CN1218540A

CN1218540A - Cylinder liner for IC engine

Info

Publication number: CN1218540A
Application number: CN97194448A
Authority: CN
Inventors: 阿兰·厄斯特高
Original assignee: MAN B&W Diesel AS
Current assignee: MAN Energy Solutions Filial af MAN Energy Solutions SE
Priority date: 1996-05-07
Filing date: 1997-04-28
Publication date: 1999-06-02
Anticipated expiration: 2017-04-28
Also published as: GB2326446A; TW384356B; DK173116B1; DK54796A; KR20000010686A; GB9823276D0; GB2326446B; CN1081739C; JP2000509460A; AU2763297A; HRP970228A2; WO1997042406A1

Abstract

A cylinder liner (1) for an internal combustion engine has a piston (5) which is movable in the liner in the longitudinal direction between a bottom dead centre at which scavenging air ports (8) in the wall of the cylinder liner are exposed above the top surface of the piston (9), and a top dead centre at which the piston is in its top position in the cylinder liner. The piston is provided with several piston rings (19, 21-23), the outer surfaces of which slide along the inner surface (13) of the liner. The cylinder liner is provided with several recesses (25) in its inner suface, said recesses being positioned opposite the top piston ring when the piston is at the top dead centre. In the longitudinal direction the extent of the individual recesses (25-27) is at least twice the height of the top piston ring (19). The recesses serve as gas flow connections between the spaces above and below the piston ring when it is positioned opposite the recesses.

Description

The cylinder liner of internal-combustion engine

The present invention relates to a kind of internal-combustion engine that is used for, cylinder liner especially for the two-cycle engine of being with slide block, motor has a piston, piston can vertically move between bottom dead center and top dead along it in lining, air-vent when bottom dead center on the lining wall is exposed on the piston-top surface, piston is in the tip position of cylinder liner when top dead, piston is provided with several piston rings, the outer surface of piston ring slides along the internal surface of lining, the internal surface of cylinder liner is provided with several grooves, and above-mentioned groove forms airflow connection between the space up and down at the piston ring facing to groove.

Existing such cylinder liner among the JP-A 62-26346, in order to lower across the pressure drop of top piston ring with for the pressure drop across all piston rings is reached evenly, it is defined on the cylinder liner internal surface should be provided with groove.Groove is quite dark, and only bigger than height of piston ring along lining longitudinal extension length.The effect of these grooves is as little cavity, during the Piston Compression stroke, filled with pressurized air, after piston ring passes through, air enters in the annulus below the piston ring, thereby increased the pressure below the piston ring, make during piston continues to move upward, diminish across the pressure drop of piston ring.An advantage can mentioning this known cylinder lining is: fill the pressurized air with cleaning in the space between piston ring, prevented that annular slot and lining internal surface are dirty.

The known setting on piston ring makes the leakage grooves of gas by piston ring, with the pressure drop of minimizing across piston ring, thereby reduces the wearing and tearing that encircle.But this leakage grooves can make the mechanical property of bearing the high piston ring that carries weaken, and has lowered the life-span of ring.Form leakage grooves and also bring such shortcoming in piston ring: in the material around the leakage grooves, and by in the leakage grooves adjacent pistons ring zone that the hot air flow of leakage hits downwards, piston ring all suffers very big heat affecting.

In the internal-combustion engine in modern times, particularly in the two-cycle engine of band slide block, firing pressure and mean effective pressure are all very high, have produced the very big pressure reduction across piston ring, and this can cause quite serious wearing and tearing to piston ring and lining.

The objective of the invention is to improve the operating conditions and the life-span of piston ring and lining, used mode only has very little negative effect to engine efficiency.

For this reason, cylinder liner of the present invention is characterised in that: when piston is in top dead, have several grooves at least facing to the top piston ring, and see vertically that along lining the extended length of single groove is the twice of top piston ring height at least.

When piston is positioned at its top dead, the position of lining internal surface upper groove is facing to the top piston ring, this means that on piston ignition produces in the firing chamber strong supercharging will cause the leakage combustion-gas flow by groove, and flow to downwards under top piston ring or the several piston ring, be the maximum engine cycles time thereby just be easy to act as pressure reduction, be reduced across the pressure reduction of top piston ring or several piston rings.This has reduced the wearing and tearing of piston ring and lining effectively.

