DE2354248A1 - Rotating element testing method - tests for irregularity of dimensions when element is slowly rotated about its axis - Google Patents

Abstract

The element axis is held immobile in space, and its surface is tested point-by-point by a feeler movable in a coordinate direction parallel to or perpendicular to the axis of rotation. When the element rotates, the feeler is moved along a nominal reference line near the tested surface, and changes in the distance between the reference line and the tested surface are measured. The nominal reference line is continuously precalculated point-by-point in accordance with the element rotation, and the separately driven feeler is guided by a follower control device. The element rotation is differentially measured in the form of a first pulse train, and the feeler linear motion is similarly measured by a second pulse train. The feeler is guided in accordance with the comparison result of the two trains.

Description

i ^J p. (upi ^r Ji5Wäit. Dipi.-Irig. W. Scherrmann Dr.-ing. R. Rüger

7300 Esslingen (Neckar), Fabrikstrasse 24, PO Box 348

October 29, T973 phone

PA 9 rest Stuttgart (0711) 356539

Telegrams patent protection Esslingenneckar

Carl Mahr / 7300 Esslingen a.N-.

Method and device for testing a rotating body Irregularities in its dimensions

The invention relates to a method ^r iur examination of a rotary body on Unregelmäßigkelten its Abmessunger-, wherein the rotary body around-its rotated space captured axis of rotation slow and a test surface of the rotary body by a in at least one parallel to or right angles running perpendicular to the axis of rotation Ko.ordinatenrichtung linear movable probe is scanned point by point ", which, based on the rotating body, is moved in dependence on the rotating movement of the rotating body along a reference line running in the vicinity of the surface to be tested.

The invention also relates to a device for Perform this procedure with at least one

• parallel or at right angles to the fixed axis of rotation of the rotating body linearly displaceable slide on which the button is located.

Rotary bodies with high demands on their dimensional accuracy be provided, such as gears., groove washers, worm gears, serrations and the like, must are often checked to see whether the manufacturing

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conditional irregularities in dimensions within the specified door limits. With gears you can such irregularities or errors to the individual. Teeth occur as skew errors or tooth shape errors.

In practice, gear testing devices are known whose mode of operation is based on the fact that with mechanical adjustment and transmission links - theoretically as precise as possible Target reference line is generated from which the changes the distance to the tooth flank surface of the gear to be tested is measured by means of a probe. These devices require a high level of mechanical effort to generate the most precise reference line possible with precision machined parts, which results in correspondingly high manufacturing costs. aside from that the devices are not universally usable without further ado, because they are only intended for gearwheels with one Tooth shape for which they are set up can be used.

In addition, GB-PS 1 264 333 discloses a device for testing a rotating body, in particular a gear Known surface defects in which, for example, in the bevel test of gears a in the direction of Gear axis of rotation movable slide is provided, which carries a driving pin, which on the flank of the to tooth to be examined. The driver pin causes a mechanical coupling of the slide with the gear

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in such a way that with a linear movement of the slide the entrained gear is rotated about its axis of rotation or conversely, the driven gear gives the carriage a linear movement. The gear and the steps are each connected to a transducer, which is responsible for the rotary movement of the gear and the linear movement of the Sledge emits characteristic electrical signals, which are compared with each other and from which a helix angle error indicative display value is determined. The procedure for the tooth form test is analogous.

Give in one embodiment of this known device the transducer of the gear and that of the carriage each send signals in the form of pulse trains, with the pulse frequency of the two transducers by one Pulse calculator depending, for example, on the helix angle and the gear diameter is set equal to, so that that occurs with a defective gear Phase shift denotes the error.

The fundamental disadvantage of this device is that that gears with a very small module with such a Device cannot be tested because the driving pin must have a certain mechanical stability, to ensure proper transmission of motion between the gear to be tested and the one carrying a transducer To ensure slide without a measuring result distorting deflection occurs. .

