Dual-fuel injector and engine

Abstract

The utility model discloses a dual-fuel injector and an engine. The dual-fuel injector comprises a nozzle structure, a first needle valve and a second needle valve, the nozzle structure is provided with a first cavity, the first needle valve is arranged in the first cavity, when the first needle valve is located at a first preset position, part of the outer wall of the first needle valve makes contact with part of the inner wall of the nozzle structure, and a first pressure chamber is formed between the first needle valve and the nozzle structure; the first needle valve is provided with a second cavity, the second needle valve is arranged in the second cavity, when the second needle valve is located at a second preset position, part of the outer wall of the second needle valve makes contact with part of the inner wall of the first needle valve, and a second pressure chamber is formed between the second needle valve and the first needle valve; on the tangent plane in the axial direction of the nozzle structure, the first pressure chamber is triangular, and the second pressure chamber is quadrilateral. According to the dual-fuel injector, the volume of the pressure chamber is small, fuel residues in the pressure chamber of the injector can be reduced, emission of the injector is improved, and carbon deposition formed in an injection hole is relieved.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a dual-fuel injector and an engine. Background Art

[0002] At present, the volume of the two needle valve pressure chambers of the dual fuel injector is relatively large. When the fuel injection of the injector is finished, the pressure at the nozzle end decreases. If the volume of the pressure chamber is too large, more fuel will remain in the pressure chamber. This part of the fuel cannot be sprayed into the combustion chamber well and cannot be completely mixed with the air, which will cause poor combustion and emission smoke. At the same time, it will accelerate the formation of carbon deposits in the nozzle hole, affecting the reliability of the injector and the engine. Utility Model Content

[0003] The embodiments of the present application provide a dual-fuel injector and an engine to solve the problem that the dual-fuel injector is prone to poor emission and carbon deposition in the spray hole.

[0004] On the one hand, an embodiment of the present application proposes a dual-fuel injector, including a nozzle structure, a first needle valve, and a second needle valve. The nozzle structure has a first cavity, the first needle valve is arranged in the first cavity, when the first needle valve is in a first preset position, part of the outer wall of the first needle valve contacts part of the inner wall of the nozzle structure, and a first pressure chamber is formed between the first needle valve and the nozzle structure. The first needle valve has a second cavity, the second needle valve is arranged in the second cavity, when the second needle valve is in a second preset position, part of the outer wall of the second needle valve contacts part of the inner wall of the first needle valve, and a second pressure chamber is formed between the second needle valve and the first needle valve. On a section along the axial direction of the nozzle structure, the shape of the first pressure chamber is a triangle, and the shape of the second pressure chamber is a quadrilateral.

[0005] According to one aspect of the embodiment of the present application, the outer wall of the first needle valve has a first surface and a second surface connected to each other, and along the axial direction of the nozzle structure, the first surface is parallel to the axial direction of the nozzle structure, and the second surface forms an angle with the axial direction of the nozzle structure; the inner wall of the nozzle structure has a third surface, and along the axial direction of the nozzle structure, the third surface forms an angle with the axial direction of the nozzle structure; the first surface, the second surface and the third surface enclose to form the first pressure chamber.

[0006] According to one aspect of the embodiment of the present application, the inner wall of the first needle valve has a fourth surface and a fifth surface connected to each other, and along the axial direction of the nozzle structure, the fourth surface is perpendicular to the axial direction of the nozzle structure, and the fifth surface forms an angle with the axial direction of the nozzle structure; the outer wall of the second needle valve has a sixth surface, and along the axial direction of the nozzle structure, the sixth surface is perpendicular to the axial direction of the nozzle structure; the fourth surface, the fifth surface and the sixth surface enclose to form the second pressure chamber.

[0007] According to one aspect of the embodiment of the present application, a first fuel channel is formed between the first needle valve and the nozzle structure, and the first fuel channel and the first pressure chamber are arranged along the axial direction of the nozzle structure; when the first needle valve is in the first preset position, the first fuel channel and the first pressure chamber are not connected to each other.

