DE2823946C2 - Troubleshooting and analysis device for pneumatic-logic circuits - Google Patents

Description

hl) voltages above and below the reference voltage is different.

9. Device according to one of the preceding claims, characterized in that the p / e converters (41 to 50) amplifier input stages (56) with high pressure-power amplification connected upstream are.

The invention relates to a device for troubleshooting and error analysis for pneumatic-logic circuits, which comprise a plurality of logic circuit elements, which are formed by logical combination of pulse-shaped Pressure input signals Pressure output signals for actuating actuators of a control or Generate control device.

Pneumatic-logic circuits which function as electronic-logic circuits analog are, are now widely used to control work machines, which by means of pneumatic Have diaphragm and / or piston actuators actuatable actuators. If the signal pressure is high enough the output signals of the logic circuit, these can then be used directly to operate the actuators will. The use of pneumatic logic circuits and control devices is particularly recommended when you use electrical control devices, for example for reasons of explosion protection have to do without. Special applications are therefore z. B. in automatically controlled painting systems Automotive industry as well as large-scale chemical process engineering systems. The one for The application of pneumatic-logic circuits can be very complex and numerous logical circuit elements and assemblies composed of such comprise, by logical Linking of input pressure pulses, which are the carriers of various information such as start commands, Feedback, control data and the like, the pressure output signals required to control a system produce.

Now occurs in such a circuit at one of the logic circuit elements, which are predominantly as pneumatically controlled multi-way valves are formed, for example for reasons of mechanical wear Errors manifested in this result in output pulses on one or more output signal lines fail or "wrong" impulses occur, so is in the Usually it is not possible to see which circuit element is working incorrectly, as there are a large number of such circuit elements are involved in the generation of an output signal pulse. In most cases, therefore, one is when you have to locate a faulty circuit element, relying on dismantling the circuit and a large number of candidate components individually with a suitable testing device Check functionality. This type of troubleshooting is of course tedious and because of the corresponding long periods of standstill of the system or machine controlled by the circuit also associated with considerable losses.

The object of the invention is therefore to provide a device that can be used in the manner of a troubleshooting and analysis device To provide logic circuit devices that are simple to operate, i. H. with a minimum of Dismantling effort a reliable function over-

Testing of sub-units and / or individual components the circuit allows

This object is achieved according to the invention in that at least a number of the signal output lines the circuit elements can be connected to stub lines to which the p / e converters are connected, which generate an electrical output signal characteristic of the pressure in the stub lines, and that recording means are provided which correlate the electrical output signals records.

The device according to the invention works with a parallel tap and simultaneous recording pressure output signals occurring at different points in the circuit, one for the function the circuit is given a characteristic pulse diagram which corresponds to the number of taps Number of pulse trains included By comparing this pulse diagram with a correct one Function of the circuit recorded pulse diagram can then be determined immediately, in which part the circuit has malfunctioned. If a "wrong" signal occurs at a certain tap, then, as a rule, the output signals of those downstream assemblies are also the pneumatic-logic Circuitry that logically link this "wrong" signal with other signals, with errors afflicted, d. H. the fault in the circuit is when faulty signals occur at several tapping points, in front of the first tap point, seen in the signal flow direction, at which a faulty output signal is to be found is produced.

Of course, all those modules whose output signals are the input signals of the structural unit monitored at the specific tapping point are to be included in the troubleshooting process, i.e. in the case of mutual interlocks or the like, also the modules downstream of the monitored module, insofar as their output signals are again input signals for the directly monitored assembly are used. It goes without saying that the localization of an assembly or a component of the logic circuit is only possible if the tapping points are arranged in such a way that both their input signals and their output signal are monitored. This means that with a given number of tapping points, the areas of the circuit which may be considered for a malfunction are more extensive the smaller the number of tapping points is. Nevertheless, the device according to the invention greatly simplifies troubleshooting, since a minimum number of tapping cells and their arrangement can always be selected according to the complexity of the overall circuit - measures that are similar to those of the pneumatic-logic circuit technology familiar person skilled in the art based on his specialist knowledge - that the circuit is divided into sub-units by the tapping points in such a way that all input and output signals are monitored for at least some of these sub-units. The most effective arrangement of the t> o points is then in all Ri 'the one in which the probability of an error occurring in a circuit unit connected upstream of a tap point is the same for all the taps. As hereinafter the Abgriffslellen are to be arranged, is then detected using the h ^r> Schaltungsaiifbaiics easily.

