Valve seat, methanol ejector and engine

Abstract

The utility model relates to the technical field of engines, in particular to a valve seat, a methanol ejector and an engine. The utility model provides a valve seat which is suitable for a methanol injector and comprises a valve seat body and a corrosion-resistant structure, and the valve seat body is provided with an oil passing channel and an injection hole communicating with the oil passing channel; a needle valve part of the methanol ejector is positioned in the oil passing channel and axially moves relative to the valve seat; a sealing part is arranged on a part of the peripheral surface of the needle valve piece, a sealing surface is formed on a part of the inner wall surface of the oil passing channel, and the sealing part of the needle valve piece is matched with the sealing surface of the oil passing channel to close the spray hole; the corrosion-resistant structure is arranged on the sealing face and comprises at least one chromium coating and at least one chromium nitride coating. The methanol ejector comprises the valve seat. The problem of cavitation of the sealing face of the valve seat of the methanol ejector can be effectively solved, the sealing performance of the valve seat is improved, then the working stability of the methanol ejector is improved, leakage is reduced, and the service life is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a valve seat, a methanol injector and an engine. Background Art

[0002] The engine is an important component of a car. Methanol engines use methanol as their primary fuel and have advantages such as clean emissions and good economic performance. Currently, methanol engines use a multi-point injection technology solution through the intake manifold. This solution has low methanol injection pressure and poor atomization, resulting in poor fuel economy and emissions. Direct injection technology has been proven in the field of gasoline engines and has significant effects on economy and improved emissions. Therefore, direct injection methanol engines are also a technology with great development prospects. However, due to the physical and chemical properties of methanol itself, the saturated vapor pressure of methanol direct injection injectors is low in the high temperature and high pressure environment. During the injection process of the methanol injector, the methanol fuel is prone to bubbles due to pressure changes. The bubbles generate micro-jets and impact force during the bursting process, which damage the surface of the sealing band (sealing area) inside the methanol injector valve seat and easily cause leakage of the methanol injector.

[0003] Therefore, it is necessary to solve the cavitation problem of the sealing strip of the valve seat of the methanol injector, improve the sealing performance of the valve seat sealing strip, and thus improve the working stability of the methanol injector.

[0004] In view of this, this application is hereby filed. Utility Model Content

[0005] In view of this, the present invention aims to at least partially address one of the technical problems in the related art. To this end, the present invention provides a valve seat, a methanol injector, and an engine that can effectively alleviate cavitation problems in the sealing area within the methanol injector valve seat and improve the sealing performance of the methanol injector valve seat.

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

[0007] According to one aspect of the present application, an embodiment of the present application provides a valve seat suitable for a methanol injector, the valve seat comprising:

[0008] A valve seat body, the valve seat body being provided with an oil passage and a spray hole communicating with the oil passage; a needle valve member of the methanol injector being partially located in the oil passage and being axially movable relative to the valve seat; a sealing portion being provided on a portion of an outer peripheral surface of the needle valve member along a direction of travel, a sealing surface being formed on a portion of an inner wall surface of the oil passage, the sealing portion of the needle valve member cooperating with the sealing surface of the oil passage to close the spray hole;

[0009] The corrosion-resistant structure is arranged at the sealing surface, and the corrosion-resistant structure includes at least one layer of chromium coating and at least one layer of chromium nitride coating.

[0010] In addition, the valve seat according to the present application may also have the following additional technical features:

[0011] In some embodiments, the corrosion-resistant structure comprises:

[0012] a first chromium coating disposed on the surface of the sealing surface;

[0013] a first chromium nitride coating disposed on the first chromium coating;

[0014] a second chromium coating layer disposed on the first chromium nitride coating layer;

[0015] The second chromium nitride coating is disposed on the second chromium coating.

[0016] In some embodiments, the thickness of the first chromium coating is 0.1 μm to 3 μm.

[0017] In some embodiments, the second chromium coating has a thickness of 0.1 μm to 3 μm.

[0018] In some embodiments, the thickness of the first chromium nitride coating is 1 μm to 4 μm.

[0019] In some embodiments, the second chromium nitride coating has a thickness of 1 μm to 4 μm.

[0020] In some embodiments, the hardness of the chromium coating and / or the chromium nitride coating is 1000 HV to 2700 HV.

[0021] In some embodiments, the oil passage includes a first channel, a transition section, and a second channel arranged in sequence, the second channel is close to the spray hole, and the aperture of the second channel is smaller than the aperture of the first channel; the sealing surface is formed on at least part of the inner wall surface of the transition section and / or at least part of the inner wall surface of the second channel.

[0022] In some embodiments, the cross-section of the oil passage is tapered.

[0023] In some embodiments, the corrosion-resistant structure is provided on the inner wall of the spray hole.

[0024] According to another aspect of the present application, an embodiment of the present application provides a methanol injector, the methanol injector comprising the valve seat as described above;

[0025] The methanol injector further comprises a valve body and a needle valve member;

[0026] The valve seat is fixed on one end of the valve body. The valve body is provided with a valve cavity. The oil passage is communicated with the valve cavity. The needle valve member is movably arranged in the valve cavity and the oil passage.

