CN111151883A - Cylinder sleeve and piston ring assembly and design method of surface texture thereof - Google Patents

Abstract

The invention provides a cylinder sleeve and piston ring assembly and a design method of surface texture thereof, which comprises the following steps: cylinder liners and piston rings; circular textures are arranged on the optimized surfaces of the cylinder sleeve and the piston ring; the circular texture is formed by a plurality of spherical pits, and the spherical pits have the same spherical diameter; the distance between the spherical pits is the same; the optimized surface textures are respectively processed on the cylinder sleeve and the piston ring by adopting a pulse Nd-YAG laser, so that the processing efficiency is higher, and the circular pits processed on the surfaces of the cylinder sleeve and the piston ring have the functions of storing lubricating oil and capturing abrasive dust.

Description

Cylinder sleeve and piston ring assembly and design method of surface texture thereof

Technical Field

The invention relates to the technical field of marine diesel engine parts, in particular to a novel cylinder sleeve and piston ring assembly for a low-speed engine.

Background

With the increasingly prominent environmental protection problem, the emission standard of the diesel engine is continuously improved, the mechanical efficiency can be improved and the fuel oil can be fully combusted through the high reinforcement of the diesel engine, so that the pollution emission is reduced. Under the high strengthening condition, the explosion pressure and the rotating speed of the diesel engine are greatly improved, so that the working condition environment of each friction pair is more and more severe, and the friction power consumption and the abrasion loss of parts are increased. Especially for cylinder liner-piston ring of friction pair of hybrid power core, the problems of friction and abrasion resistance become one of the key bottleneck technical problems restricting further healthy development of high-power intensified hybrid diesel engine. Therefore, the friction reduction and wear resistance problems of the friction pair are urgently needed to be deeply researched, and a basis is provided for further improving the performance of the whole transmission machine of the reinforced diesel engine and improving the design technical level and reliability of the power reinforced hybrid diesel engine. The surface texture has obvious effects on antifriction and friction force bearing improvement, and becomes an important method for improving the frictional wear behavior of the cylinder sleeve-piston ring.

The surface texture technology is to process a lattice of pits or micro-grooves with a certain size and arrangement on a friction surface, and is one of effective means for improving the friction and wear performance of a friction pair. There are many methods for processing the surface texture, such as machining; chemical etching method; a laser etching method; the laser etching method for processing the microtexture has the advantages of high efficiency in processing process, wide application material range, environmental friendliness, wide application range and the like. Although the texture is prepared on the surface of the cylinder sleeve-piston ring friction pair, the friction coefficient can be reduced, the abrasion loss can be reduced, and the service life of the friction pair can be prolonged, the size, the density, the geometric shape and the lubricating condition of the texture can influence the friction and abrasion behavior of the cylinder sleeve-piston ring, so that the surface texture after reasonable optimization can have a better antifriction effect on the cylinder sleeve-piston ring friction pair. So far, there are few patents on laser textured antifriction on liner-piston rings.

Disclosure of Invention

In view of the above-mentioned technical problems, a new cylinder liner and piston ring assembly for a low speed engine is provided.

The technical means adopted by the invention are as follows:

a cylinder liner and piston ring assembly comprising: cylinder liners and piston rings;

circular textures are arranged on the optimized surfaces of the cylinder sleeve and the piston ring;

the specific parameters of the circular texture are as follows: the diameter of the texture on the cylinder sleeve is 100-150 mu m, the depth is 30-50 mu m, and the area occupancy rate is 5-20%; the diameter of the texture on the piston ring is 100-150um, the depth is 30-50um, and the area occupancy is 5-20%;

the circular texture is formed by a plurality of spherical pits, and the spherical pits have the same spherical diameter.

The spherical pits have the same distance with each other.

A design method for surface textures of a cylinder sleeve and a piston ring assembly comprises the following steps:

s1, designing the surface texture of the cylinder sleeve-piston ring: designing a surface texture which forms 90 degrees with the relative motion direction of the cylinder sleeve and the piston ring, wherein the diameter of the texture on the cylinder sleeve is 150um, the depth of the texture is 30um, and the area occupancy rate of the texture is 10 percent; the diameter of the texture on the piston ring is 150um, the depth is 30um, and the area occupancy rate is 5 percent;

s2, processing of cylinder sleeve-piston ring surface texture: cutting the cylinder sleeve with the inner diameter of 110mm and the wall thickness of 8mm at 9 degrees/min along the circumferential direction, wherein the axial length is 42mm, and thus obtaining a cylinder sleeve sample; cutting 20 parts (18 degrees) of a piston ring with the outer diameter of 110mm and the ring height of 3mm in an equal way along the circumferential direction to obtain a piston ring sample;

