Fluid piping

Abstract

This fluid piping comprises a piping body (16) through which a fluid flows thereinside and a partition plate (17) that divides the inside of the piping body into a plurality of flow channels in the axial direction (Y) of the piping body, wherein an end surface (171) on the upstream side of the partition plate includes: an inclined surface (173) that is inclined with respect to the axial direction of the piping body; a gradual sloping surface (172) that connects an end part (171a) of the end surface on the upstream side of the partition plate and an inner wall surface (161a) of the piping body; and a curved surface (174) that is continuous with the gradual sloping surface and has a uniform radius (R) of curvature in the axial direction of the piping body.

Description

Fluid Piping

[0001] The present invention relates to fluid piping.

[0002] An exhaust pipe structure is known in which a partition plate is provided inside a curved pipe section of an automobile muffler to divide the exhaust gas flow path into multiple flow paths along the extension direction of the curved pipe section (Patent Document 1).By providing a partition plate in the curved pipe section of the muffler, it is said that the exhaust gas passing through the curved pipe section is rectified and secondary flow occurring in the curved pipe section can be prevented or suppressed.

[0003] Japanese Patent Application Laid-Open No. 2004-116374

[0004] However, when a partition plate is installed in the exhaust gas flow path, the upstream end face of the partition plate has a thickness, which causes vortices in the air flow caused by the exhaust gas to occur around the end face, thereby hindering the straightening effect of the partition plate.

[0005] The problem to be solved by the present invention is to provide a fluid pipe that can suppress the impairment of the flow straightening effect of a partition plate provided in a fluid flow path.

[0006] The present invention solves the above problem by providing a fluid pipe having a partition plate that divides the inside of the pipe body into multiple flow paths, in which the upstream end face of the partition plate includes an inclined surface that is inclined with respect to the axial direction of the pipe body (or the radial direction of the pipe body).

[0007] According to the present invention, when the fluid flowing down toward the partition plate strikes the upstream end face of the partition plate, the fluid flows down along the inclined surface, so that the vortex of the airflow generated around the upstream end face of the partition plate can be eliminated while still small, before it grows large, thereby preventing the rectifying effect of the partition plate from being impaired.

[0008] Fig. 1 is a cross-sectional view showing one embodiment of an automotive muffler to which the fluid piping according to the present invention is applied. Fig. 2 is a cross-sectional view showing the tail pipe of Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III of Fig. 2. Fig. 4 is a plan view showing part A of Fig. 2. Fig. 5 is a plan view showing another embodiment of part A of Fig. 2. Fig. 6 is a plan view showing yet another embodiment of part A of Fig. 2. Fig. 7 is a plan view showing yet another embodiment of part A of Fig. 2. Fig. 8 is a plan view showing yet another embodiment of part A of Fig. 2.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The fluid pipe according to the present invention is a tubular member through which a gas, a liquid, or a gas-liquid mixture flows, and includes pipes made of various materials, such as metal pipes including iron, stainless steel, copper, and aluminum, synthetic resin pipes including vinyl chloride, polypropylene, polyethylene, and polyamide, and ceramic pipes including alumina and silicon nitride.

[0010] The fluid piping according to the present invention can be embodied and utilized as an exhaust pipe including a muffler for an automobile engine, a cooling water pipe for an automobile engine, a refrigerant pipe for an automobile air conditioner, or an air duct for an automobile air conditioner. When the fluid piping according to the present invention is utilized in an exhaust pipe including a muffler for an automobile engine, the fluid serves as exhaust gas discharged from the automobile engine. When the fluid piping according to the present invention is utilized in a cooling water pipe for an automobile engine, the fluid serves as cooling water for cooling the automobile engine. When the fluid piping according to the present invention is utilized in a refrigerant pipe for an automobile air conditioner, the fluid serves as refrigerant for the cooling cycle of the automobile air conditioner. When the fluid piping according to the present invention is utilized in an air duct for an automobile air conditioner, the fluid serves as conditioned air for the automobile air conditioner.

[0011] In the embodiments described below, the fluid piping according to the present invention is used in an exhaust pipe including a muffler of an automobile engine to explain the embodiment of the present invention, but the same configuration can be achieved and the same effects can be obtained when used in the cooling water piping of an automobile engine, the refrigerant piping of an automobile air conditioning system, or the air duct of an automobile air conditioning system.

