EP1935823B1 - Method for preventing the collision of two lift cabins moving in one shaft and corresponding lift system - Google Patents

Description

The invention relates to a method for preventing a run-up of two elevator cars which can be moved in the same shaft of an elevator installation and to an elevator installation which can be operated according to the preamble of claim 6.

Elevator systems with several elevator cars in the same shaft, which are also referred to as multi-mobile elevator systems, usually each have a drive and brake system per elevator car. Furthermore, such elevator systems are equipped with a collision protection system by which collisions of the elevator cars are to be avoided.

In addition to conventional electronically controlled Auffahr protection systems such as in the WO 2004/043 842 is through the European patent application EP-A-06 120 359 an elevator system with a collision protection system has been described with mechanically triggered, electro-mechanical switching mechanisms. The aforementioned collision protection system is simple in construction and reliable in its effect. The disadvantage, however, is that its triggering takes place only when the critical minimum distance between two approaching elevator cars is undershot, without taking into account further braking criteria, such as the relative speed between the elevator cars or the instantaneous effective distance, respectively, after the holding brakes have been triggered. Especially at high cabin speeds and in emergency situations can not be guaranteed with the last certainty that an upper or lower located further Elevator car still stops in time to avoid a collision.

• ein Verfahren vorzuschlagen, um bei einer Multimobil-Aufzugsanlage eine zusätzliche Bremsung auszulösen, wenn sich die Distanz zwischen den Aufzugskabinen trotz des Auslösens von Haltebremsen mittels eines Auffahr-Schutzsystems weiterhin so vermindert, dass ein sofortiger Notstop erforderlich ist;
• eine Multimobil-Aufzugsanlage zu schaffen, die gemäss diesem Verfahren betreibbar ist.

The object of the invention is

• propose a method for triggering additional braking in a multi-vehicle elevator installation if the distance between the elevator cars, despite the release of holding brakes by means of a collision protection system, continues to diminish so that an immediate emergency stop is required;
• To provide a multi-mobile elevator system, which is operable according to this method.

The emergency stop system should be designed as far as possible so that it does not cause an enlargement of the shaft cross-section.

• für das Verfahren durch die Merkmale des Anspruchs 1; und
• für die Aufzugsanlage durch die Merkmale des Anspruchs 6.

The solution of the task takes place

• for the method by the features of claim 1; and
• for the elevator installation by the features of claim 6.

Advantageous embodiments and further developments of the invention are described by the respective dependent claims.

The new elevator system has at least one upper elevator car and a lower elevator car. The two elevator cars can move up and down vertically in a common elevator shaft of the elevator installation, essentially independently of one another.

The upper elevator car has a first drive and brake system, which comprises a first holding brake (preferably an engine brake). The lower cab has a second drive and brake system that detects a second holding brake (preferably an engine brake). According to the invention in addition, the first elevator car is equipped with a first (emergency) brake and the second elevator car is equipped with a second (emergency) brake, the function of which will be explained below.

Furthermore, the elevator system has a collision protection system in order to avoid collisions between the elevator cars. The collision protection system preferably comprises a first electro-mechanical switching mechanism on the upper elevator car, and a second electro-mechanical switching mechanism on the lower elevator car, with which a deceleration of the upper elevator car by the first holding brake and / or a deceleration of the lower elevator car through the second holding brake can be triggered. In particular, but not mandatory, the elevator cars and the collision protection system according to the EP-A-060120359 be educated.

According to the invention, an emergency stop system is also provided. The emergency stop system is designed so that it continuously or repeatedly determines the instantaneous state of motion of the two elevator cars after triggering the delay or braking by the holding brakes and triggers an additional braking of one or both moving elevator cars by means of an associated cabin brake, if so taking into account the movement state of the elevator cars on the one hand and taking into account definable braking criteria on the other hand is necessary.

Among other things, the state of motion of the elevator cars is essentially a function of their relative speed.

Braking criteria can be set in advance in principle, but advantageously the current state of motion of the elevator cars is included.

