JPS61112723A - Cooling device of forcedly air-cooled v-engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention comprises a pair of first and second cylinders arranged in a V-shape, a cooling centrifugal fan provided at the end of the crankshaft, and a cooling centrifugal fan installed at the end of the crankshaft. placed inside the housing, inside the fan housing,
This invention relates to a cooling device for a forced air-cooled type engine equipped with a partition wall that distributes and guides cooling air to each cylinder.

(Prior art and its problems) As a prior art, there is a cooling device as disclosed in Japanese Patent Application Laid-Open No. 53-59144. However, in the above-mentioned cooling system, the air extraction range from the fan to each cylinder is only 120"L around the crankshaft, which results in wasted fan rotation range, and the fan utilization efficiency is low. .

Furthermore, while the fan is rotating, cooling air may escape to other cylinders through the back surface of the fan, making it difficult to evenly distribute the cooling air to the left and right cylinders, for example.

(Objective of the Invention) An object of the present invention is to reduce the loss of a cooling centrifugal fan and the cooling air excited thereby, and to significantly improve the efficiency of their use.

Another object of the present invention is to enable equal distribution of cooling air to the left and right cylinders.

(Means for Achieving the Object) In order to achieve the above object, in the first invention of the present application, a partition wall for distributing airflow is formed in a spiral shape, and a total of two partition walls are provided for each cylinder, and both spiral partitions are provided. The wind guide starting ends of the walls are positioned so as to have a phase difference of approximately 180° from each other.

In the second invention, in addition to the purpose of the first invention, in order to make the engine more compact, the partition walls for distributing airflow are formed in a spiral shape, and a total of two partition walls are provided for each cylinder. The starting ends of the wind guide are approximately 180 degrees apart from each other.
The air guide starting end of the first partition wall for sending cooling air to the first cylinder located on the rear side in the fan rotation direction with respect to the bank is connected to the second cylinder. Approximately 45° around the crankshaft relative to the center line
It is located within the range of

In the third invention, the partition wall of the distribution S Fugetsu is formed in a spiral shape, and a total of two partition walls are provided for each cylinder, and furthermore, a cylindrical back partition wall is provided near the outer periphery of the back of the fan, which is co-centered with the crankshaft. There is.

(Example) Figure 1 shows a forced air cooling system applying the first, second, and third inventions.
2 is a horizontal cross-sectional view (I-■ cross-sectional view in FIG. 2) of the engine. In FIG. 1, the first and second cylinders 1.2 are arranged in a V shape with a phase difference of about 90 degrees. There is. ■The rear side of the crankshaft 3 in the rotational direction R with respect to the bank is the first
The cylinder is the cylinder 1, and the front side is the second cylinder 2. The common rank t*3 is arranged vertically and is integrally provided with a cooling centrifugal fan 5 at its upper end. A cooling fan housing 6 that covers the fan 5 is provided above both cylinders 1.2 and the crankcase 4.
A cooling air intake (imaginary line) 8 is opened in the center of the upper surface of the housing 6 and is coaxial with the crankshaft 3 .

A total of two spiral-shaped first and second partition walls 9.10 are provided in the fan housing 6 for each cylinder 1.2. The first partition wall 9 for guiding the cooling air to the first cylinder 1 has its air guide starting end 9a connected to the second cylinder 2.
It is provided at a position that is in the same phase as the cylinder center line O'. The first partition wall 9 turns from its starting end 9a toward the front side in the fan rotation direction R while expanding its diameter around the crankshaft center, and reaches the first cylinder 1. The second partition wall 10 for guiding cooling air to the second cylinder 2 has an air guide starting end 10a located at a phase difference of 180° around the crankshaft with respect to the air guide starting end 9a of the first partition wall 9. and on the same circumference as the air guide starting end 9a of the first partition wall 9. From the starting end 10a of the second partition wall 10,
It turns forward in the fan rotation direction R while expanding its diameter around the crankshaft center, and reaches the second cylinder 2. Both starting ends 9a and 10a are close to the outer peripheral end of the fan 5. Further, a portion 9b of the first partition wall 9 on the side opposite to the V bank is in contact with the outer peripheral wall of the housing 6.

A guide wall 11.12 is provided in each of the inner parts of the housing 6 on the front side in the fan rotation direction R of both cylinders 1.2. Reference numeral 13 denotes an air cleaner, and its fresh air intake port 14 opens into an air chamber 15 within the housing 6.

Near the outer periphery of the back (lower side) of the cooling centrifugal fan 5,
A cylindrical back partition wall 20 having approximately the same diameter as the outer diameter of the centrifugal fan 5 is arranged.

In FIG. 2, a cylindrical back partition wall 20 is formed integrally with (or within) the upper end surface of the crankcase 4, and extends upward to near the lower end surface of the fan 5.

A cylindrical cooling air hood 21 extending in the vertical direction is provided on the outer periphery of the second cylinder 2. The upper end of the hood 21 communicates with the inside of the fan housing 6, and the lower end is open. Although not shown, the first cylinder 1 is also provided with a cooling air hood similar to the second cylinder 2.

In FIG. 2, 22 is a carburetor, 23 is an intake manifold, and 24 is an ignition coil.

(Function) Cooling air is taken into the housing 6 from the intake port 8 by the rotation of the centrifugal fan 5 and is pressurized. Half of the pressurized air is guided by the first partition wall 9 and
The remaining half is guided to the cylinder 1, and the remaining half is the second partition wall 10.
is guided to the second cylinder 2. The air cools each cylinder 1.2 while passing through the cooling air hood 21 of each cylinder 1.2, and is discharged downward.

