Elevator load measurement device and method

Abstract

A load measuring device for an elevator, comprising: a lifting machine (3) for driving an elevator car (2) in an elevator hoistway (1); a lifting machine bottom plate (11) supporting the lifting machine; and at least one load weighing sensor (20) located between the lifting machine (3) and the lifting machine floor (11). The load measuring device comprises alignment means (25) for placing the at least one load weighing sensor (20) at one or more predetermined points between the lifting machine (3) and the lifting machine floor (11). The invention discloses an elevator load measuring method.

Description

Technical Field

[0001] The present invention relates to load measurement of an elevator. The elevator is preferably an elevator for transporting passengers and / or freight. Background Art

[0002] For example, elevator car load information is needed to detect overload conditions and for run-time torque control of the elevator hoisting machinery.

[0003] Elevator systems may have load sensors, such as strain gauges attached to the car floor or rope hooks, to collect load information.

[0004] Document EP3705435A1 discloses a combined elevator vibration isolation and load measuring element. It has a vibration isolation pad and a load sensor device. An elastic material layer has been attached to one surface of the vibration isolation pad. The load acting on the combined elevator vibration isolation and load measuring element can be measured by the load sensor device based on the compression of the elastic material layer. The combined elevator vibration isolation and load measuring element can be installed between the lifting machine and the machine bottom plate. The bottom plate can be fixed to the guide rail of the elevator system. Document EP3705441A1 shows the use of this combined vibration isolation and load measuring element for car jam detection.

[0005] Accurate load measurement of elevators is required. Summary of the invention

[0006] The object of the present invention is to introduce an improved elevator load measuring device and an improved method for elevator load measurement.The present invention provides a solution to the problems related to elevator load measurement accuracy.

[0007] The load measuring device for an elevator according to the invention is defined in the independent claim 1 .

[0008] The load measuring device of an elevator comprises a hoisting machine for driving an elevator car in an elevator shaft, a hoisting machine bedplate supporting the hoisting machine, and at least one load weighing sensor located between the hoisting machine and the hoisting machine bedplate.

[0009] The load measuring device comprises alignment means for placing at least one load load cell at one or more predetermined points between the lifting machine and the lifting machine floor.

[0010] Preferred further details of the invention are described below, which further details may be combined individually or in any combination.

[0011] According to an embodiment, the alignment means comprises at least one recess for at least one load load cell on at least one mating surface of the lifting machine and the lifting machine floor.

[0012] According to an embodiment, at least two load load cells are located between the lifting machine and the lifting machine floor.

[0013] According to an embodiment, the load measuring device comprises two load weighing sensors and the distance between the two sensors is substantially one third of the width of the lifting machine floor.

[0014] According to an embodiment, the load load cell is placed vertically below a traction sheave comprised by the lifting machine.

[0015] According to an embodiment, the at least one load load cell is placed vertically below the load line of a rope guided on a traction sheave comprised by the hoisting machine.

[0016] According to an embodiment, the two load load cells are placed horizontally at a predetermined distance from each other such that they are arranged symmetrically with respect to the lifting machine floor.

[0017] According to an embodiment, the device comprises an adapter plate having one or more load load cells at predetermined points of the plate.

[0018] According to an embodiment, the alignment means comprises an adapter plate having one or more load cells at predetermined points of the plate.

[0019] According to an embodiment, the adapter plate is configured to be mounted between the lifting machine and the lifting machine floor.

[0020] According to an embodiment, the adapter plate comprises at least one structural element, such as one or more holes or pins or clips, for aligning the adapter plate at a predetermined position between the lifting machine and the lifting machine floor.

[0021] According to an embodiment, the at least one load load cell comprises a sensor selected from the group consisting of: a capacitive sensor, a strain gauge, a load cell, a compression measurement of an elastic element, and a hydraulic sensor.

[0022] According to an embodiment, an elastic damping element is mounted between the lifting machine and the lifting machine base plate and is connected to the at least one load load cell.

[0023] According to an embodiment, a hoisting machine comprises a motor, a traction sheave and at least one hoisting machine brake.

