JPH0930750A - Braking characteristic evaluating device for elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a braking characteristics evaluating device which is capable of being operated even by an inexperienced maintenance personnel and by which the braking characteristics can be automatically evaluated in a short time. SOLUTION: The number of revolutions of an induction motor 6 detected by a speed detector 9 at the time of maintenance lowering operation when an elevator forced to travel downward from a specified floor is suddenly stopped, is stored in a RAM 14, and then a microcomputer 12 reads out the number of revolutions to differentiate a speed of a elevator, and checks up points of change in the speed to calculate the times t1 ', t2 ' between the points of change in the speed. Successively, the microcomputer calculates the differences from the delay time t1 of operation at the time of normal operation, the time t2 of return change of operation lever, the deceleration P1 immediately before stopping of the elevator (t1 '-t1 ), (t2 '-t2 ), (P1 '-P1 ) to judge whether or not these values fall in specified ranges respectively, and to evaluate and judge the braking characteristics of the elevator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator brake characteristic evaluation device in which a brake shoe is pressed against a brake drum by an elastic force of a braking spring to exert a braking force on a rotating shaft of an electric motor.

[0002]

2. Description of the Related Art A brake called a drum brake is used as a braking device for an electric motor that drives an elevator. FIG. 8 is a block diagram showing the outline of a braking device for an electric motor including a drum brake that is generally used for the electric motor. A brake drum 82 is directly connected to a rotary shaft 81 of the electric motor, and a pair of braking arms 84 (a, b) having brake shoes 83 (a, b) for braking are provided at positions facing the outer peripheral surface of the brake drum 82. ) Is provided. One end of each of the braking arms 84 (a, b) is rotatably supported, and the other end of each of the braking arms 84 (a, b) is pressed by the braking spring 85 (a, b) against the brake drum 82. Being energized. The release of the braking force of the electric motor by the braking arms 84 (a, b) resists the elastic force of the braking spring 85 (a, b) due to the downward movement of the operating rod 87 driven by the energization of the electromagnetic coil 86. Then, the braking arm 84 (a, b) is urged in the direction of expanding outward as shown by the arrow a through the crank mechanism.

As described above, in the drum brake, the braking force of the electric motor utilizes the antagonistic state of the elastic force of the braking springs 85 (a, b) and the electromagnetic force of the electromagnetic coil 86 acting on the operating rod 87. The braking force required for different electric motors having different capacities depends on the magnitude of the rated coil current of the electromagnetic coil 86 and the braking spring 85 depending on the capacity of the electric motor.
The values of the elastic constants (a, b) are determined by being selected. By the way, generally, the brake characteristics of an electric motor are evaluated by the brake operation characteristics and the braking force characteristics. Specifically, the operating characteristics of the brake are evaluated by comparing the braking duration time of the electric motor measured by the maintenance personnel with the capacity of the electric motor and the specified value preset for each brake type. It was Further, regarding the braking force characteristic of the brake, the electric motor is driven with the braking force of the braking spring 85 (a, b) on the braking arm 84 (a, b) weakened by rotating the adjusting screw, and the sheave of the brake drum 82 starts to slide. The driving force at that time was measured a plurality of times for different braking forces, and the braking force of the brake under the rated braking force was estimated from the obtained measurement data.

[0004]

In the above-mentioned brake characteristic evaluation of the electric motor, for example, when evaluating the operation characteristic of the brake, the maintenance staff listens to the operation sound of the electric motor and measures the operation time thereof. It takes many years of experience for employees to be able to correctly evaluate the operating characteristics of electric motor brakes. Further, the work of finding out the specified value of the electric motor from a large number of tables arranged according to the capacity of the electric motor and the type of brake is also a complicated operation.

