CN220056162U - Brake detection mechanism - Google Patents

Abstract

A brake detection mechanism belongs to the technical field of traction machine braking. Including having the static iron core of arranging the installation in proper order, moving the stopper of iron core and brake component, supply the stopper mount pad of stopper installation and install the non-contact switch on moving iron core or static iron core or stopper mount pad, the last brake shoe of installing of brake component, the prescribed value of brake shoe wearing and tearing is set to H, and characteristics are: the non-contact switch is provided with a first sensing piece and a second sensing piece, a first triggering piece and a second triggering piece which trigger the first sensing piece and the second sensing piece are arranged on corresponding parts of the first sensing piece and the second sensing piece respectively, when the movable iron core and the static iron core are attracted or separated, the first triggering piece and the second triggering piece are respectively close to or far away from the sensing surfaces of the first sensing piece and the second sensing piece, so that the working state of the brake is detected by the first sensing piece, and the abrasion H of the brake shoe is larger than or equal to H, the second sensing piece is triggered, and signals are fed back to the control system. The advantages are that: meanwhile, the working state of the brake and the abrasion state of the brake shoe are detected, and the functions are various.

Description

Brake detection mechanism

Technical Field

The utility model belongs to the technical field of traction machine brakes, and particularly relates to a brake detection mechanism.

Background

Conventionally, a micro switch is mounted on a brake of an elevator hoist to detect braking and releasing operations of the brake. Namely, when the micro switch is triggered by related components on the brake to perform corresponding actions, the normally open point is closed, and the normally closed point is opened, namely, a signal for normal operation of the brake is given to the control system, otherwise, the control system has corresponding program starting, for example: alarm, emergency brake activation, etc. Microswitches are generally composed of a spring contact and a movable contact, wherein when the contact is subjected to external force, the movable contact is displaced, so that the state of the switch is changed. Because the micro switch is a mechanical switch, each action part has the problem of mechanical fatigue in the frequent working process of the brake, and errors can be generated in long-term use, so that frequent maintenance, debugging and replacement are required.

Therefore, the industry starts to use the non-contact switch to replace the micro switch to realize the detection of the braking and releasing actions of the brake, and the non-contact switch has the advantages of high detection precision, reliable action, stable performance, long service life and the like, and overcomes the defects of the micro switch. However, the existing contactless switch installed on the elevator traction machine can only detect whether the brake is in a braking state or a releasing state, and has no other functions and single function.

In view of the above-described prior art, there is a need for a reasonable improvement in the structure of existing brake detection mechanisms. To this end, the inventors have advantageously devised that the technical solutions described below are created in this context.

Disclosure of Invention

The utility model aims to provide a brake detection mechanism which can detect the working state of a brake and the abrasion state of brake shoes at the same time and has various functions.

The utility model accomplishes the task like this, a kind of brake detection mechanism, including having static iron core, moving iron core and brake part that are arranged and installed sequentially, the brake mount pad for the brake to install, and install the non-contact switch on moving iron core or static iron core or brake mount pad of the brake, install the brake shoe on the said brake part, the stated value of the brake shoe wearing and tearing is H, the characteristic is: the non-contact switch is characterized in that a first sensing piece and a second sensing piece are arranged in the non-contact switch, a first triggering piece and a second triggering piece which trigger the first sensing piece and the second sensing piece are arranged on corresponding parts of the first sensing piece and the second sensing piece respectively, when a movable iron core and a static iron core of the brake are in attraction or separation, the first triggering piece and the second triggering piece are close to or far away from sensing surfaces of the first sensing piece and the second sensing piece respectively, so that the working state of the brake is detected by the first sensing piece, the abrasion H of a brake shoe is larger than or equal to H, the second sensing piece is triggered, and a signal is fed back to a control system.