[0012] Fig. 1 is a cross-sectional view showing one embodiment of an automotive muffler 1 incorporating fluid piping according to the present invention, with the automotive muffler 1 included in part of an exhaust pipe of an automotive engine. The automotive muffler 1 of this embodiment is a type that is mounted transversely relative to the fore-and-aft direction of the vehicle (the X direction in the drawing), and includes a cylindrical muffler body 11, a left end plate 12 that closes the left end of the muffler body 11, and a right end plate 13 that closes the right end of the muffler body 11. In each of Figs. 1 to 8, the fore-and-aft direction of the vehicle when the automotive muffler 1 of this embodiment is mounted on a vehicle is shown as the X direction, the left-and-right direction of the vehicle as the Y direction, and the up-and-down direction of the vehicle as the Z direction.

[0013] The automotive muffler 1 of this embodiment is provided with an inlet pipe 14 for introducing exhaust gas generated by the automotive engine into the muffler body 11, an outlet pipe 15 for directing the exhaust gas that has passed through the muffler body 11 to the outside, and a tail pipe 16 that is connected to the outlet pipe 15 and extends outside the muffler body 11 to discharge the exhaust gas into the atmosphere.

[0014] The muffler body 11 is formed in a cylindrical shape, and within the muffler body 11, from left to right, a first separator 111, a second separator 112, and a third separator 113 are provided, which divide the interior of the automotive muffler 1 into, from left to right, a first chamber 114, a second chamber 115, a third chamber 116, and a fourth chamber 117. A plurality of through holes (reference numerals omitted) are formed radially within the surfaces of each of the first separator 111, the second separator 112, and the third separator 113, and a through hole (reference numerals omitted) is formed approximately at the center of each of the first separator 111, the second separator 112, the third separator 113, and the right end plate 13, for passing the outlet pipe 15 therethrough.

[0015] The inlet pipe 14 is formed in a cylindrical shape and is inserted from the front of the vehicle through a through-hole (reference numeral omitted) provided in the wall surface of the muffler body 11, with its tip portion disposed in the third chamber 116 of the muffler body 11. In addition, the portion of the inlet pipe 14 located inside the muffler body 11 has a plurality of through-holes (reference numeral omitted) formed along its outer circumferential surface.

[0016] The outlet pipe 15 is formed in a cylindrical shape and extends in the left-right direction relative to the muffler body 11, passing through holes (numbers omitted) formed in the first separator 111, the second separator 112, the third separator 113, and the right end plate 13, with the inlet side opening end on the left side facing the first chamber 114.

[0017] The tail pipe 16 is formed by bending a cylindrical pipe into a quarter arc, and is formed so that the open end on the outlet side faces the rear of the vehicle. The open end on the inlet side of the tail pipe 16 is connected to the open end on the outlet side of the outlet pipe 15 at the position of the right end plate 13.

[0018] Exhaust gas emitted from the engine is introduced into the muffler body 11 through the inlet pipe 14 as shown by the arrows, and is then radially discharged into the third chamber 116 through a number of through-holes provided at the tip of the inlet pipe 14. Some of this exhaust gas is introduced into the second chamber 115 through through-holes formed in the second separator 112, while the remaining exhaust gas is first introduced into the fourth chamber 117 through through-holes formed in the third separator 113, then again through these through-holes into the third chamber 116, and then through through-holes formed in the second separator 112 into the second chamber 115. The exhaust gas introduced into the second chamber 115 is then introduced into the first chamber 114 through through-holes formed in the first separator 111, and then introduced into the outlet pipe 15 through an opening on the inlet side of the outlet pipe 15, passes through the tail pipe 16, and is discharged into the atmosphere through an opening on the outlet side of the tail pipe 16. In this way, exhaust gases repeatedly expand, contract, and interfere as they pass from the first chamber 114 through the fourth chamber 117, thereby reducing airflow noise, that is, performing a noise reduction process.

[0019] Next, the detailed structure of the rear end portion of the outlet pipe 15 and the tail pipe 16, which are the main parts of this embodiment, will be described with reference to Figures 2 and 3. The rear end portion of the outlet pipe 15 and the tail pipe 16 correspond to the piping main body according to the present invention, and the partition plate 17 described below corresponds to the partition plate according to the present invention.

[0020] Fig. 2 is a plan view showing the rear end of the outlet pipe 15 and the tail pipe 16, and Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. As shown in Fig. 2, the tail pipe 16 is made up of a first straight pipe section 161 connected to the rear end of the outlet pipe 15, a curved pipe section 162 that is continuous with the first straight pipe section 161 and has a substantially quarter-circular arc shape, and a second straight pipe section 163 that is continuous with the curved pipe section 162 and has an opening to the atmosphere.

