JP5369616B2 - Elevator - Google Patents

Abstract

An elevator, wherein damage on the surface of a rope is reduced, the diameter of a hoist sheave of the elevator is reduced, and the elevator is compact in size and occupies a reduced space. An elevator is provided with an elevator car (1) lifted and lowered by winding up and down a rope (6) by a sheave (2), a rotational speed detection means for the sheave (2), a brake device for applying braking torque to the sheave (2) and activated when the speed of the rope (6) is higher than a predetermined level, and a calculation section for calculating the slip speed between the rope (6) and the sheave (2) on the basis of the rotational speed of the sheave (2) and the speed of the rope (6).  Braking torque of the brake device after the brake device is activated is determined on the basis of the value of the calculated slip speed.

Description

  The present invention relates to an elevator having a brake device, and is particularly suitable for an elevator in which a car is forcibly stopped by a brake device in an emergency or maintenance.

  In the inspection of the elevator, as an emergency braking test, an abnormal speed increase of the car is detected, and the car is forcibly stopped using a brake device provided in the hoisting machine.

  Conventionally, in order to reduce the impact on the car during emergency stop and shorten the braking distance of the car, after applying full braking force to the drive sheave during emergency braking, a braking force weaker than the total braking force is applied to the drive sheave. It is known that when the absolute value of the acceleration of the car becomes smaller than a predetermined value, the braking force is again applied to the drive sheave.

  Also, in elevators that employ resin-coated main ropes, a small resistor must be installed on the electromagnetic brake coil when the electromagnetic brake device is activated to suppress the deceleration of the car during an emergency stop or sudden stop to an appropriate value. It is known to slow the rise of braking force by connecting in parallel, and is described in Patent Document 2.

JP 2006-8333 A JP 2003-221171 A

  In the above prior arts, all of them only relieve the stop shock of the car, and the rope surface damage is not considered. That is, if the damaged portion of the rope coincides with a portion where the number of passages of the sheaves and pulleys is large, there is a high possibility that the damage will proceed. Moreover, when the diameter of the hoisting sheave is to be reduced using a rope made of a highly flexible material such as a fiber or a belt, it is necessary to further prevent damage to the surface.

  An object of the present invention is to solve the above-mentioned problems of the prior art and reduce damage to the rope surface. Another object of the present invention is to make the elevator sheave smaller in diameter so that the elevator is compact and suitable for space saving.

In order to solve the above-mentioned problems, the present invention provides an elevator having a car that is lifted and lowered by winding a rope with a sheave, a rotation speed detecting means of the sheave, and a brake device that applies braking torque to the sheave. The brake device that operates when the speed of the rope becomes greater than a predetermined value, and a calculation unit that calculates the sliding speed of the rope and the sheave from the rotational speed of the sheave and the speed of the rope, After the operation, when the calculated sliding speed is related to the formation of indentations on the rope surface and becomes larger than a predetermined value depending on the rope speed , the energization is turned on to release the brake device, Thereafter, when the calculated said slip rate is smaller than the predetermined value, the intermittently so it turns off the energization Kikasu the brake device There are those in the subsequent normal operation prevent the progression of damage to the rope surface.

According to the present invention, after the brake device is operated when the speed of the rope becomes greater than a predetermined value, the slip speed is related to the formation of indentations on the rope surface and is greater than the predetermined value depending on the rope speed. When it becomes larger, the energization is turned on to release the brake device.After that, when the sliding speed becomes lower than the predetermined value, the energization is turned off and the brake device is used intermittently . Deterioration of the damage level resulting in formation of indentation can be prevented , and the progress of damage on the rope surface can be reduced in the subsequent normal operation .

  Elevators are installed in hoisting machines to raise and lower the car, governor device that detects the speed increase of the car in an abnormal situation, brake device that brakes the car based on the signal of the governor device, and car part And an emergency stop device for gripping the rail.

