Hydraulic tensioning device for belt storage bin of telescopic belt conveyor

Abstract

The utility model discloses a hydraulic tensioning device for a belt storage bin of a telescopic belt conveyor, which solves the problem of short hydraulic tensioning stroke through a lockable moving trolley and a tensioning trolley, realizes the application of hydraulic tensioning to the tensioning of the belt storage bin of the telescopic belt conveyor, and can realize the automatic adjustment of the tensioning stroke and the automatic adjustment of the tensioning force. And the tensioning force applied to the two sides of the tensioning trolley is balanced, the situation that the tensioning trolley inclines is avoided, the structure is simple, and maintenance is convenient.

Description

Technical Field

[0001] The utility model belongs to the field of belt conveyors, and particularly relates to a hydraulic tensioning device for a storage bin of a retractable belt conveyor. Background Art

[0002] The tensioning device of the storage bin is an important part of the retractable belt conveyor. Its main function is to adjust the position of the movable trolley in the storage bin, control the distance between the movable trolley and the belt storage and turning frame, realize the storage and release of the conveyor belt, and at the same time provide sufficient tension for the normal operation of the retractable belt conveyor to ensure that the conveyor belt meets the sag requirements and non-slip requirements during operation. With the development of tunnel boring or coal mining technology, it is required that the retractable belt conveyor can achieve a larger length adjustment range, which means that more conveyor belts need to be stored in the storage bin, and higher requirements are put forward for the tensioning stroke, tensioning force, and tensioning force control of the tensioning device in the storage bin.

[0003] Most of the existing tensioning devices for storage bins are combined hydraulic and winch tensioning. The winch is used to achieve the large-stroke function of the tensioning device, and the hydraulic device is used to adjust the tensioning force and relieve the tension fluctuation of the conveyor during startup or braking. However, the combined winch and hydraulic tensioning device has a complex structure, a high failure rate, a high cost, and high control requirements, and it is easy for the movable trolley to skew due to unbalanced tension during the process of taking in or releasing the belt, resulting in belt deviation during the operation of the conveyor belt in the storage bin. Summary of the Utility Model

[0004] To solve the above problems, the utility model provides a hydraulic tensioning device for a storage bin of a retractable belt conveyor, which can effectively overcome the shortcomings of the existing technology.

[0005] Another object of the utility model is to provide a replacement method based on the hydraulic tensioning device for a storage bin of a retractable belt conveyor.

[0006] The utility model provides the following technical solution: A hydraulic tensioning device for a storage bin of a retractable belt conveyor, which is controlled based on a PLC system, includes a track device, a moving device and a tensioning trolley device installed on the track device, hydraulic locking devices respectively installed on the moving device and the tensioning trolley device, and a hydraulic control system for controlling the moving device and the tensioning trolley device.

[0007] The hydraulic locking device includes a pin shaft, pin shaft holes, springs, end caps, pin pulling rods, and pin pulling hydraulic cylinders. The hydraulic locking devices are respectively installed on a moving device and a tensioning trolley device. In the hydraulic locking device on the moving device, there are at least two pin shafts, and pin shaft holes are respectively provided. The pin shafts are slidably fitted in the pin shaft holes. Springs are sleeved outside the pin shafts. End caps are fixedly connected to the outer circumferences of the outer sides of the pin shafts. One end of the spring abuts against a boss on the outer circumference of the middle part of the pin shaft, and the other end abuts against the end cap. The end caps are respectively connected to the moving device and the tensioning trolley device. The pin pulling hydraulic cylinders are respectively connected to the moving device and the tensioning trolley device. The top end of the hydraulic rod of the pin pulling hydraulic cylinder is connected with a pin pulling rod. The top end of the pin pulling rod is sleeved on the pin shaft. A retaining ring is connected to the top end of the pin shaft. A nut is provided at the top end of the retaining ring. The nut is screwed with the pin shaft to press and connect the pin pulling rod.

[0008] The moving device includes a moving trolley, moving wheels, bearings, and bushings. The moving trolley is arranged in an L shape. Moving wheels are respectively connected to the four corners at the bottom end of the horizontal part of the moving trolley and are arranged on the track. Bearings are respectively installed on the left and right sides of the moving wheels. Bushings are sleeved on the bearings. The bushings are in coaxial contact with the inner rings of the bearings. Hydraulic locking devices are connected to the left and right sides at the rear end of the moving trolley. At least two tensioning hydraulic cylinders are hinged on the vertical part of the moving trolley. The hydraulic rods in the tensioning hydraulic cylinders extend horizontally and are hinged to the tensioning trolley device. The tensioning trolley device includes a tensioning vehicle frame and tensioning rollers. Moving wheels are respectively fixedly connected to the four corners at the bottom end of the tensioning vehicle frame. A number of bearing seats are respectively and evenly arranged on the left and right sides at the top end of the tensioning vehicle frame. Tensioning rollers are connected between the left and right bearing seats. A conveyor belt is arranged on the tensioning rollers. Hydraulic locking devices are connected to the left and right sides at the front end of the tensioning vehicle frame.

