EP0390972B1 - Arrangement and method to detect physical parameters of an elevator - Google Patents

Abstract

The invention relates to a method of detecting physical parameters, in particular motion parameters, of a goods and/or passenger lift, whose car is suspended on a cable pull driven by a driving pulley. It is the object of the invention to propose a test method for such lifts in which there is a reduction in the amount of work by contrast with previously known test methods, while the test quality is simultaneously increased. According to the invention, this object is achieved when the physical parameters of the lift are determined by connecting at least one displacement sensor to the cable pull and/or the driving pulley in order to generate displacement signals, by connecting the displacement sensors to an evaluation unit which contains a time generator, in order to feed the displacement signals to the evaluation unit, and by connecting the evaluation unit to switching points of the control circuit, at which signals are present which control the sequence of motions of the lift, in order to determine physical parameters from the displacement signals and the control signals. The method can be used advantageously to check the drivability of the driving pulley. <IMAGE>

Description

The invention relates to a method for detecting physical parameters, in particular movement parameters, of a goods and / or passenger elevator, the elevator having at least one cable pull guided over a traction sheave, at one end of which a car and at the other end of which a counterweight hangs , is driven by a drive motor controlled by an electrical control circuit and operates on the traction sheave and comprises a braking device connected to the traction sheave and controlled by the control circuit, the physical parameters being determined by connecting at least one distance sensor to the cable pull and / or the traction sheave is to generate distance signals, the distance sensors are connected to an evaluation unit provided with a timer in order to supply the distance signals to the evaluation unit, and by the evaluation unit having switching points of the control circuit at which the Control signals are applied to control the motion sequence of the elevator, is connected.

The background for the present invention is safety checks on goods and passenger lifts. Such lifts must be subjected to regular checks, whereby, for example, characteristic values such as travel paths, braking distances, catching paths and the slip resistance (driving ability) of the cable pull driven by the traction sheave must be determined.

Up to now, the inspection of elevators has required a lot of work, since the effectiveness of the brake and the safety gear had to be loaded onto the elevator with the permissible payload and, when checking the slip resistance, even with at least one and a half times the payload. The loading and unloading of appropriate weights is not only time-consuming, but also involves heavy physical work. There is also the fact that the components of the elevator system are heavily stressed during the weight test.

DE-A-3 822 466 discloses methods for checking the position and movements of cable-driven transport devices. It is used in mining shaft hoisting systems to determine the exact position of the car, taking into account the elongation or the slipping of the rope.

The turns of the rope are detected optically and the location of the car is determined depending on the number of turns.

The known method regulates the daily operation of the elevator and has no relation to safety checks. The driving ability is not determined, but only a possible rope slide is corrected.

It is the object of the present invention to propose a method for checking freight and / or passenger lifts by means of which the workload for the test is considerably reduced while at the same time increasing the test quality.

According to the invention, this object is achieved in that the driving ability and / or from the distance and control signals of the braking and / or catching path, or the braking and / or catching curve as a record of distances, speed and Acceleration values are determined as a function of time or the path.

According to such a method, kinematic data of the elevators, that is to say travel path and associated time measurement values, can be determined with little effort as a function of the signals controlling the movement sequence of the elevator, the required test characteristic values being able to be determined from the kinematic data. In particular, the determination and recording of distances, speed and acceleration values can advantageously take place as a function of time or of the path. The braking and catching curves recorded in this way are output on a screen or printer and with calculated envelopes (which ones permissible upper and lower limits) superimposed. This makes it easy to determine the effectiveness of the brake and safety gear. The determined curves can be saved on a data carrier.

In an expedient embodiment, in the method according to the invention, the cable pull is connected to a force measuring signal transmitter, by means of which the forces transmitted by the cable pull and determining the movement sequence of the car can be determined. With the aid of such a force measurement, in particular the testing of the slip resistance of the cable pull driven by the traction sheave can advantageously be carried out. You can determine the driving ability from one to x ropes and extrapolate it to the total driving ability.

A computer, preferably a personal computer, is expediently included in the method.

