Electronic fuel injector assembly structure

Abstract

This application relates to the field of electronically controlled high-pressure fuel injectors. To further improve the service life of fuel injectors, an electronically controlled fuel injector assembly structure is provided, including a valve body, and a plunger chamber and a high-pressure oil chamber that are interconnected within the valve body. A metering valve, a guide sleeve, and a clamping sleeve are arranged from bottom to top within the high-pressure oil chamber. A first valve core assembly is arranged within the guide sleeve, and a metering channel is arranged within the metering valve. The first valve core assembly includes a solenoid armature, with a hemispherical socket formed at the lower end of the armature, and a ceramic hemisphere that mates with the socket. The ceramic hemisphere is used to control the opening or closing of the metering channel. Multiple degassing structures are provided within the socket. By providing degassing structures, residual gas between the ceramic hemisphere and the socket is stored, thereby reducing the probability of cavitation on the surface of the ceramic hemisphere or the socket, and improving the service life of the fuel injector.

Description

Technical Field

[0001] This application relates to the field of electronically controlled high-pressure fuel injectors, and in particular to an electronically controlled fuel injector assembly structure. Background Technology

[0002] The high-pressure common rail fuel injection system mainly consists of an electronic control unit (ECU), a high-pressure fuel pump, a common rail, electronically controlled injectors, and various sensors. Among these, the electronically controlled injector is the most critical and complex component of the common rail fuel system. Its function is to control the opening and closing of a solenoid valve based on control signals from the ECU, injecting fuel from the high-pressure rail into the combustion chamber at optimal injection timing, quantity, and rate. The electronically controlled injector includes the injector nozzle, control piston, control orifice, and control solenoid valve. When the solenoid valve is de-energized, it closes the control piston, shutting off the nozzle; when the solenoid valve is energized, the injector begins to inject fuel.

[0003] To improve the sealing accuracy of the high-pressure return oil point and the working precision of the armature, prior art (201310626493.5) discloses a high-pressure common rail electronically controlled fuel injector, including: a solenoid valve, an armature assembly, a control valve assembly, a hemispherical ball valve, and a fuel injector assembly. The lower end of the armature shaft of the armature assembly has a ball socket, and the spherical surface of the hemispherical ball valve mates with the ball socket. The plane of the hemispherical ball valve seals the high-pressure return oil hole of the control valve assembly. This hemispherical ball valve structure achieves high sealing accuracy at the high-pressure return oil point of the fuel injector and precise armature working. This hemispherical ball valve structure is simple and has good injection performance; however, with the gradual increase in vehicle emission requirements, fuel systems are also moving towards higher injection pressures, placing higher demands on the fuel injector's resistance to cavitation erosion and wear resistance. Because of its large contact area, the hemispherical structure is prone to cavitation erosion.

[0004] To reduce the probability of cavitation corrosion, surface strengthening and coating treatments are usually applied to related components to improve their hardness. However, surface treatment of related components increases the manufacturing cost of fuel injectors. Summary of the Invention

[0005] To further reduce the probability of injector cavitation and improve its service life, this application provides an electronically controlled injector assembly structure.

[0006] This application provides an electronically controlled fuel injector assembly structure, the specific technical solution of which is as follows: It includes a valve body with an oil inlet channel; it also includes a plunger chamber and a high-pressure oil chamber that are interconnected within the valve body, wherein the oil inlet channel is connected to the plunger chamber; a metering valve, a guide sleeve, and a clamping sleeve are arranged from bottom to top within the high-pressure oil chamber, wherein the clamping sleeve is threadedly connected to the valve body and is used to limit the relative position of the guide sleeve and the metering valve; a first valve core assembly is arranged within the guide sleeve, and a metering channel is arranged within the metering valve. The first valve core assembly includes a solenoid armature, the lower end of which forms a hemispherical ball socket, and a ceramic hemisphere that mates with the ball socket; one end of the ceramic hemisphere corresponds to the metering channel, and the ceramic hemisphere is used to control the opening or closing of the metering channel; wherein multiple degassing structures are arranged within the ball socket.

[0007] Furthermore, the plurality of degassing structures include a first degassing structure and a second degassing structure; wherein the first degassing structure is located at the top of the ball socket, and the second degassing structure is located on the side of the ball socket.

[0008] Furthermore, the first degassing structure and / or the second degassing structure are rotating structures.

[0009] Furthermore, the metering channel includes a first diffusion hole, a first shrinking hole, a second shrinking hole, and a second diffusion hole arranged sequentially.

