CN110118138A - A kind of gaseous-fuel injector - Google Patents

Abstract

The invention belongs to the technical field of fuel injection systems for internal combustion engines, and in particular relates to a gas fuel injector. The gas fuel injector includes a valve body, an oil tank, an air rail and a hydraulic common rail. The air hole on the valve body communicates with the air rail. A needle valve control chamber is left between the needle valve in the valve body and the intermediate body. The needle valve The control chamber communicates with the hydraulic common rail through the oil inlet hole on the intermediate body, and communicates with the oil tank through the communication valve. Its beneficial effects are: the injector is applied to the direct injection technology of compressed natural gas, the engine compression ratio is high, the thermal efficiency is high, the fuel consumption is low, and it can meet the requirements of higher and higher emission standards; the injector passes through the two-position two-way valve Or the two-position three-way valve controls the opening and closing of the needle valve, thereby controlling the injection time and injection volume of natural gas, and can realize the timing, quantitative, and multiple accurate injection of compressed natural gas; the common rail injection technology is continued, the structure is simple, and the processing It is convenient and reduces the production cost.

Description

A gas fuel injector

technical field

The invention belongs to the technical field of fuel injection systems for internal combustion engines, and in particular relates to a gas fuel injector.

Background technique

Most of the traditional vehicle power systems use liquid fuels such as gasoline and diesel as combustion media, and some use natural gas as fuel.

Diesel internal combustion engines need to adopt the latest high-pressure common rail injection technology. The injected diesel oil is directly injected into the combustion chamber of the engine in the form of tiny particles for combustion. The tiny particles cannot be completely combusted, and some PM particles will be emitted into the air. Diesel internal combustion engines also emit a large amount of NOx, COx, SOx and other gases that pollute the environment during combustion. In order to reduce the emission of polluting gases and PM particles, various post-treatment methods such as DOC, SCR, and DPF are required, and the structure is complex and the cost is high. The realization of the National VI emission standards has reached the limit of diesel engine emissions, and it is difficult for diesel engines to meet the requirements of higher emission standards. And diesel is a non-renewable resource, which cannot guarantee the sustainable supply of energy.

When the gasoline internal combustion engine is burning, it cannot perform high-pressure direct injection. It can only perform low-pressure combustion after fuel and air are premixed. The compression ratio is low and the thermal efficiency is low. Along with the combustion of gasoline, there will also be a large amount of NOx, COx, SOx, etc. The emission of gas and PM particles that pollute the environment pollutes the environment. Gasoline is also a non-renewable resource and cannot guarantee a sustainable supply of energy.

The few existing natural gas internal combustion engines on the market are all port injection. The ignition device is used to ignite the natural gas at the intake manifold. The compression ratio of the engine is low, and the thermal efficiency is low, and the natural gas will enter the cylinder with the air and enter the cylinder during the compression process. In the gap, the natural gas (CH4) in the gap cannot be burned, and is directly discharged, which will pollute the air.

With the development of science and technology, natural gas internal combustion engine direct injection technology has appeared. When the internal combustion engine is working, compressed natural gas is injected near the compression top dead center, and the natural gas is ignited by the ignition device to perform combustion and work. Compressed natural gas direct injection technology, with high compression ratio, high thermal efficiency, low fuel consumption, can meet the needs of power and energy consumption. The main component of natural gas is methane (CH4), and the combustion products are mainly carbon dioxide and water, which can greatly reduce the emission of NOx, COx, SOx and other gases that pollute the environment and PM particles. Natural gas can be produced artificially and is a renewable resource that can ensure sustainable energy supply. The development of compressed natural gas direct injection technology has attracted the attention of countries all over the world. The German Volkswagen Group has begun to vigorously develop compressed natural gas direct injection technology. By 2025, about 2,000 CNG filling stations will be built in Germany, increasing the supply to one million compressed natural gas vehicles.

At present, the natural gas direct injection internal combustion engine in the market is still in the research and development stage, and no mature technical route has been formed. The structural design of the natural gas injector is relatively complicated, and the production cost is very high, and there are relatively large fluctuations when the injector controls the injection amount of compressed natural gas.

