EP2808285B1 - Lift assembly - Google Patents

Description

The present invention relates to an elevator installation with a monitoring device for a suspension element, and to a method for monitoring at least one suspension element in an elevator installation.

In elevator systems, steel cables have traditionally been used as support means for carrying and / or driving an elevator car. According to a further development of such steel cables, belt-type suspension elements which have tension members and a jacket arranged around the tension members are also used. However, such belt-like support means can not be monitored in a conventional manner, because the tension members, which determine a breaking load of the suspension element, are not visible through the sheath.

To monitor such tension members in belt-like suspension means, a test current can be applied to the tension members. In the circuit thus formed or in a plurality of circuits thus formed, a current flow, a voltage, an electrical resistance or an electrical conductivity is measured. On the basis of a size measured in this way, it is possible to deduce an integrity or a degree of wear of the suspension element. Namely, reduces the diameter of a tension member by fractures of individual wires or by metallic abrasion, the electrical resistance of this tension member increases.

The patent US7123030B2 discloses such a method for determining a degree of wear of a belt-type suspension element. Based on a specific electrical resistance of electrically conductive tension members is closed on a breaking force of the suspension element.

Another method for monitoring a state of wear of a belt-type suspension element in an elevator installation is disclosed in the document US 2011/148442 A1 known.

In this case, different levels of wear are detected by monitoring the electrical resistance of the tension members of the suspension element.

With such a monitoring method described in the prior art, however, only a general statement can be made about the condition of a suspension element become. It is therefore desirable to have a more detailed monitoring of sheathed tension members in support means in order to be able to trigger an appropriate reaction.

It is therefore an object of the present invention to provide a method of monitoring a suspension in an elevator system to provide, which allows a precise statement about the state of the suspension means. In addition, the process should be feasible with cost-effective means. It is also an object of the present invention to provide an elevator installation with a suspension element, wherein such a method can be carried out in the elevator installation.

• Überwachen eines elektrischen Widerstandes der Zugträger, wobei durch eine Überwachungsvorrichtung zumindest zwei der Zustände: unterbrochener Zugträger, geerdeter Zugträger, und beschädigter Zugträger feststellbar sind;
• Auswerten der festgestellten Zustände der Zugträger, wobei die Zustände einem Warnzustand zugeordnet werden; und
• Weiterbetreiben oder Weiterbetreiben unter Absetzung einer Vorwarnung oder Ausserbetriebnehmen der Aufzugsanlage unter Berücksichtigung des Warnzustandes.

To solve this problem, a method for monitoring at least one suspension element in an elevator installation is initially proposed. The support means comprises electrically conductive tension members, which are surrounded by an electrically insulating jacket. The method comprises the following steps:

• Monitoring an electrical resistance of the tension members, wherein by a monitoring device at least two of the states: interrupted tension members, grounded tension members, and damaged tension members are detectable;
• Evaluating the detected states of the train carriers, the states being associated with a warning state; and
• Continue or continue operating by canceling an advance warning or putting the lift system out of service, taking into account the warning condition.

Such a method has the advantage that a situation-appropriate reaction to the different states of the suspension element is made possible. By dividing it into three different damaged states of the tension members on the basis of a change in the electrical characteristics of the tension members, it is possible by appropriate weighting of these states to assign a warning means to a suspension element or all suspension elements of an elevator installation. Such a warning state can in turn be used in a simple manner to trigger a corresponding reaction in accordance with the situation. Thus, this method allows to assess the condition of a suspension more accurate and thus avoid unnecessary shutdown of the elevator system or to prevent dangerous further operation of the elevator system.

In an advantageous development, three states can be detected by the monitoring device during monitoring. This has the advantage that a condition of the suspension element can be estimated even more accurately than is possible with only two different defective states of the tension members.