The invention is based on this prior art the task of creating a method and a device suitable for carrying out this method, which Realize with a much lower mechanical effort can, through a wide range of possible uses

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and also the flawless examination For example, gears with a small module or serrations etc. are permitted.

To solve this problem, the method mentioned at the outset is characterized according to the invention in that the The target reference line is continuously calculated in advance as a function of the rotary movement of the rotating body and the externally driven one Button is tracked accordingly by an electrical follow-up control.

The precalculation of the reference line as a function of the rotational movement of the rotating body can be carried out with per se of any precision. The tracking of the probe within correspondingly narrow tolerance limits also offers no fundamental difficulty. It can be made without the use of complicated ones to be manufactured with high precision mechanical parts such as rolling arcs, hobbing rulers, Achieve stencils and the like.

Simple relationships arise when the solitary reference line is calculated in advance point by point. This can be done with a preferred embodiment proceeded in this way, that the rotary movement of the rotary body is digital in the form of a first pulse series and the linear movement of the probe can also be measured digitally in the form of at least a 2nd pulse series, each pulse interval of the 1st pulse series is compared with the second series of pulses and adjusted depending on the comparison result of the button will.

The reference line can be based on a predetermined mathematical function depending on the rotational movement of the

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Rotating body can be calculated. When examining surfaces but with a complicated profile shape can also be of this type proceeded v / earth that the reference line is calculated in additional dependence on predetermined data.

The device mentioned at the beginning for carrying out the new The method is characterized according to the invention that the slide carrying the button has its own the drive source generating the longitudinal movement of the slide coupled and the rotating body and the slide are each coupled with its own transducer, one of which is for the rotary movement of the rotating body and the other emit electrical signals characteristic of the linear movement of the carriage, and that one that processes the signals characteristic of the rotary movement of the rotary body and one of the reference line The computer providing the output variable is provided, which is followed by a follow-up control unit, which the output size of the computer and the for the Linear movement of the, carriage characterizing signals are supplied and the resulting drive source derives the manipulated variable influencing the slide in the sense of the tracking.

The arrangement can be made such that the transducer of the rotating body and the transducer of the slide each have electrical signals in the form of one Generate number of pulse trains containing discrete pulses.

The sensors are followed by pulse counters with the advantage of which the those responsible for the rotary motion of the

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Rotary body characterizing pulses counting counter via the computer and the for the linear movement of the The counters that count the impulses that characterize the slide directly feed a respective downstream memory, the content of the two memories digitally with one another by an assigned comparator of the readjustment unit are compared and the comparator is followed by a control part acting as a digital / analog converter, which, depending on the comparison result, sends an analog control signal as a control variable to the drive source of the slide gives away.

In addition, the slide carrying the button can be on a be arranged at right angles to its movement linearly movable second carriage, which also has its own Linear movement of the carriage causing drive source and its own transducer are assigned, the for the linear movement of the second slide, the signals of the assigned transducer, which are characteristic of the linear movement, are also the follow-up Control unit can be supplied.

In addition, the Pechner can optionally be programmed from outside in order to open up the possibility of using the device for testing practically any rotating body to be able to use without difficulty, which is possible because only the programming of the Pechers is changed according to the reference line to be calculated for the respective rotating body.

In the drawing, an embodiment of the subject matter of the invention is shown. Show it:

1 shows a device according to the invention for testing a rotating body for irregularities in its dimensions,

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_, ₇ _ ■■ = ■ ".-;. .235424

in perspective, schematic representation and,

Fig. 2 is a schematic block diagram of the device according to Fig. 1.

