Self-adaptive electric cylinder tensioning device for belt conveyor and control method of self-adaptive electric cylinder tensioning device

Abstract

The invention relates to a self-adaptive electric cylinder tensioning device for a belt conveyor and a control method of the self-adaptive electric cylinder tensioning device. The self-adaptive electric cylinder tensioning device comprises an electric control box which is electrically connected with a driving motor of the belt conveyor; the prop pulling winch is electrically connected to the electric cabinet; the electric cylinder is electrically connected with the electric cabinet, and the electric cylinder is connected with the moving trolley through a steel wire rope; the buffering device comprises an oil cylinder and an energy accumulator, a piston rod of the oil cylinder is connected with one free end of a steel wire rope, the middle of the steel wire rope is wound with a traveling trolley and an electric cylinder, and the other free end is connected with the prop pulling winch; the energy accumulator is communicated with the oil cylinder; and the pressure transmitter is arranged on the connecting pipeline between the oil cylinder and the energy accumulator, and the pressure transmitter is electrically connected to the electric cabinet. By the adoption of the structure, self-adaptive matching of the tensioning force and the load is achieved, excessive tensioning under no-load and low-load conditions is avoided, the service life of an adhesive tape and mechanical parts is prolonged, and accurate adjustment of the tensioning force is achieved through multi-stage adjustment; the buffer device reduces the influence of impact on the system.

Description

Technical Field

[0001] This invention relates to the field of belt conveyor technology, and more specifically to an adaptive electric cylinder tensioning device and its control method for belt conveyors. Background Technology

[0002] Belt conveyors are continuous conveying equipment widely used in industries such as coal mining, ports, power, metallurgy, and building materials. The tensioning device is one of the key components of a belt conveyor; its function is to ensure sufficient tension on the conveyor belt, prevent slippage of the drive drum, and limit the sag of the conveyor belt between idlers, thereby ensuring the normal operation of the conveyor.

[0003] Traditional tensioning devices mainly include screw tensioners, counterweight tensioners, winch tensioners, and hydraulic tensioners. These traditional devices maintain a fixed tension force and cannot dynamically adjust according to load changes. They are typically set according to the maximum tension required by the conveyor. However, in actual operation, the conveyor spends most of its time under no-load or low-load conditions, where maximum tension is not needed. This over-tensioning not only increases energy consumption but also accelerates the wear of the belt and mechanical parts, shortening equipment lifespan. Traditional tensioning devices cannot adjust their tension in real time, nor can they achieve precise adaptive adjustment, resulting in poor adaptability to large fluctuations in external environments.

[0004] Therefore, there is an urgent need to provide an adaptive electric cylinder tensioning device and its control method for belt conveyors to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and defects of the prior art and provide an adaptive electric cylinder tensioning device and its control method for belt conveyors. This device achieves adaptive matching between tension force and load, avoids excessive tension under no-load and low-load conditions, extends the life of the belt and mechanical components, and enables precise adjustment of tension force through multi-level adjustment. The buffer device reduces the impact of shock on the system.

[0006] The objective of this invention is achieved through the following technical solution: An adaptive electric cylinder tensioning device for a belt conveyor, comprising: An electrical control box is electrically connected to the drive motor of the belt conveyor and is used to acquire signals such as motor power in real time. The return winch, electrically connected to the electrical control box, is used to provide the basic tensioning stroke; An electric cylinder, electrically connected to the electrical control box, is used to precisely fine-tune the tension force based on the tension stroke provided by the return winch. The electric cylinder is connected to the traveling trolley via a steel wire rope. The buffer device includes a hydraulic cylinder and an accumulator. The piston rod of the hydraulic cylinder is connected to one free end of the wire rope. The wire rope is wound around the traveling trolley and the electric cylinder in the middle, and the other free end is connected to the return winch. The accumulator is connected to the hydraulic cylinder to regulate and stabilize the oil pressure in the hydraulic cylinder. A pressure transmitter is installed on the connecting pipeline between the hydraulic cylinder and the accumulator, and the pressure transmitter is electrically connected to the electrical control box.

