EP2304213A1

EP2304213A1 - Components comprising a surface coating for gas injection systems (cng+lpg) of internal combustion engines

Info

Publication number: EP2304213A1
Application number: EP08773496A
Authority: EP
Inventors: Jochen Brand; Christian Welker; Peter Kaestner
Original assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Current assignee: Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date: 2008-06-18
Filing date: 2008-06-18
Publication date: 2011-04-06
Also published as: WO2009152831A1

Abstract

The invention relates to the production of components for gas injection systems and/or internal combustion engines, said components having low fault liability and a long service life. To this end, the components, which come into contact with liquefied gas or natural gas, are coated at least in the regions which come into contact with gas. The coating is characterised in by a high resistance to wear, high corrosion resistance, favourable friction properties, and a good anti-adhesive action.

Description

Components with surface coating for gas injection systems (CNG + LPG) of internal combustion engines

The present invention relates in the field of internal combustion engine technology to the provision of components for gas injection systems, which have a low susceptibility and a long service life.

For several years, attempts have increasingly been made to operate internal combustion engines, in particular of motor vehicles, not as usual with gasoline or diesel, but to use gas as fuel. In particular, liquid gas and / or natural gas is used. On the one hand, it is possible to convert a vehicle whose internal combustion engine is usually supplied with gasoline or diesel, so that the internal combustion engine can be operated with gas. On the other hand, vehicles are currently being manufactured whose internal combustion engines are specially set for gas operation.

The typical gases for use as fuel LPG and natural gas. Liquefied Petroleum Gas (LPG), also referred to as LPG, contains 40% to 60% propane (C ₃ H ₈ ), traces of propene or propylene (C ₃ H ₆ ) with a C double bond, 60% to 40% butane (C ₄ H ₁₀ ) and traces of butene or butylene (C ₄ H ₈ ) with a C double bond. Natural gas (compressed natural gas, CNG) is present in a wide variety of compositions. Normally, a distinction is made between natural gas with the designation "L" and natural gas with the designation "H" from the North Sea region or from the territory of the CIS states. Natural gas labeled "L" typically contains about 85% methane, 4% other alkanes, such as ethane, propane, butane or pentane, and 11% inert gases, and "H" natural gas from the North Sea Region contains about 89% % Methane, 8% other alkanes (ethane, propane, butane, pentane) and 3% inert gases. By contrast, natural gas labeled 'H' from the CIS contains approximately 98% methane, 1% other alkanes (ethane, propane, butane, pentane) and 1% inert gases.

In addition to the major components of liquefied natural gas and natural gas just mentioned, the two gases contain various types of impurities and / or impurities, e.g. Paraffin, oil derivatives, sulfur, carbon black, iron oxide and similar impurities and / or admixtures.

In order to be able to operate a conventional internal combustion engine with LPG or natural gas, one needs a gas injection system. Depending on whether natural gas or LPG is to be used, the respective injection systems differ slightly from each other. When using LPG, an evaporator is used, which evaporates the LPG and with warms the cooling water heat to about 75 ⁰ C. The thus treated gas then has a pressure between 1.2 bar and 2 bar. In contrast, natural gas is a so-called. Pressure reducer, also called pressure regulator used. This reduces the pressure of the natural gas from approx. 200 bar in the tank to 2 bar to 8 bar. By relaxing the gas, heat is removed from the environment (expansion cold). To counteract this, the evaporator and the pressure reducer are connected to the cooling water circuit of the engine. The now properly treated gas is fed into the gas filter and from there to the gas nozzles (injectors). The injectors inject the gas with converted gasoline injection nozzle signals from the gas control unit into the intake manifold of the engine per cylinder. Another possibility when using liquefied petroleum gas as fuel is the method of LPG direct injection, as used by VW (model FSI) and Toyota (model WTi) for gasoline direct injection engines. The liquid gas phase is injected directly into the combustion chamber of the engine, for which a pressure booster pump is needed to achieve high injection pressures. For safety shutdown of the gas line typically various solenoid valves are installed in the respective gas injection system.

Due to the large number of impurities and admixtures in both the LPG and in the natural gas, it is necessary to install a gas filter before the supply of gas to the injectors. With its help, for example, precipitated Olifene and possibly existing solid particles are filtered out, so that they can not damage the injectors. The task of the injectors or the gas injection valves is to distribute the treated gas to the individual cylinders of the engine. These are electro-pneumatic valves. The very fast-flowing gas and the concomitant cooling at full load require a range of application that extends far below 0 ⁰ C. The different power of the motors makes a corresponding spraying of the injectors necessary. Just like the petrol injection nozzles, high demands on working speed, working accuracy and wear resistance must be met.

