JP2002227821A - Crankshaft of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem with a crankshaft of an engine that the durability and reliability of the crankshaft may be lowered when a bearing pressure applied to a thrust metal is large since the diameter of the thrust metal cannot be made larger than the diameter of a cylindrical crankshaft end part having a thrust metal receiving face formed thereon. SOLUTION: In this crankshaft 25 of the engine E having the thrust metal 52 installed thereon, the metal receiving face 25d of the crankshaft 25 in contact with the thrust metal 52 is formed in a flange shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a configuration of an engine crankshaft.

[0002]

2. Description of the Related Art Generally, a crankshaft of an engine converts a reciprocating motion of a piston into a rotary motion via a connecting rod, and is rotatably supported on a cylinder block via a bearing member. Further, a thrust metal is provided on the bearing portion for receiving a thrust acting in the axial direction of the crankshaft and for positioning the crankshaft in the axial direction.

For example, a crankshaft 101 shown in FIG.
The main journal 101a is supported by the bearing member 102. Shaft end 101c of the main journal 101a
Is formed in a substantially cylindrical shape having a diameter larger than that of the main journal 101a, and protrudes outside the cylinder block.
A metal receiving surface 101d is formed on the inner side surface of the shaft end portion 101c, and a thrust metal 103 interposed between the bearing member 102 and the metal receiving surface 101d is in contact with the metal receiving surface 101d. .

A flywheel 105 is integrally rotatably attached to a shaft end 101c protruding outside. Further, lubricating oil passages 111 and 112 are formed in the main journal 101a and the crank pin 101b, respectively, so as to lubricate bearing portions of the main journal 101a and the crank pin 101b.

[0005]

SUMMARY OF THE INVENTION The aforementioned crankshaft 10
1 the lubricating oil passage 112 of the crankpin 101b
However, if burrs at the time of processing remain on the peripheral edge of the opening, there is a problem such as a cause of fatigue destruction of the crank pin 101b. Therefore, as shown in FIG. 9 and FIG. Burrs were removed by chamfering.

However, since the chamfering is performed by buffing or the like by a manual operation of an operator, it is difficult to perform a precise machining, and the lubricating oil passage 112 after the chamfering is performed.
In some cases, the width dimension r of the chamfered portion 112a at the periphery of the opening may become larger than a specified value. As a result, the peripheral edge of the opening of the lubricating oil passage 112 leaks from the bearing end, and the lubricity is deteriorated, and the durability and reliability of the crankshaft may be reduced.

Further, the diameter of the thrust metal 103 cannot be made larger than the diameter of the shaft end 101c on which the metal receiving surface 101d is formed, so that when the surface pressure applied to the thrust metal 103 is large, However, the durability and reliability of the crankshaft may be reduced. Further, the size of the crankshaft 101 and the thrust metal 103 varies depending on the size and specifications of the engine.
01 also has a different outer diameter, so the flywheel 105 attached to the shaft end 101c also
It was necessary to prepare different specifications for the engine size and specifications.

[0008]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, in claim 1, the engine crankshaft provided with the thrust metal,
The thrust metal receiving surface of the crankshaft in contact with the thrust metal was formed in a flange shape.

In the present invention, the flange diameter of the thrust metal receiving surface is changed according to the engine specifications, and the shaft end diameter of the crankshaft is constant regardless of the engine specifications.

[0010] According to a third aspect of the present invention, an opening edge of an oil passage formed in the crankshaft of the engine is chamfered by a rotary cutting blade.

[0011]

Next, an embodiment of the present invention will be described. 1 is a side sectional view showing an engine having a crankshaft of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a side view showing a crankshaft, and FIG. 4 is a diagram showing a lubricating oil passage formed in the crankshaft. 5, FIG. 5 is a front view, FIG. 6 is a side cross-sectional view showing a state of chamfering an opening peripheral portion of a lubricating oil passage, FIG. 7 is a front cross-sectional view, and FIG. 8 shows a conventional crankshaft. FIG. 9 is a side view, FIG. 9 is a plan view showing a state of chamfering a peripheral edge of an opening of a conventional lubricating oil passage, and FIG.

First, a schematic structure of an engine having a crankshaft according to the present invention will be described with reference to FIGS. A cylinder head 1 is attached to an upper end of a cylinder block 15 of the engine E, and a valve arm chamber 2 is formed above the cylinder head 1.

