EP2607282A1 - Safety device for a lift with multiple cabins - Google Patents

Abstract

The lift (1) has two cages (2, 3) moved along a common travel path. The cages include two drives. A shaft information system determines speed and position information for the cages. A safety device (22) monitors the cages. The safety device is connected to the shaft information system. The safety device initiates a first braking measure for one of the cages when a distance between the cages falls below a safety spacing (D), predetermines a retardation plot for the cage and initiates a second braking measure for the cage when a result of the retardation plot is exceeded.

Description

The present invention relates to an elevator with two independently movable cabins and with a safety device for avoiding a collision between the two cabins according to the subject-matter of the independent claim.

When operating elevators with at least two cabins, which can be moved along a common roadway, there is always the problem of collision avoidance.

In the European patent specification 1 562 848 Alwird a safety device is presented, which takes into account the above-mentioned problem. This safety device prevents a collision between two cabins by the safety device monitors whether the cabs comply with a minimum safety distance. When falling below this safety distance, the safety device initiates an emergency stop. The safety device continues to monitor the distance between the two cabs when performing the emergency stop. If, despite the emergency stop, a further approach of the cabins takes place and a critical safety distance is undershot, the safety device initiates a catch braking.

In this two-stage braking process as a function of a minimum and a critical safety distance, the distance between the two elevator cars is to be continuously monitored. This continuous monitoring of the distance places relatively high demands on the computing capacity of the safety device.

Accordingly, it is the object of the present invention to develop an elevator with a safety device that easily and reliably prevents a collision between the cars.

The object is achieved by a lift according to the subject of the independent claim.

The elevator includes a first and a second cabin, which share a common

Roadway are movable, a safety device with which the two cabins are monitored, and a shaft information system, which is connected to the safety device and with which the speed and position of the two cabins can be determined. In this case, by means of the safety device for at least one first cabin, a first braking action can be initiated when the two cars fall below a safe distance. The elevator is characterized in that a deceleration curve for the at least first cabin can be predetermined by means of the safety device when the first braking measure is initiated. By means of the safety device, when the deceleration curve is exceeded, a second braking measure can be introduced through the at least first cabin.

The advantage of this elevator is that, after the first braking measure has been initiated, the safety device specifies a deceleration curve for the first car. As a result, the distance between the first car and the second car no longer needs to be monitored. During the deceleration, the safety device compares only the speed of the first car with the predetermined speed value of the deceleration curve per distance traveled. This simple value comparison places relatively low demands on the computing capacity of the safety device.

• Fig. 1 einen Aufzug mit einer Sicherheitseinrichtung zum Verhindern einer Kollision zwischen zwei entlang einer gemeinsamen Fahrbahn unabhängig verfahrbaren Kabinen.
• Fig. 2 Weg-Geschwindigkeits-Verläufe zweier hintereinander herfahrender Kabinen bei Eingreifen der Sicherheitseinrichtung; und
• Fig. 3 Weg-Geschwindigkeits-Verläufe zweier aufeinander zufahrender Kabinen bei Eingreifen der Sicherheitseinrichtung.

In the following the invention will be clarified by exemplary embodiments and figures and further described. Show it:

• Fig. 1 an elevator with a safety device for preventing a collision between two cabs independently movable along a common roadway.
• Fig. 2 Path-speed curves of two successive cabs when the safety device is engaged; and
• Fig. 3 Path-speed profiles of two approaching cabins when the safety device intervenes.

The FIG. 1 shows an elevator 1 with at least two cabins 2, 3. Each of these cabins 2, 3 is substantially independently along a common roadway movable. in the As shown, the roadway is defined by a pair of car guide rails 5.1, 5.2 installed in a hoistway 4.

The cabins 2, 3 are each suspended on a support means 8, 9.1, 9.2. Here, the suspension ratio of 1: 1 shown here is a common suspension ratio in elevator construction. However, the skilled person is free to choose a deviating higher suspension ratio of 2: 1, 3: 1 or higher.

The upper car 2 is suspended at a first suspension point 21 on a first support means 8. The suspension point 21 preferably lies centrally on the upper side of the upper car 2. From the first suspension point 21, the suspension element extends upwards into the upper region of the elevator shaft 4. There, the first suspension element 8 runs over a first traction sheave. By means of the traction sheave and optional first pulleys, the first support means 8 is again guided down to a first counterweight. The first counterweight is also suspended from the first support means 8 and balances the weight of the upper car 2.

