KOLBENRING

Description

[0001] The invention relates to a sealing piston ring with a particularly high sealing effect.

[0002] The state of the art describes a wide variety of different piston rings. Piston rings are used in mechanical engineering and automotive technology, particularly in engines, hydraulic cylinders, and many other applications. Their basic function is to seal the gap between the cylinder bore and the piston's outer surface against liquid and gaseous pressure media. Split piston rings are used for this purpose according to the state of the art. The interruption in the piston ring around the circumference is also referred to as the annular gap; piston rings are generally designed to be resilient in order to adapt to the cylinder bore. Piston rings are manufactured in a spring-loaded oval shape. The rings assume their intended round shape, which fits snugly against the cylinder wall, when installed and then exhibit a certain preload.Since the annular gap does not close completely when installed to compensate for thermal expansion, a certain amount of leakage always exists. This results in a pressure loss and overflow of the medium. Since the sealing function of the piston ring depends on many factors, there is still a great need for optimization in this area.

[0003] Firstly, the sealing surfaces are formed on the sliding surface, which is created on the outer surface of the cylinder bore, and on a shoulder surface of the piston's annular groove. Therefore, the surface pressure of the sealing function depends on the pressure of the medium and the preload force of the sealing ring. The latter dependence is a constant value, meaning that only the pressure of the medium has a dynamic effect.

[0004] Furthermore, it is 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 thus the pressure loss and media transfer. The disadvantage of this is that the sealing effect achieved is too weak for many applications and that the remaining leakage increases with increasing wear. ES2079991 A1 discloses a piston ring according to the preamble of claim 1.

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

[0006] The problem is solved by the features listed in patent claim 1.

[0007] Preferred further training courses are set out in the subclaims.

[0008] The piston ring according to the invention is a substantially rotationally symmetrical part which has an interruption on the circumference and thus has a ring body and a ring joint.

[0009] The ring body has a ring body surface and a first and second ring body end.

[0010] The ring body surface has in particular a radial ring surface and an inclined ring surface.

[0011] The radial annular surface is designed as a sliding contact surface that can be displaced axially relative to a cylindrical inner surface of a cylinder. Thus, in a conventional manner, the radial annular surface is in contact with the inner cylinder wall when the piston according to the invention is used as intended, with the contact being a sliding contact when the piston moves relative to the cylinder.

[0012] In addition, the ring body surface has an inclined ring surface which is designed as a contact surface to an inclined ring groove surface of an outer ring groove of a piston.

[0013] The design of the inclined ring surface, which, when used as intended, engages with a correspondingly designed inclined lateral ring surface of a circumferential ring groove in the piston, promotes the dynamic expansion of the piston ring. This occurs via the obliquely acting force of the inclined ring surface. The axially acting force resulting from the pressure load of the pressure medium leads to an obliquely acting contact force on the inclined surface of the piston groove. In addition, the wedge effect on the inclined ring surface leads to a radial expansion of the piston ring and to a force acting on the surface pressure between the radial ring surface and the inner surface of the cylinder. This in turn ensures an increased sealing effect. At the same time, when the piston moves back without working pressure, the surface pressure is reduced to the surface pressure due to the spring effect, thus reducing wear.

[0014] In addition, the inclined ring surface supports automatic adjustment of the piston ring in the event of wear on the radial ring surface or on the inner cylinder wall.

[0015] According to the invention, the ring body ends are arranged opposite each other at the ring joint. They thus form the ring joint.

[0016] According to the invention, the first ring body end and the second ring body end are designed to complement each other. Specifically, the first ring body end has a projection portion and the second ring body end has a base portion.

[0017] The first ring body end has the projection section with a projection contour cross-section. The projection contour cross-section is determined by the shape of the projection and refers to the contour of the projection section in a radial sectional plane parallel to the main longitudinal axis. The projection contour is thus formed by a physical section of the piston ring.

[0018] The second annular body end has a base section with a base section contour, wherein the base section simultaneously forms a receiving contour with a receiving contour cross-section. The base section contour is formed by a physical section of the piston ring, while the receiving contour is a free space. The receiving contour cross-section is determined by the space not filled by the base section contour, which is also a contour in the radial sectional plane parallel to the main longitudinal axis. This is the same sectional plane as the projection section contour cross-section.

[0019] Furthermore, according to the invention, the overhang section engages the receiving contour. The receiving contour cross-section and the overhang contour cross-section coincide. The overhang contour cross-section, as a physical category, fills the receiving contour cross-section as a free space.

