CN-122016003-A - Liquid level detection assembly

CN122016003ACN 122016003 ACN122016003 ACN 122016003ACN-122016003-A

Abstract

The invention discloses a liquid level detection assembly, which comprises a mounting plate, wherein the mounting plate is fixed on a base, a linear guide rail is arranged on the mounting plate, a sampling device slides up and down on the linear guide rail, a power device is fixed on the mounting plate and provides power for the sampling device, the sampling device is connected with a detection device, the detection device is used for detecting capacitance change generated when the sampling device contacts with a liquid level, the detection device controls the sampling device to slide up and down, high-precision detection and automatic control of the liquid level are realized through interaction of all parts, and after the detection device detects that the sampling device contacts with the liquid level, signals are transmitted to the power device to instruct the sampling device to stop or adjust the movement of the sampling device, so that the sampling device can accurately stay at a serum position to collect a sample.

Inventors

XU XINGSHANG
LI YIHAO
AI LIN
MA JUN

Assignees

南京岚煜生物科技有限公司

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (14)

1. The utility model provides a liquid level detection subassembly, includes the mounting panel, the mounting panel is fixed on the base, be provided with linear guide on the mounting panel, sampling device is in slide from top to bottom on the linear guide, be fixed with power device on the mounting panel, power device does sampling device provides power, its characterized in that, sampling device is connected with detection device, detection device is used for detecting the capacitive variation that produces when sampling device and liquid level contact, detection device control sampling device's upper and lower slip.
2. The liquid level detection assembly according to claim 1, wherein the power device is a screw motor, the screw motor is connected with a screw through a coupler, a first bearing seat is arranged below the coupler, the screw is embedded in the first bearing seat, the tail end of the screw is located in the base, and the base serves as a second bearing seat of the screw.
3. The liquid level detection assembly according to claim 2, wherein a thread sleeve is arranged on the screw rod, the sampling device is connected with the screw rod through the thread sleeve, the sampling device comprises a sampling needle sliding block, a sampling needle driving block and a sampling needle pressing plate, the thread sleeve is nested inside the sampling needle sliding block, the surface of the sampling needle sliding block is contacted with the linear guide rail and slides up and down along the linear guide rail, the lower end face of the sampling needle sliding block is connected with the sampling needle driving block, the sampling needle is positioned inside the sampling needle driving block, and the sampling needle pressing plate is fixed above the sampling needle driving block.
4. The fluid level detection assembly of claim 3, wherein the sampling needle comprises an inner needle, a sleeve and a limiting block, the limiting block is clamped inside the sampling needle driving block and the sampling needle pressing plate, the outer edge of the sleeve is attached to the inner peripheral edge of the limiting block, and the inner needle is positioned in the sleeve.
5. The fluid level detection assembly of claim 4, wherein the needle top structure of the sampling needle is configured to produce a change in capacitance when in contact with a fluid level.
6. The liquid level detection assembly according to claim 5, wherein the sampling device is connected with the detection device, the detection device can detect the capacitance change of the sampling needle, and the detection device controls the up-and-down movement of the sampling needle sliding block through the rotation of the screw rod which drives the screw rod motor to be linked.
7. The fluid level detection assembly of claim 1, wherein the sampling device is coupled to the mounting plate via a synchronous chain, the synchronous chain being of a multi-chain configuration.
8. The fluid level detection assembly of claim 7, wherein the synchronous chain is fixed at the upper end of the mounting plate by a synchronous chain bracket, and the synchronous chain is connected to the sampling needle slider by a synchronous chain fixing plate.
9. The liquid level detection assembly of claim 1, wherein an optocoupler is fixed to the mounting plate, and an optocoupler baffle is fixed to the sampling device.
10. The liquid level detection assembly according to claim 1, wherein the detection device comprises a liquid level detection circuit structure, the liquid level detection circuit structure comprises a needle capacitance signal input device, a phase discriminator, a loop filter, a voltage-controlled oscillator and a signal output device, which are sequentially connected in series, and a frequency divider is further connected between the voltage-controlled oscillator and the phase discriminator.
11. The liquid level detection assembly according to claim 10, wherein the needle capacitance signal input device comprises a square wave amplification circuit, the square wave amplification circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4 and an operational amplifier U1, the positive input end of the operational amplifier U1 is connected with the resistor R1, the negative input end of the operational amplifier U1 is connected with the resistor R2, the resistor R4 is connected between the positive input end of the operational amplifier U1 and the output end of the operational amplifier U1, one end of the resistor R3 is connected with the negative input end of the operational amplifier U1, and the other end of the resistor R3 is grounded.
12. The liquid level detection assembly according to claim 10, wherein the voltage-controlled oscillator comprises an LC oscillating circuit, the LC oscillating circuit comprises a capacitor C1, a capacitor C2, a resistor R5 and an inductor L1, the capacitor C1 is connected with the output end of the LC oscillating circuit after being connected with the resistor R5 in series, and the capacitor C1 is connected with the input end of the LC oscillating circuit; the capacitor C2 and the inductor L1 are connected between the resistor R5 and the output end of the LC oscillating circuit, and the capacitor C2 and the inductor L1 are grounded.
13. The liquid level detection assembly according to claim 10, wherein the loop filter comprises a rectifying and filtering circuit, the rectifying and filtering circuit comprises a resistor R7, an operational amplifier U2, an operational amplifier U3 and a capacitor C3, the input end of the rectifying and filtering circuit is sequentially connected with a resistor R6, a resistor R8, a resistor R9, a resistor R10 and a resistor R11, and the resistor R11 is connected with the output end of the rectifying and filtering circuit; The positive input end of the operational amplifier U2 is connected between the resistor R6 and the resistor R8, and the negative input end of the operational amplifier U2 is grounded, the positive electrode of the diode D2 is connected between the resistor R8 and the resistor R9, and the negative electrode of the diode D2 is respectively connected with the output end of the operational amplifier U2 and the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected with the positive input end of the operational amplifier U2; One end of the resistor R7 is connected with the input end of the rectifying and filtering circuit, and the other end of the resistor R7 is connected with the positive input end of the operational amplifier U3, the negative input end of the operational amplifier U3 is grounded, and the output end of the operational amplifier U3 is connected between the resistor R10 and the resistor R11; one end of the inductor C3 is connected between the resistor R11 and the output end of the rectifying and filtering circuit, and the other end of the inductor C is grounded.
14. The liquid level detection assembly of claim 10, wherein the phase detector comprises a comparison circuit comprising an operational amplifier U4, a capacitor C4, and a resistor R12; The positive input end of the operational amplifier U4 is connected with a signal, the negative input end of the operational amplifier U4 is connected with a power supply VDD, one end of the resistor R12 is connected with the output end of the operational amplifier U4, the other end of the resistor R12 is connected with the power supply VDD, one end of the capacitor C4 is connected with the output end of the operational amplifier U4, and the other end of the capacitor C4 is grounded.

