WO2024061227A1

WO2024061227A1 - Crankshaft connecting rod assembly, engine and automobile

Info

Publication number: WO2024061227A1
Application number: PCT/CN2023/119774
Authority: WO
Inventors: 黄鹏华; 闫雪华; 文怀军; 莫煜; 蓝志宝
Original assignee: 上汽通用五菱汽车股份有限公司
Priority date: 2022-09-20
Filing date: 2023-09-19
Publication date: 2024-03-28
Also published as: CN115653749A; CN115653749B

Abstract

The present application provides a crankshaft connecting rod assembly, an engine, and an automobile. The crankshaft connecting rod assembly comprises a piston part, a connecting rod and a piston ring. The piston part comprises a piston head and a piston skirt connected to the lower end of the piston head. The connecting rod comprises a first end and a second end. The first end is configured to be hingedly connected to the piston skirt, and the second end is configured to be connected to a crankshaft. The piston ring is fitted over the periphery of the piston head. An upper end face is arranged on the side of the piston ring away from the connecting rod, and a lower end face is arranged on the side of the piston ring close to the connecting rod. The piston ring further comprises a first fillet surface and a second fillet surface. The first fillet surface is connected to the upper end face and the outer peripheral face of the piston ring, and the second fillet surface is connected to the lower end face and the outer peripheral face of the piston ring. The fillet radius of the first fillet surface is greater than the fillet radius of the second fillet surface. According to the crankshaft connecting rod assembly provided by the present application, the friction loss between the piston ring and a cylinder hole is reduced on the premise that an oil scraping effect is ensured, so that the overall working efficiency of the crankshaft connecting rod assembly is improved.

Description

Crankshaft connecting rod components, engines and automobiles

This application claims priority to the Chinese patent application filed with the China Patent Office on September 20, 2022, with the application number 202211145895.9 and the application name "Crank and Connecting Rod Assembly, Engine and Automobile", the entire content of which is incorporated into this application by reference. middle.

Technical field

The present invention relates to the technical field of engine design, and in particular to a crankshaft connecting rod assembly, an engine and an automobile.

Background technique

With the introduction of policies and regulations such as energy conservation and emission reduction, carbon peaking and carbon neutrality, society has put forward higher requirements for the existing vehicle fuel consumption and emissions.

During the operation of the engine, its internal parts rub against each other to generate friction work. Excessive friction work will reduce the efficiency of the engine, and the crankshaft connecting rod mechanism accounts for about 50% of the friction work loss. Therefore, developing a crankshaft connecting rod mechanism with lower friction loss to reduce engine fuel consumption and improve engine thermal efficiency is the focus of technicians.

This Background section is provided to generally present the context of the invention, the work of the inventors currently named, the work to the extent described in this Background section, and the description in this section that does not constitute prior art at the time of filing. aspects are neither expressly nor implicitly admitted to be prior art to the present invention.

Contents of the invention

In view of this, the present application provides a crankshaft connecting rod assembly engine and automobile to solve the problem in the prior art of low engine efficiency caused by high friction work of the crankshaft connecting rod mechanism.

The present application provides a crankshaft connecting rod assembly, which includes a piston, a connecting rod and a piston ring. The piston includes a piston head and a piston skirt connected to the lower end of the piston head. The connecting rod includes a first end and a second end. The first end is used for hinge connection with the piston skirt, and the second end is used for connection with the crankshaft. The piston ring is sleeved on the outer periphery of the piston head, the side of the piston ring away from the connecting rod is provided with an upper end surface, and the side of the piston ring close to the connecting rod is provided with a lower end surface. The piston ring also includes a first rounded arc surface and a second rounded arc surface, the first rounded arc surface is connected to the upper end surface and the outer peripheral surface of the piston ring, and the second rounded arc surface is connected to on the lower end surface and the outer peripheral surface of the piston ring. Wherein, the chamfering radius of the first rounded arc surface is greater than the chamfering radius of the second rounded arc surface.

