Mine belt auxiliary transfer device and control method thereof

Abstract

The present application relates to mine conveying equipment technical field, disclose a kind of mine belt auxiliary transfer device and its control method, device includes main guide chute, auxiliary discharge component, buffer storage component, pressure detection component, sequential opening mechanism, quantitative return component and controller.Pile up coal material to push movable pressure plate, sequential opening mechanism first opens auxiliary discharge component to increase instantaneous discharge capacity, then open buffer feed inlet, and temporarily store coal material exceeding instantaneous discharge capacity in buffer storage bin;When peak disappears and downstream belt has residual conveying capacity, quantitative return component returns temporarily stored coal material in batches;When storage reaches upper limit and high pile continues, first reduce upstream speed, and only stop when speed is reduced and not restored to corresponding safe state. The device can grade expansion flow, temporary storage peak shaving and delayed return for instantaneous large flow, reduce transfer point blocking, scattering and frequent shutdown.

Description

Technical Field

[0001] This invention relates to the technical field of continuous bulk material conveying equipment in mines, specifically to an auxiliary transfer device for mining belts and its control method. Background Technology

[0002] Coal mine underground and coal preparation systems typically utilize multi-stage belt conveyors to continuously transport raw coal and gangue. Transfer between adjacent belts is accomplished via coal hoppers or chutes. Coal transported by the upstream belt detaches from the belt surface at the discharge drum and enters the chute, then falls from the chute to the downstream belt. Due to the fluctuating output of coal from mining equipment, high coal seams or large pieces of gangue may form on the belt surface in localized areas, causing transfer points to receive coal flows far exceeding the average flow rate within seconds to tens of seconds. The geometry of the chute and the allowable coal seam thickness of the downstream belt are usually designed for stable operating conditions. When the instantaneous flow rate exceeds the immediate throughput capacity of the chute, coal will accumulate from the bottom of the chute upwards, potentially causing spillage, dust, belt eccentricity, and blockage protection activation. Simply enlarging the entire chute or continuously increasing the downstream belt speed to handle occasional peak flows would increase equipment space requirements, energy consumption, and belt wear, and would be difficult to adapt to the limited installation conditions underground.

[0003] Chinese patent document CN221369257U discloses a coal mine belt conveyor with an anti-clogging structure. It features a clearing mechanism consisting of a motor, turntable, and clearing rod at the trough, and a separating mechanism above the conveyor belt to separate and clear coal as it enters the trough. While this solution can agitate the coal to address existing blockages in the trough, its primary method is mechanical clearing of the coal entering the trough. It does not create an independent storage space to absorb instantaneous flow peaks, nor does it disclose a structure for quantitatively returning temporarily stored coal after the peak flow ends, based on the remaining conveying capacity of the downstream belt.

[0004] Chinese patent document CN111242108B discloses a method for identifying coal blockage at conveyor belt transfer points based on target detection. It determines blockage and triggers an alarm by acquiring images of the transfer point, identifying large coal blocks, and determining whether the large coal blocks move within a set time. Chinese patent document CN218808541U discloses a conveyor belt loading and transport device for underground coal mines, which sets up coal hoppers, buffer beds, buffer chains, and coal-blocking devices at the connection points of multiple conveyors to reduce the impact of falling coal and limit coal spillage. The above solutions focus on coal blockage identification and alarm, mechanical unblocking, impact buffering, or coal-blocking and diversion, respectively. However, for operating conditions where the average conveying capacity meets requirements but short-term peaks exceed the immediate throughput capacity of the transfer point, they still lack a continuous adjustment path that first expands the flow according to the degree of accumulation, then temporarily stores the coal, and then smoothly returns the temporarily stored coal to the downstream conveyor belt after the peak disappears.

[0005] Therefore, a mining belt auxiliary transfer device and its control method are needed to maintain low additional resistance at the transfer point under normal operating conditions. When there is a sudden large flow of coal, the device can increase the discharge channel and buffer volume in stages according to the degree of accumulation, temporarily store the coal exceeding the immediate receiving capacity of the downstream belt, and return it in batches after the downstream belt has a conveying capacity. At the same time, the shutdown protection should only intervene when the buffer capacity is exhausted and the high-level accumulation continues, thereby reducing unnecessary production interruptions while ensuring the safety of transfer. Summary of the Invention

[0006] This invention provides an auxiliary transfer device for mining belt conveyors and its control method, aiming to solve the problem that when mining belt transfer points face a large instantaneous flow of coal, relying solely on unblocking or shutdown protection is insufficient to absorb and subsequently return the peak coal volume under continuous conveying conditions.

[0007] A mining conveyor belt auxiliary transfer device is installed between the unloading end of the upstream conveyor belt and the receiving section of the downstream conveyor belt. It includes a transfer frame, a main feed chute, an auxiliary discharge assembly, a buffer storage assembly, a pressure detection assembly, a sequential opening mechanism, a quantitative return assembly, and a controller. The main feed chute has auxiliary discharge chambers connected to its sides, each forming an auxiliary discharge port at its lower part. Two buffer storage bins are connected to the upper area of ​​their respective auxiliary discharge chambers via corresponding buffer inlets. The sequential opening mechanism, moving with the movable pressure plate, first synchronously opens two discharge gates, then synchronously opens two buffer inlet gates. The quantitative return assembly is used to return the coal from the two buffer storage bins to the downstream conveyor belt.

[0008] Its effect is as follows: normal coal flow can directly enter the downstream conveyor belt along the main feed chute, while the auxiliary discharge channel and buffer storage bin do not continuously participate in the conveying, thereby reducing friction and retention between the coal and the auxiliary channels. When the instantaneous flow rate increases, causing insufficient discharge speed at the bottom of the main feed chute, the coal accumulates from bottom to top and exerts a continuous force on the movable pressure plate. The displacement of the movable pressure plate can reflect the actual degree of obstruction inside the feed chute. The sequential opening mechanism first opens the auxiliary discharge port, dividing the coal flow concentrated in the main feed chute into the main coal flow and the auxiliary coal flow. By increasing the effective discharge cross-section and dispersing the drop position along the downstream conveyor belt direction, the existing receiving space of the downstream conveyor belt is used first to absorb smaller peak values. Only when the accumulation continues to develop is the buffer feed port opened, allowing the portion of coal exceeding the immediate discharge capacity to enter the buffer storage bin. After the peak value disappears, the temporarily stored coal is not dumped all at once, but is returned in batches by the quantitative return component according to the remaining conveying capacity of the downstream conveyor belt. This forms a continuous processing chain of "normal direct flow, primary flow amplification, secondary temporary storage, low-load return, and extreme shutdown," enabling the transfer device to achieve short-term peak absorption capacity without increasing the main body size and the rated speed of the downstream belt in the long term, and reducing the probability of slight fluctuations triggering a shutdown of the entire line.

