FI120302B - Arrangement and procedure in a lift without counterweight - Google Patents

Description

The present invention relates to an arrangement for braking an elevator car as defined in the preamble of claim 1, a brake power supply circuit as defined in the preamble of claim 5 and a method for braking an elevator car as defined in the preamble of claim 9.

Quite commonly, the machine brake is mechanically engaged with the rotating part of the elevator machine as an elevator car brake device. When the elevator car is braked, for example, in an emergency stop by a mechanical brake, the power supply circuit of the brake control coil is cut off, for example, by a relay or a contactor. When the brake power supply is interrupted, the brake releases 15, whereupon the brake shoe engages mechanically with the rotating part of the machine and begins to brake the movement of the elevator machine and thus the elevator car. The release of the brake is effected by the release delay, which is determined by the electrical parameters of the brake and any damping circuit, such as the inductance and resistance of the brake, 20 and the impedance of the damping circuit, if any. When the brake is released, the movement of the elevator car begins to decelerate with the deceleration determined by the mechanical engagement of the brake shoe.

• t · · · ·: · The brake release delay has traditionally been minimized: 1 · 25 · in emergency stop, to achieve the shortest possible operating time • · · 2 '·.

• · ··· • · · · · · ·. ···. JP 2003081543 discloses elevator brake control, where the brake is controlled in the emergency stop of the elevator with a shorter ... 30 release delay than in normal stop.

In order to overcome the above problems and improve the braking function of the counterweight: the invention is the invention of a novel type of counterweightless lift brake control. In the invention ···. ·. 35 also illustrates a controlled brake power supply circuit.

The brake control according to the invention is intended to provide a safer and more comfortable user experience for the elevator passenger, especially in the emergency stop of the elevator. The control of the brake 40 is also intended to reduce the noise caused by the operation of the brake 2.

The arrangement for braking the elevator car according to the invention is characterized in what is set forth in the characterizing part of claim 15. The brake power supply circuit according to the invention is characterized in what is stated in the characterizing part of claim 7. The method of braking the elevator car according to the invention is characterized by what is disclosed in the characterizing part of claim 9. Other embodiments of the invention are characterized by what is set forth in the other claims. Inventive embodiments are also disclosed in the specification of this application. The inventive content 15 of the application may also be defined otherwise than as set forth in the claims below. The inventive content may also consist of several separate inventions, especially if the invention is considered in the light of its expressions or implicit subtasks or in terms of the benefits or classes of benefits achieved. In this case, some of the attributes contained in the following claims may be · · ·: · * out of the scope of discrete inventive ideas • »♦ *. * *. For example, the • · ·. * ·· counterweight elevator system shown in Fig. 1 may be fitted with a safety circuit according to Fig. 2 and / or Fig. 3: Y: brake power supply circuit.

• · · · · · · · · · ·

In the present invention, an unweighted elevator system refers to an elevator system which does not include * * · 30 counterweights that have traditionally set the elevator load equilibrium state. In one such non-weighted elevator system according to the invention, the elevator car • · · is moved by a linear motor, whereby, for example, the rotor may be attached to the elevator car. On the other hand, in the • · · 35 counterweightless elevator system according to the invention, the elevator car can also be moved via elevator ropes connected to the rotating drive wheel of the elevator machine. In this case, the counterweightless elevator system may be similar to a roller elevator, and the · · 3 counterweightless elevator system may also be similar to, for example, WO 2005/049470 A2. The elevator machine according to the invention may be located, for example, in an elevator shaft, an engine room or, for example, in connection with an elevator car 5.

One controllable brake according to the invention is a mechanical brake.

One controllable brake of the invention is a guide brake engaging between the elevator car and the guide of the elevator car.

In one embodiment of the invention, two controllable elevator brakes are fitted to the elevator machine.

The brake of the invention may be, for example, a drum brake or a disc brake.

In one embodiment of the invention, the elevator system is provided with an electronic control unit which is adapted to read the security sensors and the safety .. of the elevator system. based on information read from the sensors to control the brake.

Said elevator system safety sensors include, for example, • · · * · '* level door safety switches, elevator shaft end limit switches, and • · speed limiter safety switch. The electronic control unit ··· * ... · 25 can then be arranged in a redundant state, whereby the control is: duplicated, for example, by two microcontrollers monitoring each other's operating conditions.

· · ·

In one embodiment of the invention, the brake power supply circuit • · ·. ···. 30 controllable switches are arranged in connection with the elevator safety circuit • · Ί '.

