CN203760928U - Intelligent type double hook wire grip - Google Patents

Abstract

The utility model discloses an intelligent type double hook wire grip. Two hook heads are connected to the sleeve through threaded connection and at least one resistance strain gauge is positioned on the surface of the sleeve or the hook head. The quantity of the resistance strain gauges is four, two of the resistance strain gauges are symmetrically patched on the two sides of the sleeve along the axes of the sleeve and the other two resistance strain gauges are symmetrically patched on the two sides of the sleeve along the circumference of the sleeve. The intelligent type double hook wire grip disclosed by the utility model obtains the deformation through the arrangement of the resistance strain gauges. In the further improvement scheme, the intelligent type double hook wire grip can automatically alarm when the external pull force exceeds the allowable value so as to prevent the occurrence of the incidence and improve the safety of the tower pole erection step during the overhead network line construction.

Description

Intelligent double-hook wire grip

Technical field

The utility model relates to the double-hook wire grip in overhead line construction, especially a kind of intelligent double-hook wire grip.

Background technology

Double-hook wire grip is the Work tool of commonly using in Overhead Transmission Line Construction.Current double-hook wire grip is in the time that pulling force overloads, and workmen can not realize in time, and double-hook wire grip will rupture, thereby cause construction safety accident difficult to the appraisal.

Double-hook wire grip mostly is Q235, the carbon constructional quality steel manufacture of Q255, and mechanical curves while being stretched by mild steel is illustrated in fig. 3 shown below, in the proportional limit of mild steel, metal material is stretched strain can occur, and removes after external force, and metal material can recover former length automatically.And in proportional limit, the stress and strain of material is linear as Fig. 3, line segment ob.In the time that external force exceedes the proportional limit of material to the stress of material production, material will be in the surrender stage.The plastic deformation that now material produced in the surrender stage will be expendable.

Summary of the invention

Technical problem to be solved in the utility model is to provide a kind of intelligent double-hook wire grip, can learn whether the distortion of double-hook wire grip reaches elastic limit of materials, further, can send alarm signal.

For solving the problems of the technologies described above, the technical scheme that the utility model adopts is: a kind of intelligent double-hook wire grip, two gib heads and sleeve are threaded connection, and are provided with at least one sheet resistor foil gauge at sleeve or gib head surface.

Described resistance strain gage is four, uniform along sleeve or gib head circumferential surface.

Described resistance strain gage wherein two stick on sleeve or gib head both sides along the axis of sleeve symmetrically, other two circumferentially stick on sleeve or gib head both sides along sleeve symmetrically.

Four described sheet resistor foil gauges adopt bridge circuit to connect.

Directly or be connected with filter by binding post, filter is connected with differential amplifier for the output signal of bridge circuit, and differential amplifier is connected with A/D converter, and A/D converter is connected with voltage comparator, and voltage comparator is connected with warning device.

Described warning device is LED lamp and/or buzzer.

The intelligent double-hook wire grip of one that the utility model provides, obtains the deformation of double-hook wire grip by the resistance strain gage arranging.In the scheme of further optimizing, can also in the time that external broach exceedes allowable value, automatically report to the police to the external world, thereby well prevent the generation of above-mentioned accident, improve the fail safe of the tower erection link in overhead line construction.

Brief description of the drawings

Below in conjunction with drawings and Examples, the invention will be further described:

Fig. 1 is overall structure schematic diagram of the present utility model.

Fig. 2 is the layout schematic diagram of resistance strain gage in sleeve outer wall expanded view in the utility model.

Mechanical curves when Fig. 3 is mild steel stretching.

Fig. 4 is the circuit connection diagram of resistance strain gage in the utility model.

Fig. 5 is that auxiliary circuit of the present utility model connects block diagram.

In figure: gib head 1, sleeve 2, fastening sleeve handle 3.

Embodiment

In Fig. 1 and 2, a kind of intelligent double-hook wire grip, two gib heads 1 are threaded connection with sleeve 2, when use, by fastening sleeve handle 3, realize stringing or loose ends, are provided with at least one sheet resistor foil gauge at sleeve 2 or gib head 1 surface., be attached on the round bar that is subject to pulling force as force cell with resistance strain gage, transducer converts the pulling force signal obtaining to the signal of telecommunication, and the signal of telecommunication, through differential amplification, is reported to the police to the external world with the form of light or sound.Structure thus, can monitor the resistance change at this place by the resistance strain gage arranging, thereby learn whether the distortion of double-hook wire grip reaches elastic limit of materials.The resistance strain gage model adopting in this example is BE120-03AA.

