EP2303749B1 - Method and device for determining the degree of service life use of a carrying means of an elevator - Google Patents

Description

Technical area

The invention relates to a method and a device for determining the Ablegereife a support means of a lift.

In the case of an elevator, the car is held and moved by means of a suspension element, whereby the suspension element wears over time during operation and is replaced from time to time. If, however, the suspension element is replaced before it is actually ready for disposal, unnecessary costs are incurred and the service interval is shortened unnecessarily. However, if it is not recognized in good time that the suspension element is ready for disposal, considerable safety risks can arise. It is therefore important to be able to determine as precisely as possible when a suspension element is so worn out that it has to be replaced.

State of the art

If steel cables or steel belts serve as suspension elements, the discard condition is determined by counting the number of wire breaks or by magnetically monitoring the suspension element. However, these methods are not suitable or only conditionally for aramid ropes as suspension means.

From the publication JP 11 035 246 A a method for detecting the wear of the supporting cable of an elevator is known. The part of the suspension rope that slips on the traction sheave is exposed to the greatest wear. In addition, the slippage of the suspension rope on the traction sheave causes the travel time to increase. Thus, there is a correlation between the degree of wear and the travel time. This correlation is now used in the wear detection process to deduce the degree of wear from the travel times determined.

First, the car call signals are detected and used to calculate the travel times that the car needs to travel from the call floors to the destination floors. Subsequently, the calculated travel times are compared with wear values in order to determine the manhole section in which the car moves most frequently. Based on this finding, the wear of the corresponding cable section is now examined.

However, this embodiment has the following disadvantage. Due to the fact that the travel time depends not only on the slip, but additionally on some other parameters, such as the load in the cabin, you can conclude by the detection of driving time only relatively inaccurate on the prevailing slip. If the travel time is prolonged, this can have different causes. Greater slippage is just one of several possible causes.

Presentation of the invention

An object of the invention is to provide a method and a device for determining the Ablegereife a support means of a lift, with the Ablegereife the support means is particularly precisely determined.

In the inventive method for determining the Ablegereife a support means of an elevator in which the support means is guided over a traction sheave and / or one or more pulleys and connects a car with a counterweight, the suspension element is divided into several sections. For each of the sections, it is determined whether the section passes the traction sheave and / or one or more of the pulleys during a trip, and if so, a degree of maturity representing the discard period is increased accordingly.

The inventive device for determining the Ablegereife comprises in addition to the above-mentioned features a controller for controlling the elevator and an evaluation unit which is connected to the controller. The evaluation unit is designed and operable such that it determines the degree of ripeness for each of the sections on the basis of the data received by the controller about the travel destinations.

Advantageous developments of the invention will become apparent from the features indicated in the dependent claims.

In one embodiment of the method according to the invention, the type of bending is determined and in the case of sections Determination of the degree of maturity considered. This is particularly advantageous in the case of counterbends because they allow the suspension element to be particularly heavily worn.

In a further embodiment of the method according to the invention, to determine the type of bending, it is detected which deflection roller causes which bending.

Advantageously, in the method according to the invention, a backbend in the determination of the degree of ripeness is taken into account more than a simple bending.

In addition, it is advantageous if, in the method according to the invention, the wrap angle is taken into account in the section-wise determination of the degree of ripeness. Thus, the determination of the Ablegereife can be made even more precise.

Furthermore, it is also advantageous if, in the method according to the invention, the diameter of the deflection rollers is taken into account in the section-wise determination of the degree of ripeness. This also allows the determination of the Ablegereife made even more precise.

To solve the problem it is further proposed that in the inventive method, a service message is generated when the maturity level for one of the sections has exceeded a certain value. In this way it is possible to dispense with regular manual checks of the maturity level of the discardability determined by the method.

According to a further feature of the invention, the support means is additionally monitored by an optical control device. Thus, the determination of the Ablegereife can be made even more precise and secure.

Brief description of the drawings

Figur 1

zeigt eine vereinfachte Darstellung eines Aufzugs mit einer Treibscheibe.

Figur 2

zeigt das Zählprinzip für einen Aufzug gemäss Figur 1.

Figur 3

zeigt eine vereinfachte Darstellung eines Aufzugs mit vier Umlenkrollen.

Figur 4

zeigt eine Tabelle und ein Diagramm mit vier Fahrten des Aufzugs gemäss Figur 3.

Figur 5

zeigt nochmals das Diagramm mit den vier Fahrten des Aufzugs und darunter eine Fahrtentabelle.

Figur 6

zeigt ein Diagramm mit den Positionen der Umlenkrollen auf den einzelnen Seilabschnitten.