In the above scheme, because the friction loss between the piston ring and the cylinder bore accounts for a large proportion of the friction loss of the entire crankshaft connecting rod assembly, it is necessary to reduce the friction between the piston ring and the cylinder bore, thereby reducing the friction work. During the working process of the piston ring, the lower part close to the connecting rod plays the main role of scraping oil, while the upper part far away from the connecting rod has less impact on scraping oil. To this end, this application uses asymmetric piston ring oil scraping technology to ensure the oil scraping effect while further reducing the tension between the piston ring and the cylinder bore to reduce the friction loss between the two and improve the overall durability of the crankshaft connecting rod assembly. Work efficiency.

In a possible design, the chamfering radius of the first rounded arc surface is between 0.6-1 mm, and the chamfering radius of the second rounded arc surface is between 0.1-0.5 mm.

In the above solution, the chamfering radius of the first chamfering arc surface and the chamfering radius of the second chamfering arc surface are further limited to ensure the oil scraping effect of the piston ring and low friction work loss.

In one possible design, the chamfering radius of the first rounded arc surface is 0.9mm, and the chamfering radius of the second rounded arc surface is 0.3mm.

In the above scheme, specific values of the chamfering radius of the first chamfering arc surface and the chamfering radius of the second chamfering arc surface are given to ensure the oil scraping effect of the piston ring and low friction work loss.

In a possible design, the piston skirt includes a main thrust surface and a secondary thrust surface arranged oppositely, and the main thrust surface and the secondary thrust surface are used to fit the cylinder wall, wherein the main thrust surface The area of the secondary thrust surface is smaller than the area of the secondary thrust surface.

In the above scheme, both the main thrust surface and the secondary thrust surface are in contact with the cylinder wall of the combustion chamber to ensure the movement accuracy of the piston relative to the cylinder wall. The area of the main thrust surface is smaller than that of the secondary thrust surface, which can reduce the distance between the piston skirt and the cylinder wall. The friction work between the cylinder walls is lost, thereby improving the overall working efficiency of the crankshaft and connecting rod assembly.

In a possible design, the crankshaft connecting rod assembly further includes a crankshaft and a connecting rod bearing bush, the crankshaft is provided with a journal, and the connecting rod The bearing bush is sandwiched between the second end and the journal neck. The width of the connecting rod bearing bush along the axial direction of the journal journal is W, and the diameter of the journal journal is R. Wherein, the W and R satisfy: 0.3≤W/R≤0.5.

In the above scheme, there is relative motion between the connecting rod bearing and the journal, and the ratio between the axial width of the connecting rod bearing along the journal and the diameter of the journal is limited, which can ensure the bearing capacity of the connecting rod bearing. At the same time, the contact area between the crankshaft and the connecting rod bearing is reduced, thereby reducing the friction work loss of the crankshaft and connecting rod assembly.

In a possible design, the W and R further satisfy: W/R=0.45.

In the above solution, the ratio between the width of the connecting rod bearing along the axial direction of the journal and the diameter of the journal is further limited to ensure the bearing capacity of the connecting rod bearing while reducing the contact area between the crankshaft and the connecting rod bearing. , thereby reducing the friction work loss of the crankshaft connecting rod assembly.

In one possible design, a surface of the connecting rod bearing bush close to the journal portion is provided with a resin coating.

In the above scheme, providing a resin coating can reduce the friction coefficient of the inner surface of the connecting rod bearing, thereby increasing the bearing capacity of the connecting rod bearing and reducing the friction work loss between the connecting rod bearing and the crankshaft.

In a possible design, the crankshaft connecting rod assembly further includes a piston pin, the piston member is provided with a first hinge hole, the first end is provided with a second hinge hole, and the piston pin passes through the The first hinge hole and the second hinge hole, the outer surface of the piston pin and the inner wall surface of the second hinge hole are both provided with diamond-like coatings.

In the above solution, providing a diamond-like coating can reduce the friction coefficient between the piston pin and the connecting rod surface, thereby reducing the friction work loss of the crankshaft connecting rod assembly.

The present application provides an engine, which includes the crankshaft connecting rod assembly described in any one of the preceding items, so it obviously has the advantages of the aforementioned crankshaft connecting rod assembly.

