Description Title of Invention: ELEVATOR DEVICE AND CALIBRATION METHOD FOR WEIGHING DEVICE
Technical Field
[0001] The present invention relates to an elevator device including a weighing device, which is easily calibratable, and to a method of calibrating the weighing device.
Background Art
[0002] A general elevator device includes a weighing device configured to detect a load state in a car. Configurations of the weighing device include a configuration in which the load state is detected based on a rope tensile force, which is changed depending on a weight in the car. Moreover, an important function of the weighing device is to sense the load state during service operation of the elevator to prevent the car from descending due to overloading.
[0003] In order to reliably prevent an incident in which the car descends due to overloading as described above, it is required for the weighing device to be calibrated so as to ensure accuracy. As such a calibration method, there is known a related-art technology in which a car is pulled upward under a state in which a pit and the car are connected with a chain, and the weighing device is calibrated based on a change in loaded condition applied on the

connecting chain (see Patent Literature 1, for example).
Citation List Patent Literature [0004] [PTL 1] JP 2007-168938 A
Summary of Invention Technical Problem
[0005] The related-art technology of Patent Literature 1 requires an operation of connecting the connecting chain, and preparation of an adjustment load cell. Therefore, there is a problem in that the calibration operation takes time. Moreover, the related-art technology of Patent Literature 1 requires an additional structure of a pit floor that can endure a load applied by the connecting chain.
[0006] The present invention has been made to solve the above-mentioned problem, and therefore has an object to provide an elevator device, with which calibration operation for a weighing device can be performed more easily than in the related art, and a method of calibrating the weighing device.
Solution to Problem
[0007] According to one embodiment of the present invention, there is provided an elevator device including: a hoisting machine; a sheave to be driven by the hoisting machine; a rope wound around

the sheave; a car suspended from a rope portion on one side of a portion of the rope that is wound around the sheave; a counterweight suspended from a rope portion on a side, which is opposite to the one side on which the car is suspended, of the portion of the rope that is wound around the sheave; a weighing device configured to detect a car weight based on a tensile load of the rope to output the car weight as a weighing value; and a controller configured to sense a load state of the car based on the weighing value output from the weighing device, the weighing device having a structure in which, with the weighing value under a no-load state of the car being a reference, the output of the weighing value has a linear characteristic with respect to a change in loading ratio in both cases in which the car weight is increased and decreased as compared to the no-load state.
[0008] Further, according to another embodiment of the present invention, there is provided a method of calibrating a weighing device, which is executed in the elevator device, the method including executing the following steps by the controller in response to a calibration command: a first step of controlling the car in the no-load state to be in a state of being held stationary, then setting an output value of a hoisting machine torque under the state of being held stationary to a value corresponding to a first loading ratio, and acquiring a first weighing value corresponding to the first loading ratio from the weighing device to generate first calibration data consisting of the first loading

ratio and the first weighing value; a second step of establishing a first state in which the car is mechanically undescendable, and, when the first state is maintained after a hoisting machine torque of a constant load is applied for a predetermined time period, setting the hoisting machine torque of the constant load to a value corresponding to a second loading ratio, and acquiring a second weighing value corresponding to the second loading ratio from the weighing device to generate second calibration data consisting of the second loading ratio and the second weighing value; and a third step of calibrating the linear characteristic based on the first calibration data and the first calibration data.
Advantageous Effects of Invention
[0009] According to one embodiment of the present invention, there is provided the weighing device, which is configured to detect the car weight based on the tensile load of the rope, and is capable of detecting both states including a case in which a rope tensile force is increased and a case in which the rope tensile force is reduced using the same calibration value. Further, with the use of the weighing device having the above-mentioned configuration, for example, the hoisting machine is driven to rotate to a side in which the car descends under a state in which the car does not descend to reduce the rope tensile force, and the weighing device can be calibrated based on a torque value of the hoisting machine obtained at the time of driving. As a result, there can be obtained

