A safety gear for an elevator applies a braking force to a car by a frictional force generated when a clamp grips a guide rail. However, the coefficient of friction between the clamp and rail has the characteristic of increasing with deceleration of the car. Therefore, a large braking force acts on the car just before it stops, and the deceleration momentarily increases. In this study, we investigated the mechanism that can suppress the maximum instantaneous deceleration acting on the car. Specifically, when the frictional force between the clamp and rail exceeds a certain level, the clamp slides to reduce the force that grips the guide rail. This paper introduces the structure of the clamp slide mechanism, analysis result, and actual car verification result.

For elevators with large car mass and loading capacity where the strength is insufficient, the guide rail is reinforced by affixing steel material with bolts. It is known to that this reinforced guide rail has a reinforcing effect against seismic loads, but it is not revealed that has a reinforcing effect against the braking force. The effect of reinforcement against braking force acting away from the center of figure of the guide rail was investigated.

Elevators are essential for means of a vertical transportation. Recently, high-rise buildings are increasing. Those elevator ropes become longer. As a result, the natural period of the elevator rope becomes closer to the natural period of the high-rise building. The risk of resonance increases. When the high-rise buildings receive an external force such as the strong wind and the earthquake, the elevator rope may sway intensely. Furthermore the rope may hook to the equipment in the hoistway. To prevent such damage, it is necessary to comprehend the vibration characteristics of each rope type. In this study, free vibration tests are carried out using an elemental test equipment, furthermore we investigate the relationship between various factors and damping ratios. Based on the results, we will develop a method for estimating ropes with higher damping ratios. Furthermore, we will plan the improvement of the response analysis by grasping vibration behavior of ropes. In this paper, free vibration tests were conducted with ropes of different rope configurations (number of strands) and rope cores (with or without resin coating). As a result, the damping ratio increased with the increase of strands number. The damping ratio with resin coating was highter than that without resin coating.

Recently, the buildings became taller. Elevator ropes also became longer. The natural period of the elevator rope became closer to that of the building. As a result, the elevator rope may sway intensely when the building receive an external force such as a strong wind and an earthquake. It is necessary to understand the rope behavior accurately during earthquake. The response analysis is one of the methods to understand rope behavior during earthquake. The damping ratio, which is one of the vibration characteristics of a rope, is constant generally in the response analysis. However, a damping ratio depended on the displacement at the range of the small displacement in free vibration tests. In this study, we develop the response analysis method of the rope with a damping ratio depending on the displacement. In this paper, we conducted free vibration tests of the elevator rope with an element testing equipment. The displacement dependence damping ratio, which was confirmed in free vibration tests, was applied to the response analysis. As a result, the response analysis was improved mainly in the low amplitude range.

In recent years, various inspection techniques have been developed to ensure elevator safety. One of the important inspection items is the diagnostic technique for a main rope. The main rope breaks occur due to various factors during operation, so there is a need for technology that comprehensively detects the types of wire breaks for safety management. In this study, we developed a rope tester to diagnose wire breaks in the elevator main rope. The measurement principle used in the rope tester is the magnetic flux leakage method, which uses a Hall sensor array to detect the magnetic flux leaking from the broken wires. As a result of measuring rope samples using the developed Hall array sensor, we detected magnetic flux leaking from the valley wire breaks. This result confirmed that the trend of magnetic flux signal input to sensors was consistent with the magnetic flux distribution obtained by magnetic simulation analysis of the damaged rope.

A wire rope can move along a sheave groove during a normal operation. However, when the rope has a large fleet angle, the rope might jump out of the sheave groove while winding the rope. The behavior of rope jumping out of the sheave groove is affected by several factors, such as fleet angle, rope tension, sheave diameter and so forth. It is difficult to evaluate above influenced factors against the rope jumping behavior by a real test system. This paper shows a simple wire rope model to evaluate the rope jumping out of sheave groove by FEM contact analysis. The derived model can estimate the influence factors by numerical analysis, especially relation of rope strand laid condition.

Today, elevators have become indispensable means of transportation and important social infrastructures. In recent years, elevators have been used in taller and taller buildings, and the elevator travel distances have been lengthened. Further improvement of the safety, security, and comfort of elevators is always an important issue, and various measures and studies are being conducted, such as research on vibration of the car and main rope. The elevator has a tail cable (traveling cable), which plays the role of supplying electric power to the car and transmitting control signals for various information such as opening and closing doors and turning on lights, etc. The cable is suspended in a U-shape between the lower part of the car and the control panel in the middle of the elevator track. In elevators with long ascending and descending travel distances, the traveling cables are subject to large vibrations caused by ascending and descending of cars and low-frequency vibrations of the car, such as wind or earthquakes, etc., and may collide with, damage, or cause malfunctions of the equipment, components, etc. in the elevator track, which is an important problem. In Hirai's study, a 64-meter traveling cable was modeled by using multi-body dynamics (MBD), an even longer traveling cable is needed to adapt taller buildings. The objective of this study is to add control to the traveling cable to suppress its vibration as described above. In this report, the complex dynamics of a 281-meter traveling cable, which is longer than in previous studies, is modeled by using MBD. A guide is attached to the underside of the car to allow the traveling cable to move freely in the direction of building sway, and the suppression effect on the maximum displacement of the traveling cable when building sway occurs is investigated.

Boarding on an escalator with strollers, wheelchairs, shopping carts, etc., can cause a risk of losing balance and falling. By alerting such users before boarding on the escalator, it is possible to dissuade them from boarding on the escalator. Various safety measures and systems have been developed. However, there are no measures in place to detect boarding action of stroller users and forestall boarding on the escalator. Therefore, we developed a system to judge boarding actions after detecting strollers by using image recognition technology from camera images overlooking an escalator entrance. In this paper, we introduce a method for judging the boarding action of stroller users on the escalator, and the evaluation results using the method.

With urbanization in recent years, the number of high rise buildings is on the rise. In high rise buildings, the sky lobby arrangement is effective in which passengers utilize shuttle elevators to reach the middle floor named sky lobby and then utilize local elevators for their destination floors. In this study, we investigated the influence of shuttle elevators on local elevator waiting time in sky lobby buildings. Using the people flow simulator that can evaluate transfers between multiple elevators, we conducted simulations under various conditions that changed the group control method and capacity of the shuttle elevators. As a result, it was confirmed that the waiting time of the local elevators worsens under conditions where the number of people flowing into the sky lobby at one time increases.

Amusement facilities such as Ferris wheels and roller coasters that involve high-altitude vehicles are required to periodically inspect the structural framework for corrosion, deformation, cracks, damage, etc. During busy periods, this periodic inspection may have to be carried out at night, which is known to be a dangerous task. Recently, to ensure the safety of inspection workers, attempts have been made to conduct visual inspections using remotely controlled drones. The hovering performance and obstacle avoidance performance of the latest drones have improved significantly, but it is unclear whether they can be used as an alternative to visual inspections performed close to structures. In this report, we are currently verifying whether a drone developed for structural inspection can be used for visual inspection of amusement facilities, and will describe the progress that has been made.