Engine cylinder cover

Abstract

The engine cylinder cover comprises a cylinder cover body and a cover plate, the cylinder cover body is provided with a plurality of air inlet channels, the air inlet ends, corresponding to the air inlet channels, of the cylinder cover body are open ends, and the cover plate is located at the open ends. According to the scheme, the anti-corrosion hydrophobic structure is arranged on the air channel wall of the air inlet channel and comprises the base body layer with the air channel wall as a base body, the anti-corrosion layer and the hydrophobic layer, and the anti-corrosion layer has the characteristic of being compact in structure and can prevent corrosive elements in fuel from permeating into the base body layer so as to prevent the base body layer with the air channel wall as the base body from being corroded and play a role in protecting the air channel wall; the service life of the engine cylinder cover is prolonged; the hydrophobic layer has the hydrophobic characteristic and can reduce attachment of fuel to the wall of the air channel so as to reduce tempering shock caused by fuel attachment to the wall. Due to the fact that the anti-corrosion layer can prevent the air channel wall from being corroded, the risk that the anti-corrosion hydrophobic structure falls off from the air channel wall due to the corrosion of the air channel wall is reduced to a certain degree, and the durability of the formed anti-corrosion hydrophobic structure is improved.

Description

Technical Field

[0001] This application relates to the technical field of engines, and particularly to an engine cylinder head. Background Art

[0002] During the development of methanol engines, problems such as prone to backfire and knocking occur. The reason is that methanol fuel adheres to the airway wall of the airway holes, and at the same time, the methanol fuel adhering to the airway wall will also corrode the airway wall, shortening the service life of the cylinder head.

[0003] Therefore, how to solve the backfire and knocking caused by methanol adhering to the wall and the corrosion of the airway wall has become a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0004] This application proposes an engine cylinder head to solve the backfire and knocking caused by methanol adhering to the wall and the corrosion of the airway wall.

[0005] To achieve the above object, this application provides an engine cylinder head, including a cylinder head body and a cover plate. The cylinder head body has a plurality of intake airways. One end of the cylinder head body corresponding to the intake end of the intake airway is an open end, and the cover plate is located at the open end.

[0006] An anti-corrosion and hydrophobic structure is provided on the airway wall of the intake airway. The anti-corrosion and hydrophobic structure includes a matrix layer with the airway wall as the matrix, an anti-corrosion layer for preventing fuel from penetrating into the matrix layer, and a hydrophobic layer for reducing fuel adhering to the wall. The matrix layer, the anti-corrosion layer, and the hydrophobic layer are arranged in layers in sequence from the airway wall to the direction away from the airway wall.

[0007] Preferably, in the above engine cylinder head, the hydrophobic layer is connected to the anti-corrosion layer through a connection layer, and the connection layer is used to enhance the connection strength between the hydrophobic layer and the anti-corrosion layer.

[0008] Preferably, in the above engine cylinder head, the anti-corrosion layer is a gradient Cr alloy layer, and / or, the thickness of the anti-corrosion layer is 0.010 mm to 0.030 mm.

[0009] Preferably, in the above engine cylinder head, the connection layer is a CrN alloy layer formed in situ on the matrix layer, and / or, the thickness of the connection layer is 0.003 mm to 0.010 mm.

[0010] Preferably, in the above engine cylinder head, the hydrophobic layer is a PMMA-SiO2 composite superhydrophobic layer, an epoxy resin-SiO2 composite superhydrophobic layer, or a PTFE-PPS composite superhydrophobic layer, and / or, the thickness of the hydrophobic layer is 0.005 mm to 0.020 mm.

[0011] Preferably, in the above engine cylinder head, mounting holes corresponding to and communicating with the intake passages are formed in the cylinder head body for mounting fuel injectors.

[0012] Preferably, in the above engine cylinder head, the intake passage has two air passage holes arranged side by side, and the fuel injectors correspond to the air passage holes one by one.

[0013] Preferably, in the above engine cylinder head, a partition is provided between two adjacent air passage holes for separating the two adjacent air passage holes to prevent air leakage between the two adjacent air passage holes.

[0014] Preferably, in the above engine cylinder head, the cover plate has a receiving cavity, and the pressure stabilizing cavity is located between the cavity wall of the receiving cavity and the free end of the partition away from the intake passage (11).