[0008] According to one aspect of the embodiment of the present application, a second fuel channel is formed between the second needle valve and the first needle valve, and the second fuel channel and the second pressure chamber are arranged along the axial direction of the nozzle structure; when the second needle valve is in the second preset position, the second fuel channel and the second pressure chamber are not connected to each other.

[0009] According to one aspect of an embodiment of the present application, the nozzle structure is provided with a first fuel injection hole, a first end of the first fuel injection hole is communicated with the first pressure chamber, and a second end of the first fuel injection hole is communicated with the outside of the nozzle structure.

[0010] According to one aspect of the embodiment of the present application, the first end of the first fuel injection hole is connected to the third surface of the nozzle structure to communicate with the first pressure chamber.

[0011] According to one aspect of an embodiment of the present application, the first needle valve is provided with a second fuel injection hole, a first end of the second fuel injection hole is connected to the second pressure chamber, and a second end of the second fuel injection hole is connected to the first needle valve and the outside of the nozzle structure.

[0012] According to one aspect of the embodiment of the present application, the first end of the second fuel injection hole is connected to the fourth surface or the fifth surface of the first needle valve to communicate with the second pressure chamber.

[0013] On the other hand, an embodiment of the present application provides an engine, comprising the dual-fuel injector as described above, wherein the nozzle structure of the dual-fuel injector is disposed in a cylinder of the engine to inject fuel into the cylinder.

[0014] The dual-fuel injector provided in the embodiment of the present application has a small volume of the first pressure chamber and the second pressure chamber, which can greatly reduce the fuel residue in the pressure chamber at the end of injector injection, improve injector emissions, reduce carbon deposits in the spray hole, reduce injector and engine failures, and improve injector and engine reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A partial structural cross-sectional view of a dual fuel injector in the related art;

[0017] Figure 2 A schematic diagram of the structure of a dual fuel injector provided in an embodiment of the present application;

[0018] Figure 3 A partial structural cross-sectional view of a dual fuel injector provided in an embodiment of the present application;

[0019] Figure 4 for Figure 3 The enlarged view of A in FIG.

[0020] Figure 5 for Figure 3 Enlarged view of point B in FIG.

[0021] Reference numerals:

[0022] 100-body; 200-nozzle structure; 300-first needle valve;

[0023] 400-second needle valve; 210-first pressure chamber; 220-second pressure chamber;

[0024] 230 - first fuel channel; 240 - second fuel channel; 250 - first fuel injection hole;

[0025] 260 - second fuel injection hole; 203 - third surface; 301 - first surface;

[0026] 302- second side; 304- fourth side; 305- fifth side;

[0027] 406-Page 6; 407-Page 7. DETAILED DESCRIPTION

[0028] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0029] In the description of the present application, it should be noted that, unless otherwise specified, the terms "first" and "second" etc. are used for descriptive purposes only and shall not be understood as indicating or implying relative importance; "plurality" means two or more; the terms "inside", "outside", "top", "bottom" etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore shall not be understood as limiting the present application.

[0030] In related technologies, such as Figure 1 As shown, of the two fuel pressure chambers of the dual fuel injector, one is the first fuel pressure chamber a, and the other is the second fuel pressure chamber b, wherein the axial cross-sectional shape of the first fuel pressure chamber a is approximately rectangular, and the axial cross-sectional shape of the second fuel pressure chamber b is approximately hemispherical, and the volumes of these two fuel pressure chambers are both large.

[0031] See also Figure 2 and Figure 3 An embodiment of the present application provides a dual-fuel injector, including a body 100, a nozzle structure 200, a first needle valve 300 and a second needle valve 400, wherein one end of the nozzle structure 200 is connected to the body 100, and the first needle valve 300 and the second needle valve 400 are arranged at the other end of the nozzle structure 200.

