Safety protection system for failure of elevator brake

Abstract

The utility model discloses an elevator brake failure safety protection system which comprises a control cabinet, a traction machine and a brake which are all arranged in an elevator machine room at the top of an elevator shaft. An elevator control device, an operation contactor, a star sealing contactor, a brake operation power supply feedback contactor and a brake state switch are arranged in the control cabinet, a frequency converter is arranged in the elevator control device, and the frequency converter is connected with a traction machine through a normally open contact of the operation contactor; a normally closed point of the star sealing contactor is connected between the operation contactor and the traction machine, the traction machine is connected with the frequency converter through the encoder, and the traction machine and the brake are in transmission through a steel wire rope. The brake is connected with the elevator control device through a normally-closed point of the brake operation power supply feedback contactor and a normally-closed point of the brake state switch. The safety protection device plays a role in safety protection when the elevator brake fails.

Description

TECHNICAL FIELD

[0001] The utility model relates to elevator safety technical field, concretely relates to a kind of safety protection system of elevator brake failure. BACKGROUND

[0002] The protection of brake failure currently has brake force detection function, whether brake shoe friction meets requirements is detected automatically once a day, and the detection of opening and closing of brake. This is established in the state of abnormal brake of elevator normal operation logic. However, brake failure risk exists when brake operation logic is normal and abnormal. When elevator operation logic is normal, such as brake force automatic detection is normal on a certain day, but before brake force detection on the second day, brake shoe friction is reduced to below minimum critical point, at this time, elevator will slide even free fall, the only protection is safety tongs, system can only report encoder fault. When elevator operation logic is abnormal, such as brake power supply circuit problem, device damage, line non-human short circuit (rat bites cable skin) etc., although brake shoe friction is enough, but power supply circuit problem, brake shoe is opened, at this time, elevator will also slide even free fall, the only protection is also safety tongs, system can only report brake power supply fault, brake shoe state fault, encoder fault. System only cuts off power supply output to hoisting machine in the above two cases, reports frequency converter stop output, and the latter is handed over to safety tongs. But safety tongs alone obviously cannot guarantee, otherwise there would not be many accidents caused by brake failure in the industry. CONTENT OF UTILITY MODEL

[0003] The utility model aims at overcoming the insufficient of prior art, provide a kind of safety protection system of elevator brake failure, and its safety protection mechanism is before safety tongs, even scheme has no damage to mechanical related equipment.

[0004] The technical scheme of the utility model is as follows:

[0005] A kind of safety protection system of elevator brake failure, including control cabinet, hoisting machine and brake, the control cabinet, hoisting machine, brake are all arranged in the elevator machine room of elevator shaft top, elevator control device, running contactor, star contactor, brake running power supply feedback contactor and brake state switch are arranged in the control cabinet, frequency converter is equipped in the elevator control device, the hoisting machine is connected with frequency converter by the always open point of running contactor, the always closed point of star contactor is connected between running contactor and hoisting machine, the hoisting machine is connected with frequency converter by encoder, the hoisting machine and brake are driven by steel wire rope, the brake is connected with elevator control device by the always closed point of brake running power supply feedback contactor and the always closed point of brake state switch respectively.

[0006] Further, the system further comprises an emergency power supply, which is arranged in the elevator machine room and connected with the frequency converter of the elevator control device.

[0007] Further, the system further comprises an upper limit switch and a lower limit switch, which are arranged on the inner wall of the elevator shaft in an up-down manner.

[0008] Further, the system further comprises a car buffer and a counterweight buffer arranged at the bottom of the elevator shaft, wherein the car buffer is arranged corresponding to the elevator car, and the counterweight buffer is arranged corresponding to the elevator counterweight.

[0009] Compared with the prior art, the utility model has the beneficial effects that: the utility model constitutes elevator control device, frequency converter, emergency power supply, operation contactor, star contactor, traction machine, encoder, brake, brake operation power supply feedback contactor and brake state switch; when the elevator starts to operate, the star contactor works first, the contactor contact is disconnected, then the frequency converter outputs zero speed torque through the operation contactor, then outputs the brake power supply, the brake is opened, and the brake state switch feeds back the state that the brake is opened to the elevator control device; when the elevator is flat and stops, the frequency converter outputs zero speed torque through the operation contactor, then cancels the brake power supply, and the brake state switch feeds back the state that the brake is closed to the elevator control device. The above operation logic will stop operating immediately if any link state has a problem, and the frequency converter cancels the torque output through the operation contactor, so that the safety protection effect is realized when the elevator brake fails. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without creative labor for those skilled in the art.

[0011] Figure 1 The circuit structure schematic diagram of the safety protection system of the elevator brake failure provided by the utility model is shown in the figure.

[0012] Figure 2 The elevator car squat bottom state diagram of the safety protection system of the elevator brake failure provided by the utility model is shown in the figure.

[0013] Figure 3 The elevator car squat bottom state diagram of the safety protection system of the elevator brake failure provided by the utility model is shown in the figure.

[0014] Figure 4 The utility model provides a kind of safety protection system's logic method schematic diagram of elevator brake failure. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantage of the utility model more clearly, the utility model is further described in detail below with the drawings and examples.It should be understood that the specific examples described herein are only used to explain the utility model, and not to limit the utility model.

