JP2008082291A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device for an engine capable of materializing both of increase of output and compact layout of the engine. <P>SOLUTION: The intake device for an engine comprises an air cleaner 4, a first surge tank part 6 communicated with the downstream side of the air cleaner and arranged in the intake side of an engine body along the direction of a cylinder row, a common passage part 10 communicated with the downstream side of the first surge tank part 6, arranged to extend downwardly from the first surge tank part 6 and attached with a throttle unit 14, a second surge tank part 16 communicated with the bottom end part of the common passage part 10 and arranged approximately in parallel with the first surge tank part 6, and a branching pipe part 18 whose one end is communicated with the second surge tank part 16 and the other end is communicated with a plurality of cylinders, wherein the capacity of the second surge tank part 16 is set smaller than that of the first surge tank part 6 and the branching pipe part 18 extends from the second surge tank part 16 curving toward the direction leaving from an engine body 1 and is arranged to pass both sides of the common passage part 10 in the direction of the cylinder row. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intake device for an engine, and more particularly, to an intake device for an engine having two surge tanks.

Conventionally, a surge tank has been installed upstream of the throttle valve in the intake pipe, and immediately before the intake valve is closed, the internal pressure of the intake system upstream of the intake valve is increased using intake pulsation (dynamic and inertial effects). ), A large amount of air is inhaled to increase volumetric efficiency and improve engine output. Such an example is disclosed in Patent Document 1, for example.
In the engine intake device of Patent Document 1, the inside of the surge tank is divided into two and a throttle valve is provided in the divided portion, and the maximum opening of the throttle valve is limited according to the engine speed, The engine output is increased.

JP-A-9-280062

Here, in the conventional engine intake device, the capacity of the surge tank is set large in order to increase the dynamic effect (inertia effect). However, when the capacity of the surge tank is increased, the output is effective due to the dynamic effect during high-speed operation of the engine (at full throttle). There is a problem that becomes slow.
On the other hand, the engine intake device must be arranged in a limited space in the engine room, and both improvement in engine output and compact arrangement must be achieved.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide an engine intake device that can achieve both improved engine output and a compact arrangement.
It is another object of the present invention to provide an engine intake device with improved serviceability of the throttle unit.

In order to achieve the above-mentioned object, the present invention is an intake device for an engine having a plurality of cylinders, and is arranged along the cylinder row direction on the intake side of the engine body in communication with the air cleaner and the downstream side of the air cleaner. A first surge tank portion, a common passage portion that communicates with the downstream side of the first surge tank portion and extends downward from the first surge tank portion, and has a throttle unit attached thereto, and a common passage portion A second surge tank portion that communicates with the lower end portion of the first surge tank portion, and a branch pipe portion with one end communicating with the second surge tank portion and the other end communicating with the plurality of cylinders, The capacity of the second surge tank part is set smaller than the capacity of the first surge tank part, and the branch pipe part is curved away from the engine body from the second surge tank part. It is characterized by being arranged to pass through the both sides of the cylinder row direction of the passing passage.
In the present invention configured as above, first, since the capacity of the second surge tank section is set smaller than the capacity of the first surge tank section, the throttle is set during high speed operation of the engine (at full throttle). The volumetric efficiency can be increased due to the inertial effect of the relatively large-capacity first surge tank portion on the upstream side of the unit. When the engine is operating at low and medium speeds, the relatively small second capacity is located on the downstream side of the throttle unit. Since the intake volume is reduced by the surge tank, the response is improved. Furthermore, in the present invention, the first surge tank portion is disposed along the cylinder row direction on the intake side of the engine body, the common passage portion is disposed so as to extend downward from the first surge tank portion, and the second surge tank The portion communicates with the lower end portion of the common passage portion and is arranged substantially parallel to the first surge tank portion, and the branch pipe portion is curved in a direction away from the engine body from the second surge tank portion to Since it is arranged so as to pass through both sides, the layout of the intake system can be made compact by utilizing the limited space in the vertical direction in the engine room.