[0032] In a specific implementation, the nozzle structure 200 has a first cavity, the first needle valve 300 is disposed in the first cavity, the first needle valve 300 can move in the first cavity, when the first needle valve 300 is in the first preset position, part of the outer wall of the first needle valve 300 contacts part of the inner wall of the nozzle structure 200, and a first pressure chamber 210 is formed between the first needle valve 300 and the nozzle structure 200. The first needle valve 300 has a second cavity, the second needle valve 400 is disposed in the second cavity, the second needle valve 400 can move in the second cavity, when the second needle valve 400 is in the second preset position, part of the outer wall of the second needle valve 400 contacts part of the inner wall of the first needle valve 300, and a second pressure chamber 220 is formed between the second needle valve 400 and the first needle valve 300.

[0033] Figure 3The x direction in the figure represents the axial direction of the nozzle structure 200. In specific implementation, on the section along the axial direction of the nozzle structure 200, the shape of the first pressure chamber 210 is approximately triangular. Compared with the first fuel pressure chamber a with a rectangular cross section in the related art, the volume of the first pressure chamber 210 in the embodiment of the present application is smaller; on the section along the axial direction of the nozzle structure 200, the shape of the second pressure chamber 220 is approximately quadrilateral. Compared with the second fuel pressure chamber b with a hemispherical cross section in the related art, the volume of the second pressure chamber 220 in the embodiment of the present application is smaller. It can be understood that the first pressure chamber 210 is actually an annular space surrounding the first needle valve 300. On the section along the axial direction of the nozzle structure 200, the first pressure chamber 210 has two sections. The above-mentioned axial section shape of the first pressure chamber 210 is triangular, which means that the shape of any one of the sections is approximately triangular.

[0034] Compared with the traditional dual-fuel injector, the dual-fuel injector provided in the embodiment of the present application has smaller volumes of the first pressure chamber 210 and the second pressure chamber 220, which can greatly reduce the fuel residue in the pressure chamber at the end of injector injection, improve injector emissions, reduce carbon deposits in the spray hole, reduce injector and engine failures, and improve injector and engine reliability.

[0035] As a possible implementation, Figure 4 As shown, the outer wall of the first needle valve 300 has a first surface 301 and a second surface 302 connected to each other. Along the axial direction of the nozzle structure 200, the first surface 301 is parallel to the axial direction of the nozzle structure 200, and the second surface 302 forms an angle with the axial direction of the nozzle structure 200. The inner wall of the nozzle structure 200 has a third surface 203. Along the axial direction of the nozzle structure 200, the third surface 203 forms an angle with the axial direction of the nozzle structure 200; and along the axial direction of the nozzle structure 200, the third surface 203 also forms an angle with the second surface 302. When the first needle valve 300 is in the first preset position, the first surface 301 and the second surface 302 are in contact with the third surface 203 respectively, and the first surface 301, the second surface 302 and the third surface 203 enclose a first pressure chamber 210, and the shape of the first pressure chamber 210 on the section along the axial direction of the nozzle structure 200 is approximately a triangle.

[0036] As a possible implementation, Figure 5As shown, the inner wall of the first needle valve 300 has a fourth surface 304 and a fifth surface 305 connected to each other. Along the axial direction of the nozzle structure 200, the fourth surface 304 is perpendicular to the axial direction of the nozzle structure 200, and the fifth surface 305 forms an angle with the axial direction of the nozzle structure 200. The outer wall of the second needle valve 400 has a sixth surface 406. Along the axial direction of the nozzle structure 200, the sixth surface 406 is perpendicular to the axial direction of the nozzle structure 200. When the second needle valve 400 is in the second preset position, the sixth surface 406 contacts the fifth surface 305, and the fourth surface 304, the fifth surface 305 and the sixth surface 406 enclose a second pressure chamber 220, and the shape of the second pressure chamber 220 on the section along the axial direction of the nozzle structure 200 is approximately a quadrilateral.

