Piston rings

Abstract

The present invention relates to a piston ring comprising a ring body (1) and a ring joint (9), wherein the ring body (1) comprises a first ring body end (7) and a second ring body end (8) positioned opposite each other and forming the ring joint (9), the first ring body end (7) comprising a protruding portion (10) having a protruding portion profile cross-section (11), the second ring body end (8) comprising a base (12) having a base profile (13), a protruding portion separation surface (16) of the protruding portion (10) and a base separation surface (17) of the base (12) facing each other in facial and sealing physical contact and forming a separation plane (18), the separation plane (18) having a reverse inclination with respect to the inclined ring face (5), the separation plane (18) forming an outer separation line (19) and an inner separation line (20), at least one of the separation lines (19, 20) having a radius of curvature concentric with the ring body (1).

Description

[Technical Field]

[0001] The present invention relates to a sealing piston ring having a particularly high sealing effect. [Background technology]

[0002] The state-of-the-art describes many different piston rings. Piston rings are used in mechanical and automotive engineering, particularly in engines, hydraulic cylinders, and many other applications. Essentially, a piston ring's function is to seal the transition gap between the cylinder bore and the piston barrel surface against liquid and gas pressure media. For this purpose, split piston rings are used in particular in the state-of-the-art. The circumferential split of the piston ring is also known as the ring gap. Piston rings typically have an elastic design to fit the cylinder bore. Piston rings are manufactured in an unstretched elliptical shape. When installed, they assume their intended rounded shape to fit the cylinder wall and then exhibit a certain amount of pretension. Because the ring gap does not completely close in the installed state to compensate for thermal expansion, there is always a certain amount of leakage. This results in pressure loss and media overflow. Because the sealing function of piston rings depends on many factors, there is still a great need for optimization.

[0003] The sealing surface is formed by the sliding surfaces of the cylinder bore and the shoulder of the piston ring groove. Therefore, the surface pressure of the sealing function depends on the pressure of the medium and the pretension of the sealing ring. The latter dependence is constant so that only the pressure of the medium has a dynamic effect.

[0004] Furthermore, it is basically known from the prior art to provide an overlap of the two opposing piston ring ends at the ring joint in order to reduce the open cross section and therefore the pressure loss and medium overflow. The drawback of this solution is that the sealing effect is too low for many applications and residual leakage increases as wear increases. Summary of the Invention

[0005] The object of the present invention is to provide a piston seal ring that is suitable for a wide range of applications, in particular hydraulic and pneumatic applications, as well as applications in combustion processes such as internal combustion engines, and that has high wear resistance and a high sealing effect.

[0006] This problem is solved by the features of claim 1. Preferred further embodiments result from the dependent claims.

[0007] The piston ring according to the invention is a substantially rotationally symmetrical component divided around the circumference and thus having a ring body and a ring joint.

[0008] The ring body has a ring body surface and first and second ring body ends.

[0009] In particular, the ring body surface has a radial ring surface and an angled ring surface.

[0010] The radial ring surface is formed as an axially displaceable sliding surface relative to the cylindrical inner barrel surface of the cylinder, and therefore comes into physical contact with the inner wall of the cylinder in a manner known per se when the piston according to the invention is used as intended, the physical contact being a sliding contact when the piston moves relative to the cylinder.

[0011] The ring body surface also has an inclined ring surface formed as a mating surface with the inclined ring groove surface of the piston's outer ring groove. When used as intended, the inclined ring surface design engages with the corresponding inclined lateral ring surface of the piston's circumferential ring groove, facilitating dynamic expansion of the piston ring. This expansion occurs through an oblique force acting on the inclined ring surface. Thus, the axial force resulting from the pressure medium load creates an oblique contact force acting on the inclined surface of the piston groove. Furthermore, the wedge effect of the inclined ring surface results in radial expansion of the piston ring, creating a force effect on the surface pressure between the radial ring surface and the inner barrel surface of the cylinder. This improves the sealing effect. At the same time, the surface pressure is reduced to a spring-like surface pressure during return movement of the piston without operating pressure, reducing wear. Furthermore, the inclined ring surface supports automatic readjustment of the piston ring in the event of wear on the radial ring surface or the inner cylinder wall.