A lower cabin 3 is attached to second and third suspension points 31.1, 31.2 on a second suspension element, which comprises two second suspension element strands 9.1, 9.2. The lower cabin 3 is preferably suspended in its lower region on opposite sides on the second suspension element strands 9.1, 9.2. From the second and third suspension points 31.1, 31.2, the suspension element strands 9.1, 9.2 extend laterally past the upper cabin 2 upwards into the upper region of the elevator shaft 4. There, the second suspension element strands 9.1, 9.2 run over second traction sheaves. By means of the second traction sheaves and optional second deflection rollers, the second suspension element strands 9.1, 9.2 are again guided downwards to a second counterweight. The second counterweight is finally also suspended from the second suspension element strands 9.1, 9.2 and balances the weight of the lower elevator car 3 from.

The first and second traction sheaves are each driven by a first and second drive. The first and second drives transmitted by means of the respectively associated traction sheave drive torque to the first and second support means 8, 9.1, 9.2. Accordingly, the two cabins 2, 3 largely independent of each other by an associated drive movable. These are equipped with the first and second drives depending on an associated engine and depending on an associated drive brake.

Furthermore, an elevator control 6 is provided, which controls the two drives of the cabins 2, 3. By means of call input devices, which are each arranged on a floor and connected to the elevator control 6, a passenger calls a car 2, 3 on a floor. Preferably, these call input devices are designed as destination call input devices. In the operation of such a destination call input device, a passenger not only displays his location at a floor on which he waits for a car 2, 3, but also notifies the elevator controller 6 of his desired destination floor. The elevator control 6 assigns a suitable car 2, 3 to this call and moves the allocated car 2, 3 to the floor and finally to the destination floor. For this purpose, the elevator control 6 controls the motor and the drive brake of the allocated cabin 2, 3 associated drive.

In addition, the elevator 1 has a shaft information system. This shaft information system comprises, for example, a code strip 7 with code marks and, per cabin 2, 3, a sensor 24, 34 for reading the code marks. The code strip 7 is mounted along the carriageway in the elevator shaft 4. The code marks preferably represent a unique, unmistakable position information. Speed information can be generated by means of an evaluation of the position information over time. The shaft information system thus provides at least information about its position and speed of the elevator control 6 and the safety device 22, 32 for each car 2, 3. The safety device 22, 32 evaluates the position information and / or speed information received from the sensors 24, 34. This also includes the calculation of a distance between the cars 2, 3 from their position information.

Optionally, the shaft information system has a distance sensor 25, which is arranged on the upper car 2. By means of this distance sensor 25, the distance to the lower cabin 3 can be detected. Similarly, the lower cabin 3 can be equipped with a distance sensor 36, with which a distance to the adjacent upper cabin 2 can be detected. The distance sensors 25, 36 are each connected to the safety device 22, 32. The safety device 22, 32 evaluates the distance information from the distance sensors 25, 36 incoming. A distance sensor 25, 36 is for example a laser distance measuring sensor or designed as Ultraschallabstandmesssensor

In addition, the safety device 22, 32 check the incoming distance information of the respective distance sensors 25, 36 for equality. In this plausibility test, the safety device 22, 32 determines whether the distance sensors 25, 32 function reliably. If the distance information of the distance sensors 25, 36 does not match, the safety device 22, 32 takes appropriate measures to bring the elevator 1 into a safe state. For example, the safety device 22, 32 can immobilize the elevator 1, since a collision between the cars 2, 3 can no longer be ruled out if the distance information is incorrectly evaluated. The distance information of the distance sensors 25, 36 are also comparable in a plausibility test with the distance calculated by the shaft information system from the position information of the cars 2, 3.

In the example shown, each cabin 2, 3 is associated with a decentralized operating safety device 22, 32 which is in each case in communication with the cabin brake 23.1, 23.2, 33.1, 33.2 associated with a car 2, 3 and the sensors 24, 34. The sensors 24, 34 transmit position and speed information to the safety device 22, 32. The car brakes 23.1, 23.2, 33.1, 33.2 can be controlled by the safety device 22, 32. In addition, the safety device 22, 32 communicates with the elevator control 6 and indirectly controls the first and second drive as well as its associated drive brakes and motors. Via the elevator control unit 6, a respective safety device 22, 32 also has information about the position and speed of the respective other car 3, 2. Alternatively, the safety device 22, 32 of a car 2, 3 is directly connected to the respective drive and their associated drive brakes and may possibly directly drive the drive or the drive brakes or motors. Deviating from the configuration with two safety devices 22, 32, which are each associated with a cabin 2, 3, a central safety device can be used, which monitors both cabins 2, 3 and controls the drives and cabin brakes 23.1, 23.2, 33.1, 33.2. Likewise, a direct exchange of information about the position and speed of each other cabin 2, 3 between the two safety devices 22, 32 is possible.