[0024] According to an embodiment, an elevator comprises:

[0025] one or more suspension ropes; and a counterweight;

[0026] The car and the counterweight are suspended by the one or more ropes, which are guided over a traction sheave to move the car vertically in the elevator shaft.

[0027] The method for elevator load measurement according to the invention is defined in the independent claim 16 .

[0028] Method for load measurement in an elevator, wherein the elevator comprises a hoisting machine for driving an elevator car in an elevator shaft; a hoisting machine bedplate supporting the hoisting machine;

[0029] This includes measuring the load of the elevator by at least one load load cell located between the hoisting machine and the hoisting machine floor.

[0030] The method comprises providing an alignment device for at least one load load cell and placing the at least one load load cell at one or more predetermined points between the lifting machine and the lifting machine floor by means of the alignment device.

[0031] Preferred further details of the invention are described below, which further details may be combined individually or in any combination.

[0032] According to an embodiment, the method comprises placing two load load cells at a distance between the two cells, wherein the distance is substantially one third of the width of the lifting machine floor.

[0033] According to an embodiment, the method comprises placing at least one load load cell vertically below a load line of a rope, the rope being guided on a traction sheave comprised by the hoisting machine.

[0034] According to an embodiment, the method comprises placing two load load cells horizontally at a predetermined distance from each other such that they are arranged symmetrically with respect to the lifting machine floor.

[0035] According to an embodiment, the method comprises mounting an elastic damping element between the lifting machine and the lifting machine bedplate and connected to the at least one load load cell.

[0036] Other embodiments and advantages of the invention are described below.

[0037] Generally, the invention involves the use of one or more load cells mounted in connection with an elevator hoisting machine. The load measuring device comprises alignment means for placing at least one load cell at one or more predetermined points between the hoisting machine and the hoisting machine floor.

[0038] According to an embodiment, the alignment means comprises at least one recess for the at least one load load cell, the at least one load load cell being located on at least one mating surface of the lifting machine and the lifting machine floor.

[0039] Possible load cell types include capacitive sensors, strain gauges / load cells, compression measurements of elastic elements, and hydraulic sensors.

[0040] Additionally or alternatively, the measuring device may comprise an adapter plate having one or more load weighing sensors at predetermined points of the plate, wherein the adapter plate is mounted between the lifting machine and the lifting machine floor. The adapter plate may comprise structural elements, such as one or more holes or pins or clips, for aligning the adapter plate at a predetermined position between the lifting machine and the lifting machine floor.

[0041] The inventors have found that placing the load load cell at a predetermined optimal point between the elevator hoisting machinery and the floor of the hoisting machinery provides an improvement in load measurement accuracy. This improvement in measurement accuracy can be achieved in various operating situations of the elevator and is independent of the car position or elevator balance. The optimal position is important for measurement accuracy.

[0042] This may mean that the load measurement accuracy is good enough for overload detection and elevator ride comfort level, as standardized for elevators. Thanks to the invention, no additional load sensors are needed in the car floor or in the rope suspension. The solution also simplifies the installation work and facilitates the maintenance of the elevator system. According to dynamic analysis, the solution works well even in special operating situations, such as in the case of buffer operation when the car or counterweight hits the buffer. The same applies to other special situations, such as when the safety device of the elevator car is operated in the downward direction and the counterweight jumps in the upward direction.

[0043] By means of the invention, other critical operating conditions besides overload situations can also be detected. For example, due to the improved measurement accuracy, a entrapment situation can be reliably detected if a person is trapped due to an operating anomaly and needs to be rescued from the elevator car.

[0044] An advantage of the invention is that the measuring device provides direct information of the load acting on the traction sheave of an elevator hoisting machinery. This information can also be used to detect other parameters besides the car load, i.e. the load received in the elevator car. The use of at least two independent sensors can provide information of the load distribution in the area between the machinery and the bedplate. This distribution information is characteristic of the load distribution at different sides of the traction sheave. Thus, the load distribution information can be useful, for example, for identifying whether a jamming situation is caused by a jammed elevator car or a jammed counterweight. A jamming situation refers to a dangerous situation in which the counterweight and / or the elevator car is jammed when the car or the counterweight is moving upwards, leading to the risk of dangerous situations such as derailment or sudden falling of the elevator mass in the elevator shaft.