Preferred scheme is as in Fig. 2, and described resistance strain gage is four, and uniform along sleeve 2 or gib head 1 circumferential surface.Preferably, wherein two stick on sleeve 2 or gib head 1 both sides along the axis of sleeve 2 symmetrically, and other two circumferentially stick on sleeve 2 or gib head 1 both sides along sleeve 2 symmetrically.Structure thus, can monitor respectively axial and circumferential distortion.And be convenient to realize the connection of electric bridge mode, be conducive to obtain more high-precision monitor signal.

As shown in Figure 4, four described sheet resistor foil gauges adopt bridge circuit to connect to the scheme of optimizing.Structure thus, further improves signal accuracy.

The scheme of optimizing as shown in Figure 5, directly or be connected with filter by binding post, filter is connected with differential amplifier for the output signal of bridge circuit, and differential amplifier is connected with A/D converter, A/D converter is connected with voltage comparator, and voltage comparator is connected with warning device.

Direct-connected mode is that filter, differential amplifier, A/D converter, voltage comparator and warning device are all arranged on double-hook wire grip, for the occasion of having relatively high expectations.The all settings separately of filter, differential amplifier, A/D converter, voltage comparator and warning device of mode that adopt binding post to connect, in the time of stringing or routine testing, are connected to bridge circuit, thereby reduce costs.

Around transducer, there is noise source, when cable transmission is passed through in measured signal, resistor produces noise, frequency is higher, and measured signal pulling force is lower, it and measured signal stack enter amplifying circuit, filter separates signaling zone according to frequency, takes out useful signal, and other frequency signal is decayed.Because pulling force signal frequency when the dynamic sampling is lower, then use low-pass filtering, low frequency signal is taken out.In order to get rid of above-mentioned factor impact, select more accurately to differentiate voltage, meet actual demands of engineering, double-hook wire grip, under pulling force allowable, adopts differential amplification.

The output signal voltage of differential amplifier and the difference of applied signal voltage are proportional, and it can complete subtraction, extract and amplify difference mode signal from signal, have higher input impedance and common-mode rejection ratio, can eliminate preferably like this interference.This example adopts ICL7650 high-gain amplifier.

The bridge circuit output voltage of resistance strain gage is less, convert A/D converter acceptable signal to, and data could gather, and finally just can show.The A/D converter model that this example adopts is ADC0809.It is 8 single chip CMOSs, 8 passage successive approximation analog to digital converters.This device can be changed 8 0～5V analog quantity Zhong, mono-roads, tunnel.Its output has tri-state latch function, and with Transistor-Transistor Logic level compatibility, output data can directly be connected with computer bus.

In the time that the output voltage of bridge circuit reaches or approach this value, apply pulling force and reach or approach pulling force allowable, voltage comparator conducting, the LED of connecting with arbiter is luminous, buzzer alarm rings, and realizes with people's light signal output more intuitively and chimes of doom.Described warning device is LED lamp and/or buzzer.

Filter in this example, differential amplifier, A/D converter, voltage comparator are this area common electric element.

When use, 4 same model resistance strain gages are arranged by shown in Fig. 3, R1, R3 be attached to parallel axes to, R2, R4 are attached to vertical direction.Fig. 3 is the expanded view on round bar surface, and 2 π ρ are surface perimeter.When round bar is subject to pulling force, the strain facies that the strain that strain gauge produces and axle produce is same, and on the same cross section of axle, R2, R4 produces transverse strain, R1, R3 produces longitudinal strain, and the strain on each resistance strain gage is respectively:

ε ₁=ε ₃=ε _L+ε _T

ε ₂=ε ₄=-με _L+ε _T

ε in formula ₁, ε ₂, ε ₃, ε ₄be respectively R ₁, R ₂, R ₃, R ₄strain, ε _trepresent the strain that variations in temperature causes, ε _lrepresent the strain that tension variations causes.