[0009] The track device includes buffer pads, I-beams, and tracks. The two I-beams are parallel and are respectively installed on the left and right sides of the ground. The bottom ends of the two I-beams are parallel to each other and are evenly distributed with a number of buffer pads to reduce vibration and enable the device to run smoothly. The other ends of the buffer pads abut against the ground. Tracks are respectively fixedly connected to the top ends of the two I-beams to guide the moving device and the tensioning trolley device.

[0010] A number of pin shaft holes are symmetrically and evenly provided on the two tracks. The interval of the pin shaft holes is half of the maximum stroke of the tensioning hydraulic cylinder.

[0011] The tensioning hydraulic cylinders are arranged parallel to the tracks.

[0012] The hydraulic control system includes an oil tank, a first filter, a first relief valve, a hydraulic pump, a first check valve, a second check valve, a first pressure reducing valve, a pressure gauge, a first solenoid directional control valve, an electro-hydraulic servo valve, a flow dividing and collecting valve, a first pressure sensor, a second pressure sensor, an accumulator, a pressure relay, a stop valve, a second solenoid directional control valve, a second relief valve, a second pressure reducing valve, a third check valve, a third relief valve, a cooler, and a second filter.

[0013] The inlet of the first filter is connected to the oil tank, and the outlet is connected to the inlet of the hydraulic pump. The outlet of the hydraulic pump is respectively connected to the first check valve and the first relief valve, and the first relief valve is connected to the oil tank. The first check valve is connected to the electro-hydraulic servo valve, and a pressure gauge is provided on the connecting oil path to form the main oil supply circuit.

[0014] The electro-hydraulic servo valve is connected to the third relief valve. The inlet of the cooler is connected to the third relief valve. The inlet of the second filter is connected to the outlet of the cooler, and the outlet of the second filter is connected to the oil tank to form the main oil return circuit.

[0015] The stop valve and the second relief valve are connected to form a safety valve group. The main inlet of the safety valve group is connected to the main oil supply circuit, the main oil return port is connected to the main oil return circuit, the S port is connected to the accumulator, and the pressure relay is connected to the accumulator.

[0016] The working inlet of the electro-hydraulic servo valve is connected to the oil supply pressure port of the flow dividing and collecting valve, and a first pressure sensor is provided between the connecting oil paths. The working inlet of the flow dividing and collecting valve is connected to the rodless cavity of the hydraulic cylinder, the working oil return port is connected to the rodless cavity of another hydraulic cylinder, and the rod end cavity of the hydraulic cylinder is connected to the working oil return port of the electro-hydraulic servo valve, and a second pressure sensor is provided between the connecting oil paths. The two hydraulic cylinders are in a parallel form to automatically adjust the synchronization of the two hydraulic cylinders and reduce the unevenness caused by unstable loads.

[0017] The P port of the first pressure reducing valve is connected to the main oil supply circuit and the P port of the first solenoid directional control valve. The main oil return port of the first solenoid directional control valve is connected to the P port of the second check valve. The P port of the second check valve is connected to the main oil return circuit. The working inlet of the first solenoid directional control valve is respectively connected to the rodless cavities of the left and right first pin pulling hydraulic cylinders, and the working oil return port is respectively connected to the rod end cavities of the left and right first pin pulling hydraulic cylinders.

[0018] The P port of the second pressure reducing valve is connected to the main oil supply circuit and the P port of the second solenoid directional control valve. The main oil return port of the second solenoid directional control valve is connected to the P port of the third check valve. The P port of the third check valve is connected to the main oil return circuit. The working inlet of the second solenoid directional control valve is connected to the rodless cavity of the second pin pulling hydraulic cylinder, and the working oil return port is connected to the rod end cavity of the second pin pulling hydraulic cylinder.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0020] By means of the lockable mobile trolley and the tensioning trolley, the problem of short hydraulic tensioning stroke is solved, and the hydraulic tensioning is applied to the tensioning of the storage bin of the extensible belt conveyor. The tensioning stroke can be automatically adjusted, the tensioning force can be automatically adjusted, and the tensioning forces applied to both sides of the tensioning trolley are balanced, avoiding the situation of the tensioning trolley skewing. The structure is simple and convenient for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the utility model.

[0022] Figure 2 It is a top view of the utility model.

