Long distance conveyor heavy hammer tensioning device and hydraulic buffering method

Abstract

The application discloses a heavy hammer tensioning device for long-distance conveyors, which comprises a heavy hammer tensioning support and a heavy hammer. A movable tensioning vehicle is arranged on the two sides of the heavy hammer and is in sliding fit with the heavy hammer tensioning support. A tensioning roller is arranged on the upper part of the heavy hammer, the rotating shafts at the two ends of the tensioning roller are in rotating fit with the corresponding movable tensioning vehicles. Buffer oil cylinders are arranged on the rotating shafts at the two ends of the tensioning roller. The cylinder bottom end of the buffer oil cylinder is hingedly connected with the heavy hammer tensioning support, and the piston rod end of the buffer oil cylinder is hingedly connected with the rotating shaft of the corresponding end of the tensioning roller. Each buffer oil cylinder is connected with a corresponding hydraulic system. The hydraulic system controls the buffer of the ascending or descending speed of the heavy hammer. The application also discloses a hydraulic buffer method of the heavy hammer tensioning device for long-distance conveyors. The buffer oil cylinders are used for increasing the buffer of the heavy hammer during the starting and stopping of the long-distance belt conveyor, limiting the running speed of the heavy hammer and reducing the impact of the heavy hammer on the equipment during the ascending and descending.

Description

Technical Field

[0001] This invention belongs to the field of conveyor technology, specifically relating to a counterweight tensioning device and hydraulic buffering method for long-distance conveyors. Background Technology

[0002] The tensioning device of long-distance belt conveyors mostly adopts the form of weighted tensioning. Weighted tensioning can provide a constant tension force and respond quickly. It can ensure that the conveyor belt has appropriate tension at the point of departure of the drive drum, preventing the conveyor from slipping. It can also ensure that there is necessary tension on the contact arc between the conveyor belt and the idler roller, preventing material spillage caused by the loosening of the conveyor belt between the two sets of idler rollers. In addition, it can compensate for the permanent deformation of the conveyor belt and the elastic elongation during start-up and stable operation under different working conditions.

[0003] However, the drawbacks of counterweight tensioning are also significant: during the start-up of a long-distance belt conveyor, the tension of the lower belt decreases sharply, and the counterweight rapidly descends to compensate for the tension required for belt elongation; during shutdown, the tension of the lower belt increases sharply, and the counterweight rapidly rises to reduce the impact of dynamic tension during shutdown, thereby minimizing the impact of dynamic tension on the equipment's service life. However, this rapid descent or ascent of the counterweight generates a large impact load on the belt and the steel structure of the counterweight tensioning bracket, affecting the service life of the device. Therefore, to prevent the impact of the rapid descent or ascent of the counterweight on the belt and the steel structure of the counterweight tensioning bracket, it is necessary to limit the operating speed of the counterweight.

[0004] Based on the above problems, this application proposes a counterweight tensioning device and hydraulic buffering method for long-distance conveyors. Two buffer cylinders are added above the counterweight to provide a reaction buffering force when the counterweight descends or rises, thereby limiting the running speed of the counterweight and reducing the impact on the conveyor belt and the steel structure of the counterweight tensioning support. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a counterweight tensioning device for long-distance conveyors.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A counterweight tensioning device for a long-distance conveyor includes a counterweight tensioning bracket and a counterweight;

[0008] The two sides of the counterweight are symmetrically fixed with movable tensioning carriages, which slide vertically with the counterweight tensioning bracket.

[0009] A tensioning roller is installed on the upper part of the counterweight, and the rotating shafts at both ends of the tensioning roller are rotated in coordination with the corresponding traveling tensioning carriage;

[0010] Buffer oil cylinders are symmetrically arranged on the rotating shafts at the two ends of the tensioning roller; the cylinder bottom end of the buffer oil cylinder is hingedly connected with the weight tensioning support, and the piston rod end of the buffer oil cylinder is hingedly connected with the rotating shaft of the corresponding end of the tensioning roller;

[0011] Each buffer oil cylinder is connected with a corresponding hydraulic system; the hydraulic system controls the buffer of the ascending or descending speed of the weight.

[0012] Preferably, the hydraulic system comprises a first branch and a second branch.

