CN115867505A

CN115867505A - Elevator with a movable elevator car

Info

Publication number: CN115867505A
Application number: CN202080103129.9A
Authority: CN
Inventors: 见延盛臣
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2023-03-28
Also published as: DE112020007566T5; WO2022049673A1; JPWO2022049673A1; JP7323078B2

Abstract

Provided is an elevator capable of suppressing the braking distance of a car at the time of emergency stop. An elevator (1) is provided with a slip detection unit (16), a sheave speed detection unit (9), and a brake control unit (17). A slip detection unit (16) detects slippage of the main rope (5) relative to the sheave (13) of the hoist (4). When the slip detection unit (16) detects the occurrence of a slip during an emergency stop, the brake control unit (17) compares the speed of the sheave (13) detected by the sheave speed detection unit (9) at the time point of the period from the start of the emergency stop to the start of the slip with a preset threshold value. When the speed of the sheave (13) exceeds a threshold value, the brake control unit (17) controls the brake (8) in accordance with a control method for eliminating slippage of the main rope (5). When the speed of the sheave (13) does not exceed the threshold value, the brake control unit (17) controls the brake (8) in such a manner that the sheave (13) decelerates at a set deceleration rate, on the basis of the braking force of the brake (8).

Description

Elevator with a movable elevator car

Technical Field

The present disclosure relates to elevators.

Background

Patent document 1 discloses an example of an elevator. In an elevator, the speed of a car to which a main rope is suspended and the speed of a sheave around which the main rope is wound are detected. The control unit controls the braking force applied to the sheave. When the difference between the speed of the sheave and the speed of the car is less than or equal to a threshold value during an emergency stop of the elevator, the control means provides a full braking force. On the other hand, when the difference between the speed of the sheave and the speed of the car exceeds a threshold value due to the slippage of the main ropes, the control means provides a braking force weaker than the full braking force.

Prior art documents

Patent literature

Patent document 1: japanese patent laid-open publication No. 2004-231355

Disclosure of Invention

Problems to be solved by the invention

However, if the braking force is weakened to suppress the sliding of the main ropes in accordance with the situation such as the speed of the car when the sliding of the main ropes occurs, the braking distance of the car may become longer.

The present disclosure relates to the solution of the above-described problem. The present disclosure provides an elevator capable of suppressing a braking distance of a car at an emergency stop.

Means for solving the problems

An elevator according to the present disclosure includes: a brake for braking a sheave around which a main rope is wound in a hoist for raising and lowering a car in an elevator shaft, the main rope suspending the car in the elevator shaft; a slip detection unit that detects whether the main rope slips with respect to the sheave; a sheave speed detecting unit that detects a speed of the sheave; and a brake control unit that, when the slip detection unit detects the occurrence of a slip at the time of an emergency stop, compares the speed of the sheave detected by the sheave speed detection unit at an arbitrary reference point that is set in advance during a period from the start of the emergency stop to the start of the slip with a speed threshold that is set in advance, and controls the brake in accordance with a slip elimination control method that eliminates the slip between the sheave and the main rope when the speed at the reference point exceeds the speed threshold, and controls the brake in accordance with a braking force control method that controls the braking force of the brake so that the sheave decelerates at a set deceleration when the speed at the reference point does not exceed the speed threshold.

An elevator according to the present disclosure includes: a brake for braking a sheave around which a main rope for suspending the car on the elevator shaft is wound, in a hoist for raising and lowering the car on the elevator shaft; a slip detection unit that detects whether the main rope slips with respect to the sheave; a car speed detection unit that detects a speed of the car; a sheave speed detecting section that detects a speed of the sheave; and a brake control unit that, when the slip detection unit detects the occurrence of a slip at the time of an emergency stop, compares the speed of the car detected by the car speed detection unit at an arbitrary reference time point set in advance during a period from the start of the emergency stop to the start of the slip with a speed threshold set in advance, controls the brake in accordance with a slip elimination control method that eliminates the slip between the sheave and the main rope when the speed at the reference time point exceeds the speed threshold, and controls the brake in accordance with a braking force control method that controls the braking force of the brake so that the sheave decelerates at a set deceleration when the speed at the reference time point does not exceed the speed threshold.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the elevator disclosed by the disclosure, the braking distance of the car can be reduced during emergency stop.

Drawings

Fig. 1 is a configuration diagram of an elevator according to embodiment 1.

Fig. 2 is a diagram showing an example of a speed waveform at the time of emergency stop of the car according to embodiment 1.

Fig. 3 is a diagram showing an example of a speed waveform at the time of emergency stop of the car according to embodiment 1.

Fig. 4 is a diagram showing an example of a speed waveform at the time of emergency stop of the car according to embodiment 1.

Fig. 5 is a diagram showing an example of a speed waveform at the time of emergency stop of the car according to embodiment 1.

Fig. 6 is a flowchart showing an example of the operation of the elevator according to embodiment 1.

Fig. 7 is a hardware configuration diagram of a main part of an elevator according to embodiment 1.

Fig. 8 is a structural diagram of an elevator according to embodiment 2.

Detailed Description

A mode for carrying out the present disclosure will be described with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and overlapping description is simplified or omitted as appropriate.

Embodiment 1.

Fig. 1 is a structural diagram of an elevator 1 according to embodiment 1.

The elevator 1 is provided in a building having a plurality of floors, for example. In the building, a lifting path 2 of an elevator 1 is provided. The hoistway 2 is a space passing through a plurality of floors.

The elevator 1 includes a car 3, a hoist 4, a main rope 5, a counterweight 6, a governor 7, a brake 8, a sheave speed detecting portion 9, a car speed detecting portion 10, a safety switch 11, and a control device 12.

The car 3 is disposed on the hoistway 2. The car 3 is a device for transporting a user or the like between a plurality of floors. The hoist 4 is a device for raising and lowering the car 3 disposed on the ascending and descending path 2. The hoisting machine 4 includes an unillustrated motor that generates a driving force and a sheave 13 that is driven to rotate by the motor. The main ropes 5 are wound around the sheave 13. The main ropes 5 suspend the car 3 in the elevator shaft 2 on one side of the sheave 13. The main rope 5 suspends the counterweight 6 in the elevator shaft 2 on the other side of the sheave 13. The counterweight 6 is a device for balancing a load applied to both sides of the sheave 13 via the main rope 5 between the counterweight and the car 3.

The governor 7 is a device that limits the speed of the car 3. The governor 7 includes a governor rope 14 and a governor sheave 15. The governor rope 14 is a rope attached to the car 3. The governor sheave 15 is a sheave around which the governor rope 14 is wound. The governor sheave 15 is rotated by the governor rope 14 that moves in conjunction with the travel of the car 3. The governor 7 limits the speed of the car 3 in accordance with the rotational speed of the governor sheave 15.

The brake 8 is a device for braking the sheave 13. The brake 8 is, for example, a disc brake, a drum brake, or another brake having a movable portion. In a normal state, when in a braking state, the brake 8 applies a braking force capable of holding the car 3 and the counterweight 6 in a stationary state to the sheave 13. The braking force is, for example, a frictional force for suppressing rotation of the sheave 13, a pressing force for generating the frictional force, or the like. On the other hand, the brake 8 does not hinder the rotation of the sheave 13 when in the released state.

The sheave speed detecting unit 9 detects the speed of the sheave 13. The speed of the sheave 13 detected by the sheave speed detecting unit 9 is, for example, the speed of the outer periphery of the sheave 13. The sheave speed detecting unit 9 includes, for example, an encoder for detecting the amount of rotation of the sheave 13. The sheave speed detecting unit 9 may be provided with a function of converting the rotation amount of the sheave 13 into the rotation speed of the sheave 13 or the speed of the outer periphery of the sheave 13.

