阅读说明：本技术 适应不同工况的提升机紧急制动系统 (Elevator emergency braking system suitable for different working conditions ) 是由 黄家海 郝惠敏 于培 落财秀 于 2019-09-17 设计创作，主要内容包括：本发明针对当前摩擦式提升机紧急制动存在的技术问题,提供一种适应不同运行工况的提升机紧急制动系统,该系统根据矿井提升机紧急制动时的提升速度、载荷、提升高度等运行参数,计算获得提升机制动时钢丝绳不发生打滑的极限制动减速度,并以该极限制动减速度进行制动,从而实现提升机的平稳制动,提高矿井提升机的安全运行性能和生产效率。(The invention provides an emergency braking system of a hoist, which is suitable for different operation conditions, aiming at the technical problems of the emergency braking of the current friction type hoist, and the system calculates and obtains the limit braking deceleration of the steel wire rope without slipping when the hoist is braked according to the operation parameters such as the hoisting speed, the load, the hoisting height and the like when the mine hoist is braked emergently, and brakes by the limit braking deceleration, thereby realizing the stable braking of the hoist and improving the safe operation performance and the production efficiency of the mine hoist.)

1. Hoist emergency braking system of adaptation different operating modes includes: the device comprises a winding drum 1, a lower head sheave 2, an upper head sheave 3, a hoisting steel wire rope 4, an I cage 5, a tail rope 6, a II cage 7, a brake 8 and a control system 9; the hoisting steel wire rope winds the winding drum, the upper head sheave and the lower head sheave, and two ends of the hoisting steel wire rope are respectively connected with the upper end surfaces of the first cage and the second cage; two ends of the tail rope are respectively connected with the lower surfaces of the first cage and the second cage and are in a natural suspension state; the brake brakes are positioned on two sides of the winding drum in pairs, and when the friction type hoisting machine carries out emergency braking, the control system sends out an emergency braking instruction to enable the brake brakes on two sides of the winding drum to be attached to the winding drum to brake; the method is characterized in that: the deceleration of the friction type hoister during emergency braking is the ultimate braking deceleration without slipping of the steel wire rope, so that the emergency braking of the hoister adapting to different operating conditions is realized;

the limit braking deceleration at which the wire rope does not slip is determined by the following method:

the dynamic tension difference delta T ═ T between two ends of the steel wire rope is obtained according to the following two formulas₁-T₂，

T₁＝(m₂+N₁ρ₁L₂+N₂ρ₂X₂)(g+a)-N₁ρ₁L_xa-N₁ρ₁L_xg sinβ_x (1)

T₂＝(m₁+N₁ρ₁L₁+N₂ρ₂X₁)(g-a)+N₁ρ₁L_sa-N₁ρ₁L_sg sinβ_s (2)

In the formula: m is₁And m₂The masses, L, of the first and second cages₁、L_S、L_X、L₂The lengths of the steel wire ropes on the upper head sheave side, the upper chord, the lower chord and the lower head sheave lifting side are X₁And X₂Respectively at the upper and lower head sheave sidesLength of tail rope, N₁The number of the hoisting steel wire ropes is; n is a radical of₂The number of tail ropes is; rho₁For increasing the linear density of the steel wire rope; rho₂Is the tail rope linear density; beta is a_xIs the lower chord elevation angle; beta is a_sIs the upper chord elevation angle; g is the acceleration of gravity; a is braking deceleration;

when the hoister is in heavy-load hoisting or lowering working condition, the ultimate braking deceleration of the steel wire rope without slipping is as follows: and the dynamic tension difference delta T of the two ends of the steel wire rope is equal to the corresponding braking deceleration when the friction force between the winding drum of the hoister and the steel wire rope.

Technical Field

The invention belongs to the technical field of safety braking of friction type hoists, and particularly relates to an emergency braking system of a hoist, which is suitable for different working conditions.

Background

The friction type hoist is widely applied to mine production with the advantages of high hoisting capacity and the like, and is an extremely important device in mine production. The friction type elevator transmits torque and movement based on a steel wire rope flexible friction transmission principle, and belongs to a typical flexible transmission system. When the friction type hoister transports heavy objects, the change of the tension difference of the steel wire ropes on the two sides of the winding drum of the friction type hoister directly influences the running state of the hoisting system, the dynamic tension difference of the steel wire ropes is mainly caused by the dynamic load of the system, if the dynamic load is overlarge, larger inertia impact can be generated, and the hoisting system is easy to slip or even break.

At present, the friction type mine hoist is braked mainly by two modes: constant torque braking and constant deceleration braking.

The constant-torque braking system applies rated braking torque to the lifting winding drum twice, the braking torque applied for the first time enables the lifting system to generate deceleration meeting the regulation, and after a set time delay, all braking torque is added for the second time, so that the lifting system is stopped and braked. This method has the following disadvantages: (1) because the lifting direction and the load magnitude are changed frequently (such as auxiliary shaft lifting), the fluctuation range of the braking deceleration is easy to be large and even exceeds the critical value of coal mine safety regulation; (2) for friction type lifting equipment, when the lifting load is large, the phenomenon of slipping of a steel wire rope easily occurs under the emergency braking working condition.