The gear testing device shown in the drawing has a receiving mandrel 1 which is rotatably mounted at 2 and held by a drive motor 4 to its space-proof vertical axis of rotation 3, can be set in rotation. With your Aufhahir.edorn .-. 1, a gear 5 to be tested is non-rotatable connected by a point coaxial with the axis of rotation · 3 is led. The side of the arbor 1 is on one machine bed, not shown, a guide 7 is arranged, on which an adjustment slide 8 at right angles "., to the axis of rotation 3 is adjustably mounted, the respective setting position by means of an optical grating scale 9 and an associated one Microscope can be determined exactly. The setting slide 8 is in its "-.- respective Ti position by means not shown, for example a locking hood, lockable. On the setting slide 8 is a horizontal slide 11 at right angles to the axis of rotation 3 ver * - running coordinate direction and mounted displaceably in a horizontal plane. The linear adjustment movement of the Horizontal slide 11 can by a ball screw are generated with a drive source 13 in the form a controllable DC motor is connected. A vertical guide 14 is attached to the horizontal slide 11, in which one in a parallel to the axis of rotation 3 Coordinate direction adjustable vertical slide 15 is slidably mounted. The adjustment of the Vertical slide 15 is done by a ball screw 16, which from a drive source 17 also in the form a controllable DC motor is driven.

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The vertical slide 15 carries a button 18, which is elastic with a replaceable on the button 18 movably mounted sensing finger 19 is provided. The button 18 is constructed in such a way that when the deflection of the Touch finger 19 from the neutral central position for the Size of this deflection emits characteristic electrical signal, which via lines 20 to a not shown Display or registration device is supplied.

With the arbor 1 is a first transducer 21 non-rotatably connected, which is responsible for the rotational movement of the receiving mandrel 1 and thus of the gear 5 to be tested emits characteristic electrical signal. The transducer 21 is "designed as a pulse generator, that is, it generates as a function of the rotational movement of the receiving mandrel 1 and caused by the drive motor of the gear 5 to be tested a pulse train, which is hereinafter referred to as the first pulse train. In the practical embodiment, the transducer 21 is of a known construction. For example, he can in the manner indicated schematically in FIG. 1 have a disk connected to the receiving mandrel 1 in a rotationally fixed manner, which carries along its circumference an optical lattice scale 22 (Fig. 2), which by a photocell 2 3 is scanned.

A second transducer 24 is rigidly connected to the setting slide; he feels you on the horizontal slide 11 attached optical lattice scale 25 and generated for the respective position of the horizontal slide 11 characteristic electrical signals in the form of a second series of pulses. "

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In addition, there is a third guide on the vertical guide 14 Mounted transducer 26, which has an optical lattice scale 27 arranged on the vertical slide 15 and for the vertical linear movement of the vertical slide T5 emits characteristic electrical signals that appear in the form of a third series of pulses. .

The three transducers 21, 24, 26 each have a counter

28, 29, 30 connected downstream of that of the respective The transducer counts incoming pulses. The counters

29, 30 is digitally stored in an actual value memory 31 and 32, respectively, while the reading of the counter 28 is entered into a computer 33, which uses this for the rotary movement of the receiving mandrel 1 and thus of the one to be tested. Gear 5 characterizing information either according to a predetermined mathematical function, ie ',. processed in accordance with a fixed programming or together with data entered externally at 34, that is, in accordance with a programming set in each case. and the calculation results of which are stored in a downstream setpoint memory 35.

The contents of the actual value memory 31, 32 and the -setpoint-, memory 35 are fed to a readjustment unit 36, which contains a comparator 37, which is based on the comparison of the pulse numbers stored in the memories 35, 31, 32 an output signal is generated which is fed to a downstream control part 38, which acts as a digital / analog converter acts and from this an electrical one forming a manipulated variable Control signal generated, which is fed to the drive motor 13 or the drive motor 17 via a line 39 or .. 40.

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The gear testing device described in its structure works as follows:

It is assumed that the gear 5, the tooth slope should be checked. At the beginning of the measurement, the setting slide 8 is dependent on the size of the to Testing gear 5 has been transferred into the correct measuring position, in which the probe 19 on the flank surface 41 of a tooth 42 rests. The same applies mutatis mutandis to the horizontal slide 11, which is set in the correct position Measurement position is determined.

