DE2035102A1 - Method and device for determining defective or incorrectly assembled components in structural units of power transmission systems for motor vehicles - Google Patents

Description

8 Munich 5, ¹ ^ _z ^{July 197} °

/> Erhardtötraße 11 H / Z

S & cftä.-On #. CatA OSoeftke Telephone 240 675 203-5102

Patent attorneys

Internationational Harvester Company 401, North Michigan Avenue
Chicago, Illinois 606ll (V, St ₀ A.)

Method and device for the detection of faulty or incorrectly assembled components in units of power transmission systems for Motor vehicles

The invention relates to a method and a test device used to carry out this method to identify faulty or incorrectly assembled = th components in structural units of power transmission systems for motor vehicles using an inertia control = erten measuring head by acting on the measuring head with the Vibrations and oscillations of the driven, to under = searching unit.

In the manufacture of power transmission systems and, in particular, of drive units , the problem has always been to reduce the running noise and the resulting vibration of the finally assembled unit to a minimum Part of the final quality control »

So far for this purpose, the motor vehicle is subjected to a road pavement in the fully assembled .Zustand by under the usual. Las «conditions the running noise, for example the

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Transmission is observed by listening and a particularly loud running noise can be sen a defect in the transmission sehlies = · Similarly, process when the accelerator = convincing is brought to a test rig and its wheels driven under idling or load '

In both cases, however, it is not possible to distinguish whether particularly high running noises are due to "whether a faulty component has been used or the components have been assembled incorrectly." which point the au examined assembly could comprise a De = fect * lip are generally such sub = is examination methods subjectively influenced _s may 'be Furthermore therefore incorrectly evaluated and judged, the expansion of a defective assembly is costly itemi a De = fect actually recognized ₉ ». - ""

Other procedures ssur finding ¥ öe irregularities ^,. For example, in Get3? iefo @ unit © n _s require highly sensitive measuring devices that have to be individually adapted to each component to be examined ^. ■ - "■" Gear unit with it _{s in} order to be able to analyze the spectrum of the running noise »In any case, the setting up and measuring require an expenditure of time that it. forbids such ^: investigation methods on a running assembly line

Also known are methods for analyzing the generated Fr © = - sequences or frequency bands of the noise spectrum. Also known is the investigation of Gefcj? I © foe @ inh © it @ n due to torsional vibrations by means of the only rotational motion detection © this investigation amettoÄea b3? Iraggin S © fewi © ability © si when adapting to a iiodera © Fließfeandlc © fet @ pit. see and require the exact adjustment of the

the structural unit to be examined by trained operator = personal, which ultimately limits the use of such examination methods or only restricts it to individual cases

With the present invention the task is pursued, while avoiding trouble-prone, complicated drive devices and bypassing tedious to build Measuring devices a method and its implementation to create a corresponding test device with which Help it is possible that of a fully assembled unit one of the power transmission systems of a motor vehicle inherent running noises in a simple manner by means of a The inertia-controlled measuring head can be scanned at any point on the unit and converted into electrical signals The signals obtained in this way are to be displayed at the output of the test device by a single measured value can be, so that even untrained workers have it in their hands to determine a defect in the assembly and this unit for further processing on one To be able to hold back the assembly line · It is intended for this decision Initially, it does not matter whether the defect is due to the Ver = The turning of a defective part or a faulty assembly

This object is achieved according to the invention by a method solved in which the structural unit is powered by its own motor driven at constant speed while idling and that running noise from rotating parts caused by the on a part of the unit detachably attached measuring head is detected, which converts the running noise into electrical signals converts whose peaks obtained by rectification = amplitudes above an adjustable level amplified and a calibrated reading device, the deflection of which both the set reference level as also the run above that assigned to this reference level = noise recorded residual level can be recognized.

009836/0262

In a preferred embodiment of this method, the vibrations and oscillations of the running noise are used as the measured variable assigned acceleration components are used

The test device for carrying out this method comprises the measuring head with a transducer, which is one of the measured variables analog and proportional voltage generated, which is fed to a switching group controlled in its response time, in which a display and compensation stage contained therein, an amplifier, a rectifier and a peak detector in Series are connected to the input signal with an adjustable reference voltage in relation and in comparison to bring which corresponds to a predetermined running noise level, and that a display device is provided which both the set reference level as well as the running noise above the running noise assigned to this reference level Shows residual level

By this method and using the fiction = According to the test device, quality control is possible directly on the assembly line, with the device only going through once pre-determined values must be calibrated and any further deflection of the display device for defects of the examined structural unit can be closed.