the elevator device, with which the calibration operation for the weighing device can be performed more easily than in the related art, and the method of calibrating a weighing device.
Brief Description of Drawings
[0010] FIG. 1 is a configuration diagram of an elevator device according to a first embodiment of the present invention.
FIG. 2 is a graph for showing a relationship between a weighing value and a loading ratio at a time of weighing device calibration with a positive load in the elevator device according to the first embodiment of the present invention.
FIG. 3 is a diagram for illustrating a configuration example of a weighing device in the first embodiment of the present invention.
FIG. 4 is a configuration diagram of an elevator device according to a second embodiment of the present invention.
FIG. 5 is a flow chart for illustrating a specific procedure of calibrating a weighing device based on an output value of a hoisting machine torque in the elevator device according to the second embodiment of the present invention.
FIG. 6 is a graph for showing a relationship between a weighing value and a loading ratio at a time of weighing device calibration with a negative load in the elevator device according to the second embodiment of the present invention.
FIG. 7A is an explanatory graph for showing a calibration

principle of the output value of the hoisting machine torque in the second embodiment of the present invention, and is a graph for showing a speed pattern.
FIG. 7B is an explanatory graph for showing the calibration principle of the output value of the hoisting machine torque in the second embodiment of the present invention, and is a graph for showing a time-varying pattern of the hoisting machine torque corresponding to the speed pattern of FIG. 7A.
FIG. 7C is an explanatory graph for showing the calibration principle of the output value of the hoisting machine torque in the second embodiment of the present invention, and is a graph for showing a relationship between a torque output and a drive load.
FIG. 8 is a flow chart for illustrating a procedure of calibrating the output value of the hoisting machine torque in the second embodiment of the present invention.
FIG. 9 is a configuration diagram of an elevator device according to a third embodiment of the present invention.
FIG. 10 is a flow chart for illustrating a series of steps of processing of emergency stop inspection to be executed by an emergency stop inspection device in the third embodiment of the present invention.
Description of Embodiments
[0011] A description is now given of an elevator device and a method of calibrating a weighing device according to preferred

embodiments of the present invention with reference to the accompanying drawings. [0012] First Embodiment
FIG. 1 is a configuration diagram of an elevator device according to a first embodiment of the present invention. A rope
3, from which a car 1 and a counterweight 2 are suspended, is wound
around a drive sheave 4.
[0013] An elevator control device 20 includes a controller 21 and a weighing value processor 22 . The controller 21 is configured to control a hoisting machine 5, to thereby rotate the drive sheave
4, which is synchronous with the hoisting machine 5. As a result,
the controller 21 runs the car 1 and the counterweight 2, which
are connected to the rope 3, up and down inside a hoistway.
[0014] A speed governor 6 is configured to output, when sensing that a speed of the car 1, which operates in synchronization with the counterweight 2, becomes a certain value or more, a command signal for actuating an emergency stop device 7 . The emergency stop device 7 is configured to hold rails 8 to mechanically avoid descending of the car 1 in response to the command signal from the speed governor 6.
[0015] A weighing device 9 is a device configured to detect a loaded weight in the car. Further, as described above, it is required for the weighing device 9 to calibrate an output value in association with an actual load in order to maintain detection accuracy. In the first embodiment, the elevator control device 2 0

includes the weighing value processor 22. The weighing value processor 22 is configured to calibrate the weighing device 9 by externally inputting a calibration command value.
[0016] A hoisting machine rotation sensor 11 is a sensor configured to output a signal for sensing a rotation angle of the hoisting machine 5. The sensed signal is used by the controller 21 in the elevator control device 20 to control an elevator.
[0017] Next, the weighing device 9 in the elevator device according to the first embodiment and a method of calibrating the weighing device 9 will be described. FIG. 2 is a graph for showing a relationship between a weighing value and a loading ratio at a time of weighing device calibration with a positive load in the elevator device according to the first embodiment of the present invention.
[0018] The "loading ratio" as used herein is a value with a state in which there is no load in the car being 0% and a state in which a load of a rated capacity is in the car being 100%. The weighing device 9 in the first embodiment has a relationship in which an output of the weighing value with respect to a change in loading ratio is linear, that is, a relationship in which both thereof are proportional to each other.
[0019] Therefore, with weighing values under the following two states: the state in which there is no load in the car (that is, state corresponding to a loading ratio of 0%) ; and a state in which a calibration weight is loaded (for example, state corresponding

