CN210599200U

CN210599200U - Cylinder jacket of diesel engine

Info

Publication number: CN210599200U
Application number: CN201921422071.5U
Authority: CN
Inventors: 李鹏; 倪松伟; 王宏
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2020-05-22
Anticipated expiration: 2029-08-29

Abstract

The utility model belongs to the technical field of the engine, a diesel engine cylinder jacket is disclosed. The utility model only has a coating in the top dead center area of the cylinder sleeve, the coating is 10-15 mm away from the top surface of the cylinder sleeve, the width of the coating is 20-30 mm, the thickness is 0.3-0.4 mm, and the surface of the coating is flush with the inner surface of the cylinder sleeve; the coating porosity is 1.5-2%. The utility model discloses avoided the problem of regional internal surface coating degree of consistency control difficulty, reduced honing technology complexity, reduced the rejection rate and the spraying cost of cylinder jacket product, when the wear resistance reduces by a wide margin than the full coating scheme, the life of cylinder jacket, wearing and tearing volume all do not have obvious reduction.

Description

Cylinder jacket of diesel engine

Technical Field

The utility model relates to the technical field of engines, especially, relate to a diesel engine cylinder jacket.

Background

Under the large background of environmental protection and energy conservation and emission reduction, the requirement on energy conservation and emission reduction of commercial vehicles is improved, the reduction of the oil consumption of commercial vehicles becomes the requirement of regulations, and one of the main technical measures for reducing the oil consumption of the engines is to reduce friction power consumption. One of the main technical measures for reducing the friction power consumption is to use low-viscosity engine oil to reduce the friction loss between the friction pairs of the main moving parts. The mainstream heavy-duty commercial vehicle engine manufacturers at home and abroad all adopt or develop low-viscosity lubricating oil technology to reduce the friction loss of the engine. The main problems of using low-viscosity engine oil are that the lubricating oil film on the surface of the part becomes thin, and the part is abraded and aggravated due to the fact that the oil film is locally lost under the condition of high oil temperature, particularly under the condition of mixed friction. The piston ring-cylinder sleeve is the most main friction auxiliary component of the engine, the piston ring does high-speed reciprocating motion in the cylinder sleeve within the range of the stroke of the engine, the motion speed of the piston ring is zero in the upper dead point area, the temperature of the area affected by high-temperature gas radiation in the explosion stroke of the engine exceeds 160 ℃, the temperature reaches the engine oil evaporation and coking temperature, an oil film is not easy to form, and the abrasion of the cylinder sleeve of the engine is the largest in the area. Under the condition of adopting low-viscosity engine oil, the abrasion is further aggravated, the service life of the cylinder sleeve is greatly reduced, and the problems of reliability and durability such as cylinder drawing and engine oil burning are further caused. The existing common platform reticulated cylinder sleeve has no special treatment in the top dead center area, the reticulated oil storage capacity is limited, lubricating oil is evaporated under the condition of high-temperature gas roasting, and particularly under the condition of adopting low-viscosity oil, the lubricating condition of the area is further worsened, the abrasion of a piston ring is aggravated, and the requirement of the low-viscosity oil cannot be met.

At home and abroad, in order to solve the problem of excessive wear of a cylinder sleeve in the upper dead point area of a piston ring under the condition of low-viscosity engine oil, three solutions are generally provided: the first solution is to strengthen the cooling of the upper dead point region of the cylinder sleeve, reduce the temperature of the region, and avoid the engine oil from excessively evaporating in the high temperature region to cause insufficient oil storage of the cylinder sleeve, thereby reducing the excessive abrasion of the engine piston ring and the cylinder sleeve. The scheme needs to process the lower parts of a cylinder sleeve and a cylinder body positioning flange, different shapes are processed to increase a cooling channel to guide water flow, and reference document [1] (publication No. CN 102317607A) discloses a large-flow cylinder sleeve cooling channel.A processing mode is adopted at the outer side near the cylinder sleeve upper flange to form an external cooling oil channel, the area of an outer ring cooling oil channel is increased, the special shape is utilized to guide the water flow cooling direction, the cooling of the outer side of the cylinder sleeve is enhanced, the temperature of the inner side of the cylinder sleeve close to a combustion chamber is reduced, and therefore the purposes of reducing abrasion, enhancing cooling and prolonging the service life of an engine are; however, in the diesel engine for the vehicle, because of the limitation of the arrangement space, the strength of the cylinder sleeve can be greatly weakened by enlarging the cooling oil passage, and the diesel engine is not suitable for the vehicle engine with the explosion pressure exceeding 200bar and only suitable for the industrial engine with larger cylinder center distance.