• · · · · · · · · ·

The controllable switches according to the invention may be mechanical switches, for example relays and contactors, and they may · · ·. ···. 35 · solid state switches, such as igbt, mosfet, thyristors and bipolar transistors.

4

In the present invention, the control terminal refers to the input of the control signal of the controlled switch. Such a control terminal is, for example, a coil of a relay or a contactor, or a gate of a thyristor, an igbt transistor or a mosfet -5 transistor, or the base of a bipolar transistor.

In the invention, elevator machinery refers to a combination of an elevator motor and machining mechanics fitted thereto. 10 The said mechanics include, for example, a drive wheel.

The machining mechanics may also comprise, for example, a machining brake. The elevator machine can also be geared.

In one embodiment of the invention, the brake release delay is selected from at least two different release delays based on the movement direction of the elevator car only when the absolute value of the elevator car velocity deviates more than a specified threshold and the brake release delay is otherwise

The invention achieves, among other things, at least one of the following advantages: · · · · · * · The brake release delay is usually modified by directly or indirectly to the voltage between the • • control coil hubs.

• · · The voltage between the control coil terminals is then increased to shorten the release delay. In this case also the emission movement; * · *; brake magnetic circuit is faster, which may. · **. 30 increases the noise from releasing the brake. When the release delay of the · · · \ brake according to the invention is selected to be longer in a given control situation, the release of the brake ··· • · may occur at a lower control voltage: Y; and distracting sound from brake release • ·. * ··. 35 decreases. This effectively reduces noise, especially in ·· «modern, machine-room-less elevator systems where the elevator drive as well as the elevator drive brakes and brake control are located in the elevator shaft.

5 - When an emergency stop is performed when the elevator car is moving upwards, the power supply to the elevator machine is also cut off during brake control. After disconnecting the power supply, the elevator car speed begins to slow down due to an imbalance in the load of the elevator car 5. In this case, increasing the brake release delay causes the elevator car speed to decelerate at the moment of brake actuation, and the braking time after the actuation moment is also shortened. In this case, the danger posed to the passenger by the upward movement of the elevator car 10 during an emergency stop is reduced. The emergency stop experience is also not as unpleasant as using a shorter release delay to control the brake.

15 - Especially with fast lifts, the speed of the elevator car when the emergency stop is started is remarkable, and the solution according to the invention can improve safety and comfort during emergency stop of the fast lift.

20 - Using a longer release delay for brake control can reduce the voltage on the brake control coil. This will also reduce the tension in the brake power supply circuit • · · # * t. and • · ·! .. * damping circuit possibly connected to the brake coil. The damping circuit often uses • · **** 25 components with a service life commensurate with the durability of the high-tension steel germination. Such components are, for example, various resistors, varistors and zener diodes ··· V · - When the lift car speed has decreased after the brake has been applied, the brake will also decrease. . ·. braking distance after switching on. Then · · ·, ···. the heat generated by the brake due to friction of the brake is reduced.

• ·

In addition, brake pad wear is also reduced.

The invention will now be described in more detail by way of non-limiting embodiments of the invention per se and with reference to the accompanying drawings, in which: FIG. 1 illustrates an iron unbalanced elevator system of the invention, FIG. 3 shows an electrical power supply circuit of the brake according to the invention, Fig. 4 shows the electrical parameters of the brake control coil in a brake control situation according to the invention, 10 Fig. 5 shows an upward movement of the elevator car

Fig. 1 shows a counterweight elevator system fitted with an arrangement according to the invention for braking the elevator car. The elevator car 1 is moved within the elevator shaft 22 by ropes connected to the drive wheel of the elevator motor 8. Power is supplied to the elevator motor 8 from the mains 10 by a frequency converter 9. The safety of the elevator system 20 is monitored by means of a safety circuit. For safety switching ... includes safety sensors located in • • · · e · · * objects important to the safety of the elevator system. Sensors are • · · '·' * located, for example, near level doors, near the elevator shaft • · *. **: and speed limiter.

··· ϊ.,. Ϊ 25 As part of the safety system for the elevator system, an electronic safety device 3 is read which reads the measurement information in the safety • ·: ***; based on the information read from sensors 20, and safety sensors, · · · controls the rotating part of the elevator machine with a mechanically engaged, duplicated brake 2, 2 '. The brake is then applied • · ·. ···. 30 elevator motor drive wheel integrated brake disc.