Fig. 1

eine Multi-Mobil-Aufzugsanlage gemäss Stand der Technik, in einer stark vereinfachten, schematisierten Darstellung;

Fig. 2

ein Auffahr-Schutzsystem und ein Notstop-System an einer Multi-Mobil-Aufzugsanlage, in einer stark vereinfachten, schematisierten Darstellung;

Fig. 3

ein Diagramm zur Darstellung des Verfahrens nach der Erfindung;

Fig. 4

Details eines besonders bevorzugten Ausführungsbeispiels.

Further details and advantages of the invention will be described below with reference to an embodiment and with reference to the drawings. Show it:

Fig. 1

a multi-mobile elevator system according to the prior art, in a highly simplified, schematic representation;

Fig. 2

a collision protection system and an emergency stop system on a multi-mobile elevator system, in a highly simplified, schematic representation;

Fig. 3

a diagram illustrating the method according to the invention;

Fig. 4

Details of a particularly preferred embodiment.

Fig. 1 shows a simple elevator system 10. Such elevator systems are, as mentioned above, known under the term multi-mobile elevator systems. The elevator installation 10 has an elevator shaft 11 in which an upper elevator car A1 and a lower elevator car A2 can move vertically. As long as a critical minimum distance d (0) between the two elevator cars A1, A2 is maintained, ie during a normal operation where the instantaneous distance di is greater than the critical minimum distance d (0), the elevator cars A1, A2 can move independently of one another in the Move elevator shaft 11. The elevator installation 10 has a drive and brake unit, wherein preferably each of the pull-out cabins A1, A2 has its own drive and brake system.

The elevator installation 10 also has a collision protection system 20. The collision protection system 20 comprises a first electro-mechanical switching mechanism 21, which is arranged in a lower region of the upper elevator car A1, and a second electromechanical switching mechanism 22, which is in an upper Area of the lower elevator car A2 is arranged. The two switching mechanisms 21, 22 are vertically aligned one above the other.

The collision protection system 20 of the elevator installation 10 preferably has per elevator car A1, A2 its own safety circuit, in which several safety elements, such as safety contacts and switches, are arranged in a series connection. The corresponding elevator car A1 or A2 can only be moved if its safety circuit and thus also all safety contacts integrated in it are closed. The safety circuit is connected to the drive and brake unit of the elevator system 10 or the drive and braking systems of the elevator cars A1, A2 in order to interrupt the driving operation of the corresponding elevator car A1 and / or A2, if the safety circuit by pressing the corresponding electro mechanical switching mechanism 21 and / or 22 is opened.

The first switching mechanism 21 comprises a weighting body 23 having a weight G suspended from an elongated flexible support member 24, which in turn is secured to the lower portion of the upper elevator car A1. The overall vertical dimension of the support member 24 and the weight body 23 substantially corresponds to the critical distance d (0) to be maintained between the elevator cars A1, A2.

The second switching mechanism 22 comprises a mechanical sensor in the form of a lever 28 (see Fig. 2 ), which acts on a contact switch 34.

In the normal case, ie when the distance di between the elevator cars A1 and A2 is greater than the critical distance d (0), the weighting body 23 hangs freely on the support element 24, which is under tension by the weight G of the weighting body 23 and is kept stretched.

When the elevator cars A1, A2 come so close that their instantaneous distance di falls below the critical distance d0, the weighting body 23 encounters the lever 28 of the second electro-mechanical switching mechanism 22. This reduces the tensile force exerted by the weighting body 23 on the support element 24, and thus largely the tensile stress in the support element 24th

Due to the considerable reduction of the tensile stress in the support element 24, the safety circuit of the first drive and brake unit of the upper elevator car A1 is opened. This triggers the braking of the upper elevator car A1 by means of the first holding brake (designed, for example, as an engine brake). As a result of the impact of the weighting body 23 on the lever 28, the safety circuit of the second drive and brake unit of the lower elevator car A2 is also opened practically at the same time. As a result, the deceleration of the lower elevator car A2 is triggered by means of the second holding brake (designed, for example, as an engine brake).

However, the emergency stop system according to the invention can also be used in elevator systems 10 whose collision protection system is designed differently or whose holding brakes can be triggered in other ways and / or which are equipped with a safety bus system instead of the mentioned safety circuits.

According to the invention, the elevator installation 10 has, in addition to the collision protection system 20, the emergency stop system, by which an additional deceleration of the moving elevator cars A1 and / or A2 is achieved after the deceleration of one or both elevator cars A1, A2 by one or both holding brakes can.

