WO2017202548A1

WO2017202548A1 - Arcuate thrust plate for a cylinder crankcase of a reciprocating piston internal combustion engine

Info

Publication number: WO2017202548A1
Application number: PCT/EP2017/059463
Authority: WO
Inventors: Mark Voigt
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2016-05-23
Filing date: 2017-04-21
Publication date: 2017-11-30
Also published as: CN109154324A; DE102016208907A1

Abstract

Thrust plate (10) of arcuate configuration for a cylinder crankcase (12) of a reciprocating piston internal combustion engine having a first free arc end (30) and a second free arc end (32), and having a main body (28) which extends between the free arc ends (30, 32), wherein the main body (28) is subdivided by a thrust plate centre axis (M) into two arcuate virtual arc regions (34a, 34b) which extend over the same angle, wherein the thickness (configured transversely with respect to the direction of extent of the main body (28)) of the main body (28) is configured so as to increase in multiple stages or so as to increase continuously in at least one thrust region (26) which is configured along the arcuate direction of extent of the main body (28) towards the thrust plate centre axis (M).

Description

description

Arc-shaped thrust washer for a cylinder crankcase of a reciprocating internal combustion engine

The invention relates to an arcuate thrust washer for a

Cylinder crankcase of a reciprocating internal combustion engine according to the preamble of claim 1. In particular, the invention relates to a trained as half ring thrust washer, which is arranged in a cylinder crankcase of a reciprocating internal combustion engine and serves as an axial thrust element for a crankshaft cheek a crankshaft of a reciprocating internal combustion engine.

From DE 10 2008 009 856 A1 a symmetrically formed half ring of a thrust washer is known, which is produced by punching out of a sheet metal strip. This half-ring has a uniform thickness. For a specific arrangement of such a half ring, in particular within a cylinder crankcase of a reciprocating internal combustion engine, this document no details can be found.

In the above-mentioned use of a thrust washer as an axial thrust element for a crankshaft cheek, it can during the fixation of a bearing cap on a

Cylinder crankcase come to an area of the cylinder crankcase widens in the axial direction, in particular during assembly of a bearing cap with a cylinder crankcase. This expansion is referred to below as Lagerstuhlaufweitung. To a Lagerstuhlaufweitung it can come in particular if the cylinder crankcase and the bearing cap are made of different materials, for example, if the cylinder crankcase made of aluminum and the bearing cap made of steel or gray cast iron. A Lagerstuhlaufweitung usually has the consequence that changes the relative position of the thrust washer relative to the crankshaft cheek (at least slightly). There is an inclination (tilting), due to an axial force acting on the thrust washer in the area of the Lagerstuhlaufweitung. It is disadvantageous in this case that the tilting leads to the thrust washer rests against the crankshaft cheek only with a contact surface extending over a small area. In the contact area Therefore, locally high material stresses occur, which can lead to premature material fatigue and possibly even material failure of the thrust washer.

The invention has for its object to provide a thrust washer available, which is improved in terms of their life.

The object is achieved according to the invention with the features of the independent claims. Further practical embodiments and advantages of the invention are in

Connection with the dependent claims.

An arcuate thrust washer according to the invention has a first free end of the arc and a second free end of the arc as well as extending between the ends of the arc

Body on. The main body is subdivided from a thrust washer center axis into two virtual arc sections extending over the same angle. The cross to the

Extension direction of the body formed thickness of the body is in at least one, along the arc-shaped extension direction of the body to

Thrust washer center axis formed toward starting region formed multi-level rising or continuously increasing. In particular, a plurality of thickness jumps which are also spaced apart from the free arched ends can be formed (optionally also with

Rounding radii or a continuous, ie rounded, outer contour while avoiding discontinuities in the mathematical sense) and / or the thickness can be formed continuously growing in the run-up area, in particular linearly increasing. In the case of an inclination (tilting) of the thrust washer, for example due to a Lagerstuhlaufweitung the cylinder crankcase can be achieved with the aid of a thrust washer according to the invention, that the thrust washer is aligned with its start-up area substantially parallel to the crankshaft cheek, so that a large-area contact with the crankshaft cheek is possible. In this case, forces acting axially on the thrust washer serving as a thrust element can be absorbed over an enlarged area and thus "distributed over a larger area", either distributed over several stages or, ideally, over a larger area in the case of a linearly formed thickness profile It is also advantageous that the production and use of a thrust washer according to the invention can be implemented relatively simply and cost-effectively, since the thrust washers according to the invention are used for the application of thrust washers according to the invention existing cylinder crankcases and bearing caps must not be changed structurally Thrust washers also the same material can be used as in known from the prior art and previously used thrust washers, so that only geometric adjustments are required for the realization of the invention as part of a redesign in a simple to implement variant.