[0027] In some embodiments, the needle valve member includes a valve stem and a valve ball connected to one end of the valve stem, and the sealing portion is provided on a portion of the outer circumference of the valve ball along the travel direction, and the sealing portion is provided to close or open the spray hole.

[0028] In some embodiments, the methanol injector further includes an electromagnetic drive assembly disposed in the valve cavity, wherein the electromagnetic drive assembly is drivingly connected to the needle valve member to drive the needle valve member to move in the valve cavity.

[0029] According to yet another aspect of the present application, an embodiment of the present application provides an engine, comprising the methanol injector as described above.

[0030] The implementation of the technical solution of this utility model has at least the following beneficial effects:

[0031] In an embodiment of the present application, the valve seat provided is suitable for use in a methanol injector. A sealing surface is formed on at least a portion of the inner wall surface of the oil passage of the valve seat. The sealing surface is adapted to cooperate with the sealing portion of the needle valve component to close the spray hole. A corrosion-resistant structure is provided on the sealing surface, and the corrosion-resistant structure includes at least one layer of chromium coating and at least one layer of chromium nitride coating. Thus, by providing the corrosion-resistant structure on the sealing surface, corrosion of the sealing surface by methanol fuel can be reduced, the sealing effect between the needle valve component and the sealing surface can be improved, dripping or leakage in the methanol injector can be prevented, and the operating stability or durability of the methanol injector can be improved. The combination of the chromium coating and the chromium nitride coating in the corrosion-resistant structure not only provides a strong bond with the sealing surface, but also exhibits strong corrosion resistance, and has the characteristics of high adhesion, high toughness, and high corrosion resistance.

[0032] The methanol injector valve seat has been tested on an engine bench for 600 hours, and the engine and injector performance are normal. When the injector is disassembled and the sealing surface of the valve seat is observed, no cavitation is found.

[0033] Additional aspects and advantages of the present application will be given in part in the following description, and in part will become apparent from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Shown is a structural schematic diagram of a valve seat provided by an embodiment of the present utility model;

[0035] Figure 2 FIG2 is a schematic structural diagram of a corrosion-resistant structure of a valve seat provided by an embodiment of the present utility model;

[0036] Figure 3 Shown is a structural schematic diagram of a valve seat and coating tooling provided in an embodiment of the present utility model.

[0037] Description of reference numerals:

[0038] 10-valve seat;

[0039] 101-valve seat body;

[0040] 111- oil passage;

[0041] 112-sealing surface;

[0042] 113-spray hole;

[0043] 102-corrosion-resistant structure; 121-first chromium coating; 122-first chromium nitride coating; 123-second chromium coating; 124-second chromium nitride coating;

[0044] 20-Coating tooling. DETAILED DESCRIPTION

[0045] The present application will be further described below with reference to specific examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application.

[0046] The endpoints of the ranges and any values ​​disclosed herein 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 endpoints of each range, the endpoints 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 to be specifically disclosed herein.

[0047] Below, embodiments of the valve seat, methanol injector, engine, etc. of the present application are described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0048] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. Unless otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0049] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0050] In the related art, direct injection of methanol significantly improves engine economy and emissions, and significantly enhances engine cold start performance. However, due to the low saturated vapor pressure of methanol and the high temperature and high pressure operating environment of methanol direct injection injectors, methanol bubbles are generated during the injection process. As the bubbles burst with pressure changes, they cause cavitation on the sealing strip (also called the sealing surface or sealing area) of the injector valve seat. This damages the surface characteristics of the sealing strip of the injector valve seat, causing injector leakage and, in severe cases, injector failure. To address this issue, the related art has addressed the issue by optimizing the material composition of the valve seat sealing strip, heat treating the surface of the valve seat sealing strip, and optimizing the valve seat structure. However, these solutions do not completely solve the cavitation problem of the injector valve seat sealing strip and are not very practical. Existing technical solutions for treating the valve seat sealing strip still suffer from cavitation, and damage to the sealing strip leads to injector leakage. Therefore, there is a need to provide effective technical means to alleviate the cavitation problem of the injector valve seat sealing strip. In view of this, the present application provides a valve seat, a methanol injector, and an engine, which are described in detail below.

[0051] See also Figures 1 to 3 As shown, in some embodiments, the present application provides a valve seat 10 , which is suitable for a methanol injector.

[0052] It should be understood that, generally, a methanol injector includes a valve seat 10, which can be disposed at the end of the methanol injector. A sealing surface 112 can be provided within the valve seat 10, and the valve seat 10 can have a spray hole 113. The methanol injector can spray a high-pressure fuel spray through the spray hole 113. Although this embodiment is proposed based on the technical defect that bubbles are easily generated during the methanol fuel injection process, which can damage the surface characteristics of the sealing surface of the injector valve seat and easily cause cavitation on the sealing surface of the methanol injector valve seat, the valve seat of this embodiment can be applied not only to methanol direct injection injectors, but also to other injectors using methanol as fuel or injectors using other fuels, and this embodiment is not limited to this.

[0053] Specifically, the provided valve seat 10 includes a valve seat body 101 and a corrosion-resistant structure 102 .

