CN107850004A

CN107850004A - Piston for internal combustion engine

Info

Publication number: CN107850004A
Application number: CN201680042821.9A
Authority: CN
Inventors: 拉尔夫·马斯克; 罗兰·博姆; 迈克尔·谢勒; 利·保罗
Original assignee: Federal Mogul Nuernberg GmbH
Current assignee: Federal Mogul Nuernberg GmbH
Priority date: 2015-07-21
Filing date: 2016-07-20
Publication date: 2018-03-27
Also published as: EP3325791A1; DE102015213689A1; WO2017013168A1; KR20180030550A

Abstract

A kind of piston for internal combustion engine, there is the cooling duct of at least one general toroidal, the cooling duct has coboundary and lower boundary.Coboundary is in corresponding at least one position (12) of the plane through piston crown axis or the plane perpendicular to aforesaid plane farther away from piston crown in region of the ratio these planes.

Description

Piston for internal combustion engine

Technical field

The present invention relates to a kind of piston for internal combustion engine.

For diesel motor piston, the edge of combustion chamber be through received heat and mechanical stress influence maximum region it One.Because the intensity of usually used piston alloy drastically reduces as temperature raises, so being conventionally formed with piston Annular cooling channel, full of one oil for coming from piston underside in the cooling duct.On the one hand, this cooling duct reduces Temperature.Cooling duct forms higher, and this effect is more notable.But simultaneously, by cavity required for this purpose, reduce Resistant to bending geometrical moment of inertia, and cause mechanical stress to raise.Accordingly, there exist a kind of specific conflict of interests, because a side Face will reduce temperature, and on the other hand keep highest geometrical moment of inertia as far as possible.

Prior art

Piston with the cooling duct relatively formed on piston crown direction is known previous use " height " Object.Moreover, in some cases by the rugose form of cooling duct system.

The content of the invention

In this context, it is an object of the invention to design a kind of piston for internal combustion engine, the piston cools down to annular Balance between the temperature decreasing effect and intensity decreases of passage influence is improved.

This purpose is achieved by the piston described by claim 1.

Therefore, the piston has the cooling duct of at least one general toroidal, and the cooling duct has coboundary and following Boundary.Herein, coboundary is corresponding at least one of the plane through piston pin axis or the plane perpendicular to aforesaid plane Farther away from piston crown in region in position than between these planes.Through piston pin axis plane include it is foregoing Axis and piston axis, the piston of substantial cylindrical are formed around the piston axis.This plane is properly termed as pin plane.Hang down Directly also comprising piston axis and operation plane is properly termed as in the plane of this pin plane.During operation, the piston is in work Bent on plug pin to a certain extent, to cause piston to be subjected to tension force and the withstanding pressure in plane is run in pin plane.

According to the present invention, the coboundary of cooling duct is at least one (and preferably several and particularly foregoing institute Having four) reduction in position makes geometrical moment of inertia increase that these are especially subjected in the region of mechanical stress.Meanwhile pass through The coboundary of cooling duct is set to realize that especially extensive temperature declines between zones closer to piston crown.Should at these In the less region of power so that the relatively large cavity for reducing geometrical moment of inertia is not crucial.

But in foregoing plane, geometrical moment of inertia can keep at a relatively high, and by being led to according to the cooling of the present invention The cooling effect that road is realized is proved to be enough in initial calculation.Especially by the region of mechanical stress, such as burning Therefore room edge, existing pressure can reduce, while, can also be widely using cooling duct by compared with gadget Mitigate the possibility of weight in the region of stress.And, it is likely that formed only by the salt core suitably changed for casting This neutral zone realizes the advantages of foregoing.

The preferable further development of the piston according to the present invention is described in other claims.

Although a feasible embodiment is lower boundary of the cooling duct around its whole circumference being maintained at same water Plane, but alternately, it is contemplated that the lower boundary of such embodiment, i.e. cooling duct is between its import and its outlet At least one region in compare in the region of inlet and outlet farther away from piston crown, that is to say, that lower boundary also reduces .In this way, on the one hand in the case where not having any negative effect to intensity, weight can extraly be saved.Separately On the one hand, do not emptied in the downward stroke of piston formed with oil conservator, the oil conservator in the region of reduction.Pass through this side In formula, the particularly partial load run when oil pump is closed, heat transmits in the cooling channel.