The invention is illustrated in the drawing on the basis of exemplary embodiments and described in the following the drawing shows:

Fig. 1 in a perspective view of the drive of the test device according to the invention in force = close connection with a drive differential;

2 shows the drive of the test device according to the invention in an enlarged perspective view in positive connection with the transmission of a motor vehicle;

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Pig · 3 in a perspective view of the Vibration transducer attached to the object to be examined on an enlarged scale;

Pig, 4 the external structure of the test according to the invention direction in a front view j

Figo .5 in an electrical block diagram of the on = take the measurement signal, its evaluation and its display serving Sehaltgruppe;

Fig. Β in an electrical circuit diagram for the regulation the switching group according to FIG. 5 and to drive the Assembling the object to be examined

The test device according to the invention can be used for analysis of vibrations, for example in vehicle = driven, vehicle differentials and generally in power over = bearing parts between the engine and wheels of a vehicle set to identify defective parts of the assembled unit or errors in assembly based on the analysis result = to know. The use of the test according to the invention = fixture takes place primarily on the * 'assembly line itself, * where "Such vehicle parts are assembled", the test of one assembled unit, is carried out with the corresponding part idling. He serves first and foremost. for quality control of a fully assembled unit "-

.Fig. 1 shows the use in a differential of an in. one. Axle housing 11-built-in drive axle, for example = way of a-farm tractor 10 * The test becomes, thereby a = directed, that -first the- to be subordinate gear parts be released from the clutch and then 'mile 13 of the Drive axis by means of a; usual air motor 12 *. is driven · The resulting from the rotation of the shaft = existing vibrations and. Vibrations /. Regardless of whether these

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are normal or due to irregularities in each other due to the rotation of meshing parts are transferred to the bearing through the rotating parts Housing 11. If the structural unit to be examined is properly assembled from faultless individual parts, the The running noises generated during rotation are always the same, regardless of the direction of rotation. However, it is a defective one Component has been used or the assembled unit has been incorrectly assembled., Cause the the vibrations and oscillations caused by this, a high level of running noise or other irregularities, depending on the Deviation from the normal running range a measure of the species or the extent of the defect

The accelerations assigned to the vibrations and setoings of the running noise are used as the measured variable, or their frequency distribution in one of - © inem. normal = spectrum deviating from the spectrum (Vibratory Hoise spectrum.)

This measured variable is voss a © M Idebar with the housing 11 be = consolidated, responding to such stripping components and transferring these into electrical quantities = recipient 14 recorded

2 illustrates a further possible use of the test device according to the invention by driving a gear 15 in idle by means of the air pressure motor 12 and detecting the running noise by the transducer 14 _{or the detachable connected to the housing}

The processing of the measured value _{D obtained,} its evaluation and the control of the Druskluftmotorantfiebes © ^ follow in two content groups 17 mod 18, ä @ F © n circuit diagram »? the Pig · 5 and β reproduce «The tefseiwaep 14 is over! ³ <s ± ne line 24 with a control circuit 16 and dessea lusgaag via a line 31 to the input of the as

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acting switching group 17 connected · The other switching group 18 forms the control device whose built-in time = switch to determine the test time as well as the duration and direction of the rotation of the air motor, and this under Coordinate with switching group 17

Fig. 3 shows the transducer 14 in the detachably attached state. The measuring element itself is inertia = in a known manner controls, i.e. that of a vibration or oscillation = indwelling inertial forces in a converter 22 Tensions that cause the vibrations and oscillations to = fundamental accelerations are proportional · The measuring element does not show one in the drawing = Provided ceramic body and is together with the converter 22 via a transferring the accelerations relatively stiff carrier 19 by means of a quickly releasable Screw bolt 23 connected to the housing 20, for example the gearbox = bes «It has been found here that the Sensitivity to vibration and oscillation acceleration i = in the transfer to the transducer straight through the Interposition of the carrier 19 can be improved In addition, this type of fastening ensures that the transducer can be attached and removed more quickly.

The control circuit 16 connected downstream of the pick-up 14 converts the received input signal into a corresponding voltage, depending on whether this input signal can be traced back to an acceleration, a speed or a displacement of the vibration, which is complex in itself is. The output signal of this control circuit 16 then gives an identifier for the acceleration and Ge = speed components of the recorded complex vibration as an output variable for further processing and Evaluation·

009886/0262

This output signal is fed via a coaxial cable 31 to a display and compensation stage 30, which the Output of the control circuit 16 below one adjustable residual voltage, which is used as a measure of the deviation, for example, from a normal Ge = noise level is to be seen in a perfectly functioning unit.

