Intake system of engine

The present invention provides an intake system of an engine, having the engine mounted on a vehicle, which has a crankshaft oriented in a widthwise direction of the vehicle, and an intake box having an inner space divided by a partition wall into an air cleaner chamber, an intake passage, and a resonator chamber. In such intake system of the engine, the air cleaner chamber is positioned above the intake manifold, the resonator chamber is positioned forward of the air cleaner chamber and the intake passage, and is formed to cover the overall width of the air cleaner chamber and the intake passage, and a through hole is formed between the air cleaner chamber and the resonator chamber, which separates a peripheral partition wall of the air cleaner chamber from a peripheral partition wall of the resonator chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Patent Application No. 2005-328602 filed Nov. 14, 2005, the entirety of which is hereby incorporated by reference as if set forth herein in full.

FIELD OF THE INVENTION

This invention relates to an intake system of an engine, and more particularly to an intake system of the engine, which avoids heat damage by the hot wind generated by a radiator and exhaust system to improve output, driving, and noise reduction performance of the engine.

BACKGROUND OF THE INVENTION

There are some vehicles having a crankshaft oriented in a widthwise direction of the vehicle. The vehicles include for example: an exhaust manifold positioned forward of the engine in a longitudinal direction of the vehicle; an intake manifold rearward of the engine; and an intake box that covers a cylinder head cover on top of the engine and the intake manifold. See, e.g., JP Laid-Open No. H10-141157, and JP Laid-Open No. H11-125158.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In conventional intake systems of the engine, there are some vehicles in which the engine is mounted on the vehicle with the crankshaft oriented in the widthwise direction of the vehicle, the exhaust manifold is mounted forward of the engine in a longitudinal direction of the vehicle, the intake manifold is mounted rearward of the engine, and the intake box having internally an intake passage, an air cleaner chamber, and a resonator chamber is mounted above the engine.

Here, hot wind generated by the radiator and the exhaust manifold disposed toward the front side of the vehicle may travel upwardly along the engine and enter below the intake box.

As a result, the outside air taken through an inlet is heated as passing the intake box, which undesirably detriments the output performance of the engine.

In addition, a fuel injection valve and a fuel delivery pipe for supplying the fuel to the injection valve are disposed in a space between the intake manifold and the intake box. The fuel in the fuel injection valve and the delivery pipe is heated by the hot air, resulting in detriment of the startability of the engine.

Further, the intake box is placed above the engine through a floating rubber. Continuous exposure of the rubber to the hot air results in harden rubber and undesirably enhances the vibration of the intake box.

The object of the present invention is to provide an intake system of an engine in which an intake box that contains an intake passage, air cleaner, and a resonator chamber is positioned above the engine, in order to prevent the intake box and surrounding parts from being heated, thereby improving the output, driving, and noise reduction performance of the engine.

Means to Solve the Problems

In order to obviate the above-mentioned inconveniences, the present invention provides an intake system of an engine. The engine is mounted on a vehicle, which has a crankshaft oriented in a widthwise direction of the vehicle. An exhaust manifold is located forward of the engine in a longitudinal direction of the vehicle, an intake manifold is located rearward of the engine. An intake box covers a cylinder head cover that is disposed on top of the engine and the intake manifold. The intake box has an inner space divided by a partition wall into an air cleaner chamber for containing a filter element, an intake passage for introducing the outside air to the air cleaner chamber, and a resonator chamber in communication with the intake passage. In such intake system of the engine, the air cleaner chamber is positioned above the intake manifold, the resonator chamber is positioned forward of the air cleaner chamber and the intake passage, and is formed to cover the overall width of the air cleaner chamber and the intake passage, and a through hole is formed between the air cleaner chamber and the resonator chamber, which separates a peripheral partition wall of the air cleaner chamber from a peripheral partition wall of the resonator chamber.