When piston suitably moves downwards when far away from top dead, piston ring slides at the lining position that is not having groove, thereby does not have leakage current.Since engine cycles during this period of time in, the pressure above the piston is very low, thus do not exist with top dead near identical wear problem.So with leakage grooves be set on the piston ring compare, cylinder liner of the present invention has following advantage: only at piston position near top dead, when the groove on the lining internal surface faced toward piston ring, the chamber pressure very important to engine efficiency just leaked under the piston ring downwards.Another advantage is that the heat that passes to around the groove is less, because the quite little period internal combustion gas groove of just flowing through in engine cycles only.

Because formed groove length is more much bigger than top piston ring height, make combustion gas to flow through one or several piston ring with the long period, and because the space between the piston ring is not subjected to the influence of groove design, so available less unit time gas leakage volume flowrate reaches desirable minimizing across piston ring pressure reduction.Therefore, can do the groove leakage area forr a short time easily, it have further limited the influence of amount of localized heat to lining material around the groove, and has reduced the stress that produces and concentrate in this material.

Owing to the effect of groove being arranged to play leakage grooves on the lining internal surface, can make the top piston ring does not at least have this leakage grooves, has therefore avoided the reduction of piston ring intensity, and has simplified the manufacturing of ring.The temperature that the lining material can bear is than piston ring height, and opposite with piston ring, and the material at position by the cooling hole cooling, has been removed the heat of passing to material usually above the lining.

Groove location on lining internal surface top also provides such advantage: groove all is in the lining district that the nominal stress magnitude is a pressure stress, they are because the thermal stress that high temperature produces when the burning beginning causes that this has significantly reduced the risk that forms fatigue crack in the groove material around.The present invention also has an advantage to be: the rate of depreciation of cylinder liner usually than piston ring slowly many, therefore with at piston ring face adopt the leakage grooves situation to compare, groove can keep for more time the leakage area of uncommon size.

In a preferred embodiment, at least be provided with three groups of grooves on the lining, when piston is in its top dead, wherein first group of groove is relative with the top piston ring, second group of groove be with relative from pushing up last second several piston rings, and circumferentially be offset with respect to other group groove along lining, and the 3rd group of groove is with relative from pushing up last the 3rd several piston rings, second group of groove extends along a lining length field, and first and the 3rd group of groove is positioned at this district at least in part.Three groups of grooves make the leakage of controlled combustion gas not only by the top piston ring, and by back to back two rings, have therefore controlled the pressure reduction across these three piston rings.As this embodiment's alternative, for example can be single group groove, when piston was in its top dead, groove length can make it pass through uppermost two or three piston rings.But this can not one by one control the pressure reduction across piston ring.In a preferred embodiment, when the top piston ring moved down by groove area in piston moves down on the way, second group groove guaranteed that combustion gas continue to leak into below the top piston ring downwards.Second group of groove can force the gas leakage that has flow through a piston ring with respect to the circumferential offset of other groove, below may continuing to flow to downwards under the piston ring before, earlier along circumferential flow.Gas leakage has been cooled off in the prolongation of this glide path, and owing to organize flowing of groove from one group to another, has produced favourable gas pressure loss.Become the set of dispense groove that following advantage also is provided: when piston is removed from top dead, during the lower end by each group groove, leakage volume can reduce the piston ring lower surface step by step downwards.

In the mode of further preferred development, the 3rd group fillistered joint is in the back of first group of groove, along groove vertically mutually distance separating greater than from pushing up last second several height of piston ring.In the time of near piston is positioned at top dead,, blocked from the firing chamber down to from pushing up the direct circulation under last several the 3rd piston ring from pushing up last several second piston ring facing to the marker space between first and the 3rd group of groove.In addition, groove being made mutually continuous two groups in position can make easily manufactured.

At least on a lengthwise position of lining, can suitably distribute at least four along the lining periphery, preferably be eight grooves at least.These grooves alternately belong to second group and first or the 3rd group along circumferentially seeing.Total leakage area is distributed in the sectional area that can reduce single groove on more grooves, and the heat affecting of gas leakage is assigned to several position, make the local pyrexia step-down.According to lengthwise position relevant on lining, in belonging to first or the 3rd group groove, insert and belong to a groove of second group, can be to passing through fluted air-flow produces the glide path of above-mentioned favourable length.If some special circumstances helps circumferentially taking shorter or longer glide path in the district along lining, then can in many grooves of other each group that the moving route of longshore current extends, save and belong to second group groove, perhaps make first to be connected with many grooves of the 3rd group, provide directly and flow, but these all not preferred ways.

