the lid portion, a constriction flow and a vortex occur, resulting in a problem that the airflow sound becomes large.

[0005] The present invention has been made in view of the above problems, and an object thereof is to be able to suppress the generation of airflow sound.

Means for Solving the Problems

[0006] According to one aspect of the present invention, a silencer comprises a silencer body, a baffle plate partitioning the inside of the silencer body, and a pipe extending from the baffle plate. The baffle plate has a partition surface that divides the inside of the silencer body into one side and the other side, an opening formed in the partition surface for allowing exhaust gas to flow into the one-side space, and a guide portion which is funnel-shaped with the partition surface recessed toward the other side, for guiding the exhaust gas from the one-side space to the pipe extending toward the other side. [Effects of the Invention]

[0007] In the above embodiment, exhaust gas sent to the one-sided space on one side of the baffle plate partition surface is guided to the connecting pipe by a funnel-shaped guide formed on the partition surface. At this time, the exhaust gas in the one-sided space is collected towards the center by the guide with a funnel-shaped opening, so that the contraction of the exhaust gas passing through the opening is suppressed. As a result, the generation of vortices in the contracted flow portion is reduced.

[0008] Therefore, the silencer can suppress the generation of airflow noise compared to a case where it is not possible to suppress the generation of vortices caused by the contraction of exhaust gas flow passing through the opening. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing the inside of a silencer according to an embodiment of the present invention. [Figure 2] Figure 2 is a side view of the baffle plate. [Figure 3] Figure 3 is a front view of the baffle plate. [Figure 4] Figure 4 is a cross-sectional view showing the baffle plate with the connecting pipe fitted inside. [Figure 5] Figure 5 is a cross-sectional view showing the baffle plate with the connecting pipe fitted onto it. [Figure 6] Figure 6 shows the evaluation results. [Figure 7]Figure 7 is an explanatory diagram illustrating the flow of exhaust gases. [Figure 8] Figure 8 shows the relationship between engine speed and airflow noise. [Figure 9] Figure 9 is a cross-sectional view showing the first modified example. [Figure 10] Figure 10 is a side view of the baffle plate of the first modified example. [Figure 11] Figure 11 is a side view of the baffle plate of the second modified example. [Figure 12] Figure 12 is a cross-sectional view showing a third modified example. [Modes for carrying out the invention]

[0010] Hereinafter, a silencer 10 according to an embodiment of the present invention will be described with reference to the drawings.

[0011] First, the overall configuration of the silencer 10 will be described with reference to Figure 1. Figure 1 is a perspective view showing the inside of the silencer 10 according to an embodiment of the present invention.

[0012] As shown in Figure 1, the silencer 10 is a device installed, for example, in the exhaust path of an automobile to reduce the exhaust noise emitted from the engine. In this embodiment, the case in which the silencer 10 is used in the exhaust path of an automobile is given as an example, but the use of the silencer 10 is not limited to this. The silencer 10 may also be used by connecting it to, for example, factory piping (ducts), air conditioning system piping, or other fluid system piping.

[0013] The silencer 10 comprises a silencer body 20, an inlet pipe 22 that guides exhaust gas G into the silencer body 20, and a plurality of baffle plates (40, 42, 44, 46, 48, 50) that partition the inside of the silencer body 20.

[0014] The baffle plate is composed of a first baffle plate 40, a second baffle plate 42, a third baffle plate 44, a fourth baffle plate 46, a fifth baffle plate48, and a sixth baffle plate 50. Each baffle plate 40, 42, 44, 46, 48, 50 is a press-formed product formed by press molding. Note that each baffle plate 40, 42, 44, 46, 48, 50 may also be formed by a 3D printer or other manufacturing methods.

[0015] The first baffle plate 40, the second baffle plate 42, the third baffle plate 44, the fourth baffle plate 46, and the fifth baffle plate 48 are formed in substantially the same shape. The sixth baffle plate 50 has a shape different from each of the baffle plates 40, 42, 44, 46, 48. Details of the sixth baffle plate 50 will be described later.