In a specific embodiment of the present utility model, the non-contact switch is mounted on a static iron core of the brake, the first trigger member and the second trigger member are mounted on a moving iron core, when the brake is powered off, assuming that a gap between the static iron core and the moving iron core is a, a trigger distance of the first sensor is L1, a trigger distance of the second sensor is L2, a distance between the first trigger member and a sensing surface of the first sensor is B, and a distance between the second trigger member and a sensing surface of the second sensor is C, then the relationships between the parameters should be satisfied: B-A < L1 < B, C=L2-H.

In another specific embodiment of the present utility model, the non-contact switch is mounted on the brake mounting seat, the first trigger piece and the second trigger piece are mounted on the movable iron core, when the brake is powered off, assuming that a gap between the static iron core and the movable iron core is a, a trigger distance of the first sensor is L1, a trigger distance of the second sensor is L2, a distance between the first trigger piece and a sensing surface of the first sensor is B, and a distance between the second trigger piece and a sensing surface of the second sensor is C, then the relationship between the parameters should be satisfied: b < L1 < b+a, c=l2+h.

In yet another specific embodiment of the present utility model, the first trigger member and the second trigger member are ejector pins screwed to the movable iron core or mounted to the movable iron core by fasteners.

In still another specific embodiment of the present utility model, the non-contact switch is mounted on the movable iron core, the first trigger member and the second trigger member are mounted on the stationary iron core, when the brake is powered off, assuming that a gap between the stationary iron core and the movable iron core is a, a trigger distance of the first sensing member is L1, a trigger distance of the second sensing member is L2, a distance between the first trigger member and a sensing surface of the first sensing member is B, and a distance between the second trigger member and a sensing surface of the second sensing member is C, then the relationship between the parameters should be satisfied: B-A < L1 < B, C=L2-H.

In still another specific embodiment of the present utility model, the first trigger member and the second trigger member are ejector pins screwed on the stationary core or mounted on the stationary core by fasteners.

In still another specific embodiment of the present utility model, the non-contact switch is mounted on the movable iron core, the first trigger member and the second trigger member are mounted on the brake mounting base, when the brake is powered off, assuming that a gap between the stationary iron core and the movable iron core is a, a trigger distance of the first sensing member is L1, a trigger distance of the second sensing member is L2, a distance between the first trigger member and a sensing surface of the first sensing member is B, and a distance between the second trigger member and a sensing surface of the second sensing member is C, then the relationships between the parameters should be as follows: b < L1 < b+a, c=l2+h.

In a further specific embodiment of the present utility model, the first trigger member and the second trigger member are push rods screwed to the brake mount or mounted to the brake mount by fasteners.

In yet another specific embodiment of the present utility model, the brake is one of a disc brake or a caliper brake or a block brake.

The utility model has the beneficial effects that due to the adoption of the structure, the utility model has the following advantages: the first detection mechanism can detect the braking or releasing working state of the brake and the abrasion state of the brake pad at the same time, timely feed back the state condition of the brake to the control system, timely replace the brake pad of the brake, improve the safety of the brake, and have simple structure and comprehensive functions; the non-contact switch adopted by the second and detection mechanisms does not generate mechanical fatigue due to frequent contact, so that the function of the detection switch is lost, and the service life is prolonged; the third, non-contact switch is not influenced by the dirt, oil, water, etc. of the detected object, only senses the ferromagnetism, and has the characteristics of water resistance, shock resistance, corrosion resistance, etc.

