JP7652595B2 - Engine intake system - Google Patents

Description

The present invention relates to an intake device that is provided as an accessory to an engine (internal combustion engine).

Air cleaners are essential for gasoline and diesel engines, as they take in and purify the air. As an engine accessory, air cleaners have relatively high design freedom, and a variety of structures and arrangements have been proposed.

For example, Patent Document 1 discloses that a resonator and an intake duct are integrally provided on the underside of the main body case that constitutes the air cleaner. Patent Document 2 also discloses that a resonator is integrally provided in the dirty chamber of the air cleaner. Integrating a resonator into the air cleaner as in Patent Documents 1 and 2 has the advantage of making the whole system more compact while suppressing intake noise.

JP 2000-064920 A JP 2002-339822 A

Now, to improve the effectiveness of elimination of intake noise, it is preferable to make the intake duct as long as possible, but since there is a limit to the length of the intake duct in Patent Documents 1 and 2, it is understood that there is also a limit to the noise elimination effect.

That is, in Patent Document 1, the intake duct is formed to surround the main body case from below, so the length of the intake duct is naturally limited by the size of the main body case. Also, in Patent Document 2, the inside of the resonator case integrated into the dirty chamber is partitioned to form a U-turn or serpentine intake duct, but even in this case, the size of the resonator case is regulated by the size of the dirty chamber, so there is a limit to how long the intake duct can be made. In either case, it is understood that there is a limit to the intake noise elimination performance.

Furthermore, if the intake duct is made to turn or snake as in Patent Document 2, the air suddenly changes direction, which may increase the air flow resistance, or the air may collide with the suddenly bent part and cause membrane vibration, which may negate the purpose of providing a resonator. Also, in Patent Document 2, the volume of the space enclosed by the intake duct is small, so there is also the question of whether the resonator can fully function.

Therefore, when considering an air cleaner equipped with an intake duct with an integrated resonator, it is necessary to make the length of the intake duct as long as possible while minimizing air flow resistance, and to arrange it compactly while securing the volume required for the resonator. Also, air can contain dust and moisture, and it is preferable to prevent this dust and moisture from reaching the filter element of the air cleaner. Furthermore, strength (rigidity) must be guaranteed. In particular, in the case of air cleaners mounted on automobiles, consideration of strength is important because they are subject to vibrations caused by driving and engine vibrations.

The present invention was made in response to this current situation, and aims to provide an improved intake device that reduces flow resistance while also providing excellent noise reduction capabilities.

The present invention includes the features of claims 1 and 2. The invention of claim 1 is as follows:
"It is equipped with an air cleaner, an intake duct that takes in air into the air cleaner, and a resonator that is integrally provided with the intake duct via a communication passage,
The intake duct has a first vertically elongated portion with an intake port opening at its upper end and through which air flows downward, a second vertically elongated portion with an exhaust port opening at its upper end and through which air flows upward, and a bottom portion connected to the lower ends of both vertically elongated portions, and a main body case constituting the dirty chamber of the air cleaner is integrally connected to the upper end of the second vertically elongated portion.
In this basic configuration,
"The air cleaner is disposed so as to overlap the entire length of the bottom of the intake duct in a plan view, while the resonator is disposed only in the space surrounded by the two longitudinal portions and the bottom of the intake duct,
The air cleaner, the resonator, and the bottom of the intake duct are arranged at different heights so as to overlap each other in a plan view.
It has the following characteristics:

On the other hand, the invention of claim 2 is as follows in claim 1:
"The intake duct is formed on the mating surface of the two shell-shaped members that are overlapped and joined together, and the first longitudinal portion, the bottom portion, and the second longitudinal portion are continuous with each other.
A substantially horizontal receiving plate in which the discharge port of the second vertically elongated portion is opened is integrally provided on one of the two shell-shaped members, and the main body case of the air cleaner is fixed to the receiving plate.
The structure is as follows.