The output of this stage 30 is via a switching device 40 connected to a linear amplifier 36. The switching mode = direction 40 is used either for manual or to an interruption of the output of the controlled by the switching group 18 in a predetermined switching cycle Step 30 with the other switching elements of the switching group 17 · To adapt the respective impedances is between the switching device 40 and the linear amplifier 36 a voltage divider consisting of two resistors 41, 42 intended.

The linear amplifier 36 is followed by a full-wave rectifier bridge 44 which converts the preamplified signals into Converted DC voltage signals, the size of which is a measure of the amplitude of the amplified input signals, which above = half of the basic level preset by level 30.

The rectifier bridge 44 is grounded on one side. Your plus = pole is also connected to input 41 of a DC voltage amplifier kers 50 is connected via a diode 48 located in the direction of this amplifier.

A capacitive network 54 sensitive to voltage peaks is connected between diode 48 and input 51 at 53, which contains a capacitor 60 grounded on one side, which can be switched off and controlled by a combination of resistors 61, 64 is bridged. By adding this resistance =

009886/0262

combination becomes the. charged by the voltage peaks Discharge capacitor 60 to a certain value · The Discharge time can be regulated by setting the resistor 64 designed as a potentiometer, which is between Ground and the negative pole of a DC voltage source 70 ge = is laid. The switch 62 between the resistors 61 and 64 is normally open and can currently be sehlies = sen.

The output 71 of the DC amplifier 50 is fed back through a diode 73 m to a further input 52 and connected to this Henden with a connected between the negative pole of Batterie70 mass and of two resistors 68, 69 = best voltage divider.

With the forward direction of the diodes 48 and 73 shown in FIG. 5, the amplifier 50 has the property of a proportional tional amplifier whose voltage at the output 71 is almost equal to = is as large as the voltage at input 51 · Due to the slight discharge of capacitor 60, however, the input impedance is of the amplifier 50 large, whereas the output impedance is low, so that a consumer with low impedance _

can be connected »Insofar as the amplifier ™ allows 50 has a uniform signal amplification, but has a high power amplification «

The display device contains a MiIIi = grounded on one side ammeter 75, the other pole of which has a diode 78 and a Resistor combination is connected to the output 71 of the DC voltage = amplifier 50 · The resistor combination is from a resistor connected in series with the diode 78 and a resistor connected to this for the sensitivity setting = nenden calibration potentiometer 77 is formed. According to the voltage amplified in the amplifier 50, the milliammeter becomes 75 indicate an analog current flow which serves as a measure for the acceleration components of the noise spectrum.

009886/0262

The second switching group 18 contains, as FIG. 6 shows, a switch 80 connected to a conventional power source closed loop. One of the two lines 83,

84 is connected to a normally closed push button switch a

85 placed, behind which a changeover switch 86 and a normally open push-button switch 87 branches off "Behind this switch 87 there is an electrically operated timer 90 and another normally open switch 91 switched" The switch 87 is bridged by the timer contacts 92, 93, from where contact 92 is normally open and contact 93 is normally closed. In the closed position of switch 91, a control relay 94 is energized at the end of lines 83 on the one hand and 85, 89 on the other hand, to which normally open contacts 95 are assigned, which bypass switch 91.As soon as a line 101 branching off from line 89 is energized, voltage is applied to the coil of a magnetically controlled air valve 10O ₉ whereby the normally- in reverse direction. held control edges of the valve are moved in the flow direction

The changeover switch 86 provided behind the switch 85 switches either the circuit via one or the other three directions of the Compressed air motor indicating lamp 104 or a lamp 106 indicating the other direction of rotation of this motor and the same = the power supply to a magnetically actuated four-way valve 105 is switched on at the same time.

The switching device 40 in the switching group 17 comprises in the one of the two lines you control time switch 90 1st and normally open contacts 107 in series with normally closed contacts 96 of the control relay 94. The closing and opening of the two contacts 107, 96 ■ ' causes a connection to be established between the display and compensation stage 30 and the linear amplifier 36 and at the same time causes switching on and termination

009886/0262

of the air motor drive. Both contacts 96 »107 can be bridged by a manually operated switch 110 when the device is calibrated or when a special object is to be tested outside of the series examinations , ■;. '., ■'

The drive of the air motor 12 is by the Switching group 18 triggered, magnetically controlled valve 100 switched on and off and also by the magne = table-controlled four-way valve 105 controlled with regard to the direction of rotation · Both valves are one behind the other and are in the vicinity of the air motor 12 arranged · The connection to the motor is made by the pressure = air source 111 from first via the valve 100, then via the line 113 and in the rest position of the valve 105 via path 114 within valve 105 and line 115 to motor 12 and back via line 116 and the path 117 inside the valve 105 into the open atmosphere. In this valve position, the motor 12 is in the forward mode driven.