Drawings

Fig. 1 is a schematic view of a disc brake equipped with a detection mechanism in a braking state in a first embodiment;

FIG. 2 is an enlarged view at a in FIG. 1;

FIG. 3 is a schematic view of a disc brake with a detection mechanism mounted thereto in a released state in accordance with the first embodiment;

FIG. 4 is an enlarged view at b in FIG. 3;

FIG. 5 is an enlarged view of a when the brake pad portion of the brake of FIG. 1 is worn h and in a braked condition;

FIG. 6 is an enlarged view of a portion of the brake pad of the brake of FIG. 3 worn h and in a released condition at b;

FIG. 7 is an enlarged view of a when the brake shoe wear of the brake of FIG. 1 reaches a predetermined value H and is in a braked state;

fig. 8 is a schematic view of a block brake equipped with a detection mechanism in the second embodiment in a braking state;

fig. 9 is a schematic view of a disc brake equipped with a detection mechanism in a braking state in the third embodiment;

FIG. 10 is an enlarged view at e in FIG. 9;

fig. 11 is a schematic view of a disc brake equipped with a detection mechanism in a released state in the third embodiment;

fig. 12 is an enlarged view at f in fig. 11;

FIG. 13 is an enlarged view of the brake pad portion of the brake of FIG. 9 worn h and in a braked condition at e;

FIG. 14 is an enlarged view of the brake pad portion of the brake of FIG. 11 worn h and in a released condition at f;

fig. 15 is an enlarged view of e when the brake shoe wear of the brake shown in fig. 9 reaches a predetermined value H and is in a braked state.

In the figure: 1. the non-contact switch, 11. The first induction piece, 12. The second induction piece; 21. a first trigger, 22; 3. static iron core, 31, coil assembly, 32, braking spring; 4. a movable iron core; 5. a brake disc; 6. a brake mount; 7. a fixed frame; 8. brake shoes.

Detailed Description

The following detailed description of specific embodiments of the utility model, while given in connection with the accompanying drawings, is not intended to limit the scope of the utility model, and any changes that may be made in the form of the inventive concepts described herein, without departing from the spirit and scope of the utility model.

In the following description, any reference to the directions or azimuths of up, down, left, right, front and rear is based on the positions shown in the corresponding drawings, and therefore, should not be construed as a limitation on the technical solutions provided by the present utility model.

Example 1

Referring to fig. 1 and 2, the present embodiment relates to a brake detection mechanism, wherein the brake is a disc brake and is mounted on a brake mounting seat 6 of a traction machine through bolts. The hoisting machine also comprises a motor and a hoisting sheave, said motor being a driving member for driving the hoisting sheave in rotation, on which a main shaft is mounted, these being conventional arrangements on the hoisting machine, which are not described in detail here.

The disc brake comprises a static iron core 3, a movable iron core 4 and a brake disc 5 which are sequentially arranged and installed, a coil assembly 31 and a brake spring 32 are installed in the static iron core 3, brake pads 8 are installed on two side surfaces of the brake disc 5, and the brake disc 5 and a traction wheel are sleeved on a main shaft on a traction machine and synchronously rotate with the main shaft.

When the brake is powered off, the brake spring 32 in the static iron core 3 pushes the movable iron core 4 to close to the brake disc 5, the movable iron core 4 and the brake mounting seat 6 are matched to clamp the brake disc 5, a brake moment is generated, the brake disc 5 and the main shaft stop rotating, and a braking effect is achieved. At this time, the gap between the stationary core 3 and the movable core 4 is the braking or releasing stroke a of the brake.

When the coil assembly 31 in the static iron core 3 is electrified, a magnetic loop is formed in the air gap between the static iron core 3 and the movable iron core 4, and electromagnetic force is generated, and overcomes the spring force of the braking spring 32, so that the static iron core 3 and the movable iron core 4 are attracted together, and the gap between the static iron core 3 and the movable iron core 4 is eliminated.