When air is guided in the housing 6, the cylindrical rear partition wall 20 prevents cold fAIII from flowing into the back. Therefore, the cooling air for the first cylinder 1 and the cooling air for the second cylinder 2 do not mix together through the back of the fan. As a result, both starting ends 9a and 10a are
Coupled with the arrangement with a phase difference of 0°, an equal amount of cooling air can be supplied to each cylinder 1.2.

(Another Embodiment) (1) A back partition wall may be formed integrally or integrally with the fan at the back of the fan.

(2) The present invention can also be applied to a horizontal-shaft V-type engine in which the crankshaft is arranged horizontally.

(3) The position of the starting end of the first partition wall is not limited to the cylinder center line of the second cylinder, but is within the range of ±45° around the crankshaft with respect to the cylinder center line of the second cylinder (first
As long as it is within the range shown in the figure).

(Effects of the Invention) As explained above, according to the first, second, and third inventions of the present application, the loss of the centrifugal fan for cold parts and the cooling air excited thereby is reduced, and the utilization efficiency of the fan, etc. is greatly increased. can be improved.

That is, in the first invention, the partition walls for distributing air guide are formed in a spiral shape, and a total of two partition walls are provided for each cylinder.
The air guide starting ends of both spiral partition walls are approximately 18 mm apart from each other.
Since they are positioned so that they have a phase difference of 0°, the cooling air extraction range for each cylinder is 180°, and the entire outer circumference of the fan can be used as the cooling air extraction range. Utilization efficiency is greatly improved.

In addition to the above-mentioned advantages, the second invention also has a thorny advantage. ■The starting end of the first partition wall for sending cooling air to the first cylinder, which is located on the rear side in the direction of fan rotation with respect to the bank, is approximately around the crankshaft relative to the cylinder center line of the second cylinder. Since it is located within a range of ±45°, the first partition wall is formed in a spiral shape to ensure sufficient swirling cooling air to the first cylinder, while the side opposite to the bank of the fan housing (the The amount of overhang of the portion 9a> in FIG. 1 can be reduced.

That is, it is possible to ensure sufficient swirling flow, and at the same time, it is possible to make the entire engine compact.

In the third invention, since the cylindrical back partition wall is provided near the outer periphery of the back of the fan and is co-centered with the crankshaft, cooling air can be prevented from flowing into the back of the fan.

Thereby, the cooling air for each cylinder can be prevented from mixing through the back of the fan, and the cooling air can be almost completely separated and supplied to each cylinder.

Therefore, it is possible to reliably and efficiently obtain a cooling air flow corresponding to the cooling air extraction range around the outer periphery of the fan, and the cooling air usage efficiency is extremely high. Incidentally, when the cooling air extraction range is set to 180 degrees as in the first invention, an equal amount of air can be obtained efficiently and reliably for both cylinders.

[Brief explanation of drawings]

Fig. 1 is a horizontal sectional view (I-1 sectional view in Fig. 1) of a forced air-cooled ■ type engine to which the first, second, and third inventions of the present application are applied, and Fig. 2 is a horizontal sectional view (I-1 sectional view in Fig. 1). It is a cross-sectional view.1.2...
1st and 2nd cylinders, 3... Crankshaft, 5... Centrifugal fan for cooling, 6... Fan housing, 9.10
...First and second partition walls, 9a, 10a... Air guide starting end, 20... Back partition wall Patent applicant Kawa #I Heavy Industries Co., Ltd. [;-21-] Figure 1

Claims (3)

[Claims] (1) A pair of first and second cylinders are arranged in a V-shape, a cooling centrifugal fan is provided at the end of the crankshaft, the fan is placed in a fan housing, and cooling air is supplied into the fan housing. In a cooling system for a forced air-cooled V-type engine that is equipped with a partition wall that distributes and guides air to each cylinder, the partition wall for distributing and guiding air is formed in a spiral shape, and a total of two partition walls are provided for each cylinder, and both spiral-shaped partitions are provided. 1. A cooling device for a forced air-cooled V-type engine, characterized in that the starting ends of the walls are positioned so as to have a phase difference of approximately 180° from each other. (2) A pair of first and second cylinders are arranged in a V-shape, a cooling centrifugal fan is provided at the end of the crankshaft, the fan is placed inside the fan housing, and cooling air is supplied into the fan housing. In a cooling system for a forced air-cooled V-type engine that is equipped with a partition wall that distributes and guides air to each cylinder, the partition wall for distributing and guiding air is formed in a spiral shape, and a total of two partition walls are provided for each cylinder, and both spiral-shaped partitions are provided. The wind guide starting ends of the walls are positioned so as to have a phase difference of approximately 180° from each other,
The first one located on the rear side in the fan rotation direction with respect to the V bank.
Forced air cooling characterized in that the air guide starting end of the first partition wall for sending cooling air to the cylinder is located within a range of approximately ±45° around the crankshaft with respect to the cylinder center line of the second cylinder. Cooling system for Type V engine. (3) A pair of first and second cylinders are arranged in a V-shape, a cooling centrifugal fan is provided at the end of the crankshaft, the fan is placed inside the fan housing, and cooling air is supplied into the fan housing. In a cooling system for a forced air-cooled V-type engine that is equipped with a partition wall that distributes and guides air to each cylinder, the partition wall for distributing and guiding air is formed in a spiral shape, and a total of two partition walls are provided for each cylinder. A cooling device for a forced air-cooled V-type engine, characterized in that a cylindrical back partition wall coaxial with the crankshaft is provided near the outer periphery of the engine.