[0021] As shown by hatching in Fig. 2 and indicated by reference numeral 17 in the cross-sectional view of Fig. 3, a partition plate 17 that divides the exhaust gas flow path into two is disposed in the center of the pipe along the extension direction of the curved pipe portion 162. In this embodiment, the partition plate 17 is disposed parallel to the X-Y plane with respect to the curved pipe portion 162, which is curved in an arc shape on the X-Y plane shown in Fig. 2. As a result, the two upper and lower exhaust gas flow paths divided by the partition plate 17 have equal volumes, and therefore the airflow resistance of the exhaust gas passing through the two flow paths is also equal.

[0022] In this way, by providing the partition plate 17 at the curved pipe portion 162 of the tail pipe 16, the flow of exhaust gas introduced through the outlet pipe 15 is rectified. As a result, secondary flows of the exhaust gas can be suppressed to make the flow uniform with little deviation, and airflow noise generated when the exhaust gas is released into the atmosphere at the open end on the outlet side can be reduced.

[0023] In this embodiment, the partition plate 17 does not necessarily need to be parallel to the curved pipe section 162, which is curved in an arc shape on the X-Y plane shown in FIG. 2 . It may be perpendicular to the X-Y plane or at a predetermined angle between parallel and perpendicular. Furthermore, the area in which the partition plate 17 is provided is not limited to the curved pipe section 162. It may be a portion of the curved pipe section 162, a portion of the first straight pipe section 161 including the curved pipe section 162, or a portion of the second straight pipe section 163 including the curved pipe section 162. It may even extend to the outlet pipe 15. However, if the length of the area in which the partition plate 17 is provided (the axial length of the piping) is too short, the flow straightening effect becomes insufficient, which is undesirable. Furthermore, if the length of the area in which the partition plate 17 is provided is too long, the airflow resistance caused by the partition plate 17 increases, which is undesirable. Therefore, it is desirable to provide the partition plate 17 within an appropriate area, taking into account the balance between the flow straightening effect and the airflow resistance.

[0024] Now, if the partition plate 17 is provided in a range including the curved pipe portion 162 of the fluid pipe through which a fluid such as exhaust gas flows, while the flow of the exhaust gas is rectified, vortices of the exhaust gas are generated around the upstream end face of the partition plate 17, which hinders the flow rectification effect of the partition plate 17 and increases the airflow resistance. This is because the partition plate 17 is a plate member and has a certain thickness. Therefore, in the fluid pipe of this embodiment, the upstream end face 171 of the partition plate 17 (the surface corresponding to the thickness of the plate) is configured to include an inclined surface 173 that is inclined with respect to the axial direction Y (or radial direction X) of the pipe body.

[0025] In the tail pipe 16 (corresponding to the fluid piping of the present invention) shown in Fig. 2, the upstream end face of the partition plate 17 means the upstream side in the direction in which exhaust gas flows downstream from the engine, and is indicated by the reference numeral 171 in Fig. 2. In contrast, the downstream end face of the partition plate 17 means the downstream side in the direction in which exhaust gas flows downstream from the engine, and is indicated by the reference numeral 176 in Fig. 2. In this embodiment, the shape of the downstream end face 176 of the partition plate 17 is not particularly limited, and may be perpendicular to the axial direction of the piping body or may be inclined.

[0026] Hereinafter, embodiments of the upstream end surface of the partition plate according to the present invention will be described with reference to Figures 4 to 8. Figures 4 to 8 are plan views showing embodiments of part A in Figure 2.

[0027] First Embodiment (FIG. 4) Figure 4 is a plan view corresponding to portion A in Figure 2, showing a first embodiment of an upstream end face of a partition plate according to the present invention. In the embodiment shown in Figure 4, the upstream end face 171 of the partition plate 17 includes a pair of gradually changing surfaces 172, 172, a pair of inclined surfaces 173, 173 continuous with each of the pair of gradually changing surfaces 172, 172, and a curved surface 174. In the upstream end face 171 of the partition plate 17 of this embodiment, one gradually changing surface 172, one inclined surface 173, the curved surface 174, the other inclined surface 173, and the other gradually changing surface 172 are continuously and smoothly connected from one end 171a of the end face 171 to the other end 171a.