In claim 1 , the intake duct and resonator can be formed into a hollow structure by stacking and joining two shell-shaped members made of synthetic resin, and by adopting this joining structure, the intake duct with a resonator can be easily manufactured.

In both of the present inventions, the intake duct is generally U-shaped, with a first vertical portion, a bottom portion, and a second vertical portion, so that the air flow does not have to change direction suddenly, and the length of the intake duct can be increased while suppressing air flow resistance. Furthermore, since the first vertical portion is not restricted by the main body case, it is possible to make the first vertical portion longer than the second vertical portion, which ensures that the length of the intake duct can be increased and improves the design freedom for the position of the intake port. Furthermore, since the air flows downward through the first vertical portion and then upward through the second vertical portion, it is possible to prevent dust, sand, and moisture from entering the air cleaner. This improves the durability of the filter element.

In the invention of claim 1, the resonator is placed in the space enclosed by the intake duct, but since the intake duct has a bottom and the area of the enclosed space is large, the length of the intake duct can be increased while effectively utilizing the space below the air cleaner, and the volume of the resonator can also be increased. Therefore, the resonator's function can be fully utilized, significantly improving the effect of eliminating noise and vibration.

In addition, in the invention of claim 1, the air cleaner, intake duct, and resonator are unitized as a single intake device, so that the number of installation locations can be reduced and work efficiency can be improved when installing them to the engine body, vehicle body, etc. As in claim 2 , when the intake duct and resonator are made hollow by joining two shell-shaped members, the resonator exerts a rib effect to reinforce the intake duct, improving the rigidity of the entire system.

It is also possible to connect the mid-height portions of the first and second vertical sections via a resonator. If this structure is adopted and applied to an automobile engine, even if the automobile drives on a flooded road and water accumulates at the bottom of the intake duct, causing it to become blocked, air can still be taken in to the air cleaner and the engine can continue to operate.

As in claim 2, when the main body case of the air cleaner is fixed to a support plate provided integrally with the intake duct, there is an advantage that the intake duct can be stably suspended by the main body case of the air cleaner while effectively utilizing the space below the air cleaner to make the intake device compact (this point is similar to claim 1). In this case, the intake duct is made up of two overlapping and joined shell-like members, and the support plate is integrally formed with one of the shell-like members in a state where it protrudes from the upper end of the shell -like member on both the front and back sides, so that the support plate and the shell-like member form a T-shaped structure, which is preferable as it significantly improves rigidity.
In addition, by integrating the main case and the receiving plate by welding or the like, the bottom plate plane of the main case facing the ground has a double structure, which significantly reduces the radiated sound emitted from the surface of the air cleaner. As a result, when applied to a vehicle, the external noise heard on the side of the vehicle due to the radiated sound from the air cleaner being reflected by the ground is also suppressed.

FIG. 2 is a perspective view of the intake device as viewed from slightly obliquely above. FIG. 2 is a perspective view of the intake device as seen from below. FIG. FIG. 2 is an exploded side view of the intake device (with the right shell-shaped member turned upside down). FIG. 2 is a separated side view of two shell-like members in an unfolded state (with mating surfaces exposed). FIG. FIG. 13 is a perspective view of a right shell-shaped member with some structure omitted. FIG. 2 is a perspective view of the air cleaner as viewed from below. 1A and 1B are diagrams showing an automobile to which an embodiment is applied, in which (A) is an overall side view, and (B) is a partially cutaway enlarged view of (A).

Next, an embodiment of the present invention will be described with reference to the drawings. Figure 9 shows a cab-over van (e.g., a minivan of one-box type), and the intake device 1 of this embodiment can be installed in this cab-over van.

That is, a cab-over van has a front compartment (driver's cab) 2 in which the front seats 2a are located, and a luggage compartment space 3 behind it, and an engine 4 is located in the space below the front seats 2a, but the intake device 1 of this embodiment is located in a part below the rear of the front seats 2a, closer to the passenger seat (the space surrounded by the vehicle body's side member (underframe), floor, and underbody (outer panel)) (it may also be located on the driver's seat side).

