Fuel oil low-cavitation flow control end structure of oil injector and oil injector

Abstract

The utility model discloses a fuel oil low-cavitation flow control end structure of an oil injector and the oil injector, and relates to the technical field of oil injectors, the fuel oil low-cavitation flow control end structure of the oil injector comprises a control valve seat, a control cavity is arranged in the control valve seat, and a control piston is connected in the control cavity in a sliding mode. An upper cavity is formed between the control piston and the top end in the control cavity, a control end oil inlet hole is formed in the side wall of the control valve seat, a control end oil outlet hole is formed in the top end of the control cavity, and the control end oil inlet hole and the control end oil outlet hole are both communicated with the upper cavity. The upper end of the control end oil outlet quantity hole is connected with a diffusion taper hole, the diameter of the diffusion taper hole is gradually increased from bottom to top, and a plugging control device is arranged at the upper end of the diffusion taper hole and can plug the diffusion taper hole. The cavitation problem of the control end of the oil sprayer can be effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of fuel injector technology, and in particular to a fuel low-cavitation flow control end structure and fuel injector. Background Technology

[0002] Internal combustion engines are the main power source in the transportation sector. Currently, energy conservation and emission reduction have become the main driving force for the development of internal combustion engines. The key technologies for energy conservation and emission reduction mainly involve increasing the injection pressure of the internal combustion engine fuel injection system and replacing traditional gasoline and diesel with carbon-neutral fuels such as methanol, ammonia, dimethyl ether, and hydrogen.

[0003] Increasing the injection pressure of the fuel injector in the fuel injection system helps internal combustion engines save energy and reduce emissions. However, the fuel outlet channel at the control valve end of the existing fuel injector is a small-diameter circular channel, so the pressure here is low. This leads to a significant increase in the pressure difference between the fuel flow at the injector end and the control valve end, resulting in increased fuel cavitation and causing cavitation damage to components.

[0004] Therefore, there is an urgent need in the field for a novel fuel injector structure for controlling fuel cavitation flow and an injector in order to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a fuel low-cavitation flow control end structure and injector for an injector, so as to solve the problems existing in the prior art and effectively reduce the cavitation problem at the injector control end.

[0006] To achieve the above objectives, this utility model provides the following solution:

[0007] This utility model discloses a fuel low-cavitation flow control end structure for an injector, including a control valve seat. A control chamber is provided within the control valve seat, and a control piston is slidably connected within the control chamber. An upper cavity is formed between the control piston and the top end of the control chamber. A control end fuel inlet orifice is provided on the side wall of the control valve seat, and a control end fuel outlet orifice is provided at the top end of the control chamber. Both the control end fuel inlet orifice and the control end fuel outlet orifice are connected to the upper cavity. A diffuser cone orifice is connected to the upper end of the control end fuel outlet orifice. The diameter of the diffuser cone orifice gradually increases from bottom to top. A sealing control device is provided at the upper end of the diffuser cone orifice, which can block the diffuser cone orifice.

[0008] Preferably, the diameter of the oil inlet orifice of the control end is smaller than the diameter of the oil outlet orifice of the control end.

[0009] Preferably, the minimum diameter of the diffuser cone is greater than or equal to the diameter of the oil outlet orifice of the control end oil outlet orifice.

[0010] Preferably, the cone angle of the diffuser cone is >0°, and the cone angle of the diffuser cone is ≤30°.

[0011] Preferably, the upper end of the diffuser cone is provided with a control valve sealing cone surface.

[0012] Preferably, the sealing cone angle of the control valve sealing cone is ≥90°, and the sealing cone angle of the control valve sealing cone is ≤130°.

[0013] Preferably, the upper end of the sealing cone of the control valve is provided with a flow guide cone, and the cone angle of the flow guide cone is greater than the cone angle of the sealing cone of the control valve.

[0014] Preferably, the sealing control device includes a sealing ball and a ball pressing device. The sealing ball can be used to seal the sealing cone surface of the control valve. When the sealing ball seals the sealing cone surface of the control valve, the ball pressing device is used to press the sealing ball tightly.

[0015] Preferably, the ball pressing device is a solenoid valve, and when the solenoid valve is activated, the armature in the solenoid valve can move upward.

