CN107244597B

CN107244597B - Measuring device for spring force of elevator drum brake

Info

Publication number: CN107244597B
Application number: CN201710461344.6A
Authority: CN
Inventors: 黄东凌
Original assignee: Shenzhen Institute Of Quality And Safety Inspection And Testing
Current assignee: Shenzhen Institute Of Quality And Safety Inspection And Testing
Priority date: 2017-06-16
Filing date: 2017-06-16
Publication date: 2023-06-30
Anticipated expiration: 2037-06-16
Also published as: CN107244597A

Abstract

The invention relates to a measuring device for spring force of an elevator drum brake, which comprises a force application mechanism, a driving mechanism and a measuring mechanism. The force application mechanism comprises a first support piece and a second support piece which can be correspondingly matched with the first support piece in a back-and-forth moving manner, and the first support piece and the second support piece are respectively matched with an end cover and a brake arm of the brake in a propping way, so that the brake arm is opened or closed. The driving mechanism drives the second supporting piece to move back and forth relative to the first supporting piece; the measuring mechanism comprises a sensing unit, and the sensing unit is arranged on the first supporting piece and abuts against the end cover; or, the sensing unit is arranged on the second support piece and is abutted against the brake arm so as to sense a pressure signal applied by the open brake arm. The measuring device can accurately obtain the pressure applied by the compression springs when the brake arm brakes the brake wheel, can simply, quickly, generally and effectively detect the numerical value of the pressure of each group of compression springs of the brake, and can check the potential safety hazard possibly existing in the brake to the greatest extent.

Description

Measuring device for spring force of elevator drum brake

Technical Field

The present invention relates to a detection device for an elevator drum brake, and more particularly to a measurement device for a spring force of an elevator drum brake.

Background

The brake is the final actuator of many safety devices of the elevator (including the overspeed of the synchronous machine upwards and the unexpected movement of the car), and is also one of the most important safety parts of the elevator, and the braking and the maintenance of the stationary state in the emergency of the elevator are directly dependent on the brake.

The too large or too small pressing force of the brake pressing spring can affect the safety performance of the elevator. The excessive pressing force of the pressing spring can cause the band brake to be unable to open and the band brake to run, and finally, accidents are caused; or may cause discomfort or even fall to the occupant; too small pressing force of the pressing spring can cause that the elevator can not stop in time, thereby causing serious consequences. Therefore, the pressing force of the brake pressing spring should meet the standards and specifications related to elevator manufacturers and countries.

The main types of elevator brakes are drum type and disc type, and the drum type brake is widely applied to asynchronous motor traction machines and most synchronous motor traction machines due to simple structure and low cost. Thus, most freight elevators and a considerable number of passenger elevators use this type of brake.

In these drum brakes, when the brake coil is deenergized, the brake shoes on both sides are abutted against the brake hub (the brake hub is connected with the traction sheave that drives the elevator up and down) under the pressure of the hold-down spring, and the brake is in a braking state. When the brake is required to be released, the coil is electrified, the iron core is opened to two sides under the action of electromagnetic force, the brake arms connected with the iron core are opened against the pressure of the compression spring, the brake shoe is released, and the brake hub is released from a braking state.

The most common elevator drum brake is one in which the compression amount of the compression spring can be adjusted by rotating the compression nut to adjust the compression value of the spring force, and the compression value is obtained by observing the corresponding position of a certain scale value of the graduated scale and the brake arm.

The method has the following defects:

1. it is difficult to directly obtain the value of the spring pressure, the spring pressure value depends on experience, and the actual pressure of the brake spring is difficult to effectively control;

2. when excessive abrasion phenomenon of the brake shoe and/or the brake wheel or grease dirt entering between the brake shoe and/or the brake wheel occurs, although the elevator can be braked effectively by adjusting the pressure of the brake spring, potential safety hazards are left on the elevator, especially the increase of the pressure of the brake spring can cause that the electromagnetic force generated by the original brake coil can not open the brake to enable the elevator to operate, and finally elevator accidents are likely to occur.

