The patent of the utility model relates to a novel magnetic suction slider type carbon film straight line Displacement sensor The linear carbon film resistance of the sensor element is sealed in the closed aluminum shell, and the electric brush is built in. According to the basic principle of magnetic heteropolar attraction, an external magnetic slider is used to attract and drag the built-in magnetic slider to move, and the built-in slider drives the brush to move, and the relative position is detected. A new principle of carbon film slide Displacement sensor 。
2、 Characteristics and advantages
Because the body shell of the sensor is a closed body, it is different from the original open structure. It has the following advantages: 1. It is easy to make the body thinner and has the following advantages: 1; 3. Because the linear protection level of the product is easy to be closed, the service life of the sensor can be greatly prolonged; 4. If the left and right suction of the magnetic slider is arranged symmetrically, or symmetrically arranged on the circumference, the left and right (or unilateral) suction can be offset each other, the friction force can be basically eliminated, the sliding block will be in floating state, the service life will be prolonged, and there will be no hysteresis between the measurement position and the actual position; 5. Due to the interactive change of three magnetic poles on each side, the dislocation of internal and external magnetic blocks can be effectively avoided; 6. The IP68 can be achieved after sealing treatment at both ends, which can meet the requirements of underwater use, thus greatly expanding the application field; 7. The application of this principle can be extended to liquid level measurement type and oil cylinder built-in structure.
3、 Schematic diagram of pole pair structure
As shown in the figure: the magnetic suction can be arranged on both sides of the external type, or in the circumferential direction of the liquid level measurement type and the built-in oil cylinder type. In short, the basic requirement is to offset the unilateral suction. (Note: not related to horizontal or vertical arrangement)
4、 Overall structure diagram (omitted)
5、 Specific implementation examples
This structure can be implemented as three different types of sensors. They are: 1) when the outer slider is a floating ball, this structure can be used as a liquid level detection linear displacement sensor; 2) when the outer slider is a built-in magnetic ring of the oil cylinder, this structure can be used as the built-in linear displacement sensor of the oil cylinder, which can be effectively replaced magnetostrictive displacement sensor When the outer slider is ordinary (neither waterproof nor buoyant), it can be used as an external ordinary linear displacement sensor when it is matched with a special shaped shell.
6、 Electrical principle
As shown in the figure: a fixed DC voltage is added at both ends of the carbon film resistance plate of the displacement sensor, and the output voltage value is contacted by the sliding brush. If we know the total length of the carbon film plate in advance, we can get the relative position through the output voltage value, that is, the absolute displacement. If the output voltage signal is processed, the current signal can be obtained for long-distance transmission.