No-load test system for the braking performance of an elevator during loaded downward travel

Abstract

A no-load test system for the braking performance of an elevator during loaded downward travel, which relates to the technology of elevator braking performance detection. It can test the average deceleration of the elevator car during the no-load braking process, and judge whether the elevator meets the bilateral downward braking performance at the lower end of the 125% rated load travel and the unilateral downward braking performance at the lower end of the 100% rated load travel through a calculation model. The braking deceleration measurement module measures the average braking deceleration of the elevator car during the elevator braking process. The braking instant detection module detects at the instant when the braking actuator brakes the brake wheel to obtain the moment of the braking execution instant. The braking trigger module triggers the braking actuator to brake the rotating brake wheel to achieve the stop of the elevator car. The main controller controls the braking trigger module to trigger the action of the elevator braking actuator and obtains the deceleration data of the elevator car measured by the braking deceleration measurement module and the action instant signal of the braking actuator detected by the braking instant detection module.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator braking performance detection, and particularly to a no-load test system for the braking performance of an elevator descending with load. Background Art

[0002] The braking performance of an elevator is like the braking performance of a car, and its role in the safe operation of the elevator is self-evident. The current national standard GB / T 7588.1-2020 "Safety Rules for the Construction and Installation of Lifts" Article 12.4.2.1 stipulates that when the car is carrying 125% of the rated load and running downward at the rated speed, operating the brake should be able to stop the traction machine. All brake mechanical components participating in applying braking force to the brake wheel or disc should be installed in two groups. If one group of components fails to function, there should still be sufficient braking force to decelerate the car carrying the rated load and running downward at the rated speed. The inspection content and requirements of item 8.13 on "Braking Test" in the elevator inspection legal regulations TSGT7001-2009 "Rules for Elevator Supervision and Periodic Inspection - Traction and Forced Drive Elevators" are: when the car is loaded with 125% of the rated load and running downward at the normal operating speed, cut off the power supply of the motor and the brake, and the brake should be able to stop the drive host. After the test, the car should have no obvious deformation or damage.

[0003] The above inspection regulations and national standards stipulate the requirements for 125% rated load bilateral braking (the meaning of bilateral braking is: both braking arms of the traction host brake simultaneously) and 100% rated load unilateral braking (the meaning of unilateral braking is: one of the two braking arms of the traction host brakes) of the elevator. The traditional detection method for the braking performance of an elevator with load requires moving weights into the car and then conducting a braking test for the car descending with load. This method is time-consuming and laborious, inconvenient for testing, has low efficiency, and there is a safety hazard of the ladder slipping during the process of moving weights. Therefore, the research on the no-load test method for the braking performance with load has always been a hot topic in the elevator industry. Currently, the no-load detection and evaluation methods for the braking performance of an elevator with load reported in the existing literature mainly include: external drive braking force detection method, no-load up and down braking method, energy conversion deceleration calculation method, multi-parameter intelligent monitoring method, pressure monitoring calculation method, no-load upward braking method, etc. The above several methods mainly have the following problems:

[0004] The external drive braking force detection method can monitor the braking force through an external frequency conversion drive, reflecting the braking ability. However, the calculation mathematical model is specific to a certain type of elevator, lacking universality in testing. The no-load up and down braking method judges whether the decelerations of double-sided braking at 125% load and single-sided braking at 100% load are greater than zero through the decelerations of two no-load tests. It can be directly corresponded to the national standard GB / T 7588.1 and the inspection regulation TSG T7001. However, it cannot calculate the specific braking deceleration value under load and cannot achieve a more in-depth evaluation of the braking performance. The energy conversion deceleration calculation method needs to know the masses of the counterweight and the car in advance when calculating the braking deceleration at 125% load based on the no-load upward braking deceleration, which is difficult to obtain in practice. The multi-parameter intelligent monitoring method comprehensively judges by substituting multiple parameters such as the brake holding gap, temperature, and braking force monitored online into the model. To a certain extent, this method reflects the comprehensive braking performance of a specific type of elevator, but it still cannot directly test the downward braking performance at 125% load and 100% load specified in the inspection regulation and the standard. The pressure monitoring calculation method indirectly calculates the braking force using a pressure sensor according to the force balance relationship. Whether it can be applied to other various forms of brakes remains to be further verified, and a reasonable range of the braking force is not given. The no-load upward braking method is a braking performance detection method widely used in the industry. The formed standard gives the reasonable ranges of the stopping distance and braking deceleration at different rated speeds, having good reference value. However, this standard does not well explain the relationship between the no-load braking deceleration, stopping distance and the downward braking performance under load in the inspection regulation and the national standard, and the correspondence with the inspection regulation is not strong enough.

[0005] Therefore, how to provide a no-load test system and method for the downward braking performance of an elevator with load, which can trigger no-load braking, measure the average deceleration during the no-load braking process, and then detect the downward braking performance of the elevator with load, has become a technical problem that needs to be solved urgently by those skilled in the art, and it has important significance. Summary of the Invention

[0006] The purpose of the present invention is to provide a no-load test system and method for the downward braking performance of an elevator with load. This system can test the average deceleration of the car during the no-load braking process of the elevator, and can judge whether the elevator meets the double-sided downward braking performance at the lower end of the 125% rated load stroke and the single-sided downward braking performance at the lower end of the 100% rated load stroke through a calculation model. This method can quickly and conveniently calculate the average braking deceleration under load based on the average braking deceleration measured in the no-load braking test.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A no-load test system for the braking performance of an elevator during loaded downward travel, comprising: a braking deceleration measurement module for measuring the average braking deceleration of the elevator car during the braking process of the elevator;

[0009] A braking instant detection module assembled on the braking actuator for detecting at the instant when the braking actuator brakes the brake wheel to obtain the moment of the braking execution instant;

[0010] A braking trigger module for controlling the power failure of the brake coil to trigger the braking actuator to brake the rotating brake wheel and stop the traction wheel coaxial with the brake wheel, thereby achieving the stopping of the elevator car;

[0011] A main controller respectively connected to the braking deceleration measurement module, the braking instant detection module and the braking trigger module, for controlling the braking trigger module to trigger the action of the elevator braking actuator, and obtaining the elevator car deceleration data measured by the braking deceleration measurement module and the action instant signal of the braking actuator detected by the braking instant detection module, so as to...

[0012] In actual application, the no-load test system for the braking performance of the elevator during loaded downward travel further comprises: a human-machine interaction module connected to the main controller for controlling the main controller to obtain test system information and achieve human-machine interaction.

[0013] Wherein, the human-machine interaction module controls the main controller in any one or more of the ways of a display screen, a mouse, a keyboard, a button or a touch screen.

[0014] Specifically, the main controller selects any one of a PLC, a personal computer, an industrial control computer or a single-chip microcomputer, and the main controller and the braking deceleration measurement module, the braking instant detection module and the braking trigger module are communicatively connected in a wired or wireless manner.

[0015] Furthermore, the wireless communication method adopts WiFi or Bluetooth, and signal relay modules are respectively arranged between the main controller and the braking deceleration measurement module, the braking instant detection module and the braking trigger module.

[0016] Even further, the braking deceleration measurement module adopts a rotary encoder module, the rotary encoder module contacts the elevator traction steel wire rope through a speed measurement roller, and the speed measurement roller is coaxially and fixedly connected to the rotary encoder module.