[0020] According to the invention, a projection section separating surface of the projection section and a base section separating surface of the base section are in planar and sealing contact, forming a separating plane. The projection section separating surface and the base section separating surface are collectively referred to below as the separating surfaces.

[0021] The parting plane has an opposite inclination to the inclined ring surface. An opposite inclination means that both the inclined ring surface and the parting plane each have an inclination relative to a main plane of the piston ring, with this inclination being towards a different side of the main plane.

[0022] According to the invention, the parting plane is further characterized in that it intersects the radial annular surface and forms an outer parting line at an intersection line of the parting plane with the radial annular surface.

[0023] In addition, the parting plane also intersects the inclined ring surface and forms an inner parting line at an intersection line of the parting plane with the inclined ring surface.

[0024] The outer dividing line and the inner dividing line are hereinafter referred to collectively as the dividing lines.

[0025] The two dividing lines also define the two dividing surfaces. These are the radial boundaries of the two dividing surfaces.

[0026] The piston ring according to the invention is characterized in that at least one of the two parting lines has a radius of curvature concentric with the ring body.

[0027] Surprisingly, a solution was found that reliably provides almost complete tightness against fluid and gaseous pressure media, as the ring body ends always automatically align themselves to each other axially, radially and tangentially due to the inclinations of the inclined ring surface and the parting plane as well as due to the concentric parting line formation, so that a sealing surface contact is formed at the parting surfaces.

[0028] The interlocking ring body ends thus formed exhibit a very precise sealing geometry, providing a sealing overlap even with variable circumferential expansion and the resulting variable annular gap. This is also due to the fact that at least one parting line, preferably both parting lines, have a concentric radius of curvature. This allows the piston ring to expand or contract circumferentially at any time, while maintaining a seal across the parting surface. The expansion or contraction across the circumference can result from a wavy shape of the cylinder's inner surface, from temperature-induced expansion or shrinkage, or from wear.

[0029] Advantageously, the piston ring according to the invention is able to compensate for these factors and at the same time maintain its particularly high tightness.

[0030] Additionally, the overhanging section can slide radially and circumferentially along the interface to the base section at any time. This ensures wear compensation at all times, resulting in consistent sealing performance.

[0031] Due to the inclined ring surface, the piston ring according to the invention advantageously has a self-centering effect, which supports a concentric alignment of the piston ring to a piston,

[0032] Furthermore, it is advantageous that the piston ring can preferably be made of metal and can therefore withstand high temperature stresses.

[0033] The piston ring according to the invention can thus be used advantageously in particular in internal combustion engines, but also in hydraulic or pneumatic working cylinders or damping cylinders as well as in all other applications in which a high degree of tightness is required or is particularly advantageous.

[0034] According to a first advantageous development, both the outer parting line and the inner parting line have a radius of curvature concentric with the annular body. Furthermore, both parting lines thus have a concentric and thus identical radius of curvature.

[0035] This further development has the particularly advantageous effect that both on the radial ring surface, which is in sealing sliding contact with the cylinder inner surface, and on the inclined ring surface, which is in sealing contact with the side surface of the ring groove of the piston, all the sealing surfaces involved meet one another and thus provide a particularly high level of tightness.

[0036] In addition, it is advantageously possible that a change in the circumference of the piston ring has no influence on the tightness, that the projection section separation surface and the base section separation surface can move tangentially, i.e. along the radius of curvature, to each other and can thereby maintain the flat sealing contact.

[0037] According to a further advantageous development, the separating surfaces of the ring body ends are designed as truncated cone surfaces.

[0038] The cantilever section separation surface, designed as a truncated cone surface, and the base section separation surface, designed as a truncated cone surface, lie opposite each other. The cantilever section separation surface is a concave inner truncated cone surface and the base section separation surface is a convex outer truncated cone surface. Both opposing truncated cone surfaces otherwise have the same geometry and are therefore movable both longitudinally and transversely relative to each other, thus ensuring particularly high tightness.

[0039] Due to this shape of the separating surfaces, the sealing effect is maintained even in the event of circumferential changes or wear. The opposite inclination to the inclined annular groove surface of the outer ring groove also increases the sealing surface pressure due to the radial force.

[0040] According to a further advantageous development, the receiving contour cross-section is designed as a triangle.