In the present invention, preferably, when the branch pipe portion passes through both sides of the common passage portion in the cylinder row direction so as to form a predetermined space around the throttle unit attached to the common passage portion, It is arranged to curve outward.
In the present invention configured as described above, since the branch pipe portion is arranged so that a predetermined space is formed around the throttle unit, this space can be used for maintenance inspection of the throttle unit. , Serviceability is improved.

In the present invention, preferably, the air cleaner is disposed above the engine main body, the first surge tank portion is disposed side by side on the air cleaner, and the air cleaner and the first surge tank portion extend laterally. It communicates with the duct part.
According to the present invention configured as described above, the intake system including the air cleaner can be arranged more compactly around the engine surface.

In the present invention, preferably, the engine body is disposed in the engine room so that the cylinder row thereof is in the vehicle width direction, and the intake side thereof is located on the front side of the vehicle.
In the present invention configured as described above, when the service person looks at the engine from the front, a space is formed around the throttle unit attached to the common passage portion. Serviceability is greatly improved when maintaining and inspecting the throttle unit.

  According to the engine intake device of the present invention, it is possible to achieve both improvement in engine output and compact arrangement. Furthermore, according to the present invention, the serviceability of the throttle unit is improved.

  Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an engine intake device according to an embodiment of the present invention, FIG. 2 is a plan view of the engine intake device shown in FIG. 1, and FIG. 3 is a front view of the engine intake device shown in FIG. FIG. 4 is a side view of the intake device for the engine shown in FIG.

As shown in FIGS. 1 to 4, in this embodiment, the engine body 1 (see FIG. 4) is a horizontal engine in which the cylinder row is arranged in the engine room 2 along the vehicle width direction.
An air cleaner 4 is disposed above the engine body 1, and a first surge tank portion 6 is disposed in the vicinity of the front of the air cleaner 4 along the cylinder row direction. The air cleaner 4 and the first surge tank portion 6 are connected to each other by a U-shaped duct portion 8 extending in the vehicle width direction from their side surfaces.

  An upper end portion 10a of the common passage portion 10 is connected to the lower surface of the first surge tank portion 6 so as to communicate therewith, and is arranged to extend downward. A throttle unit 14 having a throttle valve 12 is attached in the middle of the common passage portion 10. The opening degree of the throttle valve 12 is adjusted by an electric motor (not shown).

  Further, the second surge tank portion 16 is connected to the lower end portion 10b of the common passage portion 10 so as to communicate therewith. The second surge tank portion 16 is arranged in parallel with the first surge tank portion 6, that is, along the cylinder row direction. Here, the capacity of the second surge tank section 16 is set to a value smaller than the capacity of the first surge tank section 6.

  Next, one end of the branch pipe portion 18 is connected to the front side of the second surge tank portion 16 so as to communicate therewith. The branch pipe portion 18 is curved and extends in a direction away from the engine body 1 from the second surge tank portion 16, and is disposed so as to pass through both sides of the common passage portion 10 in the cylinder row direction. More specifically, the branch pipe portion 18 has one end portion 18a extending from the second surge tank portion 16 in the direction away from the engine body 1 (toward the front), and then the intermediate portion 18b is directed upward. Furthermore, the lower end 18c of the lower end 18c is U-turned and connected to an extended intake port (a plurality of cylinders) toward the engine body 1.

  Further, when the intermediate portion 18b of the branch pipe portion 18 extends upward, a space 20 for service or the like is formed around the throttle unit 14 as shown in FIG. It is formed to bend outward in the cylinder row.

Next, functions and effects of the above-described embodiment of the present invention will be described.
First, since the capacity of the second surge tank section 16 is set to a value smaller than the capacity of the first surge tank section 6, the first surge tank section 6 has a relatively large capacity and the second surge tank section The tank unit 16 has a relatively small capacity. As a result, when the engine is operating at high speed (at the time of full throttle), the volumetric efficiency can be increased due to the inertial effect by the relatively large-capacity first surge tank section 6 on the upstream side of the throttle unit 14.