[0015] Preferably, in the above engine cylinder head, an intake elbow is provided on one side in the length direction of the cover plate, and the intake elbow communicates with the receiving cavity;

[0016] The intake elbow and the cover plate are in the same plane.

[0017] The engine cylinder head provided by the embodiment of the present application includes a cylinder head body and a cover plate. The cylinder head body has a plurality of intake passages. One end of the cylinder head body corresponding to the intake end of the intake passage is an open end, and the cover plate is located at the open end. In this solution, an anti-corrosion and hydrophobic structure is provided on the airway wall of the intake passage, including a substrate layer, an anti-corrosion layer, and a hydrophobic layer with the airway wall as the substrate. The substrate layer, the anti-corrosion layer, and the hydrophobic layer are sequentially stacked in a direction away from the airway wall. The anti-corrosion layer has the characteristic of a dense structure, which can prevent corrosive elements in the fuel from penetrating into the substrate layer to prevent the substrate layer with the airway wall as the substrate from being corroded, play a protective role for the airway wall, and extend the service life of the engine cylinder head; the hydrophobic layer has a hydrophobic characteristic, which can reduce the adhesion of fuel on the airway wall to reduce the backfire detonation caused by fuel (such as methanol) adhering to the wall. In addition, since the anti-corrosion layer can prevent the airway wall from being corroded, it also reduces the risk of the anti-corrosion and hydrophobic structure falling off from the airway wall caused by the corrosion of the airway wall to a certain extent, improves the durability of the anti-corrosion and hydrophobic structure, and has good prospects in practical applications. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings, and the present application can also be applied to other similar scenarios according to the provided drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0019] Figure 1 is a schematic structural diagram of the anti-corrosion and hydrophobic structure of the engine cylinder head disclosed in the present application;

[0020] Figure 2 is a schematic structural diagram of the engine cylinder head disclosed in the present application;

[0021] Figure 3 is an exploded view of the engine cylinder head disclosed in the present application;

[0022] Figure 4 is a front view of the engine cylinder head disclosed in the present application;

[0023] Figure 5 is Figure 4 a cross-sectional view along A-A in;

[0024] Figure 6 is Figure 4 a cross-sectional view along A-A without a partition in;

[0025] Figure 7 is Figure 4 a cross-sectional view along B-B in;

[0026] Figure 8 is a schematic structural diagram of the engine cylinder head (without showing the cover plate) of the present application.

[0027] The description of the drawings is as follows:

[0028] 1 - cylinder head body; 11 - intake passage; 12 - anti-corrosion and hydrophobic structure; 121 - matrix layer; 122 - anti-corrosion layer; 123 - hydrophobic layer; 124 - connection layer; 13 - mounting hole; 14 - partition; 2 - cover plate; 21 - accommodating cavity; 22 - intake elbow. Detailed implementation manners

[0029] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant application, rather than limiting the application. The described embodiments are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0030] It should be noted that for the convenience of description, only the parts related to the relevant application are shown in the drawings. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily, as long as the combined technical features are not contradictory. All feasible feature combinations are the technical contents clearly recorded herein. Any one of the multiple sub-features included in the same statement can be applied independently without necessarily being applied together with other sub-features.

[0031] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. An element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity, or device including the element.

[0032] Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; the "and / or" herein is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality" means two or more than two.

[0033] Please refer to Figures 1-8 。

[0034] Some embodiments of the present application disclose an engine cylinder head, which is applicable to a methanol engine, but is not limited to a methanol engine, and may also be an engine of other fuels that will have wall attachment and corrode the airway wall, which is not specifically limited herein.

[0035] In some embodiments, the engine cylinder head includes a cylinder head body 1 and a cover plate 2. The cylinder head body 1 has a plurality of intake channels 11 arranged side by side, such as Figure 3 and Figure 8As shown, a plurality of intake ports 11 are arranged in sequence along the plane direction of the cylinder head body 1. One end of the cylinder head body 1 corresponding to the intake end of the intake port 11 is an open end. The cover plate 2 is located at the open end. There is a distance between the intake end of the intake port 11 and the cover plate 2. The space between the intake end of the intake port 11 and the cover plate 2 forms a pressure stabilizing cavity. After the air enters the pressure stabilizing cavity through the cover plate 2, the pressure fluctuation of the intake air is reduced.

