Double-winch hydraulic tensioning system of belt conveyor and hydraulic tensioning control method

Abstract

The invention discloses a belt conveyor double-winch hydraulic tensioning system and a hydraulic tensioning control method. The belt conveyor double-winch hydraulic tensioning system comprises a traveling trolley, a tensioning device, a double-winch tensioning device, a hydraulic oil supply device and a control device. A fixed pulley is arranged at the right end of the moving trolley; the tensioning device comprises a fixing frame and a tensioning oil cylinder. A rope guide wheel is mounted at the extending end of the tensioning oil cylinder; the double-winch tensioning device comprises a winch base, two winding drums, two power parts and a steel wire rope. The two winding drums are coaxially and rotationally installed on the winch base, each winding drum is provided with a tension sensor in communication connection with the control device, and the output end of each power part is connected with the input end of the corresponding winding drum. One end of the steel wire rope is wound on one winding drum, and the other end of the steel wire rope sequentially bypasses the fixed pulley and the rope guide wheel and then is wound back to the other winding drum; the hydraulic oil supply device is in communication connection with the control device. When the conveying belt is tensioned, the tensioning force at the two ends of the steel wire rope can be ensured to be consistent, the stable movement of the traveling trolley is realized, and the phenomenon of off tracking or off-rail is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of belt conveyors, and particularly to a double winch hydraulic tensioning system and a hydraulic tensioning control method for a belt conveyor. Background Art

[0002] Since the tension of the conveyor belt varies along the entire length of the conveyor, and there are many influencing factors, to ensure the normal operation of the conveyor, the tension of the conveyor belt must meet the following two conditions: 1. Under any load condition, the circumferential force acting on all the rollers is transmitted to the conveyor belt through friction, and no slippage should occur between the conveyor belt and the rollers; 2. The tension acting on the conveyor belt should be large enough so that the sag of the conveyor belt between two groups of load-carrying idlers is less than a certain value. Currently, the tensioning methods for belt conveyors include: screw tensioning, weight tensioning, weight car tensioning, ordinary hydraulic tensioning, winch-equipped hydraulic tensioning, etc.

[0003] Winch-equipped hydraulic tensioning is widely used in retractable belt conveyors. To meet the requirements of the mining (heading) of the face conveyor, a retractable belt conveyor is equipped with a tape storage device. The tape storage device stores the excess tape in the tape storage bin, and during use, the length of the tape is matched with the length of the conveyor. Hydraulic tensioning realizes the automatic compensation of the tape and provides a certain tension for the belt conveyor.

[0004] Currently, the installation method of hydraulic tensioning is as Figure 1 shown. The tensioning cylinder is fixed on the tape storage bin frame of the belt conveyor by bolts. One end of the steel wire rope is fixed on the tape storage bin frame, and the other end is wound around the pulley groups of the tensioning trolley and the tensioning cylinder, and finally wound on the winch. By the forward and reverse rotation of the winch, the tightness of the steel wire rope is realized, and a suitable tension is provided for the belt conveyor.

[0005] In this hydraulic tensioning arrangement, the end of the steel wire rope is arranged on the side of the cylinder. One side is the fixed end, fixed on the tensioning frame of the tape storage bin, and the other side is wound around the winch drum. During the operation of the belt conveyor, by controlling the winch, the winch drum rotates, changing the length of the steel wire wound on the drum, and realizing the movement of the tensioning trolley. Since one end of the steel wire rope is fixed, only the steel wire rope at the winch end changes. There is a certain friction between the steel wire rope and the pulleys of the tensioning trolley. The force is transmitted from one end to the other end. The force on the winch end on both sides of the pulley of the tensioning trolley is always greater than the tension of the fixed end of the pulley. And the winch end pulley always experiences the tension change earlier than the fixed end, resulting in the deviation of the trolley during the movement. The tensioning trolley will deviate towards the side with greater force on the steel wire rope, thus causing the phenomenon that the trolley wheels get stuck or jammed with one side of the track. In the light case, the wheels are damaged and the conveyor belt on the tensioning trolley deviates. In the severe case, the trolley derails, leading to safety accidents. Summary of the Invention

[0006] In order to solve the technical problems existing in the above-mentioned technology, it is necessary to provide a belt conveyor double winch hydraulic tensioning system.

