JP2015190444A - Intake system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the vibration and noise of an intake system while uniformly and sufficiently supplying intake air to each cylinder.SOLUTION: An upstream chamber 15 is disposed on an upstream side of an air cleaner 14. An air inlet 18 of the upstream chamber 15 is open upward, to which an air intake duct 19 is connected. On the other hand, an air outlet 16 of the upstream chamber 15 is similarly open generally upward and is connected to a dirty chamber 14b of the air cleaner 14 by a rubber hose 17. Since the upstream chamber 15 is present upstream of the air cleaner 14, pulsated intake air counterflowing from the air cleaner 14 is attenuated/absorbed. Since the air inlet 18 and the air outlet 16 of the upstream chamber 15 are open almost in the same direction, it is possible to ensure a high buffer effect, an excellent pulsation elimination performance, and an excellent performance for uniformly supplying the air to the air cleaner 14.

Description

  The present invention relates to an intake device for an internal combustion engine mounted on a vehicle.

  Generally, an intake device for an internal combustion engine starts with an air cleaner, and a surge tank is disposed between the throttle valve and the intake manifold. However, Patent Document 1 discloses that sufficient inertial intake in a high rotation range is realized. It is disclosed that a surge tank is also provided between the air cleaner and the throttle valve for the purpose of enhancing the control response in the low rotation range.

  Patent Document 2 discloses disposing a pre-cleaner on the upstream side of a main air cleaner for the purpose of dust removal in an internal combustion engine for construction machinery. Patent Document 3 discloses an air cleaner and a filter. It is disclosed to make a double structure of a rear chamber provided with an upstream chamber connected to the upstream side thereof (that is, to connect the upstream chamber to the dirty chamber of the air cleaner).

JP 2008-82291 A JP 2013-177748 A JP 2002-147302 A

  The surge tank is a volume chamber having a cross-sectional area larger than that of the flow path. By storing air in this chamber, a sufficient amount of air can be uniformly supplied to each cylinder in the multi-cylinder internal combustion engine, and intake pulsation can be achieved. It can contribute to the suppression of vibration by dampening.

  On the other hand, in a vehicle internal combustion engine, generally, a surge tank is provided only on the downstream side of an air cleaner as in Patent Document 1, but the air intake of the air cleaner is only open to the atmosphere (engine room). Since the downstream pulsation is transmitted as it is to the air cleaner, there is a problem that not only is it difficult to suppress the vibration of the air cleaner itself, but also the pulsation damping performance is limited.

  Regarding this point, if a pre-cleaner is further provided upstream of the air cleaner as in Patent Document 2 or an upstream chamber is connected to the dust side of the air cleaner as in Patent Document 3, the amount of air entering the air cleaner is restricted. Therefore, it can be said that a pulsation damping effect on the downstream side of the air cleaner can be expected. However, if a volume chamber such as a chamber is disposed upstream of the air cleaner, a phenomenon in which air passes through the chamber occurs and the pulsation damping effect cannot be expected so much.

  The present invention has been made in view of the present situation as described above.

The present invention relates to an intake device for an internal combustion engine for a vehicle, and the intake device is provided with an upstream chamber on the upstream side of an air cleaner so that an air intake port and an air outlet are opened in substantially the same direction in the upstream chamber. Provided. In this case, the air intake port and the air outlet can be provided on the side surface or the front surface of the upstream chamber, for example, but are preferably provided on the upper surface from the viewpoint of effective use of the engine room.

  The invention of the present application also includes the configuration described in claim 2. In the invention of claim 1, the upstream chamber is supported from below by a lower bracket fixed to the battery mounting table, and the upper part is the vehicle body. It is attached to the upper bracket fixed to the frame. In this second aspect, as the structure for attaching the upstream chamber to the upper bracket, it may be suspended by being fixed to the upper bracket with a bolt or the like, or it may be held in a state not to be laterally displaced.

  In order to prevent the vibration of the flow chamber from being transmitted to the air cleaner or the vibration of the air cleaner from being transmitted to the upstream chamber, the air cleaner and the upstream chamber are preferably connected by a rubber hose.

