CN2182388Y

CN2182388Y - High-precision contacting three-dimensional gauge head

Info

Publication number: CN2182388Y
Application number: CN 93244360
Authority: CN
Inventors: 马云辉; 袁哲俊; 马玉林; 陶崇德
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 1993-11-09
Filing date: 1993-11-09
Publication date: 1994-11-09
Anticipated expiration: 2003-11-09

Abstract

The utility model discloses a high-precision contact three dimensional probe, composed of a probe, a measuring rod, a shell body, a spring, and a displacement sensor. The middle part of the measuring rod is provided with a hemispherical slide block with a smooth surface, and the slide block is supported by the spring; the slide block is arranged in a taper hole base which is fixed to the shell body and has a smooth inner surface. The end part of the measuring rod is provided with a guide ball limited by a guide hole; the guide ball measures displacement quantities as the sensing head of the displacement sensor. The displacement sensor transforms the displacement quantities into electrical signals which are used to measure forces acting on the probe from all directions in three-dimensional space. The probe overcomes the defects of inhomogeneous opening forces of the prior art, and enhances measurement precision.

Description

High-precision contacting three-dimensional gauge head

The utility model relates to a kind of survey sensor gauge head, especially for the milling center, and the three dimensional probe, 3-D probe on robot measurement and the three-coordinate measuring machine.

Along with improving constantly of atomization degree, the three-coordinate measuring machine of multifunction high-precision has obtained application more and more widely on automatic production line.Coordinate measuring machine is realized the part shape dimensioning by its axis coordinate motion distance.Be the terminal of control survey machine, all use three dimensional probe, 3-D probe on the three coordinate measuring machine, when measuring machine moves, if the probe of gauge head contacts with workpiece, then gauge head sends signal, makes this point coordinate value of control system record storage, according to calculating and handle the actual measured value that can obtain measured workpiece.On some high-grade Milling Machining Center, also is furnished with same three dimensional probe, 3-D probe, in order to finish to the on-line measurement of workpiece size and the work such as coordinate position of looking for register pin, hole, in flexible manufacturing system (FMS), can also see at present the robot measurement of using the multidimensional probe, the multidimensional gauge head that they use is representative with Britain's product " Lei Lixiao " gauge head, and this gauge head has simple, the repetitive positioning accuracy advantages of higher of principle.

The Lei Lixiao gauge head has made full use of the high resolution of dotted line contact-making switch, the principle of work of gauge head is the series connection of three contact-making switches and is equilateral triangle and is evenly distributed on the plane, the plane is vertical with measuring staff, when the probe of the ruby on the measuring staff is subjected to the power of any direction, wherein have at least a switch to disconnect, sensor produces a level step signal thus.Its principle of work is seen accompanying drawing 4.

Fig. 4 A, B, C are three switches, are cascaded, an end ground connection wherein, other end P is a signal output part, 17,18,19, be the switch abutment, their mutual insulatings are under the spring force effect, A, B, C conducting, P point output low level " 0 ", after gauge head M is stressed, A, B, C must have a switch to disconnect, and then the P point is exported high level " 1 ", and P point output signal can be as the control signal of coordinate motion terminal.

In order to make the gauge head reliable reset, even six whole conductings of contact point provide a pretightning force by spring.Therefore, need an external force effect to open contact point during gauge head work, then this power is called opening force (F _K).The opening force value generally is set in about 70-100g, according to calculating, the common material of the long 100mm of diameter phi 5mm will produce the natural bow of 50 μ m under this power effect, promptly to make gauge head send signal, then probe will depart from gauge head center 50 μ m earlier, if all directions opening force is identical, then the amount of deflection deviation of external force effect generation can be eliminated by the way that compensates or establish amount of bias, otherwise this error can be brought measurement result into.