[0037] In a specific implementation, the outer wall of the second needle valve 400 may further have a seventh surface 407 , and the seventh surface 407 is connected to the sixth surface 406 . Along the axial direction of the nozzle structure 200 , the seventh surface 407 forms an angle with the axial direction of the nozzle structure 200 . When the second needle valve 400 is in the second preset position, the seventh surface 407 contacts the fifth surface 305, and the fourth surface 304, the fifth surface 305, the sixth surface 406 and the seventh surface 407 enclose the second pressure chamber 220. At this time, the second pressure chamber 220 includes two parts, wherein the first part is an annular space surrounding the second needle valve 400, and the second part is an approximately frustum-shaped space located between the second needle valve 400 and the first needle valve 300 in the axial direction of the nozzle structure 200. On the section along the axial direction of the nozzle structure 200, the first part of the first pressure chamber 210 has two sections, and the shapes of these two sections are approximately triangles; the shape of the second pressure chamber 220 as a whole on the section along the axial direction of the nozzle structure 200 is approximately a quadrilateral plus two triangles, and the area of ​​this shape is larger than the area of ​​the quadrilateral. The seventh surface 407 contacts the fifth surface 305, that is, the inclined surface of the outer wall of the second needle valve 400 contacts the inclined surface of the inner wall of the first needle valve 300, which provides a certain degree of buffering effect for the contact between the second needle valve 400 and the first needle valve 300. The second needle valve 400 and the first needle valve 300 are not easily damaged, and the working stability of the injector is relatively high.

[0038] In a possible embodiment, Figure 3As shown, a first fuel channel 230 is formed between the first needle valve 300 and the nozzle structure 200. In actual application, the first fuel flows through the first fuel channel 230 and then is injected outside the injector. The first fuel channel 230 and the first pressure chamber 210 are arranged along the axial direction of the nozzle structure 200, and when the first needle valve 300 is in the first preset position, the first fuel channel 230 and the first pressure chamber 210 are not connected to each other. A second fuel channel 240 is formed between the second needle valve 400 and the first needle valve 300. Similar to the first fuel channel 230, in actual application, the second fuel flows through the second fuel channel 240 and then is injected outside the injector. The second fuel channel 240 and the second pressure chamber 220 are arranged along the axial direction of the nozzle structure 200, and when the second needle valve 400 is in the second preset position, the second fuel channel 240 and the second pressure chamber 220 are not connected to each other.

[0039] In a specific implementation, the nozzle structure 200 is provided with a first fuel injection hole 250, the first end of the first fuel injection hole 250 is communicated with the first pressure chamber 210, and the second end of the first fuel injection hole 250 is communicated with the outside of the nozzle structure 200. In practical applications, when the first needle valve 300 leaves the first preset position, that is, when the first fuel channel 230 is communicated with the first pressure chamber 210, the first fuel flows from the first fuel channel 230 to the first pressure chamber 210, and then passes through the first fuel injection hole 250 to be injected outside the injector. The number of the first fuel injection holes 250 can be multiple, and the multiple first fuel injection holes 250 are arranged at intervals around the axial direction of the nozzle structure 200, and the angles between adjacent first fuel injection holes 250 can be the same. Specifically, when there are multiple first fuel injection holes 250, the first ends of some or all of the first fuel injection holes 250 are connected to the third surface 203 of the inner wall of the nozzle structure 200, so as to realize the communication between the first fuel injection hole 250 and the first pressure chamber 210.

[0040] In a specific implementation, the first needle valve 300 is provided with a second fuel injection hole 260, the first end of the second fuel injection hole 260 is communicated with the second pressure chamber 220, and the second end of the second fuel injection hole 260 is communicated with the outside of the first needle valve 300 and the nozzle structure 200, that is, the second end of the second fuel injection hole 260 is communicated with the outside of the injector. In practical applications, when the second needle valve 400 leaves the second preset position, that is, when the second fuel channel 240 is communicated with the second pressure chamber 220, the second fuel flows from the second fuel channel 240 to the second pressure chamber 220, and then passes through the second fuel injection hole 260 to be injected to the outside of the injector. Similarly, the number of the second fuel injection holes 260 can be multiple, and the multiple second fuel injection holes 260 are arranged at intervals around the axial direction of the nozzle structure 200, and the angles between adjacent second fuel injection holes 260 can be the same. Specifically, when there are multiple second fuel injection holes 260 , the first ends of some or all of the second fuel injection holes 260 are connected to the fourth surface 304 or the fifth surface 305 of the inner wall of the first needle valve 300 to achieve communication between the second fuel injection holes 260 and the second pressure chamber 220 .