«· ♦ ··

The electronic safety device 3 reads the measurement data from the safety sensors ···: ... · 20 while driving the lift. On the basis of the information read, the electronic safety device determines the operating status of the elevator system, and • · · 35 performs an emergency stop if necessary. In this case, the electronic safety device controls a switch arrangement 6 for interrupting the power supply to the elevator motor. The electronic safety device then also controls the elevator machine brake 2, 2 'by transmitting a control signal 21 according to the control request to at least one of the controllable switches of the brake power supply circuit 12 to disable the power supply of the brake control circuit 12.

5 Electronic safety device 3 controls brake 2, 2 'with release delay. The release delay then includes, in addition to the delay due to the brake power supply circuit and the brake mechanics, a separate delay defined by the electronic safety device which may vary in length and may be reduced to zero. The electronic safety device 3 selects the brake control with an additional release delay from among at least two release delays of 4.5 different lengths.

The release delay 4.5 to be used is selected based on the movement direction of the elevator car 15. The electronic safety device 3 determines the direction of movement of the elevator car from a signal indicating movement of the elevator machine, such as a tachometer or encoder signal connected to the elevator machine, or from the source voltage of the elevator motor.

The electronic safety device 3 controls the brake 2,2 'with the first 20 shorter release delays 4 when the car 1 ... the movement direction is downward, and the second longer • · · • · *., * release delay 5 when the movement direction of the elevator car 1 is • · · *; ''.

The magnitude of said release delay 4.5 may vary. The release delay • · can then be determined, for example, based on the speed of the elevator car and / or the nominal speed of the elevator, whereby said second release delay 5 can be extended as the speed and / or rated speed of the elevator car increases.

. -. Fig. 5 shows the velocity v of the elevator car 1 when traveling in a emergency stop according to the invention.

· · ·

At time tto, the contactors 6 of the elevator motor power supply circuit are controlled to disconnect the elevator motor power supply.

• ·. ···. 35 After the opening delay 7, the contactors open and the power supply to the motor · · stops. The elevator car starts to slow down due to an unbalanced load on the elevator system, whereupon the elevator car is braked by gravity. After a specified release delay 5 of the brake control 8, the brake 2, 2 'engages to brake the movement of the elevator car, thereby increasing the deceleration of the elevator car. Since the elevator car speed v has already begun to decrease during the release delay of the braking control 5, the braking distance of the braking with 5 greater deceleration is reduced when compared to the situation where the activation of the brake 2,2 'would have occurred at the initial emergency stop speed.

Fig. 2 shows a safety circuit 19 of the elevator system 10 according to the invention, which has a series connection of elevator safety switches 20 which act as safety sensors. Serial connection of the safety switches is connected to the coil 6 of the main motor contactor and to the coil 25 of the relay 25 fitted to the brake power supply circuit. The hazard situation 15 is detected by the opening of at least one safety switch 20, whereby the power supply to the coil of the main contactor 6 and the relay 25 stops. In this case, the main contactor 6 opens, likewise the relay 25 opens, preventing the power supply via the power supply circuit 12 to the brake coil 11, whereby the brake is released based on the status of the safety switches 20.

20 ... Figure 3 illustrates a Jarmon power supply circuit 12 according to the invention. The power supply circuit comprises an alternating current circuit 13 and a direct current circuit 14 connected to each other by a rectifier bridge 15. The DC circuit Along with the control coil 11 of the 14 brake • · · 25, a damping circuit 16 is provided which here comprises a series connection of the diode and the varistor.

• ·; ***; The DC circuit has a first controllable switch 17 for controlling the brake • · · with a first shorter release delay 4. The AC circuit has a second controllable switch 18 for controlling a brake * · · '···' 30 with a second longer release delay 5. Said • · * 1 ' the switches here are relays. The relay control logic 24 is adapted as part of the elevator control electronics. The control logic can be implemented, for example, by discrete ie circuits or by software, such as a microcontroller.

• · • · ·

The control of the brake 2,2 'is effected by controlling the first 17 and second 18 controllable clutches of Figure 3 as follows: as the elevator car moves downward, the brake is controlled by a first shorter release delay 4. The clutch 17 is then released.

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The voltage across the damping circuit forms a control voltage for the coil 11 5, which causes the coil current to decrease rapidly. In Figure 4, the top graph shows the control voltage of the brake coil 11 and the second top graph shows the current of the brake coil 11 when controlling the brake with a first shorter release delay 4. The change in current 10 in Figure 4 results from the opening of the brake magnetic circuit. As the magnetic circuit opens, the reluctance of the magnetic circuit changes, and the change in reluctance induces a voltage in the brake coil 11, which causes said change in the current of coil 11.

