A control method of a buffer structure of a goods elevator car roof

Abstract

This invention discloses a control method for a buffer structure on the top of a freight elevator, relating to the field of elevator safety buffer control technology. The method includes responding to an abnormal upward signal from the freight elevator by activating the compensation flow path between the compensation hydraulic chamber and the low-pressure reservoir in each composite buffer unit; after contact of any composite buffer unit, acquiring the compensation compression stroke and the force state of the first freight elevator, generating a locking command and cutting off each compensation flow path; acquiring the force state of the second freight elevator, determining the target damping state of each energy-absorbing buffer component based on the force state of the second freight elevator, and adjusting the corresponding damping adjustment component to buffer and stop the car. This invention can coordinate the contact compensation and subsequent energy absorption process at different buffer positions, improving the smoothness of abnormal upward stopping of the freight elevator.

Description

Technical Field

[0001] This invention belongs to the field of elevator safety buffer control technology, specifically relating to a control method for a buffer structure on the top of a freight elevator car. Background Technology

[0002] Freight elevators typically have large rated load capacities and car dimensions, and the placement and weight distribution of goods within the car vary considerably. In the event of an abnormal upward movement of the freight elevator, a bottom buffer structure is needed to restrict further car movement to ensure the safety of the car, goods, and hoistway equipment.

[0003] Existing traction freight elevators typically have buffers installed in the pit at the bottom of the shaft, corresponding to the car and the counterweight respectively. When the car abnormally descends and approaches the bottom limit position of the shaft, the car contacts the corresponding buffer, and the compression of the buffer absorbs the kinetic energy of the car. When the car abnormally ascends, the counterweight connected to the car moves synchronously to the bottom of the shaft. When the counterweight descends to its limit position, it contacts the corresponding counterweight buffer, and the transmission relationship between the traction rope and the traction sheave indirectly restricts the car from continuing to ascend, thus providing a buffer protection effect for abnormal upward movement.

[0004] However, when the car abnormally ascends, existing buffer structures typically use a counterweight buffer located at the bottom of the hoistway to cushion the descending counterweight, and the transmission relationship between the traction rope and the traction sheave inhibits the car from continuing to ascend. Since this buffering effect is first applied to the counterweight side, the buffering effect obtained by the car needs to be indirectly transmitted through the traction system. The buffering process mainly depends on the motion state of the counterweight side and the force transmission process of the traction system. For the car that is already close to the limit position at the top of the hoistway, there is a lack of a buffer structure between the car body and the top of the hoistway that can directly compress and absorb energy as the car continues to ascend. Therefore, the remaining kinetic energy of the car at the end of the abnormal ascent is difficult to be directly released on the car side, which can easily cause a large impact at the end of the braking process, affecting the buffering stability during the abnormal ascent. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing traction freight elevators only indirectly restrict the upward movement of the car through the bottom counterweight buffer, which results in the remaining kinetic energy not being effectively absorbed by the direct compression displacement and easily generating a large braking impact. Therefore, this invention proposes a control method for the buffer structure on the top of the freight elevator car.

[0006] This invention provides a control method for a freight elevator car top buffer structure, applied to a freight elevator car top buffer structure. The freight elevator car top buffer structure includes multiple composite buffer units, each composite buffer unit including a contact compensation component and an energy-absorbing buffer component arranged in series. The contact compensation component includes a compensation hydraulic chamber, a low-pressure storage chamber, and a compensation control valve. The energy-absorbing buffer component includes a main hydraulic chamber and a damping adjustment component. The method includes: In response to the abnormal upward signal of the freight elevator, a compensation activation command is generated and sent to each compensation control valve so that the compensation control valve opens the compensation flow path between each compensation hydraulic chamber and the corresponding low-pressure reservoir. The contact signal of each composite buffer unit is detected. After any composite buffer unit generates a contact signal, the compensation compression stroke and the force state of the first freight elevator corresponding to each contacted composite buffer unit are obtained. The force state of the first freight elevator includes the initial load distribution and off-center load direction of the freight elevator. Based on the compensation compression stroke of each composite buffer unit and the force state of the first freight elevator, a locking command is generated so that each compensation control valve cuts off each compensation flow path according to the locking command, and the force state of the second freight elevator is collected. Based on the force state of the second freight elevator, the target damping state of each energy-absorbing buffer component is determined, a damping adjustment command is generated and sent to each damping adjustment component, and the damping adjustment command is used to adjust the corresponding energy-absorbing buffer component to the target damping state to buffer and stop the car.

[0007] Optionally, obtain the compensated compression stroke and the force state of the first freight elevator corresponding to each contacted composite buffer unit, including: According to the timing of the contact signals generated by each composite buffer unit, the compensation displacement data of each contacted composite buffer unit is read, and the change in the compensation displacement data after the contact time is taken as the corresponding compensation compression stroke. Collect first load data corresponding to different stress positions of the freight elevator car, take the sum of each first load data as the first total load, and calculate the load ratio of each first load data to the first total load and the first load difference between relative stress positions. The initial load distribution is obtained based on the proportion of each load, and the off-center load direction is obtained based on the positive and negative relationship of the difference between each first load. The initial load distribution and the off-center load direction are combined to form the first stress state of the freight elevator.

[0008] Optionally, a locking command is generated based on the compensation compression stroke of each composite buffer unit and the force state of the first freight elevator, including: Calculate the difference in compensation compression stroke between the relatively set composite buffer units based on the compensation compression stroke of each contacted composite buffer unit. The target locking stroke of each composite buffer unit is determined based on the compensation compression stroke difference and the force state of the first freight elevator. The compensation compression stroke of each composite buffer unit is compared with the corresponding target lock-up stroke. When the compensation compression stroke reaches the corresponding target lock-up stroke, a lock-up command for the corresponding compensation control valve is generated.

[0009] Optionally, the stress state of the first freight elevator includes the initial load distribution and the off-center load direction. The step of determining the target locking stroke corresponding to each composite buffer unit based on the compensation compression stroke difference and the stress state of the first freight elevator includes: The corresponding basic locking stroke is determined based on the current compensation compression stroke and compensation compression stroke difference of each composite buffer unit; The locking stroke correction direction for each composite buffer unit is determined based on the off-center load direction, and the corresponding locking stroke correction amount is determined based on the initial load distribution. The basic locking stroke is then corrected to obtain the candidate locking stroke. The corresponding compensation compression speed is determined based on the compensation displacement data continuously acquired by each composite buffer unit, and the corresponding remaining time is determined based on the current compensation compression stroke, compensation compression speed, and candidate locking stroke. The candidate locking strokes are corrected based on the differences between the remaining times to obtain the target locking strokes for each composite buffer unit.

