Methanol injector valve ball, preparation method thereof, methanol injector and engine

Abstract

The invention relates to the technical field of engines, in particular to a methanol injector valve ball, a preparation method thereof, a methanol injector and an engine. The invention provides a methanol ejector valve ball. The methanol ejector valve ball comprises a valve ball body; the first coating is arranged on at least part of the outer surface of the valve ball body, and the material of the first coating comprises Cr; the second coating is arranged on at least part of the outer surface of the first coating, and the material of the second coating comprises CrN; the third coating is arranged on at least part of the outer surface of the second coating, and the material of the third coating comprises DLC. The methanol ejector comprises the methanol ejector valve ball. The problem of cavitation of the valve ball of the methanol injector can be effectively relieved, the sealing performance of the valve ball and the valve seat is improved, the leakage phenomenon of the methanol injector is reduced or avoided, and the service life of the methanol injector is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a methanol injector valve ball and a preparation method thereof, a methanol injector and an engine. Background Art

[0002] The engine is an important part of the car. Among them, the methanol engine uses methanol as the main fuel, which has the advantages of clean emissions and good economic performance. At present, methanol cars use the intake manifold multi-point injection technology solution, which has low methanol injection pressure and poor atomization, resulting in poor fuel economy and emissions. As users have higher and higher requirements for economy and emission regulations are becoming more and more stringent, the technological innovation of the methanol supply system is becoming more urgent. The direct injection technology has been verified in the field of gasoline engines, and has obvious effects on economy and emission improvement; for example, the technical route of gasoline engines has been improved from multi-point injection of the intake manifold to direct injection in the cylinder; compared with gasoline intake manifold injection engines, gasoline direct injection engines have the characteristics of low emissions and good fuel economy; gasoline injectors have been verified through actual bench tests, and gasoline injectors have no cavitation on the valve ball surface. Therefore, similarly, direct injection methanol engines are also a technical route with great development prospects.

[0003] However, methanol direct injection injectors work in a high-temperature and high-pressure environment. Due to the physical and chemical properties of methanol itself, the saturated vapor pressure is low. During the injection process of the injector, methanol fuel is prone to generate bubbles due to pressure changes. During the bubble bursting process, microjets and impact force are generated. The microjets and impact force destroy the surface characteristics of the valve ball. That is, the surface of the valve ball is easily cavitated, resulting in a poor seal between the valve ball and the valve seat, leading to leakage in the injector.

[0004] Therefore, how to solve the cavitation problem of the valve ball of the methanol injector, improve the sealing of the valve ball and valve seat, and reduce or avoid the leakage of the methanol injector is an important issue in the current research of the methanol injector system. Summary of the invention

[0005] In view of this, the present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present invention provides a methanol injector valve ball and a preparation method thereof, a methanol injector and an engine, which can alleviate the problem of easy cavitation on the surface of the methanol injector valve ball and reduce or avoid leakage of the methanol injector.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] According to a first aspect of the present application, an embodiment of the present application provides a methanol injector valve ball, the methanol injector valve ball comprising:

[0008] Valve ball body;

[0009] A first coating layer is disposed on at least a portion of the outer surface of the valve ball body, wherein the material of the first coating layer includes Cr;

[0010] A second coating layer is disposed on at least a portion of the outer surface of the first coating layer, wherein the material of the second coating layer comprises CrN;

[0011] The third coating layer is disposed on at least a portion of the outer surface of the second coating layer, and the material of the third coating layer includes DLC.

[0012] In addition, the methanol injector valve ball according to the present application may also have the following additional technical features:

[0013] In some embodiments, the thickness of the first coating layer is 0.1 μm to 2 μm.

[0014] In some embodiments, the second coating has a thickness of 0.1 μm to 2 μm.

[0015] In some embodiments, the third coating has a thickness of 1 μm to 6 μm.

[0016] In some embodiments, the hardness of the total coating consisting of the first coating, the second coating and the third coating is in the range of 2000 HV to 3000 HV.

[0017] According to a second aspect of the present application, an embodiment of the present application provides a method for preparing a methanol injector valve ball, the method comprising:

[0018] forming a first coating layer on at least a portion of the outer surface of the valve ball body, wherein the material of the first coating layer includes Cr;

[0019] forming a second coating layer on at least a portion of the outer surface of the first coating layer, wherein the material of the second coating layer includes CrN;

[0020] A third coating layer is formed on at least a portion of the outer surface of the second coating layer, wherein the material of the third coating layer includes DLC.

[0021] In some embodiments, the forming of the first coating specifically includes: in an inert gas atmosphere, using Cr as a target material, forming the first coating on at least a portion of the outer surface of the valve ball body by an arc ion plating process; wherein the gas pressure during the arc ion plating process is 0.2Pa~0.8Pa, the bias voltage is 220V~280V, the target current is 55A~75A, the deposition temperature is 200℃~250℃, and the arc ion plating time is 5h~8h.

[0022] In some embodiments, the forming of the second coating specifically includes: using pure chromium as a target material and nitrogen as a reaction gas, and forming the second coating on at least a portion of the outer surface of the first coating by an arc ion plating process; wherein, when implementing the arc ion plating process, the flow range of the nitrogen is 260sccm to 550sccm, the target current is 80A to 110A, and the arc ion plating time is 5h to 8h.

