CN112943925A

CN112943925A - Piston ring

Info

Publication number: CN112943925A
Application number: CN202110110015.3A
Authority: CN
Inventors: 蒋文涛; 曾少波
Original assignee: Mahle Automobile Technology China Co ltd
Current assignee: Mahle Automobile Technology China Co ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-06-11
Anticipated expiration: 2041-01-27
Also published as: CN112943925B

Abstract

The invention provides a piston ring, which comprises a ring body (1) and an oil scraping component (2) arranged on the outer peripheral side of the ring body (1), wherein the oil scraping component (2) comprises a first side surface (21), a second side surface (22) and an oil scraping surface (3) positioned between the first side surface (21) and the second side surface (22), the oil scraping surface (3) comprises a first oil scraping surface (31), a second oil scraping surface (32) and a third oil scraping surface (33), the first oil scraping surface (31) is positioned between the second oil scraping surface (32) and the third oil scraping surface (33) in the axial direction (A) of the piston ring, and the first oil scraping surface (31) is higher or lower than the second oil scraping surface (32) and the third oil scraping surface (33) in the radial direction (R) of the piston ring. According to the piston ring disclosed by the invention, three contact surfaces can be continuously and durably contacted in sequence, so that eccentric wear of the piston ring can be effectively prevented, and the service life of the piston ring can be prolonged.

Description

Piston ring

Technical Field

The invention relates to an engine fitting, in particular to a piston ring for an engine.

Background

With the development of high burst pressure and high power engine technology, the art places stringent requirements on engine durability.

The piston ring is used as one of core parts of an engine, the durability of the piston ring is one of the most important factors influencing the reliability of the engine, and the durability of the piston ring in the whole life cycle can be well ensured by prolonging the durability of the piston ring.

One of the important links for improving the durability of the piston ring is the design of the contact surface of the piston ring. In the piston ring of the prior art, the wear-resistant layer 200 is generally disposed on the contact surface to improve durability, but it is still insufficient for use.

Fig. 1 shows a possible piston ring, the contact ring surface of which is arranged stepwise and comprises a first step contact surface 101 and a second step contact surface 102, the outer peripheral side of which is provided with a wear resistant layer 200. However, each contact ring surface has only two steps, and in practice, the piston ring is found to have higher ring edge height and thin edge when the piston ring is in first-order contact operation with the contact ring surface, so that the ring edge strength is poor, the stress is uneven, the piston ring is easy to deform, the piston ring vibrates or is abraded unevenly during operation, and the oil scraping capacity is finally influenced.

And when the wear-resistant layer 200 of the piston ring contact surface is worn, only the base material or the nitrided layer remains on the contact surface, and the wear resistance of the contact surface is greatly reduced. In addition, when the first-stage contact surface 101 is not protected by a wear-resistant layer, and the second-stage contact surface 102 is protected by a wear-resistant layer, the piston ring is prone to eccentric wear, which affects not only the oil scraping capability of the piston ring, but also the oil consumption.

Disclosure of Invention

In order to overcome the above-mentioned drawbacks of piston rings, the object of the present invention is to overcome or at least alleviate the above-mentioned drawbacks of the prior art and to provide a piston ring which is capable of reducing eccentric wear and has a longer life.

The invention provides a piston ring, comprising a ring body and an oil scraping component arranged on the outer periphery of the ring body,

the oil scraping part comprises a first side surface, a second side surface and an oil scraping surface positioned between the first side surface and the second side surface, the oil scraping surface comprises a first oil scraping surface, a second oil scraping surface and a third oil scraping surface, and the first oil scraping surface is positioned between the second oil scraping surface and the third oil scraping surface in the axial direction of the piston ring,

in the radial direction of the piston ring,

the first oil scraping surface is higher than the second oil scraping surface and the third oil scraping surface, or

The first oil scraping surface is lower than the second oil scraping surface and the third oil scraping surface.

In at least one embodiment, the second oil scraping surface and the third oil scraping surface are at the same height in the radial direction.

In at least one embodiment, the outer peripheral side of the oil scraping surface is covered with a wear resistant layer.