[0007] Optionally, the pressure transmitter is used to collect the system pressure in real time and transmit it to the electrical control box to convert it into a tension value. When the tension suddenly increases, the piston rod of the hydraulic cylinder extends to reduce the tension; when the tension suddenly decreases, the piston rod of the hydraulic cylinder retracts to increase the tension.

[0008] Optionally, the electric cylinder includes a motor, a reduction gearbox, a lead screw, a lead screw nut, a thrust bearing, and a cylinder body. The reduction gearbox is connected to the output end of the motor, the lead screw is connected to the output end of the reduction gearbox, and the lead screw nut is sleeved on the lead screw. The thrust bearing is located at the end of the lead screw near the reduction gearbox. The lead screw, lead screw nut, and thrust bearing are all housed within the cylinder body, and the lead screw nut is fixedly connected to the inner wall of the cylinder body to convert the rotational motion of the lead screw into linear motion.

[0009] Optionally, the electric cylinder further includes a position switch disposed on the cylinder body to limit the stroke of the lead screw.

[0010] Optionally, the electrical control box integrates a PID control module, which is used to calculate the control quantity and output it to the return winch and the electric cylinder.

[0011] Optionally, the load state of the drive motor is divided into five intervals: A0, A0.25, A0.5, A0.75 and A1, and corresponds to preset target tension forces of N0, N0.25, N0.5, N0.75 and N1; A0 corresponds to N0.25, A0.25 corresponds to N0.5, A0.5 corresponds to N0.75, and A0.75 and A1 correspond to N1.

[0012] A control method for an adaptive electric cylinder tensioning device for a belt conveyor includes the following steps: S1: The electrical control box reads signals such as the power of the drive motor of the belt conveyor in real time, and monitors the actual tension force in real time through the pressure transmitter. S2: Determine the preset range of the current load based on the power and other signals, and retrieve the target tension force corresponding to the preset range; S3: Compare the target tension force with the actual tension force and calculate the deviation value; S4: If the deviation value exceeds the first preset value, control the return winch to perform coarse adjustment of the tension so that the actual tension is close to the target tension. S5: After the coarse adjustment is completed, if the deviation value still exceeds the second preset threshold but is not greater than the first preset threshold, the electric cylinder is controlled to perform fine adjustment of the tension so that the actual tension reaches and stabilizes at the target tension. S6: If the tension fluctuates in a short period of time during the operation of the device, the buffer device will absorb the fluctuation; if the fluctuation amplitude exceeds the third preset threshold and the duration exceeds the preset time, the electric cylinder will be activated for active adjustment and compensation.

[0013] Optionally, the first preset value is 15% to 20% of the target tension, the second preset value is 3% to 5% of the target tension, the third preset threshold is 8% to 10% of the target tension, and the preset time is 2 to 5 seconds.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In this invention, the adaptive electric cylinder tensioning device for the belt conveyor includes an electrical control box, a return winch, an electric cylinder, a buffer device, a pressure transmitter, and a wire rope. The electrical control box is electrically connected to the drive motor of the belt conveyor to acquire real-time signals such as motor power. The return winch is mounted on a support and electrically connected to the electrical control box to provide a basic tensioning stroke; the return winch is connected to one free end of the wire rope. The electric cylinder is mounted on a support and electrically connected to the electrical control box, which controls its extension and retraction. The buffer device includes a hydraulic cylinder and an accumulator; the piston rod end of the hydraulic cylinder is used to connect the wire rope. The accumulator is connected to the hydraulic cylinder via a pipeline to regulate and stabilize the hydraulic pressure within the cylinder. The pressure transmitter is installed on the connecting pipeline between the hydraulic cylinder and the accumulator to monitor the hydraulic pressure within the cylinder in real time and feed the monitoring signal back to the electrical control box. One end of the wire rope is fixedly connected to… At the piston rod end of the hydraulic cylinder, a steel wire rope is wound around the traveling trolley and electric cylinder, with the other end connected to the return winch. The electrical control box determines the current load range based on signals such as the power of the drive motor, retrieves the corresponding target tension, and controls the return winch and electric cylinder to work together based on the actual tension signal fed back by the pressure transmitter. Through the above component settings, adaptive matching between tension and load is achieved, avoiding excessive tension under no-load or low-load conditions, extending the life of the conveyor belt and mechanical parts, and multi-level adjustment enables precise adjustment of tension. The buffer device reduces the impact of shocks on the system. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the winch model of the present invention.