In a practical embodiment, the starting region extends from a free end of the arc. By this is meant that - viewed in the circumferential direction of a

arcuate thrust washer having two free bottom ends - the starting region begins immediately or very close to the end of the sheet, with very close to the

The end of the sheet should in particular be enclosed in an angular range of up to 20 °, preferably of up to 10 ° or up to 5 °. The thickness of the thrust washer thus increases in this case immediately beginning at the free end of the sheet or at least within the above-mentioned angle range in a measurable order of magnitude. This has the advantage that the geometric adaptation already explained above is (also) implemented in the area in which a bearing block expansion typically occurs.

It has a particularly positive effect on the service life if the starting area extends over a curved area of the thrust washer of at least 20 ° and / or over a height of at least 10 mm. The starting region preferably extends over at least 30 ° and more preferably over at least 45 °. As angle ranges of a start-up area

In particular, ranges between 30 ° and 75 °, more preferably between 45 ° and 70 °, and particularly preferably between 50 ° and 60 ° (based on an inner contour of the base body) are suitable. As height the extension of the

Start-up area along the thrust washer center axis, in particular when the starting area extends from a free end (or from both free ends). The height of the starting region is preferably at least 12 mm, more preferably at least 15 mm. As ranges of values for the height of the starting region are preferred heights between 10 mm to 30 mm, more preferably between 15 mm and 25 mm and particularly preferably between 18 mm and 22 mm. These values apply in particular to starting areas in which the thickness is designed to increase in a linear manner, so that the starting area can come into abutment with a complementarily formed surface of a (rotating) crankshaft cheek contour, so that forces acting in the axial direction extend over as large a surface as possible Thrust washer be initiated.

In conjunction with reciprocating internal combustion engines used by the applicant, it has proven to be particularly suitable if the thickness in the at least one Start-up area increased by a total of at least 20 μηι. The thrust washer can with their starting area then occurring in experience Lagerstuhlaufweitungen and

existing assembly operations after the Lagerstuhlaufweitung be aligned substantially parallel to the outer contour of the (rotating) crankshaft cheeks. More preferably, the thickness increases over a starting range by at least 50 μηι. preferred

Value range for increasing the thickness in a (in particular linear trained) starting range are between 20 μηι and 300 μηι, more preferably between 50 μηι and 250 μηι. As an angle for start-up areas are particularly suitable angles smaller than 2 °, in particular in an angular range between 0.1 ° and 1, 7 °.

In a further practical embodiment, at least one lubrication groove extending from an inner contour of the main body to an outer contour of the main body is formed on the main body on at least one functional surface, which extends over the

Thrust washer central axis, i. the thrust washer center axis in this case passes through the lubrication groove. In particular, the lubrication groove may be formed symmetrically with respect to the thrust washer center axis. By a in the field of

One or more start-up areas spaced apart from the lubrication groove can be formed over a larger arc area, in particular if the respective start-up area extends starting from a free end. The formation of a lubricating groove has the advantage that lubricant, in particular oil, can be conveyed from an outer contour in the direction of the inner contour, so that the

Lubricant can get into the inner arc portion of a thrust washer to the crankshaft, in particular to the crankshaft bearing. The in the thickness direction of the thrust washer

extending depth of the lubrication groove is preferably chosen between 50 μηι and 450 μηι, especially if the thickness of the thrust washer is between 2 mm and 3 mm,

in particular between 2.4 mm and 2.5 mm.

In an embodiment that is simple to produce, the lubricating groove and the at least one starting region are formed on the same functional surface, in particular on one

Side surface of the thrust washer, which extends in a direction transverse to the thrust washer center axis, in particular in a plane perpendicular to the thrust washer center axis. The

Machining the thrust washer can in this case only on one (common)

Functional surface done.

In order to provide a sufficiently large distance between a lubrication groove and a starting region, in particular if the starting region is to be produced by embossing is the angular range over which the lubrication groove extends, in a practical embodiment, is restricted to a range of at most 70 °, in particular over a maximum of 60 ° and more preferably over a maximum of 45 °. The lubrication groove preferably further extends over a maximum length of at least 20 mm, preferably over a maximum of 16 mm, perpendicular to the thrust washer central axis. The smaller the lubricating groove is formed, the larger a starting region can be formed, in particular a starting region, which is spatially separated from the lubricating groove by a transition region of constant thickness and thus separated from the lubricating groove.