[0041] An embodiment of the present application also provides an engine, including a dual-fuel injector as in the above embodiment, wherein the nozzle structure 200 of the dual-fuel injector is disposed in the cylinder of the engine, for injecting fuel into the cylinder and controlling the injection amount of the fuel, thereby providing the engine with stable fuel to ensure normal operation of the engine.

[0042] Those skilled in the art should understand that the above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A dual fuel injector, characterized in that: It includes a nozzle structure, a first needle valve and a second needle valve; The nozzle structure has a first cavity, the first needle valve is arranged in the first cavity, when the first needle valve is in a first preset position, part of the outer wall of the first needle valve contacts part of the inner wall of the nozzle structure, and a first pressure chamber is formed between the first needle valve and the nozzle structure; The first needle valve has a second cavity, the second needle valve is arranged in the second cavity, when the second needle valve is in a second preset position, part of the outer wall of the second needle valve contacts part of the inner wall of the first needle valve, and a second pressure chamber is formed between the second needle valve and the first needle valve; On a section along the axial direction of the nozzle structure, the first pressure chamber is in a triangular shape, and the second pressure chamber is in a quadrilateral shape.

2. The dual fuel injector according to claim 1, characterized in that: The outer wall of the first needle valve has a first surface and a second surface connected to each other, and along the axial direction of the nozzle structure, the first surface is parallel to the axial direction of the nozzle structure, and the second surface forms an angle with the axial direction of the nozzle structure; The inner wall of the nozzle structure has a third surface, and along the axial direction of the nozzle structure, the third surface forms an angle with the axial direction of the nozzle structure; The first surface, the second surface and the third surface together form the first pressure chamber.

3. The dual fuel injector according to claim 1, characterized in that The inner wall of the first needle valve has a fourth surface and a fifth surface connected to each other, and along the axial direction of the nozzle structure, the fourth surface is perpendicular to the axial direction of the nozzle structure, and the fifth surface forms an angle with the axial direction of the nozzle structure; The outer wall of the second needle valve has a sixth surface along the axial direction of the nozzle structure, and the sixth surface is perpendicular to the axial direction of the nozzle structure; The fourth surface, the fifth surface and the sixth surface together form the second pressure chamber.

4. The dual fuel injector according to claim 1, characterized in that A first fuel channel is formed between the first needle valve and the nozzle structure, and the first fuel channel and the first pressure chamber are arranged along the axial direction of the nozzle structure; When the first needle valve is in the first preset position, the first fuel channel and the first pressure chamber are not connected to each other.

5. The dual fuel injector according to claim 1, characterized in that A second fuel channel is formed between the second needle valve and the first needle valve, and the second fuel channel and the second pressure chamber are arranged along the axial direction of the nozzle structure; When the second needle valve is in the second preset position, the second fuel channel and the second pressure chamber are not connected to each other.

6. The dual fuel injector according to claim 2, characterized in that The nozzle structure is provided with a first fuel injection hole, a first end of the first fuel injection hole is communicated with the first pressure chamber, and a second end of the first fuel injection hole is communicated with the outside of the nozzle structure.

7. The dual fuel injector according to claim 6, characterized in that A first end of the first fuel injection hole is connected to the third surface of the nozzle structure to communicate with the first pressure chamber.

8. The dual fuel injector according to claim 3, characterized in that The first needle valve is provided with a second fuel injection hole, a first end of the second fuel injection hole is communicated with the second pressure chamber, and a second end of the second fuel injection hole is communicated with the first needle valve and the outside of the nozzle structure.

9. The dual fuel injector according to claim 8, characterized in that The first end of the second fuel injection hole is connected to the fourth surface or the fifth surface of the first needle valve to communicate with the second pressure chamber.

10. An engine, characterized in that: The dual fuel injector comprises the dual fuel injector as claimed in any one of claims 1 to 9, wherein the nozzle structure is arranged in a cylinder of the engine to inject fuel into the cylinder.

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