DE2063651B2 - Pistons for internal combustion engines - Google Patents

Description

Reaches the area of the counterpressure side of the piston. 55 This leads to the fact that in the ring belt on the opposite

The invention relates to a piston for the combustion pressure side, in particular in the area of piston engines on the circumference of the shaft-side compression ring, an excess of piston shaft applied by machining, rounded lubricant is offered and consequently the oil grooves, which have a sawtooth-like profile with a thick lubricating film in this area than on the have an obtuse profile angle. 60 pressure side of the piston is formed. The printing

However, the working stroke of the piston in one combustion side is comparatively much higher The engine exerts a tiny combustion surface pressure, which is created by the thicker amount of hydrogen gas at least on the upper dynamic compression lubricant film on the counter pressure side ringing over. Since the compression rock is also increased as the counter pressure side The following bar is suspended again with the hot upper 65. One can therefore often observe that Cylinder section in which combustion took place previously due to insufficient lubricant, come into contact, the lubrication of the supply is on the pressure side, especially on the upper compression rings a complicated problem. piston head compression ring, burn marks,

3 4

more or less large bite marks and an over-oil dragging noticeably J * ™ ^^ E £ ^ * J £

average wear and tear occur. The sub- consequently remains in the ⁰ * ^ Ρ ^. ™ .J ™

Different thicknesses of the lubricating film on pressure and entry of the piston one for the development of a

The pressure side also has the consequence that the oil on the circumference of the piston. thick

When the piston is moving downwards, the required SJn »« toftnej ^ ge

the cylinder liner in the area of the counter pressure stores. These advantages Wen am so ° * ™ g ™

Do not completely remove the side sticking abrasive material, the sharper the bottom of the groove of the oil nozzle

can. The remaining lubricant is coked and then grooved. c ^; «^" r. _n tv * ct.At

and the oil coke formed as a result is a further embodiment of the invention

part way between piston and compression ring io that the smaller _Flank enwuutJ αουι ·

so that the formation of a hydrodynamic drag groove in a piston for stroke combustion

Lubricating film disturbed and wear not tmcr- voltage power ^machines _ ^{K. oIbe} _R ⁿ f ^; f _on S

is increased significantly. causing the lubricant towards the

The difficulty with a two-stroke engine is that the crankshaft _{space is required Vprhrennunes}

the relatively small amount from the fuel mixture.

The lubricant portion between the piston engine is the smaller one of the

to hold the shaft and cylinder raceway and to grate them in the oil slide to the piston crown, se. that

Conveying up the ring belt of the piston. so that the lubricant moves towards the R.ngpart.c

a hydrodynamic is promoted up on the circumference of the piston shaft. AUr-hlpnnrillen remains

Mixer lubricant film can build up. .0 In the oil drag line according to the invention Wc b

The invention has now set itself the task. even when the combustion engine mast is upright ne e, n

which adhere to the aforementioned prior art - such amount of lubricant stored that hu.α

to eliminate the deficiency and in particular to start immediately again a hydrodynamic bchmu.-

Säiiezahn-like profile with blunt profile · · angle can build on nlm. ,, _{r PrfillHl} , _n ,

«• milling on the circumference of the piston skirt spa-, 5 A preferred further development of the invention

nend applied rounded oil grooves consists in the fact that in itself from aer a «« ¹ «-"«; · ¹

to shape that in the "operation of the combustion patent specification 437 422 known, way on de G-

engine a uniformly thick film of lubricant on the pressure side of the piston of ^the " ^e ™""f ^ J ¹ ^

between the piston and cylinder liner Jer upstream angle of ölschleppnllen to the plunger stem walls and _t

is tied, so that both on the pressure side and on the 30 on the pressure side rum piston crown we.s ^ on d.

Counter-pressure side always the same hydrodynamic way is achieved that ^a V. ^f d " ⁰ ^ ™ ™ ^ ' ¹ "

Pressure formation in the lubricating film is guaranteed and where the accumulation of lubricant peat is coarser than outside

Pressure formation in the lubricating film is guaranteed and where the accumulation of lubricant peat is greater

there is no longer any superfluous lubricant in the side. de. "Scj-.mierstoff nach Unt, en in the Ku b .-

Can reach the combustion chamber. Furthermore, the wave space and on the pressure side should be upwards ir d ..

Lubricant consumption can be further reduced without requiring 35 ring belts. Here, eη glc. -

that on the pressure side of the piston the moderately thick lubricating film at g.i «.hzritiger Stnkun ..

Containment minimum undercut wi.d. of lubricant consumption achieved.

This object is achieved according to the invention in the manner The invention is illustrated in the drawings. Ha

solved that with known per se, represented towards zero and will be explained in more detail below, t.s.

running radius of curvature and per se known 40 shows. . , " _{Nopnrrinpten mi} ,

th. different large flank angles of the F i g. 1 a number in a cylinder 11

Profile angle d: r oil slide. I 100 to 170 °, its piston 2 connected to a connecting rod 3 for a Vc r-

small flank angle 0.5 b-.s 10- and their depth cycle internal combustion engine. Geinaß F1 g 1 a.

1 to 20 to be, with the profile angle of the an enlarged section of big. 1 dar-

Angle between L flanks of an oil slide 45 is the piston sheep, with the ^ "according to the measure

and with the flank angle the angle between a trained, oil-dragging 4 provided of which Uc.-

Flank of an Ölsch'epprille and the cylinder inner flank angle to the end of the piston skirt

area is designated and the groove base is sharp-edged.

