DE202011102030U1 - Non-contact switching state monitoring for spring-applied brakes - Google Patents

Abstract

Switching status monitoring for spring-loaded brakes (FDB) actuated by closed-circuit current for use in vertical axes, hoists or elevators, the axial stroke of the armature disk (3) occurring during a switching cycle of the spring-loaded brake being detected directly by a contactless switch (6) integrated into the spring-loaded brake, characterized in that the Contactless switch (6) has a switching point deviation of less than 0.20 mm, which is made up of the factors temperature drift, switching hysteresis and repeatability of the switching path and that the contactless switch has a space-optimized cubic design V4 according to the terminology of mechanical subminiature microswitches.

Description

The complexity of technical systems and the associated controls has been steadily increasing for years.

As a rule, the systems are made up of a large number of individual components, which today usually have their own internal sensors.

By means of their signals, the individual process sequences and work cycles of the system are now almost completely monitored and processed in the system control in order to achieve high process reliability.

With regard to the safety of a plant with regard to the prevention of accidents involving personal injury, the plant and control concept is decisive in particular.

However, as far as the reliability of a plant is concerned with regard to its technical availability and compliance with relevant process parameters, the probability of failure of the components used with the associated sensors plays a decisive role.

In the field of sensors, both systems for detecting complex physical or chemical measured variables and systems for the sole detection of simple switching state changes are used.

As an example of the mentioned technical systems here are various vertical axis applications, hoists and elevators mentioned. These also consist of a large number of components, most of which have their own internal sensors. One of these components with particular importance for accident prevention in the system is the brake for the drive, which is closer to here.

Such brakes on vertical axis, hoists and lifts are designed for safety reasons as quiescent-actuated spring-applied brakes, which means that the brakes are held by an internal energy storage such as springs in engagement and the brake is opened by the supply of external energy.

The external energy is usually supplied electrically or via pressure medium.

Today, these brakes are already equipped as standard with a large number of switches and sensors, via which the current operating status is constantly queried and reported to the control system.

Examples include sensors for the temperature of important brake components, sensors for the wear state of the brake pads, encoders for measuring rotational speed and / or angular position of the brake parts and sensors for the switching state monitoring of the brake called.

The present invention relates to the latter sensors.

The torque build-up especially of brakes for vertical axes, hoists and lifts is usually done by a spring-loaded switching element, hereinafter referred to as the anchor plate, which frictionally clamped on a shaft rotatably mounted rotor between the armature disc and a flange plate. When the brake is released external energy is supplied from the outside, which moves the armature disk against the force of the springs and releases the rotor via an electromagnet or a cylinder-piston system.

For the monitoring of this switching state change - brake closed - brake open - mostly mechanical switches have been used for years.

In this case, high demands are placed on the switches themselves in terms of switching reliability, because a malfunction of the switch immediately leads to a failure of the overall system.

• – Der richtigen Auswahl des Schalters für die Anwendung.
• – Dem korrekten Anbau und der korrekten Justage des Schalters an der Bremse.
• – Dem Ausbleiben von äußeren Beschädigungen des Schalters im Betrieb.

The switching reliability of the switches depends on several factors:

• - The correct selection of the switch for the application.
• - Correct mounting and correct adjustment of the switch on the brake.
• - The absence of external damage to the switch during operation.

When selecting the suitable sensor, on the one hand, the technical reliability of the switch itself plays a role, ie. H. the number of switching operations, according to the statistically considered a failure of the switch is expected and on the other hand, the general suitability of the switch for the application, are to be sampled in the movements in the range of a few tenths of a millimeter, a crucial role.

Mechanical switches have here only a limited number of switching cycles to statistical failure, which has its cause in the generally wear-prone metallic contact pairing and the wear of other mechanical components.

In addition, mechanical switches usually have a relatively high temperature drift, a large switching hysteresis and a low switching path. Repeat accuracy on what their suitability for querying short distances of a few tenths of a millimeter under certain circumstances in question.

To solve this fundamental problem are non-contact switch without wear-intensive metallic contact pairing known, inter alia, in DD 21 82 31 A1 be proposed in connection with a quiescent actuated electromagnetic spring pressure brake.