Injectors can be designed in different ways. Among the best known are the piston injector, the needle injector and the valve injector. In a piston injector, an electromagnetic head moves a piston in a cylinder, which opens a bore with a underside designed as a seal and closes with spring loading. In this case, a non-contact guidance of the piston in the interior of the injector is possible, wherein the position of the piston is influenced either with a spring or a magnetic field. In a needle injector, an electromagnetic head moves a needle in a guide that opens a bore with a conical tip and closes spring loaded. In a flap injector, an electromagnetic head moves an override lever or directly one or more flaps per injector, which open with a designed as a seal underside of a bore and close spring loaded. When using LPG and / or CNG instead of gasoline or diesel as the fuel for an internal combustion engine, the chemical and physical properties of the two types of gas are problematic. On the one hand, impurities in the gases also lead to contamination of those components which are in direct contact with the gas. Furthermore, natural gas and liquefied gas are dry gases which have a very low hydrodynamic and hydrostatic lubricating effect. This leads to the fact that metallic and non-metallic components, which are in constant motion during the operation of the internal combustion engine and rub against each other, degrease very quickly and are impaired by strong friction. In addition, the two types of gas contain aggressive components, which can damage surfaces of metallic and non-metallic components by chemical reactions.

The problems mentioned are currently solved by the use of filters which filter out impurities from the gases, as well as by the admixture of additives to the two types of gas. On the one hand, such additives can grease the components in contact with the gas and bind the aggressive components of the gases, so that there are no chemical reactions with the surface of the components. Nevertheless, the life of the components in contact with the gas in an internal combustion engine is limited. The use of liquefied natural gas or natural gas as fuel in internal combustion engines is currently maintenance-intensive and often leads to disruptions.

The aim of the present invention is therefore to provide components for an internal combustion engine and / or a gas injection system, which are in constant contact with liquefied petroleum gas or natural gas, to provide, which are resistant to the effects caused by the liquefied gas or natural gas, such as impurities, negative friction effects and chemical reactions with the surface.

This object is achieved by the component according to claim 1 and the gas injection system according to claim 10 and the engine according to claim 11. Advantageous developments of the component according to the invention are given in the respective dependent subclaims. Furthermore, the object according to the invention is achieved by the method according to claim 12 for producing a component according to the invention as well as its advantageous embodiments according to the associated dependent claims.

According to the invention, at least a first surface of a component, which with gas, in particular with

Liquefied gas and / or with natural gas, comes in contact with a coating having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m. The low surface energy of the coating expresses its good anti-adhesive effect. The coating is preferably additionally distinguished by favorable frictional properties.

Said first side of the component is exposed to the influence of gas. The first side is preferably completely coated, but may also be only partially coated at particularly stressed areas. By a coating of the component, which When it comes into contact with gas, the wear and friction of the components caused by the very low hydrostatic or hydrodynamic lubrication of liquefied natural gas and natural gas is reduced, the adhesion of impurities or impurities from the gases is reduced, and the aggressive effect of the gases at least partially prevented on the surfaces of the components.

Preferably, a second surface of the component, which does not come into contact with the gas, coated, wherein the coating again has a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or Ober - Surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m having. By coating the first and the second surface of the component, which comes into contact with gas, it is avoided that at the transition points between the first and second surface of the component

Defects in the coating occur, which continue when the component is stressed, for example over the entire coating of the first surface of the component.

The properties of the coating, namely a high wear resistance, a high corrosion resistance, favorable friction properties and a good anti-adhesive effect, are met in particular by carbon-based and / or chromium-based materials, so that materials are preferably selected for the coating, which consists of carbon-based and or chromium-based materials or contain such.

To the favorable carbon-based layers These include, in particular, amorphous carbon coatings (DLC), which are summarized in VDI Guideline 2840 for carbon coatings, as they are characterized by high wear resistance, high corrosion resistance, favorable friction properties and good non-stick properties. Particularly advantageous are the DLC layer variants a-C: H, aC: H: Me, where Me is a metal from the 4th to 6th subgroup of the Periodic Table, aC, ta-C and modifications of aC: H with silicon ( a-C: H: Si) and / or oxygen (aC: H: Si: O).