[0028] The pair of gradually changing surfaces 172, 172 are surfaces that connect, by smooth curves, each of both end portions 171 a, 171 a of the upstream end face 171 of the partition plate 17 and each of the inner wall surfaces 161 a, 161 a of the piping main body (first straight pipe section 161 in the illustrated example). "Gradually changing" means that the inclination changes gradually, and the gradually changing surface 172 is a surface that is gradually angled on the end face 171 so as to smoothly connect to the inclined surface 173.

[0029] The pair of inclined surfaces 173, 173 are continuous with the pair of gradually changing surfaces 172, 172, respectively, and are linear surfaces that are inclined with respect to the axial direction Y or the radial direction X of the pipe main body toward the central portion 171 b of the upstream end face 171 of the partition plate 17. That is, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the axial direction Y of the first straight pipe section 161, which is the pipe main body. In other words, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the radial direction X of the first straight pipe section 161, which is the pipe main body. Furthermore, the curved surface 174 is continuous with the pair of inclined surfaces 173, 173, respectively, and is a surface that is curved convexly in the downstream direction of the pipe main body (the first straight pipe section 161 in the illustrated example), in other words, a U-shaped curved surface having a constant curvature (radius of curvature = R) along the axial direction Y of the pipe main body.

[0030] In a tailpipe 16 having a partition plate 17 configured as described above, when an airflow such as exhaust gas collides with the upstream end face 171 of the partition plate 17, a vortex of the exhaust gas airflow is generated around the end face 171. This vortex is indicated by a circular arrow E in FIG. 4 . The provision of an inclined surface 173 on the upstream end face 171 of the partition plate 17 generates the vortex E. The negative pressure generated by this vortex E causes the exhaust gas airflow to flow slightly downstream of the inclined surface 173 of the partition plate 17 and along the inclined surface 173 (indicated by arrow F in FIG. 4 ). This exhaust gas airflow F collides with small vortices E that have not yet grown around the end face 171 of the partition plate 17 immediately after they are generated around the end face 171 of the partition plate 17, allowing the vortex E to disappear while still small. This suppresses the generation of large vortices E1 (see the third embodiment shown in FIG. 6 ), thereby suppressing the airflow noise caused by the large vortex E1 and the increase in airflow resistance due to the generation of the large vortex.

[0031] Furthermore, by providing a gradually changing surface 172 at the end 171a of the upstream end face 171 of the partition plate 17, the airflow of exhaust gas that has flowed along the inner wall surface 161a of the tail pipe 16 is more likely to follow the inclined surface 173 of the partition plate 17. This allows the airflow F to flow closer to the end face 171 of the partition plate 17 where the vortex E is generated, and the airflows can collide while the vortex E is still small, causing the vortex E to disappear. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be improved.

[0032] Furthermore, by providing a curved surface 174 at the center portion 171b of the upstream end face 171 of the partition plate 17, the airflows F flowing from the respective inclined surfaces 173 are caused to converge coaxially at the center portion 171b, thereby reducing the speed of the airflow F and making the airflow speed approach zero, thereby suppressing collision with the inner wall surface 161a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0033] Second Embodiment (FIG. 5) FIG. 5 is a plan view corresponding to portion A in FIG. 2 , showing a second embodiment of the upstream end face of a partition plate according to the present invention. In the embodiment shown in FIG. 5 , the upstream end face 171 of the partition plate 17 includes one inclined surface 173 and a curved surface 174 continuous therewith, and the inclined surface 173 and the curved surface 174 are continuously connected from one end 171 a of the end face 171 to the other end 171 a. In this embodiment, the gradually changing surface 172 is not a constituent element. Furthermore, while the curved surface 174 is included, it is located at a position other than the central portion 171 b of the end face 171. Furthermore, the upstream end face 171 includes one inclined surface 173, but does not include a pair of inclined surfaces 173, 173.

[0034] The inclined surface 173 is connected to the inner wall surface 161a of the piping main body (the first straight pipe section 161 in the illustrated example) and is a linear surface that is inclined toward the opposing inner wall surface 161a with respect to the axial direction Y or the radial direction X of the piping main body. That is, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the axial direction Y of the first straight pipe section 161, which is the piping main body. In other words, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the radial direction X of the first straight pipe section 161, which is the piping main body. The curved surface 174 is a surface that is convexly curved in the downstream direction of the piping main body, with one end continuing to the inclined surface 173 and the other end connecting to the inner wall surface 161a of the piping main body (the first straight pipe section 161 in the illustrated example). In other words, it is a U-shaped curved surface with a constant curvature (radius of curvature = R) along the axial direction Y of the piping main body.