[0041] Preferably, this takes the form of an isosceles triangle. The base side rests against the inner surface of the cylinder, and the first leg rests against the base section in the receiving contour. The second leg corresponds to the inclined annular surface and rests against the side wall of the piston's annular groove. The same applies even if it is not an isosceles triangle.

[0042] The triangular contour of the receiving contour cross-section enables a particularly closure-related compensation of the positional relationships between the base section, the projection section, and the inner surface of the cylinder, while maintaining the flat sealing contact and thus the sealing effect. These components thus align themselves automatically with each other, thus ensuring a seal-independent seal.

[0043] In a further advantageous development, the parting surfaces are formed as wire-cut EDM surfaces. This precise manufacturing process results in surfaces with a high degree of overlap between the cantilever section parting surface and the base parting surface. Leakage current through gaps between the parting surfaces, which can occur with other manufacturing processes, is advantageously minimized or even completely eliminated. The result is a reliable sealing effect.

[0044] According to the invention, the annular body has a further inclined annular surface, wherein the further inclined annular surface is inclined opposite to the inclined annular surface. The piston ring thus preferably has a trapezoidal cross-section.

[0045] This design offers particular advantages, especially in double-acting cylinders. Here, the pressure medium acts on the piston in alternating axial directions. To achieve the same effect in both load cases, the two inclined surfaces of the piston ring are axially opposite each other and inclined in opposite directions.

[0046] According to the invention, the first annular body end has a further projection section with a further projection contour cross-section. In addition, the base section has a further receiving contour with a further receiving contour cross-section. Furthermore, the further projection section engages with the further receiving contour, and the further receiving contour cross-section and the further projection contour cross-section coincide. Accordingly, a further projection section separating surface of the further projection section and a further base section separating surface of the base section lie opposite one another in planar and sealing contact and form a further separating plane. The further separating plane also has an opposite inclination to the further inclined annular surface, wherein the further separating plane intersects the radial annular surface and forms a further outer separating line at an intersection line of the further separating plane with the radial annular surface.In addition, the additional parting plane intersects the additional inclined annular surface and forms an additional inner parting line at an intersection of the additional parting plane and the additional inclined annular surface, which defines the additional parting surfaces. Furthermore, the additional parting lines have a radius of curvature concentric with each other and with the annular body.

[0047] This further development of the piston ring according to the invention provides a solution with particular advantages for a double-acting cylinder. The piston ring geometry is mirrored on the axially vertical planar surface of the piston ring – also referred to as the main planar plane – and the piston ring now has two opposing, mutually inclined annular surfaces. Furthermore, the geometry of the ring body ends is mirrored in the main planar plane. Thus, the wedge effect, which acts on the piston ring in the distal radial direction and stretches it over the circumference, is also present during alternating piston movement in both piston movement directions. The piston ring is pressed with its radial annular surface against the inner surface of the cylinder during both retraction and extension of the piston.

[0048] According to a further advantageous development, the piston ring has at least one weakening recess. Preferably, there are several weakening recesses arranged at a uniform angular distance from one another and from the ring joint, distributed over the circumference.

[0049] This reduces the spring-force-induced contact forces on the inner surface of a cylinder evenly across the circumference, supporting the free movement and self-adjusting effect between the projection section and the base section. At the same time, the advantageous contact forces caused by the operating pressure of a pressure medium remain unaffected. This is particularly advantageous because the spring-force-induced contact force of a piston ring with the same initial geometry and the same material can be easily adapted to the respective application requirements.

[0050] A piston ring arrangement not according to the invention has a first and a second piston ring, wherein these two piston rings are not according to the invention.

[0051] The piston rings each have an axial annular surface. Furthermore, the piston rings are arranged parallel, with the axial annular surface of the first piston ring and the axial annular surface of the second piston ring in contact with each other. The two piston rings are thus arranged either rotated or mirrored to each other in the same annular groove of the piston. The annular groove has a trapezoidal, radially widening cross-section and, for this purpose, has two, preferably symmetrically inclined, groove side surfaces.

[0052] This arrangement not according to the invention represents a further solution with particular advantages for a double-acting cylinder. Two piston rings that are mirrored to one another are placed on top of one another. This makes it possible to seal with equal effect against a pressure medium that acts alternately from two axially opposite sides. This variant also has the advantage that the compensation of different tolerances in the cylinder-piston arrangement is significantly improved by the floating installation position of the rings. There is also the technological and cost advantage that the first and second piston rings are preferably identical and thus only two of one type of piston ring can be used. The trapezoidal cross-section of the ring groove, in conjunction with the inclined ring surfaces of the piston rings, advantageously centers the rings automatically relative to one another.