The constant deceleration braking system makes the lifting winding drum brake to stop emergently according to a certain preset and constant deceleration by adjusting the braking force of the brake. Compared with a constant-torque braking system, the method effectively improves the braking stability and reduces the braking impact and vibration phenomena, but because the constant-deceleration braking system does not consider the influence of the braking initial operation condition parameters and the flexible transmission characteristics of the steel wire rope, the constant-deceleration braking system adopts the preset deceleration for braking, and although the constant-deceleration braking system can realize the stable braking of the hoisting drum, the stable braking of the hoisting container hung at the tail end of the steel wire rope can not be realized; in addition, because of the difference of the lifting parameters such as the lifting height, the operating speed and the lifting load of the friction type lifter during braking, if the friction type lifter is braked by adopting the preset deceleration, the system can easily generate larger impact and vibration phenomena, and even induce the serious accidents such as the slipping of the steel wire rope and the rope breakage.

Disclosure of Invention

The invention provides an emergency braking system of a hoist, which is suitable for different operation conditions, aiming at the technical problems of the emergency braking of the current friction type hoist, and the system calculates and obtains the limit braking deceleration of the steel wire rope without slipping when the hoist is braked according to the operation parameters such as the hoisting speed, the load, the hoisting height and the like when the mine hoist is braked emergently, and brakes by the limit braking deceleration, thereby realizing the stable braking of the hoist and improving the safe operation performance and the production efficiency of the mine hoist.

In order to achieve the purpose, the invention adopts the following technical scheme:

hoist emergency braking system of adaptation different operating modes includes: the device comprises a winding drum 1, a lower head sheave 2, an upper head sheave 3, a hoisting steel wire rope 4, an I cage 5, a tail rope 6, a II cage 7, a brake 8 and a control system 9; the hoisting steel wire rope winds the winding drum, the upper head sheave and the lower head sheave, and two ends of the hoisting steel wire rope are respectively connected with the upper end surfaces of the first cage and the second cage; two ends of the tail rope are respectively connected with the lower surfaces of the first cage and the second cage and are in a natural suspension state; the brake brakes are positioned on two sides of the winding drum in pairs, and when the friction type hoisting machine carries out emergency braking, the control system sends out an emergency braking instruction to enable the brake brakes on two sides of the winding drum to be attached to the winding drum to brake; the deceleration of the friction type hoister during emergency braking is the ultimate braking deceleration without slipping of the steel wire rope, so that the emergency braking of the hoister adapting to different operating conditions is realized;

the limit braking deceleration at which the wire rope does not slip is determined by the following method:

the dynamic tension difference delta T ═ T between two ends of the steel wire rope is obtained according to the following two formulas₁-T₂，

T₁＝(m₂+N₁ρ₁L₂+N₂ρ₂X₂)(g+a)-N₁ρ₁L_xa-N₁ρ₁L_xgsinβ_x (1)

T₂＝(m₁+N₁ρ₁L₁+N₂ρ₂X₁)(g-a)+N₁ρ₁L_sa-N₁ρ₁L_sgsinβ_s (2)

In the formula: m is₁And m₂The masses, L, of the first and second cages₁、L_S、L_X、L₂The lengths of the steel wire ropes on the upper head sheave side, the upper chord, the lower chord and the lower head sheave lifting side are X₁And X₂The lengths of tail ropes at the sides of the upper and lower hoisting sheaves, N₁The number of the hoisting steel wire ropes is; n is a radical of₂The number of tail ropes is; rho₁For increasing the linear density of the steel wire rope; rho₂Is the tail rope linear density; beta is a_xIs the lower chord elevation angle; beta is a_sIs the upper chord elevation angle; g is the acceleration of gravity; a is braking deceleration;

when the hoister is in heavy-load hoisting or lowering working condition, the ultimate braking deceleration of the steel wire rope without slipping is as follows: and the dynamic tension difference delta T of the two ends of the steel wire rope is equal to the corresponding braking deceleration when the friction force between the winding drum of the hoister and the steel wire rope.

Compared with the prior art, the invention has the following advantages:

the invention overcomes the defect that the traditional constant deceleration braking system carries out emergency braking according to the preset deceleration curve, and comprehensively considers the influence of the operation parameters such as the lifting speed, the load, the lifting height and the like of the hoister on the system stability in the braking process; braking is carried out by the ultimate deceleration of the steel wire rope without slipping, so that the hoisting system is ensured not to slip, the impact and vibration generated in the braking process of the hoisting container are reduced, and the high-efficiency braking of the hoisting machine is realized.

Drawings

FIG. 1 is a schematic diagram of the emergency braking system of the elevator adapted to different working conditions;

in the figure: the hoisting device comprises a winding drum 1, a lower head sheave 2, an upper head sheave 3, a hoisting steel wire rope 4, an I-th cage 5, a tail rope 6, an II-th cage 7, a brake 8 and a control system 9.

