EP2457860B1 - Safety device for a lift - Google Patents

Description

The invention relates to a safety device for a lift with the features of the preamble of claim 1.

Such safety devices are from the EP 2 165 960 A1 known. They are used in elevators, which have a car which is vertically movable in a shaft up and down to transport people and / or loads. The car has at least one car door, whose opening and closing state can be detected by a door sensor. If the car leaves a stop, the door must be closed. If this is not the case, the car must be brought to a standstill within a very short time for safety reasons. An uncontrolled leaving a stop with open car door is prevented by the safety device.

Object of the present invention is to provide a safety device of the type mentioned, which is as inexpensive as possible and requires the least possible space and ensures a high level of security.

This object is achieved by a safety device having the features of patent claim 1.

The idea flows into the invention that the uncontrolled leaving of a stop with open car door can be reliably prevented by means of standard provided assemblies of the elevator and by means of standard measured values, which are also evaluated for moving the car during normal operation of the elevator. For this purpose, the evaluation device comprises the elevator control provided as standard and the control device provided as standard, which controls the drive device. The control unit has a frequency converter as usual. The elevator control and the control unit act as an evaluation device of the safety device in such a way that the drive motor is switched off and the service brake is activated when the car leaves the door zone with the door open and also if the acceleration and / or speed of the car within the door zone assume impermissible values. In both cases, the car can be brought to a standstill within a range of one meter from the stop. This is achieved in that the relevant door zone is correspondingly short, so that the car can be braked reliably in said area.

In the area of a stop it may be necessary to correct the position of the car relative to a leveling position. Such corrections may arise, for example, when loading and unloading the car due to the associated weight change. For this purpose, the car can be moved within the door zone at low speed and with low acceleration. For adjusting the car, maximum permissible values of the speed and the acceleration can be specified.

If the evaluation device in the form of the elevator control and the control unit detects that the acceleration and / or speed present in the door zone exceeds the permissible maximum value, then the drive device is switched off and the service brake is activated, so that the car is in the range of one meter after the Stop safely comes to a halt.

According to the invention, non-safe output signals provided by the measuring device can be monitored with regard to their plausibility by means of the evaluation device. It can be provided, for example, that discontinuities of the output signals can be detected by the evaluation device. If there is a discontinuity, the drive motor can be switched off by means of the evaluation device and the service brake can be activated.

The safety device according to the invention is used in particular for elevators with gearless drives. Here, the service brake may be approved as a safety brake.

The at least one door zone can be defined by zone flags installed in the shaft, which can be detected optically, magnetically, capacitively or inductively.

It is advantageous if the measuring device comprises at least one door zone monitoring circuit and at least one pulse generator of the drive device or a speed limiter. Speed limiters are known per se to the person skilled in the art. They are used to decelerate a car that has an inadmissibly high speed within a very short time. The measuring device may include a cooperating with the speed limiter pulse generator, which provides the evaluation device in response to the speed of the car pulses. It can also be provided that the pulse generator cooperates with the drive motor or a drive pulley of the elevator in order to provide pulses to the evaluation device which depend on the speed of the elevator car. In addition to the at least one pulse generator the measuring device has at least one door zone monitoring circuit. During normal operation of the elevator, by means of the at least one door zone monitoring circuit, the position of the car relative to a door zone is detected such that the door zone monitoring circuit provides the elevator controller with a signal that depends on whether the car is inside or outside the door zone. As already mentioned, zone flags installed in the shaft can be used for this purpose.

These can be detected by a door zone sensor located on the car. If a zone flag is detected by the door zone sensor, the elevator control receives the information that the car is located within the door zone.

It is favorable if the braking device comprises a service brake of the elevator, which is approved as a safety brake. An additional safety brake can be eliminated.

The evaluation device preferably consists exclusively of the elevator control and the control device of the drive device. Additional components can be omitted.

It is advantageous if the part of the evaluation device, which recognizes leaving the door zone, is implemented within the elevator control and switches off the drive device without the use of the control unit when leaving a door zone uncontrolled. In such an embodiment, the drive device can be switched off by the evaluation device without the control device having to be used for this purpose. For this purpose, the elevator control can cooperate, for example, with a safety chain of the elevator, which shuts off the drive device in the event of a fault. Such a disturbance can be detected by the elevator control by determining that a car door is open when leaving a door zone. If this is the case, then the drive motor can be switched off immediately by the elevator control, without the control unit of the drive motor has to be used.

