Patent Application
20100018810
The present invention relates to an elevator apparatus employing a plurality of hoisting machines to raise/lower a single car.
In recent years, there have been demands for an elevator capable of transporting more passengers more speedily along with constructions of high-rise buildings. For satisfying such demands, enlargement of a car is conceivable as one method. To attain the enhancement of the car, however, a large-size hoisting machine with large torque and a large output is required, so the costs of manufacture, lifting/setup, and the like increase.
On the other hand, there has been proposed an elevator apparatus employing two hoisting machines to raise/lower a single car instead of increasing the size of a single hoisting machine. In this elevator apparatus, the car and a counterweight are provided with fall blocks, respectively, to eliminate an inconvenience ascribable to a difference in speed generated between the two hoisting machines (e.g., see Patent Document 1).
Patent Document 1: JP 0742063 A
In the conventional elevator apparatus constructed as described above, the car and the counterweight are provided with the fall blocks, respectively, so an endless rope is required as a main rope. However, the endless rope is manufactured by connecting both ends of a single rope to each other, so it is difficult to eliminate a step at a joint of both the ends of the rope. Further, there is an individual difference in operation timing or braking force between brakes provided on the two hoisting machines, so the difference between the running distances of the main rope made by two drive sheaves increases at the time of an emergency stop. In consequence, the joint moves past the drive sheaves and the fall blocks due to a shift in the position of the rope, so the car may develop vibrations.
The present invention has been made to solve the above-mentioned problems, and it is therefore an object of the present invention to provide an elevator apparatus capable of ensuring a stable stop with a small amount of shift in the position of a rope even at the time of emergency braking while employing a plurality of hoisting machines.
An elevator apparatus according to the present invention includes: a plurality of hoisting machines having drive sheaves and hoisting machine bodies, respectively, the hoisting machine bodies including electric motors for rotating the drive sheaves, respectively, and hoisting machine brakes for braking rotation of the drive sheaves; at least one main rope wound around the drive sheaves; a car and a counterweight that are suspended by the main rope to be raised/lowered by the hoisting machines; a safety gear for stopping the car as an emergency measure when a speed of the car reaches a preset overspeed; and a raised/lowered body-mounted brake device, mounted on at least one of the car and the counterweight, for stopping the car as an emergency measure on a condition different from a condition set for the safety gear.
Further, an elevator apparatus according to the present invention includes: a plurality of hoisting machines having drive sheaves and hoisting machine bodies, respectively, the hoisting machine bodies including electric motors for rotating the drive sheaves, respectively, and hoisting machine brakes for braking rotation of the drive sheaves; at least one main rope wound around the drive sheaves; a car and a counterweight that are suspended by the main rope to be raised/lowered by the hoisting machines; and a rope brake device for applying a braking force to the main rope to stop the car as an emergency measure.
Still further, an elevator apparatus according to the present invention includes: a plurality of hoisting machines having drive sheaves and hoisting machine bodies, respectively, the hoisting machine bodies including electric motors for rotating the drive sheaves, respectively, and hoisting machine brakes for braking rotation of the drive sheaves; at least one main rope wound around the drive sheaves; a car and a counterweight that are suspended by the main rope to be raised/lowered by the hoisting machines; and a brake safety circuit for monitoring operating states of the hoisting machine brakes and causing, when one of the hoisting machine brakes performs a braking operation, the other hoisting machine brakes to perform braking operations as well.
Yet further, in an elevator apparatus according to the present invention: a plurality of hoisting machines is employed to move a single car; neither of the hoisting machines has a brake; and at least one of the car serving as a raised/lowered body and another raised/lowered body have brakes.
Best modes for carrying out the present invention will be described hereinafter with reference to the drawings.
The counterweight 5 has a counterweight body 16 serving as a raised/lowered main body, a rocking member (rope connection member) 17 rockably connected to the counterweight body 16, and a connection member 18 for connecting the counterweight body 16 and the rocking member 17 to each other. The counterweight body 16 is suspended from the rocking member 17 via the connection member 18.
