HK1139116B - Elevator system with an elevator car and a braking device for stopping said elevator car in a special operating mode and a method for stopping an elevator car in a special operating mode - Google Patents

Description

The invention relates to an elevator system with a lifting cab and a brake device for shutting down the lifting cab in special operation and a method for shutting down a lifting cab in special operation according to the general concept of the independent claims.

The lift system is built into a shaft. It consists essentially of an elevator cab which is connected to a counterweight by means of load-bearing equipment. By means of a drive which acts either on the load-bearing equipment, directly on the cab or directly on the counterweight, the cab is moved along an essentially vertical guideway. In normal operation the elevator cab is accelerated, kept in constant motion and decelerated by the driveway according to a normal course of action. A stop brake controlled in conjunction with the driveway keeps the elevator in a stationary position.

If the lift cab deviates from the normal course of normal operation, this is detected by a safety monitoring system. The moving lift cab is then delayed to a standstill by a braking system, by means of a braking force applied by the braking system together with a brake line, in a special operation and then kept in standstill. A special operation occurs when a planned course of operation must be interrupted due to a fault and a planned destination cannot be reached accordingly. This includes, for example, a deviation of an effective movement from the normal course, a disruption of drivers, a failure of the operating systems or even a failure of the means of containment.

EP1792864 shows such a braking device in the form of a catching device. When a malfunction is detected, the catching device is actuated, which stops the lift cab quickly and safely. The braking force is generated by the application of a force to the brake line by a brake pad. This force is called the normal force and the braking force is derived from this normal force and a specific friction value for the brake coupling. The brake force is determined by the brake pad and the brake line.

Another such lifting system or braking system is known from EP0648703, where the lifting cabin is held in a special operation by means of a controllable braking system independent of the drive.

A lifting system according to the general concept of the claim is known, for example, from GB-A-1469576.

The disadvantage of these elevator systems is that after a response to this brake device in special operation, the elevator cabin stops randomly. Usually, a long waiting time follows until service personnel are on site to free any trapped persons. Furthermore, it is not clear how to detect a state of the stationary cabin to keep it safe even after a stop.

The purpose of the system is to facilitate the release of persons trapped in the cabin in the event of a malfunction, to ensure that the cabin is kept in a safe position after braking in special operations, and to have a simple and clear functional structure.

The invention defined in the independent claims solves this problem by showing a solution which allows people in the elevator cabin to be easily released from the special operation.

According to the invention, the braking system calculates the delay required to bring the lift cabin to a standstill within an exit zone in special operation. This is advantageous because it allows easy release of persons in the lift cabin in special operation.

Alternatively or additionally, the braking system further detects a completed lifting cabin stop when a leaping change in braking force and/or a measured actual acceleration is detected. The braking system sets a braking force specification or a normal force when the completed stop is detected according to a holding force. This is advantageous because it ensures that the lifting cabin is securely secured after braking. This allows the lift to be released to exit the lift. A slip of the lifting cabin while people are leaving the lifting cabin or when, for example, service personnel enter the lifting cabin is prevented.

The brake system is also equipped with a brake force sensor, which measures the brake force easily, quickly and safely. The brake force sensor is also usually part of the brake system itself. This also results in a simple and clear functional structure and a cost-effective design.

A change in the direction of action of the braking force can be determined particularly easily if a change in the direction of action of the braking force is observed. A sudden change in braking force can also be detected when a deceleration fraction of the braking force is lost at the moment when the lift stops. The loss of the deceleration fraction or acceleration fraction can be detected simply by measuring the actual acceleration or by measuring the braking force. These are particularly simple and safe variants for the safe determination of the stopping force.Fault situation. For example, if a low-loaded lift cab is moving downwards and this cab needs to be stopped due to an unexpected event, only a very small braking force is needed to delay the lift cab, as it is already delayed due to the overweight of the counterweight. If the cab now comes to a stop, the cab will want to move upwards due to the still existing overweight of the counterweight. This can now be determined because the braking force changes and the braking force specification can be increased so that a high and safe holding force is maintained. The cab can thus be held gently and still be delayed safely.