The second solution is to carry on the whole spraying wear-resisting coating to the internal surface of cylinder liner, reference [2] (publication No. CN 107130204A) has disclosed a kind of wear-resisting coating cylinder liner and its preparation method, prepare the tungsten carbide wear-resisting coating with thickness of 0.2-0.4mm in the whole working surface of the cylinder inner wall, the said preparation method needs to carry on the whole spraying to the cylinder liner and reserves the relatively large machining allowance, may even cause the reduction of the effective wall thickness of the cylinder or space size to increase; meanwhile, the spraying area and the spraying depth of the inner surface of the cylinder sleeve are large, so that the requirements on process equipment are high, the process cost is high, and the uniformity of a coating is not easy to control; the nickel-based tungsten carbide has complex components and high hardness, is unfavorable for wear of a piston ring, and has high cost of a full-area honing process due to the difficulty of honing and machining.

The third solution is to introduce lubricating oil into the working surface of the cylinder liner to make the distribution of the lubricating oil on the surface more uniform and sufficient, thereby achieving the purpose of reducing wear, and reference [3] (publication No. CN 208347943U) discloses a sealed cylinder liner with lubricating oil holes, wherein a supporting shoulder and an upper waistband are formed on the outer wall of the upper end surface of the cylinder liner body, a water sealing ring groove is formed between the supporting shoulder and the upper waistband, and an oil inlet channel extending along the side wall of the cylinder liner body is formed inside the side wall of the cylinder liner body, and the oil inlet channel is respectively provided with an oil inlet communicated with the outer surface of the cylinder liner body and an oil outlet communicated with the inner surface of the cylinder liner body, so that the distribution of the lubricating oil is more uniform, and the lubricating effect is more stable. The technical scheme of reference [3] is that engine oil is introduced to the working surface of the cylinder sleeve through a lubricating oil passage to enhance the distribution of lubricating oil on the working surface of the cylinder sleeve and enhance the lubrication to achieve the purpose of reducing the abrasion of the cylinder sleeve; however, the solution has a complex structure, the oil passage needs to be processed in the wall thickness range of the cylinder sleeve, the processing cost is high, and the processing technology is difficult to realize mass production when the diameter of the oil passage is limited by space and is generally below 5 mm.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a diesel engine cylinder jacket is applicable to the heavy-duty car diesel engine of low viscosity machine oil to solve current cylinder jacket processing complicacy, problem with high costs.

To achieve the purpose, the utility model adopts the following technical proposal:

the utility model discloses only have the coating in the top dead center region of cylinder jacket.

Optionally, the liner inner surface is prepared in the coating region with a depth region of coating thickness and height.

Optionally, the coating is 10-15 mm from the top surface of the cylinder liner, the coating is 20-30 mm wide and 0.3-0.4 mm thick.

Preferably, the coating is 10 mm from the top surface of the cylinder liner, the height of the coating is 20 mm, and the thickness of the coating is 0.3 mm.

Preferably, the coating is 15mm from the top surface of the cylinder liner, the height of the coating is 30mm, and the thickness of the coating is 0.4 mm.

Preferably, the coating is 10 mm from the top surface of the cylinder liner, the height of the coating is 25 mm, and the thickness of the coating is 0.3 mm.