The engine 4 is mounted vertically with the crankshaft facing the front-to-rear direction of the vehicle, and the cylinder bore axis is significantly slanted so that it approaches the horizontal side. The intake side is also positioned facing upward. In Figure 6 (B), 4a is the transmission case, and 4b is the drive shaft.

In the following, the terms front, rear, left and right are used to specify directions, but these directions are the same as the front, rear, left and right directions of a vehicle. In other words, they are the same as the front, rear, left and right directions as seen by the driver. Directions are indicated appropriately in each diagram.

(1) Overview As shown in FIG. 1, the intake system 1 comprises an air cleaner 5 and a duct unit 6 the majority of which is located below the air cleaner 5. As shown in FIG. 4, the air cleaner 5 comprises a main body case 7 made of synthetic resin located at the bottom and having a dirty chamber, a cover case 8 made of synthetic resin which constitutes a clean chamber and overlaps the main body case 7 from above, and a filter element 9 sandwiched between the two.

The cover case 8 is in the form of a tray that opens downward, and each corner is fixed to the main case 7 by a roughly C-shaped clip 10. Therefore, the cover case 8 of this embodiment is removable. Therefore, a surrounding edge 11a is integrally formed on the outside of the opening edge of the cover case 8, and the clip 10 is hooked to the edge 11a against elasticity. In addition, an exhaust port 12 for purified air protrudes from the side of the cover case 8. The cover case 8 may be an openable type that rotates around one side of the cover case 8.

The main body case 7 of the air cleaner 5 is in the shape of a box that opens upward, and a rim 11b similar to that of the cover case 8 is integrally formed on the outside of the opening edge, and the lower end of the clip 10 is engaged at the rim 11b. In addition, bracket parts 13 for fixing to the vehicle frame are integrally formed on the outer surface and inner corners of the main body case 7. The bracket parts 13 are fixed to the vehicle frame (not shown) by bolts 14 equipped with vibration-proof grommets.

As shown in FIG. 8, the main case 7 has an inlet 15 at one corner of its bottom surface, while as shown in FIG. 6, the duct unit 6 has a receiving plate 16 on which the main case 7 is fixed, and the receiving plate 16 has an outlet 17 that communicates with the inlet 15 of the main case 7. The receiving plate 16 and the main case 7 are fixed (joined) by welding such as vibration welding.

As shown in FIG. 8, the underside of the main case 7 is formed with downward ribs 18 for welding that surround the periphery and the inlet 15 and cross in the front, back, left and right directions, while the receiving plate 16 of the duct unit 6 is also formed with upward ribs 19 for welding that correspond to the downward ribs 18 for welding on the main case 7.

However, in addition to the upward ribs 19 for welding, a group of auxiliary ribs 20 for reinforcement is also formed on the receiving plate 16 of the duct unit 6, and the upward ribs 19 for welding and the group of auxiliary ribs 20 form a lattice shape. In Figure 6, the upward ribs 19 for welding are shown with hatching, but as can be seen from this figure, grooves are formed in the upward ribs 19 for welding.

Although not shown in Figure 8, a groove is also formed in the downward rib 18 for welding of the main case 7 (the upward rib 19 for welding in Figure 6 is shown wider than it actually is). Note that Figure 7 only shows a portion of the upward rib 19 for welding, and a portion of the upward rib 19 for welding and all of the auxiliary rib 20 are omitted. Note that the shape of the rib that welds the backing plate 16 and the main case 7 can be changed in various ways.

(2) Duct unit As shown in Figures 4 and 5, the duct unit 6 is made up of a pair of shell-shaped members, a left shell-shaped member 21 and a right shell-shaped member 22, and is formed hollow by stacking the two shell-shaped members 21, 22 and joining them by vibration welding or the like, and is provided with an intake duct 23 and first and second resonators 24, 25. Therefore, both shell-shaped members 21, 22 are formed with a bulge that forms the intake duct 23 and a bulge that forms the resonators 24, 25. The aforementioned support plate 16 is integrally molded with the upper end of the right shell-shaped member 22.