It follows that the compression force of the compression springs of such widely used elevator drum brakes is undetected due to the lack of a viable field inspection device, thus leaving a safety hazard for elevator operation.

Disclosure of Invention

The invention aims to solve the technical problem of providing a measuring device for the spring force of an elevator drum brake.

The technical scheme adopted for solving the technical problems is as follows: constructing a measuring device for the spring force of an elevator drum brake, comprising a force application mechanism, a driving mechanism and a measuring mechanism;

the force application mechanism comprises a first support piece and a second support piece which can move back and forth and is correspondingly matched with the first support piece, and when the second support piece moves relative to the first support piece, the first support piece and the second support piece are respectively matched with an end cover and a brake arm of the brake in a propping way, so that the brake arm is opened or closed;

the driving mechanism drives the second supporting piece to move back and forth relative to the first supporting piece;

the measuring mechanism comprises a sensing unit, and the sensing unit is arranged on the first supporting piece and abuts against the end cover; or, the sensing unit is disposed on the second support member against the brake arm to sense a pressure signal applied to open the brake arm.

Preferably, the first support member is provided with a first force application part which abuts against the end cover, and the sensing unit is arranged on the side, opposite to the end cover, of the first force application part.

Preferably, the first force application portion is provided with a mounting hole for mounting the sensing unit.

Preferably, the first support member includes a support tube, and the first force application portion is disposed at one end of the support tube;

the second support member is engaged with the first support member so as to be movable back and forth in the axial direction of the support tube.

Preferably, the second support member includes a support rod having one end inserted into an inner hole of the support tube, and a second force application part provided on the support rod;

the second force application part extends out laterally so as to be propped against the brake arm, and moves along the sliding groove along the supporting rod in the axial direction of the supporting tube.

Preferably, a sliding groove arranged along the axial direction is arranged on the side wall of the supporting tube, the second force application part is positioned on the part of the supporting rod inserted into the supporting tube, and the second force application part extends out of the sliding groove.

Preferably, the driving mechanism comprises a driving piece in threaded fit with the supporting rod, the driving piece is in rotary fit with the supporting tube, and when the driving piece rotates relative to the supporting rod, the driving piece drives the supporting rod to move relative to the supporting tube.

Preferably, the driving mechanism further comprises a force application member sleeved outside the driving member and driving the driving member to rotate.

Preferably, the handle is arranged outside the supporting tube, and the force application piece comprises a lantern ring sleeved outside the driving piece and a handle connected with the lantern ring.

Preferably, a scale is provided on the first support or the second support to measure the displacement of the relative movement of the first support and the second support.

The measuring device for the spring force of the drum brake of the elevator has the following beneficial effects: the pressure applied by the compression spring when the brake arm brakes the brake wheel can be accurately obtained through the measurement of the measuring device, the numerical value of the pressure of each group of the compression spring of the brake can be simply, quickly, generally and effectively detected, and whether the pressure of the compression spring is in the range of the design requirement of a manufacturer or not can be confirmed by comparing the measured pressure with the design pressure of the compression spring of the brake, so that potential safety hazards possibly existing in the brake can be checked in advance to the greatest extent.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

fig. 1 is a schematic view of the construction of an elevator drum brake in an embodiment of the invention;

fig. 2 is a schematic view of the structure of the measuring device of the spring force of the drum brake of the elevator in the embodiment of the invention when the measuring device is respectively abutted against the end cover and the brake arm;

fig. 3 is a schematic view of the measuring device of fig. 2 after the second support member has moved the flip brake arm away from the first support member.

Detailed Description

For a clearer understanding of technical features, objects and effects of the present invention, a detailed description of embodiments of the present invention will be made with reference to the accompanying drawings.