This application also provides an automobile. The automobile includes the aforementioned engine, which obviously has the advantages of the aforementioned crankshaft connecting rod assembly and engine.

Additional features and advantages of the embodiments will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments. The objectives and other advantages of the embodiments of the present application are realized and obtained by the structures particularly pointed out in the description and drawings.

Description of the drawings

Figure 1 is a schematic structural diagram of a crankshaft connecting rod assembly provided by an embodiment of the present application;

Figure 2 is an exploded view of the crankshaft connecting rod assembly provided by the embodiment of the present application;

Figure 3 is a schematic diagram of the assembly of piston rings and piston parts provided by the embodiment of the present application;

Figure 4 is a schematic structural diagram of a piston provided by an embodiment of the present application.

Reference signs:

100. Crankshaft connecting rod assembly; 1. Piston part; 11. Piston head; 111. First hinge hole; 12. Piston skirt; 121. Main thrust surface; 122. Secondary thrust surface; 2. Connecting rod; 21. First end; 211, second hinge hole; 22, second end; 3, piston ring; 31, upper end surface; 32, lower end surface; 33, first rounded arc surface; 34, second rounded arc surface; 4. Crankshaft; 41. journal; 5. connecting rod bearing; 6. piston pin.

Detailed ways

In order to better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

It should be clear that the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be understood that the term "and/or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

The terminology used in the embodiments of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application. As used in the embodiments and the appended claims, the singular forms "a," "the" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the embodiment of this application In the description, "multiple" means two or more, unless otherwise clearly and specifically limited.

Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of this application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to It is more than two pieces (including two pieces).

In the description of the embodiments of this application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right" and "vertical" The orientation or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the embodiments of the present application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the implementation of the present application. Example limitations. Additionally, it should be understood in this context that when an element is referred to as being connected "on" or "under" another element, it can not only be directly connected "on" or "under" the other element, but also can be directly connected "on" or "under" the other element. Indirectly connected "on" or "below" another element through an intermediate element.

In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

In the use of the engine, the tight fit between the piston ring 3 and the inner wall of the cylinder hole is usually used to prevent the lubricating grease from being driven from one side of the piston ring 3 to the other side of the piston ring 3, thereby avoiding the leakage in the combustion chamber. The gas mixed with lubricating grease also avoids the blockage caused by the lubricating grease in the gas delivery pipeline. Therefore, the oil scraping efficiency of the piston ring 3 directly affects the operating stability of the engine. However, because the friction loss between the piston ring 3 and the cylinder bore accounts for a large proportion of the overall friction loss of the crankshaft connecting rod assembly 100, it is necessary to reduce the friction between the piston ring 3 and the cylinder bore, thereby reducing the friction work.

Specific embodiments of the crankshaft connecting rod assembly will be described below based on the structure of the crankshaft connecting rod assembly provided in the embodiment of the present application.

This application provides a crankshaft connecting rod assembly 100, which includes a piston 1, a connecting rod 2, and a piston ring 3. The piston 1 includes a piston head 11 and a piston skirt 12 connected to the lower end of the piston head 11. The connecting rod 2 includes a first end 21 and a second end 22 . The first end 21 is used for hinge connection with the piston skirt 12 , and the second end 22 is used for connection with the crankshaft 4 . The piston ring 3 is sleeved on the outer periphery of the piston head 11. The side of the piston ring 3 away from the connecting rod 2 is provided with an upper end face 31, and the side of the piston ring 3 close to the connecting rod 2 is provided with a lower end face 32. The piston ring 3 also includes The first rounded arc surface 33 and the second rounded arc surface 34. The first rounded arc surface 33 is connected to the upper end surface 31 and the outer peripheral surface of the piston ring 3. The second rounded arc surface 34 is connected to the lower end surface 32 and the piston ring. 3 outer surface. The chamfering radius of the first rounded arc surface 33 is greater than the chamfering radius of the second rounded arc surface 34 .

