Engine intake system

Abstract

To provide an engine air intake device capable of: causing air intake sound having a frequency capable of giving an occupant of a vehicle driving satisfaction to be propagated inside a vehicle interior; and reducing air intake sound having a frequency giving the occupant a sense of discomfort, while curbing increase in manufacturing cost and an occupied space in an engine room.SOLUTION: An air cleaner case 100 and an air cleaner cover 103 are connected to each other so as to form a container having an interior space. A filter 102 is installed so as to cover an upper section of the interior space 100a of the air cleaner case 100. An inner cover 104 is installed in the interior space at a position opposite to an upper face 102a of the filter 102 with a distance therefrom so as to form a cover gap space SP between the inner cover and the air cleaner cover 103. Fresh air introduced through an intake air duct 11 is partially introduced to the cover gap space SP, after passing through the filter 102, as shown by an arrow B5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to an engine intake system, and more particularly to the structure of an air cleaner. [Background technology]

[0002] For vehicles, it is necessary to reduce the intake noise emitted outside the vehicle. As a measure to reduce external noise, for example, Patent Document 1 discloses a structure in which a resonator is provided inside the air cleaner.

[0003] Incidentally, while it is required that sounds that people find unpleasant (hearing sounds) be reduced in vehicles, it is also required that the driver and passengers of the vehicle be able to feel a sense of satisfaction from driving the vehicle through auditory means. A conventional structure used to enable drivers and others to perceive pleasant sounds will be explained using Figure 8.

[0004] As shown in Figure 8, an engine 90 is mounted in the engine compartment 9a of the vehicle 9. An intake manifold 91 is attached to the intake side of the engine 90, and an exhaust manifold 92 is attached to the exhaust side. An intake duct 93 is connected to the intake manifold 91 to introduce fresh air into the intake manifold 91, and an exhaust pipe 94 is connected to the exhaust manifold 92 to discharge exhaust gas.

[0005] An air cleaner 95 is connected to the intake duct 93 on the upstream side in the direction of fresh air flow, and an intake duct 96 that takes in fresh air from the outside is connected to the air cleaner 95. In the conventional structure shown in Figure 8, a branch pipe 97 is connected to the intake duct 93, and a resonator 98 is joined to the branch pipe 97. The resonator 98 is equipped with a vibrating membrane, and the vibrating membrane is configured to close the end of the resonant pipe, which includes the branch pipe 97. The resonator 98 can propagate intake sound of a specific frequency with increased sound pressure into the vehicle compartment 9b by vibrating the vibrating membrane due to air column resonance at a specific frequency that occurs inside the resonant pipe. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2010-180773 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, conventional technologies, including the structure described using Figure 8, require branch pipes and resonators, which leads to problems such as increased manufacturing costs and the need for additional space in the engine compartment.

[0008] The present invention aims to solve the above-mentioned problems and provides an engine intake system that can transmit intake noise at frequencies that give the occupants of the vehicle a sense of satisfaction in driving, while suppressing increases in manufacturing costs and the space occupied in the engine compartment, and reducing intake noise at frequencies that people find unpleasant. [Means for solving the problem]

[0009] An engine intake system according to one aspect of the present invention is an engine intake system for introducing fresh air into an engine, comprising an intake duct, an air cleaner, and an introduction duct. The intake duct is a duct that takes in fresh air and sends it to the air cleaner. The air cleaner is connected to the intake duct and filters the fresh air that has passed through the intake duct. The introduction duct is connected to the air cleaner and is a duct that introduces the fresh air filtered by the air cleaner into the engine.

[0010] In the engine intake system according to this embodiment, the air cleaner comprises an air cleaner case, an air cleaner cover, and a filter. The air cleaner case has an intake communication portion that communicates with the intake duct. The air cleaner cover is joined to the air cleaner case and together with the air cleaner case constitutes a container having an internal space. The filter is disposed in the internal space and filters the fresh air.

[0011] In the above air cleaner, the air cleaner cover is arranged such that there is an introduction space between it and the filter through which the filtered fresh air is introduced. And the air cleaner is, The aforementioned intake duct Connected to introduction The device further includes an inner cover disposed in the introduction space, which has an opening, a gap between it and the filter, and a cover space between it and the air cleaner cover. In the engine intake system according to the above embodiment, the space between the covers is in communication with the intake duct only through the gap between the filter and the inner cover. In the engine intake system according to the above embodiment, the air cleaner cover is the introduction duct and the inner cover Interior space It has an outlet pipe section that relays fresh air between it and together It has one or more columnar joints that protrude toward the inner cover. do. The aforementioned inner cover is The inner end of the outlet pipe portion of the air cleaner cover is joined to an outlet opening, One or more joined parts to be joined to the joint portion of the air cleaner cover and , an insertion edge formed to protrude toward the introduction duct in the portion surrounding the outlet opening and, It has the following features. The joint and the joined part are joined to each other by sliding them so that the insertion edge is inserted into the outlet pipe.