[0007] A belt conveyor double winch hydraulic tensioning system, comprising a traveling trolley, a tensioning device, a double winch tensioning device, a hydraulic oil supply device, and a control device; The traveling trolley is arranged on the left side of the tensioning device, and three fixed pulleys are evenly distributed on the right end of the traveling trolley along the direction perpendicular to the axis of the traveling trolley; The tensioning device comprises a fixed frame and a tensioning oil cylinder fixed on the top of the fixed frame; a guide rope wheel is installed on the protruding end of the tensioning oil cylinder and faces the traveling trolley, and the axis of the tensioning oil cylinder is coaxial with the axis of the traveling trolley and the fixed frame; The double winch tensioning device comprises a winch base, a drum, a power unit and a steel wire rope; the winch base is arranged on the right side of the fixed frame, the two drums are coaxially mounted on the winch base, each drum is correspondingly mounted with a tension sensor that establishes a communication connection with the control device, the power unit has two groups, and the output end of each group of power units is correspondingly connected to the input end of each drum; one end of the steel wire rope is wound around one of the drums, and the other end of the steel wire rope is sequentially wound around the fixed pulley and the guide rope wheel, and then wound back to the other drum; The hydraulic oil supply device is used to provide hydraulic power to the tensioning cylinder, and the hydraulic oil supply device establishes a communication connection with the control device.

[0008] Preferably, the hydraulic oil supply device includes a hydraulic oil pump, the outlet end of the hydraulic oil pump is connected to the oil circuit reversing valve, the outlet ends of the oil circuit reversing valve are respectively connected to the tensioning cylinder and the hydraulically controlled one-way valve, the outlet ends of the hydraulically controlled one-way valve are respectively connected to the accumulator and the electromagnetic reversing valve, the outlet end of the accumulator is connected to the tensioning cylinder, the outlet end of the electromagnetic reversing valve is connected to the pressure controller, and the outlet end of the pressure controller is connected to the hydraulic oil pipe.

[0009] Preferably, the inlet end of the hydraulic oil pump is connected to a coarse filter and a fine filter in sequence.

[0010] Preferably, an overflow valve connected to the hydraulic oil tank is provided between the outlet end of the hydraulic oil pump and the inlet end of the oil circuit reversing valve.

[0011] Preferably, a pressure gauge is installed at the outlet end of the hydraulically controlled one-way valve.

[0012] Preferably, the power unit includes a reduction mechanism and a hydraulic motor; the output end of the reduction mechanism is transmitted to the input end of the reel in a gear meshing manner, and the output end of the hydraulic motor is connected to the input end of the reduction mechanism.

[0013] Preferably, a brake is installed between the hydraulic motor and the input end of the speed reduction mechanism.

[0014] It is also necessary to provide a hydraulic tensioning control method for a belt conveyor with double winches.