[0036] In this solution, an anti-corrosion and hydrophobic structure 12 is provided on the airway wall of the intake port 11. The function of the anti-corrosion and hydrophobic structure 12 is to prevent the airway wall from being corroded and reduce methanol adhering to the wall at the same time.

[0037] In some embodiments, the anti-corrosion and hydrophobic structure 12 includes a substrate layer 121 with the airway wall as the substrate, an anti-corrosion layer 122 for preventing fuel from penetrating into the substrate layer 121, and a hydrophobic layer 123 for reducing fuel adhering to the wall. The substrate layer 121, the anti-corrosion layer 122, and the hydrophobic layer 123 are stacked in sequence from the airway wall to the direction away from the airway wall. Optionally, the coverage area of the hydrophobic layer 123 is larger than the coverage area of the anti-corrosion layer 122.

[0038] The anti-corrosion layer 122 is closer to the airway wall than the hydrophobic layer 123, and the anti-corrosion layer 122 is located between the hydrophobic layer 123 and the substrate layer 121. The anti-corrosion layer 122 has the characteristic of a dense structure, which can prevent the corrosive elements in the fuel from penetrating into the substrate layer 121, play a role in preventing the substrate layer 121 with the airway wall as the substrate from being corroded, protect the airway wall, and extend the service life of the engine cylinder head to a certain extent; the hydrophobic layer 123 has a hydrophobic property, which can reduce the adhesion of fuel on the airway wall and reduce the backfire detonation caused by fuel (such as methanol) adhering to the wall.

[0039] In addition, since the anti-corrosion layer 122 can prevent the airway wall from being corroded, it also reduces the risk of the anti-corrosion and hydrophobic structure 12 falling off from the airway wall caused by the corrosion of the airway wall to a certain extent, and improves the durability of the anti-corrosion and hydrophobic structure 12. The durability of the anti-corrosion and hydrophobic structure 12 is the maintenance time of the anti-corrosion and hydrophobic structure 12 on the airway wall. The longer the maintenance time of the anti-corrosion and hydrophobic structure 12 on the airway wall, the better the durability of the anti-corrosion and hydrophobic structure 12, and the better the prospect in practical applications.

[0040] The thickness of the anti-corrosion layer 122 is 0.010 mm to 0.030 mm.

[0041] In some embodiments, the anti-corrosion layer 122 is a gradient Cr alloy layer. The gradient Cr alloy layer is an alloy layer with a gradient change in the content of alloy element Cr. Specifically, from the side close to the substrate layer 121 to the side away from the substrate layer 121, the content of alloy element Cr in the anti-corrosion layer 122 gradually increases, and there is no sudden change in the content of alloy element Cr.

[0042] The material of the anti-corrosion layer 122 is not limited to the above embodiments, and can also be other materials with strong corrosion resistance, such as Ni, etc., which are not specifically defined here.

[0043] The gradient Cr alloy layer has the characteristic of a dense structure, which can prevent corrosive elements from penetrating through the anti-corrosion layer 122 into the substrate layer 121 and damaging the material of the substrate layer 121.

[0044] To further optimize the above technical solution, the hydrophobic layer 123 is connected to the anti-corrosion layer 122 through the connection layer 124, so as to enhance the connection strength between the hydrophobic layer 123 and the anti-corrosion layer 122, and further enhance the durability of the anti-corrosion and hydrophobic structure 12.

[0045] In some embodiments, the connection layer 124 is a CrN chromium nitride alloy layer formed in-situ on the substrate layer 121. In-situ formation is achieved by ion nitriding process, chemically infiltrating on the surface of the Cr alloy to obtain CrN.

[0046] The ion nitriding process is a chemical heat treatment method for strengthening the metal surface, which enables the connection layer 124 to be directly formed on the anti-corrosion layer 122, replacing the way that the connection layer 124 and the anti-corrosion layer 122 are connected by chemical binders or mechanical structures. The connection layer 124 and the anti-corrosion layer 122 are an integral structure, ensuring the connection strength between the connection layer 124 and the anti-corrosion layer 122. At the same time, micropores will be formed on the surface of the in-situ formed CrN. This microporous structure increases the contact area between the connection layer 124 and the hydrophobic layer 123, improves the bonding force between the hydrophobic layer 123 and the connection layer 124, and enhances the connection strength between the connection layer 124 and the hydrophobic layer 123.