  In the elevator inspection, an emergency braking test is conducted to confirm the operation of emergency braking. Emergency braking is to detect an abnormal speed increase of the car and forcibly stop the car using the brake device provided in the hoisting machine. Slip may occur and damage to the rope surface may occur. If the damaged part coincides with a part where the number of passages of the sheave or pulley is large, there is a high possibility that the damage will proceed.

  In recent years, the diameter of the hoisting sheave has been reduced using a rope made of a highly flexible material such as a fiber or a belt, and in order to prevent damage to the surface, the slip between the rope and the sheave is required to be smaller.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of the elevator apparatus. The car 1 on which the passenger gets is moved up and down by hoisting the rope 6 with the hoisting machine 7. The hoisting machine 7 has a brake drum that rotates in the same manner as the sheave 2, a set of brake devices, and an encoder 9 that detects the amount of rotation of the sheave. The brake device includes brake shoes 3a and 3b, braking springs 31a and 31b for pressing the shoes, and electromagnetic coils 33a and 33b for separating the springs from the braking surface.

  When the car is stopped, the electromagnetic coils 33a, 33b are not energized, the brake shoes 31a, 31b press the brake shoes 3a, 3b against the drum, the sheave 2 does not rotate, and the car is stopped. It becomes.

  When the car 1 starts to move up and down, current is passed through the electromagnetic coils 33a and 33b to separate the brake shoes 3a and 3b from the braking surface. This basic operation is the same even in a disc brake system in which a brake disc and an electromagnetic coil are combined.

  When the car 1 is abnormally accelerated, the car 1 must be stopped safely and promptly in order to protect passengers' safety. As a means for detecting this abnormal speed, a governor pulley 4 is disposed in the hoistway. This includes a governor rope 5 coupled to the car 1, a governor pulley around which the governor rope 5 is wound, and a trigger mechanism (not shown) for detecting that the pulley exceeds a predetermined rotational speed.

  When the governor device detects an abnormal speed of the car, the power to the electromagnetic coil is cut off and the brake shoes 3a and 3b are forcibly pressed against the braking surface. At this time, it is necessary to operate the brake device so that the acceleration becomes a certain value or less.

  The damage on the surface of the rope 6 occurs when the friction between the rope 6 and the sheave 2 is small, because the rope 6 slides on the sheave 2 so that an indentation is formed on the surface of the rope strand. In particular, the higher the speed of the car 1, the worse the damage level. For this reason, in the normal operation after the emergency braking is performed, if the damaged portion of the rope 6 is frequently passed over the sheave 2, the damage may progress.

  The damage on the surface of the rope 6 does not manifest itself only in the steel wire rope. When a belt or a twisted rope in which a rope strand or strand group is covered with a resin such as urethane or rubber is used, the hardness of the resin is further increased. Under low conditions, the resin surface may be seriously damaged.

  The speed of the rope 6 is detected by using the output of the governor rope 5 that moves in the same manner as the car 1, that is, the governor pulley 4. At the same time, the rotation amount of the sheave 2 is detected by the rotation speed of the encoder 9 directly connected thereto. From the two values, the relative sliding velocity ΔV of the rope 6 and the sheave 2 can be obtained by rs × ωs−re × ωe. Here, rs and re are the radii of the sheave 2 and governor pulley, respectively, and ωs and ωe are the rotational angular velocities of the sheave 2 and governor pulley, respectively.

  During emergency braking, the brake system changes the timing of turning off the electromagnetic coil (braking) or the braking torque step by step (or intermittently) so that the relative speed, that is, the sliding speed is reduced. It is good to let them. Specifically, the rope and sheave sliding speed is calculated by the calculation unit based on the sheave rotation speed and the rope speed, and the braking torque after the operation is determined based on this value.

  When the sliding speed becomes larger than a predetermined value, the braking torque is reduced or the energization is turned on to release (release) the brake. Thereafter, when the sliding speed becomes smaller than a predetermined value, the braking torque is increased or the energization is turned off (released) to apply the brake.