[0053] The invention is illustrated by way of example with reference to Fig. 1 Oblique view of a piston ring not according to the invention Fig. 2 Top view of a piston ring not according to the invention not according to the invention Fig. 3 Cross-sectional view of a piston ring Fig. 4 Detail of a piston ring not according to the invention at the ring body ends as an oblique view Fig. 5 Sectional view and schematic representation of the ring body ends Fig. 6 Cross-sectional view of a piston ring not according to the invention with two inclined ring surfaces Fig. 7 Cross-sectional view of a piston ring according to the invention with two inclined ring surfaces and two projection sections Fig. 8 Schematic view of a piston ring according to the invention with two inclined ring surfaces and two projection sections according to the invention Fig. 9 Schematic view of the base section of a piston ring with two inclined ring surfaces and two projection sections Fig. 10 Top view of a piston ring with weakening recesses not according to the invention Fig. 11 Cross-sectional view of a piston ring arrangement explained in more detail.

[0054] The Figure 1 shows the piston ring for a first overview in an oblique view; the Figure 2 shows the piston ring in a top view along the main longitudinal axis, which corresponds to the axis of movement of the piston. Shown in the two Figure 1 and 2 The annular body 1 with the annular body surface 2, which has the radial annular surface 3 and the inclined annular surface 5. The annular body 1 is interrupted at one point. Here, a first annular body end 7 and a second annular body end 8 face each other. The interruption between them is the annular joint 9.

[0055] The ring is shown in the unassembled, stress-relieved manufacturing position, also referred to as the stress-relieved position. In this exemplary embodiment, the ring body ends 7, 8 do not protrude beyond each other in the stress-relieved position. In an alternative embodiment—not shown here—the ring body ends 7, 8 partially protrude into the respective other ring body end 7, 8 already in the stress-relieved position.

[0056] The Figure 3shows the cross-section of the ring body 1 through the ring joint 9. The ring body surface 2 denotes the surface of the entire piston ring. The outer surface of the ring body 1 is the radial ring surface 3. On one axial side, the ring body 1 has the inclined ring surface 5. This allows the piston ring to engage with the matching mating contour of a circumferential ring groove of a piston. Furthermore, the projection section 10 with the projection contour cross-section 11—highlighted by the dashed circle—as well as the projection section separation surface 16 are shown.

[0057] The Figure 4 shows the section of the piston ring at the ring joint 9 and at the ring body ends 7, 8 as an oblique view.

[0058] The uninstalled form of the piston ring is shown in the relaxed position. The view points to the outside of the piston ring in the direction of the radial ring surface 3. The inclined ring surface 5 is located circumferentially and inclined to this. The projection section 10 is located at the first ring body end 7. This projection section points opposite to the direction of view of Fig. 3 the cantilever section separation surface 16.

[0059] The corresponding counterpart at the second ring body end 8 is the base section 12. The receiving contour 14 is defined by the parting plane 18; it forms the base section parting surface and receives the projection section 10 in a flat manner. In the clamped installation position, the projection section 10, with the projection section parting surface 16, rests flat on the base section 12, specifically on the base section parting surface 17. The parting plane 18 is formed there. The surface contact between the projection section parting surface 16 and the base section parting surface 17 in the parting plane 18 reseals the piston ring interrupted at the ring joint 9.

[0060] In the present embodiment, the parting plane 18 has the shape of a section of a truncated cone surface in the overlap zone of the projection section parting surface 16 and the base section parting surface 17. The inner parting line 20 is formed at the curved edge toward the inclined ring surface 5, and the outer parting line 19 is formed at the curved edge toward the radial ring surface 3. The parting lines 19, 20 describe circular arcs arranged concentrically to the circle center of the ring body, which enables the projection section parting surface 16 and the base section parting surface 17 to slide congruently onto one another during a circumferential expansion or reduction of the piston ring.

[0061] The Figure 5 shows a schematic representation of the piston ring in its installed state. The individual gaps between the various components are greatly enlarged for clarity and are not shown to scale. Fig. 5The diagram is intended to illustrate the position and movement relationships of the components as well as the acting forces.