The triggering of this additional delay takes place taking into account the current state of motion of the elevator cars A1, A2 and on the basis of the emergency stop criteria.

The emergency stop system of the invention may include structural elements of a collision protection system 20 and additional structural elements. That is, in this case, the emergency stop system is at least partially integrated with the collision protection system 20.

d0

kritische Distanz (maximale Detektionsdistanz)

di

momentane Distanz der Aufzugskabinen A1, A2

ωi

momentane Winkelgeschwindigkeit der Rolle 30

vi(rel)

momentane Relativgeschwindigkeit der Aufzugskabinen A1, A2

vi

momentane Geschwindigkeit einer der Aufzugskabinen

vi(A1)

momentane Geschwindigkeit der oberen Aufzugskabine A1

vi(A2)

momentane Geschwindigkeit der unteren Aufzugskabine A2

a(min)

minimal erzielbare Verzögerung bei Notstop

s_stop(min) I

minimale Stop-Distanz, wenn nur eine Aufzugskabine A1 oder A2 in Bewegung ist (d.h. wenn vi(rel)= vi ist)

s_stop(min) II

minimale Stop-Distanz, wenn beide Aufzugskabinen A1 und A2 in Bewegung sind
(d.h. wenn (v(rel)/2) = vi ist)

In a collision protection system according to the invention of an elevator installation 10 according to FIG Fig. 2 it is provided that the flexible support member 24 is not fixed directly or fixed to the lower region of the upper elevator car A1 or to a lever located there, but is attached to a roller 30. The roller 30 is in turn rotatably mounted at the lower portion of the upper elevator car A1. This attachment is in Fig. 2 Not shown. The roller 30 has an internal energy storage 31 (or an attached energy storage 31, as in Fig. 4 ), preferably in the form of a helical spring, which exerts a force which tends to rotate the roller 30 (in the example shown, this rotation would act in a clockwise direction) in that the flexible support element 24 is wound onto the roller 30. In the normal case, ie when the instantaneous distance di between the elevator cars A1 and A2 is greater than the critical distance d0, the roller 30 is blocked against rotation by the tensile force exerted on the flexible support member loaded with the weight G of the weighting body 23 24 exercises. That is, the roller 30 can not be brought into rotation by means of its internal energy storage 31 because of this blockage. Once a delay of the elevator cars A1, A2 has been initiated by the holding brakes, because the instantaneous distance di between the elevator cars A1 and A2 falls below the critical distance d0, the Emergency stop system or its control system activated. In the present case, this is done by hitting the weighting body 23 on a sensor (eg the lever 28 in conjunction with a switch 34) of the switching mechanism 22 of the lower elevator car A2. After the impact of the weighting body 23, the tensile force in the flexible support element 24 drops away, through which the roller 30 was blocked. The roller 30 is now released and rotates under the roll-up torque supplied by its internal energy store 31 so that the flexible support element 24 is wound onto the roll 30. The release of the roller 30 takes place virtually simultaneously with the actuation of the electro-mechanical switching mechanisms 22 and the deceleration of the elevator cars A1, A2 by their holding brakes.
The roller 30 rotates after its release, and that part of the flexible support element 24 is wound up, which essentially corresponds to the difference between the critical distance d0 and the instantaneous distance d1 of the elevator cars A1, A2. In this case, however, the weighting body 23 may not be pulled upwards. The roll-up torque exerted by the internal energy store 31 on the roller 30 must therefore exert a winding force on the flexible support element 24 which is less than the weight G (23) of the weighting body 23, but greater than the weight G (24 ) of the flexible support member 24, wherein the frictional forces are taken into account.
The rotation of the roller 30 makes it possible to determine the current state of motion of the elevator cars A1, A2, based on the instantaneous angular speed ωi, and to determine the instantaneous distance di between the elevator cars A1 and A2. As the roller 30 rotates, its angular velocity ωi, which is a function of time, is detected by an incremental encoder 32. From this angular velocity ωi can then the current Relative speed vi (rel) of the elevator cars A1, A2 are determined. The instantaneous distance di between the elevator cars A1, A2 can likewise be determined, either by means of a distance measuring sensor 35 or mathematically using the instantaneous angular speed ωi of the roller 30. Subsequently, it is clarified whether an additional one is taking into account the thus determined state of motion and the emergency stop criteria Delay one or both elevator cars A1, A2 to be triggered by the cabin brakes.
How this can be realized is explained below by way of example.
The following symbols are used:

d0

critical distance (maximum detection distance)

di

instantaneous distance of the elevator cars A1, A2

.omega..sub.i

instantaneous angular velocity of the roller 30

vi (rel)

current relative speed of the elevator cars A1, A2

vi

instantaneous speed of one of the elevator cars

vi (A1)

instantaneous speed of the upper elevator car A1

vi (A2)

instantaneous speed of the lower elevator car A2

a (min)

minimally achievable delay in emergency stop

s _stop (min) I

minimum stop distance if only one elevator car A1 or A2 is in motion (ie if vi (rel) = vi)

s _stop (min) II

minimum stop distance when both elevator cars A1 and A2 are in motion
(ie if (v (rel) / 2) = vi)

The following assumptions or rules apply in the following:

In the context of the present description, when both elevator cars A1 and A2 travel, they approach each other at equal velocities vi (A1) = vi (A2), where vi (A1) and vi (A2) are absolute values.

If a contact switch 34 of the safety circuit of the lower elevator car A2 open and / or the instantaneous distance di between the elevator car A1 and A2 is less than the critical distance d0, there is a delay of each moving elevator car A1, A2 by braking by means of their holding brakes.

Emergency stop criteria

An emergency stop or braking by one or both cab brakes is triggered, in addition to the braking by the holding brakes, if one of the two following emergency stop criteria is met:

Emergency Stop Criterion A: When an elevator car A1 or A2 is traveling and the instantaneous distance di between the cars A1 and A2 is less than or equal to the corresponding minimum stop distance s _stop (min) I, braking by the car brake of the traveling elevator car A1 or A2 triggered.

Emergency Stop Criterion B: When both elevator cars travel and the instantaneous distance di between the elevator cars A1 and A2 is less than or equal to the corresponding minimum stop distance s _stop (min) II, deceleration is triggered by cabin braking of both elevator cars A1 and A2.

$${\mathrm{S}}_{\mathrm{stop}}\left(\min \right)\mathrm{I}\mathrm{=}{\left(\mathrm{vi}\left(\mathrm{rel}\right)\right)}^{\mathrm{2}}\mathrm{/}\left(\mathrm{2}\mathrm{*}\mathrm{a}\left(\min \right)\right)$$

$${\mathrm{S}}_{\mathrm{stop}}\left(\min \right)\mathrm{II}\mathrm{=}{\left(0.5\mathrm{vi}\left(\mathrm{rel}\right)\right)}^{\mathrm{2}}\mathrm{/}\left(\mathrm{2}\mathrm{*}\mathrm{a}\left(\min \right)\right)$$

The following are recorded or calculated for the determination of the state of motion and the comparison with the emergency stop criteria: By measurement: Is not a cabin in motion? By calculations: Is contact 34 of the safety circuit of the lower elevator car A2 open? $$\mathrm{vi}\left(\mathrm{A}\mathrm{1}\right)\mathrm{=}\mathrm{vi}\left(\mathrm{A}\mathrm{2}\right)\mathrm{=}\mathrm{vi}\mathrm{=}\mathrm{0.5}\mathrm{vi}\left(\mathrm{rel}\right)$$

$${\mathrm{S}}_{\mathrm{Stop}}\left(\min \right)\mathrm{I}\mathrm{=}{\left(\mathrm{vi}\left(\mathrm{rel}\right)\right)}^{\mathrm{2}}\mathrm{/}\left(\mathrm{2}\mathrm{*}\mathrm{a}\left(\min \right)\right)$$

$${\mathrm{S}}_{\mathrm{Stop}}\left(\min \right)\mathrm{II}\mathrm{=}{\left(0.5\mathrm{vi}\left(\mathrm{rel}\right)\right)}^{\mathrm{2}}\mathrm{/}\left(\mathrm{2}\mathrm{*}\mathrm{a}\left(\min \right)\right)$$

Fig. 3 shows a diagram with which the flow of the entire braking process using both the holding brakes and the cabin brakes is exemplified.

