CN1746635A - Resistance strained sensor with protector - Google Patents

Abstract

A transducer of resistance strain type with protective device is prepared as sticking resistance foil gauge on elastic body surface, fixing contact on free end of elastic body, setting cavity in protective sleeve, setting boss for fixing elastic body fixing end at one side of cavity bottom surface and setting bosses having spacing gap and corresponding to elastic body free end separately on top surface and bottom surface of cavity, and setting through hole on protective sleeve to let contact pass.

Description

Resistance strain type sensor with protective device

One, technical field

The present invention relates to a kind of sensor, a kind of specifically resistance strain type sensor with protective device.

Two, background technology

Sensor is a kind of electronic detecting device, it can accept the information of object being measured, and export after detected information being for conversion into according to certain rules the information of electric signal or other desired forms, to satisfy requirements such as transmission of Information, processing, storage, demonstration, record and control.It is a primary link of realizing detection automatically and automatic control.Sensor can be divided into sensors such as resistance, electric capacity, electromagnetism, inductance, voltage, Hall, photoelectricity, grating, thermopair by the principle of work classification.Resistance strain type sensor is a kind of in the resistance sensor, and it is mainly as the survey sensor of electronic-weighing instrument.

The structure of resistance strain type sensor mainly comprises elastic body, resistance strain gage, contact, elastic body is generally made by aluminium alloy, be the beam type setting, contact is fixed on elastomeric free end, resistance strain gage sticks on elastomeric surface, and link to each other with the testing circuit of outside by lead, its principle of work is: the free end that acts on the elastic body semi-girder when external force, elastic body promptly produces elastic bending deflection, make the resistance strain gage that sticks on its surface also in company with producing distortion, after the resistance strain gage distortion, its resistance will change (increase or reduce), through the relevant detection circuit this change in resistance is converted to electric signal (voltage or electric current) output again, thereby has finished the process that external force is transformed to electric signal.In real work, when externally applied forces excessive and when surpassing elastomeric rated load or sensor and being subjected to powerful impulsive force, can make the inside crystal phase structure of elastomeric material impaired, lattice crystal grain can't restore to the original state and cause physical damnification, parameter changes such as the creep of sensor and output at zero point, the also corresponding increase of output error can make sensor normally use when serious.At present, the protective device of existing resistance strain type sensor is at the free-ended upper and lower of elastic body stop to be set, keep certain clearance between stop and the free end, this gap is determined according to the measurement range of sensor, when the external force that acts on is in measurement range, the elastic body deflection is within rated capacity, and free end does not contact with stop; When the external force that surpasses measurement range acted on sensor, the elastic body distortion increased, and then free end contacts with stop, made elastic body no longer continue to be out of shape and to cause physical damnification, had guaranteed the operate as normal of sensor.The main body of existing stop and sensor generally is to install respectively, do not integrate, even the sensor of band stop, it is bigger just to be limited to volume, does not have stop for the strain gauge transducer of general small size, therefore, cause installation and debugging all very difficult, particularly,, and influenced the normal use of sensor often because alignment error is bigger for the adjustment in the very high spacing gap of accuracy requirement.In addition, because the performance of sensor depends on the physical characteristics of elastic body and resistance strain gage, the shape of elastic body and resistance strain gage just can not have bigger change satisfying under the condition of request for utilization like this, and when such sensor application was in product, just the general plan to each parts in the product design had caused influence.

Three, summary of the invention

1, goal of the invention: the purpose of this invention is to provide a kind of resistance strain type sensor with protective device; this sensor integrates stop and sensor main body; and can all realize spacing to elastomeric both direction up and down in the sensor; guaranteed the operate as normal of sensor; the shape of sensor can design as required; and it is simple in structure, and is easily manufactured, and production cost is lower.

2; technical scheme: the resistance strain type sensor with protective device of the present invention; it comprises elastic body; resistance strain gage and contact; elastic body has stiff end and free end; resistance strain gage sticks on elastomeric upper and lower surface; contact is fixed on elastomeric free end; it is characterized in that: it also is provided with protective sleeve; be provided with cavity in the described protective sleeve; one side of cavity bottom surface is provided with the fixedly boss of elastic body stiff end; be respectively equipped with and the corresponding positive stop lug boss of elastic body free end at cavity end face and bottom surface; have spacing gap between positive stop lug boss and the elastic body free end, on protective sleeve, be provided with the through hole that contact is passed.

Since in the outer setting of sensor protective sleeve, make the sensor critical piece that is arranged in protective sleeve can not be subjected to the influence of other parts of detection system, effectively protected the operate as normal of sensor.Stop and sensor main body integrate, and sensor its spacing gap when dispatching from the factory is good with regard to adjusted, has avoided the alignment error that may occur in installation process.