[0010] Furthermore, the length and diameter of the first diffusion hole are greater than the sum of the lengths of the first shrinking hole, the second shrinking hole, and the second diffusion hole.

[0011] Furthermore, an oil drain chamber is provided between the metering valve and the guide sleeve; wherein the oil drain chamber includes a first oil drain area located in the metering valve and a second oil drain area located in the guide sleeve.

[0012] In this application, the valve body is the main structure of the electronic fuel injector assembly, and is used to install other components of the fuel injector. The valve body contains an inlet channel, as well as a plunger chamber and a high-pressure oil chamber that communicate with each other. The plunger chamber is located below the valve body, and the high-pressure oil chamber is located above the valve body. Fuel enters the plunger chamber through the inlet channel, and the plunger's up-and-down movement within the plunger chamber creates high-pressure oil that enters the high-pressure oil chamber. Within the high-pressure oil chamber, from bottom to top, are a metering valve, a guide sleeve, and a clamping sleeve. The metering valve is cylindrical and slides with the valve body. The guide sleeve is also cylindrical, with a guide hole inside which a first valve core assembly is located. The guide sleeve is also slidably connected to the valve body. The clamping sleeve is threaded to the valve body and is used to define the relative positions of the guide sleeve and the metering valve within the valve body.

[0013] The first valve core assembly includes a solenoid armature with a hemispherical socket at its lower end and a ceramic hemisphere that mates with the socket. When energized, the solenoid armature moves up and down within a guide sleeve according to a control command, thereby causing the ceramic hemisphere to move up and down. A metering channel is provided within the metering valve, with one end of the ceramic hemisphere corresponding to the metering channel. Specifically, the overall structure of the ceramic hemisphere includes a hemisphere formed by a hemispherical surface and a bottom surface. The hemispherical surface mates with the socket, and the bottom surface mates with the upper surface of the metering channel. The up and down movement of the ceramic hemisphere controls the opening or closing of the metering channel, thereby opening or closing the oil drain channel within the high-pressure fuel chamber. Furthermore, the ceramic hemisphere of this application, based on its mating with the spherical surface of the solenoid armature, enhances its adaptive adjustment capability, automatically adjusts the sealing angle, and improves the overall sealing performance. Additionally, in this invention, multiple degassing structures are also provided within the socket of the solenoid armature. By incorporating a degassing structure to store residual gas between the ceramic hemisphere and the socket during operation, the probability of cavitation corrosion on the surface of the ceramic hemisphere or socket is reduced, thus extending the injector's service life. Furthermore, the reduction of residual gas between the ceramic hemisphere and socket also decreases the gas resistance within the socket, improving the response speed of the high-pressure chamber control valve and consequently enhancing the injector's injection accuracy. Additionally, the degassing structure can be equipped with lubricating oil, further increasing the operating speed of the ceramic hemisphere within the socket and further improving the response speed of the high-pressure chamber control valve, ultimately enhancing the injector's injection accuracy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of an electronically controlled fuel injector assembly according to the present invention;

[0015] Figure 2 This is a schematic cross-sectional view of the overall structure of an electronically controlled fuel injector assembly according to the present invention;

[0016] Figure 3 for Figure 2 Schematic diagram of the structure at point A in the middle;

[0017] Figure 4 This is a schematic diagram of a metering valve in an electronically controlled fuel injector assembly according to the present invention;

[0018] Figure 5 This is a schematic diagram of a guide sleeve for an electronically controlled fuel injector assembly according to the present invention;

[0019] Explanation of reference numerals in the attached figures:

[0020] 100 Valve body, 101 Oil inlet channel, 110 Piston cavity, 200 High-pressure oil cavity, 210 Metering valve, 2100 Metering channel, 2101 First diffuser hole, 2102 First narrowing hole, 2103 Second narrowing hole, 2014 Second diffuser hole, 220 Guide sleeve, 221 First valve core assembly, 222 Solenoid valve armature, 2220 Ball socket, 2221 First degassing structure, 2222 Second degassing structure, 223 Ceramic hemisphere, 224 Guide hole, 230 Pressing sleeve, 240 Oil drain cavity, 241 First oil drain area, 242 Second oil drain area. Detailed Implementation

[0021] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limiting this invention.