[0023] In some embodiments, the forming of the third coating specifically includes: in an inert gas atmosphere, using a carbon target as a target material, forming the third coating on at least a portion of the outer surface of the second coating by an arc ion plating process; wherein the gas pressure during the arc ion plating process is 0.3Pa~0.9Pa, the bias voltage is 220V~280V, the target current is 65A~80A, the deposition temperature is 220℃~250℃, and the arc ion plating time is 5h~8h.

[0024] In some of the embodiments, before forming the first coating, the method also includes: cleaning the methanol injector valve ball at least once, each cleaning time being 20 minutes to 30 minutes; drying the cleaned methanol injector valve ball; matching the coating tooling with the dried methanol injector valve ball, and then placing the coating tooling and the methanol injector valve ball into the coating preparation equipment together.

[0025] According to a third aspect of the present application, an embodiment of the present application provides a methanol injector, the methanol injector comprising the aforementioned methanol injector valve ball or a methanol injector valve ball prepared according to the previous method;

[0026] The methanol injector also includes a valve body, a valve seat and a valve stem; the valve body is provided with a valve cavity, the valve seat is fixed at one end of the valve body, and the valve seat is communicated with the valve cavity, and the valve seat is provided with an inner cavity for accommodating the methanol injector valve ball; the valve ball is fixedly connected to one end of the valve stem, and the valve stem and the valve ball are movably arranged in the valve cavity and the inner cavity respectively.

[0027] According to a fourth aspect of the present application, an embodiment of the present application provides an engine, which includes the aforementioned methanol injector.

[0028] Implementing the technical solution of the present invention has at least the following beneficial effects:

[0029] In an embodiment of the present application, a methanol injector valve ball body and a coating structure arranged on the surface of the valve ball body are provided, and the coating structure includes a first coating, a second coating and a third coating which are sequentially stacked on the outer surface of the valve ball body, wherein the material of the first coating includes Cr (chromium), the material of the second coating includes CrN (chromium nitride), and the material of the third coating includes DLC (diamond-like carbon). Therefore, by setting the above-mentioned coating structure, the corrosion resistance of the methanol injector valve ball can be improved, especially, the first coating made of Cr material not only has a strong bonding force with the valve ball body, but also has strong corrosion resistance; the second coating made of CrN material is set between the first coating and the third coating to play the role of a transition coating, which can improve the bonding force between the first coating and the third coating, reduce or avoid the phenomenon of shedding or peeling of the coating structure during use, which is not only beneficial to improving the overall structural stability of the coating structure, but also has certain corrosion resistance, chemical resistance and lubricity; the third coating made of DLC material not only has the characteristics of low stress, high adhesion, high toughness and high corrosion resistance, but also has certain corrosion resistance and chemical resistance to aqueous solutions, and has certain lubricity, which can further improve the corrosion resistance of the coating structure.

[0030] Therefore, through the coordinated arrangement of the above-mentioned first coating, second coating and third coating, the corrosion resistance of the methanol injector valve ball is improved, that is, the cavitation resistance of the methanol injector valve ball is improved, the cavitation problem of the methanol injector valve ball is effectively alleviated, the sealing of the valve ball and the valve seat is improved, the leakage of the methanol injector is reduced or avoided, and the durability of the methanol injector can be improved.

[0031] The methanol injector valve ball has been subjected to 800 hours of durability on the injector unit and 600 hours of durability on the engine bench. The engine and injector perform normally. The methanol injector is disassembled and no cavitation is observed on the valve ball.

[0032] Additional aspects and advantages of the present application will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Shown is a structural schematic diagram of a methanol injector provided by an embodiment of the present invention;

[0034] Figure 2 Shown is a structural schematic diagram of a methanol injector valve ball and valve stem provided by an embodiment of the present invention;

[0035] Figure 3 Shown is a schematic structural diagram of a coating structure of a methanol injector valve ball provided by an embodiment of the present invention;

[0036] Figure 4The figure shows a scanning electron microscope image of a coating structure on the surface of a methanol injector valve ball provided by an embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of disassembling a methanol injector and observing that there is no cavitation on the valve ball surface provided by an embodiment of the present invention;

[0038] Figure 6 The figure is a schematic diagram of the cavitation phenomenon of the valve ball of the methanol injector in the prior art;

[0039] Figure 7 Shown Figure 6 A partial enlarged schematic diagram of the .

[0040] Description of reference numerals:

[0041] 10-methanol injector valve ball (valve ball); 101-valve ball body;

[0042] 110-first coating; 120-second coating; 130-third coating;

[0043] 20-valve stem;

[0044] 30-valve seat;

[0045] 40-valve body;

[0046] 50-return spring;

[0047] 60-Electromagnetic drive component. DETAILED DESCRIPTION

[0048] The present application is further described below in conjunction with specific embodiments. It should be understood that these embodiments of the present application are only used to illustrate the present application and are not used to limit the scope of the present application.