[0017] Alternatively, the braking deceleration measurement module adopts an acceleration sensor, and the acceleration sensor is placed inside the elevator car.

[0018] Furthermore, the braking trigger module can disconnect the main relay contact in the power circuit of the control cabinet and trigger the elevator control system to output a braking command externally, so that the braking coil of the brake loses power, realizing the braking of the brake wheel.

[0019] Compared with the prior art, the no-load test system for the braking performance of an elevator with load during downward travel has the following advantages:

[0020] In the no-load test system for the braking performance of an elevator with load during downward travel provided by the present invention, since the braking deceleration measurement module can be used to measure the average braking deceleration of the car during the braking process of the elevator, the braking instant detection module can be used to detect at the instant when the braking actuator brakes the brake wheel to obtain the moment of the braking execution instant, the braking trigger module can be used to control the power failure of the brake coil to trigger the braking actuator to brake the rotating brake wheel and stop the traction wheel coaxial with the brake wheel, realizing the stopping of the elevator car, and the main controller can be used to control the braking trigger module to trigger the action of the elevator braking actuator and obtain the deceleration data of the elevator car measured by the braking deceleration measurement module and the action instant signal of the braking actuator detected by the braking instant detection module. Therefore, the braking instant detection module can accurately identify the moment of the brake braking instant, which is beneficial to improving the accuracy of the average braking deceleration calculation. The braking trigger module can automatically trigger the braking process of the car at a specified position, reducing the problem of inaccurate judgment of the car position during manual power-off. And during the test, there is no need to carry weights, and it can realize the rapid evaluation of the braking performance with load through three no-load braking tests, thus effectively reducing manpower and material resources and improving the test efficiency and the safety of the test process.

[0021] A no-load test method for the braking performance of an elevator with load during downward travel includes the following steps:

[0022] Step S1, establish a calculation model for the deceleration a125 in the case of bilateral braking during downward travel of the elevator car at 125% of the rated load and the deceleration a100 in the case of unilateral braking during downward travel of the elevator car at 100% of the rated load;

[0023] Step S2, according to the judgment conditions of the calculation model, conduct a no-load test on the braking performance of the elevator with load during downward travel;

[0024] Among them, the specific steps of step S1 include the following steps:

[0025] Step S11, establish a dynamic model of the elevator braking process according to the eccentric load moment and the moment of inertia;

[0026] Step S12, conduct dynamic analysis on different braking conditions according to the dynamic model;

[0027] Step S13: Calculate the bilateral braking deceleration when the lower end of the 125% rated load stroke descends as

[0028] Step S14: Calculate the unilateral braking deceleration when the lower end of the 100% rated load stroke descends as

[0029] The specific steps of the said Step S2 include the following steps:

[0030] Step S21: Consult materials or conduct a balance coefficient test to obtain the balance coefficient K of the elevator to be measured;

[0031] Step S22: Operate the elevator to run upward without load from the bottom layer at the normal operating speed. When the car runs to the middle of the stroke, cut off the power supply of the elevator, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 1 ;

[0032] Step S23: Operate the elevator to run downward without load from the top layer at the normal operating speed. When the car runs to the middle of the stroke, cut off the power supply of the elevator, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 2 ;

[0033] Step S24: Operate the elevator to run downward without load from the top layer at the normal operating speed. When the car runs to the lower part of the stroke, cut off the power supply of the elevator, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 0 ;

[0034] Step S25: Process the data, and based on the obtained balance coefficient and the three braking decelerations measured in the above three steps, judge whether it meets and If it meets it indicates that the elevator meets the bilateral braking requirements for descending at 125% rated load, otherwise it does not meet; if it meets it indicates that the elevator meets the unilateral braking requirements for descending at 100% rated load, otherwise it does not meet.

[0035] Furthermore, the specific steps of the said Step S11 include: According to the torque balance relationship, ignoring the influence of the guide rail friction on the system, the dynamic model of the traction elevator braking at different positions, different running directions, and different loading masses can be obtained:

[0036] Further, the step S12 specifically includes: performing dynamic analysis on the braking process for three no-load conditions and two loaded conditions of the elevator car. The three no-load conditions are respectively bilateral braking during upward movement in the middle of the no-load travel, bilateral braking during downward movement in the middle of the no-load travel, and bilateral braking during downward movement at the lower end of the no-load travel. The two loaded conditions are respectively the bilateral braking condition during downward movement at the lower part of the 125% rated load travel and the unilateral braking condition during downward movement at the lower part of the 100% rated load travel. The values of c and x under the five braking conditions are shown in Table 1 below:

[0037]

[0038]

[0039] Assuming that the bilateral braking torque of the brake is M, and the unilateral braking torque is half of the bilateral braking torque, the braking torque, eccentric load torque, and rotational inertia corresponding to the car load under the five braking conditions are shown in Table 2 below:

[0040]

[0041]

[0042] Further, the step S13 specifically includes: The actual transmission efficiency is approximately 100%. To simplify the calculation process, assume that the transmission efficiency is 100%, that is, η = 1; and the braking deceleration expression for bilateral braking during downward movement at the lower end of the 125% rated load travel is sorted out:

[0043]

[0044] Even further, the step S11 specifically includes: During the elevator braking process, an eccentric load torque will be generated on the axis of the brake wheel due to the weight difference on both sides of the traction wheel. Assume that the positive direction of the eccentric load torque is the direction of the car deceleration movement, that is, the opposite direction of the braking torque during braking. Then the eccentric load torque can be expressed as: In the formula:

[0045] M P —— Eccentric load torque, unit N·m;

[0046] x —— Loading coefficient, that is, the ratio of the car load to the rated load;

[0047] m s1 —— Mass of the wire rope on the car side of the traction wheel, unit kg;

[0048] m b1 —— Mass of the compensating rope (chain) on the car side of the traction wheel, unit kg;

[0049] m s2 —— Mass of the wire rope on the counterweight side of the traction wheel, unit kg;

[0050] m b2 —— The mass of the compensating rope (chain) on the counterweight side of the traction sheave, unit: kg;

[0051] W —— The mass of the counterweight, unit: kg;

[0052] P —— The mass of the car, unit: kg;

[0053] Q —— The rated load, unit: kg;

[0054] D —— The pitch diameter of the traction sheave, unit: m;

[0055] i —— The traction ratio, that is, the ratio of the moving speed of the steel wire rope to the moving speed of the car during the operation of the elevator;

[0056] r —— The transmission ratio from the brake wheel to the traction sheave, that is, the ratio of the rotational speed of the brake wheel to the rotational speed of the traction sheave, which is equal to 1 for synchronous motors;

[0057] g —— The gravitational acceleration coefficient, with a value of 9.8 m·s -2 ;

[0058] If the total lifting height of the elevator car is H and the total mass of the compensating rope (chain) is m b , then:

[0059] m s1 =(1 - c)m s —— (2), where:

[0060] m s —— The total mass of the steel wire rope, unit: kg;

[0061] c —— The car position coefficient, dimensionless, with a value range from 0 to 1, 0 indicates that the car is at the bottom terminal station, and 1 indicates that the car is at the top terminal station;

[0062] The mass of the steel wire rope on the counterweight side of the traction sheave is: m s2 =cm s —— (3), the mass of the compensating rope (chain) on the car side of the traction sheave is: m b1 =cm b —— (4), where:

[0063] m b —— The total mass of the compensating rope (chain), unit: kg;

[0064] The mass of the compensating rope (chain) on the counterweight side of the traction sheave is: m b2 =(1 - c)m b —— (5), substituting equations (2), (3), (4), and (5) into equation (1) gives: The off - loading moment is related to the loading mass of the elevator car and the position of the elevator car. If the steel wire ropes and compensating ropes (chains) reach the ideal compensation state, the off - loading moment is only related to the position of the car.