The non-contact switch 1 which can work without direct contact with a moving part is arranged on the static iron core 3, two induction pieces, namely a first induction piece 11 and a second induction piece 12, are arranged in the non-contact switch 1, and a first trigger piece 21 and a second trigger piece 22 which correspond to the first induction piece 11 and the second induction piece 12 respectively are correspondingly arranged on the movable iron core 4. The first sensing member 11 sends the control system the operating position of the brake, depending on whether it is triggered by the first triggering member 21 or not. The second sensing member 12 signals to the control system whether the brake shoe 8 is worn or not, depending on whether it is triggered by the second trigger member 22 or not. That is, the second sensing member 12 is not triggered until the brake shoe 8 is worn to the predetermined wear amount H, and when the brake shoe 8 is worn to the predetermined wear amount H, the second sensing member 12 is triggered by the second triggering member 22 to send a signal indicating that the brake shoe 8 is worn to the control system. The specific structure is as follows:

as shown in fig. 2, the triggering distance corresponding to the first sensing element 11 is L1, and when the distance between the first triggering element 21 and the first sensing element 11 is smaller than L1, the first sensing element 11 will be triggered. When the brake is installed, the brake is in a power-off state, the distance between the first trigger piece 21 and the first sensing piece 11 is B, and the installation needs to be satisfied: B-A is less than L1 and less than B.

The triggering distance corresponding to the second sensing element 12 is L2, and when the distance between the second triggering element 22 and the second sensing element 12 is greater than or equal to L2, the second sensing element 12 will be triggered. The wear thickness H of the brake shoe 8 is set to be H at maximum, and H is a predetermined value, and the brake is in a normal state as long as the wear thickness of the brake shoe 8, that is, the wear amount H is smaller than H. When the brake is powered off and the static iron core 3 and the movable iron core 4 are not attracted, the gap between the static iron core 3 and the movable iron core 4 is A, the distance between the second trigger piece 22 and the second sensing piece 12 is C, C is required to be smaller than L2, and the second sensing piece 12 is not triggered; as shown in fig. 4, when the stationary core 3 and the movable core 4 are attracted, the distance C-se:Sub>A between the second trigger member 22 and the second sensing member 12 is smaller than L2, and the second sensing member 12 is not triggered.

With the use of the brake, when the abrasion loss H of the brake shoe 8 is more than or equal to H, and when the static iron core 3 and the movable iron core 4 are not absorbed, the gap between the static iron core 3 and the movable iron core 4 is more than or equal to A+H, the distance between the second trigger piece 22 and the second sensing piece 12 is C+h, C+h is more than or equal to C+H=L2, the second sensing piece 12 is triggered, and the second sensing piece 12 sends out a signal of abrasion of the brake shoe 8, so the distance C between the second trigger piece 22 and the second sensing piece 12 is set to be L2-H.

With continued reference to fig. 1 to 7, the working principle of the brake detection mechanism according to the present embodiment is as follows:

as shown in fig. 2, when the brake is just put into use, when the brake is powered off, a gap a exists between the static iron core 3 and the movable iron core 4, at this time, the distance between the first trigger piece 21 and the first sensing piece 11 is B, and because B > L1, the first sensing piece 11 is not triggered, and the signal received by the control system is that the brake is in a braking state. As shown in fig. 3 and 4, when the brake is powered on, the static iron core 3 and the movable iron core 4 are attracted, the gap ase:Sub>A is eliminated, at this time, the distance between the first trigger piece 21 and the first sensing piece 11 is B-ase:Sub>A, and the first sensing piece 11 is triggered due to the fact that B-ase:Sub>A is smaller than L1, and the signal received by the control system is that the brake is in ase:Sub>A released state. This is the function of the first sensing member 11 and the first triggering member 21.

As shown in fig. 5, with the long-term use of the brake, the amount of wear of the brake shoe 8 becomes H, and H does not reach the predetermined value H of wear, and when the brake is not energized, the stationary core 3 and the movable core 4 do not engage, and the movable core 4 is closer to the brake mount 6, and the gap between the movable core and the stationary core 3 increases, and a+h is set. Meanwhile, the distance between the first triggering element 21 and the first sensing element 11 is b+h, the distance between the second triggering element 22 and the second sensing element 12 is c+h, and the first triggering element 21 and the second sensing element 12 are not triggered because b+h > L1 and c+h < L2. As shown in fig. 6, when the brake is energized, the static iron core 3 and the movable iron core 4 are attracted, the gap a+h is eliminated, and at this time, the distance between the first trigger member 21 and the first sensing member 11 is (b+h) - (a+h) =b-ase:Sub>A, and since B-ase:Sub>A < L1, the first sensing member 11 is triggered, so that the wear of the brake shoe 8 has no influence on the operation of the first sensing member 11. The distance (c+h) - (a+h) =c-se:Sub>A, C-se:Sub>A < L2 of the second triggering element 22 from the second sensing element 12, certainly does not trigger the second sensing element 12.