In Figures 5 and 7, the welded surfaces (overlapped surfaces) of both shell-shaped members 21 and 22 are shown hatched (so the hatching does not represent a cross section). Grooves (not shown) are also formed on the welded surfaces of both shell-shaped members 21 and 22.

1, 4 and 5, the intake duct 23 has a first vertically elongated portion 23a at the upper end of which the intake port 26 opens and through which air flows downward, a second vertically elongated portion 23b at the upper end of which the discharge port 17 described above opens and through which air flows upward, and a bottom portion 23c connected to the lower ends of both vertically elongated portions 23a and 23b and through which air flows horizontally. Therefore, the intake duct 23 extends continuously in a substantially U-shaped form in a side view, and resonators 24 and 25 are disposed in the space surrounded by both vertically elongated portions 23a and 23b and the bottom portion 23c. A drain portion 27 for discharging water is provided downwardly at the corner portion where the first vertically elongated portion 23a and the bottom portion 23c are connected.

The upper end of the second vertically elongated portion 23b opens into the receiving plate 16, so the second vertically elongated portion 23b is necessarily positioned lower than the air cleaner 5, but the air intake 26 at the upper end of the first vertically elongated portion 23a is at approximately the same height as the upper end of the air cleaner 5. For example, as can be seen from FIG. 2, the air intake 26 opens in a substantially horizontal direction (sideways) toward the cover case 8 of the air cleaner 5 (the opening direction can be set arbitrarily).

The upper half of the first vertically elongated portion 23a is therefore positioned in front of the air cleaner 5, but because the resonators 24, 25 are positioned below the air cleaner 5, the lower half of the first vertically elongated portion 23a is bent so as to fit below the air cleaner 5. By taking such considerations into account, the intake device 1 can be made compact.

The first vertical portion 23a is bent at a gentle angle, and the radius of curvature of the connecting portion between the first vertical portion 23a and the bottom portion 23c is also curved as large as possible. Furthermore, the connecting portion between the bottom portion 23c and the second vertical portion 23b is curved greatly, and the second vertical portion 23b itself is curved so as to bulge toward the outside of the vehicle body. Therefore, while the intake duct 23 forms a U-shape as a whole, the connecting portion is smoothly curved, the first vertical portion 23a is smoothly curved, and the second vertical portion 23b is curved greatly. This bending shape allows air to flow smoothly inside the intake duct 23 with almost no resistance. Therefore, intake resistance is significantly suppressed.

The first resonator 24 is disposed close to the first vertically elongated portion 23a, and its lower end is connected to the bottom 23c via the first communication passage 28. On the other hand, the second resonator 25 is housed in a recess formed by curving the second vertically elongated portion 23b outward, and its lower end is connected to the lower portion of the second vertically elongated portion 23b via the second communication passage 29. The first resonator 24 has a larger volume than the second resonator 25, but it is also possible to set the two to the same volume, or to set the second resonator 25 to a larger volume than the first resonator 24.

On the other hand, the second resonator 25 is fitted into a recess formed by bending the second vertically elongated portion 23b outward. This effectively utilizes the space created by bending the second vertically elongated portion 23b, preventing the occurrence of dead space. The lower end of the second resonator 25 is connected to the lower portion of the second vertically elongated portion 23b via the second communication passage 29.

As can be seen from Figures 1 and 2, the resonators 24, 25 bulge on both the front and rear of the mating surfaces of the two shell-shaped members 21, 22, with the amount of bulging of the right shell-shaped member 22 being greater than the amount of bulging of the left shell-shaped member 21. In other words, the resonators 24, 25 bulge significantly toward the rear. Because the resonators 24, 25 can bulge significantly in the left-right direction, the necessary volume can be secured while effectively utilizing the space below the air cleaner 5. This is one of the major advantages of this embodiment.