The test method according to the invention also represents a significant improvement in terms of safety technology in that no high loads are placed on the elevator during the test.

Further advantageous design options of the invention emerge from the subclaims.

Fig. 1

eine Aufzugsanlage (schematisch), zu deren Überprüfung das erfindungsgemäße Verfahren vorgesehen ist,

Fig. 2

ein Ausführungsbeispiel für eine Vorrichtung gemäß dem erfindungsgemäßen Verfahren,

Fig. 3

ein Ausführungsbeispiel für einen bei dem erfindungsgemäßen Verfahren verwendbaren Wegstreckenaufnehmer in Vorderansicht,

Fig. 4

den Wegstreckenaufnehmer gemäß der Fig. 3 in Seitenansicht,

Fig. 5

Zeitdiagramme der von dem Wegstreckenaufnehmer gemäß der Fig. 3 und 4 abgegebenen Meßsignale,

Fig. 6

eine Auswerteschaltung für die von dem Wegstreckenaufnehmer gemäß der Fig. 3 und 4 abgegebenen Meßsignale,

Fig. 7

ein Ausführungsbeispiel für einen bei dem erfindungsgemäßen Verfahren verwendbaren Kraftmeßsignalgeber,

Fig. 8

ein bei dem Kraftmeßsignalgeber gemäß der Fig. 7 als Meßwandler verwendeter Wegstreckenaufnehmer.

Fig. 9

ein weiteres Ausführungsbeispiel für einen bei dem erfindungsgemäßen Verfahren verwendbaren Kraftmeßsignalgeber.

Fig.10

ein Fangdiagramm mit der tatsächlich aufgezeigten Funktion "Weg über Zeit",

Fig.11

ein Fangdiagramm mit Hüllkurven als Grenzwerte für die Fangkurve, und

Fig.12

eine Gegenüberstellung der Kräfte bei beladenem Aufzug und angeschlossenem Kraftmesser.

The invention will now be explained and described with reference to exemplary embodiments and the accompanying drawings. Show it:

Fig. 1

an elevator installation (schematic), for the checking of which the method according to the invention is provided,

Fig. 2

an embodiment of a device according to the inventive method,

Fig. 3

1 shows an exemplary embodiment of a distance sensor that can be used in the method according to the invention, in front view,

Fig. 4

the distance sensor according to FIG. 3 in side view,

Fig. 5

3 and 4, time diagrams of the measurement signals emitted by the distance sensor,

Fig. 6

an evaluation circuit for the measuring signals emitted by the distance sensor according to FIGS. 3 and 4,

Fig. 7

1 shows an exemplary embodiment of a force transducer which can be used in the method according to the invention,

Fig. 8

a distance transducer used as a transducer in the force measuring signal generator according to FIG. 7.

Fig. 9

a further embodiment for a force measuring signal generator that can be used in the method according to the invention.

Fig. 10

a catch diagram with the actually shown function "way over time",

Fig. 11

a catch diagram with envelopes as limit values for the catch curve, and

Fig. 12

a comparison of the forces when the elevator is loaded and the dynamometer connected.

In order to be able to better describe the method according to the invention later, an elevator installation is to be described first with reference to FIG. 1, the method according to the invention being provided for checking.

In Fig. 1, the reference numeral 1 designates a traction sheave which has two guide grooves for a cable pull 2 formed in the present case by two cables. A car 3 is attached to one end of the cable 2. A counterweight 4 hangs at the other end of the cable 2. The mass of the counterweight 4 usually corresponds to the mass of the car 3 plus half the permissible car load. 5 designates a motor-gear unit for driving the traction sheave 1, this unit having a handwheel 10 for rotating the traction sheave 1. A braking device, not shown in FIG. 1, is arranged between the motor-transmission unit 5 and the drive pulley 1. The motor-gear unit 5 with the traction sheave 1 is arranged above a ceiling 11 which closes the elevator shaft upwards.