[0012] In the intake device of the engine according to the above aspect, in the air cleaner, the inner cover is disposed so as to leave a gap with respect to the filter and to form a cover space between the air cleaner cover. That is, in the intake device of the engine according to the above aspect, the downstream side of the filter in the fresh air flow direction in the air cleaner has a double cover structure of the air cleaner cover and the inner cover. By adopting such a structure, the cover space between the air cleaner cover and the inner cover forms a Helmholtz resonator, and the gap between the inner cover and the filter becomes a communication pipe that connects the intake passage and the resonator. That is, in the intake device of the engine according to the above aspect, by disposing the inner cover between the filter and the air cleaner cover in the air cleaner, a resonator is formed inside the air cleaner. Therefore, in the intake device of the engine according to the above aspect, it is possible to reduce the annoying intake sound only by adding the inner cover to the air cleaner, without adding a branch pipe or a resonator separately from the air cleaner as in the prior art, and to propagate the intake sound of a frequency that can give the vehicle occupants a sense of satisfaction of being in control into the passenger compartment.

[0013] In addition, in the intake device of the engine according to the above aspect, the frequency of the intake sound to be reduced can be defined by setting the gap between the filter and the inner cover, and the frequency of the intake sound to be propagated into the passenger compartment can be defined by setting the volume of the cover space between the air cleaner cover and the inner cover.

[0015] Also, In the intake device of the engine according to the above aspect, the cover space between the air cleaner cover and the inner cover is configured to communicate with the introduction duct only through the path passing through the gap between the filter and the inner cover. Therefore, it is preferable for forming a Helmholtz resonator by preventing air from leaking from the cover space between the air cleaner cover and the inner cover through a path other than the above gap.

[0017] Also,In the intake device of the engine according to the above aspect, since the air cleaner cover is configured to have a lead-out pipe portion, while forming the cover space between the air cleaner cover and the inner cover with a capacity suitable for the frequency of the sound that attempts to generate the cover space, the introduction duct can be connected to the inner cover without adding a separate member.

[0019] Also, In the intake device of the engine according to the above aspect, the inner cover can be attached to the air cleaner cover by sliding and joining the joint portion of the air cleaner cover and the joint portion of the inner cover, and the insertion edge portion of the inner cover can be inserted into the lead-out pipe portion of the air cleaner cover. Therefore, while joining the air cleaner cover and the inner cover with a simple structure, the introduction duct can be connected to the lead-out opening of the inner cover in a state where the lead-out pipe portion is inserted.

[0020] In the intake device of the engine according to the above aspect, the lead-out opening of the inner cover is provided at a location on one side in a direction intersecting the direction facing the filter in the inner cover, and the wall portion facing the filter in the inner cover The aforementioned outlet opening may be formed to be inclined so as to gradually approach the filter as it moves away from the side where it is formed in the intersecting direction.

[0021] In the intake device of the engine according to the above aspect, since the opposing wall portion of the inner cover is formed to be inclined as described above, the fresh air guided into the inner cover after passing through the filter flows along the inner surface of the opposing wall portion toward the lead-out opening. Therefore, in the intake device of the engine according to the above aspect, the flow resistance of the fresh air in the air cleaner can be kept small.

[0022] In the engine intake system according to the above embodiment, the intake duct may include a duct pipe and a screw-hardened member. The duct pipe has an intake port for taking in fresh air from the outside, and an opening separate from the intake port in the middle of the path that guides the taken-in fresh air to the air cleaner case. The porous member is a sheet-like or plate-like member provided to close the opening of the duct pipe.

[0023] In the engine intake system according to the above embodiment, an opening is made in the duct pipe of the intake duct, and a porous member is provided to cover the opening. This allows intake sound to be transmitted from the opening of the duct pipe through the engine compartment to the passenger compartment, and the porous member can reduce the sound pressure level of the transmitted intake sound to a level that does not cause discomfort to the occupants. Thus, in the engine intake system according to the above embodiment, intake sound that gives the occupants of the vehicle a sense of satisfaction in driving can be transmitted into the passenger compartment without adding a branch pipe or resonator separately from the air cleaner, as in the prior art.

[0024] In the engine intake device according to the above embodiment, the porous member is formed using a fibrous material, and the fiber basis weight of at least the portion that closes the opening is 130 g / m². 2 ~400g / m 2 It may also be stated that it is set within the range of [this range].