[0016] In order to explain the technical scheme described in the utility model, the following is described by specific examples.

[0017] EMBODIMENT

[0018] Please refer to Figures 1 to 3 The embodiment provides a kind of safety protection system of elevator brake failure, including control cabinet 1, traction machine 2, brake 3 and emergency power supply 4, control cabinet 1, traction machine 2, brake 3, emergency power supply 4 All be set in the elevator machine room 20 of elevator shaft 10 top, elevator control device 11, running contactor 12, star contactor 13, brake running power supply feedback contactor 14 and brake state switch 15 are provided in control cabinet 1, elevator control device 11 is equipped with frequency converter 111, frequency converter 111 is connected with traction machine 2 by the normally open point of running contactor 12, the normally closed point of star contactor 13 is connected between running contactor 12 and traction machine 2, traction machine 2 is connected with frequency converter 111 by encoder 21, traction machine 2 and brake 3 are driven by steel wire rope 5, brake 3 is connected with elevator control device 11 by the normally closed point of brake running power supply feedback contactor 14 and the normally closed point of brake state switch 15 respectively, emergency power supply 4 is connected with the frequency converter 111 of elevator control device 11.

[0019] Its operation logic is that when elevator starts running, star contactor 13 works first, contactor contact is disconnected, then frequency converter 111 outputs zero speed torque through running contactor 12, then outputs brake power, brake 3 opens, and brake state switch 15 feeds back the state that brake opens to elevator control device 11;When elevator is flat and stops, frequency converter 111 outputs zero speed torque through running contactor 12, then cancels brake power output, and brake state switch 15 feeds back the state that brake 3 closes to elevator control device 11.The above operation logic will immediately stop running when any link state has problem, and frequency converter 111 cancels torque output through running contactor 12 in priority, so that the effect of safety protection is realized when elevator brake fails.

[0020] The system further comprises an upper limit switch 6, a lower limit switch 7, a car buffer 8 and a counterweight buffer 9, the upper limit switch 6 and the lower limit switch 7 are arranged on the inner wall of the elevator shaft 10 in up and down directions, and the car buffer 8 and the counterweight buffer 9 are arranged at the bottom of the elevator shaft 10 and correspond to the elevator car 30 and the elevator counterweight 40 respectively.

[0021] The safety accident caused by brake failure mainly occurs when the elevator is ready to stop. Figure 4 As shown in the figure, when the stop operation logic of the elevator ends, it is clear that the elevator car 30 should stop at the landing position at this time, but the brake fails due to some reasons, so that the elevator car 30 appears to be rolling, at this time the frequency converter 111 will find the change of the encoder 21 pulse, which proves that the car is moving, at this time the elevator system does not open the door, and immediately starts the operation to return the elevator car 30 to the landing, when the elevator car 30 returns to the landing operation logic ends, the encoder 21 pulse changes again, at this time it is determined that the brake 3 fails; after determining that the brake 3 fails, the elevator system starts to operate again, and then runs at a speed of 0.2 m / s in the direction of the rolling car, cancels the running limit function, until the elevator car 30 hits the upper limit switch 6 or the lower limit switch 7 of the elevator shaft 10, the safety circuit is disconnected, and the elevator system stops running, at this time the elevator will continue to roll about 400 mm, the elevator counterweight 40 presses the counterweight buffer 9 or the elevator car 30 presses the car buffer 8, as shown in the figure. Figure 2 、 Figure 3 At this time, the rolling of the elevator car 30 is completely finished, and it is in a safe and stationary state.

[0022] In addition, the emergency power supply 4 is added to prevent the brake 3 from failing when the city power supply is disconnected, so that it can also operate according to the above operation logic.

[0023] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A safety protection system for elevator brake failure, characterized by: The system comprises a control cabinet, a traction machine and a brake, which are arranged in an elevator machine room at the top of an elevator shaft, the control cabinet is provided with an elevator control device, an operation contactor, a star contactor, a brake operation power feedback contactor and a brake state switch, the elevator control device is provided with a frequency converter, the frequency converter is connected with the traction machine through the normally open point of the operation contactor, the normally closed point of the star contactor is connected between the operation contactor and the traction machine, the traction machine is connected with the frequency converter through an encoder, the traction machine is driven by a steel wire rope with the brake, the brake is connected with the elevator control device through the normally closed point of the brake operation power feedback contactor and the normally closed point of the brake state switch.

2. A safety system for elevator brake failure according to claim 1, characterized in that The system further comprises an emergency power supply, which is arranged in the elevator machine room and connected with the frequency converter of the elevator control device.

3. A safety system for elevator brake failure according to claim 1, characterized in that: The system further comprises an upper limit switch and a lower limit switch, which are arranged on the inner wall of the elevator shaft in an up-down manner.

4. A safety system for elevator brake failure according to claim 1, characterized in that: The system further comprises a car buffer and a counterweight buffer at the bottom of the elevator shaft, the car buffer is arranged corresponding to the elevator car, and the counterweight buffer is arranged corresponding to the elevator counterweight.

Images