[0047] The connection layer 124 is not limited to being formed in-situ on the substrate layer 121, and can also be in other forms such as PVD (Physical Vapor Deposition) or cold spraying, etc., which are not specifically defined here.

[0048] The thickness of the connection layer 124 is 0.003 mm to 0.010 mm.

[0049] The contact angle between the superhydrophobic layer 123 and water is greater than 150°, and the rolling angle is less than 10°, having properties such as self-cleaning and anti-pollution.

[0050] In some embodiments, a PMMA-polymethyl methacrylate - SiO2 composite superhydrophobic layer, an epoxy resin - SiO2 composite superhydrophobic layer, or a PTFE - PPS composite superhydrophobic layer, or other hydrophobic layers.

[0051] The PMMA - SiO2 composite superhydrophobic layer is prepared by using the engineering plastic PMMA as the matrix and introducing hydrophobic nano - SiO2 powder. The water contact angle of the PMMA - SiO2 composite superhydrophobic layer is as high as 163°.

[0052] The epoxy resin-SiO2 composite superhydrophobic layer uses epoxy resin with excellent bonding properties as raw materials to prepare an epoxy resin-SiO2 composite superhydrophobic layer with good bonding force to the matrix layer 121. The water contact angle is as high as 160°. At the same time, the friction coefficient of the epoxy resin-SiO2 composite superhydrophobic layer is lower than that of epoxy resin, and as the contact angle increases, the friction coefficient of the epoxy resin-SiO2 composite superhydrophobic layer decreases.

[0053] The PTFE-PPS composite superhydrophobic layer is formed by introducing PPS polyphenylene sulfide into PTFE polytetrafluoroethylene. The PTFE-PPS composite superhydrophobic layer has a secondary structure similar to the lotus leaf surface, with a static contact angle with water of 155° and a rolling angle of 7°.

[0054] The hydrophobic layer 123 is not limited to the above embodiments and can also be made of other materials, which are not specifically defined here.

[0055] The thickness of the hydrophobic layer 123 is 0.005 mm to 0.020 mm.

[0056] In this solution, the intake end of the cylinder head body 1 corresponding to the intake passage 11 is an open end. The staff can see the intake passage 11 of the cylinder head body 1 through the open end. The staff sets the anti-corrosion and hydrophobic structure 12 on the airway wall of the intake passage 11 through the open end, reducing the setting difficulty of the anti-corrosion and hydrophobic structure 12 on the airway wall of the intake passage 11. As Figure 3 shown, the open end communicates with a plurality of intake passages 11. The cylinder head body 1 has only one open end, and the opening area of the open end is larger than the sum of the intake end areas of the plurality of intake passages 11, providing a large enough operating space for the staff.

[0057] In some embodiments, the cover plate 2 is connected to the cylinder head body 1. Optionally, the cover plate 2 is connected to the cylinder head body 1 by bolts. As Figure 2 and 4 shown, mounting holes 13 are circumferentially arranged on the cover plate 2, and threaded holes corresponding to the positions of the mounting holes 13 and communicating therewith are formed on the cylinder head body 1. The cover plate 2 is connected to the cylinder head body 1 by bolts that cooperate with the mounting holes 13 and the threaded holes.

[0058] The connection between the cover plate 2 and the cylinder head body 1 is not limited to bolt connection and can also be other connection forms, such as detachable connection methods such as snap connection or fixed connection methods such as welding.

[0059] In some embodiments, an installation hole 13 for installing a fuel injector is integrated on the cylinder head body 1. The installation hole 13 is opened at a position corresponding to the intake passage 11 and communicates with the intake passage 11, realizing the integration of the fuel injector on the cylinder head body 1, changing the way in the related art where the fuel injector is separately provided and the intake passage of the cylinder head is supplied with air through a separately provided intake pipe, and simplifying the structure of the engine cylinder head.

[0060] At the same time, by integrating the fuel injector on the cylinder head body 1, the way of mixing air and fuel before intake in the related art is changed, realizing the pre - mixing of fuel and air in the cylinder and entering the engine cylinder in a certain air flow organization form, optimizing the mixing effect of fuel and air.

[0061] In some embodiments, the fuel injector is integrated on the engine cylinder head through a common rail pipe.

