Injector and internal combustion engine

Abstract

The present application provides an injector comprising: an injector body; and a valve needle disposed in the inner space of the injector body. The ejector body is provided with an ejector end, a plurality of spray holes are formed in the ejector end, the spray holes penetrate through the end wall of the ejector end and extend from the inner space of the ejector body to the outside of the ejector body, and the valve needle end of the valve needle can make contact with or be spaced from the inner surface of the ejector end of the ejector body. Wherein the end wall is provided with a recess configured to have a concave surface facing the inner space of the injector body, and the entrance ports of the plurality of injection holes are provided at the concave surface. An internal combustion engine incorporating the injector is also provided. According to the ejector, the concave part is arranged on the end wall of the ejector end part of the ejector body, so that the distance between incident ports is not too small while the arrangement of the incident ports of larger spray holes is allowed, the flow of fluid passing through the spray holes is increased, and the stability of the ejector is not reduced.

Description

Technical Field

[0001] The utility model relates to the field of internal combustion engines, in particular to an injector and an internal combustion engine comprising the injector. Background Art

[0002] In order to meet high emission requirements, carbon peak and carbon neutrality goals, an internal combustion engine using, for example, natural gas as fuel is a feasible technical solution with economic advantages. In such an internal combustion engine, a gas injector is used to replace the existing fuel injector. Generally, both injectors include an injector body and a valve needle arranged inside the injector body. A spray hole is provided at the injector end (nozzle) of the injector body. When the sealed cavity formed between the valve needle and the injector body is destroyed by moving the valve needle, the high-pressure fluid in the sealed cavity will be ejected from the spray hole.

[0003] However, compared with fuel, since the mass volume of gas is relatively small, more volume of gas needs to be consumed per unit time to achieve the same power as fuel. Therefore, without increasing the number of nozzles, the diameter of the nozzle of the gas injector needs to be designed to be 2 to 3 times the diameter of the fuel injector. This results in the gap between the injection ports of the nozzles becoming very small, and in some cases they even overlap. In addition, this larger nozzle diameter leads to increased pressure on the injection port of the nozzle, making it difficult to ensure the reliability of the tip of the injector body.

[0004] In the fuel injector which also requires a large flow rate, there are similar problems as those of the above-mentioned gas injector.

[0005] Therefore, it is necessary to redesign the existing injector to solve the above problems. Utility Model Content

[0006] The object of the present application is to provide an injector and an internal combustion engine including the injector to solve at least one problem existing in the prior art.

[0007] According to one aspect of the present application, an injector is provided, which includes: an injector body; and a valve needle arranged in the internal space of the injector body, wherein the injector body has an injector end, and a plurality of spray holes are arranged on the injector end, and the plurality of spray holes respectively penetrate the end wall of the injector end and extend from the internal space of the injector body to the outside of the injector body, and the valve needle end of the valve needle can contact the inner surface of the injector end of the injector body so that the spray hole is not connected with the fuel channel fluid opened in the injector body, or the valve needle end can be spaced apart from the inner surface so that the spray hole is connected with the fuel channel fluid, wherein a recess is arranged on the end wall of the injector end, and the recess is configured to have a concave surface facing the internal space of the injector body, and the inlet ports of the plurality of spray holes are arranged at the concave surface.

[0008] According to an embodiment of the present application, the inlet ports of the plurality of nozzle holes are arranged at a predefined distance.

[0009] According to an embodiment of the present application, the concave surface includes a bottom and a first side and a second side located on both sides of the bottom.

[0010] According to an embodiment of the present application, the incident port is arranged at the bottom.

[0011] According to an embodiment of the present application, the recess has a depth, and the depth is associated with the diameter of the entrance port and the predefined distance.

[0012] According to an embodiment of the present application, an axial cross-section of the recess is arc-shaped.

[0013] According to an embodiment of the present application, the outer surface of the injector tip is conical.

[0014] According to an embodiment of the present application, the injector is a gas fuel injector.

[0015] According to an embodiment of the present application, the valve needle end of the valve needle has a shape matching the injector end of the injector body.

[0016] According to another aspect of the present application, an internal combustion engine is provided. The internal combustion engine comprises the injector as described above. The injector is mounted on a cylinder head of the internal combustion engine. The injector is used to inject fuel into a combustion chamber of the internal combustion engine.