[0012] According to the invention, the ring body ends are arranged opposite each other at the ring joint, so that they form a ring joint.

[0013] According to the present invention, the first ring body end and the second ring body end are designed to complement each other, specifically, the first ring body end includes a protruding portion and the second ring body end includes a base portion.

[0014] The first ring body end has a protrusion having a protrusion profile cross-section, which is determined by the shape of the protrusion and describes the profile of the protrusion in a radial cross-sectional plane parallel to the major longitudinal axis, and thus the protrusion profile is defined by the physical portion of the piston ring.

[0015] The second ring body end has a base having a base contour, and the base simultaneously forms a receiving contour with a receiving contour cross-section. The base contour is formed by the physical portion of the piston ring, while the receiving contour cross-section is free space. The receiving contour cross-section is defined by the free space not filled by the base contour and is also a contour in a radial cross-sectional plane parallel to the major longitudinal axis. The cross-sectional plane is the same as one of the protruding portion contour cross-sections.

[0016] According to the invention, the protruding portion engages in a receiving profile, where the receiving profile cross section and the protruding profile cross section coincide, and the protruding profile cross section as a physical category satisfies the receiving profile cross section as a free space.

[0017] According to the present invention, the protruding portion separation surface of the protruding portion and the base separation surface of the base are provided opposite to each other in surface-to-surface and sealing physical contact to form a separation plane. Hereinafter, the protruding portion separation surface and the base separation surface will also be collectively referred to as the separation surface.

[0018] The parting surface has a reverse inclination relative to the inclined ring surface. Reverse inclination should be understood such that both the inclined ring surface and the parting surface each have an inclination relative to the main surface of the piston ring, and these inclinations are on different sides of the main surface.

[0019] According to the invention, the parting plane intersects with the radial ring surface to define an outer parting line at the intersection of the parting plane and the radial ring surface.

[0020] The separation line also intersects with the inclined ring surface to form an inner separation line at the intersection of the separation plane and the inclined ring surface.

[0021] Hereinafter, the outer and inner separation lines will be collectively referred to as separation lines.

[0022] The two separation lines also define two separation planes, which are the radial boundaries of the two separation planes.

[0023] In particular, the piston ring according to the invention is characterized in that at least one of the two parting lines has a radius of curvature that is concentric with the ring body.

[0024] Therefore, surprisingly, a solution has been found in which the ring body ends always automatically align with each other axially, radially and even tangentially due to the inclination of the inclined ring surfaces and parting planes and the concentric parting line design, so that sealing surface physical contact is established at the parting surfaces, thereby reliably providing a nearly perfect seal against fluid and gas pressure media.

[0025] The ring body ends, designed in this way to engage one another, have a very precise seal geometry, exhibiting seal overlap even with variable circumferential expansion and resulting variable ring clearance. This feature also results from the fact that at least one, and preferably both, parting lines have concentric radii of curvature. Thus, the piston ring can expand or contract circumferentially at any time, while maintaining a seal through the parting lines. The expansion or contraction around the circumference can be due to the corrugation of the cylinder's inner barrel surface, temperature-induced expansion or contraction, or wear.

[0026] Advantageously, the piston ring according to the invention is able to compensate for these factors while at the same time maintaining its particularly high tightness.

[0027] The protruding portion can also slide radially and circumferentially on the separation surface from the base portion at any time, which ensures constant wear compensation and consistent sealing performance.

[0028] Due to the inclined ring surfaces, the piston ring according to the present invention advantageously exhibits a self-centering effect which supports the concentric alignment of the piston ring relative to the piston.

[0029] Furthermore, the piston rings may preferably be made of metal and therefore advantageously be able to withstand high temperature stresses.

