CN2383055Y

CN2383055Y - Polar distance changing differential capacitive force sensor

Info

Publication number: CN2383055Y
Application number: CN 99241984
Authority: CN
Inventors: 陈玉鹏
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-08-19
Filing date: 1999-08-19
Publication date: 2000-06-14
Anticipated expiration: 2009-08-19

Abstract

The utility model relates to a polar distance changing differential capacitive force sensor which comprises a force arm plate which loads pressure, an elastic body, a capacitance pole plate arranged under the elastic body, and a transmission rod which penetrates through the force arm plate, the elastic body and the middle part of the capacitance pole plate, wherein, the capacitance pole plate has a three-layered structure, an upper pole plate and a lower pole plate are fixed pole plates which are stationary, a middle pole plate is a movable pole plate connected with a movable end pin shaft through an insulating washer, and two fixed pole plates are connected with a fixed end pin shaft through an insulating washer. The middle part of a straining region of the elastic body is provided with parallel double-hole groove holes. The utility model has the advantages of simple and reasonable structure, and higher sensitivity and precision. The utility model has a temperature coefficient compensatory function.

Description

Pole-changing is apart from the differential capacitance type force transducer

The utility model relates to a kind of capacitive force transducer, and especially a kind of elastic body has the pole-changing distance, capacitor plate is the capacitive force transducer of differential structure.

Anthropological measuring at present etc. does not require the measurement occasion of degree of precision, the capacitance type sensor easily that electronic scales often adopts is with low cost, use.The structure of existing capacitive force transducer is stressed by drive link, pull down, because elastic body one end is fixed, depress elastomeric not stiff end and arm board is stressed, elastic body deformation, the movable plate electrode that drives electric capacity moves, and produces changes in capacitance, thereby pass out stressed and electric signal that change, finish the sensing process of power.This structure because capacitance is little between dynamic and static two capacitor plates, is again a single capacitor at first, is subjected to the influence of factors such as circuit distributed capacitance easily, and sensitivity is lower, and precision is also low.In addition, existing elastomeric strain position is the rectangle slotted eye, so the strain variation amount is not obvious, also is difficult to make capacitor plate to produce parallel displacement, causes the reduction of precision and the raising of error once more.

The purpose of this utility model is to provide a kind of pole-changing apart from the differential capacitance type force transducer, and it is highly sensitive, and error is little, and has temperature compensation function.

The purpose of this utility model is achieved in that a kind of pole-changing is apart from the differential capacitance type force transducer, it comprises arm board, the elastic body that bears pressure, the transmission rod that is installed in the capacitor plate under the elastic body and passes arm board, elastic body and capacitor plate centre, wherein said capacitor plate is a three-decker, its upper and lower pole plate is fixed fixed plate, and middle plate is a movable plate electrode, movable plate electrode is connected with the moved end bearing pin by insulating washer, and two fixed plates are connected with the fixed end bearing pin by insulating washer.

Parallel double pass slotted eye is offered at described elastomeric strain regions middle part.

According to the technique scheme analysis as can be known, the utlity model has following advantage:

1, because the differential capacitance electrode plate structure has the function of tc compensation, overcomes the interference of intrinsic factor, obviously sensitivity and the degree of accuracy that improves.

2, the distortion sensitivity that improves greatly of the structure of elastic body strain regions can make the pole plate parallel displacement simultaneously, further improves the levels of precision of signal.

Below in conjunction with accompanying drawing and specific embodiments the utility model is described in further detail.

Fig. 1 is the utility model structural representation;

Fig. 2 is the utility model cross-sectional view;

Fig. 3 is a movable plate electrode structural representation of the present utility model;

Fig. 4 is a fixed plate structural representation of the present utility model;

Fig. 5 is an elastomer structure synoptic diagram of the present utility model.

Referring to Fig. 1, provided the utility model structural representation.The utility model be a kind of pole-changing apart from the differential capacitance type force transducer, it comprises the arm board 1 that bears pressure, the moved end 3 of the affixed elastic body 2 of an end of arm board 1, arm board 1 is provided with the sheathed hole of transmission rod; The other end of elastic body 2 is fixed end 4, and

capacitor plate

5,6,7 is installed in elastic body 2 times; Transmission rod 8 is worn the centre of elastic body 2 and

capacitor plate

5,6,7.

Shown in Fig. 2,3,4,

capacitor plate

5,6,7 of the present utility model is a three-decker, its upper and lower pole plate is fixed

fixed plate

5,7, and middle plate is a movable plate electrode 6, movable plate electrode 6 is connected with moved end 3 bearing pins by insulating washer, two

fixed plates

5,7 are connected with fixed end 4 bearing pins by insulating washer, so moved end 3 bearing pins pass corresponding perforations on the

fixed plate

5,7, and do not contact with

fixed plate

5,7; Fixed end 4 bearing pins do not contact with movable plate electrode 6 yet.When transmission rod 8 stressed, when pulling down power arm plate 1, elastic body 2 is stressed to be S shape, movable plate electrode 6 be fixed

plate

5,7 owing to it is upper and lower, so the total displacement variable quantity of its upper and lower relatively pole plate becomes both closing along with moved end 3 bearing pin displacements, improved sensitivity, simultaneously relative differential values has deducted the influence of temperature coefficient and intrinsic parameter influence, has further improved its degree of accuracy.

As shown in Figure 5, parallel double pass slotted eye 9,10 is offered at the strain regions of elastic body 2 of the present utility model middle part.Because the existence of two ends slotted eye 9,10, the width of distorted area is narrower, therefore when being subjected to S shape power, becomes the flexural deformation maximum, is easy to generate tangible strain, and sensitivity improves.Owing to elastic body both sides structural symmetry, S shape is the parallel displacement of easier assurance capacitor plate when stressed again.So the distortion sensitivity that the structure of this elastic body strain regions improves greatly, and further improve the levels of precision of signal, make things convenient for follow-up signal to handle.

Claims

1, a kind of pole-changing is apart from the differential capacitance type force transducer, it comprises arm board, the elastic body that bears pressure, the transmission rod that is installed in the capacitor plate under the elastic body and passes arm board, elastic body and capacitor plate centre, it is characterized in that: described capacitor plate is a three-decker, wherein upper and lower pole plate is fixed fixed plate, and middle plate is a movable plate electrode, movable plate electrode is connected with the moved end bearing pin by insulating washer, and two fixed plates are connected with the fixed end bearing pin by insulating washer.

2, pole-changing according to claim 1 is characterized in that apart from the differential capacitance type force transducer: parallel double pass slotted eye is offered at described elastomeric strain regions middle part.