The car speed detection unit 10 is a unit that detects the speed of the car 3. The speed of the car 3 detected by the car speed detecting unit 10 is, for example, a traveling speed of the car 3 in the vertical direction. The car speed detection unit 10 includes, for example, an encoder for detecting the amount of rotation of the governor sheave 15. The car speed detection unit 10 may be provided with a function of converting the rotation amount of the governor sheave 15 into the running speed of the car 3. The car speed detection unit 10 may detect the speed of the car 3 based on a detection result of a position sensor, a speed sensor, an acceleration sensor, or the like provided in the car 3, for example. The car speed detecting unit 10 may detect the speed of the car 3 by detecting the speed of the main rope 5, the counterweight 6, or the like that operates in conjunction with the car 3.

The safety switch 11 is provided on the lifting path 2. The safety switches 11 are disposed at the upper end and the lower end of the ascending/descending path 2. The safety switch 11 is a switch for detecting that the car 3 has traveled past a landing position of the uppermost floor or the lowermost floor to continue traveling, for example. When the safety switch 11 is operated, the elevator 1 may be kept on standby without traveling until the elevator receives an inspection by a maintenance worker or the like, for example. In this case, there is a possibility that a user riding on the car 3 may be trapped.

The control device 12 is a device that controls the operation of the elevator 1. The operation of the elevator 1 includes, for example, traveling of the car 3 and operation of the brake 8. The actuation of the brake 8 comprises an emergency stop. The emergency stop is an operation of stopping the traveling car 3 due to input of an emergency stop signal, detection of an emergency stop event, occurrence of a power failure, or the like. The emergency stop is started by detecting some abnormality while the car 3 is traveling, for example. The abnormality that starts the emergency stop is detected by an abnormality detector or the like, not shown, provided in the elevator 1. The abnormality detector is, for example, a safety device provided in the elevator 1. The control device 12 includes a slip detection unit 16 and a brake control unit 17.

The slip detector 16 detects whether or not there is a slip between the main rope 5 and the sheave 13. Here, the brake 8 applies a braking force to the sheave 13 that rotates together with the main rope 5 at the time of emergency stop. At this time, the main rope 5 may slip with respect to the sheave 13 depending on the position in the elevator shaft of the car 3 in conjunction with the main rope 5, the traveling direction, the traveling acceleration, and the mass, the load in the car 3 that varies depending on the number of passengers and the equipment mounted on the car 3, the shape of the rope groove of the sheave 13, the friction coefficient between the main rope 5 and the sheave 13, and the braking force of the brake 8. The slip detector 16 detects the presence or absence of slip of the main rope 5 at such an emergency stop or the like. The slip detection unit 16 detects the presence or absence of slip of the main rope 5 by, for example, detecting relative movement of the main rope 5 in the circumferential direction with respect to the outer circumferential portion of the sheave 13. The slip detection unit 16 detects the presence or absence of a slip as follows, for example.

The slip detection unit 16 calculates a difference between the speed of the car 3 and the speed of the sheave 13 detected by the car speed detection unit 10 and the sheave speed detection unit 9, respectively, as the relative speed of the main rope 5 with respect to the sheave 13. The slip detection unit 16 detects the occurrence of the slip of the main rope 5 when the calculated relative speed exceeds a preset threshold value. On the other hand, the slip detection unit 16 detects the elimination of the slip of the main rope 5 when the calculated relative speed is lower than the preset threshold value.

In addition, when there is a resonance system from the car 3 to the car speed detecting unit 10, the slip detecting unit 16 may use an inverse model filter of the mechanical characteristics from the car 3 to the car speed detecting unit 10 for the output of the car speed detecting unit 10, and perform a process of removing the influence of the mechanical characteristics. The slip detection unit 16 may calculate the relative speed with respect to the output of the sheave speed detection unit 9, for example, after the processing is completed. The slip detection unit 16 may calculate the relative speed of the main rope 5 with respect to the sheave 13 by using the output of the car speed detection unit 10 to which the position from the hoist 4 to the car 3 and the mechanical property filters from the car 3 to the car speed detection unit 10 are applied and the speed of the car 3. Thus, since influences due to expansion and contraction of the main ropes 5 and the like other than sliding of the main ropes 5 are removed, the relative speed of the main ropes 5 with respect to the sheave 13 can be calculated with high accuracy. Therefore, since the threshold value for detecting the presence or absence of a slip can be reduced, the accuracy of the slip detection of the main rope 5 can be improved.

The brake control unit 17 controls the operation of the brake 8. The brake control unit 17 controls the operation of the brake 8 by switching a plurality of control methods. The plurality of control modes include a braking force control mode and a slip elimination control mode.

The braking force control system is a control system that controls the braking force of the brake 8 so that the sheave 13 decelerates at a set deceleration. The set deceleration is at the 1 st deceleration a ₁ And the 2 nd deceleration a ₂ With a predetermined constant deceleration. Here, the deceleration is an acceleration that decreases the absolute value of the velocity. In this example, the 1 st deceleration a ₁ Is less than the 2 nd deceleration a ₂ Is large. The control of the brake 8 in the braking force control system may be performed based on the speed of the sheave 13 detected by the sheave speed detecting unit 9. Further, since the speed of the car 3 and the speed of the sheave 13 are almost equal to each other in a state where no slip occurs, the control of the brake 8 in the braking force control system may be performed based on the deceleration of the sheave 13 estimated from the speed of the car 3 detected by the car speed detecting unit 10.

1 st deceleration a ₁ Is expected to be at the 1 st deceleration a in absolute value ₁ In the case of a small deceleration emergency stop, the deceleration at which the slip between the main rope 5 and the sheave 13 does not occur. 1 st deceleration a ₁ According to volumeThe predicted value of the towing ability of the crane 4 is calculated in advance. The predicted value of the traction ability is, for example, a degree of difficulty in sliding the main ropes 5 with respect to the sheave 13, which is calculated based on specifications such as shapes and materials of the sheave 13 and the main ropes 5 of the hoist 4, or design values. The predicted value of the traction ability does not take into consideration a local reduction in friction conditions such as abrasion between the sheave 13 and the main ropes 5. In addition, at the 1 st deceleration a ₁ The calculation of (a) takes into account the traveling direction of the car 3 and the load condition, etc., in which the main ropes 5 are likely to slip. The condition where the sliding is likely to occur includes, for example, a condition at the time of rising under no load or a condition at the time of falling under a maximum load. 1 st deceleration a ₁ For example, the upper limit deceleration is calculated in advance so that no slip occurs when a local reduction in friction conditions is not taken into consideration.

2 nd deceleration a ₂ Is expected to be at the absolute value ratio 2 nd deceleration a ₂ When the car 3 is stopped suddenly at a high deceleration, the car does not travel to the position where the safety switch 11 is disposed. 2 nd deceleration a ₂ The calculation is performed in advance based on specifications such as the weight of the car 3, the counter weight 6, the main rope 5, and the sheave 13, and the rated speed of the car 3, design values, and the like. At the 2 nd deceleration a ₂ The running direction of the car 3 and the load condition in which the amount of travel of the car 3 increases are considered in the calculation of (a). Here, the amount of travel is a distance from a landing position of a terminal floor such as the uppermost floor or the lowermost floor to a position at which the car 3 travels the landing position and stops. The condition that the travel amount of the car 3 becomes large includes, for example, a condition at the time of rising under no load or a condition at the time of falling under a maximum load. 2 nd deceleration a ₂ For example, the deceleration is calculated in advance as the lower limit deceleration at which the safety switch 11 does not operate when the overshoot of the control of the brake 8 is not taken into consideration. Here, overshoot of the control of the brake 8 indicates that the braking force is too large relative to the command.