[0010] Optionally, the stress state of the second freight elevator can be collected, including: After each compensation control valve cuts off the corresponding compensation flow path, the second load data corresponding to different stress positions of the freight elevator car are collected again. Based on the second load data, the load distribution relationship between each force-bearing position after locking and the second load difference are determined, and the force state of the second freight elevator is obtained.

[0011] Optionally, the target damping state of each energy-absorbing buffer component is determined based on the force state of the second freight elevator, including: The current upward speed of the freight elevator and the effective buffer stroke of the energy-absorbing buffer components are obtained. The impact energy to be absorbed is determined based on the current upward speed and the total load of the freight elevator. The total target buffer force is determined based on the impact energy to be absorbed and the effective buffer stroke. Based on the stress state of the second freight elevator, the total target buffer force is distributed to each energy-absorbing buffer component to obtain the target buffer force corresponding to each energy-absorbing buffer component. The target pressure of the corresponding main buffer chamber is determined based on each target buffer force, and the target throttling state of the corresponding damping adjustment component is determined based on each target pressure. The target throttling state is then used as the target damping state of the corresponding energy-absorbing buffer component.

[0012] Optionally, the total target buffer force is distributed to each energy-absorbing buffer component according to the stress state of the second freight elevator, resulting in the target buffer force corresponding to each energy-absorbing buffer component, including: Based on the load distribution relationship corresponding to each stress position in the stress state of the second freight elevator, the total target buffer force is distributed to each energy-absorbing buffer component to obtain the basic buffer force corresponding to each energy-absorbing buffer component; Based on the second load difference between the relative stress positions, determine the buffer force adjustment amount between the corresponding energy-absorbing buffer components, and determine the adjustment direction of the basic buffer force corresponding to the relative stress position based on the positive and negative relationship of the second load difference; According to the adjustment direction, the basic buffer force corresponding to the relative force position is adjusted by the buffer force adjustment amount to obtain the target buffer force corresponding to each energy-absorbing buffer component.

[0013] Optionally, the method also includes: During the buffering process of each energy-absorbing buffer component according to the corresponding target damping state, the actual pressure of each main buffer buffer chamber is obtained; Calculate the pressure deviation between the actual pressure of each main buffer chamber and the corresponding target pressure, and determine the damping adjustment amount of the corresponding damping adjustment element based on the pressure deviation change between the relatively set main buffer chambers; The target damping state of the corresponding energy-absorbing buffer component is adjusted according to the damping adjustment amount.

[0014] The beneficial effects of this invention are: 1. This application sets up multiple composite buffer units on the top of the freight elevator car, so that when the freight elevator abnormally ascends and approaches the top of the shaft, a buffer force path can be directly established on the car side. Compared with the existing method of indirectly restricting the car's upward movement through the traction system via the counterweight buffer at the bottom of the shaft, the remaining upward kinetic energy of the car can be directly released through the compression process of the car top buffer structure, thereby reducing the braking impact at the end of the abnormal upward movement and improving the buffer stability of the freight elevator's overshoot protection. 2. This application sets contact compensation components and energy-absorbing buffer components in series in each composite buffer unit. When multiple buffer positions make contact sequentially due to off-center load or attitude differences, the contact compensation components are used to compensate for the contact differences at different positions. The locking process of each compensation position is coordinated according to the compensation compression stroke and the force state of the freight elevator. After the contact compensation is completed, the energy-absorbing buffer components are adjusted differently according to the actual load distribution after locking. This allows multiple buffer positions to participate in subsequent energy absorption in a more coordinated manner, reducing local force concentration and car deflection, and improving the force balance and stability during abnormal upward braking process. Attached Figure Description

[0015] The invention will now be further described with reference to the accompanying drawings.

[0016] Figure 1 A diagram of a buffer structure on the top of a freight elevator provided in an embodiment of the present invention; Figure 2 A structural diagram of a composite buffer unit provided in an embodiment of the present invention; Figure 3 A flowchart illustrating a control method for a freight elevator car top buffer structure provided in an embodiment of the present invention; In the diagram: 100, top pressure-bearing structure of the shaft; 200, composite buffer unit; 210, contact compensation component; 211, compensation hydraulic chamber; 212, compensation control valve; 213, low-pressure storage chamber; 220, energy-absorbing buffer component; 221, main buffer hydraulic chamber; 222, damping adjustment component; 300, car top mounting bracket; 400, freight elevator car. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] It should be noted that all formula calculations in the scheme are purely numerical calculations.

[0019] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1

[0021] This invention provides a buffer structure for the top of a freight elevator car, see [link / reference]. Figure 1 The freight elevator car top buffer structure includes a shaft top pressure-bearing structure 100, multiple composite buffer units 200, and a car top mounting frame 300. The car top mounting frame 300 is located on the top of the freight elevator car 400. The multiple composite buffer units 200 are spaced apart on the car top mounting frame 300 and are respectively positioned opposite to the shaft top pressure-bearing structure 100. When the freight elevator car 400 abnormally ascends and approaches the top of the shaft, each composite buffer unit 200 can contact the shaft top pressure-bearing structure 100 to form a buffer force path between the shaft top pressure-bearing structure 100 and the freight elevator car 400.

[0022] The freight elevator car top buffer structure also includes a controller, which is communicatively connected to the freight elevator operation control system, each compensation control valve 212 and each damping adjustment component 222. It is used to control each compensation control valve 212 and damping adjustment component 222 according to the freight elevator operation status, the contact status of each composite buffer unit 200 and the force status of the freight elevator. It is also used to respond to the abnormal upward signal of the freight elevator output by the freight elevator operation control system.

[0023] For the specific structure of the composite buffer unit 200, please refer to [link / reference]. Figure 2Each composite buffer unit 200 includes a contact compensation assembly 210 and an energy-absorbing buffer assembly 220 connected in series along the force direction. The contact compensation assembly 210 includes a compensation hydraulic chamber 211, a compensation control valve 212, and a low-pressure reservoir 213. The compensation hydraulic chamber 211 and the low-pressure reservoir 213 are connected via a compensation flow path. The compensation control valve 212 is located in the compensation flow path and is used to control the opening or closing of the compensation flow path. The energy-absorbing buffer assembly 220 includes a main buffer pressure chamber 221 and a damping adjustment component 222. The damping adjustment component 222 is used to adjust the hydraulic damping of the main buffer pressure chamber 221. The contact compensation assembly 210 is located near the top pressure-bearing structure 100 of the wellbore, and the energy-absorbing buffer assembly 220 is located near the car top mounting frame 300, so that the force exerted by the top pressure-bearing structure 100 of the wellbore on the composite buffer unit 200 is transmitted sequentially to the car top mounting frame 300 via the contact compensation assembly 210 and the energy-absorbing buffer assembly 220.