[0049] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range or the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0050] Hereinafter, the methanol injector valve ball, the method for preparing the methanol injector valve ball, the methanol injector and the engine, etc. of the present application will be specifically disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0051] If there is no special description, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. If there is no special description, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0052] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0053] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0054] In the related art, direct injection of methanol can significantly improve engine economy and emissions, and significantly improve engine cold start performance. However, due to the low saturated vapor pressure of methanol, the high temperature and high pressure working environment of methanol direct injection injector causes methanol to generate bubbles during the injection process. The bubbles burst with pressure changes, causing cavitation on the injector valve ball, destroying the surface features of the injector valve ball (such as Figure 6 to Figure 7 As shown), the seal between the injector valve ball and the valve seat is affected, and in severe cases, the injector leaks. In addition, there is currently no methanol direct injection injector in the world, and a methanol direct injection injector specifically adapted to the cylinder needs to be developed. Therefore, the present invention discloses a high-pressure methanol injector valve ball to effectively alleviate the above-mentioned problems. In view of this, the present application provides a methanol injector valve ball and a preparation method thereof, a methanol injector and an engine, and the present application is described in detail below.

[0055] See also Figures 1 to 4 As shown, in some embodiments, the present application provides a methanol injector valve ball 10, and the methanol injector valve ball 10 includes:

[0056] Valve ball body 101;

[0057] A first coating 110 is disposed on at least a portion of the outer surface of the valve ball body 101, wherein the material of the first coating 110 includes Cr;

[0058] A second coating 120, disposed on at least a portion of the outer surface of the first coating 110, wherein the material of the second coating 120 includes CrN;

[0059] The third coating layer 130 is disposed on at least a portion of the outer surface of the second coating layer 120 , and the material of the third coating layer 130 includes DLC.

[0060] In the present application, the methanol injector valve ball 10 includes a valve ball body 101, and also includes a coating structure arranged on the valve ball body 101, the coating structure including a first coating 110, a second coating 120 and a third coating 130 sequentially stacked on the outer surface of the valve ball body 101. In the methanol injector valve ball 10 (also referred to as a valve ball) of this embodiment, the coating structure can be divided into at least three layers, and the coating material types of each layer are different. Among them, the material of the first coating 110 includes Cr (chromium), the material of the second coating 120 includes CrN (chromium nitride), and the material of the third coating 130 includes DLC (diamond-like carbon).

[0061] The first coating 110 is disposed on at least part of the outer surface of the valve ball body 101, which means that the first coating 110 can cover a part of the outer surface of the valve ball body 101, or completely cover the entire outer surface of the valve ball body 101; preferably, the first coating 110 completely covers the entire outer surface of the valve ball body 101. The second coating 120 is disposed on at least part of the outer surface of the first coating 110, which means that the second coating 120 can cover a part of the outer surface of the first coating 110, or completely cover the entire outer surface of the first coating 110; preferably, the second coating 120 completely covers the entire outer surface of the first coating 110. The third coating 130 is disposed on at least part of the outer surface of the second coating 120, which means that the third coating 130 can cover a part of the outer surface of the second coating 120, or completely cover the entire outer surface of the second coating 120; preferably, the third coating 130 completely covers the entire outer surface of the second coating 120.

[0062] It should be understood that the valve ball provided can be used in a methanol injector, in which the valve ball and the valve seat 30 can be used in conjunction with each other, the valve seat 30 has a spray hole for injecting fuel, and the valve ball and the inner cavity of the valve seat 30 can be used to open or close the spray hole. For example, in different use states, the spray hole is connected or disconnected with the valve cavity of the methanol injector, and the movement of the valve ball can be controlled to connect or disconnect the spray hole with the valve cavity of the methanol injector.

[0063] After extensive research, the inventors of this application have discovered that conventional methods such as optimizing the valve ball material composition, heat treating the valve ball material surface, optimizing the valve ball shape structure, and adding traditional coatings to the valve ball surface in the prior art cannot completely solve the cavitation problem on the valve ball surface; more effective technical means are needed to solve this problem. Therefore, the inventors of this application have developed a coating structure specifically for methanol injector valve balls to address the cavitation problem of methanol injector valve balls. The coating structure has high hardness, strong bonding force, and strong cavitation resistance, in order to fundamentally solve the cavitation problem of the spray hole. In detail:

[0064] In the embodiment of the present application, in the provided methanol injector valve ball 10, a coating structure is arranged on the surface of the valve ball body 101, and the coating structure includes a first coating 110, a second coating 120 and a third coating 130 which are sequentially stacked on the outer surface of the valve ball body 101, wherein the material of the first coating 110 includes Cr (chromium), the material of the second coating 120 includes CrN (chromium nitride), and the material of the third coating 130 includes DLC (diamond-like carbon); the above-mentioned first coating 110 can be used as a base layer, the second coating 120 can be a transition layer (intermediate transition layer or bonding layer), and the third coating 130 can be used as a functional layer; that is, the coating structure is a Cr-CrN-DLC coating, Cr is a base layer, CrN is a transition layer or bonding layer, and the DLC coating is a functional layer. Among them, based on the structure or application characteristics of the valve ball, the first coating 110 made of Cr material is used as the base layer, which not only has a strong bonding force with the valve ball body 101, but also has strong corrosion resistance; the third coating 130 made of DLC material is used as the functional layer, which not only has the characteristics of low stress, high adhesion, high toughness, and high corrosion resistance, but also has certain corrosion resistance and chemical resistance to aqueous solutions, and has certain lubricity, which can further enhance the corrosion resistance and wear resistance of the coating structure. Furthermore, the present application not only sets up the first coating 110 and the third coating 130, but also sets up the second coating 120 between the first coating 110 and the third coating 130. The second coating 120 is made of CrN material and can be used as a transition layer or a bonding layer. By using the second coating 120 made of CrN material as a transition layer or a bonding layer, the overall consistency (integration) of the coating structure can be improved. That is, the second coating 120 made of CrN material can enhance the bonding force between the first coating 110 and the third coating 130, improve the close contact performance between the coatings, reduce or avoid the phenomenon of shedding or peeling of the coating structure during use, and is not only beneficial to improving the overall structural stability of the coating structure, but also has certain corrosion resistance, chemical resistance and lubricity.

