JP2001065354A - Structure for uniflow type two-cycle multicylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve distributing performance of new air for scavenging each cylinder while enlargement of size is avoided due to integrally providing of a pump casing in a cylinder block, in a uniflow type two-cycle multicylinder internal combustion engine. SOLUTION: A pump casing 22 in a cooling water pump 27 is integrally provided in a part adjacent to one end in a cylinder block 7 of its one lengthwise side surface, while an air inlet 29 to a scavenge chamber 14 surrounding the periphery of each cylinder 8 is formed on a shape slender in a lateral direction and opened to a part leading to the other end from the pump casing 22 in the cylinder block 7 of its one lengthwise side surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a uniflow type two-cycle multi-cylinder internal combustion engine having a scavenging port for introducing new air into the cylinder at the lower part of the cylinder and an exhaust valve at the top of the cylinder. It is about structure.

[0002]

2. Description of the Related Art Generally, in a uniflow type two-stroke internal combustion engine of this type, a plurality of scavenging ports in a lower portion of a cylinder are opened at the end of a downward movement of a piston due to an explosion stroke, as is well known. At the same time, when the exhaust valve at the top of the cylinder is opened, scavenging of discharging exhaust gas in the cylinder from the exhaust valve while introducing new air from each of the scavenging ports into the cylinder is performed. The scavenging port is closed, and the exhaust valve is closed to shift to a compression stroke.In the cylinder block containing the cylinder, a scavenging chamber is provided in the cylinder in the scavenging chamber. Provided so as to surround the outside of each scavenging port,
New air from a scavenging pump driven by the internal combustion engine is sent into the scavenging chamber.

When the uniflow type two-stroke internal combustion engine is configured as a multi-cylinder engine, the scavenging chamber is formed so as to surround the entirety of a plurality of cylinders arranged in a line (for example, an actual open flat 9 cylinder). -158737).

In a recent multi-cylinder internal combustion engine,
As described in Japanese Utility Model Publication No. 7-16026, a pump casing of a cooling water pump for the internal combustion engine is provided integrally on a side surface of a cylinder block.

[0005]

However, in the case where the pump casing of the cooling water pump is integrally provided on the side surface of the cylinder block in the uniflow type two-cycle multi-cylinder internal combustion engine, the following will be described. There was such a problem.

That is, when the pump casing of the cooling water pump is configured to bite into a part of the scavenging chamber surrounding the entire cylinder, the size of the internal combustion engine can be prevented from being increased, but the scavenging chamber has a new structure. The distribution of air to each cylinder is deteriorated by the intrusion of the pump casing into the scavenging chamber, and in order to avoid the deterioration of the distribution, the pump casing is configured not to bite into the scavenging chamber. In such a case, the protrusion of the pump casing leads to a corresponding increase in the size of the internal combustion engine.

The present invention focuses on the fact that a new air supply line from a scavenging pump is connected to the scavenging chamber.
It is an object of the present invention to improve the distribution of new air to each cylinder by utilizing this fact and to solve the above problem.

[0008]

In order to achieve this technical object, the present invention provides a fuel cell system comprising: an exhaust valve and a fuel injection nozzle provided at the top of each cylinder arranged in a line; A plurality of scavenging ports are bored into the cylinder, and further, a scavenging chamber surrounding the scavenging port in each cylinder is formed in a cylinder block containing the cylinder, and an air inlet to the scavenging chamber is formed. In the uniflow type two-cycle multi-cylinder internal combustion engine in which a new air supply pipe line from a scavenging pump is connected, and a pump casing of a cooling water pump is integrally provided in the cylinder block, one of the cylinder block A pump casing of the cooling water pump is provided on a portion adjacent to one end of the longitudinal side surface, while the cylinder block is It takes a portion extending to the other end of the pump casing of one of the longitudinal sides, an air inlet into the scavenging chamber, and to the air inlet to the elongated shape in the lateral direction in the configuration of the opening to. ".

[0009]

Since a new air supply line from the scavenging pump is connected to the air inlet to the scavenging chamber, as described above, a portion of one of the longitudinal side surfaces of the cylinder block adjacent to one end thereof. The pump in the cooling water pump is provided by providing a pump casing in the cooling water pump while opening an air inlet to the scavenging chamber in a part of the one longitudinal side surface from the pump casing to the other end. The casing will be located on the side of the new air supply line connected to the air inlet to the scavenging chamber.