[0016] (Silencer body) The silencer body 20 has a cylindrical portion 34 formed in a cylindrical shape, a one-end side end plate 38 provided at one end of the cylindrical portion 34 for closing the end opening at the one-end side, and a the other-end side end plate 36 provided at the other end of the cylindrical portion 34 for closing the end opening at the other-end side. The inlet pipe 22 described above is connected to the cylindrical portion 34 of the silencer body 20, and the exhaust gas G discharged from the engine is introduced into the silencer body 20 through the inlet pipe 22.

[0017] In the silencer body 20, the baffle plates 40, 42, 44, 46, 48, 50 are arranged in order at intervals in the longitudinal direction of the silencer body 20. Inside the silencer body 20, a first space 60, a second space 62, a third space 64, a fourth space 66, a fifth space 68, a sixth space 70, and a seventh space 72 partitioned by the baffle plates 40, 42, 44, 46, 48, 50 are formed.

[0018] The first baffle plate 40, the second baffle plate 42, the third baffle plate 44, the fourth baffle plate 46, and the fifth baffle plate 48 are formed with communication holes (not shown) that connect adjacent spaces (60, 62, 64, 66, 68, 70). As a result, some of the exhaust gas G guided from the inlet pipe 22 into the fifth space 68 flows into the sixth space 70, while the rest flows into the first space 60 via the fourth space 66, the third space 64, and the second space 62.

[0019] Inside the silencer body 20, there is a cylindrical introduction pipe 80 through which each of the baffle plates 40, 42, 44, 46, and 48 is inserted, guiding the exhaust gas G in the first space 60, which is the upstream side, to the seventh space 72, which is the side space. Also inside the silencer body 20, there is a connecting pipe 82, which is a cylindrical pipe that is constructed separately from each of the baffle plates 40, 42, 44, 46, 48, and 50, and extends from the sixth baffle plate 50, specifically connected to the sixth baffle plate 50.

[0020] The connecting pipe 82 passes through each of the baffle plates 40, 42, 44, 46, and 48, and extends outside the silencer body 20 by passing through the end plate 36 on the other end. A tailpipe 84 is connected to the end of the connecting pipe 82 that extends outside the silencer body 20. The tailpipe 84 discharges the exhaust gas G that flows in from the connecting pipe 82 through an outlet 86 that is open to the outside.

[0021] (Sixth baffle plate) Next, using Figures 2 to 5, we will specifically describe the sixth baffle plate 50 into which the introduction pipe 80 is inserted and the connecting pipe 82 is connected.

[0022] Figure 2 is a side view of the sixth baffle plate 50 as a baffle plate. Figure 3 is a front view of the sixth baffle plate 50 as a baffle plate. Figure 4 is a cross-sectional view showing the sixth baffle plate 50 with the connecting pipe 82 fitted inside. Figure 5 is a cross-sectional view showing the sixth baffle plate 50 with the connecting pipe 82 fitted outside.

[0023] As shown in Figures 2 and 3, the sixth baffle plate 50 has a partition surface 100 that divides the inside of the silencer body 20 into one side I, the seventh space 72 side, and the other side T, the sixth space 70. The partition surface 100 is formed in the same shape as the cross-sectional shape of the silencer body 20 (see Figure 3). A flange 102 extending toward the seventh space 72 side is formed around the entire periphery of the partition surface 100 (see Figures 1 and 2). The flange 102 is fixed to the inner surface of the silencer body 20 when the sixth baffle plate 50 is placed inside the silencer body 20 (see Figure 1).

[0024] As shown in Figure 3, a circular opening 104 is formed on the lower side of Figure 3, with the longitudinal center of the partition surface 100 as the boundary, for allowing exhaust gas G to flow into the seventh space 72, which is the one-sided space of one side I. The opening 104 allows the aforementioned introduction pipe 80 to be inserted, and the introduction pipe 80 is fixed to the sixth baffle plate 50 (see Figure 1).