In the following some excerpts from the mentioned guideline VDI 2840 for carbon coatings are cited. For example, amorphous carbon films are typically classified into seven types of coatings, identified by the abbreviation "aC" (a: amorphous, C: chemical symbol for carbon.) This abbreviation is provided with additional letters (eg "Me") to delineate the seven types of layers ,

Two subgroups can be formed: the hydrogen-free and the hydrogen-containing amorphous carbon layers. Since even without the addition of hydrogen gas small amounts of hydrogen, eg. B. from residual gases are incorporated into the layers, a limit of about 3 at.% Hydrogen content can be regarded as a transition from hydrogen-free to the hydrogen-containing carbon layers.

Hydrogen - free amorphous carbon films are distinguished by the type of bonding of carbon atoms, which predominates in the layers, and by possible additives:

• Hydrogen-free amorphous carbon layers aC Depending on how much energy is given to the particles during deposition, the carbon atoms on the substrate surface are predominantly formed in one of the two hybrid states. At low energies, predominantly sp ² hybridizations result. The layers are so softer. These hydrogen-free amorphous carbon films are given the abbreviation "aC" without additional letters.

• Tetrahedral hydrogen-free amorphous carbon layers ta-C At high deposition energies, predominantly sp ³ hybridizations of the tetrahedral arrangement are formed, which lead to higher hardnesses and also to an increase in residual compressive stresses. These tetrahedral hydrogen-free amorphous carbon layers are then given the abbreviation "ta-

• Metal-containing hydrogen-free amorphous carbon layers aC: Me The third variant differs from the aC layers in that it contains metallic elements. For example, metals are used in which the metal is incorporated into the layer as a compound with the carbon in the form of carbides. Typically, the metals of the 4th to 6th subgroup of the Periodic Table of the Elements are used. These metal-containing, hydrogen-free, amorphous carbon films are denoted by "aC: Me", where "Me" stands for "metal." Instead, they can also the concrete metals are called, for example with tungsten aC: W or with titanium aC: Ti.

For identification of hydrogen-containing amorphous

Carbon layers are appended to the abbreviation a-C with an H as a chemical symbol for hydrogen with a colon. The colon indicates the chemical bonding of the two elements. These layers can be further subdivided into unmodified and modified hydrogen-containing amorphous carbon layers. Modified layers contain additional elements in addition to hydrogen:

• Hydrogen-containing amorphous carbon layers a-C: H

The unmodified hydrogen-containing amorphous carbon layers containing only hydrogen in addition to the carbon are abbreviated as "aC: H." The amount of hydrogen contained can vary widely and affect the properties of the layer.The lower the hydrogen content, the stronger the carbon - atoms networked and the harder it is

Layer. In this type of layer, either the sp ² or sp ³ bond between the carbon atoms may predominate.

• Tetrahedral hydrogen-containing amorphous

Carbon Layers ta-C: H The hydrogen-containing amorphous carbon layers, too, can form predominantly sp ³ hybridizations between the carbon atoms. The modified hydrogen-containing amorphous carbon layers divide into two further groups after the modifying elements: the metal-containing and nonmetal-modified hydrogen-containing amorphous carbon layers. The additional built-in elements are also appended with their abbreviations to the abbreviation aC: H (eg aC: H: SI: O):

• Metal-containing hydrogen-containing amorphous carbon layers a-C: H: Me

The metal-containing hydrogen-containing amorphous carbon layers contain metallic elements, e.g. Tungsten (a-C: H: W) or titanium (a-C: H: Ti).

Modified Hydrogen-Containing Amorphous Carbon Layers a-C: H: X The non-metal-modified hydrogen-containing amorphous carbon layers contain non-metallic elements, e.g. Silicon (Si), oxygen (O), nitrogen (N), fluorine (F) or boron (B), which may also partially form carbides (e.g.

Si and B).

Alternatively, as materials for the inventive coating of the component, chromium-based materials can be selected. Materials which contain or consist of chromium nitride and / or chromium carbide and / or chromium carbonitride are particularly advantageous. Such chromium-based materials likewise have high wear resistance, high corrosion protection and good non-stick properties. Work up.

The coating of the component according to the invention preferably has a thickness in the range of 0.05 μm and 25 μm, in particular in the range of 0.1 μm and 12 μm, in particular in the range of 0.5 μm and 6 μm. Depending on the component and application as well as tolerance requirements, the layer thickness can vary within the stated range.

