阅读说明：本技术 用于生产内燃机用活塞的方法、内燃机用活塞、用于生产活塞的活塞坯件、和用于生产活塞坯件的铸模或锻模 (Method for producing a piston for an internal combustion engine, piston blank for producing a piston, and casting or forging die for producing a piston blank ) 是由 亨兹尔德·乌尔里希 哈拉德·默勒 克里斯托弗·施莫尔 于 2018-07-02 设计创作，主要内容包括：本发明涉及一种用于生产内燃机用活塞的方法。作为活塞坯件的生产的一部分,至少一个箱壁在该箱壁大致的中央沿厚度方向设有增厚部,所述增厚部至少部分地与冷却通道齐平。以此方式生产的活塞坯件或活塞、以及在工艺中使用的铸模或锻模以相应方式设计。(The invention relates to a method for producing a piston for an internal combustion engine. As part of the production of the piston blank, at least one wall is provided with a thickening in the thickness direction substantially in the center of the wall, which thickening is at least partially flush with the cooling channel. The piston blanks or pistons produced in this way, and the casting or forging dies used in the process, are designed in a corresponding manner.)

1. A method for producing a piston (30) for an internal combustion engine, wherein, as part of the production of a piston blank (10), a thickening (14) is formed in at least one wall (12) in the thickness direction substantially in the centre of the wall (12), the thickening (14) being at least partially flush with a cooling channel.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the at least one tank wall (12) is formed on the outside on the piston pin boss (16).

3. The method according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the piston blank (10) is produced by forging or by casting methods, in particular iron or steel casting.

4. The method according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the piston blank is made of iron or steel.

5. The method according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

mechanically reworking the at least one thickened portion (14) such that the at least one coolant inlet or outlet opening is at least partially formed funnel-shaped.

6. The method according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

two thickenings (14) are formed in each of the two tank walls (12).

7. The method according to any one of the preceding claims,

it is characterized in that the preparation method is characterized in that,

the cooling channel is filled with a coolant and then sealed.

8. A piston (30) for an internal combustion engine has at least one wall in which a thickening is formed approximately centrally in the thickness direction, said thickening being free of mechanical reworking except for a bore (32) formed therein.

9. The piston as set forth in claim 8,

it is characterized in that the preparation method is characterized in that,

the bore (32) is formed in at least one thickening (14), the bore (32) being at least partially formed funnel-shaped.

10. A piston blank (10) for producing a piston (30) for an internal combustion engine, the piston blank (10) having at least one wall (12), at least one thickening (14) being formed in the at least one wall (12) approximately centrally in the thickness direction, the thickening being at least partially flush with a cooling channel.

11. A mould or die for producing a piston blank for a piston for an internal combustion engine, the mould or die having at least one profile configured for forming at least one thickening in the thickness direction substantially centrally in a wall of the piston blank.

Technical Field

The invention relates to a method for producing a piston for an internal combustion engine, a piston blank for producing a piston, and a casting or forging die for producing a piston blank.

In the field of pistons for internal combustion engines, generally annular cooling channels are formed for the purpose of cooling the piston, which cooling channels are supplied with cooling oil by means of at least one inlet opening extending substantially parallel to the piston axis, said cooling oil leaving the cooling channel at least one outlet opening also extending substantially parallel to the piston axis.

Background

JP 58190538A relates to a forged piston in which coolant inlets and outlets are formed directly in the region of piston pin bosses (piston pin bosses). The same applies to the piston according to CN 205297761U.

Finally, DE 102014222416 a1 shows an aluminium piston in which the coolant inlet and outlet are formed on the outside of a so-called box wall (box wall) which extends between the (load-bearing) shaft walls and accommodates the piston pin boss.

Disclosure of Invention

Against this background, the object of the invention is firstly to create a method for producing a piston, by means of which a piston can be produced in an efficient manner, which piston is improved with respect to the so-called retention rate, in other words with respect to the proportion of cooling oil which actually reaches the cooling channel. Furthermore, corresponding pistons, piston blanks, and casting or forging dies are to be created for them.

This object is achieved with a method as described in claim 1.

As part of the production of the piston blank, a thickening is therefore already formed in the at least one wall in the thickness direction approximately in the center of the at least one wall, which thickening is at least partially flush with the cooling channel. The described thickenings can be used to form coolant inlets and outlets, in which thickenings openings, in particular bores, are created which open into the cooling channel. Thus, only a few production steps are required, without additional components, thereby enabling a simple and cost-effective production. At the same time, it can be ensured that a sufficient amount of cooling oil reaches the cooling channels during operation.

Furthermore, since the thickening is formed in the wall of the tank without being directly adjacent to the piston pin boss, undesired material build-up (mass) is avoided. In addition, a sufficiently large distance from a moving part, such as a connecting rod, can be maintained in an advantageous manner.

Preferred measures and preferred further developments for this purpose are described in the other claims.

At least in some applications, it is advantageous if at least one tank wall is formed on the outside on the piston pin boss, since sufficient space for the bore is thereby created in an advantageous manner, while at the same time the necessary distance from the connecting rod as moving part is maintained.

Although the production of a light metal, in particular an aluminum piston, and/or the production by casting is also possible as part of the method according to the invention, it is currently preferred according to the invention to produce the piston blank by forging and/or from iron or steel. Steel or iron casting, in particular ductile iron (ductile iron), is preferred as the casting method.

The retention rate can be further increased in an advantageous manner by mechanically reworking the at least one thickening, so that the at least one coolant inlet or outlet opening is at least partially formed funnel-shaped.

In certain applications, it has further proved advantageous if two thickenings are formed in each of the two tank walls, so that there are a total of four inlet or outlet openings.

It also provides advantages in some cases if the cooling channel is filled with a coolant, such as sodium, and subsequently sealed.

According to the method described above, the piston according to the invention is provided with at least one thickening which advantageously does not undergo mechanical reworking, except for the holes which may be formed therein. The piston blank according to the invention, and the casting or forging die according to the invention for this purpose correspond to the aforementioned features of the method according to the invention. The same applies to the preferred embodiments and it should be mentioned that all features mentioned in connection with the method, the piston blank, the casting mould and/or the forging die are equally applicable to the respective other subject matter of the present application and vice versa.

Drawings

Examples of preferred embodiments of the present invention are described in more detail below with reference to the accompanying drawings. It shows that:

FIG. 1 shows a bottom view of a piston blank according to the invention, an

Figure 2 shows a cross-section through a piston according to the invention.

Detailed Description

As shown in fig. 1, a piston blank 10 according to the invention has two load-bearing axial wall portions 18 and two case walls 12 which receive piston pin bosses 16. It can also be seen in the figure that a thickening 14 is formed in the wall at two diametrically opposite points, which thickening 14 is situated approximately in the centre of the wall, so that the wall extends in an imaginary continuous path through the thickening 14 approximately in the centre. In other words, the tank wall "bulges" in both directions to the inside and the outside in order to form the described thickening. In other words, the individual thickenings are preferably formed substantially symmetrically with respect to the tank wall 12 as axis of symmetry.

As can be seen in fig. 2, a bore 32 is created in a direction generally parallel to the piston axis (perpendicular to the reference plane in fig. 1, from top to bottom in fig. 2), which is capable of supplying cooling oil 34 from a cooling nozzle 36 into a cooling gallery 38, as shown in fig. 2. To increase the retention rate in this respect, the bore 32 widens in a funnel shape at its end opposite the cooling channel 38.

Fig. 1 also shows the case where the case wall 12 is shown formed on the outside on the piston pin boss 16. However, the piston pin boss 16 may protrude or rebound relative to the case wall 12.