[0024] In one implementation, four composite buffer units 200 are provided, respectively located at the front left corner, front right corner, rear left corner, and rear right corner of the car top mounting bracket 300. Each composite buffer unit 200 is rectangularly distributed along the length and width of the top of the freight elevator car 400, and the force axis of each composite buffer unit 200 is set along the vertical direction of the freight elevator car 400, and is respectively opposite to the corresponding pressure-bearing position on the pressure-bearing structure 100 at the top of the shaft.

[0025] It should be noted that the top pressure-bearing structure 100 of the hoistway can be a steel pressure-bearing plate fixed to the top load-bearing beam or the top frame of the hoistway, which has a pressure-bearing surface that can contact multiple composite buffer units 200; the car top mounting frame 300 can be a welded steel frame, a bolted frame, or a top crossbeam of the freight elevator car frame, used to install and support each composite buffer unit 200; the freight elevator car 400 can adopt the existing car structure of a traction freight elevator. The composite buffer unit 200 can adopt a composite hydraulic buffer structure formed by two-stage hydraulic cylinders connected in series along the axial direction. The contact compensation component 210 can adopt a low-resistance hydraulic cylinder structure, and the compensation hydraulic chamber 211 can be formed by the cylinder barrel, piston, and piston rod of the hydraulic cylinder. The low-pressure storage chamber 213 can be a hydraulic oil tank, a low-pressure accumulator, or a low-pressure accumulator with a flexible diaphragm, used to receive the hydraulic medium discharged from the compensation hydraulic chamber 211. The compensation control valve 212 can be an electromagnetic switch valve, an electromagnetic shut-off valve, or a two-position two-way hydraulic solenoid valve, used to control the opening and closing of the compensation flow path. The energy-absorbing buffer component 220 can adopt a hydraulic buffer cylinder, and the main buffer pressure chamber 221 is formed by the buffer cylinder body and piston, used to generate hydraulic resistance when the composite buffer unit 200 is pressurized. The damping adjustment component 222 can be a proportional throttle valve, an electrically controlled variable throttle valve, or a proportional flow valve, used to adjust the buffer damping by changing the effective flow area of ​​the hydraulic medium discharge channel of the main buffer pressure chamber 221. The controller can be a PLC, an industrial controller, or an embedded controller with data acquisition and control output functions, and can be connected to the freight elevator operation control system, compensation control valve 212, damping adjustment component 222 and corresponding detection elements through digital interface, analog interface or fieldbus.

[0026] Example 2

[0027] Based on Embodiment 1, this embodiment of the invention provides a control method for a freight elevator car top buffer structure, applied to the freight elevator car top buffer structure. The freight elevator car top buffer structure includes multiple composite buffer units 200, each composite buffer unit 200 including a contact compensation component 210 and an energy-absorbing buffer component 220 arranged in series; the contact compensation component 210 includes a compensation hydraulic chamber 211, a low-pressure storage chamber 213, and a compensation control valve 212; the energy-absorbing buffer component 220 includes a main hydraulic pressure chamber 221 and a damping adjustment component 222. See also... Figure 3 The method includes the following steps: S1, in response to the abnormal upward signal of the freight elevator, generates a compensation opening command and sends it to each compensation control valve 212, so that each compensation control valve 212 opens the compensation flow path between the corresponding compensation hydraulic chamber 211 and the low-pressure storage chamber 213. S2, detect the contact signal of each composite buffer unit 200, and after any composite buffer unit 200 generates a contact signal, obtain the compensation compression stroke and the force state of the first freight elevator corresponding to each contacted composite buffer unit 200. S3, based on the compensation compression stroke of each composite buffer unit 200 and the force state of the first freight elevator, a locking command is generated so that each compensation control valve 212 cuts off the compensation flow path between the corresponding compensation hydraulic chamber 211 and the low-pressure storage chamber 213 according to the locking command, and the force state of the second freight elevator is collected. S4. Based on the force state of the second freight elevator, determine the target damping state of each energy-absorbing buffer component 220, generate a damping adjustment command and send it to each damping adjustment component 222. The damping adjustment command is used to adjust the corresponding energy-absorbing buffer component 220 to the target damping state and buffer the freight elevator car 400 to stop.

[0028] This application incorporates multiple distributed composite buffer units 200 on the top of the freight elevator car, enabling direct energy absorption and buffering of the car when the freight elevator abnormally approaches the top of the shaft. Since the composite buffer units 200 are distributed at different positions on the car top, they may contact the pressure-bearing structure 100 at the top of the shaft sequentially when there is uneven loading of goods or a shift in the car's posture. If the first contact position immediately enters the energy-absorbing buffer state, it can easily cause asynchronous force establishment at each buffer position. Therefore, each composite buffer unit 200 is equipped with a series-connected contact compensation component 210 and an energy-absorbing buffer component 220. The contact compensation component 210 first compensates for the contact differences at different positions, and cuts off the compensation flow path after reaching the corresponding compensation state. Then, each energy-absorbing buffer component 220 adjusts its damping according to the force state of the freight elevator after locking, allowing multiple buffer positions to participate in subsequent energy absorption after contact coordination, reducing localized force concentration and car deflection, and improving the buffering stability during abnormal upward braking.

[0029] In step S1, the abnormal upward movement signal of the freight elevator refers to the trigger signal used to characterize that the freight elevator car 400 is in an abnormal upward movement state. This abnormal upward movement signal can be generated by the freight elevator operation control system based on the car's running direction, speed, and shaft position detection results. For example, when it is detected that the freight elevator car 400 is continuing to move upward and has entered the preset protection zone at the top of the shaft, or when the upward speed exceeds the allowable range under the corresponding operating conditions, the abnormal upward movement signal is generated and sent to the controller of the freight elevator car top buffer structure.

[0030] The compensation opening command is a control command used to switch each compensation control valve 212 to the open state, so that a compensation flow path is formed between the compensation hydraulic chamber 211 and the corresponding low-pressure reservoir 213, allowing the hydraulic medium to flow, thereby putting the contact compensation component 210 in a compressible compensation state.

[0031] One method for generating compensation activation commands is as follows: the controller receives an abnormal upward signal from the freight elevator operation control system, judges the validity of the abnormal upward signal, and after confirming that the freight elevator car 400 is in an abnormal upward state, generates corresponding compensation activation commands based on the communication addresses of each compensation control valve 212.

