CN103353365A - Point-contact pin-type force sensor - Google Patents

Abstract

A point-contact pin-type force sensor relates to the technology field of sensors of measuring mechanical-structure joint loads. Three drum type bosses are successively arranged on a pin body in an axial direction, the pin body between two adjacent drum type bosses is a sensing part, a lead laying groove is mounted on a peripheral surface of every drum type boss and the whole three lead laying grooves are collinear along the pin-body axial direction. Four resistance strain gages are uniformly disposed on a peripheral surface of every sensing part, every resistance strain gage is connected with a lead; the lead passes by the lead laying groove, penetrates a lead wire hole arranged in a pin base, and is connected with a lead fixed terminal; and the lead fixed terminal is mounted on a peripheral surface of the pin base. The force sensor provided by the invention achieves purposes of good reproducibility of measuring results, high precision, large-load measuring applicability and high reliability.

Description

A kind of some contact pin-type load force cell

Technical field

The present invention relates to the technical field of the sensor of measurement mechanical structural joint load.

Background technology

Jointing is the key position that engineering structure connects and biography is carried, and the carrying of Measurement accuracy joint is big or small and loading direction is checked safety of structure and fail-safe analysis is significant.In the existing force cell, generally adopt hollow, line/face contact type design.The hollow structure load-bearing capacity a little less than, be not suitable for the measurement that the heavy construction structure is subjected to large load; And line/load distribution inequality on the sensor when face contact form easily causes measuring passes the form of carrying to change, and especially for large load, statically indeterminate structure, can produce the adverse effect that measurement result is unstable, measuring error is larger.

Summary of the invention

The object of the invention provides that a kind of measurement result multiplicity is good, and precision is high, is applicable to the measurement of large load, the some contact pin-type load force cell that reliability is high.

A kind of some contact pin-type load force cell, comprise shank, be positioned at the key seat of shank one end, arrange successively three cydariform boss on shank is axial, shank is the detecting means section between adjacent two cydariform boss, be furnished with a wire arrangements groove on the outer peripheral face of each cydariform boss, three wire arrangements grooves are along the axial conllinear of shank altogether, the outer peripheral face of each detecting means section is evenly arranged four resistance strain gages, connect wire on each resistance strain gage, pass the fairlead that is positioned on the key seat behind the wire process wire arrangements groove and be connected with the wire fixed terminal, described wire fixed terminal is arranged on the outer peripheral face of key seat.

Above-mentioned wire arrangements groove of the present invention is 3, is arranged in totally 16 in the interior wire of wire arrangements groove; Above-mentioned detecting means section is two, has arranged altogether 8 resistance strain gages on the two detecting means sections; Each resistance strain gage links to each other with two wires, and each wire passes fairlead through the wire arrangements groove, is connected on the wire fixed terminal.

Resistance strain gage of the present invention is pasted on the outer peripheral face of detecting means section; 4 resistance strain gages are arranged at 90 ° at interval on the outer peripheral face of each detecting means section, 180 ° at interval over against two foil gauges be a measurement group, the upper equidirectional two groups of foil gauges of two detecting means sections form a full bridge measurement circuit.

The present invention adopts technique scheme, compared with prior art has following advantage:

1, some contact pin-type load force cell of the present invention adopts the carrying of some contact, compares line/face contact type force cell, and the carrying position is fixed, and passes the form of carrying clear and definite, and the measurement result multiplicity is good, and precision is high;

2, some contact pin-type load force cell of the present invention adopts solid construction, possesses stronger load-bearing capacity than the hollow-core construction force cell, is applicable to the measurement of large load;

Adopt clearance fit when 3, some contact pin-type load force cell of the present invention is installed, avoided the impact of interference fit on shank and structural joint contact form, guarantee to pass the form of carrying and carry for the some contact passes, be beneficial to the assurance measuring accuracy;

4, the foil gauge arrangement of some contact pin-type load force cell of the present invention not only can satisfy the measurement of any direction load, and still can obtain effective measurement result by all the other measurement data when the part foil gauge damages, and product reliability is higher.

Description of drawings

Fig. 1 is a kind of structural representation of the present invention.

Among the figure: 1, shank, 2, the drum type boss, 3, the wire arrangements groove, 4, the detecting means section, 5, the wire fixed terminal, 6, key seat, 7, resistance strain gage, 8, wire, 9, fairlead.

Embodiment

Below in conjunction with accompanying drawing technical scheme of the present invention is elaborated:

As shown in Figure 1, a kind of some contact pin-type load force cell, comprise shank 1, be positioned at the key seat 6 of shank 1 one ends, shank 1 axially on arrange successively three cydariform boss 2, shank is detecting means section 4 between adjacent two cydariform boss 2, be furnished with a wire arrangements groove 3 on the outer peripheral face of each cydariform boss, totally three wire arrangements grooves on each drum type boss are along the axial conllinear of shank, the outer peripheral face of each detecting means section 4 is evenly arranged four resistance strain gages 7, connect wire 8 on each resistance strain gage 7, pass the fairlead 9 that is positioned on the key seat 6 behind the wire 8 process wire arrangements grooves 3 and be connected with wire fixed terminal 5, described wire fixed terminal 5 is arranged on the outer peripheral face of key seat 6.