The connection member 18 is turnably coupled at an upper end thereof to a rocking center of the rocking member 17, namely, a rocking shaft 17a. The rocking shaft 17a extends horizontally and parallel to a thickness direction of the counterweight body 16. The connection member 18 is connected at a lower end thereof to the center of an upper portion of the counterweight body 16. The connection member 18 is provided at the upper end thereof with rocking detecting means (not shown) for detecting a rocking state of the rocking member 17. Employed as the rocking detecting means is, for example, an encoder.
A first hoisting machine 6 and a second hoisting machine 7 are disposed in an upper portion of the hoistway 1. The first hoisting machine 6 has a first drive sheave 8 and a first hoisting machine body 9. The first hoisting machine body 9 includes a first electric motor for rotating the first drive sheave 8, and a first hoisting machine brake for braking rotation of the first drive sheave 8.
The second hoisting machine 7 has a second drive sheave 10 and a second hoisting machine body 11. The second hoisting machine body 11 includes a second electric motor for rotating the second drive sheave 10, and a second hoisting machine brake for braking rotation of the second drive sheave 10. The first hoisting machine 6 and the second hoisting machine 7 are disposed such that rotary shafts of the drive sheaves 8 and 10 extend horizontally.
At least one main rope 12 is wound around the first drive sheave 8 and the second drive sheave 10. The car 4 and the counterweight 5, which are suspended within the hoistway 1 by means of the main rope 12, are raised/lowered within the hoistway 1 due to driving forces of the first hoisting machine 6 and the second hoisting machine 7. The counterweight 5 is raised/lowered in the direction opposite to the car 4.
The main rope 12 has a first rope end 12a connected to the rocking member 17 on one side of the rocking shaft 17a of the rocking member 17, and a second rope end 12b connected to the rocking member 17 on the other side of the rocking shaft 17a. The first rope end 12a and the second rope end 12b are connected to the rocking member 17 at positions equidistant from the rocking shaft 17a.
A first deflector pulley 14 for leading the first rope end 12a to the counterweight 5 and a second deflector pulley 15 for leading the second rope end 12b to the counterweight 5 are disposed in the upper portion of the hoistway 1. The first deflector pulley 14 and the second deflector pulley 15 are disposed such that rotary shafts thereof extend horizontally.
A balance pulley 13 rotatable around a horizontal rotary shaft is provided above the car 4. An intermediate portion of the main rope 12 is wound around the balance pulley 13.
The first hoisting machine 6 and the second hoisting machine 7 are controlled by a control device 19. In response to a signal from the rocking detecting means, the control device 19 controls the first hoisting machine 6 and the second hoisting machine 7 so as to counterbalance the rocking of the rocking member 17, namely, to return the rocking member 17 to a horizontal state.
A safety gear 20 for stopping the car 4 as an emergency measure when the speed of the car 4 reaches a preset overspeed (e.g., time and four-tenths of a rated speed) is mounted on a lower portion of the car 4.
The car 4 is also mounted with a pair of car-mounted brake devices 21a and 21b as raised/lowered body-mounted brake devices for stopping the car 4 as an emergency measure on a condition different from a condition set for the safety gear 20. The car-mounted brake devices 21a and 21b grip the car guide rails 2 to brake the car 4. Employed as the car-mounted brake devices 21a and 21b are, for example, electromagnetic brake devices.
A terminal slowdown device and an overrun limiting device are provided in the vicinity of each of an uppermost floor and a lowermost floor within the hoistway 1. As a result, the car 4 is usually decelerated and stopped according to a preset speed curve in the vicinity of each of the uppermost floor and the lowermost floor within the hoistway 1. However, when the speed of the car 4 deviates from the speed curve for some reason, a safety circuit within the control device 19 is shut off, and an emergency stop command is output from the control device 19. As a result, the car 4 is forcibly stopped as an emergency measure by the car-mounted brake devices 21a and 21b independently of the first hoisting machine brake and the second hoisting machine brake.
In the elevator apparatus constructed as described above, the first hoisting machine 6 and the second hoisting machine 7 are controlled by the control device 19 so as to be operated in synchronization with each other. However, owing to a manufacturing error between the drive sheaves 8 and 10, a minor slippage caused between each of the drive sheaves 8 and 10 and the main rope 12 at the time of acceleration/deceleration, braking, or the like of the car 4, fluctuations in the torques of the hoisting machine bodies 9 and 11, and the like, a minor error is generated between the running distance of the main rope 12 on the first drive sheave 8 side with respect to the car 4 and the running distance of the main rope 12 on the second drive sheave 10 side with respect to the car 4. This minor error between the running distances is absorbed through the rocking (inclination) of the rocking member 17, which serves as a scale-type balance mechanism.