  In the present invention, since the air intake and the air outlet of the upstream chamber are opened in substantially the same direction, the air that has entered the upstream chamber from the air intake circulates around the inside of the upstream chamber. It is discharged from the exit. For this reason, air can be prevented from entering the upstream chamber while the pulsation of the air cleaner is maintained, and a high buffer effect can be secured. As a result, vibration and noise of the air cleaner (or the entire intake system) due to pulsation or the like can be greatly suppressed.

  That is, even if the air cleaner tries to pulsate, the upstream chamber absorbs the pulsation, so that the entire pulsation of the intake system can be greatly suppressed. In this case, it goes without saying that a necessary amount of air can be supplied to the air cleaner by ensuring a sufficient capacity in the upstream chamber.

  Further, since the upstream chamber has a pulsation elimination function, it is possible to reduce the capacity of the surge tank disposed on the downstream side of the throttle valve, thereby improving design freedom.

  Further, in the present invention, since the air swirls greatly inside the upstream chamber, dust contained in the air can be attached to the inner surface of the upstream chamber, thereby reducing the burden on the filter in the air cleaner. Is also possible. In addition, since air is mixed evenly in the upstream chamber, dust (foreign matter) is dispersed, so that a specific part of the filter in the air cleaner is prevented from being contaminated, and it can contribute to prolonging the life of the filter. .

  Now, when the upstream chamber is provided, low suction resistance must be ensured in the same way as when the air cleaner's air intake port is directly opened to the engine room, and then the upstream chamber becomes considerably large and has a certain weight. It cannot be denied. On the other hand, since the battery for vehicles has a considerable weight, the battery mounting table on which the battery is mounted has a structure that is highly stable and hardly vibrates.

  Therefore, if the configuration of claim 2 is adopted, even if the upstream chamber is heavy, it is stably supported from below by a highly stable battery mounting table, and the upper part is attached to the vehicle body frame via the upper bracket. Therefore, vibrations in the vertical and horizontal directions can be remarkably suppressed. Further, since the vibration of the upstream surge tank can be blocked from propagating to the vehicle body frame, the vibration of the vehicle body caused by the vibration of the upstream surge tank can be prevented or significantly suppressed.

1 is an overall schematic plan view of an embodiment. It is a rough right view of FIG. It is a top view of the principal part. FIG. 4 is a right side view taken along the line IV-IV in FIG. 3. FIG. 5 is a cross-sectional view taken along line V-V in FIG. 3. (A) is the VI-VI sectional view taken on the line of FIG. 3, (B) is the BB sectional view of (A). (A) is a principal part right view of a modification, (B) is BB view sectional drawing of (A).

(1). Outline Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline will be described based on FIGS. In the following explanation, the front / rear / left / right wording is used to specify the direction, which is defined as the direction in which the driver seated on the driver's seat is facing forward, and is specifically shown in FIG. doing.

  The vehicle includes a front frame 2 that defines an opening edge of a front end portion of the engine room 1 and an inclined frame 3 that is continuous with the front frame 2, and a radiator 4 is disposed below the front frame 2. Therefore, the front frame 2 can be rephrased as a radiator support frame.

  In the engine room 1, the engine body 5 is arranged in a vertical position with the crank axis 6 facing in the front-rear direction. The engine body 5 has a conventionally known structure, and has a cylinder block 7 and a cylinder head 8 fixed to the upper surface thereof as main elements, and a head cover 9 is fixed to the upper surface of the cylinder head 8.

  As shown in FIG. 2, an intake manifold 10 is fixed to one longitudinal side surface (right side surface) of the cylinder head 8, a surge tank 11 is connected to a collecting portion of the intake manifold 10, and a throttle tank is further connected to the surge tank 11. The outlet of the valve 12 is connected, and the outlet hole of the clean chamber 14 a in the air cleaner 14 is connected to the inlet of the throttle valve 12 via the intake pipe 13. The internal combustion engine of this embodiment has four cylinders, and therefore the intake manifold 10 has four branch pipes.

  The air cleaner 14 is disposed directly above the intake manifold 10, and the upper surface is located above the upper surface of the engine body 5. A bonnet (not shown) is placed on the air cleaner 14 via a small space. Be placed.

  An upstream chamber 15 is disposed in front of the engine body 5, and an air outlet 16 of the upstream chamber 15 and an inlet of the dirty chamber 14 b in the air cleaner 14 are connected by a rubber hose 17. An air intake duct 19 is connected to the air intake port 18 of the upstream chamber 15, and the air intake duct 19 opens sideways (rightward). As shown in FIG. 1, the dirty chamber 14b of the air cleaner 14 has two front and rear arms 14c that overlap the head cover 9 from above, and the arms 14c are fastened to the head cover 9 with bolts.

