Chain automatic tensioning method

Abstract

The application provides a chain automatic tensioning method for a scraper conveyor, the scraper conveyor comprising a telescopic oil cylinder and a tail, a middle trough and a head connected in sequence along a coal conveying direction, chain wheels arranged at the head and the tail and used for winding chains, the method comprising: acquiring a real-time conveying capacity of the scraper conveyor; calculating a pre-tightening force of the chain and a theoretical pressure strength of the telescopic oil cylinder based on the real-time conveying capacity; controlling movement of the telescopic oil cylinder based on the theoretical pressure strength; detecting an instantaneous tension of the chain; comparing the instantaneous tension with the pre-tightening force in real time, and adjusting a working state of the telescopic oil cylinder based on a comparison result. Thus, the tensioning degree of the chain can be accurately controlled, problems such as accumulation, chain breakage or chain jamming caused by the chain being too loose can be avoided, excessive wear and damage of equipment caused by the chain being too tight can be prevented, and the stability and reliability of the scraper conveyor operation are greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of scraper conveyors, and particularly relates to a chain automatic tensioning method. BACKGROUND

[0002] As a key transport equipment of a fully mechanized coal mining face in a coal mine, a scraper conveyor has a working principle that torque generated by a motor is transmitted to a sprocket shaft set via a speed reducer, so as to pull a scraper chain to move, and a closed chain traction system is constructed. Under the action of the system, coal is brought from a tail to a head, and is transferred to a transfer machine after reaching the head, so that the coal is transported out of the working face.

[0003] The scraper chain, that is, the chain, is an elastic body, and will be elastically elongated after being subjected to a pulling force in the running process. The elongation will cause the chain to be relaxed at a meshing and separating position of the chain and the sprocket, and even possibly accumulated, thereby causing chain breaking and chain jamming accidents. Therefore, in the use process of the scraper conveyor, a certain pre-tightening force needs to be applied to the chain. However, in actual use, the elastic elongation of the chain is often difficult to effectively control, so that the chain is difficult to be in an ideal tensioning state. SUMMARY

[0004] Therefore, the technical problem to be solved by the application is to provide a chain automatic tensioning method, which adjusts the working state of a telescopic oil cylinder by comparing an instantaneous tension of a chain with a pre-tightening force in real time, so as to ensure that the chain is always in a relatively ideal tensioning state, and reduces equipment failures and running fluctuations caused by improper tensioning of the chain.

[0005] In order to solve the above problems, the application provides a chain automatic tensioning method for a scraper conveyor, the scraper conveyor comprising a telescopic oil cylinder and a tail, a middle trough and a head connected in sequence in a coal transportation direction, the head and the tail being provided with sprockets for winding a chain, and the method comprising:

[0006] Obtaining a real-time transportation amount of the scraper conveyor;

[0007] Calculating a pre-tightening force of the chain and a theoretical pressure strength of the telescopic oil cylinder based on the real-time transportation amount;

[0008] Controlling movement of the telescopic oil cylinder based on the theoretical pressure strength;

[0009] Detecting an instantaneous tension of the chain;

[0010] Comparing the instantaneous tension with the pre-tightening force in real time, and adjusting the working state of the telescopic oil cylinder based on a comparison result.

[0011] Optionally, the pre-tightening force of the chain meets a formula:

[0012]

[0013] In the formula, T0 is the pre-tightening force of the chain; S1 is the theoretical tension of the chain at the outgoing point of the sprocket arranged at the tail; S2 is the theoretical tension of the chain at the incoming point of the sprocket arranged at the tail; S3 is the theoretical tension of the chain at the outgoing point of the sprocket arranged at the head; and S4 is the theoretical tension of the chain at the incoming point of the sprocket arranged at the head.

[0014] Optionally, S1 is in the range of 2-3 kN.