[0054] The valve seat body 101 is provided with an oil passage 111 and a spray hole 113 communicating with the oil passage 111. For example, the oil passage 111 is formed within the valve seat body 101, and the spray hole 113 is provided at the end of the valve seat body 101. The spray hole 113 communicates with the oil passage 111. A sealing surface 112 is formed on at least a portion of the inner wall surface of the oil passage 111. The corrosion-resistant structure 102 is provided at the sealing surface 112.

[0055] The methanol injector's needle valve is partially located within the oil passage 111 and moves axially relative to the valve seat 10. A sealing portion is provided on a portion of the needle valve's outer circumference along the direction of travel. This sealing portion cooperates with a sealing surface 112 of the oil passage 111 to close the spray hole 113. For example, the needle valve is adapted to abut against the corrosion-resistant structure 102 at the sealing surface 112 to close the spray hole 113, or to move away from the corrosion-resistant structure 102 at the sealing surface 112 to open the spray hole 113.

[0056] In the present application, the corrosion-resistant structure 102 includes at least one chromium coating layer and at least one chromium nitride coating layer.

[0057] Generally, the operating principle of a methanol injector is based on the on-off operation of a solenoid valve. When the electromagnetic coil is energized, an electromagnetic force is generated, which pulls the needle valve member up, that is, the needle valve member moves away from the sealing surface 112 of the valve seat 10, thereby opening the oil passage 111. Fuel is ejected at high speed through the spray hole 113 (also referred to as the oil spray hole) at the oil outlet end of the oil passage 111, forming a mist. This atomized fuel facilitates thorough mixing with air, improving combustion efficiency. When the power is turned off, the electromagnetic force disappears, and the needle valve member, under the action of the return spring, blocks the oil passage 111. That is, the sealing portion of the needle valve member seals with the sealing surface 112 inside the valve seat 10, stopping the injection of fuel. The valve seat 10 of the methanol injector is an important component of the valve assembly in the injector. It cooperates with the needle valve member of the methanol injector to control the opening or closing of the spray hole 113, thereby achieving accurate and efficient injection of fuel.

[0058] In the present application, the valve seat 10 includes a valve seat body 101 and a corrosion-resistant structure 102. The valve seat body 101 is the main structure of the valve seat 10, and an oil passage 111 is formed inside the valve seat 10, that is, a passage for guiding fuel, and at least part of the wall surface of the oil passage 111 is formed with a sealing surface 112. The sealing surface 112 here refers to the surface inside the oil passage 111 for sealing with the needle valve member; and a plurality of spray holes 113 are provided at one end of the valve seat body 101. After passing through the oil passage 111, the fuel can be sprayed out at high speed through the spray holes 113 to form a mist.

[0059] It should be understood that the methanol injector may include the valve seat 10 and a needle valve member (not shown) mentioned above. The valve seat 10 and the needle valve member are used in conjunction with each other, and the needle valve member can be used to open or close the injection hole 113.

[0060] Illustratively, the valve seat body 101 is provided with an inner cavity for accommodating the needle valve member and guiding fuel, that is, it has an oil passage 111 , and the spray hole 113 can be provided on the bottom wall of the oil passage 111 and penetrate the bottom wall. Furthermore, the valve seat body 101 may be provided with a side wall and a bottom wall, the bottom end of the side wall being connected to the upper edge of the bottom wall, and the side wall and the bottom wall may enclose an inner cavity, i.e., an oil passage 111, which may be used to accommodate a needle valve component and diverting fuel, and the oil passage 111 has a sealing surface 112 for cooperating with a sealing portion of a valve ball in the needle valve component; when the sealing portion of the valve ball in the needle valve component cooperates with the sealing surface 112, the valve ball may be used to close the spray hole 113, i.e., methanol fuel cannot be sprayed out through the spray hole 113 at this time; when the valve ball is separated from (or away from) the sealing surface 112, a gap exists between the sealing portion of the valve ball and the sealing surface 112, which may open the spray hole 113, and methanol fuel may be sprayed out through the spray hole 113 at this time.

[0061] The spray holes 113 are disposed on the bottom wall of the oil passage 111. For example, multiple spray holes 113 may be evenly distributed along the circumference of the bottom wall, and the spray holes 113 may extend through the bottom wall to achieve the purpose of injecting fuel. The specific arrangement of the valve seat body 101 and the spray holes 113 can be designed based on actual conditions. This application does not limit the specific structure and shape of the valve seat body 101.

[0062] In the present application, the valve seat 10 provided is provided with a corrosion-resistant structure 102, which is arranged at the sealing surface 112 of the valve seat body 101, that is, the corrosion-resistant structure 102 is arranged on the surface of the sealing surface 112, which can improve the corrosion resistance or anti-cavitation effect at the sealing surface 112, thereby improving the sealing performance of the sealing surface 112 and the needle valve component (valve ball). The needle valve component in the methanol injector can move axially along the valve seat 10 to open or close the spray hole 113; for example, when the valve ball of the needle valve component abuts against the corrosion-resistant structure 102 at the sealing surface 112, the two are sealed and cooperated to block the oil passage 111, that is, the spray hole 113 can be closed, and at this time the fuel cannot be sprayed out through the spray hole 113; or when the valve ball of the needle valve component is away from the corrosion-resistant structure 102 at the sealing surface 112, the valve ball of the needle valve component is separated from the corrosion-resistant structure 102, and the oil passage 111 can be opened, that is, the spray hole 113 can be opened, and at this time the fuel inside the oil passage 111 can be sprayed out through the spray hole 113 and form a mist.

