WO2020063162A1

WO2020063162A1 - Rear cover type disc spring force monitoring sensor for brake of hoist

Info

Publication number: WO2020063162A1
Application number: PCT/CN2019/100512
Authority: WO
Inventors: 孙正; 张晓光; 徐桂云; 刘珍; 蒋奇; 孙佳胜; 张然; 卢纪丽
Original assignee: 枣庄学院; 徐州大恒测控技术有限公司; 中国矿业大学
Priority date: 2018-09-27
Filing date: 2019-08-14
Publication date: 2020-04-02
Also published as: CN109027071A

Abstract

A rear cover type disc spring force monitoring sensor for a brake of a hoist, comprising a transparent cover (6) provided on a front disc type brake and a cover plate provided at an outer end surface of the transparent cover (6), wherein a center line of the transparent cover (6) coincides with a center line of the front disc type brake; an outer part of the transparent cover (6) is stepped; an outer annular groove is provided on the outer end surface; a plurality of strain gauges (7) arranged in pairs are uniformly distributed in the outer annular groove, and the strain gauges (7) arranged in pairs are closely attached to an outer diameter in the annular groove at a certain deflection angle α; the strain gauges (7) acquire the deformation of the sensor, the deformation of the sensor destroys the balance of a bridge, and the bridge outputs a voltage signal corresponding to a pressure. Without changing the installation size and structure of the original rear cover, the present invention achieves the bearing function of the original rear cover, and may also achieve the real-time online monitoring of a disc spring force P, thereby determining disc spring fatigue and fractures, achieving monitoring brake safety, and greatly improving the reliability of a disc brake of a hoist. The present rear cover type disc spring force monitoring sensor for the brake of the hoist has a simple structure, is convenient to install and perform maintenance, and has high measurement accuracy.

Description

Rear cover type disc spring force monitoring sensor for brake brake of elevator

Technical field

The invention relates to a back cover sensor, in particular to a back cover sensor suitable for monitoring a disc spring disc spring of a cylinder.

Background technique

In China, coal resources are the main body of production and consumption, and 80% of them are transported by elevators. The safe and reliable operation of the mine hoisting system will have positive significance for the national economic development and people's living standards. Coal mine safety accidents are caused by many factors such as people, elevators, and the environment. Among them, the insufficient positive pressure of the disc brake is a typical cause. In the safety production of coal mines, insufficient brake brake pressure is one of the main reasons leading to transportation problems.

The disc brake is an important braking unit on the hoist equipment and is very important for the braking action of the hoist. The disc brake uses the butterfly spring to generate braking force and releases the brake by oil pressure. When the hydraulic oil enters the hydraulic unit, the hydraulic pressure pushes the piston, which drives the cylinder, the brake shoe moves, compresses the butterfly spring, and the brake shoe leaves the brake disc, showing a brake release state. When the hydraulic unit is relieved of pressure, the butterfly spring returns to the original compression and deformation state, and the cylinder and the brake shoe are pressed against the brake disc by the spring force to generate a braking force, thereby achieving the purpose of the elevator braking. From the perspective of the action of the brake, the butterfly spring is one of the most critical parts to achieve braking. In the coal mine safety regulations, if the disc spring is found to be fatigued and worn, it should be replaced immediately. Generally, the inspection of the disc spring is half-year maintenance and one-year overhaul. During disc spring braking, if the disc spring is fatigued, it will lead to a reduction in the positive pressure of the brake, which will cause long braking time, long sliding distance during braking, and small braking torque. Fracture of the reed will cause the brake shoe components to become stuck in the hydraulic cylinder and cannot be released, which can not be found in time, causing serious wear of the brake shoes, and causing the elevator drum to move axially, affecting the braking performance and lifting performance of the elevator. It can be seen that the fatigue, wear or fracture of the disc spring will bring great personnel and property damage to the production. If direct online monitoring of disc spring force can be achieved, disc spring leaf fatigue and fracture can be found in time. In the current technology, the positive pressure of the brake is monitored to monitor the safety of the brake, but there is a large error between the positive pressure of the disc brake and the actual positive pressure of the disc brake, and it is impossible to accurately monitor the positive pressure of the brake.