  If a large braking torque is suddenly applied in the initial stage, the sheave 2 stops suddenly. If the automobile is taken as an example, the tire is locked, and the rope 6 slides on the sheave 2. If the braking torque of the sheave 2 is gradually or stepwise (intermittently), the slip of the rope 6 can be reduced.

  Since the signal output of each of the encoder attached to the governor pulley 4 and the encoder 9 attached to the hoisting machine is usually a pulse output, it is converted into a continuous signal. Further, since the diameter of the sheave 2 and the diameter of the governor pulley 4 are different from each other, both are converted into a sliding speed, and the controller 10 controls the timing of turning off the power.

Next, another embodiment will be described with reference to FIG.
A speed detector 19 such as a Doppler type speed sensor is mounted on the car 1. In this system, the governor rope 5 that moves in synchronization with the car 1 is unnecessary, and the elevator hoistway cross-sectional area can be reduced. Note that, when the power supply to the speed detector 19 is stopped during emergency braking, the control signal output is lost, and therefore, the emergency power source 32 is mounted on the car 1 to prevent this. Also in this configuration, as in the first embodiment, the braking torque of the brake device is controlled by comparing and calculating the outputs of the speed detector 19 of the car 1 and the encoder 9 of the hoisting machine 7.

  The example of controlling the braking torque at the time of emergency braking has been described above. However, for example, in the operation mode in which the car 1 is braked by the brake device as in the maintenance operation, the effect of preventing the rope 6 from being damaged by the slip is obtained. It is done.

  In general, the elevator has a position detector (17 in FIG. 1) provided with a shielding plate (17 in FIG. 1) installed on the car-side rail 15a in order to accurately place the car 1 on the floor level of the building. 1) and the hoisting machine 7 is controlled. According to this example, the shielding plate is not required, and the landing of the car 1 to the floor level is enabled by using both the encoder information of the motor and the information on the slip speed of the rope and sheave.

  FIG. 3 shows time history waveforms of signals before and after emergency braking in each embodiment. The condition at this time indicates a condition in which the balance of the weight of the car 1 and the balance weight 20 is large.

  The uppermost signal “a” indicates the emergency braking trigger signal from the governor device, and thereafter, the applied current to the brake, the sheave speed, the car speed, and the rope and sheave sliding speed in the downward direction of the figure. When an emergency braking trigger is applied, the motor current and the braking device are cut off. Since there are two brake devices, here, the timing of turning off the current (cutting off the applied current) is changed with a time difference (b1, b2). When energization of the brake is turned off, braking torque is generated in the sheave 2 by the braking spring, and the speed of the sheave 2 is reduced. Here, the speed of the sheave 2 and the car 1 is increased by the interval La immediately after the emergency braking trigger because the car 1 is free-running due to the balance of the car 1 and the balance weight 20. is there.

  By controlling the braking timing of the brake device, the sheave 2 is gently stopped (c2) compared to the waveform (c1) when the control is not performed. When the brake device is not controlled, the rope 6 finally stops while sliding on the sheave 2 even after the sheave 2 stops.

  The lowermost figure shows the speed difference between the sheave 2 and the car 1, that is, the sliding speed. This figure shows the slip speed when the brake device is not controlled. By controlling the brake device, the slip speed (or slip amount) of the sheave 2 and the rope 6 is set to a predetermined value or less. be able to.

FIG. 4 shows a general relationship diagram between the sliding speed and the friction coefficient. When the sliding speed is small, the friction coefficient is large , and when the speed is large, the friction coefficient is small . Therefore, if the brake device is controlled stepwise and the relative speed between the sheave 2 and the rope 6 is lowered, the friction coefficient of both will continue to be high and slipping will be difficult. This principle is the same as the ABS control of a car and the operation of a pumping brake.