to a loading ratio of 10%), not only a positive loading ratio but also a negative loading ratio can be detected accurately.
[0020] With the use of the above-mentioned relationship, more specifically, by setting a load factor for determining rope loosening as a reference, a rope loosening state can be detected accurately based on a measurement result of a weighing value.
[0021] FIG. 3 is a diagram for illustrating a configuration example of the weighing device 9 in the first embodiment of the present invention. The weighing device 9 in the first embodiment is provided between the rope 3 and the car 1, and includes displacement detectors 91, linear compression springs 92, rods 93, and a fixed plate 94.
[0022] When the loaded weight of the car is increased, the linear compression springs 92 are compressed. Those changes in compression may be detected by the displacement detectors 91 to sense changes in load on the ropes. As illustrated in FIG. 3, when the number of ropes 3 is three, a change in load state can be sensed based on a total of the changes in load on the ropes 3 sensed by the three displacement detectors 91.
[0023] Moreover, the weighing device having the above-mentioned configuration can determine, in a range in which the springs change linearly, a state in which the ropes are loosened further from the state in which there is no load in the car. Therefore, the weighing device in the first embodiment can detect with high accuracy a direction in which a rope tensile force is

reduced. In other words, the weighing device in the first embodiment can be applied to a function of sensing the state in which the rope tensile force is loosened.
[0024] As described above, the elevator device according to the first embodiment has the configuration in which a car weight is detected based on tensile loads of the ropes, and in which the same calibration value can be used in both states including the case in which the car weight is increased with respect to the no-load state and the case in which the car weight is reduced with respect to the no-load state. As a result, loosening of the rope tensile force can be sensed with high accuracy with the use of the weighing device calibrated with a weight being loaded in the car.
[0025] More specif ically, the elevator device according to the first embodiment can drive the hoisting machine to rotate to the side in which the car descends under the state in which the car does not descend to reduce the rope tensile force, and calibrate the weighing device based on a torque value of the hoisting machine at that time of driving, for example. As a result, as compared to the related-art technology, operation of connecting a connecting chain and preparation of an adjustment load cell are not required, and the weighing device can be calibrated efficiently.
[0026] Moreover, the structure of a pit floor that can withstand a chain load and other such structure are not required, and the weighing device can be calibrated easily and with high accuracy with a general elevator configuration.

[0027] Further, the elevator device according to the first embodiment has the configuration in which the weighing device is directly calibrated based on the state in which the rope tensile force is weakened. Therefore, higher accuracy can be ensured for the direction in which the rope tensile force is reduced, for example, and the calibration principle can be used for the function of sensing the loosened rope tensile force.
[0028] As a result, a case in which the load applied on the car is reduced by dropping off of car equipment and a hanging rope for weight adjustment can be detected based on a reduction of the output of the weighing device to less than 0% load.
[0029] Second Embodiment
FIG. 4 is a configuration diagram of an elevator device according to a second embodiment of the present invention. In the configuration of the first embodiment illustrated in FIG. 1 described above, a weighing device calibration command for the elevator control device 20 is externally input. In contrast, a configuration of the fourth embodiment illustrated in FIG. 4 is a configuration in which the weighing device calibration command is input from the controller 21 to the weighing value processor 22. As a result, the elevator device according to the second embodiment can directly calibrate the weighing value processor 22 based on a command from the controller 21.
[0030] Next, a weighing device 9 in the elevator device according to the second embodiment will be described in detail.