As shown in fig. 1, an elevator drum brake in a preferred embodiment of the present invention includes a brake wheel 1, a brake arm 2, and an end cover 3. The brake arm 2 is swingably provided, and a shoe holder 21 and a shoe 22 are provided on the brake arm 2. The brake arm 2 is provided with a compression spring 4 which provides elasticity to enable the brake arm 2 to overturn towards the brake wheel 1, and when the brake arm 2 approaches the brake wheel 1, the brake shoe 22 is propped against the brake wheel 1 to brake the brake wheel 1.

The end cover 3 is internally provided with an iron core 31, a coil 32 and a brake release wrench 33, after the coil 32 is electrified, the iron core 31 opens to two sides, the brake arm 2 connected with the iron core 31 opens against the pressure of the compression spring 4, the brake shoe 22 is released, and the brake wheel 1 is released from a braking state. After the coil 32 is powered off, the elastic force of the compression spring 4 drives the brake arm 2 to turn over towards the brake wheel 1, and the brake shoe 22 brakes the brake wheel 1.

As shown in connection with fig. 1 to 3, the measuring device 5 of the spring force of the drum brake of an elevator in a preferred embodiment of the invention comprises a force application mechanism 51, a drive mechanism 52 and a measuring mechanism 53.

The force applying mechanism 51 includes a first support 511 and a second support 512 that is correspondingly engaged with the first support 511 in a back-and-forth movable manner, and when the second support 512 moves relative to the first support 511, the first support 511 and the second support 512 are respectively engaged with the end cover 3 and the brake arm 2 of the brake, so that the brake arm 2 is opened or closed.

The driving mechanism 52 drives the second support member 512 to move back and forth relative to the first support member 511, and moves the second support member 512 away from the first support member 511 to different positions according to the measurement requirement, so that the measuring mechanism 53 measures the elastic force of the compression spring 4 at the corresponding position.

The measuring mechanism 53 comprises a sensing unit 531, the sensing unit 531 being arranged on the first support 511 against the end cap 3. Preferably, when the force applying mechanism 51 is placed, the sensing unit 531 is placed on the end cover 3 at a position opposite to the pressing spring 4 on the brake arm 2, and after the brake arm 2 and the brake shoe 22 are separated from the brake wheel 1, the elastic force of the pressing spring 4 and the pressing force between the sensing unit 531 and the first support 511 can be ensured to be the same.

Since the horizontal distance D from the rotation center of the brake arm 2 to the abutment measuring surface of the second support member 512 and the brake arm 2 is much smaller than the vertical distance H from the rotation center of the brake arm 2 to the abutment measuring surface of the second support member 512 and the brake arm 2, for the convenience of calculation, d=0 is set, and if the brake arm 2 is turned over to the first position A1 immediately after the brake wheel 1 is separated, the pressure of the hold-down spring 4 is all borne by the force applying mechanism 51, and then no force is applied between the brake shoe 22 and the brake wheel 1.

When the second support member 512 continues to move away from the first support member 511, the brake arm 2 is driven to turn outwards, and turns to the second position A2 and the third position A3 in sequence, and when the brake arm 2 is located at the first position A1, the second position A2 and the third position A3, the acting forces of the compression spring 4 measured by the measuring mechanism 53 are F1, F2 and F3 respectively, so that the spring force calculation process is as follows:

when the brake arm 2 is in the first position A1, the horizontal distance between the brake arm 2 and the end cap 3 is L1, and at this time, the brake shoe 22 and the brake wheel 1 are not completely separated from contact, and a force is applied between the brake shoe 22 and the brake wheel 1. When the brake arm 2 is opened to the second position A2, the brake shoe 22 and the brake wheel 1 are completely separated from contact, the acting force of the compression spring 4 measured by the measuring mechanism 53 is F2, and the horizontal distance between the brake arm 2 and the end cover 3 is L2. In order to measure the value of the stiffness coefficient K of the hold-down spring 4, the brake arm 2 is opened again to the third position A3, and at the same time the corresponding force F3 is read, at which point the horizontal distance between the brake arm 2 and the end cap 3 is L3.