  The upper end of the upstream chamber 15 is attached to the front frame 2 via two left and right upper brackets 20 ′ and 20. On the other hand, a battery mounting table 22 on which the battery 21 is placed is provided on the right side of the upstream chamber 15, but as shown in FIG. 2, the upstream chamber 15 is connected to the battery mounting table via the lower bracket 23. 22 is supported from below.

(2) Structure of Air Cleaner and Upstream Chamber Next, details of the portion of the intake device upstream of the throttle valve will be described with reference to the drawings of FIG. First, the air cleaner 14 will be described. The air cleaner 14 has a structure in which a clean chamber 14a is provided on the upper side and a dirty chamber 14b is provided on the lower side, and of course, a filter (not shown) is disposed inside.

  In the clean chamber 14 a of the air cleaner 14, an inclined portion 25 facing diagonally right front is provided at a front side portion, and a cylindrical air outlet 16 is provided in the inclined portion 25. The throttle valve 12 is arranged at the front side portion of the intake manifold 10, but since the throttle valve 12 is located below the inclined portion 25, the air cleaner is simply bent to the L-shape. 14 and the throttle valve 12 can be connected. For this reason, intake air can flow smoothly from the air cleaner 14 to the throttle valve 12 without resistance.

  Further, in the air cleaner 14, since the clean chamber 14a is disposed on the dirty chamber 14b, it is possible to loosen the bending of the intake pipe 13 and eliminate flow resistance while making the height of the air cleaner 14 as low as possible.

  Next, the upstream chamber 15 will be described. The upstream chamber 15 is basically in the shape of a horizontally long rectangular parallelepiped, and the air intake port 18 opens to a left side portion (or right side) of the upper surface of the upstream chamber 15, and an air intake duct 19 slightly rises from the air intake 18 and faces to the right, and the front end (opening edge) of the air intake duct 19 is positioned near the right end of the upstream chamber 15.

  Therefore, the air intake duct 19 is located in the area above the upstream chamber 15, but with this arrangement, the dead space can be used effectively and the air intake duct 19 interferes with other members. Can be prevented.

  For example, as shown in FIG. 4, the air intake duct 19 has a shape that is crushed from above and below. For this reason, the height can be made as low as possible without reducing the volume, and the distance from the hood can be kept as large as possible. Further, the air intake duct 19 has a vertical width that increases from the front end toward the rear end, but by selecting such a shape, the resistance of the traveling wind can be suppressed. Further, as shown in FIG. 5, for example, a throttle portion 19 b for reducing vibration and rectifying intake air is provided near the tip of the air intake duct 19.

  A portion of the front surface of the upstream chamber 15 on the right side of the air intake port 18 is, for example, as shown in FIG. 4, an inclined portion 26 that is lowered backward as it goes downward in a side view. A cylindrical air outlet 16 is provided in a protruding position on the left side of 26. Therefore, the upper surface of the upstream chamber 15 is narrow at the inclined portion 26. A forward projecting portion 28 is formed in a portion of the upstream chamber 15 that is approximately in front of and below the air outlet 16.

  It is assumed that the angle formed by the inclined portion 26 with respect to the horizontal is approximately 30 °. By providing the air outlet 16 in the inclined portion 26, the rubber hose 17 can be set to a position in which it is laid down. For this reason, the bending of the rubber hose 17 can be made as gentle as possible to eliminate the flow resistance.

As shown in FIG. 4, the inlet cylinder 29 of the dirty chamber 14b in the air cleaner 14 is slightly inclined with respect to the horizontal so as to rise upward. For this reason, the rubber hose 17 can be bent without difficulty. It is possible to use a resin pipe or a metal pipe instead of the rubber hose 17, but if the rubber hose 17 is used, vibration can be prevented from being transmitted between the air cleaner 14 and the upstream chamber 15, and the air cleaner 14 and the upstream Even if the distance from the side chamber 15 is slightly different, there is an advantage that it can be easily absorbed by changing the degree of bending. The spiral member 30 is fitted into the rubber hose 17 from the outside, but the rubber hose 17 may have a bellows structure.