The arbor 1 and the gear 5 to be tested are at first standing in the vicinity of the upper or lower face of the gear 5; Measuring probe 19 slowly in rotation offset, the pulses emitted by the first transducer of the first pulse series in the pulse counter 2 are counted. The computer 33 calculates from the thus counted impulses for the rotational movement of the gear to be tested 5 represent indicative signals, a reference line related to the flank surface 41 of the gearwheel 5, along which the feeler finger 19 of the follow-up control unit 36 is tracked. The button 18 thus measures the distance between the reference line and the line that has just been scanned Points of the flank surface 41, which forms a measure of the skew error of the gearwheel 5.

For this purpose, depending on the helix angle ßd & s gearwheel 5, the vertical slide 15 with the button 18 must cover a certain height path with a given rotary movement of the gearwheel 5. This means that in-between two successive pulses of the output from the first transmitter 21 first pulse train period of which the linear vertical movement of the vertical slide 15 indicating transmitter 26 a certain SOIL

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number of pulses must have been generated. This target number of pulses is determined by the computer 33 for each of the pulse generator of the mandrel 1 output pulse is recalculated and stored in the memory 35. The comparator 37, which can be designed, for example, as a differential counter can, now compares the one stored in the memory 35 Setpoint pulse number precalculated by computer 33 with the actual value memory 32 stored in tlem and corresponding to the actual movement of vertical slide 15 Actual pulse number. The difference determined by the comparator 37 between the target and the actual pulse number is An analog electrical control signal is converted by the control part 38 /, which is fed to the controllable direct current motor 17 via the line 39. The DC motor 17, which has a very small mechanical time constant, increases or decreases under the influence of the supplied control signal its speed, so that the vertical slide 15 is tracked and the sensing finger 19 on the pre-calculated point on the flank surfaces 41 related reference line is set.

When the next pulse emitted by the transducer 21 assigned to the arbor 1 occurs in the course the further rotary movement of the receiving mandrel 1 is repeated this process, so that the probe 19 always exactly along the pre-calculated reference line to be led.

The pre-calculation of the reference line by the computer is carried out using the tooth bevel test described the mathematical relationship resulting from the specified gear parameters:

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A pulse from the transducer 21 = χ Pulses from the pulse generator 26 of the vertical slide 15.

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The resolution of the pulse generator 21 is 0.5 Angular seconds and a resolution of the linear pulse encoder 26 of 0.0001 mm assumed.

With a gear wheel diameter of, for example, 300 mm and a helix angle of [J> = 20, the direct current motor 17 must therefore adjust the vertical slide 15 by a distance of 9.99011075 pulses at the linear pulse generator 26 for each pulse emitted by the transducer 21 of the mounting mandrel 1 is equivalent to.

Since the computer 33 recalculates the target number of pulses for each pulse output by the transducer 21, can if the resolution of the linear pulse generator is high enough, the digits after the decimal point are neglected, like this is obvious for the specified embodiment. The resulting error cannot be greater than 0.1 / µm.

While with the described tooth bevel check the Horizontal slide 11 was stopped, the vertical slide 15 is locked during the tooth shape test. Of the The test procedure is carried out in the manner already described, in which case the drive motor 13 of the Horizontal slide 11 is influenced by the control signals emitted by the readjustment unit. The computer is programmed in such a way that in the mathematical relationship given above, instead of the factor tan β the Factor 1 occurs.

If tooth shapes deviating from the involute shape are to be checked, the computer 33 is set according to the existing ones Tooth shape is preprogrammed so that it has the correct reference line for this case, i.e. the one corresponding to this reference line Pre-calculates target pulse numbers, which are then converted into

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stored in the memory 35 and in already written Way can be compared by the comparator 37 with the actual pulse numbers stored in the memory 31.

