Needle valve rotating structure of dual-fuel injector and dual-fuel injector

Abstract

The utility model discloses a dual-fuel injector needle valve rotating structure and a dual-fuel injector, and belongs to the technical field of injectors, the dual-fuel injector needle valve rotating structure comprises a first needle valve in a needle valve body, and a second needle valve is arranged in the first needle valve in a penetrating manner; a first fuel channel is defined between the outer wall of the first needle valve and the inner wall of the needle valve body; a second fuel channel is defined between the outer wall of the second needle valve and the inner wall of the first needle valve; the outer walls of the first needle valve and the second needle valve are each provided with a plurality of flow guide grooves, and the flow guide grooves are obliquely arranged. Under the action of pressure, the first fuel or the second fuel washes a flow guide groove of the first needle valve or the second needle valve, so that the first needle valve or the second needle valve rotates; the first needle valve drives the second fuel spray hole to rotate, so that local carbon deposition blockage caused by long-term high temperature of the local second fuel spray hole is avoided; and the second needle valve rotates, and the second fuel rotates to stir the second fuel in the second fuel channel and the pressure chamber, so that the second fuel is more easily thrown out from the second fuel spray hole, and the fuel storage amount in the pressure chamber is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of injector technology, specifically relating to a dual-fuel injector needle valve rotation structure and a dual-fuel injector. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] In direct injection engines, the fuel injector is mounted on the cylinder head, with its head exposed inside the engine combustion chamber, where it operates under high temperature and pressure. To achieve simultaneous supply of different fuels through a single injector, dual-fuel injectors are often designed with multiple fuel supply channels.

[0004] A dual-fuel injector disclosed in the prior art includes an injector body, a needle valve body, a methanol needle valve, and a fuel needle valve; under fuel injection conditions, the fuel needle valve moves to open the fuel injection orifice, allowing fuel to be injected from the fuel injection orifice; under methanol injection conditions, the methanol needle valve moves to open the methanol injection orifice, allowing methanol to be injected from the methanol injection orifice.

[0005] The above solution has the following problems:

[0006] The fuel needle valve and methanol needle valve have pressure chambers at their tips. There is a certain height difference between the bottom of the pressure chamber and the fuel injection hole, which makes it easy for some fuel to be stored. The stored fuel is slowly coked by the high temperature and high pressure working environment. Furthermore, due to the uneven combustion in the cylinder, there are temperature differences in the location of each fuel injection hole. Over time, some injection holes in the high temperature environment are prone to coking. The continuous accumulation of coking products eventually causes the fuel injection holes to become blocked, resulting in abnormal combustion and affecting engine performance and emissions. Utility Model Content

[0007] To address the aforementioned problems, this utility model provides a dual-fuel injector needle valve rotation structure and a dual-fuel injector. By providing inclined guide grooves on the outer walls of both the first and second needle valves, when the first fuel channel is connected to the first fuel injection hole, and the second fuel channel is connected to the second fuel injection hole, under pressure, the first or second fuel will scour the guide grooves on the outer walls of the first or second needle valves. This scouring action causes the first or second needle valve to rotate. The rotation of the first needle valve causes the second fuel injection hole to rotate and change position, resulting in more even heating and preventing localized carbon buildup and blockage caused by prolonged high temperatures in some areas of the second fuel injection hole. Under the fluid scouring, the second needle valve can rotate, and the second fuel will also rotate to a certain extent under the action of the guide grooves, agitating the second fuel in the second fuel channel and pressure chamber, making it easier for the second fuel to be ejected from the second fuel injection hole, reducing the amount of fuel stored in the pressure chamber, thereby reducing carbon buildup. The overall structure is simple, requiring no additional parts, and has a lower manufacturing cost.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A dual-fuel injector needle valve rotation structure is provided at the head of the injector, including a first needle valve passing through the inside of the needle valve body, and a second needle valve passing through the inside of the first needle valve.

[0010] The outer wall of the first needle valve and the inner wall of the needle valve body form a first fuel passage.

[0011] A second fuel passage is formed between the outer wall of the second needle valve and the inner wall of the first needle valve.