[0025] In the engine intake system according to the above embodiment, the porous member covering the opening of the duct pipe in the intake duct has a fiber basis weight of 130 g / m². 2 ~400g / m 2 By employing fiber materials set within a certain range, it is possible to transmit intake noise into the cabin that gives the occupants of the vehicle a sense of satisfaction in driving, while keeping manufacturing costs down.

[0026] Furthermore, the inventors conducted intensive research on the sound pressure level of intake noise transmitted into the vehicle cabin and found that it is desirable to set the sound pressure level of the transmitted intake noise within the range of 78 dB to 82 dB. In the intake system of the engine according to the above embodiment, the fiber basis weight is 130 g / m 2 ~400g / m 2 By covering the opening with a fibrous material (for example, nonwoven fabric) set within a certain range, it is possible to keep the sound pressure level of the transmitted intake sound within the range of 78 dB to 82 dB. [Effects of the Invention]

[0027] In the engine intake systems according to each of the above embodiments, it is possible to transmit intake noise at frequencies that give the vehicle occupants a sense of satisfaction in driving the vehicle, while suppressing increases in manufacturing costs and the amount of space occupied in the engine compartment, and reducing intake noise at frequencies that people find unpleasant. [Brief explanation of the drawing]

[0028] [Figure 1] This is a perspective view showing the intake system of an engine according to an embodiment. [Figure 2] This is a cross-sectional view showing the structure of the air cleaner. [Figure 3] This is a cross-sectional view showing the arrangement of the inner cover, filter, and air cleaner cover. [Figure 4] This is a perspective view showing the structure of the air cleaner cover. [Figure 5] This is a perspective view showing the structure of the inner cover. [Figure 6] This is a plan view showing the arrangement of the inner cover on the filter. [Figure 7] (a) is a front view showing the structure of the air cleaner, and (b) is a schematic diagram showing the structure of the intake duct. [Figure 8] This is a schematic diagram showing the intake system of a conventional engine. [Modes for carrying out the invention]

[0029] The embodiments of the present invention will be described below with reference to the drawings. The forms described below are merely examples of the present invention, and the present invention is not limited to these forms except for its essential configuration.

[0030] 1. Schematic configuration of the engine intake system 1 The schematic configuration of the engine intake system 1 according to this embodiment will be explained with reference to Figure 1.

[0031] As shown in Figure 1, the intake system 1 of the engine according to this embodiment includes an air cleaner 10, an intake duct (fresh air duct) 11, and an introduction duct 12. The air cleaner 10 is connected to the intake duct 11 and the introduction duct 12, and filters the fresh air sent from the intake duct 11 and leads it to the introduction duct 12. The intake duct 11 is mounted, for example, on the radiator shroud and, as indicated by arrow A1, forms a path that takes in fresh air from the intake port 11a and sends it to the air cleaner 10. The introduction duct 12 is connected to an intake manifold (not shown) and is a path that sends the fresh air filtered by the air cleaner 10 to the engine via the intake manifold, as indicated by arrow A2.

[0032] 2. Structure of Air Cleaner 10 The structure of the air cleaner 10 will be explained using Figure 2.

[0033] As shown in Figure 2, the air cleaner 10 includes an air cleaner case 100, an inlet pipe 101, a filter 102, an air cleaner cover 103, and an inner cover 104. The air cleaner case 100 has an opening that faces upward in the Z direction and has a wall portion that is recessed downward in the Z direction from the opening edge surrounding the opening at the top in the Z direction. That is, the air cleaner case 100 has a dome shape that faces upward in the Z direction. The inlet pipe 101 is connected to the lower part of the air cleaner case 100 in the Z direction and connects the intake duct 11 and the air cleaner case 100. One opening (inlet opening) 101a of the inlet pipe 101 is located in a position where it enters the internal space 100a of the air cleaner case 100. The location where the inlet pipe 101 is connected in the air cleaner case 100 corresponds to the intake communication section.

[0034] The filter 102 is fitted into the air cleaner case 100 from the opening toward the inside (downward in the Z direction). As the fresh air that has flowed from the inlet pipe 101 through the internal space 100a, as indicated by arrows B1 and B2, passes through the filter 102, as indicated by arrow B3, the filter 102 filters out dust and other particles contained in the fresh air.