[0035] In a tailpipe 16 having a partition plate 17 configured as described above, when an airflow such as exhaust gas collides with the upstream end face 171 of the partition plate 17, a vortex of the exhaust gas airflow is generated around the end face 171. This vortex is indicated by a circular arrow E in FIG. 5 . The provision of an inclined surface 173 on the upstream end face 171 of the partition plate 17 generates the vortex E. The negative pressure generated by this vortex E causes the exhaust gas airflow to flow slightly downstream of the inclined surface 173 of the partition plate 17 and along the inclined surface 173 (indicated by arrow F in FIG. 5 ). This exhaust gas airflow F collides with small vortices E that have not yet grown around the end face 171 of the partition plate 17 immediately after they are generated around the end face 171 of the partition plate 17, allowing the vortex E to disappear while still small. This suppresses the generation of large vortices E1 (see the third embodiment shown in FIG. 6 ), thereby suppressing the airflow noise caused by the large vortex E1 and the increase in airflow resistance due to the generation of the large vortex.

[0036] Furthermore, by providing a curved surface 174 on the upstream end surface 171 of the partition plate 17, the airflow F flowing from the inclined surface 173 and the airflow F flowing from the curved surface 174 on the opposite side to the inclined surface 173 are joined together coaxially to reduce the speed of the airflow F, thereby making it possible to bring the airflow speed close to zero and suppress collision with the inner wall surface 161 a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0037] Third Embodiment (FIG. 6) FIG. 6 is a plan view corresponding to portion A in FIG. 2 , showing a third embodiment of the upstream end face of a partition plate according to the present invention. In the embodiment shown in FIG. 6 , the upstream end face 171 of the partition plate 17 includes one gradually changing surface 172, one inclined surface 173 continuous with the gradually changing surface 172, and one parallel surface 175 continuous with the inclined surface 173. The gradually changing surface 172, the inclined surface 173, and the parallel surface 175 are continuously connected from one end 171 a of the end face 171 to the other end 171 a. In this embodiment, the curved surface 174 is not a constituent element. Furthermore, the gradually changing surface 172 and the inclined surface 173 are included, but the pair of gradually changing surfaces 172, 172 and the pair of inclined surfaces 173, 173 are not included. Furthermore, the upstream end face 171 of the partition plate 17 includes a parallel surface 175 other than the gradually changing surface 172, the inclined surface 173, and the curved surface 174.

[0038] The gradually changing surface 172 is a surface that connects the end 171 a of the upstream end face 171 of the partition plate 17 and the inner wall surface 161 a of the piping main body (the first straight pipe section 161 in the illustrated example) with a smooth curve. "Gradually changing" means that the inclination changes gradually, and the gradually changing surface 172 is a surface that is gradually angled at the end face 171 so as to smoothly connect to the inclined surface 173. The inclined surface 173 is a linear surface that is continuous with the gradually changing surface 172 and inclined toward the other end 171 a of the upstream end face 171 of the partition plate 17 with respect to the axial direction Y or the radial direction X of the piping main body. That is, inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the axial direction Y of first straight pipe section 161, which is the piping main body, or in other words, inclined surface 173 is a surface inclined at an angle greater than 0° and less than 90° with respect to the radial direction X of first straight pipe section 161, which is the piping main body. Furthermore, parallel surface 175 is continuous with inclined surface 173 and is a linear surface that is parallel to the radial direction X of the piping main body (first straight pipe section 161 in the illustrated example).

[0039] In a tailpipe 16 having a partition plate 17 configured as described above, when an airflow such as exhaust gas collides with the upstream end face 171 of the partition plate 17, a vortex of the exhaust gas airflow is generated around the end face 171. This vortex is indicated by the circular arrow E in FIG. 6 . Around the parallel surface 175, the exhaust gas airflow vortex E changes from a small state to a large vortex E1. The generation of many such large vortices E1 increases airflow noise and airflow resistance. However, by providing the inclined surface 173 on the upstream end face 171 of the partition plate 17, the vortex E is generated. The negative pressure generated by this vortex E causes the exhaust gas airflow to flow along the inclined surface 173 of the partition plate 17 slightly downstream of the inclined surface 173 (indicated by the arrow F in FIG. 6 ). This exhaust gas airflow F collides with the small vortex E immediately after it is generated around the end face 171 of the partition plate 17 before it grows, and the small vortex E can be eliminated. Therefore, on the inclined surface 173, the generation of a large vortex E1 that occurs when a small vortex E grows can be suppressed, and the airflow noise caused by the large vortex E1 and the increase in air resistance due to the generation of the large vortex can be suppressed.