On the other hand, in order to evaluate the braking force characteristic of the brake, it is necessary for a maintenance worker to turn the adjusting screw of the braking spring 85 (a, b) to weaken the braking force on the braking arm 84 (a, b). Therefore, not only does it take a lot of time and effort to adjust the braking force, but also the original adjustment position may not be known or the adjustment may be erroneous during the restoration adjustment operation of the braking force. The present invention has been made to solve the above problems in the prior art, and can be operated even by a maintenance staff who does not have much experience, and brake characteristic evaluation can be performed automatically in a short time. It is an object of the present invention to provide an elevator brake characteristic evaluation device that can be used.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a speed detecting means for detecting the speed of an elevator and a drum brake which is operated at a predetermined speed and then a drum brake is operated. The brake shoe is pressed against the brake drum by an elastic force to exert a braking force on the rotating shaft of the electric motor to perform a maintenance traveling operation for stopping the elevator, and a maintenance traveling operation means for the elevator to perform a maintenance traveling operation. During operation, the speed detection means stores the speed of the elevator detected by the speed detection means at any time, and the speed of the elevator stored in the speed storage means is read to differentiate the speed, that is, to calculate the deceleration. Speed calculation means, change point detection means for detecting a change point of deceleration calculated by the deceleration calculation means, and change point detection Brake characteristic judging means for judging the brake characteristic of the elevator by comparing the value of the time interval between the deceleration change points detected by the step or the deceleration value calculated by the deceleration calculating means with a preset standard value With.

[0007]

The maintenance traveling operation means causes the elevator to travel at a predetermined speed at a predetermined time and then operates the drum brake to press the brake shoe against the brake drum by the elastic force of the braking spring to apply the braking force to the rotating shaft of the electric motor. To act
Perform maintenance running operation to stop the elevator. The speed detecting means detects the speed of the elevator while the elevator is performing the maintenance traveling operation. The speed storage means stores the speed of the elevator detected by the speed detection means at any time. The deceleration calculation means reads out the speed of the elevator stored in the speed storage means and calculates the deceleration. The changing point detecting means detects the changing point of the deceleration calculated by the deceleration calculating means. The brake characteristic determination means compares the value of the time interval between the deceleration change points detected by the change point detection means or the deceleration value calculated by the deceleration calculation means with a preset standard value to brake the elevator. Determine the characteristics.

[0008]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an outline of an elevator brake characteristic determination device according to an embodiment of the present invention. In the figure, 1 is a car, 2 is a counterweight for adjusting the load with the car 1, 3 is a main rope that suspends the car 1 and the counterweight 2 at both ends, and 4 is a main rope 3 which is bent together with a car. A sheave 5 to be wound around is a speed reducer that reduces the rotational speed of a driving force transmitted from an induction motor, which will be described later, and transmits it to the sheave 4, and 6 is an induction motor that serves as a drive source.
Reference numeral 7 is an inverter that once converts commercial three-phase AC power into DC power, and then again converts it into three-phase AC power, and 8 is provided in the driving force transmission path of the induction motor 6 and the speed reducer 5 to control the induction motor 6. A drum brake that applies power to stop and hold the car 1, 9 is a speed detector that detects the rotation speed of the induction motor 6, and 10 is connected to a control panel installed in the machine room of the elevator to force the elevator. A brake characteristic determination device 20, which transmits and receives a stop signal and various status signals to determine the brake characteristic of the elevator, is a monitoring center that is provided in a remote place and monitors the elevator.

Further, in the internal structure of the brake characteristic judging device 10, 11 is an interface circuit for controlling the input / output of the output signal of the speed detector 9 and the control signal from the monitoring center 20, and 13 is the control program and the normal operation of the drum brake 8. ROM that stores various data in advance when operating
Reference numeral 2 denotes a microcomputer that performs various calculations based on speed data or the like input through the interface circuit 11 and compares the characteristics with reference data to determine the characteristics of the drum brake 8. Reference numeral 14 denotes an elevator that is input through the interface circuit 11. RA for storing speed data etc.
M and 15 are display units that display speed data, calculation results, determination results, and the like. The weight of the counterweight 2 is the weight of the car 1
It is set to be balanced with the sum of the weight of the car and the load of 40 to 50% of the rated load of the car.

Next, the operation of this embodiment will be described. FIG. 7 is an explanatory diagram showing the relationship between the inertial performance rate and the torque of the elevator apparatus together with their relational expressions. In the figure, ω is the rotational angular velocity of the induction motor 6, J _M is the inertial performance rate of the induction motor 6, τ _M is the rotational torque of the induction motor 6, J _B is the inertial performance rate of the drum brake 8, and τ _B is the drum brake 8. Braking torque, i is the reduction ratio, J _L is the inertial ratio of the load including the car 1 and the counterweight 2, τ _ub is the unbalanced torque of the car 1 and the counterweight 2 acting on the rotation axis of the sheave 4, D _S Is the diameter of the sheave 4, M _C is the weight of the car 1, M _CW is the counterweight 2.
Represents the weight of. The total inertial performance ratio J and the total torque τ converted with respect to the rotation axis of the induction motor 6 are expressed by the equations (1) and (2), respectively, and the unbalanced torque τ _ub is (3).
In the equation, the relational expression between the total inertial performance ratio J and the total torque τ is expressed by the equation (4).

