JPH0247807Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a piston pin for an internal combustion engine.

[Conventional technology]

One of the conventional piston pins for large diesel engines
Examples are shown in FIGS. 4 and 5.

In the figure, 10 is a piston pin, 1 is an oil reservoir provided at the center of the piston pin, 2 is an oil inlet hole, 3 is an oil outlet hole, and 11 is a plug that covers the oil reservoir 1.

The piston pin 10 is designed to transmit load between the piston body (not shown) and the connecting rod (not shown) and to effectively guide lubricating oil to the bearing, as shown in the figure. , a plurality of oil inlet holes 2 and oil outlet holes 3 are radially bored in the radial direction from the central oil sump 1.

[Problems that the idea should solve]

However, the conventional piston pin 10 described above is
Due to the way the load is applied to this, oil comes out, and stress concentration at the corner of the opening end of the inlet holes 3 and 2 to the oil sump 1 (section A in Figure 4) becomes excessive, causing cracks to occur. Become.

Further, when chamfering the A section in order to reduce stress concentration, the chamfering operation is difficult and requires a large number of man-hours.

The present invention was devised in view of the above, and aims to provide a piston pin that is low in cost and highly reliable by improving the fatigue strength of the piston pin and reducing the number of manufacturing steps.

[Means and actions to solve the problem]

In order to solve the above-mentioned problems, the present invention has a solid piston pin with a plurality of oil holes that intersect with each other by making the piston pin perpendicular to each other when projected onto a plane perpendicular to its axis, but inclined in the axial direction. It is characterized by being perforated to prevent

Since the present invention has the above-mentioned configuration, the opening of the oil hole becomes the outer circumferential surface of the piston pin, so stress concentration can be minimized, and the oil hole can be processed and chamfered extremely easily.

〔Example〕

1 to 3 of the present invention.
To explain an embodiment, in the figure, 20 is a solid piston pin, 21 and 22 are vertical oil holes bored in the left half of the piston pin 20, and 2
3 and 24 are horizontal oil holes drilled in the right half of the piston pin 20.

The vertical oil holes 21 and 22 are connected to the piston pin 2.
0 from around the lower end of the outer periphery to around the upper end of the outer periphery, it is slanted in the axial direction (Z-Z direction in the figure) in a cross-shaped manner and parallel to the axis-perpendicular direction (Y-Y direction in the figure). . In addition, the horizontal oil holes 23, 24
is the left end (or right end) of the outer circumference of the piston pin 20
As shown in Figure 3, the hole is inclined in the axial direction (Z-Z direction) in the shape of a swivel and parallel to the axis-perpendicular direction (X-X direction). . Each of the above oil holes 21, 22, 23, 2
4 are bored so as not to intersect with each other, as shown in the figure.

Therefore, the vertical oil holes 21 and 22 and the horizontal oil holes 2
3 and 24 refer to the axis line 26 as shown in FIG.
When projected onto a plane perpendicular to , they will be drilled in directions perpendicular to each other. In addition, each of the oil holes 21, 2
A chamfer 25 is applied to the open end portions 2, 23, and 24.

In the piston pin 20 having the above configuration,
The lubricating oil supplied via the connecting rod is supplied to each oil hole 21, 2.
2, 23, 24 through the opening 21a in the center of the piston pin 20, and after flowing through each oil hole 21, 22, 23, 24 as shown by the arrow in the figure, the oil near the end of the piston pin 20 flows. It flows out from the opening 21b etc. and is sent to the piston cooling chamber (not shown).
Note that the lubricating oil also lubricates the outer peripheral surface of the piston pin 20.

Unlike the conventional piston pin 20, the above piston pin 20 does not have an oil reservoir in the center, so the stress around the opening of the oil hole is small, and the pin is easy to machine. There is no need for such a plug.

[Effect of idea]

The present invention is constructed as described above, and has the following advantages.

Since the oil hole opens on the outer circumferential surface of the cylinder, the machinability of the piston pin is improved and the number of machining steps is reduced.

Since each oil hole is drilled independently,
There are no intersections between holes, so there is no stress concentration. Therefore, the number of piston pins is significantly reduced compared to the conventional one.

There is no need for a plug like in conventional ones, and the number of parts is reduced.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, in which FIG. 1 is a front external view, and FIGS. 2 and 3 are a view taken in the direction of the arrow in FIG. 1, and a view taken in the direction of the arrow, respectively. FIG. 4 and FIG. 5 are a longitudinal cross-sectional view showing an example of a conventional piston pin, and a cross-sectional view taken along the line (-) in FIG. 4. 20... Piston pin, 21, 22... Vertical oil hole, 23, 24... Horizontal oil hole.

Claims (1)

[Scope of utility model registration request] A plurality of oil holes are formed from one part of the outer circumferential surface of a solid piston pin to another part in directions substantially perpendicular to each other when projected on a plane perpendicular to the axis of the pin and inclined in the direction of the axis. A piston pin characterized in that the piston pins are bored so that they do not intersect with each other.