Figur 7

zeigt ein Flussdiagramm für das Verfahren zur Ermittlung der Ablegereife eines Tragmittels eines Aufzugs.

In the following the invention will be explained with several embodiments with reference to seven figures.

FIG. 1

shows a simplified representation of an elevator with a traction sheave.

FIG. 2

shows the counting principle for an elevator according to Figure 1.

FIG. 3

shows a simplified illustration of an elevator with four pulleys.

FIG. 4

shows a table and a diagram with four trips of the elevator according to FIG. 3 ,

FIG. 5

shows again the diagram with the four rides of the elevator and below a trip table.

FIG. 6

shows a diagram with the positions of the pulleys on the individual cable sections.

FIG. 7

shows a flowchart for the method for determining the Ablegereife a support means of a lift.

Ways to carry out the invention

In order to determine the service life of a suspension element, for example an aramid rope, corresponding tests are carried out in advance and empirical values are used. In particular, the arrangement of the traction sheave, the deflection rollers, the cable guide, the wrap angle, the traction sheave and the Umlenkrollendurchmesser have an impact on the stability or the wear. The knowledge gained from this leads to a bending cycle number that indicates the maximum number of bending cycles that are permitted before the suspension element is ready for disposal. The bending cycle number is also referred to below as the limit bending cycle number. The more often the suspension element is bent, the greater is its wear.

To ensure that the service life and thus the Ablegereife the support means can be determined as precisely as possible, the permissible number of bending cycles of that support means section, which is the most stressed plays a special role. As long as the bending cycle number of the most heavily loaded support means section is not exceeded, the support means need not be replaced.

In the embodiments of the invention described herein, all types of rollers are referred to as pulleys. For example, deflection rollers should fall under the term deflection rollers.

First embodiment

In FIG. 1 a simplified representation of an elevator with a 1: 1 suspension is shown. A cabin 8 is connected to a counterweight 9 via a suspension element 5, which is also referred to below as a suspension cable or shortly as a cable. The support means 5 may also be a belt or belt and is guided over a traction sheave 20. In order to move the cabin 8 from one floor 12 to another floor 11, the suspension element 5 is driven via the traction sheave 20, which is coupled to a drive, not shown. At the beginning of the journey, ie at time t0, the cable section Ai is located, as in FIG FIG. 1 shown left below the traction sheave 20. The cable section Ai carries in this position the reference numeral Ai (t0). At the end of the journey, ie at time t1, the cabin 8 is located on the floor 11 and the cable section Ai is now partially on the traction sheave 20. The cable section Ai carries in this position the reference numeral Ai (t1). The control of the elevator by means of an elevator control 31. The determination of the Ablegereife the support means 5 by means of an evaluation unit 32, which is connected to the elevator control 31.

To determine the Ablegereife the support means 5, the support means 5 is first divided into as many sections Ai as there are floors. Then each floor is assigned that portion of the suspension element which lies on the traction sheave 20 when the cabin 8 is in the corresponding floor. Thus, for example, that support means section which on the traction sheave 20 when the car is on the floor 12, the section number A12 is assigned.

In addition, each floor or the corresponding support means section is assigned a memory in which each entrance to the floor, each exit from the floor in the opposite direction and each passage of the corresponding floor is counted. In FIG. 2 this is shown graphically. On the left is the shaft with a total of 25 floors (-2 to 22) shown, right next to a symbolic representation of a first drive 1 of the cabin from the floor 0 to the floor 8. Right next to it, the corresponding memory is shown, which also referred to as Biegewechselzähler becomes. The memory comprises as many memory locations as the building floors has less than one, that is to say in the present exemplary embodiment a total of 24 memory locations SP1 to SP24 for a total of 24 cable sections A1 to A24. The first cable section A1 is located at the counterweight 9 and the 24th cable section A24 is located at the car 8.

If the elevator car 8 moves upwards from the lowermost stop (floor -2), the first cable section A1 runs over the traction sheave 20. On the other hand, if the elevator car 8 moves downwards from the uppermost stop (floor 22), the cable section A24 runs over the traction sheave 20 ,

In the example in FIG. 2 the cabin 8 moves from the floor 0 to the floor 8 during the drive 1. The evaluation unit 32 receives the floor information (call information) from the elevator control 31 and then increases the contents the corresponding eight memory locations SP3 to SP10 by the value one. This means that the cable sections A3 to A10 run over the traction sheave 20 and are subjected to a bending. When driving 2, the car 8 moves from the floor 8 by three floors further up to the floor 11. Thus, the cable sections A11 to A13 are moved over the traction sheave 20 and thereby subjected to a bend. Therefore, the values in the next three memory locations SP11, SP12 and SP 13 are also increased by one. At ride 3, the cabin moves from floor 11 down to floor -1. As a result, the values in the corresponding memory locations SP13 to SP2 are again increased by the value one. Finally, the car moves up to the floor 3 during travel 4, so that the values in corresponding memory locations SP2 to SP5 are again increased by the value one.