[0015] S2 satisfies the formula:

[0016]

[0017] In the formula, k is the resistance coefficient of the chain around the sprocket. r

[0018] S3 satisfies the formula:

[0019] S3 = S2 - Lq0 (μ * cos β ± sin β)

[0020] In the formula, L is the laying length of the scraper conveyor; q0 is the weight per unit length of the chain; μ * is the equivalent friction coefficient of the lower chain of the scraper conveyor; and β is the inclination angle of the working surface of the scraper conveyor.

[0021] S4 satisfies the formula:

[0022] S4 = S1 + Lq (μ * cos β ± sin β)

[0023] In the formula, q is the coal load per unit length of the scraper conveyor; and μ * is the equivalent friction coefficient of the upper chain of the scraper conveyor.

[0024] Optionally, the equivalent friction coefficient μ * of the lower chain of the scraper conveyor satisfies the formula:

[0025]

[0026] The equivalent friction coefficient μ * of the upper chain of the scraper conveyor satisfies the formula:

[0027]

[0028] ​In the formula, V is the movement speed of the chain; γ is the efficiency loss of the telescopic oil cylinder; h is the coal loading height of the scraper conveyor;

[0029] The coal loading height h of the scraper conveyor meets the formula:

[0030]

[0031] In the formula, B is the slot width of the middle slot; h1 is the slot depth of the middle slot;

[0032] The coal load per unit length q of the scraper conveyor meets the formula:

[0033]

[0034] In the formula, W is the real-time traffic volume of the scraper conveyor; g is the acceleration of gravity.

[0035] Optionally, a plurality of middle slots are arranged, and each of the plurality of middle slots is provided with a coal quantity scanner, and the coal quantity scanner is used to acquire the real-time traffic volume of the scraper conveyor.

[0036] The interval distance between adjacent two coal quantity scanners is the slot length of the middle slot.

[0037] Optionally, the theoretical pressure strength of the telescopic oil cylinder meets the formula:

[0038]

[0039] In the formula, n is the number of the telescopic oil cylinder; D is the inner diameter of the telescopic oil cylinder; γ is the efficiency loss of the telescopic oil cylinder.

[0040] Optionally, the instantaneous tension of the chain meets the formula:

[0041]

[0042] In the formula, is the instantaneous tension of the chain; is the actual tension of the unwinding point of the sprocket arranged at the tail of the chain; is the actual tension of the winding point of the sprocket arranged at the tail of the chain; is the actual tension of the unwinding point of the sprocket arranged at the head of the chain; is the actual tension of the winding point of the sprocket arranged at the head of the chain;

[0043] In the formula, and both meet the formula:

[0044] F = AEe

[0045] In the formula, F is the tension; A is the cross-sectional area of the chain; E is the modulus of elasticity of the chain; and e is the strain value of the chain.

[0046] Optionally, the scraper conveyor further comprises a tension detection module, which is configured to sense the strain values at the positions of the chain wheels arranged at the tail end and the head end of the chain.

[0047] The chain comprises a plurality of steel rings, and the tension detection module comprises at least two wireless receivers, a plurality of wireless collectors and a plurality of strain sensors. The at least two wireless receivers are arranged at the tail end and the head end of the chain respectively, and the plurality of wireless collectors and the plurality of strain sensors are arranged on the plurality of steel rings in one-to-one correspondence.

[0048] Optionally, the method further comprises:

[0049] comparing the instantaneous tension with a preset setting interval in real time.

[0050] If the instantaneous tension is within the preset setting interval, the extension amount of the telescopic cylinder is kept unchanged; if the instantaneous tension is greater than the upper limit value of the preset setting interval, the extension amount of the telescopic cylinder is controlled to decrease; and if the instantaneous tension is less than the lower limit value of the preset setting interval, the extension amount of the telescopic cylinder is controlled to increase.

[0051] The preset setting interval is T0±⊿T, and ⊿T = 10% T0.