When the loading load of the car 1 is 0, that is, when the car 1 is descending at a constant speed with no load,
The total inertial coefficient J is a constant because each term on the right side of the equation (1) is constant. Further, as described above, since the weight M _{C of the} car 1 is smaller than the weight M _CW of the counterweight 2, the unbalanced torque τ
_ub becomes a negative value from the formula (3), that is, it acts in the direction of raising the car 1. Also, since the elevator device is running at a constant speed, the left side of equation (4) becomes 0,
The total torque τ becomes 0. Since no braking force acts on the drum brake 8, the braking torque τ _B is also zero. Therefore, the equation (2) becomes τ _M =-(1 / i) · τ _ub , and the induction motor 6 generates a rotating torque τ _M of a magnitude obtained by dividing the unbalanced torque τ _ub by the reduction ratio i, and the elevator is operated. It means that it is operating at a constant speed.

FIG. 3 is a timing chart of various signals and transitions showing brake characteristics when a braking force is applied to the drum brake 8 to forcibly stop it while the elevator is running at a constant speed. As shown in the figure,
At the same time as the output of the forced stop signal, the main circuit power supply for supplying power to the inverter 7 is cut off. Along with this, since the coil current of the drum brake 8 is also cut off, after a short operation delay time t ₁ , the elastic force of the braking springs 85 (a, b) causes the operating rod to start returning and changing, and the braking arm is moved. Brake shoe 8
3 (a, b) is pressed against the brake drum 82 to apply a braking force to the elevator.

[0013] During the operation delay time t _1, since the τ _M = τ _B = 0 in equation (2), τ = (1 / i) · τ ub becomes, by the action of negative unbalanced torque tau _ub The elevator slows down. Further, thereafter, while the operating rod is returning and changing (time t ₂ ), an increasing braking force is applied to the brake drum 82, so that the braking torque τ _B is applied to cause the elevator to decelerate. Braking spring 85 (a, b)
When the elastic force finishes transition back to full actuation rod, the maximum braking force applied to the brake drum 82, after the elevator is decelerated running of the braking time t _3, and stops. As shown in the lowest figure, the speed differential therebetween elevator stepwise increases with lapse of time t ₁ ~t _3, becomes 0 when the elevator is stopped.

The above-mentioned brake characteristic describes the state when the drum brake 8 operates normally. However, when the brake characteristic is abnormal, the above-mentioned operation timing is deviated. 4, 5 and 6 are timing charts showing brake characteristics when the drum brake 8 has a braking operation delay, when there is an operating rod displacement delay, and when the braking force is insufficient. First, the brake characteristics when the drum brake 8 has a braking operation delay will be described with reference to FIG. The braking characteristic in this case is represented by a characteristic curve indicated by a broken line in the figure. That is,
When the braking operation delay occurs in the drum brake 8 due to the stickiness of the operating rod or the like, the operation delay time t ₁ ′ until the start of braking becomes considerably longer than the operation delay time t _{1 in the} normal operation.
Therefore, the braking timing thereafter is all time (t ₁ ′).
-T ₁ ) is delayed and it takes extra time for the elevator to stop.

Next, when there is a delay in displacement of the operating rod as shown in FIG. 5, the operating rod return displacement time becomes long due to factors such as an increase in the frictional force of the operating portion of the operating rod. At this time, the braking rod return transition time t ₂ ′ becomes longer, that is, the braking timing after that is all delayed by the time (t ₂ ′ −t ₂ ), and an extra time is required until the elevator stops. It hangs. Further, when the drum brake 8 shown in FIG. 6 has insufficient braking force, that is, the tightening of the braking spring 85 (a, b) is insufficient, and the friction surfaces of the brake shoe 83 (a, b) and the brake drum 82 are contaminated with oil. When the braking force of the drum brake 8 is reduced due to such a cause as the braking force is insufficient when the operating rod is completely returned and changed, the differential value of the speed of the elevator during the braking time (P ₁ '), i.e., decreases the value of the elevator deceleration, braking time t _3' elevator only is long minute it takes extra time until stopping.