[0030] The piston ring according to the invention can therefore be used advantageously in particular in combustion engines, but also in hydraulically or pneumatically actuated or damping cylinders, as well as in all other applications in which a high degree of gas tightness is required or particularly advantageous.

[0031] According to a first advantageous further development, both the outer and inner separating lines have radii of curvature that are concentric with respect to the ring body. Furthermore, both separating lines are therefore concentric with each other and therefore have the same radii of curvature.

[0032] This development has the particularly advantageous effect that all involved sealing surfaces, both the radial ring surfaces in sealing sliding contact with the inner barrel surface of the cylinder and the inclined ring surfaces in sealing contact with the flanks of the ring groove of the piston, come together and therefore provide a particularly high level of sealing.

[0033] Furthermore, advantageously, the parting surfaces of the protruding portion and the parting surfaces of the base can move tangentially to one another, i.e., along the radius of curvature, and thus maintain surface-sealing physical contact, allowing variations in the circumference of the piston ring to have no effect on the seal.

[0034] According to a next advantageous further development, the parting surfaces of the ring body ends are designed as lateral frustoconical surfaces.

[0035] In this development, the separation surface of the protruding part, which is designed as a frustoconical surface, and the separation surface of the base, which is designed as a frustoconical surface, face each other, the separation surface of the protruding part being a concave inner frustoconical surface and the separation surface of the base being a convex outer frustoconical surface. Both opposing frustoconical surfaces have the same geometric shape and can therefore move relative to each other both longitudinally and transversely, thus ensuring a particularly high level of tightness.

[0036] This shape of the parting surface maintains the sealing effect even in the event of circumferential changes or wear. Furthermore, the reverse inclination of the outer ring groove to the inclined ring groove surface enhances the sealing surface pressure through a radial force effect.

[0037] According to a further advantageous development, the receiving profile cross section is designed as a triangle.

[0038] Preferably, the shape forms an isosceles triangle, with the base resting on the cylinder's inner barrel surface, the first leg resting on the receiving contour of the base, and the second leg corresponding to the inclined ring surface resting against the side wall of the piston's ring groove. The same applies if the triangle is not isosceles.

[0039] The triangular profile of the receiving profile cross section allows compensation for positional relationships, particularly wear-induced, between the base, the protruding portion, and the inner barrel surface of the cylinder while maintaining surface-sealing physical contact and therefore sealing effectiveness. Thus, the above-mentioned components automatically align themselves relative to one another, thus providing airtightness regardless of wear.

[0040] In a next advantageous further development, the separation surface is designed as a wire-erosion surface. This precise manufacturing process results in a surface with a high degree of overlap between the protruding part separation surface and the base separation surface. Therefore, leakage through gaps between the separation surfaces, which may be caused by other manufacturing processes, is advantageously minimized or completely eliminated. As a result, a reliable sealing effect is obtained.

[0041] In a next advantageous further development, the ring body has a further inclined ring surface, the inclination of which is opposite to that of the inclined ring surface. The piston ring therefore preferably has a trapezoidal cross section.

[0042] This further development has particular advantages in double-acting cylinders, where the pressure medium acts on the piston in alternating axial directions. To achieve the same mode of action for both loads, the two inclined ring surfaces of the piston ring are axially opposite each other and inclined in opposite directions.

[0043] In a next advantageous further development of the just-described variant, the first ring body end has a further protruding portion having a further protruding profile cross-section. Furthermore, the base has a further receiving profile having a further receiving profile cross-section. Furthermore, the further protruding portion engages with the further receiving profile, and the further receiving profile cross-section and the further protruding profile cross-section coincide with each other. As a result, the further protruding portion separation surface of the further protruding portion and the further base separation surface of the base are in face-to-face, surface-to-face, and sealing physical contact, forming a further separation plane. Furthermore, the further separation plane has a reverse inclination relative to the further inclined ring surface, and the further separation plane intersects with the radial ring surface, forming a further outer separation line at the intersection line between the further separation plane and the radial ring surface. Furthermore, the further separation plane intersects with the further inclined ring surface, forming a further inner separation line at the intersection line between the further separation plane and the further inclined ring surface, which define a further separation plane. Furthermore, the further separation lines have radii of curvature that are concentric with each other and with the ring body.

