Resonator-integrated duct and method for manufacturing a resonator-integrated duct

Abstract

This design enables the easy manufacture of integrated resonator ducts. [Solution] The resonator-integrated duct 14 comprises a duct section 24 through which intake air flows, and a resonator chamber 30 integrally molded with the duct section 24 and in contact with the duct section 24 such that the outer wall of the duct section 24 forms a partition wall 25. The resonator chamber 30 has a plurality of openings 32, 34 having openings 32a, 34a that penetrate the outer wall 31 of the resonator chamber 30, a communication hole 36 formed in the partition wall 25 at a position opposite to the opening 34a of one of the openings 34 and communicating with the duct section 24, and a plurality of cover members 38 that close the openings 32a, 34a of the plurality of openings 32, 34.

Description

Technical Field

[0001] The present invention relates to a resonator integrated duct and a method for manufacturing the resonator integrated duct.

Background Art

[0002] Patent Document 1 below discloses the structure of an intake duct in which a resonator chamber is integrally formed, and a communication hole is formed in the partition wall between the duct portion and the resonator chamber. A cover for closing one opening through which the core (sand) is removed during casting is attached to this resonator chamber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Normally, the core is provided with a support portion so as to insert through the opening, and the operation of flowing the molten metal into the mold is performed while supporting the support portion. However, in the case of the above structure, since there is only one opening, the support portion is also one, and the support of the core by the support portion becomes unstable. In this case, the position of the core in the mold fluctuates, and the quality of the resonator integrated duct, which is a cast product, may deteriorate.

[0005] Therefore, the present invention has been made in view of these points, and an object thereof is to realize a structure capable of suppressing a decrease in quality during the molding of the resonator integrated duct.

Means for Solving the Problems

[0006] In a first embodiment of the present invention, a resonator-integrated duct is provided, comprising: a duct section through which intake air flows; a resonator chamber integrally molded with the duct section and in contact with the duct section such that the outer wall of the duct section acts as a partition wall, wherein the resonator chamber has a plurality of openings having openings penetrating the outer wall of the resonator chamber; a communication hole formed in the partition wall at a position opposite to an opening of one of the plurality of openings and communicating with the duct section; and a plurality of cover members closing the openings of the plurality of openings.

[0007] Furthermore, the duct section may be curved from the upstream side to the downstream side, the resonator chamber may be provided in the duct section such that the curved outer wall of the duct section becomes the partition wall, and the communication hole may be formed in the downstream part of the partition wall.

[0008] Furthermore, the openings of the plurality of openings may be spaced apart in the outer wall of the resonator room.

[0009] Furthermore, the inner circumferential surfaces of the multiple openings may be the same shape, and the outer circumferential surfaces of the multiple lid members that fit with the multiple openings may also be the same shape.

[0010] Furthermore, the inner circumferential surface may be circular, and the outer circumferential surface may also be circular. Furthermore, the inner circumferential surfaces of the openings of the plurality of openings and the outer circumferential surfaces of the plurality of lid members that fit into each of the openings may be circular, and the diameters of the inner circumferential surfaces and the outer circumferential surfaces may be smaller than the diameter of the duct portion.

[0011] Furthermore, the diameter of the communication hole may be smaller than the diameter of the opening of the first opening.

[0012] A second aspect of the present invention provides a method for manufacturing a resonator-integrated duct, comprising: a first step of forming a casting in which a duct section having a first cavity and a resonator chamber having a second cavity are integrally structured with a partition wall in between; a second step of removing a core filling the second cavity from an opening in a plurality of openings penetrating the outer wall of the resonator chamber of the casting; a third step of inserting a tool into an opening in one of the plurality of openings to form a communication hole in the partition wall at a position opposite to the opening in the one opening that connects the resonator chamber and the duct section; and a fourth step of closing the openings in the plurality of openings with a cover member. [Effects of the Invention]