It is particularly advantageous if the pneumatic / electrical converters and the drawings are correct form a unit combined in a common housing, each with one of the pressure inputs the converter is provided with communicating connections to those of the tapping points of the circuit outgoing flexible pressure lines can be connected. Such a unit can be used as a portable troubleshooting and analyzer be designed for troubleshooting a wide variety of pneumatic controlled systems can be used. According to a preferred embodiment of the invention are T-pieces are provided at the branch points of the logic circuit, their to the p / e converter Connectable branches facing away from it can be shut off, for which purpose they can be operated manually Shut-off valves can be provided which are closed during normal operation of the circuit. You can then also use a troubleshooting device according to the invention that has fewer signal inputs than there are a total of taps on the circuit, examine them completely by looking at the connects individual signal inputs of the device in groups one after the other with different tapping points. Although this increases the amount of work required for troubleshooting, for this, however, the fault-finding device can be constructed very simply and can therefore also be manufactured cheaply. It is also not 'absolutely necessary that the tapping points of the circuit by permanently built-in T-pieces are realized with lockable branching branches. Rather, it is also possible to use the T-pieces only in the Insert case into the circuit; the branches of the T-pieces branching off then do not have to be separated be lockable.

Since it essentially corresponds to the mode of operation of a logic circuit in troubleshooting It depends on the determination of whether certain pressure signals can occur at the right time provided as a p / e converter to a lower limit value of the signal pressure responsive signal converter be, which at pressure values above this limit value with a first constant voltage signal high (or low) signal level and a second constant voltage signal for pressure values below this limit value output with a low (or high) signal level.

Converters suitable for this purpose can be of very simple construction and are more expedient Embodiment of the invention under the influence of the signal pressure against an elastic restoring force movable encoder part. which actuates an electrical contact device via which a recording voltage is sent to a transducer assigned to the respective transducer Input channel of the recording device can be applied. A counter is suitable as a movable encoder part the restoring force proportional to the stroke of a helical spring of a displaceable piston, the one acting as a microswitch trained end position switch is actuated, but also an elastic one that arches under the signal pressure Membrane or an elastic membrane that bulges under the signal pressure or one under the Signal pressure lengthening bellows, which from a certain camber or extension stroke on close an electrical contact via which the drawing voltage is then applied to the respective input of the Recording device is present. It is again useful if the recording voltage is in turn can be selected and fixed, so that the output voltage level of the p / e converter is simple

for a clear recording by the recording device, for example a multi-track recorder, required values can be set.

It is also advantageous if, in a further embodiment of the invention, the pressure limit values to the Address p / e converters, can be selected and preset, be it by the fact that the elastic restoring force can set suitably or by the fact that the necessary for the actuation of the electrical Kontakteinrichlungen Stroke of the movable encoder part can be changed. You can then the invention Troubleshooting device to different working pressure values of the in connection with the logical Circuit used pneumatic auxiliary power system adjust.

You don't just want to find out when an error has occurred in the pneumatic-logic circuit, but rather also track signs of wear in order to repair or maintain individual circuit elements if necessary to be able to make before an error actually occurs, then it is advantageous if, according to a In another embodiment of the invention, the p / e converter is a signal pressure analog, in particular electrical voltage output signal proportional to signal pressure generate so already from the height of the signal level and / or from the edge shape the signal pulse edges draw conclusions about leaks in the signal lines of the circuit and / or Changes in the friction conditions in the case of movable ones Parts of the circuit elements can be drawn.