[0044] This further development of the piston ring according to the present invention provides a solution with particular advantages for double-acting cylinders. The geometry of the piston ring is mirrored in a plane perpendicular to the axial direction of the piston ring, also known as the main plane, where the piston ring has two opposing, alternatingly inclined ring surfaces. Furthermore, the geometry of the ring body end is mirrored within the main plane. In this way, the wedge effect acting on the piston ring in the distal radial direction and stretching it around the circumference is also achieved during piston movement in both directions of piston movement. The radial ring surface of the piston ring is pressed against the inner barrel surface of the cylinder during both inward and outward piston movement.

[0045] According to a further advantageous further development, the piston ring is provided with at least one weakened recess. Preferably, there are several weakened recesses distributed around the circumference at uniform angular distances from each other and from the ring joint. This design uniformly reduces the spring-induced contact forces on the cylinder's inner barrel surface, which are distributed around the circumference, and supports free movement and self-adjustment between the protrusion and the base. At the same time, the beneficial contact forces caused by the operating pressure of the pressure medium remain intact. Therefore, it is particularly advantageous that piston rings having the same initial shape and material can be easily adapted to individual application requirements by adjusting the spring-induced contact pressure.

[0046] A further aspect of the present invention is a piston ring configuration having first and second piston rings, the two piston rings being piston rings according to the present invention.

[0047] In this design, each piston ring has an axial ring surface. Furthermore, the piston rings are arranged parallel, with the axial ring surface of the first piston ring and the axial ring surface of the second piston ring physically contacting each other. Therefore, the two piston rings are rotated or mirror-imaged relative to each other within the same ring groove of the piston. The ring groove has a trapezoidal radially expanding cross section and two inclined, preferably symmetrically inclined, groove flanks.

[0048] This configuration of the present invention represents a further solution with particular advantages for double-acting cylinders. Two mirror-image piston rings are used, one above the other. This allows for equally effective sealing against pressure media acting alternately from two axially opposite sides. This variant also has the advantage that compensation for different cylinder-piston tolerances is significantly improved by the floating ring installation position. The first and second piston rings are preferably identical, thus offering the technical and cost advantages of using only one type of piston ring in both instances. The trapezoidal cross section of the ring groove, combined with the inclined ring faces of the piston rings, also has the effect of automatically centering them relative to each other.

[0049] The invention will now be explained in more detail using exemplary embodiments and on the basis of the accompanying drawings, in which: FIG. [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 2 is a perspective view of a piston ring. [Figure 2] FIG. 2 is a top view of the piston ring. [Figure 3] FIG. 2 is a cross-sectional view of a piston ring. [Figure 4] FIG. 2 is a perspective cross-sectional view of a piston ring at an end of a ring body. [Figure 5] 1A and 1B are cross-sectional and schematic views of the end of a ring body. [Figure 6] FIG. 1 is a cross-sectional view of a piston ring having two inclined ring surfaces. [Figure 7] FIG. 1 is a cross-sectional view of a piston ring having two inclined ring surfaces and two protruding portions. [Figure 8] 1 is a schematic diagram of a piston ring having two inclined ring surfaces and two protruding portions. FIG. [Figure 9] 1 is a schematic diagram of the base of a piston ring having two inclined ring surfaces and two protruding portions. FIG. [Figure 10]FIG. 2 is a top view of a piston ring having a weakened recess. [Figure 11] FIG. 1 is a cross-sectional view of a piston ring configuration.