[0023] Figure 3 It is a front view of the utility model.

[0024] Figure 4 It is Figure 3 The enlarged view of part A in

[0025] Figure 5 It is Figure 3 The enlarged view of part B in

[0026] Figure 6 It is a hydraulic system diagram.

[0027] In the figure: 1, buffer pad; 2, I-beam; 3, track; 4, mobile trolley; 5, first pin shaft; 6, first pin pulling rod; 7, first pin pulling hydraulic cylinder; 8, second pin shaft; 9, tensioning hydraulic cylinder; 10, third pin shaft; 11, second pin pulling rod; 12, conveyor belt; 13, tensioning roller; 14, bearing seat; 15, tensioning frame; 16, second pin pulling hydraulic cylinder; 17, first nut; 18, first retaining ring; 19, first end cover; 20, first spring; 21, second nut; 22, second retaining ring; 23, second end cover; 24, second spring; 25, bushing; 26, bearing; 27, connecting pin shaft; 28, bolt pin; 29, n-shaped bracket; 30, oil tank; 31, first filter; 32, first relief valve; 33, hydraulic pump; 34, first check valve; 35, second check valve; 36, first pressure reducing valve; 37, pressure gauge; 38, first electromagnetic directional valve; 39, electro-hydraulic servo valve; 40, flow dividing and collecting valve; 41, first pressure sensor; 42, second pressure sensor; 43, accumulator; 44, pressure relay; 45, stop valve; 46, second electromagnetic directional valve; 47, second relief valve; 48, second pressure reducing valve; 49, third check valve; 50, second filter; 51, cooler; 52, second filter; 53, PLC controller; 54, positioning sensor; 55, displacement sensor; 56, second positioning sensor; 57, tension sensor. Detailed implementation manners

[0028] In order to make the technical means, creative features, achieved purposes and functions implemented by the present utility model easy to understand, the present utility model will be further described below in conjunction with specific implementation manners.

[0029] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0031] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0032] Embodiment 1: Please refer to Figures 1-5 , a hydraulic tensioning device for a storage bin of a telescopic belt conveyor, which is controlled based on a PLC system, includes a track device, a moving device and a tensioning trolley device installed on the track device, hydraulic locking devices respectively installed on the moving device and the tensioning trolley device, and a hydraulic control system for controlling the moving device and the tensioning trolley device.

[0033] The mobile device includes a mobile trolley 4, mobile wheels, bearings 26, and a bushing 25. The mobile trolley 4 is arranged in an L shape. The mobile trolley 4 is the main moving component, arranged in an L shape for moving along the track 3. At the four corners of the bottom end of the lateral end of the mobile trolley 4, mobile wheels are respectively connected and are placed on the track 3. The mobile wheels are used for moving on the track 3. The circumference of the middle part of the mobile wheels is smaller than that of the two sides, and they are stuck on the track 3 for movement, making the device operate smoothly without tilting. On the left and right sides of the mobile wheels, bearings 26 are respectively installed, and a bushing 25 is sleeved on the bearings 26. The bushing 25 is in coaxial contact with the inner ring of the bearing 26. On the left and right sides at the rear end of the mobile trolley 4, a hydraulic locking device is connected. The hydraulic locking device is used to limit the position of the mobile device. On the vertical end of the mobile trolley 4, at least two tensioning hydraulic cylinders 9 are hinged. The hydraulic rods in the tensioning hydraulic cylinders 9 extend horizontally and are hinged to the tensioning trolley device.

[0034] The tensioning trolley device includes a tensioning vehicle frame 15 and a tensioning roller 13. At the four corners of the bottom end of the tensioning vehicle frame 15, mobile wheels are respectively and fixedly connected. On the left and right sides at the top end of the tensioning vehicle frame 15, a number of bearing seats 14 are respectively and evenly arranged. The bearing seats 14 are located on the left and right sides at the top end of the tensioning vehicle frame 15 for supporting and fixing the tensioning roller 13. A tensioning roller 13 is connected between the two bearing seats 14 on the left and right. The tensioning roller 13 is used for tensioning the conveyor belt, which helps to maintain the tension and smooth operation of the belt. A conveyor belt is placed on the tensioning roller 13. On the left and right sides at the front end of the tensioning vehicle frame 15, a hydraulic locking device is respectively connected.