The present invention has been made based on the above facts, and in this embodiment, it is checked whether the timing or the characteristic value representing the brake characteristic of the elevator is within a predetermined range, and the drum brake 8 is operated. The quality of the braking characteristic is determined. FIG. 2 is a flowchart of the brake characteristic quality determination processing for the elevator. The elevator brake characteristic quality determination processing will be described with reference to FIG. First of all, when there is a passenger in the car 1, maintenance operation is performed to judge the brake characteristics in order to guide the passenger to the evacuation. Use is restricted (S1). Whether or not there are passengers in the car 1 is determined by the load cell or the like in the car 1 (S2). If the result of the determination is No, the preparation run for the maintenance descent operation, that is, the maintenance descent operation is possible. Ascending operation to the next floor (S3). When the car 1 reaches the predetermined floor, the maintenance descent operation is started (S4). Then, the output signal of the speed detector 9 is fetched through the interface circuit 11 and stored in the RAM 14 at any time (S
5). When the car 1 is lowered to the predetermined position, the main circuit power supply of the elevator is cut off to forcibly stop the elevator (S6).

When the elevator stops, the elevator speed data stored in the RAM 14 is read out and the differential operation is performed. Then, the change points of the differential of the elevator speed are examined, and the times t ₁ ′ to t ₃ ′ between the respective speed change points are examined.
Is calculated (S7). Next, the operation delay time t in the normal operation, which is stored in the ROM 13 in advance and read therefrom,
₁ and the time from the first speed change point to the second speed change point, that is, the operation delay time t ₁ ′ is compared, and (t ₁ ′ −t ₁ ).
It is determined whether or not <Δt ₁ (preset allowable time) (S8). If the result of the determination is No, that is, if the operation delay time t ₁ ′ measured during the maintenance descent operation is deviated by the allowable time Δt ₁ or more from the operation delay time t ₁ during normal operation, then the operation delay failure occurs. It is determined that the information is RAM14
(S9).

If the result of the determination in step S8 is Yes, it is stored in the ROM 13 in advance and read out from it, and the operation rod return transition time t _{2 in} normal operation and the third from the second speed change point are read.
The time to the speed change point, that is, the operation rod return transition time t ₂ ′ is compared, and it is determined whether or not (t ₂ ′ −t ₂ ) <Δt ₂ (preset allowable time) (S10). If the determination result is No, i.e., when the maintenance falling back working rod measured during operation transition time t ₂ 'there is permissible time Delta] t ₂ or more offset with respect to actuating rod return transition time t ₂ during normal operation Judges that the operation rod return displacement is defective, and the information is stored in RAM.
It is stored in 14 (S11). If the result of the determination in step S10 is Yes, the speed change immediately before the elevator is stopped, that is, the deceleration P ₁ ′ is checked, and stored in the ROM 13 in advance, and immediately before the elevator is stopped during normal operation. It is compared with the deceleration P _1, (P ₁ '-
It is determined whether or not P ₁ ) <ΔP (predetermined allowable deceleration range) (S12). If the determination result is No, that is, if the deceleration P ₁ ′ immediately before the elevator stops deviates from the deceleration P ₁ during normal operation by the allowable deceleration range ΔP or more, it means that the braking force is poor. Judgment and RA
If the result of the determination is Yes, the brake characteristic of the elevator is determined to be good, and the information is stored in the RAM 14 (S13).

Next, the information on the brake characteristic of the elevator stored in the RAM 14 is read and transmitted to the monitoring center 20 via the interface circuit 11 (S1).
5). Then, it is determined whether or not there is a defective item in the brake characteristic information (S16). If the determination result is No, that is, if the elevator braking characteristics are good,
Restart the automatic operation before the maintenance descent operation is started (S17),
If the result of the determination is Yes, that is, if there is any defective item in the brake characteristic information, the elevator is suspended (S18). As described above, in this embodiment, the quality of the braking characteristic of the drum brake 8 can be automatically determined by performing the maintenance lowering operation of the elevator, and if there is a defective item in the braking characteristic, the defective braking characteristic is determined. Not only what items are displayed can be visually recognized on the display unit 15, but also the monitoring center 20 can be grasped. Therefore, the determination result of the brake characteristics depends on the skill and experience of the maintenance personnel, and the determination operation of the brake characteristics can be performed. Accordingly, the maintenance staff can know the detailed defective portion of the brake characteristic of the elevator before going to the site without making a mistake, so that the drum brake 8 can be quickly and accurately performed without bothering the maintenance staff. It is possible to judge whether or not the braking characteristic of No. 2 is good and to take prompt measures against the braking failure of the drum brake 8.