[0032] It should be noted that when the compensation control valve 212 is in the open state, the hydraulic medium between the compensation hydraulic chamber 211 and the low-pressure reservoir 213 can flow through the compensation flow path, making the compression resistance of the contact compensation component 210 less than the compression resistance of the energy-absorbing buffer component 220 in the current state. Therefore, when the composite buffer unit 200 comes into contact with the pressure-bearing structure 100 at the top of the wellbore and is subjected to axial force, the contact compensation component 210 preferentially generates a compression displacement to absorb the difference in contact position between different composite buffer units 200. After the compensation control valve 212 cuts off the compensation flow path, the hydraulic medium in the compensation hydraulic chamber 211 is restricted from flowing, and the compression position of the contact compensation component 210 is maintained, so that the subsequent force is mainly transmitted to the energy-absorbing buffer component 220, which generates the main buffering effect through the main buffer pressure chamber 221 and the damping adjustment component 222. Thus, the composite buffer unit 200 can sequentially form a contact compensation stage and an energy-absorbing buffer stage, avoiding a large buffering reaction force generated at the initial contact position.

[0033] It should be noted that by pre-opening the compensation flow path before each composite buffer unit 200 contacts the pressure-bearing structure 100 at the top of the well, the contact compensation component 210 is kept in a low hydraulic constraint state. When the composite buffer units 200 at different positions contact the pressure-bearing structure 100 at the top of the well in sequence, the first contact position can preferentially generate compensation compression through the contact compensation component 210, instead of immediately establishing a large buffer force by the energy-absorbing buffer component 220. This provides a basis for compensation stroke to eliminate the contact differences between each buffer position in the future.

[0034] In step S2, the contact signal refers to the detection signal used to characterize that the composite buffer unit 200 has made contact with the pressure-bearing structure 100 at the top of the well. The contact signal can be generated by a contact switch, pressure sensor, or other contact detection element disposed at the contact end of the composite buffer unit 200. For example, when the composite buffer unit 200 contacts the pressure-bearing structure 100 at the top of the well, a corresponding contact signal is generated when the force on the contact end reaches a preset contact threshold.

[0035] The compensation compression stroke refers to the compression displacement generated by the contact compensation component 210 after the composite buffer unit 200 generates a contact signal, while the compensation hydraulic chamber 211 and the low-pressure reservoir 213 remain connected. It is used to reflect the degree of compensation that the corresponding composite buffer unit 200 has completed since the contact occurred.

[0036] The first load state of the freight elevator refers to the load distribution state between various load-bearing positions of the freight elevator car 400 obtained during the contact compensation phase, including the initial load distribution and the off-center load direction, which is used to reflect the current load imbalance of the freight elevator car 400.

[0037] In one embodiment, the compensation compression stroke and the first freight elevator stress state corresponding to each contacted composite buffer unit 200 are obtained, specifically: according to the timing of the contact signals generated by each composite buffer unit 200, the compensation displacement data of each contacted composite buffer unit 200 are read, and the change in compensation displacement data after the contact time is taken as the corresponding compensation compression stroke; the first load data corresponding to different stress positions of the freight elevator car 400 are collected, the sum of each first load data is taken as the first total load, and the load ratio of each first load data to the first total load and the first load difference between the relative stress positions are calculated; the initial load distribution is obtained according to each load ratio, and the off-center load direction is obtained according to the positive and negative relationship of each first load difference; the initial load distribution and the off-center load direction are combined as the first freight elevator stress state.

[0038] The compensation displacement data refers to the data used to characterize the current compression position of the contact compensation component 210, which can be continuously collected by a displacement sensor installed on the contact compensation component 210. Using the compensation displacement data corresponding to the generation of the contact signal by the composite buffer unit 200 as the starting displacement, the difference between the compensation displacement data at subsequent sampling times and the starting displacement can be used as the corresponding compensation compression stroke.

[0039] The first load data refers to the real-time force data corresponding to different force-bearing positions of the freight elevator car 400. Different force-bearing positions can be set according to the distribution positions of multiple composite buffer units 200 on the car top, for example, the load data of the corresponding positions on the front, rear, left and right sides of the car can be obtained respectively; the first load data can be collected by load detection elements set at the car frame support position, weighing support position or other positions that can reflect the local load of the car.

[0040] The first load difference refers to the difference between the first load data corresponding to two relatively set force-bearing positions. For example, the first load data of the first force-bearing position can be subtracted from the first load data of the second force-bearing position relative to it as the corresponding first load difference, so that the absolute value of the first load difference reflects the degree of load imbalance between the relatively force-bearing positions, and the positive and negative relationship of the first load difference reflects the direction of load offset.

[0041] It should be noted that when obtaining the initial load distribution based on the load ratios, the first load data corresponding to each stress location can be compared with the first total load to obtain the proportion of the first total load borne by each stress location. The initial load distribution is then formed according to the spatial distribution relationship of each stress location. By using load ratios instead of solely using absolute load values, the influence of changes in the total load capacity of the freight elevator on the comparison results between different stress locations can be reduced, thus more directly reflecting the current load distribution of goods within the freight elevator car 400.

[0042] It should be noted that when obtaining the off-center load direction based on the sign relationship of each first load difference, the direction can be calculated according to the pre-defined relative force position difference, establishing a mapping relationship between the sign of the first load difference and the corresponding force position. For example, when the first load difference obtained by subtracting the second force position from the first force position is positive, the load is determined to be offset in the direction of the first force position; when the first load difference is negative, the load is determined to be offset in the direction of the second force position. In this way, the spatial direction can be determined while obtaining the degree of load imbalance, providing a force basis for subsequently determining the compensation locking state for different composite buffer units 200.

[0043] It should be noted that when the freight elevator car 400 experiences off-center loading or attitude deviation, each composite buffer unit 200 may contact the pressure-bearing structure 100 at the top of the shaft sequentially. Therefore, it is difficult to determine the compensation differences that have formed between the buffer positions based solely on the contact signals. By simultaneously acquiring the compensation compression stroke of each composite buffer unit 200 and the first freight elevator force state of the freight elevator car 400 after contact, the actual contact compensation degree of each buffer position and the current load deviation of the freight elevator can be obtained simultaneously. This provides a data basis for subsequently determining the target locking stroke of each composite buffer unit 200 by combining the geometric compensation state and load distribution, thereby reducing the multi-point force incoordination caused by locking based solely on a single contact state.