Right in FIG. 2 the values summed up at the end of the journey 4 during the four journeys are shown, which are referred to as ripeness R (A1) to R (AN). The largest value in the bending change memory corresponds to the maximum number of bending cycles of the elevator installation. As can be seen, a total of three memory locations SP3, SP4 and SP5 are assigned the value 3. This means that during the four journeys the three support means sections A3, A4 and A5 were each subjected to a bending cycle three times. For the suspension element section A1, a degree of maturity R (A1) = 0, the suspension element section A2 a degree of maturity R (A2) = 2 and the support center section A3 a maturity R (A3) = 3. The cable sections A3, A4 and A5 thus have the largest Maturity R (A3) = R (A4) = R (A5) = 3 and thus subject to the greatest wear.

To record the bending cycles, the call information from the elevator control 31 can be used and evaluated. For example, a gray code can be used for this purpose.

The described embodiment can be integrated into the elevator control 31 or executed as a separate device, which is equipped with a corresponding interface to the elevator control 31. The floor information can then be transmitted via the interface. The elevator control 31 and the evaluation unit 32 can be combined in the same housing or in the same module.

Each trip from one floor to the other is assigned to the cable section of the floor, which is bent at the appropriate drive on the traction sheave and the pulley. With the bending counter, the bending changes of each section of rope are counted. Decisive for the rope life is that rope section with the most bending changes.

Second embodiment

With a hinge factor = 2, ie a 2: 1 suspension, the above considerations apply as well. The individual cable sections can be loaded in addition to the bends on the traction sheave 2 with bends over the pulleys 1, 3, 4 on the counterweight 9 or on the car 8. The pulleys 1, 3, 4 are also referred to as Pulleys or pulleys.

In the second embodiment described here, these bends are not counted separately. It is assumed that each cable section is bent both on the traction sheave 2 and on the pulleys 1, 3, 4 on the counterweight 9 or the car 8. For this reason, it is spoken of bending cycles and not bending bends. A bending cycle contains both the bending over the traction sheave 2 and the bends over the corresponding pulleys 1, 3, 4. In the life tests bending cycles (bending of the same rope piece on traction sheave 2 and pulleys 1, 3, 4) are tested. Therefore, this counting method is sufficiently secure. However, it is also possible to count the individual bends separately via the traction sheave 2 and the pulleys 1, 3, 4 (see third embodiment).

Advantageously, a separate limit bending cycle number is determined for each elevator layout (disposition) by appropriate life tests with defined traction sheave and pulley diameters.

Third embodiment

In FIG. 3 is a lift with a 2: 1 suspension simplified. The support cable 5 is attached to a first attachment point 6 on the shaft and via a first guide roller 1, which is secured to the counterweight 9, via a traction sheave 2, which is secured to the shaft and further deflection rollers 3 and 4, on the underside of Cabin 8 are arranged, to a second attachment point 7 in the shaft. The shaft is down bounded by a bottom 10 and up through a ceiling 13.

In FIG. 4 is a table and a diagram with four rides F1 - F4 of the elevator shown. Left in FIG. 4 For example, if the height of the shaft is in meters, and on the right next to it, the floors are indicated as numbers 0 to 50. Right next to it four rides F1 to F4 are shown. At the first drive F1 the car 8 moves from the floor 0 to the landing 8. At the second drive F2 the car 8 moves on to the floor 32. At the third drive F3 the car 8 moves on to the floor 25. At the fourth drive F4 finally the cabin 8 goes back to the floor 0. In the four columns right next to the positions of the three pulleys 1, 3 and 4 and the traction sheave 2 on the rope 5 are given as absolute values in meters relative to the rope beginning at the attachment point 6.

FIG. 5 shows again the diagram with the four runs F1 to F4 of the elevator and below the resulting trip table. It can be seen from this table which position the four pulleys 1 to 4 have at the beginning of the respective journey (start) and at the end of this journey on the carrying cable 5. Thus, for example, in the first drive F1, the deflection roller 1 is located at the beginning 0.8 m from the beginning of the rope (attachment point 6). At the end of the first drive F1, the guide roller 1 is then located 24.8 m from the beginning of the rope. That is, there are 24.8 m rope between the guide roller 1 and the attachment point 6. The rope 5 is thus overrun during the drive F1 from Pulley 1 on the route between 0.8 m and 24.8 m.