[0012] Several flow guide grooves are provided on the outer wall of both the first and second needle valves, and the flow guide grooves are inclined on the outer wall of the first or second needle valve.

[0013] Preferably, a first diameter-changing step is provided at the bottom of the inner wall of the needle valve body. The upper end of the first diameter-changing step is connected to the upper channel of the needle valve body, and the lower end is connected to the lower channel of the needle valve body. The bottom of the lower channel is open, and a first fuel injection hole is provided at the top of the lower channel.

[0014] Preferably, the outer wall of the first needle valve is provided with a second diameter-changing step, the upper end of the second diameter-changing step is connected to the outer wall of the first upper needle valve, the lower end is connected to the outer wall of the first lower needle valve, and a ring of protrusions is provided at the bottom of the second diameter-changing step, which is stuck at the bottom of the first diameter-changing step.

[0015] Preferably, the bottom of the first needle valve is plugged in the bottom opening of the lower channel of the needle valve body, and the bottom of the first needle valve extends out of the bottom opening of the needle valve body by a certain length, which is the exposed end.

[0016] Preferably, a second fuel injection hole is provided on the exposed end side.

[0017] Preferably, a conical limiting step is provided at the bottom of the inner wall of the first needle valve, the lower end of the conical limiting step is connected to the pressure chamber, and the second fuel injection hole is provided on the side of the pressure chamber.

[0018] Preferably, a limiting cone is provided at the bottom of the outer wall of the second needle valve, the size of the limiting cone matches the conical limiting step, and the bottom end of the limiting cone is flush with the bottom end of the conical limiting step.

[0019] Preferably, several rows of guide grooves are evenly arranged on the outer circumference of the first needle valve or the second needle valve, with multiple guide grooves in each row arranged in parallel.

[0020] Preferably, the first fuel passes through the first fuel passage, and the second fuel passes through the second fuel passage.

[0021] A dual-fuel injector includes a dual-fuel injector needle valve rotary structure as described above.

[0022] Compared with the prior art, the advantages and positive effects of this utility model are:

[0023] This invention features inclined guide grooves on the outer walls of both the first and second needle valves. When the first fuel channel is connected to the first fuel injection hole, and the second fuel channel is connected to the second fuel injection hole, pressure causes either the first or second fuel to scour the guide grooves on their outer walls. This scouring action rotates the first or second needle valve. The rotation of the first needle valve causes the second fuel injection hole to rotate and change position, resulting in more even heating and preventing localized carbon buildup and blockage caused by prolonged exposure to high temperatures in certain areas. The fluid scouring also causes the second needle valve to rotate, and the second fuel, guided by the guide grooves, also rotates, agitating the second fuel in the second fuel channel and pressure chamber. This makes it easier for the second fuel to exit through the second fuel injection hole, reducing the amount of fuel stored in the pressure chamber and thus reducing carbon buildup. The overall structure is simple, requiring no additional components and resulting in lower manufacturing costs. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0025] Figure 1 This is a schematic diagram of the injector according to an embodiment of the present invention;

[0026] Figure 2 This is an embodiment of the present utility model. Figure 1 Enlarged cross-sectional view at point I;

[0027] Figure 3This is a schematic diagram of the first needle valve guide groove according to an embodiment of the present utility model;

[0028] Figure 4 This is a schematic diagram of the second needle valve guide groove according to an embodiment of the present invention;

[0029] In the picture:

[0030] 1. Needle valve body; 2. First needle valve; 21. First needle valve guide groove; 3. Second needle valve; 31. Second needle valve guide groove; 4. Second fuel passage; 5. First fuel passage; 6. Pressure chamber; 7. First fuel nozzle; 8. Second fuel nozzle. Detailed Implementation

[0031] This utility model discloses a dual-fuel injector needle valve rotation structure. The rotation of the first needle valve drives the second fuel injection orifice to rotate, ensuring uniform heating and avoiding localized carbon buildup and blockage caused by uneven temperature distribution. The rotation of the second needle valve agitates the second fuel in the second fuel passage and pressure chamber, making it easier for the second fuel to be ejected from the second fuel injection orifice, reducing the amount of fuel stored in the pressure chamber and thus reducing carbon buildup. Furthermore, this utility model also discloses a dual-fuel injector with the aforementioned dual-fuel injector rotation structure.

