Intake Manifold

Abstract

To provide an intake manifold that can suppress the deterioration of function. [Solution] The intake manifold 10 has a curved passage 14 that extends in a curved direction. The curved passage 14 is composed of a first divided body 20 and a second divided body 30 that are divided in the longitudinal direction of the curved passage 14 and welded to each other via a welding portion 70. The welding portion 70 has a main welding portion 71 and a sub-welded portion 72. The main welding portion 71 extends in an annular shape in the circumferential direction of the curved passage 14. The sub-welded portion 72 is located at a position radially away from the main welding portion 71 of the curved passage 14 and is provided on the inner circumferential side of the curved passage 14 in the curvature direction.

Description

Technical Field

[0001] The present invention relates to an intake manifold.

Background Art

[0002] Patent Document 1 discloses an intake manifold that supplies intake air to an internal combustion engine. The intake manifold includes a surge tank into which intake air is introduced, and an intake pipe portion that extends curvedly from the surge tank. The end of the intake pipe portion is attached to the cylinder head of the internal combustion engine.

[0003] The intake pipe portion is composed of a plurality of cylindrical divided materials divided in the length direction of the intake pipe portion. The plurality of divided materials are welded to each other.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Bending stress caused by vehicle vibration, collision, etc. may act on the intake manifold. In the intake manifold described in Patent Document 1, when bending stress acts on the intake pipe portion so that the curvature of the intake pipe portion becomes smaller, stress concentration is likely to occur in the inner peripheral side portion in the bending direction of the intake pipe portion. As a result, there is a possibility that the welded portion between the divided materials peels off. When the welded portion peels off, since the intake pipe portion communicates with the outside, the function of supplying intake air to the internal combustion engine in the intake manifold may deteriorate.

[0006] Such problems are not limited to the intake pipe portion attached to the cylinder head, but also occur in the same manner in the curved and extending portions of the intake manifold. [Means for solving the problem]

[0007] An intake manifold for solving the above problems is an intake manifold having a curved flow path that extends in a curved manner, wherein the curved flow path is composed of a first divided body and a second divided body that are divided in the longitudinal direction of the curved flow path and welded to each other via a welded portion, and the welded portion has a main welded portion that extends annularly in the circumferential direction of the curved flow path and a secondary welded portion that is located at a position away from the main welded portion in the radial direction of the curved flow path and is provided on the inner circumferential side of the curved flow path in the curvature direction.

[0008] In the inner circumference portion of a curved channel in the direction of curvature, stress concentration is likely to occur when bending stress is applied in such a way that the curvature of the curved channel becomes smaller. According to the above configuration, the secondary weld is located at a position radially away from the main weld in the curved flow path, and is provided on the inner circumferential side of the curved flow path in the direction of curvature. Therefore, in the inner circumferential side of the curved flow path, the welding strength of the weld is increased by both the main weld and the secondary weld. As a result, when bending stress acts on the curved flow path in such a way that the curvature of the curved flow path decreases, the degree of stress concentration in the inner circumferential side of the curved flow path can be reduced. Therefore, delamination of the weld can be suppressed. Consequently, a decrease in the function of the intake manifold can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing an intake manifold of one embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the curved flow path of the intake manifold in Figure 1. [Figure 3] Figure 3 is an enlarged cross-sectional view showing the welded area in Figure 2. [Figure 4] Figure 4 is a bottom view showing the first divided section of the intake manifold shown in Figure 1. [Figure 5]Figure 5 is a plan view showing the second segment of the intake manifold shown in Figure 1. [Figure 6] Figure 6 is a cross-sectional view of the intake manifold along the line 6-6 in Figure 4. [Modes for carrying out the invention]

[0010] An embodiment of the intake manifold will be described below with reference to Figures 1 to 6. (Overall configuration of intake manifold 10) The intake manifold 10 shown in Figure 1 supplies intake air to, for example, a horizontally opposed type internal combustion engine for a vehicle. The intake manifold 10 is made of a resin material.