[0013] The two ends of the first branch are respectively communicated to the rod cavity and the rodless cavity of the buffer oil cylinder, and a first one-way valve and a first electromagnetic overflow valve are arranged on the first branch; the flow direction of the first one-way valve is from the rodless cavity of the buffer oil cylinder to the rod cavity, and the first electromagnetic overflow valve is arranged on the pipeline at the oil inlet end of the first one-way valve.

[0014] The two ends of the second branch are respectively communicated to the rod cavity and the rodless cavity of the buffer oil cylinder, and a second one-way valve and a second electromagnetic overflow valve are arranged on the second branch; the flow direction of the second one-way valve is from the rod cavity of the buffer oil cylinder to the rodless cavity, and the second electromagnetic overflow valve is arranged on the pipeline at the oil inlet end of the second one-way valve.

[0015] Preferably, a first pressure transmitter is arranged on the first branch between the first electromagnetic overflow valve and the rodless cavity of the buffer oil cylinder.

[0016] A second pressure transmitter is arranged on the second branch between the second electromagnetic overflow valve and the rod cavity of the buffer oil cylinder.

[0017] Preferably, a travel switch for monitoring the extension length of the piston rod is arranged on the buffer oil cylinder.

[0018] Preferably, the first electromagnetic overflow valve, the first pressure transmitter, the second electromagnetic overflow valve, the second pressure transmitter and the travel switch are connected with a controller.

[0019] Preferably, the rotating shafts at the two ends of the tensioning roller are rotationally matched with corresponding movable tensioning vehicles through movable bearing seats.

[0020] Preferably, the piston rod end of the buffer oil cylinder is hingedly connected with the movable bearing seat of the corresponding end of the tensioning roller.

[0021] The application further provides a hydraulic buffer method of the weight tensioning device for the long-distance conveyor.

[0022] A hydraulic buffer method of a weight tensioning device for a long-distance conveyor,

[0023] The hydraulic buffer method of the weight descending during the starting process of the long-distance conveyor comprises the following steps:

[0024] Step 11: the piston rod of the buffer cylinder extends downward following the descent of the weight;

[0025] The hydraulic oil flows to the rodless chamber along the second branch through the second electromagnetic overflow valve and the second check valve; meanwhile, the second pressure transmitter monitors the pressure of the hydraulic oil in the rod chamber of the buffer cylinder in real time and transmits the pressure to the controller;

[0026] Step 12: the pressure of the hydraulic oil in the rod chamber of the buffer cylinder continues to rise, and the back pressure generated by the second electromagnetic overflow valve gradually slows down the descent speed of the weight;

[0027] Step 13: when the pressure of the hydraulic oil in the rod chamber of the buffer cylinder monitored by the second pressure transmitter rises to the set value of the second electromagnetic overflow valve, the controller controls the second electromagnetic overflow valve to be unloaded;

[0028] Step 14: after the second electromagnetic overflow valve is unloaded, the tensioning force generated by the weight is fully applied to the belt, and the rated tensioning force is reached;

[0029] The hydraulic buffering method when the weight rises during the parking process of the long-distance conveyor includes the following steps:

[0030] Step 21: the piston rod of the buffer cylinder retracts upward following the rise of the weight;

[0031] The hydraulic oil flows to the rod chamber along the first branch through the first electromagnetic overflow valve and the first check valve; meanwhile, the first pressure transmitter monitors the pressure of the hydraulic oil in the rodless chamber of the buffer cylinder in real time and transmits the pressure to the controller;

[0032] Step 22: the pressure of the hydraulic oil in the rodless chamber of the buffer cylinder continues to rise, and the back pressure generated by the first electromagnetic overflow valve gradually slows down the rise speed of the weight;

[0033] Step 23: when the pressure of the hydraulic oil in the rodless chamber of the buffer cylinder monitored by the first pressure transmitter rises to the set value of the first electromagnetic overflow valve, the controller controls the first electromagnetic overflow valve to be unloaded;

[0034] Step 24: after the first electromagnetic overflow valve is unloaded, the tensioning force generated by the weight is fully applied to the belt, and the rated tensioning force is reached.