[0009] Preferably, the main feed trough includes an upper receiving section, a middle buffer section and a lower discharge section in sequence along the coal movement direction. The extension length of the middle buffer section along the coal movement direction is greater than that of the upper receiving section. The lower discharge section is inclined towards the conveying direction of the downstream belt. The auxiliary discharge ports of the two auxiliary discharge chambers are offset from the main discharge port along the conveying direction of the downstream belt.

[0010] Its effects are as follows: the middle buffer section has a longer buffer stroke in the direction of coal movement, which can reduce the rising speed of coal in the feed chute and allow time for pressure detection and gate opening; the inclined lower discharge section allows the coal to obtain a velocity component in the same direction as the belt surface movement when it falls to the downstream belt; after the main discharge port and the auxiliary discharge port are staggered, the coal flow is distributed in different longitudinal positions of the downstream belt, avoiding the formation of an excessively thick coal seam in a single position after the flow is expanded.

[0011] Preferably, the pressure detection assembly includes a movable pressure plate, a sliding frame, an elastic reset component, a damping component, and a displacement sensor. The movable pressure plate is located at the pressure detection position in the middle buffer section and moves along the pressure direction. The sliding frame is connected to the movable pressure plate and moves along the pressure direction.

[0012] Its effects are as follows: the movable pressure plate mainly bears the continuous force formed by the accumulation of coal, and does not directly use the instantaneous impact of a single coal block as the control basis; the damping component can suppress the rapid displacement caused by short-term collision; the elastic reset component is used to return the movable pressure plate to its original position after the accumulation is released; and the displacement sensor provides a continuous signal for feedback control, deceleration control and fault alarm.

[0013] Preferably, the sequential opening mechanism includes a first drive slot and a second drive slot disposed on the sliding frame, a first follower, a second follower, a first rotating shaft and a second rotating shaft, the first rotating shaft synchronously driving two discharge gates, the second rotating shaft synchronously driving two buffer feed gates, and the effective driving section of the first drive slot is located before the effective driving section of the second drive slot.

[0014] Its effect is that the same continuous displacement of the movable pressure plate can be converted into two gate actions with a sequence, without relying on two actuators to receive control commands separately, and can maintain a clear action sequence in downhole environments with poor dust, vibration and communication conditions; by setting the idle travel section, tilt drive section and holding section, the opening start point, opening speed and maximum opening degree can also be defined respectively.

[0015] Preferably, both the first drive groove and the second drive groove include an idle stroke section, an inclined drive section and a holding section. The first drive groove drives the first follower and the first rotating shaft first, and the second drive groove drives the second follower and the second rotating shaft later.

[0016] Its effect is that by defining two action ranges through the mechanical groove shape, the first-stage current amplification and the second-stage temporary storage can be naturally segmented during the continuous movement of the moving pressure plate, and the corresponding gate opening can be maintained by the holding section when the moving pressure plate continues to move, thereby reducing the probability of repeated opening and closing near the threshold.

[0017] Preferably, the buffer storage silo includes a fixed silo body, an expansion swing arm, a guide rod, and an expansion reset assembly. The lower two sides of the fixed silo body are provided with expansion guide walls that can expand outward. The expansion swing arm is located on the outside of the fixed silo body and is connected to the expansion guide wall in a transmission manner. The buffer feed inlet is located on the upper part of the fixed silo body, and the buffer feed gate is located at the buffer feed inlet. The expansion guide wall can move outward as the coal material in the silo increases and reset after the coal material is discharged.

[0018] Its effects are as follows: the buffer storage bin maintains a small width under normal conditions, and increases the effective volume by expanding the expansion guide wall and swinging the expansion swing arm when a continuous peak occurs, which is suitable for installation environments with limited lateral space in the roadway; the swing position of the expansion swing arm can simultaneously indicate the amount of material stored in the bin, providing a direct basis for ultimate protection.

[0019] Preferably, a loosening rod is installed inside the buffer storage silo above the return outlet, a return outlet is installed at the bottom of the buffer storage silo, and an arch-breaking tooth is installed near the outlet of the confluence guide chute.

[0020] Its effects are as follows: the loosening rod is located on the path where the coal converges to the return outlet, which disperses the downward-moving coal; the arch-breaking teeth further break up the clumps of coal near the outlet of the confluence guide chute, which can reduce the probability of static coal forming arches or clumps; when the return outlet adopts a larger effective width, it can also improve the passage capacity of large pieces of coal gangue.

[0021] Preferably, the quantitative return assembly includes a return guide, a return drive, multiple unidirectional pushers, a confluence guide chute, and a check plate. The return drive causes the unidirectional pushers to move periodically between a push position and an avoidance position. The confluence guide chute directs the coal discharged from the left and right buffer storage bins to the middle of the downstream conveyor belt.

[0022] Its effects are as follows: the amount of material fed back per unit time can be adjusted by changing the frequency of the unidirectional pusher; the avoidance action can reduce the reverse dragging of the remaining coal; the coal from the left and right flows first and then falls to the middle of the downstream belt, which can avoid the belt surface being unbalanced due to unilateral feeding; and the check plate restricts the coal that has entered the confluence guide chute from moving in the reverse direction during the reset process of the feeding mechanism.

[0023] Preferably, the detection components include an upstream speed sensor, a downstream speed sensor, a coal seam thickness sensor, a high-level material level sensor, a storage capacity sensor, and a load detector. The controller controls the feedback frequency, the operating status of the upstream and downstream belt drive devices, and the audible and visual alarms based on the displacement of the movable pressure plate, the high-level material level of the main feed chute, the storage capacity of the buffer storage silo, the coal seam thickness of the downstream conveyor belt, the drive load, and the speed of the upstream and downstream conveyor belts.

[0024] Its effects are as follows: the displacement of the moving pressure plate is used to indicate the degree of obstruction in the transfer channel; the high material level is used to confirm whether severe accumulation continues; the storage volume is used to determine the remaining buffer capacity; the coal seam thickness and drive load are used to determine whether the downstream belt has a return margin; and the upstream and downstream belt speeds are used to confirm the operating status of the transfer system. The controller can adjust the return amount and upstream feeding speed accordingly, and keep the downstream belt running during the shutdown and cleaning phase. Multiple signals correspond to different physical states, which can avoid shutdown control based solely on a single material level signal.