[0035] The hydraulic locking device includes a pin shaft, which provides a connection and locking function between the mobile device and the tensioning trolley device, a pin shaft hole, a spring, an end cover, a pin pulling rod, and is connected to the hydraulic system for pushing the pin shaft to release the locked state when unlocking. There is a pin pulling hydraulic cylinder, which drives the movement of the pin pulling rod through hydraulic pressure to achieve the locking and unlocking functions. The hydraulic locking device is respectively installed on the mobile device and the tensioning trolley device. In the hydraulic locking device on the mobile device, at least two pin shafts are provided and respectively provided with pin shaft holes. The pin shafts are slidably fitted in the pin shaft holes. A spring is sleeved on the pin shafts. A convex platform on the outer circumference of the middle part of the pin shaft abuts against one end of the spring, and the other end abuts against the end cover. The end covers are respectively connected to the mobile device and the tensioning trolley device. The pin pulling hydraulic cylinders are respectively connected to the mobile device and the tensioning trolley device. The top end of the hydraulic rod of the pin pulling hydraulic cylinder is connected with a pin pulling rod. The top end of the pin pulling rod is sleeved on the pin shaft. A retaining ring is connected to the top end of the pin shaft, and a nut is arranged at the top end of the retaining ring and is screwed with the pin shaft for tightly connecting the pin pulling rod. When locking, the pin shaft passes through the pin pulling hydraulic cylinder, moves downward, inserts into the pin shaft hole opened in the device, and at the same time penetrates the preset pin shaft hole in the device and inserts into the pin shaft hole opened on the track 3 to lock the device.

[0036] The hydraulic locking device of the above-mentioned mobile device is provided with at least two pin shafts. When unlocking, the working pressure required by the left and right first pin-pulling hydraulic cylinders 7 is relatively small. It uses the P1 port of the first pressure reducing valve 36 to be connected to the main oil supply circuit, and the P2 port is connected to the P port of the first electromagnetic reversing valve 38 to reduce the pressure of the oil supply circuit. The A port of the first electromagnetic reversing valve 38 is respectively connected to the rodless chambers of the left and right first pin-pulling hydraulic cylinders 7, and the B port is respectively connected to the rod chambers of the left and right first pin-pulling hydraulic cylinders 7. When the first electromagnetic reversing valve 38 is in the left position, the hydraulic rods of the left and right first pin-pulling hydraulic cylinders 7 drive the left and right first pin-pulling rods 6 to move downward. The inner diameters of the mounting holes at both ends of the pin-pulling rods are larger than the diameters of the first pin shaft 5 and the second pin shaft 8. Therefore, the two pin shafts will not be pushed downward. Under the push of the left and right first springs 20 and another set of springs, the first pin shaft 5 and the second pin shaft 8 move downward and are inserted into the pin holes corresponding to the left and right tracks 3, realizing the locking of the mobile trolley 4, that is, the mobile trolley 4 is fixed on the track 3. When the first electromagnetic reversing valve 38 is in the right position, the hydraulic rods of the left and right first pin-pulling hydraulic cylinders 7 drive the left and right first pin-pulling rods 6 to move upward, pushing the first pin shaft 5 and the second pin shaft 8 to move upward. The left and right first springs 20 and another set of springs are compressed, realizing the unlocking of the mobile trolley 4, that is, the mobile trolley 4 is released from fixation.

[0037] For the hydraulic locking device of the tensioning device, a pin shaft is installed in the middle. The unlocking process is similar to the locking and unlocking of the above-mentioned mobile trolley 4. When the second electromagnetic reversing valve 46 is in the left position, the hydraulic rod of the second pin-pulling hydraulic cylinder 16 moves downward, driving the second pin-pulling rod 11 to move downward. Under the push of the second spring 24 and another set of springs, the left and right third pin shafts 10 move downward and are inserted into the pin holes corresponding to the left and right tracks 3, realizing the locking of the tensioning trolley, that is, the tensioning trolley is fixed on the track 3. When the second electromagnetic reversing valve 46 is in the right position, the hydraulic rod of the second pin-pulling hydraulic cylinder 16 moves upward, driving the second pin-pulling rod 11 to move upward, thereby pushing the third pin shaft 10 to move upward. The second spring 24 and another set of springs are compressed, realizing the unlocking of the tensioning trolley, that is, the tensioning trolley is released from fixation.

[0038] The track device includes a buffer pad 1, an I-beam 2, and a track 3. The two I-beams 2 are installed in parallel on the left and right sides of the ground respectively. The bottom ends of the two I-beams 2 are parallel to each other and are evenly distributed with a number of buffer pads 1. Through the use of the buffer pads 1, it can effectively reduce vibration, improve the stability and smoothness of the device, protect the equipment and increase the comfort of operation, be used to reduce vibration and make the device run smoothly. The other end of the buffer pad 1 abuts against the ground. The top ends of the two I-beams 2 are respectively fixedly connected with a track 3, which is used to guide the mobile device and the tensioning trolley device.