[0035] The air cleaner cover 103 has an opening that faces downward in the Z direction and a wall portion that is recessed upward in the Z direction from the opening edge surrounding the lower part of the opening in the Z direction. That is, in this embodiment, the air cleaner cover 103 has a dome shape that opens downward in the Z direction. The air cleaner cover 103 has an outlet pipe portion 103b that penetrates the wall portion on the left side in the X direction. The outlet pipe portion 103b is open toward the internal space 103a of the air cleaner cover 103. The inner opening end 103c of the outlet pipe portion 103 is disposed in the internal space 103a of the air cleaner cover 103. On the other hand, the outer end of the outlet pipe portion 103b is connected to the introduction duct 12. Specifically, the outer end of the outlet pipe portion 103b is connected to the introduction duct 12 by being inserted through the connection opening 12a of the introduction duct 12.

[0036] The inner cover 104 has an opening that faces downward in the Z direction and has a wall portion that is recessed upward in the Z direction from the opening edge surrounding the lower part of the opening in the Z direction. The inner cover 104 has a dome shape that is slightly smaller than the air cleaner cover 103 and is disposed between the upper surface 102a of the filter 102 and the inner surface of the wall portion of the air cleaner cover 103. On the left side of the wall portion of the inner cover 104 in the X direction, there is an outlet opening to which the inner end of the outlet pipe portion 103b of the air cleaner cover 103 is joined.

[0037] A portion of the fresh air that has passed through the filter 102 is sent from the internal space 104a of the inner cover 104 through the outlet pipe section 103b of the air cleaner cover 103 to the introduction duct 12, as indicated by arrow B4. In addition, a portion of the fresh air that has passed through the filter 102 flows into the space SP between the air cleaner cover 103 and the inner cover 104, as indicated by arrow B5. However, since the air cleaner cover 104 does not have an outlet for fresh air except for the opening at the bottom in the Z direction, the fresh air that flows into the space SP between the covers also passes through the gap between the inner cover 104 and the filter 102, and is sent from the internal space 104a of the inner cover 104 through the outlet pipe section 103b of the air cleaner cover 103 to the introduction duct 12.

[0038] 3. Detailed arrangement of the inner cover 104, filter 102, and air cleaner cover 103 The detailed arrangement of the inner cover 104, the filter 102, and the air cleaner cover 103 will be explained with reference to Figure 3.

[0039] As shown in Figure 3, the air cleaner 10 employs a so-called double-lid structure. That is, as described above, the opening edge surrounding the opening at the top of the air cleaner case 100 in the Z direction and the opening edge surrounding the opening at the bottom of the air cleaner cover 103 in the Z direction are joined to each other, and an inner cover 104 opening downward in the Z direction is disposed between the filter 102 and the air cleaner cover 103.

[0040] The air cleaner cover 103 is provided with multiple joining protrusions (joints) 103d extending from the top to the bottom in the Z direction. The inner cover 104 is provided with joining bosses (parts to be joined) 104d at locations corresponding to the joining protrusions 103d of the air cleaner cover 103. The inner cover 104 is joined to the air cleaner cover 103 by joining the tip portions of the joining protrusions 103d to the joining bosses 104d. Each joining protrusion 103d and each joining boss 104d are welded to each other by sliding in the X direction.

[0041] Furthermore, the inner cover 103 is connected to the air cleaner cover 103 by an inlet edge that is inserted from the inner opening end 103c of the outlet pipe portion 103b of the air cleaner cover 103, surrounding the outlet opening 104c toward the inside of the outlet pipe portion 103b and protruding toward the outlet pipe 103b. The structure around the outlet opening 104c in the inner cover 103 will be described later.

[0042] In the air cleaner 10, the inner cover 104 has an edge portion (opposing edge portion) 104b surrounding the opening at the bottom in the Z direction, which faces the upper surface 102a of the filter 102 with a gap G between them. In other words, the inner cover 104 is suspended from the air cleaner cover 103 and is positioned so that the opposing edge portion 104b does not come into contact with the upper surface 102a of the filter 102.

[0043] 4. Detailed structure of air cleaner cover 103 and inner cover 104 The detailed structure of the air cleaner cover 103 and the inner cover 104 will be explained using Figures 4 and 5. Figure 4 shows the air cleaner cover 103 before it is joined to the inner cover 104, and Figure 5 shows the inner cover 104 before it is joined to the air cleaner cover 103.

[0044] As shown in Figure 4, the air cleaner cover 103 has a rectangular opening and an internal space 103a in the shape of a flattened rectangular parallelepiped. The air cleaner cover 103 also has an outlet pipe portion 103b that penetrates a part of the peripheral wall. As described above, the outer open end 103g of the outlet pipe portion 103b is inserted through the connection opening 12a of the introduction duct 12, connecting the outlet pipe portion 103b and the introduction duct 12, and the inner open end 103c of the outlet pipe portion 103b is inserted through the insertion edge portion around the outlet opening 104c of the inner cover 104, thus connecting them to each other.

