Analysis of brake fault prevention and safety inspection

Analysis of brake fault prevention and safety inspection

The elevator

Elevator braking equipment belongs to safety equipment, and its function is normal braking and emergency braking. Therefore, whether the equipment can operate effectively and stably will directly affect the comfort of the elevator ride and the safety of the user. Generally, only under the premise of accurate operation and safe operation of the brake equipment can the elevator play the role of transmission, so its key is self-evident. Therefore, it is very important to complete the safety inspection of brake equipment, reduce safety accidents and eliminate safety threats.

I. elevator safety test

Here the main test criteria are discussed.

From the perspective of structure, most of the current elevators use friction braking equipment, which is usually closed. The components are centered on electromagnet, brake spring and tile, and feature strong reliability. At present, China has issued relevant laws on the safety test of brake equipment, so that the test can be based on evidence. Therefore, in the control practice stage, the tester should take the related requirements as the reference to carry out a comprehensive test on the brake equipment to reduce the failure rate.

In general, relevant criteria for brake equipment detection include:

1. The braking equipment runs well and has high action sensitivity; The brake clamp and the brake disc bite tightly, however, the two should not collide with each other in the normal operation of the elevator, and the surface is free of stains. Detection of this link is the focus of detection.

2. When the elevator is in normal operation state, more than 2 electrical equipment shall be used to disconnect the circuit of the brake equipment. To detect it efficiently, we must combine the power design drawing with the actual situation to finish the simulation mode.

The elevator

3. In the situation of smooth operation of the box door, if the circuit of the brake equipment is disconnected, the box door should cooperate with the operation and should not break down.

In addition to the above part of the detection, the current regulations of elevator detection in China still have the requirements of detailed processing, the author will not repeat here.

The problem of safety detection of brake equipment

The key issues are:

1. Electrical problems

1. The contact sensitivity of the coil of the brake equipment is reduced or bonded, which is sometimes broken, resulting in the collision between brake shoe and brake wheel, which damages the service life and leads to poor braking.

2. Design of control circuit of brake equipment

The upper contactor (KS) and the lower contactor (KX) attract after receiving the command, and then form a loop through KS and KX in parallel, and attract with KJT. At this stage of the brake equipment coil, the direction of current flow is shown in the figure. However, in this situation, if KS or KX are glued, the KJT power supply is switched on, leading to automatic loop access and lock. The control circuit of such braking equipment is not in accordance with world standards.

The elevator

2. Problems related to equipment

1. The machine is blocked, which leads to the failure of closing the gate or the difficulty of closing the power supply after the brake equipment is cut off. The brake equipment cannot be opened or partially opened.

2. The brake equipment is not well installed, parts of the brake equipment are damaged, and part of the bearing wear is 3-5% of the nominal inner diameter. Excessive gap; Brake wheel loss is too large; Brake shoe wear, rivet outcrop; The section area between brake wheel and brake shoe does not reach 80%, so the braking effect is not good.

There are other issues that are not covered here.

The strategy of preventing brake equipment from failure

1. Enterprises using elevators should follow relevant legal regulations and technical standards, construct elevator scientific and technological documents, build and implement elevator operation safety control system, set up elevator safety control department or deploy professional safety control personnel, and the maintenance and maintenance of elevators should be completed by qualified enterprises. If necessary, the old lift should be improved or replaced. Timing the spring on the brake equipment, pin, such as the implementation of NDT testing.

2. The daily maintenance and maintenance enterprises of elevators shall abide by the safety technical standards issued by China to ensure the safety characteristics of elevators during the maintenance and maintenance stage. The training of maintenance personnel should be strengthened to familiarize them with the technical standards of elevators, solutions to routine problems and improve maintenance efficiency. On the premise of routine maintenance and maintenance, the maintenance plan with clear purpose is established to ensure the safe use of the elevator.

3. Elevator production enterprises should comply with safety technical standards to avoid mistakes in the creation and manufacture of brake equipment. When there is no response to the device element of braking force applied to the brake wheel, a certain braking effect should be guaranteed, so that the ladder body that bears the given load and falls at the given rate will be lowered. In the opinion of the author, the experiment was repeated, and the bolt of the brake spring was closed after the experiment was confirmed to be effective. Relevant staff should be responsible for the adjustment in accordance with relevant standards in the elevator repair and improvement work.

4. The elevator safety regulator should intensify publicity efforts to improve people's awareness of elevator safety. According to the international and domestic trend of elevator scientific and technological progress and the specific situation of the region under control, the compilation of elevator safety documents should be completed. It is necessary to strengthen the integration intensity of the market order of elevator installation and maintenance in cooperation with relevant national authorities to avoid the problems of braking equipment in elevator operation.

To sum up, the elevator is an important means of transportation for modern people and brings aspects to people. Elevator manufacturing enterprises should ensure the safe and stable operation of elevators, and work according to laws and regulations to ensure the safety of people's lives.