[0065] During the elevator braking process, the moment of inertia of the moving system can be composed of two parts: J = J Z + J 0 ——(7), where:

[0066] J——The total moment of inertia of the system, unit kg·m 2 ;

[0067] J 0 ——The moment of inertia of rotating components such as the traction sheave and brake sheave, unit kg·m 2 ;

[0068] J Z ——The moment of inertia of the remaining linear - motion components except for rotating components such as the traction sheave and brake sheave, that is, the total moment of inertia of the car, counterweight, load in the car, steel wire ropes, and compensating ropes (chains), unit kg·m 2 ;

[0069] From rigid - body dynamics, the following relationship exists between the moment of inertia and mass of a linearly - moving object: where:

[0070] ω——The angular velocity of the brake - wheel rotation, unit s -1 ;

[0071] v——The running speed of the car, unit m·s -1 ;

[0072] m——The total mass of the car, counterweight, and load, unit kg;

[0073] m can be expressed as: m = P + W + xQ ——(9), and the relationship between the angular velocity of the brake - wheel rotation and the linear velocity of the car is: Substituting Equation (9) and Equation (10) into Equation (8) gives:

[0074] The definition of the balance coefficient in Appendix G2.4 of GB 7588 is "the amount by which the rated load and car mass are balanced by the counterweight or balance weight". According to this definition, the relationship between P, W, and Q is:

[0075] W = P + KQ ——(12), where:

[0076] K——The balance coefficient, dimensionless;

[0077] Substituting Equation (12) into Equation (11) and after rearrangement, J Z is composed of two parts: J Z = JZ1 +J Z2 ——(13), where:

[0078] J Z1 —— The moment of inertia of the inherently rectilinear moving parts of the system, i.e., the total moment of inertia of the car, counterweight, wire rope, compensating rope (chain), with the unit kg·m 2 ;

[0079] J Z2 —— The moment of inertia of the load in the car when the load factor is x, with the unit kg·m 2 ;

[0080] J Z1 Can be expressed as: J Z2 Can be expressed as: For a given elevator system, the car mass, counterweight mass, balance factor, traction ratio, wire rope mass, compensating rope (chain) mass, traction wheel diameter, and transmission ratio can be considered constant. Therefore, J Z1 Is a constant, and J Z2 Is related to the weight of the object carried in the car;

[0081] According to the moment balance relationship, ignoring the influence of the guide rail friction on the system, the braking torque during the braking process is the sum of the off-load torque M P And the inertia torque ηJε, and we can get: M Z -M P = ηJε ——(16), where:

[0082] M Z —— The braking torque, whose direction is opposite to the direction of the car movement, with the unit N·m;

[0083] ε —— The angular deceleration of the brake wheel, with the unit rad·s-2;

[0084] η —— The transmission efficiency from the brake wheel to the traction wheel, dimensionless;

[0085] The relationship between the angular deceleration of the brake wheel and the car deceleration is: where:

[0086] a —— The car braking deceleration, m·s -2 ;

[0087] Substituting equations (7), (13), and (17) into equation (16), we can obtain the dynamic model of the traction elevator during braking at different positions, different running directions, and different loading masses:

[0088] Furthermore, the step S12 specifically includes: performing dynamic analysis on the braking processes of three no-load conditions and two loaded conditions of the elevator car. The three no-load conditions are respectively bilateral braking during upward travel in the middle of the no-load stroke, bilateral braking during downward travel in the middle of the no-load stroke, and bilateral braking during downward travel at the lower end of the no-load stroke. The two loaded conditions are respectively the bilateral braking condition during downward travel in the lower part of the 125% rated load stroke and the unilateral braking condition during downward travel in the lower part of the 100% rated load stroke. The values of c and x under the five braking conditions are shown in Table 1 below:

[0089]

[0090]

[0091] When bilateral braking during upward travel in the middle of the no-load stroke or bilateral braking during downward travel in the middle of the no-load stroke, the masses of the wire ropes on both sides of the traction sheave and the mass of the compensating rope (chain) are equal. The positive direction of the unbalanced load moment is opposite to the direction of the braking moment. Substituting the parameters in Table 1 into Equation (6) gives the unbalanced load moments under the two conditions, as shown in Equations (19) and (20) respectively:

[0092] For bilateral braking during downward travel at the lower end of the no-load stroke, it can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side. Substituting the parameters in Table (1) into Equation (6) gives the unbalanced load moment under this condition:

[0093] In the standard GB7588-2003 for the bilateral braking condition at 125% rated load, the car is at the lower end of the stroke. It can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side. The unbalanced load moment is: From Equation (15), it can be known that the moment of inertia corresponding to the load under this condition is:

[0094] In the standard GB7588-2003 for the unilateral braking condition at 100% load, the car is at the lower end of the stroke. It can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side. The unbalanced load moment is: From Equation (15), it can be known that the moment of inertia corresponding to the load under this condition is:

[0095] Assuming that the bilateral braking moment of the brake is M, and the unilateral braking moment is half of the bilateral braking moment, combining with the definition of the balance coefficient in Equation (11) to simplify Equations (19), (20), (21), (22) and (24), the braking moments, unbalanced load moments, and the moments of inertia corresponding to the car load under the five braking conditions are shown in Table 2 below:

[0096]

[0097]

[0098] Furthermore, the step S13 specifically includes: the actual transmission efficiency is approximately 100%. To simplify the calculation process, it is assumed that the transmission efficiency is 100%, that is, η = 1. According to the parameter values in Equation (18) and Table 2, a dynamic equation set for three no-load braking conditions and the 125% rated load braking condition is established:

[0099] In the above equation set:

[0100] a 1 —— The braking deceleration of bilateral braking during the upward movement in the middle of the no-load stroke, unit m·s -2 ;

[0101] a 2 —— The braking deceleration of bilateral braking during the downward movement in the middle of the no-load stroke, unit m·s -2 ;

[0102] a 0 —— The braking deceleration of bilateral braking during the downward movement at the lower part of the no-load stroke, unit m·s -2 ;

[0103] a 125 —— The braking deceleration of bilateral braking during the downward movement at the lower end of the 125% rated load stroke, unit m·s -2 ;

[0104] A, B, and C are custom constants used to simplify the calculation process, and are respectively:

[0105] X is related to the moment of inertia generated by 125% of the rated load: Dividing Equation (26) by Equation (27) and substituting it into Equation (33) gives:

[0106] Adding Equation (26) and Equation (27) and substituting it into Equation (34) gives:

[0107] Subtracting Equation (28) from Equation (29) gives: 1.25A = Ba 0 -(B + X)a 125 —— (36);

[0108] Substitute Equation (30), Equation (33) and Equation (35) into Equation (36), and after arrangement, the braking deceleration expression for the downward movement of the lower end of the 125% rated load stroke with bilateral braking is obtained:

[0109]