performing laser surface texture processing by using a pulse Nd-YAG laser according to the standard designed by S1, and performing ultrasonic cleaning for 15min by using gasoline and alcohol respectively after the laser processing;

s3, testing the surface texture of the cylinder sleeve-piston ring: a sample level test is adopted, namely an opposite reciprocating type friction wear testing machine is utilized to carry out a friction wear test on the surface texture of the cylinder sleeve-piston ring through a simulation criterion of wear form-condition unification so as to evaluate the antifriction effect of the surface texture of the cylinder sleeve-piston ring;

s4, optimal size of surface texture of the cylinder sleeve-piston ring: and selecting the optimal pit diameter, depth and area occupancy rate according to the friction and wear test result.

The invention has the advantages that: the optimized surface textures are respectively processed on the cylinder sleeve and the piston ring by adopting a pulse Nd-YAG laser, so that the processing efficiency is higher, and the circular pits processed on the surfaces of the cylinder sleeve and the piston ring have the functions of storing lubricating oil and capturing abrasive dust.

The friction coefficient of the cylinder sleeve-piston ring assembly is reduced, the wear resistance of the cylinder sleeve-piston ring assembly is improved, and the service life of the cylinder sleeve-piston ring assembly is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a cut-away schematic view of a cylinder liner of the present invention.

Figure 2 is a schematic cut-away view of a piston ring according to the invention.

FIG. 3 is a schematic representation of a cut single block of the cylinder liner of the present invention.

Figure 4 is a schematic representation of a cut single piece of a piston ring of the present invention.

Fig. 5 is a schematic illustration of laser surface texturing according to the present invention.

Fig. 6 is an enlarged view of a portion of the surface of fig. 5.

Fig. 7 is a partial cross-sectional view of the location of fig. 6.

In the figure: 1. cylinder liner, 2, piston ring, 3, cylinder liner inner surface, 4, cylinder liner pit, 5, piston ring outer surface, 6, piston ring pit, 7, pit row, 8, cylinder liner-piston ring body.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. Any specific values in all examples shown and discussed herein are to be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the absence of any contrary indication, these directional terms are not intended to indicate and imply that the device or element so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be considered as limiting the scope of the present invention: the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

A cylinder liner and piston ring assembly as shown in figures 1 to 7, comprising: cylinder liners and piston rings;

circular textures are arranged on the optimized surfaces of the cylinder sleeve and the piston ring;

the specific parameters of the circular texture are as follows: the diameter of the texture (the monomer is a spherical pit) on the cylinder sleeve is 100-150um, the depth is 30-50um, and the area occupancy is 5-20%; the diameter of the texture on the piston ring is 100-150um, the depth is 30-50um, and the area occupancy is 5-20%;

as shown in fig. 4, 5 and 6, the circular texture is formed by a plurality of spherical pits, which form the cylinder liner pits 4 on the inner surface 3 of the cylinder liner and the piston ring pits 6 on the outer surface 5 of the piston ring, and finally appear as pit rows 7, and the spherical pits have the same spherical diameter.

As shown in fig. 4, 5 and 6, the spherical pits are spaced at the same interval from each other.

A design method for surface textures of a cylinder sleeve and a piston ring assembly comprises the following steps:

s1, designing the surface texture of the cylinder liner-piston ring body 9: designing a surface texture which forms 90 degrees with the relative motion direction of the cylinder sleeve 1 and the piston ring 2, wherein the diameter of the texture on the cylinder sleeve is 150um, the depth of the texture on the cylinder sleeve is 30um, and the area occupancy rate of the texture on the cylinder sleeve is 10 percent; the diameter of the texture on the piston ring is 150um, the depth is 30um, and the area occupancy rate is 5 percent;

s2, processing of cylinder sleeve-piston ring surface texture: cutting the cylinder sleeve with the inner diameter of 110mm and the wall thickness of 8mm at 9 degrees/min along the circumferential direction, wherein the axial length is 42mm, and thus obtaining a cylinder sleeve sample; cutting 20 parts (18 degrees) of a piston ring with the outer diameter of 110mm and the ring height of 3mm in an equal way along the circumferential direction to obtain a piston ring sample;

performing laser surface texture processing by using a pulse Nd-YAG laser according to the standard designed by S1, and performing ultrasonic cleaning for 15min by using gasoline and alcohol respectively after the laser processing;

s3, testing the surface texture of the cylinder sleeve-piston ring: a sample level test is adopted, namely an opposite reciprocating type friction wear testing machine is utilized to carry out a friction wear test on the surface texture of the cylinder sleeve-piston ring through a simulation criterion of wear form-condition unification so as to evaluate the antifriction effect of the surface texture of the cylinder sleeve-piston ring;

s4, optimal size of surface texture of the cylinder sleeve-piston ring: and selecting the optimal pit diameter, depth and area occupancy rate according to the friction and wear test result.