The pass of strain variation relative to resistance is:

$\frac{\mathrm{\ΔR}}{R}=\mathrm{K\ϵ}$

If R ₁=R ₂=R ₃=R ₄=R; ?

$\frac{{\mathrm{\ΔR}}_2}{R}=\frac{{\mathrm{\ΔR}}_4}{R}=K(-\mathrm{\μ}{\mathrm{\ϵ}}_L+{\mathrm{\ϵ}}_T);$

$\frac{{\mathrm{\ΔR}}_1}{R}=\frac{{\mathrm{\ΔR}}_3}{R}=K({\mathrm{\ϵ}}_L+{\mathrm{\ϵ}}_T);$

In formula: the resistance value that R is resistance strain gage; The resistance change of △ R resistance strain gage; K is the sensitivity coefficient of resistance strain gage; μ is the Poisson's ratio of material.

In order to obtain maximum signal output, improve the sensitivity of measuring, adopt DC full-bridge.4 resistance strain gages are connected into electric bridge form as shown in Figure 4.If bridge voltage is U altogether ₀, the now output voltage U of electric bridge _yfor:

$U_Y=\frac{\mathrm{\ΔR}}{R}{U}_0=\mathrm{K\ϵ}{U}_0=2K(1+\mathrm{\μ}){\mathrm{\ϵ}}_L{U}_0;$

Know according to the mechanics of materials: σ=Ε ε

So: $U_Y=2K(1+\mathrm{\μ})\frac{\mathrm{\σ}}{E}{U}_0=2K(1+\mathrm{\μ})\frac{F_L}{\mathrm{SE}}{U}_0;$

In formula: S is stressed round bar sectional area; E is the elastic feel quantity of material.

From above formula, when one timing of round bar sectional area, bridge output voltage is directly proportional to pulling force.By measuring bridge output voltage with regard to the known pulling force size that applies.

For the double-hook wire grip of can reporting to the police, known double-hook wire grip pull bar sectional area S, pulling force T allowable, bridge output voltage is made as the differentiation voltage of voltage comparator.In the time that pulling force reaches restriction pulling force, Light-Emitting Diode LED continues light yellow, and the warning of sounding.

The double-hook wire grip pull bar model material of test adopts the Q235 identical with double-hook wire grip material.Make model parameter as follows:

Material: Q235 proportional limit σ _p=200MPa, [σ]=140MPa allowable

Shape: column type bar is long: 150mm, diameter: 22mm

Chamfering 2mm, surface smoothness 2.5

The stress of model is Tmax=A[σ]=5.319t;

In test, get restriction pulling force T=3 ton.At T=3 ton, when electric bridge input voltage is 6V, the mean value that records output voltage is 10.8mV.The differentiation voltage of voltage comparator is 10.8mV.

Experimental phenomena: the differentiation voltage of getting voltage comparator is 10.8mV, voltage comparator works in its rated voltage 5V, in the time that pulling force reaches 2.8t, LED starts flicker, along with the increase of pulling force, the flicker frequency of LED constantly increases, and continues light yellow to 3 ton hour LEDs, and reports to the police.

Claims (4)

1. an intelligent double-hook wire grip, two gib heads (1) are threaded connection with sleeve (2), it is characterized in that: be provided with four sheet resistor foil gauges at sleeve (2) or gib head (1) surface, uniform along sleeve (2) or gib head (1) circumferential surface;

Described resistance strain gage wherein two stick on sleeve (2) or gib head (1) both sides along the axis of sleeve (2) symmetrically, other two circumferentially stick on sleeve (2) or gib head (1) both sides along sleeve (2) symmetrically.

2. the intelligent double-hook wire grip of one according to claim 1, is characterized in that: four described sheet resistor foil gauges adopt bridge circuit to connect.

3. the intelligent double-hook wire grip of one according to claim 2, it is characterized in that: the output signal of bridge circuit directly or be connected with filter by binding post, filter is connected with differential amplifier, differential amplifier is connected with A/D converter, A/D converter is connected with voltage comparator, and voltage comparator is connected with warning device.

4. the intelligent double-hook wire grip of one according to claim 3, is characterized in that: described warning device is LED lamp and/or buzzer.