Contents of the invention

In order to make up for the defects of the prior art, the invention provides a gas fuel injector with low fuel consumption and convenient processing.

The present invention is achieved through the following technical solutions:

A gas fuel injector, including a valve body, an oil tank, an air rail and a hydraulic common rail, the air hole on the valve body communicates with the air rail, a needle valve control cavity is left between the needle valve and the intermediate body in the valve body, and the needle The valve control chamber communicates with the hydraulic common rail through the oil inlet hole on the intermediate body, and communicates with the oil tank through the two-position two-way valve.

Further, a sealing ring is provided between the needle valve and the valve body in the valve body, and the sealing ring can effectively realize the sealing between the compressed natural gas and the hydraulic oil.

Further, the end of the valve body is provided with an injection hole, and an injection cavity is left between the needle valve and the injection hole in the valve body. The needle valve is located at the needle valve control cavity and a needle valve sleeve is provided. With needle spring.

Further, the intermediate body is provided with an oil inlet hole and an oil outlet hole, the oil inlet hole and the oil outlet hole communicate with the needle valve control chamber respectively, and the oil outlet hole communicates with the oil tank through a two-position two-way valve.

Further, the intermediate body is provided with an oil inlet hole, and the oil inlet hole communicates with the hydraulic common rail and the oil tank through a two-position three-way valve.

The beneficial effects of the invention are: the injector is applied to the direct injection technology of compressed natural gas, the engine compression ratio is high, the thermal efficiency is high, the fuel consumption is low, and the requirements of higher and higher emission standards can be met; The one-way valve or two-position three-way valve controls the opening and closing of the needle valve, thereby controlling the injection time and injection volume of natural gas, and can realize timing, quantitative, and multiple accurate injection of compressed natural gas; it continues the common rail injection technology and has a simple structure , processing is convenient, and the production cost is reduced.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Accompanying drawing 1 is the structural representation of gas injector of the present invention;

Accompanying drawing 2 is the structural representation of embodiment 2 of the present invention;

Accompanying drawing 3 is the structural diagram of the needleless valve sleeve of the gas injector of the present invention.

In the figure, 1 valve body, 2 needle valve, 3 intermediate body, 4 needle valve spring, 5 needle valve sleeve, 6 air rail, 7 hydraulic common rail, 8 oil tank, 9 two-position two-way valve, 10 injection chamber, 11 air hole , 12 oil inlet hole, 13 oil outlet hole, 14 needle valve control chamber, 15 sealing ring, 16 nozzle hole, 17 two-position three-way valve, 18 first channel, 19 second channel, 20 third channel.

Detailed ways

The present invention is further described below in conjunction with embodiment.

Example 1

Accompanying drawing 1 is a kind of specific embodiment of the present invention. This invention is a gas fuel injector, including a valve body 1, a fuel tank 8, an air rail 6 and a hydraulic common rail 7, the air hole 11 on the valve body 1 communicates with the gas rail 6, and the needle valve 2 in the valve body 1 communicates with the gas rail 6. A needle valve control chamber 14 is left between the intermediate bodies 3 , and the needle valve control chamber 14 communicates with the hydraulic common rail 7 through the oil inlet hole 12 on the intermediate body 3 , and communicates with the oil tank 8 through the two-position two-way valve 9 .

Further, a sealing ring 15 is provided between the needle valve 2 in the valve body 1 and the valve body 1, and the sealing ring 15 effectively realizes the sealing between the compressed natural gas and the hydraulic oil.

Further, the end of the valve body 1 is provided with an injection hole 16, and an injection chamber 10 is left between the needle valve 2 and the injection hole 16 in the valve body 1, and the needle valve 2 is provided with a needle valve sleeve 5 at the needle valve control chamber 14. , A needle valve spring 4 is set between the needle valve sleeve 5 and the needle valve 2 .

Further, the intermediate body 3 is provided with an oil inlet hole 12 and an oil outlet hole 13, the oil inlet hole 12 and the oil outlet hole 13 communicate with the needle valve control chamber 14 respectively, and the oil outlet hole 13 communicates with the two-position two-way valve 9 and Fuel tank 8 communicates.