[0052] Optionally, before the method of obtaining the real-time conveying capacity of the scraper conveyor, the method further comprises:

[0053] determining whether the scraper conveyor is in a running state or a stopped state; if the scraper conveyor is in the stopped state, controlling the telescopic cylinder to be completely retracted; and if the scraper conveyor is in the running state, controlling the scraper conveyor to enter an automatic tensioning mode.

[0054] Advantages

[0055] The chain automatic tensioning method provided in the embodiments of the present application can accurately control the tensioning degree of the chain by acquiring the conveying capacity of the scraper conveyor in real time and calculating the chain pre-tightening force and the theoretical pressure strength of the telescopic oil cylinder, thereby avoiding problems such as accumulation, chain breakage or chain jamming due to the chain being too loose, preventing the equipment from being excessively worn and damaged due to the chain being too tight, and greatly improving the stability and reliability of the operation of the scraper conveyor. Meanwhile, the instantaneous tension of the chain is compared with the pre-tightening force in real time, and the working state of the telescopic oil cylinder is adjusted according to the comparison result, so as to ensure that the chain is always in the best tensioning state, reduce the probability of equipment failure, and prolong the service life of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0056] Fig. 1 Flow chart of the chain automatic tensioning method of an optional embodiment of the present application;

[0057] Fig. 2 Structure schematic diagram of the tail of the scraper conveyor of an optional embodiment of the present application;

[0058] Fig. 3 Structure schematic diagram of the middle trough of the scraper conveyor of an optional embodiment of the present application;

[0059] Fig. 4 Structure schematic diagram of the tension detection module of an optional embodiment of the present application.

[0060] The reference signs are as follows:

[0061] 1, telescopic oil cylinder; 2, chain wheel; 3, telescopic frame body; 4, fixed trough body; 5, coal quantity scanner; 6, tension detection module; 61, wireless receiver; 62, wireless collector; 63, strain sensor. DETAILED DESCRIPTION

[0062] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0063] In addition, the terms "first", "second", "third", etc. are used herein only to describe different instances, and are not used to indicate or imply relative importance or a number of indicated technical features. Thus, features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0064] In the present application, unless otherwise explicitly and specifically defined, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0066] For reference Figs. 1 to 4 As shown, according to the embodiments of the present application, a chain automatic tensioning method is provided for a scraper conveyor, the scraper conveyor includes a telescopic oil cylinder 1 and a tail, a middle trough and a head connected in sequence along the coal conveying direction, the head and the tail are both provided with a sprocket 2, and the sprocket 2 is used to wrap a chain.

[0067] Among them, the middle trough is the conveying trough body of the scraper conveyor, and the middle trough is used to provide a stable channel for coal and other materials.

[0068] Specifically, a driving motor is arranged at the head, and an auxiliary motor is arranged at the tail. The chain is installed inside the middle trough, and under the cooperative action of the driving motor and the auxiliary motor, the chain moves circularly along the middle trough, and drives the scraper to convey the coal and other materials from the tail to the head.

[0069] Among them, the sprocket 2 includes a driving sprocket and a driven sprocket, the driving sprocket is installed at the head, and the driven sprocket is installed at the tail. The driving sprocket and the driven sprocket are engaged with the chain, and the power of the driving motor and the auxiliary motor is transmitted to the chain to drive the scraper to move.

[0070] Among them, the tail is also provided with a telescopic oil cylinder 1, and the telescopic oil cylinder 1 is used to adjust the position of the tail, so as to change the tension degree of the chain.

[0071] Specifically, the tail includes a fixed groove body 4 and an extension frame body 3, the fixed groove body 4 and the extension frame body 3 are overlapped with each other along the material conveying direction, the extension oil cylinder 1 is arranged on the fixed groove body 4, the fixed groove body 4 is fixed relative to the cylinder body of the extension oil cylinder 1, and the driving end of the extension oil cylinder 1 is connected with the extension frame body 3. In actual application, when the driving end of the extension oil cylinder 1 is lengthened, the extension frame body 3 is driven to move towards the direction away from the fixed groove body 4, so that the tension of the chain is increased; when the driving end of the extension oil cylinder 1 is shortened, the extension frame body 3 is driven to move towards the direction close to the fixed groove body 4, so that the tension of the chain is reduced.

