JPH04256673A - Method for improving elevator - Google Patents

Abstract

PURPOSE:To improve the controlling performance for an elevator cage without requiring replacement of winch. CONSTITUTION:An elevator device as object for application of the present invention comprises a winch 8 to wind up a main cable 3 to whose one end a cage 2 is fixed, a motor to drive the winch 8, and a control board to control this motor. To improve this elevator, the control board is substituted with a new one 32 which emits AC current with variable frequency while the motor is replaced with a new motor 31 of variable frequency responsive type, and further a spacer 34 for coupling of this new motor 31 with the winch 8 is furnished between the new motor 31 and winch 8. This method enables shortening the period of the elevator improving works.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving an elevator by replacing part or all of the elevator equipment, and more particularly to a method for improving an elevator to improve the accuracy of car loading.

0002

[Prior Art] Generally, in elevators, as existing elevators age, improvement work is carried out to replace some or all of the equipment to improve car safety, ride comfort, loading error, power consumption, etc. may be significantly improved. In particular, the landing error of the car is an important performance indicator of elevators, as passengers getting on and off the car may trip over the difference in level formed between the landing and the car due to this landing error. To this day, it has always been rated as one of the best by users. In addition, in recent years, there has been a strong emphasis on responding to an aging society, and there is an increasing need to prevent the accidents mentioned above from tripping over steps out of consideration for the elderly. Since this is the same, it is necessary to improve the accuracy of car loading, and for this reason, when the functions of an existing elevator become obsolete, work to improve the elevator is often carried out.

FIG. 3 is a block diagram showing a conventional structure of an elevator, FIG. 4 is a speed characteristic diagram of a car provided in the elevator of FIG. 3, and FIG. 5 is a diagram of the speed characteristics of a car provided in the elevator of FIG. It is a characteristic diagram.

The elevator shown in FIG. 3 includes a car 2 and a counterweight 2a that move up and down in a hoistway 1, a main rope 3 to which these cars 2 and the counterweight 2a are attached at both ends, and a main rope 3. a deflection wheel 4 and a sheave 5 around which the winding machine 8 is made up of the sheave 5, a speed reducer 6, a magnetic brake 7, a coupling device 8a, etc.; an electric motor that drives the hoist 8; For example, it has a three-phase induction motor 9 and a control panel 10 that controls the three-phase induction motor 9. This control panel 10 includes upward contactors 11A, 11B, 11C and a downward contactor 12 connected to a three-phase induction motor 9.
A, 12B, 12C, and a three-phase induction motor 9 connected to the drive circuit 13 and the brake 7.
a control circuit 14 that controls the operation and rotation direction of the car 2 as well as the operation of the brake 7; a management circuit 15 that is connected to the control circuit 14 and detects the floor at which the car 2 stops;
Main switches 16A, 16B, and 16C are provided between the drive circuit 13 and the three-phase AC power source 17. In the elevator configured in this way, the frequency of the three-phase AC power supply 17 is set to 50 Hz or 60 Hz and is substantially constant, so the three-phase induction motor 9 rotates at a constant speed. Therefore, as shown in FIG. 4, the speed characteristics of the car 2 change as shown by a polygonal line 21 when ascending or descending under a light load, and as shown by another polygonal line 22 when ascending or descending under a heavy load. It changes as shown. For example, when a heavy load is applied to the car 2, if startup control is performed on the control panel 10 at time T0, the electric motor 9 will rotate and the car 2 will be driven via the hoisting machine 8, and At T1, the speed of the car 2 reaches the predetermined speed V1. Then time T
2, when the car 2 approaches the stop floor to a predetermined distance, the control circuit 14 starts the stop control of the car 2 in response to the detection by the management circuit 15, and at time T3, the car 2 is stopped.
is now stopped. That is, although it is possible to control the start and stop of the car 2, it is not possible to control the speed during operation. In addition, when the rotational speed of the three-phase induction motor 9 changes due to voltage fluctuations of the three-phase AC power supply 17, load fluctuations of the car 2, etc., or when the braking force decreases due to wear and deterioration of the brake 7, etc., the above-mentioned Since the time Ts required for the car 2 to stop completely from time T2 to time T3 changes, the braking distance S during that time varies, causing a landing error of the car 2. At this time, as shown in FIG. 5, by increasing the braking torque of the brake machine 7, the landing error of the car 2 becomes smaller, but at the same time, there is a problem that the stop shock becomes larger, and therefore, the braking torque is increased. There was a limit to how big it could be. Furthermore, even if this braking torque is once set to the appropriate value Tp, if the rotational speed of the three-phase induction motor 9 changes as described above, or if the braking force becomes small due to wear and deterioration of the brake 7, etc. The landing error of car 2 sometimes became large again.