Please refer to Figures 1, 2 and 3. The piston 1 can be a cylindrical structure, which is slidably disposed in the cylinder bore of the engine along the axis of the cylinder. The piston 1 includes an upper piston head 11 and a lower piston head 11. The piston skirt 12, the outer circumference of the piston head 11 is covered with a piston ring 3, and the outer circumferential surface of the piston ring 3 is in contact with the inner wall of the cylinder bore. During the reciprocating motion of the piston 1, the piston ring 3 is in constant contact with the cylinder bore. Scrape the oil back to the side of the piston 1 close to the connecting rod 2 to ensure that the crankshaft connecting rod assembly 100 is fully lubricated. The piston ring 3 has an upper end surface 31, a lower end surface 32 and an outer circumferential surface arranged on its outer circumference. The first rounded arc surface 33 is transitionally connected to the upper end surface 31 and the outer circumferential surface of the piston ring 3, and the second rounded arc surface 34 is transitionally connected to The lower end surface 32 and the outer peripheral surface of the piston ring 3. The first rounded arc surface 33 and the second rounded arc surface 34 can be a common rounded arc surface. It can be understood that the larger the chamfer radius of the rounded arc surface, the greater the contact area between the rounded arc surface and the inner wall of the cylinder hole. The smaller it is, the smaller the friction loss between the two. During the working process of the piston ring 3, its lower half close to the connecting rod 2 plays a major role in scraping oil, while its upper half far away from the connecting rod 2 has less impact on oil scraping.

Therefore, this embodiment uses asymmetric piston ring 3 oil scraping technology to further reduce the tension between the piston ring 3 and the cylinder bore on the premise of ensuring the oil scraping effect, so as to reduce the friction loss between the two and improve the crankshaft connection. Overall operating efficiency of rod assembly 100.

In one embodiment, the chamfer radius of the first chamfered arc surface 33 is between 0.6-1 mm, specifically, it can be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. The chamfer radius of the second chamfered arc surface 34 is between 0.1-0.5 mm, specifically, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. In a certain embodiment, the chamfering radius of the first rounded arc surface 33 is 0.9 mm, and the chamfering radius of the second rounded arc surface 34 is 0.9 mm. The chamfer radius is 0.3mm.

The test data of the upper and lower ends of the piston ring under different chamfer radii are given below: Table 1 and Table 2:

Table 1, the chamfering radius of the first rounded arc surface is constant, and the chamfering radius of the second rounded arc surface gradually increases.

Table 2, the chamfering radius of the second rounded arc surface is constant, and the chamfering radius of the first rounded arc surface gradually increases.

Among them: the frictional resistance values of the piston rings in Examples 2 to 6 in Table 1 are relative reference values calculated based on the test values of the frictional resistance of the piston rings in Example 1. In Table 1 The values of the oil return rate in Examples 2 to 6 are relative reference values calculated based on the test value of the oil return rate in Example 1.

The friction resistance values of the piston rings in Examples 8 to 12 in Table 2 are relative reference values calculated based on the test values of the friction resistance of the piston rings in Example 7. The values of the oil return rate in Examples 8 to 12 are relative reference values calculated based on the test value of the oil return rate in Example 7.

The aforementioned oil return rate refers to the ratio between the amount of grease located at the end of the piston ring close to the connecting rod and the total amount of grease after the piston ring reciprocates a certain number of times (for example, 100 times) under simulated working conditions.

Combining Table 1 and Table 2, it can be seen that as the chamfer radius of the second rounded arc surface 34 gradually increases, the friction resistance of the piston ring 3 gradually becomes smaller, but the chamfering radius of the second rounded arc surface 34 exceeds 0.5 mm, the oil return rate decreases rapidly. As the chamfering radius of the first rounded arc surface 33 gradually increases, the friction resistance experienced by the piston ring 3 gradually becomes smaller. Before the chamfering radius of the first rounded arc surface 33 increases to 1 mm, the oil return rate is basically Not affected.

Referring to Figures 1 and 2, the provision of the first chamfered arc surface 33 can reduce the contact area between the piston ring 3 and the inner wall of the cylinder bore, thereby reducing friction and improving efficiency. In addition, the lower part of the piston ring 3 will be subject to greater extrusion stress during movement. In order to avoid damage and failure of the piston ring 3, this embodiment sets a smaller chamfer radius than the first chamfered arc surface 33. The second chamfered arc surface 34 is formed to ensure the oil scraping effect while taking into account the service life of the piston ring 3.