[0013] The present invention offers the advantage of realizing a structure that allows for the easy manufacture of a resonator-integrated duct. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing the configuration of the intake device 1 according to one embodiment. [Figure 2] This is a schematic diagram showing the external configuration of the resonator-integrated duct 14. [Figure 3] This is a schematic diagram showing the internal structure of the resonator-integrated duct 14. [Figure 4] This is a flowchart showing the manufacturing process for a resonator-integrated duct. [Figure 5] This is a schematic diagram illustrating the created casting. [Figure 6] This is a schematic diagram illustrating the machining of the communication hole 36. [Modes for carrying out the invention]

[0015] <Overview of the intake system> Figure 1 is a schematic diagram showing the configuration of an intake device 1 according to one embodiment. The intake device 1 is a device that supplies intake air to the engine 2. As shown in FIG. 1, the intake device 1 includes an intake pipe 5, an air cleaner 6, and an intake manifold 7.

[0016] The intake pipe 5 is a pipe through which the intake air flowing toward the engine 2 passes. The intake pipe 5 is connected to the intake manifold 7. The intake pipe 5 includes an upstream duct 12, a resonator-integrated duct 14, and a downstream duct 16. Although not shown in FIG. 1, a compressor of a supercharger may be provided in the intake pipe 5.

[0017] The upstream duct 12 is a duct having an air intake port 12a for taking in intake air. The upstream duct 12 is connected to the upstream side of the resonator-integrated duct 14. The intake air taken in at the air intake port 12a flows through the upstream duct 12 and into the resonator-integrated duct 14.

[0018] The resonator-integrated duct 14 is an intermediate duct located between the upstream duct 12 and the downstream duct 16. The resonator-integrated duct 14 is connected to the upstream duct 12 and the downstream duct 16, and the intake air flowing through the resonator-integrated duct 14 flows into the downstream duct 16.

[0019] The resonator-integrated duct 14 of the present embodiment has a structure in which a duct portion and a resonator chamber are integrated. The resonator chamber reduces the noise in the high-frequency band generated during intake. The energy of the sound that enters the resonator chamber is converted into thermal energy due to friction, and the noise of a specific frequency is reduced. The detailed configuration of the resonator-integrated duct 14 will be described later.

[0020] The downstream duct 16 is located on the downstream side of the resonator-integrated duct 14. The downstream duct 16 is connected to the intake manifold 7, and the intake air flowing through the downstream duct 16 flows into the intake manifold 7.

[0021] The air cleaner 6 is installed in the intake pipe 5 and has the function of purifying the intake air. The air cleaner 6 removes fine dust (dirt, etc.) from the intake air. The air cleaner 6 is installed in the upstream duct 12 of the intake pipe 5.

[0022] The intake manifold 7 is connected to the downstream duct 16 of the intake pipe 5. The intake manifold 7 is a multi-manifold that distributes the intake air flowing in from the intake pipe 5 to each of the multiple cylinders of the engine 2.

[0023] <Detailed configuration of the integrated resonator duct> Figure 2 is a schematic diagram showing the external configuration of the resonator-integrated duct 14. Figure 3 is a schematic diagram showing the internal configuration of the resonator-integrated duct 14. Figure 3 shows a cross-sectional view of the resonator-integrated duct 14 cut in a plane parallel to the plane of Figure 2.

[0024] As shown in Figures 2 and 3, the resonator-integrated duct 14 has an inlet section 22, a duct section 24, a blow-by gas return section 26, an outlet section 28, and a resonator chamber 30. The inlet section 22 has an opening through which intake air flows in. The inlet section 22 is connected to the upstream duct 12. Intake air that has flowed through the upstream duct 12 flows from the inlet section 22 into the duct section 24.

[0025] The duct section 24 forms a flow path through which the intake air flowing in from the inlet section 22 flows. The duct section 24 is a tube with a cavity (hereinafter referred to as the first cavity 24a) formed inside, and the intake air flows through the first cavity 24a. The duct section 24 is made of metal. The intake air in the duct section 24 flows toward the outlet section 28. The duct section 24 is not a straight flow path, but a curved flow path as shown in Figure 3.

