JP2003193919A - Intake device for inclined engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inertia effect of intake air by lengthening a port length. <P>SOLUTION: In this intake device of an inclined engine, an engine cylinder- shaft line is tilted to one side from the vertical direction in a view from a crankshaft, an intake-manifold fitting surface for a cylinder head is formed on an upper side of an engine cylinder-shaft line, and a surge tank disposed on the other side of the intake-manifold fitting surface is connected with the intake-manifold fitting surfaces with a plurality of inlet pipes. The center line of the inlet pipe is tilted to one side from the intake-manifold fitting surface and extended upward in an on-vehicle state, then, bent to the other side. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake device for a tilt engine, and more particularly to an intake device for a tilt engine that obtains an inertial effect of intake by increasing a port length. is there. 2. Description of the Related Art In a vehicle, for example, a cab-over type vehicle, an engine is mounted in a layout below a seat or below a floor. At this time, it is necessary to keep the overall height of the engine in a small and compact size due to the securing of ground clearance, the cabin space, the height of the loading platform, etc. There is. [0003] As an intake device for the tilt engine, there is one disclosed in Japanese Patent Application Laid-Open No. 11-200968. The intake device in a slanted multi-cylinder internal combustion engine disclosed in this publication includes a connection part to a chamber in a part of the intake pipes of each intake pipe, and a connection part to a chamber in a remaining intake pipe of each intake pipe. , Shifted up and down so that one is above and the other below.
In a slant type internal combustion engine, the size and weight are reduced, and the distribution of intake air to each cylinder is improved. [0004] Further, there is one disclosed in JP-A-2001-3825. The engine component arrangement structure disclosed in this publication connects an intake manifold to an upper part of a cylinder head of an engine that is inclined in a crankshaft rotation direction,
A branch pipe structure that is directed downward from the surge tank side located on the side opposite to the cylinder head connection side and connects to the cylinder head along the cylinder block, and is provided above the connection part between the cylinder head and the intake manifold. A delivery pipe is provided above the injector, and the engine control parts are arranged in a space in which the branch pipe is directed downward and appears between the injector, the delivery pipe, and the surge tank. The layout is such that the various parts in the upper part of the cylinder head are kept low,
The overall height of the engine in the mounting position is kept small, a gap is secured between the engine body and the vehicle body members, and the intake manifold has a curved branch pipe structure to save space. [0005] Further, there is one disclosed in JP-A-2001-41118. The intake device of the internal combustion engine disclosed in this publication is configured such that the distal end portion of the branch pipe of the intake manifold is bent downward, a surge tank is connected to the distal end portion, and the throttle body is offset so as to be displaced from the extending direction. It is arranged and the tip part is bent downward to lengthen the branch pipe, improving the engine torque at low and medium speeds. [0006] Furthermore, there is another one disclosed in Japanese Utility Model Laid-Open No. 6-67853. The intake device of a slant engine disclosed in this publication is configured such that a surge tank is integrally formed with an oil pan joined to a lower part of a cylinder block in the slant engine, and the surge tank and an intake port of a cylinder head are connected by an intake manifold, In a slant engine, the intake manifold is made longer by increasing the length of the intake manifold, and the cost is reduced. [0007] In the conventional intake device for a tilted engine, the intake manifold structure of the engine 102, which is a tilted engine, has a structure as shown in FIG. That is, the cylinder axis SL of the engine 102 is inclined by 60 degrees from the vertical direction VL to one side (which can also be called a right side or an exhaust side in FIG. 4) in a vehicle-mounted state. An intake manifold mounting surface 114 is formed at an end of the intake port 124 in parallel with the cylinder axis SL. The intake pipe 120 of the intake manifold 22
Is perpendicular to the intake manifold mounting surface 114 of the cylinder head 106 at an angle of 90 degrees, and is inclined by 30 degrees from the vertical direction VL to the other side (the left side in FIG. 4). It is in a state. At this time, the intake manifold 22
Of the intake pipe 120 is largely curved in an S-shape in order to secure a required port length. As a result, there is a disadvantage that the intake pipe 120 of the intake manifold 22, which is largely curved in an S-shape, increases the intake resistance and cannot output the original engine output. Also, the intake pipe 120 of the intake manifold 22
Cannot be further curved to extend the required port length of the intake manifold 22, and therefore, there is an inconvenience that the current layout cannot improve the engine torque in low and medium speed ranges. [0013] In order to eliminate the above-mentioned disadvantages, the present invention has been developed in view of the crankshaft direction.
