JPH05280359A - Air charge device for 2-cycle engine - Google Patents

Abstract

PURPOSE:To provide a air charge device of 2-cycle engine which makes the entire engine compact and reduces air intake resistance. CONSTITUTION:A uni-flow V-type 2-cycle engine l in which multiple scavenging ports 9 are provided around the periphery of a cylinder wall is provided with a supercharger 12 and an intercooler 13 located in the downstream of the supercharger. The area between right and left banks 1a and 1b of the engine is closed by a partition 10 on the upper side, and an air intake chamber 8 which connects to the scavenging port 9 by the inner wall and partition of both banks is formed. The partition is provided with a specified opening 10a, a discharge port of the supercharger is connected to the opening in the partition through a connecting pipe 11, and the opening is connected to the air intake chamber through a cooling fin part of the intercooler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-type two-cycle engine air supply device, and more particularly to a V-type two-cycle engine air supply device including a supercharger and an intercooler.

[0002]

2. Description of the Related Art Conventionally, various types of two-cycle engines have been proposed (for example, JP-A-59-4931).
6, JP-A-59-79040, JP-A-62-113.
820, JP-A-63-248915, JP-A-64-
63617, JP-A-62-135655, etc.).

In such a two-cycle engine, there is known one in which a supercharger and an intercooler are provided in the air supply system in order to improve the air supply performance of the air supply system (for example,
JP-A-62-135655). Further, in a two-cycle engine having a V-shaped cylinder arrangement, in order to effectively utilize the V-shaped space formed between the left and right banks, a structure is proposed in which this space is used as an intake chamber of an intake system.

[0004]

When a supercharger and an intercooler are provided in a V-type two-cycle engine using a V-shaped space between banks as an intake passage, the following design has been conventionally made. That is, in the conventional design, (1) the intercooler is arranged above the intake chamber, the supercharger is arranged above the intercooler, or (2) the supercharger is arranged above the intake chamber, The intercooler was placed outside the engine body, and the supercharger and the intercooler were interconnected by the air supply line.

However, according to such a design example, the total height of the area occupied by the entire engine must be set to be considerably large, or an installation area for the intercooler must be secured outside the engine. Further, an air supply pipe must be provided between the supercharger and the intercooler, and between the intercooler and the intake chamber, and the resistance of the air supply path is added to the intake resistance of the engine.

The present invention has been made in view of the above circumstances, and in a V-type two-cycle engine equipped with a supercharger and an intercooler, the entire engine can be made compact and the intake resistance can be reduced. It is an object of the present invention to provide an air supply device for a V-type two-cycle engine that can be used.

[0007]

In order to solve the above problems, the present invention is configured as follows. The engine according to the present invention is a so-called uniflow V-type two-cycle engine having a plurality of scavenging ports on the peripheral wall of the cylinder bore. The engine air supply device includes a supercharger and an intercooler provided downstream of the supercharger. An upper part of the region between the V banks of the engine is closed by a plate-shaped member having an opening portion, and an intake chamber communicating with the scavenging port is formed by each inner wall of the left and right banks and the plate-shaped member. The supercharger is disposed above the plate-shaped member with its discharge port facing the plate-shaped member, and the discharge port is provided through the opening of the plate-shaped member and the cooling fin part of the intercooler to the intake chamber. Communicate with.

[0008]

According to the above configuration of the present invention, the supercharger can be supported by the plate-like member, so that the mounting bracket of the supercharger can be simplified or omitted, and the required space of the entire engine can be made compact. Can be designed. Also,
The intake pipe line between the supercharger and the intercooler and the intake pipe line between the intercooler and the intake chamber can be significantly shortened or omitted to reduce the intake resistance.

In the preferred embodiment of the invention, the intercooler is located in the intake chamber. With this configuration, the required space of the entire engine can be designed more compactly.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a vertical sectional view showing an embodiment of a two-cycle engine to which the present invention is applied. The engine 1 of this example is configured as a so-called uniflow type V-type two-cycle engine. Cylinder bores 2 are formed in the left and right banks 1a and 1b, respectively.
A piston 3 is slidably arranged in the. Piston 3
Is connected to a crankshaft 6 in a crank chamber 5 that takes out combustion energy as rotary power via a connecting rod 4.

The upper space defined by the upper portion of the cylinder bore 2 and the upper surface of the piston 3 constitutes a combustion chamber 7. A large number of scavenging ports 9 are provided on the peripheral wall of the cylinder bore 2 so as to be spaced apart from each other. An intake passage 8 is formed around the scavenging port 9, and the intake chamber 8 is connected to the combustion chamber 7 via the scavenging port 9.
Communicate with.

Above the scavenging port 9, there is a cylinder bore 2
A cooling water passage 17 is arranged so as to surround the entire circumference of the combustion chamber 7, and an exhaust passage 18 is connected to the upper portion of the combustion chamber 7.
In the opening of the exhaust passage 18, that is, the exhaust port 19,
An exhaust valve 20 is attached. The engine 1 of this example is of a cylinder injection type, and an injector 21 for injecting fuel is attached near the exhaust passage 18. Further, a spark plug 22 is attached to the upper part of the combustion chamber 7.

The engine 1 is provided with a horizontal partition plate 10 which defines the upper end of the intake chamber 8, and the partition plate 10 is
It is arranged so as to bridge the upper ends of the left and right banks 1a, 1b. The intake chamber 8 includes a partition plate 10 and a bank 1.
It is composed of a main passage 8a having a V-shaped cross section formed by the inner side walls of a and 1b, and an extension passage 8b extending from the main passage 8a to the outer circumference of the cylinder bore 2. Preferably, the capacity of the intake chamber 8 is set to a capacity capable of eliminating the influence of pressure pulsation generated during air supply (for example, a capacity of about 3L in an engine having a displacement of 1L).

