CN201215516Y

CN201215516Y - Differential capacitor load sensor

Info

Publication number: CN201215516Y
Application number: CNU2008200695782U
Authority: CN
Inventors: 于晓光; 司柽宇; 卢满怀; 彭芳; 潘奇明
Original assignee: University of Electronic Science and Technology of China Zhongshan Institute
Current assignee: University of Electronic Science and Technology of China Zhongshan Institute
Priority date: 2008-03-06
Filing date: 2008-03-06
Publication date: 2009-04-01
Anticipated expiration: 2018-03-06

Abstract

A differential capacitor load sensor is mainly composed of a fixed terminal post, a dynamic terminal post, a measuring element (elastomer), a measuring head and a casing. When the measuring head is acted by external force, the force is transferred to the measuring element (elastomer), the measuring element generates elastic deformation and is compressed axially, the measuring head and the capacitor dynamic terminal post displace correspondingly, the covered area between the two terminal posts of the capacitor sensor is changed to change the capacitance value of the sensor, while the variable quantity of the capacitance value is one-to-one related to the displacement of the measuring head. The capacitance variable quantity is output to external circuits via electrode lead wires to be processed and output to obtain the value of the external load. The utility model is characterized in that the differential capacitor load sensor has high sensitivity to pick up signals easily, the polar plates have no contact, no deformation, no abrasion and long service life, the capacitor sensor is affected by temperature little, and the differential capacitor load sensor has good dynamic performance.

Description

The differential capacitance load transducer

One, technical field

The utility model relates to the differential capacitance sensor of a kind of various loads of detection (power) size.

Two, background technology

At present, in the middle of numerous sensors that is used for load (power) detection, the overwhelming majority is a resistance strain type sensor, does not have capacitance type sensor product or design to come out temporarily.The drawback one of resistance-strain type load transducer is that detection sensitivity is not high enough, and general error is about 0.5%; The 2nd, resistance strain gage is subject to the influence of environment temperature, makes measurement numerical value inaccurate; The 3rd, the paste position precision and the firmness of resistance strain gage all can cause measuring error; The 4th, the resistance strain gage signal changes faint, is unfavorable for detecting.

Three, summary of the invention

The technical problems to be solved in the utility model is: provide a kind of brand-new differential capacitance load transducer, to overcome the deficiencies in the prior art.

The technical solution adopted in the utility model is: it is mainly formed by deciding pole, moving pole, measuring sensor, measuring head, housing, moving pole and measuring head are connected to one, decide pole and housing is connected to one, measuring head and housing are clearance fit, and measuring sensor is installed between measuring head and the housing base; Deciding the fairlead of electrode outlet line on outer casing base that the pole and the moving utmost point lean on draws.

The moving utmost point is leant on, is decided pole and adopts stupalith to do substrate, and the surface is coated with one deck silver respectively, constitutes two electrodes of electric capacity, and silver layer surface is coated with one deck inert metal rhodium again; The electrode of deciding pole also is covered with one deck polyvinyl chloride layer outward.

The electrode two ends of moving pole are respectively equipped with the electric capacity equal potential belt.

Good effect of the present utility model is: 1, compare with the resistance-strain type load transducer of present widespread usage, simple in structure, adaptability is strong, dynamic corresponding good, temperature stability is good, can realize non-cpntact measurement, have between pole plate and do not contact, advantage such as do not wear and tear, the life-span is long; 2, the relatively independent installation of measuring sensor, easy accessibility; 3, adopt the long-pending form of differential pole-changing cylinder, input is good with the output line sexual intercourse, and the measuring accuracy height can reach below the um level; 4, moving, decide the electric capacity pole adopts stupalith to do substrate, the insulating property height; Electrode adopts spray silvering on ceramic bases, and then plating one deck inert metal rhodium, has reached both to make the electrodes conduct performance good, and electrode is sealed relatively, plays dustproof, moistureproof, anticorrosion, anti-oxidant, wear-resistant effect, has reduced temperature coefficient simultaneously; 5, moving pole adopts the equal potential belt technology can effectively eliminate the edge effect of electric capacity, makes that the linear relationship of the input of sensor and output is better, and measuring accuracy is higher; 6, moving, decide to adopt the dielectric of pvc material between the pole as electric capacity, relative dielectric constant is higher, sensor initial capacitance value height, be convenient to signal extraction, measurement, handle and reduce that signal disturbs and the raising measuring accuracy.