[0025] As shown in Figures 2 and 3, a guide portion 106 is formed in the longitudinal center of the partition surface 100. The guide portion 106 is positioned offset to one side from the short-side center of the partition surface 100. Note that the guide portion 106 can also be located in the center of the partition surface 100 to obtain the effects described later.

[0026] The guide section 106 is formed in a funnel shape with the partition surface 100 recessed toward the sixth space 70, which is the other side T. As a result, the exhaust gas G that flows from the introduction pipe 80 into the seventh space 72 is guided to the guide section 106 along the surface of the partition surface 100 of the sixth baffle plate 50. The guide section 106 then guides the guided exhaust gas G to the connecting pipe 82 which is connected to the end that protrudes toward the sixth space 70, which is the other side T.

[0027] Specifically, the guide portion 106 has a cylindrical portion 110 to which the connecting pipe 82 is connected, a flared portion 112 that widens in diameter from the cylindrical portion 110 toward the partition surface 100, and a rounded curved portion 114 formed between the cylindrical portion 110 and the flared portion 112. Note that the guide portion 106 may also have a structure without the curved portion 114, as will be described later (see Figure 9).

[0028] (cylindrical part) The cylindrical portion 110 is formed in a cylindrical shape. A cylindrical connecting pipe 82 is connected to the cylindrical portion 110. Methods for connecting the cylindrical portion 110 and the connecting pipe 82 include fitting the end of the connecting pipe 82 into the cylindrical portion 110 (see Figure 4) and fitting the end of the connecting pipe 82 into the cylindrical portion 110 (see Figure 5).

[0029] (Flare section) The flared portion 112 is positioned offset to one side from the center of the partition surface 100 in the short direction. Therefore, the first length N1 of the flared portion 112 on one side in the short direction of the partition surface 100 is shorter than the second length N2 on the other side in the short direction of the partition surface 100 (see Figure 3).

[0030] The flare angle α, which is the angle formed between the central axis C of the connecting pipe 82 connected to the guide section 106 and the inner surface 112A of the flared section 112, is set within the range of 20 degrees to 70 degrees. Preferably, this flare angle α is set within the range of 30 degrees to 50 degrees.

[0031] Furthermore, if the flare angle α of the flared portion 112 exceeds 70 degrees, the flared portion 112 may come into contact with the outer edge of the partition surface 100, or the widened flared portion 112 may reach the adjacent opening 104. For this reason, the upper limit of the flare angle α is set to 70 degrees in order to ensure the appropriate shape of the flared portion 112.

[0032] (Curved surface part) The curved surface portion 114 has a corner radius (R) that indicates its curvature, which is set within the range of R3 to R40. It is preferable that this corner radius be set to the largest value within the range of R3 to R40, which is R40.

[0033] R3 represents the curve represented by a circular arc with a radius of 3 mm. R40 represents the curve represented by a circular arc with a radius of 40 mm.

[0034] Furthermore, if the radius of the corner of the curved portion 114 exceeds R40, the curved portion 114 will encroach upon the area of ​​the flared portion 112. For this reason, the upper limit of the radius of the corner of the curved portion 114 is set to R40 in order to properly form the curved portion 114 and maintain the shape of the flared portion 112.

[0035] (Evaluation results) Figure 6 shows the evaluation results, which are obtained from the perspective of the flare angle α and angle R of the guide section 106.

[0036] [Noise Reduction Evaluation Test] In the noise reduction evaluation test, a comparative product was set in the silencer 10, in which a cylindrical pipe was inserted through a baffle plate, and the tip of the cylindrical pipe, which had multiple small holes formed on its circumferential surface, protruded from the baffle plate. The airflow noise was then measured in the silencer 10 with the comparative product set in it.

[0037] Furthermore, a sixth baffle plate 50 with a predetermined flare angle α of the guide section 106 and a predetermined angle R was used as a simulation product. The airflow noise generated in the silencer 10 with the simulation product installed was analyzed by simulation and compared with a comparative product.