[0011] The intake manifold 10 comprises a surge tank 11, an inlet pipe 12, and a number of branch pipes 13. For example, the intake manifold 10 may have four branch pipes 13.

[0012] As shown in Figure 2, the surge tank 11 has an inlet 11a into which intake air is introduced. The inlet 11a opens into the bottom wall of the surge tank 11. The intake pipe 12 extends downward from the surge tank 11 and then bends and extends diagonally upward. The intake pipe 12 extends cantilevered from the surge tank 11. The intake pipe 12 has a communication hole 12a that communicates with the inlet 11a. The communication hole 12a opens upward. The intake pipe 12 is connected to a throttle body 100 which houses a throttle valve (not shown). The intake pipe 12 introduces intake air flowing inside the throttle body 100 into the surge tank 11 through the communication hole 12a.

[0013] As shown in Figure 1, two of the four branch pipes 13 extend in the vehicle width direction from one side of the surge tank 11 in the vehicle width direction and then bend downwards. The remaining two branch pipes 13 extend in the vehicle width direction from the side of the surge tank 11 opposite to the one side in the vehicle width direction and then bend downwards. The lower end of each branch pipe 13 is connected to the intake port (not shown) of the internal combustion engine.

[0014] The intake manifold 10 is constructed by welding together a first section 20, a second section 30, a third section 40, a fourth section 50, and two fifth sections 60. The first section 20 constitutes the lower part of the surge tank 11 and the lower part of each branch pipe 13. The second section 30 constitutes the downstream part of the inlet pipe 12 having a communication hole 12a. The third section 40 constitutes the upstream part of the inlet pipe 12 connected to the throttle body 100. The fourth section 50 constitutes the upper part of the surge tank 11 and the upper part of each branch pipe 13. One of the two fifth sections 60 constitutes the lower end of the two branch pipes 13 extending from one side of the surge tank 11. The other of the two fifth sections 60 constitutes the lower end of the two branch pipes 13 extending from the side opposite to the side of the surge tank 11.

[0015] As shown in Figure 2, the first segment 20 and the second segment 30 are welded to each other via a welding portion 70. The second segment 30 and the third segment 40 are welded to each other via a welding portion 80. The first segment 20 and the fourth segment 50 are welded to each other via a welding portion 90. The first segment 20 and each fifth segment 60 are welded to each other via a welding portion (not shown). The welding portion 70 is an example of a "welded portion".

[0016] (Configuration of the curved channel 14) The intake manifold 10 has a curved flow path 14 that extends in a curved manner. The curved flow path 14 is composed of a surge tank 11 and an introduction pipe 12 that extends from the surge tank 11 in a bent manner. More specifically, the curved flow path 14 is divided in the length direction of the curved flow path 14 and is composed of a first divided body 20, a second divided body 30, a third divided body 40, and a fourth divided body 50 that are welded to each other.

[0017] In the curved flow path 14, the flow direction of the intake air flowing through the introduction pipe 12 and the flow direction of the intake air flowing through the surge tank 11 are different from each other. The first divided body 20 and the second divided body 30 are divided at the corner where the flow direction of the intake air in the curved flow path 14 changes.

[0018] (Configuration of the welding portion 70) The welding portion 70 has a main welding portion 71 and a sub-welding portion 72. The main welding portion 71 extends annularly in the circumferential direction of the curved flow path 14. The main welding portion 71 seals the boundary portion between the first divided body 20 and the second divided body 30 in the curved flow path 14 over the entire circumference of the curved flow path 14. The sub-welding portion 72 is provided at a position separated from the main welding portion 71 in the radial direction of the curved flow path 14. The sub-welding portion 72 is provided only on the inner peripheral side portion in the bending direction of the curved flow path 14. The cross-sectional shape of the sub-welding portion 72 orthogonal to the length direction of the curved flow path 14 is a rectangular shape with rounded corners. The sub-welding portion 72 joins the first divided body 20 and the second divided body 30. The sub-welding portion 72 does not seal the boundary portion between the first divided body 20 and the second divided body 30 in the curved flow path 14.

