DD255784A1 - COORDINATE GUARD HEAD WITH MEASURING KIT FOR TEMPERATURE FOR COORDINATE MEASURING DEVICES - Google Patents

Abstract

The invention relates to a coordinate probe with means for measuring force stabilization for Koordinatenmessgeraete, which has a deflectable in three coordinates from a stable zero position Meßinsatztraeger 6. In the directions of movement along the coordinates x; y; z are a total of six electromagnetic Meßkraftkompensatoren 15 to 20 in a Tastkopfgehaeuse 1 or in a Zwischenstueck 2 fixed, with two Meßkraftkompensatoren 19; 20 an armature 21 fixedly connected to the intermediate piece 2 and four measuring force compensators 15 lying opposite each other in pairs; 16; 17; 18 is associated with an arranged on a Federstabfuehrungssystem anchor 22. Fig. 1

Description

Object of the invention

It is an object of the invention to eliminate the disadvantages of the prior art, to reduce the measurement uncertainty and the technical complexity and to achieve a wide range of application of the coordinate probe heads.

Essence of the invention

The invention has for its object to provide a coordinate probe with means for Meßkraftstabilisierung for coordinate, in which the Meßkraftstabilisierung is achieved with simple, no control requiring means with reduction of heat generation to a minimum in one and in several coordinates over the entire probing range.

According to the invention this object of the invention in a coordinate probe with means for Meßkraftstabilisierung, especially for coordinate, comprising a probe housing in which, along a vertical coordinate from a stable zero position deflectable, an intermediate piece is mounted in diaphragm springs, in which, along two further orthogonal Coordinates from a stable zero position of deflectable Meßeinsatzträger with measuring inserts is arranged on a spring bar guide system, achieved in that in the total of six directions of movement of the Meßeinsatzträgers along the three coordinates x; y; ζ in a defined distance from the zero positions of the diaphragm springs and spring rod guide system up to a total of six preferably electromagnetic, acted upon with adjustable excitation current Meßkraftkompensatoren in the probe housing or in the intermediate piece are fixed, with two Meßkraftkompensatoren a fixedly connected to the spacer anchor and four pairs opposite Meßkraftkompensatoren assigned to the spring rod guide system arranged anchor.

It is advantageous if the Meßkraftkompensatoren are preferably designed as a pot magnets whose magnetic flux is guided over the respective associated armature and whose force effects are directed so that they counteract the restoring forces of the diaphragm springs and the spring rod guide system in their deflection from the zero position. A further advantage is that the pole faces of the Meßkraftkompensatoren have a precisely defined distance from these anchors at zero position of the respective anchor.

This causes in a coordinate probe of the kind set in the directions of movement of the Meßeinsatzträgers by the Meßkraftkompensatoren that upon excitation of the pot magnets with a constant current one with increasing deflection of the Meßeinsatzträgers from its rest or zero position due to the reduction of the magnetic resistance between pot magnet and respective anchor one of the restoring force of the diaphragm springs or the spring rod guide system opposing force exerted on the respective guide system and thus a Meßkraftkompensation or stabilization is brought about. Likewise, a change in the measuring or probing force of the measuring inserts on the measurement object and its direction can be realized by a defined change in the excitation currents according to size and direction in the respective Meßkraftkompensatoren. Thus, it can be achieved that the probe can work both in the wake as well as in the flow principle, whereby the application is substantially expanded in terms of a continuous Konturabtastung with low technical effort.

embodiment

The invention will be explained in more detail using an exemplary embodiment. In the drawing show

1 shows a longitudinal section through the coordinate probe,

2 shows a cross section A-A through the probe

Figure 3: force-displacement curve with compensated measuring force and

Fig.4: force-displacement curve with set measuring force

The coordinate probe shown in Fig. 1 comprises a probe housing 1, in which an intermediate piece 2 in a Z-coordinate movable, mounted in diaphragm springs 3 and 4 torsionally rigid about the z-coordinate. The probe housing 1 is arranged in a receptacle 5 on the meter. In the intermediate piece 2 a deflectable along the coordinates X and Y Meßeinsatzträger 6 is guided in a torsionally rigid, elastic, consisting of four bending bars 7 spring rod guide system, the torsional stiffness is achieved against rotation about the z-coordinate by a stabilizer 8, which is arranged in the intermediate piece 2 is a located in the xy plane torsion-resistant spring rod system 9; 10 and is connected to both the intermediate piece 2 and with the Meßeinsatzträger 6.