As in the first embodiment described above, the weighing device 9 in the second embodiment also has a relationship in which an output of a weighing value is linear with respect to a change in loading ratio, that is, a relationship in which both thereof are proportional to each other. Therefore, with weighing values under two load states, the output from the weighing device 9 can be calibrated.
[0031] Moreover, according to the second embodiment, in particular, there is adopted a configuration in which an output value of a hoisting machine torque can be directly input from the controller 21 to the weighing value processor 22. Therefore, without changing an actual loaded weight of the car with the use of a weight, the weighing device 9 can be calibrated based on the output value of the hoisting machine torque.
[0032] FIG. 5 is a flow chart for illustrating a specific procedure of calibrating the weighing device 9 based on the output value of the hoisting machine torque in the elevator device according to the second embodiment of the present invention. First, after a state of no human in the car 1 is confirmed, calibration operation is started.
[0033] Next, in Step S501, the controller 21 executes control to hold the hoisting machine. That is, the controller 21 controls the hoisting machine 5 such that the car 1 is held stationary. The output value of the hoisting machine torque at this time corresponds to a weight difference between the car 1 and the counterweight 2

under a 0% load state.
[0034] Next, in Step S502, the controller 21 stores the output value of the hoisting machine torque corresponding to the weight difference between the car 1 and the counterweight 2 under the 0% load state and a weighing value that is an output value of the weighing device 9 under this state as calibration data 1 in the weighing value processor 22 .
[0035] Next, in Step S503, the controller 21 controls the car 1 to actuate the emergency stop device. Further, in Step S504, the controller 21 outputs a hoisting machine torque of a constant load in a direction in which the car 1 descends under a state in which the emergency stop device is operated.
[0036] Next, in Step S505, the controller 21 determines whether the state in which the hoisting machine torque of the constant load is maintained for a predetermined time period. Then, when the state in which the hoisting machine torque of the constant load is output is maintained for the predetermined time period, the controller 21 determines that it is confirmed that the car has not descended, and the processing proceeds to Step S506. [0037] The controller 21 may further check in Step S505 whether the hoisting machine 5 is not rotated by a hoisting machine rotation detector, to thereby ensure that the car has not descended more reliably.
[0038] Under a state in which the car 1 has not descended, a tensile force of the ropes 3 connecting from the drive sheave 4

to the car 1 is reduced than in the 0% load state. Therefore, under this state, a weight corresponding to a reduced amount of the tensile force is borne by the emergency stop device.
[0039] In view of the above, when confirming the state in which the car has not descended, the controller 21 stores, in Step S506, an output value of the hoisting machine torque and a weighing value that is an output value from the weighing device 9 under this state as calibration data 2 in the weighing value processor 22. [0040] Meanwhile, when the hoisting machine has rotated or a torque output is not stable at a constant value in the determination of Step S505, the processing proceeds to Step S508, and the controller 21 determines the processing as an error and ends the series of steps of processing.
[0041] After learning of the calibration data 2 in Step S506 is complete, the processing proceeds to Step S507, and the weighing value processor 22 performs processing of calibrating the weighing value. In executing the calibration processing, the weighing value processor 22 uses the calibration data 1 and the calibration data 2.
[0042] FIG. 6 is a graph for showing a relationship between the weighing value and the loading ratio at a time of weighing device calibration with a negative load in the elevator device according to the second embodiment of the present invention, and showing a relationship between two points of the calibration data 1 and the calibration data 2. In the case of FIG. 6, for example, the output

value of the hoisting machine torque in the calibration data 2 corresponds to the loaded weight of -10%.
[0043] As shown in FIG. 6, the weighing value processor 22 performs the calibration processing by performing linear interpolation between the calibration data 1 and the calibration data 2. With this processing, the weighing value processor 22 can acquire an "increase/decrease ratio of the weighing value with respect to a change in loaded weight" and an "origin of the weighing value (weighing value corresponding to the state in which there is no loaded weight)" as calibration parameters.
[0044] With those parameters, the weighing value processor 22 can calculate, with the origin of the weighing value being a reference, a change in loaded weight corresponding to a change in weighing value output from the value, to thereby sense a loaded weight state accurately. The series of steps of processing ends with the processing of Step S507.
[0045] In the processing described above, the weighing value corresponding to a loaded weight less than 0% load (this state is hereinafter referred to as "negative value"), which is not used in a normal weighing device, is used. As a result, the elevator device according to the first embodiment can produce a state in which an external load variation corresponding to the loaded weight is applied to the weighing device 9 without loading the counterweight 2, and the calibration data can be acquired and used to perform the calibration of the weighing device 9.