[0032] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a dual-fuel injector needle valve rotation structure, such as... Figure 1 , Figure 2 As shown, the rotating structure is located at the head of the injector, which is used to mount the injector on the cylinder head. Its head is exposed to the engine combustion chamber, operating in a high-temperature, high-pressure environment. Figure 2 As shown, the rotating structure includes a first needle valve 2 and a second needle valve 3 disposed inside the needle valve body 1. Specifically, a first diameter-changing step is provided at the bottom of the inner wall of the needle valve body 1. The upper end of the first diameter-changing step is connected to the upper channel of the needle valve body 1, and the lower end is connected to the lower channel of the needle valve body 1. The bottom of the lower channel is open, and a first fuel injection hole 7 is provided at the top of the lower channel. The first fuel injection hole 7 penetrates the inner and outer walls of the needle valve body 1 in an inclined manner.

[0034] like Figure 2As shown, the first needle valve 2 is inserted inside the needle valve body 1. The outer wall of the first needle valve 2 and the inner wall of the needle valve body 1 form a first fuel passage 5 for the first fuel. A second diameter-changing step is provided on the outer wall of the first needle valve 2. The upper end of the second diameter-changing step connects to the outer wall of the first upper needle valve, and the lower end connects to the outer wall of the first lower needle valve. A ring of protrusions is provided at the bottom of the second diameter-changing step. These protrusions are used to lock the bottom of the first diameter-changing step (i.e., the lower end of the first diameter-changing step), restricting the first needle valve 2 from sliding further downwards, and simultaneously isolating the first fuel passage 5 from the first fuel injection port 7. It can be understood that when the first needle valve 2 moves upwards, the protrusions move upwards, the first fuel passage 5 connects with the first fuel injection port 7, and the first fuel is injected into the engine combustion chamber through the first fuel injection port 7.

[0035] like Figure 2 As shown, the bottom of the first needle valve 2 is plugged into the bottom opening of the needle valve body 1. At the same time, the bottom of the first needle valve 2 extends out of the bottom opening of the needle valve body 1 by a section. This extended section is the exposed end, and a second fuel injection hole 8 is opened on the side of the exposed end.

[0036] like Figure 2 As shown, a second needle valve 3 is inserted inside the first needle valve 2. A second fuel passage 4 for the second fuel is formed between the outer wall of the second needle valve 3 and the inner wall of the first needle valve 2. A conical limiting step is provided at the bottom of the inner wall of the first needle valve 2, and the lower end of the conical limiting step connects to the pressure chamber 6. The second fuel injection hole 8 is located on the side of the pressure chamber 6. A limiting cone is provided at the bottom of the outer wall of the second needle valve 3. The size of the limiting cone matches the conical limiting step, and the bottom end of the limiting cone at the bottom of the second needle valve 3 is flush with the lower end of the conical limiting step. It can be understood that when the second needle valve 3 moves upward, the limiting cone moves upward, the second fuel passage 4 connects to the pressure chamber 6, and simultaneously connects to the second fuel injection hole 8; the second fuel is injected into the engine combustion chamber through the second fuel injection hole 8.

[0037] Both the first needle valve 2 and the second needle valve 3 can move vertically relative to the needle valve body 1, and the second needle valve 3 can also move vertically relative to the first needle valve 2. For example... Figure 1 As shown, when the first needle valve 2 moves the second needle valve 3 upward, the first fuel passage 5 connects with the first fuel injection orifice 7. At this time, under pressure, the first fuel moves rapidly downward through the first fuel passage 5 and is injected into the engine combustion chamber through the first fuel injection orifice 7. When the first needle valve 2 is closed and the second needle valve 3 moves upward, the second fuel passage 4 connects with the second fuel injection orifice 8. At this time, under pressure, the second fuel moves rapidly downward through the second fuel passage 4 and is injected into the engine combustion chamber through the second fuel injection orifice 8, where a certain amount of the second fuel is stored in the pressure chamber 6.