Four, description of drawings

Accompanying drawing 1: structural representation of the present utility model;

Accompanying drawing 2: the moving pole synoptic diagram of this sensor;

Accompanying drawing 3: this sensor decide the pole synoptic diagram.

Five, embodiment

As shown in Figure 1, this sensor is by deciding pole 5, moving pole 6, measuring sensor 3, measuring head 1, housing 2 constitutes, moving pole 6, deciding pole 5 all adopts stupalith to do substrate, be shaped as hollow cylindrical, inside surface at moving pole 6, the outside surface of deciding pole 5 plates the silver that is no more than 0.1mm with thickness respectively, as two electrodes 11 of electric capacity, 13 (as Fig. 2, shown in 3), and then the inert metal rhodium that plates a layer thickness 0.05mm is as electrode protecting layer, both make the electrodes conduct performance good to reach, electrode is sealed relatively, play dustproof, moistureproof, anticorrosion, anti-oxidant, wear-resistant effect can reduce temperature coefficient again simultaneously; Outside the electrode 13 of deciding pole 5, apply again with the thick polyvinyl chloride layer 14 of 0.5mm,, increase capacitance to improve specific inductive capacity.As shown in Figure 2, moving pole 6 electrode two ends are respectively equipped with electric capacity equal potential belt 10, can effectively eliminate the edge effect of electric capacity.Decide pole 5 and adopt bonding way and housing 2 to be connected as a single entity, moving pole 6 is bonded as one with measuring head 1; Measuring sensor 3 adopts spring in an embodiment, can make series of products, selects the measuring sensor of different elasticity coefficient arbitrarily for use according to detected object, scope difference; Measuring head 1 and housing 2 adopt iron-nickel alloy to do material, can reduce the influence of temperature variation to measuring accuracy; Measuring head 1 also can be made dissimilar according to the detected object difference; Housing 2 adopts the iron-nickel alloy materials, good stability, and temperature coefficient is low, and the electric capacity of inside is played good shielding action, and the antinoise signal jamming performance is good.

Principle of work of the present utility model is: during working sensor, measuring head 1 is subjected to the external force effect, and this acting force passed to measuring sensor 3, elastic deformation takes place in measuring sensor 3, be compressed vertically, measuring head 1 and moving pole 6 produce corresponding displacement together, then the area coverage of capacitive transducer the two poles of the earth intercolumniation changes, the capacitance that causes sensor changes thereupon, this capacitance outputs to additional circuit by

electrode outlet line

4,9, detect, handle, export by the capacitance of circuit, just can obtain the size of imposed load sensor.

Claims

1, a kind of differential capacitance load transducer, it is characterized in that: it is mainly formed by deciding pole (5), moving pole (6), measuring sensor (3), measuring head (1), housing (2), moving pole (6) is connected to one with measuring head (1), deciding pole (5) is connected to one with housing (2), measuring head (1) is a clearance fit with housing (2), and measuring sensor (3) is installed between measuring head (1) and housing (2) base; Deciding the fairlead (8) of electrode outlet line (4,9) on shell (2) base of pole (5) and moving pole (6) draws.

2, differential capacitance load transducer according to claim 1 is characterized in that: moving pole (6), decide pole (5) and do substrate by stupalith, the surface is coated with one deck silver respectively, and silver layer surface is coated with one deck inert metal rhodium; Decide outer one deck Polyvinylchloride (14) layer that also is covered with of electrode (13) of pole (5).

3, differential capacitance load transducer according to claim 1 and 2 is characterized in that: electrode (11) two ends of moving pole (6) are respectively equipped with electric capacity equal potential belt (10).