Field F1 shows measured or available values, namely

vi (rel); di; vi (1); vi (2); Position of the contact 34; After these values are available, question Q1 is answered. With question Q1, it is determined whether the contact 34 is open and / or di <d0.

If question Q1 is answered with no N, obviously no braking is required, neither by the holding brakes nor by the cabin brakes.

If question Q1 is answered with yes J, then according to field F2 the holding brakes are triggered, ie the emergency stop system is not caused to trigger additional braking by the cabin brakes.

Then it is determined with question Q2 whether both elevator cars are in motion.

If question Q2 is answered with no N, ie if only one of the elevator cars is in motion, then question Q3 is asked.

With question Q3 it is determined whether di is equal to or even less than s _stop (min) I.

If question Q3 is answered with yes J, ie if the minimum stop distance for this case has been reached or undershot, then according to field F3 an additional stop by the corresponding cabin brake takes place for an emergency stop.

If question Q3 is answered with no N, then another question is asked, Q4.

Question Q4 clarifies whether the relative speed of the elevator cars is zero.

If question Q4 is answered with yes J, this can only mean that both cabins are no longer moving. Because according to field F2 the holding brakes are triggered and according to answer no N on question Q2 is only one elevator car A1 or A2 in motion. According to field F4 then no further braking by cabin brake application is required because obviously the braking effect of the holding brake has sufficed.

If question Q4 is answered with no N, question Q2 is asked again.

If question Q2 is answered with yes J, ie if both elevator cars A1 and A2 are in motion, then question Q5 is asked.

With question Q5 it is clarified whether di is equal to or even smaller than S _stop (min) II.

If question Q5 is answered with no N, then question Q4 is asked for further clarification, that is, question Q4 clarifies whether the relative speed vi (rel) of the elevator cars A1, A2 is zero. If this is the case, then according to box F4 no additional braking with cabin brakes is necessary.

If, on the other hand, question Q5 is answered with yes J, additional braking by the cabin brakes takes place in accordance with field F3 for an emergency stop.

If more than two elevator cars run in the same elevator shaft 11, then a corresponding emergency stop system can also be set up between these elevator cars.

In Fig. 4 a presently particularly preferred embodiment of an essential part of the emergency stop system 21 is shown. It can be seen the role 30, on which the support means 24 winds up when it is not burdened by the weight of the hanging weight body 23 thereon. On the same shaft 42 as the roller 30 sits a spring output 31, which is also referred to here as energy storage. About a clutch 40, an incremental encoder 32 is grown. The connection is made via an adapter 41.

Claims (9)

1. Method of preventing collision of two lift cages (A1, A2), which move substantially independently of one another in a common shaft (11), of a lift installation (10), wherein a collision protection system (20) triggers a retardation of each moved lift cage (A1, A2) by a stopping brake when an effective distance (di) between the lift cages (A1, A2) falls below a critical minimum distance (dk), characterised in that after triggering of the stopping brake an emergency stop system (21)

   - ascertains, by means of a control system, instantaneous movement states of the cages (A1, A2) on collision course and

   - triggers, by means of cage brakes associated with the lift cages (A1, A2), an additional retardation of one or both lift cages (A1, A2) when the movement state thereof fulfils definable emergency stop criteria.
2. Method according to claim 1, characterised in that the emergency stop criteria are ascertained with consideration of the instantaneous movement states of the lift cages (A1, A2).
3. Method according to claim 1 or 2, characterised in that the control system for ascertaining the instantaneous movement states of the lift cages (A1, A2) repeatedly

   - detects the instantaneous relative speed (vi(rel)) of the lift cages (A1, A2) and

   - with consideration of the instantaneous relative speed (vi(rel))

   - ascertains instantaneous effective distance (di) between the lift cages (A1, A2),

   - ascertains as emergency stop criteria an instantaneous minimum emergency stopping distance (s_stop(min)I, s_stop(min)II) and