By reducing the 1 st deceleration a ₁ And the 2 nd deceleration a ₂ The operation of the brake 8 is controlled by the brake control section 17 in accordance with the braking force control system with the deceleration therebetween being set as the deceleration, even when an emergency stop is performedIn this case, the occurrence of slippage of the main rope 5 and the occurrence of a user being trapped can be suppressed. However, the main rope 5 may slip due to a local reduction in friction conditions, an overshoot in the control of the brake 8, or the like. Therefore, the brake control unit 17 switches the slip cancellation control method in accordance with the condition such as the speed of the car 3 when the slip occurs, so as to prevent the braking distance of the car 3 from becoming long.

The slip cancellation control method is a control method for canceling the slip between the sheave 13 and the main rope 5. The state where the slip between the sheave 13 and the main rope 5 is eliminated is a state where the relative speed of the main rope 5 and the sheave 13 becomes 0 and the ropes move integrally. In the slip elimination control method, the brake control unit 17 controls the braking force of the brake 8 so that the speed of the sheave 13 follows the speed of the car 3, for example. The brake control unit 17 controls the deceleration of the sheave 13 by adjusting the magnitude of the braking force applied to the sheave 13 so that, for example, the difference between the speed of the car 3 detected by the car speed detection unit 10 and the speed of the sheave 13 detected by the sheave speed detection unit 9 becomes small. This eliminates the slippage of the main rope 5, i.e., performs traction recovery. Preferably, the brake control unit 17 controls the brake 8 while adjusting the braking force so that the state of the brake 8 is maintained in the braking state and the state is not changed to the released state in the slip elimination control system. Alternatively, the brake control unit 17 may release the brake 8 before the slip detection unit 16 detects the elimination of the slip. If the slip is eliminated, the method of controlling the brake 8 in the slip elimination control system may be arbitrary.

Next, an example of the braking distance of the car 3 at the time of emergency stop will be described with reference to fig. 2 and 3.

Fig. 2 and 3 are diagrams showing examples of speed waveforms at the time of emergency stop of the car 3 according to embodiment 1.

The horizontal axes of fig. 2 and 3 represent time. The vertical axes in fig. 2 and 3 show the speeds of the car 3 and the sheave 13. In fig. 2 and 3, the solid line indicates a speed waveform of the car 3. In fig. 2 and 3, the broken line indicates the speed waveform of the sheave 13. For the purpose of explanation, fig. 2 and 3 show an example of a velocity waveform in a case where the brake torque is simplified so as to rise in a stepwise manner.

Fig. 2 shows an example in which the brake control unit 17 does not switch the control method.

When the abnormality detector of the elevator 1 detects an abnormality, a detection signal is input to the control device 12. At this time, the control device 12 performs an emergency stop of the car 3. The control device 12 outputs a power stop instruction to the hoist 4. The hoisting machine 4 stops the rotational driving of the sheave 13 based on the input command. For example, when the detection signal is input to the control device 12, the brake control unit 17 starts an emergency stop of the car 3. Point a in fig. 2 corresponds to the time at which the brake control unit 17 starts the emergency stop of the car 3.

When the emergency stop is started, the brake control unit 17 controls the brake 8 according to the braking force control method. The brake control unit 17 outputs a brake control command to the brake 8. The brake 8 starts braking of the sheave 13 after a brake control command is input. Here, there is a delay time due to the operation of the movable part of the brake 8 and the like until the braking force is generated after the command is input to the brake 8. Point B in fig. 2 corresponds to the time when the brake 8 generates the braking force after a delay time has elapsed since the input of the command.

During the delay time from the point a to the point B when the brake 8 generates the braking force, the car 3 and the sheave 13 are accelerated or decelerated by the unbalanced torque of the car 3 and the counterweight 6. In this example, the case where the car 3 accelerates is shown as a situation where the braking distance of the car 3 becomes long. The condition in which the car 3 is accelerated by the unbalanced torque is, for example, when the car is raised under no load or when the car is lowered under a maximum load. The car 3 is accelerated at a constant acceleration during the delay time from the point a to the point B. Although there may be cases where the acceleration is not constant due to the imbalance of the rope, the present embodiment will be described with a model simplified assuming that the acceleration is constant.

When deceleration is generated in the sheave 13 by the braking force of the brake 8 after the delay time, the sheave 13 and the car 3 start decelerating. Here, the speed of the sheave 13 and the car 3 immediately before the start of deceleration is referred to as a maximum speed. When the sheave 13 and the main ropes 5 are decelerated by the braking force of the brake 8, the main ropes 5 slip with respect to the sheave 13. Fig. 2 shows an example of the case where a slip occurs immediately after the brake 8 generates a braking force. That is, point B in fig. 2 corresponds to the time when the main rope 5 starts to slide.

When the sliding of the main rope 5 occurs, the sliding detection unit 16 detects the sliding of the main rope 5. The slip detector 16 outputs a detection signal to the brake controller 17. When the detection signal is input from the slip detection unit 16, the brake control unit 17 detects the speed of the car 3 or the sheave 13 at the reference time point by the car speed detection unit 10 or the sheave speed detection unit 9. The reference time is an arbitrary preset arbitrary time from the start of the emergency stop to the start of the slip. Since the main ropes 5 have not yet slipped at the reference time point, the speed of the car 3 and the speed of the sheave 13 linked to the main ropes 5 are equal to each other. Therefore, the brake control unit 17 can use the value of at least one of the speed of the car 3 detected by the car speed detection unit 10 and the speed of the sheave 13 detected by the sheave speed detection unit 9 as the speed at the reference time point. When the detection signal is input, the brake control unit 17 determines whether or not the speed at the reference time point exceeds a speed threshold V _lim . Speed threshold V _lim Is a value of the speed of the car 3 that is set in advance so as to suppress the braking distance of the car 3 at the time of emergency stop.

When the detection signal is input from the slip detection unit 16, the brake control unit 17 in this example determines the velocity V at the point B using the point B at which the slip starts as a reference point _B Whether or not the speed threshold V is exceeded _lim . The brake control unit 17 may set the detected value of the car speed detection unit 10 or the sheave speed detection unit 9 when the detection signal is input, for example, as the speed V at the point B _B . Alternatively, the brake control unit 17 may calculate the time when the sliding starts by interpolation, extrapolation, or the like based on time series data of the detection value of the car speed detection unit 10 or the sheave speed detection unit 9Velocity V at point B _B . In the example of fig. 2, the contents of the present embodiment are not applied, and the speed waveform when the main rope 5 continues to slide during the emergency stop operation is shown. In addition, V is relative to the content to which the present embodiment is applied _B Does not exceed the speed threshold V _lim That is, the velocity waveform in the case where the main rope 5 continues to slide is the same as the velocity waveform of fig. 2 in general, and the velocities at the points a and B are small, and the time between BC is shortened.

After the main ropes 5 slip, the sheave 13 and the car 3 are decelerated at different decelerations. In this example, the brake control unit 17 maintains the braking force control system, and therefore, stops at the point C1 after the sheave 13 decelerates at a constant deceleration. The car 3 is decelerated at a constant deceleration by friction of the main ropes 5 sliding on the sheave 13, and then stopped at a point F1.