[0040] Furthermore, by providing a gradually changing surface 172 at the end 171a of the upstream end face 171 of the partition plate 17, the airflow of exhaust gas that has flowed along the inner wall surface 161a of the tail pipe 16 is more likely to follow the inclined surface 173 of the partition plate 17. This allows the airflow F to flow closer to the end face 171 of the partition plate 17 where the vortex E is generated, and the airflows can collide while the vortex E is still small, causing the vortex E to disappear. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be improved.

[0041] Fourth Embodiment (FIG. 7) FIG. 7 is a plan view corresponding to portion A in FIG. 2 , showing a fourth embodiment of the upstream end face of a partition plate according to the present invention. In the embodiment shown in FIG. 7 , the upstream end face 171 of the partition plate 17 includes one inclined surface 173 and one parallel surface 175 continuous with the inclined surface 173. The inclined surface 173 and the parallel surface 175 are continuously connected from one end 171 a of the end face 171 to the other end 171 a. In this embodiment, the gradually changing surface 172 and the curved surface 174 are not required as constituent elements. Furthermore, the inclined surface 173 is included, but the pair of inclined surfaces 173, 173 is not included. Furthermore, the upstream end face 171 of the partition plate 17 includes a parallel surface 175 other than the gradually changing surface 172, the inclined surface 173, and the curved surface 174.

[0042] The inclined surface 173 is continuous with the inner wall surface 161a of the piping main body (the first straight pipe section 161 in the illustrated example) and is a linear surface that is inclined with respect to the axial direction Y or the radial direction X of the piping main body toward the other end 171a of the upstream end face 171 of the partition plate 17. That is, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the axial direction Y of the first straight pipe section 161, which is the piping main body. In other words, the inclined surface 173 is a surface that is inclined at an angle greater than 0° and less than 90° with respect to the radial direction X of the first straight pipe section 161, which is the piping main body. Furthermore, the parallel surface 175 is continuous with the inclined surface 173 and is a linear surface that is parallel to the radial direction X of the piping main body (the first straight pipe section 161 in the illustrated example).

[0043] In a tailpipe 16 having a partition plate 17 configured as described above, when an airflow such as exhaust gas collides with the upstream end face 171 of the partition plate 17, a vortex of the exhaust gas airflow is generated around the end face 171. This vortex is indicated by the circular arrow E in FIG. 7 . Around the parallel surface 175, the exhaust gas airflow vortex E changes from a small state to a large vortex E1. The generation of many such large vortices E1 increases airflow noise and airflow resistance. However, by providing the inclined surface 173 on the upstream end face 171 of the partition plate 17, the vortex E is generated. The negative pressure generated by this vortex E causes the exhaust gas airflow to flow along the inclined surface 173 of the partition plate 17 slightly downstream of the inclined surface 173 (indicated by the arrow F in FIG. 7 ). This exhaust gas airflow F collides with the small vortex E immediately after it is generated around the end face 171 of the partition plate 17 before it grows, and the small vortex E can be eliminated. Therefore, on the inclined surface 173, the generation of a large vortex E1 that occurs when a small vortex E grows can be suppressed, and the airflow noise caused by the large vortex E1 and the increase in air resistance due to the generation of the large vortex can be suppressed.

[0044] Fifth Embodiment (FIG. 8) FIG. 8 is a plan view corresponding to portion A in FIG. 2 , showing a fifth embodiment of the upstream end face of a partition plate according to the present invention. In the embodiment shown in FIG. 8 , the upstream end face 171 of the partition plate 17 includes only one inclined surface 173, which is linearly continuous from one end of the end face 171 to the other end. In this embodiment, the gradually changing surface 172 and the curved surface 174 are not required as constituent elements. Furthermore, although the inclined surface 173 is included, the pair of inclined surfaces 173, 173 is not included. Furthermore, the parallel surfaces 175 other than the gradually changing surface 172, the inclined surface 173, and the curved surface 174 are not included.

[0045] The inclined surface 173 is a linear surface that is continuous with the inner wall surface 161a of the piping main body (the first straight pipe section 161 in the illustrated example) at both end portions 171a, 171a of the end face 171, and is inclined with respect to the axial direction Y or the radial direction X of the piping main body from one end portion 171a of the end face 171 on the upstream side of the partition plate 17 toward the other end portion 171a. That is, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the axial direction Y of the first straight pipe section 161, which is the piping main body. In other words, the inclined surface 173 is inclined at an angle greater than 0° and less than 90° with respect to the radial direction X of the first straight pipe section 161, which is the piping main body.