Around aforesaid plane extend at least ± 10 ° and/or at most ± 25 ° for the periphery of those positions it is verified Be it is favourable, the coboundary of cooling duct in those positions than in region therebetween farther away from piston crown.Herein, Annular cooling channel is looked up in the side of piston axis and therefore annular cooling channel extends on 360 ° of whole circle.It is preferred that Ground, coboundary are maintained at same level in foregoing circumference extension.

Preferably, the coboundary of cooling duct and optional lower boundary on corresponding border farther away from the position of piston crown Put and obliquely extend between therebetween region.

At present, few about 10 ° are circumferentially extended obliquely to and/or at most about 25 ° (preferably approximately 20 °) are special Preferably.

As for the increased distance with piston crown, when being measured along piston axis in " higher " region, if this Individual distance adds at least about the 20% of cooling duct total height, then is presently preferred.

Using the desired cooling effect that cooling duct can be realized according to the piston of the present invention, particularly if cooling is logical The upper groove side of the piston ring groove of coboundary and the top of the road on the horizontal plane closer to piston crown is along piston axis It is approximately at sustained height.

Preferably, according to the piston of the present invention except the piston ring support member of casting that alternatively sets and/or alternatively A part can be made beyond the piston bushing of the subsequent adaptation set.But original two part of piston is not provided Construct (such as be divided into upper and lower part and be subsequently assembled).

In this context, it is preferably cast member according to the piston of the present invention.

Material according to the piston of the present invention is preferably aluminium, aluminium alloy or steel, particularly in the framework of casting process.

Brief description of the drawings

Hereinafter, by more specifically being described by the embodiments of the invention shown in the example in figure.

The figure shows the perspective view of the salt core for forming cooling duct in the piston according to the present invention.

Embodiment

Salt core 10 shown in figure is as can be seen that the salt core is used for the cooling duct for forming general toroidal, shown In situation, the cooling duct is formed in four positions 12 than having lower height in region therebetween, this four positions 12 extend ± 10 ° around pin plane and operation plane.That is, ratio is therebetween in aforementioned location for the coboundary of cooling duct Region in farther away from piston crown (being located at top in figure).On top between two horizontal planes on boundary, in region 14, It circumferentially obliquely extends about 20 °, between make it that about 30 ° of region is kept at slope circumferentially, In the present case, the coboundary of cooling duct is in higher position on constant horizontal plane.

In the example shown, the lower boundary 16 of cooling duct is maintained substantially in same level.Moreover, shown Embodiment in, the cross section of cooling duct is generally elliptical, and in the present case, and the cross section of cooling duct is omited It is micro- outward-dipping.

Claims

1. a kind of piston for internal combustion engine, it includes the cooling duct of at least one general toroidal, and the cooling duct has Coboundary and lower boundary (16), the coboundary is corresponding to the plane through piston pin axis or vertical with aforesaid plane flat Farther away from piston crown in region of the ratio between these planes at least one position (12) in face.

2. the piston according to claim 1 for internal combustion engine, it is characterised in that moreover, the cooling duct is described Lower boundary is at least one region between lower boundary import and lower boundary outlet than in the import and the outlet Region in farther away from the piston crown.

3. the piston according to claim 1 or 2 for internal combustion engine, it is characterised in that have farther away from the piston The position (12) of the coboundary on head around foregoing plane extend in a circumferential direction at least ± 10 ° and/or maximum ± 25°。

4. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that the cooling duct The coboundary with region (14) farther away from the position (12) of the coboundary of the piston crown and therebetween Between obliquely extend.

5. the piston according to claim 4 for internal combustion engine, it is characterised in that inclination, which extends along circumferential, to be turned into extremely Few about 10 ° and/or about 25 ° of maximum, preferably extend about 20 °.

6. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that in the coboundary In those positions of the piston crown, when being measured along the piston axis, the coboundary is before Rheme put between a region in than logical farther away from least about described cooling of the piston crown between zones The 20% of the height in road.

7. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that be located closer to On the horizontal plane of the piston crown, the upper side of the piston ring groove of the coboundary and the top of the cooling duct is in About the same height.

8. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that the piston is made One part, alternatively the piston ring support member with least one casting and/or the work alternatively with least one adaptation Fill in bushing.

9. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that the piston is casting Forging piece.

10. the piston according to any one of the preceding claims for internal combustion engine, it is characterised in that the piston by Aluminium, aluminium alloy or steel are made.