[0026] The outlet section 28 has an opening through which intake air flows out. The outlet section 28 is connected to the downstream duct 16. Intake air that has flowed through the duct section 24 flows out from the outlet section 28 into the downstream duct 16.

[0027] The return section 26 has an opening that allows the engine's blow-by gas to be returned to the duct section 24. The returned blow-by gas flows out through the outlet section 28 to the downstream duct 16 along with the intake air that has flowed through the upstream duct 12. The blow-by gas is combustion gas that has leaked into the crankcase from gaps in the piston rings of the engine 2, gaps in the turbocharger, etc.

[0028] The resonator chamber 30 cancels intake noise through resonance, utilizing Helmholtz's theory. Here, intake noise refers to high-frequency noise generated during intake. According to Helmholtz's theory, when air is introduced through an air hole in a resonant chamber, the air inside the chamber resonates at a specific frequency (resonance frequency). In a resonator utilizing this phenomenon, noise corresponding to the resonance frequency can be canceled out by resonance. Here, the resonance frequency generated in the resonant chamber is determined based on the length and cross-sectional area of ​​the air hole and the volume of the resonant chamber. Specifically, the resonance frequency increases with increasing cross-sectional area of ​​the air hole and decreases with increasing length of the air hole and increasing volume of the resonant chamber. In this embodiment, the resonator chamber 30 functions as a resonant chamber, and the communication hole 36 functions as an air hole. A cavity (hereinafter referred to as the second cavity 30a) is formed inside the resonator chamber 30. The resonator chamber 30 communicates with the duct section 24 via the communication hole 36 (see Figure 3). Specifically, the second cavity 30a is in communication with the first cavity 24a via a communication hole 36. According to Helmholtz's theory, the resonance frequency increases with increasing cross-sectional area of ​​the communication hole 36 and decreases with increasing length of the communication hole 36 and increasing volume of the resonator chamber 30.

[0029] The resonator chamber 30 is made of metal and is integrally molded with the duct section 24. Specifically, the metal resonator chamber 30 and the duct section 24 are integrally molded by casting. When the resonator chamber 30 and the duct section 24 are integrated, there is no need to connect the resonator chamber 30 and the duct section 24 with connecting members or the like.

[0030] The resonator chamber 30 is provided in the duct section 24 such that the outer wall of the duct section 24 acts as a partition wall 25. The partition wall 25 is a wall-like member that separates the resonator chamber 30 from the duct section 24. In this embodiment, the duct section 24 is curved from the upstream side to the downstream side. The resonator chamber 30 is provided in the duct section 24 such that the curved outer wall of the duct section 24 acts as a partition wall 25. The partition wall 25 separating the resonator chamber 30 from the duct section 24 also serves as a part of the outer wall of the resonator chamber 30. Therefore, no gap is formed between the resonator chamber 30 and the duct section 24. As a result, the volume of the resonator chamber 30 can be increased.

[0031] As shown in Figure 3, the resonator chamber 30 has an outer wall 31, a communication hole 36, and a cover member 38. The outer wall 31 of the resonator chamber 30 has a first opening 32. The outer wall 31 is a wall facing the partition wall 25. The first opening 32 has a first opening 32a that penetrates the outer wall 31. The first opening 32a is a circular through-hole. More specifically, the first opening 32a is a through-hole with a circular inner surface. The first opening 32a is an outlet for removing the core that fills the second cavity 30a during the manufacturing of the resonator.