[0005] Therefore, as a means for reducing the landing error of the car 2 as described above, for example, Japanese Patent Laid-Open No. 62-196
As shown in Publication No. 291, the existing control panel and electric motor were replaced with an inverter control system that continuously controls the speed of the car from startup to acceleration, constant speed, deceleration, and stop, and the hoisting machine was also replaced. Improvements have been proposed to replace elevators with new ones.

[0006]

[Problems to be Solved by the Invention] However, in the conventional elevator improvement method described above, not only the control panel and electric motor but also the hoisting machine are replaced. There was a problem in that large-scale work was required and the work period was long. In particular, if there are no hanging hooks on the ceiling of the machinery room where these control panels, electric motors, and hoisting machines are installed, the lifting device must be installed in a fairly narrow machinery room, so the lifting device A large amount of time was spent setting up the car, lifting the car, and lowering it.

[0007] The present invention has been made in view of the actual situation in the prior art, and its purpose is to provide an elevator improvement method that can improve the controllability of a car without requiring replacement of the hoisting machine. Our goal is to provide the following.

[0008]

[Means for Solving the Problems] In order to achieve this object, the present invention provides a hoisting machine for hoisting a main rope to which a car is attached at one end, an electric motor for driving this hoisting machine, and a hoisting machine for hoisting a main rope to which a car is attached at one end. In a method for improving an elevator having a control panel, the control panel is replaced with a new control panel that outputs alternating current at a variable frequency, the motor is replaced with a new motor compatible with variable frequency, and the newly installed A connecting member is provided between the electric motor and the hoisting machine to connect the newly installed electric motor and the hoisting machine.

[0009]

[Operation] As described above, the present invention replaces the existing control panel with a new control panel that outputs alternating current at a variable frequency, and replaces the existing motor with a new motor compatible with variable frequency. Therefore, when braking the car, if the speed of the car is excessive, reducing the frequency of the alternating current output from the new control panel will reduce this frequency. According to the change, the rotation speed of the new electric motor and the hoisting machine will also decrease.
Since the speed of the car is reduced, the accuracy of landing the car on the floor can be improved. At the same time, by adjusting the frequency of the alternating current so that it does not become less than a predetermined frequency, it is possible to prevent a shock from increasing when the car is stopped. This makes it possible to improve the controllability of the car. In addition, a connecting member is provided between the new electric motor and the existing hoisting machine to connect the new electric motor and the existing hoisting machine, so the existing hoisting machine is driven by the new electric motor. Therefore, even after replacing the existing motor with a new motor, the existing hoisting machine can be used, and there is no special need to replace the existing hoisting machine.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the elevator improvement method of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating an embodiment of the elevator improvement method of the present invention, and FIG. 2 is a sectional view showing a mounting structure for a hoist provided in the elevator of FIG. 1. In addition, in FIGS. 1 and 2, the above-mentioned FIG.
Components equivalent to are given the same reference numerals. That is, 1 is a hoistway, 2 is a car, 2a is a counterweight, 3 is a main rope, 4 is a deflection wheel, 5 is a sheave, 6 is a speed reducer, 7 is a magnetic brake, 8 is a hoist, 8a is a coupling device, and 17 is a three-phase AC power source.

As shown in FIG. 1, the elevator to which the improvement method of this embodiment is applied includes a newly installed electric motor 31 that drives a hoisting machine 8, and a newly installed control panel 3 that controls this newly installed electric motor 31.
2, a speed detection device 33 that detects the rotational speed of the newly installed electric motor 31, and a speed detection device 33 that is provided between the newly installed electric motor 31 and the hoisting machine 8, as shown in FIG. It has a connecting member, for example, a spacer 34, that connects the two. The newly installed electric motor 31 described above is a variable frequency compatible three-phase induction motor. Newly installed control panel 3 mentioned above
2 is connected to a drive circuit 35 that outputs an alternating current with a variable voltage and variable frequency, this drive circuit 35, the speed detection device 33, and the brake 7, and controls the operation and rotation direction of the newly installed electric motor 31, and also controls the brake A control circuit 36 for controlling the operation of the car 7, and a control circuit 36 for controlling the operation of the car 2.
a main switch 38a provided between the control circuit 37, the drive circuit 35, and the three-phase AC power supply 17;
38b and 38c. The drive circuit 35 includes a converter 41 connected to the main switches 38a to 38c,
The converter 41 includes an inverter 42 connected to the converter 41 and the newly installed electric motor 31, and a capacitor 43 provided between the converter 41 and the inverter 42.