[0063] The above-mentioned corrosion-resistant structure 102 includes at least one layer of chromium coating and at least one layer of chromium nitride coating. For example, the corrosion-resistant structure 102 may include a layer of chromium coating (Cr coating) and a layer of chromium nitride coating (CrN coating), or the corrosion-resistant structure 102 may include multiple layers of chromium coating (Cr coating) and multiple layers of chromium nitride coating (CrN coating).

[0064] Preferably, in this embodiment, the corrosion-resistant structure 102 may include a multi-layer chromium coating (Cr coating) and a multi-layer chromium nitride coating (CrN coating), wherein the Cr coating and the CrN coating are stacked in sequence, that is, Cr coating, CrN coating, Cr coating, CrN coating... and so on, stacked in sequence.

[0065] Therefore, based on the above configuration, the present application specifically studies and develops a corrosion-resistant structure 102, i.e., a coating structure at the valve seat sealing surface 112, to address the cavitation problem of the valve seat sealing surface 112, in order to solve the cavitation problem of the valve seat sealing surface 112. By providing the corrosion-resistant structure 102 at the sealing surface 112, the present application can reduce the corrosion of the sealing surface 112 by methanol fuel, improve the sealing effect between the needle valve and the sealing surface 112, prevent dripping or leakage in the methanol injector, and improve the working stability or durability of the methanol injector. The combination of the chromium coating and the chromium nitride coating in the corrosion-resistant structure 102 not only has a strong bonding force with the sealing surface 112, but also has strong corrosion resistance, and has the characteristics of high adhesion, high toughness, and high corrosion resistance.

[0066] By coordinating the multi-layer chromium coating and the multi-layer chromium nitride coating, the corrosion resistance can be enhanced. For example, when one layer of the chromium coating and the chromium nitride coating is corroded or damaged, the remaining chromium coating and the chromium nitride coating can continue to play a corrosion-resistant role, thereby ensuring that the sealing surface 112 is not corroded or damaged, further improving the corrosion resistance and the sealing effect.

[0067] In some embodiments, the corrosion-resistant structure 102 includes:

[0068] A first chromium coating 121 is provided on the surface of the sealing surface 112;

[0069] A first chromium nitride coating 122 is disposed on the first chromium coating 121;

[0070] A second chromium coating 123 is disposed on the first chromium nitride coating 122;

[0071] The second chromium nitride coating 124 is disposed on the second chromium coating 123 .

[0072] The corrosion-resistant structure 102 includes a first chromium coating 121, a first chromium nitride coating 122, a second chromium coating 123 and a second chromium nitride coating 124 which are stacked in sequence, wherein the first chromium coating 121 is located on the surface of the sealing surface 112, which can enhance the corrosion resistance. For example, when the second chromium coating 123 and the second chromium nitride coating 124 are corroded or damaged, the first chromium coating 121 and the first chromium nitride coating 122 can continue to play a corrosion-resistant role, thereby ensuring that the sealing surface 112 is not corroded or damaged, further improving the corrosion resistance and improving the sealing effect.

[0073] Thus, the valve seat 10, through the corrosion-resistant structure 102, especially the corrosion-resistant structure 102 formed by the first chromium coating 121, the first chromium nitride coating 122, the second chromium coating 123 and the second chromium nitride coating 124 (Cr-CrN-Cr-CrN coating structure), cooperates with the needle valve component to realize the on-off control of the oil passage 111 or the spray hole 113. Since the Cr-CrN-Cr-CrN coating structure has good corrosion resistance, when it is applied to a scenario where methanol is used as fuel, the corrosion-resistant structure 102 will not be damaged by the corrosion of methanol, or in other words, the sealing surface 112 in the valve seat 10 will not be damaged by the corrosion of methanol, thereby ensuring the sealing between the sealing surface 112 and the needle valve component of the injector, avoiding engine jitter caused by poor sealing of the injector, and thus ensuring the normal use of the engine.

[0074] The Cr-CrN-Cr-CrN coating provided in this application has a complex structure and a high degree of process difficulty, but has been successfully verified after multiple rounds of verification. After experimental verification, it was found that after a methanol injector single-unit durability test and a 600-hour engine bench durability test, the methanol injector valve seat survived the 600-hour engine bench durability test, and the engine and injector performance were normal. Disassembly of the methanol injector to observe the sealing surface 112 showed no cavitation, that is, no cavitation failure occurred at the sealing surface 112. Therefore, the performance of the valve seat provided in this application meets the design requirements and meets the needs of use.

[0075] Optionally, the corrosion-resistant structure 102, such as the Cr-CrN-Cr-CrN coating structure, has a coating process temperature of 150-250°C, controls the valve seat deformation to be less than 0.01 mm, and has a coating operating temperature of less than 600°C.

