CN2335135Y

CN2335135Y - Steel bar stress sensor

Info

Publication number: CN2335135Y
Application number: CN 98206296
Authority: CN
Inventors: 王德盛
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-07-01
Filing date: 1998-07-01
Publication date: 1999-08-25
Anticipated expiration: 2008-07-01

Abstract

The utility model relates to a steel bar stress sensor (or a steel bar gauge) which belongs to force measuring devices. The gravity suction anchor is characterized in that a converting pipe, a circuit chamber and an outer shell are integrated into one body, and screw holes which are arranged at two heads of the outer shell are provided with connecting rods which are welded with a measured steel bar. Both ends of the converting pipe are respectively provided with an adjusting rod which is provided with a magnetic core and coil magnet core assemblies to constitute a sensing unit. A capacitor and an oscillator which are arranged in the coil and the circuit chamber are connected into an L-C oscillating circuit. Direct current voltage is input and frequency modulated signal are output through cables. The steel bar stress sensor has the advantages of high signal-to-noise ratio, anti interference, easy of far transmission, simple and firm structure, tight encapsulation, earthquake proof and water proof and can stably and reliably monitor the steel bar stress for long time in severe environment.

Description

The reinforcement stresses sensor

The reinforcement stresses sensor has another name called the reinforcing bar meter, and it is a kind of device for measuring force.In order to be embedded in hydraulic engineering or other concrete steel building internal measurement reinforcement stresses.

Known reinforcement stresses sensor is a differential resistance type reinforcing bar meter (GB3409-82), this reinforcing bar meter is to be welded across respectively on two square irons by two groups of thin steel wires, when the sensor under tension or compression, the resistance ratio of two groups of steel wires changes, utilizing special water conservancy project ratio electric bridge to measure resistance ratio changes, can determine the reinforcement stresses size, this sensor weak point is: the steel wire resistance ratio becomes with temperature, needing to measure temperature revises, resistance ratio is influenced by cable length, requirement cable resistance symmetry, jumper also need to revise.In addition, this sensor construction is firm inadequately, and steel wire is thin, can not tolerate vibration and impacts, and need just can bury underground after concrete hardening, and inside also needs to fill neutral transformer oil, therefore makes and uses all inconvenient.

The purpose of this utility model provides a kind of simple in structure and firm, and encapsulation is tight, and earthquake-resistant water-proof is anti-interference, and insensitive to temperature variation and cable length influence, the resolution height is convenient to the teletransmission remote measurement, the reinforcement stresses sensor that can use in rugged surroundings.

The purpose of this utility model is achieved in that the elastic deformation pipe, shell and circuit chambers are integrated, fixing adjuster bar and magnetoelectricity assembly respectively at the two ends of elastic deformation pipe, the end of adjuster bar is stained with magnetic core, the magnetoelectricity assembly is then by coil, magnetic core and magnetic core seat combine, between two magnetic cores an air gap is arranged, constitute a closed magnetic circuit, two of coil enters circuit chambers and the oscillator that is positioned at wherein by lead-in wire, electric capacity, ground wire, cable core, shielding line couples together by Fig. 2, constitute the L-C oscillatory circuit, by the shielded cable input DC power, the output FM signal.When sensor is subjected to tensile force or force of compression, the elastic deformation pipe can produce and elongate or shorten, so that changed with magnetic core that its two ends link to each other between air gap and magnetic resistance, thereby cause the change of inductance and oscillatory circuit output signal frequency, suitably rotate adjuster bar and can change air gap and output signal frequency, thereby make the zero frequency f of sensor ₀Change, and make its sensitivity and the linearity reach optimum value.

