JPS6229607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine oil return device, and more particularly to an oil return device that returns engine oil quickly and efficiently onto an oil pan.

(Prior Art) In an engine that employs a split type crankcase that is divided in the axial direction from the crankshaft, the crankcase is reinforced by forming a wall surface that is continuous with the lower part of the crankshaft. In such an engine oil return device, the oil that lubricates the crankshaft is collected in the lower part of the crank chamber defined by the wall, and the oil collected in the lower part of the crank chamber is pumped through the hole formed on the side of the crankcase or the wall. The oil is collected in an oil reservoir such as an oil pan through a cutout or the like formed in the oil pan.

(Problems to be Solved by the Present Invention) However, with such an oil return device, the action of draining oil from the crank chamber and returning it to the oil reservoir is slow, and the crank web is damaged when the crankshaft rotates at high speeds. There was a problem that the engine came in contact with the oil in the crank chamber and agitated the oil that had accumulated in the crank chamber, increasing friction.

The present invention has been made in view of the above-mentioned problems, and provides an oil return device that can quickly and efficiently return oil accumulated at the bottom of a crank chamber to an oil reservoir. The aim is to reduce

(Means for Solving the Problems) The oil return device according to the present invention has the following advantages:
In an engine that separates a crank chamber in which a crankshaft is arranged and an oil reservoir chamber in which lubricating oil is stored, the crankcase is divided into two parts in the axial direction of the crankshaft.
and a partition wall located below the crank web of the crankshaft to separate the crank chamber and the oil reservoir chamber, and a partition wall on the axial side of the crank web. an oil return port communicating between the crank chamber and the oil reservoir chamber is formed between opposing ends of each of the partition walls; The gist is that a guide wall is integrally formed, which extends in the axial direction of the crankshaft and is positioned rearward from the oil return port in the rotational direction of the crankshaft.

(Function) According to the oil return device according to the present invention, oil scattered by the rotation of the crankshaft is received by the guide wall and guided onto the partition wall, and the oil accumulated on the partition wall is transferred to the return valve located below the partition wall. Since the oil is returned to the oil reservoir from the mouth, the oil can be quickly and smoothly returned to the oil reservoir. Also,
Since the crankcase is reinforced by the side walls, partition walls, and guide walls and has increased rigidity, no other reinforcing members are required. And the crankcase is
The half body is manufactured integrally with the guide wall by mold forming such as casting, and since the guide wall extends in the axial direction of the cradle shaft, it is easy to demold.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a schematic side view of a motorcycle 1, in which a front fork 4 supporting a front wheel 5 is supported by a head tube 3 at the front end of a frame 2 via a top bridge 6 so as to be steerable by a handlebar 7.
A fuel tank 8 is provided at the upper front part of the frame 2, and a seat 9 is provided behind the fuel tank 8. A rear fork 10 that supports a rear wheel 11 is pivotally extended from the rear lower part of the frame to the rear, and a space between the rear fork 10 and the frame is provided. A reaction unit 12 is provided.

An engine 13 is mounted in the lower front part of the frame below the fuel tank 8, and the embodiment shows a water-cooled engine with V-shaped sides and a horizontal crankshaft. Engine 13
The crankcase consists of a crankcase 20 with the lowest transmission case at the rear, front and rear cylinder blocks 14 above this, a cylinder head 15 above this, a cylinder head cover 16 above this, etc., and is formed by the cylinder block and cylinder head. The piston 17 is slidably fitted into the combustion chamber of the piston 1.
7 is connected to the crankshaft 1 via the connecting rod 18.
It is connected to the pin section 9.

The crankcase 20 is divided into left and right halves 21,
It consists of 22 zygotes, and Figure 3 shows the right half 2 of this.
Figure 4 shows the inner surface of the divided state of 1, and the same left half body 22.
shows. Inner bottom parts 21a, 22a of halves 21, 22
An oil reservoir 20a that forms a sealed dish-shaped oil pan is provided at the time of joining, and crankshaft support holes 21b and 22b are provided in the upper part of the front part of the oil reservoir 20a, and further above, a cylinder base is formed when the parts are joined. Portions 21c, 21b, 22c, and 22d are provided in a V-shape at the front and rear.