[0076] In some embodiments, the thickness of the first chromium coating 121 is 0.1 μm to 3 μm. In the present application, the first chromium coating 121 can serve as a base coat. Using a Cr coating as a base coat provides strong adhesion to the substrate and the Cr coating itself has high hardness and corrosion resistance. For example, the thickness of the first chromium coating 121 can be any of 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 1.2 μm, 1.5 μm, 2 μm, 2.5 μm, and 3 μm, or a range of values ​​therebetween.

[0077] In some embodiments, the thickness of the second chromium coating 123 is 0.1 μm to 3 μm. For example, the thickness of the second chromium coating 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, 2 μm, 2.5 μm, and 3 μm, or any range therebetween.

[0078] If the thickness of the first chromium coating 121 or the second chromium coating 123 is too thin, it will not effectively improve the corrosion resistance of the sealing surface 112, and the bonding between the sealing surface 112 substrate and the first chromium coating 121 will also be reduced. If the thickness of the first chromium coating 121 or the second chromium coating 123 is too thick, it will increase costs. Therefore, by controlling the thickness of the first chromium coating 121 or the second chromium coating 123 within the above range, it not only facilitates processing and saves costs, but also ensures that the first chromium coating 121 or the second chromium coating 123 has better application effects and meets the requirements of anti-cavitation performance.

[0079] In some embodiments, the thickness of the first chromium nitride coating 122 is 1 μm to 4 μm. For example, the thickness of the first chromium nitride coating 122 can be any one of 1 μm, 1.2 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, and 4 μm, or a range therebetween.

[0080] In some embodiments, the second chromium nitride coating 124 has a thickness of 1 μm to 4 μm. For example, the thickness of the second chromium nitride coating 124 can be any one of 1 μm, 1.2 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, and 4 μm, or a range therebetween.

[0081] In the present application, the first chromium nitride coating 122 and the second chromium nitride coating 124 can act as functional layers. The CrN coating has the characteristics of low stress, high adhesion, high toughness, high corrosion resistance, and corrosion resistance and chemical resistance to aqueous solutions, and has certain lubricity.

[0082] If the thickness of the first chromium nitride coating 122 or the second chromium nitride coating 124 is too thin, it will not effectively improve the corrosion resistance of the sealing surface 112. If the thickness of the first chromium nitride coating 122 or the second chromium nitride coating 124 is too thick, it will increase costs. Therefore, by controlling the thickness of the first chromium nitride coating 122 or the second chromium nitride coating 124 within the above range, it is not only easier to process and save costs, but also the first chromium nitride coating 122 and the second chromium nitride coating 124 can achieve better application effects and meet the requirements of anti-cavitation performance.

[0083] In some embodiments, the hardness of the chromium coating and / or the chromium nitride coating is 1000 HV to 2700 HV. That is, the hardness of the chromium coating is 1000 HV to 2700 HV, or the hardness of the chromium nitride coating is 1000 HV to 2700 HV, or the hardness of the chromium coating and the chromium nitride coating is 1000 HV to 2700 HV. As an example, the hardness of the coating can be any one of 1000 HV, 1200 HV, 1500 HV, 1800 HV, 2000 HV, 2500 HV, and 2700 HV, or a range of values ​​therebetween.

[0084] In some embodiments, the inner wall of the spray hole 113 is provided with a corrosion-resistant structure 102 .

[0085] Optionally, the corrosion-resistant structure 102 at the nozzle hole 113 may be a first chromium coating 121, a first chromium nitride coating 122, a second chromium coating 123, and a second chromium nitride coating 124 stacked in sequence, i.e., a Cr-CrN-Cr-CrN coating structure. Alternatively, the corrosion-resistant structure 102 at the nozzle hole 113 may be a first chromium coating 121 and a first chromium nitride coating 122 stacked in sequence, i.e., a Cr-CrN-coating structure.

[0086] Optionally, the corrosion-resistant structure 102 at the spray hole 113 may also be a ceramic layer.

[0087] By providing the above-mentioned corrosion-resistant structure 102 on the inner wall of the nozzle 113, the corrosion resistance or cavitation resistance of the nozzle 113 is improved, the cavitation failure of the nozzle 113 is reduced, and the corrosion resistance or cavitation resistance of the valve seat as a whole is improved, thereby improving the working stability of the valve seat.

[0088] In the present application, the preparation method of the above-mentioned corrosion-resistant structure 102 can be prepared by a method known in the relevant art. As an example, the preparation of the above-mentioned corrosion-resistant structure 102 includes the following steps (a) to (f):

[0089] (a) Preprocessing.

[0090] In step (a), before preparing the first chromium coating 121, the valve seat 10 is pretreated, specifically including: performing plasma cleaning on the valve seat 10 at least once, each cleaning time being 20 minutes to 30 minutes; drying the cleaned valve seat 10; placing the coating tooling 20 into the inner cavity of the dried valve seat body 101, and then placing the coating tooling 20 and the valve seat 10 together into the coating preparation equipment.

[0091] This embodiment does not limit the specific material of the valve seat body 101, and the valve seat body 101 material commonly used in the relevant field can be used.