When driving, the car 3 is moved via the cable 2, which is driven by the motor-transmission unit via the traction sheave 1. For the elevator system to operate properly, it is necessary that the cable is laid over the traction sheave in a non-slip manner. The car can be used in an emergency as well Repairs or checks can also be moved by the handwheel 10.

In FIG. 2, 6 denotes an evaluation unit, which in the present exemplary embodiment comprises a personal computer 12, an input / output interface 13 and an interface module 14. The dashed outline 6 'is intended to indicate that the input / output interface 13 and the interface module 14 form a functional unit. As usual, the personal computer has a screen 36 as a display device and an input keyboard 37. Between the individual components of the evaluation unit, data traffic takes place in both directions in accordance with the arrows that connect the components. In the present exemplary embodiment, the evaluation unit 6 is in each case via one of the lines 15 to 17 with a first distance sensor 7, which can be connected to a cable of the cable 2, a second distance sensor 18, which can be connected to the traction sheave 1, and a force measuring signal transmitter 8 connected, the lines being connected to the evaluation unit via inputs provided on the interface module. 9 designates lines via which the evaluation unit is connected to the control circuit of the elevator system. The lines 9, like the lines 15 to 17, are connected to inputs which are provided on the interface module 14.

In the present exemplary embodiment, the lines 9 are combined to form a 12-wire shielded cable which has at one end a test plug or terminals and which can be connected to the control circuit of the elevator system has a circuit board connector with a voltage protection circuit at the other end.

The interface module 14 comprises four modules. For electrical signals that are transmitted from the control circuit via the lines 9 to the evaluation unit, a control subinterface is provided, which has an optocoupler for each input for a galvanic separation of the evaluation unit from the control circuit, one that can be operated with only one operating voltage, with a capacitive feedback provided operational amplifier for signal amplification and a Schmitt trigger. A largely symmetrical sensor sub-interface is provided for recording and preprocessing signals from the distance sensors and the force measuring signal transmitter. Pulse-forming Schmitt triggers are used as input modules, the output of which is connected to a monoflop with a narrow pulse width. In addition, logic modules are provided for linking signals from different inputs of the sensor sub-interface. As a third module, the interface module 14 has a divider module for dividing the system clock of the personal computer. Finally, the interface module contains an acoustic signal generator which has a monoflop with a pulse width of approximately 500 ms and a downstream piezo beeper.

The input / output interface has a decoder, an input / output and a timer module. The timer block contains a universally programmable counter, whose clock input is connected to the via the divider block of the interface block System clock of the personal computer is connected.

3 and 4 show an embodiment of a distance sensor in front and side view, as it can be used in the method according to the invention. The distance sensor has a perforated disk 19 with light passage holes 20 arranged concentrically around the pivot point of the perforated disk at equal intervals. The perforated disk is concentrically connected to a drive disk 21 having a guide groove for a driving cable rope. The perforated disk 19 with the drive disk 21 has an axis of rotation 24 which is rotatably mounted in a holder 23. 25 denotes a first and 26 denotes a second light barrier measuring device, the light rays of which pass through the perforated disk or are interrupted by the perforated disk. The distance between the two light barriers and the distance between the light through holes on the perforated disk was chosen so that when the perforated disk rotates in one direction for the signals of the two light barrier devices, the pulse diagrams shown in FIG. 5 with temporally offset pulses result. The direction of rotation can be determined by evaluating the measurement signals emitted by both light barriers. Such an evaluation circuit is shown in FIG. 6. In addition to travel pulses, the number of which is characteristic of the travel path of the car, the circuit also supplies a signal indicating the direction of movement of the car.

FIG. 7 shows an exemplary embodiment of a force transducer 8 that can be used in an arrangement according to FIG. 2. The Force transducer has a helical compression spring 28 guided in a guide sleeve 27, which can be compressed by a pull rod 29 which has a disc 30 at one end against which the spring 28 comes into contact and an eyelet 31 at the other end. 32 with a distance transducer is designated by which a displacement of the pull rod 29 against the guide sleeve 27 can be detected and thus a measurement signal for the force acting on the pull rod can be supplied. The distance sensor 32 is shown separately in FIG. 8. 3 and 4, it has a perforated disk 19 'and two light barrier measuring devices 25' and 26 '(25' not visible in FIG. 8). The perforated disk 19 'is connected via an axis of rotation 24' to a drive wheel 33 which comes against the tie rod 29 and is driven by the tie rod.