[0025] A control method for a mining belt auxiliary transfer device includes acquiring operating parameters, primary flow amplification, secondary temporary storage, quantitative return, and limit protection; when the movable pressure plate moves to the position corresponding to the first displacement threshold, the discharge gate is opened by a sequential opening mechanism; when the movable pressure plate moves to the position corresponding to the second displacement threshold, the buffer feed gate is opened by the sequential opening mechanism; when the displacement falls back and the downstream belt has spare capacity, return is performed; when the buffer storage bin reaches the upper limit of storage and high-level accumulation continues, the upstream speed is reduced first, and the machine is stopped only if it has not recovered to the corresponding safe state after deceleration.

[0026] Its effect is that each control action intervenes step by step according to the degree of accumulation and buffer margin. First, the continuous transfer is maintained by the structure's own current expansion and temporary storage capabilities. Then, the return is controlled by the hysteresis threshold and downstream load conditions. Finally, deceleration and shutdown are executed, which can reduce the frequent opening and closing of the gate and the repeated start and stop of the whole line.

[0027] Preferably, the first displacement threshold, the second displacement threshold, the reset displacement threshold, and the recovery storage threshold constitute a hysteresis relationship, and the feedback frequency is determined based on the downstream conveyor coal seam thickness margin and the drive load margin; if the displacement of the active pressure plate is lower than the reset displacement threshold, the high-level material level signal is released, and the storage volume of the buffer storage bin is lower than the recovery storage threshold after the upstream deceleration, then normal operation is restored; if the high-level material level continues to exceed the set time, then the upstream conveyor is stopped, and the downstream conveyor is kept running until it is emptied.

[0028] Its effects are as follows: the hysteresis threshold can prevent the detection value from fluctuating near the critical point, causing frequent state switching; the return amount changes with the actual remaining amount of the downstream belt, which can avoid overload caused by the return of temporarily stored coal; the speed is reduced before shutdown and the downstream is kept empty after shutdown, so that the shutdown protection has a clear gradual process.

[0029] By adopting the above technical solution, the beneficial effects of the present invention are as follows: First, the device uses a movable pressure plate to sense the continuous force generated by coal accumulation and a damping structure to suppress malfunctions caused by the impact of a single piece of coal gangue, enabling the device to identify the imbalance between discharge capacity and feed flow rate before the feed chute is completely blocked.

[0030] Second, the sequential opening mechanism allows the auxiliary discharge port and buffer feed port to open in sequence according to the degree of accumulation. Smaller peak values ​​are digested first by increasing the discharge area and dispersing the landing point, while larger peak values ​​are absorbed by the buffer storage silo, avoiding unnecessary coal retention caused by the simultaneous operation of all adjustment structures.

[0031] Third, the variable volume buffer storage bin expands outward only when the storage increases, providing short-term storage capacity within the limited underground space; the loosening bar, arch-breaking teeth, and wider return outlet work together to reduce coal bridging within the bin, adapting to raw coal and gangue with uneven particle size.

[0032] Fourth, the quantitative return component adjusts its operating frequency according to the thickness of the coal seam in the downstream conveyor belt and the driving load, and returns the temporarily stored coal in batches during the low-load stage after the peak ends, so as to realize the peak shaving and valley filling of the coal flow and avoid emptying the storage silo at one time and forming a new instantaneous overload.

[0033] Fifth, the control method sets the shutdown as the final protection measure after the buffer capacity is exhausted, and performs upstream deceleration before shutdown and maintains downstream venting after shutdown. This can reduce the interruption of the entire production line caused by short-term coal flow fluctuations, while retaining the safety protection capability in the event of severe material blockage. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall structure of the auxiliary transfer device for mining belts of the present invention.

[0035] Figure 2 This is a schematic cross-sectional view of the main feed trough, auxiliary discharge assembly, and buffer storage assembly of the present invention.

[0036] Figure 3 This is a partial cross-sectional view of the pressure detection component and sequential opening mechanism of the present invention.

[0037] Figure 4 This is a partial cross-sectional view of the buffer storage assembly and anti-bridging assembly of the present invention.

[0038] Figure 5 This is a schematic diagram of the cooperation structure between the quantitative return component and the downstream belt of the present invention.

[0039] Figure 6 This is a connection block diagram of the control system of the present invention.

[0040] Figure 7 This is a flowchart of the control method of the present invention.

[0041] Figure label: 1. Upstream conveyor belt; 2. Downstream conveyor belt; 3. Transfer conveyor frame; 4. Main feed chute; 41. Upper receiving section; 42. Middle buffer section; 43. Lower discharge section; 5. Auxiliary discharge assembly; 51. Auxiliary discharge chamber; 52. Discharge gate; 53. Auxiliary discharge port; 54. Auxiliary coal flow; 6. Buffer storage assembly; 61. Buffer storage bin; 62. Buffer feed inlet; 63. Buffer feed gate; 64. Fixed bin body; 65. Expansion swing arm; 66. Guide rod; 67. Expansion reset assembly; 68. Return outlet; 69. Guide liner; 7. Pressure detection assembly; 71. Movable pressure plate; 72. Sliding frame; 73. Elastic reset component; 74. Damping component; 75. Displacement sensor 8. Sequential opening mechanism; 81. First drive groove; 82. Second drive groove; 83. First follower; 84. Second follower; 85. First rotating shaft; 86. Second rotating shaft; 9. Quantitative return assembly; 92. Return guide; 93. Return drive; 94. Unidirectional pusher; 95. Converging guide chute; 96. Check plate; 10. Anti-bridging assembly; 101. Loosening rod; 102. Arch breaking tooth; 11. Detection assembly; 111. Upstream speed sensor; 112. Downstream speed sensor; 113. Coal seam thickness sensor; 114. High-level material level sensor; 115. Storage capacity sensor; 116. Load detector; 12. Controller; 13. Audible and visual alarm. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] like Figures 1-7 As shown, the auxiliary transfer device for mining belts in this embodiment is installed between the unloading end of the upstream belt 1 and the receiving section of the downstream belt 2. The device includes a transfer frame 3, a main feed chute 4, an auxiliary discharge assembly 5, a buffer storage assembly 6, a pressure detection assembly 117, a sequential opening mechanism 8, a quantitative return assembly 9, an anti-bridging assembly 10, a detection assembly 11, a controller 12, and an audible and visual alarm. The transfer frame 3 spans both sides of the downstream belt 2. The unloading end of the upstream belt 1 is located above the main feed chute 4, and the discharge end of the main feed chute 4 is located in the middle of the width direction of the downstream belt 2.