[0045] Two connecting protrusions 103d are formed protruding in the Z direction from the inner surface of the ceiling wall (wall portion facing the filter 102) 103e of the air cleaner cover 103. The two connecting protrusions 103d are formed at positions spaced apart from each other in the Y direction. In addition, one connecting protrusion 103d is formed protruding in the Z direction from the outer surface 103f of the pipe on the internal space 103a side of the outlet pipe portion 103b of the air cleaner cover 103. The connecting protrusion 103d formed protruding from the outer surface 103f of the pipe is positioned at a position spaced apart in the X direction from the two connecting protrusions 103d formed protruding from the inner surface of the ceiling wall 103e.

[0046] The three connecting protrusions 103d have an I-shape, with the tip 103h in the Z direction extending in the X direction.

[0047] Next, as shown in Figure 5, the inner cover 104 also has a dome shape, similar to the air cleaner cover 103. The inner cover 104 has an opening on the left side in the X direction of its peripheral wall (an outlet opening 104c is provided). As described above, the outlet opening 104c of the inner cover 104 is an opening for sending fresh air that has passed through the filter 102 to the intake duct 12. The opening edge surrounding the outlet opening 104c of the inner cover 104 is inserted into and connected to the outlet pipe section 103b of the air cleaner cover 103 from its inner opening end 103c.

[0048] The ceiling wall 104f (the wall portion facing the filter 102) of the inner cover 104 is formed inclined such that it gradually decreases in the Z direction (gradually approaches the filter 102) as you move from the left side in the X direction, where the outlet opening 104c is provided, to the right side in the X direction.

[0049] The inner cover 104 is provided with three joining boss portions (parts to be joined) 104d. The three joining boss portions 104d are positioned to correspond to each of the joining protrusions 103d of the air cleaner cover 103. Each joining boss portion 104d is provided with a protruding receiving portion 104e that accepts the insertion of the tip portion 103h of the joining protrusion 103d. The protruding receiving portion 104e is formed by a hole or notch.

[0050] In this embodiment, with the tip portion 103h of the joining projection 103d inserted into the protruding receiving portion 104e of the joining boss portion 104d, the air cleaner cover 103 and the inner cover 104 are slid in the X direction, and the tip portion 103h of the joining projection 103d is welded to the joining boss portion 104d.

[0051] 5. Arrangement configuration of the inner cover 104 relative to the filter 102 in a plan view. The arrangement of the inner cover 104 relative to the filter 102 in a plan view will be explained using Figure 6. Figure 5 is a plan view showing the filter 102 and inner cover 104 with the air cleaner cover 103 removed.

[0052] Figure 6As shown, the filter 102 has the same rectangular shape as the opening of the air cleaner case 100 when viewed from the Z direction in plan view. The inner cover 104 is positioned to cover a portion of the upper surface 102a of the filter 102. If a virtual line L is drawn passing through the center of the filter 102 in the X direction and extending in the Y direction, the area of ​​the filter 102 covered by the inner cover 104 in the portion C1 to the left of the virtual line L in the X direction is smaller than the area C2 to the right of the virtual line L in the X direction. In other words, in plan view, the inner cover 104 is positioned such that in portion C1, the area of ​​the region of the upper surface 102a of the filter 102 that is not covered by the inner cover 104 is larger than that of portion C2.

[0053] Furthermore, the inner cover 104 is formed such that the peripheral wall 104g on the side where the outlet opening 104c is provided (opening-side peripheral wall) 104g is inclined with respect to the Y-axis direction, while the peripheral wall 104h on the opposite side of where the outlet opening 104c is provided (opposite-side peripheral wall) 104h is formed to align with the Y-axis direction.

[0054] 6. Structure of the intake duct 11 The structure of the intake duct 11, which takes in fresh air from the outside, will be explained using Figure 7.

[0055] As shown in Figure 7(a), the intake duct 11 comprises a duct pipe 110, a nonwoven fabric (sheet-like porous material) 111, and a retaining member 112. The duct pipe 110 is a pipe that constitutes a path for guiding fresh air taken in from the intake port 11a (see Figure 1) to the air cleaner case 100 of the air cleaner 10. Although detailed illustrations are omitted, in this embodiment, the intake port 11a of the intake duct 11 is mounted on the radiator shroud and opens toward the front of the vehicle.