The SeTe flank angle of the oil drag grooves Fig. 2 in a W ^. \ ^% 2% Zg

preferably has a size of! up to 5 °, especially> a connecting rod 3 connected piston 2 for a two, -

the other 2 to 3 ^r , while the profile angle, 1 of the oil cycle internal combustion engine. According to F1 g.2a,

towing grooves preferably 130 to 170 °, in particular an enlarged section from hig._ dar-

which is 150 to 170 ^J. The radius of curvature represents the piston skirt with the according to the invention

the base of the oil drills is 0 to ⁴ designed oil drills, the smaller ones

0.1 mm, preferably 0 to 0.01 mm. 55 Flank angles directed towards the piston head and their

As part of the further training, the invented groove base is sharp-edged.

dung is the depth of the oil drag grooves in particular. 3 an arranged in a cylinder 1 mt

of which 6 to 12 pistons 2 connected by a connecting rod 3 for a V.

By the inventively designed on the cycle internal combustion engine. According to Fig. 3a Piston skirt-attached oil drag grooves runs 60 and 3b, each an enlarged section the Abbtfsche curve, which shows the change in the load-bearing capacity from F i g. 2 is the smaller flank angle part of the sawtooth-like profiling by the oil drag grooves 4 on the counter-pressure side to the Represents wear, straight from 0 to 100%. The piston skirt end is straightened, while the smaller one means that even after a relatively small flank angle of the oil drag grooves 4 on the pressure wear the profile tips have a sufficiently large side to the piston crown. The bottom of the groove Have bearing portion without the depth of the oil drag grooves 4 being sharp-edged.

1 sheet of drawings

Claims (8)

On the one hand, the ring assembly should prevent ... lubricant from entering the combustion chamber; to patent claims: on the other hand, the top compression ring must be so 1. Pistons for internal combustion engines a lot of lubricant is available that this with on the circumference of the KolbeSschafts cutting 5 - despite the high Betnebstemperatar - still applied rounded oil drag grooves that are sufficiently lubricated wml. Sufficiently lubricated a sawtooth profile with a blunt profile means that the top ring should have neither burns angle dadurchgeke η η ζ e i ch - get even tiny Freßmarken and seinVern et that known at to, zero comparable to wear - just like the wear dr «; Cylindrical radius of curvature and in and of itself the piston and its limits remain, known, differently large flank angles. Sufficient lubrication in the range of the ring profile angle of the oil slide grooves 100 to i 70 °, is primarily due to the design with its smaller Hanken angle 0.5 to 10 ° and their adhesion of a hydrodynamic lubricating film - depth 1 to 20 μπι. even in sparse supply of lubricant - between 2. Pistons for internal combustion engines * 5 see piston skirt and cylinder barrel fluidized according to claim 1, characterized in that a hydrodynamic lubricating film the smaller flank angle of the oil drag grooves between the piston skirt and the cylinder raceway can be from -1 to 5 °, preferably from 2 to 3 °, has been in particular for a number of years 3. Piston for internal combustion engine of the piston skirt with a machined according to Ahmet Avenge 1 and 2, characterized by this 20 minimum surface roughness, the surface roughness depending on shows that the profile angle of the oil-dragging according to the engine type is generally not less than _ to 6 .mu.m Grooves 130 to 170 °, preferably 150 to 170 ". Provided. Such a surface roughness. on the one hand favors the running behavior of the Ko! 4. "Pistons for internal combustion engines bens by forming a smear film with the help according to claims 1 to 3. thereby marked 25 of the lubricant stored in the roughness depths draws that the radius of curvature of the oil and on the other hand limits the wear between drag grooves 0 to 0.1 mm, in particular 0 to the piston skirt and cylinder track. 0.01 mm. amounts to. For this purpose it is for example from the 5. Pistons for internal combustion engines German patent application Sch 5976 Ia 4i, _L - \ according to claims I to 4, thereby gekemi- 30 P 20 63 651.5-13, known, on the scope of the records that the depth of the oil grooves 6 to the so-called piston skirt oil drills. which is a 12 µm. half-rice, curved or sawtooth-shaped 6. Pistons for internal combustion engines have a kelsyrrmetrical profile, cutting open the claims 1 to 5, among other things known. ' When the piston runs in, the hollow of the shows that the smaller flank angle of the oil profile is initially due to the greater wear drag grooves on a piston for a four-strong worn. Although this wear and tear with / utakt internal combustion engine is limited to the piston taking contact portion of the profile, takes the shaft end is directed. the sensitivity of the colts to eating, as 7. Pistons for internal combustion engines follow the Rauhnach, which is reduced by wear Claims 1 to 5, as a result of which only relatively little lubricant is left in the oil. that the smaller flank angle of the oil drag grooves can hold. This is the training drag grooves in a piston for a two- one on the entire circumference of the piston skirt Cycle combustion engine to the piston crown hydrodynamic lubricating film when straightening up and down is. reverse motion of the piston is not always ensured. 8. Pistons for internal combustion engines 45 From British patent specification 349 248 are t'ernach Claims 1 to 7, thereby affixed to the circumference of the piston skirt draws that in a manner known per se on the oil drag grooves with different g of the piston skirt is the smaller angle and the rounded-off flank angle running towards zero known from the oil drag grooves to the piston radii. end of the shaft and on the pressure side to the piston so it must also be taken into account that in the case of a Verboden is directed. internal combustion engine driven by the crankshaft lubricant thrown off as a result of their direction of rotation material almost exclusively on the cylinder liner in the