In at least one embodiment, the wear-resistant layers include a first wear-resistant layer on an outer peripheral side of the first oil scraping surface, a second wear-resistant layer on an outer peripheral side of the second oil scraping surface, and a third wear-resistant layer on an outer peripheral side of the third oil scraping surface,

in the radial direction of the piston ring,

in a case where the first oil scraping surface is higher than the second oil scraping surface and the third oil scraping surface, an outer diameter of at least one of the second wear layer and the third wear layer is equal to or larger than an outer diameter of the first oil scraping surface, and outer diameters of the second wear layer and the third wear layer are smaller than an outer diameter of the first wear layer,

in a case where the first oil scraping surface is lower than the second oil scraping surface and the third oil scraping surface, an outer diameter of the first wear-resistant layer is equal to or larger than at least one of outer diameters of the second oil scraping surface and the third oil scraping surface, and an outer diameter of the first wear-resistant layer is smaller than outer diameters of the second wear-resistant layer and the third wear-resistant layer.

In at least one embodiment, the generatrix of the first wiping surface, the generatrix of the second wiping surface and the generatrix of the third wiping surface are all parallel to the axis of the piston ring.

In at least one embodiment, the included angle of the generatrix of the first oil scraping surface, the generatrix of the second oil scraping surface and the generatrix of the third oil scraping surface with the axis of the piston ring is greater than 0 ° and not greater than 30 °.

In at least one embodiment, the oil scraping surface further comprises transition surfaces comprising a first transition surface, a second transition surface, a third transition surface, and a fourth transition surface,

in the axial direction, the first transition surface is located between the first side surface and the second wiping surface, the second transition surface is located between the second wiping surface and the first wiping surface, the third transition surface is located between the first wiping surface and the third wiping surface, and the fourth transition surface is located between the third wiping surface and the second side surface,

the transition surface gradually increases in outer diameter during the axial extension, or

The transition surface gradually decreases in outer diameter during the axial extension.

In at least one embodiment, the first, second and third oil wiping surfaces have a dimension in the axial direction of no more than 0.15mm, and/or

The size of the oil scraping surface is not more than 0.5 mm.

In at least one embodiment, the first, second, third and fourth transition surfaces have a dimension in the axial direction of no more than 0.15mm, and/or

The footpath upwards, first wearing layer with the difference in height of second wearing layer first wearing layer with the difference in height of third wearing layer the second wearing layer with the difference in height of the minimum external diameter of first transition face the third wearing layer with the difference in height of the minimum external diameter of fourth transition face all is not less than 5um and is not more than 200 um.

In at least one embodiment, the piston ring has two oil scraping means.

The piston ring has simple structure and strong wear resistance, and is not easy to generate eccentric wear.

Drawings

Figure 1 is a schematic view of a possible piston ring.

Fig. 2 is a sectional view of a partial structure of a piston ring according to a first embodiment of the invention;

fig. 3 is a partially enlarged schematic view of fig. 2.

Fig. 4 is a sectional view of a partial structure of a piston ring according to a second embodiment of the present invention.

Description of reference numerals:

1 a ring body; 2, an oil scraping component; 21 a first side; 22 a second side; 3, scraping the oil surface; 31 a first oil scraping surface; 32 second oil-scraping surface; 33 a third oil scraping surface; 34 a first transition surface; 35 a second transition surface; 36 a third transition surface; 37 a fourth transition surface; 4, a wear-resistant layer; 41 a first wear layer; 42 a second wear layer; 43 a third wear layer;

Detailed Description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the detailed description is intended only to teach one skilled in the art how to practice the invention, and is not intended to be exhaustive or to limit the scope of the invention.

A piston ring according to the present invention will be described with reference to fig. 2 to 4, in which a represents an axial direction of the piston ring and R represents a radial direction of the piston ring, unless otherwise specified.

(first embodiment)

Fig. 2 shows a first embodiment of the piston ring according to the invention. As shown in fig. 2, the piston ring mainly includes a ring body 1 and an oil scraping member 2 provided on an outer peripheral side of the ring body.

The material of which the ring body 1 is made comprises, for example, cast iron or steel.

