JPS5973618A - Crankshaft of internal combustion engine - Google Patents

Abstract

PURPOSE:To surely and adequately lubricate the large end area of a connecting rod by providing oil grooves on a side of a crank web. CONSTITUTION:A crankshaft 10 has several oil grooves 19, which span from the circumferential end of a crank web 12 to the crank pin base, on both contact surfaces 18 of the crank web on which both sides of the large end of a connecting rod slide. When the crankshaft 10 rotates, the lubrication oil which is splashed around is induced from an opening 19A to the oil grooves 19 to lubricate the contact surfaces 18 of the crank web 12 as well as a bearing 16. As the oil grooves are engraved on a circle having its center on the center of rotation of a main shaft 11, and have the opening 19A which is wider toward the outside, the induction of the nearby lubrication oil into the oil grooves can be done smoothly as the crankshaft 10 rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crankshaft of an internal combustion engine suitable for use in outboard motors and the like. is very large, and it is necessary to lubricate this part reliably.

SUMMARY OF THE INVENTION An object of the present invention is to provide a crankshaft for an internal combustion engine in which the area around the large end of a connecting rod can be reliably and sufficiently lubricated.

In order to achieve the above object, the crankshaft of the internal combustion engine according to the present invention has an oil groove carved in the contact surface of the crank web with the side surface of the large end of the connecting rod, extending from the peripheral edge to the base of the crank pin. This is what I did.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a front view of main parts of the same embodiment, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is a FIG. 3 is an enlarged view showing the main parts of FIG. 3;

In the crankshaft 10 according to this embodiment, as shown in FIG. 1, the main shaft portion 11, the crank web 12, and the crank pin 13 are all integrally formed. As shown in FIG. 2, a connecting rod 1 is attached to the crank pin 13 of the crankshaft 10.
4 are connected via a bearing 16 consisting of a half-shaped retainer and a needle.

Therefore, in the crankshaft 10, the connecting rod 14
The crank web 1 in which both sides 17 of the large end 15 of the crank web 1 slide into contact with each other.
Two oil grooves 19 (one groove or a plurality of three or more grooves may be used) are cut into both contact surfaces 18 of the crank web 12 from the outer peripheral edge of the crank web 12 to the base of the crank pin. As shown in FIG. 3, the oil groove 19 has a circular arc shape with a radius around the rotation center of the main shaft portion 11. Further, as shown in FIG. 4, both side walls of the outer peripheral edge side 03 of the crank web 12 defining the outer opening 19A of the oil groove 19 are each shaped like an arc of '1 + '2, and the opening 19A is opened widely to the outside.

Next, - the operation of the above embodiment will be explained.

When the crankshaft 10 is used in a two-stroke internal combustion engine, since a mixture containing lubricating oil remains in the crank chamber in which the crankshaft 10 rotates, the lubricating oil flows from the opening 19A to the oil groove 19. will be introduced in Furthermore, when the crankshaft is used in a 10 force S4 cycle internal combustion engine, the lubricating oil in the oil pan is scattered inside the crank chamber in which the crankshaft 10 rotates, so the lubricating oil flows from the opening 19A into the oil groove. It will be introduced on 19th. The lubricating oil introduced into the oil groove 19 in this way is transferred to the side surface 17 of the large end 15.
The contact surface 18 of the crank web 12 is lubricated, and the bearing 16 is lubricated. Note that the oil groove 19 is located in the main shaft portion 11.
When engraved on an arc centered on the rotation center of
Since the opening 19A is wide open outward,
As the crankshaft 10 rotates, surrounding lubricating oil can be smoothly introduced into the oil groove 19.

In the above embodiment, the contact surface 18 of the crank web 12 is provided with a large number of circular four portions 20 as shown by two-dot chain lines in FIG. 3, and the lubricating oil can be stored in the recesses 20. Good too.

Furthermore, in the embodiment F, a case has been described in which lubricating oil existing around the crankshaft 10 is introduced into the oil groove 19 provided in the crank web 12. However, crankshaft 1
Within the axis of
1, an oil passage 21 that opens on the outer periphery of the crank pin 13 and communicates with the oil feed passage on the crankcase side, an oil passage 22 that communicates with the oil passage 21, and an oil passage 23 that communicates with the oil passage 22 and opens on the outer periphery of the crank pin 13. If the crank pin 13 is bored, the lubricating oil flowing out from the outer circumference of the crank pin 13 is introduced into the oil groove 19 to lubricate the side surface 17 of the big end 15 and the contact surface 18 of the crank web 12. Good too.

Further, in the above embodiment, the crank web 1 of the crankshaft 10 is
The case where the oil groove 19 is carved only in the groove 2 has been described. However, if it is necessary to cool the area around the large end more sufficiently due to higher engine output, lower fuel consumption, etc., in the above embodiment, the side surface 17 of the large end 15 of the connecting rod 14 may be
By providing an oil groove in both sides, the side surface 17 of the large end portion 15 and the contact surface 18 of the crank web 12 can be more fully brought into contact with each other.

Further, the present invention can also be applied to an assembled crankshaft in which the end of a crank pin is press-fitted into a fitting hole provided in a crank web, for example.

As described above, the crankshaft of the internal combustion engine according to the present invention is
An oil groove extending from the peripheral edge of the crank web to the base of the crank pin is cut into the contact surface of the crank web with the side surface of the large end of the connecting rod. Therefore, if there is lubricating oil around the crankshaft, the surrounding lubricating oil is introduced into the oil groove.
It becomes possible to lubricate the big end side surface and the contact surface of the crank web, and also to lubricate the big end bearing. Also,
When an oil passage is drilled in the crankshaft, the lubricating oil flowing out from the opening force 1 on the outer circumference of the crank pin is introduced into the oil groove to lubricate the side surface of the big end and the contact surface of the crank web. becomes possible. That is, according to the present invention, it is possible to reliably and sufficiently lubricate the area around the large end of the connecting rod.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is a front view of main parts of the same embodiment, Fig. 3 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 4 is a FIG. 3 is an enlarged view showing the main parts of FIG. 3; 10... Crankshaft, 12... Crank web, 1
3... Crank pin, 14... Connecting rod, 15... Big end, 17... Side surface, 18... Contact surface, 19... Oil groove. Agent Patent Attorney Osamu Shiokawa

Claims (1)

[Claims] (1) A crankshaft for an internal combustion engine in which an oil groove extending from the periphery to the base of the crank pin is carved on the contact surface of the crank web with the side surface of the large end of the connecting rod.