[0015] A hydraulic tensioning control method for a belt conveyor with double winches uses the above-mentioned hydraulic tensioning system of the belt conveyor with double winches to perform tensioning control on the conveyor belt. The tensioning control of the conveyor belt includes tensioning control during the startup state of the conveyor, tensioning control during the conveying state of the conveyor, and tensioning control during the belt retracting state of the conveyor. Step A: When the conveyor is in the startup state, the belt conveyor is in an unstable state and the travel of the floating trolley is small (1 - 2 m). The control device controls the telescoping of the tensioning cylinder by controlling the hydraulic oil supply device, and dynamically adjusts the tension of the conveyor belt by the telescoping of the tensioning cylinder. The specific steps are as follows: A1: The control device obtains the signals of the tension sensors on each drum, and analyzes and compares the difference between the tension value of each drum and the preset value. A2: When the difference is equal to 0, it indicates that the conveyor belt is in a normal state and no adjustment is required. When the difference is greater than 0, it indicates that the conveyor belt is over-tensioned. The control device issues a command to start the hydraulic oil pump, open the electromagnetic directional valve, and switch the hydraulic oil supply oil path of the oil path reversing valve. The hydraulic oil is transported into the tensioning cylinder through the oil path reversing valve. The piston of the tensioning cylinder squeezes the internal hydraulic oil and returns through the electromagnetic directional valve, and the tensioning cylinder contracts until the tensioning cylinder stops contracting when the conveyor belt tension reaches the normal state requirement. When the difference is less than 0, it indicates that the conveyor belt is slack. The control device issues a command to start the hydraulic oil pump, close the electromagnetic directional valve, and switch the hydraulic oil supply oil path of the oil path reversing valve. The hydraulic oil is transported into the tensioning cylinder through the pilot-operated check valve. The piston of the tensioning cylinder squeezes the internal hydraulic oil and returns to the hydraulic oil pipeline through the electric stop valve, and the tensioning cylinder extends until the tensioning cylinder stops extending when the conveyor belt tension reaches the normal state requirement. Step B: When the conveyor is in the conveying state, the floating trolley has a small displacement. The control device controls the telescoping of the tensioning cylinder by controlling the hydraulic oil supply device, and dynamically adjusts the tensioning force by the telescoping of the tensioning cylinder. The specific steps are as follows: B1: The control device issues a command to start the hydraulic oil pump to keep the pressure of the hydraulic oil supply device within the normal working range, so as to maintain the pressure of the hydraulic oil supply device. B2: After completing step B1, the conveyor enters the startup state, and dynamic tensioning control is performed on the conveyor belt according to the tensioning method during the startup state of the conveyor. Step C: When the conveyor is in the belt retracting state, the travel of the floating trolley is relatively large. First, the reel is quickly tensioned. The control device first drives the reel to rotate through the control of the power unit to quickly tension the conveyor belt, and then fine-tunes through the control of the tensioning cylinder to ensure the normal tensioning state of the conveyor belt. The specific steps are as follows: C1: The control device obtains the signals of the tension sensors on each reel and analyzes and compares the difference in the tension values of the two reels; C2: When the difference exceeds the set value, the control device issues an adjustment signal to adjust the rotation speeds of the two reels to decrease or increase respectively, thereby quickly adjusting the tension of the conveyor belt; C3: After completing Step C2, the conveyor enters the carrying state, and the dynamic tension control of the conveyor belt is carried out according to the tensioning method in the carrying state of the conveyor.

[0016] Preferably, in Step B1, the following method is adopted: The control device issues a command, the hydraulic oil pump starts, the solenoid valve is energized and closed, and the hydraulic pressure rises rapidly. When the pressure reaches the low specified value of the pressure controller, the solenoid valve is de-energized and connected, and the electric control box sends a "normal pressure" signal to the centralized control; When the system pressure reaches the high set value (adjustable) of the pressure controller; the oil pump motor stops; until the system pressure is lower than the middle set value (adjustable) of the pressure controller, the hydraulic pump starts to run again; this process is repeated to keep the system pressure within the normal working range. If the pressure value is abnormal (lower than the low specified value of the pressure controller), a "fault signal" is issued.

[0017] Preferably, in Step C2, When the difference between the tension value of the left reel and the tension value of the right reel is greater than the set value, the control device issues a command to control the hydraulic motor of the left reel to reverse, and at the same time control the hydraulic motor of the right reel to rotate forward; When the difference between the tension value of the right reel and the tension value of the left reel is greater than the set value, the control device issues a command to control the hydraulic motor of the right reel to reverse, and at the same time control the hydraulic motor of the left reel to rotate forward.

