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CN-121976889-A - Bimodal hold driving waveform control method for electromagnetic ammonia hydrogen gas fuel injector

CN121976889ACN 121976889 ACN121976889 ACN 121976889ACN-121976889-A

Abstract

The invention relates to a bimodal hold drive waveform control method for an electromagnetic ammonia hydrogen gas fuel injector, which comprises the steps of (a) applying a high voltage to an injector coil, enabling the coil current to rapidly rise to a first peak current value Ip1 in a very short time and maintain for a short period of time Tp1, (b) reducing the coil current to a second peak current value Ip2 and maintaining for a period of time Tp2, and (c) reducing the coil current to a hold current value Ih and maintaining the current for the whole rest of injection pulse width time Th. The armature movement is actively decelerated through the second peak stage, stable and controlled reaching of the full open position is achieved, mechanical impact is greatly reduced, high consistency of valve core lift and the full open position in each injection is ensured, and therefore accuracy of gas fuel metering is improved.

Inventors

  • XU ZHONGMIN
  • LI HAIHAI
  • WANG JIA
  • ZHU QUANHE
  • WANG WENMING

Assignees

  • 常州慧勤新能源科技有限公司

Dates

Publication Date
20260505
Application Date
20260302

Claims (6)

  1. 1. A bimodal hold-in drive waveform control method for an electromagnetic ammonia hydrogen gas fuel injector, comprising the steps of: (a) Applying a high voltage to the injector coil to rapidly increase the coil current to a first peak current value Ip1 in a very short time, and maintaining for a short time Tp1; (b) Reducing the coil current to a second peak current value Ip2 and maintaining for a period of time Tp2; (c) The coil current is then reduced to a hold current value Ih and maintained throughout the remaining injection pulse width time Th.
  2. 2. The method of claim 1, wherein in step (a), the ECU controls the drive circuit to apply a high voltage to the injector coil at the start of the injection command.
  3. 3. The bimodal hold-up driving waveform control method for an electromagnetic ammonia hydrogen gas fuel injector according to claim 1 or 2, wherein in step (a), the extremely short time is 0.1-1ms, preferably 0.1-0.5ms, and the short time Tp1 is 0.3-1.0 ms.
  4. 4. The method of claim 1 or 2, wherein in step (a), the first peak current value Ip1 is 80% to 150% of the rated current.
  5. 5. The method of claim 1, wherein in step (b), the second peak current value Ip2 is greater than the holding current value Ih and the second peak current value Ip2 is less than the first peak current value Ip1.
  6. 6. The method of claim 5, wherein in step (b), the period of time Tp2 is 0.2-0.8 ms.

Description

Bimodal hold driving waveform control method for electromagnetic ammonia hydrogen gas fuel injector Technical Field The invention belongs to the technical field of fuel injection control of internal combustion engines, relates to a driving waveform control method, and in particular relates to a bimodal holding driving waveform control method for an electromagnetic ammonia hydrogen gas fuel injector. Background Gaseous fuels, represented by hydrogen, ammonia and natural gas, are increasingly used in internal combustion engines, in particular medium-and heavy-duty commercial vehicles, ships and power systems for engineering machines. The performance and life of a gaseous fuel engine is largely dependent on the reliability and accuracy of its core components (gaseous fuel injectors). The electromagnetic ammonia hydrogen gas fuel injector generally comprises an electromagnetic coil, an iron core, an armature (or linked with a valve core/a plunger), a valve seat and other components, and the operating principle of the electromagnetic ammonia hydrogen gas fuel injector is that when an ECU applies driving current to the coil, the generated electromagnetic force attracts the armature to overcome the pretightening force of a spring to move so as to drive the valve core to be separated from the valve seat, thus opening a fuel passage, after the current is disconnected, the electromagnetic force disappears, and the armature and the valve core are reset under the action of the spring to close the passage. Compared to conventional liquid fuel injectors, gaseous fuel injectors present a serious challenge in drive control in that gaseous media provide little effective hydraulic damping. In liquid injectors, the viscosity of the fuel can cushion the impact of moving parts (armature, valve core) at the end of travel, but in gas injectors, the moving parts can impact a limiting structure (such as a core or mechanical limiter) with high kinetic energy under electromagnetic force drive, or impact a valve seat at high speed when closed, such a lack of damped "hard-to-hard" impact can result in severe mechanical wear, noise, and ultimately affect the life and seal reliability of the injector. To address this challenge, the prior art has been primarily improved from two paths: (1) The mechanical structure improves the path focusing on physically buffering the impact by optimizing the hardware design, wherein the main mode is that ① sets a physical gap, as disclosed in the Chinese patent publication No. CN116753088A, by precise mechanical design, the armature is ensured to keep a tiny preset interval with the iron core when moving to the limit position (preset position), thereby completely avoiding direct collision of the armature and the iron core and transferring the impact energy to other more impact-resistant limiting components. This approach, while effective, increases the complexity of the mechanical design and the machining accuracy requirements, and does not eliminate the impact, but merely shifts the impact point. ② The buffer material or damping device is introduced, and part of the technology adopts elastic materials such as rubber or the like or independent hydraulic damping chambers to absorb the impact energy. However, these materials may suffer from poor high temperature resistance and susceptibility to aging failure, and additional damping devices may increase system complexity and cost, and may present sealing challenges. (2) And driving and controlling an optimized path, wherein the path focuses on the management of the kinetic energy of the moving part from the source through optimizing an electric control strategy. Classical Peak-and-Hold driving is the most dominant driving mode at present, the driving current waveform of which comprises an initial high Peak current (Peak) phase and a subsequent lower Hold current (Hold) phase. The high peak current is used for quickly generating enough electromagnetic force to overcome static friction and spring force and quickly start the armature, and then the current is reduced to lower holding current to just maintain the fully opened state of the valve port until the injection is finished. The conventional unimodal-hold waveform is relatively extensive in controlling the motion process, its peak current is typically applied at a fixed parameter, intended to quickly complete opening, but not fine-tuned the velocity of the armature near the fully open position, which results in the armature and linkage components still striking the limit structure with high residual kinetic energy in environments where the gaseous fuel lacks damping, causing shock and wear. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a bimodal hold driving waveform control method for an electromagnetic ammonia hydrogen gas fuel injector. In order to achieve the aim, the technical scheme adopted by the invention is that the bimodal keep driving waveform c