[0046] In particular, when the rope tensile force and the weighing value have a linear characteristic for both of positive and negative sides of the 0% laod as in the weighing device according to the first embodiment, even in a case where a calibration method with a negative value is adopted, the weighing device 9 can be maintained at high accuracy without reducing the accuracy of the weighing device 9 .
[0047] Moreover, with the configuration in which the change in loaded weight is associated with a variation in rope tensile force as in the weighing device 9 according to the first embodiment, a reduction in tensile force of the ropes 3 can be detected with the use of a result of an output for the negative load of the weighing value.
[0048] As described above, in the case of using the output value for the negative load, the weighing value corresponding to the reduced state of the rope tensile force is used to directly calibrate the weighing device 9. Therefore, the weighing device according to the ninth embodiment can also be used as a device configured to detect the reduced state of the rope tensile force during the calibration, and higher reliability can be ensured.
[0049] Here, in order to further increase calibration accuracy for the weighing value, a measure of increasing accuracy of the torque output of the hoisting machine as calibration source data itself is conceivable. Specifically, the change in hoisting machine torque during travel may be calibrated in association with

a physical phenomenon to achieve the increase in accuracy.
[0050] FIG. 7A to FIG. 7C are explanatory graphs for showing a calibration principle of the output value of the hoisting machine torque in the second embodiment of the present invention. In FIG. 7A, a speed pattern is shown, and in FIG. 7B, a time-varying pattern of the hoisting machine torque corresponding to the speed pattern of FIG. 7A is shown.
[0051] The hoisting machine torque at this time corresponds to a tension difference value, which is a difference between a tension value of the ropes 3 on a side to which the car 1 is connected and a tension value of the ropes 3 on a side to which the counterweight 2 is connected. A drive load is changed at the time of acceleration and deceleration during travel, and hence as shown in FIG. 7B, the hoisting machine torque also varies in correspondence with the variation in drive load as: Tl, T2, and T3.
[0052] In FIG. 7C, a relationship between the torque output and the drive load is shown. Theoretically, the torque output and the drive load have a linear characteristic as shown in FIG. 7C. Moreover, in FIG. 7C, the hoisting machine torques Tl, T2, and T3 correspond to magnitudes of drive loads Tl', T2', and T3', respectively. Further, the drive loads can be defined as the following relationships with an acceleration of gravity being represented by G:
Tl'=("weight of counterweight"-"car weight")xG+("weight of counterweight"+"car weight")xacceleration;

T2'=("weight of counterweight"-"car weight")xG; and T3'=("weight of counterweight"-"car weight")xG-("weight of counterweight"+"car weight")xacceleration.
[0053] From the above-mentioned relationships, the drive load during travel can be identified, and hence the torque output can be calibrated so that the linear characteristic corresponds to the magnitude of the drive load, to thereby achieve high accuracy.
[0054] FIG. 8 is a flow chart for illustrating a procedure for calibrating the output value of the hoisting machine torque in the second embodiment of the present invention. Specifically, in FIG. 8, there is illustrated a procedure of calibrating the torque output value by acquiring the torque output values Tl, T2, and T3.
[0055] First, after a state of no human in the car 1 is confirmed, the controller 21 starts running the car 1 in Step S801. The subsequent procedure corresponds to the travel pattern of FIG. 7A.
[0056] Next, in Step S802 and Step S803, the controller 21 acquires the torque output Tl during constant acceleration after the car 1 starts traveling. Thereafter, the controller 21 similarly acquires the torque output T2 during traveling at a constant speed in Step S804 and Step S805, and acquires the torque output T3 during the constant acceleration in Step S806 and Step S807.
[0057] Then, inStepS808, as described with reference to FIG. 7C, the controller 21 calibrates the hoisting machine torque output by using the correspondence between the torque output value and