[0016] This utility model discloses a fuel injector, including the fuel low-cavitation flow control end structure of the above-mentioned fuel injector.

[0017] This utility model achieves the following technical advantages over the prior art:

[0018] This invention adds a diffuser cone hole at the upper end of the fuel outlet hole at the control end. Since the inner diameter of the diffuser cone hole gradually increases from bottom to top, the fuel flow rate will gradually decrease while the fuel pressure will gradually increase during the process of fuel being injected from bottom to top. This increases the fuel pressure at the control end and thus reduces the cavitation problem. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the fuel low-cavitation flow control end structure of the injector in Embodiment 1;

[0021] In the diagram: 1-Solenoid valve; 2-Sealing ball; 3-Control valve seat; 4-Control piston; 5-Control chamber; 301-Control end oil inlet orifice; 302-Control end oil outlet orifice; 303-Diffuser cone orifice; 304-Control valve sealing cone surface; 305-Flow guide cone surface; 306-Sealing ring line; α1-Diffuser cone orifice cone angle; α2-Sealing cone surface cone angle; α3-Flow cone surface cone angle; d0-Inlet orifice diameter; d1-Outlet orifice diameter; d2-Minimum diameter of diffuser cone orifice. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] The purpose of this invention is to provide a fuel low-cavitation flow control end structure and injector for an injector, so as to solve the problems existing in the prior art and effectively reduce the cavitation problem at the injector control end.

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides a fuel low-cavitation flow control end structure for an injector, including a control valve seat 3. A control chamber 5 is provided within the control valve seat 3, and a control piston 4 is slidably connected vertically within the control chamber 5. An upper chamber is formed between the control piston 4 and the top end of the control chamber 5. A control end fuel inlet orifice 301 is provided on the side wall of the control valve seat 3, which communicates with the fuel inlet channel of the injector. A vertical control end fuel outlet orifice 302 is provided at the top end of the control chamber 5, and both the control end fuel inlet orifice 301 and the control end fuel outlet orifice 302 are connected to the upper chamber. Fuel in the fuel inlet channel of the injector enters the upper chamber through the control end fuel inlet orifice 301, while fuel in the upper chamber is discharged through the control end fuel outlet orifice 302. The innovation of this embodiment is that: the upper end of the oil outlet orifice 302 of the control end is connected to a diffuser cone orifice 303, the diameter of the diffuser cone orifice 303 gradually increases from bottom to top, and a sealing control device is provided at the upper end of the diffuser cone orifice 303, which can block the diffuser cone orifice 303.

[0027] When the fuel injector needs to inject fuel, the blocking control device must be activated to prevent it from blocking the upper end of the diffuser cone orifice 303. Fuel entering the upper chamber from the control end inlet orifice 301 flows out from the control end outlet orifice 302 and the diffuser cone orifice 303. At this time, the pressure at the injector control end is lower than the pressure at the injector injection end, so the control piston 4 moves upward, opening the injector port and initiating fuel injection. During fuel injection, because the inner diameter of the diffuser cone orifice 303 gradually increases from bottom to top, compared to a straight orifice flow channel, the fuel flow rate gradually decreases while the fuel pressure gradually increases. This increases the fuel pressure at the control end, thus reducing cavitation.

[0028] In this embodiment, the diameter d0 of the inlet orifice 301 of the control end is smaller than the diameter d1 of the outlet orifice 302 of the control end. The purpose of this setting is to make the inlet flow rate of the upper cavity less than the outlet flow rate, thereby reducing the fuel volume inside the upper cavity and reducing the pressure at the upper cavity, thereby driving the control piston 4 to move upward.

[0029] In this embodiment, the minimum diameter d2 of the diffuser cone 303 (i.e. Figure 1 The lower diameter of the diffuser cone 303 is greater than or equal to the orifice diameter d1 of the control end fuel outlet orifice 302. This design aims to gradually increase the fuel pressure flowing from the control end fuel outlet orifice 302. If the minimum diameter d2 of the diffuser cone 303 is smaller than the orifice diameter d1 of the control end fuel outlet orifice 302, the fuel pressure will decrease, which will exacerbate cavitation problems.