On the other hand, if the low-loaded lift cab goes upwards and this cab has to be stopped due to an unexpected event or a fault, the overweight of the counterweight accelerates the cab further. It is therefore necessary to have a braking force which on the one hand compensates for a static overweight of the counterweight and produces a dynamic braking force.

The high holding force ensures that the cab does not suddenly slip away during subsequent service activities. For example, a braking system may be used in which a normal force is regulated or controlled to achieve a certain braking or holding force. In this case, the braking force specification is converted into a normal force specification according to which the braking system sets an effective normal force. To achieve a necessary high holding force, a correspondingly high normal force specification is made. In another example, a direct brake force control or a deceleration control is used, and a correspondingly high brake force or deceleration specification is applied to achieve the required high brake force, which necessarily results in the brake system producing a maximum delivery force or normal force based on the brake force specification, since only one brake force corresponding to the brake force can be measured at standstill in the stationary lifting cabin and the brake unit can therefore attempt to increase this value, since this value is lower than the brake force specification in the direction of the stop.

However, it also shows that, of course, the braking system can be spared when using a normal force control, since only one normal force required to hold can be specified. The term 'normal force' is used in this context below, but includes as an equivalent the additional force generated by a brake control or deceleration control.

The advantage is that the braking system sets the normal force to a value corresponding to the braking force after a maximum expected braking time or when a brake failure is detected. This gives a secondary safety, since a safe braking force is set after a time when the cab should have safely stopped if the braking system is broken.

The exit zone is determined by an approach area of the lift cabin in relation to the shaft door or notch door, which is advantageous as this design allows the exit of the cabin at a normal stop. A normal stop is a stop which is also approached in normal operation. The exit zone is, for example, the area in which a cabin door is in contact with a shaft door and can thus be opened safely by hand or at least electrically controlled. It is clear that in a special operation an exact orientation from cabin door to shaft door is not necessary. A step formation of up to 0.25 m can be quite acceptable in a special operation. Also, in this event a warning message or indicator can be provided indicating a possible step. Persons are thus warned.

In particular buildings, emergency exit zones may also be defined, which is useful when there are longer driving distances without normal stops, as is the case for example in elevator systems with so-called express zones.

According to the invention, the braking system is designed to calculate several times during the movement of the lift cabin in normal operation a hypothetical required delay which would be necessary to bring the lift cabin to a standstill within the exit zone in special operation. This enables the braking system to react quickly. Furthermore, this repeated calculation process allows the hypothetical required delay to be controlled, since the hypothetical required delay can be subjected to a plausibility check. It is advantageous that the calculation of the hypothetical required delay takes place in a shorter time interval or continuously. The time interval is used to ensure that an accurate exit interval is possible. The time interval required for the calculation of the hypothetical required delay can usually be calculated as a fraction of a second.

The following are the main factors that affect the time taken to reach the exit zone: the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle, the speed of the vehicle.

According to the invention, the hypothetical required delay in the event of an unexpected event is defined and used directly to perform braking as the required delay, whereby the braking device uses this required delay to determine other brake control parameters such as braking force or normal force. This solution gives a clear functional structure. From the moment the unexpected event occurs, braking can be performed autonomously, since the braking device only needs to comply with the preset delay value.

The brake system is preferably able to determine a time delayed brake application point or the brake system determines the deceleration in the form of any reference acceleration curve if this is necessary to reach a nearest exit zone. For example, any form of reference acceleration curve is a curve that first involves a high deceleration and then slides to the exit zone after a correspondingly high deceleration phase with a low delay. These possibilities are advantageous because, depending on the distance to the nearest possible exit zone, the time to reach the exit zone can be optimized according to the needs. Preferably, a brake calculator, at least functionally separate from other control functions, is used to calculate the required decelerations.