Detailed Description

The detailed technical scheme of the invention is described in the following with the accompanying drawings:

the emergency braking system of the hoist that adapts to different working conditions, as shown in fig. 1, includes: the device comprises a winding drum 1, a lower head sheave 2, an upper head sheave 3, a hoisting steel wire rope 4, an I cage 5, a tail rope 6, a II cage 7, a brake 8 and a control system 9; the hoisting steel wire rope winds the winding drum, the upper head sheave and the lower head sheave, and two ends of the hoisting steel wire rope are respectively connected with the upper end surfaces of the first cage and the second cage; two ends of the tail rope are respectively connected with the lower surfaces of the first cage and the second cage and are in a natural suspension state; the brake brakes are positioned on two sides of the winding drum in pairs, and when the friction type hoisting machine carries out emergency braking, the control system sends out an emergency braking instruction to enable the brake brakes on two sides of the winding drum to be attached to the winding drum to brake; the deceleration of the friction type hoister during emergency braking is the ultimate braking deceleration without slipping of the steel wire rope, so that the emergency braking of the hoister adapting to different operating conditions is realized;

in FIG. 1, the masses of the first cage and the second cage are m₁And m₂The lengths of the wire ropes on the upper head sheave side, the upper chord, the lower chord and the lower head sheave lifting side are respectively L₁、L_S、L_X、L₂The lengths of the tail ropes of the upper and lower aerial wheels are X respectively₁And X₂According to the rigid body dynamics theory, the tension T of the steel wire rope at the contact point of the lower chord steel wire rope and the winding drum₁And the tension T of the steel wire rope at the contact point of the upper chord steel wire rope and the winding drum₂Respectively as follows:

T₁＝(m₂+N₁ρ₁L₂+N₂ρ₂X₂)(g+a)-N₁ρ₁L_xa-N₁ρ₁L_xgsinβ_x (1)

T₂＝(m₁+N₁ρ₁L₁+N₂ρ₂X₁)(g-a)+N₁ρ₁L_sa-N₁ρ₁L_sgsinβ_s (2)

in the formula: n is a radical of₁The number of the hoisting steel wire ropes is; n is a radical of₂The number of tail ropes is; rho₁For increasing the linear density of the steel wire rope; rho₂Is the tail rope linear density; beta is a_xIs the lower chord elevation angle; beta is a_sIs the upper chord elevation angle; g is the acceleration of gravity; a is the braking deceleration.

Wire rope tension T₁And T₂The difference value of (2) is the dynamic tension difference at two ends of the hoisting steel wire rope, and the hoisting machine can normally work only by ensuring that the friction force is greater than the dynamic tension difference at two ends of the hoisting steel wire rope in the process of transmitting power. As can be seen from the equations (1) and (2), the load (m) of the system is changed₁And m₂) Or braking deceleration (a) or the likeThe hoisting parameters can change the dynamic load of the system, thereby changing the dynamic tension difference of the steel wire rope. When the difference of the dynamic tension at the two ends of the steel wire rope is larger than the friction force of the system, the steel wire rope can slip, so that the sudden change point of the slipping of the hoisting system can be determined according to the gradual increase of the difference of the dynamic tension of the steel wire rope.

The limit braking deceleration at which the wire rope does not slip is determined by the following method:

for the heavy-load lowering working condition, the lowering height before the elevator brakes, the maximum running speed, the braking deceleration and the lifting side load are set to be constant, the lowering side load is gradually increased by taking a smaller fixed value as a step length, when the elevator performs constant deceleration braking, the dynamic load of the system is gradually increased, the dynamic tension difference at two ends of the steel wire rope is increased, the possibility of system slippage is increased, when the dynamic tension difference at two ends of the steel wire rope is just equal to the friction force between the winding drum and the steel wire rope, the lifting system is in a critical slippage state, and the braking deceleration at the moment is the ultimate braking deceleration at which the steel wire rope does not slip under the working condition.

For a heavy-load lifting working condition, the lifting height, the maximum running speed, the load on the lowering side and the load on the lifting side of the lifting machine before braking are set to be constant, the braking deceleration is gradually increased by taking a smaller fixed value as a step length, the possibility of system slippage is increased along with the increase of the dynamic load of the system, and when the dynamic tension difference at two ends of the steel wire rope is just equal to the friction force between the winding drum and the steel wire rope, the braking deceleration at the moment is the limit braking deceleration at which the steel wire rope does not slip under the working condition.

By adopting the method for determining the limited braking deceleration without the slippage of the steel wire rope, two lifting parameters (load and braking deceleration) which have large influence on the dynamic load of the system are segmented according to the maximum rated load and the maximum allowable braking deceleration of the lifting machine. For example: the lifting load is divided into 1-2t, the limit braking deceleration without slipping of the system is determined by experiments when the load is 2t, and the braking deceleration can be used as the upper limit for the lifting working condition that the lifting load is greater than 1t and less than 2t, so that the phenomenon that the lifting machine slips in the braking process is avoided. The higher the classification precision of the load and the braking deceleration is, the more accurate the corresponding limit braking deceleration is, thereby realizing the emergency braking of the hoister adapting to different working conditions.