[0022] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0023] In the description of this specification, the references to "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] As shown in the attached drawings, this invention discloses an electronically controlled fuel injector assembly structure, including a valve body 100, with an oil inlet channel 101 disposed within the valve body 100; it also includes a plunger chamber 110 and a high-pressure oil chamber 200 disposed within the valve body 100 and communicating with each other, wherein the oil inlet channel 101 communicates with the plunger chamber 110; a metering valve 210, a guide sleeve 220, and a clamping sleeve 230 are disposed from bottom to top within the high-pressure oil chamber 200, wherein the clamping sleeve 230 is threadedly connected to the valve body 100 and is used to limit the relative position of the guide sleeve 220 and the metering valve 210. Position; A first valve core assembly 221 is provided inside the guide sleeve 220, and a metering channel 2100 is provided inside the metering valve 210. The first valve core assembly 221 includes a solenoid armature 222, and a hemispherical ball socket 2220 is formed at the lower end of the solenoid armature 222, and a ceramic hemisphere 223 that cooperates with the ball socket 2220. One end of the ceramic hemisphere 223 corresponds to the metering channel 2100, and the ceramic hemisphere 223 is used to control the opening or closing of the metering channel 2100. The ball socket 2220 is provided with multiple degassing structures.

[0025] like Figures 1 to 5 As shown, in this application, the valve body 100 is the main structure of the electronic fuel injector assembly, and other components of the fuel injector are installed through the valve body 100. An oil inlet channel 101 is provided in the valve body 100, and a plunger chamber 110 and a high-pressure oil chamber 200 are also provided in communication with each other. The plunger chamber 110 is located below the valve body 100, and the high-pressure oil chamber 200 is located above the valve body 100. After the fuel enters the plunger chamber 110 through the oil inlet channel 101, the high-pressure oil is formed by the up and down movement of the plunger in the plunger chamber 110 and enters the high-pressure oil chamber 200. A metering valve 210, a guide sleeve 220, and a clamping sleeve 230 are arranged from bottom to top within the high-pressure oil chamber 200. The metering valve 210 is cylindrical in shape and slides with the valve body 100. The guide sleeve 220 is also cylindrical in shape and has a guide hole 224. A first valve core assembly 221 is arranged in the guide hole 224. The guide sleeve 220 is also slidably connected to the valve body 100. The clamping sleeve 230 is threadedly connected to the valve body 100 and is used to limit the relative positions of the guide sleeve 220 and the metering valve 210 within the valve body 100.

[0026] The first valve core assembly 221 includes a solenoid armature 222, the lower end of which has a hemispherical socket 2220, and a ceramic hemisphere 223 that mates with the socket 2220. When energized, the solenoid armature 222 can move up and down within the guide sleeve 220 according to the control command, thereby driving the ceramic hemisphere 223 to move up and down. A metering channel 2100 is provided inside the metering valve 210. One end of the ceramic hemisphere 223 corresponds to the metering channel 2100. Specifically, the overall structure of the ceramic hemisphere 223 includes a hemisphere formed by a hemispherical surface and a bottom surface. The hemispherical surface mates with the socket 2220, and the bottom surface mates with the upper surface of the metering channel 2100. The up and down movement of the ceramic hemisphere 223 drives the opening or closing of the metering channel 2100, thereby realizing the opening or closing of the oil drain channel in the high-pressure fuel chamber. Meanwhile, the ceramic hemisphere 223 of this application, based on its spherical fit with the armature 222 of the solenoid valve, can improve its adaptive adjustment capability, automatically adjust the sealing angle, and improve the sealing performance of the overall structure. In addition, in this invention, multiple degassing structures are also provided in the ball socket 2220 of the armature 222 of the solenoid valve. By incorporating a degassing structure to store residual gas between the ceramic hemisphere 223 and the socket 2220 during operation, the probability of cavitation corrosion on the surface of either the ceramic hemisphere 223 or the socket 2220 is reduced, thus extending the injector's service life. Furthermore, the degassing structure reduces residual gas between the ceramic hemisphere 223 and the socket 2220, thereby reducing gas resistance within the socket and improving the response speed of the high-pressure chamber control valve, ultimately enhancing the injector's injection accuracy. Additionally, the degassing structure can be equipped with lubricating oil, further increasing the operating speed of the ceramic hemisphere 223 within the socket, further improving the response speed of the high-pressure chamber control valve and ultimately enhancing the injector's injection accuracy.