In the described embodiment of a gear testing device the skew test takes place in one of the. Teeth form test separate process. Another The possibility of gear testing, which can be carried out with the new method, consists in that each of the two linear transducers 24, 26 of the horizontal and vertical slide 11 "" or. 15 a separate one of the Counter 28 fed computer 33 with a downstream memory 35 and associated adjustment part 36 is assigned, so that the tooth shape with simultaneous bevel testing is checked. In this way it is possible, for example, to check the tooth shape distributed over the width of the gear,

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Claims (10)

Claims 1. ) Method for testing a rotating body for irregularities in its dimensions, in which the rotating body is slowly rotated around its fixed axis of rotation and a surface of the rotating body to be tested is scanned point by point by a probe that can be linearly moved in at least one coordinate direction parallel or at right angles to the axis of rotation, which is moved in relation to the rotating body as a function of the rotational movement of the rotating body along a reference line running in the vicinity of the surface to be tested, the change in the distance of the scanned points of the surface to be tested from the reference line being measured, characterized in that the The target reference line is continuously calculated in advance as a function of the rotary movement of the rotating body and the externally driven button is tracked accordingly by an electrical follow-up control. 2. The method according to claim 1, characterized in that the target reference line is precalculated point by point. 3. The method according to claim 2, characterized in that the rotary movement of the rotary body digitally in the form of a first pulse series and the linear movement of the probe are also measured digitally in the form of at least a second pulse series and that each pulse interval of the first pulse series is compared with the second pulse series and in Depending on the comparison result, the button is tracked. 4. The method according to claim 1, characterized in that the reference line is calculated in additional dependence on predetermined data. 509819 / 01S 1 J). 5. Device for carrying out the method according to one of the preceding claims, with at least one parallel or at right angles to the spatially fixed axis of rotation of the rotating body linearly displaceable carriage on which the button is arranged, characterized in that the slide (15) carrying the button (18) with a own, the longitudinal movement of the carriage (15) generating Drive source (17) coupled and the rotating body (5) and the carriage (15) each with its own transducer (21, 26) are coupled, one of which (21) for the rotary movement of the rotating body (5). and the. other (26) emit electrical signals characteristic of the linear movement of the carriage (15), and that one processes the signals characteristic of the rotary movement of the rotary body (5) and a computer (33) emitting output variable corresponding to the reference line is provided, the a follow-up control unit (36) is connected downstream, which the output of the computer (33) and the signals characteristic of the linear movement of the carriage (15) are supplied and the resulting one influencing the drive source (17) of the carriage (15) in terms of tracking Derives manipulated variable. 6. Apparatus according to claim 5, characterized in that the transducer (21) of the rotating body (5) and the transducer (26) of the carriage (15) each have electrical signals in Form of pulse trains containing a number of discrete pulses generate, of which the linear movement of the carriage (15) assigned pulse series has a higher pulse repetition frequency having. 7. Apparatus according to claim 5 or 6, characterized in that - 16 5098 19/015 1 ' that the computer (33) is optionally programmable from the outside is. 8. Apparatus according to claim 6 or 7, characterized in that that the transducers (21, 26) are followed by pulse counters (28, 30), of which the one for the rotary movement the rotary body (5) characterizing pulses counting counter (28) via the computer (33) and the for the linear movement of the carriage (15) counting pulses counting counter (30) directly a respective downstream memory (35; 32) feed and that the content of the two memories (35, 32) through an associated comparator (37) of the follow-up Control unit can be compared digitally with one another and the comparator (37) as a digital / analog converter acting control part (38) is connected downstream, which depending on the comparison result, an analog control signal outputs as a manipulated variable to the drive source (17) of the slide (15). 9. Device according to one of claims 5-8, characterized in that the slide (15) carrying the button (18) a second slide (11) which is linearly movable at right angles to its direction of movement is also arranged bring about its own linear movement of the slide (11) Drive source (13) as well as its own transducer (2 4) are assigned and that for the linear movement of the second Carriage (11) characterizing signals of the assigned Sensor (24) also of the follow-up control unit (36) are supplied. 10. Apparatus according to claim 9, characterized in that the transducers (2 4, 26) of the two carriages (15, 11) each its own, its own target reference line that calculates in advance 509819 / 01-51 Computer (33) is assigned and that the button (18) simultaneously along both, in two on top of each other right-angled planes extending reference lines can be tracked. 5Ö9B19 / Ö1S1 Blank page