   - ascertains whether the instantaneous effective distance (di) is smaller than or equal to the instantaneous minimum stopping distance (s_stop(min)I, s_stop(min)II) so as to then trigger the cage brake of each moved lift cage (a1, a2).
4. Method according to claim 3, characterised in that the control system detects the relative speed (vi(rel)) of the lift cages (A1. A2) in that a rotational frequency (ωi) of a roller (30), which is fastened to the upper lift cage (A1) and on which is wound up a flexible support element (24) having an unwound length substantially corresponding with the critical minimum distance (d0), when on falling below of the minimum distance (d0) a weighting body (23) impinges on the lower lift cage (A2) and in that case releases the roller (30) for rotation.
5. Method according to claim 4, characterised in that

   - a tension force (G) exerted by the weighting body (23) on the support element (24) secures the roller (30) against rotation thereof before the weighting body (23) impinges on the lower lift cage (A2) and

   - the roller (30) is released for rotation when the tension force (G) exerted by the weighting body (23) on the support element (24) ceases when the weighting body (23) impinges on the lower lift cage (A2).
6. Lift installation (10) with at least one upper lift cage (A1) and at least one lower lift cage (A2), which in normal operation of the lift installation (10) are vertically movable independently of one another in a common shaft (11), wherein

   - the upper lift cage (A1) has a first driving and braking system with a first stopping brake and

   - the lower lift cage (2) has a second driving and braking system with a second stopping brake and wherein

   - a collision protection system (20) is provided, by which triggering of the stopping brakes can be initiated when an instantaneous distance (di) between the lift cages (A1, A2) is less than a critical minimum distance (d0), characterised in that an emergency stop system (21) is provided

   - with a control system by which the instantaneous movement state of the lift cages (A1, A2) is detectable in the case of a further falling below of the minimum distance (d0) after triggering of the stopping brakes and emergency stop criteria are ascertainable and

   - with a first cage brake for the upper lift cage (A1) and a second cage brake for the lower lift cage (A2), wherein one or both cage brakes can be triggered when the emergency stop criteria are fulfilled.
7. Lift system (10) according to claim 6, characterised in that the control system for detecting the instantaneous movement state of the lift cages (A1, A2) after triggering of the holding brakes comprises:

   - means for determining the instantaneous effective distance (di) between the lift cages (a1, a2),

   - means for determining the relative speed (bi(rel)) of the lift cages (A1, A2),

   - means for determining the minimum stopping distance of the lift cages (A1, A2) with consideration of the relative speed of the lift cages (A1, A2),

   - means for comparing the instantaneous minimum stopping distance with the instantaneous effective distance and

   - means for triggering the cage brake of each moved lift cage (A1, A2) when the effective distance is less than or equal to the minimum stopping distance.
8. Lift system (10) according to claim 7, characterised in that the means for determining the relative speed and the effective distance of the lift cages (A1, A2) comprise

   - a flexible support element (24)

   - with a first end which is fixed to a roller (30) and can be wound up on this roller (30) and

   - with a second end to which a weighting body (23) is fastened,

   wherein the length of the flexible support element together with the weighting body (23) corresponds with the critical minimum distance, and wherein

   - the roller (30)

   - is rotatably fastened to the upper lift cage (A1),

   - comprises an internal energy store (31) by which a winding force can be exerted on the roller (30) by which the roller can be set into rotation,

   - is coupled with means (32) for detecting its rotational frequency,

   - is blocked against rotation by a tension force, which is exerted by the weighting body (23) on the support element (24), when the distance between the lift cages (A1, A2) is greater than the critical minimum distance and

   - rotates under the winding force when the weighting body (23) has impinged on the lower lift cage (A2),

   - and with means for calculating the relative speed and the effective distance from the rotational frequency of the roller (30).
9. Lift system (10) according to claim 6, characterised in that the collision protection system (20) comprises:

   - a first safety circuit with a first electromechanical switching mechanism (21), by which the stopping brake of the first lift cage (A1) can be triggered, at the first lift cage (A1) and

   - a second safety circuit with a second electromechanical switching mechanism (22), by which the stopping brake of the second lift cage (A2) can be triggered, at the second lift cage (A2),

   wherein the first switching mechanism (21)

   - comprises the support element and the weighting body (23),

   - is held under the weight of the weighting body (23) in a travel setting and by which

   - the first holding brake can be activated after impinging of the weighting body (23), and

   wherein the second switching mechanism (22)

   - is arranged below the weighting body (23),

   - is held in a travel setting before the impinging of the latter and by which

   - the second holding brake is activatable after impinging of the weighting body (23).

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