[0035] The beneficial effects of the present application are:

[0036] (1) The present application uses the buffer cylinder to increase the buffering of the weight during the starting and parking processes of the long-distance belt conveyor, limits the running speed of the weight, can realize the original characteristics of the weight tensioning, and can reduce the impact of the weight on the equipment when the weight rises and descends; at the same time, due to the buffering effect, the safety factor of the belt of the long-distance belt conveyor is reduced, so that the design strength of the steel structure of the weight tensioning support can be reduced.

[0037] (2)The stroke switch in the application can monitor the broken belt accident condition and give an alarm; when the belt is broken, the stroke switch installed on the buffer oil cylinder will monitor the piston rod to extend beyond the tension stroke of the weight, that is, beyond the maximum descending distance of the weight, at this time the stroke switch will transmit the information to the controller and give an alarm, and the controller will control the conveyor to stop after receiving the signal.

[0038] (3) In the event of a broken belt, the weight and tensioning drum in the application are lifted and fixed through the buffer oil cylinder, thereby preventing the weight from falling to the ground and avoiding the expansion of the accident. BRIEF DESCRIPTION OF DRAWINGS

[0039] The drawings accompanying the specification of this application are used to provide further understanding of the application, the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute an improper limitation on the application.

[0040] Figure 1 is a structural schematic front view of the weight tensioning device for long distance conveyor of the application;

[0041] Figure 2 is a structural schematic side view of the weight tensioning device for long distance conveyor of the application;

[0042] Figure 3 is a hydraulic system principle diagram in the application;

[0043] Among them:

[0044] 0-belt, 1-weight tensioning support, 2-weight, 3-tensioning drum, 4-traveling tensioning vehicle, 5-buffer oil cylinder, 6-traveling bearing seat;

[0045] 7-first branch, 71-first check valve, 72-first electromagnetic overflow valve, 73-first pressure transmitter;

[0046] 8-second branch, 81-second check valve, 82-second electromagnetic overflow valve, 83-second pressure transmitter; 9-stroke switch. DETAILED DESCRIPTION

[0047] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the application belongs.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0049] In this invention, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are merely relational terms determined for the convenience of describing the structural relationship of the various components or elements of this invention, and do not specifically refer to any component or element in this invention, and should not be construed as limiting this invention.

[0050] In this invention, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0052] Example 1:

[0053] like Figures 1-2 As shown, a counterweight tensioning device for a long-distance conveyor includes a counterweight tensioning bracket 1 and a counterweight 2.

[0054] The movable tensioning carriages 4 are symmetrically fixed on both sides of the counterweight 2, and the movable tensioning carriages 4 slide in the vertical direction with the counterweight tensioning bracket 1.

[0055] The upper part of the counterweight 2 is equipped with a tensioning roller 3. The rotating shafts at both ends of the tensioning roller 3 are rotated and engaged with the corresponding moving tensioning carriage 4, that is, the tensioning roller 3 can rotate freely with the conveyor belt 0.

[0056] Buffer cylinders 5 are symmetrically arranged on the rotating shafts at both ends of the tensioning roller 3; the bottom end of the buffer cylinder 5 is hinged to the counterweight tensioning bracket, and the piston rod end of the buffer cylinder 5 is hinged to the rotating shaft at the corresponding end of the tensioning roller 3.

[0057] Each buffer cylinder 5 is connected to a corresponding hydraulic system; the hydraulic system buffers and controls the speed at which the weight 2 rises or falls.

[0058] Preferred, such as Figure 3 As shown, the hydraulic system includes a first branch 7 and a second branch 8;

[0059] The two ends of the first branch 7 are communicated to the rod cavity and the rodless cavity of the buffer oil cylinder 5, and the first one-way valve 71 and the first electromagnetic overflow valve 72 are arranged on the first branch 7.

[0060] The two ends of the second branch 8 are communicated to the rod cavity and the rodless cavity of the buffer oil cylinder 5, and the second one-way valve 81 and the second electromagnetic overflow valve 82 are arranged on the second branch 8.

[0061] Preferably, the first pressure transmitter 73 is arranged on the first branch 7 between the first electromagnetic overflow valve 72 and the rodless cavity of the buffer oil cylinder 5.