[0019] As shown in FIG. 3, the first divided body 20 has a first main welding convex portion 21 that constitutes the main welding portion 71 and a first sub-welding convex portion 22 that constitutes the sub-welding portion 72. The first main welding convex portion 21 protrudes from the peripheral edge portion 20a surrounding the inlet 11a toward the second divided body 30. The first sub-welding convex portion 22 protrudes from the peripheral edge portion 20a toward the second divided body 30. The first main welding convex portion 21 is an example of a "main welding convex portion". The first sub-welding convex portion 22 is an example of a "sub-welding convex portion".

[0020] As shown in Figure 4, the first main welding projection 21 is annular in shape, surrounding the inlet 11a. The first secondary welding projection 22 is located radially away from the first main welding projection 21 in the curved channel 14, and is provided on the inner circumferential side of the curved channel 14 in the direction of curvature. The cross-sectional shape of the first secondary welding projection 22, which is perpendicular to the longitudinal direction of the curved channel 14, is rectangular in shape with a long side extending in the circumferential direction of the first main welding projection 21 and rounded corners. In Figure 4, the welded surfaces of the first main welding projection 21 and the first secondary welding projection 22 are illustrated with dot hatching.

[0021] The first segmented body 20 has a first outer peripheral rib 23 that covers the first sub-welded projection 22 from the side. The first outer peripheral rib 23 includes a portion that covers the first sub-welded projection 22 from the side opposite to the first main welded projection 21, and portions that cover both ends of the first sub-welded projection 22 in the longitudinal direction. The first outer peripheral rib 23 is not provided between the first sub-welded projection 22 and the first main welded projection 21. A gap G1 is provided throughout the entire space between the first outer peripheral rib 23 and the first sub-welded projection 22.

[0022] As shown in Figure 3, the second divided body 30 has a second main welding projection 31 that constitutes the main welding portion 71 and a second secondary welding projection 32 that constitutes the secondary welding portion 72. The second main welding projection 31 protrudes toward the first divided body 20 from the peripheral edge 30a surrounding the communication hole 12a. The second secondary welding projection 32 protrudes toward the first divided body 20 from the peripheral edge 30a.

[0023] As shown in Figure 5, the second main welding projection 31 is annular in shape, surrounding the communication hole 12a. The width of the second main welding projection 31 is greater than the width of the first main welding projection 21. The second sub-welding projection 32 is located radially away from the second main welding projection 31 in the curved channel 14, and is provided on the inner circumferential side of the curved channel 14 in the direction of curvature. The cross-sectional shape of the second sub-welding projection 32, which is perpendicular to the longitudinal direction of the curved channel 14, is rectangular with a long side extending in the circumferential direction of the second main welding projection 31 and rounded corners. The long and short sides of the second sub-welding projection 32 are greater than the long and short sides of the first sub-welding projection 22. In Figure 5, the welded surfaces of the second main welding projection 31 and the second sub-welding projection 32 are shown using dot hatching.

[0024] The second divided body 30 has a second outer peripheral rib 33 that covers the second sub-welded projection 32 from the side. The second outer peripheral rib 33 includes a portion that covers the second sub-welded projection 32 from the side opposite to the second main welded projection 31, and portions that cover both ends of the second sub-welded projection 32 in the longitudinal direction. The second outer peripheral rib 33 is not provided between the second sub-welded projection 32 and the second main welded projection 31. A gap G2 is provided throughout the entire space between the second outer peripheral rib 33 and the second sub-welded projection 32.

[0025] As shown in Figure 3, in the main welded portion 71, the first main welded projection 21 and the second main welded projection 31 are joined to each other by vibration welding with their butt joints extending around the entire circumference. In the secondary welded portion 72, the first secondary welded projection 22 and the second secondary welded projection 32 are joined to each other by vibration welding with their butt joints extending around the entire circumference.