In particular, the coating of the first surface, i. The surface of the component, which comes into contact with the gas, in particular LPG and / or natural gas, should meet special quality conditions. This includes in particular that the thickness of the coating over the entire surface should not vary as possible. Advantageously, the layer thickness varies over the entire first surface by less than 20%, in particular by less than 10% of the total layer thickness. For many components, e.g. with a piston for an injector, an uneven coating would lead to errors in symmetry.

Depending on the material of the coating, the layer is deposited by means of physical vapor deposition (PVD) or chemical vapor deposition (CVD) or plasma enhanced chemical vapor deposition. For the deposition of carbon-based layers, both PVD and CVD methods are suitable. For the deposition of chromium-based materials PVD processes are preferred.

Examples of components which come into contact with gas in a gas injection system or a motor are, for example, evaporators, which comprise a housing, a pressure regulating diaphragm, a pressure regulating valve, a pressure relief valve and a seal, and / or gas filters and / or electromagnetic Gasabsperrventile containing a housing, a valve piston, a spring, a piston guide and a seal, and / or gas injection valves, which a piston, a Needle, a flap, a spring, a guide, a sealing cone and a seal included, and / or booster pumps, which include a pump piston or a pump rotor, a pressure regulating diaphragm, a spring, a piston guide and a seal. Main reasons for the coating of the above components are:

1. the reduction of wear and friction of metallic and non-metallic components.

2. the reduction of the adhesion of impurities and admixtures in gases on metallic and non-metallic components.

3. the protection of metallic and non-metallic components against aggressive components of the gases.

According to the invention, a gas injection system contains at least one component whose at least one first surface comprises a material having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m, coated. Preferably, all components which come into contact with gas, in particular with LPG or natural gas, with the said material, in particular a carbonaceous and / or chromium-containing material coated.

An engine according to the invention also has at least one component and / or a gas injection system, wherein at least one component on its first side, which comes into contact with gas, with a material having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m, and / or low coefficient of friction is coated. Advantageously, all components of the engine, which come into contact with gas, coated.

The coating of the individual components in gas injection systems and / or motors serves to reduce the friction between moving adjacent components, to produce a non-stick effect against impurities and admixtures of gases, and to prevent aggressive action of the gases on the surfaces of the components. In addition, in particular with gas injectors, the reduction in friction between moving parts additionally achieves a shorter response time, which makes more accurate engine control possible.

For the production of gas-contacting components for gas injection systems and / or engines with a long service life and / or low susceptibility to interference, in particular a first surface of the component, which is in direct contact with the gas, with a material having a hardness in the range of 600 HV and 6000 HV, in particular in the range of

800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m, coated by means of physical vapor phase separation and / or chemical vapor deposition. Plasma-assisted chemical vapor deposition is also used.

The gas-contacting components of a gas injection system or engine are coated with carbon-based, in particular diamond-like, carbon-based materials and / or chromium-based materials. Advantageously, the above-mentioned DLC layers are deposited by means of PVD and / or CVD methods at least on the first side of the component which comes into contact with gas. On the other hand, chromium-based materials are preferably produced by the PVD process. The respective deposition process is carried out until a layer having a thickness in the range of 0.05 μm and 25 μm, in particular in the range of 0.1 μm and 12 μm, in particular in the range of 0.5 μm and 6 μm, is deposited is.

In the following, some examples of components according to the invention are given, with the reasons for the coating of the respective components being given in each case.

Preferably, at least all of the following components of carburetors, electromagnetic gas shut-off valves, injectors, and booster pumps should be coated with a low surface energy hard coat and / or low coefficient of friction.

Since the inside of the housing of an evaporator usually Made of resistant materials, the coating of these insides therefore serves only to reduce the adhesion of impurities. By contrast, the pressure-regulating membrane of an evaporator usually has an elastic material which is less resistant to chemical reactions. A coating is therefore necessary in order to produce an anti-adhesive effect on the one hand and to shield the component against the aggressive components of the gases on the other hand. The pressure regulating valves as well as the overpressure valves of an evaporator and their individual constituents are filigree components which are subjected to high stress. Their coating therefore serves to protect against wear and excessive friction as well as to protect against the adhesion of impurities and to protect against undesired chemical reactions.