[0072] The automatic chain tensioning method comprises the following steps.

[0073] Step S1: acquiring the real-time conveying capacity of the scraper conveyor.

[0074] The coal quantity scanner 5 can be arranged above the middle trough, and the coal quantity scanner 5 can scan the coal quantity passing through the middle trough in real time, so as to accurately acquire the real-time conveying capacity of the scraper conveyor.

[0075] It can be understood that, since the scraper conveyor has a long laying length, the coal loading quantity on the scraper conveyor changes when the shearer is walking and cutting coal on the scraper conveyor. It is difficult to scan the real-time coal loading quantity on the entire scraper conveyor through a fixed point, and the application adopts a multi-point laser scanning method to determine the real-time coal loading quantity of the scraper conveyor, thereby providing a basis for automatic chain tensioning control. Specifically, in actual application, a plurality of middle troughs are arranged, and a plurality of coal quantity scanners 5 are arranged, the plurality of coal quantity scanners 5 are arranged in one-to-one correspondence with the plurality of middle troughs, and the interval distance between two adjacent coal quantity scanners 5 is the length of the middle trough.

[0076] The coal quantity scanner 5 can be a laser coal quantity scanner, which emits a laser beam and receives a signal reflected from the coal and other materials, calculates the distance L between the coal and other materials and the laser coal quantity scanner i In the case where the distance H between the laser coal quantity scanner and the middle trough middle plate is known, the accumulation height H of the coal and other materials can be determined i = H-L i Finally, the real-time conveying capacity W of the scraper conveyor is calculated.

[0077] Specifically, the cross-sectional view of the coal and other materials can be divided into a plurality of small strips with a width of b, and the height H of the center of each small strip is accumulated i Then, the width of the small strip is multiplied, so that the area A of the cross-sectional surface of the coal and other materials is determined iThe total length of the scraper conveyor is L, the interval distance of two adjacent laser coal quantity scanners is l, the number of the laser coal quantity scanners is m=L / l, and the total volume V of the coal or other materials transported on the scraper conveyor satisfies the formula:

[0078]

[0079] The total weight Q of the coal or other materials transported on the scraper conveyor satisfies the formula:

[0080]

[0081] The real-time transport capacity W of the scraper conveyor satisfies the formula:

[0082] W=Q

[0083] Wherein, A i satisfies the formula:

[0084] A i =∑b H i =∑b(H-L i )

[0085] Specifically, the real-time transport capacity W of the scraper conveyor satisfies the formula:

[0086]

[0087] In the formula, p is the specific gravity of the coal or other materials, and is 0.9 t / m3; b is the width of the small strip, and is 0.01 m; L is the total length of the scraper conveyor, and is 300 m; l is the length of the middle trough, and is 1.75 m; H is the distance between the laser coal quantity scanner and the middle trough plate of the scraper conveyor, and is 2 m; L i is the distance between the coal or other materials and the laser coal quantity scanner, and is 1.3-1.7 m.

[0088] In this embodiment, the real-time transport capacity W of the scraper conveyor is calculated by step S1 to be 2500 t / h.

[0089] Step S2: Calculate the pre-tightening force of the chain and the theoretical pressure strength of the telescopic oil cylinder 1 based on the real-time transport capacity.