A surge tank that inclines the cylinder axis of the engine from the vertical direction to one side, forms an intake manifold mounting surface of the cylinder head above the cylinder axis of the engine, and is disposed on the other side of the intake manifold mounting surface; In an intake device for an inclined engine in which a plurality of intake pipes communicate with an intake manifold mounting surface, a center line of the intake pipe is inclined upward to one side from the intake manifold mounting surface and extends upward in a vehicle-mounted state. Later, it is curved to the other side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The center line of the intake pipe is inclined to one side from the intake manifold mounting surface and extends upward in the vehicle-mounted state, then curved to the other side, keeping the intake pipe length long and reducing intake resistance While maintaining sufficient intake inertia efficiency, the charging efficiency is increased. Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show an embodiment of the present invention. 1 and 2, reference numeral 2 denotes an engine having, for example, four cylinders, 4 denotes a cylinder block, 6 denotes a cylinder head, and 8 denotes a cylinder head cover. The engine 2 includes the cylinder block 4, a cylinder head 6 mounted on the upper surface of the cylinder block 4, a cylinder head cover 8 mounted on the upper surface of the cylinder head 6, and a lower surface of the cylinder block 4. And an oil pan 10 to be mounted. The cylinder block 4 of the engine 2 has a piston (not shown) slidably provided in a cylinder bore (not shown). The piston has a top portion, a lower surface of the cylinder head 6, and an inner surface of the cylinder bore. Thus, a combustion chamber 12 is formed. As shown in FIG. 1, the engine 2 has a cylinder axis SL of a cylinder bore as viewed from a crank axis direction of a crank center C of a crank shaft (not shown).
From the vertical direction VL to one side (which may also be called the right side or the exhaust side in FIG. 1) by an angle α, for example, 60 degrees. For this reason, the cylinder axis SL is in a state of rising 30 degrees from the horizontal state. (So,
It can be referred to as "tilt engine". At this time, the intake manifold mounting surface 14 of the cylinder head 6 is formed above the cylinder axis SL of the engine 2, and the throttle is mounted on the other side (left side in FIG. 1) of the intake manifold mounting surface 14 from the upstream side. Body 1
6 and the surge tank 18 are sequentially arranged, and the surge tank 1
8 and the intake manifold mounting surface 14 are connected by a plurality of intake pipes 20. That is, as shown in FIGS. 1 and 2, four intake pipes 20-1 are respectively attached to the surge tank 18 so as to be aligned on the same plane. , 20-2, 20-3, and 20-4. These first to fourth intake pipes 20-1, 20-2, and 2-4
An intake manifold 22 is formed by the surge tank 18 and 0-3 and 20-4. The downstream side of the intake manifold 22 is connected to an intake port 24 formed in the cylinder head 6 of the engine 2 via an intake manifold mounting surface 14 formed above the cylinder axis SL. is there. The first to fourth intake pipes 20-1, 20-2, 20-3, located downstream of the intake manifold 22,
As shown in FIGS. 1 and 2, the downstream side of 20-4 is attached to the intake manifold attachment surface 14 so as to have the same attachment surface. Further, the first to fourth intake pipes 20-1, 2
The center lines CL of 0-2, 20-3, and 20-4 are configured to be inclined to one side from the intake manifold mounting surface 14 in the vehicle-mounted state, to extend upward, and then to be curved to the other side. More specifically, the first to fourth intake pipes 20-
As shown in FIG. 1, the center line CL of each of 1, 20-2, 20-3, and 20-4 is located on one side (FIG.
At the right or exhaust side).
Only, for example, it is extended upward while being inclined by three degrees. The first to fourth intake pipes 20-1,
After extending the center line CL of 20-2, 20-3, and 20-4 upward while inclining only three degrees to one side from the vertical direction VL, the first to fourth intake pipes 20- 1, 20-
The center lines CL of 2, 20-3, and 20-4 are curved to the other side (the left side in FIG. 1) in a small S-shape. At this time, the first to fourth intake pipes 20-
As shown in FIG. 1, the intake manifold mounting surface 14 to which 1, 20, 20-3, 20-4 is mounted has a first
-Fourth intake pipes 20-1, 20-2, 20-3, 20-4
Is inclined by 67 degrees to one side from the center line CL, and is inclined by 70 degrees to one side from the vertical direction VL. Next, the operation will be described. First, it is necessary to take into consideration that the cylinder axis SL of the cylinder bore is tilted from the vertical direction VL to one side (the right side in FIG. 1) by an angle α, for example, 60 degrees, when the engine 2 is mounted on a vehicle. The first to fourth intake pipes 20 are mounted on the intake manifold mounting surface 14 of the cylinder head 6 of the engine 2.