In this context, the term "interrupted tension member" means a situation in which a tension member is substantially interrupted at one location such that substantially no electrical current can flow over that location. The term "grounded tension member" in this context means that a tension member is in contact with a grounded member such that electrical current applied to the tension member substantially drains off this grounded member. The term "damaged tension member" in this context means that the tension member at at least one point damage, for example in the form of individual wire breaks or in the form of rusted wires, so that changes an electrical resistance of this tension member due to these damaged areas. Such damage to the tension members usually have the effect of increasing the electrical resistance of an affected tension member. A "damaged tension member" may also be present if, due to damage, two adjacent tension members are in electrical contact with each other. This is the case, for example, when the jacket material between two tension members is damaged or when a broken wire of a tension member contacts an adjacent tension member. Such cross-connections between tension members usually have the effect of reducing the electrical resistance of an affected tension member.

These three different defective states of a tension member can be determined in a simple manner by determining an electrical resistance of the tension member. If the electrical resistance of a tension member tends to infinity, there is an interrupted tension member. If the electrical resistance of the tension member tends towards zero, then there is a grounded tension member. If the electrical resistance of a tension member changes, then there is a damaged tension member with at least one damaged point. According to the invention, each warning element is assigned to each individual suspension element with all associated tension members as well as a sum of all the suspension elements in the elevator installation with all associated tension members. Such a method has the advantage that both dangerous situations due to individual defective suspension means are recognized, as well as dangerous situations due to a sum of defects in various suspension elements of an elevator installation. For example, small defects in each one of three Carrying means of a lift system represent a dangerous condition, although the individual suspension means considered alone would not have to be assigned to a dangerous condition. On the other hand, by such a method, a dangerous situation can be detected, in which only one of several support means of a lift system has defects, but so serious defects that a dangerous situation for the entire elevator system is present. If, in such a situation, one would only consider the totality of the defects of all the means of suspension, this situation would not be able to be correctly assessed. According to the invention, the most serious warning state, selected from the most serious warning state of each individual suspension element and the warning state of the sum of all suspension elements, is decisive for the continued operation or decommissioning of the elevator installation. This ensures that any kind of dangerous situation can be detected.

• kein Fehler
• Fehler 1. Grades
• Fehler 2. Grades

zugeordnet werden. Durch eine derartige Aufteilung bei der Auswertung anhand der festgestellten Zustände der Zugträger ist es möglich, situationsgerechte Massnahmen einzuleiten.
In einer beispielhaften Ausführungsform führt beim Weiterbetreiben oder Weiterbetreiben unter Absetzung einer Vorwarnung oder Ausserbetriebnehmen der Aufzugsanlage der Warnzustand kein Fehler zum Weiterbetreiben der Aufzugsanlage, der Warnzustand Fehler 1. Grades zum Weiterbetreiben unter Absetzung einer Vorwarnung, und der Warnzustand Fehler 2. Grades zur Ausserbetriebnahme des Aufzuges.In an exemplary embodiment, the tension members can at least the warning states

• no mistake
• 1st degree error
• 2nd degree error

be assigned. By such a division in the evaluation based on the detected states of the train carriers, it is possible to initiate appropriate measures.
In an exemplary embodiment, if the elevator installation is warned or taken out of service, the warning state does not cause an error to continue driving the elevator installation, the first-degree error warning state to continue operating with a warning being canceled, and the second-level error message to decommission the elevator ,

In an exemplary embodiment, when evaluated, an interrupted tensile member or a grounded tensile member results in a more severe warning condition than a damaged tensile member. The advantage of such an exemplary weighting of the various defects of the tension members is that, depending on the nature of the

Tragmittels can be responded to the situation of defects in the tension members.

In an exemplary embodiment, a suspension element with an interrupted tension member or a grounded tension member is assigned a second-order error in each case.

In an exemplary embodiment, a support means with at least one damaged tensile carrier then leads to a fault of the first degree if at most one tension member per suspension element has a damaged tension member and if the number of damaged tension members is smaller than the number of suspension elements. In addition, a support means with at least one damaged tensile carrier then leads to a second-degree error if more than one tensile member per suspension element is damaged or if the number of damaged tensile members is equal to or greater than the number of suspension elements. Such an exemplary weighting of the various defective states of the tensile carriers has the advantage that an elevator installation can continue to be operated in the case of non-hazardous defects with the deduction of an advance warning, but can be put out of operation in the event of dangerous defects of the tensile carriers.