Summary of the Invention

Technical problem: The purpose of the present invention is to overcome the shortcomings of the prior art, and provide a back cover sensor for disc brake monitoring disc spring force, which is simple in structure, high in reliability, and capable of monitoring braking safety.

Technical solution: A rear disc-type disc spring force monitoring sensor of a hoist brake of the present invention includes a transparent cover provided on a front disc brake and a cover plate provided on an outer end surface of the transparent cover, and a center of the transparent cover The line coincides with the center line of the front disc brake. The outside of the transparent cover is stepped. An outer annular groove is provided on the outer end surface. A plurality of pairs of strain gauges are arranged in the outer annular groove, arranged in pairs. The strain gauges are closely attached to the outer diameter of the annular groove at a certain deflection angle α; the inner hole of the transparent cover is stepped, and an inner ring is provided at a position corresponding to the outer annular groove opened on the outer end surface. The inner diameter of the shoulder in the inner hole of the transparent cover is the same as the inner diameter of the disc spring of the front disc brake. The inner diameter of the shoulder rests on the disc spring of the front disc brake. It is connected to the hydraulic cylinder and support of the disc brake by screws.

The plurality of strain gauges are 6-10 pieces, all of which are distributed on the inner and outer diameters of the annular groove.

The certain deflection angle α is 5-10 °.

Beneficial effect: Since the above technical solution is adopted, the back cover sensor of the present invention is specifically used for disc brakes with a back cover of a hoist and a conveyor, and utilizes the limited space of the existing disc brake structure of a mine hoist without changing. The original installation size of the rear cover can be directly replaced on site without changing the existing performance parameters of the existing brake and the structural dimensions of other parts. It not only has the bearing capacity of the original rear cover, but also enables real-time online monitoring of the disc spring force. This judges the disc spring fatigue and fracture conditions, and realizes the monitoring of brake safety, which greatly improves the reliability of the hoist disc brake. Because the disc spring force of the disc brake can be directly monitored online, the disc spring fatigue and fracture can be diagnosed directly online to ensure that the disc spring applying the positive brake pressure is intact. The back cover type disc spring sensor has a simple structure, convenient installation and maintenance, high measurement accuracy, and wide practicability.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a structural diagram of a back cover sensor of the present invention;

FIG. 2 is a schematic diagram of installing a back cover sensor of the present invention; FIG.

FIG. 3 is a force analysis diagram of a sensor according to the present invention.

In the picture: 1—brake disc; 2—brake shoe assembly; 3—hydraulic cylinder; 4—piston; 5—disc spring; 6—back cover sensor; 7—strain gauge; α—pairs of strain gauges arranged in pairs Angle, P—disc spring force, P′—supporting force provided by the bolt.

detailed description

An embodiment of the present invention is further described below with reference to the accompanying drawings:

As shown in FIG. 1, a rear disc type disc spring force monitoring sensor of a hoist brake of the present invention is mainly composed of a transparent cover 6 provided on a front disc brake and a cover plate provided on an outer end surface of the transparent cover. The centerline of the transparent cover 6 coincides with the centerline of the front disc brake. The outside of the transparent cover 6 is stepped, and an outer annular groove is provided on the outer end surface. A plurality of pairs are arranged in the outer annular groove. The strain gauges 7 are 6-10 pieces, all of which are distributed on the inner and outer diameters of the annular groove. The strain gauges 7 arranged in pairs abut on the outer diameter of the annular groove with a certain deflection angle α; the certain deflection angle α is 5-10 °. The inner hole of the transparent cover 6 is stepped, and an inner annular groove is provided at a position corresponding to the outer annular groove opened on the outer end surface. The inner diameter of the shoulder in the inner hole of the transparent cover 6 is similar to that of the front disc brake. The disc springs have the same inner diameter and abut on the disc springs of the front disc brakes. The outer ring of the largest diameter of the transparent cover 6 is provided with a countersunk hole, which is connected to the hydraulic cylinder and the support of the disc brake by screws. The diameter of the inner hole of the back cover sensor 6 is equal to the inner diameter of the disc spring 5 of the front disc brake. From the structural point of view, the back cover sensor 6 is a thin ring strain beam of varying thickness. It is divided into three rings according to thickness and force. The small ring a is supported on the small diameter of the disc spring 5, and the large ring c is provided with a countersunk hole, which is connected to the hydraulic cylinder 3 and the support of the disc c brake by screws. The small ring a is thicker and bears the disc spring force P generated by the disc spring 5. The large ring is thicker and bears the tensile force P ′ provided by the screw. The middle ring b is thinner. The middle ring b is generated by the disc spring force P and the pull force P ′. Shear strain. The plurality of strain gauges 7 arranged obliquely and symmetrically in the middle ring b, and the deflection angle α between the pair of strain gauges 7 is 5-10 °.