[0038] like Figure 3As shown, a plurality of first needle valve guide grooves 21 are provided on the outer wall of the first needle valve 2. When the first needle valve 2 is placed perpendicular to the ground, the first needle valve guide grooves 21 have an angle with the horizontal plane, and the angle is an acute angle, that is, the first needle valve guide grooves 21 are inclinedly arranged on the outer wall of the first needle valve 2. The plurality of first needle valve guide grooves 21 are evenly arranged on the outer wall of the first needle valve 2. Specifically, a plurality of rows of first needle valve guide grooves 21 are evenly arranged in the circumferential direction of the outer wall of the first needle valve 2, and the plurality of first needle valve guide grooves 21 in each row are arranged in parallel.

[0039] like Figure 4 As shown, several second needle valve guide grooves 31 are also provided on the outer wall of the second needle valve 3. When the second needle valve 3 is placed perpendicular to the ground, the second needle valve guide grooves 31 form an acute angle with the horizontal plane, that is, the second needle valve guide grooves 31 are inclinedly arranged on the outer wall of the second needle valve 3. Several rows of second needle valve guide grooves 31 are also evenly arranged around the outer wall of the second needle valve 3, and the multiple second needle valve guide grooves 31 in each row are also arranged in parallel.

[0040] It should be noted that, since the first needle valve and the second needle valve are different in size (because the circumferential length of the needle valves is different, and the external surface area is also different), the external surface areas of the first needle valve and the second needle valve are in a certain proportion. Therefore, the guide groove of the first needle valve is larger than that of the second needle valve. The dimensions of the guide groove of the first needle valve and the guide groove of the second needle valve are also in a certain proportion, which is the same as the proportion between the external surface areas of the first needle valve and the second needle valve.

[0041] When the first needle valve 2 moves upward, the first fuel moves downward within the first fuel channel 5, scouring the first needle valve guide groove 21 on the outer wall of the first needle valve 2, such as... Figure 3 As shown by the arrow, due to the inclined design of the first needle valve guide groove 21, the first fuel changes from flowing downward to flowing laterally and downward under the guidance of the first needle valve guide groove 21, and scours the side wall of the guide groove at the end of the first needle valve guide groove 21, applying a certain torque to the first needle valve 2; therefore, during the upward / downward movement of the first needle valve 2, the first fuel scours the first needle valve guide groove 21 under pressure, and under the scour of the fluid, the first needle valve 2 rotates to a certain extent when it moves vertically.

[0042] It should be explained that the needle valve in the injector is often equipped with a stroke component at the tail end that can limit the upward movement height of the needle valve. Therefore, in this embodiment, the upper part of the first needle valve 2 and the second needle valve 3 also has such a limiting component. However, since this embodiment only improves the internal part of the needle valve body at the head of the injector, the tail end of the needle valve will not be described in detail.

[0043] Similarly, when the second needle valve 3 moves upward, the second fuel will also scour the second needle valve guide groove 31 as it moves downward in the second fuel channel 4, and will also apply a certain torque to the second needle valve 3, thereby causing the second needle valve 3 to rotate.

[0044] Under the flushing of fluid, the first needle valve 2 rotates to a certain extent, which will cause the second fuel injection hole 8 to change position. This will prevent some of the second fuel injection holes 8 from being at high temperature for a long time, and prevent the fuel inside some of the second fuel injection holes 8 from easily coking under long-term high temperature. The continuous accumulation of coking products will eventually cause the second fuel injection hole to become blocked.

[0045] Under the flushing of fluid, the second needle valve 3 can rotate, and the second fuel will also rotate under the action of the guide groove, stirring the second fuel in the second fuel channel and the pressure chamber 6, making it easier for the second fuel to be thrown out from the second fuel nozzle 8, reducing the amount of fuel stored in the pressure chamber 6, thereby reducing the generation of carbon deposits.