The brake system preferably includes an accelerometer and an accelerometer which, during braking, uses the required deceleration as the set value and the normal force as the set value, as specified by the brake calculator, and the brake system preferably includes at least two brake units each acting on one brake line, the brake system determining brake control values for each of the individual brake units. The braking system is more advantageous in the form of an electromechanical or a hydraulic or a fully mechanical friction braking system. A combination of different braking systems can also be used. This increases the reliability of the overall system, as different types usually complement each other advantageously in failure situations.

The advantage is that the brake line is connected to the control line in one piece, which gives a cost-effective overall solution.

In a further training, the required delay and/or time delayed brake application point is determined by taking into account a speed, a current position of the lift cabin in relation to a shaft, the shaft door, the notch or another lift cabin, a mode of operation of the lift system, or a condition of the brake system, so as to achieve the most comfortable and yet safe stopping of the lift cabin in special operation at all times.

The following illustration of the invention is given by means of an example of an embodiment in the context of the figures: Figure 1a schematic view of a lifting systemFigure 1a view of the lifting system from Figure 1Figure 2a running diagramFigure 3a functional diagram of a brake device

Fig. 1 together with the accompanying diagram in Fig. 1a shows an example of a lift system 1. The lift system 1 comprises a lift cabin 2 which is connected to a counterweight 20 by means of load 21 . The lift cabin 2 is driven by means of load 21 by a drive 22. The lift cabin 2 is led by guideways 4 essentially in a vertical direction to a lift shaft 10. The lift cabin 2 and the counterweight 20 move in parallel in the lift shaft 10. The lift cabin 2 is used for transporting a conveyor load GQ. The lift shaft has shaft doors 9 which are arranged on which floors and allow access to the lift cabin 2 or lock.In operation, the lift cabin is moved along the shaft doors 9 . The lift cabin 2 is stopped for loading or unloading in an exit area 8 of the associated shaft door 9 . The locations of the individual shaft doors 9 and the associated exit areas 8 are known in the form of absolute positions 19 . In Figure 1 the absolute positions 19 are given the values SH0 to SHn . Instead of shaft doors 9 on certain floors there may be only a note 13 door . This is often used when a lift cabin 2 does not normally have to stop over large driving distances or express zones.normally the movement of the lift cab is controlled by a lift control (not shown) which controls the drive 22 accordingly.

The lifting cab 2 shown is equipped with a brake device 3 installed on the lifting cab 2 which can, if necessary, brake and/or hold the lifting cab 2 from a stationary position to a standstill. The brake device 3 intervenes in a brake line 5 for this purpose. In the example shown, the brake line 5 and the guide line 4 are formed by a guide rail 6 which is known to be a T-guide rail. In the example shown, the braking system 3 comprises two brake units 15 each capable of operating on a guide rail 6 located on either side of the cab 2. The braking system 3 also comprises a brake calculator 7 and an accelerator 18 and associated sensors. One sensor is, for example, a brake force sensor 16 which measures a braking force applied by the brake unit 15 or an acceleration sensor 17 which detects a current acceleration state of the lift cab 2.

In a special operating situation or an emergency situation, for example, when, in an extreme situation, the means of support 21 shown fail, the braking system 3 or the brake units 15 are controlled in such a way that the lifting cab 2 stops autonomously within the nearest possible exit zone 8. The precision of the control need not be absolutely accurate. It is sufficient if the lifting cab stops in an approach area 11. The approach area 11 is preferably such that the shaft door 9 or the brake door 13 can be opened without special precautions.This approach area 11 covers an area of approximately 250 mm to the nearest exit zone 8. The lifting unit 2 can be held in a normal position and the brake unit 2 can be held in a fixed position at this point.

The brake calculator 7 continuously calculates, during normal operation, a hypothetical required delay ANh which would be required if the lifting cab had to be brought to a rapid halt in an emergency. The brake calculator 7 knows the momentary position of the Sabs of the lifting cab 2 and compares this momentary position with a data store 19 which contains the absolute positions ANSH0 to SHn of the AN 8 exit ranges. The brake calculator 7 continuously calculates a distance dS from the next exit range 8 and, under the current acceleration, determines the hypothetical maximum speed required. An example of this is the hypothetical AN 8 and a new value can be determined if the hypothetical AN 8 is required to reach the next exit range.