Optionally, the coating surface is flush with the liner inner surface.

Optionally, the coating is a molybdenum coating or a molybdenum alloy coating, the porosity is 1.5-2%, and the Vickers hardness of the coating is 400-600HV 0.1.

The utility model has the advantages that:

1. the utility model discloses carry out subregion to cylinder jacket working surface and handle, only prepare the coating in the top dead center region, avoided the problem of the regional internal surface coating degree of consistency control difficulty, reduced the scuffing of cylinder risk.

2. The utility model provides a cylinder jacket, because only carry out spraying treatment to wearing and tearing great top dead center region, reduced the rejection rate and the spraying cost of product, when porosity and wear resistance reduce by a wide margin than the full coat scheme, the life of cylinder jacket, wearing and tearing volume all do not have obvious reduction.

3. In the aspect of the honing, because the utility model discloses the molybdenum coating of selection and the machining performance of molybdenum alloy coating are excellent, need not to adopt independent honing process, still adopt platform honing process mode, compare with the cylinder jacket of the tungsten carbide coating spraying among the prior art, processing cost and complexity also reduce by a wide margin.

4. The utility model discloses select the design with coating area to the position of coating region, fully considered wearing and tearing volume, cost and life. The top dead center area is a key area influencing the abrasion loss and the service life; too large a coating area will increase the wear of the piston ring, too small a coating area will not achieve satisfactory lubrication effect, and the service life will be affected.

Drawings

Fig. 1 is a schematic position diagram of a preprocessing depth area on a cylinder liner of a diesel engine of the present invention.

Fig. 2 is a schematic diagram of the position of the coating region on the cylinder liner of the diesel engine of the present invention.

In the figure:

1. a cylinder liner; 2. a depth region; 3. and (4) coating molybdenum.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The utility model provides a diesel engine cylinder jacket is applicable to the heavy automobile-used diesel engine of low viscosity machine oil. According to the operation condition of the piston ring, the cylinder sleeve can be divided into three areas, namely a firepower bank area, a top dead center area and a hydraulic lubrication area, wherein the top dead center area is the area where the cylinder sleeve is worn most seriously, the maximum wear loss of the cylinder sleeve is achieved, and the wear loss in other areas is only 10-15% of the maximum wear loss. Reducing the amount of wear in the top dead center region is therefore an important task to reduce the overall wear of the cylinder liner.

The utility model discloses a reduce the maximum wearing and tearing volume of cylinder jacket the top dead center region carry out local coating and handle, adopt high-speed flame spraying, high-speed plasma spraying or electric arc spraying technology to prepare molybdenum coating or molybdenum alloy coating in the top dead center region. The coating is 10-15 mm away from the top surface of the cylinder sleeve, the height of the coating is 20-30 mm, and the thickness of the coating is 0.3-0.4 mm. Because a depth area is preprocessed at the position of the inner surface of the cylinder sleeve where the coating needs to be prepared, the prepared coating is flush with the inner surface of the cylinder sleeve, the mechanical processing performance of the coating is excellent, and a platform honing process mode is still adopted without adopting a separate honing process.

Several embodiments of the diesel cylinder liner of the present invention are given below.

Example 1:

as shown in fig. 1, a depth zone 2 is prepared on the inner surface of a cylinder liner 1 where a molybdenum coating layer 3 is to be prepared. The upper end of the depth area 2 is 10 mm away from the top surface of the cylinder sleeve 1, the depth is 0.3 mm, and the width is 20 mm.

Then, carrying out high-speed flame molybdenum spraying treatment in the preprocessed depth area 2 to prepare a molybdenum coating 3; as shown in fig. 2, the molybdenum coating 3 fills the prefabricated depth zone 2.