From the in FIG. 5 The trip table shown can be found in FIG. 6 shown diagram, in which the positions of the pulleys 1 to 4 are shown on the individual cable sections A1, A2, A3 to AN.

By means of the following formula it is given by way of example how the current position (PosPulleyl) on the rope 5 can be calculated for the pulley 1: $$\mathrm{PosPulley}\mathrm{1}\mathrm{=}\mathrm{H}\mathrm{3}\mathrm{-}\mathrm{H}\mathrm{4}\mathrm{+}\frac{\mathrm{HQ}\mathrm{\cdot }\mathrm{current\; stock\; factory}}{\mathrm{Number\; of\; storeys}}$$

• H3 = Abstand zwischen Umlenkrolle 1 und Treibscheibe 2
• H4 = Abstand zwischen Seilanfang 6 und Treibscheibe 2
• HQ = Stockwerkshöhe

Where:

• H3 = distance between pulley 1 and traction sheave 2
• H4 = distance between rope beginning 6 and traction sheave 2
• HQ = floor height

FIG. 7 shows a flowchart for the method for determining the Ablegereife the suspension element of an elevator.

In an initialization phase (S1, S2), the cable 5 is divided into N sections A1 to AN, and the positions of the pulleys 1 to 4 on the cable 5 are assigned to each floor 0-50. The attachment point 6 forms the zero point or reference point. However, the reference point can also be any other location, such as the attachment point 7. Thereafter, for each trip F1 to F4 and each Pulley 1 to 4 the roll over length is recorded (see FIG. 5 ).

For each section of rope A1 to AN (this can be arbitrarily large or small depending on the requirement) will be ongoing the number of rollovers recorded by the pulleys 1 to 4 ( FIG. 5 and S3, S4, S7 in FIG. 7 ). Depending on requirements, the different bends and their degree of damage per pulley 1 to 4 can also be taken into account, eg diameter, wrap angle, traction sheave, deflection roller, counterbending, single bending. Thus, at any time for each cable section A1 to AN, the degree of damage or the number of bending changes can be recognized and evaluated (see FIG. 6 ).

Those cable sections with the most or most damaging bending changes can be detected at any time. A limit can be set for the permissible damage, ie for the permissible number of bending changes. When this number is reached (S5), a service message can be issued (S6) to indicate that the suspension means 5 should be replaced. But it can also be determined only the section on the rope 5, which has received the greatest damage. In the latter case, this cable section can then be visually or by means of auxiliary equipment, e.g. magnetically inspected.

wobei gilt:

• SB = die Anzahl der einfachen Biegungen
• RB = die Anzahl der Rückbiegungen.

Bends, which are also referred to as counterbends, let the suspension 5 wear faster and are therefore in FIG. 6 multiplied by a weighting factor GF = 4 when calculating the maturity level R (Ai). For the maturity level R (Ai) of the rope section Ai applies in this case: $$\mathrm{R}\left(\mathrm{Ai}\right)\mathrm{=}\mathrm{SB}\mathrm{+}\mathrm{4}\mathrm{*}\mathrm{RB}$$

where:

• SB = the number of simple bends
• RB = the number of reverse bends.

A support means section Ai is subject to a simple bend when this support means section Ai is bent on one of the deflection rollers 1, 3 or 4 or on the traction sheave 2 in a first direction. If this support means section Ai is bent at a later time in the opposite direction, this support means section Ai is then subject to a return bend. For example, the suspension element section, which is located at the in FIG. 3 shown cabin position POS1 is located on the guide roller 3, a simple bend. Later, when the car 8 is then in the position POS2, the support means section is located on the traction sheave 2 and is now also subject to a back bend.

Whether it is a simple bend or a back bend results from the elevator layout and the lift height. The evaluation unit 32 ( Fig. 3 ) can thus determine on the basis of certain geometries that result from the elevator layout, for example the parameter H1 - H4, HQ and BK and the lifting height of the car 8, whether a particular cable section Ai is subjected during a trip to a simple bend and / or a back bend ,

The diameter of the guide rollers 1 to 4 is marked with the reference symbol D. As already mentioned above, the diameter D of the pulleys 1 to 4 can be taken into account in determining the Ablegereife. In addition, the wrap angle can also be taken into account when determining the expiry date. For example, the weighting factor GF can be based on the diameter D of the pulley 1 to 4 be related. For a deflection roller 1 to 4 with a small diameter D, the weighting factor GF is chosen greater than in the case of a deflection roller 1 to 4 with a large diameter D. Likewise, the weighting factor GF can be related to the wrap angle of the traction sheave 2. If the wrap angle of the suspension element 5 on the traction sheave 2 is large, the weighting factor GF is selected to be smaller than if the wrap angle of the suspension element 5 on the traction sheave 2 is small. In addition, the weighting factor can be related to the load suspended on the suspension element 5. The larger this load, the greater the weighting factor GF is chosen.

