PISTON FOR AN INTERNAL COMBUSTION ENGINE

Abstract

A piston for an internal combustion engine may include a lower piston part, a combustion chamber bowl part, and a ring section part. The lower piston part, the combustion chamber bowl part, and the ring section part may be welded together. The piston may include a first ring collar arranged on the combustion chamber bowl part. The piston may include a second ring collar arranged on the ring section part. The first and second ring collar may abut on one another and separate a first air insultation chamber from a coolant channel.

Claims

1. A piston for an internal combustion engine, comprising: a lower piston part, a combustion chamber bowl part, and a ring section part welded to one another; a first ring collar arranged on the combustion chamber bowl part; a second ring collar arranged on the ring section part; and wherein the first ring collar and the second ring collar abut on one another and separate a first air insulation chamber from a coolant channel.

2. The piston according to claim 1, wherein: the first ring collar protrudes outwards from the combustion chamber bowl part; and the second ring collar protrudes at least one of (i) inwards from the ring section part and (ii) downwards to the lower piston part.

3. The piston according to claim 1, further comprising a second air insulation chamber, wherein: the second air insulation chamber is separated from the first air insulation chamber and is arranged coaxially within the first air insulation chamber and the coolant channel; and the second air insulation chamber is disposed between the lower piston part and the combustion chamber bowl part.

4. The piston according to claim 2, wherein at least one of: the first ring collar protrudes from the combustion chamber bowl part at a first angle and extends obliquely to a piston axis; and the second ring collar protrudes from the ring section part at a second angle and extends one of obliquely and parallelly to the piston axis.

5. The piston according to claim 4, wherein at least one of: the first angle is equal to the second angle; and at least one of the first angle and the second angle is 45 degrees.

6. The piston according to claim 1, wherein: the first ring collar includes a ring-shaped, cross-sectional reduction, which divides the first ring collar into a first portion connected to the combustion chamber bowl part and a cantilevered second portion.

7. The piston according to claim 6, wherein: the first ring collar abuts with the second portion on the second ring collar in at least one of an elastically pre-tensioned manner and a plastically deformed manner.

8. The piston according to claim 1, wherein at least one of: the first ring collar has a larger radial extension than the second ring collar; and a piston bottom section of the ring section part extends radially farther inwards than the second ring collar.

9. The piston according to claim 1, wherein: the first ring collar and the second ring collar abut on one another so as to overlap, tightly, and under pre-tension.

10. The piston according to claim 1, wherein: the lower piston part, the internal combustion bowl part, and the ring section part are welded to one another via at least one of a laser welded joint and a friction welded joint.

11. The piston according to claim 1, wherein: the lower piston part is composed of at least one of a 42CrMo4 steel and a 38MnVs6 steel.

12. The piston according to claim 3, wherein: the first air insulation chamber is enclosed by the ring bowl part and the ring section part; and that the second air insulation chamber is enclosed by the ring bowl part, the ring section part, and the lower piston part.

13. An internal combustion engine, comprising a cylinder and a piston, the piston including: a lower piston part, a combustion chamber bowl part, and a ring section part welded to one another; a first ring collar arranged on the combustion chamber bowl part; a second ring collar arranged on the ring section part; and wherein the first ring collar and the second ring collar abut on one another and separate a first air insulation chamber from a coolant channel.

14. A piston for an internal combustion engine, comprising: a lower piston part, a combustion chamber bowl part, and a ring section part welded to one another; a first ring collar arranged on the combustion chamber bowl part; a second ring collar arranged on the ring section part; wherein the first ring collar and the second ring collar abut on one another and separate a first air insulation chamber from a coolant channel; wherein the first ring collar protrudes outwards from the combustion chamber bowl part; wherein the second ring collar protrudes at least one of (i) inwards from the ring section part and (ii) downwards to the lower piston part; wherein the first ring collar protrudes from the combustion chamber bowl part at a first angle and extends obliquely to a piston axis; and the second ring collar protrudes from the ring section part at a second angle and extends one of obliquely and parallelly to the piston axis.

15. The piston of claim 14, wherein the first ring collar includes a ring-shaped, cross-sectional reduction, which divides the first ring collar into a first portion connected to the combustion chamber bowl part and a cantilevered second portion.

16. The piston of claim 14, wherein at least one of: the first angle is equal to the second angle; and at least one of the first angle and the second angle is 45 degrees.