With the principle of work of " Lei Lixiao " gauge head as can be known, (in the XY plane) its opening force value is uneven, and three identical opening force distributive province are arranged on the Zhou Fangxiang of garden, and wherein the difference of maximal value and minimum value is 1/3F _KTherefore, because the force direction difference must produce corresponding measured deviation, and this deviation is difficult to be eliminated by compensation method owing to its unevenness.In order to reduce the measuring error that natural bow produces, generally adopt the overstriking measuring staff in the practice, shorten measuring staff length, selection quality matetrial increase measuring staff rigidity etc. reduces the way of opening force.But these ways are to can't being eliminated and compensate by the inhomogeneous error that causes of opening force, because it is an original reason error.

The purpose of this utility model is to propose a kind of high-precision three-dimensional gauge head, and this gauge head has overcome the uneven shortcoming of Lei Lixiao gauge head opening force from principle, thereby eliminates the measuring error that causes thus.This gauge head not only can be used to judge the terminal of measuring machine measuring process, and can provide the quantitative values of gauge head displacement in measuring process.

The utility model high precision contact-type 3 D gauge head comprises gauge head 1, measuring staff 2, housing 4, spring 6, with a displacement transducer that the mechanical shift change transitions is become electric signal, its main points are that the middle part of measuring staff 2 has a semisphere slide block 3 with smooth surface, this semisphere slide block 3 is supported by spring 6 and places one to have slippery inner surface and be fixed in the taper hole pedestal 5 on the housing 4, spring 6 places between semisphere slide block 3 and the guide way 8, measuring staff 2 afterbodys have SDeflector 7, SDeflector 7 places in the pilot hole of guide way 8 and is subjected to the spacing of pilot hole, guide way 8 is fixed on the housing 4, SDeflector 7 provides displacement as the sensor of displacement transducer, said structure makes the displacement that power produced of any one direction in the three dimensions on the gauge head 1 act on measuring staff 2, through pilot hole spacing to the SDeflector 7 of measuring staff 2 afterbodys, all will cause the axial displacement of measuring staff 2, this displacement signal is transformed into electric signal output through above-mentioned displacement transducer.

Mechanical displacement sensor described in the utility model can be a sensor that mechanical shift is transformed into switched electrical signal, be used to judge the terminal of measuring machine measuring process, also can be one mechanical displacement is transformed into the sensor of analog quantity electric signal, in order to measure gauge head corresponding displacement in measurement.

The three dimensional probe, 3-D probe that the utility model proposes, the power of any one direction does the time spent (not comprising axial force) in gauge head 1 is subjected to from three dimensions, all will cause the relative slip of semisphere slide block and taper hole pedestal, after guiding, be transformed into axial displacement, be transformed into electric signal output through displacement transducer, this measuring staff structure has overcome 3 uneven problems of contact measuring head opening force of Lei Lixiao from principle.For from axial acting force, to directly produce axial displacement and act on displacement transducer, but therefore will change compensate uniformly into by the inhomogeneous natural bow deviation that can not compensate that causes of opening force, thereby improve the measuring accuracy of gauge head greatly, its measuring accuracy can reach 0.5um.

Description of drawings:

Fig. 1 is the structure principle chart of an example of the utility model three dimensional probe, 3-D probe;

Fig. 2 is the structure principle chart of another example of the utility model three dimensional probe, 3-D probe;

Fig. 3 is a geometric relationship synoptic diagram between the utility model three dimensional probe, 3-D probe measuring staff and the slide block;

Fig. 4 is the principle schematic of Britain Lei Lixiao gauge head;

Fig. 5 is the correlation curve synoptic diagram that the utility model three dimensional probe, 3-D probe is opened the natural bow deviation that the natural bow deviation cause causes Lei Lixiao gauge head opening force.

Embodiment 1:

Three dimensional probe, 3-D probe as shown in Figure 1 is the three dimensional probe, 3-D probe that is used to judge measuring machine measuring process terminal, its displacement transducer is a displacement transducer that mechanical shift is transformed into switched electrical signal, this sensor is that the SDeflector 7 by measuring staff 2 afterbodys constitutes pair of electrodes with switching motherboard 9, switching motherboard 9 is by spring 10 resiliency supported and be enclosed within on the micrometer screw 13, micrometer screw 13 combines with thousand fens screw 12 screw threads, have semisphere positioning bead and sliding sleeve 11 positioning combination on thousand fens screws 12, sliding sleeve 11 is on pilot hole 8 stationary housings.