[0044] The transfer frame 3 can be composed of steel columns, beams, and detachable connecting plates. The columns are connected to the belt conveyor foundation or the downstream belt 2 frame via bases. The main feed chute 4, auxiliary discharge channel, and buffer storage bin 61 are bolted to the transfer frame 3 to facilitate separate transport and assembly in the confined underground space. The inner wall in contact with the coal can be lined with wear-resistant steel plates, ceramic liners, or polymer wear-resistant liners. Flexible sealing strips are fixed at the joints with pressure plates to reduce the leakage of fine coal dust from the splicing points.

[0045] The main feed trough 4 is formed sequentially along the direction of coal movement by an upper receiving section 41, a middle buffer section 42, and a lower discharge section 43. The inlet of the upper receiving section 41 surrounds the unloading trajectory of the upstream conveyor belt 1, and the upper edge of the inlet is higher than the maximum throwing trajectory. The width and front-to-back length of the middle buffer section 42 are both greater than those of the upper receiving section 41, which reduces the velocity of the coal flow entering the main feed trough 4 and provides lateral expansion space. The lower discharge section 43 is inclined towards the conveying direction of the downstream conveyor belt 2, and its centerline forms an acute angle with the belt surface of the downstream conveyor belt 2, so that the coal gradually acquires a component velocity consistent with the running direction of the downstream conveyor belt 2 as it slides down the lower discharge section 43.

[0046] In one feasible structure, the effective width of the upper receiving section 41 is 35% to 55% of the effective carrying width of the downstream belt 2, and the maximum effective width of the middle buffer section 42 is 50% to 75% of the effective carrying width of the downstream belt 2. The outlet width of the lower discharge section 43 is smaller than the width of the trough surface of the downstream belt 2 and is aligned with the centerline of the downstream belt 2. The above proportions are used to ensure that the main coal flows into the middle of the belt surface, and the actual dimensions can be determined according to the belt width, coal particle size, and installation drop.

[0047] Two auxiliary discharge chambers 51 are respectively located on the left and right sides of the middle buffer section 42, with the lower edge of the auxiliary discharge chambers 51 higher than the lower discharge port of the main feed trough 4. When the coal in the main feed trough 4 is in a normal flow state, the coal is mainly discharged along the lower discharge section 43 and will not continuously enter the auxiliary discharge chambers 51; when the lower discharge speed is lower than the feeding speed and the coal accumulates to the height of the auxiliary discharge chambers 51, the discharge gate 52 is opened, and the auxiliary discharge chambers 51 can directly share the accumulated coal.

[0048] Each auxiliary discharge chamber 51 extends from the corresponding side outward to the outside of the main feed trough 4 and forms an auxiliary discharge port 53 at the bottom. The left and right auxiliary discharge chambers 51 are symmetrically arranged with respect to the main feed trough 4, and the two auxiliary discharge ports 53 are staggered with respect to the main discharge port along the downstream belt belt 2 running direction, so that the main coal flow and the auxiliary coal flow 54 are distributed in front and behind on the belt surface, rather than superimposed at the same cross-section. Figure 2 This mainly indicates the relative positions of the main feed trough 4, the auxiliary discharge chamber 51, the buffer storage silo 61, and the return outlet 68 at the bottom of the buffer storage silo 61.

[0049] The effluent gate 52 is positioned at the connection point between the auxiliary effluent chamber 51 and the main feed trough 4. Both effluent gates 52 are connected to the first rotating shaft 85 via transmission components. When closed, the effluent gate 52 seals the connection between the main feed trough 4 and the auxiliary effluent chamber 51. When open, it moves into the auxiliary effluent chamber 51, allowing some coal from the main feed trough 4 to enter the auxiliary effluent chamber 51. Wear-resistant sealing strips can be installed on the edges of the effluent gate 52. A clearance is provided between the gate and the auxiliary effluent chamber 51 to allow fine particles to pass through, preventing the gate from failing to open after coal powder compaction.

[0050] Buffer storage bins 61 are respectively located outside the two auxiliary discharge chambers 51. Each buffer storage bin 61 has a buffer feed inlet 62 at its upper part, which is connected to the high-level area of ​​the corresponding auxiliary discharge chamber 51 through a short-circuit guide section. When the auxiliary discharge chamber 51 can discharge material in time, the coal is discharged to the downstream conveyor belt 2 along the auxiliary discharge port 53. When the coal bed in the auxiliary discharge chamber 51 rises and the buffer feed gate 63 is opened, the coal above the bottom edge of the buffer feed inlet 62 enters the buffer storage bin 61 through the short-circuit guide section, so that the buffer storage bin 61 only receives coal exceeding the immediate discharge capacity of the auxiliary discharge assembly 5.

[0051] A buffer feed gate 63 is rotatably mounted at the buffer feed inlet 62. Two buffer feed gates 63 are connected to the second rotating shaft 86 via transmission components. When the buffer feed gate 63 is closed, it seals the buffer feed inlet 62; when it is open, it makes way for the buffer storage silo 61. The effective area of ​​the buffer feed inlet 62 can be smaller than the effective area of ​​the connection between the auxiliary discharge chamber 51 and the main feed trough 4, allowing the coal to first be discharged to the downstream conveyor belt 2 through the auxiliary discharge assembly 5, and then the portion that cannot be discharged in time is guided into the buffer storage silo 61.

[0052] The pressure detection component 117 is located at the pressure detection position in the middle buffer section 42. The force-bearing surface of the movable pressure plate 71 interacts with the accumulated coal in the main feed trough 4, and a flexible dust cover is provided around the periphery of the movable pressure plate 71. The movable pressure plate 71 is positioned to avoid direct impact from the upstream coal flow, so that normally falling coal blocks will not continuously strike the movable pressure plate 71 head-on; when accumulation occurs at the bottom of the main feed trough 4, the accumulated coal exerts a continuous force on the movable pressure plate 71 under its own weight and the action of the subsequent coal flow.

[0053] The movable pressure plate 71 is connected to the sliding frame 72, which is slidably mounted on the transfer frame 3 along the pressure direction of the movable pressure plate 71 via a linear guide rail or guide sleeve. An elastic reset member 73 is disposed between the movable pressure plate 71 or the sliding frame 72 and the transfer frame 3, and a damping member 74 is disposed in parallel with the elastic reset member 73. The elastic reset member 73 determines the base pressure required for the movable pressure plate 71 to begin moving, and the damping member 74 limits the moving speed of the movable pressure plate 71 under short-term impact. Figure 3To clearly illustrate the action transmission relationship between the pressure detection component 117 and the sequential opening mechanism 8, the pressure direction is shown in a vertical format on the drawing. This expanded representation does not change the actual installation orientation of the movable pressure plate 71 on the main feed trough 4.