[0030] In this embodiment, the diffuser cone angle α1 of the diffuser cone 303 is greater than 0°. If the diffuser cone angle α1 = 0°, then it is the same as the control end oil outlet orifice 302, both being circular through holes. Therefore, the cone angle α1 of the diffuser cone 303 must be greater than 0°. Furthermore, the diffuser cone angle α1 of the diffuser cone 303 is less than or equal to 30°. If the diffuser cone angle α1 is too large, it will cause fuel flow separation, resulting in unstable fuel flow.

[0031] In this embodiment, the upper end of the diffuser cone 303 is provided with a control valve sealing cone 304. The diameter of the control valve sealing cone 304 gradually decreases from top to bottom, and the lower end of the control valve sealing cone 304 is integrally formed with the upper end of the diffuser cone. The sealing control device contacts the control valve sealing cone 304, thereby sealing the diffuser cone 303. The fuel flowing out of the diffuser cone 303 flows out along the control valve sealing cone 304 and eventually flows into the return oil hole for return oil.

[0032] In this embodiment, the sealing cone angle α2 of the control valve sealing cone 304 is ≥90° and ≤130°. In addition, those skilled in the art can adjust the specific size of the sealing cone angle α2 according to actual needs, and are not limited to this one method.

[0033] In this embodiment, the upper end of the control valve sealing cone 304 is provided with a flow guide cone 305. The diameter of the flow guide cone 305 gradually decreases from top to bottom, and the lower end of the flow guide cone 305 is integrally formed with the upper end of the control valve sealing cone 304. It should be noted that the cone angle α3 of the flow guide cone 305 is greater than the cone angle α2 of the sealing cone 304. This design aims to make the flow guide cone 305 more streamlined, with a smaller angle to the horizontal plane, allowing fuel to flow out more easily and quickly. If air bubbles are present in the fuel, this facilitates faster expulsion of the bubbles, preventing their accumulation and damage to the injector.

[0034] In this embodiment, the sealing control device includes a sealing ball 2 and a ball pressing device. The sealing ball 2 can be located on the sealing cone surface 304 of the control valve. When the sealing ball 2 is located in the sealing cone surface 304 of the control valve, the sealing ball 2 can be used to seal the sealing cone surface 304 of the control valve. The circular contact line between the sealing ball 2 and the sealing cone surface 304 of the control valve is a sealing ring line 306, thereby forming a line seal. When the sealing ball 2 seals the diffuser cone orifice 303, the ball pressing device is located at the upper end of the sealing ball 2, and the ball pressing device can be used to press the sealing ball 2 tightly.

[0035] In this embodiment, the ball pressing device is a solenoid valve 1 commonly used in fuel injectors, also called a fuel injector solenoid valve. The existing fuel injector solenoid valve structure is similar to that of "a solenoid valve and fuel injector" disclosed in patent number CN113803197A, including a magnetic pole, a coil, an armature assembly, and a return spring. The magnetic pole is placed on the valve body (i.e., the control valve seat 3 in this embodiment), the coil is placed in the magnetic pole, the magnetic pole contact surface faces the armature assembly, and the return spring acts on the armature assembly, pushing the armature assembly away from the magnetic pole contact surface. In the initial state when the armature assembly is not engaged, there is a small magnetic gap between the armature assembly and the magnetic pole contact surface. When the coil is energized, an electromagnetic force is generated on the magnetic pole, attracting the armature assembly and overcoming the return spring force to produce displacement. Similarly, when the solenoid valve 1 in this embodiment is energized, it will attract the armature and move upward. Without the downward pressing action of the armature, the sealing ball 2 will move upward under the oil pressure in the upper cavity, thereby opening the control end oil outlet orifice 302. Of course, those skilled in the art can also set the sealing ball 2 and the armature as an integral structure, so that when the armature moves upward, the sealing ball 2 can also move upward synchronously.

[0036] Example 2

[0037] An injector includes the fuel cavitation flow control end structure of the injector disclosed in Embodiment 1.