[0018] Compared with the prior art, the belt conveyor double winch hydraulic tensioning system and the hydraulic tensioning control method provided by the present invention have the following advantages: (1) The floating trolley is tensioned by two reels to achieve the tensioning of the conveyor belt. The tensioning cylinder and the two reels can operate synchronously, independently, or alternately, realizing arbitrary adjustment of the tension and the steel wire rope; (2) During the start-up process of the conveyor, the conveyor belt changes from a loose state to a tensioned state, and the tensioning cylinder can quickly extend and retract, avoiding the occurrence of oscillation, belt beating, and over-tensioning of the conveyor belt due to stress waves during the change process; (3) As the tail of the extensible belt conveyor is retracted, the tension of the conveyor belt gradually decreases, which can be synchronously reduced by controlling the tension of the winch to avoid over-tensioning of the conveyor belt and meet the tensioning requirements of the self-propelled tail for the extensible belt conveyor tail. (4) When tensioning the conveyor belt, it can ensure that the tension forces at both ends of the steel wire rope are the same, and the tension transmitted to the pulley of the floating trolley is the same, so as to realize the smooth movement of the floating trolley without deviation or derailment. Description of the Drawings

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic structural diagram of hydraulic tensioning in the prior art.

[0021] Figure 2 It is a schematic structural diagram of the present invention.

[0022] Figure 3 It is a schematic structural diagram of the double-winch tensioning device of the present invention.

[0023] Figure 4 It is a schematic diagram of the hydraulic oil supply device of the present invention.

[0024] Figure 5 It is a schematic diagram of the hydraulic pressure maintaining control principle of the present invention.

[0025] Figure 6 It is a schematic diagram of the control principle for comparing the tension values of the drums of the present invention.

[0026] In the figure: floating trolley 01, fixed pulley 11, tensioning device 02, tensioning oil cylinder 21, fixing frame 22, wire guiding pulley 23, double-winch tensioning device 03, winch base 31, drum 32, power unit 33, speed reduction mechanism 331, hydraulic motor 332, brake 333, steel wire rope 34, hydraulic oil supply device 04, hydraulic oil pump 41, oil circuit reversing valve 42, pilot-operated check valve 43, accumulator 44, electromagnetic reversing valve 45, pressure controller 46, coarse filter 47, fine filter 48, overflow valve 49, pressure gauge 410, electric stop valve 411, control device 05. Detailed Embodiments

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower", etc. indicating the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0029] Please refer to Figures 1 to 4 , in one embodiment, the present invention provides a double-winch hydraulic tensioning system for a belt conveyor, including a floating trolley 01, a tensioning device 02, a double-winch tensioning device 03, a hydraulic oil supply device 04, and a control device 05; Among them, the floating trolley 01 is arranged on the left side of the tensioning device 02, and three fixed pulleys 11 are evenly distributed at the right end of the floating trolley 01 along the direction perpendicular to the axis of the floating trolley 01.

[0030] Among them, the tensioning device 02 includes a fixed frame 22 and a tensioning oil cylinder 21 fixed on the top of the fixed frame 22; a guide pulley 23 is installed at the extending end of the tensioning oil cylinder 21 and faces the floating trolley 01, and the axis of the tensioning oil cylinder 21 is coaxial with the axes of the floating trolley 01 and the fixed frame 22.

[0031] Among them, the double-winch tensioning device 03 includes a winch base 31, a drum 32, a power unit 33, and a steel wire rope 34; the winch base 31 is arranged on the right side of the fixed frame 22, the drum 32 can be arranged in two sets, the two drums 32 are rotatably installed on the winch base 31 coaxially, and a tension sensor communicatively connected to the control device 05 is correspondingly installed on each drum 32. There are two sets of power units 33, and the output end of each set of power units 33 is correspondingly connected to the input end of each drum 32; one end of the steel wire rope 34 is wound around one of the drums 32, and the other end of the steel wire rope 34 sequentially bypasses the fixed pulley 11 and the guide pulley 23, and then winds back to the other drum 32. The winch base 31 is installed in the tensioning part of the storage bin of the telescopic belt conveyor. Since the double-winch structure is symmetrically arranged along the center line of the belt conveyor, it can be installed on the left or right in the telescopic belt conveyor.

[0032] The hydraulic oil supply device 04 is used to provide hydraulic power for the tensioning cylinder 21, and the hydraulic oil supply device 04 establishes a communication connection with the control device 05. There are two communication modes, one is a wired communication mode, and the other is a wireless communication mode, which can be reasonably selected according to actual use requirements.