As described above, in the present embodiment, the quality of the braking characteristics of the drum brake 8 can be automatically determined, but not only the current quality of the braking characteristics but also the deterioration of the braking characteristics in the near future. It is also possible to predict the possibility of. FIG. 9 is a flowchart of the elevator braking characteristic deterioration sign diagnosis processing. The operation of the elevator braking characteristic deterioration sign diagnosis operation will be described with reference to FIG. First, for example, the above-described brake characteristic quality determination processing is performed at a predetermined time of midnight on a specific day of every month (S20). Then, the traveling time of the elevator during the maintenance descent operation, the operation delay time t ₁ ′ obtained in the course of this processing, and the operating rod return transition time t ₂ ′
And deceleration P ₁ ′ immediately before the elevator stops R
It is stored in the AM 14 (S21). And RAM14
The characteristic data obtained in the past three braking characteristic pass / fail judgment processes are read out, and the respective characteristics that should be obtained in the next braking characteristic pass / fail judgment process from the rate of change of the above three characteristic data. The data, that is, the operation delay time t ₁ ″, the operation rod return transition time t ₂ ″, and the deceleration P ₁ ″ immediately before the elevator stops are predicted.

Next, each characteristic data at the time of normal operation, that is, the operation delay time t ₁ and the operating rod return transition time t ₂
And (t ₁ ″ −t ₁ ) <Δt ₁ , after calculating the difference from the deceleration P ₁ immediately before the elevator stops.
(T ₂ ″ −t ₂ ) <Δt ₂ or (P ₁ ″ −P ₁ ) <
It is determined whether or not ΔP ₁ is satisfied. If even one judgment result is No, that is, if the allowable range for each characteristic data during normal operation is exceeded, it is determined that the braking characteristic may be determined to be defective in the next brake characteristic quality determination process. Yes (S22). Then, the diagnosis result is transmitted to the monitoring center 20 via the interface circuit 11 (S23). FIG. 10 is an explanatory diagram showing an actual example of the characteristic data obtained as a result of the diagnostic processing in step S22.

In this way, by performing the elevator braking characteristic deterioration symptom diagnosis processing, when it is diagnosed that there is a possibility that the braking characteristic is defective in the next brake characteristic quality determination processing, it is determined that the braking characteristic is defective. Since it is possible to place an order for a repair part and a tool for a determination item that may possibly occur, maintenance work for a defective braking characteristic of an elevator can be executed very well. In this embodiment, the speed of the elevator is detected from the rotation speed of the induction motor 6, but the moving speed of the car 1 may be directly detected. Further, in the brake characteristic good / bad determination processing, the braking characteristic of the elevator during the maintenance lowering operation is determined, but of course, the braking characteristic of the elevator during the maintenance rising operation may be determined.

[0023]

As described above, according to the first aspect of the present invention, after the elevator is run at a predetermined speed, the brake is operated to stop the elevator during the maintenance running operation. The speed is detected, the detected speed is stored at any time, and the deceleration is calculated.
Since the change point of the deceleration is detected and the value of the time interval between the change points of the deceleration or the deceleration value is compared with a preset standard value, the brake characteristic of the elevator is judged. Even a maintenance person who has not had much experience can easily operate it, and can perform automatic brake characteristic evaluation in a short time without any work error or determination variation.

According to the second aspect of the present invention, the value of the time interval between the detected deceleration change points or the detected deceleration value and the deceleration change point of the elevator having the normal braking characteristic are detected. The difference between the time interval value or the deceleration value is calculated, and when the difference is smaller than the predetermined range, it is determined that the elevator braking characteristics are good. Since it is possible to perform the brake characteristic determination according to the brake characteristic, it is possible to easily perform the maintenance work of the elevator determined to have the brake characteristic failure.
According to the invention described in claim 3, each time the elevator is made to perform the maintenance running operation, the value of the time interval between the detected deceleration change points or the value of the deceleration is stored and stored. Value of the time interval between the deceleration change points of or the time interval between the deceleration change points that should be detected the next time the elevator is made to perform maintenance operation based on the deceleration value Value or the deceleration value is predicted, and the presence or absence of a sign of deterioration of the elevator braking characteristics is diagnosed based on the value of the time interval between the predicted deceleration change points or the deceleration value. Even before the brake characteristic failure is determined, deterioration of the brake characteristic of the elevator can be predicted in advance, so that appropriate maintenance work can be set up.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an elevator brake characteristic determination device according to an embodiment of the present invention.