And after the spraying is finished, carrying out honing processing on the inner surface of the cylinder sleeve 1 to obtain a finished product cylinder sleeve. In the finished cylinder sleeve, a molybdenum coating 3 is arranged at a position 10 mm away from the top surface of the cylinder sleeve 1, the depth of the molybdenum coating 3 is 0.3 mm, and the width of the molybdenum coating is 20 mm.

The prepared molybdenum coating 3 is tested, and the result shows that the porosity of the molybdenum coating 3 is 2%, and the Vickers hardness of the coating is 400-500HV 0.1. For the full internal surface tungsten carbide wear-resistant coating that the thickness that reference [2] (publication No. CN 107130204A) disclosed is 0.2-0.4mm, under same experimental conditions, the utility model provides a cylinder liner with local molybdenum coating's life does not have obvious reduction, can adapt to the adverse conditions of mixed lubrication, great reduction the wearing and tearing volume of piston ring and cylinder liner, make the life of piston ring obtain very big promotion under the operating condition of low viscosity oil. The utility model discloses well molybdenum coating wearability and oil storage performance all descend for reference [2], but do not influence the life of cylinder jacket, and molybdenum coating's machining performance is excellent moreover, consequently need not to adopt independent honing process, still adopts platform honing process mode, has reduced the honing complexity. Because the utility model only needs to coat the local area in the cylinder sleeve, the coating cost is greatly reduced; for the cylinder sleeve, the inner diameter allowance prepared by processing the coating in advance is not needed, and only a depth area with the same thickness as the coating needs to be processed on the local part of the cylinder sleeve, so the processing requirement on the cylinder sleeve is reduced, and the standardization is easier to realize.

Example 2:

referring to fig. 1, a depth zone 2 is prepared on the inner surface of a cylinder liner 1 where a molybdenum alloy coating layer 3 is to be prepared. The upper end of the depth area 2 is 15mm away from the top surface of the cylinder sleeve 1, the depth is 0.4mm, and the width is 30 mm.

Then, high-speed plasma spraying treatment is carried out in the preprocessed depth area 2 to prepare a molybdenum alloy coating; the molybdenum alloy coating fills the pre-machined depth zone 2. The molybdenum alloy coating is made of MoCrN or MoCrC alloy.

And after the spraying is finished, carrying out honing processing on the inner surface of the cylinder sleeve 1 to obtain a finished product cylinder sleeve. And a molybdenum alloy coating is arranged in the finished cylinder sleeve at a position 15mm away from the top surface of the cylinder sleeve 1, the depth of the molybdenum alloy coating is 0.4mm, and the width of the molybdenum alloy coating is 30 mm.

The prepared molybdenum alloy coating is tested, and the result shows that the porosity of the molybdenum alloy coating is 1.5%, and the Vickers hardness of the coating is 550-600HV 0.1. For reference [2], under same experimental condition, the utility model provides a cylinder jacket with local molybdenum alloy coating's life does not have obvious reduction, can adapt to the lubricated adverse conditions of mixed, great reduction the wearing and tearing volume of piston ring and cylinder liner, make the life of piston ring obtain very big promotion under the operating condition of low viscosity oil. The utility model discloses well molybdenum alloy coating's machining performance is excellent, has consequently reduced the honing complexity, has reduced the wearing and tearing volume to the piston ring. Because the utility model only needs to coat the local area in the cylinder sleeve, the coating cost is greatly reduced; for the cylinder sleeve, the inner diameter allowance prepared by processing the coating in advance is not needed, and only a depth area with the same thickness as the coating needs to be processed on the local part of the cylinder sleeve, so the processing requirement on the cylinder sleeve is reduced, and the standardization is easier to realize.

Example 3:

as shown in fig. 1, a depth zone 2 is prepared on the inner surface of a cylinder liner 1 to be prepared with a molybdenum coating. The upper end of the depth area 2 is 10 mm away from the top surface of the cylinder sleeve 1, the depth is 0.3 mm, and the width is 25 mm.

Then, carrying out high-speed flame molybdenum spraying treatment in the preprocessed depth area 2 to prepare a molybdenum coating; the molybdenum coating fills the pre-machined depth zone 2.

