Summary of the invention
An object of the present invention is to provide a kind of new solution of inertia measuring module.
According to a first aspect of the invention, provide a kind of inertia measuring module, comprising:
Substrate, and be positioned at the first pole piece as bottom electrode on substrate,
The unsettled mass in surface; Described mass is provided with the top electrode forming Z axis Detection capacitance with the first pole piece;
For the elastic beam of connection substrate and mass, described elastic beam comprises two the first elastic beams being positioned at X-direction and is positioned at Y direction and the second elastic beam be connected with two the first elastic beam right-angled intersections, wherein, the two ends of the second elastic beam are connected on the anchor point of substrate, the two ends quality of connection block respectively of two the first elastic beams; Wherein, described two the first elastic beams are symmetrical along the center line of mass X-direction, and described second elastic beam departs from the center line of mass Y direction;
Described mass is also respectively arranged with the first movable electrode, the second movable electrode in Y-axis, X-direction; Described substrate is provided with for forming Y-axis Detection capacitance, the first fixed electorde of X-axis Detection capacitance, the second fixed electorde respectively with the first movable electrode, the second movable electrode.
Preferably, described mass is provided with through hole, and described first elastic beam is connected on the sidewall of through hole both sides.
Preferably, the quantity of described first pole piece has two, is symmetrically distributed in the both sides of the second elastic beam.
Preferably, described first movable electrode and/or the second movable electrode are respectively arranged with two, lay respectively at the both sides that mass is relative.
Preferably, comb capacitance structure is formed between the first movable electrode and the first fixed electorde and/or between the second movable electrode and the second fixed electorde.
Another object of the present invention is to provide a kind of three axis accelerometer, comprises the inertia measuring module of two structural symmetry; Also comprise the tie-beam coupled together respectively the both sides of mass in two inertia measuring modules.
Preferably, described tie-beam comprises the crossbeam be positioned in X-direction, also comprise be positioned in Y direction, one end is connected the longeron that one end is connected with mass sidewall with crossbeam; Described longeron and the second elastic beam are point-blank.
Preferably, be also provided with the buttress brace of connection two crossbeams, wherein, the second elastic beam in two inertia measuring modules is symmetrical relative to buttress brace.
Preferably, described buttress brace is provided with two, and two buttress braces be arranged in parallel, surround a rectangle frame with crossbeam.
Preferably, the cant beam being positioned at rectangle frame is also comprised.
Inertia measuring module of the present invention, the motion of a certain axle in plane can not be subject to the impact of structure eccentric nature.And adopt two the first elastic beam quality of connection blocks along mass X-direction center line symmetry, no matter mass is subject to the acceleration in which direction, can guarantee that mass can not deflect along the first elastic beam, only can there is line between mass and the first elastic beam to move, thus improve the precision of detection; Nor the coupling of between centers can be aggravated.
The present inventor finds, in the prior art, when mass is subject to certain axial acceleration, mass is actual, and what make is wobbling action, is not also the independent line motion of expection or independent rotation.Therefore, the technical assignment that the present invention will realize or technical matters to be solved are that those skilled in the art never expect or do not anticipate, therefore the present invention is a kind of new technical scheme.
By referring to the detailed description of accompanying drawing to exemplary embodiment of the present invention, further feature of the present invention and advantage thereof will become clear.
Embodiment
Various exemplary embodiment of the present invention is described in detail now with reference to accompanying drawing.It should be noted that: unless specifically stated otherwise, otherwise positioned opposite, the numerical expression of the parts of setting forth in these embodiments and step and numerical value do not limit the scope of the invention.
Illustrative to the description only actually of at least one exemplary embodiment below, never as any restriction to the present invention and application or use.
May not discuss in detail for the known technology of person of ordinary skill in the relevant, method and apparatus, but in the appropriate case, described technology, method and apparatus should be regarded as a part for instructions.
In all examples with discussing shown here, any occurrence should be construed as merely exemplary, instead of as restriction.Therefore, other example of exemplary embodiment can have different values.
It should be noted that: represent similar terms in similar label and letter accompanying drawing below, therefore, once be defined in an a certain Xiang Yi accompanying drawing, then do not need to be further discussed it in accompanying drawing subsequently.
With reference to figure 1, the invention provides the inertia measuring module in a kind of three axis accelerometer, comprise substrate (view does not provide), on the substrate can the parts such as circuit of Butut inertia measuring module.This substrate is provided with the first pole piece 4 (being represented by dotted lines in view) as bottom electrode.
Inertia measuring module of the present invention also comprises the mass 1 being positioned at surface, and this mass 1 is supported on the support system 5 of surface.This support system 5 can be an elastic beam, and mass 1 passes through this elastic beam flying shore above substrate.