[0044] In step S3, the lock-up command is a control command used to switch the compensation control valve 212 from the open state to the closed state. After the compensation control valve 212 responds to the lock-up command and cuts off the compensation flow path, the hydraulic medium in the compensation hydraulic chamber 211 stops flowing to the low-pressure reservoir 213, keeping the contact compensation component 210 in its current compensation compression state and establishing a stable force transmission relationship between the composite buffer unit 200 and the freight elevator car 400.

[0045] The second load state of the freight elevator refers to the load distribution state that is re-formed between different load positions of the freight elevator car 400 after each contact compensation component 210 has completed locking. It is used to characterize the actual load borne by each load position after the contact compensation stage ends and the load differences between them.

[0046] In one possible implementation, a locking command is generated based on the compensating compression stroke of each composite buffer unit 200 and the force state of the first freight elevator. Specifically: the difference in compensating compression stroke between the relatively arranged composite buffer units 200 is calculated based on the compensating compression stroke of each contacted composite buffer unit 200; the target locking stroke corresponding to each composite buffer unit 200 is determined based on the difference in compensating compression stroke and the force state of the first freight elevator; the compensating compression stroke of each composite buffer unit 200 is compared with the corresponding target locking stroke, and when the compensating compression stroke reaches the corresponding target locking stroke, a locking command for the corresponding compensating control valve 212 is generated.

[0047] The compensation compression stroke difference refers to the difference between the corresponding compensation compression strokes of the two relatively positioned composite buffer units 200 at the current moment, reflecting the difference in the degree of compression formed between the two buffer positions during the contact compensation phase. The larger the compensation compression stroke difference, the more obvious the difference in the contact state between the two corresponding buffer positions.

[0048] The target locking stroke refers to the target compression stroke corresponding to the end of compensation and the cut-off of the compensation flow path when the contact compensation component 210 ends compensation. Different composite buffer units 200 can have different target locking strokes to adapt to the differences in contact sequence, compensation degree, and load distribution at each buffer position.

[0049] It should be noted that each composite buffer unit 200 does not use the same fixed compression stroke as the locking condition. When the freight elevator experiences off-center loading or attitude deviation, the first contact position and the last contact position have already formed different compensating compression strokes at the same time. If control is performed according to the same locking stroke, it is easy for the time when each contact compensation component 210 reaches the locking position to be different. Therefore, this embodiment determines the target locking stroke of each composite buffer unit 200, so that different positions can end compensation at different compression positions, and the expected arrival time of each target locking stroke is coordinated with each other.

[0050] Furthermore, the target locking stroke of each composite buffer unit 200 is determined based on the difference in the compensated compression stroke and the stress state of the first freight elevator. Specifically: the basic locking stroke is determined based on the current compensated compression stroke and the difference in the compensated compression stroke of each composite buffer unit 200; the locking stroke correction direction of each composite buffer unit 200 is determined based on the off-center load direction, and the corresponding locking stroke correction amount is determined based on the initial load distribution to correct the basic locking stroke and obtain candidate locking strokes; the corresponding compensated compression speed is determined based on the continuously acquired compensated displacement data of each composite buffer unit 200, and the corresponding remaining time is determined based on the current compensated compression stroke, compensated compression speed, and candidate locking strokes; the candidate locking strokes are corrected based on the difference between the remaining times to obtain the target locking stroke of each composite buffer unit 200.

[0051] The basic locking stroke refers to the initial locking position determined based on the current compensation compression stroke and the difference in compensation compression stroke between the relative buffer positions, without considering the off-center load state of the freight elevator or the difference in compression speed between the various contact compensation components 210. Specifically, the compensation compression stroke with the larger current compensation degree among the relatively set composite buffer units 200 can be used as a reference. The corresponding compensation stroke to be compensated is determined based on the difference in compensation compression stroke between other composite buffer units 200 and this reference stroke, and the corresponding basic locking stroke is obtained by combining it with the current compensation compression stroke.

[0052] It should be noted that the purpose of setting the basic locking stroke is to first determine a preliminary compensation endpoint based on the actual contact differences that have already formed at each buffer position, so that the target locking position has a geometric compensation basis. Then, it is further corrected by combining the freight elevator's off-center load state and the actual compression speed of each contact compensation component 210, so as to avoid directly determining the locking position based on a single load state and ignoring the compensation differences that have already formed at each buffer position.

[0053] The compensation compression rate refers to the change in the compensation compression stroke of the contact compensation component 210 per unit time when the compensation flow path is in the conducting state. The displacement change between adjacent sampling times can be calculated based on continuously collected compensation displacement data, and the ratio of the displacement change to the corresponding sampling time interval is used as the compensation compression rate.

[0054] Specifically, for example, at a certain sampling moment after all four composite buffer units 200 generate contact signals, the current compensation compression strokes of the four contact compensation components 210 are 12mm, 7mm, 10mm, and 5mm, respectively. Based on the difference in compensation compression strokes and the force state of the first freight elevator, the candidate locking strokes are determined to be 14mm, 13mm, 14mm, and 13mm, respectively. Based on the continuous compensation displacement data, the corresponding compensation compression speeds are 120mm / s, 130mm / s, 118mm / s, and 128mm / s, respectively. Therefore, each contact compensation component 210 needs to compress by 2mm, 6mm, 4mm, and 8mm to reach its corresponding candidate locking stroke, with corresponding candidate remaining times of approximately 16.7ms, 46.2ms, 33.9ms, and 62.5ms, respectively. To ensure that each contact compensation component 210 can lock essentially simultaneously, while minimizing the adjustment degree between the target locking stroke and the candidate locking stroke, let the common locking time be T. Then, the expected further compression strokes of the four contact compensation components 210 within time T are as follows: , , and The adjustment amounts relative to the aforementioned 2mm, 6mm, 4mm, and 8mm candidate remaining strokes are respectively , , and The minimum sum of squares of all adjustment amounts is used as the selection criterion for the common lock-up time, even if... To obtain the minimum value, we get The time is approximately 0.0408s, or 40.8ms. Based on this common locking time, the target locking strokes of the four contact compensation components 210 are redefined to be approximately 16.9mm, 12.3mm, 14.8mm, and 10.2mm, respectively. This ensures that although each contact compensation component 210 has a different target locking position, the time required to reach the corresponding target locking stroke from the current state is approximately 40.8ms. This allows each compensation control valve 212 to basically synchronously cut off the compensation flow path while maintaining the candidate locking positions obtained based on contact differences and off-center load conditions as much as possible.