the drive load, and completes the series of steps of processing. [0058] As described above, according to the elevator device of the second embodiment, the output value of the weighing device can be calibrated based on the torque output value. Specifically, the elevator device has the configuration in which the rope tensile force is reduced by the hoisting machine under the state in which the emergency stop is applied, and in which the weighing device can be calibrated based on the hoisting machine torque output at that time. As a result, the weighing device can be configured without loading the weight in the car. In particular, the reduction in rope tensile force can be directly calibrated, and hence high accuracy can be ensured also for the function of detecting the reduction in rope tensile force. [0059] Third Embodiment
As described above, in the configuration of the elevator device according to the present invention, the reduction in rope tensile force from the state in which the loaded weight is 0% load can be detected quantitatively. In view of this, in a third embodiment of the present invention, a description is given in particular of a technology of applying this function of detecting the reduction in rope tensile force to actuation check of an emergency stop device.
[0060] It is mandatory for the emergency stop device to be installed on an elevator, and the emergency stop device is a safety device configured to brake and hold the car 1 when the car 1 cannot

be suspended by the ropes 3 and the car 1 descends at an excessive speed. Therefore, it is required for the emergency stop device to be inspected regularly for its operation and function so as to be appropriately installed as the safety device on the elevator and reliably perform its function.
[0061] In the regular inspection, it is confirmed that the car 1 is undescendable under the state in which the emergency stop device is applied. As a specific method, the hoisting machine torque in a rotation direction in which the car 1 descends is output from the hoisting machine 5 under the state in which the emergency stop device is applied. Then, under this output state, a "state in which the ropes 3 slide in a sheave groove of the hoisting machine 5" or a "state in which the ropes 3 from which the car 1 is suspended are loosened" is confirmed, to thereby confirm that the emergency stop is actuated.
[0062] However, in order to attain the "state in which the ropes slide in the sheave groove", a large hoisting machine capable of outputting a considerably high torque is required. In contrast, in the elevator device according to the third embodiment, with the use of the weighing device 9 in the present invention, it can be determined that "the ropes from which the car is suspended are loosened" under the state in which the emergency stop device is applied. As a result, without providing the large hoisting machine to confirm the "state in which the ropes slide in the sheave groove", the actuation check of the emergency stop device can be performed.

[0063] FIG. 9 is a configuration diagram of the elevator device according to the third embodiment of the present invention. In FIG. 9, there is illustrated the configuration of the elevator device in which the " state in which the ropes from which the car is suspended are loosened" is determined with the use of the weighing device 9 to inspect the emergency stop device. The configuration of FIG. 9 is different from the configuration of FIG. 4 described above only in that an emergency stop inspection device 21a configured to perform a procedure of inspecting the emergency stop is included in the controller 21. Therefore, a description is given mainly of the difference below.
[0064] FIG. 10 is a flow chart for illustrating a series of steps of processing of emergency stop inspection to be executed by the emergency stop inspection device 21a in the third embodiment of the present invention. The procedure of performing the inspection of the emergency stop device with the configuration of FIG. 9 will be described in detail following FIG. 10.
[0065] First, in Step S1001, the emergency stop inspection device 21a actuates the emergency stop. Next, in Step S1002, the emergency stop inspection device 21a outputs a predetermined hoisting machine torque in the direction in which the car 1 descends .
[0066] Thereafter, in Step S1003, the emergency stop inspection device 21a checks whether the weighing value is lower than a first threshold value. In this case, it is required to confirm a state in which the emergency stop is actuated and the