In order to reach minimum possible combustion-chamber pressure loss, should make lining like this: when piston was in its top dead, groove did not extend to below the bottom piston ring.Therefore, one group of piston ring on the piston provides the firing chamber downward disconnection fully, only at three piston rings in the quite short time facing to groove topmost, gas leakage just flow to downwards they below.

Minimizing is the most obvious to the top piston ring across the demand of piston ring pressure reduction.In one embodiment, when piston between the top dead and following piston position of bent axle 0 degree: is 15 to 20 crank angle scopes before and after the top dead for the top piston ring, for being 10 to 15 crank angle scopes from pushing up last second several piston rings, for being 5 to 8 crank angle scopes from pushing up last the 3rd several piston rings, this moment, groove was just by one or several formation airflow connection in three the top piston rings.The total movement of piston from top dead to the dead point, bottom is to produce from 0 to 180 crank angle, can find out from above-mentioned angular range, can be located at position very high on the cylinder liner internal surface to groove easily.

For the air-flow by the top piston ring, the leakage area A that is formed by groove is preferably at D ²/ 70000 to D ²/ 2000mm ²In the scope, wherein D is that unit is the lining internal diameter of mm, and A is that unit is mm ²Area.If leakage area is less than D ²/ 70000mm ², then the pressure reduction across piston ring will become greatly inadequately, cause the high flow rate of gas leakage, and the result has increased thermal force in the material around the groove, and piston ring and lining are caused quite serious wearing and tearing.If leakage area is greater than D ²/ 2000mm ², then the pressure reduction across piston ring will become too little, make that piston ring is difficult to be close to sealing with the cylinder liner internal surface on the contrary, cause the major component of firing pressure above the piston to have the risk of the piston ring that escaped.

Know that in other open text of EP-B 0558583, can be provided with cooling hole on the position on cylinder liner, the longitudinal axis in hole is made diagonally extending with respect to the lining longitudinal axis.If this lining uses in conjunction with the present invention, then the longitudinal axis of every groove is preferably parallel with the longitudinal axis of adjacent cooling hole basically.This groove direction assists in removing the heat that gas leakage spreads out of, thereby the temperature in the groove material around suitably remains on low magnitude, and as far as possible along keeping identical magnitude on the whole length of groove.Above-mentioned EP patent issue textual description: from the cooling hole position of the most close lining internal surface, rely on install or removal cut off cooling fluid supply dividing plate, the intensity of cooling of the single cooling hole of may command.Extend if groove faces cooling hole,, do not have the zone of groove strong near the cooling effect ratio feasible there then at the dividing plate that can remove facing to the position of groove in the cooling hole.

This measure has increased the cooling effect facing to groove, as its alternative, can further develop lining of the present invention, make cylinder liner have along equally distributed several cooling hole of lining periphery, the extension of every groove basically in even distribution cooling hole hithermost two cooling hole be equidistant, and, evenly in the zone between the distribution cooling hole additional cooling hole is being set facing to groove.Additional cooling hole can be removed the heat of passing to the groove material around.

In order to provide extra cooling, be preferably in facing to the additional cooling hole that belongs to first group of groove and extend on the lining wall than even distribution cooling hole height to the material around the position, first group of groove the top.

Referring now to appended sketch, below will further describe embodiments of the invention, wherein:

Fig. 1 is the part longitudinal sectional drawing, has represented cylinder liner profile of the present invention,

Fig. 2 is the longitudinal sectional drawing that ratio is amplified, and has represented to be contained in position above the in-engine cylinder liner,

Fig. 3 launches view, has represented on the internal surface above the reeded cylinder liner one of the position section, and a part that is positioned at the piston of top dead is inserted in the left side of figure, have protrude cooling hole longitudinal profile be inserted in the right side of figure,

Fig. 4 has represented near the lining zone enlarged portion Fig. 3 further groove,

Fig. 5 is cylinder liner transversal profile figure of the present invention,

Fig. 6 has represented near the barrel part the groove shown in the circle S among Fig. 5 with magnification ratio.