[0062] The second pressure transmitter 83 is arranged on the second branch 8 between the second electromagnetic overflow valve 82 and the rod cavity of the buffer oil cylinder 5.

[0063] Preferably, the buffer oil cylinder 5 is provided with the travel switch 9 for monitoring the extension length of the piston rod, wherein the travel switch 9 has an alarm function.

[0064] The travel switch 9 is used to monitor the belt breakage accident condition and give an alarm.

[0065] The long-distance belt conveyor is prone to belt breakage accidents due to overload and belt fatigue aging. When the belt breaks, the travel switch 9 installed on the buffer oil cylinder 5 will monitor that the extension length of the piston rod exceeds the tension travel of the weight 2, that is, exceeds the maximum downward distance of the weight 2. At this time, the travel switch 9 transmits information to the controller and gives an alarm. After receiving the signal, the controller controls the conveyor to stop.

[0066] In addition, in the event of a belt breakage, the weight 2 and the tensioning drum 3 in the application are lifted and fixed by the buffer oil cylinder 5, thereby preventing the weight 2 from falling to the ground and avoiding the expansion of the accident.

[0067] Preferably, the first electromagnetic overflow valve 72, the first pressure transmitter 73, the second electromagnetic overflow valve 82, the second pressure transmitter 83 and the travel switch 9 are connected to the controller.

[0068] Preferably, the rotating shafts at both ends of the tensioning drum 3 are rotatably connected to the corresponding movable tensioning vehicles 4 through the movable bearing seats 6.

[0069] Preferably, the piston rod end of the buffer oil cylinder 5 is hingedly connected to the movable bearing seat 6 at the corresponding end of the tensioning drum 3.

[0070] Embodiment 2:

[0071] The hydraulic buffering method for the long distance conveyor weight tensioner in example 1 is as follows.

[0072] During the start-up of the long distance conveyor, the length of the plastic elongation transferred by the return belt of the long distance conveyor accumulates due to the plastic elongation of the belt and the lag of the running speed of the return belt. The accumulated length is stored by the descent of the weight 5, thereby maintaining the belt tension.

[0073] The hydraulic buffering method for the descent of the weight 2 during the start-up of the long distance conveyor includes the following steps:

[0074] Step 11: The piston rod of the buffer cylinder 5 extends downward following the descent of the weight 2;

[0075] The volume of hydraulic oil in the rod cavity of the buffer cylinder 5 is compressed, and the hydraulic oil flows to the rodless cavity along the second branch 8 through the second electromagnetic overflow valve 82 and the second check valve 81. At the same time, the second pressure transmitter 83 monitors the pressure of the hydraulic oil in the rod cavity of the buffer cylinder 5 in real time and transmits it to the controller;

[0076] Step 12: The pressure of the hydraulic oil in the rod cavity of the buffer cylinder 5 continues to rise, and the back pressure generated by the second electromagnetic overflow valve 82 gradually slows down the descent speed of the weight 2;

[0077] Step 13: When the pressure of the hydraulic oil in the rod cavity of the buffer cylinder 5 monitored by the second pressure transmitter 83 rises to the set value of the second electromagnetic overflow valve 82, the controller controls the second electromagnetic overflow valve 82 to unload;

[0078] Step 14: After the second electromagnetic overflow valve 82 is unloaded, the tensioning force generated by the weight 2 is fully applied to the belt 0, reaching the rated tensioning force.

[0079] During the shutdown of the long distance conveyor, the belt tension of the long distance conveyor increases dramatically due to the existence of the belt dynamic tension, and the belt quickly contracts along the running direction. The weight at the lowest point in the normal running state quickly rises with the contraction of the belt.