In a further practical embodiment, the base body is formed of steel and provided on at least one side, in particular on a directed to a crankshaft cheek functional surface, with a sliding layer of another material. Steel is available as a material for a thrust washer according to the invention not only cost-effective, but also due to its high bending and torsional rigidity and its

Temperature resistance particularly suitable. A suitable sliding layer may for example be formed of aluminum and applied by plating on a base made of steel.

As already mentioned, a starting region of a thrust washer can be produced in a particularly simple and cost-effective manner by embossing. The lubricating groove can also be produced by embossing. In this case, however, the lubrication groove and the starting region are sufficiently spaced apart from each other in order to avoid - especially when embossing a starting region according to already formed lubricating groove - that the lubricating groove destroys or geometrically impairs embossing of the starting region.

Alternatively or in addition to the starting area and / or the lubrication can be formed by milling or other machining. Although this requires a higher production cost, but this has the advantage that a minimum distance between the lubrication and start-up area does not necessarily have to be complied with. This may result in functional advantages in particular insofar as the starting area can extend over a larger area of the thrust washer.

If at least a partial region of the starting region is produced by embossing at least twice, in particular by a second local embossing process in the region of the free arc ends, any accumulations of material produced by a first embossing step can be smoothed, which may result in further functional advantages. Preferably, the second embossment is made over a 1 mm to 5 mm high area, in particular over a 1 mm to 3 mm high area, preferably over an approximately 1, 5 mm to 2.5 mm high area, each starting from the free arc ends ,

Further practical embodiments of the invention are described below in conjunction with the drawings. Show it:

1 shows an arrangement of a thrust washer according to the invention in the form of a half ring in a cylinder crankcase with a bearing cap and two crank webs in a schematic sectional view through a crankshaft axis,

2 shows a thrust washer according to the invention from FIG. 1 in a front view, FIG.

Fig. 3 shows the thrust washer according to the invention of FIG. 2 in a sectional view along the line III-III in Fig. 2 and

Fig. 4 is an enlargement of the area marked IV in Fig. 3 with a

exaggerated starting range.

In Fig. 1 is a schematic sectional view of an arrangement of two

according to the invention, in each case identically designed as a half ring thrust washers 10 shown in a cylinder crankcase 12. The section runs through the central axis M _K a

Crankshaft, of which only two crankshaft cheeks 14 are shown. The

Crankshaft cheeks 14 are connected to each other via a bearing portion of the crankshaft, not shown. The bearing section, not shown, is of the

Cylinder crankcase 12 and a bearing cap 16 enclosed in the circumferential direction.

The thrust washers 10 are each inserted in a recess 18 formed in the cylinder crankcase 12. In this case, each thrust washer 10 has a first functional surface 20, which is directed to the cylinder crankcase 12 and a second functional surface 22, which is directed to the opposite crankshaft cheek 14.

When mounting the bearing cap 16, which is usually secured by means of a screw, not shown, to the cylinder crankcase 12, it can, as shown in Fig. 1 in exaggerated form, characterized in that the cylinder crankcase 12 in a region 24, the - the screw - with forces of the bearing cap 16th is applied, come to a Lagerstuhlaufweitung in the axial direction. As a result, the thrust washers 10 within the recess 18 - as shown in exaggerated form in FIG. 1 - tilt. In the thrust washers 10 according to the invention, which will be explained in detail below in conjunction with Figures 2 to 4 in their geometric design, the second functional surfaces 22 are designed so that the thrust washers 10 in axial movement of the crankshaft in a starting region 26 parallel to the

Crankshaft cheeks 14 are aligned so that it between the start-up region 26 and the crankshaft cheeks 14 to a large-area contact and only small, local

Burdens comes. For this purpose, the start-up area 26 must be adapted to an expected or determined Lagerstuhlaufweitung.

As can be seen in particular in Figures 2 to 4, the thrust washer 10 has a base body 28 which extends between a first free end of the sheet 30 and a second free end of the sheet 32. The main body 28 is subdivided from a thrust washer center axis M into two arched virtual arc regions 34a, 34b extending over the same angle. In the present case, the arc regions 34a, 34b extend over 90 ° in each case. The main body 28 has an outer contour Ka and an inner contour Ki, which each extend in a circular arc over almost 90 °. At the second free end of the sheet 32, a projection 36 is formed as anti-rotation for mounting. This ensures that the thrust washers 10 can only be inserted into the depressions 18 such that the first functional surface 20 is respectively directed towards the cylinder crankcase 12 and the second functional surface 22 is directed toward the crankshaft web 14 (see FIG. As

can be seen in particular in Figures 3 and 4, a start-up region 26 is formed with a continuously increasing thickness on the second functional surface 22.