[0032] The outer wall 31 of the resonator chamber 30 has a second opening 34. The second opening 34 has a second opening 34a that penetrates the outer wall 31. The second opening 34a is a circular through-hole. More specifically, the first opening 34a is a through-hole with a circular inner surface. The outer wall 31 has the second opening 34a at a different position from the first opening 32a. The outer wall 31 has the first opening 32a at a position opposite to the upstream portion of the partition wall 25, and the second opening 34a at a position opposite to the downstream portion of the partition wall 25. The second opening 34a is an outlet for removing the core filling the second cavity 30a during the manufacturing of the resonator. In this embodiment, as shown in Figure 3, the outer wall 31 has the first opening 32a and the second opening 34a at positions spaced apart in the direction of the intake air flowing through the duct section 24. This allows for efficient removal of the core filling the second cavity 30a. Furthermore, in this embodiment, the outer wall 31 of the resonator chamber 30 has two openings, but is not limited to this, and may have three or more openings.

[0033] As described above, when the resonator chamber 30 is manufactured by casting together with the duct section 24, a core is used in the portion corresponding to the cavity of the resonator chamber 30. The core has a support portion (support portion 52 shown in Figure 5) that can support the core when molten metal is poured into the mold. In this embodiment, when the resonator chamber 30 has multiple openings (a first opening 32 and a second opening 34), the core can have multiple support parts connected to the core via the first opening 32 and the second opening 34. In this case, supporting the core with multiple support parts suppresses the floating and rotation of the core when molten metal is poured into the mold, making it less likely for the core's position to fluctuate.

[0034] Since the first opening 32 and the second opening 34 are located apart in the outer wall 31, the core can be more stably supported. Furthermore, when multiple openings are provided at arbitrary positions in the outer wall 31, the degree of freedom in the external shape of the resonator chamber 30 is increased compared to when a single large opening is provided. As a result, it becomes easier to increase the volume of the resonator chamber 30. In this case, the smaller the openings of the multiple openings, the greater the degree of freedom in the external shape of the resonator chamber 30. In this embodiment, the diameter of the inner circumferential surface of the openings of the multiple openings and the outer circumferential surface of the lid member 38 are smaller than the diameter of the duct portion 24.

[0035] The communication hole 36 is a through-hole that penetrates the partition wall 25, connecting the duct section 24 and the resonator chamber 30. This allows the duct section 24 and the resonator chamber 30 to be connected without the need for a separate connecting member. Furthermore, when the through-hole in the partition wall 25 is the communication hole 36, the length of the communication hole 36 can be determined by adjusting the thickness of the partition wall 25. In this embodiment, the communication hole 36 is circular. When the communication hole 36 is circular, the cross-sectional area can be determined by adjusting the diameter of the communication hole 36.

[0036] The communication hole 36 is formed in the partition wall 25 at a position opposite to the second opening 34a of the second opening 34. On the other hand, the communication hole 36 is not formed in the partition wall 25 at a position opposite to the first opening 32a of the first opening 32. Thus, the communication hole 36 is formed in the partition wall 25 at a position opposite to the second opening 34a, which is one of the multiple openings in the outer wall 31 of the resonator room 30.

[0037] The communication hole 36 is formed in the downstream portion of the partition wall 25, which curves from the upstream side to the downstream side. By forming the communication hole 36 in the downstream portion of the partition wall 25, which curves from the upstream side to the downstream side, it is possible to prevent the intake air flowing through the duct section 24 from passing through the communication hole 36 and heading towards the resonator chamber 30. This allows the intake air to be supplied to the engine 2 appropriately.

[0038] The diameter of the communication hole 36 is smaller than the diameter of the second opening 34a of the second opening 34. For example, the diameter of the communication hole 36 is 1 / 2 to 2 / 3 the size of the diameter of the second opening 34a. The communication hole 36 is formed by machining using a tool (e.g., a drill) inserted through the second opening 34a, as will be described later. Therefore, because the diameter of the communication hole 36 is smaller than the diameter of the second opening 34a, it becomes easier to machine the communication hole 36 by inserting a tool through the second opening 34a.

