Pressure Balance Valve Common Rail Injector

Abstract

The invention discloses a pressure-balanced valve type common-rail fuel injector which comprises a fuel injector body, a piston rod, fuel nozzle matching parts, pressure-balanced valve matching parts and an electromagnetic valve assembly.The fuel injector body is connected with the electromagnetic valve assembly, the pressure-balanced valve matching parts are connected with the fuel injector body, and the fuel injector body is connected with the fuel nozzle matching parts.The fuel nozzle matching parts comprise a needling valve, a step-shaped cavity is formed in the axial center of the fuel injector body, a sealing cavity is formed between the pressure-balanced valve matching parts and the piston rod, a protrusion is arranged on one side of the fuel injector body and provided with an inclined first fuel inlet hole of the fuel injector body, and a second fuel inlet hole of the fuel injector body is formed in the lower side of the first fuel inlet hole and is communicated with a fuel storage cavity in the lower portions of the pressure-balanced valve matching parts.The fuel injector body is connected with a high-pressure rail pipe, a fuel injector body fuel inlet is communicated with an upper portion inner hole, the upper portion inner hole is connected with a sealing cavity through a throttling hole, and a valve seat installation hole is formed in the upper portion of the upper portion inner hole and matched with the pressure-balanced valve matching parts.The diameter of the sealing surface on the upper portion of the piston rod is larger than the diameter of the intersecting line of the needle valve.

Description

technical field [0001] The invention relates to a fuel injection system used in an automobile internal combustion engine, in particular to a pressure balance valve type common rail fuel injector. Background technique [0002] Today, no matter from the goal of "National Thirteenth Five-Year Plan"---energy saving and emission reduction, or from the key goal of "Made in China 2025" (breaking through the injection pressure of diesel engines for key parts manufacturing to reach 2000bar), the high-pressure common rail fuel injection The system performance puts forward higher requirements. Only by further increasing the system injection pressure P and increasing the multiple injection capability can the stringent emission regulations be met. [0003] Existing high-pressure common rail electronically controlled injectors, such as figure 1 , figure 2 , Figure 9 In the structure shown, after the high-pressure fuel passes through the slit filter element 303 in the high-pressure co...

AI Technical Summary

Problems solved by technology

[0004] The existing high-pressure common rail electronically controlled fuel injector adopts a ball valve sealing structure, and the ball valve sealing diameter is 802, which will restrain each other in increasing the system injection pressure P and increasing the multiple injection capacity, because in order to increase the system pressure P, due to P =F / S formula, when the spring force F is constant, the sealing diameter must be reduced; however, reducing the sealing diameter will cause the control fuel flow opening area to become smaller under the same lift condition, which will Affects the injection rate of the injector; in order to optimize the injection rate, it is necessary to increase the lift; increasing the lift will inhibit the multiple injection capability

Therefore, the high-pressure fuel injection system of the prior art cannot well solve the difficult problem of not only further improving the system injection pressure P, but also increasing the multiple injection capability.

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