However, if there is a difference in operation timing or braking force when the hoisting machine brakes are operated in an emergency, a major error is generated in a short period of time between the running distance of the main rope 12 on the drive sheave 8 side and the running distance of the main rope 12 on the drive sheave 10 side and may not be completely absorbed by the scale-type balance mechanism. In an emergency, therefore, instead of operating the first hoisting machine brake and the second hoisting machine brake, only the car-mounted brake devices 21a and 21b are operated to forcibly stop the car 4 as an emergency measure. In this manner, there is no difference between the distance by which the main rope 12 is raised/lowered and the distance by which the car 4 is raised/lowered even when the car 4 is braked. As a result, the car 4 can be stopped stably. In particular, if the pair of the car-mounted brake devices 21a and 21b are mechanically interlocked with each other, it is possible to operate the car-mounted brake devices 21a and 21b more reliably at the same time.
The construction of each of the car-mounted brake devices 21a and 21b may be partially shared by the safety gear 20.
In an emergency, the first hoisting machine brake and the second hoisting machine brake may be used in addition to the car-mounted brake devices 21a and 21b. In this case, it is preferable to adopt a sequence circuitry designed such that the hoisting machine brakes are operated after the car-mounted brake devices 21a and 21b have been operated.
It is also appropriate to construct a system without the hoisting machine brakes, namely, exclusively with the car-mounted brake devices 21a and 21b, and use the car-mounted brake devices 21a and 21b in braking the car 4 at the time of a normal stop thereof at each floor as well. In this case, the hoisting machine brakes are omitted, so the number of parts is reduced. As a result, a simplification of the system and a cost reduction can be achieved.
The number of the hoisting machines for driving should not be limited to two. For example, additional hoisting machines may be disposed at the positions of the deflector pulleys 14 and 15.
Reference will be made next to
In the elevator apparatus constructed as described above, the car 4 is forcibly stopped as an emergency measure by the counterweight-mounted brake devices 22a and 22b independently of the first hoisting machine brake and the second hoisting machine brake in an emergency. Therefore, the difference between the running distance of the main rope 12 on the drive sheave 8 side and the running distance of the main rope 12 on the drive sheave 10 side is prevented from increasing due to a difference between braking forces of the hoisting machine brakes. That is, the stopping distance of the car 4 can be more stably controlled independently of the hoisting machine brakes. In particular, if the pair of the counterweight-mounted brake devices 22a and 22b are mechanically interlocked with each other, it is possible to operate the counterweight-mounted brake devices 22a and 22b more reliably at the same time.
With the employment of the counterweight-mounted brake devices 22a and 22b, vibrations or noise resulting from an emergency braking operation are unlikely to be transmitted to the inside of the car 4.
Reference will be made next to
The first hoisting machine 6 and the second hoisting machine 7 are disposed side by side such that each of the main ropes 12 moves past the first drive sheave 8 and the second drive sheave 10 in succession. That is, the first drive sheave 8 and the second drive sheave 10 are disposed radially offset from each other.
A rope brake device 23 for applying a braking force to each of the main ropes 12 to stop the car 4 as an emergency measure is installed in the upper portion of the hoistway 1 (within a machine room or the hoistway 1). The rope brake device 23 grips all the main ropes 12 at the same time to brake the movement thereof, thereby braking the car 4.
In the elevator apparatus constructed as described above, the car 4 is forcibly stopped as an emergency measure by the rope brake device 23 independently of the first hoisting machine brake and the second hoisting machine brake in an emergency. Therefore, the difference between the running distance of each of the main ropes 12 on the drive sheave 8 side and the running distance of each of the main ropes 12 on the drive sheave 10 side is prevented from increasing due to a difference between braking forces of the hoisting machine brakes. That is, the stopping distance of the car 4 can be more stably controlled independently of the hoisting machine brakes.
The main ropes 12 are gripped at the time of emergency braking, so the drive sheaves 8 and 10 idly rotate with respect to the main ropes 12 even in the unlikely event that the hoisting machines 6 and 7 fail to be stopped. As a result, the car 4 can be stopped more reliably.