[0046] In a tailpipe 16 having a partition plate 17 configured in this manner, when an airflow such as exhaust gas collides with the upstream end face 171 of the partition plate 17, a vortex of the exhaust gas airflow is generated around the end face 171. This vortex is indicated by the circular arrow E in FIG. 8 . The provision of the inclined surface 173 on the upstream end face 171 of the partition plate 17 generates the vortex E, and the negative pressure generated by this vortex E causes the exhaust gas airflow to flow along the inclined surface 173 of the partition plate 17, slightly downstream of the inclined surface 173 (indicated by the arrow F in FIG. 8 ). This exhaust gas airflow F collides with small vortices E that have not yet grown around the end face 171 of the partition plate 17 immediately after they are generated around the end face 171 of the partition plate 17, allowing the vortex E to disappear while still small. Therefore, the inclined surface 173 can suppress the generation of large vortices E1 that result from the growth of small vortices E, thereby suppressing the airflow noise caused by the large vortex E1 and the increase in airflow resistance due to the generation of large vortices. Around one end 171a of the inclined surface 173 (the upper end 171a shown in FIG. 8), the vortex E of the airflow caused by the exhaust gas changes from a small state to a large vortex E1.

[0047] As described above, in the fluid piping of this embodiment, which includes the tail pipe 16 through which the fluid flows and the partition plate 17 that divides the interior of the tail pipe 16 into a plurality of flow paths, the upstream end face 171 of the partition plate 17 includes the inclined surface 173 that is inclined with respect to the axial direction Y or the radial direction X of the piping body, so that the exhaust gas airflow F flows along the inclined surface 173 of the partition plate 17 and collides with small vortices E that have not yet grown immediately after they are generated around the end face 171 of the partition plate 17, thereby eliminating the small vortices E. This makes it possible to suppress the airflow noise caused by large vortices E1 and the increase in airflow resistance due to the generation of large vortices.

[0048] Furthermore, in the fluid piping of this embodiment, the inclined surface 173 includes a gradually changing surface 172 that connects the end 171a of the upstream end face 171 of the partition plate 17 and the inner wall surface 161a of the tail pipe 16, so that the airflow of exhaust gas that has flowed along the inner wall surface 161a of the tail pipe 16 is more likely to follow the inclined surface 173 of the partition plate 17. This allows the airflow F to flow closer to the end face 171 of the partition plate 17 where the vortex E is generated, thereby eliminating the small vortex E. As a result, the airflow noise caused by the large vortex E1 and the increase in ventilation resistance due to the generation of the large vortex can be suppressed.

[0049] Furthermore, in the fluid piping of this embodiment, the upstream end face 171 of the partition plate 17 is continuous with the inclined surface 173 and includes a curved surface 174 of a constant curvature R along the axial direction Y of the tail pipe 16. Therefore, the airflow F flowing from one side of the curved surface and the airflow F flowing from the other side are caused to merge coaxially, thereby reducing the speed of the airflow F and bringing the airflow speed close to zero, thereby suppressing collision with the inner wall surface 161 a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0050] Furthermore, in the fluid piping of this embodiment, the upstream end face 171 of the partition plate 17 includes inclined surfaces 173, 173 that are inclined from both end portions 171 a, 171 a of the end face 171 toward the center portion 171 b, so that the airflow F flowing from one side of the inclined surface 173 and the airflow F flowing from the other side are merged to reduce the speed of the airflow F, thereby making the airflow speed approach zero and suppressing collision with the inner wall surface 161 a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0051] Furthermore, in the fluid piping of this embodiment, the upstream end face 171 of the partition plate 17 includes a pair of inclined surfaces 173, 173 that are inclined from both end portions 171 a, 171 a of the end face 171 toward the central portion 171 b, and a curved surface 174 that is continuous with each of the pair of inclined surfaces 173, 173 and has a constant radius of curvature R along the axial direction Y of the tail pipe 16. Therefore, the airflow F flowing from one of the inclined surface 173 and the curved surface 174 and the airflow F flowing from the other are coaxially merged to reduce the speed of the airflow F, thereby making it possible to reduce the speed of the airflow F to near zero and suppress collision with the inner wall surface 161 a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0052] In addition, in the fluid piping of this embodiment, the upstream end face 171 of the partition plate 17 includes a pair of gradually changing surfaces 172, 172 connecting each of the two end portions 171a, 171a of the end face 171 to each of the inner wall surfaces 161a, 161a of the tail pipe 16, a pair of inclined surfaces 173, 173 that are continuous with each of the pair of gradually changing surfaces 172, 172 and each inclined toward the central portion 171b of the end face 171, and a curved surface 174 that is continuous with each of the pair of inclined surfaces 173, 173 and has a constant radius of curvature R that runs along the axial direction Y of the tail pipe 16.Therefore, the airflow of exhaust gas that flows along the inner wall surface 161a of the tail pipe 16 is more likely to follow the inclined surface 173 of the partition plate 17. Furthermore, by causing the airflow F flowing from one of the inclined surface 173 and the curved surface 174 and the airflow F flowing from the other to merge coaxially, the speed of the airflow F can be reduced, thereby making the airflow speed approach zero and suppressing collision with the inner wall surface 161 a of the tail pipe 16. As a result, the function of suppressing increases in airflow noise and ventilation resistance can be further improved.