[0080] The hydraulic buffering method for the ascent of the weight 2 during the shutdown of the long distance conveyor includes the following steps:

[0081] Step 21: The piston rod of the buffer cylinder 5 retracts upward following the ascent of the weight 2;

[0082] The volume of hydraulic oil in the rodless cavity of the buffer cylinder 5 is compressed, and the hydraulic oil flows to the rod cavity along the first branch 7 through the first electromagnetic overflow valve 72 and the first check valve 71. At the same time, the first pressure transmitter 73 monitors the pressure of the hydraulic oil in the rodless cavity of the buffer cylinder 5 in real time and transmits it to the controller;

[0083] Step 22: The pressure of the hydraulic oil in the rodless cavity of the buffer cylinder 5 continues to rise, and the back pressure generated by the first electromagnetic overflow valve 72 makes the lifting speed of the weight 2 gradually slow down;

[0084] Step 23: When the pressure of the hydraulic oil in the rodless cavity of the buffer cylinder 5 monitored by the first pressure transmitter 73 rises to the set value of the first electromagnetic overflow valve 72, the controller controls the first electromagnetic overflow valve 72 to be unloaded;

[0085] Step 24: After the first electromagnetic overflow valve 72 is unloaded, the tension generated by the weight 2 is fully applied to the belt 0, and the rated tension is reached.

[0086] Specifically, in the present application, the first electromagnetic overflow valve 72 and the second electromagnetic overflow valve 82 are both normally closed overflow valves.

[0087] Specifically, in the present application, the set value of the second electromagnetic overflow valve 82 is determined according to the degree of weight descent buffering required by the actual site, that is, according to the time required by the weight to descend to the actual site, and the specific method is: according to the actual site, if the time required for the weight to descend is t1, then the pressure value of the second electromagnetic overflow valve 82 is set from small to large, and the time of each weight descent is recorded, until the time of the weight descent reaches t1, then the corresponding pressure value is the set value of the second electromagnetic overflow valve 82.

[0088] Specifically, in the present application, the set value of the first electromagnetic overflow valve 72 is determined according to the degree of weight ascent buffering required by the actual site, that is, according to the time required by the weight to ascend to the actual site, and the specific method is: according to the actual site, if the time required for the weight to ascend is t2, then the pressure value of the first electromagnetic overflow valve 72 is set from small to large, and the time of each weight ascent is recorded, until the time of the weight ascent reaches t2, then the corresponding pressure value is the set value of the first electromagnetic overflow valve 72.

[0089] In addition, according to the tension requirements of the conveyor under different working conditions, the controller can set different values for the corresponding electromagnetic overflow valves, thereby adjusting the back pressure of the corresponding electromagnetic overflow valves, and then the buffer cylinder 5 can provide part of the tension required by the long-distance belt conveyor, thereby adjusting the tension of the long-distance belt conveyor during operation.

[0090] The present application uses the buffer cylinder 5 to increase the buffering of the weight 2 during the start and stop of the long-distance belt conveyor, which not only realizes the original characteristics of the weight tensioning, but also reduces the impact of the weight on the equipment during the lifting and descending; at the same time, due to the buffering effect, the safety factor of the long-distance belt conveyor is reduced, thereby the design strength of the steel structure of the weight tensioning support can be reduced.

[0091] The above describes the specific embodiments of the present application in connection with the drawings, but is not a limitation of the present application, and those skilled in the art should understand that various modifications or changes made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A heavy hammer tensioning device for long distance conveyors, comprising a heavy hammer tensioning support and a heavy hammer; characterized in that, a mobile tensioning vehicle is symmetrically fixed on both sides of the heavy hammer and vertically slides with the heavy hammer tensioning support; a tensioning roller is arranged on the upper part of the heavy hammer, the rotating shafts at both ends of the tensioning roller are rotationally connected with the corresponding mobile tensioning vehicles; a buffer oil cylinder is symmetrically arranged on the rotating shafts at both ends of the tensioning roller; the bottom end of the buffer oil cylinder is hingedly connected with the heavy hammer tensioning support, and the piston rod end of the buffer oil cylinder is hingedly connected with the rotating shaft of the corresponding end of the tensioning roller; each buffer oil cylinder is connected with a corresponding hydraulic system; the hydraulic system controls the buffer of the ascending or descending speed of the heavy hammer; the hydraulic system comprises a first branch and a second branch; the two ends of the first branch are respectively connected with the rod cavity and the rodless cavity of the buffer oil cylinder, and a first one-way valve and a first electromagnetic overflow valve are arranged on the first branch; the flow direction of the first one-way valve is from the rodless cavity of the buffer oil cylinder to the rod cavity, and the first electromagnetic overflow valve is arranged on the pipeline at the oil inlet end of the first one-way valve; the two ends of the second branch are respectively connected with the rod cavity and the rodless cavity of the buffer oil cylinder, and a second one-way valve and a second electromagnetic overflow valve are arranged on the second branch; the flow direction of the second one-way valve is from the rod cavity of the buffer oil cylinder to the rodless cavity, and the second electromagnetic overflow valve is arranged on the pipeline at the oil inlet end of the second one-way valve; the piston rod of the buffer oil cylinder extends downward following the descending of the heavy hammer, and the hydraulic oil flows to the rodless cavity through the second electromagnetic overflow valve and the second one-way valve along the second branch; the piston rod of the buffer oil cylinder retracts upward following the ascending of the heavy hammer, and the hydraulic oil flows to the rod cavity through the first electromagnetic overflow valve and the first one-way valve along the first branch.