[0056] As shown in Fig. 7(b), an opening 110a different from the intake port 11a is provided in the duct pipe 110 in the middle of the longitudinal direction. As an example, the opening 110a is opened in the wall portion on the rear side of the vehicle of the duct pipe 110. That is, it is opened toward the passenger compartment side. In the present embodiment, as an example, the opening area of the opening 110a is 2000 mm 2 ~5000 mm 2 and is set within this range. The opening area of the opening 110a in the duct pump 110 is set within the above range in relation to the sound pressure level of the intake sound propagated to the passenger compartment. That is, as the opening area of the opening 110a increases, the value of the sound pressure level of the intake sound gradually increases. For this reason, when trying to achieve a sound pressure level range of 78 dB to 82 dB, which is suitable for giving the driver a sense of satisfaction in driving, the opening area of the opening 110a is set to 2000 mm 2 ~5000 mm 2 and it is desirable to set it within this range.

[0057] The non-woven fabric 111 is provided as a member (sound pressure control member) for controlling the sound pressure of the sound propagated from the opening of the duct pipe 110. As shown in Fig. 7(b), the non-woven fabric 111 is formed in a size equal to or slightly larger than the opening 110a and is arranged to cover the entire opening 110a. In the present embodiment, the non-woven fabric 111 having a fiber basis weight in the range of 130 g / m 2 ~400 g / m 2 is used. By covering the opening 110a with the non-woven fabric 111 having this fiber basis weight, the sound pressure level of the intake sound propagated from the opening 110a of the duct pipe 110 to the passenger compartment through the engine room can be made within the range of 78 dB to 82 dB.

[0058] As a result of the inventors' study, if a non-woven fabric with a fiber basis weight less than 130 g / m 2 is used, the air warmed in the engine room by the driving of the engine may be sucked into the duct pipe 110 from the opening 110a of the duct pipe 110. For this reason, when the fiber basis weight is less than 130 g / m 2By using the nonwoven fabric 111 described above, it is possible to suppress the intake of heated air from the opening 110a into the duct pipe 110, thereby suppressing a decrease in engine output.

[0059] Furthermore, there is a relationship between the fiber basis weight of the nonwoven fabric 111 and the sound pressure level of the intake sound transmitted into the vehicle cabin, where the sound pressure level gradually decreases as the fiber basis weight of the nonwoven fabric 111 increases. For this reason, in order to give the driver in the vehicle cabin a sense of satisfaction in driving, the fiber basis weight of the nonwoven fabric 111 should be 400 g / m 2 It is desirable that the sound pressure level of the intake sound be in the range of 78 dB to 82 dB.

[0060] The retaining member 112 is a grid-like frame member provided with a plurality of openings 112a, and is a member for fixing the nonwoven fabric 111 by sandwiching it between the edge of the opening 110a and the retaining member 112.

[0061] 7. Effects In the intake system 1 of the engine according to this embodiment, an inner cover 104 is provided in the air cleaner 10 such that there is a gap G between it and the filter 102, and a cover space SP is provided between it and the air cleaner cover 103. That is, in the intake system 1, the air cleaner 10 has a double-lid structure with the air cleaner cover 103 and the inner cover 104 downstream of the filter 102 in the direction of fresh air flow. By adopting such a structure, the cover space SP between the air cleaner cover 103 and the inner cover 104 constitutes a Helmholtz resonator, and the gap G between the inner cover 104 and the filter 102 becomes a connecting pipe that connects the intake passage and the resonator. In other words, in the intake system 1, a resonator is formed inside the air cleaner 10 by providing the inner cover 104 between the filter 102 and the air cleaner cover 103 in the air cleaner 10. Therefore, in the intake system 1, without adding a branch pipe or resonator separately from the air cleaner as in conventional technology, simply by adding an inner cover 104 to the air cleaner 10, it is possible to reduce unpleasant intake noise while transmitting intake noise at a frequency that gives the vehicle occupants a sense of satisfaction in driving the vehicle into the cabin.

[0062] In the intake system 1 of the engine according to this embodiment, the frequency of intake noise to be reduced can be defined by setting the gap G between the filter 102 and the inner cover 104, and the frequency of intake noise to be propagated into the passenger compartment can be defined by setting the volume of the inter-cover space SP between the air cleaner cover 103 and the inner cover 104.

[0063] Furthermore, in the intake system 1 of the engine according to this embodiment, the cover space SP between the air cleaner cover 103 and the inner cover 104 is configured to communicate with the introduction duct 12 only through the gap G between the filter 102 and the inner cover 103. This configuration ensures that there are no other paths through which fresh air can leak from the cover space SP between the air cleaner cover 103 and the inner cover 104 besides the gap G, making it suitable for configuring a Helmholtz resonator.