[0016] Figure 2 This is a schematic diagram of the general structure of the present invention.

[0017] Figure 3 This is a cross-sectional structural diagram of the electric cylinder in this invention.

[0018] The above figures include the following reference numerals: 1. Electrical control box; 11. Traveling trolley; 2. Return winch; 3. Electric cylinder; 31. Electric motor; 32. Gearbox; 33. Lead screw; 34. Lead nut; 35. Thrust bearing; 36. Cylinder body; 37. Position switch; 38. Wire rope; 4. Buffer device; 41. Hydraulic cylinder; 42. Accumulator; 5. Pressure transmitter. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0020] The present invention proposes an adaptive electric cylinder tensioning device and its control method for belt conveyors.

[0021] Reference Figures 1 to 3 In this embodiment, it includes: Electrical control box 1 is electrically connected to the drive motor of the belt conveyor and is used to acquire signals such as motor power in real time. The return winch 2 is electrically connected to the electrical control box 1 to provide the basic tensioning stroke; Electric cylinder 3 is electrically connected to electric control box 1 and is used to precisely fine-tune the tension force based on the tension stroke provided by return winch 2. Electric cylinder 3 is connected to moving trolley 11 by steel wire rope 38. The buffer device 4 includes a hydraulic cylinder 41 and an accumulator 42. The piston rod of the hydraulic cylinder 41 is connected to one free end of a wire rope 38. The wire rope 38 is wound around the moving trolley 11 and the electric cylinder 3 in the middle, and the other free end is connected to the return winch 2. The accumulator 42 is connected to the hydraulic cylinder 41 and is used to regulate and stabilize the oil pressure in the hydraulic cylinder 41. The pressure transmitter 5 is located on the connecting pipeline between the oil cylinder 41 and the accumulator 42, and the pressure transmitter 5 is electrically connected to the electrical control box 1.

[0022] Optionally, in this embodiment, the adaptive electric cylinder tensioning device for the belt conveyor includes an electrical control box 1, a return winch 2, an electric cylinder 3, a buffer device 4, a pressure transmitter 5, and a wire rope 38. The electrical control box 1 is installed near the head of the conveyor and is electrically connected to the drive motor of the belt conveyor to obtain signals such as the motor power in real time. The return winch 2 is mounted on the support and electrically connected to the control box 1, which controls its rotation to provide basic tension stroke. The return winch 2 is connected to one free end of the wire rope 38. The electric cylinder 3 is mounted on the support and electrically connected to the control box 1, which controls its extension and retraction. The buffer device 4 includes a hydraulic cylinder 41 and an accumulator 42. The piston rod end of the hydraulic cylinder 41 is provided with a connection point for connecting the wire rope 38. The accumulator 42 is connected to the hydraulic cylinder 41 through a pipeline to regulate and stabilize the oil pressure in the hydraulic cylinder 41. The pressure transmitter 5 is installed on the connecting pipeline between the hydraulic cylinder 41 and the accumulator 42 to monitor the hydraulic pressure in the hydraulic cylinder 41 in real time and transmit the monitored pressure. The signal is fed back to the electrical control box 1; one end of the wire rope 38 is fixedly connected to the piston rod end of the hydraulic cylinder 41, the middle of the wire rope 38 is wound around the traveling trolley 11 and the electric cylinder 3, and the other end is connected to the return winch 2; the electrical control box 1 determines the current load range based on signals such as the power of the drive motor, retrieves the corresponding target tension, and controls the return winch 2 and the electric cylinder 3 to work together based on the actual tension signal fed back by the pressure transmitter 5; when a large range of tension stroke adjustment is required, the electrical control box 1 controls the return winch 2 to raise and lower the winch wire rope 38 to achieve coarse tension adjustment; when precise tension adjustment is required based on coarse adjustment, the electrical control box 1 controls the extension and retraction of the electric cylinder 3 to achieve fine tension adjustment. This achieves adaptive matching between tension and load, avoids excessive tension under no-load or low-load conditions, extends the life of the conveyor belt and mechanical parts, and multi-level adjustment enables precise tension adjustment; the buffer device 4 reduces the impact on the system.