[0062] When the fuel is methanol, due to the problem of difficult cold start of methanol, to solve the above problem, in some examples, a methanol heater can be added in front of the fuel injector as an auxiliary combustion device for the methanol engine. In some other embodiments, an auxiliary fuel injector is integrated on the engine cylinder head. The auxiliary fuel injector is used to inject auxiliary fuel into the intake passage 11. The auxiliary fuel can be hydrogen, natural gas or gasoline, etc. The boiling point of the auxiliary fuel is lower than that of methanol. As Figure 4 shown, the fuel injector and the auxiliary fuel injector are respectively arranged on the upper side and the lower side of the engine cylinder head.

[0063] When the methanol injector and the auxiliary fuel injector are integrated on the engine cylinder head at the same time, the methanol injector and the auxiliary fuel injector can work simultaneously, alternately, or only one of them can work, so that the engine with this engine cylinder head can select the appropriate fuel according to actual needs.

[0064] In this solution, the fuel injector is integrated on the cylinder head body 1. Preferably, the fuel injector is arranged facing the intake passage 11, so that the fuel injector can inject fuel facing the intake passage 11, reducing fuel wall attachment and shortening the fuel injection duration at the same time, and completing the injection of the target amount of fuel in a shorter time.

[0065] In some embodiments, there are two airway holes arranged side by side in the intake passage 11, and the fuel injector corresponds to the airway hole one by one. That is to say, each airway hole corresponds to a fuel injector. Compared with the way of sharing one fuel injector for two airway holes, it can not only improve the uniformity of fuel distribution in different intake passages 11, but also reduce fuel wall attachment.

[0066] As Figure 3As shown, an installation hole 13 for installing a fuel injector is provided at the upper part of the intake end of the air passage hole. The installation hole 13 is arranged towards the center of the air passage hole. Optionally, the extension direction of the installation hole 13 is close to the setting direction of the air passage hole.

[0067] The engine cylinder head disclosed in this application realizes multi-point injection. Compared with the single-point injection method in the related art, it not only improves the uniformity of fuel distribution in different cylinders, but also can reduce fuel wall attachment.

[0068] An intake passage 11 is formed on the cylinder head body 1. The length of the intake passage 11 is relatively short. After part of the fuel is injected into the intake passage 11, reflux will occur, as Figure 7 shown, the refluxed fuel will enter the pressure stabilizing cavity. Since the pressure stabilizing cavity is connected to all the intake passages 11 of the cylinder head body 1, the fuel refluxed into the pressure stabilizing cavity will enter other intake passages 11 (also known as air leakage). Coupled with the fact that the fuel injection is before the intake valve opens, the fuel quantity in each cylinder is inconsistent and the fuel quantity in each intake passage 11 is unstable, resulting in inconsistent and unstable combustion states in each cylinder.

[0069] To solve the above problems, a partition 14 is provided between two adjacent intake passages 11. The partition 14 is used to separate two adjacent intake passages 11 to prevent air leakage between two adjacent intake passages 11.

[0070] The setting of the partition 14 extends the length of the intake passage 11 to a certain extent. The partition 14 blocks the fuel refluxing from the intake passage 11 to prevent it from flowing to the two side cylinders, so that the fuel refluxing from the intake passage 11 still remains between the two partitions 14 corresponding to the intake passage 11 where the reflux occurs and will not flow to other intake passages 11.

[0071] The partition 14 and the intake passage 11 can be separately connected or integrally cast with the engine cylinder head.

[0072] In this solution, the length of the intake passage 11 is extended by the partition 14. A pressure stabilizing cavity is formed between the edge of the end of the partition 14 far from the intake passage 11 and the cover plate 2. Preferably, the set length of the partition 14 is the limit distance for the fuel to move towards the cover plate 2 after refluxing from the intake passage 11, increasing the distance between the pressure stabilizing cavity and the intake end of the intake passage 11, so as to achieve the purpose of reducing the amount of fuel refluxing into the pressure stabilizing cavity, ensuring the consistency of the fuel quantity in each intake passage 11, and then improving the combustion consistency, and also being beneficial to maintaining the combustion consistency of the same cylinder among different engine cycles.