[0033] For the control device 05, a PLC control cabinet can be selected for implementation.

[0034] Specifically, the hydraulic oil supply device 04 includes a hydraulic oil pump 41, the outlet end of the hydraulic oil pump 41 is connected to the oil circuit reversing valve 42, the outlet end of the oil circuit reversing valve 42 is respectively connected to the tensioning cylinder 21 and the hydraulically controlled one-way valve 43, the outlet end of the hydraulically controlled one-way valve 43 is respectively connected to the accumulator 44 and the electromagnetic reversing valve 45, the outlet end of the accumulator 44 is connected to the tensioning cylinder 21, the outlet end of the electromagnetic reversing valve 45 is connected to the pressure controller 46, and the outlet end of the pressure controller 46 is connected to the hydraulic oil pipe.

[0035] Of course, in order to ensure the cleanliness of the hydraulic oil, a coarse filter 47 and a fine filter 48 are connected in sequence to the inlet end of the hydraulic oil pump 41 .

[0036] Secondly, an overflow valve 49 connected to the hydraulic oil tank is provided between the outlet end of the hydraulic oil pump 41 and the inlet end of the oil circuit reversing valve 42 .

[0037] A pressure gauge 410 is installed at the outlet end of the hydraulically controlled one-way valve 43 .

[0038] Specifically, the power unit 33 includes a speed reduction mechanism 331 and a hydraulic motor 332. The output end of the speed reduction mechanism 331 is connected to the input end of the drum 32 by means of gear meshing, and the output end of the hydraulic motor 332 is connected to the input end of the speed reduction mechanism 331. The hydraulic motor 332 is a bevel-axis plunger pump with high structural strength, large variable range, wide application range, and can output different speeds. Secondly, a brake 333 is installed between the hydraulic motor 332 and the input end of the speed reduction mechanism 331. The brake 333 is a fail-safe type. The brake 333 is engaged when the power is off and is released when the power is on.

[0039] In one embodiment, the present invention provides a belt conveyor double winch hydraulic tensioning control method, using the belt conveyor double winch hydraulic tensioning system to control the tension of the conveyor belt, the tension control of the conveyor belt includes tension control when the conveyor is in the starting state, tension control when the conveyor is in the carrying state, and tension control when the conveyor is in the belt-receiving state; Step A: When the conveyor is in the starting state, the belt conveyor is in an unstable state, and the travel of the floating trolley 01 is relatively small (1 - 2 m). The control device 05 controls the telescoping of the tensioning cylinder 21 by controlling the hydraulic oil supply device 04, and dynamically adjusts the tension of the conveyor belt by using the telescoping of the tensioning cylinder 21. The specific steps are as follows: A1: The control device 05 acquires the signals of the tension sensors on each reel 32, and analyzes and compares the difference between the tension value of each reel 32 and the preset value; A2: When the difference is equal to 0, it indicates that the conveyor belt is in a normal state and no adjustment is required; When the difference is greater than 0, it indicates that the conveyor belt is over-tensioned. The control device 05 issues an order to start the hydraulic oil pump 41, open the electromagnetic directional valve 45, and switch the hydraulic oil supply oil path of the oil circuit reversing valve 42. The hydraulic oil is transported into the tensioning cylinder 21 through the pilot-operated check valve 43. The piston of the tensioning cylinder 21 squeezes the internal hydraulic oil and returns through the electromagnetic directional valve 45. The tensioning cylinder 21 contracts until the tensioning cylinder 21 stops contracting when the conveyor belt tension reaches the normal state requirement; When the difference is less than 0, it indicates that the conveyor belt is slack. The control device 05 issues an order to start the hydraulic oil pump 41, close the electromagnetic directional valve 45, and switch the hydraulic oil supply oil path of the oil circuit reversing valve 42. The hydraulic oil is transported into the tensioning cylinder 21 through the pilot-operated check valve 43. The piston of the tensioning cylinder 21 squeezes the internal hydraulic oil and returns to the hydraulic oil pipeline through the electric stop valve 411. The tensioning cylinder 21 extends until the tensioning cylinder 21 stops extending when the conveyor belt tension reaches the normal state requirement.