[0027] Furthermore, in other embodiments of this application, the plurality of degassing structures include a first degassing structure 2221 and a second degassing structure 2222; wherein the first degassing structure 2221 is located at the top of the ball socket 2220, which not only facilitates the reduction of gas resistance when the ceramic hemisphere 223 rotates in the ball socket 2220, making the ceramic hemisphere 223 more efficient in adapting the sealing angle in the ball socket 2220, thus improving the sealing performance of the hemisphere structure, but also facilitates the processing of the degassing structure and reduces the overall processing cost. For example, if the first degassing structure 2221 is set as a rotating body structure, it can be directly processed by drilling, resulting in low processing cost. Similarly, the second degassing structure 2222 involved in this invention is located on the side of the ball socket 2220; it can also reduce the gas resistance of the ceramic hemisphere 223 when it rotates in the ball socket 2220, making the ceramic hemisphere 223 more efficient in adapting the sealing angle in the ball socket 2220, improving the sealing performance of the hemisphere structure, and at the same time facilitating the processing of the degassing structure and reducing the overall processing cost.

[0028] As attached Figure 3 As shown, the second degassing structure 2222 is a grooved type located at the ball socket 2220, and also adopts a rotating body structure. It can be manufactured using turning or other common machining methods, resulting in a simple overall structure and low manufacturing cost. Furthermore, the rotating body structure ensures overall symmetry and further improves the stability of the injector assembly. In practical use, some grease can be added to the first and / or second degassing mechanisms to enhance the rotational flexibility of the ceramic hemisphere 223 and the ball socket 2220, further improving the control accuracy of the electronically controlled injector assembly of this application.

[0029] Furthermore, such as Figure 4As shown, in other embodiments of this application, the metering channel 2100 includes a first diffusion hole 2101, a first shrinkage hole 2102, a second shrinkage hole 2103, and a second diffusion hole 2104 arranged sequentially. As shown in the attached figure, the first diffuser hole 2101, the second constriction hole 2103, and the second diffuser hole 2104 are all cylindrical holes, while the first constriction hole 2102 is conical. The first diffuser hole 2101 is connected to the plunger cavity 110. High-pressure fuel formed by the plunger compression in the plunger cavity 110 flows into the first diffuser hole 2101. The inner diameter of the first diffuser hole 2101 is significantly larger than that of the second constriction hole 2103 and the second diffuser hole 2104, which is used to reduce the fuel velocity and maintain the fuel pressure. Secondly, the flow space of the fuel is further compressed by the funnel-shaped first constriction hole 2102 to increase the fuel pressure and injection speed, while also avoiding fuel turbulence and reducing the probability of fuel forming bubbles after entering the second constriction hole 2103. The large end diameter of the first constriction hole 2102 matches that of the first diffuser hole 2101, and the small end diameter of the first constriction hole 2102 matches that of the second constriction hole 2103. After passing through the first narrowing orifice 2102, the fuel enters the second narrowing orifice 2103, where the pressure and flow rate of the fuel are further stabilized. After passing through the second narrowing orifice 2103, the fuel enters the second diffuser orifice 2104. The inner diameter of the second diffuser orifice 2104 is larger than that of the second narrowing orifice 2103 but smaller than that of the first diffuser orifice 2101, thereby reducing the fuel velocity and maintaining the pressure.

[0030] In this work, fuel enters the second compression hole after passing through the first diffuser hole 2101 and the first compression hole. Due to the further compression of the flow space, bubbles are easily formed. These bubbles cause uneven pressure on the bottom surface of the ceramic hemisphere 223 under high pressure, thus affecting the control accuracy of the injector assembly. In order to further reduce the bubble formation rate or reduce the impact of bubbles on the ceramic hemisphere 223, in this application, on the one hand, the length and diameter of the first diffuser hole 2101 can be selected to be greater than the sum of the first narrowing hole 2102, the second narrowing hole 2103 and the second diffuser hole 2104; the longer first diffuser hole 2101 is used to stabilize the pressure fluctuation and flow rate fluctuation of fuel from low pressure to high pressure, and then combined with the funnel-shaped first narrowing hole 2102, thereby reducing the factors that generate bubbles from the source. On the other hand, by setting the length and diameter ratio of the second narrowing orifice 2103 and the second diffuser orifice 2104, the factors that generate fuel bubbles can also be reduced. Generally speaking, the smaller the difference in diameter between the second narrowing orifice 2103 and the second diffuser orifice 2104, the lower the possibility of bubble generation; and the longer the distance of the second diffuser orifice 2104, the smaller the impact of bubbles on the ceramic hemisphere 223. However, a longer distance of the second diffuser orifice 2104 will increase the overall length of the injector assembly structure, which not only increases the cost but also increases the volume of the injector assembly. To further optimize the cost of the injector assembly, this application sets the aperture ratio of the second diffuser hole 2104 to the second constriction hole 2103 to be 'a', and the length ratio of the second diffuser hole 2104 to the second constriction hole 2103 to be 'b'. When the ratio of a to b is between 1.9 and 2.2, the ceramic hemisphere 223 involved in this application is least affected by cavitation. For example, in a specific implementation, the aperture of the second constriction hole 2103 is approximately 0.3 mm, and its length is approximately 0.6 mm; the aperture of the second diffuser hole 2104 is approximately 0.4 mm, and its length is approximately 0.4 mm. This significantly reduces the likelihood of fuel bubbles forming at the location corresponding to the ceramic hemisphere 223 and the metering valve 210. This explains why it is difficult for fuel bubbles to form as it travels from the second constriction hole 2103 to the second diffuser hole 2104, and even if bubbles do form, they easily rupture within the second diffuser hole 2104, reducing the unstable impact of fuel on the ceramic hemisphere 223 and thus improving the service life of the injector assembly.