Referring to fig. 7, until the thickness H of the brake pad 8 is greater than or equal to H, when the brake is not energized, the gap between the static iron core 3 and the movable iron core 4 is a+h, the distance between the second trigger member 22 and the second sensing member 12 is c+h, and at this time c+h is greater than or equal to c+h=l2, the second sensing member 12 is triggered, and the second sensing member 12 sends out a signal of the wear of the brake pad 8, so the distance C between the second trigger member 22 and the second sensing member 12 should be set to L2-H.

Example two

Referring to fig. 8, the difference between the present embodiment and embodiment 1 is that: the related brake is a block type brake, and during braking, the brake band-type brake is arranged on the radial outer circular surface of a brake wheel of the traction machine. Specifically, a braking component for braking the braking wheel is arranged on the surface of the movable iron core 4 facing the braking wheel, the braking component comprises a brake shoe 8 which generates friction braking with the braking wheel during braking and a fixed frame 7 for fixing the brake shoe 8, and the fixed frame 7 is fixedly arranged on the movable iron core 4. Other components and their structures are the same as those of embodiment 1. Before the brake shoe 8 of the brake is not worn, the first sensing piece 11 detects the braking and releasing state of the block brake, the second sensing piece 12 is not triggered until the wear H of the brake shoe 8 of the brake is more than or equal to H, the distance between the second triggering piece 22 and the second sensing piece 12 reaches C+h, and the second sensing piece 12 is triggered due to the fact that C+h is more than or equal to L2, and the second sensing piece 12 sends out a signal of the wear of the brake shoe 8.

Example III

In addition to the two embodiments described above, the non-contact switch 1 may also be mounted on the brake mount 6. As shown in fig. 9 and 10, when the brake is put into use, when the brake is powered off, a gap a exists between the static iron core 3 and the movable iron core 4, at this time, the distance between the first trigger piece 21 and the first sensor piece 11 is B, B < L1 is set, the first sensor piece 11 is not triggered, and the signal received by the control system is that the brake is in a braking state; meanwhile, the distance between the second triggering element 22 and the second sensing element 12 is C, and C > L2 is set so as not to trigger the second sensing element 12. As shown in fig. 11 and 12, when the brake is energized, the static iron core 3 and the movable iron core 4 are attracted, the gap a is eliminated, at this time, the distance between the first trigger piece 21 and the first sensing piece 11 is b+a, b+a > L1 is set, the first sensing piece 11 is triggered, and the signal received by the control system is that the brake is in a released state; meanwhile, the distance between the second triggering element 22 and the second sensing element 12 is C+A > L2, and the second sensing element 12 is not triggered.

As shown in fig. 13, with the long-term use of the brake, the thickness of the brake shoe 8 is H, H does not reach the predetermined value H of wear, that is, H < H, and when the stationary core 3 and the movable core 4 are not attracted, the movable core 4 is closer to the brake mount 6, and the gap with the stationary core 3 increases, and a+h is set. Meanwhile, the distance between the first trigger piece 21 and the first sensing piece 11 is B-h, and because B-h is smaller than L1, the first trigger piece 21 is not triggered, meanwhile, the distance between the second trigger piece 22 and the second sensing piece 12 is C-h, C-h is larger than L2, and the second sensing piece 12 is not triggered. As shown in fig. 14, when the brake is energized, the gap a+h is eliminated when the stationary core 3 and the movable core 4 are attracted, and at this time, the distance between the first trigger member 21 and the first sensing member 11 is (B-h) + (a+h) =b+a, and since b+a > L1, the first sensing member 11 is triggered, so that the wear of the brake shoe 8 has no effect on the operation of the first sensing member 11; meanwhile, the distance (C-h) + (a+h) =c+a, c+a > L2 between the second triggering element 22 and the second sensing element 12 is definitely not triggering the second sensing element 12.