When the car 3 stops, the brake control unit 17 determines that the car 3 is stopped. The stop determination of the car 3 is performed based on, for example, the speed of the car 3 detected by the car speed detection unit 10. The brake control unit 17 determines that the car 3 is stopped when, for example, the absolute value of the speed of the car 3 is lower than a preset threshold value. Alternatively, the brake control unit 17 may determine that the car 3 is stopped when the absolute value of the speed of the car 3 is lower than a preset speed threshold and the temporal rate of change of the speed is lower than a preset rate threshold. The brake control unit 17 may determine the stop of the car 3 based on the speed of the sheave 13 detected by the sheave speed detecting unit 9, for example, when the main ropes 5 do not slip with respect to the sheave 13. When the main ropes 5 do not slip, the speed of the car 3 and the speed of the sheave 13 are the same, so the brake control section 17 can perform stop determination of the car 3 using the speed of the sheave 13 by the same method as the stop determination using the speed of the car 3. The brake control unit 17 may determine the stop of the car 3 by another method. After determining that the car 3 is stopped, the brake control unit 17 applies a braking force to the sheave 13 that can hold the car 3 and the counterweight 6 in a stationary state as in the normal state. On the other hand, when it is determined that the car 3 is not stopped, the brake control unit 17 continues the control of the brake 8 at the time of an emergency stop.

Braking distance S of car 3 in the case of fig. 2 ₁ Corresponding to the velocity waveform shown by the solid line and the area of the portion between the horizontal axes. Thus, the braking distance S ₁ The estimated value of (b) is represented by the following formula (1).

Here, S _AB Indicating the distance traveled by the car 3 between points a and B. a is _rope Is a predicted value of the deceleration of the car 3 when the main ropes 5 are decelerated while sliding on the sheave 13. Acceleration a _rope Corresponds to the inclination of the line segment connecting point B and point F1 in fig. 2. Acceleration a _rope Since the acceleration decreases the absolute value of the speed of the car 3, the acceleration takes a negative value when the running direction of the car 3 is positive.

In addition, the distance S _AB For example, the calculation may be performed by the following equation (2).

Herein, a _k The predicted value of the idling acceleration of the car 3 due to the unbalanced torque is shown. Acceleration a _k This corresponds to the inclination of the line segment connecting point a and point B in fig. 2. Acceleration a _k The acceleration increases the absolute value of the speed of the car 3, and therefore takes a positive value when the running direction of the car 3 is in the positive direction. T is a unit of ₁ The predicted value of the time until the brake 8 generates the braking force between the point a and the point B is shown. Predicted value T ₁ Including the predicted time required for the state transition of the brake 8 from the released state to the braked state.

In addition, the brake control unit 17 may start the emergency stopPoint A as the reference point, based on the velocity V at point A _A The brake 8 is controlled. In this case, in the equations (1) and (2), the velocity V from the point a using the following equation (3) may be used _A Calculated velocity V _B The value of (c).

V _B ＝V _A +a _k T ₁ …(3)

In addition, the velocity V can be matched _B Similarly, the brake control unit 17 can use the value of at least one of the speed of the car 3 detected by the car speed detection unit 10 and the speed of the sheave 13 detected by the sheave speed detection unit 9 as the speed V _A . The brake control unit 17 may control the brake 8 based on the speed at a reference time point, which is an arbitrary time point between a point a at which the emergency stop starts and a point B at which the main rope 5 starts to slide. In this case, the velocity V calculated from the velocity at the reference time point in the same manner as in expression (3) may be used _B And so on.

On the other hand, fig. 3 shows an example in which the brake control unit 17 switches the control method.

Fig. 3 shows an example of the case where a slip occurs immediately after the brake 8 generates a braking force, as in fig. 2.

The brake control unit 17 of this example determines the velocity V at the point B as the reference time point when the detection signal is input from the slip detection unit 16 _B Whether or not the speed threshold V is exceeded _lim . In this example, the velocity V _B Exceeding a speed threshold V _lim . At this time, the brake control unit 17 switches the control method from the braking force control method to the slip elimination control method.

Here, there is a delay time from the occurrence of the slip until the slip detection unit 16 outputs the detection signal. During this delay time, the sheave 13 and the car 3 are decelerated at different decelerations. Since the brake control unit 17 does not switch the control method from the braking force control method during the delay time, the sheave 13 decelerates at a constant deceleration. The car 3 is decelerated at a constant deceleration by friction of the main ropes 5 sliding on the sheave 13.

Then, after a delay time due to a detection delay of the slip detection or the like, the brake 8 starts braking of the sheave 13 according to the slip elimination control method. Point C2 in fig. 3 corresponds to the time at which the braking force of the brake 8 is changed from the braking force control method by switching to the slip elimination control method after the elapse of the delay time from the occurrence of the slip. Here, the delay time between the points B and C includes a detection delay of the slip and a control response delay of the brake 8. According to the slippage elimination control method, the brake 8 is controlled to eliminate slippage of the main rope 5. For example, the brake control unit 17 controls the braking force applied to the sheave 13 by the brake 8 so that the speed of the sheave 13 follows the speed of the car 3. Point D of fig. 3 corresponds to the timing at which the slippage of the main rope 5 is eliminated according to the slippage elimination control method. Here, there is a delay time from the elimination of the slip until the detection by the slip detection unit 16, similarly to the detection of the occurrence of the slip. During this delay time, the brake 8 supplies the sheave 13 with a braking force based on the slip elimination control method. Point E of fig. 3 corresponds to the time when the braking force by the braking force control method is generated by the brake 8 after the delay time has elapsed since the slip elimination.

In the example of fig. 3, the braking force based on the slip elimination control method is smaller than the braking force based on the braking force control method so that the slip of the main rope 5 occurring in the braking force control method can be eliminated. Therefore, during the delay time from the point D to the point E when the brake 8 generates the braking force, the car 3 is accelerated or decelerated in accordance with the unbalanced torque of the car 3 and the counterweight 6. In this example, the case where the car 3 is accelerated in a situation where the braking distance of the car 3 is long is shown. The car 3 is accelerated at a constant acceleration during the delay time from the point D to the point E.

After the delay time, at point E, the sheave 13 and the car 3 start decelerating. At this time, the main ropes 5 and the sheave 13 move integrally because the slippage of the main ropes 5 is eliminated. Therefore, the car 3 and the sheave 13 are decelerated at a constant deceleration equal to each other and then stopped at a point F2.

Braking distance S of car 3 in the case of fig. 3 ₂ Corresponding to the velocity waveform shown by the solid line and the area of the portion between the horizontal axes. Thus, the braking distance S ₂ The estimated value of (b) is represented by the following formula (4).