[0051] FIG. 1 shows a first perspective view of a piston ring. FIG. 2 shows the piston ring in a top view along a major longitudinal axis corresponding to the axis of piston movement. Both FIGS. 1 and 2 show a ring body 1 having a ring body surface 2, which includes a radial ring surface 3 and an inclined ring surface 5. The ring body 1 is interrupted at a point, where a first ring body end 7 and a second ring body end 8 are positioned opposite each other. The interruption between them forms a ring joint 9.

[0052] The rings are shown in their unassembled, relaxed manufacturing position, also referred to as the relaxed position. In this embodiment, the ring body ends 7, 8 do not overhang above or below in the relaxed position. In an alternative design not shown here, partial overhang of each other's ring body ends 7, 8 is already present in the relaxed position.

[0053] FIG. 3 shows a cross section of the ring body 1 through the ring joint 9. The ring body surface 2 represents the overall surface of the piston ring. The outer barrel surface of the ring body 1 is the radial ring surface 3. On the axial side, the ring body 1 has an inclined ring surface 5, by which the piston ring engages with a matching opposing profile of the circumferential ring groove of the piston. Additionally, the protrusion 10, with the protrusion profile cross section 11 highlighted by a dashed circular line, as well as the protrusion separation surface 16 are shown.

[0054] FIG. 4 shows a perspective view of a cross section of a piston ring at the ring joint 9 and the ring body ends 7, 8.

[0055] This figure shows the unmounted configuration of the piston ring in a relaxed position. This is shown on the outside of the piston ring in the direction of the radial ring surface 3. The inclined ring surface 5 is located circumferentially at an angle relative to this. The protrusion 10 is located at the first ring body end 7 and includes a protrusion separation surface 16 facing away from the drawing direction of FIG. 3.

[0056] The mating part of the second ring body end 8 forms the base 12. The receiving contour 14 is defined by a parting plane 18, which forms the parting surface of the base and receives the protruding portion 10 in a face-to-face manner. In the tensioned installation position, the protruding portion 10 with the protruding portion parting surface 16 lies flat on the base 12, i.e., on the base parting surface 17, where the parting plane 18 is formed. The piston ring interrupted at the ring joint 9 is again sealed by the face-to-face contact of the protruding portion parting surface 16 and the base parting surface 17 at the parting plane 18.

[0057] In the overlap zone of the protruding portion separation surface 16 and the base separation surface 17, the separation plane 18 has a cross-sectional shape of a frustoconical surface in this exemplary embodiment. The inner separation line 20 is formed at a curved edge to the inclined ring surface 5, and the outer separation line 19 is formed at a curved edge to the radial ring surface 3. The separation lines 19, 20 represent arcs arranged concentrically with respect to the circular center point of the ring body, thus allowing the protruding portion separation surface 16 and the base separation surface 17 to overlap and slide congruently against each other during circumferential expansion or contraction of the piston ring.

[0058] Figure 5 is a schematic diagram of an installed piston ring. The individual gaps between the various components have been greatly enlarged for better visibility and are not to scale. Figure 5 is a schematic diagram showing the relative positions and movements of each component and the forces acting on each component.

[0059] Thus, according to FIG. 5, the ring body 1 is installed in the ring groove 6 of the piston 21. This groove is designed with an inclined ring groove surface 23. When the piston moves in the cylinder, the piston ring slides axially away from the inner barrel surface 4 of the cylinder 22 via the radial ring surface 3. The pressure medium acts on the flat axial ring surface (not labeled) of the piston ring with pressure p. The piston ring is pressed against the inclined ring groove surface 23 in the ring groove 6 of the piston 21 and slides along the inclined ring groove surface 23 via the inclined ring surface 5. The inclination is designed to provide a sealing effect against the pressure medium while at the same time inducing a radial force on the piston ring due to a wedge effect, thus expanding the piston ring. This ensures that the radial ring surface 3 is pressed against the inner barrel surface 4 of the cylinder 22, improving the sealing effect. Furthermore, the protrusion profile section 11 can slide both transversely, as indicated by the double arrow between the separation surfaces 16, 17, and longitudinally, i.e., circumferentially, by virtue of the protrusion separation surface 16 on the base separation surface 17 of the base profile 13. At the same time, the protrusion 10 and the base 12 can be axially displaced relative to each other along the radial ring surface 3 and the inner barrel surface 4, so that the gap between the separation surfaces 16, 17 can always be reclosed, even if worn.

