CN215370059U

CN215370059U - High-wear-resistance piston ring

Info

Publication number: CN215370059U
Application number: CN202121375815.XU
Authority: CN
Inventors: 喻晓妹
Original assignee: Nanjing Feiyan Piston Ring Co ltd
Current assignee: Nanjing Feiyan Piston Ring Co ltd
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2021-12-31
Anticipated expiration: 2031-06-21

Abstract

The utility model discloses a high-wear-resistance piston ring, wherein a base material is martensitic stainless steel, a nitriding layer is processed on the outer layer of the base, a diamond-chromium composite coating is arranged outside the nitriding layer, and a diamond-like coating is arranged outside the diamond-chromium composite coating. The diamond chromium composite coating comprises diamond particles, and micro cracks capable of storing oil are formed on the surface of the diamond chromium composite coating. The utility model can effectively reduce the abrasion of the piston ring and the ring groove, improve the service life of the piston ring while ensuring the working performance, has high abrasion resistance and tensile cylinder capacity, and is particularly suitable for engines with complex working conditions.

Description

High-wear-resistance piston ring

Technical Field

The utility model relates to a piston ring sealing system of an internal combustion engine, in particular to a piston ring with good wear resistance.

Background

The piston ring sealing system of the internal combustion engine mostly consists of three rings, namely a first compression ring, a second compression ring, an oil control ring and the like. The first compression ring is closest to the combustion chamber of the piston, and the combustion temperature, the explosion pressure and the lubrication at the position are the highest, the explosion pressure is the largest and the lubrication is the least sufficient, so that the working condition is the worst, and the engine fault is caused by the failures of excessive wear (excircle wear and end face wear) and cylinder scuffing and the like under the extreme working conditions, wherein the extreme working conditions include but are not limited to: the air filter and/or the oil filter which meet the requirements are not maintained and replaced as required, the engine oil which meet the requirements is not maintained and replaced as required, the engine is carried in an overspeed overload manner, the sand and dust in the working environment of the engine are serious, and the cooling water is hard so that the excircle of the cylinder sleeve is scaled to cause poor heat conduction and the like. In order to solve the problems, the existing first compression ring design adopts coating means such as ceramic chromium plating, diamond chromium plating, end face chromium plating, PVD (physical vapor deposition), DLC (diamond like carbon), and the like, but the abrasion phenomenon cannot be effectively improved.

The utility model with the publication number of CN201439816U provides a piston ring with a nitrided layer and a chromium-ceramic composite coating layer, which has improved wear resistance compared with the conventional chromium layer, but still cannot meet the use requirements under the aforementioned extreme working conditions due to the frictional wear characteristics of the coating layer itself, and shows the defects of insufficient wear resistance and insufficient tensile cylinder capacity.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model aims to provide a piston ring with excellent wear resistance.

The technical scheme is as follows: the high-wear-resistance piston ring is made of martensitic stainless steel as a base material, a nitriding layer is processed on the outer layer of the base, a diamond-chromium composite coating is arranged outside the nitriding layer, and a diamond-like coating is arranged outside the diamond-chromium composite coating. The diamond chromium composite coating comprises diamond particles with the size of 0.1-5.0 mu m, and the content of the particles accounts for 0.3-2.5% of the volume ratio of the composite coating; the diamond chromium composite coating has microcracks with the density of 40-120 pieces/mm; the section of the piston ring is rectangular, wedge-shaped or trapezoidal, and the outline of the outer circle of the piston ring is a symmetrical barrel surface, an asymmetrical barrel surface or a conical surface; the diamond-like coating comprises a chromium layer, a tungsten-containing amorphous carbon layer and an amorphous carbon layer from inside to outside in sequence.

The depth of the nitriding layer is 0.01-0.06 mm; the thickness of the diamond chromium composite coating is 0.03-0.08 mm; the thickness of the diamond-like coating is 0.004-0.010 mm, preferably 0.005-0.008 mm.

Has the advantages that: compared with the prior art, the utility model has the following advantages: the wear-resistant piston ring can effectively reduce the wear of the piston ring and the ring groove, the service life of the piston ring is prolonged while the working performance is guaranteed, the wear resistance and the tensile cylinder capacity are high, and the wear-resistant piston ring is particularly suitable for engines with complex working conditions.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a view showing the assembly relationship of the present invention with a cylinder block;

FIG. 3 is a block diagram of an embodiment having a rectangular cross-section;

FIG. 4 is a block diagram of an embodiment having a wedge-shaped cross-section;

FIG. 5 is a block diagram of an embodiment having a trapezoidal cross-section;

FIG. 6 is a diagram of the construction of an embodiment in which the contour of the outer circle is a symmetrical barrel surface;

FIG. 7 is a block diagram of an embodiment of an asymmetric barrel face having an outer contour;

FIG. 8 is a structural view of an embodiment in which the outer peripheral contour is a tapered surface.

Detailed Description

The technical scheme of the utility model is further explained by combining the attached drawings.