The utility model is owing to adopt the inductance fm principle, the square wave or the sinusoidal wave FM signal of output constant amplitude, the signal to noise ratio (S/N ratio) height, antijamming capability is strong, long cable transmission is to not influence of signal frequency, thereby do not influence measuring accuracy, adopt same material and Technology for Heating Processing owing to the elastic deformation pipe with its almost isometric adjuster bar simultaneously, its linear expansion coefficient is the same, significantly reduced the influence of variation of ambient temperature, and the utility model adopts also in resonant circuit the electric capacity of different temperature coefficients that circuit integral body is compensated, therefore to sensor, under general condition, can exempt the temperature correction.Also can in the circuit chamber, increase the electric capacity of a high-temperature coefficient and inductance and oscillator of low-temperature coefficient simultaneously, and they are connected into another L-C oscillatory circuit, can increase temp sensing function, constitute reinforcement stresses-temperature complex sensor.

The utility model part is few, simple in structure firm, employing is threaded and adds gluing connect and to space, circuit chamber and two ends bottom of thread infusion epoxy resin glue, cable also compresses with hollow screw and rubber ring, and with the sealing of 703 glue, so the water-tight performance is good especially, working stability is reliable, concrete construction do not required take special safeguard procedures, just bury underground after more needn't waiting concrete hardening.

Change planform, size and material, technology, can make the compound sensor that pull pressure sensor, load sensor, strain transducer, mine pillar pressure transducer and they constitute with temperature sensor.

The utility model accompanying drawing

The insight structural map of Fig. 1 the utility model reinforcement stresses sensor

Fig. 2 the utility model schematic block circuit diagram

Fig. 3 tension-compression sensor insight structural map

Fig. 4 load sensor insight structural map

Fig. 5 strain transducer insight structural map

Fig. 6 mine pillar pressure transducer insight structural map

The theory diagram of Fig. 7 built-in temperature sensor

Fig. 1 is the embodiment of the utility model reinforcement stresses sensor 1.

Ground wire is welded on the weld tabs, with screw (15) and nut (14) weld tabs (13) is fixed, and screw (16) is filled up with epoxy resin or 703 glue.Coil (22) is exoskeletal type, with the high-strength polyester enameled wire on special mould, interlayer is coated with epoxide-resin glue and by corresponding technology and solidifies, curing and demolding, solder taul (10), embed in the ring groove of the magnetic core of gluing (18), blended rubber is filled upper space, but can not surpass the magnetic core plane, and then this magnetic core is enclosed within on the small column of magnetic core seat (17), with glue it is bonded on the magnetic core seat (17), the magnetoelectricity assembly of making like this (11) with the ring groove gluing of circuit chamber (5) bottom, is put into base apertures with the magnetic core (18) of magnetoelectricity assembly (11) through after solidifying with sampling technology, little exerting pressure makes it to cement; Meanwhile, with an end gluing of adjuster bar (22), magnetic core (20) bottom surface is bonded at rod end outwardly again, both solidify by corresponding technology together again.

The adjuster bar (22) that will be stained with magnetic core (20) is screwed in elastic deformation pipe (23) hole, and rotation adjuster bar (22) makes between magnetic core (20) and (18) and leaves minimum air gap, measures coil (19) two ends inductance, till predetermined value, gland nut (24) is tightened.Shielded cable (6) is repaiied head, put rubber ring (7), hollow line pressing bolt (8), penetrate in the cable aperture (9) on the housing, make it to be linked to be the L-C oscillatory circuit by Fig. 2 with coil (19), electric capacity (3), oscillator (4).Be placed on then and carry out the temperature compensation test in the high-low temperature test chamber, adopt the electric capacity of different temperature coefficients and electric capacity, up to reaching centre frequency f ₀And till the variable quantity in the set point of temperature scope reaches requirement, then oscillator (4), electric capacity (3) are wrapped with insulating material (as insulating varnished silk), filled in the circuit chamber (5), on force measuring machine, carry out service check at last, as qualified, cable aperture (9) is coated with 703 glue, is pressed into rubber ring (7), be screwed into line pressing bolt (8), and fill up circuit chamber (5) and adjuster bar gland nut (24) top with epoxide-resin glue, the bottom of thread up to connecting rod (2,27) is by solidifying with sampling technology.Defective as indivedual performance calibratings, can littlely tune pole, calibrating again encapsulates by above-mentioned technology after qualified again.