Arc-shaped partition walls 23 and 24 are provided above the bottoms of the front and middle portions of the halves 21 and 22, with the support holes 21b and 22b as centers and radiuses thereof.
When joining 1 and 22, the end surfaces 23 of the partition walls 23 and 24
b, 24b are in contact with each other, and the oil reservoir 20a below
An intermediate bottom wall 20b is formed to partition the crankshaft side crank chamber from the partition wall 20b as shown in FIG.
On both sides of 3 and 24, there are side walls 21e that partition the sides.
22e is provided. The inner walls 23a, 24a of the above partition walls 23, 24 have a larger diameter than the locus of the crank web 19a of the crankshaft 19, and a predetermined constant clearance is formed between the inner walls 23a, 24a and the locus of the crank web 19a of the crankshaft 19. Cutouts 23c and 24c are provided near the lower part to open toward the joining end surfaces 23b and 24b and penetrate vertically.
The crankshaft 19 of the return port 25, and therefore the crank web 19, is formed as shown in FIG.
A guide wall 2 stands upward on the inner edge in the rotation direction of a, counterclockwise in FIG. 3 and clockwise in FIG.
6, 27 are provided, the end surfaces of which form a gap (S) during joining, and stand up entirely at the end of the return port 25 in the rotational direction, and the bases of the guide walls 26, 27 are connected to the inner walls of the side walls 21e, 22e. It is continuous with and is formed integrally with this and also with the partition walls 23 and 24. In addition, the above-mentioned gap S is created by cranking the guide walls 26 and 27.
It may also be formed by shifting the phase with respect to the rotation center of the shaft 19. Such guide walls 26, 27
The upper halves 26b and 27b of the crank web 19a
The upper end portion is slightly curved and inclined in the opposite direction to the rotation direction of the crank web 19a, and the upper end portion is designed to maintain a slight clearance from the locus of the crank web 19a. The guide walls 28, 29 are provided integrally with the partition walls 23, 24 and the side walls 21e, 22e. Passage 3 communicating with both ends
1 and 31 are installed vertically on the side walls 21e and 22e, and guide oil to the support holes 21b and 22b.

By the way, FIG. 2 is a cross-sectional plan view of the front cylinder section of the engine in an expanded state, and numeral 32 is a transmission consisting of a crankshaft 19 and gears.

Next, to explain its functions and effects in detail, oil is sent from the oil pump to the journal portion of the crankshaft 19 via passages 30, 31, 31, and the lubricated oil is sent to the intermediate bottom formed by the partition walls 23, 24. It drips onto the wall 20b and also onto the crankshaft 19.
The oil adhering to the bottom wall 20b falls onto the intermediate bottom wall 20b due to centrifugal force. Since the intermediate bottom wall 20b is curved in an arc shape, the oil is guided along this to the lowest intermediate part, and is discharged from the return port 25 having a length in the width direction of the intermediate part, and is discharged from the lower oil pool 20a.
will be collected. By the way, guide walls 26 and 27 are set up in the direction of rotation of the crankshaft at the return port 25.
As a result, the oil does not move beyond the return port 25, but is forcibly guided and discharged from the return port 25 downward.
The return of oil to the oil reservoir and recovery will be carried out smoothly and quickly.

Further, in this engine oil return device, the halves 21 and 22 are molded integrally with guide walls 26 and 27, respectively, but the guide walls 26 and 27 are arranged in the axial direction of the crankshaft 19, which is the direction of mold removal. Because it extends over the entire length, it is easy to remove the mold during molding.

(Effects of the Invention) As explained above, according to the engine oil return device according to the present invention, in an engine having an oil reservoir separated from the lower part of the crank chamber, the oil in the crank chamber is forcibly drained. It has the effect of smoothly and quickly guiding and discharging the oil into the oil reservoir, returning it to the oil reservoir, and collecting it smoothly, and preventing oil from entering the breather B at the top of the crankcase. The opening has a sufficient length in the width direction, and also has a sufficient width in the front-back direction, and the opening area of the oil return port is also large enough to further improve the smoothness and speed of oil return and recovery. By forming the guide wall, the rigidity of the intermediate wall and, by extension, the crankcase can be increased, and furthermore, the molding of the crankcase can be easily removed from the mold, which has many advantages.

[Brief explanation of the drawing]

Figure 1 is a side view of the motorcycle, Figure 2 is a cross-sectional view of the engine in an expanded state, Figure 3 is an inside view of one half of the crankcase, and Figure 4 is an inside view of the other half of the crankcase. Side view, Figure 5 is 5-5 in Figures 3 and 4.
A line sectional view is an explanatory cross-sectional plan view of the main parts of the crankcase in a joined state, and FIG. 6 is a vertical cross-sectional front view of the same. In the drawing, 20 is a crankcase, 20a is an oil reservoir, 20b is a partition wall, 25 is a return port, 26,
27 is a guide wall, and 19 is a crankshaft. 〓〓〓〓

Claims (1)

[Claims] 1. In an engine that separates a crank chamber in which a crankshaft is disposed in a crankcase and an oil reservoir chamber in which lubricating oil is stored, the crankcase is divided in the axial direction of the crankshaft. and a partition wall located below the crank web of the crankshaft to separate the crank chamber and the oil reservoir chamber, and an axis of the crank web. side walls located on the lateral sides of the direction are integrally provided, an oil return port communicating between the crank chamber and the oil reservoir chamber is formed between opposing ends of each of the partition walls, and each of the partition walls is provided with an oil return port that communicates with the crankshaft. An engine oil return device characterized by integrally forming a guide wall that extends in the axial direction of the crankshaft, facing the center, and is positioned rearward from the oil return port in the rotational direction of the crankshaft.