Conveniently, the part of the evaluation unit, which already recognizes impermissible accelerations and / or impermissible speeds within the door zone, is implemented within the control unit. This makes it possible, with an impermissible acceleration and / or an impermissible speed of the car within the door zone, the drive motor shut down without the elevator control must be used. The shutdown can rather be done directly from the controller.

It is advantageous if the evaluation device has a first part which detects the leaving of a door zone, and a second part which detects impermissible accelerations and / or speeds within the door zone, wherein the two parts mutually monitor their function by means of bidirectionally exchanged signals cause a shutdown of the drive motor in case of failure.

It is advantageous if the door zones of the safety device have a different length than door zones of other functional units of the elevator. Thus, for example, be provided that at each stop a first door zone and a second door zone are formed, wherein the first door zone of the safety device is assigned and the second door zone is decisive for the retraction of the car with the car door opening into a stop. The retraction of the car with the door opening can, for example, take place in an area of 35 cm relative to the leveling position of the car at the stop, whereas the door zone cooperating with the safety device can occupy a shorter range, for example a range of only 10 cm relative to the leveling position of the car Car at the bus stop. The two door zones can each be designed as zone fins installed in the shaft, which are detectable optically, magnetically, capacitively or inductively by an associated door zone sensor. It can also be provided that at least one door zone can be computationally detected, for example by evaluating the signals of a pulse generator.

In a particularly preferred embodiment of the safety device according to the invention, the control device comprises a safe pulse lock which safely separates control pulses which are provided by a control element of the control device of a power electronics of the control device. During normal operation of the elevator, the drive motor receives the supply voltage from power electronics as a function of control signals a control member, such as a microcontroller provided. The transmission of the control signals via a secure pulse lock, which conveniently has at least two in series with each other connected optocouplers. The transmission of control signals can be interrupted within a very short time, for example, by the fact that the operating voltage of the optocoupler is interrupted. The provision of a pulse lock thus enables the safety device according to the invention to reliably separate the drive motor from its supply voltage within a very short time.

It is particularly advantageous if forcibly the electrical supply of the service brake can be interrupted by means of the safe pulse lock. In such an embodiment, the pulse lock interrupts not only the control signals for the power electronics of the control unit, but in addition interrupts the pulse lock also the supply voltage of the service brake, so that this occurs and thereby the car is braked.

Alternatively or additionally, it can be provided that an electromagnetic short circuit in the drive motor can be generated by the control unit for rapid shutdown of the drive motor.

It is advantageous if the measuring device comprises an absolute value-related position detection of the car, which is connected to the elevator control and is designed at least two channels. By means of the absolute value-related position detection, the elevator control can control the travel of the car during normal operation of the elevator by the position detection permanently provides position information of the car. The position detection is designed here safe, that is, it is at least two channels. For example, a coded magnetic tape can be used as absolute value-related position detection in combination with at least two magnetic field-sensitive sensors which scan the magnetic tape during a drive of the car. The magnetic tape extends over the entire length of the Shaft, so that over the entire length of the shaft position information of the elevator control can be provided.

In a particularly cost-effective embodiment of the safety device according to the invention, the measuring device consists of the above-mentioned absolute value-related position detection and a pulse generator of the drive device and / or a speed limiter.

In the event that the safety device has an absolute value-related position detection of the car, door zones can be mapped in the software of the elevator control. A distinction in different sized door zones for different functions per stop can be implemented in the software without additional costs.

Figur 1:

eine schematische Darstellung eines Aufzugs mit einer erfindungsgemäßen Sicherheitseinrichtung;

Figur 2:

ein Blockschaltbild der erfindungsgemäßen Sicherheitseinrichtung;

Figur 3:

einen Teil einer Auswerteeinrichtung der Sicherheitseinrichtung, wobei dieser Teil in ein Steuergerät integriert ist und

Figur 4:

ein Blockschaltbild eines Frequenzumformers des Steuergerätes aus Figur 3.