In an exemplary embodiment, when the elevator installation is taken out of operation, a predefined position of an elevator car is approached before the elevator installation is put out of operation for further journeys. Such a predefined position of the elevator car can be, for example, the next public stop starting from a current position of the elevator car. This has the advantage that passengers who are in the elevator car at the time of detection of a more serious defect of the suspension means can leave the elevator installation as quickly as possible.

In an exemplary embodiment, when continuing to operate an advance warning, a maintenance center responsible for the elevator installation is informed of the detected condition of the tension members or of the warning status assigned thereto. This has the advantage that the maintenance center responsible for the elevator installation can plan a service or maintenance of the elevator installation according to this information.

• Anzeigen eines festgestellten Zustandes der Zugträger oder eines den Tragmitteln zugeordneten Warnzustandes an einer in der Aufzugsanlage angeordneten Anzeigeeinrichtung. Ein solches Verfahren hat den Vorteil, dass ein Aufzugstechniker vor Ort unmittelbar den Zustand der Zugträger bzw. der Tragmittel ablesen kann.

In an exemplary embodiment, the method further comprises the step:

• Display of a detected state of the tension members or a warning state assigned to the suspension elements on a display device arranged in the elevator installation. Such a method has the advantage that an elevator technician can directly read the condition of the tension members or the suspension elements on site.

The object stated at the outset is also achieved by an elevator installation with at least one suspension element, wherein the suspension element comprises electrically conductive tension members, which are surrounded by an electrically insulating jacket. The elevator installation further comprises a monitoring device associated with the suspension element, wherein a method as described above can be carried out in the elevator installation.

The method disclosed here for monitoring a suspension element in an elevator installation can be used in different types of elevator installations. For example, elevator systems with or without shaft, with or without counterweight, or elevator systems with different gear ratios can be used. Thus, any suspension means comprising electrically conductive tension members surrounded by an electrically insulating jacket in an elevator installation can be monitored by the method or apparatus disclosed herein.

Figur 1

eine beispielhafte Ausführungsform einer Aufzugsanlage;

Figur 2

eine beispielhafte Ausführungsform eines Tragmittels; und

Figur 3

beispielhafte Auswertungstabellen zum Auswerten festgestellter Zustände von Zugträgern.

The invention will be explained symbolically and by way of example with reference to figures. Show it:

FIG. 1

an exemplary embodiment of an elevator system;

FIG. 2

an exemplary embodiment of a support means; and

FIG. 3

exemplary evaluation tables for evaluating determined states of tension members.

In the FIG. 1 schematically illustrated lift system 40 includes an elevator car 41, a counterweight 42 and a support means 1 and a traction sheave 43 with associated drive motor 44. The traction sheave 43 drives the support means 1 and thus moves the elevator car 41 and the counterweight 42 gegengleich. Of the Drive motor 44 is controlled by an elevator control 45. The cabin 41 is designed to receive people or goods and to transport between floors of a building. Cabin 41 and counterweight 42 are guided along guides (not shown). In the example, the cabin 41 and the counterweight 42 are each suspended on support rollers 46. The support means 1 is fastened to a first support means fastening device 47, and then first guided around the support roller 46 of the counterweight 42. Then, the suspension element 1 is placed over the traction sheave 43, guided around the support roller 46 of the car 41, and finally connected by a second support means fastening device 47 with a fixed point. This means that the suspension element 1 runs at a higher speed via the drive 43, 44, in accordance with a transfer factor, than the car 41 or counterweight 42 move. In the example, the wrap factor is 2: 1.

A loose end 1.1 of the suspension element 1 is provided with a contacting device 2 for temporary or permanent electrical contacting of the tension members and thus for monitoring the suspension element 1. In the example shown, such a contacting device 2 is arranged at both ends 1.1 of the suspension element 1. In an alternative embodiment, not shown, only one contacting device 2 is arranged on one of the support means ends 1.1, and the tension members on the other support means end 1.1 are electrically connected to each other. The Tragmittelenden 1.1 are no longer burdened by the tensile force in the suspension element 1, as this tensile force is already passed through the suspension means fastening devices 47 into the building. The contacting devices 2 are thus arranged in a non-overrun area of the suspension element 1 and outside the loaded area of the suspension element 1.