In Fig. 9, another embodiment of a force transducer is shown, which differs from the embodiment of FIG. 7 in that one end of the tie rod 29 'formed as a hook 34 and a distance sensor for detecting the displacement of the tie rod 29' against the guide sleeve 27 'is provided, which has a tie rod 29' connected to the guide sleeve, displaceable against the guide sleeve 35 with equidistantly arranged in a line light passage holes 20 '. To scan the through holes 20 ', a first light barrier device 25˝ and a second light barrier device 26˝ are provided.

By using two light barriers in each of the distance sensors for the force measuring signal transmitters, a determination of the direction of movement of the Pull rod.

With the device described with reference to FIGS. 2 to 9, measurements of travel distances, speeds and accelerations of the car as a function of time or of the path as a function of the signals of the control circuit of the elevator system controlling the movement of the car can be carried out and recorded according to the inventive method will.

These curves can be output on the computer screen or on a printer.

By comparing with the target curves, statements about the effectiveness of the brake and safety gear can be made.

FIGS. 10 and 11 show a catching test carried out in practice. In FIG. 10, the catching path s of the car over the catching time t is recorded in the form of a curve f.

11 shows the same curve f, but with the envelope curves h calculated as limit values.

With the help of the new method, the slip resistance (driving ability) of the cable can also be advantageously determined. For this purpose, the pull rod of the force transducer (from FIG. 7 or FIG. 9) is to be connected to one or more cables of the cable using a suitable cable clamp. The guide sleeve of the force transducer is expediently attached to the ceiling 11 closing the elevator shaft at a fixed point. By turning the handwheel or moving the drive, this is the case with the slip test long to increase the tractive force until either a determined limit value is reached and the signal generator emits a warning signal, or the rope or the ropes on the traction sheave begin to slide. The driving capacity of the entire traction sheave is calculated from the value of the measured force of one x ropes. The onset of slipping at the maximum driving force that can be transmitted by the traction sheave can be registered by evaluating the signals of the first distance sensor that can be connected to the cable pull and the second distance sensor that can be connected to the traction sheave, or only visually by the elevator inspector.

According to the described method, it is also possible to check the control circuit of the elevator by checking the chronological sequence of the control signals. E.g. the time it takes for the control to switch off the drive or to apply a brake after a safety switch has been opened can be determined.

The evaluation unit 6 has a number of functional devices (in the present exemplary embodiment partially implemented as a software solution). A functional device is provided for determining the speed and / or acceleration values. The measurement of the speed and acceleration can be triggered by actuating the keyboard of the personal computer or triggered by signals from the control circuit of the elevator. Measurement results can be displayed on the screen of the personal computer and, if necessary, can be output as a complete test report on a connected printer. Around In particular to draw attention to impermissible test values, the acoustic signal transmitter contained in the interface module 14 or activatable via the software in the personal computer can be activated. The screen can also be used to display instructions for operating the device.

In the described embodiment, the sensor interface causes the personal computer when an external event, e.g. Advance the perforated disc to interrupt its work and update the corresponding internal memory for distance and possibly time.

However, it is also possible to feed these pulses to an up / down counter and to display the result using a conventional display module. Corresponding forces or distances can then be assigned to the values shown.

In the exemplary embodiment described, the timer and acoustic signal transmitter with the necessary control were accommodated in the sensor interface. Alternatively, there is the option of dispensing with these modules and instead, controlled by software, using the corresponding modules in the personal computer.

In the embodiment described above, the values to be measured were immediately converted into digital signals. Alternatively, there is the possibility of performing the measured value acquisition analogously and, for example, of registering speeds (and thus also distances and accelerations) with a tachometer generator, or forces can be measured using strain gauges or piezoelectric pressure transducers can be determined. These analog signals can be converted into digital signals with an A / D converter and then further processed with an evaluation unit.