If you also see comparison devices before which the electrical output signals of the converter with a Compare specifiable fixed reference voltage and generate a constant voltage signal as a recording signal, its level for output voltages of the converter above and below the reference voltage is different, then you can use electrical means to adapt the troubleshooting device to the different possible output signal pressures, which in many cases is easier than a mechanical one Adjustment of the preload of return springs or a minimum stroke required for making contact.

In all of the aforementioned cases, it is advantageous if the p / e converters are used as an amplifier with a high power gain trained F.input stages are connected upstream so that the pneumatic circuit through the Picking up the pressure signals is not significantly loaded.

Further details and advantages of the invention emerge from the following description special embodiments based on the drawing. It shows

Fig. 1 is a simplified block diagram of an inventive Device for troubleshooting and analysis of pneumatic-logic circuits,

Figure 2 shows details of a signal tapping and recording system the device according to FIG. 1 with p / e converters and a multi-track recorder for Recording of the converter output signals,

3 shows, in a simplified, schematic representation, the structure of the p / e converter and the recorder according to Fig. 2, which can be used within the framework of the device according to FIG Pressure output signals occurring at several pick-off points in a pneumatic-logic circuit. in a view from nhcn.

F i g. 4 shows the front view of the front panel of the device according to FIG. 3.

A pneumatic-logic shown schematically in FIG. 1 Circuit 10 is a part of a more extensive circuit, otherwise not shown in detail for controlling a production plant, for example a paint shop for automobiles. She has seven Inputs 11 to 17 for pulsed pressure input signalsc, which are the carriers of input information such as

ίο initial position reached, rinsing process ended, color selection made or the like. By their logical combination at output 18 of circuit 10, a pressure output signal is generated that is either used as a control signal, for example as a start signal for a new painting process, or is processed into a control signal in a downstream circuit unit only after logical connection with other pressure signals. The output stage of the sound system 10 is a two-input AND element 19, which combines the pressure output signals of a first sub-unit 21 and a second sub-unit 22 of the circuit 10, which in turn are linked by logical combination of the pressure occurring at the inputs 11 to 17 -Input signals each generate a pressure output signal. The two sub-units 21 and 22 each have five inputs 11 to 14 and 23 or 15 to 17 as well as 24 and 25 and comprise a plurality of pneumatic-logic circuit elements, not shown, which can be designed as multi-way valves, check valves or the like and combine the input signals of the two sub-units 21 and 22 to form an output signal each. At its fifth input 23, the first sub-unit 21 receives the output signal of the second sub-unit 22 as an input signal and is in this respect connected downstream of it. The second subunit 22 receives the same input signals at its fourth and fifth inputs 24 and 25 as the first subunit 21 does at its third and fourth inputs 13 and 14, so that the two subunits are also connected in parallel to this extent. The subunits 21 and 22 generate a high level output signal for certain combinations of high and low level pressure input signals and a low level pressure output signal for other combinations of such input signals, while the AND gate 19 generates a high level output signal. Level pressure output signal is only generated when an input signal with a high pressure value is present at its two inputs 26 and 27. The correct operating state of the circuit 10 is accordingly determined by a rVJfri » \ ir \ n Λ HCiTfOn (TC. Onii ^ L-imniilci ^ n Un Al * n AliCCTÜntTPn

1 Ul £, <- TV ·. I »UJ £, U (>_& .J m ^ M U, - ·» · I «'f ~.>. * ~" - ·· · - · -— _{O O}

28 and 29 of the first and second sub-units 21 and 29 of the first and second sub-units 21 and 29, respectively.

22 and at the output 18 of the circuit 10.

If an error occurs in circuit 10, then is

based on the changes in the pulse sequence at the output 18 of the sound and their correlation with the different input signal combinations at the inputs 11 to 17 of the circuit in general not can be seen in which part of the circuit the error occurred. In case of malfunction of the pneumatic-logic circuit 10 to be able to quickly localize the faulty component or

t> ^r · at least to be able to limit the source of the error to such an extent that a dismantling of the shell 10 to a partial area, which is then still required for the final localization of the defective component

remains limited, are in the special embodiment according to FIG. 1 of the inputs 11 to 14 of the first sub-unit 21 and from the inputs 15 to 17 of the second sub-unit 22 as well from the outputs 28 and 29 of the two sub-units and from the output of the AND gate 19 branching off Branch lines 31 to 40 'are provided. Via these, p / e converters 41 to 50 receive the inputs 11 to 17 and 23 to 25 of the subunits 21 and 22 or at the inputs 26 and 27 of the AND gate 19 and signal pressures occurring at the output 18 of the circuit 10 and generate characteristic for them Voltage output signals, which by means of a ten-track recorder 51 continuously or from time to time recorded simultaneously.