[0038] The predetermined angles for flare angle α were set to 5 degrees, 10 degrees, 20 degrees, 30 degrees, 35 degrees, 40 degrees, 50 degrees, 60 degrees, and 70 degrees. The predetermined values ​​for angle R at each flare angle α were set to R3, R10, R15, R20, and R40. The generated airflow noise was calculated based on the magnitude of vorticity analyzed for each simulated product.

[0039] In the noise reduction evaluation test, a silencer 10 equipped with the simulated product was deemed to pass if the airflow noise level was -3 dB(A) or less than that of the silencer 10 equipped with the comparison product.

[0040] As a result, the airflow noise level of all silencers 10 equipped with the simulation product was -3 dB(A) or less than that of the silencer 10 equipped with the comparison product, and therefore passed the test.

[0041] In other words, it was found that a silencer 10 in which the flare angle α of the guide portion 106 is within the range of 5 degrees to 70 degrees, and the corner radius R of the guide portion 106 is within the range of R3 to R40, has a higher sound-reducing effect than a silencer 10 equipped with a comparative product.

[0042] Furthermore, it was found that the sound-dampening effect of the silencer 10 with the simulated product installed was particularly high when the angle radius R was R40 and the flare angle α was between 40 and 60 degrees.

[0043] [Manufacturability Test] The manufacturability test evaluates manufacturability based on the rate of plate thickness reduction when forming the sixth baffle plate 50 by press forming a flat blank material.

[0044] The manufacturability test involves simulating and analyzing the rate of reduction in plate thickness when a blank material is press-formed with a predetermined flare angle α of the guide portion 106 and a predetermined corner radius.

[0045] Table T in Figure 6 shows the results based on the reduction rate of plate thickness when the predetermined flare angle α is 5 degrees, 10 degrees, 20 degrees, 30 degrees, 35 degrees, 40 degrees, 50 degrees, 60 degrees, and 70 degrees, and the predetermined values ​​of the angle R at each flare angle α are R3, R10, R15, R20, and R40.

[0046] In Table T, the specific values ​​for the rate of reduction in plate thickness are omitted, and the acceptable region P, where the rate of reduction in plate thickness is 30% or less, is indicated by a diagonal line.

[0047] According to this manufacturability test, silencers 10 with a flare angle α of the guide section 106 within the range of 20 degrees to 70 degrees and an angle radius (R) within the range of R3 to R15 were found to be acceptable. Furthermore, it was found that if the flare angle α of the guide section 106 was within the range of 30 degrees to 50 degrees, all silencers 10 were acceptable regardless of the angle radius (R) set within the range of R3 to R40.

[0048] Furthermore, considering the conditions in the noise reduction evaluation test where the angle R was R40 and the flare angle α was between 40 and 60 degrees, it was found that it is desirable to set the guide section 106 to the high-effectiveness region K, where the angle R is R40 and the flare angle α is between 40 and 50 degrees.

[0049] (Mechanism of Action and Effects) The above embodiment provides the following effects. The operation and effects of this embodiment will be explained with reference to Figures 7 and 8. Figure 7 is an explanatory diagram illustrating the flow of exhaust gas G. Figure 8 is a diagram showing the relationship between engine speed and airflow noise.

[0050] The silencer 10 of this embodiment comprises a silencer body 20, a sixth baffle plate 50 as a baffle plate that partitions the inside of the silencer body 20, and a connecting pipe 82 extending from the sixth baffle plate 50. The sixth baffle plate 50 comprises a partition surface 100 that partitions the inside of the silencer body 20 into one side I and the other side T, and an opening 104 formed in the partition surface 100 for allowing exhaust gas G to flow into the seventh space 72, which is the one-side space of the one-side I. The sixth baffle plate 50 has a funnel shape with the partition surface 100 recessed toward the other side T, and has a guide portion 106 that guides the exhaust gas G from the seventh space 72, which is the one-side space, to the connecting pipe 82 that protrudes toward the other side T.

[0051] In this configuration, the exhaust gas G sent to the seventh space 72 on one side I of the partition surface 100 of the sixth baffle plate 50 is guided to the connecting pipe 82 by a funnel-shaped guide portion 106 formed on the partition surface 100 (see Figure 7).