Effects of the Invention

According to the present invention, the engine is mounted on a vehicle, which has a crankshaft oriented in a widthwise direction of the vehicle. An exhaust manifold is located forward of the engine in a longitudinal direction of the vehicle, an intake manifold is located rearward of the engine. An intake box covers a cylinder head cover that is disposed on top of the engine and the intake manifold. The intake box has an inner space divided by a partition wall into an air cleaner chamber for containing a filter element, an intake passage for introducing the outside air to the air cleaner chamber, and a resonator chamber in communication with the intake passage. In such intake system of the engine, the air cleaner chamber is positioned above the intake manifold, the resonator chamber is positioned forward of the air cleaner chamber and the intake passage, and is formed to cover the overall width of the air cleaner chamber and the intake passage, and a through hole is formed between the air cleaner chamber and the resonator chamber, which separates a peripheral partition wall of the air cleaner chamber from a peripheral partition wall of the resonator chamber. Consequently, the air cleaner chamber is positioned above and away from the radiator and the intake manifold, which are the source of the heat, so that the air cleaner chamber is prevented from being heated by the hot air. In addition, since the resonator chamber with air layer or air space is thus positioned forward of the air cleaner and the intake passage to cover the overall width of the air cleaner chamber and the intake passage, the resonator chamber functions as a thermal insulating material to prevent the intake passage and the air cleaner chamber from being heated. Further, the through hole prevents the heat from transmitting from a peripheral partition wall of the resonator chamber to peripheral partition walls of the intake passage and the air cleaner chamber, so that the intake passage and the air cleaner chamber are not heated. The above-mentioned arrangement prevents the outer air taken into through the intake passage and the air cleaner chamber from being heated and therefore improves the output performance of the engine.

Best Mode for Carrying Out the Invention

According to the present invention, the air cleaner chamber is positioned above and away from the radiator and the intake manifold, which are the source of the heat, so that the air cleaner chamber is prevented from being heated by the hot air. In addition, since the resonator chamber with air layer or air space is thus positioned forward of the air cleaner and the intake passage to cover the overall width of the air cleaner chamber and the intake passage, the resonator chamber functions as a thermal insulating material to prevent the intake passage and the air cleaner chamber from being heated. Further, the through hole prevents the heat from transmitting from a peripheral partition wall of the resonator chamber to peripheral partition walls of the intake passage and the air cleaner chamber, so that the intake passage and the air cleaner chamber are not heated. The above-mentioned arrangement prevents the outer air taken into through the intake passage and the air cleaner chamber from being heated and therefore improves the output performance of the engine.

DETAILED DESCRIPTION

The present invention is explained in detail with reference to the drawings.

FIGS. 1-7illustrate an embodiment of the present invention. InFIGS. 3-5, reference numeral1designates a vehicle,2a vehicle body,3a right side frame,4a left side frame,5a front bumper member,6a front lower cross member,7a front upper cross member,8a front center member,9front vehicle wheels, and10rear vehicle wheels.

The vehicle1includes a dash panel11extending sidewardly of the vehicle body2, and an engine room15surrounded by right and left fenders12,13and an engine hood14forward of the dash panel11.

In the engine room15, an engine17and a transmission18are arranged side-by-side transversely of the length of the vehicle for mounting on the vehicle1with a crankshaft16oriented sidewardly of the vehicle.

As shown inFIGS. 3-5, the engine17is angled forwardly and supported by a right engine mount19, a left engine mount (not shown), a front engine mount20, and a rear engine mount21for mounting on a right side of the engine room15.

The automatic transmission18is joined to a joining surface F on a left side of the engine17and is mounted on the left side of the engine room15.

Further, in the engine room15, a widthwise elongated radiator22is attached to the lower and upper front cross members6,7forward of the engine17and the transmission18through a bracket (not shown).

As shown inFIGS. 4-7, the radiator22includes: on the front side thereof, an air conditioner sensor24that is elongated widthwise of the vehicle; on the rear side, an electronic fan25for radiator; and at an upper center part, a reserve tank26. The radiator22is connected to the engine17through a radiator inlet piping27and a radiator outlet piping (not shown).