In the example shown! hai man three Circuit units, namely the subunit 21 and 22 and the AND gate 19, for both all Input signals as well as their output signals are monitored. Since you have the output signal behavior knows these circuit units for all possible input signal combinations, can be derived from the simultaneous immediately read recorded input and output pulse diagrams in which of the three circuit units 21, 22 or 19 an error has occurred, if the circuit 10 is malfunctioning overall.

For tapping the at inputs 11 to 17 and outputs 28, 29 and 18 of subunits 21 and 22 or 19 of the pneumatic-logic circuit 10 occurring signal pressures are shown in the FIG. 1 apparent arrangement T-junction pieces 52 provided, of the branching branches 53 to the Converters ti to 50 leading stub lines 31 to 40 go out, which for simplification together with the Reference numeral 54 should be provided, which is shown in FIG. 2 solely to explain the arrangement of the Branch lines are used.

The p / e converter 41 to 50, these upstream Input stages 56 and the ten-track recorder 51 are accommodated in a common housing 57 and thus combined to form a transportable device 58, the structure of which is based on the following the F i g. 2 and 3 are explained in more detail:

The input stages 56 each have a pressure supply input 59 with which they are connected to a supply line 61 of a pneumatic auxiliary energy system are connected, which is responsible for the control of the Converter 41 to 50 provides required pneumatic energy, and a signal input 62 at which the the signal pressure tapped is present. The input stages 56 are pneumatic switches or in the Saturation powered amplifier designed, ar. whose Outputs 63 the working pressure of the auxiliary power system is present if and for as long at their signal input 62 there is a signal pressure which is greater than a certain lower limit value The output signal level of the input stages 56 is high as long as a logical one is present at their signal input 62 is and low as long as a logic zero is present, the p / e converters 41 to 50 include in a special embodiment a pneumatic piston which, under the influence of the high output signal pressure of the input stages 56 a switch designed as a microswitch is operated as long as the normally open contact is active which is movable against the action of a return spring in its one, the low output signal pressure corresponding position is the assigned voltage signal input of the ten-track recorder 51 grounded; in the other position of the normally open contact corresponding to the high output signal pressure above this is a high auxiliary voltage suitable for recording at the recorder input at. In the embodiment of the device 58 described, the recorded information is "digital"; H. ultimately on the information: functions correctly and incorrectly limited. When using input stages and / or p / e converters that are connected to the Taps of the logic circuit 10 deliver proportional output signals, can be from the level of Output signal level and the form of the signal provide additional information on the degree of wear of individual components the circuit and, if necessary, recognize the possibility of an error before it actually occurs.

