JP2001140643A - engine - Google Patents

Abstract

(57) [Summary] To provide an engine capable of securing an appropriate heat radiation area of a cooling fin in a limited space. A cooling fin protrudes from a cylinder block in a direction perpendicular to an axis of a cylinder.
, The cooling fin 11 is partially bent in the axial direction of the cylinder 6. Thereby, the projection length of the cooling fins 11 can be extended without changing the projection height from the cylinder 6,
The heat radiation area can be enlarged. Therefore,
Even when the space around the engine body 2 is limited, the engine body 2 can be appropriately cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an engine,
In particular, the present invention relates to an engine having cooling fins projecting from a cylinder block in a direction perpendicular to the axis of the cylinder.

[0002]

2. Description of the Related Art Hitherto, in order to reduce the overall height of an engine and reduce the size of the engine, an inclined engine having inclined cylinders has been employed. FIG. 3 is a schematic diagram showing a conventional example. Reference numeral 1 denotes a general-purpose engine used for a portable small generator or the like, and includes an engine body 2, a fuel tank 3, an air cleaner 4, and the like.

[0003] The engine body 2 has a cylinder block 7 in which a crankcase 5 and a cylinder 6 are integrally formed, and a cylinder head 8 provided above the cylinder 6 in the axial direction.

A base 5a for fixing to a frame (not shown) is provided on the crankcase 5 of the cylinder block 7.
A cylinder 6 is formed on the upper right side of the crankcase 5 in FIG.

[0005] The cylinder 6 has a substantially cylindrical shape, and a cooling fin 11 is protruded from a side wall 6a thereof. The cooling fins 11 are for maintaining the temperature of the engine body 2 in an appropriate state by heat radiation cooling, and project from the side wall 6 a of the cylinder 6 in a direction perpendicular to the axis 6 b of the cylinder 6. And a plurality of them are provided continuously at predetermined intervals in the axial direction so as to be continuous in the circumferential direction and spaced apart from each other by a predetermined distance.

On the other hand, the fuel tank 3 is disposed above the cylinder block 7, and the air cleaner 4 is disposed above the cylinder head 8. Fuel tank 3
Is fixed to a frame (not shown), and an oil supply port 3a is provided at an upper portion thereof.

The lower surface 3b faces the upper portion of the cylinder block 7 at a predetermined distance, and the lower surface 3b of the fuel tank 3 facing the cylinder 6 is substantially parallel to the cylinder 6. Tank inclined bottom surface 3 to extend
c is formed.

As described above, by disposing the cylinder 6 at an angle and disposing the fuel tank 3 and the air cleaner 4 at a low position by approaching the engine main body 2, the overall height of the engine 1 is reduced and the size of the engine 1 is reduced. I have.

[0009]

However, in order to maintain the temperature of the engine body 2 in an appropriate state by radiating heat from the cooling fins 11, the cooling fins 11 are protruded by a predetermined length or more, and a predetermined heat radiating area is required. Need to be secured.

Therefore, when the space around the engine main body 2 is limited, for example, when the fuel tank 3 or the like is brought close to the engine main body 2 in order to reduce the size of the engine 1, it faces the tank inclined bottom surface 3c. It becomes difficult to secure a sufficient length of the cooling fin 11 at the portion where the cooling is performed, and there is a possibility that the cooling efficiency of the engine body 2 may be reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an engine capable of securing an appropriate heat radiation area of a cooling fin in a limited space. .

[0012]

In order to solve the above problem, an engine according to the present invention is provided so as to protrude from a cylinder block of the engine in a direction perpendicular to the axis of the cylinder. In the engine having the cooling fin, a part of the cooling fin is bent in an axial direction of the cylinder.

[0013] Thus, the projection length of the cooling fin can be extended without changing the projection width from the cylinder, and the heat radiation area can be increased. Therefore, when the space around the cylinder is limited, the cooling fins at that portion are bent and extended to secure an appropriate heat dissipation area and cool the engine body to an appropriate temperature state. can do.

The engine according to the second aspect of the present invention
A part of the cooling fin is bent toward a cylinder head at a tangential portion contacting an outer wall surface of the cylinder. According to this, it is possible to secure a longer length of the cooling fin at a portion protruding from the outer wall surface of the cylinder.
Therefore, the heat radiation area can be further increased.

The engine according to the third aspect of the present invention
In the installation state, the cooling fin has a cylinder disposed so that the axial direction of the cylinder is inclined, and a portion of the cooling fin located above the upper surface of the side wall of the inclined cylinder is bent toward the cylinder head. It is characterized by the following.