In the engine room15, a master back28for brake and an ABS (Anti-lock brake system) unit29are attached to the dash panel11rearward of the engine17and the transmission18.

Further, in the engine room15, a battery30is attached to the left side frame4on the upper left side of and away from the transmission18.

As shown inFIG. 5, the engine17includes a cylinder head32on top of a cylinder block31to which a cylinder head cover33is attached. To a lower part of the cylinder block31, a crank case34is attached to support the crankshaft16. An oil pan35is attached to a lower part of the crank case34.

To the cylinder head cover33, an oil filler cap36is attached/detached on a front right side when viewed from the side of the vehicle.

The engine17includes a chain cover on right sides of the cylinder block31and the cylinder head32. The transmission18is attached to left sides of the cylinder block31, the crank case34, and the oil pan35.

As shown inFIGS. 4-7, the engine17includes an exhaust manifold38that forms an exhaust system37forwardly of the cylinder head32.

In the exhaust system37, the exhaust manifold38is connected to a catalytic converter that is connected to an exhaust pipe extending rearwardly.

To the engine17, an intake manifold40is attached which forms a part of an intake system39rearward of the cylinder head32.

As shown inFIGS. 3-7, above the intake manifold40, an intake box41is disposed which covers the cylinder head cover33on top of the engine17and the intake manifold40.

As shown inFIGS. 1,2,6, and7, an air inlet pipe52for introducing the outside air is positioned on a front left side of the intake box41. An air outlet pipe53is positioned on a rear left side of the intake box41.

On an upstream side of the air inlet pipe52orienting toward the left side of the vehicle, an air inlet duct54is connected as shown inFIGS. 4 and 5. The air inlet duct54includes an inlet hole section55at an upstream end, an intermediate hose section56, and a duct section57at a downstream end, which is formed in a cylindrical shape.

In order not to inhale the hot wind that passed the radiator22, the air inlet duct54is disposed in the left end part of the engine room15where the intake hole section55at the upstream end is positioned forward and above the transmission18away from the radiator22. The intermediate hose section56extends rearward of the vehicle1above the transmission18. The duct section57at the downstream end is bent toward the engine17side for connection to the air inlet pipe52.

As shown inFIGS. 4-7, the air outlet pipe53is connected to an air outlet hose58. The air outlet hose58is formed in a hose shape and is bent below behind the engine17for connection to a throttle body59. The throttle body59is connected to a surge tank60of the intake manifold40.

As shown inFIGS. 1,2, and6, the intake box41is formed by an upstream side case42provided with the air inlet pipe52positioned on a front side of the vehicle and by a lower side case43provided with the air outlet pipe53positioned on a rear side. A filter element44is sandwiched between the upper and lower cases42,43.

Inner space45within the intake box41is separated by a partition wall46into an air cleaner chamber47for containing the filter element44, an intake passage48, and a resonator chamber49in connection to the intake passage48. The intake passage connects between the air inlet pipe52and the air cleaner47for introducing the outside air to the air cleaner47.

Then the air cleaner chamber is disposed above the intake manifold40at widthwise center of the intake box41. The intake passage48is formed to extend widthwisely from the vicinity of the air inlet pipe52, and is bent rearwardly of the vehicle at generally center of the intake box41so that the downstream section is connected to the air cleaner chamber47. The resonator chamber49is formed by first and second resonator chambers49a,49bcommunicated with an upstream side of the intake passage48, a third resonator chamber49ccommunicated with the intermediate section of the passage48, and a fourth resonator chamber49dcommunicated with the downstream side. The first resonator chamber49a, the third resonator chamber49c, and the fourth resonator chamber49dare located forward of the air cleaner chamber47, and are formed to cover the overall width of the air cleaner chamber47and the intake passage48.