Referring to fig. 15, until the wear H of the brake pad 8 is greater than or equal to H, the gap between the static iron core 3 and the movable iron core 4 is a+h, the distance between the second trigger member 22 and the second sensing member 12 is C-H, and at this time C-H is less than or equal to C-h=l2, the second sensing member 12 is triggered, and the second sensing member 12 sends out a signal indicating that the brake pad 8 is worn, so the distance C between the second trigger member 22 and the second sensing member 12 should be set to l2+h.

Furthermore, the non-contact switch 1 may be mounted on the movable core 4, and the first sensing member 11 and the second sensing member 12 are mounted on the stationary core 3. When the brake is not electrified just when the brake is put into use, the distance B between the first sensing piece 11 and the first triggering piece 21 is set to be B-A < L1 < B; the distance C between the second trigger piece 22 and the second sensing piece 12 is set to be L2-H, C is smaller than L2, the second trigger piece 22 is not triggered when abrasion is not generated or the abrasion amount H is smaller than H, and the distance C+h is larger than or equal to L2 between the second trigger piece 22 and the second sensing piece 12 when the abrasion amount H is larger than or equal to H, so that the second trigger piece 22 is triggered.

Alternatively, the non-contact switch 1 may be further mounted on the movable core 4, and the first sensing member 11 and the second sensing member 12 are mounted on the brake mounting base 6. When the brake is not electrified just when the brake is put into use, the distance B between the first sensing piece 11 and the first triggering piece 21 is set to be B < L1 < B+A; the distance C between the second trigger piece 22 and the second sensing piece 12 is set to be L2+H, C is larger than L2, when abrasion is not generated or the abrasion amount H is smaller than H, the second trigger piece 22 is not triggered, and when the abrasion amount H is larger than or equal to H, the distance C-H between the second trigger piece 22 and the second sensing piece 12 is smaller than or equal to L2, and the second trigger piece 22 is triggered.

The brake structure related to the utility model is not limited at all, and can be one of a disc brake, a caliper brake or a block brake, wherein the brake comprises a static iron core 3, a movable iron core 4 and a brake component which are sequentially arranged and mounted, a brake shoe 8 is mounted on the brake component, a first sensing element 11 is triggered when the movable iron core 4 is close to or far from the static iron core 3, and a second sensing element 12 is triggered when the brake shoe 8 is worn to a specified value H and the movable iron core 4 is far from the static iron core 3. The installation position of the non-contact switch 1 may be determined according to the construction of the traction machine, and the trigger distance of the non-contact switch 1 may be set according to the installation position of the non-contact switch 1.

Furthermore, the first trigger piece 21 and the second trigger piece 22 are ejector rods which are screwed on the movable iron core 4 or are mounted on the movable iron core 4 through fasteners, and are also mounted on the static iron core 3 or the brake mounting seat 6 in the same manner.