[0017] By providing a recessed portion on the end wall of the injector end of the injector body, the perimeter of the inner surface of the injector end at the injection port position of the injection hole is increased, thereby allowing the arrangement of injection holes with larger injection ports and ensuring that the gap between the injection ports meets the minimum gap requirement. This increases the flow rate through the injection hole and ensures that the life of the injector is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described below are only used to explain the present application, rather than to limit the scope of the present application. In the accompanying drawings:

[0019] Figure 1 shows a cross-sectional view of an injector according to an exemplary embodiment of the present application;

[0020] Figure 2 Shows Figure 1 An enlarged view of region A of the ejector;

[0021] Figure 3 A cross-sectional view of an ejector in the prior art is shown;

[0022] Figure 4 Shows Figure 1 A cross-sectional view of the ejector along line E-E';

[0023] Figure 5 Shows Figure 1 Magnified view of region A of the injector. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present application are described in detail below in conjunction with examples. In the embodiments of the present application, the present application is described by taking an injector for an internal combustion engine as an example. However, it should be understood by those skilled in the art that these exemplary embodiments do not mean that any limitation is formed on the present application. In addition, the features in the embodiments of the present application can be combined with each other in the absence of conflict. In different drawings, the same parts are represented by the same figure numerals, and for the sake of brevity, other parts are omitted, but this does not mean that the injector of the present application cannot include other parts. It should be understood that the size, proportional relationship and number of parts of the various parts in the drawings are not used as limitations on the present application.

[0025] Figure 1 1 shows a cross-sectional view of an injector 100 according to an exemplary embodiment of the present application, Figure 2 Shows Figure 1 An enlarged view of region A of the injector 100 in FIG.

[0026] Figure 1 , an injector 100 according to an exemplary embodiment of the present application is shown, and the injector 100 includes an injector body 110 and a valve needle 120 arranged in the internal space of the injector body 110. The injector body 110 is the main structure of the injector 100, and the gas channel or the oil channel (fuel channel 111) is opened inside the injector body 110. At the same time, a gas inlet or an oil inlet (fuel inlet) is opened on the injector body 110. The fuel flows into the fuel channel 111 through the fuel inlet, and then enters the gap 130 between the injector body 110 and the valve needle 120. A one-way valve (not shown) is also provided, and the conduction direction of the one-way valve is from the fuel inlet to the fuel channel to prevent fuel backflow. A pressure regulating structure is provided in the injector body 110. Through the pressurization or decompression of the pressure regulating structure, the valve needle 120 is pushed toward or pulled away from the injector end 112 of the injector body 110, thereby separating the gap 130 from the spray hole 113 (see Figure 2 ) are in contact or spaced apart. There are many ways to increase or decrease the pressure, for example, through hydraulic oil.

[0027] like Figure 2As shown, the injector body 110 has an injector end 112, and a spray hole 113 is provided on the injector end 112. The spray hole 113 penetrates the end wall of the injector end 112 and extends from the inner space of the injector body 110 to the outside of the injector body 110, thereby allowing the fluid (in the embodiment, the fuel, which can be a gas, such as natural gas, or a liquid, such as diesel) to be sprayed out from the injector 100. In this embodiment, eight spray holes 113 are shown (see Figure 3 ), however, the number of the nozzle holes 113 may vary. It should be noted that in order to achieve better control of the fluid ejected from the nozzle holes 113, it is preferred to provide a plurality of nozzle holes 113. Figure 1 and Figure 2 In the embodiment, the valve needle 120 contacts the inner surface of the injector end 112, thereby separating the nozzle hole 113 from the above-mentioned gap 130 (i.e., the fluid is not connected). In this way, the gap 130 between the injector body 110 and the valve needle 120 is formed into a gap cavity. The fuel enters the injector body 110 through the fuel inlet and the fuel channel 111 and is retained in the gap cavity (gap 130), while the plurality of nozzle holes 113 are isolated outside the gap cavity. This achieves that when the valve needle 120 contacts the inner surface of the injector end 112, the fuel in the gap cavity is restricted from being ejected from the nozzle hole 113 (i.e., the fuel channel 111 and the gap cavity are not in fluid communication with the plurality of nozzle holes 113), and when the valve needle 120 is no longer in contact with the inner surface of the injector end 112, the fuel in the gap 130 is ejected through the nozzle hole 113 (i.e., the fuel channel 111 and the gap cavity are in fluid communication with the plurality of nozzle holes 113). It should be noted that the inner surface of the injector end 112 can be formed into any shape. In this embodiment, the inner surface is approximately a cone with a tip as the vertex, but other shapes are also feasible.

[0028] Figure 3 A cross-sectional view of an injector in the prior art is shown. Figure 4 Shows Figure 1 FIG. 1 is a cross-sectional view of the injector 100 along line EE′, wherein EE′ represents a cross-sectional position along the position of the injection port 113 a of the injection hole 113 .