The housing inner sides of electromagnetic gas shut-off valves for liquefied petroleum gas injection systems are provided by the coating in particular with a non-stick effect. Since springs are also exposed to no direct friction and consist of materials which are usually not attacked by the aggressive components of the gas, the coating of the springs also serves to prevent adhesion of impurities. Valve piston and piston guide of electromagnetic Gasabsperrventilen touch during the movement of the valve piston in the piston guide, so that it can cause friction and thus wear of the material. In this case, the coating serves to protect against wear and to protect against the adhesion of impurities and to protect the piston, in particular, against aggressive components of the gases. The most endangered components of a piston injector due to the influence of gas, in particular liquid gas and / or natural gas, are the piston and the piston guide. The coating protects the piston and piston guide against wear, adhesion of impurities and chemical reactions. In the case of a needle injector in particular needle and sealing cone must be protected from wear and adhesion of impurities, since these two components allow the sealing effect of the injector. On the other hand, the flap of a flap injector is not exposed to any friction and a coating therefore serves only to prevent the adhesion of impurities since otherwise no sealing effect would be achieved. The leadership of a Klappeninjektors is coated to avoid wear on the one hand, on the other hand to prevent the adhesion of impurities. The said conventional injectors have in common that they have one or more springs. A coating of these serves only for the purpose of reducing the adhesion of impurities.

As already mentioned, one needs a booster pump for direct injection of LPG. The heart of such a pump is the pump piston or pump rotor. Its coating aims to protect the pump piston or pump rotor from wear, adhesion of impurities and aggressive components of the gases. The pressure control diaphragm of the booster pump usually contains easily reacting materials, so that the coating serves both to protect against the adhesion of impurities and to protect against a chemical reaction with aggressive components of the gases. Also booster pumps have one or more springs which are coated with the aim of reducing the adhesion of impurities. A piston guide in the form of a cylinder is coated to reduce friction and provide a better anti-adhesive effect.

All of the components described, ie evaporators, electromagnetic gas shut-off valves, injectors and / or pressure booster pumps contain various seals. Since gaskets are usually composed of plastic-containing materials, they are less resistant to aggressive components of the gases. The sole purpose of coating seals is therefore to avoid chemical reactions between the components of the seals and the aggressive components of the gases.

In the following, some arrangements of several of the components according to the invention are given by means of figures. Show it:

Figure 1 is a perspective view of a

Passenger car, which is a device containing various inventive

Components, for a drive with Autobzw. Has liquefied gas; and FIG. 2 is a perspective view of one

Passenger cars, which contain a device various inventive

Components, having a drive with natural gas.

Figure 1 shows the outline of a conventional car 8. This car 8 has, optionally in addition to a filler neck for gasoline or diesel (in the figure not shown), a tank neck 1 for LPG on. Through this gas can be introduced via a gas line Ia LPG in the in the trunk 9 of the car 8 Autogastank 2 (Ersatzradmuldentank). To switch from gasoline to LPG operation, the switch 6 must be operated. Via a further gas line 2a then the LPG is passed into an evaporator 3 in the engine compartment 10. Preferably, all the gas-carrying lines Ia, 2a, etc. and the inner space of the tank 2 are coated according to the invention. The evaporator 3a, whose components are coated as described above according to the component according to the invention, evaporates the LPG and warms it up with the cooling water heat to 75 ° C. The treated gas is fed further into the gas filter 4, where precipitated Olifene and possibly solid particles are filtered out. The purified LPG is passed on to the gas nozzles 5, which distribute the gas to the individual cylinders. The gas nozzles 5 are controlled by means of a gas control unit. The components of both the gas filter 4 and the gas nozzles 5 are provided with a coating having a hardness in the range of in the range of 600 HV and 6000 HV, and / or a surface energy of less than or equal to 50 mN / m.

Figure 2 shows, as already Figure 1, the structure of a car 8, which has a device for driving with natural gas. In the trunk 9 of the car 8 is a cylindrical tank 2 (bottle tank) into which can be introduced via the filler neck 1 natural gas. After suitable adjustment of the switch 6 flows through the gas line 2a, the natural gas in the pressure reducer 3b, which reduces the pressure of the natural gas of 200 bar in the tank 2 to 2 to 8 bar. The prepared gas is from there through the gas filter 4 directed to the gas nozzles 5 and distributed to the individual cylinders. For operation with natural gas all components coming into contact with natural gas, ie gas lines 1a, 2a, tank 2, pressure reducer 3, gas filter 4 and gas nozzles 5 are coated in accordance with the component according to the invention.