[0038] Regarding the specific structure of the injector, a lower cavity is provided at the lower end of the control piston 4 and the control chamber 5. A needle valve is provided in the lower cavity. The upper end of the needle valve is fixedly connected to the control piston 4, and the lower end of the needle valve can be used to block the injector nozzle. A fuel inlet channel is provided on the side wall of the control valve seat 3. One of the fuel inlet channel outlet branches is connected to the control end fuel inlet orifice 301, and the other fuel inlet channel outlet branch is connected to the pressure chamber at the injector nozzle. The pressure chamber at the injector nozzle is also connected to the injector nozzle. When the solenoid valve 1 is energized, the pressure in the upper cavity decreases, while the pressure in the pressure chamber at the injector nozzle remains unchanged. Therefore, the control piston 4 and the needle valve move upward, thereby opening the injector nozzle, and the fuel in the pressure chamber at the injector nozzle is discharged through the injector nozzle. Of course, these are all existing injector structures. In addition, injectors also include structures such as needle valve return springs. The two ends of the needle valve return spring abut against the needle valve and the control valve seat 3, respectively. The function of the needle valve return spring is to provide a downward elastic force to the needle valve, driving it to move downwards and seal the injection port. Besides these, injectors also include other structures, and these other related structures are all existing technologies, so they will not be elaborated upon here.

[0039] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] If this utility model discloses or relates to mutually fixedly connected parts or structural components, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured using a casting process) (except where it is obviously impossible to use an integral forming process).

[0042] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this utility model to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0043] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0044] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0045] It should also be noted that in the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0046] Any adaptive changes made according to actual needs are within the protection scope of this utility model.

[0047] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A fuel low-cavitation flow control end structure for an injector, comprising a control valve seat, a control chamber therein, a control piston slidably connected within the control chamber, an upper cavity between the control piston and the top end of the control chamber, a control end fuel inlet orifice on the side wall of the control valve seat, and a control end fuel outlet orifice at the top end of the control chamber, both the control end fuel inlet orifice and the control end fuel outlet orifice communicating with the upper cavity, characterized in that: The upper end of the oil outlet orifice of the control terminal is connected to a diffuser cone orifice. The diameter of the diffuser cone orifice gradually increases from bottom to top. A sealing control device is provided at the upper end of the diffuser cone orifice. The sealing control device can block the diffuser cone orifice.

2. The fuel low-cavitation flow control end structure of the injector according to claim 1, characterized in that: The diameter of the oil inlet orifice of the control end is smaller than the diameter of the oil outlet orifice of the control end.

3. The fuel low cavitation flow control tip structure of an oil injector according to claim 1, characterized by: The minimum diameter of the diffuser cone is greater than or equal to the diameter of the oil flow rate orifice at the control end.

4. The fuel low cavitation flow control tip structure of an oil injector according to claim 1, characterized by: The diffuser cone angle of the diffuser cone is greater than 0°, and the diffuser cone angle of the diffuser cone is less than or equal to 30°.

5. The fuel low cavitation flow control tip structure of an oil injector according to claim 1, characterized by: The upper end of the diffuser cone is provided with a control valve sealing cone surface.

6. The fuel low cavitation flow control tip structure of an oil injector according to claim 5, characterized by: The sealing cone angle of the control valve sealing cone is ≥90° and the sealing cone angle of the control valve sealing cone is ≤130°.

7. The fuel low cavitation flow control tip structure of an oil injector according to claim 5, characterized by: The upper end of the sealing cone of the control valve is provided with a flow guide cone, and the cone angle of the flow guide cone is greater than the cone angle of the sealing cone of the control valve.

8. The fuel low cavitation flow control tip structure of an oil injector according to claim 5, characterized by: The sealing control device includes a sealing ball and a ball pressing device. The sealing ball can be used to seal the sealing cone surface of the control valve. When the sealing ball seals the sealing cone surface of the control valve, the ball pressing device is used to press the sealing ball tightly.

9. The fuel low cavitation flow control tip structure of an oil injector according to claim 8, characterized by: The ball pressing device is a solenoid valve. When the solenoid valve is activated, the armature in the solenoid valve can move upward.

10. An oil injector characterized by: The fuel cavitation flow control end structure of the injector as described in any one of claims 1-9.

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