In the example, the contacting device 2 is connected at one end of the support means 1.1 with a monitoring device 3. The monitoring device 3 interconnects the tension members of the suspension element 1 as electrical resistors in an electrical circuit for the determination of electrical resistances. The monitoring device 3 is also connected to the elevator control 45. This connection can be formed for example as a parallel relay or as a bus system. As a result, a signal or a measured value can be transmitted from the monitoring device 3 to the elevator control 45 in order to control the state of the suspension element 1 as determined by the monitoring device 3 in a control of the elevator 40 consider.

The elevator installation 40 shown in FIG FIG. 1 is exemplary. Other capping factors and arrangements, such as counterbalanced lift systems, are possible. The contacting device 2 for contacting the support means 1 is then arranged according to the placement of the support means fastening devices 47.

In FIG. 2 a section of an exemplary embodiment of a support means 1 is shown. The support means 1 comprises a plurality of mutually parallel electrically conductive tension members 5, which are enveloped by a jacket 6. For electrical contacting of the tension members 5, the jacket 6 can be pierced or removed, for example, or the tension members 5 can also be electrically contacted on the face side by a contacting device 2.
In this example, the suspension element is equipped with longitudinal ribs on a traction side. Such longitudinal ribs improve a traction of the support means 1 on the traction sheave 43 and also facilitate lateral guidance of the support means 1 on the traction sheave 43. However, the support means 1 can also be designed differently, for example without longitudinal ribs, or with a different number or different arrangement of the tension members 5. It is essential for the invention that the tension members 5 are designed to be electrically conductive.

In FIG. 3 exemplary evaluation tables for the evaluation of the detected states of the tension members are shown. By means of such evaluation tables, the determined states of the tension members can be assigned to a warning state. In each case the warning state is shown in the leftmost column. The determined states of the tension members are shown in the remaining columns.

The topmost table in FIG. 3 , which represents an exemplary evaluation table for an individual suspension, can be interpreted as follows:
If there are zero interrupted tension members, zero grounded tension members and zero damaged tension members, then the warning condition "no error" is assigned to the suspension element. If there is only one damaged tension member, the warning condition "1st degree error" is assigned to the suspension element. However, if at least one interrupted tension member or at least one grounded tension member or at least two damaged tension members are present, then so the warning means "fault 2nd degree" is assigned to the suspension element. Due to the assigned warning state, the system will continue to operate or continue operating with the removal of a warning or taken out of service.

The second, third and fourth evaluation table in FIG. 3 is in each case an exemplary embodiment of elevator systems with two, three or four suspension elements. In doing so, as above, the first table in FIG. 3 executed, assigned different Wamzustände for different defects of the tension members. In this example, damaged tension members only lead to a second-degree error if the number of damaged tension members is equal to or greater than the number of suspension elements in the elevator installation. However, an interrupted or grounded tension member will always result in a 2nd degree error.

In the evaluation table for an individual suspension element, the warning states were designated with the suffix "a", and in the evaluation tables for elevator systems with several suspension elements the warning states were supplemented with the suffix "b". In an exemplary embodiment, an alert state for each individual suspension element is determined in an elevator installation with a plurality of suspension elements as well as a warning state for the entire elevator installation. The warning state for each individual suspension element has the suffix "a" and the warning state for the elevator installation as a whole has the suffix "b". Decisive for the continued operation or decommissioning of the elevator system is now the most serious warning condition. This can be both a warning state of an individual suspension means, as well as a warning condition for the entire elevator installation.
For example, lead two damaged tension members in the evaluation table for a lift system with three support means to a 1st degree error. If these two damaged tension members occur in the same suspension element, this leads to an error of the second degree for this individual suspension element (see evaluation table for an individual suspension element). Accordingly, it can be distinguished by this exemplary method, whether defective tensile carriers frequently occur in a suspension means or not. An increased incidence of defects in a single suspension means tends to be more dangerous to the overall condition of the elevator installation and, therefore, in this embodiment, is more severely weighted than a distributed occurrence of defects in tension members distributed among various suspension means.

