CN100403001C

CN100403001C - Differential piezoelectric three-dimensional force sensor

Info

Publication number: CN100403001C
Application number: CNB2006100543145A
Authority: CN
Inventors: 刘俊; 刘京诚; 秦岚; 李敏
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2006-05-19
Filing date: 2006-05-19
Publication date: 2008-07-16
Anticipated expiration: 2026-05-19
Also published as: CN1851427A

Abstract

The present invention relates to a differential piezoelectric three-dimensional force sensor which comprises a dynamometer which is composed of quartz crystal wafers and a fixed insulation positioning frame, a base provided with a signal leading socket, and a cover of the base, wherein the insulation positioning frame is provided with eight positioning holes. A connecting line of centers of the positioning holes forms a square. The four positioning holes are positioned at four corners of the square. The quartz crystal wafers in the four corners are respectively an X0 DEG trimming quartz crystal. X axes of the quartz crystal wafers are perpendicular to the square, and the axial directions of the crystal wafers in the adjacent corners are opposite. In addition, the four positioning holes are positioned on center points of four edges of the square. The quartz crystal wafers in the positioning holes on the center points are respectively a Y0 DEG trimming quartz crystal. Y axes of the quartz crystal wafers are parallel to a corresponding edge, and the axial directions of the crystal wafers at the opposite edges are opposite. The present invention has the advantages of simple structure, easy fabrication and manufacture, and high measuring precision. The differential measurement for a force signal can be realized. A measurement error caused by environmental (such as temperature, humidity) variation can be overcome. The present invention is suitable for the measurement of spatial three-dimensional force in various occasions.

Description

Differential piezoelectric three-dimensional force sensor

Technical field

The present invention relates to a kind of sensor of measurement space three-dimensional force.

Background technology

At present, known piezoelectric three dimension force transducer is to be drawn parts such as socket to constitute by pedestal, lid, quartz wafer, electrode, insulation keeper, signal.As accompanying drawing 1～shown in Figure 5, this piezoelectric three dimension force transducer is to be installed in the pedestal the inside after at an angle of 90 mode is combined mutually by the peak response axle with three bauerite wafers, then lid and pedestal is welded together.When non-coplanar force acts on the sensor, reflect the size of space three-dimensional power by the electric charge output quantity that detects three bauerite wafers.But this piezoelectric three dimension force transducer is weak output signals when external force is less not only, and measuring accuracy is not high, can't overcome simultaneously the error that the variation because of environment (as temperature, humidity) brings to measurement.

Summary of the invention

The technology that the present invention will solve is, overcome the deficiency of existing piezoelectric three dimension force transducer, propose a kind ofly not only when external force is less, output signal is strong, measuring accuracy is high, can also overcome the piezoelectric three-dimensional force sensor of the error of bringing to measurement because of the variation of environment (as temperature, humidity) simultaneously.

The technical scheme that its technical matters of solution the present invention is adopted is a kind of differential piezoelectric three-dimensional force sensor.Its aspect same as the prior art is, this sensor comprise by the quartz wafer that has signal output electrode and fix dynamometer that the insulation locating rack of this quartz wafer constituted, not only have this dynamometer of encapsulation within it inner chamber but also have signal and draw the pedestal of socket and be pressed on the quartz wafer in advance and cover the lid of this pedestal.The quartz wafer that wherein has signal output electrode is so-called piezoelectric element.Improvements of the present invention are, insulation locating rack wherein is provided with eight pilot holes, and the line of centres of each pilot hole is a square.Foursquare four jiaos at this of four pilot holes are positioned at four jiaos of quartz wafers in the pilot hole and are X0 ° of cut type quartz crystal, and the X-axis of these four wafers is all perpendicular to the axial opposed of this square and adjacent angular wafer; In addition four pilot holes are at the mid point on these square four limits, and the quartz wafer that is positioned in the four limit mid point pilot holes is Y0 ° of cut type quartz crystal, and the X-axis of these four wafers all is parallel to the axial opposed of each self-corresponding limit and relative edge's wafer.

When the space three-dimensional masterpiece is used on the sensor of the present invention, is positioned on the upper surface of two pairs of X0 ° of cut type quartz crystal slices in two groups of diagonal orientation holes and will produces the charge variation of positive charge and negative charge respectively; Be positioned on the upper surface of two groups of two pairs of Y0 ° of cut type quartz crystal slices in the opposite side mid point pilot hole and also will produce the charge variation of positive charge and negative charge respectively.Just can realize differential measurement by the differential type charge amplifier to the space three-dimensional force signal.