[0065] Thus, by the coordinated arrangement of the first coating 110, the second coating 120 and the third coating 130, the porosity of the coating structure can be lowered, the density and crystallinity of the coating structure can be improved, the internal residual stress of the coating structure can be reduced, and the corrosion resistance of the coating structure can be improved. In addition, the first coating 110, the second coating 120 and the third coating 130 provided are coordinated and arranged according to the application characteristics, structural characteristics, etc. of the methanol injector valve ball.

[0066] Furthermore, the present invention aims at the characteristics of the methanol injector valve ball and provides a methanol injector valve ball 10. Through the coordinated arrangement of the above-mentioned first coating 110, second coating 120 and third coating 130, the corrosion resistance of the methanol injector valve ball 10 is improved, that is, the anti-cavitation ability of the methanol injector valve ball 10 is improved, the cavitation problem of the methanol injector valve ball 10 is effectively alleviated, the sealing of the valve ball and the valve seat 30 is improved, the leakage of the methanol injector is reduced or avoided, and the durability of the methanol injector can be improved. Moreover, the methanol injector valve ball 10 has been tested for 800 hours of durability on the injector monomer and 600 hours of durability on the engine bench. The engine and injector performance are normal, such as Figure 5 As shown, the methanol injector is disassembled and observed that the valve ball has no cavitation phenomenon. Therefore, the performance of the methanol injector valve ball 10 provided in the present application meets the design requirements and meets the use requirements.

[0067] It should be pointed out that in the present application, the methanol injector includes a methanol injector valve ball 10, which can be movably arranged in the inner cavity of the valve seat 30 of the methanol injector, and the methanol injector valve seat 30 is provided with a spray hole, and the valve ball can be used to open or close the spray hole. When the spray hole is opened, the methanol injector can spray high-pressure fuel spray through the spray hole. Although this embodiment is proposed based on the technical defect that bubbles are easily generated during the methanol fuel injection process, which leads to damage to the surface characteristics of the injector valve ball and easily causes cavitation of the valve ball of the methanol injector, the methanol injector valve ball 10 of this embodiment can be applied to methanol direct injection injectors, and can also be applied to other injectors using methanol as fuel or injectors using other fuels, and this embodiment does not limit this.

[0068] It should also be pointed out that the diameter range of the methanol injector valve ball 10 can be designed according to actual needs, and this embodiment does not impose any limitation on this.

[0069] In some embodiments, the thickness of the first coating 110 is 0.1 μm to 2 μm. As an example, the thickness of the first coating 110 can be any one of 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, and 2 μm, or a range of any two thereof.

[0070] If the thickness of the first coating 110 is too thin, it cannot effectively improve the corrosion resistance of the valve ball surface, and the bonding effect between the valve ball body 101 and the first coating 110 will be reduced; if the thickness of the first coating 110 is too thick, the cost will increase and the sealing effect may be affected. Therefore, by controlling the thickness of the first coating 110 within the above range, it is not only convenient for processing and cost saving, but also can make the application effect of the first coating 110 better and meet the anti-cavitation performance.

[0071] In some embodiments, the thickness of the second coating 120 is 0.1 μm to 2 μm. As an example, the thickness of the second coating 120 can be any one of 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, or any range therebetween.

[0072] If the thickness of the second coating 120 is too thin, it cannot effectively improve the corrosion resistance of the valve ball surface, and the bonding effect between the first coating 110 and the third coating 130 will be reduced; if the thickness of the first coating 110 is too thick, the cost will increase and the sealing effect may be affected. Therefore, by controlling the thickness of the second coating 120 within the above range, it is not only convenient for processing and cost saving, but also can make the application effect of the second coating 120 better and meet the anti-cavitation performance.

[0073] In some embodiments, the thickness of the third coating 130 is 1 μm to 6 μm. As an example, the thickness of the third coating 130 can be any one of 1 μm, 1.2 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, and 6 μm, or a range of any two thereof.

[0074] If the thickness of the third coating 130 is too thin, it cannot effectively improve the corrosion resistance of the valve ball surface; if the thickness of the third coating 130 is too thick, it will increase the cost and affect the sealing effect of the valve ball. Therefore, by controlling the thickness of the third coating 130 within the above range, it is not only convenient for processing and cost saving, but also can make the application effect of the third coating 130 better and meet the anti-cavitation performance.

[0075] In some embodiments, the hardness of the total coating composed of the first coating 110, the second coating 120 and the third coating 130 ranges from 2000 HV to 3000 HV. As an example, the hardness of the coating can be any one of 2000 HV, 2200 HV, 2500 HV, 2800 HV, and 3000 HV, or a range between any two of them.

[0076] The higher the hardness of the coating structure on the surface of the methanol injector valve ball 10, the less likely it is to be damaged when impacted. If the hardness is too high, the surface of the methanol injector valve ball 10 will be more brittle and will be easily damaged when impacted. In addition, too high hardness will also reduce the anti-friction and wear resistance of the coating. Therefore, by making the hardness range of the coating between 2000HV and 3000HV, it is beneficial to make the hardness of the coating structure moderate, avoid defects caused by too high or too low hardness, and improve the anti-friction and wear resistance of the coating, and improve the durability of the coating structure.