Herein, a _c Is a command value of deceleration after recovery of traction, that is, after the slippage of the main rope 5 is eliminated. Acceleration a _c This corresponds to the inclination of the line segment connecting point E and point F2 in fig. 3. Acceleration a _c Since the acceleration decreases the absolute value of the speed of the car 3, the acceleration takes a negative value when the running direction of the car 3 is directed positively. a is _tr The predicted value is the acceleration of the car 3 during the delay time after the recovery of traction. Acceleration a _tr This corresponds to the inclination of the line segment connecting point D and point E in fig. 3. Acceleration a _tr Since the acceleration increases the absolute value of the speed of the car 3, a positive value is assumed when the traveling direction of the car 3 is set to a positive direction. Further, when the slip state is canceled by releasing the brake 8, the acceleration a is set to be equal to _tr And the idling acceleration a _k And are equal. T is ₂ Is a predicted value of the time between point B to point D until traction is restored. Predicted value T ₂ Including the delay time of detection of the occurrence of a slip by the slip detection unit 16. When the state of the brake 8 is changed from the braking state to the released state during the switching from the braking force control method to the slip elimination control method, the predicted value T is predicted ₂ Including the predicted time required for the state transition. T is ₃ The predicted value of the time until the brake 8 generates the braking force according to the braking force control method is between the points D to E. Predicted value T ₃ Including the delay time of detection of the elimination of the slip by the slip detection section 16. In addition, the control mode is switched from the slip elimination control mode to the braking force control modeWhen the state of the shift brake 8 is changed from the released state to the braking state, the predicted value T is ₃ Including the predicted time required for the state transition.

The slip of the main ropes 5 is caused by a local factor such as a reduction in friction coefficient, a temporary factor such as an overshoot of brake control, or the like, and therefore the command value a of deceleration after the traction resumption _c The deceleration is set to a normal range in which no slip occurs. In addition, the instruction value a _c The absolute value of (a) is set to be larger than the predicted value a of deceleration in the case where slip occurs, for example _rope Is large. Instruction value a _c The value of (b) is, for example, a value for setting deceleration. By making the instruction value a _c Absolute value ratio predicted value a of _rope The absolute value of (a) is sufficiently large, and even when the car 3 is accelerated to resume traction, the influence of the acceleration on the braking distance can be eliminated.

In this example, the predicted value a used in the formulae (1) to (4) _k 、a _rope 、a _tr 、T ₁ 、T ₂ And T ₃ For example, a value set or calculated in advance based on the specification or design value of the elevator 1. In addition, the instruction value a _c Is a preset value.

Next, the speed threshold V will be described with reference to fig. 4 and 5 _lim Examples of (3).

Fig. 4 and 5 are diagrams showing examples of speed waveforms at the time of emergency stop of the car 3 according to embodiment 1.

The horizontal axes of fig. 4 and 5 represent time. The vertical axes of fig. 4 and 5 show the speed of the car 3. In fig. 4 and 5, the solid line indicates a speed waveform when the brake control unit 17 switches the control method. In fig. 4 and 5, the broken line indicates a velocity waveform when the brake control unit 17 does not switch the control method. Fig. 4 and 5 show an example of a velocity waveform in the case where the brake torque is simplified so as to rise in a stepwise manner, as in fig. 2 and 3.

Fig. 4 shows the braking distance when the brake control unit 17 does not switch the control methodS ₁ Braking distance S from the case where the control mode is switched ₂ The example is equal.

Speed threshold V _lim Is set as the braking distance S ₁ And a braking distance S ₂ The speed at the reference time point of equality. In this example, since the point B is set as the reference time point, the velocity threshold V _lim Is set as the braking distance S ₁ And a braking distance S ₂ The velocity at point B being equal. By setting S in the formulae (1) to (4) ₁ ＝S ₂ The obtained speed threshold value V _lim From the predicted value a _k 、a _rope 、a _tr 、T ₁ 、T ₂ And T ₃ And an instruction value a _c Etc. In this example, the braking distance S ₁ And a braking distance S ₂ Or a speed threshold V _lim Based on the preset operating conditions for evaluation. The operation conditions for evaluation include conditions such as the magnitude of the load in the car 3 and the traveling direction of the car 3. The operation conditions for evaluation may include conditions of acceleration of the car 3 determined in accordance with the position of the car 3, and the like.

Since the braking distance of the car 3 corresponds to the area of the portion between the velocity waveform and the horizontal axis, the braking distance S ₁ And a braking distance S ₂ Difference and area alpha of ₁ And area alpha ₂ The difference in (c) corresponds to (d). Here, the area α ₁ The area of the portion where the velocity waveform of the broken line is larger than that of the solid line. Area alpha ₂ The area of the portion where the velocity waveform of the solid line is larger than that of the broken line. In FIG. 4, due to the braking distance S ₁ And a braking distance S ₂ Are equal, therefore, the area α ₁ And area alpha ₂ Are equal.

In fig. 5, the velocity V at the reference time point B is shown _B Exceeding a speed threshold V _lim The case (1). In this example, the velocity V _B Value of (3) to speed threshold value V _lim Is larger than the speed difference av.

Speed threshold V _lim Is a braking distance S ₁ Andbraking distance S ₂ The same time refers to the speed at time B. Therefore, in the region above the one-dot chain line in fig. 5, the area of the portion where the velocity waveform of the solid line is larger than the velocity waveform of the broken line is equal to the area of the portion where the velocity waveform of the broken line is larger than the velocity waveform of the solid line. Thus, the area α ₁ Specific area alpha ₂ The area below the one-dot chain line is increased. Thus, the braking distance S ₁ Specific braking distance S ₂ Is large.

Likewise, the velocity V at the reference point B _B Below a speed threshold V _lim In case (not shown), area α ₁ Specific area alpha ₂ Is small. Thus, the braking distance S ₁ Specific braking distance S ₂ Is small.

The brake control section 17 controls the brake based on the speed V at the reference time point B _B And a speed threshold V _lim Can control the brake 8 so that the car 3 can be braked by the braking distance S ₁ And a braking distance S ₂ The shorter braking distance in between stops. The brake control unit 17 may set any time point from a point a at which the emergency stop starts to a point B at which the main rope 5 starts to slide as a reference time point. In this case, the brake control section 17 may control the brake 8 so that the car 3 stops at a short braking distance by switching the control method based on the comparison result between the speed threshold value similarly set with respect to the reference time point and the speed at the reference time point.

Next, an example of the operation of the elevator 1 will be described with reference to fig. 6.

Fig. 6 is a flowchart showing an example of the operation of the elevator 1 according to embodiment 1.

Fig. 6 shows an example of the operation of the brake control unit 17 related to the emergency stop.

In step S1, when the emergency stop is started, the brake control unit 17 controls the brake 8 to brake according to the braking force control method. Then, the operation of the elevator 1 proceeds to step S2.

In step S2, the brake control unit 17 determines whether or not the slip detection unit 16 detects a slip based on the presence or absence of the detection signal or the like. If the determination result is yes, the operation of the elevator 1 proceeds to step S3. If the determination result is no, the operation of the elevator 1 proceeds to step S6.

In step S3, the brake control unit 17 detects the speed V at the reference time B with the time when the slip starts being set as the reference time _B . Then, the operation of the elevator 1 proceeds to step S4.

In step S4, the brake control unit 17 determines the speed V _B Whether or not the speed threshold V is exceeded _lim . If the determination result is yes, the operation of the elevator 1 proceeds to step S5. If the determination result is no, the operation of the elevator 1 proceeds to step S6.

In step S5, the brake control unit 17 controls the brake of the brake 8 according to the slip elimination control method. Then, the operation of the elevator 1 proceeds to step S2.

In step S6, the brake control unit 17 controls the braking of the brake 8 according to the braking force control method. Then, the operation of the elevator 1 proceeds to step S7.

In step S7, the brake control unit 17 determines whether the car 3 is stopped. If the determination result is negative, the operation of the elevator 1 proceeds to step S2. If the determination result is yes, the operation of the elevator 1 for emergency stop is ended.