[0062] According to Fig. 5the ring body 1 is installed in an annular groove 6 of a piston 21. This is designed with an inclined annular groove surface 23. When the piston moves in the cylinder, the piston ring slides axially on the inner surface 4 of the cylinder 22 with the radial annular surface 3. The pressure medium acts with the pressure p on the planar, axial annular surface of the piston ring (without reference symbol). The piston ring is pressed in the annular groove 6 of the piston 21 against the inclined annular groove surface 23 and slides onto it with its inclined annular surface 5. The inclination is designed in such a way that it provides a sealing effect against the pressure medium and at the same time, through the wedge effect, causes a radial force on the piston ring, thus expanding it. This in turn ensures that the radial annular surface 3 is pressed against the inner surface 4 of the cylinder 22, which increases the sealing effect.In addition, the overhang contour cross-section 11 with the overhang section separation surface 16 can slide on the base section separation surface 17 of the base section contour 13 both transversely—as represented by the double arrow between the separation surfaces 16, 17—and longitudinally, i.e., along the circumference. At the same time, the overhang section 10 and the base section 12 are axially displaceable relative to one another along the radial annular surface 3 and the inner circumferential surface 4, so that the gap between the separation surfaces 16, 17 can always be closed again, even in the event of wear.

[0063] This sliding of the separating surfaces 16, 17 transversely and longitudinally in conjunction with the axial displaceability of the sections 10, 12 enables the compensation of wear-related material removal on the piston ring and always ensures a flat contact and thus a consistent sealing effect over the service life.

[0064] Figure 6shows an embodiment in which the piston ring has a further inclined ring surface 23.

[0065] First of all, the explanations to Fig. 2 in a corresponding manner. Additionally, the further inclined annular surface 23 is present here. In this embodiment, the annular surfaces 5, 23 are symmetrically opposite each other.

[0066] Figure 7 and Figure 8 show an embodiment in which the piston ring has, in addition to the further inclined ring surface 24, a further projection section 25 and a further projection contour 26. For better illustration, Fig. 7 schematically shows the symmetrical structure in the exemplary embodiment, where here, as in Fig. 4 the gaps between the different components are greatly enlarged for better visibility and are not shown to scale.

[0067] The projection section 10 is assigned the inclined annular surface 5, the projection section separating surface 16 and, opposite, the base section separating surface 17 of the base section 12 with the separating surface 18 forming therebetween, which is delimited by the inner separating line 20 and the outer separating line 19.

[0068] The further projection section 25 is assigned the further inclined annular surface 24, the further projection section separating surface 29 and, opposite this, the further base section separating surface 30 of the base section 12 with the further separating surface 31 forming therebetween, which is delimited by the further inner separating line 33 and the further outer separating line 32.

[0069] Figure 9 shows the base section 12 in a schematic sectional view in a radial sectional plane. Fig. 8represents in particular the receiving contour 14 with its receiving contour cross-section 11 as well as the further receiving contour 27 with its receiving contour cross-section 28. Otherwise, the description contents and reference symbols apply to Fig. 7 in a corresponding manner. In the installation space spanned by the further receiving contour 27, the further projection section 25 is arranged in a tension position, as shown Fig. 7 Accordingly, in the installation space spanned by the receiving contour 14, the projection section 10 is arranged in a stressed position, as Fig. 7 also shows.

[0070] Figure 10shows a piston ring in which weakening recesses 38 are arranged opposite the radial ring surface 3. In the exemplary embodiment, there are a total of seven weakening recesses 38, each arranged at an angle of 45 degrees to one another. Furthermore, the weakening recesses 38 adjacent to the ring joint 9 each enclose an angle of 45 degrees to the ring joint 9. Due to the weakening recesses 38 and their uniform distribution, the spring-induced contact forces on an inner circumferential surface 4 of a cylinder are evenly reduced over the circumference, and the free mobility and self-adjusting effect between the projection section and the base section are supported. At the same time, however, the advantageous contact forces caused by the operating pressure of a pressure medium remain unaffected.