[0040] When the belt conveyor starts, the belt conveyor is in an unstable state, and the travel of the tensioning trolley is relatively small (1 - 2 m). Tensioning is achieved by the rapid telescoping of the tensioning cylinder 21 to tension the belt, thereby reducing the elastic oscillation caused by the elastic change of the conveyor belt, and thus reducing the impact dynamic load on the drive during the start of the conveyor.

[0041] Step B: When the conveyor is in the carrying state, the floating trolley 01 has a small displacement. The control device 05 controls the telescoping of the tensioning cylinder 21 by controlling the hydraulic oil supply device 04, and dynamically adjusts the tensioning force by using the telescoping of the tensioning cylinder 21. The specific steps are as follows: B1: The control device 05 issues an order to start the hydraulic oil pump 41 to keep the pressure of the hydraulic oil supply device 04 within the normal working range, thereby maintaining pressure on the hydraulic oil supply device 04; B2: After completing step B1, the conveyor enters the starting state, and dynamic tensioning control of the conveyor belt is performed according to the tensioning method in the starting state of the conveyor.

[0042] When the conveyor is working normally, due to the uneven incoming material situation, the belt tension changes, and the tensioning trolley has a small displacement. At this time, the tensioning oil cylinder 21 in the automatic tensioning is used to adjust the tension force. To prevent the oil cylinder from relieving pressure, a pressure-holding system is set for the tensioning oil cylinder 21, which can ensure that the tension of the tensioning oil cylinder 21 is a constant value and play a buffering role at the same time.

[0043] Step C: When the conveyor is in the belt take-up state, the travel of the floating trolley 01 is large. First, the reel 32 is used for rapid tensioning. The control device 05 first drives the reel 32 to rotate through the control of the power unit 33 to rapidly tension the conveyor belt, and then fine-tunes through the control of the tensioning oil cylinder 21 to achieve the normal tensioning state of the conveyor belt. The specific steps are as follows: C1: The control device 05 obtains the signals of the tension sensors on each reel 32 and analyzes and compares the difference in the tension values of the two reels 32. C2: When the difference exceeds the set value, the control device 05 issues an adjustment signal to respectively adjust the rotation speeds of the two reels 32 to decrease or increase, so as to adjust the rapid tensioning of the conveyor belt. C3: After completing step C2, the conveyor enters the carrying state, and the dynamic tensioning control of the conveyor belt is carried out according to the tensioning method in the carrying state of the conveyor.

[0044] When the belt needs to be replaced, the travel of the tensioning trolley can reach more than 40 meters. The winch is used for rapid tensioning to reduce or eliminate the wave surge and belt beating phenomena of the belt under this working condition.

[0045] Please refer to Figure 5 for a more specific description. In step B1, the following method is adopted: The control device 05 issues an order to start the hydraulic oil pump 41, the solenoid valve is energized and closed, and the hydraulic pressure rises rapidly. When the pressure reaches the low specified value of the pressure controller 46, the solenoid valve is de-energized and connected, and the electric control box sends a "pressure normal" signal to the centralized control; When the system pressure reaches the high set value (adjustable) of the pressure controller 46; the oil pump motor stops; until the system pressure is lower than the middle set value (adjustable) of the pressure controller 46, the hydraulic pump starts to run again; and so on, so that the system pressure is maintained within the normal working range. If the pressure value is abnormal (lower than the low specified value of the pressure controller 46), a "fault signal" is issued.

[0046] Please refer to Figure 6 for a more specific description. In step C2, The tension value of the left reel is the tension value 1, and the tension value of the right reel is the tension value 2; the serial number of the hydraulic motor 332 of the left reel is 1, and the serial number of the hydraulic motor 332 of the right reel is 2; when the difference between the tension value of the left reel and the tension value of the right reel is greater than the set value, the control device 05 issues a command to control the hydraulic motor 332 of the left reel to reverse, and at the same time controls the hydraulic motor 332 of the right reel to rotate forward; When the difference between the tension value of the right reel and the tension value of the left reel is greater than the set value, the control device 05 issues a command to control the hydraulic motor 332 of the right reel to reverse, and at the same time controls the hydraulic motor 332 of the left reel to rotate forward.