Fig. 1 has illustrated the cylinder liner of representing with 1 summary, and it is used to the large-scale two-stroke motor with slide block, and motor can be used as the propelling motor of the stationary engine or the boats and ships of power station.Relevant with the size of motor, cylinder liner can make different size, usually the cylinder bore diameter scope be 250mm to 1000mm, length range commonly used accordingly is that 1000mm is to 4500mm.Lining is generally cylinder iron made, and can be integrated type, or be divided into two or more parts of end-to-end.In split lining situation, also can be made of a steel upper part.The band crosshead engine of above-mentioned pattern has developed into high effective compression ratio, for example 1: 16 to 1: 20, makes and born heavy load on piston ring.

In the drawings, half lining on longitudinal shaft 2 right sides is expressed as longitudinal profile.(referring to Fig. 2) in known manner can pack lining in the drawings in the motor of only part expression, relies on downward annular surface 3, is placed on the top board 4 of engine housing or cylinder block.Subsequently piston 5 is packed in the cylinder liner, and at the lining top cylinder head 6 is placed on the upwards annular surface 7 of lining, be clamped on the top board with bonnet bolt not shown in the figures.

One row's hoop scavenge port 8 is arranged at the bottom of cylinder liner.Piston can be along vertically the moving between top dead and bottom dead center of lining, and in top dead, piston upper surface 9 is in the hole of cylinder head 6, be in the position of A mark among Fig. 1, at bottom dead center, piston upper surface 9 is right after below the scavenge port lower end, is in the position of B mark.

By piston rod 10, slide block and connecting rod, press known way piston is connected with the bent axle of motor.Each bent axle three-sixth turn, piston moves to top dead from bottom dead center, and returns again.Therefore there is clear and definite association between the angular orientation of bent axle and the position of piston in cylinder liner.If the angular orientation corresponding to the piston head dead point is defined as 0 crank angle degrees, then piston occurs in the 180 crank angle degrees processes then towards moving downward of bottom dead center.

On the piston position of 40 degree or more crankshaft angles under the top dead, the lining internal surface is provided with corrugated oil groove 11, by oil supply hole 12 to its supplying lubricating oil, with the running surface of lubricious liner tube inner surface 13.

Above between

surface

3 and 7 in the position, cylinder liner forms bigger external diameter, top at this position has been bored many vertical cooling hole 14 from outside recess 15 to the lining wall, makes the longitudinal axis of cooling straight hole with respect to the lining longitudinal axis 2 direction that tilts or twist be arranged.In each cooling hole, insert a pipe or guide plate, be used for the cooling liquid that flows from recess 15 be directed to the hole above dead end, cooling liquid is to dirty therefrom, and enters cavity 16, cooling liquid enters cylinder head by managing 17 therefrom.It should be noted that the cooling hole of Fig. 2 is drawn to such an extent that seem that its longitudinal axis extends in the institute tangent plane, but in fact they are to make diagonally extending with respect to the plane.Recess 15 is surrounded by circumferential butt 18.Know that cooling hole can have other design, as adopting curved tube, they are cast in the lining wall, and outwards lead in the cavity at lining outer surface top.

Fig. 2 has represented the piston 5 in top dead.Four piston rings are arranged on the piston, and wherein top piston ring 19 gastight type preferably that is to say that the form of cut or cuts of the ring among Fig. 5 shown in 20 can prevent the otch of gas by encircling basically.This can realize, for example, ring is designed to have the ring end of mutual overlap joint, and an end has flat tab, and it extend in the ring the other end in the corresponding recess.Tab and recess have the radial width littler than piston ring, thereby at the internal surface that encircles, the part of wall has covered recess, prevents the gas stream mistake.From second piston ring 21 of few top, from the 3rd piston ring 22 and the bottom piston ring 23 of few top all are common rings, and their form of cut or cuts is the gap that the upper surface from ring extends to lower surface along peripheral, oblique.Gap diagonally extending direction from the 3rd piston ring of few top is preferably with opposite from the gap direction of second piston ring of few top and bottom piston ring.As the alternative that adopts air-tight top piston ring 19, ring also can adopt and the identical form of piston ring 21～23 that is right after below.The ring outer surface that slides along lining internal surface 13 is smooth, and can make no leakage grooves form.Noun piston ring in this article means compression piston ring.