car 1 is lifted up. Therefore, it is a criterion that the weighing value is at least less than the 0% load state. Therefore, it is required that the first threshold value be set to a negative value.
[0067] Moreover, the first threshold value may be further decreased considering the effect in which the car 1 is lifted up by a factor other than the emergency stop, it can be confirmed that the car 1 is lifted up reliably by the actuation of the emergency stop. Specifically, in consideration of a contact friction force between the car 1 and the rails 8, it is conceivable to set, as the first threshold value, a value that is lower than the 0% load state by the friction force.
[0068] When a result of the determination in Step S1003 is "yes", the processing proceeds next to Step S1004, in which the emergency stop inspection device 21a checks whether a torque value is higher than a second threshold value . In this case, it is checked whether a torque of the hoisting machine 5 is output at a level that is enough to loosen the ropes 3.
[0069] Further, when a result of the determination in Step S1004 is "yes", the processing proceeds next to Step S1005, in which the emergency stop inspection device 21a determines whether the torque of the second threshold value or more has been maintained for a predetermined time period. When a result of the determination in Step S1005 is "yes", the emergency stop inspection device 21a determines that it has been confirmed that the car 1 has not descended, and completes the inspection.

[0070] Although not shown in FIG. 10, the emergency stop inspection device 21a can further guarantee that the car 1 has not descended more reliably by also confirming that the hoisting machine 5 has not rotated by the hoisting machine rotation detector.
[0071] Meanwhile, when none of the conditions of Step S1003, Step S1004, and Step S1005 is satisfied and the result of the determination is "no", the processing proceeds to Step S1006, in which the emergency stop inspection device 21a determines an inspection error, and ends the series of steps of procedure. With the above-mentioned procedure, the emergency stop inspection device 21a can confirm the state in which the emergency stop is reliably actuated to support the car 1 upward.
[0072] As described above, the elevator device according to the third embodiment has a configuration in which the torque of the hoisting machine is generated in the direction in which the car descends under the state in which the emergency stop device is actuated, and in which, when the state in which the car weight is reduced as compared to the predetermined weight is detected by the weighing device, it can be determined that the operation and function of the emergency stop device are normal. As a result, with the use of the weighing device with which a guarantee of high accuracy for the reduction in rope tensile force can be achieved, the operation and function of the emergency stop can be confirmed reliably.
[0073] In the configuration diagrams of FIG. 1, FIG. 4, and

FIG. 9 described above, the description is given of the configuration in which the weighing value processor 22 is included in the elevator control device 20. However, as long as required information can be sent and received, there may be adopted a configuration in which the weighing value processor 22 is provided as a separate device external to the elevator control device 20. Similarly, as long as required information can be sent and received, there may also be adopted a configuration in which the emergency stop inspection device 21a in FIG. 9 is included as a separate device external to the elevator control device 20.
[0074] Moreover, in the description of the procedure in Step S503 of FIG. 5, in order to establish the state in which the car is mechanically undescendable, the emergency stop device is actuated, but the present invention is not limited to the procedure. As long as the car is set to the state of being mechanically undescendable, another means, for example, lowering the car to the bottom floor so as not to descend further, may be adopted in Step S503.
[0075] Further, in regard to the calibration data 2 , the loaded weight is exemplified as being -10% in FIG. 6, but may be another value as long as the value is a negative value smaller than 0% load.

We Claim:
[Claim 1] An elevator device, comprising:
a hoisting machine;
a sheave to be driven by the hoisting machine;
a rope wound around the sheave;
a car suspended from a rope portion on one side of a portion of the rope that is wound around the sheave;
a counterweight suspended from a rope portion on a side, which is opposite to the one side on which the car is suspended, of the portion of the rope that is wound around the sheave;
a weighing device configured to detect a car weight based on a tensile load of the rope to output the car weight as a weighing value; and
a controller configured to sense a load state of the car based on the weighing value output from the weighing device,
the weighing device having a structure in which, with the weighing value under a no-load state of the car being a reference, the output of the weighing value has a linear characteristic with respect to a change in loading ratio in both cases in which the car weight is increased and decreased as compared to the no-load state.
[Claim 2] The elevator device according to claim 1, wherein the controller is configured, in response to a calibration command, to acquire a first weighing value corresponding to a first loading