[0054] The displacement sensor 75 is fixed on the transfer frame 3, and its detection end corresponds to the movable pressure plate 71 or the sliding frame 72. The displacement sensor 75 can be a rod-type displacement sensor 75, a magnetostrictive displacement sensor 75, or a proximity switch group. When a continuous displacement sensor 75 is used, the controller 12 can obtain the real-time displacement of the movable pressure plate 71; when a proximity switch group is used, a first position switch, a second position switch, and an extreme position switch can be sequentially set along the moving direction of the sliding frame 72, corresponding to the first-level current amplification, second-level temporary storage, and extreme protection states, respectively.

[0055] A sequential opening mechanism 8 is installed between the sliding frame 72, the first rotating shaft 85, and the second rotating shaft 86. The first drive groove 81 and the second drive groove 82 are arranged along the moving direction of the sliding frame 72, and each drive groove sequentially includes a free travel section, a tilting drive section, and a holding section. A first follower 83 is installed on the swing arm of the first rotating shaft 85 and cooperates with the first drive groove 81, and a second follower 84 is installed on the swing arm of the second rotating shaft 86 and cooperates with the second drive groove 82. The follower can be a roller to reduce sliding friction in a coal dust environment.

[0056] The inclined drive section of the first drive groove 81 is closer to the initial position of the movable pressure plate 71 than the inclined drive section of the second drive groove 82. When the movable pressure plate 71 moves from its initial position toward the pressure direction, the first follower 83 first enters the inclined drive section of the first drive groove 81, and the first rotating shaft 85 rotates accordingly, opening the bleed gate 52; at this time, the second follower 84 is still in the idle stroke section of the second drive groove 82, and the buffer feed gate 63 remains closed. After the movable pressure plate 71 continues to move, the first follower 83 enters the holding section to maintain the opening of the bleed gate 52, and the second follower 84 enters the inclined drive section and opens the buffer feed gate 63.

[0057] The inclination angles of the first drive groove 81 and the second drive groove 82 can be determined according to the required opening force of the gate and the allowable stroke of the movable pressure plate 71. To prevent the gate from rebounding rapidly when the coal pressure is suddenly released, rotational damping structures can be installed on the first rotating shaft 85 and the second rotating shaft 86 respectively. When the sliding frame 72 returns to its original position, the second follower 84 first moves in the opposite direction along the second drive groove 82 and closes the buffer feed gate 63. Then, the first follower 83 moves in the opposite direction along the first drive groove 81 and closes the discharge gate 52, thereby stopping the feeding of material into the storage bin and restoring the normal straight-through state of the main feed chute 4.

[0058] The fixed silo body 64 constitutes the main cavity of the buffer storage silo 61. Its upper part forms a feeding area that communicates with the high-level area of ​​the auxiliary discharge chamber 51, and its lower part forms a transition area that converges towards the return outlet 68. Expanding guide walls that can move outward relative to the fixed silo body 64 are provided on both sides of its lower part. Figure 4 The expansion guide wall is supported and reset by the outer expansion swing arm 65, guide rod 66, and expansion reset assembly 67. Under normal conditions, the expansion reset assembly 67 keeps the expansion swing arm 65 in its initial position, the expansion guide wall is close to the fixed hopper 64, and the buffer storage hopper 61 maintains a small volume.

[0059] After the coal enters the buffer storage silo 61, it gradually pushes against the expansion guide wall. The expansion guide wall, through a transmission connection, drives the expansion swing arm 65 to move outward against the force of the expansion reset component 67, and the volume of the buffer storage silo 61 increases with the amount of coal stored. The maximum outward swing position of the expansion swing arm 65 is limited by a mechanical limiter, and the limit position corresponds to the upper limit of the allowable storage of the buffer storage silo 61. The storage level sensor 115 can detect the position of the expansion swing arm 65, and the controller 12 determines the state such as empty silo, normal storage, approaching the upper limit, and reaching the upper limit based on the position of the expansion swing arm 65.

[0060] The lower part of the fixed silo 64 is inclined towards the return outlet 68, and a guide liner 69 is provided on the inclined wall surface. The return outlet 68 has an effective width that allows the largest coal block designed to pass through, avoiding the formation of an excessively small hopper neck. The anti-bridging assembly 10 includes multiple loosening rods 101 disposed above the return outlet 68 and anti-bridging teeth 102 disposed near the outlet of the confluence guide chute 95. When the expansion swing arm 65 reciprocates or when the coal in the silo falls, the loosening rods 101 disturb the coal in the silo; when the coal passes through the confluence guide chute 95, the anti-bridging teeth 102 disperse the clumped coal.

[0061] The quantitative return component 9 is located between the return outlet 68 of the buffer storage silo 61 and the downstream belt 2. Figure 5 For ease of explanation, only one buffer storage bin 61 and its corresponding quantitative return assembly 9 are shown; the structure on the other side is symmetrically arranged. Return guides 92 are respectively arranged on both sides of the return outlet 68. Multiple unidirectional pushers 94 cooperate with the return guides 92 through swing arms or sliding seats. The return drive 93 drives the unidirectional pushers 94 to move periodically through a transmission shaft, connecting rod, or eccentric mechanism. Figure 5 The diagram shows a structure in which the return drive 93 is located on one side and synchronously drives the two unidirectional pushers 94 through the transverse transmission component.

[0062] The unidirectional pusher 94 has a pushing surface facing the confluence guide trough 95 and a clearance surface facing away from the confluence guide trough 95. During the pushing stroke, the unidirectional pusher 94 remains extended and moves the coal falling from the return outlet 68 towards the confluence guide trough 95; during the reset stroke, the unidirectional pusher 94 retracts to the clearance position under the reaction force of the coal or the action of the reset elastic element, returning from the side or below the coal to be returned. The controller 12 adjusts the return amount per unit time by changing the operating frequency of the return drive 93, so that the coal in the storage bin will not be discharged in a concentrated manner in a short period of time.

[0063] The return outlets 68 of the left and right buffer storage bins 61 feed materials to both sides of the confluence guide trough 95, the bottom of which slopes towards the middle of the downstream conveyor belt 2. A check plate 96 is installed at the outlet of the confluence guide trough 95. The check plate 96 makes way when the coal moves towards the downstream conveyor belt 2 and restricts the reverse movement of coal that has entered the confluence guide trough 95 when the unidirectional pusher 94 resets. The arch-breaking teeth 102 are located near the outlet of the confluence guide trough 95 to disperse the agglomerated coal that is about to fall onto the downstream conveyor belt 2. The outlet of the confluence guide trough 95 is located downstream of the main discharge port, so that the returned coal is staggered from the main coal flow on the belt surface.