When piston was in its top dead, piston ring all facing to the top position of lining internal surface, represented with 24 in Fig. 1 by this position.Fig. 3 has represented this position with the ratio of amplifying.In the embodiment shown, when top dead shown in piston is in, the lining internal surface is provided with first group of groove 25, they facing to and cross top piston ring 19, be provided with second group of groove 26, they facing to and cross second piston ring 21 from few top, and be provided with the 3rd group of groove 27, they facing to and cross the 3rd piston ring 22 from few top.Corresponding to each piston ring central authorities, be marked at lengthwise position on the lining with the line shown in 19 ', 21 ', 22 ' and 23 ' among Fig. 4 in top dead.

In institute's example, similar to cooling hole 14, also for tilting or distortion, so groove is arranged essentially parallel to adjacent cooling hole and extends the groove y direction with respect to the lining longitudinal axis 2.Also can find out under bottom piston ring 23, do not have groove to extend.The 3rd group of groove 27 and first group of groove 25 extend in parallel and are attempted by its back, but mutual separation distance 28, and separation distance is preferably big than the height from second piston ring 21 of few top, but is not to do like this.Second group groove 26 is longer than other groove, thus at top piston ring 19 before moving down into groove 27 lower ends, provide the continuous gas by top piston ring 19 to leak.Branch has been represented a possible example in Fig. 4 right side, has at least a groove 27 to extend far than other groove of the 3rd group on lining downwards, and feasible gas leakage stream by groove 27 is blocked step by step and opens.

In top dead, the firing chamber of combustion gas above piston of heat flows to the annulus between

piston ring

19 and 21, between outer surface of piston and lining internal surface by groove 25 downwards.Gas can be along circumferentially flowing to groove 26 then, and flow into downwards in the annulus between

piston ring

21 and 22, and gas can be again along circumferential flow therefrom, and arrive annuluses between the

piston rings

22 and 23 downwards by groove 27.Simultaneously, gas also can flow by the rings cut in piston ring 21～23, if top piston ring 19 is not an air-tight, also can flow by its rings cut.When piston moves downward, when piston ring passes through the lower end of groove 27, leakage volume will reduce.

Cooling hole 14 evenly distributes along the lining periphery, and each groove of 25～27 equates from two nearest cooling hole distances.Facing to the groove 26 between corresponding cooling hole 14 just in time, be drilled with and replenish cooling hole 14 ', be used to remove the heat that the leakage current by groove 26 spreads out of.Facing to the

groove

25 and 27 between corresponding cooling hole 14 just in time, be drilled with and replenish cooling hole 14 ", be used to remove the heat that the leakage current by

groove

25 and 27 spreads out of.Cooling hole 14 " on the lining wall, extend than cooling hole 14 height.Can be placed to groove 25～27 just in time facing to equally distributed cooling hole 14, to avoid making additional cooling hole.

Viewgraph of cross-section shown in Figure 5 just in time extends on top piston ring 19 for piston, extends on low slightly height for lining, makes the upper end that can see cooling hole in the cross section.For the sake of clarity, omitted piston itself among the figure.First group has along equally distributed four grooves 25 of lining periphery, is second group of groove 26 in the middle of them just in time.Below groove 25, four the 3rd group of grooves 27 are arranged.Obviously, each group can have still less, and for example two, or more, six, eight, ten or 12 grooves for example.This number is adapted to the cross-section area of desirable single groove, and is adapted to desirable air-flow maximum leakage area by the top piston ring.If the top piston ring is not an air-tight, then long-pending must the counting in the maximum leakage area of clearance cross section on the rings cut of piston outside makes and can make some grooves less on the lining internal surface.

Can be used as example and propose, if be 600mm at 1 internal diameter of the cylinder liner shown in Fig. 5, for one group be the situation of four grooves, it is suitable for the long-pending 12.5mm that is about of each groove cross section ²If groove has the favourable shape of cross section shown in Figure 6 of counter stress, from piston one side, its bottom is recessed central area, carry out the transition to the lateral areas of two epireliefs smoothly, tangentially carry out the transition to the internal surface 13 of lining again, then adopt along the recess width of circumferential about 9mm and radially the depth of groove of about 2.5mm just can reach above-mentioned area.Because of engine operation makes lining when wearing and tearing since towards groove direction internal surface 13 certain distance that worn and torn downwards, leakage area will reduce.If leakage area reaches lower limit, need overhaul processing to lining, recover the shape of groove.