[0023] Optionally, in this embodiment, the pressure transmitter 5 collects the hydraulic pressure of the pipeline between the cylinder 41 and the accumulator 42 in real time and transmits the signal to the control box 1. The control box 1 calculates the actual tension force based on the pressure value. When the tension force suddenly increases, the wire rope 38 pulls the piston rod of the cylinder 41 outward, and the hydraulic oil in the rod chamber of the cylinder 41 is forced into the accumulator 42, compressing the gas in the accumulator 42, thereby absorbing energy and reducing the peak tension force. At this time, the pressure transmitter 5 detects the pressure increase, and the control box 1 can determine that a tension impact has occurred. When the tension force suddenly decreases (e.g., unloading or belt slackening), the gas in the accumulator 42 expands, pushing the hydraulic oil back into the rod chamber of the cylinder 41, pushing the piston rod back, thereby increasing the tension force. At this time, the pressure transmitter 5 detects a decrease in pressure. Through the cooperation of the cylinder 41 and the accumulator 42, the buffer device 4 achieves the buffering and absorption of the instantaneous fluctuation of the tension force, reduces the impact of the impact on the system, and improves the stability of operation.

[0024] Optionally, in this embodiment, the electric cylinder 3 includes a motor 31, a reduction gearbox 32, a lead screw 33, a lead screw nut 34, a thrust bearing 35, and a cylinder body 36. The output shaft of the motor 31 is connected to the input end of the reduction gearbox 32. The reduction gearbox 32 can be a planetary gear reduction mechanism to reduce the speed and increase the torque. The output end of the reduction gearbox 32 is connected to the lead screw 33, which is installed inside the cylinder body 36. A thrust bearing 35 is provided at one end near the reduction gearbox 32 to bear the axial load. The lead screw nut 34 is sleeved on the lead screw 33 and threadedly engaged with it. The outer circumference of the lead screw nut 34 is connected to the inner wall of the cylinder body 36. When the motor 31 rotates, the rotational motion is reduced and increased in torque by the reduction gearbox 32, which drives the lead screw 33 to rotate. The rotational motion of the lead screw 33 is converted into the linear motion of the lead screw nut 34 through the threaded engagement between the lead screw 33 and the lead screw nut 34, thereby driving the output component to extend and retract axially, realizing the linear drive of the electric cylinder 3. The transmission through the lead screw 33 is efficient and precise in positioning. Furthermore, a position switch 37 is also provided on the cylinder body 36. The position switch 37 can be a proximity switch, limit switch or photoelectric switch, used to detect the travel position of the lead screw 33. When the lead screw 33 moves to the limit position at one end, the corresponding position switch 37 is triggered. The position switch 37 sends a signal to the electrical control box 1, and the electrical control box 1 immediately stops the electric cylinder 3 from continuing to move, preventing mechanical damage caused by overtravel operation, ensuring the safe operation of the electric cylinder 3, and can also be used for initial position calibration.

[0025] Optionally, in this embodiment, the electrical control box 1 integrates a PID control module. This module uses the target tension force as the set value and the actual tension force fed back by the pressure transmitter 5 as the actual value to calculate the deviation. The PID control module performs calculations based on the deviation and outputs control quantities to the motors of the return winch 2 and the electric cylinder 3 for separate control and operation. Specifically, for the return winch 2, it controls its forward and reverse rotation and running time; for the electric cylinder 3, it controls its extension and retraction direction and amount, so that the actual tension force quickly and smoothly approaches the target tension force, thereby improving the system's response speed.