The following description of a preferred embodiment of the invention serves in conjunction with the drawings for further explanation. Show it:

FIG. 1:

a schematic representation of an elevator with a safety device according to the invention;

FIG. 2:

a block diagram of the safety device according to the invention;

FIG. 3:

a part of an evaluation of the safety device, said part is integrated in a control unit and

FIG. 4:

a block diagram of a frequency converter of the control unit off FIG. 3 ,

In FIG. 1 schematically illustrated an elevator 10 with a car 12, which is movable by means of a drive means 14 in a shaft 16 in the vertical direction upwards and downwards, wherein he at various stops, of which in FIG. 1 only three stops 18, 19 and 20 are shown, can stop to be loaded and unloaded.

The drive device 14 comprises a drive motor 22, which is controlled by a control unit 24, wherein the drive motor 22 via the control unit 24 - as explained in more detail below - a supply voltage is provided. In addition, the drive device 14 comprises a traction sheave 26, which is rotated by the drive motor 22 in rotation. A rope 28 is passed around the traction sheave 26 and connects the car 12 with a counterweight 30th

The traction sheave 26 is associated with a service brake 32 which, like the control unit 24, is connected to an elevator control 34.

The traction sheave 26 is associated with a pulse generator 36 which detects the rotation of the traction sheave 26 and provides a dependent of the rotation of the traction sheave 26 pulse signal.

The car 12 has a car door 38 with a first door leaf 39 and a second door leaf 40, the opening and closing position is detected by a door sensor 41 and 42, respectively. About a not shown in the drawing, the person skilled in the known hanging cable, the two door sensors 41, 42 are connected to the elevator control 34.

Within the shaft 16 extends over the entire length of a magnetic tape 44, which are scanned by a first position sensor 45 and a second position sensor 46, both of which are arranged on the car 12 can. The two position sensors 45, 46 in combination with the magnetic tape 44 a secure, namely two-channel absolute value-related position detection of the car 12. The position sensors 45 and 46 are also connected via the above-mentioned suspension cable to the elevator control 34.

At each stop 18, 19 and 20 a first zone flag 48 and a second zone flag 49 are arranged in the shaft 12, which can be detected by a first door zone sensor 51 and a second door zone sensor 52. The two door zone sensors 51 and 52 are fixed to the car 12 and connected via the above-mentioned hanging cable with the elevator control 34.

As already mentioned, the car 12 can be moved in the shaft 16 by means of the drive device 14. For loading and unloading, the car 12 may occupy a position flush with a stop 18, 19 or 20. By loading and unloading, the weight of the car changes 12. This can cause the car 12 changes its position relative to the stop 18, 19 and 20 slightly. It can then the position of the car 12 relative to the respective stop 18, 19 and 20 readjusted by the drive means 14 is activated. The adjustment movement takes place here with very low speed and very low acceleration within a first door zone, which is predetermined by the first zone lug 48. An adjusting movement of the car 12 can only take place when the first door zone sensor 51 detects the first zone flag 48. The first zone lug 48 extends in the illustrated embodiment, starting from a flush position of the car 12 100 mm vertically upwards and downwards.

If the car 12 approaches a stop 18, 19 or 20, then the car door 38 can already be opened even before the car 12 has reached its leveling position. The opening of the car door 38 can take place as soon as the second door zone sensor 52 detects the second zone flag 49. The second zone flag thus defines a second door zone; within the second door zone, when the elevator car 12 approaches a stop 18, 19 and 20, the car door 38 are opened. The second zone flag 49 extends in the illustrated embodiment, starting from a flush position of the car 12 350 mm vertically upwards and downwards. The second door zone is thus longer than the first door zone. In the illustrated embodiment, the length of the second door zone is more than three times the first door zone.

If the car 12 leaves a stop 18, 19 or 20, it must be ensured that the car door 38 is closed. If this is not the case, the car 12 is brought to a standstill within a range of one meter after the leveling position. Here is a below with reference to the FIGS. 2 to 4 described in detail safety device 55 is used. The safety device 55 comprises a measuring device 57, an evaluation device 58 and a braking device 59. The measuring device 57 is formed by the pulse generator 36 and by a door zone monitoring circuit 61, which consists of the first door zone sensor 51 and the first zone flag 48. By means of the door zone monitoring circuit 61 it can be determined whether the car 12 is within the first door zone defined by the first zone flag 48.