ratio from the weighing device to generate first calibration data, to acquire a second weighing value corresponding to a second loading ratio from the weighing device to generate second calibration data, and to calibrate the linear characteristic based on calibration data at two points consisting of the first calibration data corresponding to the first loading ratio and the first calibration data corresponding to the second loading ratio.
[Claim 3] The elevator device according to claim 2, wherein the controller is configured to:
generate the first calibration data by controlling the car in the no-load state to be in a state of being held stationary, then setting an output value of a hoisting machine torque under the state of being held stationary to a value corresponding to the first loading ratio, and acquiring the weighing value under the state of being held stationary;
generate the second calibration data by actuating an emergency stop device installed on the car to establish a first state, in which the car is undescendable, and, when the first state is maintained after a hoisting machine torque of a constant load is applied in a direction in which the car descends, setting the hoisting machine torque of the constant load to a value corresponding to the second loading ratio, and acquiring the weighing value under the first state; and
calibrate the linear characteristic based on the first

calibration data and the second calibration data.
[Claim 4] The elevator device according to claim 3, wherein the controller is configured to:
acquire, as a first weighing value from the weighing device, a car weight under a state in which the emergency stop device is actuated;
acquire, as a second weighing value from the weighing device, a car weight under a state in which the emergency stop device is actuated and the hoisting machine torque is generated in the direction in which the car descends; and
determine, when the second weighing value is a value smaller than the first weighing value, that operation and function of the emergency stop device are normal.
[Claim 5] The elevator device according to claim 4, wherein the controller is configured to determine, when detecting that a value of the hoisting machine torque at a time when the second weighing value is acquired is larger than a difference between a weight of the counterweight and a weight of the car, that the operation and function of the emergency stop device are normal.
[Claim 6] The elevator device according to claim 4 or 5, wherein the controller is configured to actuate the emergency stop device and monitor, with a time point at which the hoisting machine torque

is generated in the direction in which the car descends being a starting point, a transition state of the weighing value acquired from the weighing device, and is configured to determine, when the weighing value is not reduced for a predetermined time period, that the operation and function of the emergency stop device are normal.
[Claim 7] The elevator device according to any one of claims 3 to 6, wherein the controller is configured to:
run an elevator to acquire hoisting machine torques at three points consisting of a first hoisting machine torque during constant acceleration, a second first hoisting machine torque during traveling at a constant speed, and a third first hoisting machine torque during constant deceleration;
calculate, based on a weight of the car, a weight of the counterweight, an acceleration of gravity, an acceleration during the constant acceleration, and an acceleration during the constant deceleration, drive loads at three points respectively corresponding to the hoisting machine torques at the three points; and
calibrate the hoisting machine torques at the three points based on values of the drive loads at the three points using a fact that the drive loads at the three points and the hoisting machine torques at the three points have a proportional relationship, to thereby execute processing of calibrating the hoisting machine torque.

[Claim 8] A method of calibrating a weighing device, which is executed in the elevator device of claim 1, the method comprising executing the following steps by the controller in response to a calibration command:
a first step of controlling the car in the no-load state to be in a state of being held stationary, then setting an output value of a hoisting machine torque under the state of being held stationary to a value corresponding to a first loading ratio, and acquiring a first weighing value corresponding to the first loading ratio from the weighing device to generate first calibration data consisting of the first loading ratio and the first weighing value;
a second step of establishing a first state in which the car is mechanically undescendable, and, when the first state is maintained after a hoisting machine torque of a constant load is applied for a predetermined time period, setting the hoisting machine torque of the constant load to a value corresponding to a second loading ratio, and acquiring a second weighing value corresponding to the second loading ratio from the weighing device to generate second calibration data consisting of the second loading ratio and the second weighing value; and
a third step of calibrating the linear characteristic based on the first calibration data and the first calibration data.