[0047] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A belt conveyor double winch hydraulic tensioning system, characterized in that: It includes a traveling trolley, a tensioning device, a double winch tensioning device, a hydraulic oil supply device, and a control device; The traveling trolley is arranged on the left side of the tensioning device, and three fixed pulleys are evenly distributed on the right end of the traveling trolley along the direction perpendicular to the axis of the traveling trolley; The tensioning device comprises a fixed frame and a tensioning oil cylinder fixed on the top of the fixed frame; a guide rope wheel is installed on the protruding end of the tensioning oil cylinder and faces the traveling trolley, and the axis of the tensioning oil cylinder is coaxial with the axis of the traveling trolley and the fixed frame; The double winch tensioning device comprises a winch base, a drum, a power unit and a steel wire rope; the winch base is arranged on the right side of the fixed frame, the two drums are coaxially mounted on the winch base, each drum is correspondingly mounted with a tension sensor that establishes a communication connection with the control device, the power unit has two groups, and the output end of each group of power units is correspondingly connected to the input end of each drum; one end of the steel wire rope is wound around one of the drums, and the other end of the steel wire rope is sequentially wound around the fixed pulley and the guide rope wheel, and then wound back to the other drum; The hydraulic oil supply device is used to provide hydraulic power to the tensioning cylinder, and the hydraulic oil supply device establishes a communication connection with the control device.

2. The belt conveyor double winch hydraulic tensioning system according to claim 1, characterized in that: The hydraulic oil supply device includes a hydraulic oil pump, the outlet end of the hydraulic oil pump is connected to the oil circuit reversing valve, the outlet end of the oil circuit reversing valve is respectively connected to the tensioning cylinder and the hydraulically controlled one-way valve, the outlet end of the hydraulically controlled one-way valve is respectively connected to the accumulator and the electromagnetic reversing valve, the outlet end of the accumulator is connected to the tensioning cylinder, the outlet end of the electromagnetic reversing valve is connected to the pressure controller, and the outlet end of the pressure controller is connected to the hydraulic oil pipe.

3. The belt conveyor double winch hydraulic tensioning system according to claim 2, characterized in that: The inlet end of the hydraulic oil pump is connected with a coarse filter and a fine filter in sequence.

4. The belt conveyor double winch hydraulic tensioning system according to claim 3, characterized in that: An overflow valve connected to the hydraulic oil tank is arranged between the outlet end of the hydraulic oil pump and the inlet end of the oil circuit reversing valve.

5. The belt conveyor double winch hydraulic tensioning system according to claim 2, characterized in that: A pressure gauge is installed at the outlet end of the hydraulically controlled one-way valve.

6. The belt conveyor double winch hydraulic tensioning system according to claim 2, characterized in that: The power unit comprises a speed reduction mechanism and a hydraulic motor; the output end of the speed reduction mechanism is driven by the input end of the reel in a gear meshing manner, and the output end of the hydraulic motor is connected to the input end of the speed reduction mechanism.

7. The belt conveyor double winch hydraulic tensioning system according to claim 6, characterized in that: A brake is installed between the hydraulic motor and the input end of the speed reduction mechanism.