As shown in FIG. 2, it is a cylinder front disc brake of a hoist and a conveyor, which includes a brake disc 1, a brake shoe assembly 2 connected to the brake disc 1, and a piston 4 integrally connected to the brake shoe assembly 2. The hydraulic cylinder 3 between the brake shoe assembly 2 and the piston 4, the disc spring 5 sleeved on the outer ring of the rear of the piston 4, the back cover sensor 6 connected to the hydraulic cylinder and against the disc spring 5, and the back cover sensor 6 is opened by The diameter of the inner hole is equal to the inner diameter of the disc spring, without changing any size of the original disc brake. A ring-shaped groove is provided on the end surface of the back cover sensor 6 on the side far from the disc spring 5. A plurality of strain gauges 7 arranged in pairs at the bottom of the groove are respectively pressed on the inner and outer diameters of the ring groove at a certain deflection angle α. The strain gage 7 is subjected to a composite stress of radial bending and axial shear, and the composite strain value is proportional to the forces P and P ′, so that even if the size b of the intermediate ring is small, the measurement accuracy is higher, which is derived from The wire leads out of the hole, and the sensor monitoring value is collected by the data acquisition system.

As shown in Figure 3, when the disc brake does not work, the strain gauge on the sensor has no external pressure, and the electric bridge is in a balanced state, which is called the zero position. When the brake is working, the disc spring force acts on the back cover disc spring sensor. After the sensor is pressed, the strain gauge resistance changes, the bridge will lose balance, and a constant current or voltage power supply will be applied to the bridge. The bridge will output and The voltage signal corresponding to the pressure, so that the resistance change of the sensor is converted into a pressure signal output through the electric bridge. The bridge detects the change in the resistance value, and after amplification, it converts the voltage and current into corresponding current signals. This current signal is compensated by the non-linear correction loop. ～ 20mA standard output signal. The data acquisition device will collect the data on the sensor and send it to the upper computer for the staff to observe and monitor.

Claims

A disc spring force monitoring sensor for a rear cover of a hoist brake is characterized in that it includes a transparent cover (6) provided on the front disc brake and a cover plate provided on an outer end surface of the transparent cover. The center line of (6) coincides with the center line of the front disc brake. The outside of the transparent cover (6) is stepped, and an outer annular groove is provided on the outer end surface. A plurality of pairs are evenly distributed in the outer annular groove. The strain gauges (7) arranged in pairs, and the strain gauges (7) arranged in pairs are respectively closely attached to the outer diameter in the annular groove at a certain deflection angle α; the inner hole of the transparent cover (6) is stepped, and An inner annular groove is provided at a position corresponding to the outer annular groove opened on the outer end surface. The inner diameter of the shoulder in the inner hole of the transparent cover (6) is the same as the inner diameter of the disc spring of the front disc brake. On the disc spring of the disc brake, a countersunk hole is formed on the outer ring of the largest diameter of the transparent cover (6), and is connected to the hydraulic cylinder and the support of the disc brake by screws.
The back cover type disc spring force monitoring sensor for a brake of a hoist according to claim 1, characterized in that said plurality of strain gauges are 6-10 pieces, all of which are distributed on the inner and outer diameters of the annular groove.
The rear cover type disc spring force monitoring sensor for a brake of a hoist according to claim 1, wherein the certain deflection angle α is 5-10 °.