The invention is a gas fuel injector. In the injector, an air hole 11 is provided on the valve body 1 . The air hole 11 communicates with the air hole on the intermediate body 3 . The lower end of the air hole 11 communicates with the injection chamber 10 . The lower end of the valve body 1 is provided with an injection hole 16, and the injection hole 16 communicates with the injection chamber 10 when the needle valve 2 is opened.

In the injector, an oil inlet hole 12 and an oil outlet hole 13 are arranged on the intermediate body 3, the diameter of the oil inlet hole 12 is smaller than that of the oil outlet hole 13, the oil inlet hole 12 is connected with the hydraulic common rail 7 pipeline, and the oil outlet hole 13 passes through two Position two-way valve 9 is connected with oil tank 8 pipelines. The lower ends of the oil inlet hole 12 and the oil outlet hole 13 communicate with the needle valve control cavity 14 . The liquid in the hydraulic common rail 7, the needle valve control chamber 14, and the fuel tank 8 can be diesel oil, engine oil, hydraulic oil and other pressure-controllable liquids.

In the injector, a sealing ring 15 is arranged between the valve body 1 and the needle valve 2, and the sealing ring 15 can effectively realize the sealing between the compressed natural gas and the hydraulic oil.

In the injector, the needle valve spring 4 is installed between the upper part of the needle valve 2 and the valve body 1. The needle valve spring 4 presses the needle valve 2 against the sealing cone surface inside the valve body 1. The injection chamber 10 is connected to the injection hole 16. isolation.

When the injector is working, the hydraulic common rail 7 and the needle valve control cavity 14 are kept unblocked, and the gas rail 11 and the injection cavity 10 are kept unblocked. When the two-position two-way valve 9 is closed, the resultant force of the hydraulic pressure on the upper part of the needle valve 2 and the spring force is greater than the gas pressure on the lower part of the needle valve 2, and the needle valve 2 is pressed against the sealing cone surface inside the valve body 1, and the injection chamber 10 is isolated from the nozzle hole 16. When the two-position two-way valve 9 is opened, the needle valve control chamber 14 communicates with the oil tank 8, because the diameter of the oil outlet hole 13 is larger than the diameter of the oil inlet hole 12, and the oil outlet flow rate is greater than the oil inlet flow rate, the pressure in the needle valve control chamber 14 decreases. The hydraulic pressure on the upper end of the needle valve 2 is reduced, and the gas pressure at the lower end of the needle valve 2 is greater than that of the needle. When the combined force of the hydraulic pressure on the upper end of the needle valve 2 and the spring force, the needle valve 2 breaks away from the sealing cone surface inside the valve body 1, moves upward, and the injection chamber 10 communicates with the nozzle hole 16, compressed natural gas is sprayed into the combustion chamber through the nozzle hole 16, and after being ignited by the ignition device, the engine burns to perform work. When the two-position two-way valve 9 is closed, the passage between the needle valve control chamber 14 and the oil tank 8 is cut off, the pressure in the needle valve control chamber 14 rises rapidly, and the resultant force of the hydraulic pressure on the upper end of the needle valve 2 and the spring force , greater than the gas pressure at the lower part of the needle valve 2, the needle valve 2 moves downward until the needle valve 2 is pressed against the sealing cone surface inside the valve body 1, the injection chamber 10 is isolated from the injection hole 16, and the injection of compressed natural gas stops.

Example 2

Accompanying drawing 2 is a kind of specific embodiment of the present invention. This invention is a gas fuel injector, including a valve body 1, a fuel tank 8, an air rail 6 and a hydraulic common rail 7, the air hole 11 on the valve body 1 communicates with the gas rail 6, and the needle valve 2 in the valve body 1 communicates with the gas rail 6. A needle valve control chamber 14 is left between the intermediate bodies 3 , and the needle valve control chamber 14 communicates with the hydraulic common rail 7 through the oil inlet hole 12 on the intermediate body 3 , and communicates with the oil tank 8 through the two-position three-way valve 17 .

Further, a sealing ring 15 is provided between the needle valve 2 in the valve body 1 and the valve body 1, and the sealing ring 15 effectively realizes the sealing between the compressed natural gas and the hydraulic oil.