[0052] The exhaust gas G in the seventh space 72 is gently collected towards the center along the inner surface 112A of the guide section 106, which has a funnel-shaped opening that opens into the seventh space 72. Furthermore, the opening of the guide section 106 that opens into the seventh space 72 is wider than the pipe opening 82A at the end of the connecting pipe 82 (see Figure 7). As a result, the constriction 130 of the exhaust gas G that passes through the opening of the guide section 106 is suppressed. Consequently, the generation of vortices 132 in the constricted portion is reduced.

[0053] Therefore, the silencer 10 can suppress the generation of airflow noise compared to a case where, for example, an opening without a guide portion 106 cannot suppress the generation of vortices 132 caused by the constriction 130 of the exhaust gas G that has passed through the opening.

[0054] Figure 8 shows the relationship between the engine speed of the engine into which the exhaust gas G is introduced and the generated airflow noise for the porous structure silencer 140 and the silencer 10 of this embodiment. In the porous structure silencer 140, a connecting pipe 82 is inserted through a sixth baffle plate 50 which does not have a guide portion 106, and a plurality of small holes are formed on the circumferential surface of the connecting pipe 82 that protrudes from the sixth baffle plate 50.

[0055] Figure 8 confirms that the silencer 10 of this embodiment can reduce airflow noise in the high-speed region 144 compared to the porous silencer 140.

[0056] Furthermore, even when the flare angle α of the guide portion 106 of the silencer 10 was varied within the range of 20 degrees to 70 degrees and the angle R being between R3 and R40, characteristics equivalent to those shown in Figure 8 were obtained.

[0057] The silencer 10 of this embodiment further includes an introduction pipe 80 that is inserted into the opening 104 and guides the exhaust gas G flowing in from the upstream side to the seventh space 72, which is a one-sided space. The guide section 106 guides the exhaust gas G that has flowed from the introduction pipe 80 into the seventh space 72, which is a one-sided space, along the surface of the sixth baffle plate 50.

[0058] In this configuration, exhaust gas G from the upstream side is introduced into the seventh space 72 via an introduction pipe 80 inserted into the opening 104 of the sixth baffle plate 50. This allows exhaust gas G from the first space 60, which is far from the seventh space 72, to be introduced into the seventh space 72 via the introduction pipe 80.

[0059] In the silencer 10 of this embodiment, the guide portion 106 has a cylindrical portion 110 that is continuous with the connecting pipe 82, and a flared portion 112 that expands in diameter as it moves from the cylindrical portion 110 toward the partition surface 100.

[0060] In this configuration as well, the silencer 10 can suppress the generation of airflow noise.

[0061] In the silencer 10 of this embodiment, the flare angle α, which is the angle formed between the central axis C of the connecting pipe 82 as a pipe and the inner surface 112A of the flared portion 112, is between 20 degrees and 70 degrees (see Figure 2).

[0062] In this configuration, even if the corner radius of the guide portion 106 of the silencer 10 is set within the range of R3 to R15, it is possible to suppress the reduction in plate thickness when pressing a flat blank material to form the sixth baffle plate 50 to 30% or less. This makes it possible to guarantee the quality of the press-formed sixth baffle plate 50.

[0063] Furthermore, compared to the case where the flare angle α is set to less than 20 degrees, the silencer 10 can suppress the flow velocity of the exhaust gas G in the connecting pipe 82 and the vorticity of the vortices 132 generated in the connecting pipe 82, thereby suppressing the generated airflow noise.

[0064] Furthermore, since the flare angle α can be adjusted over a wide range of 20 to 70 degrees, it is possible to tune the airflow noise reduction effect while suppressing the generated airflow noise.

[0065] Furthermore, in the silencer 10 of this embodiment, the flare angle α is 30 degrees or more and 50 degrees or less.

[0066] In this configuration, even if the corner radius of the guide portion 106 of the silencer 10 is set within the range of R3 to R40, it is possible to suppress the reduction in plate thickness when pressing a flat blank material to form the sixth baffle plate 50 to 30% or less. This makes it possible to guarantee the quality of the press-formed sixth baffle plate 50.

