Oscillating Piston Pump Flow Sensing Without a Separate Meter

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Solution Overview

Problem

Existing beverage preparation devices with oscillating piston pumps require additional flow meters for precise flow rate measurement, which complicates the design, increases costs, and generates noise, especially when operating without a load.

Innovation Solution

A detection device that measures the change in path and/or current position of the oscillating piston to indirectly determine the flow rate, eliminating the need for a separate flow meter and allowing for quieter operation by controlling the magnetic coil's power supply to prevent piston impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a flow meter is integrated into the beverage preparation device to measure flow rate, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveflow rate measurementVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the flow measurement function with the existing magnetic coil of the oscillating piston pump. The magnetic coil serves dual purposes: generating the magnetic field for piston oscillation and detecting the piston position through inductance changes. This integration eliminates the need for a separate flow meter, thereby reducing device complexity while maintaining measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnetic coil is designed to perform multiple functions: it generates the magnetic field necessary for piston oscillation during pumping and simultaneously acts as an inductive sensor to detect piston position. By making the magnetic coil multi-functional, the patent avoids adding extra components for flow measurement, thus simplifying the overall device structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If a flow meter is added to the beverage preparation device, then measurement precision is improved, but production costs increase

Engineering Contradiction:
Improveflow rate measurementVSAvoidproduction costs
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges the flow measurement function with the existing magnetic coil, eliminating the need to manufacture and assemble additional flow meter components. This integration reduces production costs by utilizing an already-present component for dual purposes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnetic coil serves itself by performing both its primary function of generating magnetic fields for piston oscillation and the secondary function of detecting piston position through inductance changes. This self-service approach eliminates the need for separate measurement devices, thereby reducing production costs.

Inventive Principle:
Principle #25Self-service

3Productivity

If the oscillating piston pump operates without load, then productivity is improved, but noise increases

Engineering Contradiction:
Improvepumping efficiencyVSAvoidnoise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback control by continuously monitoring the piston position through inductance changes detected by the magnetic coil. This position information is used to control the power supply to the magnetic coil, allowing the system to adjust operation to minimize noise during no-load conditions while maintaining pumping efficiency when needed.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the power supply to the magnetic coil based on real-time piston position feedback. By making the power supply dynamic rather than static, the system can optimize performance and reduce noise during different operating conditions, particularly during no-load operation.

Inventive Principle:
Principle #15Dynamics

4Productivity

If the oscillating piston pump operates without load, then productivity is improved, but energy consumption increases

Engineering Contradiction:
Improvepumping efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent uses feedback from piston position detection to control the power supply dynamically. This feedback mechanism allows the system to minimize energy consumption during no-load operation by adjusting power delivery based on actual pumping needs, while maintaining high productivity when load is present.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The power supply to the magnetic coil is made dynamic, adjusting in real-time based on piston position and loading conditions. This dynamic control enables the system to reduce energy consumption during no-load operation while maintaining pumping efficiency when required.

Inventive Principle:
Principle #15Dynamics

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 solution simplifies the device structure, reduces production costs, enables faster and more precise flow rate measurement, and reduces noise and energy consumption by up to 30%, while maintaining precise temperature control for brewing processes.

Implementation Method 1

The change in path and/or the position of the oscillating piston can also be derived indirectly from the inductance of the magnet coil, since the inductance of the magnet coil changes depending on the immersion depth of the oscillating piston in the interior of the magnet coil.

Methodology Applied
Scientific EffectInductance change: Electromagnetic Induction

Implementation Method 2

The functioning of an oscillating piston pump is based on a magnetic field generated by the magnetic coil, which tensions the ferromagnetic oscillating piston against a spring and then releases it again.

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 3

The magnetic field initially presses the oscillating piston against the tension of the spring into a first end position. Due to the negative pressure, liquid is sucked into the pump chamber on the inlet side.

Methodology Applied
Scientific EffectNegative pressure suction: Suction

Implementation Method 4

The magnetic field is then interrupted and the oscillating piston is moved to a second end position by relaxing the spring. The liquid sucked in is displaced out of the pump chamber on the outlet side.

Methodology Applied
Scientific EffectSpring elastic recovery: Spring

Data Source

PatentEP2637533B1Beverage preparation device having flow measurement
Publication Date: 2015.03.18 BSH HAUSGERATE GMBH
  • EP2637533B1 patent drawingFigure 1
  • EP2637533B1 patent drawingFigure 2~3
  • EP2637533B1 patent drawingFigure 4~5

AI summary

The invention relates to a beverage preparation device (1), comprising an oscillating piston pump (10) having a pump housing (9), a pump chamber (11), an oscillating piston (18) in the pump chamber (11), and a magnetic coil (16) coaxially surrounding the pump chamber (11), characterized by a measuring unit (60) which measures the change in travel and/or the current position of the oscillating piston (18) in the pump chamber (11) during a pumping process. It also relates to a method for operating a beverage preparation device (1).