The devices for the gas operation of a motor vehicle shown in FIGS. 1 and 2 contain a number of components which come into contact with liquid gas or natural gas and therefore with a coating having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m. Such devices are suitable for operating a vehicle over long distances without complications with gas. Practical experience has shown that in conventional, uncoated devices after only 4000 km to 8000 km first problems caused by contamination and wear emerge, while devices containing components of the invention can be at least 40,000 km in use, without causing problems which are due to the gas operation.

The coating of components that come into contact with gas in internal combustion engines, where the internal combustion engines are operated instead of gasoline or diesel with LPG or natural gas, solves the problems caused by the use of LPG and / or natural gas, such as by very small hydrostatic or hydrodynamic lubricating effect of the gases occurring high friction phenomena, the adhesion of impurities and Admixtures and the aggressive effect of gases on the surface of the components.

Claims

claims

1. Component of a gas injection system with at least a first surface of the component, which with

Gas, in particular with LPG and / or natural gas, comes into contact, characterized in that the first surface of the component a coating having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800

HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m.

2. Component according to the preceding claim, characterized in that a second surface of the gas-conducting component, which does not come into contact with gas, a coating having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal to 50 mN / m, in particular less than or equal to 30 mN / m.

3. Component according to one of the preceding claims, characterized in that the coating of carbon-based and / or chromium-based

Materials or contains such materials.

4. Component according to one of the preceding claims, characterized in that the coating is a diamond-like, amorphous carbon layer, in particular aC: H and / or aC: H: Me, where Me is a metal of the 4th to 6th subgroup of the Periodic Table , and / or aC and / or ta-C and / or aC: H: Si and / or aC: H: Si: O, contains or consists of.

5. Component according to one of claims 1 to 3, characterized in that the coating is a chromium nitride and / or chromium carbide and / or chromium carbonitride-containing layer or consisting thereof.

6. Component according to one of the preceding claims, characterized in that the coating of the component has a thickness in the range of 0.05 .mu.m and 25 .mu.m, in particular in the range of 0.1 .mu.m and 12 .mu.m, in particular in the range of 0.5 microns and 6 μm.

7. Component according to one of the preceding claims, characterized in that the thickness of the coating of the first surface over the entire first surface by less than

20%, in particular less than 10%, varies.

8. Component according to one of the preceding claims, characterized in that the coating is deposited by means of physical vapor deposition or chemical vapor deposition or plasma-enhanced chemical vapor deposition.

9. Component according to one of the preceding claims, characterized in that the gas-conducting

Component an evaporator, in particular at least one element from the group comprising housing, pressure control diaphragm, pressure control valve, pressure relief valve and seal, and / or a gas filter and / or an electromagnetic Gasabsperrventil, in particular at least one element from the group comprising housing, valve piston, spring, piston guide and Seal, and / or a gas inlet Blow valve, in particular at least one element from the group comprising the piston, needle, flap, spring, guide, sealing cone and seal, and / or a booster pump, in particular at least one element from the group containing

Pump piston, pump rotor, pressure control diaphragm, spring, piston guide and seal, and / or an additional component in a gas injection system, in particular in a motor is.

10. Gas injection system, characterized in that the gas injection system comprises at least one component according to one of the preceding claims.

11. Engine, characterized in that the engine comprises at least one component and / or a gas injection system according to one of the preceding claims.

12. A method for producing a gas, in particular with natural gas and / or liquefied gas, in contact standing component for gas injection systems and / or engines with a long service life and / or low susceptibility to failure, characterized in that a first surface of the component, which with Gas, in particular with natural gas and / or liquid gas, comes into contact, with a material having a hardness in the range of 600 HV and 6000 HV, in particular in the range of 800 HV and 3000 HV, and / or a surface energy of less than or equal 50 mN / m, in particular less than or equal to 30 mN / m, by means of physical vapor deposition or chemical vapor deposition or plasma-enhanced chemical vapor deposition is coated.

13. The method according to the preceding claim, characterized in that the coating contains or consists of a carbon-based, in particular diamond-like carbon-based, material and / or chromium-based material.

14. The method according to any one of claims 12 and 13, characterized in that a component and / or a gas injection system and / or a motor of any one of claims 1 to 11 is prepared.