The oil scraping member 2 comprises a first side surface 21, a second side surface 22 and an oil scraping surface 3 located between the first side surface 21 and the second side surface 22. The surface of the oil scraping surface 3 is covered with a wear-resistant layer 4.

The wiping surfaces 3 comprise a first wiping surface 31, a second wiping surface 32 and a third wiping surface 33, which for convenience of description will hereinafter also be referred to as main wiping surfaces, which provide the main working base for the wiping action. These three main oil scraping surfaces form a step shape, the first oil scraping surface 31 is located between the second oil scraping surface 32 and the third oil scraping surface 33 in the axial direction a, and the first oil scraping surface 31 is higher than the second oil scraping surface 32 and the third oil scraping surface 33 in the radial direction R (i.e. the outer diameter of the first oil scraping surface 31 is larger than the outer diameter of the second oil scraping surface 32 and the third oil scraping surface 33). Preferably, the second oil scraping surface 32 and the third oil scraping surface 33 have an equal outer diameter.

According to this arrangement, the first oil scraping surface 31 is worn first, and the second oil scraping surface 32 and the third oil scraping surface 33 are worn later. In the case where the first scraping surface 31 is worn as the first step, the second scraping surface 32 and the third scraping surface 33 contact each other as the second step on both sides in the axial direction of the first scraping surface 31, which is advantageous for improving the anti-eccentric capability of the oil scraper ring, and in particular, when the second scraping surface 32 and the third scraping surface 33 are equal in height (equal in outer diameter) in the radial direction R, the symmetrical design makes the anti-eccentric capability of the oil scraper ring better. This will be more easily understood when describing the wear resistant layer 4 below.

The generatrix of the main oil scraping surface can be a straight line or an arc line. In the case that the generatrix of the main oil scraping surface is a straight line, it may be parallel to the axial direction a, or may form an angle (for example, not greater than 10 °) with the axial direction a. When the generating line of main oil scraping surface is the straight line that is on a parallel with axial A, the working life of piston ring is long, prevents the effect of eccentric wear preferred.

Preferably, the oil scraping surface 3 further comprises a first transition surface 34, a second transition surface 35, a third transition surface 36 and a fourth transition surface 37. In the axial direction a, a first transition surface 34 connects the first flank 21 and the second scraping surface 32, a second transition surface 35 connects the second scraping surface 32 and the first scraping surface 31, a third transition surface 36 connects the first scraping surface 31 and the third scraping surface 33, and a fourth transition surface 37 connects the third scraping surface 33 and the second flank 22.

The above-mentioned transition surfaces (first transition surface 34, second transition surface 35, third transition surface 36 and fourth transition surface 37) have the effect of a smooth transition between the main wiping surfaces or between the main wiping surfaces and the side surfaces (first side surface 21 and second side surface 22). Specifically, the transition surface gradually changes (gradually increases or gradually decreases) in its outer diameter in a direction of change during the extension in the axial direction a. Preferably, the transition surface forms an obtuse angle at an axial end with the main oil scraping surface or the side surface to which it is connected. The transition surface can guide the oil outside the main oil scraping surface to flow to the first side surface 21 and the second side surface 22; on the other hand, the smooth transition of the transition surface also makes the wear-resistant layer 4 introduced below not easy to fall off, and ensures the eccentric wear prevention effect of the piston ring.

In the present embodiment, the wear-resistant layer 4 covers the entire oil-scraping surface 3. The wear-resistant layer 4 includes a first wear-resistant layer 41 on the outer peripheral side of the first oil wiping surface 31, a second wear-resistant layer 42 on the outer peripheral side of the second oil wiping surface 32, and a third wear-resistant layer 43 on the outer peripheral side of the third oil wiping surface 33.

In the radial direction R, the outer diameter of at least one of the second wear-resistant layer 42 and the third wear-resistant layer 43 is equal to or larger than (preferably equal to) the outer diameter of the first oil scraping surface 31, and the outer diameters of the second wear-resistant layer 42 and the third wear-resistant layer 43 are smaller than the outer diameter of the first wear-resistant layer 41. Therefore, before or just after the wear-resistant layer (i.e., the first wear-resistant layer 41 in the present embodiment) on the higher surface of the main oil scraping surface is worn out, the lower wear-resistant layers (i.e., the second wear-resistant layer 42 and the third wear-resistant layer 43 in the present embodiment) adjacent to the higher surface can enter into operation, which not only prolongs the service life of the piston ring, but also effectively prevents eccentric wear, and is beneficial to prolonging the service life of the piston ring.