The base body 28 of the thrust washer 10 is in the present case made of steel, wherein the second functional surface 22 of the main body 28 is provided with an additional sliding layer. In the embodiment shown, aluminum material was applied as a sliding layer by plating.

In Fig. 2, the thrust washer 10 according to the invention is shown with a view of the second functional surface 22, on which both the start-up region 26 and a lubrication groove 38 are formed.

The starting areas 26 formed here over the same height H extend starting from the two free ends 30, 32 in the direction of the thrust washer center axis M over a range of 20 mm, or over an arc range α of 45 ° (measured to the inner contour Ki). , As can be seen in the illustrations of Figs. 3 and 4, the thickness - starting from the free ends 30, 32 - in the direction of the thrust washer center axis M in the starting region 26 at an angle of γ = 0.15 ° on the Height H continuously rising. The thickness thus increases in the starting region 26 by a total of AD = 50 μm. The thickness D of the thrust washer 10 above the starting region 26 is 2.5 mm.

The lubrication groove 38 is present symmetrically about the thrust washer center axis M.

educated. It extends on the second functional surface 22 between the inner contour Ki and the outer contour Ka of the main body 28. The lubrication groove 38 also extends over an arc range ß of 30 ° with respect to the inner contour Ki or over a width B of 16 mm. The depth of the lubrication groove 38 is 200 μηι in the embodiment shown.

Both the start-up region 26 and the lubrication groove 38 are shown in FIG

Embodiment produced by embossing. Between the lubrication groove 38 and the

Starting region 26 extends a transition region 40, which has the full thickness D of the main body 28. The transition region 40 is designed such that during the embossing process of the starting region 26, which previously formed by embossing

Lubricating 38 is not affected.

The broken line 42 indicates that it may be advantageous to have a portion of the part extending from the respective free end 30, 32 to the dashed line

Restrict start-up region 26 again, in particular to smooth material accumulations of a first embossing process. The position of the line 42 can be shifted as needed in the direction of the height H and thus be selected as needed (see Fig. 2).

It is also possible, moreover, to perform further embossing operations in the same subarea or in other subareas, in particular by further smoothing

make. LIST OF REFERENCE NUMBERS

10 thrust washer

12 cylinder crankcase

14 crankshaft cheek

16 bearing caps

18 deepening

20 first functional area

22 second functional area

24 expanded area

26 start-up area

28 basic body

30 first free bow end

32 second free end of the sheet

34a, 34b bow area

36 advantage

38 lubrication groove

40 transition area

42 embossing line a second embossing step

M _K center axis of the crankshaft

M thrust washer center axis

Ki inner contour

Ka outer contour

Claims

claims

1 . An arcuate thrust washer for a cylinder crankcase of a reciprocating internal combustion engine having a first free end of a bow (30) and a second free end of a bow (32) and with a between the free bow ends (30, 32) at least partially arcuately extending main body (28), wherein the main body (28) of a thrust washer center axis (M) is divided into two extending over the same angle virtual arc regions (34 a, 34 b), characterized in that the transverse to the extension direction of the base body (28) formed thickness of the base body (28) in at least one, extending along the arcuate

Extension direction of the base body (28) to the thrust washer central axis (M) formed starting region (26) is formed multi-stage rising or continuously increasing.

Second thrust washer according to one of the preceding claims, characterized in that the starting region (26), starting from a free end of the arc (30, 32).

3. thrust washer according to one of the preceding claims, characterized in that the starting area (26) over an arc range of at least 20 ° and / or over a height of at least 10 mm.

4. thrust washer according to one of the preceding claims, characterized in that the thickness in the at least one starting region (26) increased by at least 20 μηι.

5. thrust washer according to one of the preceding claims, characterized in that on the base body (28) on at least one functional surface (22) at least one of an inner contour (Ki) of the base body (28) to an outer contour (Ka) of

Main body (28) extending lubricating groove (38) is formed, which extends over the

Thrust washer center axis (M) extends across.

6. thrust washer according to the preceding claim, characterized in that the lubricating groove (38) and the at least one starting region (26) on the same

Functional surface (22) are formed.

7. thrust washer according to one of the preceding claims, characterized in that extending the lubrication groove (38) in the circumferential direction over an arc range of up to 70 °.

8. thrust washer according to one of the preceding claims, characterized in that the base body (28) is formed of steel and is provided on at least one side with a sliding layer of another material.

9. thrust washer according to one of the preceding claims, characterized in that the starting region (26) is produced by embossing.

10. thrust washer according to the preceding claim, characterized in that

at least a portion of the starting area (26) is produced by embossing at least twice.