[0055] It should be noted that since the contact time and compensating compression speed of multiple composite buffer units 200 may differ, if the same locking stroke is directly set, each contact compensation component 210 will usually lock sequentially, causing the locked positions to establish stronger support in advance, while other positions remain in a compensable state, easily leading to uneven stress again. This embodiment determines different target locking strokes for different composite buffer units 200 and coordinates the expected arrival time of each target locking stroke using the compensating compression speed, enabling each contact compensation component 210 to finish compensation at different compression positions at approximately the same time. Each compensation control valve 212 then locks in the same or adjacent control cycles, thereby maintaining the actual compensation differences at each position while allowing multiple composite buffer units 200 to uniformly switch from the contact compensation stage to the energy absorption buffer stage, providing a more stable force foundation for the subsequent joint bearing of multiple energy absorption buffer components 220.

[0056] In one possible implementation, the stress state of the second freight elevator is collected. Specifically, after each compensation control valve 212 cuts off the corresponding compensation flow path, the second load data corresponding to different stress positions of the freight elevator car 400 is collected again. Based on each second load data, the load distribution relationship and the second load difference between each stress position after locking are determined to obtain the stress state of the second freight elevator.

[0057] The second load data refers to the real-time load data corresponding to different force positions of the freight elevator car 400 after each contact compensation component 210 has completed locking. The collection position can be consistent with the force position corresponding to the first load data.

[0058] The second load state of the freight elevator is formed by the load distribution relationship after locking and the second load difference. It is used to characterize the load relationship of the freight elevator car 400 actually acting on different buffer positions after each contact compensation component 210 completes position compensation and forms a stable support.

[0059] The load distribution relationship refers to the proportional relationship between the load borne by each force-bearing position after locking and the total load of each force-bearing position. It is used to characterize the actual distribution of the current load among different buffer positions.

[0060] The second load difference refers to the difference between the second load data corresponding to the two relatively set force positions after locking. Its calculation direction can be consistent with the first load difference to reflect the current load difference and the direction of the difference between the relatively set force positions.

[0061] It should be noted that the first freight elevator stress state is obtained during the contact compensation stage. At this time, each composite buffer unit 200 may be in different contact and compression states. It is mainly used to determine how each contact compensation component 210 completes compensation locking in combination with the initial off-center load. After each compensation flow path is cut off, the compression position of each contact compensation component 210 is fixed, and the stress path between the freight elevator car 400 and multiple composite buffer units 200 is re-established. The actual load distribution at each stress position may change relative to the compensation stage. Therefore, if the first freight elevator stress state is directly used to determine the damping state of the energy-absorbing buffer component 220, it may not accurately reflect the actual stress relationship at the beginning of the formal energy absorption stage. By re-obtaining the second freight elevator stress state after locking is completed, the actual load distribution after contact compensation can be used as the basis for subsequent buffer force distribution and damping adjustment, so that contact compensation control and energy absorption buffer control are based on the actual stress state of their respective stages.

[0062] In step S4, the target damping state refers to the hydraulic damping state that the energy-absorbing buffer assembly 220 needs to achieve in the formal buffering stage. It can be characterized by the throttling opening, flow area or throttling level corresponding to the damping adjustment component 222, so that different energy-absorbing buffer assemblies 220 generate buffering resistance corresponding to their target buffering force.

[0063] The damping adjustment command refers to the control command generated by the controller according to the target damping state of each energy-absorbing buffer component 220. It is used to drive the corresponding damping adjustment component 222 to change the hydraulic medium flow state of the main buffer pressure chamber 221, thereby adjusting the corresponding energy-absorbing buffer component 220 to the target damping state and buffering the elevator car 400 to stop.

[0064] In one embodiment, the target damping state of each energy-absorbing buffer component 220 is determined according to the stress state of the second freight elevator. Specifically, the current upward speed of the freight elevator and the effective buffer stroke of the energy-absorbing buffer component 220 are obtained. The impact energy to be absorbed is determined based on the current upward speed and the total load of the freight elevator, and the total target buffering force is determined based on the impact energy to be absorbed and the effective buffer stroke. The total target buffering force is distributed to each energy-absorbing buffer component 220 according to the stress state of the second freight elevator to obtain the target buffering force corresponding to each energy-absorbing buffer component 220. The target pressure of the corresponding main buffer pressure chamber 221 is determined based on each target buffering force, and the target throttling state of the corresponding damping adjustment component 222 is determined based on each target pressure. The target throttling state is used as the target damping state of the corresponding energy-absorbing buffer component 220.

[0065] The current upward speed of the freight elevator refers to the upward speed of the freight elevator car 400 when each contact compensation component 210 completes locking and the freight elevator enters the formal energy absorption stage. It can be obtained from the freight elevator operation control system, encoder or position detection data.

[0066] The total load of the freight elevator is used to characterize the total motion load of the freight elevator car 400 and the cargo it carries, which is based on the self-weight of the freight elevator car 400 and the weight of the cargo obtained by weighing detection.

[0067] Effective buffer stroke refers to the compression stroke of the energy-absorbing buffer component 220 from the start of its main buffering function to the maximum allowable compression position, during which it can absorb impact energy.

[0068] The impact energy to be absorbed refers to the remaining upward kinetic energy that the elevator car 400 and its cargo still need to be consumed by the car top buffer structure when entering the formal energy absorption stage; for example, the corresponding kinetic energy can be calculated based on the total moving mass of the elevator and the current upward speed, and the energy expected to be borne by other braking mechanisms in the corresponding stage can be deducted as needed.

[0069] The total target buffer force refers to the overall buffer force level when multiple energy-absorbing buffer components 220 jointly absorb the impact energy to be absorbed within the effective buffer stroke. For example, the total target average buffer force can be determined based on the ratio of the impact energy to be absorbed to the effective buffer stroke.

[0070] One method for determining the target throttling state is as follows: Based on the target buffer force and the effective pressure-bearing area of ​​the main buffer hydraulic chamber 221, determine the corresponding target pressure. Then, based on the pre-calibrated correspondence between the hydraulic chamber pressure and the throttling opening of the damping adjustment component 222, determine the target throttling opening that can generate the target pressure, and use this target throttling opening as the target throttling state. In other embodiments, a lookup table can be established based on the pressure and flow characteristics corresponding to different throttling levels of the damping adjustment component 222, allowing the target throttling state to be retrieved from the target pressure.

[0071] It should be noted that after the contact compensation phase, although each energy-absorbing buffer component 220 is basically in a consistent initial compression state, the actual load borne by each buffer position is not the same due to the uneven load on the freight elevator. Therefore, if each energy-absorbing buffer component 220 uses the same damping, insufficient buffering may occur at locations with larger local loads, while excessive reaction forces may be generated at other locations. This embodiment first determines the overall buffering effect required based on the current upward speed and the total load of the freight elevator, and then distributes the buffering effect to different energy-absorbing buffer components 220 according to the second force state of the freight elevator actually formed after locking, so that the damping state of each buffer position is adapted to its actual load-bearing condition, thereby taking into account both the overall energy absorption requirements during abnormal upward movement and the stability of multi-point force distribution.