[0092] Optionally, in step (a), the valve seat 10 is first cleaned, such as by plasma cleaning. For example, the methanol injector valve seat 10 can be plasma cleaned by placing it in a cleaning chamber and performing one or more plasma cleanings. The plasma collides with gas molecules in the cleaning chamber, generating a chemical reaction that completely removes dirt and harmful substances from the sealing surface 112 of the valve seat body 101. In this embodiment, the valve seat body 101 is plasma cleaned twice, each time for 20 to 30 minutes, and then dried.

[0093] After drying, the coating tool 20 is placed in the inner cavity of the dried valve seat body 101, and then the coating tool 20 and the methanol injector valve seat 10 are placed together in a coating preparation device (such as a coating furnace).

[0094] like Figure 3 As shown, by placing the coating tool 20 into the inner cavity of the dried valve seat body 101, it is possible to prevent the coating on the valve seat guide surface from changing the gap between the valve ball and the guide surface and affecting the movement of the valve ball.

[0095] The coating tool 20 may include a top cover and a mounting portion. The mounting portion is used to install the coating tool 20 into the valve seat body 101, and the top cover is used to shield the coating from the inner cavity during the preparation of the methanol injector. The coating tool 20 cooperates with the inner cavity of the valve seat body 101, and the installation of the coating tool 20 prevents the coating from forming on the valve seat guide surface.

[0096] (b) Preparing the first chromium coating 121.

[0097] In step (b), a first chromium coating 121 is formed on the pre-treated sealing surface 112 of the valve seat body 101 .

[0098] Optionally, in step (b), before forming the first chromium coating 121, step (b) also includes a vacuuming step, that is, after placing the coating tooling 20 and the methanol injector valve seat 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 10Pa, start the molecular pump, and further pump the air pressure to the ultimate vacuum degree. Maintain the ultimate vacuum environment for a period of time to maximize the removal of air in the furnace. Vacuuming can increase the density of the coating and reduce the porosity of the coating.

[0099] In the present application, in step (b), the first chromium coating 121 is formed, which specifically includes: in an inert gas atmosphere, using pure chromium (purity ≥99.9%) as a target material, forming the first chromium coating 121 on the sealing surface 112 through an arc ion plating process; wherein, the gas pressure during the arc ion plating process is 0.3Pa~0.9Pa, which can prevent the coating from being oxidized and nitrided, the bias voltage is 220V~240V (preferably 230V), the target (chromium target) current is 60A~80A, the deposition temperature is 150℃~250℃, and the arc ion plating time is 5h~9h.

[0100] 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 the inert gas, ie, as the protective gas.

[0101] It should be pointed out that the specific operation method of preparing the first chromium coating 121 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.

[0102] Therefore, the prepared first chromium coating 121 has a strong bonding force with the substrate and the Cr coating itself has strong corrosion resistance, which is beneficial to improving the corrosion resistance of the sealing surface 112.

[0103] (c) Preparing a first chromium nitride coating 122 .

[0104] In some embodiments, in step (c), forming a first chromium nitride coating 122 on the surface of the first chromium coating 121 specifically includes: using pure chromium as a target material and nitrogen (N2) as a reaction gas, forming the first chromium nitride coating 122 on the surface of the first chromium coating 121 through an arc ion plating process; wherein, when implementing the arc ion plating process, the flow rate of the reaction gas nitrogen changes linearly with time in the range of 300 sccm to 500 sccm, the target current is 70 A to 110 A, and the arc ion plating time is 20 h to 25 h.

[0105] Optionally, the mass purity of the above-mentioned pure chromium target is not less than 99.9%.

[0106] Therefore, the prepared first chromium nitride coating 122 has 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.

[0107] (d) A second chromium coating 123 is prepared.

[0108] In some embodiments, in step (d), forming a first chromium coating 121 on the surface of the first chromium nitride coating 122 specifically includes: in an inert gas (such as argon) atmosphere, using pure chromium (purity ≥99.9%) as a target material, forming a second chromium coating 123 on the first chromium nitride coating 122 by an arc ion plating process; wherein the gas pressure during the arc ion plating process is 0.3 Pa to 0.9 Pa, which can prevent the coating from being oxidized and nitrided, the bias voltage is 220 V to 240 V (preferably 230 V), the target (chromium target) current is 60 A to 80 A, the deposition temperature is 150° C. to 250° C., and the arc ion plating time is 5 h to 9 h.

[0109] In the present application, the process conditions for preparing the first chromium coating layer 121 may be the same as the process conditions for preparing the second chromium coating layer 123 .

[0110] (e) Preparing a first chromium nitride coating 122.

[0111] In some embodiments, in step (e), forming a second chromium nitride coating 124 on the surface of the second chromium coating 123 specifically includes: using pure chromium as a target material and nitrogen (N2) as a reaction gas, forming the second chromium nitride coating 124 on the surface of the second chromium coating 123 by an arc ion plating process; wherein, when implementing the arc ion plating process, the flow rate of the reaction gas nitrogen changes linearly with time in the range of 300 sccm to 500 sccm, the target current is 70 A to 110 A, and the arc ion plating time is 20 h to 25 h.