(3) Support structure of the upstream chamber As shown in FIG. 5, approximately the left and right intermediate portions of the upstream chamber 15 are supported from below by a lower bracket 23 fixed to the upper surface of the battery mounting table 22 by bolts 32. The upstream chamber 15 is supported by the lower bracket 23 so as not to be displaced. The lower bracket 23 may be fixed to the battery mounting table 22 by welding or may be provided integrally with the battery mounting table 22. The battery mounting table 22 is stably held by a bracket (not shown).

  Since the battery 21 is quite heavy, the battery mounting table 22 is also stably held in a state where it is difficult to vibrate. Since the upstream chamber 15 is supported by the battery mounting table 22 with high stability via the lower bracket 23, the upstream chamber 15 is held in a state in which it is difficult to vibrate. That is, the upstream chamber 15 is supported by the lower bracket 23 on the battery mounting table 22 on which a heavy object is placed, so that vibration is suppressed.

  Further, when the upstream chamber 15 vibrates, the vibration tends to propagate to the vehicle body side via the brackets, but in the present embodiment, the battery mounting table 22 vibrates because the heavy battery 21 is pressed. Since it is difficult to prevent or significantly suppress the vibration of the upstream chamber 15 from being transmitted to the front frame 2 via the lower bracket 23, the vibration caused by the vibration of the upstream chamber 15 is transmitted to the driver and passengers and is not effective. It is possible to prevent problems such as hitting pleasure.

  As described above, the upstream chamber 15 is attached to the front frame 2 via the left and right upper brackets 20 ', 20. For example, as shown in FIG. The upper bracket 20 on the right side is attached to a stepped portion 34 formed on the right side portion of the upstream chamber 15.

  Therefore, the upper bracket 20 on the right side has an upper horizontal portion 20a that overlaps the front frame 2 and a lower horizontal portion 20b that overlaps the step-down portion 34, and both are integrally connected via an inclined portion. . In any case, the left and right upper brackets 20 ′ and 20 are fixed to the front frame 2 with bolts 35. As shown in FIG. 5, a stepped portion 34 is located below the tip of the air intake duct 19.

  Then, taking the upper bracket 20 on the right side for explanation, as shown in FIG. 6 (B), a rubber grommet 36 that wraps the upper surface and the lower surface of the lower horizontal portion 20b is fitted into the stepped portion. A grommet 36 is fitted into a boss 37 provided integrally with 34. The mounting structure of the left upper bracket 20 'is the same. Further, the support structure of the upstream chamber 15 by the lower bracket 23 is the same, and the boss 37 protrudes downward as shown in FIG.

  Therefore, in the present invention, the upstream chamber 15 is supported by the lower bracket 23 from the bottom, and is held so as not to be displaced forward and backward and left and right by the left and right upper brackets 20 ′ and 20. Since the rubber grommet 36 is interposed between the boss 37 and the boss 37, vibration can be prevented from being transmitted between the upstream chamber 15 and the front frame 2.

In the present embodiment, the left upper bracket 20 ′ is attached to the front side of the upstream chamber 15, and the right upper bracket 20 is attached to a substantially middle part in the front and rear of the upstream chamber 15. For this reason, it is possible to securely prevent the upstream chamber 15 from swinging in the front-rear direction or swiveling in plan view.

  In addition, if the step-down part 34 is provided below the front-end | tip of the air intake duct 19 like embodiment, it can suppress that the water (for example, rainwater) which entered the engine room 1 enters into the air intake duct 19. FIG. In other words, rain water or the like may enter the engine room 1 from the gap between the front end of the bonnet and the front frame 3 when the vehicle is running or washing, and this water reaches the upper surface of the upstream chamber 15. If the upper surface of the upstream chamber 15 exists below the air intake duct 19, water easily enters the air intake duct 19 by jumping from the upper surface of the upstream chamber 15. However, as in this embodiment, the air intake duct is used. If a stepped portion 34 is provided below the tip of 19, even if water enters the engine room 1, the water falls downward due to the presence of the stepped portion 34. Inhalation can be prevented.

(4). Example of a battery detachment prevention protection bar As shown in FIG. 1, a protection bar 38 for preventing detachment of the battery 21 can be disposed on the battery 21. An example of the protection bar 38 will be described with reference to FIG.