A gear case 23 for accommodating a gear for transmitting the driving force from the crankshaft 25 to the camshaft 14, the fuel injection pump 12, and the like is connected to one side surface of the cylinder block 15. A gear case cover 29 for housing the lubricating oil pump 22 is provided on the outer surface of the gear case 23.
Are connected. The gear case 23 and the gear case cover 29 constitute a gear case portion. A flywheel housing 27 that accommodates a flywheel 28 is connected to the other side of the cylinder block 15.

An oil pan 21 is provided below the cylinder block 15, and lubricating oil is stored in the oil pan 21. The oil pan 21 is the spacer 18
Through the cylinder block 15. The spacer 18 extends from one end of the cylinder block 15 to the gear case 23 and the gear case cover 29, and is connected to the cylinder block 15.
3 is further connected to the spacer 18, and a gear case cover 29 connected to the gear case 23 is also connected to the spacer 18.

The crankshaft 25 is rotatably supported by the cylinder block 15 via bearing members 51 which are divided into upper and lower parts. The bearing members 51 are provided at a plurality of locations, and each support the crankshaft 25.

Next, the configuration of the crankshaft 25 will be described. As shown in FIG. 3, in the crankshaft 25, a main journal 25a is supported by a bearing member 51 via a bearing 51a.
The shaft end 25c of 5a projects outside the cylinder block 15. A flywheel 28 is integrally rotatably attached to the shaft end 25c protruding outside.

A metal receiving surface 25 is provided on the inner surface of the shaft end 25c.
d is formed. The metal receiving surface 25 d is
5c, and has a flange shape protruding radially outward from the shaft end 25c. A thrust metal 52 is interposed between the bearing member 51 and the metal receiving surface 25d, and the thrust metal 52 is in contact with the metal receiving surface 25d. Thereby, the crankshaft 2
5, the thrust acting in the axial direction, and the positioning of the crankshaft 25 in the axial direction.

That is, the metal receiving surface 2 which is conventionally formed in a substantially cylindrical shape and has the same diameter as the outer diameter of the shaft end portion 25c.
5d is formed larger in diameter than the shaft end 25c. Therefore, the thrust metal 52 contacting the metal receiving surface 25
Can be increased in diameter. Thereby, the surface pressure applied to the thrust metal 52 can be reduced, and the durability and reliability of the crankshaft 25 can be improved.

Further, in the crankshaft 25 of this embodiment,
Since the metal receiving surface 25d is formed in a flange shape,
Even if the size of the main journal 25a or the thrust metal 52 changes according to the size or specification of the engine E or the crankshaft 25, the diameter of the shaft end 25c is not changed, and the metal receiving member formed into a flange shape according to the specification is not changed. The diameter of the surface 25d is changed so that the thrust metal 52 is
d.

For example, when the diameter of the thrust metal 52 is increased, the diameter is increased by changing the diameter of the metal receiving surface 25d while maintaining the shaft end 25c at the same diameter. Thrust metal 52 to metal receiving surface 2
It becomes possible to receive at 5d.

Thus, regardless of the size and specification of the engine E (the size of the main journal 25a and the thrust metal 52), the flywheel 28 of the same size can be mounted on the shaft end 25c and should be prepared. The number of flywheels 28 can be reduced,
Cost reduction can be achieved. Also, the shaft end 25
Since c is formed to have a smaller diameter than the diameter of the thrust metal 52, the weight of the crankshaft 25 can be reduced as a whole.

As shown in FIG. 3 to FIG. 6, lubricating oil passages 61 and 62 are formed in the main journal 25a and the crank pin 25b, respectively, and a bearing portion of the main journal 25a and the crank pin 25b is formed. I try to lubricate. Both ends of the lubricating oil passage 61 of the main journal 25a are open.
One end of the lubricating oil passage 62 of 5b is open, and the other end thereof communicates with the lubricating oil passage 61.

The periphery of the opening of the lubricating oil passage 61 and the periphery of the opening at one end of the lubricating oil passage 62
To form a chamfered portion 61a and a chamfered portion 62a, respectively. Rotary cutting blade 66
Is constituted by, for example, an end mill. In the case of this example, the rotary cutting blade 66 is set so that the rotation axis 66a is substantially parallel to the cutting surface and substantially perpendicular to the axis of the crankshaft 25. , And the peripheral edge of the opening of the lubricating oil passages 61 and 62 is chamfered by the blade on the outer peripheral side surface of the rotary cutting blade 66.