That is, in plan view, a space is formed between one end of one of the longitudinal side surfaces and the new air supply pipe, and a pump casing of the cooling water pump can be disposed in this space.

In addition, the air inlet to the scavenging chamber is opened at a portion of the one side surface from the pump casing to the other end so that the air inlet is elongated in the lateral direction, so that a new air supply is provided. The fresh air from the conduit can be directed evenly to each cylinder with a lateral spread at this laterally elongated air inlet.

Therefore, according to the present invention, the size of the internal combustion engine can be reliably prevented from being increased by integrally providing the pump casing with the cylinder block, and the distributing property of the fresh air for scavenging to each cylinder can be greatly reduced. It has an effect that can be improved.

As described above, when the air inlet to the scavenging chamber and the pump casing of the cooling water pump are provided side by side on one longitudinal side surface of the cylinder block, the suction chamber of the pump casing is provided with a radiator. Must be connected, which not only considerably complicates the shape and structure in this part, but also in some cases connects the cooling water return passage to the suction chamber in the pump casing. For this reason, there must be a considerable gap between the pump casing and the air inlet, which reduces the lateral length at the air inlet, thus distributing fresh scavenging air to each cylinder. Will be reduced.

On the other hand, according to the present invention, as set forth in claim 2, a suction passage communicating with a suction chamber in the pump casing is provided inside the cylinder block, and the suction passage is provided on the other side of the cylinder block. It is proposed that the cooling water return passage from the radiator to the suction chamber in the pump casing be connected to the cooling water pump in the left and right longitudinal sides of the cylinder block. And since it can be performed on the other longitudinal side surface where the new air supply pipe is not provided, the shape and structure of the suction chamber portion in the pump casing can be prevented from being complicated, and the air inlet to the scavenging chamber can be prevented. Can be extended long to the part close to the pump casing. It can be further improved distribution of the new air scavenging against.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a uniflow type two-cycle multi-cylinder internal combustion engine. The multi-cylinder internal combustion engine 1 includes a crank axis 4 in a front engine room 3 of a vehicle body frame 2 and a traveling direction of the vehicle. The transmission 5 is connected to one end face in the direction of the crank axis 4 of the transmission 5.
A radiator 6 for cooling the internal combustion engine 1 is mounted in front of the internal combustion engine 1 in the front engine room 3.

The internal combustion engine 1 includes a cylinder block 7 in which a plurality of cylinders 8 are arranged in a line and a cylinder head 9 fastened to an upper surface of the cylinder block 7 with a plurality of head bolts 10. Inside each of the cylinders 8, a piston 11 having a combustion chamber 12 formed on the top surface is provided so as to reciprocate.

A plurality of scavenging ports 13 which are opened and closed by the reciprocating motion of a piston 11 therein are formed in the lower part of each cylinder 8 so as to be inclined obliquely upward and downward. In block 7,
A scavenging chamber 14 is formed so as to surround a portion of each scavenging port 13 of each cylinder 8, and a cooling water jacket 15 is formed so as to surround an upper portion of each cylinder 8.

On the other hand, the cylinder head 9 at the top of each of the cylinders 8 has a plurality of exhaust valves 16 and one of the left and right longitudinal sides of the cylinder head 9 from one of the exhaust valves 16 on the front side of the vehicle. An exhaust port 17 extending toward the cylinder 8, a fuel injection nozzle 18 into the cylinder 8, and a glow plug 19 for starting ignition are provided for each cylinder 8, and cooling water in the cylinder block 7 is provided. A cooling water jacket 20 communicating with the jacket 15 is formed, and an exhaust manifold 21 is joined to one longitudinal side surface of the cylinder head 9 so as to communicate with each exhaust port 17.

A suction chamber 23 is provided on one longitudinal side of the cylinder block 7 on the front side of the vehicle, on one longitudinal side of the cylinder block 7 and on one end of the cylinder block 7 opposite to the transmission 5. The pump casing 22 provided is integrally provided so that a discharge chamber 24 in the pump casing 22 communicates with the cooling water jacket 15.
A cooling water pump 27 is configured by attaching a lid plate 25 having an impeller 26, and the cooling water pump 27 is configured to be driven by power transmission from a crankshaft in the internal combustion engine 1 via a belt 28. I do.