[0029] According to an exemplary embodiment of the present application, a recess 140 is formed on the end wall of the injector end 112, and the recess 140 is configured to have a concave surface facing the inner space of the injector body 110. The spray hole 113 includes an inlet 113a located in the injector body 110 and an outlet 113b outside the injector body 110, wherein the inlet 113a is arranged at the concave surface. Figure 3As shown, in the prior art, it is not possible to simultaneously set enough injection ports (incident ends) 113a of the nozzle holes 113 at the position indicated by the dotted line (the dotted line indicates the tangent circle formed by the plane at the position and the inner surface). Figure 4 As shown in the figure, when the recess 140 is provided, at the same position, the diameter of the tangent circle of the inner surface indicated by the dotted line is significantly increased compared to when there is no recess 140. That is, the circumference of the inner surface at this position is increased, thereby allowing more inlets 113a of the nozzle holes 113 to be provided at this position, or in the case of having the same number of inlets 113a of the nozzle holes 113, the spacing between the inlets 113a of the nozzle holes 113 is increased. Figure 5 This is further explained. In this way, when the diameter of the injection port 113a of the injection hole 113 needs to be increased, the injector end 112 provided with the recess 140 can still satisfy the requirement that the distance between the injection ports 113a is greater than the minimum allowable distance, thereby ensuring that there is a sufficient gap between the injection ports 113a of the injection hole 113 to meet the strength requirement. At the same time, the sufficient gap also improves the reliability of the injector end 112 of the injector body 110, thereby improving the reliability of the entire injector 100.

[0030] Preferably, the inlet ports 113a of the plurality of spray holes 113 located in the recess 140 are arranged at a predefined distance. In this way, the fuel can be uniformly sprayed through the spray holes 113, thereby allowing the fuel to be better distributed in the combustion chamber of the internal combustion engine. However, alternatively, in some embodiments, the inlet ports 113a of the spray holes 113 are arranged to be spaced at different distances. For example, some spray holes 113 are uniformly distributed in one half of the recess 140, and the same number of spray holes 113 are also uniformly distributed at the same intervals in the other half, and no spray holes 113 are provided at the boundaries adjacent to each half, so as to achieve selective spraying of fuel in different directions.

[0031] According to an exemplary embodiment of the present application, Figure 2 As shown in FIG. 1 , the concave surface of the recess 140 has a bottom 143 and a first side 141 and a second side 142 located on both sides of the bottom 143. That is, in a cross section (axial cross section) including the central axis of the injector end 112, the outer contour of the recess 140 is a quadrilateral. For example, the outer contour in the axial cross section may be as follows: Figure 214 is shown as a trapezoid, that is, the bottom 143 is parallel to the rest of the inner surface of the corresponding side, but in practice the bottom 143 is formed in a ring shape. Alternatively, the outer contour of the recess 140 can be any shape suitable for processing, as long as the shape can increase the circumference of the tangent circle of the inner surface at the position where the injection port 113a of the injection hole 113 is set compared to not having the recess 140. In this embodiment, the second side 142 is also formed in a ring shape, but in other embodiments, the second side can be conical, or circular, that is, the inner surface of the injector body does not have a tip 150.

[0032] In order to maximize the circumference of the inner surface at the EE′ cross section, according to an exemplary embodiment of the present application, the injection port 113 a of the spray hole 113 is disposed at the bottom 143 of the concave surface of the recess 140 .

[0033] Combine the following Figure 5 The method of calculating the dimensions of the trapezoidal recess will be described in detail. Figure 5 Shows Figure 1 FIG. 1 is an enlarged view of region A of the injector 100 in FIG. 1 , wherein the parameters required to calculate the size of the recess are identified.

[0034] The recess 140 has a trapezoidal cross-sectional shape, and thus the recess 140 has a depth Δh measured perpendicular to its bottom surface. The depth Δh determines the thickness that needs to be machined on the conical inner surface of the injector end 112 of the injector body 110 during the machining of the injector 100, and is therefore a critical parameter. At the injector end 112 of the injector body 110, the diameter s of the tangent circle of the inner surface at the EE' section is calculated as:

[0035] s=(t+d)×n / π (1)

[0036] Wherein, t is the distance between the inlet ports 113a of the nozzle holes 113 (predetermined distance), d is the diameter of the inlet ports 113a of the nozzle holes 113, and n is the number of the nozzle holes 113. Figure 5 In the figure, s1 represents the diameter of the cut circle of the inner surface of the injector at the E-E' section in the prior art, and s2 represents the diameter of the cut circle of the inner surface of the injector 100 at the E-E' section according to the embodiment of the present application. It can be seen that when the distance t between the inlets 113a increases, the diameter s of the cut circle of the inner surface at the E-E' section increases from s1 to s2 accordingly, which also leads to the need for processing depth Δh. Therefore, the depth Δh is a parameter associated with the diameter d of the inlets 113a and the distance t between the inlets 113a.

[0037] Alternatively, the recess 140 may be in other shapes. For example, in the interface including the central axis of the injector end 112 , the outer contour of the recess 140 is arc-shaped (i.e., the axial cross section of the recess 140 is arc-shaped) to reduce the stress generated on the recess 140 during the operation of the injector 100 .