17. The piston of claim 14, wherein: the first ring collar includes a ring-shaped, cross-sectional reduction, which divides the first ring collar into a first portion connected to the combustion chamber bowl part and a cantilevered second portion; and the first ring collar abuts with the second portion on the second ring collar in at least one of an elastically pre-tensioned manner and a plastically deformed manner.

18. The piston of claim 14, wherein: the first ring collar has a larger radial extension than the second ring collar; and a piston bottom section of the ring section part extends radially farther inwards than the second ring collar.

19. The piston of claim 14, further comprising a second air insulation chamber, wherein: the second air insulation chamber is separated from the first air insulation chamber and is arranged coaxially within the first air insulation chamber and the coolant channel; and the second air insulation chamber is disposed between the lower piston part and the combustion chamber bowl part.

20. The piston of claim 19, wherein: the first air insulation chamber is enclosed by the ring bowl part and the ring section part; and the second air insulation chamber is enclosed by the ring bowl part, the ring section part, and the lower piston part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In each case schematically,

[0024] FIG. 1 shows a sectional illustration through a piston according to the invention,

[0025] FIG. 2 shows a detailed illustration through a possible embodiment of a piston according to the invention in the region of the first and second ring collar,

[0026] FIG. 3 shows a detailed illustration as in FIG. 2, but in the case of another second ring collar.

DETAILED DESCRIPTION

[0027] According to FIGS. 1 to 3, a piston 1 according to the invention of an internal combustion engine 2, which is likewise in accordance with the invention, has a lower piston part 3, a combustion chamber bowl part 4, as well as a ring section part 5, which are welded to one another. A first ring collar 6, which protrudes outwards (see in particular FIG. 2) is thereby arranged on the combustion chamber bowl part 4, while a second ring collar 7 is arranged on the ring section part 5. When the piston 1 is fully assembled, as it is illustrated according to FIG. 1, the first and second ring collar 6, 7 thereby abut on one another and separate a first air insulation chamber 8 from a coolant channel 9.

[0028] The second ring collar 7 can be formed as second ring collar 7a, which protrudes inwards from the ring section part 5 (see FIG. 2) or as second ring collar 7b, which protrudes downwards to the lower piston part 3 (see FIG. 3).

[0029] By means of the piston 1 according to the invention it is possible for the first time to create a piston 1 comprising a first air insulation chamber 8 and a coolant channel 9, which is separated therefrom, via only three joints 10, 11, 12, namely a first joint 10 between the lower piston part 3 and the combustion chamber bowl part 4, a second joint 11 between the combustion chamber bowl part and the ring section part 5, and a third joint 12 between the ring section part 5 and the lower piston part 3.

[0030] A second air insulation chamber 13, which is separated from the first air insulation chamber 8 and which is arranged coaxially within the first air insulation chamber 8 and the coolant channel 9, is furthermore provided between the lower piston part 3 and the combustion chamber bowl part 4. The second air insulation chamber 13 is thereby enclosed by the lower piston part 3 and the combustion chamber bowl part 4. A temperature of the combustion chamber bowl part 4 can be kept comparatively high via the two air insulation chambers 8 and 13, whereby the combustion in the combustion chamber of the internal combustion engine 2 as well as an efficiency of the internal combustion engine 2 can be optimized. The lower piston part 3, the internal combustion bowl part 4, as well as the ring section part 5 can thereby be welded to one another, for example via a laser welded joint or a friction welded joint at the individual joints 10, 11, 12.

[0031] When looking at the two ring collars 6, 7, 7a, 7b in more detail, it can be seen in particular in FIG. 2 that they abut on one another other so as to overlap, tightly, and preferably under pre-tension when the piston 1 is fully assembled, wherein the pre-tension can in particular also be attained by means of a different elasticity of the first ring collar 6 and of the second ring collar 7, 7a, 7b. The first ring collar 6 can thereby have a higher elasticity than the second ring collar 7, 7a, 7b, so that the second ring collar 7, 7a, 7b is formed to be stiffer compared to the first ring collar 6. According to FIG. 3, the second ring collar 7b protrudes downwards from the ring section part 5 to the lower piston part 3, and abuts on the first ring collar 6. The higher elasticity of the first ring collar 6 can be attained, for example, by means of a further collar width and, in the illustrated case, additionally by means of a ring-shaped cross sectional reduction 14, which divides the first ring collar 6 into a first portion 15 connected to the combustion chamber bowl part 4 and a cantilevered second portion 16. In response to a joining of the piston 1, the combustion chamber bowl part 4 is thus firstly attached to the lower piston part 3, and subsequently the ring section part 5 to the lower piston part 3. The comparatively stiff second ring collar 7, 7a, 7b thereby pushes the second portion 16 of the first ring collar 6 slightly downwards and thus deforms the second portion 16 of the first ring collar 6 elastically or plastically, and thus creates a tight and pre-tensioned connection between the first and second ring collar 6, 7, 7a, 7b, and thus a tight separation between the first air insulation chamber 8 and the coolant duct 9.