[0064] Furthermore, in the intake system 1 of the engine according to this embodiment, the air cleaner cover 103 is configured to have an outlet pipe portion 103b, so that the inter-cover space SP between the air cleaner cover 103 and the inner cover 104 is formed with a volume suitable for the frequency of the sound that is to be generated, and the introduction duct 12 can be connected to the inner cover 104 without adding any other components.

[0065] Furthermore, in the engine intake device 1 according to this embodiment, the inner cover 104 can be attached to the air cleaner cover 103 by sliding the joining protrusion (joint portion) 103d of the air cleaner cover 103 and the joining boss portion (jointed portion) 104d of the inner cover 104 in the X direction to join them, and the insertion edge portion (the portion surrounding the outlet opening 104c) of the inner cover 104 can be inserted into the outlet pipe portion 103b of the air cleaner cover 103. Thus, the air cleaner cover 103 and the inner cover 104 can be joined with a simple structure, and the introduction duct 12 can be connected to the outlet opening 104c of the inner cover 104 with the outlet pipe portion 103b interposed between them.

[0066] Furthermore, in the intake system 1 of the engine according to this embodiment, the ceiling wall (wall portion facing the filter 102) 104f of the inner cover 104 is formed to be inclined so as you move from the side where the outlet opening 104c is provided to the opposite side, gradually approaching the filter 102, as shown in Figure 5. Therefore, fresh air that has passed through the filter 102 and been guided into the internal space 104a of the inner cover 104 flows along the inner surface of the ceiling wall 104f toward the outlet opening 104c. Thus, in the intake system 1, the flow resistance of fresh air within the air cleaner 10 can be kept to a minimum.

[0067] Furthermore, in the engine intake system 1 according to this embodiment, an opening 110a is made in the duct pipe 110 of the intake duct 11, and a nonwoven fabric (sheet-like porous material) 111 is provided to cover the opening 110a. This allows intake sound to be transmitted from the opening 110a of the duct pipe 110 through the engine compartment to the passenger compartment, and the sound pressure level of the transmitted intake sound can be set to a level that does not cause discomfort to the occupants by the nonwoven fabric 111. Thus, the intake system 1 can transmit intake sound into the passenger compartment that gives the occupants of the vehicle a sense of satisfaction in driving, without having to add a branch pipe or resonator separately from the air cleaner as in the conventional technology.

[0068] Furthermore, in the intake system 1 of the engine according to this embodiment, the fiber basis weight of the nonwoven fabric 111 covering the opening 110a of the duct pipe 110 in the intake duct 11 is 130 g / m². 2 ~400g / m 2 Because it falls within this range, it is suitable for transmitting intake sounds into the cabin that give the occupants a sense of satisfaction in driving the vehicle, while keeping manufacturing costs down.

[0069] In addition, the fiber weight of the intake device 1 is 130 g / m². 2 ~400g / m 2 By covering the opening 110a with a nonwoven fabric 111 set within a certain range, it is possible to set the sound pressure level of the transmitted intake sound within the range of 78 dB to 82 dB.

[0070] As described above, the engine intake device 1 according to this embodiment can transmit intake noise at frequencies that give the occupants of the vehicle a sense of satisfaction in driving, while suppressing increases in manufacturing costs and the space occupied in the engine compartment, and can also reduce intake noise at frequencies that people find unpleasant.

[0071] [Differentiation] In the above embodiment, the air cleaner cover 103 of the air cleaner 10 is also dome-shaped. However, in the present invention, the shape of the air cleaner cover 103 is not limited to this, as long as there is space to accommodate the inner cover 104 between the filter 102 and the air cleaner cover 103. For example, a flat air cleaner cover 103 can also be used.

[0072] Furthermore, various shapes can be adopted for the air cleaner case 101 and the air cleaner cover 103, as long as they can be joined together to form a container with an internal space.

[0073] In the above embodiment, the space SP between the air cleaner cover 103 and the inner cover 104 in the air cleaner 10 is connected to the outlet opening only through the gap G between the filter 102 and the opposing edge 104b of the inner cover 104. However, the present invention is not limited thereto. It is also possible to adopt a configuration in which fresh air flows from the space SP between the air cleaner cover 103 and the inner cover 104 to the introduction duct 12, provided it is a small amount.

[0074] Furthermore, in the above embodiment, the air cleaner cover 103 has an outlet pipe section 103b, and the internal space 104a of the inner cover 104 and the introduction duct 12 are in communication via the outlet pipe section 103b. However, in the present invention, it is also possible to adopt a configuration in which the inner cover 104 has a pipe section that can be directly connected to the introduction duct 12.