More particularly, the second resonator chamber49bis disposed rearward of the intake passage48. The first resonator chamber49ais positioned at the forefront section in the intake box41and has a rear section covered by a first partition46athat extends widthwisely of the vehicle. Behind the first partition46a, the third resonator49cis positioned toward the left side of the vehicle and the fourth resonator chamber49dis positioned on the right side. Also, an annular peripheral partition67that forms the air cleaner chamber47is disposed so as to abut a rear section of the first partition46aat the boundary of the air cleaner chamber47, the third resonator chamber49c, and the fourth resonator chamber49d. Then a through-hole68is formed in the peripheral partition67so that the peripheral partition67of the air cleaner chamber47is separated from the first partition46aof the resonator chamber49between the air cleaner chamber47and the resonator chamber49. The second resonator chamber49bis formed by an L-shaped second partition46bextending widthwisely from the vicinities of the air inlet pipe52and bending toward the air cleaner chamber47.

Consequently, when the hot air travels from the radiator22and the exhaust manifold38, the resonator chamber49with the air layer or air space functions as a thermal insulating material to prevent the intake passage48and the air cleaner chamber47from being heated. The through-hole68prevents the heat transmission form the partition wall46of the resonator chamber49to the peripheral partition67of the air cleaner chamber47, which prevents heat increase in the air inhaled the engine17through the intake passage48and the air cleaner chamber47and therefore improves output performance of the engine17.

Also, when forming the partition wall46, convex sections are formed which protrude toward the inner of the intake box41from respective upper and lower surfaces of the intake box41, and the tip of the convex sections are abutted each other to form the partition wall46.

When viewing the intake box41from axis of the crankshaft, as shown inFIGS. 2,5, and7, the top surface of the intake box41is formed to have the same level to provide a certain clearance with respect to the engine hood14, and the lower surface thereof is formed to have the resonator chamber49, and a shallow bottom section50is formed at front section above the cylinder head cover33of the engine17. The air cleaner chamber47is formed which is connected to the shallow bottom section50and contains the filter element44. A deep bottom section51is formed at rear section above the intake manifold40.

As shown inFIGS. 5-7, a fuel injection valve61for injecting the fuel to the cylinders of the engine17and a delivery pipe62for distributing the fuel to the fuel injection valve61are attached on a rear side of the cylinder head32of the engine17to which the intake manifold40is attached.

To the fuel delivery pipe62, a fuel piping63is connected. The fuel injection valve61and the delivery pipe62are disposed in a space64which is rearward of the cylinder head32and which is surrounded by the intake manifold40attached to the rear side of the cylinder head32and the intake box41. When viewing the intake box41from above the vehicle1, the through-hole68are configured to connect to the space64in which the fuel injection valve61and the fuel delivery pipe62are disposed.

The fuel piping63is directed rearwardly passing the left side of the air outlet hose58. Below the fuel piping63and sidewardly of the intake manifold40, a heater inlet piping66and a heater outlet piping66are disposed.

Thus the fuel injection valve61and the fuel delivery pipe62are disposed in the space64between the intake manifold40and the intake box41, and the through-hole68is communicated with the space64. Accordingly, the hot air adjacent the fuel injection valve61and the delivery pipe62can be discharged upwardly from the through-hole68, which prevents heat increase in the fuel flowing through the fuel injection valve61and the fuel delivery pipe62and therefore improves startability of the engine17.

Further, when viewing the intake box41from above the vehicle1, a support section70that is supported to the engine17through a floating rubber69is disposed in an inner circumference of the intake box41. The support section70is disposed in an inner circumference of the through-hole68.

More particularly, as shown inFIGS. 1 and 2, the support section70includes a first support section70aat a center portion of the intake box41, a second support section70bbelow the air cleaner chamber47of the intake box41and on the left side of the vehicle, and a third support section70cbelow the air cleaner chamber47of the intake box41and on the right side of the vehicle, The first support section70ais disposed in the inner circumference of the through-hole68.

Accordingly, by positioning the first support section70ain the inner circumference of the through-hole68, the hot air adjacent the floating rubber69can be discharged upwardly from the through-hole68. This avoids thermal degradation of the floating rubber69as well as enhancement of the vibration of the intake box41.