[0039] The lid member 38 closes the first opening 32a of the first opening 32 and the second opening 34a of the second opening 34. The lid member 38 is press-fitted into the first opening 32 and the second opening 34. The outer circumferential surface of the lid member 38 that fits with the first opening 32a has the same shape as the inner circumferential surface of the first opening 32a. More specifically, the outer circumferential surface of the lid member 38 that fits with the first opening 32a is circular, just like the inner circumferential surface of the first opening 32a. Furthermore, the shape of the lid member 38 that closes the first opening 32a is the same as the shape of the lid member 38 that closes the second opening 34a. This allows the use of two small lid members 38, thereby reducing manufacturing costs compared to using one large lid member. However, the shapes of the two lid members 38 may be different, and this is not limited to the above.

[0040] <Manufacturing process for integrated resonator ducts> Figure 4 is a flowchart showing the manufacturing process of a resonator-integrated duct.

[0041] First, the worker prepares the mold and core (step S102). The mold is assumed to consist of an upper mold and a lower mold. The cores are the core filling the first cavity 24a of the duct section 24 and the core filling the second cavity 30a of the resonator chamber 30. For example, the worker sets the core inside the lower mold, and then sets the upper mold.

[0042] Next, the worker pours molten metal into the mold prepared in step S102 (step S104). As the temperature of the poured molten metal decreases, it solidifies, creating a casting. When pouring the molten metal into the mold, the core is supported by two support parts 52 of the core 50 shown in Figure 5. The two support parts 52 are fitted into the mold. This support by the two support parts 52 stabilizes the support of the core 50 within the mold, suppressing floating and rotation of the core within the mold.

[0043] Figure 5 is a schematic diagram illustrating the created casting. Figure 5 shows the casting after the mold has been removed. The created casting has a duct section 24 having a first cavity 24a and a resonator chamber 30 having a second cavity 30a, separated by a partition wall 25. Here, it is assumed that the core 54 remains in the first cavity 24a and the core 50 remains in the second cavity 30a. The support portion 52 of the core 50 is inserted through the first opening 32a and the second opening 34a. Note that in Figure 5, the support portion of the core 54 is omitted for the sake of explanation.

[0044] Next, the worker removes the core 50 filling the second cavity 30a of the resonator chamber 30 from the first opening 32a and the second opening 34a in the outer wall 31 of the cast iron resonator chamber 30 (step S106). For example, the worker vibrates the sand core 50 to break it and discharge the sand from the first opening 32a and the second opening 34a. At this time, the worker also removes the core 54 that fills the first cavity 24a of the duct section 24. Specifically, the worker breaks the core 54 that fills the first cavity 24a and removes it through the openings of the inlet section 22, the outlet section 28, and the return section 26.

[0045] Next, the worker forms a communication hole 36 in the partition wall 25 between the duct section 24 and the resonator chamber 30 (step S108). Specifically, the worker forms a communication hole 36 in the partition wall 25 at a position opposite the second opening 34a, which connects the resonator chamber 30 and the duct section 24. This allows the communication hole 36 to be formed through the second opening 34a even if the duct section 24 and the resonator chamber 30 are integrally molded.

[0046] Figure 6 is a schematic diagram illustrating the formation of the communication hole 36. The worker inserts a tool (e.g., a drill) into the second cavity 30a through the second opening 34a in the direction indicated by the arrow. The worker then forms the communication hole 36 by machining a predetermined position in the partition wall 25 with the inserted tool (see Figure 3). In this way, when the communication hole 36 is formed using a tool, it is possible to form the communication hole 36 at a desired position in the partition wall 25 with high precision and a desired diameter, compared to when the communication hole 36 is formed during casting.

[0047] Next, the worker closes the first opening 32a and the second opening 34a with the cover member 38 (step S110). For example, the worker presses the cover member 38 into each of the first opening 32a and the second opening 34a to close them (see Figure 3).

[0048] This completes the resonator-integrated duct 14. In Figure 4, step S104 corresponds to the first step, step S106 to the second step, step S108 to the third step, and step S110 to the fourth step.