Elastic beam comprises two the first elastic beams 12 being positioned at X-direction, and be positioned at Y direction second elastic beam 11, these two the first elastic beams 12 and the second elastic beam 11 right-angled intersection are fixed together, that is, the first elastic beam 12 right-angled intersection that the second elastic beam 11 is arranged in parallel with two is respectively fixed together.Preferably, two the first elastic beams 12 distribute relative to the Central Symmetry of the second elastic beam 11.
Wherein, the two ends of the second elastic beam 11 are connected on the anchor point 6 of substrate, two the first elastic beam 12 quality of connection blocks 1.By the first elastic beam 12, second elastic beam 11, anchor point 6, mass 1 is supported on the top of substrate, makes mass 1 be in unsettled state.In the present invention's specific embodiment, described mass 1 is provided with through hole, the two ends of described first elastic beam 12 are connected on the sidewall of through hole both sides.
When this needs to point out, the relation of the present invention just for convenience of description between the first elastic beam 12 and the second elastic beam 11, first elastic beam 12 is decided to be X-direction, second elastic beam 11 is decided to be Y direction, certainly, also the first elastic beam 12 can be decided to be Y direction, the second elastic beam 11 is decided to be X-direction, is therebetween relative.
Inertia measuring module of the present invention, described mass 1 is also respectively arranged with the first movable electrode 9, second movable electrode 10 in Y-axis, X-direction; These two movable electrodes are fixed on mass 1, such as, can be arranged on the edge of mass 1, and can be synchronized with the movement along with the motion of mass.Accordingly, described substrate is arranged the first fixed electorde 2, second fixed electorde 3 being used for forming Y-axis Detection capacitance, X-axis Detection capacitance respectively with the first movable electrode 9, second movable electrode 10.These two fixed electordes are fixedly mounted on substrate, when two movable electrodes move along with mass 1, change the area between fixed electorde and movable electrode or distance, thus change the electric capacity of corresponding capacitance, to realize the measurement of the party's upwards acceleration.
Wherein, described first movable electrode 9 is provided with two, lays respectively at the both sides that mass 1 is relative.With reference to the view direction of figure 1, two the first movable electrodes 9 are separately positioned on the top and bottom of mass 1, accordingly, substrate is provided with two the first fixed electordes 2 coordinated with two the first movable electrodes 9, when there being Y direction acceleration, mass moves along Y direction, the area between one of them the first movable electrode 9 and first fixed electorde 2 or distance is made to become large, and area between another the first movable electrode 9 and first fixed electorde 2 or distance diminish, these two Y-axis Detection capacitances constitute differential capacitance structure, improve the precision of Y-axis acceleration detection.
Based on same reason, described second movable electrode 10 also can be provided with two, lays respectively at mass 1 both sides in the X-axis direction.With reference to the view direction of figure 1, two the second movable electrodes 10 are separately positioned on left end and the right-hand member of mass 1, accordingly, substrate is provided with two the second fixed electordes 3 coordinated with two the second movable electrodes 10, when there being the acceleration of X-direction, mass 1 moves along X-direction, the area between one of them the second movable electrode 10 and second fixed electorde 3 or distance is made to become large, and area between another the second movable electrode 10 and second fixed electorde 3 or distance diminish, these two X-axis Detection capacitances constitute differential capacitance structure, improve the precision of X-axis acceleration detection.
Between first movable electrode 9 and the first fixed electorde 2 and/or can adopt the capacitance structure of comb teeth-shaped between the second movable electrode 10 and the second fixed electorde 3, the structure of comb electric capacity belongs to existing technology, no longer illustrates at this.
Inertia measuring module of the present invention, described two the first elastic beams 12 are symmetrical along the center line of mass X-direction, and described second elastic beam 11 departs from the center line of mass Y direction.When this inertia measuring module is when being subject to the acceleration of Z-direction, due to the eccentric setting of the second elastic beam 11, make mass 1 with the second elastic beam 11 for axle deflects motion.
Particularly, with the view direction of Fig. 1 for reference, article two, the first elastic beam 12 is symmetrical relative to the center line of mass X-direction, and the second elastic beam 11 departs from the center line of mass Y direction, that is, the second elastic beam 11 to mass 1 left end distance and its distance arriving mass 1 right-hand member not etc.Such as, second elastic beam 11 deviates to the right of mass Y direction center line, when mass 1 runs into the acceleration of Z-direction, due to the eccentric setting between mass 1 and the second elastic beam 11, mass 1 can be rotated relative to the second elastic beam 11.