Further, the end of the valve body 1 is provided with an injection hole 16, and an injection chamber 10 is left between the needle valve 2 and the injection hole 16 in the valve body 1, and the needle valve 2 is provided with a needle valve sleeve 5 at the needle valve control chamber 14. , A needle valve spring 4 is set between the needle valve sleeve 5 and the needle valve 2 .

Further, the intermediate body 3 is provided with an oil inlet hole 12 , and the oil inlet hole 12 communicates with the hydraulic common rail 7 and the oil tank 8 through a two-position three-way valve 17 .

This invention is a gas fuel injector. The opening and closing of the needle valve 2 is controlled by the two-position three-way valve 17. When the two-position three-way valve 17 is powered off, the first channel 18 is connected to the third channel 20, and the needle valve 2 The resultant force of the upper hydraulic pressure and the spring force is greater than the air pressure at the lower part of the needle valve 2, the needle valve 2 is pressed tightly on the sealing cone surface inside the valve body 1, and the spray chamber 10 is isolated from the spray hole 16. When the two-position three-way valve 17 is energized, the second passage 19 is connected to the third passage 20, the needle valve control chamber 14 communicates with the oil tank 8, the pressure in the needle valve control chamber 14 decreases, and the hydraulic pressure on the upper end of the needle valve 2 When the gas pressure at the lower end of the needle valve 2 is greater than the resultant force of the hydraulic pressure at the upper end of the needle valve 2 and the spring force, the needle valve 2 breaks away from the sealing cone inside the valve body 1 and moves upward, the injection chamber 10 communicates with the injection hole 16, and the compressed natural gas It is sprayed into the combustion chamber through the nozzle hole 16, and after being ignited by the ignition device, the engine burns to perform work. When the two-position three-way valve 17 is powered off, the first passage 18 is connected to the third passage 20, the passage between the needle valve control chamber 14 and the oil tank 8 is cut off, the pressure in the needle valve control chamber 14 rises rapidly, and the needle The resultant force of the hydraulic pressure on the upper end of the valve 2 and the spring force is greater than the air pressure on the lower part of the needle valve 2, and the needle valve 2 moves downward until the needle valve 2 is pressed tightly on the sealing cone surface inside the valve body 1, and the injection chamber 10 Isolated from the nozzle hole 16, the injection of compressed natural gas stops.

When a gas fuel injector of the present invention is applied to a lower pressure system, the needle valve sleeve 5 in the injector can be eliminated, as shown in FIG. 3 , so as to reduce the cost of production and processing.

The present invention is not limited to the above-mentioned embodiments, and anyone should know that the same or similar technical solutions as the present invention made under the inspiration of the present invention fall within the protection scope of the present invention.

The technologies, shapes and construction parts not described in detail in the present invention are all known technologies.

Claims (5)

1. A gaseous fuel injector, comprising a valve body, an oil tank, an air rail and a hydraulic common rail, is characterized in that the air hole on the valve body is communicated with the air rail, and a gap is left between the needle valve in the valve body and the intermediate body The needle valve control chamber communicates with the hydraulic common rail through the oil inlet hole on the intermediate body, and communicates with the oil tank through the communication valve. 2. A gas fuel injector according to claim 1, characterized in that: a sealing ring is provided between the needle valve and the valve body in the valve body, and the sealing ring between the compressed natural gas and the hydraulic oil is effectively realized by the sealing ring . 3. A gas fuel injector according to claim 1 or 2, characterized in that: the end of the valve body is provided with an injection hole, and an injection cavity is left between the needle valve and the injection hole in the valve body, and the needle valve is located at A needle valve sleeve is arranged at the needle valve control cavity, and a needle valve spring is sleeved between the needle valve sleeve and the needle valve. 4. A gas fuel injector according to claim 1, characterized in that: the intermediate body is provided with an oil inlet hole and an oil outlet hole, and the oil inlet hole and the oil outlet hole communicate with the needle valve control chamber respectively, The oil outlet hole communicates with the fuel tank through a two-position two-way valve. 5. A gas fuel injector according to claim 1, characterized in that: said intermediate body is provided with an oil inlet hole, and the oil inlet hole communicates with the hydraulic common rail and the fuel tank through a two-position three-way valve.