In addition, the safety device 22, 33 of a car 2, 3 with one of the respective Cabin 2, 3 associated with the car brake 23.1, 23.2, 33.1, 33.2 connected and can control this in a dangerous approach of the two cabins 2, 3.

This in Fig. 1 The example shown relates to a snapshot in which the upper car 2 drives ahead in a direction A and a lower car 3 follows in a same direction B of the upper car 2.

The safety device 32 of the lower trailing cab 3 compares the current distance with a permissible safety distance D. For this purpose, the safety device 32 has at least one processor and a memory unit, wherein a program for comparing a current distance with the safety distance D is stored on the memory unit and Processor calls this program and makes the comparison. This program compares distance information provided by the hoistway information system with a safety distance D. This safety distance D is stored on the memory unit either as a fixed preset value or as another program enabling a speed-dependent calculation of the safety distance D.

The permissible safety distance D represents a distance at which just a safe deceleration of the following lower cabin 3 is possible. If this permissible safety distance is exceeded, the safety device 32 initiates a first braking action in order to prevent a collision between the two cars 2 and 3. For this purpose, the safety device 32 controls the drive of the following lower cab 3 to decelerate the lower cab 3. The first braking measure is preferably carried out by actuation of a drive brake assigned to the drive. Alternatively or additionally, the first braking measure with a motor associated with the drive by applying a rotational movement of an associated traction sheave opposite torque can be performed.

When initiating the first braking measure, the safety device 32 gives the following lower cabin 3 a deceleration curve. In a first embodiment, this delay curve is stored permanently on the memory unit. In this case, the deceleration curve preferably depends on the nominal speed which a car 2, 3 reaches during normal operation of the elevator 1. In a second embodiment is the delay curve by means of another program, which is stored on the storage unit, speed-dependent calculable. To do this, the processor calls this program and performs the corresponding calculation.

During the first braking measure, the safety device 22, 32 compares the braking distance traveled by the instantaneous speed of the following lower cabin 3 with the speed value predetermined by the deceleration curve. For this comparison, another program is stored on the memory unit, which the processor calls and executes. If this deceleration curve can not be maintained by means of the first braking action, i.e. if a speed associated with an achieved braking distance is exceeded, the safety device 32 initiates a second braking action.

In this second braking measure, the safety device 32 controls the cabin brake 33.1, 33.2 assigned to the following lower cabin 3 to brake the lower cabin 3.

In the case of two cabins 2, 3 traveling in the same direction, preferably only the following lower cab 3 is braked with the first braking measure or second braking measure. The preceding first upper cabin 2 can continue the journey and thereby defuses the dangerous approach of the two cars 2, 3. Of course, the above information is applicable to a preceding lower cabin 3 and a trailing upper cabin 2. In this case, in a dangerous approach between the two cars 2, 3, only the following upper cabin 2 is braked by means of a first or second braking measure.

Similarly, the invention can be applied to opposite directions of travel of the cabins 2, 3, wherein the lower cabin 3 as in the Fig. 1 shown moves in a direction B and the upper cabin 2 in a direction opposite to the direction A on the lower cabin 3 moves. In the case of two cabins 2, 3 approaching each other, the safety distance D is doubled to 2 * D. If this safety distance falls below 2 * D, the safety device 22, 32 controls both drives or drive brakes or motors in order to initiate a first braking action. Both cabins 2, 3 are braked. Again, the safety distance 2 * D is speed-dependent from the safety device 22, 32 can be fixed. The faster a car 2, 3 is moved, the greater the safety distance D can be determined.

At the initiation of the first braking action for the upper and lower cabin 2, 3, the safety device 22, 32 for each car 2, 3 before a deceleration curve. If one of the two cabins 2, 3 or even both cabins 2, 3 can not or can not comply with this deceleration curve or exceed or exceed a speed for a predetermined braking distance achieved, the safety device 22, 32 initiates a second braking action for the affected cabin 2 , 3 on. For this purpose, the safety device 22, 32 controls the cabin brake 23.1, 23.2, 33.1, 33.2 of the respective car 2, 3 in order to decelerate the car 2, 3. In opposite directions of travel A, B of the two cabins 2, 3 so by means of the safety device 22, 32 for the first and for the second car 2, 3 depending on a first or possibly a second braking action can be introduced.

In the Fig. 2 and 3 are two braking examples based on a path-speed curve of the two cabins 2, 3 shown.

