JPS6137778Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention mainly relates to an oil supply device for a piston pin metal of a medium- to large-sized internal combustion engine.

(Prior art) A conventional structure in which the explosion pressure is supported by as many surfaces as possible of the piston pin metal has been proposed, for example, in Publication of Utility Model Publication No. 46-21129 (No. 3).
Fig. 4). However, according to the structure, shaft hole 1
3' crosses the joining dividing surface 7' between the fixed bearing half 3' of the connecting rod and the cap 4', and also interferes with the bolt 6', so that the sealing ring 15' is attached to the dividing surface 7'. Further, sealing portions 16' are required at both ends of the bolt 6', making the sealing structure complicated and expensive. Furthermore, since the shaft hole 13' is machined separately for the body portion 2' and the cap 4', the number of man-hours increases and costs increase. Furthermore, since the oil passage formed by the shaft hole 13' has a chamber 14', etc. in the middle, it is slightly bent, which makes the flow of oil to the piston uneven and reduces the lubrication and cooling effects.

Another conventional example will be explained with reference to FIG. 1. In order to support the explosion pressure in the direction of arrow P, which the piston 15 receives in FIG. No oil groove is provided on the inner surface of the crank pin metal 6 or the inner surface of the crank pin metal support hole 5 in
It is known that oil grooves 19 and 20 are provided in parts that avoid the above range, and in that case, the connecting rod trunk 23 has oil grooves extending along the connecting rod center line A from the piston side to the vicinity of the large end. A perforated hole 22a is opened, and a perforated hole 22b is provided at the large end 2 so as to communicate with the lower end of the perforated hole 22a,
Further, in order to communicate the perforation hole 22B with the oil groove 19, a perforation hole 22c is opened from the side of the cap 3, and a plug 22d is attached to the end of the perforation hole 22b. In that case, three types of holes 22a, 22b, 22c
Because of the necessity to provide a piston, not only does the number of machining steps increase and costs are unavoidable, but the flow of oil to the piston tends to become uneven. A plug 22d is also required. Some models have the drilled hole 22b on the side where the serration part 4 is located (the right side in Figure 1), but in that case, a connecting piece (pipe) is attached to the serration part 4 to prevent oil leakage in the serration part 4. Therefore, the number of man-hours increases further.

(Purpose of the invention) The purpose of this invention is to improve durability by absorbing the explosion pressure from as many surfaces as possible on the crank pin metal, and to allow oil to flow to the piston metal by simply drilling one (one type) of holes. In addition, by eliminating the need for sealing rings and other sealing mechanisms to prevent leakage, both processing man-hours and costs are reduced, and the shape of the oil passage is simplified to ensure smooth oil flow to the piston. The purpose is to do the following.

(Structure of the invention) The invention consists of a serration section that divides the connecting rod big end 2 and the cap 3 into a side closer to the piston pin and a side farther from the piston pin on a plane inclined with respect to the center line of the connecting rod trunk 23. 4, and the cap 3 is fastened with a stud bolt 7 fixed on the large end side, in the crank pin metal support hole 5 of the connecting rod large end 2 and the inner surface of the crank pin metal 6, Oil grooves 19 and 20 communicating with each other via the hole 21 are provided in a portion of the piston pin 14 side excluding the high load support range, and an oil groove 19 is provided inside the crank pin metal support hole on the side where the serration portion 4 located far from the piston pin is located. Connect the piston pin side end to the oil groove 26 of the piston pin metal support hole 11 in a substantially tangential direction through one drilled hole 22 inclined in the same direction as the serration portion 4 with respect to the center line of the connecting rod trunk. This oil supply device to a piston pin metal is characterized in that the oil groove 26 of the piston pin metal support hole 11 is connected to the inner surface of the piston pin metal. The load applied to the piston is supported over a wide range by the piston pin metal in areas without oil grooves. Also, the oil supplied from the crankpin side to the piston side moves smoothly through one drilled hole.

(Example) First, an example of the present invention will be described with reference to the drawings.
In FIG. 1, which shows a vertical cross section, the large end 2 of the connecting rod 1 and the cap 3 are joined via the serration portion 4, and the stud bolt is inserted with the crank pin metal 6 fitted into the crank pin metal support hole 5. It is tightened by 7. 8 is a crank pin. Small end 1 of connecting rod 1
A piston pin metal 12 is fitted into the piston pin metal support hole 11 of No. 0, and is prevented from rotating by a bolt 13. A piston pin 14 is rotatably supported within the piston pin metal 12, and both ends of the piston pin 14 protruding from the piston metal 12 are fitted into holes 17 provided in a piston boss portion 16 of a piston 15, as shown in FIG. are doing.