Reference will be made next to
In the elevator apparatus constructed as described above according to the 2:1 roping arrangement as well, the car 4 is forcibly stopped as an emergency measure by the rope brake device 23 independently of the first hoisting machine brake and the second hoisting machine brake in an emergency. Therefore, the difference between the running distance of each of the main ropes 12 on the drive sheave 8 side and the running distance of each of the main ropes 12 on the drive sheave 10 side is prevented from increasing due to a difference between braking forces of the hoisting machine brakes. That is, the stopping distance of the car 4 can be more stably controlled independently of the hoisting machine brakes.
In an emergency, the first hoisting machine brake and the second hoisting machine brake may be used in addition to the rope brake device 23. In this case, it is preferable to adopt a sequence circuitry designed such that the hoisting machine brakes are operated after the rope brake device 23 has been operated.
Reference will be made next to
In addition, the hoisting machine brakes 26 to 29 are respectively provided with operation monitoring portions (operation monitoring circuits) 26c, 27c, 28c, and 29c for monitoring operating positions of brake shoes, respectively. The operation monitoring portions 26c, 27c, 28c, and 29c are respectively provided with micro switches that are opened through braking operations of the brake shoes, respectively.
All the energization monitoring portions 26b, 27b, 28b, and 29b and all the operation monitoring portions 26c, 27c, 28c, and 29c are connected to a brake safety circuit 30. The brake safety circuit 30 monitors operating states of the first hoisting machine brakes 26 and 27 and the second hoisting machine brakes 28 and 29. When one of the first hoisting machine brakes 26 and 27 and the second hoisting machine brakes 28 and 29 performs a braking operation, the brake safety circuit 30 causes the other hoisting machine brakes to perform braking operations as well. More specifically, when even one of the energization monitoring portions 26b, 27b, 28b, and 29b and the operation monitoring portions 26c, 27c, 28c, and 29c detects a braking operation, the brake safety circuit 30 causes all the hoisting machine brakes 26 to 29 to perform braking operations, respectively.
The brake safety circuit 30 is connected in series to an elevator safety circuit of the control device 19. When the elevator safety circuit is shut off due to an abnormality in an elevator system or the like, the brake safety circuit 30 causes all the hoisting machine brakes 26 to 29 to perform braking operations.
In the elevator apparatus constructed as described above, when one of the first hoisting machine brakes 26 and 27 and the second hoisting machine brakes 28 and 29 performs a braking operation, the single brake safety circuit 30 causes the other hoisting machine brakes to perform braking operations as well. Therefore, the stopping distance of the car 4 at the time of emergency braking can be more stably controlled while employing the plurality of the hoisting machines 6 and 7.
In Embodiment 5 of the present invention, only the operations of the hoisting machine brakes 26 to 29 are monitored by the brake safety circuit 30. However, in employing the car-mounted brake devices 21a and 21b of Embodiment 1 of the present invention, the counterweight-mounted brake devices 22a and 22b of Embodiment 2 of the present invention, the rope brake device 23 of Embodiment 3 or 4 of the present invention, or the like, it is appropriate to monitor those components and interlock the braking operations thereof with those of the hoisting machine brakes 26 to 29.
As shown in
Further, in the example of
Still further, brake safety circuits may be provided separately for the respective hoisting machines 6 and 7. Referring to FIG. 7, for example, a first brake safety circuit 30a corresponding to the first hoisting machine 6 and a second brake safety circuit 30b corresponding to the second hoisting machine 7 are employed. Signals can be exchanged between the first brake safety circuit 30a and the second brake safety circuit 30b.
By configuring the brake safety circuits 30a and 30b separately for the respective hoisting machines 6 and 7 as described above, each of the hoisting machines 6 and 7 can be provided as a unit. As a result, the same specification of hoisting machine can be shared by an elevator apparatus employing a single hoisting machine and an elevator apparatus employing two hoisting machines.
As shown in, for example,
Further, as a matter of course, a rope with a circular cross-section or a belt-shaped rope may be employed as the main rope 12.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-055906 | Mar 2005 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP06/02832 | 2/17/2006 | WO | 00 | 6/25/2007 |