[0032] The first ring collar 6 can thereby have a larger radial extension than the second ring collar 7, 7a, 7b, whereby a comparatively simple attachment of the ring section part 5 to the lower piston part 3 can be attained during the joining of the piston 1. A piston bottom section 17 of the ring section part 5 thereby extends farther inwards than the second ring collar 7, 7a, 7b, whereby the axial attachment of the ring section part 5 to the lower piston part 3 is made possible in the case of an already available combustion chamber bowl part 4.

[0033] The first ring collar 6 thereby preferably protrudes from the combustion chamber bowl part 4 at an angle a obliquely to a piston axis 18, while the second ring collar 7, 7a protrudes from the ring section part 5 at an angle β obliquely to the piston axis 18. □ and β can thereby be equal, in particular have 45°. When the piston 1 is fully assembled, the second portion 16 of the first ring collar 6 can be bent to the first portion 15 of the first ring collar 6 by and angle γ, whereby the abutment of the two ring collars 6, 7, 7a or of the second portion 16, respectively, under pre-tension on the second ring collar 7, 7a is attained. The piston axis 18 is thereby delineated so as to be offset in the direction of the ring section 5 in FIG. 2, in order to clarify the angles α and (3. When the piston 1 is fully assembled, the angle γ is likely to be greater than 0, and the angles could thus be (a +y) >fr Prior to the assembly, the angle γ could equal 0, and the angles could thus be (α+γ)>β, for example.

[0034] When looking at the second ring collar 7, 7a according to FIGS. 1 and 2 once again, it can be seen that it extends inwards under the angle β and downwards in the direction of the lower piston part 3, whereby it goes without saying that a purely radial alignment to the piston axis 18 is also conceivable. Due to the inclined arrangement of the second ring collar 7, 7a, however, a recess 19 is possible, by means of which a distance between the coolant channel 9 and annular grooves 20 arranged in the ring section 5 can be decreased, and an improved cooling of the annular grooves 20 or piston rings arranged therein and not shown, respectively, can be attained.

[0035] A recess 19′ of this type is also conceivable in the first air insulation chamber 8 due to the obliquely arranged second ring collar 7, for example, whereby a more even temperature distribution in the region of a piston bottom 21 can be attained.

[0036] According to FIG. 3, the first ring collar 6, in turn, protrudes from the combustion chamber bowl part 4 at an angle a obliquely to a piston axis 18, while the second ring collar 7, 7b protrudes from the ring section part 5 parallel to the piston axis 18. In this case, β equals 0. No recesses 19, 19′ are drawn in this case, but it goes without saying that they could likewise be provided.

[0037] The lower piston part 3 can be made, for example, of a 42CrMo4 steel or a 38MnVs6 steel, wherein the combustion chamber bowl part 4 and/or the ring section part 5 can be made of a more heat-resistant steel and thus of a more high-quality steel, in order to be able to absorb the temperatures arising in a combustion chamber in a wear-free manner or at least in a low-wear manner, respectively, in the long term.

[0038] A significantly simplified joining of a three-part piston 1 can be attained by means of the piston 1 according to the invention and the internal combustion engine 2 according to the invention, with simultaneously provided first air insulation chamber 8 and coolant channel 9, in the same way as an improved temperature management, for example a more even and higher temperature in the region of the combustion chamber bowl part 4, and an improved cooling in the region of a lower region of the ring section part 5 and of the lower piston part 3. The piston 1 according to the invention can furthermore be manufactured by means of only a single joining process (e.g. laser welding), which is cost-efficient, because different systems are not required.