[0075] Furthermore, in the above embodiment, the ceiling wall 104f of the inner cover 104 is formed at an inclination as shown in Figures 2, 3, and 5. However, in the present invention, it is not necessarily required that the ceiling wall 104f of the inner cover 104 be inclined. For example, it is also possible to use an inner cover 104 having a ceiling wall 104f with an inner surface parallel to the upper surface 102a of the filter 102.

[0076] Furthermore, in the above embodiment, the inner cover 104 is attached to the air cleaner cover 103 by joining (welding) the joining protrusion 103d on the air cleaner cover 103 to the joining boss portion 104d on the inner cover 104. However, in the present invention, it is not necessarily required to join the joining protrusion 103d on the air cleaner cover 103 to the inner cover 104 by joining the joining protrusion 103d on the air cleaner cover 103 to the joining boss portion 104d. For example, it is also possible to provide one or more bosses on the inner surface of the air cleaner cover 103 and join the air cleaner cover 103 and the inner cover 104 by bonding (adhesion with adhesive or welding, etc.) a part of the outer surface of the inner cover 104 to these bosses, or to join the air cleaner cover 103 and the inner cover 104 using rivets, screws, etc.

[0077] Furthermore, in the above embodiment, a sheet-like nonwoven fabric 111 was attached to cover the opening 110a of the duct pipe 110 in the intake duct 11. However, in the present invention, the opening 110a can also be covered with a porous material other than nonwoven fabric. For example, the same effect can be obtained by covering the opening 110a with a foamed resin sheet or a resin panel.

[0078] Furthermore, the fiber weight of the porous material can be appropriately set according to the sound pressure level of the intake sound. [Explanation of symbols]

[0079] 1. Intake system 10 Air Cleaner 11 Intake duct 11a Intake 12. Inlet duct 12a Connection opening 100 Air Cleaner Case 101 Introductory tube 102 filters 102a Top side 103 Air Cleaner Cover 103d Joint protrusion (joint) 104 Inner cover 104b Opposing edge 104d Joint boss portion (part to be joined) 104f Bowl bottom wall 110 Duct pipe 111 Nonwoven fabric (porous material)

Claims

1. An engine intake system that introduces fresh air into the engine, An intake duct that takes in fresh air, An air cleaner connected to the intake duct filters the fresh air that has passed through the intake duct, An introduction duct connected to the air cleaner, which introduces the fresh air filtered by the air cleaner into the engine, Equipped with, The aforementioned air cleaner is, An air cleaner case having an intake communication section that communicates with the aforementioned intake duct, An air cleaner cover is joined to the air cleaner case and, together with the air cleaner case, constitutes a container having an internal space; A filter is disposed in the aforementioned internal space and filters the fresh air, It has, The air cleaner cover is arranged such that there is an introduction space between it and the filter through which the filtered fresh air is introduced. The air cleaner has an inlet opening connected to the intake duct, and further has an inner cover disposed in the inlet space such that it is separated from the filter and there is a gap between the inner cover and the air cleaner cover. The space between the covers is connected to the introduction duct only through the gap between the filter and the inner cover. The air cleaner cover has an outlet pipe section that relays the passage of fresh air between the introduction duct and the internal space of the inner cover, and has one or more columnar joint sections that protrude toward the inner cover. The inner cover has an outlet opening to which the inner end of the outlet pipe portion of the air cleaner cover is joined, one or more joined portions to which the joint portion of the air cleaner cover is joined, and an insertion edge portion that protrudes toward the introduction duct in the portion surrounding the outlet opening. The joint and the joined portion are joined to each other by sliding them so that the insertion edge is inserted into the outlet pipe portion. Engine intake system.

2. In the intake system for the engine according to Claim 1, The outlet opening of the inner cover is provided at one location on the inner cover in a direction intersecting the direction facing the filter, and the wall portion of the inner cover facing the filter is formed to be inclined so as it moves away from the side where the outlet opening is formed in the intersecting direction, it gradually approaches the filter. Engine intake system.

3. In the intake system for an engine according to Claim 1 or Claim 2, The aforementioned intake duct is A duct pipe having an air intake port for taking in fresh air from the outside, and an opening separate from the air intake port located in the middle of the path that guides the taken-in fresh air to the air cleaner case, A porous member, which is a sheet-like or plate-like member, is provided to close the opening of the duct pipe, Having, Engine intake system.

4. In the intake system for the engine according to Claim 3, The porous member is formed using a fibrous material, and the fiber weight of at least the portion that closes the opening is 130 g / m². ２ ~400g / m ２ It is set within the range, Engine intake system.

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