[0073] As Figure 3As shown, along the direction perpendicular to the plane where the cylinder head body 1 is located (hereinafter referred to as the first direction), the partition 14 is connected to both inner walls of the open end in the first direction; along the direction parallel to the plane where the cylinder head body 1 is located (hereinafter referred to as the second direction), the length of the partition 14 in the second direction is designed by those skilled in the art according to actual needs.

[0074] In the second direction, towards the direction away from the intake passage 11, the thickness of the partition 14 gradually decreases. The thickness of the partition 14 is the dimension of the partition 14 in the third direction, and the third direction is perpendicular to both the first direction and the second direction.

[0075] The thickness of the partition 14 gradually decreases to form a flow passage with a gradually narrowing spacing between two adjacent partitions 14, so as to accelerate the air and improve the mixing effect of air and fuel.

[0076] The dimension of the partition 14 in the third direction is not limited to the above embodiments. In some embodiments, the dimensions of the partition at each position in the third direction are equal. In some embodiments, the partition can be a flat plate or a curved plate.

[0077] In some embodiments, the design method of the length of the partition 14 in the second direction is as follows:

[0078] First, define the initial length of the partition 14 as L0, and the initial length L0 = cylinder bore * α, where the cylinder bore is the diameter of the cylinder liner and α is an empirical coefficient, α = 0.5;

[0079] Observe the backflow situation of the fuel through the CFD calculation model, and according to the simulation results, output the proportion P of methanol flowing back to the pressure stabilizing chamber, P ≤ 5%;

[0080] According to the proportion P of methanol flowing back to the pressure stabilizing chamber output by the simulation results, adjust the length L of the partition 14 to obtain the minimum proportion P' of methanol flowing back to the pressure stabilizing chamber output by the simulation results. The length of the partition 14 corresponding to the minimum proportion P' of methanol flowing back is the target length L' of the partition 14.

[0081] Since this solution extends the distance between the intake passage 11 and the pressure stabilizing chamber, in order to ensure the stability of intake, in some embodiments, the engine cylinder head is lengthened in the second direction to ensure the volume of the pressure stabilizing chamber. In some other embodiments, the cover plate 2 is improved to ensure the volume of the pressure stabilizing chamber.

[0082] In the embodiments where the engine cylinder head is lengthened in the second direction to ensure the volume of the pressure stabilizing chamber, the cover plate 2 can be in the shape of a flat plate or an arc-shaped plate.

[0083] In the embodiments where the cover plate 2 is improved to ensure the volume of the pressure stabilizing chamber, the cover plate 2 has a receiving cavity 21, such as Figure 3 and Figure 7As shown, the accommodation cavity 21 has an open end facing the intake passage 11, and the pressure stabilizing cavity is located between the accommodation cavity 21 and the free end of the partition plate 14.

[0084] The cross-section of the accommodation cavity 21 on the cover plate 2 along the direction perpendicular to the length direction of the cover plate 2 can be semi-circular, rectangular, etc.

[0085] The shape of the cover plate 2 can be the same as or different from the shape of the accommodation cavity 21. For example, Figure 7 As shown, for the embodiment where the shape of the cover plate 2 is the same as the shape of the accommodation cavity 21, the cross-section of the cover plate 2 along the direction perpendicular to its own length direction is semi-circular.

[0086] The cover plate 2 is a three-dimensional structure with an open cavity. This way can achieve the desired technical effect with the least improvement, not only with low development cost, but also with a small increase in the volume of the engine cylinder head.

[0087] For example, Figure 7 As shown, the cross-section of the cover plate 2 along the direction perpendicular to its own length direction is semi-circular.

[0088] In some embodiments, a flow guiding plate is further arranged in the accommodation cavity 21 of the cover plate 2 to guide the air flow and improve the uniformity of the air-fuel mixture.

[0089] In some embodiments, an air inlet is arranged in the middle of the cover plate 2 in the length direction. After the air is fed into the pressure stabilizing cavity through the air inlet, it then moves towards both ends of the cover plate 2 in the length direction and finally enters each intake passage 11.

[0090] In some embodiments, an air inlet is arranged at one end of the cover plate 2 in the length direction. For example, Figure 4 As shown, after the air is fed into the pressure stabilizing cavity through the air inlet, the air moves along the length direction of the cover plate 2 from the air inlet towards the direction away from the air inlet and finally enters each intake passage 11. In this embodiment, the included angles between the moving direction of the air in the cover plate 2 and each intake passage 11 are all equal, improving the uniformity of air intake.