8. A belt conveyor double winch hydraulic tensioning control method, using the belt conveyor double winch hydraulic tensioning system according to any one of claims 1 to 7 to control the tensioning of the conveyor belt, characterized in that: The tension control of the conveyor belt includes the tension control when the conveyor is in the starting state, the tension control when the conveyor is in the carrying state, and the tension control when the conveyor is in the belt-retracting state. Step A: When the conveyor is started, the belt conveyor is in an unstable state, and the travel of the traveling trolley is small (1-2m). The control device controls the extension and retraction of the tensioning cylinder by controlling the hydraulic oil supply device, and dynamically adjusts the tension of the conveyor belt by using the extension and retraction of the tensioning cylinder. The specific steps are as follows: A1: The control device obtains the signal of the tension sensor on each roll, analyzes and compares the difference between the tension value of each roll and the preset value; A2: When the difference is equal to 0, it indicates that the conveyor belt is in normal condition and no adjustment is required; When the difference is greater than 0, it indicates that the conveyor belt is over-tensioned. The control device issues a command, the hydraulic oil pump starts, the electromagnetic reversing valve opens, and the hydraulic oil supply oil circuit of the oil circuit reversing valve is switched. The hydraulic oil is transported to the tensioning cylinder through the oil circuit reversing valve. The piston of the tensioning cylinder squeezes the internal hydraulic oil and returns through the electromagnetic reversing valve. The tensioning cylinder contracts until the conveyor belt tension is in the normal state and the tensioning cylinder stops contracting. When the difference is less than 0, it indicates that the conveyor belt is in a state of relaxation. The control device issues a command, the hydraulic oil pump starts, the electromagnetic reversing valve is closed, and the hydraulic oil supply oil circuit of the oil circuit reversing valve is switched. The hydraulic oil is transported to the tensioning cylinder through the hydraulic control one-way valve. The piston of the tensioning cylinder squeezes the internal hydraulic oil and returns it to the hydraulic oil pipeline through the electric stop valve. The tensioning cylinder extends until the tension of the conveyor belt is in the normal state and the tensioning cylinder stops extending. Step B: When the conveyor is in the transporting state, the traveling trolley has a small displacement. The control device controls the extension and retraction of the tensioning cylinder by controlling the hydraulic oil supply device, and dynamically adjusts the tensioning force by using the extension and retraction of the tensioning cylinder. The specific steps are as follows: B1: The control device issues a command, and the hydraulic oil pump starts to keep the pressure of the hydraulic oil supply device within the normal working range, thereby maintaining the pressure of the hydraulic oil supply device; B2: After completing step B1, the conveyor enters the start-up state, and the conveyor belt is dynamically tensioned according to the tensioning method in the start-up state of the conveyor; Step C: When the conveyor is in the belt-retracting state, the travel of the traveling trolley is relatively large. First, the reel is used for rapid tensioning. The control device first drives the reel to rotate by controlling the power unit to quickly tension the conveyor belt, and then fine-tunes the tensioning cylinder to achieve normal tensioning of the conveyor belt. The specific steps are as follows: C1: The control device obtains the signal of the tension sensor on each roll, analyzes and compares the difference between the tension values ​​of the two rolls; C2: When the difference exceeds the set value, the control device sends an adjustment signal to adjust the speed of the two reels to reduce or increase, thereby quickly adjusting the tension of the conveyor belt; C3: After completing step C2, the conveyor enters the carrying state, and the conveyor belt is dynamically tensioned and controlled according to the tensioning method in the conveyor carrying state.

9. The belt conveyor double winch hydraulic tensioning control method according to claim 8, characterized in that: In step B1, the following method is adopted: The control device issues a command, the hydraulic oil pump starts, the solenoid valve is powered on and closed, and the hydraulic pressure rises rapidly. When the pressure reaches the low-level specified value of the pressure controller, the solenoid valve is powered off and connected, and the electric control box sends a "normal pressure" signal to the centralized control; When the system pressure reaches the high setting value (adjustable) of the pressure controller, the oil pump motor stops; until the system pressure is lower than the middle setting value (adjustable) of the pressure controller, the hydraulic pump starts and runs again; this cycle is repeated to keep the system pressure within the normal working range. If the pressure value is abnormal (lower than the low setting value of the pressure controller), a "fault signal" is issued.

10. The belt conveyor double winch hydraulic tension control method according to claim 8, characterized in that: In step C2, When the difference between the tension value of the left reel and the tension value of the right reel is greater than the set value, the control device issues a command to control the hydraulic motor of the left reel to reverse and control the hydraulic motor of the right reel to rotate forward; When the difference between the tension value of the right reel and the tension value of the left reel is greater than the set value, the control device sends a command to control the hydraulic motor of the right reel to reverse and control the hydraulic motor of the left reel to rotate forward.

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