These non-contact inductive proximity switches according to the prior art already have a very high level of technical reliability. However, the proximity switches of the cited prior art are not designed to interrogate said short paths.

This requires optimization of the proximity switch in the direction of very short switching distances and in the direction of low temperature drift, low switching hysteresis and high switching path repeatability.

For the correct installation and the correct adjustment of the switch the technical functioning of the switch plays a decisive role, d. H. whether the switch operates on the principle of a mechanical switch or a proximity switch.

Mechanical switches must be connected to an electrical control unit during installation and adjustment to the brake in order to accurately determine the switching point and to fix the switch finally.

With proximity switches with a predefined switching distance, on the other hand, it is possible to adjust the switch with a setting gauge, which, like a feeler gauge, is placed directly between the damping surface of the switch and the scanned position of the anchor plate.

For the risk of mechanical damage to the switch during operation of the brake finally the geometric shape and size of the switch or its integration in the brake itself are of crucial importance. Proximity switches according to the prior art are here difficult to integrate because of their usually elongated cylindrical shape and usually straight outgoing cable at the rear end in the brake or can be easily damaged without complex mechanical protection measures during operation.

The majority of mechanical switches, however, has a cubic design, which can be easily integrated into recesses of the brake and thus provides little access points for mechanical damage.

Object of the present invention is therefore to provide a switching state monitoring for quiescent-actuated spring brakes in vertical axes hoists and lifts that combines the advantage of the geometric design of known mechanical switch with the high reliability and the safe and easy adjustment of non-contact switch.

Further features of the switching state monitoring according to the invention will become apparent from the dependent claims of the invention.

In the pictures below, embodiments of the switching state monitoring according to the invention for quiescent-actuated spring-applied brakes in vertical axes, hoists and elevators are explained in more detail.

Show accordingly

1 the spatial representation of a spring-actuated electromagnetic spring pressure brake FDB concentric construction with mounted mechanical switch according to the prior art,

1A a longitudinal section through the brake 1 with a detail A,

2 a representation of a disc brake based on a quiet current actuated electromagnetic brake caliper BZ in floating caliper construction with attached non-contact switch in cubic design,

2A a longitudinal section through the brake 2 with a detail B,

3 the spatial representation of a non-contact switch in a cylindrical design according to the prior art,

4 a spatial representation of a mechanical switch according to the prior art,

5 the spatial representation of an inventively improved non-contact switch in cubic design,

6 Finally, a spatial representation of the improved non-contact switch with optimized departure of the cable.

1 shows first the spatial representation of a static current actuated electromagnetic released spring pressure brake FDB in one to the axis of rotation A of the rotor 4 concentric design.

According to 1A the brake here consists of a coil carrier 1 with integrated electromagnetic coil 1.1 and spring bores 1.2 for absorbing springs 2 , against a non-rotatably and axially movable armature disc 3 Press and thereby the rotor 4 frictionally between armature disc 3 and the fixed flange plate 5 Clamp.

The brake is in 1A shown in this braked state and it is the air gap LS to see the switch 6 is to be detected.

To open the brake, the solenoid coil 1.1 energized, resulting in the coil carrier 1 an electromagnetic field that builds up the armature disk 3 against the power of the springs 2 to the coil carrier 1 pulls and thus the clamping of the rotor 4 between anchor plate 3 and flange plate 5 picks. Thus, the air gap LS = "zero" and the rotor 4 is freely rotatable about the axis of rotation A.

The in 1A and mechanical switches shown in detail A. 6 touches it over the plunger 6.1 the stroke of the armature disk 3 which is equal to the air gap LS and outputs a corresponding signal to the controller.

2 shows the spatial representation of an electromagnetic ventilated disc brake based on a central rotor 4 and one to the rotation axis A of the rotor 4 parallel offset brake caliper BZ in so-called floating caliper construction.

The function of the illustrated brake corresponds to the brake in 1 , although here as well 2A apparent, the rotor 4 through in spring bores 1.2 of the bobbin 1 lying feathers 2 between anchor plate 3 and flange plate 5 is clamped so that the apparent from detail B air gap LS forms.