According to this, at the time of manufacturing the cylinder block with the mold, the mold forming the upper portion of the cylinder can be pulled out upward. Therefore, conventionally, when casting an engine in which the cylinder is inclined, two molds are provided, one for forming the upper part of the cylinder and the other for forming the upper part of the crankcase. It was necessary to pull out the mold forming the upper part of the crankcase upward, but pull out both the mold forming the upper part of the cylinder and the mold forming the upper part of the crankcase upward. These can be combined into a single template. Therefore, it is possible to shorten the casting time due to the ease of removing the mold, and to reduce the cost by reducing the number of molds.

[0017]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an engine according to the embodiment. Note that the same components as those in the above-described conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

The cooling fins 11 are provided at upper portions 6c of the side wall portions 6a.
Is bent at a tangent portion 12 extending horizontally in contact with
The portion below the tangent portion 12 is the same as the conventional shaft center 6b.
And a plurality of them are provided along the outer circumference of the cylinder 6 and are spaced apart from each other by a predetermined distance at predetermined intervals in the axial direction.

The upper protruding portion 13 located above the tangential portion 12 is bent toward the cylinder head 8 at the tangential portion 12, and is formed so as to extend substantially vertically.

FIG. 2 is an enlarged view of a portion X in FIG.
The solid line in the figure shows the upwardly protruding portion 13 of the cooling fin in the present embodiment, and the dotted line in the figure shows the shape of the conventional cooling fin 11.

The upwardly protruding portion 13 in the present embodiment
Has a protrusion width substantially equal to that of the related art, and has a length h longer than the conventional protrusion length h ′ (h ′ <h). Therefore, even in a space where the periphery of the cylinder 6 is limited by the fuel tank 3 or the like, the protruding length of the cooling fins can be further increased, and the heat radiation area of the cooling fins can be sufficiently secured.

Further, since each of the upwardly projecting portions 13 is formed so as to extend in the vertical direction, the mold forming the upper portion of the cylinder 6 can be pulled upward when the cylinder block 7 is cast.

Therefore, conventionally, when casting the engine body 2 in which the cylinder 6 is inclined, two molds are required, one for forming the upper part of the cylinder 6 and the other for forming the upper part of the crankcase 5. The mold forming the upper part had to be pulled out in the inclined direction in which the cooling fins 11 protruded, and the mold forming the upper part of the crankcase 5 had to be pulled upward. Can be pulled out upward in both directions.

Further, the two molds can be combined into one mold to facilitate the removal of the mold. For this reason, the casting time can be reduced due to the ease of removing the mold, and the cost can be reduced by reducing the number of molds.

It should be noted that the present invention is not limited to the above-described embodiment, and various changes can be made within the gist of the present invention. For example, in the above-described embodiment, an example has been described in which the portion of the cooling fin located above the inclined cylinder is bent, but when the space below the cylinder 6 is limited, this corresponds to that portion. The cooling fins 11 may be bent.

[0026]

As described above, according to the engine of the present invention, in an engine having cooling fins projecting from the cylinder block of the engine in a direction orthogonal to the axis of the cylinder, the cooling fins Since a part of the cooling fin is bent in the axial direction of the cylinder, the length of the cooling fin can be extended, and the heat radiation area can be increased. Therefore, even in a space where the periphery of the cylinder is limited, an appropriate heat radiation area of the cooling fins can be secured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an engine according to an embodiment.

FIG. 2 is an enlarged view of a portion X in FIG. 1;

FIG. 3 is a schematic view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Engine main body 3 Fuel tank 3c Tank inclined bottom surface 6 Cylinder 6a Side wall part 7 Cylinder block 8 Cylinder head 11 Cooling fin 13 Upper protruding part

Claims (3)

[Claims] 1. An engine having a cooling fin protruding from a cylinder block of the engine in a direction orthogonal to an axis of the cylinder, wherein a part of the cooling fin is bent in an axial direction of the cylinder. Engine. 2. The engine according to claim 1, wherein a part of the cooling fin is bent toward a cylinder head at a tangential portion in contact with an outer wall surface of the cylinder. 3. A cylinder having a cylinder disposed so that an axial direction of the cylinder is inclined in an installed state, and a portion of the cooling fin located above an upper surface of a side wall portion of the cylinder disposed inclined is a cylinder head. The engine according to claim 1, wherein the engine is bent to the side.