2. The heavy weight tensioner for long distance conveyors as claimed in claim 1 wherein, a first pressure transmitter is arranged on the first branch between the first electromagnetic overflow valve and the rodless cavity of the buffer oil cylinder; a second pressure transmitter is arranged on the second branch between the second electromagnetic overflow valve and the rod cavity of the buffer oil cylinder.

3. The long distance conveyor heavy weight tensioner as claimed in claim 2, wherein, a travel switch for monitoring the extension length of the piston rod is arranged on the buffer oil cylinder.

4. The heavy weight tensioner for long distance conveyors as claimed in claim 3 wherein, The first electromagnetic overflow valve, the first pressure transmitter, the second electromagnetic overflow valve, the second pressure transmitter and the travel switch are connected with a controller.

5. The long distance conveyor heavy weight tensioner as claimed in claim 4, wherein, The rotating shafts at both ends of the tensioning roller are rotationally connected with the corresponding mobile tensioning vehicles through mobile bearing seats.

6. The long distance conveyor heavy weight tensioner as claimed in claim 5, wherein, The piston rod end of the buffer oil cylinder is hingedly connected with the mobile bearing seat of the corresponding end of the tensioning roller.

7. A hydraulic buffer method based on the heavy hammer tensioning device for long distance conveyors according to any one of claims 4-6, characterized in that, the hydraulic buffer method when the heavy hammer descends during the starting of the long distance conveyor comprises the following steps: Step 11: the piston rod of the buffer oil cylinder extends downward following the descending of the heavy hammer; the hydraulic oil flows to the rodless cavity through the second electromagnetic overflow valve and the second one-way valve along the second branch; at the same time, the second pressure transmitter monitors the pressure of the hydraulic oil in the rod cavity of the buffer oil cylinder in real time and transmits it to the controller; Step 12: the pressure of the hydraulic oil in the rod cavity of the buffer oil cylinder continuously rises, and the back pressure generated by the second electromagnetic overflow valve makes the descending speed of the heavy hammer gradually slow down. Step 13: When the pressure of the hydraulic oil in the rod cavity of the buffer cylinder monitored by the second pressure transmitter rises to the set value of the second electromagnetic overflow valve, the controller controls the second electromagnetic overflow valve to unload; Step 14: After the second electromagnetic overflow valve is unloaded, the tension force generated by the weight is fully applied to the belt, reaching the rated tension force; The hydraulic buffering method when the weight rises during the parking process of the long-distance conveyor includes the following steps: Step 21: The piston rod of the buffer cylinder retracts upward following the rising of the weight; The hydraulic oil flows to the rod cavity along the first branch through the first electromagnetic overflow valve and the first check valve; at the same time, the first pressure transmitter monitors the pressure of the hydraulic oil in the rodless cavity of the buffer cylinder in real time and transmits it to the controller; Step 22: The pressure of the hydraulic oil in the rodless cavity of the buffer cylinder continues to rise, and the back pressure generated by the first electromagnetic overflow valve gradually slows down the rising speed of the weight; Step 23: When the pressure of the hydraulic oil in the rodless cavity of the buffer cylinder monitored by the first pressure transmitter rises to the set value of the first electromagnetic overflow valve, the controller controls the first electromagnetic overflow valve to unload; Step 24: After the first electromagnetic overflow valve is unloaded, the tension force generated by the weight is fully applied to the belt, reaching the rated tension force.

Images