And after the spraying is finished, carrying out honing processing on the inner surface of the cylinder sleeve 1 to obtain a finished product cylinder sleeve. And a molybdenum coating is arranged in the finished cylinder sleeve at a position 10 mm away from the top surface of the cylinder sleeve 1, the depth of the molybdenum coating is 0.3 mm, and the width of the molybdenum coating is 25 mm.

The prepared molybdenum coating is tested, and the result shows that the porosity of the molybdenum coating is 2%, and the Vickers hardness of the coating is 400-550HV 0.1. For the full internal surface tungsten carbide wear-resistant coating that the thickness that reference [2] (publication No. CN 107130204A) disclosed is 0.2-0.4mm, under same experimental conditions, the utility model provides a cylinder liner with local molybdenum coating's life does not have obvious reduction, can adapt to the adverse conditions of mixed lubrication, great reduction the wearing and tearing volume of piston ring and cylinder liner, make the life of piston ring obtain very big promotion under the operating condition of low viscosity oil. The utility model discloses well molybdenum coating wearability and oil storage performance all descend for reference [2], but do not influence the life of cylinder jacket, and molybdenum coating's machining performance is excellent moreover, consequently need not to adopt independent honing process, still adopts platform honing process mode, has reduced the honing complexity. Because the utility model only needs to coat the local area in the cylinder sleeve, the coating cost is greatly reduced; for the cylinder sleeve, the integral machining allowance design is not needed, and only a depth area with the same thickness as the coating is needed to be machined on the existing thickness of the cylinder sleeve, so that the machining requirement on the cylinder sleeve is reduced, and the standardization is easier to realize; the whole performance of the cylinder sleeve is not affected.

The utility model forms a coating wear-resistant belt with a width of 20-30 mm in the top dead center area of the piston ring, the cylinder sleeve is greatly higher than the cylinder sleeve matrix and the platform reticulate pattern structure, and the service life of the engine B10 is prolonged; although slightly being less than the wearability and the oil storage nature of reference [2], but not have cylinder jacket life loss, also not have the wearing and tearing volume to increase, when the assurance performance does not descend, the utility model discloses still have low cost, promote the piston ring life-span, reduce the advantage of honing complexity, reduced the original processing requirement to the cylinder jacket, reduced the risk of drawing a jar.

It is obvious that the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, rearrangements and substitutions will now occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A cylinder liner for a diesel engine, characterized by a coating only in the top dead center region of the cylinder liner.

2. The cylinder liner for a diesel engine according to claim 1, characterized in that the coating is 10-15 mm from the top surface of the cylinder liner, 20-30 mm in height and 0.3-0.4 mm in thickness.

3. The cylinder liner for a diesel engine according to claim 1 or 2, characterized in that the coating is 10 mm from the top surface of the cylinder liner, 20 mm in height and 0.3 mm in thickness.

4. The cylinder liner for a diesel engine according to claim 1 or 2, characterized in that the coating is 15mm from the top surface of the cylinder liner, the coating has a height of 30mm and a thickness of 0.4 mm.

5. The cylinder liner for a diesel engine according to claim 1 or 2, characterized in that the coating is 10 mm from the top surface of the cylinder liner, the coating has a height of 25 mm and a thickness of 0.3 mm.

6. The diesel cylinder liner according to claim 1, characterized in that the coating surface is flush with the cylinder liner inner surface.

7. The diesel cylinder liner according to claim 1, characterized in that the liner inner surface is prepared in the coating region in a depth region of the coating thickness and height.

8. The cylinder liner for a diesel engine according to claim 1, characterized in that said coating is a molybdenum coating or a molybdenum alloy coating, and the porosity of the coating is 1.5-2%.

9. The diesel cylinder liner of claim 1, wherein said coating is prepared using a high velocity flame spray, a high velocity plasma spray, or an electric arc spray process.