Pump Flow Restriction via Cross-Flow Throttle Separation

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Solution Overview

Problem

Existing devices for limiting the flow rate on suction-throttled feed pumps in fuel injection systems for internal combustion engines are costly to manufacture and inefficient, as they require complex geometries and high manufacturing effort, leading to suboptimal performance and power loss.

Innovation Solution

A compact and low-effort device with a pressure regulating valve as an overflow valve controls the discharge quantity through a throttle with a cylindrical bore, aligned on the axis of the inlet channel, which introduces a cross flow that increases flow separation and reduces the throttle coefficient, optimizing flow rate limitation and reducing power loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a throttle valve is used to control flow rate, then the flow rate can be regulated, but the manufacturing cost and device complexity increase significantly

Engineering Contradiction:
Improveflow rate controlVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention extracts the flow rate control function from a complex throttle valve and implements it through a simple cylindrical bore (throttle opening) in the inlet channel wall. This simple geometric feature, combined with a diversion channel that creates cross-flow, achieves the desired flow limitation without requiring complex moving parts or expensive components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive, complex throttle valves with a simple cylindrical bore that can be easily manufactured using standard machining operations. The simple geometric features (cylindrical bore, diversion channel) require minimal manufacturing effort and can be produced cost-effectively as integral parts of the pump housing.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Productivity

If the throttle cross section is reduced to increase throttling effect, then flow rate limitation improves, but manufacturing effort and cost increase

Engineering Contradiction:
Improveflow rate limitationVSAvoidmanufacturing effort
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention extracts the flow rate control function from a complex throttle valve and implements it through a simple cylindrical bore (throttle opening) in the inlet channel wall. This simple geometric feature, combined with a diversion channel that creates cross-flow, achieves the desired flow limitation without requiring complex moving parts or expensive components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the flow dynamics parameters by introducing cross-flow through the diversion channel. This cross-flow creates flow separation that effectively reduces the throttle coefficient and enhances the throttling effect of the cylindrical bore, achieving better flow rate limitation without changing the physical dimensions of the throttle opening.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a throttle valve is used for flow rate control, then flow regulation is achieved, but power loss increases

Engineering Contradiction:
Improveflow rate regulationVSAvoidpower loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention changes the flow dynamics parameters by introducing cross-flow through the diversion channel. This cross-flow creates flow separation that effectively reduces the throttle coefficient and enhances the throttling effect of the cylindrical bore, achieving better flow rate limitation without changing the physical dimensions of the throttle opening.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses hydraulic principles by utilizing the kinetic energy and flow direction changes of the liquid fuel itself to create the throttling effect. The cross-flow from the diversion channel interacts with the main flow through the cylindrical bore, creating flow separation and pressure drops that regulate flow rate without requiring additional mechanical components that would increase power consumption.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

The solution allows for efficient flow rate limitation, reducing power loss and increasing service life by adjusting the throttle coefficient based on pressure differences, achieving a balanced flow that minimizes hydraulic losses and optimizes pressure regulation.

Implementation Method 1

an overflow valve (7), which is designed as a pressure regulating valve (7), controls a discharge quantity through the discharge channel (6) as a function of a pressure difference between the input side (10) of the discharge channel (6) and the output side (13) of the discharge channel (6)

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

with an increasing amount of discharge that flows into the inlet channel via the discharge channel, an increasing flow separation occurs within the throttle, whereby the effective throttle diameter is reduced and the throttling effect increases

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Data Source

PatentEP2399030B1Device for restricting the throughflow quantity at a pump, and pump arrangement having a device of this type
Publication Date: 2019.06.05 ROBERT BOSCH GMBH
  • EP2399030B1 patent drawingFigure 1~2

AI summary

A device (2) for restricting the throughflow quantity at a pump (3), in particular at a suction-throttled delivery pump for fuel injection systems of air-compressing, self-igniting internal combustion engines, has a feed channel (4) on the suction side of the pump (3), which feed channel (4) is connected on an outlet side (8) to an inlet (9) of a pump (3), a cut-off channel (6) which can be connected on its inlet side (10) at least indirectly to an outlet (12) of the pump (3) and which opens on its outlet side (13) laterally at an opening point (14) into the feed channel (4), and a pressure control valve (7) which is arranged in the cut-off channel (6). Furthermore, a throttle (5) is provided which is arranged in the feed channel (4) between the opening point (14) and the outlet side (8) of the feed channel (4). A transverse flow is caused at the opening point (14) by a cut-off quantity which is discharged via the cut-off channel (6), which transverse flow is superimposed with a main flow through the feed channel (4). As a result, a lateral incident flow of the throttle (5) can be achieved, as a result of which the effective throttle diameter is reduced. A given pressure difference at the pump (3) can therefore be reduced. Furthermore, Furthermore, a pump arrangement (1) with the pump (3) and the device (2) for restricting the throughflow quantity is disclosed.