To sum up, this embodiment further limits the chamfering radius of the first rounded arc surface 33 and the chamfering radius of the second rounded arc surface 34. Furthermore, this embodiment also provides the first rounded arc surface 33. The specific values of the chamfering radius and the chamfering radius of the second chamfering arc surface 34 are to ensure the oil scraping effect of the piston ring 3 and low friction work loss.

In one embodiment, the piston skirt 12 includes a main thrust surface 121 and a secondary thrust surface 122 arranged oppositely. The main thrust surface 121 and the secondary thrust surface 122 are used to fit with the cylinder wall, where the area of the main thrust surface 121 is smaller than the area of secondary thrust surface 122.

Please refer to Figures 1 and 2. During the movement of the piston 1, the piston skirt 12 is in full contact with the inner wall of the cylinder bore. It can be understood that the larger the contact area between the piston skirt 12 and the inner wall of the cylinder bore, the larger the piston 1 The more stable the motion within the cylinder bore, the more stable the motion of the crankshaft connecting rod assembly 100 will be. At the same time, as the contact area between the piston skirt 12 and the inner wall of the cylinder hole increases, the relative friction area between the two increases, thereby increasing the friction work loss between the piston member 1 and the inner wall of the cylinder hole.

The up and down movement of the piston 1 exerts different pressures on the inner wall of the cylinder bore. When the fuel in the combustion chamber is burned, the piston 1 is driven by the fuel gas and moves closer to the connecting rod 2 because the connecting rod 2 is tilted to one side of the crankshaft 4 at this time, so there is a large stress between the main thrust side of the piston skirt 12 and the inner wall of the cylinder bore. When the piston 1 moves away from the connecting rod 2 under the inertial force of the crankshaft 4, there is a large stress between the secondary thrust side of the piston skirt 12 and the inner wall of the cylinder bore. However, at this time, the piston skirt 12 and The stress between the inner walls of the cylinder bore is much smaller than the stress generated when the piston 1 moves toward the connecting rod 2 driven by the fuel gas. Based on this, this embodiment is provided with a main thrust surface 121 and a secondary thrust surface 122 on the main thrust side and the secondary thrust side of the piston 1, and the two surfaces are arranged oppositely, and the area of the main thrust surface 121 is smaller than the area of the secondary thrust surface 122, so , both the main thrust surface 121 and the secondary thrust surface 122 are in contact with the inner wall of the cylinder bore of the combustion chamber to ensure the movement accuracy of the piston 1 relative to the cylinder wall, and the area of the main thrust surface 121 is smaller than the area of the secondary thrust surface 122, which can reduce the piston skirt. The friction work loss between the portion 12 and the cylinder wall is thereby improved, thereby improving the overall working efficiency of the crankshaft connecting rod assembly 100 .

In one embodiment, the crankshaft connecting rod assembly 100 further includes a crankshaft 4 and a connecting rod bearing 5. The crankshaft 4 is provided with a journal 41, and the connecting rod bearing 5 is sandwiched between the second end 22 and the journal 41. The width of the connecting rod bearing 5 along the axial direction of the journal 41 is W, and the diameter of the journal 41 is R, where W and R satisfy: 0.3≤W/R≤0.5.

Please refer to Figure 1 and Figure 2. The crankshaft 4 is the most important component in the engine. It bears the force from the connecting rod 2 and converts it into torque, which is output through the crankshaft 4 and drives other accessories on the engine to work. The crankshaft 4 is affected by the centrifugal force of the rotating mass, the periodically changing gas inertia force and the reciprocating inertia force, causing the crankshaft 4 to bear the bending and torsional load. The part of the crankshaft 4 connected to the connecting rod 2 is the journal 41. The journal 41 is a cylindrical structure. The diameter of the journal 41 is R. In some embodiments, R is 42 mm. In order to reduce the size of the crankshaft 4 Due to the centrifugal force generated by mass and movement, the journal 41 is often designed to be hollow, and an oil hole is opened on the surface of each journal 41 to introduce or extract engine oil to lubricate the journal 41 surface.