The slip detection unit 16 may detect the presence or absence of slip of the main rope 5 from a change in apparent inertial mass of the sheave 13 as follows. When there is no slippage of the main ropes 5, the apparent inertial mass of the sheave 13 is an inertial mass obtained by adding the inertial mass of the sheave 13 itself to the inertial mass of the car 3 and the counterweight 6. On the other hand, when there is a slip of the main ropes 5, the apparent inertial mass of the sheave 13 is only the inertial mass of the sheave 13 itself. Therefore, even when the torque applied to the sheave 13 and the braking force applied to the sheave 13 by the brake 8 are the same, the deceleration of the sheave 13 changes depending on the presence or absence of slip. Since the deceleration of the sheave 13 increases when the main ropes 5 slip, the slip detection unit 16 may detect the occurrence of slip when the deceleration of the sheave 13 exceeds a predetermined threshold value. Here, the slip detector 16 may calculate the deceleration of the sheave 13 based on the speed of the sheave 13 detected by the sheave speed detector 9, for example. Further, the slide detection unit 16 may perform slide detection using the following information: acceleration of deceleration or acceleration of the sheave 13 or the car 3 based on speed information of at least one of the speeds detected by the sheave speed detecting unit 9 and the car speed detecting unit 10; and a deceleration command value of the braking force control system. The slip detection unit 16 may perform the slip elimination detection based on the following information: acceleration of deceleration or acceleration of the sheave 13 or the car 3 based on speed information of at least one of the speeds detected by the sheave speed detecting unit 9 and the car speed detecting unit 10; and the control state of the brake 8. The slip detector 16 may be combined with various means for detecting the presence or absence of slip of the main rope 5.

In the present disclosure, the case where the speed of the car 3 increases with respect to the traveling direction due to the unbalanced torque of the car 3 and the counter weight 6 is described as an example, but the present disclosure can be applied even in the case of deceleration. In the case of deceleration, although the speeds of the sheave 13 and the car 3 immediately before the deceleration start are not the maximum speed, they are referred to as the maximum speed for convenience in the present disclosure.

As described above, the elevator 1 according to embodiment 1 includes the brake 8, the slip detection unit 16, the car speed detection unit 10, and the brake control unit 17. The main rope 5 suspending the car 3 from the elevator shaft 2 is wound around the sheave 13 of the hoist 4. The hoist 4 raises and lowers the car 3 in the hoistway 2. The brake 8 brakes the sheave 13 in the hoist 4. The slip detector 16 detects whether the main rope 5 slips with respect to the sheave 13. The car speed detecting unit 10 detects the speed of the car 3. When the occurrence of a slip is detected by the slip detection section 16 at the time of an emergency stop, the brake control section 17 compares the speed of the car 3 detected by the car speed detection section 10 at the reference time point with a preset speed threshold value. The reference time is a preset arbitrary time during a period from the start of the emergency stop to the start of the slip.

The elevator 1 according to embodiment 1 may be provided with both the car speed detection unit 10 and the sheave speed detection unit 9, or may be provided with the sheave speed detection unit 9 instead of the car speed detection unit 10. The sheave speed detecting section 9 detects the speed of the sheave 13. At this time, when the slip detection unit 16 detects the occurrence of a slip at the time of an emergency stop, the brake control unit 17 compares the speed of the car 3 detected by the car speed detection unit 10 or the speed of the sheave 13 detected by the sheave speed detection unit 9 at the reference time point with a preset speed threshold value.

When the speed at the reference time point of comparison exceeds the speed threshold value, the brake control unit 17 controls the brake 8 according to the slip elimination control method. The slip cancellation control method is a control method for canceling the slip between the sheave 13 and the main rope 5. On the other hand, when the speed at the reference time point of comparison does not exceed the speed threshold value, the brake control unit 17 controls the brake 8 according to the braking force control method. The braking force control method is a control method of controlling the braking force so as to decelerate the sheave 13 at a set deceleration.

According to this configuration, the control method of the brake 8 after the main ropes 5 start sliding is selected so that the braking distance of the car 3 becomes shorter in accordance with the situation such as the speed of the car 3 or the sheave 13 at the reference time point in the period from the emergency stop to the start of sliding. Therefore, even when the speed of the car 3 increases due to the delay time of the operation of the brake 8, the delay time of the slide detection, or the like, the braking distance of the car 3 at the time of the emergency stop can be suppressed. Further, since the control method is selected based on the speed at the reference time point before the start of the slip, the brake control unit 17 can quickly perform the control of the brake 8 according to the selected control method after the occurrence of the slip is detected.

Here, when the relative speed of the main ropes 5 and the sheave 13 increases, the friction between the main ropes 5 and the sheave 13 when the main ropes 5 slip decreases. Therefore, even when the braking force control method is continuously maintained after the occurrence of the slip is detected, the deceleration of the car 3 varies until the car 3 stops. From the start of sliding to the stop of the sheave 13During the period until that time, the absolute value of the deceleration of the car 3 gradually decreases from the deceleration at the start of sliding. Then, after the sheave 13 is stopped, the relative speed decreases, and therefore the deceleration of the car 3 gradually increases. Then, at the latest until the car 3 stops, the absolute value of the deceleration of the car 3 becomes smaller to the deceleration at the time of starting the sliding. Therefore, the velocity waveform in which the fluctuation of the deceleration of the car 3 is considered is a waveform above the velocity waveform in fig. 2 or the like in which the deceleration at the time of starting the sliding is maintained and the constant deceleration is performed. Therefore, the braking distance S calculated by the equation (1) ₁ The braking distance is calculated under the minimum condition when the control of the brake 8 by the slip elimination control method is not performed. The brake control unit 17 is set at the braking distance S ₂ Below the braking distance S ₁ Since the brake 8 is controlled by the slip cancellation control method, the braking distance of the car 3 is not increased by switching the control method.

The brake control unit 17 sets the time point at which the main rope 5 starts to slide as a reference time point. Thereby, due to the braking distance S ₁ And a braking distance S ₂ The influence of the braking distance before the time point of starting the slip is eliminated in the evaluation of (2), and therefore, the speed threshold value V _lim Without being affected by the movement of the car 3 before the main rope 5 actually starts to slide. Therefore, even when the main rope 5 does not start to slip immediately after the brake 8 starts to apply the braking force to the sheave 13, the speed threshold V is easily performed _lim Is calculated and is compared with a speed threshold value V _lim Comparison of (d), etc.

The brake control unit 17 sets the time of the start of the emergency stop as a reference time. Thus, the reference time and the speed threshold value can be compared before the main rope 5 starts to slip, and therefore, the brake control unit 17 can control the brake 8 more quickly according to the selected control method after the occurrence of the slip is detected.

The brake control unit 17 controls the brake 8 according to the braking force control method before the slip detection unit 16 detects the occurrence of the slip at the time of the emergency stop. When the slip detection unit 16 detects the elimination of the slip, the brake control unit 17 controls the brake 8 according to the braking force control method. Thus, when the main ropes 5 do not slip, the car 3 can be decelerated at a large deceleration such as a set deceleration. Thus, the braking distance of the car 3 becomes shorter.

The brake control unit 17 estimates the braking distance S ₁ And an estimated value S of the braking distance ₂ The speed of the car 3 or the sheave 13 at the same reference time point is set as the speed threshold V _lim The slip cancellation control method and the braking force control method are switched. Braking distance S ₁ Is an estimated value of the braking distance of the car 3 when the slide detecting section 16 detects the occurrence of the slide and controls the brake 8 according to the braking force control method. Braking distance S ₂ Is an estimated value of the braking distance of the car 3 when the brake 8 is controlled according to the slip cancel control method when the slip detection section 16 detects the occurrence of the slip. Thus, due to the speed threshold V _lim Estimated value S based on braking distance ₁ And an estimated value S of the braking distance ₂ The braking distance of the car 3 at the time of emergency stop can be more reliably suppressed because of the setting.