In Fig. 1, the crank pin metal support hole 5
Among them, the high load support range on the piston pin 14 side (angle α
An arc-shaped oil groove 19 is provided in a portion that avoids 1), and a substantially annular oil groove 20 is provided in a portion of the inner surface of the crank pin metal 6 that excludes the high load support range of the angle α1. , the bottom of the oil groove 20 and the oil groove 19 are formed by a plurality of holes 2 provided in the metal 6.
1, and the end of the oil groove 19 on the piston pin 14 side is connected to the lower end of the drilled hole 22.

The drilled hole 22 extends inside the connecting rod trunk 23 at an angle of α2 with respect to the center line A connecting the center of the crank pin 8 and the center of the piston pin 14 in FIG. 1, and its upper end is closed by a plug 24. There is. When the connecting rod 1 is made of a forged material, there is only a hole 25 in the small end 10 that is smaller in diameter than the piston pin metal support hole 11 shown in the figure. The tip does not come out into the hole 25 (because the gun drill passes only through the thickness of the small end 10), there is no risk of the gun drill swinging out, and the drill hole 22 can be drilled accurately. Then, when the piston pin metal support hole 11 is processed so as to enlarge the hole 25 after drilling the perforation hole 22, the support hole 11 and the annular oil groove 2 in the center thereof are formed.
6, the perforated hole 22 communicates with it in a tangential direction. Note that an arc-shaped oil groove 27 is provided only in the upper half of the inner surface of the piston pin metal 12 opposite to the crank pin 8, and this oil groove 27 is connected to the hole 28.
It communicates with the oil groove 26 through. The piston pin 14 is cylindrical and has four radial holes 29 so as to communicate with the oil groove 27, and a passage 32 with an annular cross section is formed between the piston pin 14 and a pipe 31 installed in the hole 30 at the center thereof. As shown in FIG. 2, the hole 33 on the piston pin 14 side in the piston boss portion 16
After that, the piston pin 14 and the piston boss part 16
It communicates with the joint surface with the hole 17. Further, pressurized oil is supplied to the crank pin 8 in FIG. It communicates with the groove 20.

During operation of the engine, pressurized oil from the oil pump driven by the engine flows from the outer peripheral surface of the crank pin 8 to the oil groove 20 through a drilled hole in the crankshaft.
Some of the oil is used to lubricate the sliding part between the crank pin 8 and the crank pin metal 6, and the remaining oil passes through the hole 21 into the oil groove 19.
from there through the cut hole 22 and into the oil groove 26.
, from the oil groove 26 to the hole 28 to the oil groove 27
After that, piston pin 14 and piston pin metal 1
Used for lubrication between 2. Some of the oil in the oil groove 27 passes through the hole 29, the passage 32, and the hole 33.
Piston pin 14 and hole 17 of piston boss portion 16
will be supplied between.

(Effects of the invention) According to the invention, it is no longer necessary to provide oil grooves on both the inner surface of the crank pin metal 6 in the high load support range (angle α1) and the inner surface of the crank pin metal support hole 5, and the explosion pressure It can be used to take charge of the damage, which improves durability. Moreover, the hole 2
2 is the main body part of the connecting rod 1 excluding the cap 3 (large end 2, small end 10, trunk 2).
Since it is only necessary to drill one drill hole 22 that is inclined with respect to the connecting rod center line A in the integral part (3), the number of processing steps is reduced and costs can be significantly reduced. That is, the drilled hole 22 does not cross the joining serration portion 4 of the connecting rod large end 2 and the cap 3, and there is no risk of interference with the stud 7 or its mounting threaded hole, thus providing a leak-proof seal. No ring or other sealing mechanism is required, and the structure is simplified. Furthermore, since the shape of the oil passage is simple, the oil flows smoothly to the piston, improving the lubrication and cooling effects.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the oil supply device according to the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG.
FIG. 4 is a vertical cross-sectional view and an enlarged view of an example of a conventional structure. 1... Connecting rod, 2...
...Large end, 5...Crank pin metal support hole, 6
... Crank pin metal, 14 ... Piston pin, 19, 20 ... Oil groove, 22 ... Drill hole.

Claims (1)

[Scope of utility model registration request] The connecting rod big end 2 and the cap 3 are butted together at a serration portion 4 that is divided into a side nearer to the piston pin and a side farther from the piston pin on a surface inclined with respect to the center line of the connecting rod trunk 23, and the big end is In the case where the cap 3 is fastened with a stud bolt 7 fixed on the side, high load support is provided on the piston pin 14 side of the crank pin metal support hole 5 of the connecting rod large end 2 and the inner surface of the crank pin metal 6. Oil grooves 19 and 20 that communicate with each other via the hole 21 are provided in the part other than the range, and the end on the piston pin side of the oil groove 19 inside the crank pin metal support hole on the side where the serration part 4 located far from the piston pin is located is connected. 1 inclined in the same direction as the serration section 4 with respect to the center line of the bearing rod trunk.
The oil groove 26 of the piston pin metal support hole 11 is connected approximately tangentially to the oil groove 26 of the piston pin metal support hole 11 through the cut hole 22 of the book.
6 is connected to the inner surface of the piston pin metal.