[0045] Since the load distribution at different sides of the traction sheave changes when the elevator car moves, the load distribution information can also be used to determine the position of the elevator car in the elevator shaft. This can be particularly useful for coverage situations where no direct positioning information of the elevator car is available. Such a coverage situation can be a third-party elevator under a maintenance contract with a separate elevator maintenance company.

[0046] By means of the invention, the condition of the elevator guide rails can also be detected based on the measurable effect of the variable guide rail friction on the moving elevator mass. It is also possible to detect a jumping load, i.e. a situation where the tension of the hoisting rope on the traction sheave decreases rapidly when the load "jumps", e.g. in an emergency stop situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be described in more detail below by means of preferred embodiments with reference to the accompanying drawings, in which:

[0048] Figure 1 shows a side view of a first elevator,

[0049] Figure 2 shows a side view of the second elevator,

[0050] Figure 3 A partial view showing a load measuring device of an elevator,

[0051] Figure 4 An embodiment of an alignment device for placing at least one load load cell between a lifting machine and a lifting machine floor is shown;

[0052] Figure 5 An embodiment of an alignment device is shown. DETAILED DESCRIPTION

[0053] Figure 1 A side view of a first elevator is shown.

[0054] The elevator may comprise a car 2, an elevator shaft 1, a hoisting machine 3, hoisting ropes 4 and a counterweight 5. A separate or integrated car frame 6 may surround the car 2.

[0055] A hoisting machine 3 may be positioned in the shaft 1. The hoisting machine may include a drive 31, a motor 32, a traction sheave 33, and a mechanical brake 34. The hoisting machine 3 may move the car 2 upward and downward in the vertically extending elevator shaft 1 in a vertical direction Z. The mechanical brake 34 may stop the rotation of the traction sheave 33, thereby stopping the movement of the elevator car 2.

[0056] exist Figure 1 In the embodiment, the car 2 is connected to the counterweight 5 by ropes 4 via a traction sheave 33. The car and the counterweight are suspended by one or more ropes 4, which are guided on the traction sheave 33 for moving the car 2 vertically in the shaft 1.

[0057] exist Figure 1 In the embodiment of the present invention, the car 2 is further supported by guide members 7 at guide rails 8 extending in the vertical direction in the shaft. The guide rails can be attached to the side wall structure 10 in the shaft by fastening brackets 9. When the car moves up and down in the shaft 1, the guide members 7 ensure the vertical movement of the car 2. The counterweight 5 can be supported in a corresponding manner on the guide rails attached to the wall structure 10 of the shaft 1.

[0058] The car 2 may transport people and / or goods between landings in a building.The elevator shaft 1 may be formed such that the wall structure 10 is formed by a solid wall, or such that the wall structure 10 is formed by an open steel structure.

[0059] In this first elevator, the roping ratio is 1: 1. When the motor 32 raises or lowers the car 2 in this first elevator by X meters, X meters of hoisting ropes 4 pass over the traction sheave 33.

[0060] The drive unit 100 (eg, a frequency converter) may be disposed close to the lifting machine 3 .

[0061] Figure 2 A side view of a second elevator is shown.

[0062] The second elevator Figure 1 The first elevator shown differs in the roping ratio. Figure 1 The roping ratio in the second elevator is 2: 1, compared to the roping ratio 1: 1 in the first elevator shown. When the motor 32 raises or lowers the car 2 in the second elevator by X meters, 2X meters of hoisting ropes 42 pass over the traction sheave 33.