[0060] The transverse and longitudinal sliding of the separating surfaces 16, 17 in conjunction with the axial displacement of the sections 10, 12 allows compensation for material wear of the piston rings due to abrasion and ensures constant surface contact and therefore a constant sealing effect throughout the service life.

[0061] FIG. 6 shows an embodiment in which the piston ring has an additional inclined ring surface 23 .

[0062] 2 applies in a corresponding manner. Also, here an additional inclined ring surface 23 is provided. In this embodiment, the ring surfaces 5, 23 are arranged symmetrically opposite each other.

[0063] 7 and 8 show an embodiment in which the piston ring has an additional protruding portion 25 and an additional protruding contour 26 in addition to an additional inclined ring surface 24. For better illustration, FIG. 7 shows a schematic representation of the symmetrical design of the exemplary embodiment, and again, as in FIG. 4, the gaps between the various components are greatly enlarged for better visibility and are not to scale.

[0064] The protruding portion 10 is assigned the inclined ring surface 5, the protruding portion separation surface 16, and the base separation surface 17 of the base 12, which faces it and has a separation plane 18 formed between and defined by the inner separation line 20 and the outer separation line 19.

[0065] The further protruding portion 25 is assigned a further base separation surface 30 of the base 12 having a further inclined ring surface 24, a further protruding portion separation surface 29 and, facing it, a further separation surface 31 formed between and defined by a further inner separation line 33 and a further outer separation line 32.

[0066] Figure 9 shows the base 12 in a schematic cross-section in a radial cross-sectional plane. Figure 9 shows in particular the receiving profile 14 with its receiving profile cross-section 11 and the further receiving profile 27 with its receiving profile cross-section 28. In all other respects, the contents of the description and reference numerals of Figure 8 apply accordingly. As shown in Figure 8, in the installation space spanning the further receiving profile 27, the further protruding part 25 is arranged in tension. Thus, the protruding part 10 is arranged in a tensioned position in the installation space spanning the receiving profile 14, as also shown in Figure 8.

[0067] 10 shows a piston ring in which weakening recesses 38 are arranged on opposite sides of the radial ring surface 3. In the exemplary embodiment, a total of seven weakening recesses 38 are provided, arranged at 45-degree angles from one another. Furthermore, each of the weakening recesses 38 adjacent to a ring joint 9 is also angled at 45 degrees relative to the ring joint 9. The weakening recesses 38 and their uniform distribution reduce the spring-induced contact force against the cylinder's inner barrel surface 4 in a uniformly distributed manner around the circumference, supporting free movement and self-adjustment between the protruding portion and the base. At the same time, the beneficial contact force induced by the operating pressure of the pressure medium remains intact.

[0068] 11 shows a piston ring arrangement comprising a first piston ring 34 and a second piston ring 35. Both piston rings 34, 35 are designed as piston rings according to the present invention. Furthermore, they have axial ring surfaces 36, 37, respectively. The two piston rings 34, 35 are arranged against each other at the axial ring surfaces 36, 37, and thus are mounted in a floating position relative to each other. [Explanation of symbols]