Preferably, the outer diameters of the second wear-resistant layer 42 and the third wear-resistant layer 43 are equal, so that the second wear-resistant layer 42 and the third wear-resistant layer 43 can synchronously contact with a cylinder sleeve of a cylinder, and the stability of the piston ring in the working process is better. The wear resistant layer 4 may be a coating or a coating, and the process of providing the wear resistant layer 4 may be selected from, for example, Physical Vapor Deposition (PVD), diamond like carbon coating (DLC), ceramic coating processes, and the like.

Fig. 3 shows the dimensions of a piston ring according to the present embodiment. The first oil scraping surface 31, the second oil scraping surface 32 and the third oil scraping surface 33 are respectively h1, h2 and h3 in the axial direction A, and all the h1, h2 and h3 are not more than 0.15 mm. The first transition surface 34, the second transition surface 35, the third transition surface 36 and the fourth transition surface 37 have the dimensions h5, h6, h7 and h8 in the axial direction A, and all the dimensions h5, h6, h7 and h8 are not greater than 0.15 mm. The total dimension h4 of the wiping surface 3 in the axial direction a is not more than 0.5 mm. In the radial direction R, the outer peripheral surface of the second wear-resistant layer 42 is raised by a dimension L1 with respect to the minimum outer diameter of the first transition surface 34, the outer peripheral surface of the first wear-resistant layer 41 is raised by a dimension L2 with respect to the outer peripheral surface of the second wear-resistant layer 42, the outer peripheral surface of the first wear-resistant layer 41 is raised by a dimension L3 with respect to the outer peripheral surface of the third wear-resistant layer 43, the outer peripheral surface of the third wear-resistant layer 43 is raised by a dimension L4 with respect to the minimum outer diameter of the fourth transition surface 37, and each of L1, L2, L3, and L4 is not less than 5um and not more.

It should be understood that in other possible embodiments, there may be a short period of wear of the first oil scraping surface 31 after the first wear resistant layer 41 is worn, after which the second wear resistant layer 42 and/or the third wear resistant layer 43 come into contact with the liner and wear occurs. I.e. in the radial direction R, the first oil scraping surface 31 is slightly higher than the second wear layer 42 and/or the third wear layer 43.

Returning to fig. 2, in the present embodiment, two oil scraping members 2 are disposed along the axial direction a of the ring body 1, and the two oil scraping members 2 are symmetrically distributed with respect to the cross section perpendicular to the axial direction a, and the symmetrical arrangement is more favorable for preventing eccentric wear of the piston ring.

In the present embodiment, the first side surface 21 and the second side surface 22 of the oil scraping member 2 are provided obliquely with respect to the cross section perpendicular to the axial direction a, and the distance in the axial direction a between the first side surface 21 and the second side surface 22 decreases toward the outside in the radial direction, and such an arrangement can prevent the oil from accumulating on the oil scraping surface 3.

(second embodiment)

Referring to fig. 4, a piston ring according to a second embodiment of the present invention will be described. The second embodiment is a modification of the first embodiment, and the same reference numerals are used in the present embodiment for the same or similar features as those of the first embodiment, and detailed descriptions of these features are omitted.

In the present embodiment, the stepped shape of the oil scraping surface 3 is set in a form that is low in the middle and high on both sides, that is, the first oil scraping surface 31 is lower than the second oil scraping surface 32 and the third oil scraping surface 33 in the radial direction R (i.e., the outer diameter of the first oil scraping surface 31 is smaller than the outer diameters of the second oil scraping surface 32 and the third oil scraping surface 33).

And preferably, the outer diameter of the first wear-resistant layer 41 is equal to or greater than (preferably equal to) at least one of the outer diameters of the second oil scraping surface 32 and the third oil scraping surface 33, and the outer diameter of the first wear-resistant layer 41 is smaller than the outer diameters of the second wear-resistant layer 42 and the third wear-resistant layer 43.