Above-mentioned reinforcement stresses sensor can be surveyed the sound attitude and stretch and compression stress.Its principle of work is: when sensor is stretched stress, and the converting pipe elongation, air gap strengthens between two magnetic cores, and magnetic resistance strengthens, and inductance reduces, so the frequency rising (

f = \sqrt{1 / LC / 2} π

); Otherwise when sensor by compression during stress, air gap reduces, and magnetic resistance reduces, and inductance increases, and frequency reduces.The stress of input and output frequency change the funtcional relationship that monodrome is arranged.Therefore,, provide the funtcional relationship of F (power)-f (frequency) during calibrating, need only the survey sensor output signal frequency, just can determine the direction and the size of reinforcing steel bar bear for each sensor.

Shown in Fig. 3,4,5,6, the sensor is changing its planform, size, material and technology, just can make compound sensor that pull pressure sensor, load sensor, strain transducer, ore deposit and pillar pressure transducer and they constitute with temperature sensor or the like.

Fig. 7 is the circuit theory diagrams that temperature passes device, adopts the electric capacity of big temperature coefficient to be linked to be another L-C oscillatory circuit as temperature-sensing element (device) with temperature coefficient little inductance and oscillator.With the sensor common circuit chamber, cable and ground wire, but will suitably extend in the circuit chamber and the cable in the single-sensor is increased a heart yearn, with the transmission temperature signal, also tackle temperature sensor and demarcate this moment, and its temperature-measuring range can not surpass the limit of working temperature scope that oscillator and inductance, electric capacity allowed.

Claims

1, a kind of reinforcement stresses sensor, comprise housing (25), connecting link (2,27), cable (6), it is characterized in that there are inductance type sensing unit (21), oscillator (4) and electric capacity (3) in sensor housing (25) inside, lead is linked to be the L-C oscillatory circuit with them.

2, by the described reinforcement stresses sensor of claim 1, it is characterized in that the housing (25) and the threaded hole (12,26) of converting pipe (23), circuit chamber (5) and installation connecting link (2,27) are combined into a part, the position, intermediate portion is converting pipe (23).

3, it is characterized in that forming inductance type sensing unit (21) by the described reinforcement stresses sensor of claim 1 by converting pipe (23) and the adjuster bar (22) and the magnetoelectricity assembly (11) that are loaded on its two ends respectively.

4, by the described reinforcement stresses sensor of claim 3, it is characterized in that adjuster bar (22) one ends have screw thread, the other end is stained with magnetic core (20).

5, the described reinforcement stresses sensor of claim 3, it is characterized in that magnetoelectricity assembly (11) is made up of exoskeletal coil (19), magnetic core (18) and magnetic core seat (17), coil (19) places in the ring groove of magnetic core (18), and is firm by the epoxy resin glue bond between the three.

6, by the described reinforcement stresses sensor of claim 1, it is characterized in that in circuit chamber (5), increasing an inductance, an electric capacity and an oscillator, the three is linked to be another L-C oscillatory circuit with lead, thereby constitutes reinforcement stresses-temperature complex sensor.

7, by the described reinforcement stresses-temperature complex sensor of claim 6, it is characterized in that adopting electric capacity is temperature-sensing element (device).

8, by the described reinforcement stresses-temperature complex sensor of claim 6, it is characterized in that shared circuit chamber, cable and a ground wire, all components and parts wrapped with insulation in circuit chamber (5), and fill up all spaces with epoxide-resin glue.

9,, it is characterized in that the cable aperture screw thread fills with 703 glue, and compress sealing with rubber ring, line ball hollow screw by claim 1,6 described reinforcement stresses sensor and reinforcement stresses-temperature complex sensor.

10, by claim 1,6 described reinforcement stresses sensor and reinforcement stresses-temperature complex sensor, change planform, size, material and technology, can make compound sensor that pull pressure sensor, load sensor, strain transducer, mine pillar pressure transducer and they and temperature sensor form together etc.