Embodiment 2:

Three dimensional probe, 3-D probe as shown in Figure 2, its displacement transducer is a displacement transducer that the mechanical shift change transitions is become analog electrical signal, it comprises a magnetic core 19 that can move between elementary drive coil 18 and

secondary coil

17 and 20, elementary drive coil 18 and

secondary coil

17 and 20 are wrapped on the support 16, support 16 is fixed on the guide way 8, on guide way 8 stationary housings 4, a high precision touch panel 15 is fixed together with magnetic core 19 and contacts with SDeflector 7,21 is spring suppport, and 22 is spring.

Geometric relationship as shown in Figure 3 acts under the displacement of the three dimensions all directions on the gauge head 1 caused measuring staff axial displacement and can be calculated as follows and obtain:

S＝K［S ₁＋ (L ₁S ₂)/(L ₁L ₂) kg (α)/2 ］

In the formula: S-measuring staff axial displacement

S ₁-F cause with the axial perpendicular displacement component of measuring staff

S ₂The displacement component that axially parallels with measuring staff that-F causes

L ₁-gauge head the centre of sphere is to the distance of the hemisphere slide block centre of sphere

L ₂-hemisphere slide block the centre of sphere is to the distance of the centre of sphere that leads

α-taper hole pedestal cone angle

The R-coefficient

Claims

1, a kind of high precision contact-type 3 D gauge head, comprise gauge head [1], measuring staff [2], housing [4], a spring [6] and a displacement transducer that the mechanical shift change transitions is become electric signal, there is a semisphere slide block [3] with smooth surface at the middle part that it is characterized in that measuring staff [2], this semisphere slide block [3] is supported by spring [6] and places one to have slippery inner surface and be fixed in the taper hole pedestal [5] on the housing [4], spring [6] places between semisphere slide block [3] and the guide way [8], measuring staff [2] afterbody has SDeflector [7], SDeflector [7] places in the pilot hole of guide way [8] and is subjected to the spacing of pilot hole, guide way [8] is fixed on the housing [4], and SDeflector [7] provides displacement as the sensing head of displacement transducer.

2,, it is characterized in that described displacement transducer is a displacement transducer that the mechanical shift change transitions is become switched electrical signal according to the described three dimensional probe, 3-D probe of claim 1.

3, according to the described three dimensional probe, 3-D probe of claim 2, it is characterized in that described displacement transducer is the SDeflector ［ 7 ］ and switching motherboard ［ 9 ］ formation pair of electrodes by measuring staff ［ 2 ］ afterbody, switching motherboard ［ 9 ］ is by spring ［ 10 ］ resiliency supported and be enclosed within on the micrometer screw ［ 13 ］, micrometer screw ［ 13 ］ combines with thousand fens screw ［ 12 ］ screw threads, have semisphere positioning bead and sliding sleeve ［ 11 ］ location on thousand minutes screw ［ 12 ］, sliding sleeve ［ 11 ］ is fixed on the housing ［ 4 ］ with pilot hole ［ 8 ］.

4, according to the described three dimensional probe, 3-D probe of claim 1, it is characterized in that described displacement transducer is a displacement transducer that the mechanical shift change transitions is become analog electrical signal, comprise one can be at elementary drive coil ［ 18 ］ and secondary coil ［ 17 ］, ［ 20 ］ magnetic core ［ 19 ］ of motion between, elementary drive coil and secondary coil ［ 17 ］ are wrapped on the support ［ 16 ］, support ［ 16 ］ is fixed on the guide way ［ 8 ］, guide way ［ 8 ］ is fixed on the housing ［ 4 ］, and a high precision touch panel ［ 15 ］ is fixed together with magnetic core ［ 19 ］ and contacts with SDeflector ［ 7 ］.