[0031] Furthermore, in other embodiments of this application, an oil drain chamber 240 is further provided between the metering valve 210 and the guide sleeve 220; wherein the oil drain chamber 240 includes a first oil drain area 241 located in the metering valve 210 and a second oil drain area 242 located in the guide sleeve 220. (See attached...) Figure 2 To be continued Figure 5The first oil drain area 241 is located in the recess at the upper end of the metering valve 210, and the second oil drain area 242 is located in the recess at the lower end of the guide sleeve 220. The cross-sectional area of ​​the first oil drain area 241 is smaller than that of the second oil drain area 242. By setting a recess at the upper end of the metering valve 210 as the first oil drain area 241, and this recessed area surrounds the sealing area between the ceramic hemisphere 223 and the metering valve 210, the oil draining speed is increased, thereby improving the feedback accuracy of the injector. Secondly, in this embodiment, as shown in the attached figure, the cross-sectional area of ​​the first oil drain area 241 is smaller than that of the second oil drain area 242, which can further increase the oil draining speed.

[0032] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. The structure of an electronically controlled fuel injector assembly, characterized in that: The system includes a valve body (100) with an oil inlet channel (101) inside; it also includes a plunger chamber (110) and a high-pressure oil chamber (200) that are interconnected within the valve body (100), wherein the oil inlet channel (101) is connected to the plunger chamber (110); the high-pressure oil chamber (200) is provided with a metering valve (210), a guide sleeve (220), and a clamping sleeve (230) from bottom to top, wherein the clamping sleeve (230) is threadedly connected to the valve body (100) and is used to limit the relative position of the guide sleeve (220) and the metering valve (210); the guide sleeve (220) is provided with a first valve core assembly (221), and the metering valve (210) is provided with a first valve core assembly (221). The device is equipped with a metering channel (2100). The first valve core assembly (221) includes a solenoid armature (222), the lower end of which forms a hemispherical socket (2220), and a ceramic hemisphere (223) that cooperates with the socket (2220). One end of the ceramic hemisphere (223) corresponds to the metering channel (2100), and the ceramic hemisphere (223) is used to control the opening or closing of the metering channel (2100). The socket (2220) is equipped with multiple degassing structures. The degassing structures are used to store the gas and / or lubricating oil remaining between the ceramic hemisphere (223) and the socket (2220) during operation.

2. The electronically controlled fuel injector assembly structure according to claim 1, characterized in that: The plurality of degassing structures include a first degassing structure (2221) and a second degassing structure (2222); wherein the first degassing structure (2221) is located at the top of the ball socket (2220) and the second degassing structure (2222) is located on the side of the ball socket (2220).

3. The electronically controlled fuel injector assembly structure according to claim 2, characterized in that: The first degassing structure (2221) and / or the second degassing structure (2222) are rotating structures.

4. The electronically controlled fuel injector assembly structure according to claim 1, 2, or 3, characterized in that: The metering channel (2100) includes a first diffusion hole (2101), a first narrowing hole (2102), a second narrowing hole (2103), and a second diffusion hole (2104) arranged in sequence.

5. The electronically controlled fuel injector assembly structure according to claim 4, characterized in that: The length and diameter of the first diffusion hole (2101) are greater than the sum of the first shrinkage hole (2102), the second shrinkage hole (2103), and the second diffusion hole (2104).

6. The electronically controlled fuel injector assembly structure according to claim 1, 2, 3 or 5, characterized in that: An oil drain chamber (240) is also provided between the metering valve (210) and the guide sleeve (220); wherein the oil drain chamber (240) includes a first oil drain area (241) located in the metering valve (210) and a second oil drain area (242) located in the guide sleeve (220).

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