Fig. 2 , shows a situation similar to that Fig. 1 equivalent. Both cabins 2, 3 are moved in the same direction of travel A, B. A first preceding car 2 is moved in the direction of travel A and a second following car 3 is moved in the direction of travel B. The following car 3 is moved before a time t1 at a speed c1, which is below the nominal speed n. The preceding car 2, on the other hand, is moved before a time t1 at a speed which is less than c1. This is the case, for example, after a stop on a floor when approaching the preceding car 2. The travel of the preceding car 2 before the time t1 is in the Fig. 2 not shown for clarity. At time t1, the safety distance D between the preceding and the following cabin 2, 3 is exceeded. Accordingly, the safety device 32 initiates a first braking action. At the same time, the safety device 32 predefines a deceleration curve b. After the first braking measure has been initiated, the following cabin 3 of the deceleration cam c2 is decelerated accordingly. At time t2, the speed of the following car 3 is above the predetermined deceleration curve b. This causes the safety device 32 for the following cabin 3 to initiate a second braking action. After initiating the second braking action, the following car 3 of the deceleration cam c3 is decelerated accordingly to standstill. During this two-stage braking process of the following car 3, the preceding car 2 can be moved on at the speed c1.

Fig. 3 , on the other hand, shows a situation in which the two cabins 2,3 approach each other. Both cabins 2, 3 are moved accordingly in the directions of travel A ', B'. An upper cabin 2 is moved in the direction of travel A 'and a lower cabin 3 is moved in the opposite direction B'. Both cars 2, 3 are moved before a time t1 'at a speed c1', which is below the rated speed n '. At time t1 ', the safety distance D' between the first and the second car 2, 3 is exceeded, wherein the safety distance D '= 2D. Accordingly, the safety device 22, 32 initiates a first braking measure for both cabins 2, 3. At the same time, the safety device 22, 32 each provide a deceleration curve b 'for both cabins 2, 3. After initiating the first braking action, the first and second car 2, 3 of the deceleration cam c2 'are decelerated accordingly. At the time t2 ', the speed of the lower car 3 is above the predetermined deceleration curve b'. This causes the safety device 32 for the lower cabin 3 to initiate a second braking action. After initiation of the second braking measure, the lower cabin 3 is decelerated accordingly until the deceleration curve c3 'stops. The upper cabin 2, however, remains after initiation of the first braking measure until reaching standstill always below the predetermined deceleration curve b '. A second braking measure is not necessary for the upper cabin 2.

Claims (8)

Elevator (1) with a first (3) and a second cabin (2) which are movable along a common roadway, - A safety device (22, 32) with which the cabins (2, 3) can be monitored, and a shaft information system (7), which is connected to the safety device and with which the speed and the position of the two cabins can be determined,
wherein by means of the safety device (22, 32) for at least one first cabin (3) a first braking measure can be initiated if the two cars (2, 3) are below a safety distance (D, D '), characterized in that by means of the safety device ( 22, 32) at the initiation of the first braking measure, a deceleration curve (b, b ') for the at least first cabin (2, 3) can be predetermined, wherein by means of the safety device (22, 32) when exceeding the deceleration curve (b, b') for the at least first cabin (3) a second braking measure can be introduced. Elevator (1) according to claim 1, characterized in that both cabins (2, 3) each have a drive, wherein by means of the safety device (22, 32) of the drive is controllable to initiate the first braking action. Elevator (1) according to one of claims 1 or 2, characterized in that both cabins (2, 3) each have a cab brake (23.1, 23.2, 33.1, 33.2), wherein by means of the safety device (22, 32) the cab brake ( 23.1, 23.2, 33.1, 33.2) can be controlled to initiate the second braking action. Elevator (1) according to one of the preceding claims, characterized in that the first cabin (2, 3) has a distance sensor (25, 36) by means of which a distance to the second cabin (2, 3) can be detected. Elevator according to one of the preceding claims, characterized in that in the same direction of travel (A, B) of the two cabins (2, 3), by means of the safety device (22, 23) a first or second braking measure can be introduced only for the following first cabin (2, 3). Elevator (1) according to one of claims 1 to 4, characterized in that in the opposite direction of travel (A, B) of the two cabins (2, 3), by means of the safety device (22, 32) for the first and for the second cabin ( 2, 3) each a first or second braking action can be initiated. Elevator (1) according to one of the preceding claims, characterized in that the safety distance (D, D ') is speed-dependent and / or dependent on the direction of travel can be predetermined. Elevator (1) according to one of the preceding claims, characterized in that the deceleration curve (b, b ') can be predetermined as a function of the speed.

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