[0063] The two ends of the hoisting rope 42 are fixed in the upper end part of the shaft 1 in fixed points A1, A2 relative to the shaft 1. The hoisting rope 42 passes vertically downward in the shaft 1 toward the lower end of the car 2 from the first fixed point A1. Then, the hoisting rope 42 turns to the horizontal direction on the first deflecting roller 43 located below the car 2. Then, the hoisting rope 42 travels in the horizontal direction to the second deflecting roller 44, which is located below the car 2 at the opposite side of the car 2 relative to the first deflecting roller 43. The car 2 is supported on the first deflecting roller 43 and on the second deflecting roller 44. After the second deflecting roller 44, the hoisting rope 42 passes vertically upward again in the shaft 2 toward the traction sheave 33. Then, the hoisting rope 42 turns again on the traction sheave 33 toward the third deflecting roller 45 in the direction pointing vertically downward in the shaft 2. The counterweight 5 is supported on the third deflecting roller 45. The hoisting ropes 42 then pass vertically upwards again in the shaft 1 to the second fixed point A2 after the third deflecting roller 45. The rotation of the traction sheave 33 in the clockwise direction moves the car 1 upwards, whereby the counterweight 5 moves downwards, and vice versa. The friction between the hoisting ropes 42 and the traction sheave 33 eliminates slipping of the hoisting ropes 42 on the traction sheave 33 under normal operating conditions.

[0064] The electric motor 32 in the lifting machine 3 may include a motor frame 35 for supporting the lifting machine 3 on the lifting machine base plate 11 .

[0065] At least one load weighing sensor 20 is located between the hoist 3 and the hoist bed 11. The vibration isolation pads 30 may be positioned between the motor frame 35 and the hoist bed 11. The hoist bed 11 may be supported on the guide rails 8 in the well 1. The hoist 3 may be supported on the guide rails 8 at any height position along the guide rails 8. The traction sheave 33 and the motor 32 may also be separated. The traction sheave 33 may be supported on the guide rails 8 in the well 1, and the motor 32 may be positioned at the bottom of a pit in the well 1, for example. Therefore, power transmission will be required between the traction sheave 33 and the motor 32.

[0066] The drive unit 100 (eg, a frequency converter) may be disposed close to the lifting machine 3 .

[0067] Figure 3 A partial view of a load measuring device of an elevator is shown.

[0068] According to an embodiment, the lifting machine 3 is located on top of a lifting machine base plate 11. Preferably, the base plate 11 is fixed to the guide rails 8 of the elevator. Another fixing point of the guide rails 8 is located on top of the lifting machine 3. Figure 3In the embodiment of the present invention, the hoisting machine 3 is substantially flat or disc-shaped and is located between the guide rails 8 and the elevator shaft wall 10, preferably at the top of the shaft 1. The hoisting machine 3 has a fixed body 35 supported on the base plate 11, which contains the stator of the hoisting motor. The hoisting machine 3 also has a rotating rotor with an integrated traction sheave 33. The rotor and the stator are arranged concentrically with the rotation axis R of the hoisting machine 3 as the center.

[0069] According to an embodiment, at least one load load cell 20 is placed vertically below the traction sheave 33. According to an embodiment, two load load cells 20 are placed vertically below the traction sheave 33. According to an embodiment, the load load cell 20 is placed vertically below the load line A of the ropes 4, 42, in particular a vertical line located in the middle of the groove of the traction sheave 33.

[0070] According to an embodiment, there are two load weighing sensors 20, which are horizontally placed at a predetermined distance C from each other so that they are symmetrically arranged relative to the lifting machine base plate 11, such as Figure 4 shown.

[0071] Figure 4 An embodiment of an alignment device 25 comprised by the load measuring arrangement is shown for placing at least one load load cell 20 at one or more predetermined points between the lifting machine 3 and the lifting machine floor 11 .

[0072] Possible load cell 20 types include capacitive sensors, strain gauges / load cells, compression measurements of elastic elements, and hydraulic sensors.

[0073] Figure 5 An embodiment of an alignment device 25 is shown, comprising at least one recess 26 for said at least one load weighing sensor 20 on at least one mating surface of the lifting machine 3 and the lifting machine floor 11. Preferably, said at least one recess 26 is configured to receive said at least one load weighing sensor 20 for positioning said sensor at a predetermined point of the plate.