[0072] In one embodiment, the total target buffer force is distributed to each energy-absorbing buffer component 220 according to the stress state of the second freight elevator, thereby obtaining the target buffer force corresponding to each energy-absorbing buffer component 220. Specifically, the total target buffer force is distributed to each energy-absorbing buffer component 220 according to the load distribution relationship corresponding to each stress position in the stress state of the second freight elevator, thereby obtaining the basic buffer force corresponding to each energy-absorbing buffer component 220; the buffer force adjustment amount between the corresponding energy-absorbing buffer components 220 is determined according to the second load difference between the relative stress positions, and the adjustment direction of the basic buffer force corresponding to the relative stress position is determined according to the positive and negative relationship of the second load difference; according to the adjustment direction, the basic buffer force corresponding to the relative stress position is adjusted respectively using the buffer force adjustment amount to obtain the target buffer force corresponding to each energy-absorbing buffer component 220.

[0073] The basic buffer force refers to the buffer force obtained by first distributing the total target buffer force according to the proportion of load borne by each force-bearing position after locking. For example, if a certain force-bearing position bears 30% of the second total load, then 30% of the total target buffer force can be first distributed to the energy-absorbing buffer component 220 corresponding to that force-bearing position as the basic buffer force.

[0074] The buffer force adjustment amount refers to the amount of buffer force change that is further locally corrected based on the actual load difference between the relative stress positions after the basic buffer force distribution is completed. Specifically, the degree of load imbalance can be determined by the ratio of the absolute value of the second load difference to the second total load, and then the buffer force adjustment amount can be determined by multiplying the degree of load imbalance by the total target buffer force. In practical applications, an adjustment coefficient can also be set or the buffer force adjustment amount can be limited through calibration relationships to avoid excessive local adjustment.

[0075] The adjustment direction refers to the direction in which the foundation buffer force corresponding to the relative stress position increases or decreases, and can be determined based on the sign of the second load difference. For example, the second load difference is obtained by subtracting the second load data of the second stress position from the second load data of the first stress position. When the second load difference is positive, an incremental adjustment is performed on the foundation buffer force corresponding to the first stress position, and a decremental adjustment is performed on the foundation buffer force corresponding to the second stress position; when the second load difference is negative, the opposite adjustment direction is adopted.

[0076] For example, if the total target buffer force is 100kN, and the load proportions corresponding to the four stress positions are 30%, 20%, 28%, and 22%, respectively, then the corresponding basic buffer forces are 30kN, 20kN, 28kN, and 22kN. For one set of relative stress positions, if the second load difference indicates that the load borne by the first stress position is higher than that of the second stress position, and the buffer force adjustment is determined to be 2kN based on this load difference, then the basic buffer force corresponding to the first stress position is adjusted from 30kN to 32kN, and the basic buffer force corresponding to the second stress position is adjusted from 20kN to 18kN; other relative stress positions can be adjusted in the same way to obtain the target buffer force corresponding to each energy-absorbing buffer component 220.

[0077] It should be noted that the initial allocation according to the load ratio ensures that the overall buffering tasks undertaken by different energy-absorbing buffer components 220 match the load distribution after locking. Further adjustments using the second load difference between relative stress positions can correct the buffer force distribution for localized load imbalances. Thus, without changing the overall buffering requirements of the car top buffer structure, the buffer positions corresponding to the load offset direction achieve a buffering effect that matches their stress state, reducing car deflection or localized impacts caused by inconsistent buffer reaction forces among multiple buffer positions.

[0078] In another possible implementation, during the buffering process of each energy-absorbing buffer assembly 220 according to the corresponding target damping state, the actual pressure of each main buffer pressure chamber 221 is obtained; the pressure deviation between the actual pressure of each main buffer pressure chamber 221 and the corresponding target pressure is calculated, and the damping adjustment amount of the corresponding damping adjustment element 222 is determined according to the pressure deviation change between the relatively set main buffer pressure chambers 221; the target damping state of the corresponding energy-absorbing buffer assembly 220 is adjusted according to the damping adjustment amount.

[0079] The actual pressure refers to the pressure of the main buffer chamber 221, which is detected in real time by the pressure sensor during the energy absorption buffering process. It is used to characterize the actual buffering effect currently generated by the corresponding energy absorption buffer component 220.

[0080] Pressure deviation refers to the difference between the actual pressure in the main buffer chamber 221 and the corresponding target pressure. When the pressure deviation is positive, it indicates that the current actual buffering effect is higher than the target state, and when the pressure deviation is negative, it indicates that the current actual buffering effect is lower than the target state.

[0081] The damping adjustment amount refers to the change in the throttling state of the damping regulator 222 determined based on the pressure deviation. Specifically, the pressure deviation change of the relatively positioned main buffer pressure chambers 221 at adjacent sampling times can be calculated, and the damping adjustment amount can be determined based on the magnitude of the pressure deviation change. For example, a proportional relationship or piecewise mapping relationship between the pressure deviation change and the throttling opening adjustment amount can be established in advance; when the actual pressure of a certain main buffer pressure chamber 221 is continuously higher than the target pressure, the throttling opening of the corresponding damping regulator 222 is increased to reduce hydraulic resistance; when the actual pressure is continuously lower than the target pressure, the corresponding throttling opening is decreased to increase hydraulic resistance. For the relatively positioned main buffer pressure chambers 221, the adjustment range of each can also be determined based on the difference in the pressure deviation between the two, so that a larger damping adjustment amount is obtained at the position with a larger pressure deviation.

[0082] It should be noted that the stress state of the second freight elevator reflects the stress state at the time of contact compensation completion. However, during the subsequent rapid compression and energy absorption process, the actual buffering force at each buffer position may deviate from the initial target value due to cargo movement, elastic deformation of the car frame, and differences in the response of different hydraulic circuits. Therefore, simply adjusting once according to the initially determined target damping state cannot guarantee that each composite buffer unit 200 maintains coordinated force throughout the entire braking process. This embodiment compares the actual pressure of each main buffer pressure chamber 221 with the corresponding target pressure and corrects the damping state based on the dynamic changes in pressure deviation, so that the actual buffering effect of each energy-absorbing buffer component 220 can continuously approach the corresponding target buffering force, thereby suppressing the recurrence of localized force concentration during the buffering process and improving the stability and smoothness of the abnormal upward braking process of the freight elevator.