The stiffness coefficient of the hold-down spring 4 is according to the spring characteristic formula:

K＝F3-F2/L3-L2，

the pressing force of the pressing spring 4 when the brake arm 2 is at L1:

F1＝F2-KL2-L1；

in other cases, because of the limitation of the elevator brake structure, the brake spring force measuring point is difficult to directly measure at the installation position of the hold-down spring 4, and at this time, the force applying point of the force applying mechanism 51 needs to be fixed at other proper positions of the brake, and this measuring point will deviate from the actual position of the hold-down spring 4, so that the conversion of the acting force and the distance needs to be performed, the pressing force between the new position sensing unit 531 and the first support 511 is converted into the elastic force of the hold-down spring 4, and finally, the pressing force of the hold-down spring 4 when the brake arm 2 brakes the brake wheel 1 is obtained.

In other embodiments, a sensing unit 531 may also be provided on the second support 512 against the brake arm 2 to sense the pressure signal applied by the expanding brake arm 2.

The pressure applied by the pressing spring 4 when the braking arm 2 brakes the braking wheel 1 can be accurately obtained through the measurement of the measuring device 5, the numerical value of the pressure of each group of pressing springs 4 of the brake can be simply, quickly, universally and effectively detected, and whether the pressure of the pressing spring 4 is in the range of the design requirement of a manufacturer or not can be confirmed by comparing the measured pressure with the design pressure of the pressing spring 4 of the brake, so that potential safety hazards possibly existing in the brake can be checked in advance to the greatest extent.

Preferably, the first support 511 or the second support 512 is provided with a scale 5111 to measure the displacement of the first support 511 and the second support 512 relative to each other, and the distance between the brake arm 2 and the end cover 3 can be obtained, and in other embodiments, the measurement can be performed by other external scales 5111.

The first support 511 is provided with a first urging portion 5112 that abuts against the end cover 3, and the sensor unit 531 is provided on a side of the first urging portion 5112 that faces the end cover 3. Preferably, the first force application portion 5112 is provided with a mounting hole 5113 for mounting the sensing unit 531, so that the sensing unit 531 can be stably placed, and measurement accuracy is ensured. The sensing unit 531 is connected with a computing device such as a computer and directly converts the pressure signal into a pressure value.

In some embodiments, the first support 511 includes a support tube 5114, and the first force applying portion 5112 is disposed at one end of the support tube 5114 so as to abut against the end cover 3. The second support member 512 is coupled to the first support member 511 to be movable back and forth in the axial direction of the support tube 5114, and the distance between the brake arm 2 and the end cap 3 can be adjusted during the movement.

Further, the second support 512 includes a support rod 5121 having one end inserted into the inner hole of the support tube 5114 and a second force applying portion 5122 provided on the support rod 5121. The second urging portion 5122 is laterally projected so as to be able to abut against the brake arm 2, and the second urging portion 5122 moves along the axial direction of the support tube 5114 with the support rod 5121.

The second support member 512 moves along the axial direction of the support tube 5114 under the driving of the driving mechanism 52, and the second force applying portion 5122 adjusts the distance between the brake arm 2 and the end cover 3 when moving along with the support rod 5121. The second force application portion 5122 may be omitted, and the end portion of the support rod 5121 extending out of the support tube 5114 directly abuts against the brake arm 2 on the premise of appropriate size, and when the support rod 5121 moves axially, the distance between the brake arm 2 and the end cover 3 is adjusted.

The side wall of the support tube 5114 is provided with a chute 5115 arranged along the axial direction, the second force application part 5122 is positioned on the part of the support rod 5121 inserted into the support tube 5114, and the second force application part 5122 extends out of the chute 5115, so that the overall length of the force application mechanism 51 can be increased, and the measurement device 5 can be conveniently operated. The scale 5111 may be provided on the outer wall surface of the support tube 5114, and the displacement is measured onto the scale 5111 corresponding to the position of the second urging portion 5122. In other embodiments, the scale 5111 may also be provided on the support rod 5121, with the length of the support rod 5121 extending out of the support tube 5114 to measure displacement.

