A high pressure fuel injector

Abstract

This utility model provides a high-pressure fuel injector, characterized in that it comprises: a lower fixed tube, with a valve seat installed at the oil outlet end of the lower fixed tube, and an upper fixed tube installed at the oil inlet end of the lower fixed tube; a sleeve, the sleeve being fitted onto the lower fixed tube, with a magnetic plate and a coil disposed between the surface of the lower fixed tube and the sleeve; a fixed iron core installed inside the oil inlet end of the lower fixed tube, and a moving iron core assembly disposed inside the lower fixed tube, both the fixed iron core and the moving iron core assembly having cavities in their middle, with adjusting pins and springs disposed in the cavities; a plurality of spray holes being opened at the oil outlet end of the valve seat; and a steel ball being installed on the moving iron core assembly; the upper and lower fixed tubes are externally encased in an injection-molded body, the injection-molded body having coil terminals connected to the internal coil. By processing the spray holes, the nozzle's spray effect becomes more uniform and stable, extending the service life of the valve seat and reducing the frequency of maintenance and replacement.

Description

Technical Field

[0001] This utility model relates to a high-pressure fuel injector. Background Technology

[0002] Direct injection is a process in which fuel is injected directly into the cylinder through a high-pressure injector, resulting in better atomization, more complete combustion, and more precise control.

[0003] In the prior art, high-pressure fuel injectors usually have a thin nozzle plate welded on the valve seat. This thin plate is generally 0.1-0.3mm thick. The nozzle plate of this design will deform when the valve core assembly moves. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a high-pressure fuel injector. By machining the nozzle orifice, the spray effect of the nozzle becomes more uniform and stable, extending the service life of the valve seat and reducing the frequency of maintenance and replacement.

[0005] The objective of this utility model can be achieved through the following technical solution: a high-pressure fuel injector, characterized in that it comprises:

[0006] The lower fixed pipe has a valve seat installed at its oil outlet end and an upper fixed pipe installed at its oil inlet end.

[0007] A sleeve is fitted onto a lower fixed tube, and a magnetic plate and a coil are provided between the surface of the lower fixed tube and the sleeve.

[0008] A fixed iron core is installed inside the oil inlet end of the lower fixed pipe, and a moving iron core assembly is provided inside the lower fixed pipe. Both the fixed iron core and the moving iron core assembly have cavities in the middle, and an adjusting pin and a spring are provided in the cavity. Several spray holes are provided at the oil outlet end in the middle of the valve seat, and a steel ball is installed on the moving iron core assembly.

[0009] The upper and lower fixing tubes are encased in an injection-molded body, which is provided with coil terminals that connect to the internal coil.

[0010] Furthermore, a sealing ring is connected to the end of the upper fixing tube.

[0011] Furthermore, a filter screen is provided inside the upper fixed tube.

[0012] Furthermore, the diameter of the oil outlet end of the lower fixed pipe is smaller than the diameter of the oil inlet end.

[0013] Furthermore, the moving iron core assembly has a certain amount of space for movement within the lower fixed tube. The moving iron core assembly includes a valve core, an elastic plate, and a mandrel. The valve core is welded and fixed to the elastic plate. One end of the mandrel is located in the middle of the elastic plate, and the other end of the mandrel can be welded and fixed to a steel ball.

[0014] Furthermore, the elastic sheet is produced by etching, and oil passage holes are provided on the elastic sheet.

[0015] Furthermore, the valve seat has several guide bosses, and an oil passage groove is formed between adjacent guide bosses.

[0016] Furthermore, the lower end of the valve seat has a hemispherical protrusion and the spray hole is disposed on the protrusion.

[0017] Compared with the prior art, the advantages of this application are: by processing the spray holes, the spray effect of the nozzle is more uniform and stable, the service life of the valve seat is extended, and the frequency of maintenance and replacement is reduced.

[0018] When the valve core assembly is closed, the resistance increases, reducing the bounce between the steel ball and the valve seat, thus making the dynamic flow more stable with small pulse widths. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a fuel injector;

[0020] Figure 2 This is a cross-sectional view of the fuel injector;

[0021] Figure 3 This is a schematic diagram of the valve seat;

[0022] Figure 4 This is a schematic diagram of an elastic sheet;

[0023] In the diagram, 1. Upper fixed tube; 11. Sealing ring; 12. Filter element; 2. Lower fixed tube; 3. Injection molded body; 31. Coil terminal; 4. Sleeve; 41. Magnetic guide plate; 5. Valve seat; 51. Protrusion; 52. Guide boss; 53. Oil groove; 54. Spray hole; 6. Fixed iron core; 61. Adjusting pin; 62. Spring; 63. Valve core; 64. Elastic sheet; 641. Oil passage hole; 65. Spindle. Detailed Implementation

[0024] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings.

[0025] like Figure 1-4 As shown, a high-pressure fuel injector is characterized in that it comprises:

[0026] The lower fixed pipe 2 is equipped with a valve seat 5 at its oil outlet end and an upper fixed pipe 1 at its oil inlet end.

[0027] Sleeve 4, which is sleeved on the lower fixed tube 2 and a magnetic plate 41 and a coil are provided between the surface of the lower fixed tube 2 and the sleeve 4;

[0028] A fixed iron core 6 is installed inside the oil inlet end of the lower fixed pipe 2, and a moving iron core assembly is provided at the oil outlet end of the lower fixed pipe 2. Both the fixed iron core 6 and the moving iron core assembly have cavities in the middle, and an adjusting pin 61 and a spring 62 are provided in the cavity. Several spray holes 54 are provided at the oil outlet end of the valve seat 5. A steel ball is installed on the moving iron core assembly.

[0029] The upper fixing tube 1 and the lower fixing tube 2 are wrapped by an injection molded body 3, and the injection molded body 3 is provided with a coil terminal 31 that is connected to the internal coil.