The invention has the beneficial effects as follows, the coupling that this differential piezoelectric three-dimensional force sensor is unable, simple in structure, be easy to processing and manufacturing, can realize differential measurement to force signal; Because adopt the variate mode, when external force was less, output signal was strong, measuring accuracy is high; Can overcome the error that the variation because of environment (as temperature, humidity) brings to measurement, and be suitable under the multiple occasion the space three-dimensional force measurement.

The present invention is further illustrated below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 is the structure diagram of existing piezoelectric three dimension force transducer;

Fig. 2 is Fig. 1 vertical view;

Fig. 3, Fig. 4 and Fig. 5 are respectively the mutual three bauerite wafers at an angle of 90 of the peak response among Fig. 1;

Fig. 6 is the dynamometer front view among the present invention;

Fig. 7 is the vertical view of Fig. 6.

Fig. 8 is a front view of the present invention;

Fig. 9 is the vertical view of Fig. 8.

Embodiment

Differential piezoelectric three-dimensional force sensor (with reference to figure 6,7,8,9).Same as the prior art, this sensor comprise by the quartz wafer that has signal output electrode and fix dynamometer that the insulation locating rack of this quartz wafer constituted, not only have this dynamometer of encapsulation within it inner chamber but also have signal and draw the pedestal of socket and be pressed on the quartz wafer in advance and cover the lid of this pedestal.Wherein, the signal output electrode of quartz wafer is drawn the corresponding one by one connection of socket 12 with the signal on the pedestal, directly connects with the differential type charge amplifier with the on line of commercially available band teflon connector then.Feature of the present invention is, insulation locating rack wherein is provided with eight pilot holes, and the line of centres of each pilot hole is a square.Foursquare four jiaos of four pilot holes in them at this, be positioned at four jiaos of quartz wafers (1,3,5,7) in the pilot hole and be X0 ° of cut type quartz crystal, the X-axis of these four wafers (1,3,5,7) is all perpendicular to the axial opposed of this square and adjacent angular wafer---obviously, diagonal angle wafer (1,5 and 3,7) axially be exactly identical; In addition four pilot holes are at the mid point on these square four limits, the quartz wafer (2,4,6,8) that is positioned in the four limit mid point pilot holes is Y0 ° of cut type quartz crystal, and the X-axis of these four wafers (2,4,6,8) all is parallel to the axial opposed of each self-corresponding limit and relative edge's wafer.That is to say that the center of 8 bauerite wafers is on the loop wire of the center of whole Q-RING; Be positioned in the square opposite side mid point pilot hole quartz wafer (2,4,6,8) peak response axle separately and the peak response axle that is positioned at the quartz wafer (1,3,5,7) in square four jiaos of pilot holes at measurement space mutually at an angle of 90.Wherein, the quartz wafer (2,6) in one group of opposite side mid point pilot hole is surveyed the power that quartz wafer (1,3,5,7) in the power of X (or Y) direction, power that the quartz wafer (4,8) in another group opposite side mid point pilot hole is surveyed Y (or X) direction, the four jiaos of pilot holes is surveyed the Z direction.When connecting with the differential type charge amplifier, with one group of two input end that are positioned at the output charge signal access differential type charge amplifier of the quartz wafer (2,6) in the square opposite side mid point pilot hole, just can obtain the size of X (or Y is because X, Y direction formula can exchange) axial force; The output charge signal that another group is positioned at the quartz wafer (4,8) in the square opposite side mid point pilot hole inserts two input ends of differential type charge amplifier, just can obtain the size of Y (or X) axial force; After output charge signal after quartz wafer (1, the 5) parallel connection that is positioned in square one group of diagonal orientation hole being inserted an input end of differential type charge amplifier, with another input end of the output charge signal access differential type charge amplifier after quartz wafer (3, the 7) parallel connection that is positioned in another group diagonal orientation hole of square, just can obtain the size of Z axial force.

X-axis in order to ensure each wafer can accurately be located according to direction separately.Further feature is (with reference to figure 6,7), eight pilot holes and the quartz wafer in pilot hole (1,2,3,4,5,6,7,8) thereof are equal-sized square, and the square limit of these eight pilot holes is all parallel with foursquare each corresponding sides of its line of centres.