The evaluation device 58 is formed by the elevator control 34 and the control unit 24, which are connected to each other via a bidirectional electrical connection 63 and which are each connected to a safety chain 65 of the elevator 10.

The braking device 59 comprises the drive motor 22 and the service brake 32.

By means of the safety device 55 can be prevented that the car 12 uncontrollably leaves a stop 18, 19 or 20 with open car door 38. If the elevator controller 34 receives the signal from the door zone monitoring circuit 61 that the car 38 leaves the first door zone, the elevator controller 34 receives the same from the door sensors 41 and / or 42 at the same time Signal that at least one door leaf 39 or 40 is not closed, the elevator control 34 opens the safety chain 65. This has the consequence that the service brake 32 is activated, that is, their power supply is interrupted, so that the service brake 59 occurs, and In addition, the drive motor 22 is turned off.

The control unit 24 is signal-connected to the pulse generator 36. The pulses provided by the pulse generator 36, which are dependent on the rotational speed of the traction sheave 26, are evaluated by the control unit 24 to determine whether an impermissibly high acceleration and / or speed of the car 12 is present. How out FIG. 3 becomes clear, the signal provided by the pulse generator 36 is first subjected to a first signal test 67, in which the provided pulse signal is checked for plausibility. It is checked here whether the pulse signal undergoes a discontinuous change or not. A discontinuous change would mean that the pulse signal is not plausible. In such a case, the safety chain 65 is also interrupted, so that the drive motor 22 is turned off and the service brake 32 are activated. If the pulse signal is plausible, it experiences a second signal check 69, in which the velocity and acceleration of the car 12 are determined from the pulse signal provided. During a correction of the position of the car 12 relative to a stop 18, 19 or 20, as explained above, the speed and the acceleration of the car are compared with permissible maximum values, that is, with speed and acceleration values within the first door zone to correct the position of the car 12 are allowed. These are provided to the controller 24 by the elevator controller. If the permissible maximum values are exceeded, the safety chain 65 is interrupted and, in addition, a pulse lock 72, which will be explained in more detail below, is activated. If there is no exceeding of the permissible maximum values, then a control element 74 of a frequency converter 76 of the control unit 24 is provided with a signal which signals normal operation.

By means of the control member 74, control signals can be provided to a power electronics 78 of the frequency converter 76 so that it provides the drive motor 22 with a supply voltage in the form of an alternating pulse pattern which allows the drive motor 22 to cause a rotational movement to rotate the traction sheave 26 and thereby moving the car 12. The supply voltage is provided to the power electronics 78 via a motor line 80.

The transmission of the control signals from the control member 74 to the power electronics 78 via the pulse lock 72. The control member 74 is connected via a total of six control lines to the power electronics 78, wherein in FIG. 4 To achieve a better overview, only a first control line 84 and a second control line 85 are shown. Via a further control line 87, the control member 74 of the frequency converter 76 is connected to a brake control 89 which controls the service brake 32. Both in the six control lines, via which the control member 74 is connected to the power electronics 78, as well as in the further control line 87, via which the control member 74 is connected to the brake control 89, two optocouplers 91, 92 are connected in series. The operating voltage of the opto-couplers 91, 92 is supplied via first switching contacts 94 which can be opened and closed by a positive-action relay, not shown in the drawing, depending on the result of the second signal check 69 within the first door zone by means of the pulse generator 36 detected acceleration and / or speed values the permissible maximum values, the operating voltage of the optocoupler of the pulse lock 72 is interrupted by means of the first switching contacts 94. As a result, the control element 74 can no longer transmit a control signal to the power electronics 78. At the same time the operating voltage of the brake control 89 is interrupted by means of second switching contacts 96, so that this electrical energy can no longer be supplied, and at the same time the transmission of control signals from the control member 74 is interrupted by means of the switched into the further control line 87 optocouplers 91, 92. This has the consequence that the service brake 32 is activated, that is, the service brake 32 is applied and thus brakes the traction sheave 26 from.