As shown in FIG. 2, an air bleed port 30 protrudes downward from the lower rear end of the first resonator 24. As shown in FIGS. 5 and 7, the inside of the resonators 24 and 25 has internal ribs 31 arranged vertically and horizontally and crossing each other in a lattice pattern when viewed from the side. The internal ribs 31 are provided primarily for reinforcement purposes.

As described above, the receiving plate 16 is integrally formed on the upper end of the right shell-shaped member 22, and protrudes on both the front and rear sides of the plates constituting the right shell-shaped member 22. Then, as shown in Figures 1, 2 and 6, for example, the first resonator 24 and the second resonator 25 are disposed below the receiving plate 16, and a group of receiving plate support ribs 32 is integrally connected to the plate portion of the right shell-shaped member 22 and the receiving plate 16. Therefore, the receiving plate 16 is stably held on the right shell-shaped member 22, and as a result, the duct unit 6 has a robust structure as a whole.
As described above, the resonators 24, 25 are disposed below the receiving plate 16, so that the air cleaner 8, the resonators 24, 25, and the bottom 23c of the intake duct 23 are disposed in an overlapping state in a plan view.

As shown in Figures 2 to 4 (particularly Figure 2), the first vertically long portion 23a of the left shell-shaped member 21 and the first vertically long portion 23a of the right shell-shaped member 22 are integrally formed with horizontal intake duct ribs 33 that are continuous with the first resonator 24, and the front and rear intake duct ribs 33 are joined to each other. Therefore, the first vertically long portion 23a and the first resonator 24 are integrated together, enhancing the stability of the first vertically long portion 23a.

As shown in Figures 6 and 7, the right shell-shaped member 22 is provided with a first side rib 34 that connects the first vertical portion 23a to the receiving plate 16, and a second side rib 35 that connects the second vertical portion 23b to the receiving plate 16. These side ribs 34, 35 also significantly improve the robustness of the intake duct 23.

(3) Summary This embodiment has the above-described configuration. After flowing downward through the intake duct 23, the air changes direction to flow upward at the second vertically elongated portion 23b and enters the main body case 7 of the air cleaner 5. However, since the intake duct 23 is roughly U-shaped, embracing the resonators 24, 25, it is possible to increase the length while making effective use of the space.

And because the intake duct 23 has a bottom 23c, flow resistance is significantly reduced compared to the U-turn or serpentine shapes of Patent Document 2. In particular, because the second vertically elongated portion 23b is curved so as to bulge on the opposite side to the first vertically elongated portion 23a, the upward direction of the air flow is changed extremely smoothly, and pressure loss can be significantly reduced.

And because two resonators 24, 25 are connected to the long intake duct 23, the resonators 24, 25 can fully function, significantly improving the vibration and noise suppression effect. Furthermore, because the resonators 24, 25 are hidden below the air cleaner 5 and expand in both the front and rear directions, as mentioned above, the space below the air cleaner 5 is effectively utilized to ensure the necessary volume, which results in a significant improvement in the air expansion and shock absorption effects, and a significant improvement in the vibration and noise suppression effect.

As mentioned above, in the minivan of the one-box type shown in FIG. 9, the air cleaner is placed in a space surrounded by the side members, flow, and lower body of the vehicle body, and this space is narrow with a limited vertical width. However, in this embodiment, the resonators 24, 25 expand in the front-rear direction below the air cleaner 5 to ensure the necessary volume, so that the height of the intake system can be made as low as possible, and the system can be applied to minivans while maintaining a high level of noise prevention effect.

In addition, because the air flows upward in the second vertically elongated portion 23b, even if sand or water is mixed in the air, the sand or water can be prevented or significantly suppressed from flowing into the main body case 7 of the air cleaner 5. This improves the durability of the filter element 9.