[0039] A number of pin shafts holes are symmetrically and evenly arranged on the two tracks 3, and the interval between the pin shafts holes is half of the maximum stroke of the tensioning hydraulic cylinder 9. The hydraulic locking device locks the device by inserting into the pin shafts holes to ensure its fixation at the required position. When the device needs to be moved or adjusted, the device can be released by inserting or pulling out, and then adjusted according to the required position, and then the device is re-locked.

[0040] The tensioning hydraulic cylinder 9 is arranged parallel to the track 3 and is used to smoothly pull the device to run and reduce the vibration load.

[0041] Example 2, please refer to Figure 6 , a hydraulic tensioning device for a retractable belt conveyor storage bin, a hydraulic control system, including an oil tank 30, a first filter 31, a first overflow valve 32, a hydraulic pump 33, a first one-way valve 34, a second one-way valve 35, a first pressure reducing valve 36, a pressure gauge 37, a first electromagnetic reversing valve 38, an electro-hydraulic servo valve 39, a flow dividing and collecting valve 40, a first pressure sensor 41, a second pressure sensor 42, an accumulator 43, a pressure relay 44, a stop valve 45, a second electromagnetic reversing valve 46, a second overflow valve 47, a second pressure reducing valve 48, a third one-way valve 49, a third overflow valve 50, a cooler 51, a second filter 52.

[0042] The oil inlet of the first filter 31 is connected to the oil tank 30, and the oil outlet is connected to the oil inlet of the hydraulic pump 33. The oil outlet of the hydraulic pump 33 is respectively connected to the first one-way valve 34 and the first overflow valve 32, and the first overflow valve 32 is connected to the oil tank 30; the first one-way valve 34 is connected to the electro-hydraulic servo valve 39, and a pressure gauge 37 is provided on the connecting oil path to form a main oil supply circuit.

[0043] The first filter 31 and the first overflow valve 32 are connected in the main oil supply circuit. The first filter 31 can filter the impurities in the hydraulic oil in the oil tank 30 to ensure the normal operation of the hydraulic system. When the hydraulic system is working properly, the first overflow valve 32 is closed. When the system pressure exceeds the set pressure, the first overflow valve 32 opens for overflow to achieve overload protection.

[0044] The electro-hydraulic servo valve 39 is connected to the third overflow valve 50. The oil inlet of the cooler 51 is connected to the third overflow valve 50. The oil inlet of the second filter 52 is connected to the oil outlet of the cooler 51. The oil outlet of the second filter 52 is connected to the oil tank 30 to form a main oil return circuit. The second filter 50, the cooler 51, and the third overflow valve 52 are connected in the main oil return circuit. The second filter 50 and the cooler 51 can filter the impurities in the hydraulic oil in the system and cool the hydraulic oil; the third overflow valve 52 will generate back pressure to make the movement of the tensioning hydraulic cylinder 9 stable and smooth.

[0045] The globe valve 45 and the second relief valve 47 are connected to form a safety valve group. The main inlet port of the safety valve group is connected to the main oil supply circuit, the main return port is connected to the main return oil circuit, the S port is connected to the accumulator 43, and the pressure relay 44 is connected to the accumulator 43.

[0046] The interface of the accumulator 43 connects the safety valve group and the pressure relay 44. The P port of the safety valve group is connected to the main oil supply circuit, and the T port is connected to the main return oil circuit. The pressure relay 43 can control the start and stop of the hydraulic pump 33. After the hydraulic pump 33 starts, the accumulator 43 stores a certain amount of energy first. When the tensioning device operates, it provides a certain amount of energy for the tensioning hydraulic cylinder 9, absorbs the impact generated by the load change during the tensioning process, and can also reduce the operating time of the hydraulic pump 33 and avoid its frequent start and stop.

[0047] The working inlet port of the electro-hydraulic servo valve 39 is connected to the oil supply pressure port of the flow dividing and collecting valve 40. A first pressure sensor 41 is provided between the connecting oil circuits. The working inlet port of the flow dividing and collecting valve 40 is connected to the rodless cavity of the hydraulic cylinder 9, and the working return port is connected to the rodless cavity of another hydraulic cylinder 9. The rod chamber of the hydraulic cylinder 9 is connected to the working return port of the electro-hydraulic servo valve 39. A second pressure sensor 42 is provided between the connecting oil circuits. The two hydraulic cylinders 9 are in a parallel form, which is used to automatically adjust the synchronization of the two hydraulic cylinders 9 and reduce the non-uniformity caused by the unstable load.