When the motor 12 is driven backwards, the control edges with the paths 118, 119 in the valve body 105 are in the position offset, in which the paths 114, 117 were connected to the lines 113, 115, 116 during forward operation · The pressure = air then passes from line 113 via path 119 the line 116 to the engine 12 and back through the line 115 and the path 118, into the open

It has been shown that certain assembly defects only occur in in one direction of rotation of the motor, but not in the other direction of rotation · Also from this Fact, conclusions can be drawn about the type of defect. It has also been shown that certain others Defects when assembling a unit to be examined or when using defective parts in one direction of rotation

009886/0262 ■

of the motor has a larger deflection than in the other direction of rotation result. From this, too, certain conclusions can be drawn and damage can be localized by For example, shims on the rotating parts can be removed or added and the measurements under constant observation of the displayed values in both directions of rotation of the motor.

Except for the valves 100, 105, the motor 12, the converter 22 and the control circuit 16, all other parts of the Switching group 18 housed in a housing 120, as illustrated in Fig. 4

The test device according to the invention works as follows:

In the case of the structural unit to be examined, the transducer 14 is first attached to the associated housing 11 in the manner shown in FIG. type shown attached. The compressed air motor 12 is then rotationally fixed with the shaft 13 *, for example the drive axle tied together. After the AC network and the DC voltage source JO have been switched on, the switch 80 becomes the Switching group 18 actuated, whereupon the lamp 104 the readiness of the compressed air motor 12 for forward operation on = shows, as long as the valve 105 is in the position shown in Fig. 6 and remains de-energized. Will the switch be 8? depressed, the timer 90 is included in the circuit and begins its switching cycle o Within contacts 92 and 107 are closed during this cycle. Since normally the contact 93 remains closed, is after pressing the switch 87 over the now closed = its contacts 92, 93 bridged during the switching cycle, so that the switch 87 can now be released. Since now the line 89 with the line 84 in electrical Is connected, the valve 100 is via the line 101 moved in the flow direction for the compressed air, so that this

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is connected to the motor via the paths 114, 117 and drives it in the forward direction. Immediately after the switch 87 has been actuated, the switch is also momentarily closed, so that the relay 94 is immediately energized, which successively the contacts 95 and 96! closes. The short-circuit of the contacts 95 bridges the switch 91, whereas the closed contacts $ 6 in the switching group 17 establish the connection of the display and compensation stage 30 and the linear amplifier 36 via the contacts 107 already short-circuited by the time switch 90.

Is the unit to be examined incorrectly installed or If it does not contain faultless components, the running noises due to accelerations will be reduced as well the signal corresponding to normal running smoothness from the Compressed air motor driven unit in the converter 22 converted into analog voltage signals and via the control = circuit 16 of the display and compensation stage 30 supplied, where they are compared with a preset reference voltage, for example the normal oscillations corresponds to an intact structural unit. The composite voltage signal passes stage 30 and comes into it Stage to display, while the unit to be examined- ^ is driven at a constant speed of rotation while idling

This composite voltage signal then reaches the Input of the linear amplifier 36 is amplified with the help of this amplifier in its performance and then in the Four-way equidistant 44 rectified. The same span = voltage component passes through the diode 48 into the capacitive Network 54, which only responds to voltage peaks. Immediately before the examination, the switch 62 is set to = pushes, causing the capacitor 60 across the resistor 62 and the potentiometer 64 charges · The potentiometer 64

009886/0262

is then set so that the capacitor 60 charges to such a potential -which- "approximately" = equal to voltage level with normal running smoothness. The up = charge of the capacitor 16 leads to a discharge current, which is to be regarded as a reference value and at the input 51 of the propor = tional amplifier 50 is applied and at its output a ent = Speaking reference voltage appears · With this output = voltage is calibrated via the potentiometer 77, the milliammeter 75 · The relevant deflection then corresponds to the noise spectrum for normal running smoothness with an intact structural unit · generate irregularities in the noise spectrum possibly a multiple deflection at the milliampere = meter 75 · You pass the step in the appropriate size and, after rectification in rectifier 44, arrive at diode 48 with correspondingly high peak voltages Correspondingly, the increase is indicated on the milliammeter 75.