[0038] Back to Figure 1 , generally, the shape of the outer surface of the injector end 112 is a body of revolution. In the present embodiment, the outer surface is formed into a conical shape identical to the inner surface, however in other embodiments, the outer surface may also be, for example, a truncated cone shape. Also, in the present embodiment, the direction of the spray hole 113 (from the injection port 113a to the injection port 113b) is substantially perpendicular to the inner surface of the injector end 112, however in other embodiments, the direction of the spray hole 113 may be arbitrary, for example, parallel to the valve needle 120.

[0039] Preferably, the valve needle end 121 of the valve needle 120 has a shape that matches the inner surface of the injector end 112 of the injector body 110. As shown in the figure, in this embodiment, the position where the valve needle 120 contacts the inner surface is located outside the recess 140, so the valve needle end 121 of the valve needle 120 is set to a truncated cone, so as to match the conical inner surface to achieve good sealing. Alternatively, the position where the valve needle end 121 of the valve needle 120 contacts the inner surface can also be located inside the recess 140, and the valve needle end 121 of the valve needle 120 can still be set to a truncated cone to abut against the surface (first side 141) of the recess 140. In another embodiment, the contact position is located at the junction of the recess 140 and other parts of the inner surface, so the valve needle end 121 of the valve needle 120 is set to two truncated cones with different vertex angles arranged in a superimposed manner. In summary, the shape of the inner surface of the injector end 112 of the injector body 110 matches the shape of the valve needle end 121 of the valve needle 120 , so as to better achieve the sealing required by the injector 100 .

[0040] The injector according to the exemplary embodiment of the present application provides a recess on the end wall, so that the distance between the injection ports of the spray holes can be changed by simple machining, so as to allow more spray holes or larger spray holes to be provided.

[0041] According to a further exemplary embodiment of the present application, an internal combustion engine is also provided, which includes the injector 100 described in any one of the above embodiments, which is installed on a cylinder head of the internal combustion engine and is used to inject fuel into a combustion chamber of the internal combustion engine.

[0042] The above-mentioned embodiment of the present application provides an injector and an internal combustion engine including the injector. According to the technical solution of the present application, by providing a recessed portion on the end wall of the injector end of the injector body, the circumference of the inner surface at the inlet of the spray hole is increased, thereby allowing the inlet of a larger spray hole to be provided while ensuring that the distance between the inlet ports is not too small, thereby increasing the fluid flow through the spray hole without reducing the stability of the injector.

[0043] The present application has been described in detail above in conjunction with specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and do not constitute a limitation to the present application. For those skilled in the art, various modifications or changes can be made to the present application without departing from the spirit of the present application, and these modifications or changes do not depart from the scope of the present application.

Claims

1. An ejector (100), comprising: An injector body (110); as well as a valve needle (120) disposed in the inner space of the injector body, The injector body has an injector end (112), and a plurality of spray holes (113) are arranged on the injector end. The plurality of spray holes respectively penetrate the end wall of the injector end and extend from the internal space of the injector body to the outside of the injector body. The valve needle end (121) of the valve needle can contact the inner surface of the injector end of the injector body, so that the spray hole is not connected to the fluid of the fuel channel (111) opened in the injector body, or the valve needle end can be spaced apart from the inner surface, so that the spray hole is connected to the fluid of the fuel channel. It is characterized in that a recess (140) is provided on the end wall of the injector end, the recess is configured to have a concave surface facing the inner space of the injector body, and the inlets (113a) of the plurality of injection holes are provided at the concave surface.

2. The injector according to claim 1, characterized in that The inlet ports of the plurality of nozzle holes are arranged at a predetermined distance from each other.

3. The injector according to claim 2, characterized in that The concave surface includes a bottom (143) and a first side (141) and a second side (142) located on both sides of the bottom.

4. The injector according to claim 3, characterized in that The incident port is arranged at the bottom.

5. The injector according to claim 4, characterized in that The recess has a depth (Δh) that is associated with the diameter of the entrance opening and the predefined distance.

6. The injector according to claim 2, characterized in that The axial cross section of the recessed portion is arc-shaped.

7. The injector according to any one of claims 1 to 6, characterized in that The outer surface of the injector tip is conical.

8. The injector according to any one of claims 1 to 6, characterized in that The injector is a gas fuel injector.

9. The injector according to any one of claims 1 to 6, characterized in that The valve needle end of the valve needle has a shape that matches the inner surface of the injector end.

10. An internal combustion engine, characterized in that: The internal combustion engine comprises the injector according to any one of claims 1 to 9, the injector being mounted on a cylinder head of the internal combustion engine, the injector being used to inject fuel into a combustion chamber of the internal combustion engine.

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