In the present embodiment, the outer diameter height of the second wear-resistant layer 42 is equal to the outer diameter height of the third wear-resistant layer 43, and the outer diameter height is the maximum outer diameter of the outer circumferential surfaces of the second wear-resistant layer 42 and the third wear-resistant layer 43. Due to the arrangement, the second wear-resistant layer 42 and the third wear-resistant layer 43 can be in contact with the cylinder sleeve at the same time, and the phenomenon that the piston ring is in unilateral contact in the early working stage to cause uneven stress is avoided.

Fig. 4 shows a second constructional dimension of the first embodiment of the piston ring. The first oil scraping surface 31, the second oil scraping surface 32 and the third oil scraping surface 33 are respectively h1, h2 and h3 in the axial direction A, and all the h1, h2 and h3 are not more than 0.15 mm. The first transition surface 34, the second transition surface 35, the third transition surface 36 and the fourth transition surface 37 have the dimensions h5, h6, h7 and h8 in the axial direction A, and all the dimensions h5, h6, h7 and h8 are not greater than 0.15 mm. The total dimension h4 of the wiping surface 3 in the axial direction a is not more than 0.5 mm. In the radial direction R, the outer peripheral surface of the second wear-resistant layer 42 is raised by a dimension L1 with respect to the minimum outer diameter of the first transition surface 34, the outer peripheral surface of the second wear-resistant layer 42 is raised by a dimension L2 with respect to the outer peripheral surface of the first wear-resistant layer 41, the outer peripheral surface of the third wear-resistant layer 43 is raised by a dimension L3 with respect to the outer peripheral surface of the first wear-resistant layer 41, the outer peripheral surface of the third wear-resistant layer 43 is raised by a dimension L4 with respect to the minimum outer diameter of the fourth transition surface 37, and each of L1, L2, L3, and L4 is not less than 5um and not more.

In summary of the above two embodiments, regarding the dimensions L1, L2, L3 and L4, it is also said that the height difference L2 between the first wear-resistant layer 41 and the second wear-resistant layer 42, the height difference L3 between the first wear-resistant layer 41 and the third wear-resistant layer 43, the height difference L1 between the second wear-resistant layer 42 and the minimum outer diameter of the first transition surface 34, and the height difference L4 between the third wear-resistant layer 43 and the minimum outer diameter of the fourth transition surface 37 are not less than 5um and not more than 200 um.

It should be understood that in case of a piston ring having a plurality of, e.g. two, scraper members 2, the two scraper members 2 have the highest height in the radial direction R being equal.

The two oil scraping members 2 may be both oil scraping members having a convex structure in a section passing through the axial direction a as described in the first embodiment (hereinafter referred to as "convex oil scraping members"), may be both oil scraping members having a concave section as described in the second embodiment (hereinafter referred to as "concave oil scraping members"), and may be one of the convex oil scraping members and the other of the concave oil scraping members.

Preferably, the oil scraping member 2 near the end of the cylinder liner opening is provided as a convex oil scraping member, and the oil scraping member far from the end of the cylinder liner opening is provided as a concave oil scraping member. This arrangement provides the piston ring with three wear surfaces in contact with the liner during the initial period of operation, with stable contact and with possible deformation of the open end of the liner.

The invention has at least one of the following advantages:

(i) the piston ring disclosed by the invention adopts a three-section stepped oil scraping surface structure, the wear of the piston ring is carried out in stages due to the stepped structure, and the wear resistance of the piston ring is good.

(ii) The middle of the stepped structure is low, the two sides are high, or the middle of the stepped structure is high, the two sides are low, so that eccentric wear of the piston ring is not easy to occur in the working process.

(iii) The thickness setting of the wearing layer 4 outside the scraping surface can be such that, on radial R, the wearing layer 4 on the next highest section scraping surface enters into operation before the wearing layer 4 on the highest section scraping surface is worn out. The wear life can be increased by at least a factor of 3 with respect to the solutions of the background art.

Of course, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications to the above-described embodiments of the present invention without departing from the scope of the present invention under the teaching of the present invention.