The second end 22 can be two split semi-annular connection structures. After the connecting rod bearing 5 is fitted to the journal neck 41, the second end 22 of the connecting rod 2 is fixed to the outside of the connecting rod bearing 5, thereby achieving a stable connection between the connecting rod 2 and the journal neck 41.

The connecting rod bearing 5 can be a curved semi-cylindrical structure. Because the connecting rod bearing 5 needs to fit on the surface of the journal 41, its curvature is the same as the curvature of the outer surface of the journal 41. The number can be set to two. The two connecting rod bearing bushes 5 are respectively attached to the upper semicircular surface and the lower semicircular surface of the journal 41. The two connecting rod bearings 5 enclose the journal 41. When the journal 41 is When the R value is larger, the design bearing capacity of the journal 41 is greater, and the corresponding connecting rod bearing 5 requires higher bearing strength, and the width of the connecting rod bearing 5 along the axial direction of the journal 41 is W, In some embodiments, W is 19 mm. The larger the value of W, the stronger the load-bearing capacity of the connecting rod bearing 5. However, the larger the value of W, the greater the contact area between the connecting rod bearing 5 and the journal portion 41. The larger it is, the greater the friction loss between the two.

Because there is relative motion between the connecting rod bearing 5 and the journal 41 , limiting the ratio between the width of the connecting rod bearing 5 along the axial direction of the journal 41 and the diameter of the journal 41 can ensure that the connecting rod bearing 5 While carrying capacity, the contact area between the crankshaft 4 and the connecting rod bearing 5 is reduced, thereby reducing the friction work loss of the crankshaft connecting rod assembly 100.

In one embodiment, W and R further satisfy: W/R=0.45.

Referring to Figures 1 and 2, the ratio between the width of the connecting rod bearing 5 along the axial direction of the journal 41 and the diameter of the journal 41 is further limited to ensure the bearing capacity of the connecting rod bearing 5 while reducing the crankshaft 4 and the contact area of the connecting rod bearing 5, thereby reducing the friction work loss of the crankshaft connecting rod assembly 100.

Table 3, relationship between friction and service life under different W/R values.

Among them: the value of the friction between the connecting rod bearing and the journal in Examples 2 to 6 in Table 3 is based on the friction between the connecting rod bearing and the journal in Example 1 in Table 3. The test value is the relative reference value calculated by the benchmark. The values of the service life of the connecting rod bearings in Examples 2 to 6 in Table 3 are relative reference values calculated based on the test values of the service life of the connecting rod bearings in Example 1 in Table 3.

It can be seen from Table 3 that the greater the ratio of W to R, the greater the friction between the connecting rod bearing 5 and the journal 41, and the longer the service life of the connecting rod bearing 5. When the ratio of W to R is greater than 0.5 , the growth rate of the service life of the connecting rod bearing bush 5 becomes smaller, while the growth rate of the friction force between the rod bush and the journal 41 becomes larger.

In one embodiment, a resin coating is provided on a surface of the connecting rod bearing 5 close to the journal portion 41 .

Referring to Figures 1 and 2, the resin coating may include polyamide-imide, and each may be composed of one or more mixtures of the following materials, including graphite, molybdenum disulfide, tungsten disulfide, Hexagonal nitriding (h-BN) or polytetrafluoroethylene (PTFE). Providing a resin coating can reduce the friction coefficient of the inner surface of the connecting rod bearing bush 5, improve the bearing capacity of the connecting rod bearing bush 5, and at the same time reduce the friction work loss between the connecting rod bearing bush 5 and the crankshaft 4.

In one embodiment, the crankshaft connecting rod assembly 100 further includes a piston pin 6. The piston member 1 is provided with a first hinge hole 111, and the first end 21 is provided with a second hinge hole 211. The piston pin 6 passes through the first hinge hole 111. The hole 111 and the second hinge hole 211, the outer surface of the piston pin 6 and the inner wall surface of the second hinge hole 211 are all provided with diamond-like coating.