[0110] Furthermore, the step S14 specifically includes: establishing the dynamic equations for three no-load braking conditions and the 100% rated load braking condition according to Equation (8) and the parameters in Table 2:

[0111] In the above equations:

[0112] a 1 —— The braking deceleration of the upward movement in the middle of the no-load stroke with bilateral braking, unit: m·s -2 ;

[0113] a 2 —— The braking deceleration of the downward movement in the middle of the no-load stroke with bilateral braking, unit: m·s -2 ;

[0114] a 0 —— The braking deceleration of the downward movement at the lower part of the no-load stroke with bilateral braking, unit: m·s -2 ;

[0115] a 100 —— The braking deceleration of the downward movement at the lower end of the 100% rated load stroke with unilateral braking, unit: m·s -2 ;

[0116] A, B and C are custom constants used to simplify the calculation process, and are respectively:

[0117] In Equation (38), X′ is related to the moment of inertia generated by the 100% rated load: Referring to the above calculation method of the braking deceleration at 125% rated load, the braking deceleration expression for the downward movement at the lower end of the 100% rated load stroke with unilateral braking is obtained:

[0118]

[0119] Furthermore, in the step S2, to meet the on-load braking performance requirements in GB7588 and TSG T7001, the braking deceleration should be greater than zero to meet the deceleration requirements. Therefore, there is:

[0120]

[0121] Substituting Equation (37) and Equation (40) into the above inequality group respectively and arranging, the relationship between the balance coefficient and the three no-load braking decelerations can be obtained:

[0122]

[0123] If the balance coefficient K and the three no-load braking decelerations a 1 、a 2 、a 0 simultaneously satisfy Equation (43) and Equation (44), it indicates that the elevator can meet the deceleration requirements for the lower part of the 125% rated load travel during downward double-sided braking and the lower part of the 100% rated load travel during downward single-sided braking, and this inspection item is qualified; Equation (43) and Equation (44) are the judgment bases for whether the elevator meets the downward double-sided braking performance of the 125% rated load travel and the downward single-sided braking performance of the 100% rated load travel.

[0124] The no-load test method for the loaded downward braking performance of the elevator and the above-mentioned no-load test system for the loaded downward braking performance of the elevator have the same advantages over the prior art, which will not be elaborated here.

[0125] In addition, the no-load test method for the loaded downward braking performance of the elevator described in the present invention has the following advantages:

[0126] First, through the calculation model, the quantitative calculation of the average deceleration during loaded downward braking can be realized, and it can be judged whether it is greater than zero to quickly judge the braking reliability of the elevator brake;

[0127] Second, when detecting the loaded braking performance of the elevator, it is only necessary to test the average deceleration under three no-load braking conditions, and the no-load test of the loaded braking deceleration can be realized through calculation, reducing the labor intensity, saving the test time and test cost;

[0128] Third, it can effectively avoid the damage to the elevator caused by carrying weights for braking tests, and since there is no need to carry weights in and out of the elevator car frequently, the safety of the test personnel is effectively protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0129] Figure 1 It is a schematic diagram of the module structure of the no-load test system for the loaded downward braking performance of the elevator provided by the embodiment of the present invention;

[0130] Figure 2 It is a schematic diagram of an installation structure of the no-load test system for the loaded downward braking performance of the elevator provided by the embodiment of the present invention;

[0131] Figure 3 It is another schematic diagram of an installation structure of the no-load test system for the loaded downward braking performance of the elevator provided by the embodiment of the present invention;

[0132] Figure 4 Schematic diagram of output signals of the braking instant detection module and the braking deceleration test module during the test in the no-load test system for the braking performance of an elevator with load during downward travel provided by an embodiment of the present invention;

[0133] Figure 5 Schematic diagram of the typical structure of a traction elevator;

[0134] Figure 6 Schematic diagram of the working condition of upward braking in the middle of the no-load bilateral travel of the elevator car;

[0135] Figure 7 Schematic diagram of the working condition of downward braking in the middle of the no-load bilateral travel of the elevator car;

[0136] Figure 8 Schematic diagram of the working condition of downward braking at the lower part of the no-load bilateral travel of the elevator car;

[0137] Figure 9 Schematic diagram of the working condition of bilateral braking during downward travel at the lower end of the 125% rated load travel of the elevator car;

[0138] Figure 10 Schematic diagram of the working condition of unilateral braking during downward travel at the lower end of the 100% rated load travel of the elevator car.

[0139] Reference numerals:

[0140] 1 - Braking deceleration measurement module; 11 - Rotary encoder module; 10 - Speed measurement roller; 12 - Acceleration sensor; 2 - Braking instant detection module; 3 - Braking trigger module; 4 - Main controller; 41 - Laptop computer; 42 - Single-chip microcomputer; 5 - Human-machine interaction module; 6 - Elevator car; 7 - Braking actuator; 71 - Brake wheel; 72 - Brake; 8 - Signal transfer module; 9 - Steel wire rope; 01 - Elevator machine room; 02 - Control cabinet. Detailed implementation manners

[0141] For ease of understanding, the no-load test system and method for the braking performance of an elevator with load during downward travel provided by an embodiment of the present invention will be described in detail below with reference to the accompanying drawings of the specification.

[0142] The no-load test system and method for the braking performance of an elevator with load during downward travel provided by an embodiment of the present invention can be used to test the average deceleration under various no-load braking conditions of the elevator, and at the same time can calculate the bilateral braking deceleration a125 during downward travel at the lower part of the 125% rated load travel of the elevator and the unilateral braking deceleration a100 during downward travel at the lower part of the 100% rated load travel of the elevator according to the calculation model, and evaluate the braking performance of the elevator according to whether a125 and a100 are greater than zero.

[0143] An embodiment of the present invention provides a no-load test system for the braking performance of an elevator during loaded downward travel, as follows Figures 1 - 4 shown, including: a braking deceleration measurement module 1, which is used to measure the average braking deceleration of the elevator car 6 during the braking process of the elevator;

[0144] a braking instant detection module 2, which is assembled on the braking actuator 7 and is used to detect at the instant when the braking actuator 7 brakes the brake wheel 71, so as to obtain the moment of the braking execution instant;

[0145] a braking trigger module 3, which is used to control the power failure of the brake coil, so as to trigger the braking actuator 7 to brake the rotating brake wheel 71 and stop the rotation of the traction wheel coaxial with the brake wheel 71, realizing the stopping of the elevator car 6;

[0146] a main controller 4, which is respectively connected to the braking deceleration measurement module 1, the braking instant detection module 2 and the braking trigger module 3, and is used to control the braking trigger module 3 to trigger the action of the elevator braking actuator 7, and obtain the deceleration data of the elevator car 6 measured by the braking deceleration measurement module 1 and the action instant signal of the braking actuator 7 detected by the braking instant detection module 2.