By means of the safety device 55 can thus be reliably prevented on the one hand that the car 12 leaves the first door zone with open car door 38. On the other hand, the car 12 within the first door zone can reliably be prevented from assuming an acceleration or a speed which is greater than maximum values permissible for a correction of the position of the car 12 within the first door zone. The safety device 55 is in this case formed by components of the elevator 10, which the elevator 10 also requires for its normal operation. The safety device 55 can therefore be provided very inexpensively and it requires no additional space. The car can be brought to a halt by means of the safety device 55 in the event of a fault in a range of one meter to a stop 18, 19, 20.

Claims (13)

1. Safety device for an elevator with an elevator controller (34), a drive device (14) controlled by a control unit (24), a service brake (32) and an elevator car (12), the elevator car (12) having at least one elevator car door (38), and it being possible by means of the safety device (55) to prevent the elevator car (12) from leaving a stop (18, 19, 20) in an uncontrolled manner with the elevator car door (38) open, the safety device (55) comprising a measuring device (57), an evaluating device (58) and a braking device (59), the position of the elevator car (12) in relation to at least one door zone formed at a stop (18, 19, 20) and the acceleration and/or speed of the elevator car (12) within the door zone being detectable by means of the measuring device (57), and the evaluating device (58) comprising the elevator controller (34) and the control unit (24), and it being possible by means of the evaluating device (58) to recognize from output signals of the measuring device (57) when the at least one door zone is left with the elevator car door (38) open and also when inadmissible accelerations and/or speeds of the elevator car (12) within the door zone are reached, and, in each case, to activate the switching-off of a drive motor (22) and the application of the service brake (32), and the length of the door zone being of such dimensions that the elevator car (12) comes to a halt within the range of one meter after the stop (18, 19, 20), characterized in that the evaluating device (58) monitors unreliable measured values with respect to their plausibility.
2. Safety device in accordance with claim 1, characterized in that the measuring device (57) comprises at least one door zone monitoring circuit (61) and at least one pulse generator (36) of the drive device (14) or of a speed governor.
3. Safety device in accordance with claim 1 or 2, characterized in that the braking device (59) comprises a service brake (32) which is authorized as safety brake.
4. Safety device in accordance with any one of the preceding claims, characterized in that the evaluating device (58) consists of the elevator controller (34) and the control unit (24).
5. Safety device in accordance with any one of the preceding claims, characterized in that the evaluating device (58) comprises a first part which recognizes when the door zone is left with the elevator car door (38) open, and which is implemented within the elevator controller (34) and causes the drive device (14) to be switched off without use of the control unit (24).
6. Safety device in accordance with any one of the preceding claims, characterized in that the evaluating device comprises a second part which recognizes inadmissible accelerations and/or speeds within the door zone and is implemented within the control unit (24) and causes the drive device (14) to be switched off without use of the elevator controller (34).
7. Safety device in accordance with any one of the preceding claims, characterized in that the evaluating device (58) comprises a first part which recognizes when the door zone is left with the elevator car door (38) open, and a second part which recognizes inadmissible accelerations and/or speeds within the door zone, the two parts mutually monitoring each other's operation by means of bidirectionally exchanged signals and causing the drive device (14) to be switched off in the event of a fault.
8. Safety device in accordance with any one of the preceding claims, characterized in that the door zones of the safety device (55) have a different length than door zones of other functional units of the elevator, in particular, a different length than the door zone which is applicable for arrival with the elevator car door opening.
9. Safety device in accordance with any one of the preceding claims, characterized in that the control unit (24) comprises a reliable pulse inhibitor (72) for switching off the drive device (14).
10. Safety device in accordance with claim 9, characterized in that the pulse inhibitor (72) inevitably interrupts the electric power supply to the service brake (32).
11. Safety device in accordance with any one of the preceding claims, characterized in that the control unit (24) creates an electromagnetic short circuit in the drive motor (22) in order to switch off the drive device (14).
12. Safety device in accordance with any one of the preceding claims, characterized in that the measuring device (57) comprises a position detecting system for detecting the position of the elevator car (12) relating to absolute values, which is of at least two-channel configuration.
13. Safety device in accordance with any one of the preceding claims, characterized in that the measuring device (57) consists of a position detecting system for detecting the position of the elevator car (12) relating to absolute values and a pulse generator (36).

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