It goes without saying that in the context of the present invention, a plurality of further evaluation tables can be realized. In the FIG. 3 Therefore, the evaluation tables used are merely illustrative of the general principle.

Claims (11)

1. Method for monitoring at least one traction means (1) in a lift assembly (40) wherein the traction means (1) comprises electrically conducting tension carriers (5) which are surrounded by an electrically conducting jacket (6), the method comprising:

   - monitoring an electrical resistance of the tension carriers (5), wherein at least two states:

   - interrupted tension carrier

   - earthed tension carrier

   - damaged tension carrier

   can be ascertained by a monitoring device (3):

   - evaluating the ascertained states of the tension carrier (5), wherein

   - an interrupted tension carrier (5) can be ascertained by an electrical resistance which tends to infinity,

   - an earthed tension carrier (5) can be ascertained by an electrical resistance which tends to zero,

   - a damaged tension carrier (5) can be ascertained by an increased or by a reduced electrical resistance and

   wherein the states are assigned to a warning state; and

   - further operating or further operating whilst delivering a pre-warning or putting the lift assembly (40) out of operation taking into account the warning state,

   characterized in that during the evaluation both each individual traction means (1) with all appurtenant tension carriers (5) and also a sum of all the traction means (1) in the lift assembly (40) with all appurtenant tension carriers (5) are each assigned a warning state and
   that for further operation or putting the lift assembly (40) out of operation a most serious warning state selected from the most serious warning state of each individual traction means (1) and the warning state of the total of all the traction means (1) is definitive.
2. The method according to claim 1, wherein during monitoring three states can be ascertained by the warning device (3).
3. The method according to one of the preceding claims, wherein the tension carriers (5) can be assigned at least the warning states

   - no fault

   - first degree fault

   - second degree fault.
4. The method according to claim 3, wherein during further operation or further operation whilst delivering a preliminary warning or putting the lift assembly (40) out of operation

   - the warning state no fault results in further operation

   - the warning state first degree fault results in further operation whilst delivering a preliminary warning

   - the warning state second degree fault results in putting the lift assembly (40) out of operation.
5. The method according to one of claims 3 or 4, wherein during the evaluation an interrupted tension carrier (5) or an earthed tension carrier (5) results in a more serious warning state than a damaged tension carrier (5).
6. The method according to one of claims 3 to 5, wherein a traction means (1) having an interrupted tension carrier (5) or an earthed tension carrier (5) is assigned a second degree error in each case.
7. The method according to one of claims 3 to 6, wherein a traction means (1) having at least one damaged tension carrier (5)

   - results in a first degree fault if at most one tension carrier (5) per traction means (1) has a damaged tension carrier (5) and if the number of damaged tension carriers (5) is smaller than the number of traction means (1),

   - results in a second degree fault if more than one tension carrier (5) per traction means (1) is damaged or if the number of damaged tension carriers (5) is equal to or greater than the number of traction means (1).
8. The method according to one of the preceding claims, wherein when putting the lift assembly (40) out of operation a predefined position of a lift cabin (41) is approached before the lift assembly (40) is put out of operation for further journeys.
9. The method according to one of the preceding claims, wherein during further operation whilst delivering a preliminary warning a maintenance point responsible for the lift assembly (40) is informed of the ascertained state of the tension carriers (5) or of the warning state assigned thereto.
10. The method according to one of the preceding claims, wherein the method further comprises the step:

    - displaying an ascertained state of the tension carrier (5) or of a warning state assigned to the traction means (1) on a display device assigned to the lift assembly (40).
11. Lift assembly (40) comprising at least one traction means (1), wherein the traction means (1) comprises electrically conducting tension carriers (5) which are surrounded by an electrically conducting jacket (6), and a monitoring device (3) assigned to the traction means (1), wherein the method according to one of claims 1 to 10 can be performed in the lift assembly (1).

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