At the in 2 as in 2A The brake shown is a non-contact switch 6 grown. Advantage of the brake concept in 2 is the possibility to increase the braking torque several brake calipers BZ on the circumference of a rotor 4 to arrange.

3 shows a non-contact inductive switch 6 according to the prior art with a cylindrical housing 6.2 , a concentric arranged at the rear end connection cable 6.3 and a Bedämpfungsfläche 6.4 on the connection cable 6.3 opposite side.

In 4 is a mechanical switch 6 to be seen in the prior art, in which the housing 6.2 is cubically shaped according to a so-called V4 for subminiature microswitch and in which the actuation of a mechanical plunger 6.1 he follows. The connection cable 6.3 is here parallel to one of the body surfaces of the housing 6.2 arranged.

5 shows the spatial representation of the present invention optimized touch-less switch 6 with cubic housing 6.2 analogous to the switch in 4 , where again the output of the connecting cable 6.3 parallel to one of the body surfaces of the housing 6.2 he follows. The component to be scanned is opposite the damping surface 6.4 of the switch 6 arranged.

6 finally shows the spatial representation of a non-contact switch 6 in cubic design, the output of the connecting cable 6.3 at an angle of about 45 ° to at least one of the body surfaces of the housing 6.2 he follows.

Through this cable guide, the connection cable 6.3 very space-saving parallel to several body surfaces of the housing 6.2 be laid without the connection cable 6.3 to bend hard. This will damage the connection cable 6.3 during assembly of the switch 6 safely avoided and the cable laying is significantly simplified. The sampling of the armature disk movement takes place again via the Bedämpfungsfläche 6.4 of the switch 6 ,

LIST OF REFERENCE NUMBERS

1

coil carrier

1.1

Electromagnetic coil

1.2

spring bore

2

feather

3

armature disc

4

rotor

5

flange

6

switch

6.1

Pestle of the switch

6.2

Housing of the switch

6.3

Connection cable of the switch

6.4

Damping surface of the switch

A

Rotation axis of the rotor

FDB

Spring-loaded brake

BZ

caliper

LS

air gap

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DD 218231 A1 [0020]

Claims (10)

Switching state monitoring for quiescent-operated spring-applied brakes (FDB) for use in vertical axes, hoists or elevators, wherein the axial stroke of the armature disk occurring during a switching cycle of the spring-loaded brake ( 3 ) directly by a non-contact switch integrated in the spring-loaded brake ( 6 ) is detected, characterized in that the non-contact switch ( 6 ) has a switching point deviation of less than 0.20 mm, which is composed of the factors temperature drift, switching hysteresis and repeatability of the switching path and that the non-contact switch has a space optimized cubic design V4 according to the terminology of mechanical subminiature micro-switch. Switching state monitoring according to claim 1, characterized in that the non-contact switch ( 6 ) works on the inductive principle. Switching state monitoring according to claim 1, characterized in that the non-contact switch ( 6 ) works on the capacitive principle. Switching state monitoring according to claims 1 to 3, characterized in that the outlet of the connecting cable ( 6.3 ) parallel to one of the outer surfaces of the cubic housing ( 6.2 ) of the switch ( 6 ) he follows. Switching state monitoring according to claims 1 to 3, characterized in that the outlet of the connecting cable ( 6.3 ) at an angle of approximately 45 ° to one of the outer surfaces of the cubic housing ( 6.2 ) of the switch ( 6 ) he follows. Switching state monitoring according to claims 1 to 5, characterized in that the spring-pressure brake (FDB) is opened by the supply of electrical energy with an electromagnet. Switching state monitoring according to claims 1 to 5, characterized in that the spring pressure brake (FDB) is opened via the supply of pressure medium in a piston-cylinder system. Switching state monitoring according to claims 1 to 7, characterized in that the spring pressure brake (FDB) is designed in a noise-damped construction. Switching state monitoring according to claims 1 to 8, characterized in that the spring pressure brake (FDB) concentric to the axis of rotation (A) of the rotor to be braked ( 4 ) is arranged. Switching state monitoring according to claims 1 to 8, characterized in that the spring pressure brake (FDB) in the form of a brake caliper (BZ) parallel offset axially to the axis of rotation (A) of the rotor to be braked ( 4 ) is arranged.

Images