  The protection bar 38 is formed of a round pipe. The front end portion 38a and the rear end portion 38b are flattened and the front end portion 38a is fixed to the upper surface of the inclined frame 3 with bolts 39. The rear end portion 38 b of the protection bar 38 is fitted into the screw shaft 40 raised from the battery mounting table 21 from above and fixed with a nut 41.

  Then, a side bracket 42 extending to the lower side of the protection bar 38 is provided in the upstream chamber 15 so as to project sideways (to the right), and a middle part of the protection bar 38 is placed on a rubber grommet 43 fitted to the side bracket 42. It is fitted from. For this reason, the swinging movement of the protection bar 38 can be prevented.

(5) Summary When the inlet cylinder 29 of the dirty chamber 14b in the air cleaner 14 opens directly into the engine room 1, the pulsation acting on the air cleaner 14 is directly transmitted to the filter, and the pressure change of the air is changed to the inlet cylinder. 29 is dissipated into the engine room 1. Therefore, the pulsation is transmitted to the air cleaner 14 as it is, and vibration and noise are likely to occur.

  On the other hand, when the upstream chamber 15 is provided as in the present invention, the upstream intake passage of the air cleaner 14 such as the upstream chamber 15 or the rubber hose 17 acts as a resistance for restricting the pulsation. It is possible to suppress the transmission to the upstream side via. As a result, vibration of the air cleaner 14 itself can be suppressed.

  Since the air intake 18 and the air outlet 16 are upward and substantially upward in the upstream chamber 15 and open in substantially the same direction, the pressure wave due to pulsation does not go to the air intake 18 but the upstream chamber. 15 will be absorbed inside. That is, the buffer effect for absorbing pulsation is high.

  As for air intake, since the air flowing into the upstream chamber 15 travels around the interior of the upstream chamber 15 and then goes to the air outlet 16, the function of the upstream chamber 15 as an air reservoir is maximized. Thus, a stable amount of air is supplied to the air cleaner 14. Therefore, the combustion in each cylinder is stabilized and the controllability is excellent.

  Further, in the upstream chamber 15, as shown by a dotted arrow in FIG. 5, the air swirls greatly inside the upstream chamber 15, so that dust contained in the air adheres to the inner surface of the upstream chamber 15. It is possible to reduce the load on the filter in the air cleaner, and since dust (foreign matter) is dispersed by the air being mixed evenly in the upstream chamber 15, the filter of the air cleaner 14 can be It can be used fully throughout and contributes to longer filter life.

  If the chamber 15 is provided on the upstream side of the air cleaner 14 in addition to the surge tank 11 on the downstream side of the air cleaner 14 as in the present invention, stable intake to each cylinder can be realized accurately and control response can be achieved. There is an advantage that drivability can be improved. In the embodiment, the relationship between the capacity (volume) of the upstream chamber 15 and the air cleaner 14 and the capacity of the surge tank 11 is the relationship of the upstream chamber 15> the air cleaner 14> the downstream surge tank 11. Relationships can be changed as needed.

  In this embodiment, improvements are made in various places, and the advantages are as described in the explanation of each place. However, these can also be independent inventions. Moreover, said embodiment is an example of this invention, and this invention can be embodied variously in addition.

  The present invention can be embodied in an intake device for an internal combustion engine for a vehicle. Therefore, it can be used industrially.

1 Engine room 2 Front frame (body frame)
3 Inclined frame (body frame)
5 Engine Body 8 Cylinder Head 10 Intake Manifold 11 Downstream Surge Tank 12 Throttle Valve 14 Air Cleaner 14a Clean Chamber 14b Dirty Chamber 15 Upstream Chamber 16 Air Outlet 17 Rubber Hose 18 Air Intake Port 20 ′, 20 Upper Bracket 21 Battery 22 Battery Mount 23 Lower bracket

Claims (2)

An upstream chamber is provided on the upstream side of the air cleaner, and an air intake and an air outlet are provided in the upstream chamber so as to open in substantially the same direction.
An intake device for an internal combustion engine for a vehicle.   2. The internal combustion engine for a vehicle according to claim 1, wherein the upstream chamber is supported from below by a lower bracket fixed to a battery mounting table, and an upper portion is attached to an upper bracket fixed to a vehicle body frame. Intake device.

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