[0053] Furthermore, in the fluid piping of this embodiment, the inclined surface 173 extends from one end 171 a to the other end 171 a of the upstream end face 171 of the partition plate 17, so that small vortices E can be eliminated over the entire area of ​​the upstream end face 171 of the partition plate 17. This makes it possible to suppress the airflow noise caused by large vortices E1 and the increase in airflow resistance due to the generation of large vortices.

[0054] The outlet pipe 15 or the tail pipe 16 in the above embodiment corresponds to the piping body of the present invention.

[0055] DESCRIPTION OF SYMBOLS 1...Automotive muffler 11...Muffler body 12...Left end plate 13...Right end plate 14...Inlet pipe 15...Outlet pipe 16...Tail pipe 161...First straight pipe section 162...Bent pipe section 163...Second straight pipe section 17...Partition plate 171...Upstream end face 171a...End portion 171b...Central portion 172...Gradually changing surface 173...Inclined surface 174...Curved surface 175...Parallel surface 176...Downstream end face

Claims

1. (delete)

2. A fluid pipe comprising a pipe body through which a fluid flows, and a partition plate that divides the inside of the pipe body into a plurality of flow paths along the axial direction of the pipe body, an upstream end surface of the partition plate being an inclined surface inclined with respect to the axial direction of the piping body; A fluid pipe including a gradually changing surface connecting an end of the inclined surface and an inner wall surface of the pipe body.

3. A fluid pipe comprising a pipe body through which a fluid flows, and a partition plate that divides the inside of the pipe body into a plurality of flow paths along the axial direction of the pipe body, A fluid pipe wherein the upstream end face of the partition plate includes a linear inclined surface inclined with respect to the axial direction of the pipe body, and a curved surface continuous with the linear inclined surface and curved in the downstream direction of the pipe body.

4. The fluid pipe according to claim 3 , wherein the upstream end face of the partition plate includes the linear inclined surfaces that are inclined from both ends of the end face toward the center.

5. The upstream end surface of the partition plate is a pair of linear inclined surfaces inclined from both ends of the end surface toward a center portion thereof; The fluid pipe according to claim 3 or 4, further comprising: a curved surface that is continuous with each of the pair of linear inclined surfaces and curves in a downstream direction of the pipe body.

6. The upstream end surface of the partition plate is A pair of gradually changing surfaces connecting both end portions of the end surface and inner wall surfaces of the piping main body, a pair of inclined surfaces each continuing from the pair of gradually changing surfaces and inclined toward a center portion of the end surface; The fluid pipe according to claim 2 , further comprising: a curved surface that is continuous with each of the pair of inclined surfaces and curves in a downstream direction of the pipe body.

7. A fluid pipe comprising a pipe body through which a fluid flows, and a partition plate that divides the inside of the pipe body into a plurality of flow paths along the axial direction of the pipe body, The upstream end surface of the partition plate is an inclined surface extending from one end of the end surface toward the other end and inclined linearly with respect to the axial direction of the piping body; a linear parallel surface, one end of which is continuous with the inclined surface and the other end of which extends to the other end of the end surface, and which is parallel to the radial direction of the pipe body.

8. The fluid piping according to any one of claims 2 to 7, wherein the fluid is exhaust gas from an automobile engine, cooling water from an automobile engine, a refrigerant for a cooling cycle of an automobile air conditioner, or conditioned air from an automobile air conditioner.

9. The fluid piping according to any one of claims 2 to 7, which is used as an exhaust pipe including a muffler of an automobile engine, a cooling water piping of an automobile engine, a refrigerant piping of an automobile air conditioning system, or an air duct of an automobile air conditioning system.