FIG. 2 is a flow chart of a process for determining whether the elevator brake characteristics are good or bad.

FIG. 3 is a timing chart showing brake characteristics of a normal elevator.

FIG. 4 is a timing chart showing braking characteristics when there is a braking operation delay.

FIG. 5 is a timing chart showing brake characteristics when there is a delay in shifting the operating rod.

FIG. 6 is a timing chart showing brake characteristics when the braking force is insufficient.

FIG. 7 is an explanatory view showing the relationship between the inertial performance rate of the elevator device and the torque together with their relational expressions.

FIG. 8 is a configuration diagram showing an outline of a braking device according to a conventional example.

FIG. 9 is a flowchart of a diagnostic process for predicting deterioration of elevator braking characteristics.

FIG. 10 is an explanatory diagram showing an example of characteristic data obtained as a result of a braking characteristic deterioration predictive diagnosis process.

[Explanation of symbols]

 1 Car Cage 2 Balance Weight 3 Main Rope 4 Sheave 5 Reducer 6 Induction Motor 7 Inverter 8 Drum Brake 9 Speed Detector 10 Brake Characteristic Judgment Device 11 Interface Circuit 12 Microcomputer 13 ROM 14 RAM 15 Display 20 Monitoring Center 82 Brake Drum 83 (a, b) Brake shoe 84 Braking arm 85 (a, b) Braking spring 86 Electromagnetic coil 87 Operating rod

Claims (3)

[Claims] 1. A sheave around which a main rope for suspending a car and a counterweight is wound, an electric motor for driving the sheave to move the car up and down, and a brake shoe is pressed against a brake drum by elastic force of a braking spring. In the elevator brake characteristic evaluation device including a drum brake that applies a braking force to the rotation shaft of the electric motor and a control device that controls the rotation operation of the electric motor and the braking operation of the drum brake, the speed of the elevator is detected. Speed detecting means for operating the elevator, and after running the elevator at a predetermined speed, operating the drum brake to apply a braking force to the rotating shaft of the electric motor to perform a maintenance running operation for stopping the elevator. While the elevator is performing maintenance traveling operation by the maintenance traveling operation means, the speed detecting means detects The speed storage means for storing the speed of the lifted elevator at any time, the deceleration calculation means for calculating the speed differential of the elevator by reading the speed of the elevator stored in the speed storage means, that is, the deceleration calculation means. A change point detecting means for detecting the calculated change point of the deceleration, and a value of a time interval between the change points of the deceleration detected by the change point detecting means or a value of the deceleration calculated by the deceleration calculating means. An elevator brake characteristic evaluation device, comprising: a brake characteristic determining unit that compares a preset standard value to determine an elevator brake characteristic. 2. The preset standard value is a value of a time interval between changing points of deceleration of an elevator having a normal braking characteristic or the deceleration value, and the braking characteristic determining means is the changing point detecting means. Calculates the difference between the value of the time interval between the deceleration change points detected by or the deceleration value calculated by the deceleration calculation means and the standard value, and when the difference is smaller than a predetermined range, the elevator The brake characteristic evaluation device for an elevator according to claim 1, wherein the brake characteristic evaluation device determines that the brake characteristic is good. 3. The value of the time interval between the deceleration change points detected by the change point detection means or the deceleration calculated by the deceleration calculation means every time the maintenance travel operation means causes the elevator to perform the maintenance travel operation. Next, based on the value of the time interval between the maintenance traveling operation data storage means for storing the value of and the latest plurality of deceleration change points read from the maintenance traveling operation data storage means or the deceleration value. The value of the time interval between the deceleration change points detected by the change point detection means when the maintenance travel operation means causes the elevator to perform the maintenance travel operation, or the deceleration value calculated by the deceleration calculation means. A next maintenance traveling operation data predicting means, and a value of a time interval between the change points of the deceleration predicted by the next maintenance traveling operation data predicting means or the value of the deceleration based on the value of the deceleration. The brake characteristic evaluation device for an elevator according to claim 1, further comprising deterioration symptom diagnosing means for diagnosing whether there is a symptom of deterioration of the brake characteristic.