[0067] Furthermore, the silencer 10 allows for a wider range of selectable angles (R) compared to when the flare angle α is set to between 20 and 70 degrees.

[0068] Furthermore, by setting the flare angle α of the silencer 10 to 30 degrees or more and 50 degrees or less, the vorticity of the vortices 132 generated in the connecting pipe 82 can be further suppressed, thereby enabling further reduction of the generated airflow noise.

[0069] In the silencer 10 of this embodiment, the guide portion 106 further has a curved portion 114 provided between the cylindrical portion 110 and the flared portion 112.

[0070] In this configuration, even if the silencer 10 has a curved portion 114 between the cylindrical portion 110 and the flared portion 112 of the guide portion 106, it is possible to suppress the generation of airflow noise in the same way as described above.

[0071] Furthermore, in the silencer 10 of this embodiment, the corner radius of the curved portion 114 is R3 or more and R40 or less.

[0072] In this configuration, the silencer 10 can suppress the flow velocity of the exhaust gas G in the connecting pipe 82 and the vorticity of the vortices 132 generated in the connecting pipe 82, compared to the case where the corner radius R of the curved portion 114 of the guide portion 106 is set to less than R3. This makes it possible to suppress the generated airflow noise.

[0073] Furthermore, since the radius of the corners of the curved section 114 can be adjusted over a wide range from R3 to R40, it becomes possible to tune the airflow noise reduction effect while suppressing the generated airflow noise.

[0074] In this embodiment, the muffler 10, specifically the sixth baffle plate 50, is a press-formed product formed by press molding.

[0075] In this configuration, since the sixth baffle plate 50 is a press-formed product, when press-forming the sixth baffle plate 50, it is possible to form a funnel-shaped guide portion 106 recessed to one side I and an opening 104 on the partition surface 100.

[0076] In this embodiment, an example of the configuration of the sixth baffle plate 50 of the silencer 10 is shown, but the sixth baffle plate 50 is not limited to this shape and may be configured as shown below.

[0077] (First torture) Figure 9 is a cross-sectional view showing the first modified example. Figure 10 is a side view of the baffle plate (50) of the first modified example. Figure 9 shows an enlarged cross-section of the sixth baffle plate 50.

[0078] As shown in Figures 9 and 10, the sixth baffle plate 50 of the silencer 200 according to the first modified example eliminates the curved portion 114 provided between the cylindrical portion 110 and the flared portion 112 of the guide portion 106, compared to the embodiment. Furthermore, in the sixth baffle plate 50 of the silencer 200 according to the first modified example, the flared portion 112 constituting the guide portion 106 is made of a curved surface.

[0079] To explain in more detail, the flared portion 112 of the sixth baffle plate 50 is formed in a curved shape so that when a plane is imagined passing through the central axis C (see Figure 9) of the connecting pipe 82, the cross-sectional shape along this plane protrudes toward the central axis C of the connecting pipe 82.

[0080] In the first modified example, the flare angle α is represented by the angle formed by the straight line 206 passing through the first contact point 202 where the flared portion 112 and the cylindrical portion 110 are in contact, and the second contact point 204 where the flared portion 112 and the partition surface 100 are in contact, and the central axis C of the connecting pipe 82.

[0081] The flare angle α is set within the range of 20 degrees to 70 degrees, similar to the embodiment. Preferably, this flare angle α is set within the range of 30 degrees to 50 degrees.

[0082] In this modified example, the same effects and advantages as in the previously described embodiment can be obtained, except for the portion where the curved surface portion 114 is formed between the cylindrical portion 110 and the flared portion 112.

[0083] Furthermore, in the silencer 10 of this embodiment, the flared portion 112 is formed in a curved shape with a cross-sectional shape that protrudes toward the central axis C of the connecting pipe 82, along a plane passing through the central axis C of the connecting pipe 82.

[0084] This configuration allows the silencer 10 to smoothly guide the exhaust gas G along the flared section 112.