In the housing 1 or in the intermediate piece 2 are three a Cartesian coordinate system (x; y; z) forming transmitter 11; 12; Arranged 13, which provide the deflections of the Meßeinsatzträgers 6 from a zero position out proportional output signals. For each coordinate a transmitter is provided.

At rest, d. H. if there is no probing of a test object, the Meßeinsatzträger 6 mounted in the spring rod guide system and in the diaphragm springs 3 and 4 with the measuring insert 14 in a precisely reproducible zero or rest position. :

Along the coordinates X; Y; Z, ie in the directions of movement + x; -x; + Y; -y; + Z; -zsihd at a defined distance a from the zero position of the spring rod guide system and in the diaphragm springs 3; 4 mounted intermediate piece 2 electromagnetically acting Meßkraftkompensatoren 15-16; 17-18 and 19-20 (Fig. 1 and 2) arranged so that when excited with a constant current i each with a to be taken deflection of the Meßeinsatzträgers 6 from the NuI I position in the direction of one of the Meßkraftkompensatoren increasing force on the respective Exercise leadership system and thus the restoring forces of the spring rod guide system or the diaphragm springs 3; Counteract 4 and thus bring about a Meßkraftstabilisierung. In this case, a reduction of the Abstandesa causes a reduction of the magnetic resistance between the armature and the magnet as a pot formed Meßkraftkompensatoren. The measuring force compensators 19 attached to the housing 1; 20 is a fixed to the spacer 2 anchor 21 and the pairwise

opposite Meßkraftkompensatoren 15-16 and 17-18 assigned to the Federstababführungssystem firmly connected anchor 22. About these anchors 21; 22, the magnetic flux of the respective pot is guided magnets.

In Figure 3, the course of the individual path-force characteristics of a pair of Meßkraftkompensatoren 15-16; 17-18 or 19-20 shown with complete compensation of the measuring force within a distance designated as measuring range b, a is the distance of the respective armature 21 or 22 in front of the armature facing surface of the associated Meßkraftkompensatoren.

Implemented using the example of the X-coordinate associated Meßkraftkompensatoren 15; 16, g is the spring characteristic of the spring rod guide system along the X coordinate, f is the force-displacement characteristic of the Meßkraftkompensators 15,

c is the force-displacement characteristic of the measuring force compensator 16,

d the resulting force-displacement characteristic of the Meßkraftkompensatoren 15 and 16 and e of the Meßkraftverlauf over the Auslenkweg, both Meßkraftkompensatoren be energized with a current i.

The course of the measuring force (curve e) shows that the measuring force in the region b, ie over a large part of the distance a is zero.

In Fig. 4 the course of the individual path-force characteristics is shown analogous to Figure 3. However, this excitation of the Meßkraftkompensators 15 with an excitation current i - and the Meßkraftkompensators 16 with an excitation current i + iein over the path coordinate s are the Meßkraftverlauf e 'reached, where Fm is the set or achieved measuring force.

In Fig.4 further

f the force-displacement characteristic of the Meßkraftkompensators 15 at excitation current i - i, c 'the force-displacement characteristic of the Meßkraftkompensators 16 at excitation current i + i and d' the resultant of the force-displacement curves fund c '.

It can be seen that the measuring force F _M (curve e!) Is constant over a wide range b, ie over a large part of the distance a. By selecting the size of the excitation currents (i ± i) on the Meßkraftkompensatoren15und 16, the amount and the direction of the measuring force can be adjusted.