[0074] Additionally or alternatively, the measuring device may comprise an adapter plate 25 having one or more load weighing sensors 20 at predetermined points of the plate. According to an embodiment, the alignment device 25 comprises an adapter plate having one or more load weighing sensors at predetermined points of the plate. According to an embodiment, the alignment device 25 comprises at least one recess 26 for the at least one load weighing sensor 20 on at least one mating surface of the lifting machine 3 and the lifting machine base plate 11.

[0075] According to an embodiment, the adapter plate is fitted in measuring use between the lifting machine 3 and the lifting machine base plate 11. According to an embodiment, the adapter plate comprises at least one structural element 27, such as one or more holes 28 or pins or clips 29, for aligning the adapter plate at a predetermined position between the lifting machine 3 and the lifting machine base plate 11.

[0076] According to an embodiment, the adapter plate 25 comprises at least one structural element which, when inserted between the lifting machine 3 and the lifting machine floor 11, extends in the direction of the lifting machine 3. According to an embodiment, the adapter plate 25 comprises at least one structural element which, when inserted between the lifting machine 3 and the lifting machine floor 11, extends in the direction of the lifting machine floor 11. The adapter plate preferably has a planar shape.

[0077] According to an embodiment, the adapter plate 25 comprises an array of recesses 26 adapted to available hoisting machines 3 of predetermined size and corresponding hoisting machine beds 11 having a predetermined rope load line A in the middle of the traction sheave 33 groove.

[0078] According to an embodiment, the load measuring device comprises two load weighing sensors 20, and the distance C between the two sensors 20 is substantially one third of the width 3C of the bottom plate 11, such as Figure 4 The elastic damping element 30 can be installed between the lifting machine 3 and the base plate 11 and connected to the load weighing sensor 20 .

[0079] One way to understand the advantageous effect of using at least two sensors for load detection is the "three-legged chair" analogy. When only one of the three legs is a sensor, there will be problems with force impacts and the situation is unstable. Whereas a more stable situation and / or improved measurement accuracy is achieved when two of the legs are sensors and the third leg, for example, optionally consists of a passive support structure. The third leg must not include a sensor. The base plate 11 optionally includes a passive support structure, such as a protruding leg, preferably forming the third leg of the above analogy with three legs.

[0080] The drive unit 100 (e.g., a frequency converter) can be arranged close to the hoisting machine 3. According to an embodiment, the drive unit is arranged at the same location as the hoisting machine 3 in the elevator shaft 1. In this way, there will be no substantial voltage drop in the cable 21 of a load weighing sensor 20 between the drive unit 100 and the hoisting machine 3, as a sensor located in connection with the elevator car or the rope hook must be wired to the drive unit. Therefore, a simpler and cost-effective measuring electronics can be used to achieve good measuring accuracy.

[0081] The use of the invention is not limited to the embodiments disclosed in the accompanying drawings. The invention can be used for any type of elevator, for example an elevator with or without a machine room, an elevator with or without a counterweight. The counterweight can be positioned on either side wall of the elevator shaft, on both sides or on the rear wall. The drive, motor, traction sheave and machine brake can be positioned in the machine room or somewhere in the elevator shaft. The elevator car guide rails can be positioned on opposite side walls of the shaft or on the rear wall of the shaft.

[0082] It is obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways.The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A load measuring device for an elevator, comprising: a lifting machine (3) for driving an elevator car (2) in an elevator shaft (1); a lifting machine bottom plate (11) for supporting the lifting machine; at least one load weighing sensor (20) located between the lifting machine (3) and the lifting machine bottom plate (11); characterized in that the load measuring device comprises an alignment device (25) for placing the at least one load weighing sensor (20) at one or more predetermined points between the lifting machine (3) and the lifting machine bottom plate (11).

2. The device according to claim 1, wherein the alignment device (25) comprises at least one recess (26) for the at least one load weighing sensor (20) on at least one mating surface of the lifting machine and the lifting machine bottom plate.