  FIG. 5 shows an example of a hoisting machine, in which the sheave 2 and the rotor 21 have an integral structure, and an outer rotor type motor having an outer peripheral surface of the rotor 21 as a braking surface is shown. The brake shoes 3a and 3b come into contact with the brake braking surface 22 to apply braking torque to the sheave 2. Since one set of electromagnetic coils 33a and 33b is installed, it can be controlled independently by two power supply circuits.

  FIG. 6 shows an example of a method for controlling the two electromagnetic coils 33a and 33b. The coil winding numbers of the coil winding portions 34a and 34b of the two electromagnetic coils 33a and 33b are set to different values. The upper diagram shows a case where the number of turns of the coil is small, and the lower diagram shows a case where the number of turns of the coil is large. The larger the number of turns, the larger the time constant and the longer the time ΔT1 until release. Therefore, it is possible to make a difference in the time from when the energization is turned off until the release of the two coils is completed.

  Further, if the gaps (δ1, δ2 in FIG. 5) between the brake braking surface 22 and the brake shoes 3a, 3b are different values, the difference in ΔT2 in time is similarly obtained at the point where the electromagnetic coils 33a, 33b start releasing. You can turn it on. In this way, even when the power-off timing is the same, the time until the two brake shoes 3a and 3b come into contact with the braking surface (22 in FIG. 5) changes, and the braking torque can be changed. it can.

  According to the above, since the timing for turning off the energization is optimized while observing the relative sliding speed of the rope 6 and the sheave 2, the sheave 2 can be stopped gently. Thereby, the sliding speed (or sliding distance) of the rope 6 and the sheave 2 can be shortened, and damage to the rope can be reduced.

The side view which shows the elevator apparatus which is one Embodiment by this invention. The side view which shows the elevator apparatus which is other embodiment by this invention. The graph showing the time change with respect to each value at the time of emergency braking by each embodiment. The graph which shows the relationship between a sliding speed and a friction coefficient. The front view which shows the winding machine which is one embodiment. The graph which shows the time change of each value at the time of the brake braking which is one embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car 2 Sheave 3a, 3b Brake shoe 4 Governor pulley 5 Governor rope 6 Rope 7 Hoisting machine 8a, 8b Balance weight side rail 9 Encoder 10 Controller 11a, 11b Buffer 12 Brake drive circuit 13 Power converter 14 Power supply 15a, 15b Car side rail 16 Position detector 17 Shielding plate 18 Rotation detector 19 Speed detector 20 Balance weight 21 Rotor 22 Brake braking surface 23a, 23b Brake arm 25a, 25b Arm fulcrum 31a, 31b Brake spring 32 Emergency power supply device 33a, 33b Electromagnetic coils 34a, 34b Winding portion δ1 Gap between braking surface and brake shoe (left side)
δ2 Gap between braking surface and brake shoe (right side)
ΔT1 Time difference due to coil turns change ΔT2 Time difference due to shoe gap change

Claims (3)

In an elevator comprising a car that is lifted and lowered by winding a rope with a sheave, a rotation speed detecting means of the sheave, and a brake device that applies braking torque to the sheave,
The brake device that operates when the rope speed is greater than a predetermined value;
A calculation unit for calculating a sliding speed between the rope and the sheave based on a rotational speed of the sheave and a speed of the rope;
And after the operation, when the calculated sliding speed is greater than a predetermined value that is related to the formation of indentations on the rope surface and depends on the rope speed , the energization is turned on and the brake device is turned on. After that, when the calculated slip speed becomes smaller than the predetermined value, the energization is turned off and intermittently performed so as to use the brake device. In the subsequent normal operation, the rope surface is damaged . An elevator characterized by preventing progress.   The thing of Claim 1 WHEREIN: The governor rope which moves in synchronization with the said riding car, and a governor pulley around which the governor rope is wound, and the speed of the rope is obtained by detecting the rotational speed of the governor pulley. Elevator characterized by being performed.   The elevator according to claim 1, wherein the speed of the rope is determined by detecting the speed of the car.

Images