[0046] In this embodiment, the first fuel can be natural gas, methanol, hydrogen, or other fuels, and the second fuel is typically diesel. It is understood that there are multiple second fuel injection holes and multiple first fuel injection holes, with the multiple second fuel injection holes evenly arranged circumferentially along the side of the pressure chamber, and the multiple first fuel injection holes evenly arranged circumferentially along the top of the lower channel.

[0047] In this embodiment, by providing inclined guide grooves on the outer walls of both the first and second needle valves, when the first fuel channel is connected to the first fuel injection hole and the second fuel channel is connected to the second fuel injection hole, under pressure, the first fuel or the second fuel will scour the guide grooves on the outer walls of the first or second needle valve, thereby causing the first or second needle valve to rotate. The structure is simple, requires no additional parts, and has a lower manufacturing cost.

[0048] In addition, this utility model also discloses a dual-fuel injector, including the dual-fuel injector rotating structure disclosed in the above embodiments. Therefore, the dual-fuel injector with the dual-fuel injector rotating structure also has all the above-mentioned technical effects, which will not be described in detail here.

[0049] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A dual-fuel injector needle valve rotary structure, disposed at the head of the injector, characterized in that, This includes a first needle valve inserted inside the needle valve body, and a second needle valve inserted inside the first needle valve; The outer wall of the first needle valve and the inner wall of the needle valve body form a first fuel passage. A second fuel passage is formed between the outer wall of the second needle valve and the inner wall of the first needle valve. Several guide grooves are provided on the outer wall of both the first needle valve and the second needle valve. The guide grooves are inclined on the outer wall of the first needle valve or the second needle valve. The first fuel passes through the first fuel passage; the second fuel passes through the second fuel passage. The first fuel or the second fuel will scour the guide groove provided on the outer wall of the first needle valve or the second needle valve, and under the action of scour, the first needle valve or the second needle valve will rotate; the rotation of the first needle valve will drive the second fuel injection hole to rotate and change position. Under the flushing of fluid, the second needle valve rotates, and the second fuel also rotates under the action of the guide groove, stirring the second fuel passage and the second fuel in the pressure chamber.

2. The dual-fuel injector needle valve rotary structure as described in claim 1, characterized in that, A first diameter-changing step is provided at the bottom of the inner wall of the needle valve body. The upper end of the first diameter-changing step is connected to the upper channel of the needle valve body, and the lower end is connected to the lower channel of the needle valve body. The bottom of the lower channel is open, and multiple first fuel injection holes are evenly arranged around the top of the lower channel.

3. The dual-fuel injector needle valve rotary structure as described in claim 2, characterized in that, The outer wall of the first needle valve is provided with a second diameter-changing step. The upper end of the second diameter-changing step is connected to the outer wall of the first upper needle valve, and the lower end is connected to the outer wall of the first lower needle valve. A ring of protrusions is provided at the bottom of the second diameter-changing step, and the protrusions are stuck at the bottom of the first diameter-changing step.

4. The dual-fuel injector needle valve rotary structure as described in claim 2, characterized in that, The bottom of the first needle valve is plugged in the bottom opening of the lower channel of the needle valve body. At the same time, the bottom of the first needle valve extends out of the bottom opening of the needle valve body by a certain length, and this extended section is the exposed end.

5. The dual-fuel injector needle valve rotary structure as described in claim 4, characterized in that, Multiple second fuel injection holes are evenly opened circumferentially on the exposed end side.

6. The dual-fuel injector needle valve rotary structure as described in claim 5, characterized in that, A conical limiting step is provided at the bottom of the inner wall of the first needle valve, and the lower end of the conical limiting step is connected to the pressure chamber. The second fuel injection hole is provided on the side of the pressure chamber.

7. The dual-fuel injector needle valve rotary structure as described in claim 6, characterized in that, A limiting cone is provided at the bottom of the outer wall of the second needle valve. The size of the limiting cone matches the conical limiting step, and the bottom end of the limiting cone is flush with the bottom end of the conical limiting step.

8. A dual-fuel injector, characterized in that, Includes a dual-fuel injector needle valve rotary structure as described in any one of claims 1-7.

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