A supercharger 12 for supercharging the intake air of the engine 1 is arranged above the partition plate 10, and a water-cooling type for cooling the intake air supercharged by the supercharger 12 is arranged below the partition plate 10. The intercooler 13 is arranged. The supercharger 12 is
It is supported by the partition plate 10 between the left and right banks 1a and 1b. The intercooler 13 is suspended on the partition plate 10,
Located in the intake chamber 8. The partition plate 10 is provided with an opening 10a in the central region thereof, and the opening 10a is the connecting pipe 1
1 is connected to the discharge port (not shown) of the supercharger 12. In the opening 10a, on the side opposite to the connecting pipe 11,
The intercooler 13 is connected.

FIG. 2 is a schematic plan view of the intercooler 13. The intercooler 13 is a cooling water inflow pipe 1
4. The cooling water return pipe 15 and the cooling fin portion 16 are provided, and the intake air passing through the cooling fin portion 16 is cooled by heat exchange between the cooling water and the intake air. As shown in FIG. 1, the cooling water inflow pipe 14 and the cooling water return pipe 15 are
The intercooler 13 arranged in the main passage 8 a extends along the main passage 8 a and is connected to a cooling water source (not shown) arranged outside the intake chamber 8.

FIG. 3 is a schematic perspective view of the connecting pipe 11.
The connecting pipe 11 is a tapered rectangular duct that widens downwards as a whole, and has a small-diameter upper end opening 11a connected to the discharge port of the supercharger 12 and a relatively large opening 10a. It has a large-diameter lower end opening 11b. in this way,
The engine 1 according to the present embodiment is a uniflow V-type two-cycle engine having a plurality of scavenging ports 9 on the peripheral wall of a cylinder bore, and includes a supercharger 12 and a downstream side of the supercharger 12.
That is, the intercooler 13 provided on the discharge side is provided. The region between the left and right banks 1a, 1b of the engine 1 is closed at its upper end by a partition plate 10, and an inner chamber of each bank 1a, 1b and a partition plate 10 form an intake chamber 8 communicating with the scavenging port 9. To be done. The partition plate 10 has a predetermined opening 10 a, and the discharge port of the supercharger 12 is connected to the opening 10 of the partition plate 10 via the connecting pipe 11.
a, and the opening 10a is further connected to the intercooler 1
The cooling fin portion 16 of No. 3 communicates with the intake chamber 8.

According to this structure, the partition plate 10 supports the supercharger, and the mounting bracket of the supercharger can be substantially omitted. Moreover, since the intercooler 13 is arranged in the intake chamber 8, the intercooler 13
It is not necessary to provide a space for installation above or outside the engine 1. Therefore, the entire required space of the engine 1 can be designed compactly. Also, the supercharger 12 and the intercooler 1
Since the supercharger 12, the intercooler 13 and the intake chamber 8 can be communicated with each other by providing the connecting pipe 11 having a relatively short length between the intake pipe 3 and the intake pipe 3, the intake pipe line can be significantly shortened. The resistance can be greatly reduced.

In the above embodiment, the cooling water pipes 14 and 15 for the intercooler 13 are exposed in the intake chamber 8, but the second pipe is provided below the pipes 14 and 15.
By providing the partition plate, the pipe lines 14 and 15 can be isolated from the intake air in the intake chamber 8, and the contact between the pipe lines 14 and 15 and fresh air can be prevented.

[0019]

According to the above configuration of the present invention, the mounting bracket of the supercharger can be simplified or omitted, and the intake pipe line can be shortened or omitted. Therefore, it is possible to provide a two-cycle engine air supply device that can reduce the intake resistance while making the entire engine compact.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a two-cycle engine to which the present invention is applied.

FIG. 2 is a schematic plan view of the intercooler shown in FIG.

FIG. 3 is a schematic perspective view of the connecting pipe shown in FIG.

[Explanation of symbols]

 1 Engine 1a, 1b Bank 2 Cylinder bore 3 Piston 4 Connecting rod 5 Crank chamber 6 Crankshaft 7 Combustion chamber 8 Intake chamber 8a Main passage 8b Extension passage 9 Scavenging port 10 Partition plate 11 Connecting pipe 11a Upper end opening 11b Lower end opening 12 Supercharger 13 Intercooler 14 Cooling water inflow pipe 15 Cooling water return pipe 16 Cooling fin part 16 17 Cooling water passage 18 Exhaust passage 19 Exhaust port 20 Exhaust valve 21 Injector 22 Spark plug

Claims (2)

[Claims] 1. A V-type two-cycle engine air supply device comprising a supercharger and an intercooler provided on the downstream side of the supercharger, wherein a plurality of scavenging ports are provided on a peripheral wall of a cylinder bore. The upper part of the inter-bank region is closed by a plate-shaped member having an opening, and the inner sidewalls of the left and right banks and the plate-shaped member form an intake chamber that communicates with the scavenging port. The discharge port is disposed above the plate-shaped member with the discharge port facing the plate-shaped member, and the discharge port communicates with the intake chamber via the opening of the plate-shaped member and the cooling fin part of the intercooler. A two-cycle engine air supply device. 2. The air supply system for a two-cycle engine according to claim 1, wherein the intercooler is arranged in the intake chamber.