[0147] Compared with the prior art, the no-load test system for the braking performance of an elevator during loaded downward travel according to the embodiment of the present invention has the following advantages:

[0148] In the no-load test system for the braking performance of an elevator during loaded downward travel provided by the embodiment of the present invention, since the braking deceleration measurement module 1 can be used to measure the average braking deceleration of the car 6 during the braking process of the elevator, the braking instant detection module 2 can be used to detect at the instant when the braking actuator 7 brakes the brake wheel 71 to obtain the moment of the braking execution instant, the braking trigger module 3 can be used to control the power failure of the brake coil to trigger the braking actuator 7 to brake the rotating brake wheel 71 and stop the rotation of the traction wheel coaxial with the brake wheel 71 to realize the stopping of the elevator car 6, and the main controller 4 can be used to control the braking trigger module 3 to trigger the action of the elevator braking actuator 7 and obtain the deceleration data of the elevator car 6 measured by the braking deceleration measurement module 1 and the action instant signal of the braking actuator 7 detected by the braking instant detection module 2. Therefore, through the braking instant detection module 2, the moment of the brake braking instant can be accurately identified, which is beneficial to improving the accuracy of the average braking deceleration calculation. Through the braking trigger module 3, the car 6 can automatically trigger the braking process at a specified position, reducing the problem of inaccurate judgment of the car position during manual power-off. And during the test, there is no need to carry weights, and the rapid evaluation of the loaded braking performance can be realized through three no-load braking tests, thus effectively reducing manpower and material resources and improving the test efficiency and the safety of the test process.

[0149] In practical applications, such as Figure 1 shown, the no-load test system for the braking performance of an elevator with load during downward travel provided by the embodiment of the present invention may further include: a human-machine interaction module 5, which is connected to the main controller 4 and can be used to control the main controller 4 to obtain test system information and achieve human-machine interaction.

[0150] Among them, the above-mentioned human-machine interaction module 5 can control the main controller 4 in any one or more ways of a display screen, a mouse, a keyboard, buttons or a touch screen.

[0151] Specifically, the above-mentioned main controller 4 can be selected from any one of a PLC, a personal computer, an industrial control computer or a single-chip microcomputer, and the main controller 4 can communicate with the braking deceleration measurement module 1, the braking instant detection module 2 and the braking trigger module 3 in a wired or wireless manner.

[0152] Furthermore, the above-mentioned wireless communication method can be WiFi, Bluetooth or 2.4G, etc., and signal transfer modules 8 can be respectively arranged between the main controller 4 and the braking deceleration measurement module 1, the braking instant detection module 2 and the braking trigger module 3, so as to effectively ensure the accurate transmission of signals through the signal transfer module 8.

[0153] Even further, as Figure 2 shown, the above-mentioned braking deceleration measurement module 1 can adopt a rotary encoder module 11, which is in contact with the elevator traction steel wire rope 9 through a speed measurement roller 10, and the speed measurement roller 10 and the rotary encoder module 11 are coaxially fixedly connected.

[0154] Alternatively, as Figure 3 shown, the above-mentioned braking deceleration measurement module 1 can adopt an acceleration sensor 12, and the acceleration sensor 12 is placed inside the elevator car 6.

[0155] Still further, as Figure 2 and Figure 3 shown, the above-mentioned braking trigger module 3 can disconnect the main relay contact in the power circuit in the control cabinet 02 and trigger the elevator control system to output a braking command externally, so that the braking coil of the brake 72 loses power (that is, the internal iron core of the brake 72 loses magnetism), thereby realizing the braking of the brake wheel 71.

[0156] As Figure 4 shown, in the no-load test system for the braking performance of an elevator with load during downward travel provided by the embodiment of the present invention, the measurement principle of the average braking deceleration of the car is as follows:

[0157] During the elevator braking process, the speed of the elevator car 6 changes from v0 to zero. t1 is the instant when the brake 72 operates, and t2 is the instant when the speed of the elevator car 6 drops to zero. Then the average braking deceleration of this process is v0 / (t2 - t1). Therefore, to accurately calculate the average braking deceleration, it is necessary to accurately obtain the moment t1 when the elevator brake 72 starts to brake the brake wheel 71. In this system, this moment is obtained by the main controller 4 analyzing the continuous signal output by the braking instant detection module 2.

[0158] Assume that the type of electrical signal monitored by the braking instant detection module 2 is the potential signal U output by the braking state confirmation switch to the elevator main control board, and this potential signal is 0 when the brake 72 does not operate, and this potential signal becomes U0 after the brake 72 brakes. Then the moment t1 of the braking instant is the start moment of the rising edge of the signal U.

[0159] The test system respectively measures four variables: the average bilateral braking deceleration a1 in the middle of the no-load upward travel of the elevator, the average bilateral braking deceleration a2 in the middle of the no-load downward travel of the elevator, the average bilateral braking deceleration a0 in the lower part of the no-load downward travel of the elevator, and the elevator balance coefficient K. A dynamic calculation model for the elevator braking process is established, and the bilateral braking deceleration a125 of the elevator when traveling downward in the lower part of the 125% rated load travel and the unilateral braking deceleration a100 of the elevator when traveling downward in the lower part of the 100% rated load travel are calculated to realize the calculation of the loaded braking deceleration through the no-load braking deceleration, and then the loaded downward braking performance is evaluated according to the positive and negative values of a125 and a100. If the relationship between these three average decelerations and the balance coefficient K satisfies it indicates that the elevator meets the bilateral braking performance requirements for 125% rated load. If the relationship between these three decelerations and the balance coefficient K satisfies it indicates that this elevator meets the unilateral braking performance requirements for 100% rated load.

[0160] Another embodiment of the present invention further provides a no-load test method for the loaded downward braking performance of an elevator, as Figure 5 shown, including the following steps: Step S1, establish a calculation model for the deceleration a125 when the elevator car travels downward bilaterally in the lower part of the 125% rated load travel and the deceleration a100 when the elevator car travels downward unilaterally in the lower part of the 100% rated load travel; Step S2, according to the judgment conditions of the calculation model, conduct a no-load test on the loaded downward braking performance of the elevator.

[0161] Among them, the specific steps of the step S1 include the following steps: Step S11, establish a dynamic model for the elevator braking process according to the eccentric load moment and the moment of inertia; Step S12, conduct a dynamic analysis on different braking conditions according to the dynamic model; Step S13, calculate that the bilateral braking deceleration when traveling downward at the lower end of the 125% rated load travel is Step S14, calculate the unilateral braking deceleration when the lower end of the 100% rated load stroke moves downward as

[0162] The specific steps of step S2 are as follows: Step S21, consult materials or conduct a balance coefficient test to obtain the balance coefficient K of the elevator to be measured; Step S22, operate the elevator to move upward without load from the bottom floor at the normal operating speed. When the car runs to the middle of the stroke, cut off the power supply of the elevator, thereby triggering the bilateral brakes to perform the braking operation, and measure the average braking deceleration a of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 1 ; Step S23, operate the elevator to move downward without load from the top floor at the normal operating speed. When the car runs to the middle of the stroke, cut off the power supply of the elevator, thereby triggering the bilateral brakes to perform the braking operation, and measure the average braking deceleration a of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 2 ; Step S24, operate the elevator to move downward without load from the top floor at the normal operating speed. When the car runs to the lower part of the stroke, cut off the power supply of the elevator, thereby triggering the bilateral brakes to perform the braking operation, and measure the average braking deceleration a of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument 0 ; Step S25, process the data, and judge whether it meets according to the obtained balance coefficient and the three braking decelerations measured in the above three steps and If it meets it indicates that the elevator meets the requirements of bilateral braking when moving downward at 125% rated load, otherwise it does not meet; if it meets it indicates that the elevator meets the requirements of unilateral braking when moving downward at 100% rated load, otherwise it does not meet. Specific embodiment 1:

[0164] A no-load test method for the braking performance of an elevator with load moving downward, including:

[0165] Step S1, establish a calculation model for the deceleration a125 when the elevator car moves downward bilaterally at the lower part of the 125% rated load stroke and the deceleration a100 when it moves downward unilaterally at the lower part of the 100% rated load stroke, specifically including:

[0166] Step S11, establish a dynamic model of the elevator braking process according to the eccentric load moment and the moment of inertia:

[0167] As Figure 5 shown, during the elevator braking process, due to the weight difference on both sides of the traction wheel, an eccentric load moment will be generated on the axis of the brake wheel. Assuming that the positive direction of the eccentric load moment is the direction of the car's decelerating motion, that is, the opposite direction of the braking torque during braking, the eccentric load moment can be expressed as:

[0168] In the formula:

[0169] M P —— Offload moment, unit: N·m;

[0170] x—— Loading coefficient, that is, the ratio of the car load to the rated load;

[0171] m s1 —— Mass of the wire rope on the car side of the traction sheave, unit: kg;

[0172] m b1 —— Mass of the compensating rope (chain) on the car side of the traction sheave, unit: kg;

[0173] m s2 —— Mass of the wire rope on the counterweight side of the traction sheave, unit: kg;

[0174] m b2 —— Mass of the compensating rope (chain) on the counterweight side of the traction sheave, unit: kg;

[0175] W—— Counterweight mass, unit: kg;

[0176] P—— Car mass, unit: kg;

[0177] Q—— Rated load, unit: kg;

[0178] D—— Pitch diameter of the traction sheave, unit: m;

[0179] i—— Traction ratio, that is, the ratio of the moving speed of the wire rope to the moving speed of the car during elevator operation;

[0180] r—— Transmission ratio from the brake wheel to the traction sheave, that is, the ratio of the rotational speed of the brake wheel to the rotational speed of the traction sheave, equal to 1 for synchronous motors;

[0181] g—— Gravitational acceleration coefficient, with a value of 9.8 m·s -2 ;

[0182] If the total lift height of the elevator car is H and the total mass of the compensating rope (chain) is m b , then: m s1 =(1 - c)ms——(2), where:

[0183] m s —— Total mass of the wire rope, unit: kg;

[0184] c—— Car position coefficient, dimensionless, with a value range from 0 to 1, 0 indicating that the car is at the bottom terminal station and 1 indicating that the car is at the top terminal station;

[0185] The mass of the wire rope on the counterweight side of the traction sheave is: m s2 =cms ——(3), the mass of the compensating rope (chain) on the car side of the traction sheave is: m b1 = cm b ——(4), where:

[0186] m b ——The total mass of the compensating rope (chain), unit: kg;

[0187] The mass of the compensating rope (chain) on the counterweight side of the traction sheave is: m b2 = (1 - c)m b ——(5), Substituting equations (2), (3), (4) and (5) into equation (1) gives: The unbalanced load moment is related to the elevator car load mass and the position of the elevator car. If the steel wire rope and the compensating rope (chain) reach the ideal compensation state, the unbalanced load moment is only related to the position of the car;

[0188] The moment of inertia of the motion system during the elevator braking process can be composed of two parts: J = J Z + J 0 ——(7), where:

[0189] J——The total moment of inertia of the system, unit: kg·m 2 ;

[0190] J 0 ——The moment of inertia of rotating components such as the traction sheave and the brake wheel, unit: kg·m 2 ;

[0191] J Z ——The moment of inertia of the remaining linear motion components other than rotating components such as the traction sheave and the brake wheel, that is, the total moment of inertia of the car, the counterweight, the load in the car, the steel wire rope, and the compensating rope (chain), unit: kg.m 2 ;

[0192] According to rigid body dynamics, there is the following relationship between the moment of inertia of a linearly moving object and its mass: where:

[0193] ω——The rotational angular velocity of the brake wheel, unit: s -1 ;

[0194] v——The running speed of the car, unit: m·s -1 ;

[0195] m——The total mass of the car, the counterweight and the load, unit: kg;

[0196] m can be expressed as: m = P + W + xQ——(9), and the relationship between the rotational angular velocity of the brake wheel and the linear velocity of the car is: Substituting equations (9) and (10) into equation (8) gives:

[0197] The definition of the balance coefficient in Appendix G2.4 of GB 7588 is "the amount by which the rated load and car mass are balanced by the counterweight or balance weight". According to this definition, the relationship among P, W, and Q is as follows:

[0198] W = P + KQ —— (12), where:

[0199] K —— balance coefficient, dimensionless;

[0200] Substituting equation (12) into equation (11) and after rearrangement, we can obtain J Z consists of two parts: J Z = J Z1 + J Z2 —— (13), where:

[0201] J Z1 —— the moment of inertia of the rotating parts of the system's inherent linear motion, i.e., the total moment of inertia of the car, counterweight, wire rope, compensating rope (chain), with the unit kg·m 2 ;

[0202] J Z2 —— the moment of inertia of the load in the car when the loading factor is x, with the unit kg·m 2 ;

[0203] J Z1 can be expressed as: J Z2 can be expressed as: For a determined elevator system, the car mass, counterweight mass, balance coefficient, traction ratio, wire rope mass, compensating rope (chain) mass, traction wheel diameter, and transmission ratio can be considered as fixed values. Therefore, J Z1 is a constant, and J Z2 is related to the weight of the object carried in the car;

[0204] According to the moment balance relationship, ignoring the influence of the guide rail friction on the system, the braking torque during the braking process is the sum of the eccentric load torque M P and the inertial torque ηJε. We can obtain: M Z -M P = ηJε —— (16), where:

[0205] M Z —— braking torque, whose direction is opposite to the direction of the car movement, with the unit N·m;

[0206] ε —— braking wheel angular deceleration, with the unit rad.s-2;

[0207] η —— transmission efficiency from the braking wheel to the traction wheel, dimensionless;

[0208] The relationship between the angular deceleration of the brake wheel and the car deceleration is as follows: Where:

[0209] a——car braking deceleration, m·s -2 ;

[0210] Substituting equations (7), (13) and (17) into equation (16), the dynamic models of traction elevators during braking under different positions, different running directions and different loading masses can be obtained:

[0211] Step S12: Conduct dynamic analysis on different braking conditions according to the dynamic model:

[0212] Conduct dynamic analysis on the braking process of three no-load conditions of the elevator car and two loaded conditions. The three no-load conditions are bilateral braking during upward travel in the middle of the no-load stroke, bilateral braking during downward travel in the middle of the no-load stroke, and bilateral braking during downward travel at the lower end of the no-load stroke. The two loaded conditions are bilateral braking during downward travel at the lower part of the 125% rated load stroke and unilateral braking during downward travel at the lower part of the 100% rated load stroke; the values of c and x under the five braking conditions are shown in Table 1 below:

[0213]

[0214] As Figure 6 and Figure 7 shown, during bilateral braking during upward travel in the middle of the no-load stroke or bilateral braking during downward travel in the middle of the no-load stroke, the masses of the wire ropes on both sides of the traction sheave and the mass of the compensating rope (chain) are equal. The positive direction of the unbalanced load moment is opposite to the direction of the braking moment. Substituting the parameters in Table 1 into equation (6) gives the unbalanced load moments under the two conditions, as shown in equations (19) and (20) respectively:

[0215]

[0216] As Figure 8 shown, during bilateral braking during downward travel at the lower end of the no-load stroke, it can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side. Substituting the parameters in Table (1) into equation (6) gives the unbalanced load moment under this condition:

[0217] As Figure 9 shown, in the case of bilateral braking at 125% rated load in the standard GB7588-2003, when the car is at the lower end of the stroke, it can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side, and the unbalanced load moment is: As can be seen from Equation (15), the moment of inertia corresponding to the load under this working condition is:

[0218] As Figure 10 shown, in the standard GB7588-2003 for the 100% load unilateral braking working condition, with the car at the lower end of the travel, it can be considered that all the wire ropes are on the car side and all the compensating ropes (chains) are on the counterweight side. The eccentric load moment is: As can be seen from Equation (15), the moment of inertia corresponding to the load under this working condition is:

[0219] Assume that the bilateral braking torque of the brake is M, and the unilateral braking torque is half of the bilateral braking torque. Combining with the definition of the balance coefficient in Equation (11), simplify Equations (19), (20), (21), (22) and (24) to obtain the braking torque, eccentric load moment, and the moment of inertia corresponding to the car load under five braking working conditions as shown in Table 2 below:

[0220]

[0221] Step S13: Calculate the downward bilateral braking deceleration at the lower end of the 125% rated load travel:

[0222] The actual transmission efficiency is approximately 100%. To simplify the calculation process, assume that the transmission efficiency is 100%, i.e., η = 1; establish the dynamic equations for three no-load braking working conditions and the 125% rated load braking working condition according to Equation (18) and the parameter values in Table 2:

[0223] In the above equations:

[0224] a 1 —— The braking deceleration of the upward bilateral braking in the middle of the no-load travel, unit m·s -2 ;

[0225] a 2 —— The braking deceleration of the downward bilateral braking in the middle of the no-load travel, unit m·s -2 ;

[0226] a 0 —— The braking deceleration of the downward bilateral braking at the lower part of the no-load travel, unit m·s -2 ;

[0227] a 125 —— The braking deceleration of the downward bilateral braking at the lower end of the 125% rated load travel, unit m·s -2 ;

[0228] A, B, and C are custom constants used to simplify the calculation process, and are respectively:

[0229] X is related to the moment of inertia generated by 125% of the rated load: Dividing Equation (26) by Equation (27) and substituting into Equation (33), we get:

[0230] Adding Equation (26) and Equation (27) and substituting into Equation (34), we get:

[0231] Subtracting Equation (28) from Equation (29), we get: 1.25A = Ba 0 -(B + X)a 125 ——(36);

[0232] Substituting Equation (30), Equation (33), and Equation (35) into Equation (36) and arranging, we obtain the braking deceleration expression for the downward movement of the lower end of the 125% rated load stroke with bilateral braking:

[0233] Step S14: Calculate the braking deceleration of the downward movement of the lower end of the 100% rated load stroke with unilateral braking:

[0234] Based on Equation (8) and the parameters in Table 2, establish the dynamic equations for three no-load braking conditions and the 100% rated load braking condition:

[0235] In the above equations:

[0236] a 1 —— The braking deceleration of the upward movement of the middle part of the no-load stroke with bilateral braking, unit m·s -2 ;

[0237] a 2 —— The braking deceleration of the downward movement of the middle part of the no-load stroke with bilateral braking, unit m·s -2 ;

[0238] a 0 —— The braking deceleration of the downward movement of the lower part of the no-load stroke with bilateral braking, unit m·s -2 ;

[0239] a 100 —— The braking deceleration of the downward movement of the lower end of the 100% rated load stroke with unilateral braking, unit m·s -2 ;

[0240] A, B, and C are custom constants used to simplify the calculation process, and they are respectively:

[0241] In Equation (38), X′ is related to the moment of inertia generated by 100% rated load: Referring to the braking deceleration calculation method for 125% rated load above, the braking deceleration expression for one-sided braking during downward travel at the lower end of the 100% rated load stroke is obtained:

[0242] Step S2: According to the judgment conditions of the calculation model, conduct a no-load test on the braking performance of the elevator during downward travel with load. To meet the requirements for braking performance with load in GB7588 and TSG T7001, the braking deceleration should be greater than zero to meet the deceleration requirements. Therefore, there is:

[0243]

[0244] Substitute Equation (37) and Equation (40) into the above inequality group respectively, and after arrangement, the relationship between the balance coefficient and the three no-load braking decelerations can be obtained:

[0245]

[0246] If the balance coefficient K and the three no-load braking decelerations a 1 、a 2 、a 0 simultaneously satisfy Equation (43) and Equation (44), it indicates that the elevator can meet the deceleration requirements for two-sided braking during downward travel at the lower part of the 125% rated load stroke and one-sided braking during downward travel at the lower part of the 100% rated load stroke, and this inspection item is qualified; Equation (43) and Equation (44) are the judgment bases for whether the elevator meets the two-sided braking performance during downward travel at the lower part of the 125% rated load stroke and the one-sided braking performance during downward travel at the lower part of the 100% rated load stroke;

[0247] Specifically, it includes:

[0248] Step S21: Consult materials or conduct a balance coefficient test to obtain the balance coefficient K of the elevator to be tested;

[0249] Step S22: Operate the elevator to travel upward without load from the bottom floor at normal operating speed. When the car reaches the middle of the stroke, cut off the power supply of the elevator, and then trigger the two-sided brake to perform the braking operation. Measure the average braking deceleration a 1 ; of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument

[0250] Step S23: Operate the elevator to travel downward without load from the top floor at normal operating speed. When the car reaches the middle of the stroke, cut off the power supply of the elevator, and then trigger the two-sided brake to perform the braking operation. Measure the average braking deceleration a 2 ; of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument

[0251] Step S24: Operate the elevator to run downward without load from the top floor at the normal operating speed. When the car runs to the lower part of the stroke, cut off the elevator power supply, thereby triggering the bilateral brake to perform the braking operation. Measure the average braking deceleration a of the car during the process from the start of the brake action to the complete stop of the elevator through an acceleration test instrument. 0 ;

[0252] Step S25: Process the data, and based on the obtained balance coefficient and the three braking decelerations measured in the above three steps, judge whether it satisfies and If it meets it indicates that the elevator meets the bilateral braking requirement for running downward at 125% of the rated load, otherwise it does not meet; if it meets it indicates that the elevator meets the unilateral braking requirement for running downward at 100% of the rated load, otherwise it does not meet. Specific Embodiment 2:

[0254] As Figure 2 shown, the main controller 4, the braking deceleration measurement module 1, the braking instant detection module 2, and the braking trigger module 3 are all placed inside the elevator machine room 01. Among them, the main controller 4 selects a laptop computer 41, and the braking deceleration measurement module 1 selects a rotary encoder module 11. The laptop computer 41 is connected to the rotary encoder module 11, the braking instant detection module 2, and the braking trigger module 3 through a wired connection method, so as to realize the control of the modules and the acquisition of data.