[0112] In the present application, the process conditions for preparing the first chromium nitride coating 122 may be the same as the process conditions for preparing the second chromium nitride coating 124 .

[0113] It should be noted that the specific operation method of preparing the chromium coating and the chromium nitride coating 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.

[0114] In the present invention, the hardness of each coating layer can be adjusted by adjusting the bias voltage, thereby adjusting the hardness of the coating layer.

[0115] (f) Turn off all power supplies, ion sources and gas sources, and the coating preparation is completed.

[0116] Therefore, the coating prepared by the above method has low porosity, improves the density and crystallinity of the coating, reduces the internal residual stress of the coating, and improves the corrosion resistance of the coating.

[0117] In some embodiments, the oil passage 111 includes a first channel, a transition section, and a second channel arranged in sequence, the second channel is close to the spray hole 113, the first channel can be arranged on the side of the first channel away from the spray hole 113, and the aperture of the second channel is smaller than the aperture of the first channel; at least part of the inner wall surface of the transition section and / or at least part of the inner wall surface of the second channel forms a sealing surface 112.

[0118] The first channel can serve as a guide channel for guiding the valve ball of the needle valve member so that it can smoothly engage with the second channel. In this embodiment, the aperture of the first channel is larger than the aperture of the second channel. This facilitates the valve ball to mate with the transition section or the second channel after being guided through the first channel.

[0119] It should be noted that the portion of the needle valve component where the valve ball abuts the sealing surface 112 is the sealing portion. The shape of the sealing surface 112 can be configured as a curved surface that matches the surface shape of the sealing portion. For example, when the surface of the sealing portion (the abutting surface) is a spherical surface, the sealing surface 112 can be configured as a concave spherical arc surface that matches the spherical surface. Of course, in some other embodiments, the sealing surface 112 can also be configured as a convex spherical arc surface.

[0120] Optionally, a corrosion-resistant structure 102 may also be provided on the inner wall surface of the first channel to prevent the methanol fuel from corroding the first channel, thereby preventing the methanol fuel from corroding the transition section and the second channel through the first channel, further ensuring the sealing effect between the sealing surface 112 and the valve ball of the needle valve component to prevent leakage.

[0121] Alternatively, in some other embodiments, the cross section of the oil passage 111 may also be tapered. The diameter of the oil passage 111 may decrease gradually from away from the spray hole 113 to closer to the spray hole 113 .

[0122] In some embodiments, the present application provides a methanol injector, the methanol injector including the aforementioned valve seat 10;

[0123] The methanol injector also includes a valve body and a needle valve member;

[0124] The valve seat 10 is fixed to one end of the valve body. The valve body is provided with a valve cavity. The oil passage 111 is communicated with the valve cavity. The needle valve member is movably provided in the valve cavity and the oil passage 111 .

[0125] Optionally, the methanol injector may be a methanol direct injection injector.

[0126] The methanol injector provided in this application solves the problem of cavitation on the sealing surface 112 in the methanol injector in the related art. Compared with the prior art, the methanol injector provided in this embodiment has the same beneficial effects as the valve seat 10 in the above embodiment, which will not be described in detail here.

[0127] In some embodiments, the needle valve assembly includes a valve stem and a valve ball connected to one end of the valve stem. A sealing portion is provided on a portion of the outer circumference of the valve ball along the direction of travel, and the sealing portion is configured to close or open the spray hole 113. Specifically, the valve ball is adapted to cooperate with the corrosion-resistant structure 102 at the sealing surface 112 to close the spray hole 113, or to move away from the corrosion-resistant structure 102 at the sealing surface 112 to open the spray hole 113.

[0128] In some embodiments, the methanol injector further includes an electromagnetic drive assembly disposed in the valve cavity, and the electromagnetic drive assembly is drive-connected to the needle valve member to drive the needle valve member to move in the valve cavity.

[0129] It should be pointed out that the core of the methanol injector is the valve seat 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, resistance drive component, etc., and reference may be made to relevant existing technologies.

[0130] As an example, the methanol injector includes a valve seat 10, a valve body, a needle valve, a return spring, and an electromagnetic drive assembly. The needle valve (not shown) includes a valve ball and a valve stem. The valve seat 10 is fixed to one end of the valve body. The valve body is provided with a valve cavity filled with fuel. The valve seat 10 is connected to the valve cavity. The valve ball is connected to one end of the valve stem. The valve stem and the valve ball are respectively movably disposed in the valve cavity and the inner cavity of the valve seat 10, that is, the oil passage 111. In other words, the valve stem is movably disposed in the valve cavity, the valve ball is fixed to the end of the valve stem, and the valve ball is movably disposed in the oil passage 111 of the valve seat 10. The above-mentioned return spring is fixed in the valve cavity and connected to the top of the valve stem. The return spring is in a compressed state. The electromagnetic drive assembly is fixed to the valve body and connected to the valve stem. The electromagnetic drive assembly can drive the valve stem to move up and down along the valve cavity.