[0049] <Effects of this embodiment> The resonator-integrated duct 14 of the above-described embodiment includes a resonator chamber 30 that is in contact with the duct section 24 such that the outer wall of the duct section 24 forms a partition wall 25. The resonator chamber 30 has a plurality of openings (first opening 32 and second opening 34) having openings that penetrate the outer wall 31, a communication hole 36 formed in the partition wall 25 at a position opposite to the second opening 34a of the second opening 34 and communicating with the duct section 24, and a plurality of lid members 38 that close the first opening 32a and the second opening 34a. In the above configuration, when manufacturing the resonator-integrated duct 14, two support parts 52 for the core 50 can be provided so as to pass through the first opening 32 and the second opening 34. As a result, the two support parts 52 support the core 50, which suppresses the floating and rotation of the core 50 when molten metal is poured into the mold, making it less likely for the position of the core 50 to fluctuate. Furthermore, since the communication hole 36 is formed in the partition wall 25 at a position opposite the second opening 34a, it becomes easier to machine the communication hole 36 from the second opening 34a, and the communication hole 36 can be formed with high precision. As a result, a structure can be realized in which the resonator-integrated duct 14 can be manufactured easily and with high precision.

[0050] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of its gist. For example, all or part of the apparatus can be configured by functionally or physically distributing and integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combinations are combined with the effects of the original embodiments. [Explanation of symbols]

[0051] 14. Resonator-integrated duct 24 Duct section 24a 1st cavity 25 Bulkhead 30 Resonator Room 30a 2nd cavity 31 Exterior Wall 32 First opening 32a 1st opening 34. Second opening 34a 2nd opening 36 Communication hole 38 Lid member

Claims

1. The duct section through which the intake air flows, A resonator chamber is integrally molded with the duct section, and is in contact with the duct section such that the outer wall of the duct section acts as a partition wall, Equipped with, The aforementioned resonator chamber is Multiple openings having openings that penetrate the outer wall of the resonator room, A communication hole is formed in the partition wall at a position opposite to one of the multiple openings, and is in communication with the duct section, The plurality of openings have a plurality of lid members that close off the openings, Resonator-integrated duct.

2. The aforementioned duct section is curved from the upstream side to the downstream side. The resonator chamber is provided in the duct section such that the curved outer wall of the duct section serves as the partition wall. The aforementioned communication hole is formed in the downstream portion of the partition wall. The resonator-integrated duct according to claim 1.

3. The openings of the aforementioned plurality of openings are spaced apart in the outer wall of the resonator room. The resonator-integrated duct according to claim 1.

4. The inner circumferential surfaces of the multiple openings have the same shape. The outer surfaces of the plurality of lid members that fit into the openings of the plurality of openings are of the same shape. The resonator-integrated duct according to claim 1.

5. The inner circumferential surface is circular, The outer surface is circular. The resonator-integrated duct according to claim 4.

6. The inner circumferential surfaces of the openings in the plurality of openings and the outer circumferential surfaces of the plurality of lid members that fit into each of the openings are circular. The diameters of the inner and outer surfaces are smaller than the diameter of the duct portion. The resonator-integrated duct according to claim 1.

7. The diameter of the communication hole is smaller than the diameter of the opening of the first opening. The resonator-integrated duct according to claim 1.

8. A first step involves forming a casting in which a duct section having a first cavity and a resonator chamber having a second cavity are separated by a partition wall and form an integral structure. A second step involves removing the core filling the second cavity from an opening in one of the multiple openings that penetrate the outer wall of the resonator chamber of the casting, A third step involves inserting a tool through an opening in one of the multiple openings to form a communication hole in the partition wall at a position opposite to the opening in the one opening, which connects the resonator chamber and the duct section. A fourth step involves closing the openings of the plurality of openings with a lid member, A method for manufacturing a resonator-integrated duct having the following characteristics.

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