[0077] Therefore, based on the above settings, in order to effectively alleviate the cavitation problem on the surface of the methanol injector valve ball 10, the present invention specifically develops a valve ball suitable for the methanol injector. In addition, in view of the fact that the methanol injector valve ball 10 is frequently subjected to the cavitation impact force of methanol under high temperature and high pressure, the traditional PVD (physical vapor deposition) and CVD (chemical vapor deposition) coatings cannot solve the valve ball cavitation problem. The inventor of the present application specifically develops a special coating structure for the injector valve ball, that is, the first coating 110 of Cr material, the second coating 120 of CrN material and the third coating 130 of DLC material, so as to effectively alleviate the cavitation problem of the methanol injector valve ball 10.

[0078] The methanol injector valve ball 10 provided by the present invention is provided with a coating structure (such as a Cr-CrN-DLC coating structure) on the outer surface of the valve ball body 101, and a first coating 110 made of Cr, a second coating 120 made of CrN and a third coating 130 made of DLC are used in combination, wherein the thickness of the first coating 110 is 0.1μm to 2μm, the thickness of the second coating 120 is 0.1μm to 2μm, the thickness of the third coating 130 is 1μm to 6μm, the process temperature is 150 to 250°C, the control valve ball deformation is less than 0.01mm, the coating hardness is 2000 to 3000HV, the coating working temperature is less than 320°C, and the friction coefficient with stainless steel is less than 0.1. After experimental verification, the methanol injector valve ball 10 has been tested for 800H durability on the injector monomer and 600H durability on the engine bench, the engine and injector performance are normal, and the injector sealing is tested to be leak-free. Figure 5 As shown, the methanol injector is disassembled and observed that the valve ball has no cavitation phenomenon, so the performance of the methanol injector valve ball 10 provided meets the design requirements and meets the use needs.

[0079] Accordingly, in some embodiments, the present application provides a method for preparing a methanol injector valve ball 10, the method comprising the following steps:

[0080] A first coating layer 110 is formed on at least a portion of the outer surface of the valve ball body 101, wherein the material of the first coating layer 110 includes Cr;

[0081] forming a second coating layer 120 on at least a portion of the outer surface of the first coating layer 110, wherein the material of the second coating layer 120 includes CrN;

[0082] The third coating layer 130 is formed on at least a portion of the outer surface of the second coating layer 120 , and the material of the third coating layer 130 includes DLC.

[0083] The preparation method of the methanol injector valve ball 10 provided in this embodiment can first form a first coating 110 on the outer surface of the valve ball body 101, then form a second coating 120 on the surface of the first coating 110, and then form a third coating 130 on the surface of the second coating 120. The preparation method provided in the embodiment of the present invention has simple process, convenient operation, strong feasibility, and is easy to realize industrialization.

[0084] It should be understood that all the features and advantages described above for the “methanol injector valve ball 10 ” are also applicable to the “method for preparing the methanol injector valve ball 10 ” and will not be described in detail here.

[0085] In some specific embodiments, the preparation method of the methanol injector valve ball 10 specifically includes the following steps (a) to (e):

[0086] (a) Preprocessing.

[0087] In step (a), before preparing the first coating 110, the methanol injector valve ball 10 is pretreated, specifically including: cleaning the valve ball body 101 of the methanol injector valve ball 10 at least once, each cleaning time being 20 minutes to 30 minutes; drying the cleaned valve ball body 101; matching the coating tooling with the dried methanol injector valve ball 10, and then placing the coating tooling and the methanol injector valve ball 10 into the coating preparation equipment together.

[0088] In the present application, it should be noted that a valve ball body 101 may be provided first, such as a valve ball seat base material may be used to make the valve ball body 101. The valve ball body 101 may be manufactured by a conventional manufacturing method, and this embodiment does not limit this. In addition, this embodiment does not limit the specific material of the valve ball body 101, and the valve ball body 101 material commonly used in the relevant field may be used.

[0089] Optionally, in step (a), the valve ball body 101 of the methanol injector valve ball 10 is first cleaned, such as by ultrasonic cleaning. As an example, the valve ball body 101 of the methanol injector valve ball 10 can be ultrasonically cleaned, and the valve ball body 101 is placed in a cleaning chamber and ultrasonically cleaned once or multiple times, wherein the cavitation effect, acceleration effect, and straight-forward flow effect of ultrasound in the liquid directly and indirectly act on the liquid and dirt, so that the dirt layer is dispersed, emulsified, and peeled off to achieve the purpose of cleaning the valve ball. In this embodiment, the valve ball body 101 is ultrasonically cleaned twice, each time for 20 to 30 minutes, and then dried.

[0090] Optionally, in step (a), after the valve ball is cleaned and dried, the valve ball is placed in a coating tool, and then the coating tool and the methanol injector valve ball 10 are placed together in a coating preparation device (such as a coating furnace).

[0091] By installing the valve ball into the coating tooling, the remaining methanol injector parts except the valve ball can be prevented from being coated, thereby avoiding affecting the working performance of the remaining parts of the methanol injector.

[0092] (b) Preparing a first coating layer 110 .