Claims (9)

1. The utility model provides a stopper detection mechanism, including have static iron core (3), movable iron core (4) and the stopper of braking part of arranging the installation in proper order, supply stopper mount pad (6) of stopper installation to and install in the movable iron core (4) of stopper or non-contact switch (1) on static iron core (3) or stopper mount pad (6), the braking part on install brake shoe (8), the prescribed value of brake shoe (8) wearing and tearing is set to H, its characterized in that: the non-contact switch (1) is provided with a first sensing piece (11) and a second sensing piece (12), corresponding parts of the first sensing piece (11) and the second sensing piece (12) are provided with a first triggering piece (21) and a second triggering piece (22) which trigger the first sensing piece (11) and the second sensing piece (12) respectively, when a movable iron core (4) and a static iron core (3) of the brake are attracted or separated, the first triggering piece (21) and the second triggering piece (22) are close to or far away from sensing surfaces of the first sensing piece (11) and the second sensing piece (12) respectively, so that the working state of the brake is detected by the first sensing piece (11), and once the abrasion H of a brake shoe (8) is more than or equal to H, the second sensing piece (12) is triggered, and a signal is fed back to a control system.

2. A brake sensing mechanism as defined in claim 1, wherein: the non-contact switch (1) install on quiet iron core (3) of stopper, first trigger piece (21) and second trigger piece (22) install on moving iron core (4), when the stopper outage, assume that clearance between quiet iron core (3) and moving iron core (4) is A, the trigger distance of first inductor (11) is L1, the trigger distance of second inductor (12) is L2, the distance between the inductive surface of first trigger piece (21) and first inductor (11) is B, the distance between the inductive surface of second trigger piece (22) and second inductor (12) is C, then the relation between each parameter should satisfy: B-A < L1 < B, C=L2-H.

3. A brake sensing mechanism as defined in claim 1, wherein: the non-contact switch (1) install on stopper mount pad (6), first trigger piece (21) and second trigger piece (22) are installed on moving iron core (4), when the stopper outage, assume that clearance between quiet iron core (3) and moving iron core (4) is A, the trigger distance of first inductor (11) is L1, the trigger distance of second inductor (12) is L2, the distance between the inductive surface of first trigger piece (21) and first inductor (11) is B, the distance between the inductive surface of second trigger piece (22) and second inductor (12) is C, then the relation between each parameter should satisfy: b < L1 < b+a, c=l2+h.

4. A brake detection mechanism according to claim 2 or 3, wherein: the first trigger piece (21) and the second trigger piece (22) are ejector rods which are in threaded connection with the movable iron core (4) or are arranged on the movable iron core (4) through fasteners.

5. A brake sensing mechanism as defined in claim 1, wherein: the non-contact switch (1) install on moving iron core (4), first trigger piece (21) and second trigger piece (22) are installed on quiet iron core (3), when the stopper outage, assume that clearance between quiet iron core (3) and moving iron core (4) is A, the trigger distance of first inductor (11) is L1, the trigger distance of second inductor (12) is L2, the distance between the inductive surface of first trigger piece (21) and first inductor (11) is B, the distance between the inductive surface of second trigger piece (22) and second inductor (12) is C, then the relation between each parameter should satisfy: B-A < L1 < B, C=L2-H.

6. A brake sensing mechanism as defined in claim 5, wherein: the first trigger piece (21) and the second trigger piece (22) are ejector rods which are in threaded connection with the static iron core (3) or are arranged on the static iron core (3) through fasteners.

7. A brake sensing mechanism as defined in claim 1, wherein: the non-contact switch (1) install on moving iron core (4), first trigger piece (21) and second trigger piece (22) are installed on stopper mount pad (6), when the stopper outage, assume that clearance between quiet iron core (3) and moving iron core (4) is A, the trigger distance of first inductor (11) is L1, the trigger distance of second inductor (12) is L2, the distance between the inductive surface of first trigger piece (21) and first inductor (11) is B, the distance between the inductive surface of second trigger piece (22) and second inductor (12) is C, then the relation between each parameter should satisfy: b < L1 < b+a, c=l2+h.

8. A brake sensing mechanism as defined in claim 7, wherein: the first trigger piece (21) and the second trigger piece (22) are ejector rods which are in threaded connection with the brake mounting seat (6) or are mounted on the brake mounting seat (6) through fasteners.

9. A brake sensing mechanism as defined in claim 1, wherein: the brake is one of a disc brake or a caliper brake or a block brake.