Described mass 1 is also provided with the top electrode (view does not provide) forming Z axis Detection capacitance with the first pole piece 4, in the present invention's preferred embodiment, the top electrode of this mass 1 inherently Z axis Detection capacitance, now, mass 1, first movable electrode 9, second movable electrode 10 can be used as the ground connection pole piece use of each self-capacitance.
The quantity of the first pole piece 4 can arrange two, is symmetrically distributed in the both sides of the second elastic beam 11.When Z-direction has acceleration, mass 1 deflects relative to the second elastic beam 11, and that is, mass 1 rotates around the second elastic beam 11, thus changes the distance between mass 1 and the first pole piece 4, realizes the change of Z axis Detection capacitance.Distance between mass 1 and one of them the first pole piece 4 becomes greatly, and the distance between another first pole piece 4 diminishes, and makes can form differential capacitance structure between two the first pole pieces 4 and mass, to improve the precision of Z axis acceleration detection.When Y direction has acceleration, mass 1 is subjected to displacement in Y direction by the distortion of the first elastic beam 12, thus measures the acceleration of Y direction by the first movable electrode 9 and the first fixed electorde 2.When X-direction has acceleration, mass 1 is subjected to displacement in the X-axis direction by the distortion of the second elastic beam 11, thus measures the acceleration of X-direction by the second movable electrode 10 and the second fixed electorde 3.
Inertia measuring module of the present invention, the motion of a certain axle (X-axis, Y-axis) in plane can not be subject to the impact of structure eccentric nature.And adopt two the first elastic beam quality of connection blocks along mass X-direction center line symmetry, no matter mass is subject to the acceleration in which direction, can guarantee that it can not deflect along the first elastic beam, only can there is line between mass and the first elastic beam to move, thus improve the precision of detection; Nor the coupling of between centers can be aggravated.
Inertia measuring module of the present invention, can be used in combination, and forms three axis accelerometer, such as, can be coupled together by the mass 1 in multiple inertia measuring module by tie-beam.
With reference to figure 3, a kind of three axis accelerometer disclosed by the invention, comprises the inertia measuring module of two structural symmetry, and adopts two tie-beams to be coupled together the both sides of mass 1 in two inertia measuring modules respectively; Described tie-beam comprises the crossbeam 7 be positioned in X-direction, and be positioned in Y direction, one end is connected the longeron 8 that one end is connected with mass 1 sidewall with crossbeam 7; Described longeron 8 and the second elastic beam 11 conllinear, that is, longeron 8 and the second elastic beam 11 point-blank, to reduce the impact that longeron 8 overturns along Z-direction mass; Further, described longeron 8 can adopt nonrigid material to make.
With reference to the view direction of figure 3, the upper end sidewall of two masses 1 links together by the crossbeam 7, the longeron 8 that are positioned at top; The lower end sidewall of two masses 1 links together by the crossbeam 7, the longeron 8 that are positioned at below; The buttress brace 130 of rigidity is also provided with between two crossbeams 7, by this buttress brace 130, two crossbeams 7 are linked together, the position of buttress brace 130 on two crossbeams 7, makes the second elastic beam 11 in two inertia measuring modules symmetrical relative to this buttress brace 130.
Three axis accelerometer of the present invention, when being subject to the acceleration of Z-direction, due to the eccentric setting between mass 1 and the second elastic beam 11, being made mass 1 deflect relative to the second elastic beam 11, being detected by two the first pole pieces 4.And when being subject to the acceleration of X-direction, due to the effect of crossbeam 7, longeron 8, buttress brace 130 and two the first elastic beams 12, make mass 1 that translation motion can only occur in the X-axis direction, thus improve the precision of X-direction detection.When mass receives the acceleration of Y direction, because the second elastic beam 11 is symmetrical relative to buttress brace 130, make center of gravity and the geometric center of gravity overlap of this Z axis structure, and adopt two the first elastic beam 12 quality of connection blocks 1, thus ensure that mass only can carry out translation in the Y-axis direction, and the phenomenon that can not twist.
In order to improve the anti-torsion ability of tie-beam further, described buttress brace 130 is provided with two, and two buttress braces 130 be arranged in parallel, surround a rectangle frame with crossbeam 7.Further, also comprising two cant beams, 131, two cant beams 131 being positioned at rectangle frame can along the diagonal angle distribution etc. of rectangle frame, with reference to figure 4.
Although be described in detail specific embodiments more of the present invention by example, it should be appreciated by those skilled in the art, above example is only to be described, instead of in order to limit the scope of the invention.It should be appreciated by those skilled in the art, can without departing from the scope and spirit of the present invention, above embodiment be modified.Scope of the present invention is limited by claims.