As shown in figure 1, the piston ring base body 1 is made of martensitic stainless steel, has the characteristics of high elastic modulus and high strength, and can be applied to a large ring height range, wherein the applicable ring height interval is 0.8-4.0 mm, and the applicable ring height interval of the nodular cast iron material is 1.2-4.0 mm; three layers of coatings are arranged on the substrate; the first layer from inside to outside is a nitriding layer 2, the depth is 0.01-0.06 mm, and the nitriding layer has the microhardness of 700-1200 HV0.1, so that the wear resistance of the end face is ensured; the second layer is a diamond-chromium composite coating 3 with the thickness of 0.03-0.08 mm, the coating comprises diamond particles with the size of 0.1-5.0 mu m, the particle content accounts for 0.3-2.5% of the volume ratio of the composite coating, the coating has microcracks with the density of 40-120 pieces/mm, the coating can play a role of oil storage, and has microhardness of 900-1300 HV0.1, compared with a common coating of a piston ring, the wear resistance of the coating is 4 times of that of a chromium layer and is 2 times of that of a ceramic chromium coating; the tensile cylinder capacity is 3 times of that of the chromium layer and 1.5 times of that of the ceramic chromium coating, so that the wear resistance of the excircle of the piston ring is effectively ensured; the third layer is a diamond-like carbon coating (DLC) which has the properties of high hardness and low friction coefficient, and takes the DLC as the outermost layer to play the roles of improving initial running-in and preventing initial cylinder scuffing and further improving the wear resistance, and the DLC coating of the utility model has the following characteristics:

the appearance is carbon black.

Secondly, depositing on the surface of the workpiece by adopting a non-equilibrium magnetron sputtering and PACVD (plasma assisted chemical vapor deposition) process.

③ coating hardness: 1800 to 3000HV 0.025.

And fourthly, the total thickness of the DLC coating is 0.004-0.010 mm, preferably 0.005-0.008 mm.

The DLC coating is sequentially provided with an amorphous carbon layer, a tungsten-containing amorphous carbon layer and a chromium layer from top to bottom, wherein the thickness of the chromium layer is not more than 1.5 mu m, and the chromium layer is used as a transition layer and can increase the bonding strength of DLC; the second layer is an amorphous carbon layer containing tungsten with a thickness of 2-2.5 μm, and the outermost layer is an amorphous carbon layer.

The assembling relation of the piston ring and the cylinder body is shown in figure 2, the lower end face has more serious abrasion compared with the upper end face because the explosion pressure and the impact force born by the lower end face are the largest, the abrasion loss ratio of the piston ring when the ring and the ring groove of the piston are made of different materials is shown in tables 1 and 2, and the upper surface, the lower surface, the inner surface and the outer surface of the piston ring have nitriding layers, so that the upper end face, the lower end face and the outer circumferential face of the piston ring have abrasion resistance by utilizing the advantages of high hardness and thick coating of the nitriding layers, particularly for the upper end face and the lower end face, the friction pair matching performance of the steel and the ring groove of the piston after nitriding is excellent, and the abrasion of the ring and the ring to the ring groove is greatly improved.

TABLE 1 lower end-face wear ratio of steel nitriding ring to nodular cast iron ring (lower end-face without chromium plating)

Ring groove material of piston	Lower end face wear ratio of ring	Wear rate ratio of lower end surface of ring grooveValue of
			Aluminium	1：1.5	1：1
Cast iron	1：3.5	1：1
			Steel	1：5	1：1

TABLE 2 lower end-face wear ratio of steel nitriding ring to nodular cast iron ring (chromium plated lower end face)

Ring groove material of piston	Lower end face wear ratio of ring	Ratio of wear loss of lower end surface of ring groove
			Aluminium	1：1.5	1：2.5
Cast iron	1：1.5	1：1.5
			Steel	1：3	1：8

The processing process of the utility model is as follows: the method is characterized in that a 6Cr13Mo stainless steel material is adopted, after the basic processing of the piston ring is completed, gas nitriding treatment is carried out, a nitriding layer is generated on each surface of the ring, then a diamond chromium coating is electroplated on the outer circle, and after the product is processed to a finished product, DLC deposition treatment is carried out on the outer circle.

The embodiment 1 of the utility model is a 4-cylinder diesel engine piston ring, the diameter of a cylinder is 91.491mm, the first compression ring is a rectangular ring made of 6Cr13Mo stainless steel material, the height of the ring is 2.5mm, the radial thickness is 3.5mm, the outer circular surface is a symmetrical barrel surface profile, the first coating is a nitriding layer, the depth of the outer circular surface is 0.04mm, the depth of the upper end surface and the lower end surface is 0.03mm, the second coating is a diamond chromium coating, the thickness is 0.06mm, and the third coating is a DLC layer, and the thickness is 0.006 mm.

Claims

1. The high-wear-resistance piston ring is characterized in that a nitriding layer (2) is processed on the outer layer of a base body (1), a diamond-chromium composite coating (3) is arranged outside the nitriding layer (2), and a diamond-like coating (4) is arranged outside the diamond-chromium composite coating (3).

2. The piston ring with high wear resistance according to claim 1, wherein the diamond-like coating (4) comprises, in order from the inside towards the outside, a chromium layer, an amorphous carbon layer containing tungsten and an amorphous carbon layer.

3. The piston ring as claimed in claim 1, wherein the nitrided layer (2) has a depth of 0.01 to 0.06 mm.

4. The piston ring with high wear resistance as claimed in claim 1, wherein the diamond-chromium composite coating (3) has a thickness of 0.03-0.08 mm.

5. The piston ring with high wear resistance according to claim 1, wherein the diamond-like coating (4) has a thickness of 0.004-0.010 mm.

6. The piston ring as claimed in claim 1, wherein the diamond-like coating (4) has a thickness of 0.005-0.008 mm.

7. The piston ring as claimed in claim 1, wherein the diamond-chromium composite coating layer (3) contains diamond particles with a size of 0.1-5.0 μm, and the content of the diamond particles is 0.3-2.5% of the volume ratio of the composite coating layer.

8. The piston ring with high wear resistance as claimed in claim 1, wherein the diamond-chromium composite coating (3) has a density of 40-120 micro cracks/mm.

9. The piston ring of claim 1, wherein the piston ring has a rectangular, wedge-shaped or trapezoidal cross-sectional shape, and has an outer circular profile of a symmetrical barrel surface, an asymmetrical barrel surface or a tapered surface.