[0093] In step (b), a first coating 110 is formed on the outer surface of the pre-treated valve ball body 101 .

[0094] Optionally, in step (b), before forming the first coating 110, step (b) also includes a vacuuming step, that is, after placing the coating tooling and the methanol injector valve ball 10 together in the coating preparation equipment (such as a coating furnace), vacuuming is required. Specifically, after closing the furnace chamber, turn on the rotary vane vacuum pump, wait for the air pressure in the furnace to drop below 12Pa, start the molecular pump, further pump the air pressure to the ultimate vacuum degree, and maintain the ultimate vacuum environment for a period of time to remove the air in the furnace to the maximum extent. Vacuuming helps to improve the density of the coating and reduce the porosity of the coating.

[0095] In the present application, in step (b), forming the first coating 110 specifically includes: in an inert gas atmosphere, using Cr as a target material, forming the first coating 110 on at least a portion of the outer surface of the valve ball body 101 by an arc ion plating process; wherein, the gas pressure during the arc ion plating process is 0.2Pa~0.8Pa, the bias voltage is 220V~280V, the target current is 55A~75A, the deposition temperature is 200℃~250℃, and the arc ion plating time is 5h~8h.

[0096] Optionally, the inert gas may be argon (Ar). Of course, in other embodiments, other rare gases such as neon and helium may also be used as inert gases, that is, as protective gases.

[0097] In the present application, the preparation method of the first coating 110 is preferably arc ion plating, and the conditions of the arc ion plating include: introducing an inert gas such as Ar into a vacuum chamber, and under an inert gas such as Ar atmosphere, the pressure is 0.2Pa~0.8Pa (such as 0.2Pa, 0.3Pa, 0.4Pa, 0.5Pa, 0.6Pa, 0.7Pa, 0.8Pa, etc.), which can prevent the coating from being oxidized and nitrided; adjusting the bias voltage to 220V~280V, preferably Preferably, the bias voltage is reduced to 230V; the target (Cr target) current is 55A-75A (such as 55A, 58A, 60A, 62A, 65A, 68A, 70A, 75A, etc.), the process temperature is 200°C-250°C (such as 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, etc.), and the arc ion plating treatment time is 5h-8h (such as 5h, 6h, 6.5h, 7h, 7.5h, 8h, etc.). Preferably, the thickness of the formed first coating 110 is 0.1μm-2μm.

[0098] It should be pointed out that the specific operation method of preparing the first coating 110 by arc ion plating can adopt the conventional arc ion plating operation method, which will not be described in detail here; except for the arc ion plating operation conditions specified above, the remaining operation conditions can be selected and set according to actual conditions, and this embodiment does not limit this.

[0099] Therefore, by controlling the operating conditions of the arc ion plating within the above range, the first coating 110 can be made to have a strong bonding force with the valve ball body 101 and the Cr coating itself has a strong corrosion resistance, which is beneficial to improving the corrosion resistance of the valve ball. In addition, by plating in an Ar atmosphere, the coating can be prevented from being oxidized and nitrided.

[0100] (c) Preparing the second coating layer 120.

[0101] In some embodiments, in step (c), a second coating 120 is formed on the surface of the first coating 110, specifically comprising: using pure chromium as a target material and nitrogen (N2) as a reaction gas, and forming the second coating 120 on at least a portion of the outer surface of the first coating 110 by an arc ion plating process; wherein the flow rate range of nitrogen during the arc ion plating process is 260sccm to 550sccm, the target current is 80A to 110A, and the arc ion plating time is 5h to 8h.

[0102] Optionally, the mass purity of the above-mentioned pure chromium target is not less than 99.9%.

[0103] In the present application, the preparation method of the second coating 120 is preferably arc ion plating, and the conditions of the arc ion plating include: using a pure chromium target as a target material, the target (pure chromium target) current is 80A to 110A (such as 80A, 85A, 90A, 95A, 100A, 105A, 110A, etc.), the flow rate of the reaction gas N2 changes linearly with time in the range of 260sccm to 550sccm, preferably in the range of 260sccm to 510sccm (such as 260sccm, 380sccm, 300sccm, 350sccm, 380sccm, 400sccm, 450sccm, 500sccm, 510sccm, 550sccm, etc.), and the processing time of the arc ion plating is 5h to 8h (such as 5h, 6h, 7h, 8h, etc.). Preferably, the thickness of the formed second coating 120 is 0.1μm to 2μm.

[0104] It should be pointed out that the specific operation method of preparing the second coating 120 by arc ion plating can adopt the conventional arc ion plating operation method, which will not be described in detail here; except for the arc ion plating operation conditions specified above, the remaining operation conditions can refer to the preparation of the first coating 110 or be selected and set according to actual conditions, and this embodiment does not limit this.

[0105] Thus, by controlling the operating conditions of arc ion plating within the above range, the obtained second coating 120 can have the characteristics of low stress, high adhesion, high toughness, high corrosion resistance, etc., and has corrosion resistance and chemical resistance to aqueous solutions, and has a certain lubricity, and the second coating 120 can improve the close contact performance between each coating.

[0106] (d) Preparing the third coating layer 130.