Still further, an oil level gauge71is disposed in the inner circumference of the through-hole68to check for the amount of oil in the engine17, as shown inFIG. 6.

The oil level gauge71in the inner circumference of the through-hole68eliminates the need for a through-hole dedicated for the oil level gauge71in the intake box41. Using of the space decreases the extent the intake passage48is bent, which improves the output performance of the engine17, or expands the resonator chamber49, which improves the noise reduction performance of the engine17.

Also, a reference numeral72designates a plug cover.

Operation of this embodiment is described as follows.

In driving of the engine17, the outside air is introduced to the engine17.

As shown in open arrows inFIGS. 4 and 6, the outside air is introduced from the intake hole section55of the air inlet duct54, then reaches the air inlet pipe52at an end of the intake box41through the intermediate hose section56and the downstream-side duct section57.

Then the air introduced into the intake box41then travels behind the first resonator chamber49aof the resonator chamber49through the intake passage48to a widthwise center section of the intake box41, as shown in the open arrows inFIG. 6. The air turns rearwardly of the vehicle along the peripheral partition67of the air cleaner47that surrounds the through-hole68, and then reaches the air cleaner chamber47.

In the air cleaner chamber47, the air passes through the filter element44of which filtering surfaces are oriented in upper and lower directions of the vehicle, and the air reaches the air outlet hose58on the downstream side of the intake box41.

Thereafter, the air passed the outlet hose58is introduced through the throttle body59to the intake manifold40and further to the engine17.

During running of the vehicle1, the cooling air (in other words “driving wind”) is introduced from the front side of the vehicle.

More particularly, as shown in solid arrows inFIGS. 6 and 7, the cooling wind for cooling the radiator22is introduced from the front side of the vehicle to the radiator22by the wind pressure during running of the vehicle1or by the electronic fan25for the radiator.

Then the cooling wind from the front of the vehicle travels through the air conditioner condenser24, the radiator22, and the electronic fan25so as to cool the radiator22as indicated by the solid arrows inFIGS. 6 and 7. After cooling the radiator22, the cooling wind now becomes the hot air and reaches the front of the engine17in the engine room15.

As indicated by the solid arrows inFIG. 7, the hot air reached engine17is merged into the hot air generated by the exhaust manifold38attached to the front side of the engine17. The hot air then travels upwardly along the front of the engine17and reaches the intake box41positioned above the engine17.

When the hot air from the radiator22and the exhaust manifold38is flown into the intake box41, the resonator chamber49with the air space functions as the thermal insulating material so as to prevent the heating of the intake passage48and the air cleaner chamber47in the intake box41. Also the through-hole68formed in the center portion of the intake box41prevents the heat transmission from the partition wall46of the resonator chamber49to the peripheral partition67of the air cleaner chamber47, which prevents heat increase in the air taken into the engine17through the intake passage48and the air cleaner chamber47.

As indicated by the solid arrows inFIG. 7, some of the hot air enters the clearance between the engine17and the intake box41and travels below the resonator chamber49and the intake passage48, and is guided into the space64between the intake manifold40and the intake box41forward of the air cleaner chamber47.

The lower surface of the air cleaner chamber47protrudes downwardly from lower surfaces of the resonator chamber49and the intake passage48, which obstructs the traveling direction of the hot air.

In the space64, since the through-hole68is formed to communicate with upside, the hot air is discharged upwardly of the intake box41from the through hole68.

In addition, the front portions of the intake passage48and the air cleaner chamber47are covered by the resonator chamber49, which decreases the area exposed to the hot air. Incidentally, the resonator chamber49is not a passage for the outside air, so that the outside air is not heated.

In addition, the fuel injection valve61and the delivery pipe62are disposed in the space64between the intake manifold40and the intake box41, and the through-hole68is communicated to the space64. Accordingly, when the cooling wind is guided to the space64, the hot air adjacent the fuel injection valve61and the delivery pipe62is discharged upwardly, which prevents heat increase in the fuel passing the fuel injection valve61and the delivery pipe62.