In this embodiment, the control panel 10 shown in FIG. 3 described above is replaced with a newly installed control panel 32, the electric motor 9 shown in FIG. 3 is removed from the hoisting machine 8 of FIG. Upper machine 8
A new electric motor 31 is installed through a spacer 34, that is, the existing electric motor 9 is replaced with a new electric motor 31, and the new electric motor 31 and the hoisting machine are installed between the new electric motor 31 and the hoisting machine 8. A spacer 34 is provided to connect the two. Before the new electric motor 31 is attached to the hoisting machine 8 as described above, the speed detection device 33 is installed in the new electric motor 31. Then, when the newly installed electric motor 31 operates, the speed detection device 33 detects the rotational speed of the newly installed electric motor 31 and outputs a speed signal corresponding to this rotational speed to the newly installed control panel 32. In this newly installed control panel 32, the control circuit 3
6 outputs a control signal for controlling the operation of the newly installed electric motor 31 according to the speed signal, and the drive circuit 35 outputs a three-phase alternating current having a voltage and frequency corresponding to the control signal. For example, when the speed of the car 2 becomes excessive when the car 2 is braked, the voltage and frequency of the three-phase alternating current output from the newly installed control panel 32 can be reduced based on the speed signal output from the speed detection device 33. Accordingly, the rotational speed of the newly installed electric motor 31 and the rotational speed of the hoisting machine 8 are reduced in accordance with this change in voltage and frequency, and as a result, the braking distance of the car 2 is shortened and landing accuracy is improved. At the same time, by maintaining the voltage and frequency of the three-phase alternating current above a predetermined voltage and frequency without making them too low, the shock when the car 2 is stopped is prevented from becoming excessive.

In the embodiment configured as described above, the car 2
The controllability of the car 2 can be improved, and not only can the landing error of the car 2 be reduced, but also passenger safety and the ride comfort of the car 2 can be improved. In addition, between the newly installed electric motor 31 and the hoisting machine 8, these newly installed electric motors 31
Since a spacer 34 is provided to connect the hoisting machine 8 and the hoisting machine 8, the hoisting machine 31 is driven by the newly installed electric motor 31, so that the existing electric motor 9 can be replaced with the new electric motor 31. The hoisting machine 8 can be used even after this, and there is no special need to replace the hoisting machine 8.

[0014]

[Effects of the Invention] Since the present invention is constructed as described above, it is possible to improve the controllability of the car without the need to replace the hoisting machine. Elevator improvement work can be carried out in a short period of time without requiring additional work.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating an embodiment of the elevator improvement method of the present invention.

FIG. 2 is a cross-sectional view showing a mounting structure of a hoist included in the elevator of FIG. 1;

FIG. 3 is a block diagram showing a conventional structure of an elevator.

FIG. 4 is a speed characteristic diagram of a car provided in the elevator of FIG. 3;

FIG. 5 is a characteristic diagram of the car provided in the elevator of FIG. 3 at the time of landing;

[Explanation of symbols]

2 Cart 3 Main rope 8 Hoisting machine 31 Newly installed electric motor 32 Newly installed control panel 33 Speed detection device 34 Spacer (connecting member) 35 Drive circuit 36 Control circuit

Claims (1)

[Claims] Claim 1. A method for improving an elevator comprising: a hoisting machine for hoisting a main rope to which a car is attached at one end; an electric motor for driving the hoisting machine; and a control panel for controlling the electric motor. The panel was replaced with a new control panel that outputs alternating current at a variable frequency, and the above motor was replaced with a new motor compatible with variable frequency. A method for improving an elevator, characterized in that a connecting member is provided for connecting the hoist to a hoisting machine.