In addition, the speed threshold V _lim Based on a predicted value a including deceleration _rope And a predicted value of acceleration _tr And the set deceleration, the predicted value of the delay time for detecting the presence or absence of a slip by the slip detection unit 16, and the predicted value of the delay time for a state transition of the brake 8. Predicted value a _rope The predicted value is the deceleration of the car 3 when the slip detection unit 16 detects the occurrence of a slip and controls the brake 8 according to the braking force control method. Predicted value a _tr The predicted value of the acceleration of the car 3 is obtained when the brake 8 is controlled according to the slip cancel control method when the slip of the main ropes 5 with respect to the sheave 13 is canceled. The predicted value of the delay time of the detection and the predicted value of the delay time of the state transition are included in the predicted value T of the delay time ₁ 、T ₂ And T ₃ And the like. Thus, the speed threshold V _lim The calculation can be performed before the slip detection based on known information or the like. Thus, the brake control section 17 is detectingAfter the occurrence of a slip is detected, the control of the brake 8 can be performed more quickly according to the selected control mode.

The brake control unit 17 may control the braking force of the brake 8 so that the brake 8 does not transition from the braking state to the released state in the slip elimination control method. Thus, since there is no time for the state transition of the brake 8, the braking delay time of the brake 8 becomes short. Therefore, the time during which the speed of the car 3 increases immediately after the traction is resumed can be suppressed.

In addition, the brake control unit 17 compares the absolute value with the 1 st deceleration a ₁ Small and absolute value ratio 2 nd deceleration a ₂ The brake 8 is controlled as a set deceleration by a large deceleration. 1 st deceleration a ₁ The deceleration, which is the upper limit of the slippage of the main rope 5 with respect to the sheave 13, is calculated in advance from the predicted value of the traction capacity of the hoisting machine 4, and is the deceleration of the car 3. 2 nd deceleration a ₂ Is the deceleration of the car 3 calculated in advance as the lower limit deceleration at which the safety switch 11 provided in the ascending/descending path 2 is not operated. This can suppress the occurrence of slippage of the main rope 5 and the occurrence of trapping due to the operation of the safety switch 11.

In addition, a part or all of the slip detection unit 16 and the brake control unit 17 may be mounted on a device external to the control device 12.

Next, an example of the hardware configuration of the elevator 1 will be described with reference to fig. 7.

Fig. 7 is a hardware configuration diagram of a main part of an elevator 1 according to embodiment 1.

The functions of the elevator 1 can be implemented by means of a processing circuit. The processing circuit is provided with at least 1 processor 100a and at least 1 memory 100b. The processing circuit may include both the processor 100a and the memory 100b and at least 1 dedicated hardware 200, or may include at least 1 dedicated hardware 200 as an alternative configuration to the processor 100a and the memory 100b.

When the processing circuit includes the processor 100a and the memory 100b, each function of the elevator 1 is realized by software, firmware, or a combination of software and firmware. At least one of the software and the firmware is described as a program. The program is stored in the memory 100b. The processor 100a realizes each function of the elevator 1 by reading and executing the program stored in the memory 100b.

The processor 100a is also called a CPU (Central Processing Unit), a Processing device, a calculation device, a microprocessor, a microcomputer, or a DSP. The memory 100b is constituted by a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM.

Where the processing circuit includes dedicated hardware 200, the processing circuit may be implemented, for example, by a single circuit, a complex circuit, a programmed processor, a parallelized programmed processor, an ASIC, an FPGA, or a combination thereof.

The functions of the elevator 1 can be implemented separately by means of a processing circuit. Alternatively, the functions of the elevator 1 can be realized centrally by the processing circuit. The functions of the elevator 1 may be partially implemented by dedicated hardware 200 and partially implemented by software or firmware. In this way the processing circuit realizes the functions of the elevator 1 by means of dedicated hardware 200, software, firmware or a combination thereof.

Embodiment 2.

In embodiment 2, a description will be given in detail about a point different from the example disclosed in embodiment 1. As for the features not described in embodiment 2, any features of the example disclosed in embodiment 1 can be adopted.

Fig. 8 is a structural diagram of an elevator 1 according to embodiment 2.

The elevator 1 includes a load detection unit 18. The load detection unit 18 is a portion that detects a load inside the car 3. The load detection unit 18 is provided, for example, at a lower portion of the car 3 or at an end portion of the main rope 5 attached to the car 3. The load detection unit 18 is used to compensate for unbalanced torque that varies depending on the load of the car 3, detect overload of the car 3, and the like, for example, in a normal state.

The control device 12 includes a direction detection unit 19. The direction detection unit 19 is a portion that detects the traveling direction of the ascending or descending car 3. The direction detection unit 19 determines the rising or falling based on, for example, the sign of the speed detected by the sheave speed detection unit 9 or the car speed detection unit 10. In this example, the brake control unit 17 controls the brake 8 with reference to the time when the sliding starts.

The load of the car 3 has an influence on the torque applied to the sheave 13 via the main rope 5. In addition, the direction in which the brake torque is applied varies depending on the traveling direction of the car 3. Therefore, the condition that the main ropes 5 do not slip varies depending on the load of the car 3 and the traveling direction. Thereby, the maximum deceleration at which the main ropes 5 start to slide varies depending on the load of the car 3 and the traveling direction. The condition that the main ropes 5 do not slip is expressed by the following equation (5).

Here, Γ represents a traction coefficient. exp denotes an exponential function. k represents a groove coefficient of the sheave 13. The groove coefficient is a coefficient determined according to the shape of the rope groove of the sheave 13 or the like. μ is a friction coefficient between the main rope 5 and the sheave 13. The product k μ of the groove coefficient k and the friction coefficient μ represents an apparent friction coefficient between the main rope 5 and the sheave 13.θ represents a wrap angle of the main rope 5 to the sheave 13. Ten1 represents the tension on the car 3 side viewed from the sheave 13. Ten2 represents the tension on the side of the counter weight 6 viewed from the sheave 13. The main rope 5 slips when the right tension ratio of equation (5) exceeds the traction coefficient Γ.

The equation of motion about the rotation axis of the sheave 13 when the main rope 5 does not slip is expressed by the following equation (6).

Here, M _tm Representing an equivalent mass equivalent to the inertia of the sheave 13. a is _tm Indicating the deceleration of the sheave 13. F _BK The force obtained by converting the brake torque into a force in the rotation direction of the sheave 13 is shown. Force F _BK Is set to be in the car3 is negative when it rises and positive when the car 3 descends.

Since the condition that the main rope 5 just starts sliding is that the tension ratio is equal to the traction coefficient in equation (5), the deceleration a at the time of starting sliding can be calculated by applying the tension satisfying the condition to equation (6) _tm . Here, the values of the tension Ten1 and the tension Ten2 can be calculated in accordance with the pulling using, for example, the masses of the hoist 4, the counterweight 6, and the ropes, the inertial mass and the mass of the pulleys, and the like. Here, the ropes include, for example, the main rope 5, the compensating rope, the control cable, the governor rope 14, and the like. The pulley types include, for example, a deflector pulley, a return pulley, and a compensation pulley.

The brake control unit 17 calculates a deceleration at the time of starting sliding corresponding to the load of the car 3 and the traveling direction of the car 3. The brake control unit 17 calculates the speed threshold V using the deceleration by, for example, the same calculation method as in embodiment 1 _lim . The brake control unit 17 calculates the speed threshold V based on the calculated speed _lim The brake control at the time of emergency stop is performed. Thus, the braking distance can be further shortened by selecting a control method according to the load condition.