15

As the elevator car moves upward, the brake is controlled by a second longer release delay 5. The first controllable clutch 17 is then held and the second controllable clutch 18 is opened, whereupon the current of the brake coil 11 begins to flow through the series connected diodes of the rectifier bridge 15. Then ... the control voltage of the brake coil 11 remains low because it is made up of • · · • · 'only the conductive state voltage of the rectifier bridge diodes.

In this case, also the current of the brake coil 11 decreases more slowly, and • · *. **: the brake release delay increases. In Figure 4, the second lowest graph • · · 25 shows the voltage of the control of the brake coil 11 and the lowest graph:: shows the current of the brake coil 11 when controlling the brake with another longer release delay ··· 5.

··· • · · · · ·, ···. The brake control illustrated in the embodiment of Fig. 3 may be adapted to start, for example, after the safety switch 20 • · · of the elevator described in the embodiment of Fig. 2 has been opened.

• · • · · · · · ·. ···. It will be apparent to one skilled in the art that various embodiments of the invention are not limited to the examples above, but may vary within the scope of the following claims.

Claims (10)

An arrangement for braking a lift basket (1) in a counterbalanced lift system, comprising an controllable brake (2, 2 ') with a control coil (11); wherein the brake control is arranged to take place via a power supply circuit (12) connected to the control coil; characterized in that the power supply circuit has an AC circuit (13) and a DC circuit (14) joined by a rectifier bridge (15), an attenuation circuit (16) arranged in the DC circuit (14) adjacent to the brake coil (11), provided with at least one first controllable electric coupler (17) which controls the brake with a first shorter release delay (4), and the alternating current circuit is provided with at least a second controllable electric coupler (18) which controls the brake with a second longer release delay (5); and that the brake is arranged to be controlled with a release delay selected according to the direction of movement of the lift basket (1). · · · · · · · · · · Arrangement according to claim 1, characterized in that the brake (2, 2 ') is arranged to be controlled with the first · ·: shorter unloading delay (4) as the elevator car moves down and with the second longer unloading delay (5). when the elevator car moves up. 3. Arrangement according to claim 1 or 2, characterized by • · ·. ···. because the arrangement comprises equipment that breaks the power supply to the lift motor (8), and that the power supply to the lift motor is broken when the brake is controlled with the release delay (4, 5 ). • · • · · • · · • ♦ Arrangement according to any of the preceding claims, characterized by the fact that the second unloading delay (5) is determined according to the speed of the lift basket (1). 5. Arrangement according to any of the preceding claims, characterized in that the elevator system comprises a safety clutch (3, 19) with safety sensors (20) and that the brake (2, 2 ') is controlled according to the status of the safety sensors (20). Arrangement according to any of the preceding claims, characterized in that the elevator system comprises a safety coupling (3) with safety sensors (20), the first (17) and the second (18) electric coupler provided with a control terminal for the control signal (21) of the safety coupling. , and that the first and second electrical couplers are controlled according to the measurement data of the safety sensors (20). 7. A power supply circuit (12) applied to a brake, with an AC circuit (13) and a DC circuit (14) joined by a rectifier bridge (15), characterized in that a damping circuit (16) is arranged in the DC circuit (14) in connection to the brake control coil (11), the direct current circuit is provided with at least one first controllable electrical coupler (17). which controls the brake with a first shorter release delay • · (4), and that the alternating current circuit is provided with at least one • · ·. second controllable switch (18) which controls the brake with a second • · ·. ···. longer unloading delay (5). 8. A power supply circuit according to claim 7, characterized in that the first (17) and the second (18) electric coupler control terminals are arranged to be connected to the serial switch (19) of the safety switches (19). • · • · • · ·. 9. Procedure for braking a lift basket (1) in one. counterbalanced lift system, in which method: Ml • · *. *. · - a controllable brake (2, 2 ') is provided in the lift system • The brake control (3, 19, 24) is arranged in connection with with the controllable brake the direction of movement of the elevator basket, the discharge delay for the control of the brake is determined from at least two different discharge delays (4, 5. on the basis of the direction of movement of the elevator basket the electric coupler in the direct current circuit is controlled so that the brake is controlled with the first shorter discharge delay electric switch second longer unloading delay. 10. A method according to claim 9, characterized in that the brake is controlled with the first shorter unloading delay (4) when the elevator car moves down, the brake is controlled with the second longer unloading delay (5) when the elevator car moves up. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·· · · · · · ··· ··· · · · · · ··· • · · · ··· • φ 1 2 3 • · · ··· ··· • · · · · · · · • · · • 1 f • · · · 2 • · • · 3