[0026] (Configuration of the connecting protrusion 24) As shown in Figure 4, the first divided body 20 has a plurality of connecting protrusions 24 that connect the first main welded protrusion 21 and the first sub-welded protrusion 22. The first divided body 20 has, for example, two connecting protrusions 24 that are spaced apart from each other in the circumferential direction of the curved flow channel 14. The two connecting protrusions 24 are connected to both ends of the first sub-welded protrusion 22 in the long side direction. Each connecting protrusion 24 protrudes downward from the lower surface of the peripheral edge 20a. Each connecting protrusion 24 extends linearly in the radial direction of the curved flow channel 14.

[0027] As shown in Figure 6, the amount of protrusion from the peripheral edge 20a of the two connecting protrusions 24 is smaller than the amount of protrusion from the peripheral edge 20a of the first sub-welded protrusion 22, and is also different from that of the other. Here, in this embodiment, the amount of protrusion from the peripheral edge 20a of the first sub-welded protrusion 22 gradually increases from the first end in the long-side direction of the first sub-welded protrusion 22 toward the second end opposite to the first end. This is due to the fact that the tip surface of the first sub-welded protrusion 22 before welding is inclined with respect to the surface direction of the peripheral edge 20a. The amount of protrusion from the peripheral edge 20a of the connecting protrusion 24 connected to the second end of the first sub-welded protrusion 22 is larger than the amount of protrusion from the peripheral edge 20a of the connecting protrusion 24 connected to the first end of the first sub-welded protrusion 22.

[0028] (Composition of Bari-tama 25) As shown in Figures 3 and 6, the first divided body 20 has a burr reservoir 25 formed therein for accumulating burrs generated during the welding of the welded portion 70. The burrs are formed around the welded portion 70 when a portion of the molten resin solidifies. The burr reservoir 25 is formed by a first main welded projection 21, a first sub-welded projection 22, and two connecting projections 24. The burr reservoir 25 is a recess that opens toward the second divided body 30. As shown in Figure 3, the gap G1 provided between the first outer peripheral rib 23 and the first sub-welded projection 22, and the gap G2 provided between the second outer peripheral rib 33 and the second sub-welded projection 32 also function as burr reservoirs.

[0029] (Configuration of welded portion 80 and welded portion 90) As shown in Figure 2, the welded portion 80 is formed, similar to the welded portion 70, by welding together annular protrusions that protrude from the second divided body 30 and the third divided body 40 and face each other.

[0030] The welded portion 90 is formed in the same way as the welded portion 70, by welding together the convex portions that protrude from the first divided body 20 and the fourth divided body 50 and face each other. The welded portion 90 has a main welded portion 91 and a sub-welded portion 92. The main welded portion 91 extends in an annular shape along the outer circumference of the boundary between the first divided body 20 and the fourth divided body 50. The main welded portion 91 seals the boundary between the first divided body 20 and the fourth divided body 50 in the curved flow channel 14 over its entire circumference. The sub-welded portion 92 is located radially away from the main welded portion 91 in the curved flow channel 14 and is provided on the inner circumference side in the curved direction of the curved flow channel 14. The sub-welded portion 92 joins the first divided body 20 and the fourth divided body 50. The sub-welded portion 92 does not seal the boundary between the first divided body 20 and the fourth divided body 50 in the curved flow channel 14.

[0031] The portion of the main welded section 91 that extends along the inlet 11a is located on the opposite side of the main welded section 71 in the welding direction between the first divided body 20 and the fourth divided body 50. The sub-welded section 92 is located on the opposite side of the sub-welded section 72 in the welding direction between the first divided body 20 and the fourth divided body 50. Therefore, the inner circumference portion of the curved flow channel 14 in the curvature direction is provided with a sub-welded section 72 where the first divided body 20 and the second divided body 30 are welded together, and a sub-welded section 92 where the first divided body 20 and the fourth divided body 50 are welded together.

