JP2656469B2 - Connecting rod for reciprocating piston type internal combustion engine - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a connecting rod for a reciprocating piston type internal combustion engine comprising a connecting rod small end surrounding a piston pin, a connecting rod main body and a connecting rod large end. The connecting rod large end forms a crankpin bearing together with a connecting rod cap fixed to the connecting rod large end, and the crankpin bearing is penetrated by a lateral hole. The bearing sleeve combined from the half part is fitted, the connecting rod is connected to the crank pin via the bearing sleeve,
In addition, an oil guide passage is provided for lubrication and cooling.This oil guide passage is formed in the connecting rod large end outside the bearing sleeve and in the supply passage for guiding oil to the bearing half through the crank pin. An opening formed in the bearing sleeve for guiding oil to at least one collecting chamber, and a hole in the collecting chamber and the large end of the continuous rod connected thereto are connected to the small end of the connecting rod. Connected to the small orifice of the connecting rod for the reciprocating piston, the hole extending from the large end of the connecting rod through the connecting rod body into the small end of the connecting rod. About.

2. Description of the Related Art Such a connecting rod is known, for example, from DE-A 2 657 467. The following problems generally occur in connecting rods. That is, at the time of a positive acceleration from the bottom dead center to the top dead center, an overpressure is formed in the oil column generated in the oil guide chamber, which is significantly higher than the normal supply hydraulic pressure. In the direction of. When the connecting rod is braked from the positive acceleration, the lubricating oil column is destroyed. This creates a vacuum,
As a result, a reaction of the broken oil column in the region of the top dead center occurs in the direction toward the crankpin bearing, which may cause a phenomenon of cavitation at the wall restricting the oil guide chamber.

In the case of a two-part connecting rod body, as previously known from DE-A 2 657 467, by incorporating a check valve in an oil hole extending inside the connecting rod body, Consideration has been given to this phenomenon.

Apart from the fact that such non-return valves are susceptible to wear in experience and the fact that incorporating the non-return valve causes the connecting rod body to have a considerable weakening of the material cross-section, this non-return valve is It cannot be incorporated into an undivided connecting rod body.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an oil guiding chamber in the range of a crankpin bearing, in which the phenomenon of cavitation due to a constantly formed negative pressure in an oil column existing in the chamber can be avoided. To form a connecting rod of a different type.

Means for Solving the Problem The means of the present invention for solving the problem is that the oil guide passage has
The passage section in the region of the crankpin bearing is in communication with the atmosphere via at least one air port.

Embodiments The different communication possibilities and dimensions of the air inlet / outlet holes according to the invention are given in the dependent claims.

Embodiments The present invention will now be described in detail with reference to the illustrated embodiments.

In the drawings, the same parts or parts corresponding to each other are denoted by the same reference numerals for easy understanding.

The drawing shows a connecting rod 1 for a reciprocating piston internal combustion engine. The connecting rod 1 has a lateral hole 3 for receiving a piston pin 4 surrounded by a bearing sleeve.
A connecting rod small end 2, a connecting rod body 5 connected to the connecting rod small end 2, and a connecting rod large end connected to the connecting rod body and enlarged relative thereto. 6 together with the connecting rod cap 8 secured thereto by means of a clamping screw 7 to form a crankpin bearing. The crankpin bearing is penetrated by a lateral hole 9, the upper half of the lateral hole being in the connecting rod large end 6 above the crankpin bearing separating surface 10 and the lower half of the lateral hole being the crankpin. Each extends below the bearing separating surface 10 into the connecting rod cap 8. In the transverse bore 9 there are provided two bearing halves 11, 12 which are combined with a complete bearing sleeve and which engage in sliding contact around the crankpin 13. By means of the supply passages 14, 15, 16 and 17, oil which serves for lubrication and for cooling is passed under pressure through the crankpin 13 first of all to the bearing halves 11, 12
From which the oil is arranged outside the bearing sleeve through openings 18, 19 in the bearing sleeve consisting of the bearing halves 11, 12, and is connected to the connecting rod large end 6 and in some cases It then reaches at least one collecting chamber which extends into the connecting rod cap 8. In the embodiment shown in FIGS. 1 to 7, two collecting chambers indicated by reference numerals 20 and 21 are provided, whereas in the embodiment shown in FIG. A single collecting chamber 28 is provided which completely surrounds 11, 12 in the form of an annular groove. Figures 1 to 7
In the case of the embodiment shown, the oil from the collecting chambers 20, 21 all extends into the connecting rod large end 6 and is connected to one another via holes 22, 23 and on the other hand. Via holes 24 and 25, it reaches into hole 26, starting from the continuous rod large end 6 and extending through the connecting rod body 5 into the connecting rod small end 2,
And here, it opens in the horizontal hole 3. From here, the oil reaches the injection hole 30 via an annular passage 27 surrounding the bearing sleeve of the piston pin, which in this case extends coaxially with the hole 26. In the case of the embodiment shown in FIG.
A hole 29 extends from the connecting rod body 5 directly from the connecting rod body 5 and, like the hole 26 in the other embodiments, opens into the lateral hole 3 and has a connecting rod small hole. It continues to the inside of end 2. The oil coming out of the injection hole 30 reaches the cooling chamber of a plunger-shaped piston (not shown) connected to the connecting rod 1 via the piston pin 4.