The determination of the current position of the cabin 2 can be done in different ways, such as using an absolute position detection system or calculating the position of the cabin 2 from the accelerometer 17. The current speed of the cabin can be measured by a speed sensor or the above-mentioned sensors, such as the absolute position detection system or the accelerometer 17, can be used to derive the current speed.

In the event of an emergency or failure event E, the accelerator 18 shall assume the hypothetical required deceleration ANh as required deceleration ANe. The accelerator 18 shall therefore determine, taking into account the current load GQ, the current acceleration state aeff and any other parameters, the required braking force FB and normal forces FNe and transmit these to the individual braking units 15, which shall then provide the required braking force FB or normal force FN. The effective braking force FB 17 shall be measured by means of the braking force sensor and transmitted to the accelerator 18 for control and correction.

The accelerator 18 can now detect if the brake force FB suddenly changes direction or if there is a sudden change in the measured brake force or actual acceleration aeff. Both events indicate that the lifting cabin 2 has reached the reference point and the accelerator 18 can increase the normal force input to the brake units to a safe value. This is important because as a result of the lifting cabin coming to a standstill in the approach area 11, a load change can be made by persons who can now leave cabin 2 or by auxiliary personnel entering the lifting cabin 2. This change can cause a shift in the weight of a load.This could lead to the lift cabin slipping away without the brake system being adjusted accordingly. Of course, it is possible to divide the functional groups into brake calculator 7 and accelerator 18. More finely structured functional groups may be used or integrated functional groups may be used which summarize the corresponding functions. In the lower part of Figure 2 a journey of a lift cab 2 is shown in the form of a speed-time diagram and in the upper part of the figure an illustrative acceleration/braking force diagram is shown.The brake calculator continuously calculates the hypothetical delay ANh required to reach the nearest possible approach range 11 to an exit range 8. The calculation is carried out at a frequency specified by a processor of the brake calculator. In a transition range A, where different exit positions SHn can be reached, decision criteria are stored to govern a selection. Such decision criteria may include the occupation of an affected exit position, evacuation options, a type of recorded event, etc. In the shown course, an event (E) occurs shortly after passing through the floor or exit SH2.This event (E) signals a deviation from the normal course of travel detected by a safety system of lifting equipment 1 and requiring emergency shutdown of the lifting cab 2. The brake calculator 7 defines the last calculated hypothetical required deceleration ANh, now as the currently required deceleration ANe. The accelerator 18 determines the required deceleration ANe from this required deceleration ANe and from current data such as momentary acceleration Aeff or load GQ and a characteristic of the associated brake units 15, the required normal forces FNe and the brake units give this normal force FNe. This produces, usually by friction, a corresponding braking force FBeff in conjunction with the brake line 5 and this now effective braking force FBeff is detected by the brake force sensor 16 and transmitted to the accelerator 18.In a first phase of braking, the total braking force FBeff_1 is applied and thereby produces a corresponding deceleration ANe1. For example, according to the required deceleration ANe, the braking force FB is increased in a second phase and the resulting braking force FBeff_2 produces a correspondingly higher final deceleration ANe2. As shown in the diagram in the upper part of the diagram, the brake force sensors 16 and their sums now measure a total braking force FB_2 as long as the lift is in motion. Once the cabin 2 reaches the turbine, a deceleration fraction is removed and the brake force 16 is reduced by the determined brake force FBeff_3B. This value is significantly reduced by the F15B. This is detected when the demand for the control unit is increased and the brake force 16 is increased by the determined brake force FBF_3B.Now, I want you to secure elevator compartment two. Depending on the current load GQ and direction of travel and the type of event (E), the change in dFBeff may in many cases involve a change in the pre-sign, which is the case if, without the action of the braking device 3, a change in direction of travel would result.