For a Umhängungsfaktor> 2 can proceed analogously.

So far, the maximum number of bending changes of the most stressed rope piece was very difficult to determine, since the traffic patterns of each elevator are different and therefore it is not obvious which support center piece is subjected to the most bending changes. The number of rides of a lift also give no indication. An advantage of the invention is that the ropes 5 can be stored very individually and thus fully exploited. If the discard condition were determined on the basis of the number of journeys or by estimation, reserves would have to be built in which could cause high costs in maintenance. With the present invention, the Ablegereife of support means 5, for example, steel cables, Aramidseilen, straps or belts with tension strands of steel strands or synthetic fibers can be found.

The suspension element 5 can additionally be provided with an optical control device 30 (FIG. FIG. 1 ) be monitored. Thus, the determination of the Ablegereife can be made even more precise and secure. As an optical control device 30, for example, a video camera can be used. However, the suspension element 5 can also be optically controlled by a service technician. In the optical control, for example, attention is paid to wire breaks, bubbles in the aramid support and changes in the geometry of the suspension 5.

The foregoing description of the embodiments according to the present invention is for illustrative purposes only, and not for the purpose of limiting the invention. Within the scope of the invention, various changes, combinations of the embodiments and modifications are possible without departing from the scope of the invention and its equivalents.

Claims (11)

1. Method of determining the discard time of a load-bearing means of a lift,
   in the case of which the load-bearing means (5) is guided over a driving pulley (2; 20) and/or one or more deflecting rollers (1, 3, 4) and connects a car (8) to a counterweight (9),
   comprising the following steps:

   the load-bearing means (5) is divided up into a plurality of portions (A1 - AN), wherein each of the plurality of portions (A1 - AN) is assigned a memory location as a bending-cycle counter,

   it is determined, for each of the portions (A1 - AN) whether, during a journey (F1-F4) of the car (8), the portion (Ai) passes by the driving pulley (20) and/or one or more of the deflecting rollers (1 - 4) and, if this is the case, a usage level (R(Ai)), which represents the discard time, is increased correspondingly, and wherein the bending cycles of each portion (A1 - AN) are counted by the bending-cycle counters and the cable portion with the most bending cycles is decisive for the service life of the cable.
2. Method according to Patent Claim 1, wherein, if the usage level (R(Ai)) of one of the plurality of portions (A1 - AN) reaches a number of bending cycles which indicates the maximum permissible number of bending cycles, the load-bearing means (5) is ready to discard.
3. Method according to Patent Claim 2, wherein, as long as the usage level (R(Ai)) of the portion (A1 - AN) which is subjected to most loading does not exceed the number of bending cycles, the load-bearing means need not yet be changed over.
4. Method according to Patent Claim 1,
   in the case of which the type of bending (SB, RB) is determined and is taken into account for determining the usage level (R(Ai)) for each portion.
5. Method according to Patent Claim 4,
   in the case of which, for the purpose of determining the type of bending (SB, RB), it is detected which deflecting roller (2, 3) causes which bending.
6. Method according to Patent Claim 5,
   in the case of which reverse bending (RB) is taken into account to a more significant extent for determining the usage level (R(Ai)) than is straightforward bending (SB).
7. Method according to Patent Claim 1,
   in the case of which a wrap angle and/or a diameter of the deflecting rollers (1, 3, 4) is taken into account for determining the usage level (R(Ai)) for each portion.
8. Method according to Patent Claim 1,
   in the case of which a service message is generated if the usage level (R(Ai)) for one of the portions (A1 - AN) has exceeded a certain value.
9. Method according to Patent Claim 1,
   in the case of which the lift is put out of operation if the usage level (R(Ai)) for one of the portions (A1 - AN) has exceeded a certain value.
10. Method according to Patent Claim 1,
    in the case of which the load-bearing means (5) is additionally monitored by an optical monitoring device (30).
11. Apparatus for determining the discard time according to one of Patent Claims 1 to 10,

    - having a control means (31) for controlling the lift, and

    - having an evaluation unit (32), which is connected to the control means (31) and is designed, and can be operated, such that it determines the usage level (R(Ai)) for each of the portions (A1 - AN) by way of the destination-related data obtained by the control means (31), and wherein each of the plurality of portions (A1 - AN) is assigned a memory location as bending-cycle counter.

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