[0107] In some embodiments, in step (d), a third coating 130 is formed on the surface of the second coating 120, specifically comprising: in an inert gas atmosphere, using a carbon target as a target material, and forming the third coating 130 on at least a portion of the outer surface of the second coating 120 by an arc ion plating process; wherein the gas pressure during the arc ion plating process is 0.3Pa~0.9Pa, the bias voltage is 220V~280V, the target current is 65A~80A, the deposition temperature is 220℃~250℃, and the arc ion plating time is 5h~8h.

[0108] In the present application, the preparation method of the third coating 130 is preferably arc ion plating, and the conditions of the arc ion plating include: in an inert gas such as Ar atmosphere, the pressure is 0.3Pa~0.9Pa (such as 0.3Pa, 0.4Pa, 0.5Pa, 0.6Pa, 0.7Pa, 0.8Pa, 0.9Pa, etc.), which can prevent the coating from being oxidized and nitrided; the bias voltage is adjusted to 220V~280V, and preferably, the bias voltage is reduced to 250V; the target (carbon target) current is 65A~80A (such as 65A, 68A, 70A, 72A, 75A, 78A, 80A, etc.), the process temperature is 220℃~250℃ (such as 220℃, 230℃, 240℃, 250℃, etc.), and the arc ion plating processing time is 5h~8h (such as 5h, 6h, 6.5h, 7h, 7.5h, 8h, etc.). Preferably, the thickness of the formed third coating layer 130 is 1 μm to 6 μm.

[0109] Optionally, during the preparation of the third coating 130 , the inert gas may be an inert gas such as Ar atmosphere.

[0110] It should be pointed out that the specific operation method of preparing the third coating 130 by arc ion plating can adopt the conventional arc ion plating operation method, which will not be described in detail here; except for the arc ion plating operation conditions specified above, the remaining operation conditions can refer to the preparation of the first coating 110 and the second coating 120 mentioned above or be selected and set according to actual conditions, and this embodiment does not limit this.

[0111] Therefore, by controlling the operating conditions of the arc ion plating within the above range, the third coating 130 can be made to have stronger corrosion resistance, wear resistance and other properties, which is beneficial to improving the anti-cavitation ability of the valve ball.

[0112] In the present application, the hardness of each of the above coatings, such as the first coating 110 , the second coating 120 , or the third coating 130 , can be adjusted by adjusting the bias voltage, thereby adjusting the hardness of the entire coating structure.

[0113] (e) Turn off all power supplies, ion sources and gas sources, and the coating preparation is completed.

[0114] Therefore, the coating structure obtained by the above method has low porosity, improves the density and crystallinity of the coating structure, reduces the internal residual stress of the coating structure, and improves the corrosion resistance of the coating structure.

[0115] In some embodiments, the present application provides a methanol injector, which includes the methanol injector valve ball 10 as described above or the methanol injector valve ball 10 manufactured according to the aforementioned method.

[0116] Optionally, the methanol injector may be a methanol direct injection injector.

[0117] The methanol injector provided by the present application solves the problem of easy cavitation of the valve ball in the methanol injector in the related art. Compared with the prior art, the methanol injector provided by the embodiment of the present invention has the same beneficial effects as the methanol injector valve ball 10 of the above embodiment, which will not be described in detail here.

[0118] Further, the methanol injector further includes a valve body 40, a valve seat 30 and a valve stem 20; that is, the methanol injector may include a methanol injector valve ball 10, a valve body 40, a valve seat 30 and a valve stem 20. The valve body 40 is provided with a valve cavity, the valve seat 30 is fixed at one end of the valve body 40, and the valve seat 30 is connected to the valve cavity, and the valve seat 30 is provided with an inner cavity for accommodating the methanol injector valve ball 10; the valve ball is fixedly connected to one end of the valve stem 20, and the valve stem 20 and the valve ball are movably arranged in the valve cavity and the inner cavity, respectively.

[0119] It should be pointed out that the core of the methanol injector is the methanol injector valve ball 10 provided in the embodiment of the present application. The present application does not limit the specific structure and connection settings of the remaining structures in the methanol injector, such as the valve body 40, valve seat 30, etc., and reference may be made to relevant prior arts.

[0120] As an example, the methanol injector may also include structures such as a return spring 50 and an electromagnetic drive 60. The valve seat 30 is fixed at one end of the valve body 40, the valve body 40 is provided with a valve cavity, the valve cavity is filled with fuel, the valve seat 30 is connected to the valve cavity, the valve stem 20 is movably arranged in the valve cavity, the valve ball 10 is fixed at the end of the valve stem 20, and the valve ball 10 is movably arranged in the valve seat 30, that is, the valve ball 10 is movable in the valve seat 30. The above-mentioned return spring 50 is fixed in the valve cavity and connected to the top of the valve stem 20, and the return spring 50 is in a compressed state. The electromagnetic drive 60 is fixed on the valve body 40 and connected to the valve stem 20, and the valve stem 20 can be driven to move up and down along the valve cavity through the electromagnetic drive 60.

[0121] Initial position of the valve ball 10: the valve ball 10 abuts against the bottom wall of the inner cavity of the valve seat 30 and cooperates with the spray hole to prevent the fuel from passing through the spray hole. When the methanol injector needs to inject fuel, the methanol injector drives the valve stem 20 to move upward along the valve cavity through the electromagnetic drive 60, and the valve ball 10 follows the valve stem 20 to move upward and away from the bottom wall, and the fuel is sprayed into the combustion chamber through the spray hole; when the methanol injector does not need to inject fuel, the electromagnetic drive 60 stops working, the return spring 50 stretches and drives the valve stem 20 to move downward along the valve cavity, and the valve ball 10 follows the valve stem 20 to move downward until it abuts against the bottom wall and cooperates with the spray hole to prevent the fuel from passing through the spray hole.