[0069] 1 ring body 2 Ring body surface 3 Radial ring surface 4 Inner barrel surface 5 Inclined ring surface 6 Piston outer ring groove 7 First ring body end 8 Second ring body end 9 Ring Joint 10 Protruding part 11. Protrusion profile cross section 12 base 13 Base Contour 14 Receiving contour 15 Acceptance profile cross section 16 Protruding part separation surface 17 Base separation plane 18 Separation plane 19 Outer separation line 20 Inner separation line 21 Piston 22 cylinders 23 Inclined ring groove surface 24 Further inclined ring surfaces 25 Further protrusions 26 Further protrusion profile cross section 27 Further acceptance contours 28 Further Acceptance Profile Sections 29 Further protruding part separation surface 30 Further base separation surface 31 Further Separation Planes 32 Further outer dividing lines 33 Further inner separation line 34 First piston ring 35 Second piston ring 36 Axial ring surface of first piston ring 37 Axial ring surface of second piston ring 38 Weakened recess

Claims

1. The ring body (1) and the ring joint (9) are provided. The ring body (1) has a ring body surface (2) having a radial ring surface (3) and an inclined ring surface (5), the radial ring surface (3) is designed as an axially displaceable sliding surface relative to the cylindrical inner barrel surface (4) of the cylinder, the inclined ring surface (5) is designed as a mating surface to rest on the inclined ring groove surface of the outer ring groove (6) of the piston; The ring body (1) has a first ring body end (7) and a second ring body end (8) on either side of the ring body (1), The first ring body end (7) and the second ring body end (8) arranged opposite each other form the ring joint (9); the first ring body end (7) has a protruding portion (10) with a protruding portion profile cross section (11); the second ring body end (8) has a base (12) with a base contour (13), the base (12) defining a receiving contour (14) with a receiving contour cross section (15); The protruding portion (10) engages with the receiving profile (14), and the receiving profile cross section (15) and the cross section of the protruding portion (10) match; a protruding portion separation surface (16) of said protruding portion (10) and a base separation surface (17) of said base (12) are provided opposite each other in facial and sealing physical contact to form a separation plane (18); the separation plane (18) has a reverse inclination with respect to the inclined ring surface (5), the separation plane (18) intersects with the radial ring surface (3), an outer separation line (19) is formed at an intersection line between the separation plane (18) and the radial ring surface (3), the separation plane (18) intersects with the inclined ring surface (5), an inner separation line (20) is formed at an intersection line between the separation plane (18) and the inclined ring surface (3), the outer separation line (19) and the inner separation line (20) define the protruding portion separation surface (16) and the base separation surface (17), and at least one of the outer separation line (19) and the inner separation line (20) has a radius of curvature concentric with the ring body (1); The ring body (1) has a further inclined ring surface, the further inclined ring surface being inclined opposite to the inclined ring surface (5), the first ring body end (7) has a further protruding portion (25) with a further protruding profile cross section (26); said base (12) having a further receiving contour (27) with a further receiving contour cross section (28); the further protruding portion (25) engages with the further receiving profile (27), the further receiving profile cross-section (28) and the further protruding portion profile cross-section (26) coincide; a further protruding portion separation surface (29) of said further protruding portion (25) and a further base separation surface (30) of said base (12) facing each other in facial and sealing physical contact to form a further separation plane (31); the further separating plane (31) has a reverse inclination with respect to the further inclined ring surface (24); the further separation plane (31) intersects with the radial ring surface (3), and a further outer separation line (32) is formed at the intersection of the further separation plane (31) and the radial ring surface (3); the further separation plane (31) intersects with the further inclined ring surface (24), and a further inner separation line (33) is formed at the intersection line between the further separation plane (31) and the further inclined ring surface (24); said further outer separation line (32) and said further inner separation line (33) define said further protruding portion separation surface (29) and said further base separation surface (30); A piston ring, wherein said further outer separation line (32) and said further inner separation line (33) have radii of curvature that are concentric with said ring body (1) and with each other.

2. the outer separation line (19) and the inner separation line (20) have concentric radii of curvature relative to the ring body (1) and each other, 2. The piston ring according to claim 1.

3. characterised in that the receiving profile cross section (15) is designed as a triangle, The piston ring according to claim 1 or 2.

4. the ring body (1) has at least one weakened recess (38) arranged radially on the inside, The piston ring according to any one of claims 1 to 3.

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