In terms of structure, the intake duct 23 and resonators 24, 25 are formed by inflating the shell-shaped members 21, 22, which exert a rib effect and greatly increase the robustness of the duct unit 6. In addition, the duct unit 6 is joined to the main body case 7 of the air cleaner 5 via the support plate 16, so the duct unit 6 and the air cleaner 5 are firmly fixed together. Therefore, there is no risk of the duct unit 6 falling off due to vibrations caused by the running of the car or vibrations of the engine 4.

Furthermore, because the receiving plate 16 and the right shell-shaped member 22 are connected by a group of receiving plate support ribs 32, the duct unit 6 has a lightweight yet robust structure. In this case, the receiving plate 16 protrudes on both the left and right sides of the right shell-shaped member 22, and the receiving plate 16 and the right shell-shaped member 22 form a T-shape when viewed from the front, so the duct unit 6 is suspended and supported by the main case 7 in a well-balanced manner.

In addition, the support plate 16 and the right shell-shaped member 22 are uniformly connected from the front to the rear by a group of support plate support ribs 32, so the duct unit 6 exhibits strong resistance to vibrations that are swayed in the fore-and-aft direction. Therefore, even if a fore-and-aft moment acts on the duct unit 6 as the car travels, the duct unit 6 can maintain high strength without swaying back and forth relative to the air cleaner 5.

Although the embodiment of the present invention has been described above, the present invention can be embodied in various other ways. For example, the number of resonators is not limited to two, but may be one or three or more. Also, in the embodiment, the air that passes through the second vertically elongated portion enters the main body case from below, but it may enter the main body case from the side (i.e., the discharge port may be opened sideways). The main body case of the air cleaner can also be fixed to the receiving plate with fasteners such as screws.

It is also possible to form the receiving plate in an inverted L shape, projecting from the upper end of the shell-shaped member on only one side, and place the resonator below the receiving plate (i.e., form the resonator so that it bulges out mainly on one of the pair of shell-shaped members).

The present invention can be embodied in an engine intake system, and is therefore industrially applicable.

REFERENCE SIGNS LIST 1 Intake device 4 Engine 5 Air cleaner 6 Duct unit 7 Main body case 8 Cover case 9 Filter element 15 Air inlet of main body case 7 16 Backing plate 17 Outlet 18 Downward rib for welding 19 Upward rib for welding 21 Left shell-shaped member 22 Right shell-shaped member 23 Intake duct 23a First vertically elongated portion 23b Second vertically elongated portion 23c Bottom portion 24, 25 Resonator 26 Intake port 27 Drain portion 28, 29 Communication passage 32 Backing plate support rib

Claims (2)

The vehicle is equipped with an air cleaner, an intake duct that takes in air into the air cleaner, and a resonator that is integrally provided with the intake duct via a communication passage,
The intake duct has a first vertically elongated portion having an intake port at an upper end through which air flows downward, a second vertically elongated portion having an exhaust port at an upper end through which air flows upward, and a bottom portion connected to the lower ends of both vertically elongated portions, and a main body case constituting a dirty chamber of the air cleaner is integrally connected to the upper end of the second vertically elongated portion,
the air cleaner is disposed so as to overlap an entire length of a bottom portion of the intake duct in a plan view, while the resonator is disposed only in a space surrounded by the both vertically elongated portions and the bottom portion of the intake duct,
The air cleaner, the resonator, and the bottom of the intake duct are arranged at different heights in a state where they overlap in a plan view.
Intake system for engines. The intake duct is formed on a mating surface of two shell-shaped members that are overlapped and joined together, and the first longitudinal portion, the bottom portion, and the second longitudinal portion are continuous with each other,
a substantially horizontal receiving plate having the discharge port of the second longitudinal portion opened therein is integrally provided on one of the two shell-shaped members, and a main body case of the air cleaner is fixed to the receiving plate;
2. An engine intake system according to claim 1 .

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