Fuel Injection Valve Weld Ring Pole Piece Stability
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Solution Overview
Problem
Conventional fuel injection valves face challenges in maintaining precise control and consistency under high fuel pressure, leading to potential misalignment of the pole piece and valve body, which affects the injection characteristics.
Innovation Solution
The design incorporates a fixing ring that abuts the pole piece, preventing its displacement and ensuring consistent lifting of the valve needle, using a combination of press fit, welding, or brazing to secure the fixing ring to the valve body, allowing precise control without altering the pole piece's shape or material selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pole piece is secured to the valve body using conventional methods (press fit only), then the assembly is simple, but the pole piece may displace under high fuel pressure affecting injection precision
Solution Approach 1:
The fixing ring is divided into two functional segments: a first fixing portion that engages with the pole piece and a second fixing portion that engages with the valve body. This segmentation allows the ring to independently secure both components, preventing pole piece displacement while maintaining a modular, manageable structure that doesn't excessively complicate the overall assembly.
Solution Approach 2:
The fixing ring acts as an intermediary element between the pole piece and the valve body. Instead of directly securing the pole piece to the valve body (which would require complex welding or threading), the fixing ring mediates the connection through its two fixing portions, providing a simpler and more reliable attachment method that prevents displacement under high fuel pressure.
2Strength
If the fixing ring is joined to the valve body using welding or brazing, then the connection strength is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent presents parameter changes in the joining method: the fixing ring can be joined to the valve body through press fit (lower strength, simpler manufacturing), welding (higher strength, more complex manufacturing), or brazing (higher strength, more complex manufacturing). This allows optimization based on specific application requirements, balancing connection strength with manufacturing ease and cost.
3Manufacturing precision
If the pole piece is allowed to move freely, then the actuator assembly is simpler, but the valve needle lifting consistency deteriorates under high fuel pressure
Solution Approach 1:
The fixing ring applies preliminary anti-action by pre-constraining the pole piece position before fuel injection occurs. The first fixing portion engages with the pole piece and the second fixing portion engages with the valve body, creating a pre-established constraint that prevents any potential displacement during high fuel pressure operation, ensuring consistent valve needle lifting without requiring complex active control mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration ensures reliable and precise fuel injection, maintaining consistent performance even under high fuel pressures, preventing pole piece movement and ensuring accurate fuel dispensation.
Implementation Method 1
an electro-magnetic coil (35), a pole piece (36) being positioned inside the cavity (18) of the valve body (12), and an armature element (33) being movable in the cavity (18) and operable to move the valve needle (14) in a predetermined direction for unsealing the fluid outlet portion (27)
Implementation Method 2
there is a spring element (39) next to the valve needle (14), wherein the spring element (39) is provided to push the valve needle (14) towards the fluid outlet portion (27)
Implementation Method 3
the fixing ring (38) is fixed to the valve body (12) by press fit and/or by a welded connection (41) and/or by a brazed connection
Implementation Method 4
an electro-magnetic coil (35), a pole piece (36) being positioned inside the cavity (18) of the valve body (12), and an armature element (33) being movable in the cavity (18)
Data Source
AI summary
The present disclosure relates to internal combustion engines. Various embodiments thereof may include a fuel injection valve for a combustion engine comprising: a valve body with a cavity; a valve needle movable in the cavity; an actuator assembly to actuate the valve needle. The actuator assembly includes an electro-magnetic coil, a pole piece positioned inside the cavity, and an armature element. The armature element moves within the cavity to move the valve needle in a predetermined direction. A fixing ring abutting the pole piece, fixed to the valve body by means of joining to a circumferential surface of the cavity.