As described above, the peripheral edges of the rotary cutting blade 66 are chamfered at the peripheral edges of the openings of the lubricating oil passages 61 and 62, and the overlap between the rotary cutting blade 66 and the processing surface during the processing is performed. By appropriately setting the amount (cutting amount) and the like, the chamfering of the peripheral edges of the openings of the lubricating oil passages 61 and 62 can be accurately performed, and the burrs on the peripheral edges of the openings can be reliably removed. In addition, it is possible to precisely control the width R (dimension in the axial direction of the crankshaft 25) R of the chamfered portions 61a and 62a after processing to be within a specified value.

Thus, the lubricating oil passages 61 and 62
Lubricating oil supplied between the main journal 25a and the bearing 51a and between the crankpin 25b and the connecting rod bearing (not shown) escapes from the end of the bearing 51a through the peripheral edges of the openings of the lubricating oil passages 61 and 62. Can be prevented, lubricity can be improved, and the durability and reliability of the crankshaft can be improved.

[0026]

As described above, the present invention has the following advantages. That is, as described in claim 1, in the engine crankshaft provided with the thrust metal, the thrust metal receiving surface of the crankshaft abutting on the thrust metal is formed in a flange shape.
The diameter of the thrust metal contacting the thrust metal receiving surface can be increased. Thereby, the surface pressure applied to the thrust metal can be reduced, and the durability and durability of the crankshaft can be reduced.
Reliability can be improved.

Furthermore, the diameter of the flange of the thrust metal receiving surface is changed according to the engine specifications and the shaft end diameter of the crankshaft is constant regardless of the engine specifications. The same size flywheel at the end of the crankshaft shaft, regardless of the size and specifications (size of the main journal and thrust metal of the crankshaft), reducing the number of flywheels to be prepared Is completed,
Cost reduction can be achieved.

Further, according to a third aspect of the present invention, in the crankshaft of the engine, the peripheral edge of the opening of the oil passage formed in the crankshaft is chamfered by a rotary cutting blade. The chamfering of the peripheral portion can be performed precisely, the burr on the peripheral portion of the opening can be reliably removed, and the width dimension (dimension in the axial direction of the crankshaft) of the chamfered portion after the processing can be precisely determined. It is possible to control and set it within a specified value. Thereby, from the lubricating oil passage,
Lubricating oil supplied between the main journal of the crankshaft and the bearing or between the crankpin of the crankshaft and the connecting rod can be prevented from escaping from the bearing end through the peripheral edge of the opening of the lubricating oil passage. Can be improved, and the durability and reliability of the crankshaft can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an engine including a crankshaft having a configuration according to the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side view showing a crankshaft.

FIG. 4 is a side sectional view showing a lubricating oil passage formed in a crankshaft.

FIG. 5 is a front view of the same.

FIG. 6 is a side sectional view showing a state of chamfering an opening peripheral portion of a lubricating oil passage.

FIG. 7 is a front sectional view of the same.

FIG. 8 is a side view showing a conventional crankshaft.

FIG. 9 is a plan view showing a state of chamfering a peripheral edge of an opening of a conventional lubricating oil passage.

FIG. 10 is a side sectional view of the same.

[Explanation of symbols]

 E Engine 15 Cylinder block 25 Crank shaft 25a Main journal 25b Crank pin 25c Shaft end 25d Metal receiving surface 52 Thrust metal 61/62 Lubricating oil passage 62a Chamfered portion 66 Rotary cutting blade

Claims (3)

[Claims] 1. A crankshaft for an engine provided with a thrust metal, wherein a thrust metal receiving surface of the crankshaft in contact with the thrust metal is formed in a flange shape. 2. The engine according to claim 1, wherein a flange diameter of the thrust metal receiving surface is changed according to an engine specification, and a shaft end diameter of a crankshaft is constant regardless of the engine specification. Crankshaft. 3. A crankshaft for an engine, wherein an opening edge of an oil passage formed in the crankshaft is chamfered by a rotary cutting blade.