Further, since the first support section70ais positioned in the inner circumference of the through-hole68, the hot air adjacent the floating rubber69can be discharged upwardly from the thorough-hole68. This avoids thermal degradation of the floating rubber69as well as enhancement of the vibration of the intake box41.

Moreover, the oil level gauge71is disposed in the inner circumference of the through-hole68, thereby eliminating the need for a through-hole dedicated for the oil level gauge71in the intake box41. Using of the space decreases the extent the intake passage48is bent so as to improve the output performance of the engine17, or provides an expanded resonator chamber49so as to improve the noise reduction performance of the engine17.

Conventionally, there existed a system in which the intake box above the engine includes therein the air cleaner chamber, the intake passage for introducing the outside air to the air cleaner chamber, and the resonator chamber in communication with the intake passage. Although this improves assembly operation by integrating intake parts in the intake box, this suffers from the problem in which the outside air taken in through the intake passage and the air cleaner chamber to the engine is heated by the hot air generated by the radiator and the exhaust pipe, thereby deteriorating the output performance of the engine.

However, according to the embodiment of the present invention, the air cleaner chamber47is prevented from being heated by the hot air, since the air cleaner chamber47is disposed above the intake manifold40away from the radiator22and the exhaust manifold38which are the source of the heat.

The resonator chamber49with the air space is located forward of the air cleaner chamber47and the intake passage48to cover the overall width of the air cleaner chamber47and the intake passage48. Accordingly, the intake passage48and the air cleaner47are prevented from being heated by the resonator chamber49functioning as the thermal insulating material.

Further, the through-hole68prevents the heat transmission from the partition wall46of the resonator chamber49to the peripheral partition67of the air cleaner chamber47, which prevents heating of the intake passage48and the air cleaner chamber47.

Accordingly, this prevents the heat increase in the outside air that is taken in through the intake passage48and the air cleaner chamber47to the engine17, thereby improving the output performance of the engine17.

In addition, when viewing the engine17from the crankshaft16, for example viewing from the left side of the vehicle, the fuel injection valve for injecting the fuel to the respective cylinders of the engine17and the fuel delivery pipe62for distributing the fuel to the fuel injection valve61are located in the space64between the intake manifold40and the intake box41. When viewing the intake box41form above the vehicle1, since the through-hole68communicates with the space64in which the fuel injection valve61and the fuel delivery pipe62are positioned, the hot air can be discharged upwardly though the space64in which the fuel injection valve61and the delivery pipe62are positioned in case the hot air generated by the radiator22and the exhaust manifold38enters below the intake box41. This prevents the heat increase in the fuel flowing the fuel injection valve61and the delivery pipe62, which improves startability of the engine17.

Further, when viewing the intake box41from above the vehicle1, the support section70that is supported to the engine17through the floating rubber69is located inside of the intake box41, and the supporting section70, i.e. the first supporting section70a, is disposed in the inner circumference of the through-hole68. Thus the supporting section70, i.e. the first supporting section70a, is located in the inner circumference of the intake box41. When the first supporting section70ais supported to the engine17through the floating rubber69, the floating rubber69may be degraded by being exposed to the hot air entering below the intake box41. In contrast, according to the embodiment, locating of the first supporting section70ain the inner circumference of the through-hole68where the air circulates avoids thermal degradation of the floating rubber69as well as enhancement of the vibration of the intake box41.

Still further, locating of the oil level gauge71for checking the oil in the engine17in the inner circumference of the through-hole68eliminates the need for a through-hole dedicated for the oil level gauge71in the intake box41. This enhances the flexibility of layout of the intake passage48and the resonator chamber49. By the intake passage48of less curved shape, the output performance of the engine17can be enhanced. By the expanded resonator49, the noise reduction performance of the engine17can also be enhanced.