According to the invention, the oil guide passage sections 20, 21, 22, 23, comprising holes and collecting chambers provided in the region of the crankpin bearing formed by the connecting rod large end 6 and the connecting rod cap 8.
24, 25, 26 or 28, 29 are communicated with the atmosphere through at least one air port 31.

As shown in FIGS. 2 and 8, the air inlet / outlet hole 31 opens into the collecting chamber 20, 21 or 28, and in this case, the connecting rod large end 6 (FIG. 2) or the connecting rod It is perforated from the outside into a rod cap 8 (FIG. 8). On the other hand, according to another embodiment, the air port 31
3, can open into a hole 22 or 24 that branches off from the collecting chamber 20 or 21, in which case it is also perforated from the outside into the connecting rod large end 6.
However, as shown in FIG. 1, the air inlet / outlet holes 31 may pass through plugs 32 formed, for example, by cylindrical screws, each of which is drilled from outside the connecting rod large end 6. The holes 23 or 25 are restricted on the outside. Another embodiment is shown in FIGS. 4 and 5, in which the air inlet / outlet hole 31 opens into the hole 23 or 25, which in the embodiment shown is, for example, a cylindrical screw. It is closed on the outside by a non-perforated plug 33 formed in this way. In both embodiments, the air port 31 is drilled from above the connecting rod large end 6. Another embodiment is shown in FIG. 6, in which the air inlet / outlet hole 31 opens in the area of the lower end of the hole 26 passing through the connecting rod body 5 and is connected to the connecting rod body 5 and the connecting rod. It is drilled obliquely into the connecting rod large end from the transition area between it and the large end 6. In the case of the embodiment shown in FIG. 7, the air inlet / outlet hole 31 opens into one of the lateral holes 23 or 25 and is perpendicular to one side 34 or 35 of the connecting rod large end 6. Perforated in the large end of the connecting rod.

Although not shown in the drawings, it is possible to provide more than two air inlet / outlet holes 31, in which case the above-described variants can be used in various combinations. As long as the set task is fulfilled, only one air port 31 can be provided, in which case one of the two air ports 31 shown in the drawing is omitted. In this case, the diameter of the air inlet / outlet hole 31 or all existing air inlet / outlet holes
Select the size of all 31 cross sections accordingly. In an advantageous embodiment of the invention, the air inlet / outlet hole 31 has a diameter of approximately 0.05 to one of the other holes 22, 23, 24, 25, 26 provided in the connecting rod.
It has a diameter corresponding to 0.25 times. When a plurality of air inlet / outlet holes 31 are provided, the diameters of the air inlet / outlet holes can each be located in a lower range of the aforementioned diameter range,
On the other hand, in the case where only one air inlet / outlet hole 31 is provided, the diameter of the air inlet / outlet hole is located toward the upper range of the above-mentioned diameter range, and accordingly, compared to the case where a plurality of air inlet / outlet holes are provided. It will have a large diameter.

Next, the operation of the connecting rod 1 according to the present invention will be described. In this case, it starts from the fact that the oil guide chamber of the connecting rod is flowed with oil, and the oil flow of this oil is generated by an oil supply pump (not shown). Connect rod 1 from bottom dead center UT to top dead center
When accelerating to OT, oil guide chambers 20, 21, 22, 23, 2 of connecting rod 1
In 4,25,26 or 28,29 the accelerating force causes an overpressure compared to the normal oil delivery pressure, which is 10 bar for large engines. When the connecting rod 1 is braked, that is, when the connecting rod runs toward the top dead center OT, the oil column sealed in the oil guide chamber is destroyed in this case by negative acceleration, and as a result, the air inlet and outlet according to the present invention If no holes 31 are provided, a vacuum is created. However, since the connecting rod 1 according to the present invention is provided with the air inlet / outlet hole 31, when the sealed oil column is broken, air is sucked from the atmosphere through the air inlet / outlet hole 31 into the oil guide chamber at almost atmospheric pressure. A mixture of air and oil is formed therein. When the connecting rod 1 travels towards the top dead center and its movement is braked, the rejoined part of the broken oil column compresses the previously sucked air by a predetermined value, and at this time, A small part of the drawn air has a throttle action.
Again blown out into the atmosphere. That is, in this case, the oil column is compressible. As a result, the impact of the oil column sealed in the oil guide chamber against the wall is significantly damped during the reaction, so that the cavitation is virtually avoided. Another advantage of the solution according to the invention is that the connecting rod 1
The oil to be cooled is not supplied exclusively to the piston to be cooled, which is connected to the piston, but is supplied to the piston and the air, which is capable of extracting heat from the hot piston wall. . Another advantage of the connecting rod 1 according to the invention is that
The point of filling the oil guide chamber itself with the oil supply pump is even better. Because the air contained in the sealed oil column and mixed with the oil is compressible, this makes it possible to replenish the oil by means of the oil supply pump and the air and oil present in the oil guide chamber of the connecting rod. Because there is little resistance in discharging the mixture into the connected piston.