Above-mentioned wire arrangements groove 3 of the present invention is three, and the wire that is arranged in the wire arrangements groove has 16; Above-mentioned detecting means section 4 is two, has arranged totally 8 resistance strain gages 7 on the two detecting means sections 4; Each resistance strain gage links to each other with two wires 8, and each wire passes fairlead 9 through wire arrangements groove 3 and is connected on the wire fixed terminal 5.

Resistance strain gage 7 of the present invention is pasted on the outer peripheral face of detecting means section 4; 4 resistance strain gages are arranged at 90 ° at interval on the outer peripheral face of each detecting means section, 180 ° at interval over against two foil gauges be a measurement group, the upper equidirectional two groups of foil gauges of two detecting means sections form a full bridge measurement circuit.

The main body of force cell of the present invention is the cylindrical pin type structure; Can utilize the anti-joint load that pushes away of electrical measuring method Combining material mechanics correlation computations.As shown in Figure 1, the present invention adopts three drum type boss as the sensor hard point, and sensor is that point contacts with the joint auricle; Joint auricle load on the sensor shank distributed uniform, be distributed symmetrically, the form of pass carrying is clear and definite; The foil gauge quantity of pasting is total up to eight, and 90 ° at per four intervals are pasted on respectively on shank two place's detecting means sections; Two foil gauges at 180 ° at interval are a measurement group on every place detecting means section, and equidirectional two groups of foil gauges form full-bridge dynamometry circuit; During installation of sensors and the joint auricle be clearance fit.

By geometric relationship and mechanics of materials correlation formula, sensor bearing load Ρ (being joint load) can calculate according to following formula:

$P=\frac{1}{64}\·\frac{{\mathrm{\πd}}^3}{a}\·E\sqrt{{({\mathrm{\ϵ}}_{11}+{\mathrm{\ϵ}}_{21}-{\mathrm{\ϵ}}_{11}^{\′}-{\mathrm{\ϵ}}_{21}^{\′})}^2+{({\mathrm{\ϵ}}_{12}+{\mathrm{\ϵ}}_{22}-{\mathrm{\ϵ}}_{12}^{\′}-{\mathrm{\ϵ}}_{22}^{\′})}^2}$

Wherein, d is detecting means section shank diameter, and a is drum type boss and adjacent biography foil gauge spacing, and E is the shank elasticity modulus of materials, ε ₁₁, ε ₁₂, ε ₂₁, ε ₂₂, ε ' ₁₁, ε ' ₁₂, ε ' ₂₁, ε ' ₂₂Be each foil gauge reading, footmark facilitates the introduction of for writing formula, presses reading sign grouping substitution during actual computation and gets final product.

Simultaneously, in actual use, if the Sensor section foil gauge damages, the measurement data of the foil gauge by 90 ° at unspoiled two intervals still can obtain possessing the joint load value of reference value.Its computing formula is:

$P=\frac{1}{16}\·\frac{{\mathrm{\πd}}^3}{a}\·E\sqrt{{\mathrm{\ϵ}}_1^2+{\mathrm{\ϵ}}_2^2}$

In the formula, d is detecting means section shank diameter, and a is drum type boss and adjacent foil gauge spacing, and E is the shank elasticity modulus of materials, ε ₁And ε ₂Be respectively the reading of two foil gauges at 90 ° at this interval.

Claims (3)

1. a point contacts the pin-type load force cell, it is characterized in that comprising shank (1), be positioned at the key seat (6) of shank (1) one end, shank (1) axially on arrange successively three cydariform boss (2), shank between adjacent two cydariform boss (2) is detecting means section (4), arrange a wire arrangements groove (3) on the outer peripheral face of each cydariform boss (2), totally three wire arrangements grooves on each drum type boss are along the axial conllinear of shank, the outer peripheral face of each detecting means section (4) is evenly arranged four resistance strain gages (7), the upper wire (8) that connects of each resistance strain gage (7), pass the fairlead (9) that is positioned on the key seat (6) behind wire (8) the process wire arrangements groove (3) and be connected with wire fixed terminal (5), described wire fixed terminal (5) is arranged on the outer peripheral face of key seat (6).

2. point according to claim 1 contacts the pin-type load force cell, it is characterized in that above-mentioned wire arrangements groove (3) is 3, the wire (8) that places in the wire arrangements groove (3) has 16, above-mentioned detecting means section (4) is two, upper 8 resistance strain gages (7) of arranging of two detecting means sections (4); One end contact resistance foil gauge (7) of per two wires, the other end connects wire fixed terminal (5).

3. some contact pin-type load force cell according to claim 1 is characterized in that above-mentioned resistance strain gage (7) is pasted on the outer peripheral face of detecting means section (4); The interval 90 on the outer peripheral face of each detecting means section ⁰Arrange 4 resistance strain gages, interval 180 ⁰Over against two foil gauges be a measurement group, the upper equidirectional two groups of foil gauges of two detecting means sections form a full bridge measurement circuit.

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