Elevator Electromagnetic Brake Noise Reduction

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Solution Overview

Problem

The electromagnetic brake device in elevators generates significant noise due to the collision of the braking piece with the rotary body when holding the car at a standstill, as existing solutions with stronger springs do not adequately reduce this noise.

Innovation Solution

An electromagnetic brake device with a first movable iron piece, a second movable iron piece, a first elastic body, and a second elastic body, where the second elastic body pushes the second movable iron piece against the first with a stronger force, and an electromagnet attracts the second movable iron piece to gently engage the first movable iron piece, reducing the noise during collision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a single strong spring is used to generate standstill retentive force, then the braking piece collides with the rotary body, but the collision noise is not sufficiently reduced

Engineering Contradiction:
Improvecollision noiseVSAvoidstandstill retentive force
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The single spring is divided into two separate springs: a first spring that provides initial pushing force and a second spring that provides additional pushing force. This segmentation allows the braking piece to be pushed gradually in two stages, reducing collision noise while maintaining the required standstill retentive force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first spring performs preliminary action by pushing the braking piece against the rotary body before the second spring engages. This preliminary pushing action reduces the impact velocity and force of the final collision, thereby reducing noise while ensuring the braking piece is already in contact with the rotary body when the second spring engages.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If two springs are used to generate standstill retentive force with the stronger spring operating first, then the standstill retentive force is sufficient, but the collision noise is not substantially reduced

Engineering Contradiction:
Improvestandstill retentive forceVSAvoidcollision noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The first spring performs preliminary action by pushing the braking piece against the rotary body before the second spring engages. This preliminary pushing action reduces the impact velocity and force of the final collision, thereby reducing noise while ensuring the braking piece is already in contact with the rotary body when the second spring engages.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The first spring acts as a cushioning element that compresses first, absorbing some of the impact energy before the second spring engages. This beforehand cushioning reduces the overall collision force and noise while maintaining the required standstill retentive force through the combined action of both springs.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Force

If the braking piece is pushed against the rotary body with strong force, then the standstill retentive force is sufficient, but the collision generates large noise

Engineering Contradiction:
Improvepushing forceVSAvoidcollision noise
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The total pushing force is segmented into two components from two separate springs. The first spring provides an initial pushing force that gradually compresses, and the second spring provides additional pushing force. This segmentation distributes the force application over time, reducing impact noise while maintaining the total required force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first spring acts as a cushioning element that compresses first, absorbing some of the impact energy before the second spring engages. This beforehand cushioning reduces the overall collision force and noise while maintaining the required standstill retentive force through the combined action of both springs.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration substantially reduces noise during the collision of the braking piece with the rotary body while maintaining a stable standstill retentive force, by controlling the energy of the collision and using the elastic body to absorb impact without additional buffer materials.

Implementation Method 1

a first elastic body having a prescribed pushing force, which is provided between the first movable iron piece and the second movable iron piece

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a second elastic body which pushes the second movable iron piece against the first movable iron piece side with a prescribed pushing force stronger than the pushing force of the first elastic body

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

an electromagnet which attracts the second movable iron piece against the pushing force of the second elastic body

Methodology Applied
Scientific EffectElectromagnetic attraction: Electromagnet

Data Source

PatentEP2657173B1Electromagnetic brake device for elevator
Publication Date: 2020.03.25 MITSUBISHI ELECTRIC CORP
  • EP2657173B1 patent drawingFigure 1
  • EP2657173B1 patent drawingFigure 2~3
  • EP2657173B1 patent drawingFigure 4~5

AI summary

Provided is an electromagnetic brake device for an elevator which can substantially reduce the noise generated when a braking piece collides with a rotary body. This electromagnetic brake device 10 includes a movable piece 21 which is provided with a braking piece 16, a movable piece 19 disposed on the side opposite to the braking piece 16 with respect to the movable piece 21, an elastic body 22 provided between the movable pieces 21 and 19, and a spring 20 which pushes the movable piece 19 to the movable piece 21 side with a prescribed pushing force stronger than the pushing force of the elastic body 22. An electromagnet attracts the movable piece 19 against the pushing force of the spring 20, and causes the movable piece 19 to attract the movable piece 21 against the pushing force of the elastic body 22.