The ratios shown on the Meßkraftkompensatoren 15 and 16 are analogous to the force acting in the y-coordinate Meßkraftkompensatoren 17 and 18 and on the acting in the Z coordinate Meßkraftkompensatoren 19 and 20 transferable.

Claims (3)

1. Coordinate probe head with Meßkraftstabilisierung for coordinate, comprising a probe housing in which, along a vertical coordinate deflected from a stable zero position, an intermediate piece is mounted in diaphragm springs, in which, along two further orthogonal coordinates from a stable zero position deflectable Meßeinsatzträger is arranged with measuring inserts on a spring bar guide system, characterized in that -daß in the total of six directions of movement of the Meßeinsatzträgers along the three coordinates X; Y; Z in a defined distance from the zero positions of the diaphragm springs (3; 4) and the spring bar guide system (7,9,10) up to a total of six preferably electromagnetic, with adjustable excitation current acted Meßkraftkompensatoren (15; 16; 17; 18; 19; 20) in Probe housing (1) or in the intermediate piece (2) are fixedly arranged, wherein two Meßkraftkompensatoren (19; 20) one with the intermediate piece (2) fixedly connected anchor (21) and four pairwise opposite Meßkraftkompensatoren (15; 16; 17; 18) associated with an arranged on the spring rod guide system armature (22). 2. coordinate probe according to claim 1, characterized in that the Meßkraftkompensatoren (15; 16; 17; 18; 19; 20) are preferably designed as Töpf magnets whose magnetic flux over the respective associated armature (21; 22) is guided and their force effects are directed so that they counteract the restoring forces of the diaphragm springs (3; 4) and the spring rod guide system in their deflection from the zero position. 3. Coordinate probe according to claim 1 and 2, characterized in that the pole faces of the Meßkraftkompensatoren (15; 16; 17; 18; 19; 20) at zero position of the respective armature (21; 22) a precisely defined distance a from these anchors (21 ; 22). For this 3 pages drawings Field of application of the invention The invention relates to a coordinate probe with means for Meßkraftstabilisierung for Koordinatenmeßgeräte, in particular a probe with spring-guided and the spring restoring force used as a measuring force probe systems for the probing of DUTs in one or more coordinates. Characteristic of the known technical solutions From DD-PS 141197 a coordinate probe, which operates on the tracking principle, known in which the spatial mobility of a plurality of measuring inserts receiving Meßeinsatzträgers is realized in a x-y plane by a spring bar guide system or in a z-direction by a diaphragm spring guide. The measuring forces are generated by the restoring forces of the spring rod guide and by the diaphragm spring guide. The spring stiffness of this elastic spring guides is dimensioned so that the Meßeinsatzträger is always held in the rest position in a reproducible position. They are a Cartesian coordinate system x; y; ζ forming transmitter provided whose output signals are processed in a computer to so-called signal balls with the radius R. If the radius R is identical to a radius Rj which depends on the preselected measuring force via the rigidity of the guidance system, a measured value acceptance is triggered. The disadvantage is that the realized measuring force is dependent on the deflection of the guide system and therefore for continuous contour scanning highest demands on minimum deviations of the Nachführachse. From DD-PS 150111 a device for path-force coordination of probing systems is known in which to achieve a constant over the measuring range measuring force, a control circuit consisting of a voltage-controlled current source, a DC linear motor, a displacement-force transducer, a position measuring system and a control amplifier, is provided. Setting means for the setpoint of the measuring force are connected via the power source with the DC linear motor and its output to the displacement-force converter. The measuring system is coupled via the control amplifier with the power source. Disadvantage of this device is that in probing systems with tracking principle due to the functionally necessary spring stiffness with increasing stylus deflection ever greater compensation forces must be generated by the DC linear motor to maintain constant the measuring force. For this purpose, relatively high currents are necessary, which lead to the measurement uncertainty of the probing system increasing heat development. Further disadvantages are that in this device both the DC linear motor and the displacement measuring system are carried out as a dipping coil system, and the application of the device is thus performed on linear guidance systems, e.g. Leaf spring guides, is bound. The equipment expense is relatively high.