[0064] The detection component 11 includes an upstream speed sensor 111, a downstream speed sensor 112, a coal seam thickness sensor 113, a high-level material level sensor 114, a storage capacity sensor 115, and a load detector 116. The upstream speed sensor 111 and the downstream speed sensor 112 can respectively detect the rotational speed of the corresponding belt-driven drum or driven drum. The coal seam thickness sensor 113 is installed above the downstream conveyor belt 2's material-bearing section and located downstream of the main discharge port and the outlet of the confluence guide chute 95 to detect the actual coal seam thickness after the coal has been transferred.

[0065] The high-level material level sensor 114 is installed near the upper receiving section 41 of the main feed chute 4. It can be a rocker arm level switch, an RF admittance level switch, or a radar level sensor installed through a wear-resistant window. The load detector 116 can read the current, torque, or inverter load rate of the downstream belt 2 drive motor. The controller 12 adopts a mine explosion-proof control box. The input terminals of the controller 12 are connected to the upstream speed sensor 111, the downstream speed sensor 112, the coal seam thickness sensor 113, the high-level material level sensor 114, the storage capacity sensor 115, the load detector 116, and the displacement sensor 75, respectively. The output terminals are connected to the return drive 93, the upstream belt 1 drive device, the downstream belt 2 drive device, and the audible and visual alarm, respectively. Figure 6 The module names are used to represent the signal relationships between each detection input, controller 12, and controlled output.

[0066] The controller 12 is pre-set with a first displacement threshold, a second displacement threshold, a limit displacement threshold, a reset displacement threshold, a return coal seam thickness threshold, a return load threshold, a storage upper limit, a recovery storage threshold, and a high-level duration. The first displacement threshold is less than the second displacement threshold, the second displacement threshold is less than the limit displacement threshold, and the reset displacement threshold is less than the first displacement threshold. By ensuring a hysteresis between the reset displacement threshold and the opening threshold, frequent state switching can be prevented when the movable pressure plate 71 reciprocates slightly near the threshold.

[0067] The control method of this device is described below. The control method is performed by controller 12 according to... Figure 7 The process is executed as shown. The mechanical sequential opening mechanism 8 is responsible for completing the sequential action of the discharge gate 52 and the buffer feed gate 63. The controller 12 coordinates and controls the return feed, belt speed and alarm based on the displacement of the movable pressure plate 71 and other detection results.

[0068] Step 1: Acquire operating parameters. Controller 12 periodically acquires the displacement of the movable pressure plate 71, the high-level material level of the main feed chute 4, the position of the movable expansion plate, the coal seam thickness of the downstream conveyor belt 2, the drive load of the downstream conveyor belt 2, and the operating speed of the upstream and downstream conveyor belts 2. The detection cycle is set according to the belt speed and the volume of the feed chute, enabling controller 12 to complete multiple status checks before the coal rises from the height of the auxiliary discharge port to the height of the high-level material sensor 114.

[0069] Step 2: Determine the primary flow amplification conditions. When the displacement of the movable pressure plate 71 is lower than the first displacement threshold, the controller 12 determines that the main feed trough 4 is in a normal straight-through state; when the displacement of the movable pressure plate 71 reaches the first displacement threshold, it determines that primary accumulation has occurred in the main feed trough 4, and allows the sequential opening mechanism 8 to enter the primary flow amplification action range.

[0070] Step 3: Perform primary flow expansion. After the movable pressure plate 71 reaches the first displacement threshold, the sliding frame 72 drives the discharge gate 52 to open via the first drive groove 81. Coal enters the auxiliary discharge channel from both sides of the main feed trough 4 and falls to the downstream conveyor belt 2 through the two auxiliary discharge ports 53. The greater the displacement of the movable pressure plate 71, the greater the distance the first follower 83 moves along the inclined drive section of the first drive groove 81, and the opening of the discharge gate 52 increases accordingly until the first follower 83 enters the holding section.

[0071] Step 4: Determine and execute secondary temporary storage. If the movable pressure plate 71 continues to move after the first-stage flow amplification and reaches the second displacement threshold, the second follower 84 enters the inclined drive section of the second drive groove 82, the buffer feed gate 63 gradually opens, and the coal material in the auxiliary discharge chamber 51 that exceeds the immediate discharge capacity enters the buffer storage bin 61, and the expansion swing arm 65 moves outward as the storage volume increases; if the movable pressure plate 71 does not reach the second displacement threshold, the first-stage flow amplification is maintained and the process returns to the operating parameter acquisition step.

[0072] Step 5: Perform quantitative return feeding. After the instantaneous high flow rate ends, the coal pressure in the main feed trough 4 decreases, and the movable pressure plate 71 returns to its original position under the action of the elastic reset component 73. After the displacement of the movable pressure plate 71 is lower than the reset displacement threshold and the high-level material level signal is released, the controller 12 determines whether the coal seam thickness and drive load of the downstream conveyor belt 2 are both lower than the corresponding return feeding threshold. When the return feeding conditions are met, the controller 12 starts the return feeding drive component 93, causing the unidirectional pusher component 94 to operate periodically at a lower frequency, sending the temporarily stored coal into the confluence guide trough 95.

[0073] During the return process, controller 12 determines the target return frequency based on the coal seam thickness margin and drive load margin of the downstream conveyor belt 2. When both the coal seam thickness and load are significantly lower than the allowable values, the operating frequency of the unidirectional pusher 94 is increased; when any parameter approaches the return threshold, the operating frequency is decreased; when any parameter reaches or exceeds the return threshold, the return is suspended. After suspending the return, the return continues only after the downstream conveyor belt 2 has conveying capacity again, until the storage capacity of the buffer storage bin 61 is reduced to an empty bin or the storage capacity threshold is restored.

[0074] Step Six: Execute Limit Protection. When the storage level sensor 115 detects that the buffer storage bin 61 has reached its upper storage limit and the high level of the main feed trough 4 remains, the controller 12 first reduces the speed of the upstream belt 1. After deceleration, if the displacement of the movable pressure plate 71 is lower than the reset displacement threshold, the high level signal is released, and the storage volume of the buffer storage bin 61 is lower than the recovery storage threshold, the controller 12 restores the normal speed of the upstream belt 1; if the high level continues to exceed the set time, the upstream belt 1 is stopped. The downstream belt 2 continues to run and continues to discharge coal from the buffer storage bin 61 when the return conditions are met.