[0131] Optionally, the axial direction of the valve body extends in a vertical direction, and the valve cavity extends along the axial direction of the valve body, which is conducive to the movement of the valve stem in the valve cavity. In this application, the driving method of the valve stem can refer to the driving structure commonly used in current methanol injectors and is not limited here.

[0132] The initial position of the valve ball: the valve ball abuts against the corrosion-resistant structure 102 at the sealing surface 112 of the oil passage 111 of the valve seat 10, and cooperates with the spray hole 113 to prevent fuel from passing through the spray hole 113. When the methanol injector needs to inject fuel, the methanol injector drives the valve stem to move upward along the valve cavity through the electromagnetic drive assembly. The valve ball follows the valve stem to move upward and away from the corrosion-resistant structure 102 at the sealing surface 112, and the fuel is sprayed into the combustion chamber through the spray hole 113; when the methanol injector does not need to inject fuel, the electromagnetic drive assembly stops working, the return spring stretches, drives the valve stem to move downward along the valve cavity, and the valve ball follows the valve stem to move downward until it abuts against the corrosion-resistant structure 102 at the sealing surface 112 and cooperates with the spray hole 113 to prevent fuel from passing through the spray hole 113.

[0133] In some embodiments, the present application provides an engine comprising the aforementioned methanol injector.

[0134] 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 structures of the engine and their connection settings. For details, please refer to the existing technology and will not be repeated here.

[0135] The valve seat, methanol injector and engine provided by the embodiments of the present invention are suitable for methanol fuel, which not only improves the corrosion resistance and wear resistance of the methanol injector valve seat, but also helps to improve the reliability of the methanol injector and the engine.

[0136] The parts of the present invention that are not described in detail are well known to those skilled in the art.

[0137] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and not restrictive, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0138] It should be noted that the terms "and / or" or " / " used herein are merely a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The singular forms "a," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0139] 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 and B are listed, the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and 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 contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0140] 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 various embodiments of the present invention.

Claims

1. A valve seat suitable for a methanol injector, characterized in that: The valve seat (10) comprises: A valve seat body (101), the valve seat body (101) is provided with an oil passage (111) and a spray hole (113) communicating with the oil passage (111); a needle valve component of the methanol injector is partially located in the oil passage (111) and moves axially relative to the valve seat; a sealing portion is provided on a portion of the outer peripheral surface of the needle valve component along the direction of travel, a sealing surface (112) is formed on a portion of the inner wall surface of the oil passage (111), and the sealing portion of the needle valve component cooperates with the sealing surface (112) of the oil passage (111) to close the spray hole (113); A corrosion-resistant structure (102) is provided at the sealing surface (112), wherein the corrosion-resistant structure (102) comprises at least one layer of chromium coating and at least one layer of chromium nitride coating.

2. The valve seat according to claim 1, characterized in that The corrosion-resistant structure (102) comprises: a first chromium coating (121) disposed on the surface of the sealing surface (112); a first chromium nitride coating (122) disposed on the first chromium coating (121); a second chromium coating (123) disposed on the first chromium nitride coating (122); A second chromium nitride coating (124) is disposed on the second chromium coating (123).

3. The valve seat according to claim 2, characterized in that The thickness of the first chromium coating (121) is 0.1 μm to 3 μm; And / or, the thickness of the second chromium coating (123) is 0.1 μm to 3 μm.

4. The valve seat according to claim 2, characterized in that The thickness of the first chromium nitride coating (122) is 1 μm to 4 μm; And / or, the thickness of the second chromium nitride coating (124) is 1 μm to 4 μm.

5. The valve seat according to claim 1, wherein: The hardness of the chromium coating and / or the chromium nitride coating is 1000HV to 2700HV.

6. The valve seat according to any one of claims 1 to 5, characterized in that: The oil passage (111) comprises a first passage, a transition section, and a second passage which are sequentially arranged, wherein the second passage is close to the spray hole (113), and the aperture of the second passage is smaller than that of the first passage; At least a portion of the inner wall surface of the transition section and / or at least a portion of the inner wall surface of the second channel is formed with the sealing surface (112); And / or, the cross section of the oil passage (111) is tapered.

7. The valve seat according to any one of claims 1 to 5, characterized in that: The inner wall of the spray hole (113) is provided with the corrosion-resistant structure (102).

8. A methanol injector, characterized in that: The methanol injector comprises a valve seat (10) according to any one of claims 1 to 7; The methanol injector further comprises a valve body and a needle valve member; The valve seat (10) is fixed to one end of the valve body. The valve body is provided with a valve cavity. The oil passage (111) is connected to the valve cavity. The needle valve member is movably arranged in the valve cavity and the oil passage (111).

9. The methanol injector according to claim 8, characterized in that: The needle valve member comprises a valve stem and a valve ball connected to one end of the valve stem, the valve ball is provided with a sealing portion on a portion of its outer circumference along the direction of travel, and the sealing portion is provided to close or open the spray hole (113); And / or, the methanol injector further includes an electromagnetic drive assembly disposed in the valve cavity, wherein the electromagnetic drive assembly is drivingly connected to the needle valve member to drive the needle valve member to move in the valve cavity.

10. An engine, characterized in that: The engine comprises the methanol injector according to claim 8 or 9.

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