-1, 20-2, 20-3, 20-4 and surge tank 1
8 is mounted. At this time, the first to fourth intake pipes 20-
As shown in FIG. 1, the center lines CL of 1, 20-2, 20-3, and 20-4 are positioned on one side from the vertical direction VL in the vehicle-mounted state (FIG.
At the right or exhaust side).
Only, for example, it is mounted so as to extend upward while being inclined by 3 degrees, and after extending upward, the first to fourth intake pipes 20-1, 20-2, 20-3, 20-
The center line CL of No. 4 is curved in an S-shape toward the other side (the left side in FIG. 1). As a result, a conventional intake manifold device for an inclined engine mounted on an underfloor of a vehicle has
In order to obtain the inertia effect of the intake, after the center line of the intake pipe is inclined upward to the other side from the intake manifold mounting surface of the cylinder head and extended upward, a large S-shaped curved part is formed in the middle in the vertical direction. Although the length of the intake pipe is increased by communicating with the surge tank through the intake pipe, the intake pipe length increases, but the problem that the intake resistance due to the curved portion increases has occurred. , First to fourth intake pipes 20-
The configuration is such that the center line CL of 1, 20-2, 20-3, and 20-4 is inclined upward to one side from the intake manifold mounting surface 14 in the vehicle-mounted state, and then curved to the other side. By doing so, it is possible to maintain a long intake pipe length without forming an excessively curved portion in the vertical direction,
It is possible to obtain sufficient intake inertia efficiency while reducing intake resistance, and to increase charging efficiency. It should be noted that the present invention is not limited to the above-described embodiment, and various applications and modifications are possible. For example, it is also possible to adopt a special configuration in which the height of the entire engine is reduced while maintaining the length of the intake pipe long. That is, the cylinder head 6 of the engine 2
As shown in FIG. 3, in the intake pipe 32 of the intake manifold 22 between the intake manifold mounting surface 14 and the surge tank 18, the maximum height position HL of the intake pipe 32 is formed in an elliptical shape in which a straight axis extends horizontally in the horizontal direction. Then, a flat portion 34 is provided. In this case, since the maximum height position HL of the intake pipe 32 is flattened, sufficient intake inertia efficiency is obtained while reducing intake resistance while maintaining the intake pipe length in a long state. This makes it possible to increase the charging efficiency and to reduce the overall height of the engine, which is practically advantageous. The intake pipe 32 is formed by, for example, four first to fourth intake pipes 32-1, 32-2, 32-3, 32-.
4, the first to fourth intake pipes 32-1 and 32-2,
When the curved state in the horizontal state of each of the intake pipes 32-3 and 32-4 is different, the flat portion 34 can be formed to extend not only to the straight portion but also to the curved portion. As described in detail above, according to the present invention, when viewed from the crankshaft direction, the cylinder axis of the engine is inclined to one side from the vertical direction, and the cylinder axis of the engine is positioned above the cylinder axis of the engine. In an intake device for a tilted engine, which forms an intake manifold mounting surface of a cylinder head and communicates between a surge tank disposed on the other side of the intake manifold mounting surface and the intake manifold mounting surface by a plurality of intake pipes,
The center line of the intake pipe is inclined to one side from the intake manifold mounting surface and extends upward in the on-board state, and then curved to the other side, so even if there is no curved part in the vertical direction or even if it occurs Since it has a small S-shape, the intake pipe length can be maintained in a long state, and sufficient intake inertia efficiency can be obtained while reducing intake resistance, and charging efficiency can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a tilt engine showing an embodiment of the present invention. FIG. 2 is a plan view of a tilt engine. FIG. 3 is a schematic plan view of an intake pipe portion of a tilt engine showing another embodiment of the present invention. FIG. 4 is a front view of a tilt engine showing the prior art of the present invention. [Description of Signs] 2 Engine 4 Cylinder block 6 Cylinder head 8 Cylinder head cover 12 Combustion chamber 14 Intake manifold mounting surface 16 Throttle body 18 Surge tank 20 Intake pipe 20-1 First intake pipe 20-2 Second intake pipe 20-3 Third intake pipe 20-4 Fourth intake pipe 22 Intake manifold C Crank center SL Cylinder axis VL Vertical direction CL Center line of intake pipe

Claims (1)

Claims: 1. A cylinder axis of an engine is inclined from a vertical direction to one side when viewed from a crankshaft direction, and
An intake manifold mounting surface of a cylinder head is formed above the cylinder axis of the engine, and a plurality of intake pipes connect between a surge tank disposed on the other side of the intake manifold mounting surface and the intake manifold mounting surface. In the intake device for an inclined engine, the center line of the intake pipe is inclined to one side from the intake manifold mounting surface and extends upward in a vehicle-mounted state, and then curved to the other side. Air intake device.