[0075] After the upstream conveyor belt 1 stops, the controller 12 does not immediately stop the downstream conveyor belt 2. The downstream conveyor belt 2 continues to run and carries away the coal discharged from the main feed chute 4, auxiliary discharge chamber 51, and confluence feed chute 95. When the movable pressure plate 71 returns to the safe range, the high-level material level signal is released, and the storage capacity of the buffer storage bin 61 decreases to the preset safe storage capacity, the controller 12 allows the upstream conveyor belt 1 to be restarted. If the high-level material level signal is not released after the upstream conveyor belt 1 stops, the controller activates the audible and visual alarm to issue a manual inspection alarm, preventing forced resumption of operation if a large foreign object is obstructing the passage.

[0076] Working principle: During normal operation, the upstream conveyor belt 1 throws coal into the main feed chute 4, and the coal enters the downstream conveyor belt 2 along the lower discharge section 43. Since the movable pressure plate 71 does not bear the continuous accumulation force, the discharge gate 52 and the buffer feed gate 63 remain closed, the buffer storage bin 61 is in a contracted state, and the quantitative return assembly 9 stops. At this time, the main coal flow path of the device is short, and the additional energy consumption mainly comes from the detection and control unit.

[0077] When the high coal seam of the upstream conveyor belt 1 reaches the transfer point, the feed rate of the main feed chute 4 suddenly increases. The lower discharge section 43 cannot discharge all the coal at the same time, and the coal seam rises from bottom to top, causing the movable pressure plate 71 to move. After the discharge gate 52 opens first, some coal is discharged along the auxiliary discharge chambers 51 on both sides. The main discharge port and the auxiliary discharge port 53 work together, and the throughput capacity of the transfer point is increased immediately. If the peak duration is short, the movable pressure plate 71 returns directly to its original position after the force of the coal decreases, and the buffer storage bin 61 does not need to be fed a large amount of material.

[0078] When the peak duration is prolonged, the movable pressure plate 71 moves further and opens the buffer feed gate 63. Coal that cannot be discharged from the auxiliary discharge chamber 51 in time enters the buffer storage bin 61, and the expansion swing arm 65 moves outward, temporarily separating coal exceeding the immediate receiving capacity of the downstream conveyor belt 2 from the continuous coal flow. Due to the symmetrical arrangement of the left and right buffer storage bins 61, the additional load on the transfer frame 3 is relatively balanced.

[0079] After the peak occurs, the movable pressure plate 71 returns to its original position, and the buffer feed gate 63 closes first to prevent normal coal flow from continuing into the buffer storage silo 61; then the discharge gate 52 closes, restoring the main feed chute 4 to direct flow. The controller 12 waits for the coal seam thickness and drive load of the downstream conveyor belt 2 to decrease before starting the quantitative return component 9. The temporarily stored coal is returned at a flow rate less than the remaining conveying capacity of the downstream conveyor belt 2, filling the low-load interval after the peak in time, thus achieving peak shaving and valley filling.

[0080] The core of this invention lies in converting the force changes caused by coal accumulation into sequential flow amplification and temporary storage actions, and quantitatively returning the temporarily stored coal based on the remaining capacity of the downstream conveyor belt 2 after the peak is cleared. The specific materials, drive methods, and sensor types of each component can be selected according to the mine's explosion-proof rating, conveyor belt specifications, coal particle size, and installation space. As long as the above structural relationships, action sequences, and control logic are maintained, the technical solution of this invention can be implemented.

Claims

1. A mining belt auxiliary transfer device, disposed between the unloading end of an upstream belt (1) and the receiving section of a downstream belt (2), comprising a transfer frame (3) and a main feed chute (4) installed on the transfer frame (3), characterized in that, It also includes an auxiliary discharge assembly (5), a buffer storage assembly (6), a pressure detection assembly (11) (7), a sequential opening mechanism (8), a quantitative return assembly (9), and a controller (12); the main feed trough (4) is provided with auxiliary discharge cavities (51) on both sides, which are connected to the side of the main feed trough (4). The auxiliary discharge assembly (5) includes two auxiliary discharge cavities (51) and two discharge gates (52). Each auxiliary discharge cavity (51) forms an auxiliary discharge port (53) at the bottom; the buffer storage assembly (6) includes two buffer storage bins (61) and two buffer feed gates (63). Each buffer storage bin (61) is connected to the high-level area of ​​the corresponding auxiliary discharge cavity (51) through a buffer feed port (62); the pressure detection assembly (7) includes an auxiliary discharge cavity (51) (51) (62), a buffer storage silo (61) (62), a buffer feed gate (63), a pressure detection assembly (11), a sequential opening mechanism (8), a quantitative return assembly (9), and a controller (12); The detection components (11) (7) include a movable pressure plate (71); the sequential opening mechanism (8) connects the movable pressure plate (71), two bleed gates (52) and two buffer feed gates (63), and is used to open the two bleed gates (52) first and then open the two buffer feed gates (63) simultaneously when the movable pressure plate (71) moves under the action of the accumulated coal; the quantitative return component (9) is set between the return outlet (68) of the buffer storage bin (61) and the downstream belt (2), and is used to send the temporarily stored coal back to the downstream belt (2); the controller (12) is connected to the driving devices of the pressure detection components (11) (7), the quantitative return component (9) and the upstream and downstream belts (2) respectively.

2. The auxiliary transfer device for mining belts according to claim 1, characterized in that, The main feed trough (4) includes an upper receiving section (41), a middle buffer section (42) and a lower discharge section (43) in sequence along the direction of coal movement. The extension length of the middle buffer section (42) along the direction of coal movement is greater than that of the upper receiving section (41) along the direction of coal movement. The lower discharge section (43) is inclined towards the conveying direction of the downstream belt (2). The two auxiliary discharge chambers (51) extend from the middle buffer section (42) to the outside of the main feed trough (4), and the two auxiliary discharge ports (53) are staggered relative to the main discharge port of the lower discharge section (43) along the conveying direction of the downstream belt (2).

3. The auxiliary transfer device for mining belts according to claim 2, characterized in that, The pressure detection assembly (11) (7) also includes a sliding frame (72), an elastic reset component (73), a damping component (74), and a displacement sensor (75). The movable pressure plate (71) is located at the pressure detection position of the middle buffer section (42) and moves along the pressure direction. The sliding frame (72) is connected to the movable pressure plate (71) and is slidably installed on the transfer frame (3) along the pressure direction. The elastic reset component (73) and the damping component (74) are respectively connected to the sliding frame (72) and the transfer frame (3). The displacement sensor (75) is used to detect the displacement of the movable pressure plate (71) or the sliding frame (72) relative to the transfer frame (3).