[0122] In some embodiments, the present application also provides an engine (not shown), which includes the methanol injector as described above.

[0123] It should be understood that, in addition to the aforementioned methanol injector, the engine also includes other conventional structural components. The embodiment of the present application does not limit the remaining structure of the engine and its connection settings, etc. For details, please refer to the prior art and will not be repeated here.

[0124] The methanol injector valve ball 10, the preparation method of the methanol injector valve ball 10, the methanol injector and the engine provided in the embodiments of the present invention are suitable for methanol fuel, which can not only improve the corrosion resistance and wear resistance of the methanol injector valve ball 10, but also help to improve the reliability of the methanol injector and the engine.

[0125] Parts of the present invention that are not described in detail are well known to those skilled in the art.

[0126] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and facilitation of understanding, rather than limitation, and the above details do not limit the present invention to being implemented by adopting the above specific details.

[0127] It should be noted that the term "and / or" or " / " used in this document is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The singular forms of "a", "the" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0128] In the detailed description and claims, a list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms may mean any combination of the listed items. For example, if items A, B are listed, the phrase "at least one of A, B" means only A; only B; or A and B. In another example, if items A, B, C are listed, the phrase "at least one of A, B, C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A methanol injector valve ball, characterized in that: The methanol injector valve ball comprises: Valve ball body; A first coating layer is disposed on at least a portion of the outer surface of the valve ball body, wherein the material of the first coating layer includes Cr; A second coating layer is disposed on at least a portion of the outer surface of the first coating layer, wherein the material of the second coating layer comprises CrN; The third coating layer is disposed on at least a portion of the outer surface of the second coating layer, and the material of the third coating layer includes DLC.

2. The methanol injector valve ball according to claim 1, characterized in that: The thickness of the first coating is 0.1 μm to 2 μm; and / or, the thickness of the second coating is 0.1 μm to 2 μm; And / or, the thickness of the third coating layer is 1 μm to 6 μm.

3. The methanol injector valve ball according to claim 1 or 2, characterized in that: The hardness of the total coating consisting of the first coating, the second coating and the third coating is in the range of 2000 HV to 3000 HV.

4. A method for preparing a methanol injector valve ball, characterized in that: The method comprises: forming a first coating layer on at least a portion of the outer surface of the valve ball body, wherein the material of the first coating layer includes Cr; forming a second coating layer on at least a portion of the outer surface of the first coating layer, wherein the material of the second coating layer includes CrN; A third coating layer is formed on at least a portion of the outer surface of the second coating layer, wherein the material of the third coating layer includes DLC.

5. The method for preparing a methanol injector valve ball according to claim 4, characterized in that: The forming of the first coating layer specifically comprises: In an inert gas atmosphere, using Cr as a target material, forming a first coating on at least a portion of the outer surface of the valve ball body by an arc ion plating process; The gas pressure during the arc ion plating process is 0.2Pa-0.8Pa, the bias voltage is 220V-280V, the target current is 55A-75A, the deposition temperature is 200°C-250°C, and the arc ion plating time is 5h-8h.

6. The method for preparing a methanol injector valve ball according to claim 4, characterized in that: The forming of the second coating layer specifically comprises: Using pure chromium as a target material and nitrogen as a reaction gas, forming a second coating on at least a portion of the outer surface of the first coating by an arc ion plating process; Wherein, the flow rate range of the nitrogen gas during the arc ion plating process is 260 sccm to 550 sccm, the target current is 80 A to 110 A, and the arc ion plating time is 5 h to 8 h.

7. The method for preparing a methanol injector valve ball according to claim 5, characterized in that: The forming of the third coating layer specifically comprises: forming a third coating on at least a portion of the outer surface of the second coating by arc ion plating process using a carbon target as a target material under an inert gas atmosphere; The gas pressure during the arc ion plating process is 0.3Pa-0.9Pa, the bias voltage is 220V-280V, the target current is 65A-80A, the deposition temperature is 220°C-250°C, and the arc ion plating time is 5h-8h.

8. The method for preparing a methanol injector valve ball according to any one of claims 4 to 7, characterized in that: Before forming the first coating, the method further comprises: Clean the methanol injector valve ball at least once, and each cleaning time is 20min to 30min; Dry the cleaned methanol injector valve ball; The coating tooling is matched with the dried methanol injector valve ball, and then the coating tooling and the methanol injector valve ball are placed together in the coating preparation equipment.

9. A methanol injector, characterized in that: The methanol injector comprises a methanol injector valve ball according to any one of claims 1 to 3 or a methanol injector valve ball made according to the method according to any one of claims 4 to 8; The methanol injector also includes a valve body, a valve seat and a valve stem; The valve body is provided with a valve cavity, the valve seat is fixed at one end of the valve body, and the valve seat is communicated with the valve cavity, and the valve seat is provided with an inner cavity for accommodating the valve ball of the methanol injector; The valve ball is fixedly connected to one end of the valve stem, and the valve stem and the valve ball are movably arranged in the valve cavity and the inner cavity respectively.

10. An engine, characterized in that: The engine includes the methanol injector of claim 9.

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