[0032] <Operation of this embodiment> In the inner circumference portion of the curved channel 14 in the direction of curvature, stress concentration is likely to occur when bending stress acts on the curved channel 14 in such a way that the curvature of the curved channel 14 becomes smaller. As shown in Figure 2, for example, when a downward external force F acts on the inlet pipe 12 due to vibration of the throttle body 100, the bending stress acting on the curved channel 14 becomes significant.

[0033] In the intake manifold 10 of this embodiment, the sub-welded portion 72 is located at a position radially away from the main welded portion 71 in the curved flow path 14, and is provided on the inner circumference side of the curved flow path 14 in the curvature direction. Therefore, in the inner circumference side of the curved flow path 14, the welding strength of the welded portion 70 is increased by both the main welded portion 71 and the sub-welded portion 72. As a result, when bending stress is applied to the curved flow path 14 in such a way that the curvature of the curved flow path 14 decreases, the degree of stress concentration in the inner circumference side of the curved flow path 14 can be reduced. Therefore, delamination of the welded portion 70 can be suppressed.

[0034] Incidentally, since the main welded portion 71 seals the boundary between the first divided body 20 and the second divided body 30 in the curved passage 14, it is undesirable for the main welded portion 71 to peel off in order to maintain the function of the intake manifold 10 in supplying intake air to the internal combustion engine. On the other hand, the sub-welded portion 72 is located at a position radially away from the main welded portion 71 in the curved passage 14, and therefore does not seal the boundary. For this reason, even if the sub-welded portion 72 peels off due to the bending stress, the function of the intake manifold 10 can be maintained as long as the main welded portion 71 does not peel off.

[0035] <Effects of this embodiment> (1) The intake manifold 10 has a curved passage 14 that extends in a curved direction. The curved passage 14 is composed of a first divided body 20 and a second divided body 30 that are divided in the longitudinal direction of the curved passage 14 and welded to each other via a welding portion 70. The welding portion 70 has a main welding portion 71 and a sub-welding portion 72. The main welding portion 71 extends in an annular shape in the circumferential direction of the curved passage 14. The sub-welding portion 72 is located at a position radially away from the main welding portion 71 of the curved passage 14 and is provided on the inner circumferential side of the curved passage 14 in the curvature direction.

[0036] According to the above configuration, the above-described effects can be achieved, thereby suppressing a decrease in the function of the intake manifold 10. (2) The first divided body 20 has a connecting projection 24 that connects the first main welding projection 21 and the first sub-welding projection 22.

[0037] According to the above configuration, since the first main welding projection 21 and the first sub-welding projection 22 are connected by the connecting projection 24, the rigidity of the first main welding projection 21 and the first sub-welding projection 22 is increased. As a result, when bending stress is applied to the curved flow channel 14 in such a way that the curvature of the curved flow channel 14 becomes smaller, the first main welding projection 21 and the first sub-welding projection 22 become less prone to deformation. Therefore, peeling of the welded portion 70 can be further suppressed.

[0038] (3) The first divided body 20 has two connecting protrusions 24 that are spaced apart from each other in the circumferential direction of the curved flow channel 14. The first divided body 20 has a burr reservoir 15 formed by the first main welding protrusion 21, the first sub-welding protrusion 22, and the two connecting protrusions 24, which accumulate burrs generated during welding of the welded portion 70.

[0039] For example, if the first main welding protrusion 21 and the first sub-welding protrusion 22 are connected by a single connecting protrusion 24 extending in the circumferential direction, the connecting protrusion 24 will be located in the space between the first main welding protrusion 21 and the first sub-welding protrusion 22. Therefore, the larger the area where the connecting protrusion 24 is located, the more difficult it may be for burrs generated around the welding portion 70 during welding to be discharged between the first main welding protrusion 21 and the first sub-welding protrusion 22. If burrs remain on the welded surface of the welding portion 70 due to insufficient burr discharge, the strength of the welding portion 70 may decrease.

[0040] In this regard, according to the above configuration, a burr accumulation area 25 is formed on the first divided body 20 by the first main welding projection 21, the first sub-welding projection 22, and the multiple connecting projections 24. Therefore, the aforementioned problems can be suppressed.