In this way, a relatively untrained operator = person carry out serial examinations on building units, in which the deflection above the zero point in both directions of rotation = The time required for this is very short, possibly 10 to 15 seconds. The time switch 90 is set beforehand to this period of time and its switching cycle in the predetermined Total time ended. This takes place as soon as the contacts 93 open again, which during the holding cycle nor = sometimes stay closed. Since this also causes the relay 94 to be de-energized, the Sehaltvorrieh = is also interrupted device 40 the circuit to the amplifier 36 and the valve 100 blocks the passage of compressed air to motor 12.

Claims 009886/0262

Claims (12)

Patent claims 1. Process for the plagiarism of faulty or incorrectly assembled components in units of the power transmission systems for motor vehicles using an inertia-controlled measuring head by applying the vibrations and oscillations of the driven unit to be examined, characterized in that the unit is characterized by its own motor (12) is driven at a constant idling speed and the running noise originating from rotating parts is detected by the measuring head which is detachably attached to a part of the structural unit and which converts the running noise into electrical signals whose peak amplitudes obtained by rectification are above an adjustable The level is amplified and fed to a calibrated reading device, the value of which reveals both the set reference level and the residual level recorded above the running noise that is ordered above this reference level. 2. The method according to claim 1, characterized in that the acceleration components assigned to the vibrations and oscillations of the running noise as a measured variable or whose frequency distribution is used in a spectrum deviating from a normal spectrum, and that the voltage obtained by the measuring head is proportional to this acceleration component 3. The method according to claim 1 and 2, characterized in that that the generated voltage amplitudes below an adjustable reference level are filtered out or the above = half of this adjustable reference level obtained amplitude values in a compensation stage (30) leave or be selected. 009886/0262 20351 - Io - 4. The method according to claim 1, characterized in that the rectified amplitude peaks to the setting = can be summed up at the reference level 5. The method according to claim 4, characterized in that the amplitudes occurring above the reference level = peaks of that originating from the structural unit being examined Running noise can be measured " 6. Method according to claim 4, characterized in that the examination time in adaptation to the examined The structural unit is limited in a repeatable manner by means of a time switch (90) in a Sehalt cycle, 7 · For individual and serial examinations for determination of faulty or incorrectly assembled components in structural units of the power transmission systems for power = vehicles using an inertia-controlled measuring head by acting on the measuring head with the Vibrations and oscillations of the driven test device to be examined for testing Execution of the method according to claim 1, characterized in that the one on vibrations or Schwin = the complex running noise of the driven Component to be returned component responsive measuring head (14) in a converter (22) one of these components analog and proportional voltage generated, which pulls a switching group (17) controlled in its response time = leads, in which a display and Compensation stage (30), an amplifier (56), a rectifier (44) and a peak detector connected in series are to bring the input signal into relation and comparison with an adjustable reference voltage corresponds to a predetermined running noise level, and that a display device is provided which both the set reference level as well as the remaining noise recorded above the running noise assigned to this reference level * level can be recognized 009886/0262 8. Test device according to claim 7, characterized in that that the adjustable reference level corresponds to that through preliminary tests determined normal running noise of an intact building block = unit corresponds, and that the display device is based on vibrations and oscillations of a defective component or amplitude peaks above normal running noise due to an incorrectly assembled unit indicates 9. Test device according to claim 8, characterized in that that the inertia-controlled measuring head (14) generates a voltage that is only a movement parameter of the together = assigned to the set noise spectrum 10. Test device according to claim 9, characterized in that that the measuring head (14) is essentially one of the accelerations supply component generated proportional voltage, and that an exclusively stress amplitudes of the acceleration = Let component through above an adjustable value = the or selecting control circuit (16) is provided. 11. Test device according to claim 7, characterized in that that the peak detector is an adjustable, an RC combi = nation containing capacitive network (60, 61, 64), to which the reference voltage can be fed and in which the capaci = tive charging depending on the DC voltage component of the amplitude peaks is above the reference voltage, and that the peak detector is a DC voltage amplifier (50) is connected downstream, which responds to the voltage rise above the reference voltage and a corresponding one Output signal generated * 12. Test device according to claim 11 ,. characterized, that the amplifier (50) a downstream DC current = The knife (75) is used as a display instrument for the output signal of the stronger (50). ^ rr 0098 86/0 262 13. Test device according to claim 7, characterized in that that in the switching group (18) a timer (90) before = is seen, the switching on and off of the motor (12) and the reversal of the direction of rotation as well the coupling of the measuring head (14) with the downstream circuits of the switching group (17) in a before = determinable and repeatable switching cycle causes. l4. Test device according to Claim 7, characterized in that the time switch (90) and a relay (94) controlled by it short-circuit contacts (107, 96, 92, 95), of which the contacts (107, 96) can be operated manually Switch (110) _{t can be} bridged for individual examinations. 009886/0262 Blank page