Please refer to Figures 1 and 2. The piston pin 6 can be a cylindrical structure. The piston pin 6 is passed through the first hinge hole 111 and the second hinge hole 211. Through the pin connection of the piston pin 6, the connecting rod 2 is hinged to the On the piston piece 1.

The hardness range of Diamond like Carbon (DLC) coating can be 59~64HRC (Rockwell hardness), and its thickness range can be 0.002~0.005mm. The diamond-like coating has excellent film density, good chemical stability, and good optical properties. Setting the diamond-like coating can reduce the friction coefficient on the surface of the piston pin 6 and the connecting rod 2, thereby reducing the crankshaft connecting rod assembly. Friction work loss of 100.

The present application provides an engine. The engine includes any of the foregoing crankshaft connecting rod assembly 100 , so it obviously has the advantages of the foregoing crankshaft connecting rod assembly 100 . The crankshaft connecting rod assembly 100 provided in this application can be applied to: Hybrid Electric Vehicle (HEV for short), Range Extended Electric Vehicle (REEV for short), Plug-in Hybrid Electric Vehicle (Plug- In the engines of Hybrid Electric Vehicle (PHEV), New Energy Vehicle (New Energy Vehicle) and ordinary fuel vehicles.

The present application also provides a car, which includes the aforementioned engine and obviously has the advantages of the aforementioned crankshaft connecting rod assembly 100 and engine.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims

A crankshaft connecting rod assembly, characterized by including:

A piston component, which includes a piston head and a piston skirt connected to the lower end of the piston head;

A connecting rod, the connecting rod comprising a first end and a second end, the first end being used for being hinged to the piston skirt, and the second end being used for being connected to the crankshaft; and

Piston ring, the piston ring is sleeved on the outer periphery of the piston head, the side of the piston ring away from the connecting rod is provided with an upper end surface, and the side of the piston ring close to the connecting rod is provided with a lower end surface. End face, the piston ring also includes a first rounded arc surface and a second rounded arc surface, the first rounded arc surface is connected to the upper end surface and the outer peripheral surface of the piston ring, and the second rounded arc surface The arc surface is connected to the lower end surface and the outer peripheral surface of the piston ring;

Wherein, the chamfering radius of the first rounded arc surface is greater than the chamfering radius of the second rounded arc surface.
The crankshaft connecting rod assembly according to claim 1, wherein the chamfering radius of the first chamfered arc surface is between 0.6-1 mm, and the chamfering radius of the second chamfered arc surface is between 0.1-0.5 mm.
The crankshaft connecting rod assembly according to claim 1, wherein the chamfering radius of the first rounded arc surface is 0.9mm, and the chamfering radius of the second rounded arc surface is 0.3mm.
The crankshaft connecting rod assembly according to claim 1, wherein the piston skirt includes a main thrust surface and a secondary thrust surface arranged oppositely, and the main thrust surface and the secondary thrust surface are used to contact the cylinder wall. Together, the area of the main thrust surface is smaller than the area of the secondary thrust surface.
The crankshaft connecting rod assembly according to claim 1, wherein the crankshaft connecting rod assembly further includes a crankshaft and a connecting rod bearing bush, the crankshaft is provided with a journal, and the connecting rod bearing bush is sandwiched between the third Between the two ends and the journal, the width of the connecting rod bearing along the axial direction of the journal is W, and the diameter of the journal is R, where W and R satisfy: 0.3≤ W/R≤0.5.
The crankshaft connecting rod assembly according to claim 5, wherein the W and R further satisfy: W/R=0.45.
The crankshaft connecting rod assembly according to claim 5 or 6, wherein a resin coating is provided on a side of the connecting rod bearing bush close to the journal portion.
The crankshaft connecting rod assembly according to claim 1, wherein the crankshaft connecting rod assembly further includes a piston pin, the piston member is provided with a first hinge hole, and the first end is provided with a second hinge hole, The piston pin passes through the first hinge hole and the second hinge hole, and the outer surface of the piston pin and the inner wall surface of the second hinge hole are both provided with diamond-like coatings.
An engine, characterized in that the engine includes the crankshaft connecting rod assembly according to any one of claims 1-8.
An automobile, characterized by comprising the engine according to claim 9.