  On the other hand, when the engine is operating at low and medium speeds, the intake volume is reduced by the relatively small-capacity second surge tank section 16 on the downstream side of the throttle unit 14, so that the response (responsiveness) is improved. If this point is demonstrated concretely, the torque responsiveness at the moment of stepping on an accelerator (because the capacity | capacitance of a 2nd surge tank part 16 is small, and a pressure rise is quick) will improve. Further, since the air responsiveness is high from the accelerator opening operation to the closing operation, a fuel cut zone can be widened and fuel consumption can be improved. Furthermore, EGR responsiveness becomes high, and more EGR can be refluxed without impairing drivability.

  Next, as described above, the air cleaner 4 is disposed above the engine body 1, the first surge tank portion 6 is disposed in the very vicinity in front of the air cleaner 4, and the lower side of the first surge tank portion 6 extends downward. A common passage portion 10 having a slit unit 14 is disposed toward the bottom, a second surge tank portion 16 is disposed at a lower end portion 10b of the common passage portion 10, and a branch pipe portion 18 is disposed at the second surge tank portion 16. Is extended in a direction away from the engine main body 1 and passes through both sides of the common passage portion 10 in the cylinder row direction, so that the layout of the intake system is limited in the vertical direction in the engine room 2. Can be made compact.

  Further, in the present embodiment, when the branch pipe portion 18 passes through both sides of the common passage portion 10 in the cylinder row direction so that a space is formed around the throttle unit 14 attached to the common passage portion 10, Since the space is curved toward the outside of the cylinder row, this space can be used for maintenance and inspection of the throttle unit 14, so that serviceability is improved.

  In the present embodiment, the air cleaner 4 is disposed above the engine body 1, and the first surge tank portion 6 is disposed side by side on the air cleaner 4, and the air cleaner 4 and the first surge tank portion 6 are arranged. Are communicated by the duct portions 8 extending laterally, so that the intake system including the air cleaner 4 can be arranged more compactly around the engine surface.

  Further, in the present embodiment, the engine body 1 is disposed in the engine room 2 so that the cylinder row thereof is in the vehicle width direction, and the intake side is located on the front side of the vehicle. When the engine is viewed from the front, a space 20 is formed around the throttle unit 14 attached to the common passage portion 10, and the presence of this space 20 allows the throttle unit 14 to be inspected from the front. , Serviceability is greatly improved.

1 is a perspective view showing an intake device for an engine according to an embodiment of the present invention. It is a top view of the intake device of the engine shown in FIG. It is a front view of the air intake device of the engine shown in FIG. It is a side view of the air intake device of the engine shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine main body 2 Engine room 4 Air cleaner 6 1st surge tank part 8 Duct part 10 Common passage part 12 Throttle valve 14 Throttle unit 16 2nd surge tank part 18 Branch pipe part 20 Space

Claims (4)

An intake device for an engine having a plurality of cylinders,
An air cleaner,
A first surge tank portion communicating with the downstream side of the air cleaner and disposed along the cylinder row direction on the intake side of the engine body;
A common passage portion that is arranged to communicate with the downstream side of the first surge tank portion and extend downward from the first surge tank portion, and to which a throttle unit is attached;
A second surge tank portion that communicates with a lower end portion of the common passage portion and is arranged substantially parallel to the first surge tank portion;
A branch pipe portion having one end communicating with the second surge tank portion and the other end communicating with the plurality of cylinders;
The capacity of the second surge tank section is set smaller than the capacity of the first surge tank section, and the branch pipe section is curved away from the engine body from the second surge tank section to An intake system for an engine, which is disposed so as to pass through both sides in a cylinder row direction.   The branch pipe portion extends outwardly from the cylinder row when passing through both sides of the common passage portion in the cylinder row direction so that a predetermined space is formed around the throttle unit attached to the common passage portion. The engine intake device according to claim 1, wherein the intake device is curved.   The air cleaner is disposed above the engine body, the first surge tank portion is disposed side by side on the air cleaner, and the air cleaner and the first surge tank portion are communicated with a duct portion extending to the sides. The intake device for an engine according to claim 1 or 2.   The engine body according to any one of claims 1 to 3, wherein the engine body is disposed in an engine room so that a cylinder row thereof is in a vehicle width direction, and an intake side thereof is located on a front side of the vehicle. Intake device.

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