Influence the operate as normal of resistance strain gage for protective sleeve is not contacted with resistance strain gage, be respectively equipped with the groove that holds resistance strain gage at cavity end face and bottom surface.

Convenience for the elastic body debugging can be provided with opening at the back side of protective sleeve.

The shape of protective sleeve can be set to rectangular parallelepiped, right cylinder or other suitable shape as required.

Principle of work: the present invention is respectively equipped with and the corresponding positive stop lug boss of elastic body free end in the end face and the bottom surface of protective sleeve cavity; and has the spacing gap of determining according to the measurement range of sensor between the two; be upward or downwards so no matter by the contact externally applied forces; when external force surpasses measurement range; the elastic body free end will contact with the end face or the bottom surface of cavity, promptly the free-ended both direction up and down of elastic body has all been implemented position limitation protection.

3, beneficial effect: the present invention compared with prior art has following characteristics: (1) is by being provided with protective sleeve, end face and bottom surface at the protective sleeve cavity are carried out spacing to the elastic body free end respectively, no matter making externally applied forces is upward or downwards, the elastic body free end has all obtained position limitation protection, has guaranteed the operate as normal of sensor; (2) elastic body, resistance strain gage and contact are set directly in the protective sleeve, have obtained effective protection at work; (3) stop and sensor main body integrate, and have avoided may occurring in installation process the alignment error in spacing gap; (4) protective sleeve can be designed to suitable shape as requested, is very beneficial for the needs in different application field; (5) this sensor construction is simple, and is easily manufactured, and production cost is lower.

Four, description of drawings

Fig. 1 is a front view of the present invention;

Fig. 2 is a vertical view of the present invention

Fig. 3 is a rear view of the present invention.

Five, embodiment

As shown in Figure 1, the resistance strain type sensor with protective device of the present invention, it comprises elastic body 1, resistance strain gage 2,contact 3 and protective sleeve 6.The elastic body 1 of present embodiment is a doubly-linked circular hole elastic body, can certainly adopt blossom type four to connect hole elastic body, three beam type elasticity of flexure bodies or three beam type shearing elasticity bodies, elastic body 1 has stiff end 4 and free end 5, resistance strain gage 2 sticks on the upper and lower surface in elastic body 1 stage casing, and links to each other with the testing circuit of outside bylead.Contact 3 is fixed on the upper surface of elastic body free end 5 by being threaded.Be provided with cavity 7 in theprotective sleeve 6; elastic body 1, resistance strain gage 2 andcontact 3 all are arranged in the cavity 7; one side of cavity 7 bottom surfaces is provided withboss 8; elastic body stiff end 4 is fixed on theboss 8 by screw or other connected mode; the middle part of cavity 7 end faces and bottom surface is respectively equipped with thegroove 11 that holds resistance strain gage 2; at the corresponding opposite side of cavity 7 and elastic body free end 5; be respectively equipped with positive stop lug boss 9 on its end face and the bottom surface; have a spacing gap between positive stop lug boss 9 and the elastic body free end 5, this gap is determined according to the measurement range of sensor.As shown in Figure 2, the end face atprotective sleeve 6 also is provided with the throughhole 10 thatcontact 3 is passed.As shown in Figure 3, be provided with at the back side ofprotective sleeve 6 and be convenient to debug elastomeric opening 12.

Claims (3)

1; a kind of resistance strain type sensor with protective device; it comprises elastic body (1); resistance strain gage (2) and contact (3); elastic body (1) has stiff end (4) and free end (5); resistance strain gage (2) sticks on the surface of elastic body (1); contact (3) is fixed on the free end (5) of elastic body (1); it is characterized in that: it also is provided with protective sleeve (6); be provided with cavity (7) in the described protective sleeve (6); one side of cavity (7) bottom surface is provided with the fixedly boss (8) of elastic body stiff end (4); end face and bottom surface at cavity (7) are respectively equipped with and the corresponding positive stop lug boss of elastic body free end (5) (9); have spacing gap between positive stop lug boss (9) and the elastic body free end (5), on protective sleeve (6), be provided with the through hole (10) that contact (3) is passed.

2, the resistance strain type sensor with protective device according to claim 1 is characterized in that: be respectively equipped with the groove (11) that holds resistance strain gage (2) at cavity (7) end face and bottom surface.

3, the resistance strain type sensor with protective device according to claim 1 and 2 is characterized in that: the back side of protective sleeve 6 is provided with is convenient to debug elastomeric opening (12).

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