SU918778A1 - Measuring head - Google Patents

Description

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The invention relates to a measuring technique, namely to a measuring head for coordinate measuring machines.

Measuring heads are known, comprising a housing, a measuring lever with a measuring tip, and a touch alarm, made in the form of an electric circuit that is closed through the measuring lever, and an electronic relay indicating the short circuit of the electrical circuit f1.

However, these measuring heads provide sufficient measurement accuracy, but are only suitable for measuring conductive objects.

The closest to the proposed technical entity is a measuring head containing a measuring lever with a measuring tip, a recording part and a touch alarm device, made in the form of a high-frequency electric oscillation generator, a piezoelectric exciter of mechanical oscillations of the measuring lever with two or more plates, and also a meter of mechanical parameters associated with the touch alarm, the mechanical vibration exciter is designed as a torsional exciter the oscillations, and the oscillation parameter meter, in the current meter consumed

10 pathogen. When the measuring tip touches the object being monitored, the friction losses and, accordingly, the excitation current of the oscillations increase, which allows us to note the moment of contact 2j.

Claims (2)

However, the known device is characterized by insufficient accuracy in recording the moment of contact, since the excitation current can be measured for other reasons, for example, due to a change in the supply voltage. The purpose of the invention is to improve the measurement accuracy. The delivered chain is achieved by the fact that the exciter of mechanical oscillations is located at the end of the measuring lever, its first excitation winding is ring-shaped, second measuring, placed inside the ring, concentric with the first one, and the meter of vibration parameters is made in the form of a phase shift meter connected between the first and second enclosures kami. In Fig.1 shows a diagram of the head with the diagram of axial oscillations measuring it lever; Fig. 2 shows the layout of the plates on the end of the measuring lever and the functional diagram of the touch alarm. The measuring head comprises a housing 1, inside of which a measuring lever 2 with a measuring tip 3 is placed. The measuring lever with its fungus k rests on the lower flange 5 of the housing, which allows it to deflect in any direction. To press the fungus to the flange, there is a spring 6.. At the end of the measuring lever, there is a piezo-electric actuator 7 axial oscillations. On a free Toiptte exciter placed (Figure 2) exciting 8 and measuring 9 plates. The exciting lining is made annular, measuring - is placed inside the annular, concentric with it. The touch detector also includes a generator of 10 high-frequency electrical oscillations, the output of which is connected to the excitation plate of the axial oscillations of a phaeoelectric exciter {the response plate is the measuring itself (the lever that is connected to the mass of the measuring machine), the phase meter 11, the inputs of which are connected to the exciting and measuring plates , and the executive part 12 connected to the output of the phase meter. The measuring head works as follows. A high voltage alternating voltage from a generator 10 is applied to the excitation plate 8, under the action of which the piezoelectric exciter 7 changes its linear dimensions and excites longitudinal (axial) oscillations in the measuring lever. 9 8 The generator frequency is chosen close to the main (first) form of natural oscillations of the measuring lever ((Fig. 1. Due to the high quality of the oscillating system of the measuring lever, the phase shift by oscillations and the supply voltage is insignificant. The phase meter marks the phase , measuring, the plate 9 energizes the voltage in phase with the mechanical oscillations of the measuring lever. At the moment of contact of the measuring lever with the object being monitored, the quality factor of the oscillatory The systems, and the phase shift between the supply voltage and the oscillation increases, as indicated by the phase meter 11 with the recording part 12. Due to the concentric positioning of the exciting and measuring plates, the measuring head is isotropic, i.e. it marks the touch with any side equally well The phase shift between oscillation and excitation voltage is practically independent of the supply voltage, which makes the measuring head insensitive to network interference. The measuring head does not form electrical circuits with a controlled object and is suitable for measuring both conductive and non-conductive parts. The invention includes a measuring head comprising a measuring arm with a measuring tip, a recording part and a touch alarm device, made in the form of a high-frequency electric oscillator, a piezoelectric mechanical oscillation driver of the measuring lever with two or more plates, and a measuring instrument for mechanical oscillation parameters that, in order to improve the accuracy of measurements, the exciter of mechanical oscillations is placed on the end of the measuring lever, its first The exciting winding is made annular, second, measuring, placed inside the ring, concentric to the first, and the mechanical vibration parameter meter is designed as a phase shift meter, switched on between the first and second plates. Sources of information taken into account during the examination 1. Markov N.N. et al. Error and choice of means for linear measurements. Mechanical Engineering, 19b7, c.ltl-l S. 2. USSR author's certificate H-, cl. B 06 B 5/00, 1966 (prototype). Fog, / 0vt. I