Suction Valve Control for Fuel Pump Air Gap Venting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electromagnetically controllable suction valves in high-pressure pumps face issues with air accumulation in the working air gap, leading to increased wear and fluctuations in flow rate, which affect pressure control accuracy due to insufficient venting and a lack of free lift during the pumping phase.

Innovation Solution

The method involves temporarily energizing the magnetic coil during the suction phase to allow the armature to perform a free stroke, decoupling it from the valve piston, which enables venting of the working air gap and reduces wear by displacing air and ensuring sufficient hydraulic damping, without requiring structural changes to the existing valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the magnetic coil is continuously energized to close the suction valve during delivery phase, then fuel delivery control is achieved, but air accumulation occurs in the working air gap causing increased wear and delivery rate fluctuations

Engineering Contradiction:
Improvevalve operation stabilityVSAvoidair accumulation in working air gap
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The magnetic coil is energized periodically rather than continuously. During delivery phase, it is energized to close the suction valve for fuel delivery control. During suction phase, it is temporarily energized to create armature free stroke for venting air from the working air gap. This periodic energizing pattern eliminates air accumulation while maintaining reliable valve operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The harmful air accumulation in the working air gap is actively removed through the armature free stroke mechanism. When the magnetic coil is temporarily energized during suction phase, the armature moves freely to vent the working air gap, extracting the harmful air that would otherwise cause increased wear and delivery rate fluctuations.

Inventive Principle:
Principle #2Taking out (Extraction)

2Force

If the armature is coupled to the valve piston to ensure synchronized movement, then valve closing force is improved, but the armature cannot perform free stroke to vent the working air gap

Engineering Contradiction:
Improvevalve closing forceVSAvoidarmature free stroke capability
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The coupling between armature and valve piston is made dynamic rather than fixed. During delivery phase, the armature is coupled to provide synchronized movement and adequate closing force. During suction phase with temporary magnetic coil energizing, the coupling is released to allow armature free stroke for venting the working air gap. This dynamic coupling adapts to different operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The armature free stroke for venting the working air gap is performed preliminarily during the suction phase before the delivery phase begins. This preliminary action removes air accumulation that would otherwise interfere with subsequent valve closing operations and fuel delivery control.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If the suction valve remains open at the beginning of delivery phase to allow fuel filling, then fuel supply is ensured, but excess fuel is pushed back through the open valve causing pressure loss

Engineering Contradiction:
Improvefuel supply to high-pressure chamberVSAvoidpressure loss from fuel pushback
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The magnetic coil is energized in advance at the beginning of the delivery phase to close the suction valve before fuel pushback occurs. This preliminary action prevents excess fuel from being pushed back through the open valve, eliminating pressure loss while ensuring adequate fuel supply to the high-pressure chamber during the filling period.

Inventive Principle:
Principle #10Preliminary action

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 approach effectively reduces wear and improves the accuracy of fuel metering and pressure control by ensuring proper venting of the air gap, maintaining the valve's operational efficiency without additional structural modifications.

Implementation Method 1

a solenoid coil (3) is energized to close the suction valve. This energizing of the solenoid coil (3) generates a magnetic field, the magnetic force of which acts on an armature (5)

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 2

the magnetic force of which acts on an armature (5) coupled to a valve piston (4), causing the armature to move

Methodology Applied
Scientific EffectMagnetic force: Lorentz Force

Implementation Method 3

against the spring force of a spring (6) towards a stroke stop (7)

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 4

the valve piston (4), which is then drawn into a valve seat (9) by the spring force of a valve spring (8)

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 5

performs a free stroke to vent a working air gap that is formed between the armature and the stroke stop

Methodology Applied
Scientific EffectHydraulic damping: Damping

Data Source

PatentEP3423702B1Method for controlling an electromagnetically controllable suction valve
Publication Date: 2021.04.21 ROBERT BOSCH GMBH
  • EP3423702B1 patent drawingFigure 1
  • EP3423702B1 patent drawingFigure 2~3

AI summary

The invention relates to a method for controlling an electromagnetically controllable suction valve (1) for a high-pressure pump (2) in a fuel injection system, wherein, in order to close the suction valve (1), current is supplied to a solenoid (3) such that a magnetic field is built up, the magnetic force of which acts on an armature (5), which is coupled to a valve piston (4), in such a way that the armature moves against the spring force of a spring (6) toward a stroke stop (7) and causes relief of the valve piston (4), which thereupon is pulled into a valve seat (9) by the spring force of a valve spring (8). According to the invention, in the time period between two current supply phases for closing the suction valve (1), current is supplied to the solenoid (3) at times such that the armature (5) is uncoupled from the valve piston (4) and performs a free stroke in order to deaerate a working air gap (10), which is formed between the armature (5) and the stroke stop (7).