Further, one of the left and right longitudinal side surfaces of the cylinder block 7 is provided on one longitudinal side surface on the vehicle front side.
The air inlet 29 to the scavenging chamber 14 is connected to the transmission 5 from a portion adjacent to the pump casing 22.
The air inlet 29 is connected to a new air supply pipe 31 from a scavenging pump 30 such as a Roots blower driven by the internal combustion engine 1.

Further, a suction passage 32 communicating with a suction chamber 23 of the cooling water pump 26 into the pump casing 22 is provided at one end of the cylinder block 7 on the side opposite to the transmission 5. Of the two left and right longitudinal sides of the vehicle, the opening is formed on the other longitudinal side on the vehicle rear side.

A cooling water return line 33 from the radiator 6 is connected to an opening of the suction passage 32. A cooling water outlet of the cylinder head 9 is connected to a cooling water circulation to the radiator 6. Line 3
4 are connected.

As described above, a portion of one of the longitudinal side surfaces of the cylinder block 7 adjacent to one end thereof includes:
While providing the pump casing 22 in the cooling water pump 27, the cooling water is opened by opening an air inlet 29 to the scavenging chamber 14 in a portion of the one longitudinal side surface from the pump casing 22 to the other end. The pump casing 22 of the pump 27 is connected to the scavenging chamber 14.
Is located at the side of the new air supply line 31 connected to the air inlet 29 to the air inlet 29, so that, in plan view, between one end of one of the longitudinal side surfaces and the new air supply line 31 The pump casing 22 of the cooling water pump 27 can be disposed in a space portion of the above.

The air inlet 29 to the scavenging chamber 14
The air inlet 29 is formed in a portion extending from the pump casing 22 to the other end of the one side surface so that the air inlet 29 is elongated in the lateral direction.
The fresh air from 1 can be directed uniformly to each cylinder 8 with a lateral expansion at this laterally elongated air inlet 29.

Further, inside the cylinder block 7, a suction chamber 24 of the pump casing 22 is provided.
The suction passage 32 communicating with the suction passage 32
Is formed so as to open on the other longitudinal side surface of the cylinder block.
The connection of the cooling water return passage 33 from the radiator 6 to the suction chamber 23 is made on the other of the left and right longitudinal side surfaces of the cylinder block 7 where the cooling water pump 27 and the new air supply pipe line 31 are not provided. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state of being mounted on a vehicle in an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a sectional view taken along line VV of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 7 Cylinder block 8 Cylinder 9 Cylinder head 11 Piston 13 Scavenging port 14 Scavenging chamber 16 Exhaust valve 18 Fuel injection nozzle 22 Pump casing 23 Suction chamber 27 Cooling water pump 29 Air inlet 30 Scavenging pump 31 New air supply pipe 32 Suction aisle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G023 AA00 AA01 AB05 AB09 AC04 AD02 AF01 AF02 AF03 3G024 AA09 AA38 BA29 DA02 DA08 DA14 DA18 EA05 FA00

Claims (2)

[Claims] An exhaust valve and a fuel injection nozzle are provided at the top of each cylinder arranged in a row, while a plurality of scavenging ports are bored into the cylinder below each cylinder. A scavenging chamber surrounding the outside of the scavenging port in each cylinder is formed in a cylinder block containing each cylinder, and a new air supply line from a scavenging pump is connected to an air inlet to the scavenging chamber, In the uniflow type two-cycle multi-cylinder internal combustion engine in which a pump casing of a cooling water pump is integrally provided on the cylinder block, a part of one of the longitudinal side surfaces of the cylinder block adjacent to one end thereof is provided with a cooling water pump. While the pump casing is provided, one of the longitudinal side surfaces of the cylinder block from the pump casing to the other end. A structure of a uniflow type two-stroke multi-cylinder internal combustion engine, characterized in that an air inlet to the scavenging chamber is opened at a leading end with the air inlet being elongated in a lateral direction. 2. The cylinder block according to claim 1, wherein a suction passage communicating with a suction chamber of the pump casing is formed inside the cylinder block so that the suction passage opens on the other longitudinal side surface of the cylinder block. The structure of a uniflow type two-cycle multi-cylinder internal combustion engine characterized by the following.