[0026] Reference Figure 2 Without the return winch 2, it is directly driven by the electric cylinder 3, resulting in a small tensioning stroke, generally less than 10 meters, suitable for short-distance conveyors; see reference. Figure 1 The system is equipped with a return winch 2, and the tensioning stroke of this structure can reach 20-30 meters. It is suitable for long-distance belt conveyors and can achieve long-stroke tensioning to meet the tensioning requirements of long-distance conveyors. The electrical control system, buffer device 4 and control method of the two structural forms are basically the same and can be selected according to user needs.

[0027] Optionally, in this embodiment, the electrical control box 1 divides the load state from no-load to full-load into five intervals according to the power P of the drive motor: A0 interval: power P < 20% of rated power (no-load). A0.25 range: 20% rated power ≤ P < 40% rated power (light load); A0.5 range: 40% rated power ≤ P < 60% rated power (medium load); A0.75 range: 60% rated power ≤ P < 80% rated power (heavy load); A1 range: P ≥80% rated power (full load); Preset target tension for each range: A0 range corresponds to target tension N0.25 (usually 40% of maximum tension), A0.25 range corresponds to target tension N0.5 (usually 60% of maximum tension), A0.5 range corresponds to target tension N0.75 (usually 80% of maximum tension), A0.75 range corresponds to target tension N1 (maximum tension), and A1 range corresponds to target tension N1; Based on the tension requirements of the drive motor under different loads, control the electric cylinder 3 and the return winch 2 to achieve the required tension. For example, when unloaded, maximum tension is not required, and a smaller N0.25 is sufficient to meet basic tension requirements. As the load increases, the tension increases accordingly. Under heavy load, the maximum tension N1 is provided to ensure sufficient friction to prevent slippage. A control method for an adaptive electric cylinder tensioning device for a belt conveyor includes the following steps: S1: The electrical control box 1 reads signals such as the power of the drive motor of the belt conveyor in real time, and at the same time monitors the actual tension force in real time through the pressure transmitter 5. S2: Determine the preset range where the current load is located based on power and other signals, and retrieve the target tension force corresponding to that range; S3: Calculate the deviation value and the relative deviation; S4: If the deviation value is greater than the first preset threshold, control the return winch 2 to perform coarse adjustment of the tension and increase the tension; during the coarse adjustment process, continue to monitor until the deviation value is lower than the first preset threshold. S5: After the coarse adjustment is completed, if the deviation value exceeds the second preset threshold but is not greater than the first preset threshold, the electric cylinder 3 is controlled to move to perform fine adjustment of the tension. The extension and retraction of the electric cylinder 3 is calculated by the PID algorithm according to the deviation value, so that the deviation value approaches the second preset threshold. S6: During the operation of the device, the fluctuation of tension is continuously monitored. If the tension fluctuates momentarily and the fluctuation amplitude is greater than the third preset threshold, the buffer device 4 will buffer and absorb it; if the fluctuation amplitude is greater than the third preset threshold and the duration exceeds the preset time, the electric cylinder 3 will be activated to actively adjust and compensate to eliminate the large fluctuation.

[0028] Through the above steps, multi-level adaptive adjustment of tension is achieved, ensuring adjustment accuracy and anti-interference capability.

[0029] Optionally, in this embodiment, the first preset threshold is 15%~20% of the target tension. When the deviation exceeds this range, the return winch 2 needs to quickly make a coarse adjustment. The second preset threshold (fine adjustment completion threshold) is 3%~5% of the target tension. When the deviation decreases to this range, the electric cylinder 3 can make a fine adjustment until it fully meets the target. The third preset threshold (active compensation start threshold) is 8%~10% of the target tension. When the fluctuation exceeds this value and the duration exceeds the preset time (2~5 seconds), it indicates that the buffer device 4 has insufficient absorption capacity, and the electric cylinder 3 needs to actively adjust and compensate. In other embodiments, the specific values ​​can be appropriately adjusted according to factors such as the model, length, and belt characteristics of the conveyor.