In order further to guarantee assembling quality of the present invention.Further feature is (with reference to figure 7), and insulation locating rack 9 is square ring stand, and the inside and outside foursquare center of this insulation locating rack 9 overlaps with the foursquare center of the above-mentioned line of centres, and three foursquare corresponding sides are parallel mutually.

Further feature is (with reference to figure 8,9) again, and pedestal 11 creates a square box, and lid 10 creates two central lines and the plug formula that square block the constituted lid that each corresponding sides is parallel to each other of size.The inner chamber of this pedestal 11 and the encapsulation square external form of insulation locating rack within it and the four limits coupling of the big square block of lid 10 thereof, the middle part of these pedestal 11 inner chambers have with the four limits coupling of the little square block of its lid 10 and less than the groove of the square hole of insulation locating rack.This pedestal 11 and lid 10 penetrate their sensor clamping hole 13, the center line in this sensor clamping hole 13 and the central lines of square block in addition simultaneously.

The manufacture course of products of optimum efficiency of the present invention is summarized as follows: at first at the center of square insulating material, process a square hole; Then, 8 square holes that match with quartz wafer (1,2,3,4,5,6,7,8) of processing on the square ring stand that obtains, just obtain the insulation locating rack of sensor, then, with 8 different cut types or different sensitive axes to quartz wafer (1,2,3,4,5,6,7,8) be installed in the insulation locating rack, just constituted the dynamometer of this differential piezoelectric three-dimensional force sensor.Follow, inner chamber (this inner chamber is slightly wideer than dynamometer) of laying dynamometer of processing according to the shape of its inner chamber, manufactures lid 10 on square base 11 again.At last, with the dynamometer vertical symmetry be installed in the pedestal 11, cover lid 10 adopts electron beam welding technology that pedestal 11 and lid 10 are welded together then, has just constituted this differential piezoelectric three-dimensional force sensor.

Claims

1. differential piezoelectric three-dimensional force sensor, this sensor comprise by the quartz wafer that has signal output electrode and fix dynamometer that the insulation locating rack of this quartz wafer constituted, not only have this dynamometer of encapsulation within it inner chamber but also have signal and draw the pedestal of socket and be pressed on the quartz wafer in advance and cover the lid of this pedestal, it is characterized in that, described insulation locating rack (9) has eight pilot holes, and the line of centres of each pilot hole is a square; Foursquare four jiaos at this of four pilot holes are positioned at four jiaos of quartz wafers (1,3,5,7) in the pilot hole and are X0 ° of cut type quartz crystal, and the X-axis of these four wafers (1,3,5,7) is all perpendicular to the axial opposed of this square and adjacent angular wafer; In addition four pilot holes are at the mid point on these square four limits, the quartz wafer (2,4,6,8) that is positioned in the four limit mid point pilot holes is Y0 ° of cut type quartz crystal, and the X-axis of these four wafers (2,4,6,8) all is parallel to the axial opposed of each self-corresponding limit and relative edge's wafer.

2. differential piezoelectric three-dimensional force sensor according to claim 1, it is characterized in that, described eight pilot holes and the quartz wafer in pilot hole (1,2,3,4,5,6,7,8) thereof are equal-sized square, and the square limit of these eight pilot holes is all parallel with foursquare each corresponding sides of the described line of centres.

3. differential piezoelectric three-dimensional force sensor according to claim 2, it is characterized in that, described insulation locating rack (9) is square ring stand, the inside and outside foursquare center of this insulation locating rack (9) overlaps with the foursquare center of the described line of centres, and three foursquare corresponding sides are parallel mutually.

4. differential piezoelectric three-dimensional force sensor according to claim 3, it is characterized in that, described pedestal (11) is a square box, and described lid (10) is two central lines and the plug formula that square block constituted lid that each corresponding sides is parallel to each other for size; Four limits of the big square block of the square external form of inner chamber of this pedestal (11) and described insulation locating rack (9) and lid (10) thereof coupling, the middle part of this pedestal (11) inner chamber have with the four limits coupling of the little square block of its lid (10) and less than the groove of the square hole of described insulation locating rack (9); This pedestal (11) and lid (10) penetrate their sensor clamping hole (13), the center line in this sensor clamping hole (13) and the central lines of square block in addition simultaneously.