The structure of the ρ / ε converter 41 to 50, whose Input stages 56 and debugger 58 comprising ten track recorder 51 is best can be seen from FIGS. 3 and 4, the details of which are expressly referred to. the p / e converters 41 to 50 and their input stages 56 are in the manner shown in Figure 3 in two parallel Arranged in rows of five and fastened with brackets 64 pivotable upwards to stretching rods 66, which are in the Distance from the housing base 67 are attached to this via feet. The p / e converters 41 ... are on the Input stages 56 put on. The pressure supply line 61 according to FIG. 2 for the input stages 56 includes two composed of pressure hoses 67 and 68 and T-pieces 69 supply branches, which from one Go out distributor head 71, which is also pivotally clamped to a bracket 72 between one of the Front plate 73 of the housing arranged connection sleeve 74 for the compressed air supply and the input 76 of the distributor head 71 are a maintenance unit 77, a pressure reducer 78, connected in series and a valve 81 which can be actuated manually by means of a toggle handle 79, with which the supply of compressed air to the distributor head 71 can be shut off or released for the compressed air supply to the The output pressure required for input stages 56 is by means of a through the front plate 73 led out Knurled screw 82 adjustable and readable on a manometer 83. If the device is activated by activating the The compressed air supply by means of the valve 81 is ready for operation shows one of the output pressure of the valve 81 acted upon display device 84 a green field of view and a red when the valve 81 is blocked Connection of the signal pressures to be monitored leading branch lines 54, which are preferably as flexible hose lines are formed, ten connection sockets 86 are provided on the Fror.tplatte 73, of which pressure hoses 87 lead to each one of the signal inputs 62 of the input stages 56. the Outputs 63 of the input stages 56 are via short U-shaped pressure hoses 88 with the pneumatic Inputs of the pneumatic-electrical converter 41 ... connected. The bushings for the electrical Auxiliary voltage supply lines and output signal lines 89 and 91 of converters 41 ... are located at the top. These electrical lines 89 and 91 are protected, so laid in pipes 92 are arranged so that the transducers 41 ... are easily accessible from above.

Based on the FIG. 2 to 4 explained troubleshooting device 58 is designed for simultaneous recording of a maximum of ten pressure output signals however, a relatively small monitoring capacity is sufficient

for most applications, since the device 58 can successively connect to different groups of meters of tapping points. The one to tap the Signal pressures required T-junctions 52 can either only then be used in a to be examined

10

Circuit can be inserted if an error has to be found, in particularly "neuralgic" places a circuit can also be provided from the outset; in this case, of course, the branches of such T-pieces can be shut off for normal operation.

For this purpose 3 sheets of drawings

Claims (8)

Claims: 10 15 20 25 30 1. Device for troubleshooting and analysis of pneumatic-logic circuits, which have a plurality of logical circuit elements, which are created by logical combination of pulse-shaped Pressure input signals Pressure output signals for actuating actuators of a control or Generate control device, characterized in that at least one number the signal output lines of the circuit elements (19, 21, 22) stub lines (54) can be connected are connected to the pneumatic / electrical converters (p / e converters) (41 to 50), which generate an electrical output signal characteristic of the pressure in the stub lines (54), and that a recording device (51) is provided with which the electrical output signals are continuously registerable. 2. Apparatus according to claim 1, characterized in that the p / e converter (41 to 50) and the Recording device (51) a structural unit combined in a common housing (57) (58) which each communicate with one of the signal pressure inputs (62) of the transducers Connections (86) is provided, to which from the tapping points of the circuit (10) outgoing flexible Pressure lines (54) can be connected. 3. Apparatus according to claim 1 or 2, characterized in that the individual tapping points logic circuit T-pieces are installed, which can be connected to the p / e converter (41 to 50) branches branching off can be shut off. 4. Device according to one of the preceding claims, characterized in that as p / e converters (41 to 50) signal converters responding to a lower limit value of the signal pressure are provided that a first voltage output signal at pressure values above this limit value with a constant signal level and a second for pressure values below this limit value Generate a voltage signal with a constant signal level different from the first signal level. 5. Apparatus according to claim 4, characterized in that the p / e converter (41 to 50) a below have the influence of the signal pressure against an elastic restoring force movable transducer part, the an electrical contact device is actuated, via which an auxiliary voltage is used as a recording voltage at an input channel of the recording device (51) assigned to the respective transducer can be applied. 6. Apparatus according to claim 4 or 5, characterized in that the pressure limit values on the the p / e converters respond, can be selected and predefined. 7. Device according to one of the preceding 'claims 1 to 3, characterized in that the p / e converter a signal pressure analogous, in particular Generate an electrical voltage output signal proportional to the signal pressure. 8. Apparatus according to claim 7 or b in conjunction with claim 3, characterized in that that comparison devices are provided which the output voltages of the converter with a Compare a predefinable fixed reference voltage and use a constant voltage signal as the recording signal whose level for output 40