On the cylinder liner basis of having come into operation, also can manufacture lining with groove of the present invention.At rering more, when for example changing the top piston ring, can on the lining internal surface, process groove 25～27, they facing to and longitudinally be parallel to existing cooling hole.

If the cooling to the groove material around does not have specific (special) requirements, for example because material can bear current temperature magnitude, then groove can extend abreast with the lining longitudinal axis 2.Lining also can make has only one group or more than three groups groove.When piston was in top dead, one or several groove can be in the position lower than bottom piston ring, but made groove then there is no benefit down to the position also lower than distributing groove again on lining.

Cylinder liner of the present invention also can be used for other engine type except that above-mentioned, for example the four-stroke medium-speed engine of no cooling hole in the lining wall.

Claims

1. one kind is used for internal-combustion engine, cylinder liner (1) especially for the two-cycle engine of being with slide block, motor has a piston (5), piston can vertically move between bottom dead center and top dead along it in lining, air-vent when bottom dead center on the lining wall (8) is exposed on the piston-top surface (9), piston is in the tip position of cylinder liner when top dead, piston is provided with several piston rings (19,21-23), the outer surface of piston ring slides along the internal surface (13) of lining, the internal surface of cylinder liner is provided with several grooves, above-mentioned groove forms airflow connection between the space up and down at the piston ring facing to groove, it is characterized in that: when piston is in top dead, have several grooves (25) at least facing to the top piston ring, and along vertically the seeing of lining, the extended length of single groove (25-27) is the twice of top piston ring (19) height at least.

2. according to the cylinder liner of claim 1, it is characterized in that: be provided with three groups of grooves on the lining (1) at least, when piston is in its top dead, wherein first group of groove (25) is relative with top piston ring (19), second group of groove (26) is with relative from pushing up last several second piston rings (21), and along lining circumferentially with respect to other the group groove (25,27) be offset, the 3rd group of groove (27) is with relative from pushing up last several the 3rd piston rings (22), second group of groove (26) extends along a lining length field, and first and the 3rd group of groove (25,27) is positioned at this district at least in part.

3. according to the cylinder liner of claim 2, it is characterized in that: the 3rd group groove (27) is connected on the back of first group of groove (25), along groove vertically mutually distance separating (28) greater than from pushing up last several second piston rings (21) highly.

4. according to the cylinder liner of claim 2 or 3, it is characterized in that: on a lengthwise position of lining, can suitably distribute at least four along the lining periphery at least, preferably be eight grooves (25,26 at least; 25,27), these grooves alternately belong to second group and first or the 3rd group along circumferentially seeing.

5. according to any cylinder liner in the claim 1 to 4, it is characterized in that: when piston was in its top dead, groove did not extend to below the bottom piston ring (23).

6. according to any cylinder liner in the claim 1 to 5, it is characterized in that: when piston (5) between the top dead and following piston position of bent axle 0 degree: is 15 to 20 crank angle scopes before and after the top dead for top piston ring (19), for being 10 to 15 crank angle scopes from pushing up last several second piston rings (21), for being 5 to 8 crank angle scopes from pushing up last several the 3rd piston rings (22), groove this moment (25-27) is just by one or several formation airflow connection in three the top piston rings.

7. the cylinder liner of any in requiring according to aforesaid right is characterized in that: for the air-flow by top piston ring (19), the leakage area A that is formed by groove (25-27) is at D ²/ 70000 to D ²/ 2000mm ²In the scope, wherein D is that unit is the lining internal diameter of mm, and A is that unit is mm ²Area.

8. the cylinder liner of any in requiring according to aforesaid right, it is characterized in that: on cylinder liner, be provided with cooling hole (14 on the position, 14 ', 14 "); the longitudinal axis in hole is made diagonally extending with respect to the lining longitudinal axis (2), the longitudinal axis of every groove (25-27) is parallel with the longitudinal axis of adjacent cooling hole basically.

9. according to the cylinder liner of claim 8, it is characterized in that: cylinder liner has along lining periphery equally distributed several cooling hole (14), the extension of every groove (25-27) basically in even distribution cooling hole hithermost two cooling hole be equidistant, and facing to groove, additional cooling hole (14 ', 14 ") is set in the even zone between the distribution cooling hole.

10. according to the cylinder liner of claim 9, it is characterized in that: on the lining wall, extend than even distribution cooling hole (14) height facing to the additional cooling hole (14 ") that belongs to first group of groove (25).