Autosampler Needle Sealing With Magnetic Hold-Down Force
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Solution Overview
Problem
Existing autosamplers face issues with sealability between the needle and injection port due to loss of pressing force when power to the motor is interrupted, leading to potential liquid leakage, especially in belt-pulley systems where the needle is more susceptible to fluid pressure and repulsive forces.
Innovation Solution
Incorporation of a magnetic force part that applies a downward force to the needle holding part, ensuring sealability by using a magnet and metallic member to maintain the needle's press against the seal part even without continuous motor power, utilizing magnetic attraction to stabilize the connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor continuously drives the needle up and down to maintain pressing force against the seal part, then the sealability between the needle and injection port is improved, but the energy consumption increases and the system becomes vulnerable to power interruptions
Solution Approach 1:
The patent replaces the motor-driven mechanical pressing system with a magnetic field-based pressing system. The magnetic force part generates a magnetic field that applies continuous pressing force to the needle tip against the seal part without requiring continuous electrical power supply for mechanical actuation, thereby reducing energy consumption while maintaining reliable sealability.
Solution Approach 2:
The magnetic force part is designed to apply pressing force in advance and maintain it continuously without requiring active control during the injection process. The magnetic field is established beforehand and sustains the pressing force on the needle tip, ensuring sealability is maintained without continuous motor operation.
2Speed
If the belt-pulley system is used to move the needle up and down, then the needle can move at higher speed, but the needle becomes more susceptible to fluid pressure and repulsive forces when power is lost
Solution Approach 1:
The patent replaces the belt-pulley mechanical transmission system with a direct magnetic actuation system. The magnetic force part directly applies force to the needle holding part without intermediate mechanical components, eliminating the vulnerability to fluid pressure and repulsive forces that affects belt-pulley systems when power is lost.
Solution Approach 2:
The magnetic field acts as an intermediary between the control system and the needle, providing a non-contact force transmission mechanism. This magnetic intermediary allows the needle to be held in position against the seal part without direct mechanical connection, making the system resistant to fluid pressure and repulsive forces.
3Loss of energy
If power supply to the motor is interrupted while the needle is fluidly connected to the injection port, then energy saving is achieved, but the pressing force is lost and liquid leakage occurs
Solution Approach 1:
The patent substitutes the electric motor-driven mechanical pressing mechanism with a magnetic field-based pressing mechanism. The magnetic force part generates a magnetic field that maintains pressing force on the needle tip without requiring continuous electrical power, thus preventing energy waste while maintaining sealability even when power supply is interrupted.
Solution Approach 2:
The magnetic force part is designed to maintain the pressing force autonomously without requiring continuous external power supply or active control. The magnetic field self-maintains the pressing force on the needle tip, making the sealing function self-sustaining and independent of continuous power supply.
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
Ensures sealability between the injection port and needle without continuous power supply, preventing liquid leakage and enabling power-saving operation by relying on magnetic force to maintain the needle's position against the seal part.
Implementation Method 1
a magnetic force part provided to apply a magnetic force in a direction that pushes down the needle holding part
Data Source
AI summary
An autosampler comprises a needle unit having a needle holding part that holds a needle for aspirating and discharging fluid through a tip thereof, the needle unit moving the needle holding part in a vertical direction while moving in a horizontal direction; an injection port having therein a flow path to which the needle is fluidly connected during sample injection, wherein an opening communicating with the flow path is provided on an upper surface, a seal part is provided inside the opening, against which an outer peripheral surface of the tip of the needle is pressed when the needle descends to a predetermined height from above the opening, and the tip of the needle being pressed against the seal part causes the needle to be fluidly connected in a liquid-tight manner to the flow path; and a magnetic force part provided to apply a magnetic force in a direction that pushes down the needle holding part, at least in a state where the outer peripheral surface of the needle is pressed against the seal part in the injection port.