[0071] Figure 11shows 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 not according to the invention. Additionally, they each have an axial ring surface 36, 37. The two piston rings 34, 35 abut one another at the axial ring surfaces 36, 37, thereby being mounted in a floating manner relative to one another. Reference symbols used Reference symbols used

[0072] 1 Ring body 2 Ring body surface 3 Radial ring surface 4 Inner surface 5 Inclined ring surface 6 Outer ring groove of a piston 7 First ring body end 8 Second ring body end 9 Ring joint 10 Overhang section 11 Overhang contour cross-section 12 Base section 13 Base section contour 14 Receptacle contour 15 Receptacle contour cross-section 16 Overhang section parting surface 17 Base section parting surface 18 Parting plane 19 Outer parting line 20 Inner parting line 21 Piston 22 Cylinder 23 Inclined ring groove surface 24 Further inclined ring surface 25 Further overhang section 26 Further overhang contour cross-section 27 Further receiving contour 28 Further receiving contour cross-section 29 Further overhang section parting surface 30 Further base section parting surface 31 Further parting plane 32 further outer parting line 33 further inner parting line 34 first piston ring 35 second piston ring 36 axial ring surface of the first piston ring 37 axial ring surface of the second piston ring 38 weakening recess

Claims

1. A piston ring, comprising a ring body (1) and a ring joint (9), wherein the ring body (1) comprises a ring body surface (2) which has a radial ring surface (3) and an inclined ring surface (5), wherein the radial ring surface (3) is designed as a sliding contact surface axially displaceable relative to a cylindrical inner barrel surface (4) of a cylinder, wherein the inclined ring surface (5) is designed as a lay-on surface to rest in an inclined ring groove surface of an outer ring groove of a piston (6), wherein the ring body (1) comprises a first (7) and a second ring body end (8), wherein the ring body ends, which are arranged opposite at the ring joint (9), form the ring joint (9), wherein the first ring body end (7) has a projection section (10) with a projection contour cross section (11), wherein the second ring body end (8) has a base section (12) with a base section contour (13), wherein the base section (12) forms a receiving contour (14) with a receiving contour cross section (15), wherein the projection section (10) engages in the receiving contour (14), and the receiving contour cross section (15) and the projection section cross section (10) coincide, wherein a projection section separating surface (16) of the projection section (10) and a base section separating surface (17) of the base section (12) are provided opposite to each other in a full-area and sealing physical contact and form a separating plane (18), wherein the separating plane (18) has an inverse inclination with respect to the inclined ring surface (5), wherein the separating plane (18) intersects the radial ring surface (3) and an outer separating line (19) is formed at an intersection line of the separating plane (18) with the radial ring surface (3), wherein the separating plane (18) intersects the inclined ring surface (5) and an inner separating line (20) is formed at an intersection line of the separating plane (18) with the inclined ring surface (5), wherein the separating lines (19, 20) delimit the separating surfaces (16, 17), and wherein at least one of the separating lines (19, 20) has a concentric curvature radius with respect to the ring body (1), characterized in that the ring body (1) comprises a further inclined ring surface (24), wherein the further inclined ring surface (24) is inclined in the direction opposite to the inclined ring surface (5), that the first ring body end (7) comprises a further projection section (25) with a further projection contour cross section (26), that the base section (12) comprises a further receiving contour (27) with a further receiving contour cross section (28), wherein the further projection section (25) engages in the further receiving contour (27) and the further receiving contour cross section (28) and the further projection contour cross section (26) coincide, wherein a further projection section separating surface (29) of the further projection section (25) and a further base section separating surface (30) of the base section (12) are provided opposite to each other in a full-area and sealing physical contact and form a further separating plane (31), wherein the further separating plane (31) has an inverse inclination with respect to the further inclined ring surface (24), wherein the further separating plane (31) intersects the radial ring surface (3) and a further outer separating line (32) is formed at an intersection line of the further separating plane (31) with the radial ring surface (3), wherein the further separating plane (31) intersects the further inclined ring surface (24) and a further inner separating line (33) is formed at an intersection line of the further separating plane (31) with the further inclined ring surface (24), wherein the further separating lines (32, 33) delimit the further separating surfaces (29,30), and wherein the further separating lines (32, 33) have a concentric curvature radius with respect to each other and to the ring body (1).

2. The piston ring according to claim 1, characterized in that the outer separating line (19) and the inner separating line (20) have a concentric curvature radius with respect to the ring body (1) and to each other.

3. The piston ring according to one of the preceding claims, characterized in that the separating surfaces are designed as truncated-cone lateral partial surfaces.

4. The piston ring according to one of the preceding claims, characterized in that the receiving contour cross section (15) is designed as a triangle.

5. The piston ring according to one of the preceding claims, characterized in that the separating surfaces are designed as wire erosion surfaces.

6. The piston ring according to one of the preceding claims, characterized in that the ring body (1) has at least one weakening recess (38) which is arranged radially on the inside.