Description

Liquid level detection assembly Technical Field The invention belongs to the technical field of fluorescence immunoassay detection equipment, and particularly relates to a liquid level detection assembly used in an analyzer. Background The sampling technology is a detection technology commonly used in biomedical inspection at present, and the technology is used for qualitatively and quantitatively detecting an analyte by utilizing the characteristic that the analyte generates fluorescence under the excitation of light with a specific wavelength. The sampling technology has a series of advantages of high sensitivity, strong specificity, high detection speed, safety, stability and the like, so that the sampling technology is widely applied to clinical detection, and has wide application prospects in the detection fields of endocrine disease detection, infectious disease detection, gynecological disease detection, tumor marker detection, genetic disease detection, blood and cytology detection and the like. The design of the liquid level detection assembly is particularly important for the sampling technology, and in Chinese patent document CN 102928041A, a small-volume liquid level detection device is disclosed, and the liquid level detection device comprises a quartz container, and is characterized in that the cross section of the quartz container is round, flat inert electrodes are arranged in pairs in the quartz container, curved inert electrodes are also arranged in pairs in the quartz container below the flat inert electrodes, one end of each curved inert electrode is fixed on the inner wall of the quartz container, the other end of each curved inert electrode is curved downwards, the tail end of each curved inert electrode is positioned at the central position of the quartz container, the flat inert electrodes and the curved inert electrodes are connected with a microcontroller through a receiving conversion circuit and a comparison amplifying circuit in sequence, and the microcontroller also controls the flat inert electrodes and the curved inert electrodes through a driving circuit respectively. The small-volume liquid level detection device has the advantages of simple structure, ingenious design and reasonable layout, and can automatically carry out accurate constant volume measurement on the organic reagent. According to the technical scheme, although the problem of inaccurate liquid level height measurement caused by liquid consistency, capillary effect and the like can be avoided as much as possible, the measurement accuracy is ensured, and the labor and time are saved. However, in a specific use process, when the sampling needle collects a serum sample, because the serum is only on the upper layer in the sample tube, if the liquid level cannot be sensed but the blood sample is collected at a fixed height, the blood plasma sample may be collected, so that the result is affected, and the sampling detection result may be affected. Therefore, it is necessary to develop a new liquid level detection assembly, so that the sampling needle can accurately stay at the serum position to collect the sample, and the collection of the plasma sample is avoided. Disclosure of Invention The invention aims to solve the technical problem of providing a liquid level detection device capable of enabling a sampling needle to accurately stay at a serum position to collect a sample. In order to solve the technical problems, the liquid level detection assembly comprises a mounting plate, wherein the mounting plate is fixed on a base, a linear guide rail is arranged on the mounting plate, a sampling device slides up and down on the linear guide rail, a power device is fixed on the mounting plate and provides power for the sampling device, and the liquid level detection assembly is characterized in that the sampling device is connected with a detection device, the detection device is used for detecting capacitance changes generated when the sampling device contacts with a liquid level, and the detection device controls the sampling device to slide up and down. The liquid level detection assembly realizes high-precision detection and automatic control of liquid level through interaction of all parts, the mounting plate provides structural support for the whole device, ensures that all parts are firmly fixed on one frame, the linear guide rail provides an accurate motion path for the sampling device, the power device is responsible for driving the sampling device to move up and down along the linear guide rail, and the detection device can send a signal to the power device after detecting that the sampling device contacts with the liquid level to instruct the power device to stop or adjust the movement of the sampling device, so that the sampling device can accurately stay at a serum position to collect a sample. Preferably, the power device is a screw motor, the screw motor is connected with the screw through a coupler, a fi