CN2044721U - Portable surface roughness measurer - Google Patents

Abstract

The utility model relates to a portable surface roughness tester used to test surface roughness value Ra of workpiece processed by a machine. The work programs of an integrator and A/D converter are controlled by using the switch of a photoelectric coupler and control circuit. The utility model whose power source is laminated battery has the advantages of good repetitiveness after multiple metering, high precision, small instrument structure, convenient operation, low cost.

Description

Portable surface roughness measurer

A kind of instrument of measurement mechanical piece surface smooth finish.

The utility model belongs to the technological improvement of surfagauge device.

General mechanical workpieces after processing, only pipe is to have reached highest smooth finish, still there is coarse uneven phenomenon in its surface, this coarse measurement relative method commonly used is realized, promptly use the detect by an unaided eye comparison or examine under a microscope comparison of standard sample and measured workpiece, and determine its any surface finish degree of roughness, relative method can only provide scope qualitatively.Other has a kind of method is to utilize the optical interferometry workpiece surface finish.A most frequently used parameter of description list surface roughness is Ra quantitatively, and it is defined by following formula:

$\mathrm{Ra}=\frac{{\∫}_O^L\left|R\right|\mathrm{dl}}{L}$

Wherein: R-is in measuring length, the deviate of real surface and average surface

L-measures length

The obtaining of Ra value is to use and comprises that driver, sensor and measurement display three partly form measuring instrument.The sensor that has contact pilotage in clamper clamping on the driver, by the internal drive mechanical hook-up, the power transformation machine rotates and is the straight reciprocating motion of clamper logotype sensor, contact pilotage reciprocatingly slides on the measured workpiece surface on the sensor, because the coarse injustice of surface of the work makes stylus vibration, through the sensor internal transducing head, the change mechanical vibration are electric signal, and electric signal is connected with the measurement display by lead, measures the value that display is pointed out the Ra on measured workpiece surface.Measure display circuit two kinds of simulation display type and digital display types are arranged: the simulation display type uses magneto-electric pointer ammeter, exists the low and measurement data of precision to be difficult for the shortcoming of further handling.Numeral shows the shortcoming that does not exist simulation to show, but because there are the to-and-fro movement error in driver and sensor and in measuring length, the unevenness of its surfaceness brings the repeatability of repeatedly measuring to be difficult to unanimity.Surfaceness ka value measuring accuracy improves can adopt the method for averaging automatically after the repeatedly measurement, but needs the long time just can finish measurement.Adopt the sensor of raising surveying instrument and the manufacturing accuracy of driver, reduced Measuring Time, but cost has increased just.The utility model purpose is not need high-precision sensor and driver, Measuring Time can be reduced to minimum again, improves measuring accuracy.

The utility model main points are shoulder rotations, average with time that on average becomes of length.

$\mathrm{Ra}=\frac{{\∫}_O^L\left|R\right|\mathrm{dl}}{L}$ Become $\mathrm{Ra}=\frac{{\∫}_O^T\left|R\right|V\·\mathrm{dt}}{V\·T}$

＝ $=\frac{{\∫}_O^T\left|R\right|\mathrm{dt}}{T}$

Set up photoelectrical coupler in the driver, be connected control circuit between photoelectrical coupler and integrator and A/D transducer.

Accompanying drawing 1: complete machine external form figure

Accompanying drawing 2: activation configuration figure

Accompanying drawing 3: circuitry theory diagram

The utility model structure is: see (accompanying drawing 1) driver (1) clamper (2) clamping sensor (3).See (accompanying drawing 2) driver (1) connecting rod (6) end by dress metal penoncel (7), penoncel (7) shape size can be inserted between the light source and reception of photoelectrical coupler (8).See that (accompanying drawing 3) driver (1) drives sensor (3), sensor (3) serial connection amplification filtering circuit (10), amplification filtering circuit (10) serial connection average reading detector (11), average reading detector (11) serial connection integrator (12), integrator (12) serial connection A/D and A/D transducer (13) are connected with photoelectrical coupler (8).Starting switch (15) and in control circuit (14).

During measuring workpieces, driver (1) is kept flat the measured workpiece surface together with clamping sensor (3), operating power switch (9), energized.Operation start switch (15) resets integrator (12) that is made of electric capacity, resistance and amplifier 7611 and the A/D transducer (13) that amasss into circuit 7116 by amassing into the control circuit (14) that circuit 4013 and 4011 forms, and is in initial wait shape.Driver (1) drives sensor (3), and the contact pilotage (4) of sensor (3) is done on the measured workpiece surface and reciprocatingly slided.Connecting rod (6) the metal penoncel (7) of driver (1) also carries out linear reciprocating motion together, then metal penoncel (7) periodically covers disconnected photoelectrical coupler (8), the characteristic of photoelectrical coupler, whenever cover and break once, photoelectrical coupler (8) produces an electric pulse, recurrence interval is T, and promptly to measure in the length back and forth the one-period required time on measured workpiece be T to sensor (3).Because: L=V.dT V-sensor (3) translational speed, thus the value of measure R a, can be with mathematical expression:

$\mathrm{Ra}=\frac{{\∫}_O^L\left|R\right|\mathrm{dl}}{L}$ Become

$\mathrm{Ra}=\frac{{\∫}_O^T\left|R\right|V\·\mathrm{dt}}{V\·T}$

＝ $=\frac{{\∫}_O^T\left|R\right|\mathrm{dt}}{T}$

With the average measurement that has on average become the time of length, photoelectrical coupler (8) produces recurrent pulses and has realized time T.The contact pilotage (4) that driver (1) drives sensor (3) the generation signal that reciprocatingly slides on the measured workpiece surface, through sensor (3), (5) transducing head becomes electric signal and sends into by amassing into circuit 7611 and being added with resistance and the amplification filtering circuit of capacitance network (10), after the amplification filtering, via resistance, the average reading detector (11) that silicon diode and amplifier 7611 constitute is transformed into pulsating current, send into integrator (12), after pressing starting switch (15), integrator (12), A/D transducer (13) resets, display board (5) zero clearing, photoelectrical coupler (8) sends first pulse, integrator (12) is started working by initial shape, photoelectrical coupler (8) sends second pulse, integrator (12) quits work, by control circuit (14) A/D transducer (13) is locked, and its changed digital signal sent into display board (5), display board (5) shows measured workpiece Ra value, finishes the one-shot measurement result thus.When wanting duplicate measurements, operation start switch (15) again, the instrument motion repeats above-mentioned working routine, obtains for the second time, measures for the third time to show.Photoelectrical coupler adopts MOC70V ₂

A kind of method is simple, measurement is rapid for the mechanical workpieces measurement provides in the technological improvement of this machine, the measurement result good reproducibility, and the precision height, instrument easy to carry, it can finish 10 microns～0.08 micron of surface of the work height, and the Ra value of 4 millimeters scopes of length is measured. Only need to use common packed cell to be power supply.

Claims (1)

1. A kind of driver that comprises, sensor and measurement display, the measuring instrument that is used for workpiece surface roughness Ra value is characterized in that said driver increases the dress photoelectrical coupler, the component part of photoelectrical coupler and measurement display: attaching control circuit between integrator and A/D transducer.