[0083] The embodiments of the present invention have been described in detail above, but the content is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made in accordance with the claims of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A control method for a buffer structure on the top of a freight elevator, characterized in that, The buffer structure is applied to the top of a freight elevator car, and the top of the freight elevator car buffer structure includes multiple composite buffer units, each of which includes a contact compensation component and an energy-absorbing buffer component arranged in series. The contact compensation assembly includes a compensation hydraulic chamber, a low-pressure reservoir, and a compensation control valve; the energy-absorbing buffer assembly includes a main buffer hydraulic chamber and a damping adjustment element; the method includes: In response to the abnormal upward signal of the freight elevator, a compensation activation command is generated and sent to each compensation control valve so that the compensation control valve opens the compensation flow path between each compensation hydraulic chamber and the corresponding low-pressure reservoir. The contact signal of each composite buffer unit is detected. After any composite buffer unit generates a contact signal, the compensation compression stroke and the force state of the first freight elevator corresponding to each contacted composite buffer unit are obtained. The force state of the first freight elevator includes the initial load distribution and off-center load direction of the freight elevator. Based on the compensation compression stroke of each composite buffer unit and the force state of the first freight elevator, a locking command is generated so that each compensation control valve cuts off each compensation flow path according to the locking command, and the force state of the second freight elevator is collected. Based on the force state of the second freight elevator, the target damping state of each energy-absorbing buffer component is determined, a damping adjustment command is generated and sent to each damping adjustment component, and the damping adjustment command is used to adjust the corresponding energy-absorbing buffer component to the target damping state to buffer and stop the car.

2. The control method for a freight elevator car top buffer structure according to claim 1, characterized in that, The process of obtaining the compensation compression stroke and the force state of the first freight elevator corresponding to each contacted composite buffer unit includes: According to the timing of the contact signals generated by each composite buffer unit, the compensation displacement data of each contacted composite buffer unit is read, and the change in the compensation displacement data after the contact time is taken as the corresponding compensation compression stroke. Collect first load data corresponding to different stress positions of the freight elevator car, take the sum of each first load data as the first total load, and calculate the load ratio of each first load data to the first total load and the first load difference between relative stress positions. The initial load distribution is obtained based on the proportion of each load, and the off-center load direction is obtained based on the positive and negative relationship of the difference between each first load. The initial load distribution and the off-center load direction are combined to form the first stress state of the freight elevator.

3. The control method for a freight elevator car top buffer structure according to claim 1, characterized in that, The method of generating locking commands based on the compensation compression stroke of each composite buffer unit and the force state of the first freight elevator includes: Calculate the difference in compensation compression stroke between the relatively set composite buffer units based on the compensation compression stroke of each contacted composite buffer unit. The target locking stroke of each composite buffer unit is determined based on the compensation compression stroke difference and the force state of the first freight elevator. The compensation compression stroke of each composite buffer unit is compared with the corresponding target lock-up stroke. When the compensation compression stroke reaches the corresponding target lock-up stroke, a lock-up command for the corresponding compensation control valve is generated.

4. The control method for a freight elevator car top buffer structure according to claim 3, characterized in that, The first freight elevator's stress state includes the initial load distribution and off-center load direction. Determining the target locking stroke corresponding to each composite buffer unit based on the compensation compression stroke difference and the first freight elevator's stress state includes: The corresponding basic locking stroke is determined based on the current compensation compression stroke and compensation compression stroke difference of each composite buffer unit; The locking stroke correction direction for each composite buffer unit is determined based on the off-center load direction, and the corresponding locking stroke correction amount is determined based on the initial load distribution. The basic locking stroke is then corrected to obtain the candidate locking stroke. The corresponding compensation compression speed is determined based on the compensation displacement data continuously acquired by each composite buffer unit, and the corresponding remaining time is determined based on the current compensation compression stroke, compensation compression speed, and candidate locking stroke. The candidate locking strokes are corrected based on the differences between the remaining times to obtain the target locking strokes for each composite buffer unit.

5. The control method for a freight elevator car top buffer structure according to claim 1, characterized in that, The collection of the force state of the second freight elevator includes: After each compensation control valve cuts off the corresponding compensation flow path, the second load data corresponding to different stress positions of the freight elevator car are collected again. Based on the second load data, the load distribution relationship between each force-bearing position after locking and the second load difference are determined, and the force state of the second freight elevator is obtained.

6. The control method for a freight elevator car top buffer structure according to claim 1, characterized in that, The determination of the target damping state of each energy-absorbing buffer component based on the force state of the second freight elevator includes: The current upward speed of the freight elevator and the effective buffer stroke of the energy-absorbing buffer components are obtained. The impact energy to be absorbed is determined based on the current upward speed and the total load of the freight elevator. The total target buffer force is determined based on the impact energy to be absorbed and the effective buffer stroke. Based on the stress state of the second freight elevator, the total target buffer force is distributed to each energy-absorbing buffer component to obtain the target buffer force corresponding to each energy-absorbing buffer component. The target pressure of the corresponding main buffer chamber is determined based on each target buffer force, and the target throttling state of the corresponding damping adjustment component is determined based on each target pressure. The target throttling state is then used as the target damping state of the corresponding energy-absorbing buffer component.

7. The control method for a freight elevator car top buffer structure according to claim 6, characterized in that, The step of distributing the total target buffer force to each energy-absorbing buffer component according to the stress state of the second freight elevator, and obtaining the target buffer force corresponding to each energy-absorbing buffer component, includes: Based on the load distribution relationship corresponding to each stress position in the stress state of the second freight elevator, the total target buffer force is distributed to each energy-absorbing buffer component to obtain the basic buffer force corresponding to each energy-absorbing buffer component; Based on the second load difference between the relative stress positions, determine the buffer force adjustment amount between the corresponding energy-absorbing buffer components, and determine the adjustment direction of the basic buffer force corresponding to the relative stress position based on the positive and negative relationship of the second load difference; According to the adjustment direction, the basic buffer force corresponding to the relative force position is adjusted by the buffer force adjustment amount to obtain the target buffer force corresponding to each energy-absorbing buffer component.

8. The control method for a freight elevator car top buffer structure according to claim 6, characterized in that, The method further includes: During the buffering process of each energy-absorbing buffer component according to the corresponding target damping state, the actual pressure of each main buffer buffer chamber is obtained; Calculate the pressure deviation between the actual pressure of each main buffer chamber and the corresponding target pressure, and determine the damping adjustment amount of the corresponding damping adjustment element based on the pressure deviation change between the relatively set main buffer chambers; The target damping state of the corresponding energy-absorbing buffer component is adjusted according to the damping adjustment amount.

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