Example 1

As shown in fig. 1 and 2, the preparation of the liner-piston ring test piece was first performed. Namely, a cylinder liner having an inner diameter of 110mm and a wall thickness of 8mm was cut at 9 °/min in the circumferential direction and an axial length of 42mm to obtain a cylinder liner sample. A piston ring having an outer diameter of 110mm and a ring height of 3mm was cut in 20 parts (18 ℃) in equal portions in the circumferential direction to obtain a piston ring sample. Then as shown in figure 2, a surface texture which forms 90 degrees with the cylinder sleeve and the piston ring is designed, the diameter of the texture on the cylinder sleeve is 150um, the depth is 30um, and the area occupancy rate is 10 percent; the diameter of the texture on the piston ring is 150um, the depth is 30um, and the area occupancy rate is 5%. Fig. 5, 6 and 7 are schematic diagrams of cylinder liner-piston ring texture processing, and the area occupancy rate s of the texture can be calculated by the following formula:

s-the area rate of the cylinder sleeve and the piston ring, unit percent.

r-radius of the pit, unit um.

L-the spacing between the pits, in um.

And preparing a laser surface texture by using a pulse Nd-YAG laser according to the standard, wherein the diameter of a light spot of the laser is 100um, the focal length of a lens is 80mm, the wavelength is 1.06um, the pulse width is about 1us, and the maximum output power is 100W. After the preparation, the sample is ultrasonically cleaned for 15min by using gasoline and alcohol respectively.

The test of the patent performance of the invention is carried out by a sample level test. The test is carried out by adopting an opposite reciprocating type friction and wear testing machine, the rotating speed of the testing machine is 200r/min, the testing temperature is 190 ℃, and the testing load is 50MPa in the testing process. After testing, the original liner-piston ring pairing was found to have a coefficient of friction of 0.120, an example coefficient of friction of 0.073. Namely, the friction coefficient of the cylinder sleeve-piston ring is reduced by processing texture on the cylinder sleeve-piston ring.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (4)

1. A cylinder liner and piston ring assembly comprising: cylinder liners and piston rings;

it is characterized in that circular textures are arranged on the optimized surfaces of the cylinder sleeve and the piston ring;

the specific parameters of the circular texture are as follows: the diameter of the texture on the cylinder sleeve is 100-150 mu m, the depth is 30-50 mu m, and the area occupancy rate is 5-20%; the diameter of the texture on the piston ring is 100-150um, the depth is 30-50um, and the area occupancy rate is 5-20%.

2. A cylinder liner and piston ring assembly as defined in claim 1, wherein:

the circular texture is formed by a plurality of spherical pits, and the spherical pits have the same spherical diameter.

3. A cylinder liner and piston ring assembly as defined in claim 1 or 2, wherein:

the spherical pits have the same distance with each other.

4. The design method of the surface texture of the cylinder sleeve and the piston ring assembly as claimed in claim 1 or 2, characterized by comprising the following steps:

s1, designing the surface texture of the cylinder sleeve-piston ring: designing a surface texture which forms 90 degrees with the relative motion direction of the cylinder sleeve and the piston ring, wherein the diameter of the texture on the cylinder sleeve is 150um, the depth of the texture is 30um, and the area occupancy rate of the texture is 10 percent; the diameter of the texture on the piston ring is 150um, the depth is 30um, and the area occupancy rate is 5 percent;

s2, processing of cylinder sleeve-piston ring surface texture: cutting the cylinder sleeve with the inner diameter of 110mm and the wall thickness of 8mm at 9 degrees/min along the circumferential direction, wherein the axial length is 42mm, and thus obtaining a cylinder sleeve sample; cutting 20 parts (18 degrees) of a piston ring with the outer diameter of 110mm and the ring height of 3mm in an equal way along the circumferential direction to obtain a piston ring sample;

performing laser surface texture processing by using a pulse Nd-YAG laser according to the standard designed by S1, and performing ultrasonic cleaning for 15min by using gasoline and alcohol respectively after the laser processing;

s3, testing the surface texture of the cylinder sleeve-piston ring: a sample level test is adopted, namely an opposite reciprocating type friction wear testing machine is utilized to carry out a friction wear test on the surface texture of the cylinder sleeve-piston ring through a simulation criterion of wear form-condition unification so as to evaluate the antifriction effect of the surface texture of the cylinder sleeve-piston ring;

s4, optimal size of surface texture of the cylinder sleeve-piston ring: and selecting the optimal pit diameter, depth and area occupancy rate according to the friction and wear test result.

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