3. The device according to any one of the preceding claims, wherein at least two load weighing sensors (20) are located between the lifting machine (3) and the lifting machine bottom plate (11).

4. The device according to any one of the preceding claims, wherein the load measuring device comprises two load weighing sensors (20), and the distance (C) between the two sensors is substantially one third of the width (3C) of the lifting machine bottom plate (11).

5. The device according to any one of the preceding claims, wherein the load weighing sensor (20) is vertically placed below the traction pulley (33) comprised in the lifting machine (3).

6. The device according to any one of the preceding claims, wherein the at least one load weighing sensor (20) is vertically placed below the load line (A) of the ropes (4, 42) guided on the traction pulley (33) comprised in the lifting machine (3).

7. The device according to any one of the preceding claims, wherein two load weighing sensors (20) are horizontally placed at a predetermined distance (C) from each other such that the two load weighing sensors are symmetrically arranged with respect to the lifting machine bottom plate (11).

8. The device according to any one of the preceding claims, wherein the device comprises an adapter plate (25) having one or more load weighing sensors (20) at predetermined points on the plate.

9. The device according to any one of the preceding claims, wherein the alignment device (25) comprises an adapter plate (25) having one or more load weighing sensors (20) at predetermined points on the plate.

10. The device according to claim 8 or 9, wherein the adapter plate (25) is configured to be assembled between the lifting machine (3) and the lifting machine bottom plate (11).

11. The device according to any one of claims 8 to 10, wherein the adapter plate (25) comprises at least one structural element (27), such as one or more holes (28) or pins or clips (29), for aligning the adapter plate in a predetermined position between the lifting machine (3) and the lifting machine base plate (11).

12. The device according to any one of the preceding claims, wherein the at least one load weighing sensor (20) comprises a sensor selected from the group consisting of: a capacitance sensor, a strain gauge, a load cell, a compression measurement of an elastic element, and a hydraulic sensor.

13. The device according to any one of the preceding claims, wherein an elastic damping element (30) is assembled between the lifting machine (3) and the lifting machine base plate (11) and is connected to the at least one load weighing sensor (20).

14. The device according to any one of the preceding claims, wherein the lifting machine (3) comprises an electric motor (32), a traction pulley (33), and at least one lifting machine brake (34).

15. The device according to any one of the preceding claims, wherein the elevator comprises: one or more suspension ropes (4, 42); and a counterweight (5); the car and the counterweight are suspended by the one or more ropes (4, 42), and the ropes (4, 42) are guided over the traction pulley (33) for vertically moving the car (2) in the elevator shaft (1).

16. A method for elevator load measurement, the elevator comprising a lifting machine (3) for driving an elevator car (2) in an elevator shaft (1); a lifting machine base plate (11) supporting the lifting machine; the method comprises: measuring the load of the elevator by at least one load weighing sensor (20) located between the lifting machine (3) and the lifting machine base plate (11); characterized in that alignment means (25) for the at least one load weighing sensor (20) are provided, and the at least one load weighing sensor (20) is placed at one or more predetermined points between the lifting machine (3) and the lifting machine base plate (11) by means of the alignment means (25).

17. The method according to claim 16, wherein two load weighing sensors (20) are placed at a distance (C) between the two sensors, wherein the distance (C) is substantially one third of the width (3C) of the lifting machine base plate (11).

18. The method according to claim 16 or 17, wherein the at least one load weighing sensor (20) is placed vertically below the load line (A) of the ropes (4, 42), and the ropes (4, 42) are guided over the traction pulley (33) comprised in the lifting machine (3).

19. The method according to any one of claims 16 to 18, wherein two load weighing sensors (20) are placed horizontally at a predetermined distance (C) from each other such that the two load weighing sensors are symmetrically arranged with respect to the lifting machine base plate (11).

20. The method according to any one of claims 16 to 19, wherein an elastic vibration damping element (30) is assembled between the lifting machine (3) and the lifting machine bottom plate (11) and is connected to the at least one load weighing sensor (20).

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