The brake control unit 17 may calculate the speed threshold V and update the speed threshold V each time the load and the traveling direction of the car 3 change _lim . Alternatively, the brake control unit 17 may refer to the speed threshold V calculated in advance for each load and each traveling direction of the car 3 _lim Update the speed threshold value V _lim 。

As described above, the elevator 1 according to embodiment 2 includes the direction detection unit 19 and the load detection unit 18. The direction detection unit 19 detects the traveling direction of the car 3. The load detection unit 18 detects the load inside the car 3. Speed threshold V _lim Based on information including the traveling direction of the car 3 detected by the direction detecting section 19 and the load of the car 3 detected by the load detecting section 18.

According to this configuration, the speed threshold V is set in accordance with the operation conditions such as the load and the traveling direction of the car 3 _lim . Thereby, the control method of the brake 8 in which the braking distance of the car 3 becomes shorter is selected in accordance with the operating conditions.

In addition, the speed threshold V _lim The calculation may be performed based on information including only one of the traveling direction of the car 3 detected by the direction detecting unit 19 and the load of the car 3 detected by the load detecting unit 18. The detected value in the traveling direction of the car 3 is not included in the calculated speed threshold V _lim When the information is, the speed threshold value V _lim The calculation may be performed based on a traveling direction of the car 3 for evaluation set in advance. The detected value of the load on the car 3 is not included in the calculated speed threshold V _lim When the information is, the speed threshold value V _lim The load of the car 3 for evaluation may be calculated based on a load set in advance.

Industrial applicability

The elevator related to the present disclosure can be applied to a building having a plurality of floors.

Description of the reference numerals

1 elevator, 2 lifting roads, 3 cars, 4 winches, 5 main ropes, 6 balancing weights, 7 speed regulators, 8 brakes, 9 rope wheel speed detection parts, 10 car speed detection parts, 11 safety switches, 12 control devices, 13 rope wheels, 14 speed regulator ropes, 15 speed regulator pulleys, 16 sliding detection parts, 17 brake control parts, 18 load detection parts, 19 direction detection parts, 100a processors, 100b memories and 200 special hardware.

Claims

1. An elevator, wherein the elevator is provided with a cage,

the elevator comprises:

a brake for braking a sheave around which a main rope is wound in a hoisting machine for hoisting and lowering a car in an elevator shaft, the main rope suspending the car from the elevator shaft;

a slip detection unit that detects whether the main rope slips with respect to the sheave;

a sheave speed detecting unit that detects a speed of the sheave; and

and a brake control unit that, when the slip detection unit detects the occurrence of a slip at an emergency stop, compares a speed of the sheave detected by the sheave speed detection unit at a predetermined reference time point between the start of the emergency stop and the start of the slip with a predetermined speed threshold value, and controls the brake in accordance with a slip cancellation control method that cancels the slip between the sheave and the main rope when the speed at the reference time point exceeds the speed threshold value, and controls the brake in accordance with a braking force control method that controls a braking force of the brake so that the sheave decelerates at a set deceleration when the speed at the reference time point does not exceed the speed threshold value.

2. The elevator according to claim 1, wherein,

the brake control unit switches the slip cancellation control method and the braking force control method using, as the speed threshold, a speed of the sheave at a reference time point at which an estimated value of a braking distance of the car when the slip detection unit detects the occurrence of the slip and controls the brake according to the braking force control method is equal to an estimated value of a braking distance of the car when the slip detection unit detects the occurrence of the slip and controls the brake according to the slip cancellation control method.

3. An elevator, wherein the elevator is provided with a cage,

the elevator comprises:

a brake for braking a sheave around which a main rope is wound in a hoist for raising and lowering a car in an elevator shaft, the main rope suspending the car in the elevator shaft;

a car speed detection unit that detects a speed of the car;

a sheave speed detecting unit that detects a speed of the sheave; and

and a brake control unit that, when the slip detection unit detects the occurrence of a slip at an emergency stop, compares a speed of the car detected by the car speed detection unit at an arbitrary reference time point set in advance during a period from the start of the emergency stop to the start of the slip with a speed threshold set in advance, and controls the brake in accordance with a slip elimination control method that eliminates the slip between the sheave and the main rope when the speed at the reference time point exceeds the speed threshold, and controls the brake in accordance with a braking force control method that controls a braking force of the brake so that the sheave is decelerated at a set deceleration when the speed at the reference time point does not exceed the speed threshold.

4. The elevator of claim 3, wherein,

the brake control unit switches the slip cancellation control method and the braking force control method using, as the speed threshold, a speed of the car at a reference time point at which an estimated value of a braking distance of the car when the brake is controlled according to the braking force control method when the slip detection unit detects the occurrence of the slip, and an estimated value of a braking distance of the car when the brake is controlled according to the slip cancellation control method when the slip detection unit detects the occurrence of the slip.

5. The elevator according to any one of claims 1 to 4,

in the brake control unit, the reference time is set in advance as a time when the main rope starts to slide.

6. The elevator according to claim 1 to 4,

in the brake control unit, the reference time is set in advance as a time when the emergency stop starts.

7. The elevator according to any one of claims 1 to 6,

the brake control unit controls the brake according to the braking force control method before the slip detection unit detects the occurrence of the slip at the time of the emergency stop.

8. The elevator according to any one of claims 1 to 7,

when the slip detection unit detects the elimination of the slip, the brake control unit controls the brake according to the braking force control method.

9. The elevator according to any one of claims 1 to 4,

the brake control unit switches the slip cancellation control method and the braking force control method based on the speed threshold calculated based on information including:

a predicted value of an idling acceleration of the car due to the unbalanced torque;

the reference time point;

a predicted value of deceleration of the car when the brake control unit does not switch the control mode of the brake and the main rope decelerates while sliding relative to the sheave when the slip detection unit detects the occurrence of a slip;

a predicted value of acceleration of the car when the brake is controlled according to the slippage control method when slippage of the main rope with respect to the sheave is eliminated;

a set deceleration in the braking force control mode;

a predicted value of delay time for detecting whether or not the slide is present in the slide detection unit; and

a predicted value of the delay time of the state transition of the brake.

10. The elevator of claim 9, wherein,

the elevator is provided with a direction detection part for detecting the running direction of the elevator car,

the brake control unit switches the slip elimination control method and the braking force control method based on the speed threshold calculated based on information including the traveling direction of the car detected by the direction detection unit.

11. The elevator of claim 9 or 10, wherein,

the elevator is provided with a load detection part for detecting the load in the elevator car,

the brake control unit switches the slip elimination control method and the braking force control method based on the speed threshold calculated based on information including the load of the car detected by the load detection unit.

12. The elevator according to any one of claims 1 to 11,

the brake control unit controls the braking force of the brake so that the brake does not transition from a braking state to a released state in the slip elimination control system.

13. The elevator according to claim 1 to 12,

the brake control unit controls the brake by using, as the set deceleration, a deceleration having an absolute value smaller than a 1 st deceleration and a larger absolute value than a 2 nd deceleration, the 1 st deceleration being a deceleration of an upper limit at which slippage of the main rope with respect to the sheave does not occur and being calculated in advance from a predicted value of a traction capacity of the hoisting machine, and the 2 nd deceleration being a deceleration of a lower limit at which a safety switch provided in the elevator shaft is not operated.