[0030] When the coil terminal 31 is energized, the magnetic plate 41 generates a magnetic field that attracts the moving iron core assembly. Fuel enters from the inlet end of the upper fixed pipe 1 and is injected downwards. It passes through the fixed iron core 6 and the moving iron core assembly, and is then sprayed out from the outlet end of the valve seat 5 of the lower fixed pipe 2 through the spray hole 54.

[0031] Furthermore, a sealing ring 11 is connected to the end of the upper fixing tube 1. The sealing ring 11 improves the sealing performance.

[0032] Furthermore, a filter screen 12 is provided inside the upper fixed pipe 1. The filter screen 12 is used to filter the incoming fuel.

[0033] Furthermore, the diameter of the oil outlet end of the lower fixed pipe 2 is smaller than the diameter of the oil inlet end.

[0034] Furthermore, the moving iron core assembly has a certain amount of space for movement within the lower fixed tube 2. The moving iron core assembly includes a valve core 63, an elastic plate 64, and a spindle 65. The valve core 63 is welded and fixed to the elastic plate 64. One end of the spindle 65 is located in the middle of the elastic plate 64, and the other end of the spindle 65 can be welded and fixed to a steel ball.

[0035] Furthermore, the elastic sheet 64 is etched, and an oil passage hole 641 is provided on the elastic sheet 64. When the injector is open, the elastic sheet can detach from the valve core, increasing the flow rate and reducing resistance; when closed, the elastic sheet is pressed against the valve core, and only the small hole allows flow, increasing the closing resistance.

[0036] The etched elastic sheet 64 generates a magnetic field when the coil is energized, attracting the valve core 63. Oil passes through the elastic sheet 64 on the valve core 63 under a pressure of 300 bar. Several oil passage holes 641 on the elastic sheet 64 are instantly bounced up, allowing oil to pass through the valve core 63 effectively and accelerating the opening time. When the coil is de-energized, the valve core 63 returns to its original position and closes under the action of the spring 62. The elastic sheet 64 instantly recovers, and fuel flows through the oil passage holes 641, increasing the resistance to movement and effectively reducing the impact force of the valve core 63 hitting the valve seat, reducing the number of bounces of the valve core 63, and significantly reducing noise. This makes the dynamic flow of the injector more stable at small pulse widths. The elastic sheet 64 acts like a damper, reducing the vibration and noise of the valve core 63 during movement and improving the overall stability and accuracy of the product.

[0037] Furthermore, the valve seat 5 has a plurality of guide bosses 52, and an oil groove 53 is formed between adjacent guide bosses 52.

[0038] Furthermore, the lower end of the valve seat 5 has a hemispherical protrusion 51 and the spray hole 54 is disposed on the protrusion 51.

[0039] Machining the nozzle 54 directly on the valve seat 5 ensures the precision and consistency of the nozzle 54. Because the machining process can be directly controlled, it avoids errors in subsequent assembly. This high-precision nozzle 54 ensures that the nozzle spray effect is more uniform and stable. This design ensures that liquid under high pressure can be sprayed stably through the nozzle 54 without leakage. Moreover, this design eliminates the need to grind the steel ball. The oil groove 53 and guide boss 52 are directly on the valve seat 5 to guide the steel ball, which can better control the sealing between the valve seat 5 and the steel ball and reduce the possibility of liquid leakage.

[0040] The above-described technical solution of this utility model addresses the problem that existing technical solutions are too simplistic and provides a solution that is significantly different from existing technologies. The parts not covered in this application's technical solution are the same as or can be implemented using existing technologies, and will not be described in detail here.

[0041] The technical solutions in the above embodiments have clearly and completely described the content of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

Claims

1. A high-pressure fuel injector, characterized in that, It includes: The lower fixed pipe has a valve seat installed at its oil outlet end and an upper fixed pipe installed at its oil inlet end. A sleeve is fitted onto a lower fixed tube, and a magnetic plate and a coil are provided between the surface of the lower fixed tube and the sleeve. A fixed iron core is installed inside the oil inlet end of the lower fixed pipe, and a moving iron core assembly is provided inside the lower fixed pipe. Both the fixed iron core and the moving iron core assembly have cavities in the middle, and an adjusting pin and a spring are provided in the cavity. Several spray holes are provided at the oil outlet end in the middle of the valve seat, and a steel ball is installed on the moving iron core assembly. The upper and lower fixing tubes are encased in an injection-molded body, which is provided with coil terminals that connect to the internal coil.

2. A high-pressure fuel injector according to claim 1, characterized in that: A sealing ring is connected to the end of the upper fixed tube.

3. A high-pressure fuel injector according to claim 1, characterized in that: A filter screen is installed inside the upper fixed tube.

4. A high-pressure fuel injector according to claim 1, characterized in that: The diameter of the oil outlet end of the lower fixed pipe is smaller than the diameter of the oil inlet end.

5. A high-pressure fuel injector according to claim 4, characterized in that, The moving iron core assembly has a certain amount of space to move within the lower fixed tube. The moving iron core assembly includes a valve core, an elastic plate, and a mandrel. The valve core is welded and fixed to the elastic plate. One end of the mandrel is located in the middle of the elastic plate, and the other end of the mandrel can be welded and fixed to a steel ball.

6. A high-pressure fuel injector according to claim 5, characterized in that, The elastic sheet is produced by etching and has oil passage holes.

7. A high-pressure fuel injector according to claim 1, characterized in that, The valve seat has several guide bosses, and an oil passage groove is formed between adjacent guide bosses.

8. A high-pressure fuel injector according to claim 1, characterized in that, The lower end of the valve seat has a hemispherical protrusion and the nozzle is disposed on the protrusion.

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