[0030] The embodiments described above merely illustrate implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An adaptive electric cylinder tensioning device for a belt conveyor, characterized in that, include: An electrical control box is electrically connected to the drive motor of the belt conveyor and is used to acquire signals such as motor power in real time. The return winch, electrically connected to the electrical control box, is used to provide the basic tensioning stroke; An electric cylinder, electrically connected to the electrical control box, is used to precisely fine-tune the tension force based on the tension stroke provided by the return winch. The electric cylinder is connected to the traveling trolley via a steel wire rope. The buffer device includes a hydraulic cylinder and an accumulator. The piston rod of the hydraulic cylinder is connected to one free end of the wire rope. The wire rope is wound around the traveling trolley and the electric cylinder in the middle, and the other free end is connected to the return winch. The accumulator is connected to the hydraulic cylinder to regulate and stabilize the oil pressure in the hydraulic cylinder. A pressure transmitter is installed on the connecting pipeline between the hydraulic cylinder and the accumulator, and the pressure transmitter is electrically connected to the electrical control box.

2. The adaptive electric cylinder tensioning device for a belt conveyor according to claim 1, characterized in that, The pressure transmitter is used to collect the system pressure in real time and transmit it to the electrical control box to convert it into a tension value. When the tension suddenly increases, the piston rod of the hydraulic cylinder extends to reduce the tension; when the tension suddenly decreases, the piston rod of the hydraulic cylinder retracts to increase the tension.

3. The adaptive electric cylinder tensioning device for a belt conveyor according to claim 1, characterized in that, The electric cylinder includes a motor, a gearbox, a lead screw, a lead screw nut, a thrust bearing, and a cylinder body. The gearbox is connected to the output end of the motor, the lead screw is connected to the output end of the gearbox, and the lead screw nut is sleeved on the lead screw. The thrust bearing is located at the end of the lead screw near the gearbox. The lead screw, lead screw nut, and thrust bearing are all housed within the cylinder body. The lead screw nut is fixedly connected to the inner wall of the cylinder body to convert the rotational motion of the lead screw into linear motion.

4. The adaptive electric cylinder tensioning device for a belt conveyor according to claim 3, characterized in that, The electric cylinder also includes a position switch, which is located on the cylinder body and is used to limit the stroke of the lead screw.

5. The adaptive electric cylinder tensioning device for a belt conveyor according to claim 1, characterized in that, The electrical control box integrates a PID control module, which is used to calculate the control quantity and output it to the return winch and the electric cylinder.

6. The adaptive electric cylinder tensioning device for a belt conveyor according to claim 1, characterized in that, The load states of the drive motor are divided into five intervals: A0, A0.25, A0.5, A0.75 and A1, and correspond to preset target tension forces of N0, N0.25, N0.5, N0.75 and N1, respectively; A0 corresponds to N0.25, A0.25 corresponds to N0.5, A0.5 corresponds to N0.75, and A0.75 and A1 correspond to N1.

7. A control method for an adaptive electric cylinder tensioning device for a belt conveyor, employing the device as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: The electrical control box reads signals such as the power of the drive motor of the belt conveyor in real time, and monitors the actual tension force in real time through the pressure transmitter. S2: Determine the preset range of the current load based on the power and other signals, and retrieve the target tension force corresponding to the preset range; S3: Compare the target tension force with the actual tension force and calculate the deviation value; S4: If the deviation value exceeds the first preset value, control the return winch to perform coarse adjustment of the tension so that the actual tension is close to the target tension. S5: After the coarse adjustment is completed, if the deviation value still exceeds the second preset threshold but is not greater than the first preset threshold, the electric cylinder is controlled to perform fine adjustment of the tension so that the actual tension reaches and stabilizes at the target tension. S6: If the tension fluctuates in a short period of time during the operation of the device, the buffer device will absorb the fluctuation; if the fluctuation amplitude exceeds the third preset threshold and the duration exceeds the preset time, the electric cylinder will be activated for active adjustment and compensation.

8. The control method for an adaptive electric cylinder tensioning device for a belt conveyor according to claim 7, characterized in that, The first preset threshold is 15%~20% of the target tension, the second preset threshold is 3%~5% of the target tension, the third preset threshold is 8%~10% of the target tension, and the preset time is 2~5s.

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