[0091] An intake elbow 22 is arranged on one side of the cover plate 2 in the length direction. The intake elbow 22 can rectify the gas to further optimize the air flow in the cover plate 2 and improve the uniformity of air intake.

[0092] The engine cylinder head disclosed in this application does not need to be provided with a separate intake pipe. The cover plate 2 can not only function as a pressure stabilizing cavity, but also function as an intake pipe, further improving the integration of the engine cylinder head.

[0093] The volume V of the accommodation cavity 21 of the cover plate 2 = engine displacement * β, where β = 0.5 - 0.8 and β is an empirical coefficient.

[0094] The airway wall of the intake passage 11 of the engine cylinder head disclosed in this application is a smooth airway wall, which further reduces fuel wall attachment and fuel backflow.

[0095] The above description is only for the preferred embodiments of this application and the explanation of the applied technical principles, and is not intended to limit this application. For those skilled in the art, various changes and modifications can be made to this application. The scope of the application involved in this application is not limited to the technical solutions formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above application concept. For example, the technical solutions formed by mutually replacing the above features with the technical features (but not limited to) having similar functions disclosed in this application.

Claims

1. An engine cylinder head, characterized in that: The invention comprises a cylinder head body (1) and a cover plate (2), wherein the cylinder head body (1) has a plurality of air inlet passages (11), one end of the cylinder head body (1) corresponding to the air inlet end of the air inlet passage (11) is an open end, and the cover plate (2) is located at the open end. The airway wall of the air intake duct (11) is provided with an anti-corrosion and hydrophobic structure (12), the anti-corrosion and hydrophobic structure (12) comprising a base layer (121) with the airway wall as a base, an anti-corrosion layer (122) for preventing fuel from penetrating into the base layer (121), and a hydrophobic layer (123) for reducing fuel adhesion to the wall, the base layer (121), the anti-corrosion layer (122), and the hydrophobic layer (123) being arranged in sequence from the airway wall to a direction away from the airway wall.

2. The engine cylinder head according to claim 1, characterized in that: The hydrophobic layer (123) is connected to the anti-corrosion layer (122) via a connecting layer (124), and the connecting layer (124) is used to enhance the connection strength between the hydrophobic layer (123) and the anti-corrosion layer (122).

3. The engine cylinder head according to claim 2, characterized in that: The anti-corrosion layer (122) is a gradient Cr alloy layer, and / or the anti-corrosion layer (122) has a thickness of 0.010 mm to 0.030 mm.

4. The engine cylinder head according to claim 3, characterized in that: The connection layer (124) is a CrN alloy layer formed in situ on the base layer (121), and / or the thickness of the connection layer (124) is 0.003 mm to 0.010 mm.

5. The engine cylinder head according to any one of claims 1 to 4, characterized in that: The hydrophobic layer (123) is a PMMA-SiO2 composite super hydrophobic layer, an epoxy resin-SiO2 composite super hydrophobic layer or a PTFE-PPS composite super hydrophobic layer. And / or, the hydrophobic layer (123) has a thickness of 0.005 mm to 0.020 mm.

6. The engine cylinder head according to claim 1, characterized in that: The cylinder head body (1) is provided with a mounting hole (13) corresponding to and in communication with the intake passage (11) and used for mounting a fuel injector.

7. The engine cylinder head according to claim 6, characterized in that: The air intake passage (11) has two air intake holes arranged side by side, and the fuel injectors correspond to the air intake holes one by one.

8. The engine cylinder head according to claim 1, characterized in that: A partition plate (14) is provided between two adjacent air intake passages (11) for separating the two adjacent air intake passages (11) to prevent blowby from occurring between the two adjacent air intake passages (11).

9. The engine cylinder head according to claim 8, characterized in that: The cover plate (2) has a receiving cavity (21), and the pressure stabilizing cavity is located between a cavity wall of the receiving cavity (21) and a free end of the partition plate (14) away from the air inlet passage (11).

10. The engine cylinder head according to claim 9, characterized in that: An air intake elbow (22) is provided on one side of the cover plate (2) in the length direction, and the air intake elbow (22) is communicated with the accommodating cavity; The air intake elbow (22) and the cover plate (2) are located on the same plane.

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