[Brief description of the drawings]

1, 2, 3, 4, 5, 6, 7 and 8 are sectional views showing different embodiments of the connecting rod according to the present invention. 1 ... connecting rod, 2 ... small end of connecting rod, 3 ... horizontal hole, 4 ...
Piston pin, 5 ... connecting rod body, 6 ... connecting rod large end,
7: Tightening screw, 8: Connecting rod cap, 9: Horizontal hole, 10: Crank pin bearing separation surface, 11, 12: Bearing half part, 13: Crank pin, 14, 15, 16, 17… Supply passage, 18,19 …… Opening, 20,21 …… Gathering room, 22,23,24,25,
26 …… Hole, 27 …… Circular passage, 28 …… Gathering room, 29 …… Hole,
30 ... injection hole, 31 ... air inlet / outlet hole, 32, 33 ... stopper, 34,
35 …… side

Claims (7)

(57) [Claims] A small connecting rod end surrounding a piston pin.
A connecting rod (1) for a reciprocating piston type internal combustion engine, comprising: a connecting rod main body (5); and a connecting rod large end (6).
The connecting rod large end forms a crankpin bearing with a connecting rod cap (8) fixed to the connecting rod large end;
The crankpin bearing is penetrated by a lateral hole (9), into which a bearing sleeve combined from bearing halves (11, 12) is fitted, and a connecting rod is inserted through the bearing sleeve. Is connected to the crank pin (13), and further provided with an oil guide passage useful for lubrication and cooling, and this oil guide passage passes through the crank pin (13) to the bearing halves (11, 12). Oil supply passage (1
4 to 17) and at least one collecting chamber (20, 21, 28) formed in the connecting rod large end (6) outside the bearing sleeve.
Openings (18, 19) formed in the bearing sleeve for guiding oil to the bearing chamber, and holes (22) in the collecting chambers (20, 21, 28) and the connecting rod large end (6) connected thereto. ~ 25) from the connecting rod large end (6), which connects to the injection hole (30) of the connecting rod small end (2) for the reciprocating piston connected to the connecting rod small end (2). Small connecting rod end (2) through connecting rod body (5)
Of the type comprising a bore (26, 29) extending inwardly, the oil guide passage being provided with a crankpin bearing (6, 8).
A connecting rod for a reciprocating piston internal combustion engine, which is in communication with the atmosphere via at least one air inlet / outlet hole (31) in the passage section in the range (1). 2. The air inlet / outlet hole (31) is provided in a collecting chamber (20, 2).
2. The connecting rod according to claim 1, wherein said connecting rod opens into (1,28). 3. The air inlet / outlet hole (31) is provided in the collecting chamber (2).
0,21,28) and open into holes (22,24) branching from
The connecting rod according to claim 1. 4. The air inlet / outlet hole (31) penetrates a plug (32), which restricts holes (23, 25) drilled from outside the connecting rod large end (6) outside. The connecting rod according to claim 1, wherein the connecting rod is provided. 5. The air inlet / outlet hole (31) opens into a hole (23, 25) drilled from outside the connecting rod large end (6), and the hole is formed by a cylindrical screw. 2. The connecting rod according to claim 1, wherein the connecting rod is closed on the outside by a perforated plug (33). 6. The air inlet / outlet hole (31) extends in the range of the lower end of the hole (26) extending through the connecting rod body (5) and extending into the connecting rod large end (6). 2. The connecting rod according to claim 1, wherein the connecting rod opens into the connecting rod. 7. An air inlet / outlet hole (31) provided is provided in another hole (22, 23, 24, 25, 26, 29) existing in the connecting rod (1).
7. The connecting rod as claimed in claim 1, wherein the connecting rod has a diameter corresponding to 0.05 to 0.25 times the diameter of one of the rods.