[0085] Furthermore, in the silencer 10 of this embodiment, the flare angle α is the angle formed by the straight line 206 passing through the first contact point 202 where the flared portion 112 and the cylindrical portion 110 are in contact and the second contact point 204 where the flared portion 112 and the partition surface 100 are in contact, and the central axis C of the connecting pipe 82 as a pipe.

[0086] In this configuration, the silencer 10 can express the flare angle α as the angle formed by the aforementioned straight line 206 and the central axis C of the connecting pipe 82.

[0087] (Second variation) Figure 11 is a side view of the baffle plate (50) of the second modified example.

[0088] As shown in Figure 11, the guide portion 106 of the sixth baffle plate 50 of the silencer 210 in the second modified example has a shorter length of the flared portion 112 in the axial direction of the connecting pipe 82 compared to the first modified example.

[0089] In this modified example, the same effects and benefits as in the second modified example can be obtained.

[0090] (Third variation) Figure 12 is a cross-sectional view showing a third modified example.

[0091] In the third modified silencer 220, the sixth baffle plate 50 of the guide portion 106 expands in diameter as it approaches the connecting pipe 82. As a result, the cross-sectional shape of the cylindrical portion 110 becomes a curve or a free curve.

[0092] In this modified example, the same effects and advantages as those of the previously described embodiment can be obtained.

[0093] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0094] In other words, although the above-described embodiment explained the case in which the sixth baffle plate 50 and the connecting pipe 82 extending from the sixth baffle plate 50 are configured as separate components, the sixth baffle plate 50 and the connecting pipe 82 may be configured as a single unit. [Explanation of symbols]

[0095] 10, 200, 220 silencer 20 Silencer body 50. Sixth baffle plate (baffle plate) 72 Seventh Space 80 Inlet pipe 82 Connecting pipes (pipes) 100 partition surfaces 104 Opening 106 Information Department 110 Cylinder part 112 Flare section 112A Inner surface 114 Curved part α flare angle

Claims

1. It is a silencer, The silencer body and A baffle plate partitions the inside of the silencer body, A pipe extending from the aforementioned baffle plate, Equipped with, The aforementioned baffle plate is The silencer body has a partition surface that divides the inside into one side and the other side, An opening is formed in the partition surface to allow exhaust gas to flow to the one side space, The partition surface is funnel-shaped with a recess toward the other side, and includes a guide portion that guides the exhaust gas from the space on one side to the pipe extending toward the other side. Having, Silencer.

2. A silencer according to claim 1, The system further includes an introduction pipe inserted into the aforementioned opening, which guides exhaust gas flowing in from the upstream side into the one-sided space, In the guide section, the exhaust gas that flows from the introduction pipe into the one-sided space is guided along the surface of the baffle plate. Silencer.

3. A silencer according to claim 1, The aforementioned guide section is A cylindrical section continuous with the aforementioned pipe, A flared portion that expands in diameter from the cylindrical portion toward the partition surface, Having, Silencer.

4. A silencer according to claim 3, The flared portion is formed in a curved shape. Silencer.

5. A silencer according to claim 4, The flared portion is formed in a curved shape, with a cross-sectional shape along a plane passing through the central axis of the pipe that protrudes toward the central axis of the pipe. Silencer.

6. A silencer according to claim 3 or claim 4, The flare angle formed by the central axis of the pipe and the inner surface of the flared portion is between 20 degrees and 70 degrees. Silencer.

7. A silencer according to claim 6, The aforementioned flare angle is between 30 degrees and 50 degrees. Silencer.

8. A silencer according to claim 6, The aforementioned flare angle is the angle formed by the straight line passing through the first contact point where the flared portion and the cylindrical portion meet, the second contact point where the flared portion and the partition surface meet, and the central axis of the pipe. Silencer.

9. A silencer according to claim 3, The guide portion further has a curved portion provided between the cylindrical portion and the flared portion. Silencer.

10. A silencer according to claim 9, The radius radius (R) of the curved portion is between R3 and R40. Silencer.

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