Claims

1. A piston ring comprising a ring body (1) and an oil scraping member (2) provided on an outer peripheral side of the ring body (1),

the scraping element (2) comprises a first side face (21), a second side face (22) and a scraping surface (3) located between the first side face (21) and the second side face (22), the scraping surface (3) comprises a first scraping surface (31), a second scraping surface (32) and a third scraping surface (33), the first scraping surface (31) is located between the second scraping surface (32) and the third scraping surface (33) in the axial direction (A) of the piston ring,

in the radial direction (R) of the piston ring,

the first oil wiping surface (31) is higher than the second oil wiping surface (32) and the third oil wiping surface (33), or

The first wiping surface (31) is lower than the second wiping surface (32) and the third wiping surface (33).

2. Piston ring according to claim 1, characterized in that the second scraping surface (32) and the third scraping surface (33) are at the same level in the radial direction (R).

3. Piston ring according to claim 1, characterized in that the outer circumferential side of the oil scraping surface (3) is covered with a wear resistant layer (4).

4. The piston ring as claimed in claim 3, characterized in that the wear layer (4) comprises a first wear layer (41) on the outer circumference of the first oil scraping surface (31), a second wear layer (42) on the outer circumference of the second oil scraping surface (32) and a third wear layer (43) on the outer circumference of the third oil scraping surface (33),

in the radial direction (R) of the piston ring,

-in case the first oil scraping surface (31) is higher than the second oil scraping surface (32) and the third oil scraping surface (33), the outer diameter of at least one of the second wear layer (42) and the third wear layer (43) is equal to or larger than the outer diameter of the first oil scraping surface (31), and the outer diameter of the second wear layer (42) and the third wear layer (43) is smaller than the outer diameter of the first wear layer (41),

in the case where the first oil scraping surface (31) is lower than the second oil scraping surface (32) and the third oil scraping surface (33), the outer diameter of the first abrasion resistant layer (41) is equal to or larger than at least one of the outer diameters of the second oil scraping surface (32) and the third oil scraping surface (33), and the outer diameter of the first abrasion resistant layer (41) is smaller than the outer diameters of the second abrasion resistant layer (42) and the third abrasion resistant layer (43).

5. Piston ring according to claim 1, characterized in that the generatrix of the first scraping surface (31), the generatrix of the second scraping surface (32) and the generatrix of the third scraping surface (33) are all parallel to the axis of the piston ring.

6. Piston ring according to claim 1, characterized in that the generatrix of the first wiping surface (31), the generatrix of the second wiping surface (32) and the generatrix of the third wiping surface (33) are at an angle of more than 0 ° and not more than 30 ° to the axis of the piston ring.

7. The piston ring of claim 4, wherein the oil scraping surface further comprises transition surfaces including a first transition surface (34), a second transition surface (35), a third transition surface (36), and a fourth transition surface (37),

in the axial direction (A), the first transition surface (34) is located between the first side and the second oil scraping surface (32), the second transition surface (35) is located between the second oil scraping surface (32) and the first oil scraping surface (31), the third transition surface (36) is located between the first oil scraping surface (31) and the third oil scraping surface (33), and the fourth transition surface (37) is located between the third oil scraping surface (33) and the second side,

the transition surface gradually increases in outer diameter during the extension in the axial direction (A), or

The transition surface gradually decreases in outer diameter during extension in the axial direction (A).

8. Piston ring according to claim 1, characterized in that the dimensions of the first, second and third scraping surfaces (31, 32, 33) in the axial direction (a) are not more than 0.15mm, and/or

The size of the oil scraping surface (3) is not more than 0.5 mm.

9. Piston ring according to claim 7, characterized in that the dimensions of the first (34), second (35), third (36) and fourth (37) transition surfaces in the axial direction (A) are not greater than 0.15mm and/or

In radial direction (R), first wearing layer (41) with the difference in height of second wearing layer (42), first wearing layer (41) with the difference in height of third wearing layer (43), second wearing layer (42) with the difference in height of the minimum external diameter of first transition face (34), third wearing layer (43) with the difference in height of the minimum external diameter of fourth transition face (37) all is not less than 5um and is not greater than 200 um.

10. Piston ring according to any one of claims 1 to 9, characterized in that it has two oil scraping means (2).