[0048] The A port of the electro-hydraulic servo valve 39 is connected to the PO port of the flow dividing and collecting valve 40. A first pressure sensor 41 is provided between the connecting oil circuits. The A port of the flow dividing and collecting valve 40 is connected to the rodless cavity of the tensioning hydraulic cylinder 9, and the B port is connected to the rodless cavity of the tensioning hydraulic cylinder 9. The rod chamber of the tensioning hydraulic cylinder 9 is connected to the B port of the electro-hydraulic servo valve 39. A second pressure sensor 42 is provided between the connecting oil circuits. The tensioning hydraulic cylinder 9 is in a parallel form; the first pressure sensor 41 and the second pressure sensor 42 can collect the pressure values in the rodless cavity and the rod chamber of the tensioning hydraulic cylinder 9 and feedback them to the PLC controller 53. The flow dividing and collecting valve 40 can realize the synchronous movement of the tensioning hydraulic cylinder 9 and avoid the deviation of the conveyor belt 12 caused by the asynchronous movement of the two tensioning hydraulic cylinders.

[0049] When the moving trolley is locked and the tensioning trolley is unlocked, when the electro-hydraulic servo valve 39 is in the left position, the hydraulic rod of the tensioning hydraulic cylinder 9 moves to the right, pushing the tensioning trolley to move to the right and reducing the tension of the conveyor belt 12 to realize the relaxation of the conveyor belt; when the electro-hydraulic servo valve 39 is in the right position, the hydraulic rod of the tensioning hydraulic cylinder 9 moves to the left, pulling the tensioning trolley to move to the left and increasing the tension of the conveyor belt 12 to realize the tensioning of the conveyor belt.

[0050] When the mobile trolley is unlocked and the tensioning trolley is locked, when the electro-hydraulic servo valve 39 is in the left position, the cylinder body of the tensioning cylinder 9 moves to the left, pushing the mobile trolley to move to the left and increasing the tensioning stroke of the tensioning cylinder 9; when the electro-hydraulic servo valve 39 is in the right position, the cylinder body of the tensioning cylinder 9 moves to the right, pulling the mobile trolley to move to the right and increasing the relaxation stroke of the tensioning cylinder 9

[0051] The P1 port of the first pressure reducing valve 36 is connected to the main oil supply circuit. The function of the first pressure reducing valve 36 is to control the pressure of the main oil supply circuit. The P2 port is connected to the P port of the first electromagnetic directional valve 38. The first electromagnetic directional valve controls the flow direction of the hydraulic oil, thereby controlling the movement direction of the hydraulic cylinder. It is achieved by controlling the pressure of the P port. The main oil return port of the first electromagnetic directional valve 38 is connected to the P1 port of the second check valve 35; the P2 port of the second check valve 35 is connected to the main oil return circuit; the working oil inlet of the first electromagnetic directional valve 38 is respectively connected to the rodless chambers of the left and right first pin pulling cylinders 7, and the working oil return ports are respectively connected to the rod chambers of the left and right first pin pulling cylinders 7.

[0052] The P1 port of the second pressure reducing valve 48 is connected to the main oil supply circuit, and the P2 port is connected to the P port of the second electromagnetic directional valve 46; the main oil return port of the second electromagnetic directional valve 46 is connected to the P1 port of the third check valve 49; the P2 port of the third check valve 49 is connected to the main oil return circuit; the working oil inlet of the second electromagnetic directional valve 46 is connected to the rodless chamber of the second pin pulling cylinder 16, and the working oil return port is connected to the rod chamber of the second pin pulling cylinder 16.

[0053] Specific usage steps:

[0054] When the conveyor needs to be extended, by shortening the distance between the tensioning trolley and the belt storage and turning frame, the PLC controller 53 releases the conveyor belt 12. First, set the extended distance of the conveyor in the PLC controller 53, and then start the hydraulic pump 33. The moving trolley 4 is fixed on the track 3 through the left and right double-pin hydraulic locking devices, enabling the tensioning trolley to move freely on the track 3. At the same time, control the electro-hydraulic servo valve 39 to be in the left position, and the hydraulic rod of the tensioning hydraulic cylinder 9 drives the tensioning trolley to move to the right to relax the conveyor belt 12. The PLC controller 53 collects the signals of the displacement sensor 55 in real time, monitors and records the displacement of the hydraulic rod of the tensioning hydraulic cylinder 9. If the movement stroke of the hydraulic rod of the tensioning hydraulic cylinder 9 is close to the maximum stroke, but the displacement of the tensioning trolley does not reach the requirement of the conveyor extension distance, when the second positioning sensor 56 on the tensioning trolley detects the pin hole on the track 3, the PLC controller 53 sends a signal to make the electro-hydraulic servo valve 39 in the middle position to stop the movement of the tensioning trolley. At the same time, make the second electromagnetic directional valve 46 in the left position to lock the tensioning trolley. Then, make the first electromagnetic directional valve 38 in the right position to unlock the moving trolley 4. Then, make the electro-hydraulic servo valve 39 in the right position to make the cylinder body of the tensioning hydraulic cylinder 9 move to the right, pulling the moving trolley 4 to move to the right. When the positioning sensor 54 on the moving trolley 4 detects the pin hole on the track 3, calculate the remaining stroke of the tensioning hydraulic cylinder 9 through the information of the displacement sensor 55. If the remaining stroke is greater than half of the maximum stroke, the tensioning hydraulic cylinder 9 continues to pull the moving trolley 4 to move to the right until the positioning sensor 54 detects the next pin hole. If the remaining stroke of the tensioning hydraulic cylinder 9 is less than half of the maximum stroke, the electro-hydraulic servo valve 39 is in the middle position, and the moving trolley 4 stops moving. Then, the first electromagnetic directional valve 38 is in the left position to lock the moving trolley 4. Then, the second electromagnetic directional valve 46 is in the right position to unlock the tensioning trolley. Then, the electro-hydraulic servo valve 39 is in the left position, and the tensioning hydraulic cylinder 9 pushes the tensioning trolley to move to the right to relax the conveyor belt 12 for the second time. If the moving distance of the tensioning trolley still does not reach the conveyor extension requirement, repeat the above actions until the released length of the conveyor belt 12 reaches the conveyor extension requirement.

[0055] The above are only the embodiments of the present invention. The specific structures and common knowledge such as characteristics known in the solution are not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

[0056] No drawing reference numeral in a claim shall be construed as limiting the claim concerned.

Claims

1. A hydraulic tensioning device for a retractable belt conveyor storage bin, based on PLC system control, characterized in that: It includes a track device, a moving device and a tensioning trolley device installed on the track device, a hydraulic locking device installed on the moving device and the tensioning trolley device respectively, and a hydraulic control system for controlling the moving device and the tensioning trolley device. The hydraulic locking device comprises a pin shaft, a pin shaft hole, a spring, an end cover, a pin pulling rod, and a pin pulling hydraulic cylinder. The hydraulic locking devices are respectively installed on the moving device and the tensioning trolley device. At least two pin shafts are arranged in the hydraulic locking device on the moving device, and pin shaft holes are respectively opened. Pin shafts are slidably fitted in the pin shaft holes, and a spring is connected to the outer sleeve of the pin shaft. An end cover is fixedly connected to the outer circumference of the pin shaft, one end of the spring is in contact with a boss on the outer circumference of the middle part of the pin shaft, and the other end is in contact with the end cover. The end covers are respectively connected to the moving device and the tensioning trolley device, and the pin pulling hydraulic cylinder is respectively connected to the moving device and the tensioning trolley device, and the top end of the hydraulic rod of the pin pulling hydraulic cylinder is connected to the pin pulling rod, and the top end of the pin shaft is connected to a retaining ring, and a nut is provided at the top end of the retaining ring. The nut is screwed with the pin shaft to press the pin pulling rod into connection.

2. The hydraulic tensioning device for the retractable belt conveyor storage bin according to claim 1, characterized in that: The mobile device comprises a mobile trolley (4), a mobile wheel, a bearing (26), and a shaft sleeve (25). The mobile trolley (4) is arranged in an L shape. The four corners of the bottom end of the lateral end of the mobile trolley (4) are respectively connected to the mobile wheels mounted on the track (3). The left and right sides of the mobile wheels are respectively installed with bearings (26). The shaft sleeve (25) is sleeved on the bearing (26). The shaft sleeve (25) is in coaxial contact with the inner ring of the bearing (26). The left and right sides of the rear end of the mobile trolley (4) are connected to hydraulic locking devices. At least two tensioning hydraulic cylinders (9) are hinged on the vertical end of the mobile trolley (4). The hydraulic rod in the tensioning hydraulic cylinder (9) is extended horizontally and hinged to the tensioning trolley device. The tensioning trolley device comprises a tensioning frame (15) and a tensioning roller (13); the four corners of the bottom end of the tensioning frame (15) are respectively fixedly connected to moving wheels; a plurality of bearing seats (14) are evenly arranged on the left and right sides of the top end of the tensioning frame (15); a tensioning roller (13) is connected between the left and right bearing seats (14); a conveyor belt is mounted on the tensioning roller (13); and hydraulic locking devices are respectively connected to the left and right sides of the front end of the tensioning frame (15).

3. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 1, characterized in that: The track device comprises a buffer pad (1), an I-beam (2), and a track (3). The two I-beams (2) are respectively installed in parallel on the left and right sides of the ground. The bottom ends of the two I-beams (2) are parallel to each other and evenly distributed with a plurality of buffer pads (1) for reducing vibration and making the device run smoothly. The other end of the buffer pad (1) contacts the ground. The top ends of the two I-beams (2) are respectively fixedly connected with the track (3) for guiding the moving device and the tensioning trolley device.

4. The hydraulic tensioning device for the retractable belt conveyor storage bin according to claim 3, characterized in that: A plurality of pin holes are symmetrically and evenly formed on the two rails (3) for use with the pins (28), and the spacing between the pin holes is half of the maximum stroke of the tensioning hydraulic cylinder (9).

5. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 1, characterized in that: The tensioning hydraulic cylinder (9) is arranged parallel to the track (3).

6. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 1, characterized in that: The hydraulic control system comprises an oil tank (30), a first filter (31), a first overflow valve (32), a hydraulic pump (33), a first check valve (34), a second check valve (35), a first pressure reducing valve (36), a pressure gauge (37), a first electromagnetic reversing valve (38), an electro-hydraulic servo valve (39), a flow dividing and collecting valve (40), a first pressure sensor (41), a second pressure sensor (42), an accumulator (43), a pressure relay (44), a stop valve (45), a second electromagnetic reversing valve (46), a second overflow valve (47), a second pressure reducing valve (48), a third check valve (49), a third overflow valve (50), a cooler (51), a second filter (52), The oil inlet of the first filter (31) is connected to the oil tank (30), and the oil outlet is connected to the oil inlet of the hydraulic pump (33). The oil outlet of the hydraulic pump (33) is respectively connected to the first non-return valve (34) and the first overflow valve (32), and the first overflow valve (32) is connected to the oil tank (30). The first non-return valve (34) is connected to the electro-hydraulic servo valve (39), and a pressure gauge (37) is provided on the connecting oil circuit to form a main oil supply circuit.

7. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 6, characterized in that: The electro-hydraulic servo valve (39) is connected to the third overflow valve (50), the oil inlet of the cooler (51) is connected to the third overflow valve (50), the oil inlet of the second filter (52) is connected to the oil outlet of the cooler (51), and the oil outlet of the second filter (52) is connected to the oil tank (30), forming a main oil return circuit.

8. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 6, characterized in that: The stop valve (45) and the second overflow valve (47) are connected to form a safety valve group, the main oil inlet of the safety valve group is connected to the main oil supply line, the main oil return port is connected to the main oil return line, the S port is connected to the accumulator (43), and the pressure relay (44) is connected to the accumulator (43).

9. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 6, characterized in that: The working oil inlet of the electro-hydraulic servo valve (39) is connected to the oil supply pressure port of the flow-dividing and collecting valve (40), and a first pressure sensor (41) is provided between the connecting oil circuits. The working oil inlet of the flow-dividing and collecting valve (40) is connected to the rodless chamber of the hydraulic cylinder (9), and the working oil return port is connected to the rodless chamber of another hydraulic cylinder (9). The rod chamber of the hydraulic cylinder (9) is connected to the working oil return port of the electro-hydraulic servo valve (39), and a second pressure sensor (42) is provided between the connecting oil circuits. The two hydraulic cylinders (9) are connected in parallel, and are used to automatically adjust the synchronization of the two hydraulic cylinders (9) to reduce the unevenness caused by load instability.

10. The hydraulic tensioning device for a retractable belt conveyor storage bin according to claim 6, characterized in that: The P1 port of the first pressure reducing valve (36) is connected to the main oil supply circuit, and the P2 port is connected to the P port of the first electromagnetic reversing valve (38); the main oil return port of the first electromagnetic reversing valve (38) is connected to the P1 port of the second one-way valve (35); the P2 port of the second one-way valve (35) is connected to the main oil return circuit; the working oil inlet of the first electromagnetic reversing valve (38) is respectively connected to the rodless chambers of the left and right first pin pulling hydraulic cylinders (7), and the working oil return port is respectively connected to the rod chambers of the left and right first pin pulling hydraulic cylinders (7). The P1 port of the second pressure reducing valve (48) is connected to the main oil supply circuit, and the P2 port is connected to the P port of the second electromagnetic reversing valve (46); the main oil return port of the second electromagnetic reversing valve (46) is connected to the P1 port of the third one-way valve (49); the P2 port of the third one-way valve (49) is connected to the main oil return circuit; the working oil inlet of the second electromagnetic reversing valve (46) is connected to the rodless chamber of the second pin pulling hydraulic cylinder (16), and the working oil return port is connected to the rod chamber of the second pin pulling hydraulic cylinder (16).

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