F_F =

Fahrkorbkraft

F_L =

Nutzlastkraft

F1 =

Kraft/Seil an Gegengewicht-Seite

F2 =

Kraft/Seil an Fahrkorb-Seite

F5 =

Kraft des eingespannten Seils <-> Treibscheibe

F6 =

Kraft eines Seils vom Fahrkorb <-> Einspannstelle

F7 =

Kraft Fixpunkt <-> Einspannstelle (gemessen)

F_Q =

Tragkraft

n =

Anzahl der Tragseile

Betrachtet man die Kräfte bei einem beladenen Aufzug, so gelten folgende Formeln:

${\text{F1= (F}}_{\text{F}}{\text{+.5*F}}_{\text{Q}}\text{)/n}$

${\text{F2= (F}}_{\text{F}}{\text{/n)+(F}}_{\text{L}}\text{/n)}$

Dieser Fall ist in Fig. 12 links dargestellt.12 shows a comparison of the forces occurring on the traction sheave when the elevator is loaded and when the dynamometer is connected. The following abbreviations apply:

F _F =

Car power

F _L =

Payload

F1 =

Strength / rope on the counterweight side

F2 =

Power / rope on the car side

F5 =

Force of the clamped rope <-> traction sheave

F6 =

Power of a rope from the car <-> clamping point

F7 =

Force fixed point <-> clamping point (measured)

F _Q =

Load capacity

n =

Number of suspension ropes

If you consider the forces in a loaded elevator, the following formulas apply:

${\text{F1 = (F}}_{\text{F}}{\text{+ .5 * F}}_{\text{Q}}\text{) / n}$

${\text{F2 = (F}}_{\text{F}}{\text{/ n) + (F}}_{\text{L}}\text{/ n)}$

This case is shown on the left in FIG. 12.

On the right, however, the situation is shown in which a rope is connected to a dynamometer and is therefore tightened. The prerequisite for the following equations is that the rope has not slipped over the traction sheave.

${\text{F5=(F}}_{\text{F}}\text{/n)+F7}$

$\text{F2=F5 =>}$
${\text{(F}}_{\text{F}}{\text{/n)+(F}}_{\text{L}}{\text{/n)=(F}}_{\text{F}}\text{/n)+F7}$

${\text{F}}_{\text{L}}\text{/n=F7}$

${\text{F}}_{\text{L}}\text{=F7*n}$

Then:

${\text{F3 = F1; F6 = F}}_{\text{F}}\text{/ n}$

${\text{F5 = (F}}_{\text{F}}\text{/ n) + F7}$

$\text{F2 = F5 =>}$
${\text{(F}}_{\text{F}}{\text{/ n) + (F}}_{\text{L}}{\text{/ n) = (F}}_{\text{F}}\text{/ n) + F7}$

${\text{F}}_{\text{L}}\text{/ n = F7}$

${\text{F}}_{\text{L}}\text{= F7 * n}$

Claims (25)