[0041] (4) The cross-sectional shape of the secondary welded portion 72 perpendicular to the longitudinal direction of the curved flow channel 14 is a polygonal shape with rounded corners. According to the above configuration, when bending stress is applied to the curved channel 14 in such a way that the curvature of the curved channel 14 decreases, the degree of stress concentration that occurs in the sub-welded portion 72 can be reduced. Therefore, peeling of the welded portion 70 can be suppressed.

[0042] (5) The secondary welding portion 72 is provided only on the inner circumference side in the curvature direction of the curved flow channel 14. According to the above configuration, for example, compared to a case where the sub-welded portion 72 is provided on the outer circumference side of the curved flow path 14 in addition to the inner circumference side of the curved flow path 14, it is possible to suppress an increase in the size of the welded portion 70 in the radial direction of the curved flow path 14. Therefore, it is possible to suppress an increase in the size of the intake manifold 10.

[0043] (6) The curved channel 14 is composed of a first divided body 20 that constitutes the surge tank 11 and a second divided body 30 that constitutes the inlet pipe 12. With the above configuration, bending stress caused by vibrations of the throttle body 100 is likely to act on the intake pipe 12, which makes it easy for stress concentration to occur in the inner circumference portion of the curved passage 14 in the direction of curvature. In this respect, the intake manifold 10 has a sub-welded portion 72 provided in the inner circumference portion of the curved passage 14 in the direction of curvature, so even if the above vibrations occur, peeling of the welded portion 70 can be suppressed.

[0044] <Example of changes> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0045] The curved passage 14 is not limited to being composed of the surge tank 11 and the inlet pipe 12. The curved passage 14 may be a curved portion of the intake manifold 10, as long as it is composed of divided parts welded to each other via a welded portion 70. For example, the curved passage 14 may be composed of a branch pipe 13.

[0046] The secondary welded portion 72 may extend in a C-shape along the main welded portion 71, or it may extend in an annular shape around the entire circumference of the main welded portion 71. Furthermore, multiple secondary welded portions 72 may be provided at intervals in the circumferential direction of the curved flow channel 14. When the secondary welded portions 72 are provided on the outer circumferential side of the curved flow channel 14, the degree of stress concentration on the outer circumferential side of the curved flow channel 14 can be reduced when bending stress is applied to the curved flow channel 14 in such a way that the curvature of the curved flow channel 14 increases. Therefore, delamination of the welded portion 70 can be suppressed.

[0047] The cross-sectional shape of the secondary welded portion 72 may be any polygonal shape with rounded corners, or it may be circular. The cross-sectional shape of the secondary welded portion 72 does not need to have rounded corners.

[0048] The first segmented body 20 may have three or more connecting protrusions 24 that are spaced apart from each other in the circumferential direction of the curved flow channel 14. In this case, the first segmented body 20 may have multiple burr reservoirs 25 formed thereon.

[0049] The first divided body 20 may have a single connecting projection 24. In this case, the connecting projection 24 may be elongated and extend in the circumferential direction of the curved flow channel 14. In this modified example, the first divided body 20 does not have a burr reservoir 25 formed thereon.

[0050] The first divided body 20 does not necessarily have to have a connecting projection 24. The second divided body 30 may have a connecting projection that connects the second main welding projection 31 and the second sub-welding projection 32.

[0051] In this embodiment, the inlet pipe 12 was composed of a second divided body 30 and a third divided body 40, but the inlet pipe 12 does not have to be divided in the longitudinal direction of the inlet pipe 12. In this case, the entire inlet pipe 12 corresponds to the "second divided body".

[0052] The intake manifold 10 can also be applied to intake manifolds for V-type and in-line internal combustion engines. <Note> The above embodiment includes the configuration described in the following appendix.