[0255] By bringing the speed measurement roller 10 fixedly connected coaxially with the rotary encoder in the rotary encoder module 11 into contact with the elevator traction steel wire rope 9, when the elevator car 6 runs, it drives the speed measurement roller 10 to rotate. The pulse signal output by the rotary encoder in the rotary encoder module 11 can be converted to realize the speed and acceleration measurement of the elevator car 6. The laptop computer 41 controls the braking trigger module 3 to disconnect the main relay contact in the power circuit in the control cabinet 02, thereby triggering the elevator control system to output a braking command externally, so that the braking coil of the brake 72 loses power, and the braking of the brake wheel 71 is realized. During the whole test process, the braking instant detection module 2 continuously monitors the on-off state of the braking state confirmation switch in the brake 72 of the elevator and feeds back the signal to the laptop computer 41. When the on-off state of the braking state confirmation switch changes at the moment when the brake 72 brakes the brake wheel 71, this moment is recorded by the laptop computer 41. Specific Embodiment 3:

[0257] As Figure 3As shown in the figure, the main controller 4, the braking instant detection module 2 and the braking trigger module 3 are all placed inside the elevator machine room 01, and the braking deceleration measurement module 1 uses an acceleration sensor 12 and is placed inside the elevator car 6. Among them, the main controller 4 is a single-chip microcomputer 42, and the braking deceleration measurement module 1 selects an acceleration sensor 12, which can directly measure the deceleration of the elevator car 6 during the braking process. The single-chip microcomputer 42 is connected to the acceleration sensor 12, the braking instant detection module 2 and the braking trigger module 3 through WIFI wireless communication to realize the control of the modules and the acquisition of data. Further, to ensure accurate signal transmission, a signal transfer module 8, such as a WIFI router, can be set between the single-chip microcomputer 42 and each module.

[0258] During the test, the acceleration sensor 12 directly measures the deceleration value of the elevator car 6 and transmits the signal to the single-chip microcomputer 42. The single-chip microcomputer 42 controls the braking trigger module 3 to disconnect the main relay contact in the power circuit of the control cabinet 02, thereby triggering the elevator control system to output a braking command externally, causing the braking coil of the brake 72 to lose power and realizing the braking of the brake wheel 71. During the entire test process, the braking instant detection module 2 continuously monitors the on-off state of the braking state confirmation switch in the brake 72 of the elevator and feeds back the signal to the single-chip microcomputer 42. When the on-off state of the braking state confirmation switch changes at the moment when the brake 72 brakes the brake wheel 71, this moment is recorded by the single-chip microcomputer 42.

[0259] In summary, the prior art cannot quantitatively calculate the loaded braking deceleration through the no-load braking deceleration. However, the no-load test system and method for the loaded downward braking performance of the elevator provided by the embodiments of the present invention can establish a quantitative calculation model for the loaded downward braking deceleration of the elevator according to the dynamic model of the elevator braking process, and can well evaluate the loaded braking performance through the no-load braking test according to this calculation model.

[0260] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A no-load test system for the braking performance of an elevator during loaded downward travel, characterized in that, it includes: A braking deceleration measurement module, which is used to measure the average braking deceleration of the elevator car during the braking process of the elevator; A braking instant detection module, which is assembled on the braking actuator and is used to detect the instant when the braking actuator brakes the brake wheel, so as to obtain the moment of the braking execution instant; A braking trigger module, which is used to control the power failure of the brake coil, so as to trigger the braking actuator to brake the rotating brake wheel and stop the traction wheel coaxial with the brake wheel, realizing the stopping of the elevator car; A main controller, which is respectively connected to the braking deceleration measurement module, the braking instant detection module and the braking trigger module, and is used to control the braking trigger module to trigger the action of the elevator braking actuator, and obtain the elevator car deceleration data measured by the braking deceleration measurement module, and the action instant signal of the braking actuator detected by the braking instant detection module; During the test, it includes the following steps: Step S1, establish a calculation model for the deceleration a125 in the case of bilateral braking during the downward travel of the elevator car at 125% of the rated load and the deceleration a100 in the case of unilateral braking during the downward travel of the elevator car at 100% of the rated load; Step S2, according to the judgment conditions of the calculation model, conduct a no-load test on the braking performance of the elevator during loaded downward travel; Among them, the specific steps of step S1 are as follows: step S11, establish a dynamic model of the elevator braking process according to the eccentric load moment and moment of inertia; step S12, conduct dynamic analysis on different braking conditions according to the dynamic model; step S13, calculate the downward bilateral braking deceleration at the lower end of the 125% rated load stroke as Step S14, calculate the downward unilateral braking deceleration at the lower end of the 100% rated load stroke as The specific steps of step S2 are as follows: Step S21, consult materials or conduct a balance coefficient test to obtain the balance coefficient K of the elevator to be measured; Step S22, operate the elevator to run upward without load from the bottom floor at the normal operating speed. When the car runs to the middle of the stroke, cut off the elevator power supply, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a1 of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument; Step S23, operate the elevator to run downward without load from the top floor at the normal operating speed. When the car runs to the middle of the stroke, cut off the elevator power supply, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a2 of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument; Step S24, operate the elevator to run downward without load from the top floor at the normal operating speed. When the car runs to the lower part of the stroke, cut off the elevator power supply, and then trigger the bilateral brake to perform the braking operation. Measure the average braking deceleration a0 of the car from the start of the brake action to the complete stop of the elevator through an acceleration test instrument; Step S25, process the data, and judge whether it meets and If it meets it indicates that the elevator meets the bilateral braking requirement for descending at 125% of the rated load, otherwise it does not meet; if it meets it indicates that the elevator meets the unilateral braking requirement for descending at 100% of the rated load, otherwise it does not meet.

2. The no-load test system for the braking performance of an elevator during loaded downward travel according to claim 1, characterized in that, it further includes: A human-machine interaction module, which is connected to the main controller and is used to control the main controller to obtain test system information and realize human-machine interaction.

3. The no-load test system for the braking performance of an elevator during loaded downward travel according to claim 2, characterized in that, The human-machine interaction module controls the main controller in any one or more of the ways of a display screen, a mouse, a keyboard, a button or a touch screen.

4. The no-load test system for the braking performance of an elevator during loaded downward travel according to claim 1, characterized in that, The main controller selects any one of a PLC, a personal computer, an industrial control computer or a single-chip microcomputer, and the main controller is communicatively connected to the braking deceleration measurement module, the braking instant detection module and the braking trigger module in a wired or wireless manner.

5. The no-load test system for the braking performance of an elevator during loaded downward travel according to claim 4, characterized in that, The wireless communication method adopts WiFi or Bluetooth, and signal transfer modules are respectively arranged between the main controller and the braking deceleration measurement module, the braking instant detection module and the braking trigger module.

6. The no-load test system for the braking performance of an elevator during loaded downward travel according to any one of claims 1-5, characterized in that, The braking deceleration measurement module adopts a rotary encoder module, the rotary encoder module contacts the elevator traction steel wire rope through a speed measurement roller, and the speed measurement roller is coaxially and fixedly connected to the rotary encoder module.

7. The no-load test system for the on-load downward braking performance of an elevator according to any one of claims 1-5, characterized in that, the braking deceleration measurement module uses an acceleration sensor, and the acceleration sensor is placed inside the elevator car.

8. The no-load test system for the on-load downward braking performance of an elevator according to any one of claims 1-5, characterized in that, the braking trigger module can disconnect the main relay contact in the power circuit of the control cabinet and trigger the elevator control system to output a braking command externally, so that the braking coil of the brake loses power and the brake wheel is braked.

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