1. A method of determining physical parameters, more particularly motion parameters, of a goods lift and/or passenger lift, the lift comprising at least one cable system (2) guided over a driving pulley (1) and having a cage (3) suspended at one end and a counter-weight (4) suspended at the other end, the lift (14) being driven by a motor (5) controlled by an electric control circuit and acting on the pulley (1), and the lift also comprising a brake device connected to the pulley and controlled by the control circuit, the physical parameters being determined by at least one travel recorder (7, 18) connected to the cable system (2) and/or to the pulley (1) so as to generate travel signals, the travel recorder being connected to an evaluating unit (6) comprising a timer, in order to supply the travel signals to the evaluating unit (6), and the evaluating unit (6) being connected to places on the control circuit where signals are received for controlling the motion of the lift, characterised in that as a safety test, the driving capacity is determined from the physical parameters and/or the braking and/or guard travel or the braking and/or guard curve as a record of distances, speeds and accelerations is determined from the travel and control signals as a function of time and/or travel.
2. A method according to claim 1, characterised in that at least one cable in the cable system (2) is connected to a dynamometer signal transmitter (8) and the dynamometer signal transmitter (8) is connected to the evaluating unit (6) in order to supply the evaluating unit (6) with a dynamometer signal, and the maximum drive force (drive capacity) transmittable by the pulley (1) to the cable system (2) is determined from the dynamometer signal and from the travel signals of a travel recorder connected to the cable system and a travel recorder connected to the pulley (1).
3. A method according to claim 1 or 2, characterised in that the drive capacity determined in the case of one or x cables is used to extrapolate the drive capacity of all cables on the pulley.
4. A method according to claim 1 or 3, characterised in that speeds and/or accelerations are determined by a device contained in the evaluating unit (6).
5. A method according to any of claims 1 to 4, characterised in that evaluation processes, e.g. determination of distances, speeds, accelerations and/or forces,, are triggered by signals from the control circuit, by means of a device contained in the evaluating unit (6).
6. A method according to any of claims 1 to 5, characterised in that evaluation processes, e.g. determination of distances, speeds and/or forces, are triggered via input switches (37) provided for the evaluating unit (6).
7. A method according to any of claims 1 to 6, characterised in that evaluation results are displayed by a display device (36) contained in the evaluating unit (6).
8. A method according to claim 7, characterised in that the evaluation results are displayed by a video display device (36).
9. A method according to claim 6 or 8, characterised in that travel distances, speeds and accelerations and/or forces are displayed by the display device (36).
10. A method according to any of claims 6 to 9, characterised in that operating instructions for the user of the device are displayed by the display device (36).
11. A method according to any of claims 1 to 10, characterised in that alarm signals depending on evaluation results are generated by signal means contained in the evaluating unit (6), e.g. in a personal computer, where they can be activated via a program.
12. A device according to claim 11, characterised in that the alarm signals are audio signals.
13. A method according to any of claims 1 to 12, characterised in that distance signals are generated by at least one light barrier (25, 26) which scans a perforated plate (19) rotatable in accordance with the length of travel to be measured.
14. A method according to claim 13, characterised in that the perforated disc (19) is scanned by a double light barrier (25, 26) in order to determine the direction of rotation.
15. A method according to claim 13 or 14, characterised in that the perforated disc (19) is driven by the pulley or by a drive roller (21) pressed against the cable system (2).
16. A method according to claim 15, characterised in that the drive roller (21) is driven by the cable system (2), in that the cable system (2) is inserted into a guide groove (22) in the drive roller (21).
17. A method according to any of claims 2 to 16, characterised in that the dynamometer signal transmitter (8) is a spring sensor.
18. A method according to claim 17, characterised in that the change in the spring travel is determined by a travel recorder (32).
19. A method according to claim 18, characterised in that the travel recorder (32) is used to generate travel signals in that a coding strip (35) formed with regularly distributed light-transmitting openings (20') is scanned by at least one light barrier.
20. A method according to claim 19, characterised in that the coding strip (35) is scanned by a double light barrier (25'', 26'') in order to determine the direction of rotation of the coding strip.
21. A method according to claim 18, characterised in that a perforated disc (19') is used as a travel recorder and is scanned by at least one light barrier, preferably by a double light barrier, in order to determine travel signals.
22. A method according to claim 21, characterised in that the test signals from the travel transmitter (7, 18) or the dynamometer signal transmitter are supplied to an interface component (14) upstream of an input/output interface (13) of a personal computer (12), and the test signals are initially processed by the interface component (14).
23. A method according to claim 22, characterised in that the direction of motion of the lift or the direction of spring travel is determined by a logic circuit contained in the interface component (14).
24. A method according to claim 22, characterised in that audio signals are delivered by an audio-signal transmitter contained with the software in the personal computer or the interface component (14).
25. A method according to any of claims 1 to 24, characterised in that signals from the control circuit are tested by a device contained in the evaluating unit (6).

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