[0053] [Note 1] An intake manifold having a curved flow path that extends in a curved manner, wherein the curved flow path is composed of a first divided body and a second divided body that are divided in the longitudinal direction of the curved flow path and welded to each other via a welded portion, and the welded portion has a main welded portion that extends annularly in the circumferential direction of the curved flow path and a secondary welded portion that is located at a position away from the main welded portion in the radial direction of the curved flow path and is provided on the inner circumferential side of the curved flow path in the curvature direction.

[0054] [Note 2] The intake manifold as described in [Note 1], wherein the first divided body has a main welded projection that is welded to the second divided body to constitute the main welded portion, a secondary welded projection that is welded to the second divided body to constitute the secondary welded portion, and a connecting projection that connects the main welded projection and the secondary welded projection.

[0055] [Note 3] The first divided body has a plurality of connecting protrusions provided at intervals from each other in the circumferential direction, and the first divided body has a burr reservoir formed by the main welding protrusion, the sub-welding protrusion, and the plurality of connecting protrusions to accumulate burrs generated during welding of the welded portion, as described in [Note 2].

[0056] [Note 4] The intake manifold described in any one of [Note 1] to [Note 3], wherein the cross-sectional shape of the sub-welded portion perpendicular to the longitudinal direction of the curved flow path is a polygonal shape with rounded corners.

[0057] [Note 5] The intake manifold according to any one of [Note 1] to [Note 4], wherein the sub-welded portion is provided only on the inner circumference side in the curvature direction of the curved flow path. [Note 6] An intake manifold as described in any one of [Note 1] to [Note 5], comprising a surge tank and an inlet pipe that bends and extends from the surge tank and is connected to a throttle body, wherein the curved passage is composed of the first divided body that constitutes the surge tank and the second divided body that constitutes the inlet pipe. [Explanation of symbols]

[0058] F...External force G1, G2... Gap 10…Intake Manifold 11… Surge tank 11a...Inlet 12...Introduction pipe 12a...Communication hole 13... Branch pipe 14…Curved channel 20...first division body 20a, 30a... Peripheral area 21...First main welded protrusion 22...First secondary welded protrusion 23…First outer rib 24... Connecting protrusion 25...Bali Accumulation 30…Second division body 31...Second main welded protrusion 32...Second secondary welded protrusion 33…Second outer rib 40...Third division body 50...4th division body 60...5th division body 70,80,90...welded part 71,91…Main welding part 72,92…Sub-weld part 100... Throttle body

Claims

1. An intake manifold having a curved flow path that extends in a curved manner, The curved channel is composed of a first divided body and a second divided body that are divided in the longitudinal direction of the curved channel and welded to each other via a welded portion. The aforementioned welded portion is The main welded portion extends annularly in the circumferential direction of the curved channel, It has a secondary welding portion located at a position radially away from the main welding portion of the curved flow path, and provided on the inner circumferential side of the curved flow path in the direction of curvature. Intake manifold.

2. The first division is The main welding protrusions that are welded to the second divided body and constitute the main welding portion, The secondary welding protrusions that are welded to the second divided body and constitute the secondary welding portion, It has a connecting projection that connects the main welding projection and the sub-welding projection, The intake manifold according to claim 1.

3. The first divided body has a plurality of connecting protrusions that are spaced apart from each other in the circumferential direction, The first divided body has a burr reservoir formed by the main welding protrusion, the sub-welding protrusion, and the plurality of connecting protrusions, which accumulates burrs generated during welding of the welded portion. The intake manifold according to claim 2.

4. The cross-sectional shape of the secondary welded portion perpendicular to the longitudinal direction of the curved flow channel is a polygonal shape with rounded corners. The intake manifold according to claim 1.

5. The aforementioned secondary welding portion is provided only on the inner circumference side in the curvature direction of the curved flow channel. The intake manifold according to claim 1.

6. It comprises a surge tank and an inlet pipe that bends and extends from the surge tank and is connected to the throttle body, The curved channel is composed of the first divided body that constitutes the surge tank and the second divided body that constitutes the inlet pipe. An intake manifold according to any one of claims 1 to 5.

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