In some embodiments, the driving mechanism 52 includes a driving member 521 in threaded engagement with the support rod 5121, the driving member 521 is in rotational engagement with the support tube 5114, and the driving member 521 moves the support rod 5121 relative to the support tube 5114 when rotated relative to the support rod 5121.

To facilitate rotation of the driving member 521, the driving mechanism 52 further includes a force application member 522 that is sleeved outside the driving member 521 and drives the driving member 521 to rotate. In general, the force application member 522 includes a collar 5221 that is fitted over the driving member 521, and a handle 5222 that is connected to the collar 5221, and the collar 5221 is fitted over the driving member 521 and then positioned circumferentially with the driving member 521, so that the driving member 521 is rotated when the handle 5222 is rotated about the support bar 5121.

Further, in order to facilitate holding and positioning the force application mechanism 51, a handle 5116 is provided outside the support tube 5114 for the user to hold, and the force application mechanism 51 is placed at a corresponding position.

It will be appreciated that the above technical features may be used in any combination without limitation.

The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present invention.

Claims

1. A measuring device (5) for the spring force of an elevator drum brake, characterized by comprising a force application mechanism (51), a driving mechanism (52) and a measuring mechanism (53);

the force application mechanism (51) comprises a first support piece (511) and a second support piece (512) which can be correspondingly matched with the first support piece (511) in a back-and-forth movement mode, when the second support piece (512) moves relative to the first support piece (511), the first support piece (511) and the second support piece (512) are respectively matched with an end cover (3) and a brake arm (2) of a brake in a propping mode, and the brake arm (2) is opened or closed;

the driving mechanism (52) drives the second support (512) to move back and forth relative to the first support (511);

the measuring mechanism (53) comprises a sensing unit (531), wherein the sensing unit (531) is arranged on the first supporting piece (511) and abuts against the end cover (3); or, the sensing unit (531) is arranged on the second support (512) against the brake arm (2) to sense a pressure signal applied by opening the brake arm (2);

the first supporting piece (511) is provided with a first force application part (5112) which is propped against the end cover (3), and the sensing unit (531) is arranged on one side of the first force application part (5112) which is opposite to the end cover (3);

the first support member (511) includes a support tube (5114), and the first urging portion (5112) is provided at one end of the support tube (5114);

the second support (512) is matched with the first support (511) in a way of moving back and forth along the axial direction of the support tube (5114);

the second support member (512) includes a support rod (5121) having one end inserted into an inner hole of the support tube (5114) and a second force application portion (5122) provided on the support rod (5121);

the second force application part (5122) extends laterally so as to be capable of abutting against the brake arm (2), and the second force application part (5122) moves along with the support rod (5121) in the axial direction of the support tube (5114).

2. The measuring device (5) according to claim 1, wherein the first force application portion (5112) is provided with a mounting hole (5113) for mounting the sensing unit (531).

3. The measuring device (5) according to claim 1, wherein a side wall of the support tube (5114) is provided with a chute (5115) arranged in an axial direction, the second urging portion (5122) is located on a portion of the support rod (5121) inserted into the support tube (5114), and the second urging portion (5122) protrudes from the chute (5115).

4. The measuring device (5) according to claim 1, wherein the driving mechanism (52) comprises a driving member (521) in threaded engagement with the support rod (5121), the driving member (521) being in rotational engagement with the support tube (5114) and, when the driving member (521) rotates relative to the support rod (5121), moving the support rod (5121) relative to the support tube (5114).

5. The measuring device (5) according to claim 4, wherein the driving mechanism (52) further comprises a force application member (522) sleeved outside the driving member (521) and driving the driving member (521) to rotate.

6. The measuring device (5) according to claim 5, wherein a handle (5116) is provided outside the support tube (5114), and the force application member (522) comprises a collar (5221) sleeved outside the driving member (521) and a handle (5222) connected to the collar (5221).

7. The measuring device (5) according to any one of claims 1 to 6, wherein a scale (5111) is provided on the first support (511) or the second support (512) for measuring the displacement of the relative movement of the first support (511) and the second support (512).