The illustration given is a way of realising the invention. If the elevator operator is aware of the present invention, he can change the shapes and arrangements at will. For example, to ensure the safe holding of the elevator cabin 2 after braking, the accelerator controls can also raise the desired value of the deceleration to a high value ANe3. Since this value cannot be reached as the cabin 2 is standing, the clamping force FN is necessarily increased to a maximum. Furthermore, the brake unit 3 naturally also takes into account the shadow 12.

In other cases, self-propelled elevator cabs may be used instead of a lifted lifting cab, and the shaft shown may be a fully or partially open shaft.

Claims (9)

1. Elevator system (1) with an elevator car (2) and with brake equipment (3), the elevator car (2) being movable in normal operating mode and being able to be decelerated to standstill and held at standstill in special operating mode by the brake equipment (3) by means of a braking force (FB) produced by the brake equipment (3) together with a brake track (5), wherein the brake equipment (3) calculates a required deceleration (ANe) in order to bring the elevator car (2) to standstill within an exit zone (11) in the special operating mode, characterised in that the brake equipment (3) during movement of the elevator car (2) in the normal operating mode calculates a plurality of times a hypothetically required deceleration (ANh), which would be required in order to bring the elevator car (2) to standstill within the exit zone (11) in the special operating mode and on occurrence of an event (E) for braking in the special operating mode, the brake equipment (3) uses the hypothetically required deceleration (ANh) as required deceleration (ANe).
2. Elevator system according to claim 1, characterised in that the brake equipment (3) with use of the required deceleration (ANe) determines on occasion further brake regulating variables such as braking force (FB) or normal force (FNe).
3. Elevator system according to claim 1, characterised in that the brake equipment (3) determines a brake application point delayed in time when this is required for reaching the exit zone (11) and/or that the hypothetically required deceleration (ANh) is a reference acceleration curve of any form suitable for reaching the exit zone (11).
4. Elevator system according to any one of the preceding claims, characterised in that the required deceleration (ANe) and/or the brake application point delayed in time is or are determined with consideration of a speed (Veff), a current position (Sabs) of the elevator car (2) with respect to a shaft door (9), an emergency door (13), a shaft end (12, 12u, 12o), a further elevator car, an operating mode of the elevator system (1) or a state of the brake equipment (3).
5. Elevator system according to any one of the preceding claims, characterised in that the brake equipment (3) includes an acceleration sensor (17) for measuring the effective acceleration (Aeff) and an acceleration regulator (18) which during braking uses the deceleration (ANe) as target value and the normal force (FN) as correcting variable.
6. Elevator system according to any one of the preceding claims, characterised in that the brake equipment (3) recognises that standstill of the elevator car (2) has taken place when an abrupt change (dFBeff) in the braking force (FB) or an abrupt change in a measured effective acceleration (Aeff) is detected.
7. Elevator system according to claim 6, characterised in that the brake equipment (3) sets the normal force (FN) in correspondence with a holding force when it is detected that standstill has taken place and/or that the brake equipment (3) sets the normal force (FN) after a maximum expected time of braking or when a brake fault is detected to a value corresponding with the holding force.
8. Method of stopping an elevator car in a special operating mode by means of brake equipment, the elevator car (2) being moved in normal operating mode and being able to be decelerated to standstill and held at standstill in special operating mode by the brake equipment (3) by means of a braking force (FB) produced by the brake equipment (3) together with a brake track (5), wherein a required deceleration (ANe) is calculated in order to bring the elevator car (2) to standstill within an exit zone (11) in the special operating mode, characterised in that

   - during movement of the lift cage (2) in the normal operating mode a hypothetically required deceleration (ANh), which would be needed in order to bring the elevator car (2) to standstill within the exit zone (11) in the special operating mode, is continually calculated and

   - on occurrence of an event (E) for braking in the special operating mode the hypothetically required deceleration (ANh) is used as required deceleration (ANe).
9. Method according to claim 8, characterised in that a standstill, which has taken place, of the elevator car (2) is recognised when an abrupt change (dFBeff) in the braking force (FB) and/or in a measured effective acceleration (Aeff) is detected.