4. The auxiliary transfer device for mining belts according to claim 3, characterized in that, The sequential opening mechanism (8) includes a first drive groove (81) and a second drive groove (82) disposed on the sliding frame (72), a first follower (83), a second follower (84), a first rotating shaft (85), and a second rotating shaft (86); the first rotating shaft (85) is drivenly connected to two bleed gates (52), and the second rotating shaft (86) is drivenly connected to two buffer feed gates (63); the first follower (83) is disposed on the first rotating shaft (85) and cooperates with the first drive groove (81), and the second follower (84) is disposed on the second rotating shaft (86) and cooperates with the second drive groove (82); the effective drive section of the first drive groove (81) is located before the effective drive section of the second drive groove (82) along the moving direction of the sliding frame (72), so that the two bleed gates (52) open before the two buffer feed gates (63).

5. The auxiliary transfer device for mining belts according to claim 4, characterized in that, Both the first drive groove (81) and the second drive groove (82) include an idle stroke section, an inclined drive section and a holding section arranged sequentially along the moving direction of the sliding frame (72). The sliding frame (72) drives the discharge gate (52) to gradually open through the first drive groove (81) in the first displacement range, and drives the buffer feed gate (63) to gradually open through the second drive groove (82) in the second displacement range after the first displacement range. The holding section is used to maintain the open state of the corresponding gate when the sliding frame (72) continues to move.

6. The auxiliary transfer device for mining belts according to claim 1, characterized in that, The buffer storage bin (61) includes a fixed bin body (64), an expansion swing arm (65), a guide rod (66), and an expansion reset assembly (67). The lower two sides of the fixed bin body (64) are respectively provided with expansion guide walls that can move outward relative to the fixed bin body (64). The expansion swing arm (65) is located outside the fixed bin body (64) and is connected to the corresponding expansion guide wall. The guide rod (66) is used to limit the movement trajectory of the expansion swing arm (65). The expansion reset assembly (67) is used to reset the expansion swing arm (65) and the expansion guide wall when the storage amount decreases. The buffer feed inlet (62) is located on the upper part of the fixed bin body (64), and the buffer feed gate (63) is rotatably located at the buffer feed inlet (62). The lower part of the buffer storage bin (61) is provided with a return outlet (68), and a release rod (101) is provided above the return outlet (68).

7. The auxiliary transfer device for mining belt conveyors according to claim 6, characterized in that, The quantitative return assembly (9) includes a return guide (92), a return drive (93), multiple unidirectional pushers (94), a confluence guide trough (95), and a check plate (96). The return guide (92) is located on both sides of the return outlet (68). The return drive (93) is used to drive multiple unidirectional pushers (94) to periodically move along the return guide (92) between the push position and the avoidance position. When the unidirectional pusher (94) is in the push position, it pushes the coal discharged from the return outlet (68) toward the confluence guide trough (95). When it is in the avoidance position, it avoids the coal to be returned. The confluence guide trough (95) is located between the return outlet (68) and the downstream belt (2), and its outlet faces the middle of the width direction of the downstream belt (2). The check plate (96) is located at the outlet of the confluence guide trough (95). An arch-breaking tooth (102) is provided near the outlet of the confluence guide trough (95).

8. The auxiliary transfer device for mining belts according to claim 7, characterized in that, It also includes a detection component (11), which includes an upstream speed sensor (111), a downstream speed sensor (112), a coal seam thickness sensor (113), a high-level material sensor (114), a storage capacity sensor (115), and a load detector (116). The high-level material sensor (114) is located at the top of the main feed trough (4), the storage capacity sensor (115) is used to detect the position of the movable expansion plate, the coal seam thickness sensor (113) is located above the material-bearing section of the downstream belt (2), and the load detector (116) is used to obtain the load of the downstream belt (2) drive device. The controller (12) controls the return drive (93), the upstream belt (1) drive device, the downstream belt (2) drive device, and the audible and visual alarm (13) according to the detection results of the displacement sensor (75) and the detection component (11).

9. A control method for a mining belt auxiliary transfer device, applied to a mining belt auxiliary transfer device including a main feed trough (4), a discharge gate (52), a buffer feed gate (63), a buffer storage bin (61), a movable pressure plate (71), a sequential opening mechanism (8), a quantitative return assembly (9), a displacement sensor (75), a high-level material level sensor (114), a storage quantity sensor (115), a coal seam thickness sensor (113), and a load detector (116), characterized in that, include: The system acquires the displacement of the active pressure plate (71), the high level of the main feed trough (4), the storage capacity of the buffer storage bin (61), the coal seam thickness of the downstream conveyor belt (2), the driving load of the downstream conveyor belt (2), and the running speed of the upstream and downstream conveyor belts (2). When the active pressure plate (71) moves to the position corresponding to the first displacement threshold, the sequential opening mechanism (8) drives the discharge gate (52) to open, allowing some coal to be discharged to the downstream conveyor belt (2) through the auxiliary discharge component (5). When the active pressure plate (71) moves to the position corresponding to the second displacement threshold, which is greater than the first displacement threshold, the sequential opening mechanism (8) drives the buffer feed gate (63) to open, allowing the excess coal to be discharged to the downstream conveyor belt (2). Coal that has passed the discharge capacity of the auxiliary discharge component (5) enters the buffer storage bin (61); when the displacement of the movable pressure plate (71) decreases to below the reset displacement threshold, and the coal seam thickness and driving load of the downstream belt (2) are both lower than the corresponding return threshold, the quantitative return component (9) controls the temporary coal to be sent back to the downstream belt (2) in batches; when the buffer storage bin (61) reaches the upper limit of storage and the high level of the main material trough (4) continues to exist, the speed of the upstream belt (1) is reduced first. If the displacement of the movable pressure plate (71), the high level of material and the storage amount of the buffer storage bin (61) do not recover to the corresponding recovery conditions after deceleration, the upstream belt (1) is stopped.

10. The control method according to claim 9, characterized in that, The first displacement threshold, the second displacement threshold, the reset displacement threshold, and the recovery storage threshold constitute the graded control thresholds. The reset displacement threshold is less than the first displacement threshold. The operating frequency of the quantitative return component (9) is determined based on the thickness margin formed by the difference between the allowable coal seam thickness and the measured coal seam thickness, and the load margin formed by the difference between the allowable load and the measured driving load. Return is suspended when any margin is not greater than zero. After the upstream belt (1) decelerates, when the displacement of the movable pressure plate (71) is lower than the reset displacement threshold, the high-level material level signal is released, and the storage volume of the buffer storage bin (61) is lower than the recovery storage threshold, the normal speed of the upstream belt (1) is restored. If the high-level material level continues to exceed the set time after deceleration, the upstream belt (1) is stopped, and the downstream belt (2) continues to run until the coal in the main feed trough (4) and the buffer storage bin (61) is reduced to the preset safe storage volume.

Images