[0090] Wherein, in order to compensate the elastic elongation of the chain under tension during operation, the pre-tightening force T0 can be applied to the chain by the telescopic oil cylinder 1 before the scraper conveyor is running, and the chain produces an elastic elongation ΔL0 under the action of the pre-tightening force T0. If the elastic elongation of the chain under the normal load of the scraper conveyor is denoted as ΔL, then ΔL and ΔL0 have the following relationship: when ΔL < ΔL0, the chain maintains a certain pre-tightening force and will not relax, but the chain is too tight, which will lead to increased power consumption and wear of the scraper conveyor, and even cause chain breakage and other accidents; when ΔL = ΔL0, the pre-tightening force just eliminates the elastic elongation ΔL of the chain during normal operation, and the chain is properly tight; when ΔL > ΔL0, the chain will relax, affecting the normal operation of the conveyor, and in severe cases, even the chain will be twisted and broken.

[0091] Specifically, the pre-tightening force T0 of the chain conforms to the formula:

[0092]

[0093] Wherein, S1 is the theoretical tension of the winding-out point of the driven sprocket at the tail of the chain, and the value of S1 is 2-3kN.

[0094] Wherein, S2 is the theoretical tension of the winding-in point of the driven sprocket at the tail of the chain, and S2 conforms to the formula:

[0095]

[0096] In the formula, k r is the resistance coefficient of the chain winding through the driving sprocket and the driven sprocket, and the value is 0.045.

[0097] Wherein, S3 is the theoretical tension of the winding-out point of the driving sprocket at the head of the chain, and S3 conforms to the formula:

[0098] S3 = S2 - Lq0(μ * cosβ±sinβ)

[0099] In the formula, L is the laying length of the scraper conveyor, and the value is 300m; q0 is the weight per unit length of the chain, and the value is 1840N / m; β is the inclination angle of the working surface of the scraper conveyor, and the value is 0 degrees; μ * is the equivalent friction coefficient of the lower chain of the scraper conveyor.

[0100] Specifically, the equivalent friction coefficient μ * of the lower chain of the scraper conveyor conforms to the formula:

[0101]

[0102] It should be noted that when the lower chain of the scraper conveyor is sealed at the bottom, μ* = 0.3-0.4; when the lower chain track of the scraper conveyor is not sealed at the bottom, μ * = 0.5-0.95.

[0103] Wherein, S4 is the theoretical tension of the entry point of the chain at the head of the driving sprocket, S4 conforms to the formula:

[0104] S4 = S1 + Lq(μ * cosβ±sinβ)

[0105] In the formula, μ * is the equivalent friction coefficient of the upper chain of the scraper conveyor; q is the coal load per unit length of the scraper conveyor.

[0106] Specifically, the equivalent friction coefficient μ * of the upper chain of the scraper conveyor conforms to the formula:

[0107]

[0108] In the formula, V is the movement speed of the chain, taking a value of 1.8 m / s; γ is the efficiency loss of the telescopic oil cylinder 1, taking a value of 0.8; h is the coal loading height of the scraper conveyor;

[0109] The coal loading height h of the scraper conveyor conforms to the formula:

[0110]

[0111] In the formula, B is the slot width of the middle slot, taking a value of 1 m; h1 is the slot depth of the middle slot, taking a value of 0.145 m;

[0112] The coal load per unit length q of the scraper conveyor conforms to the formula:

[0113]

[0114] In the formula, g is the acceleration of gravity, taking a value of 9.80 m / s 2 ; V is the movement speed of the chain, taking a value of 1.8 m / s; W is the real-time capacity of the scraper conveyor, which is calculated by step S1 to be W = 2500 t / h.

[0115] It can be understood that T0 = nF, n is the number of telescopic oil cylinders 1 at the tail, and F is the thrust of a single telescopic oil cylinder 1.

[0116] In the formula, the thrust F of a single telescopic oil cylinder 1 conforms to the formula:

[0117]

[0118] Then Since The theoretical pressure strength P of the single telescopic oil cylinder 1 is derived according to the formula:

[0119]

[0120] In the formula, n is the number of telescopic oil cylinders 1 at the tail of the machine, and is 2; D is the inner diameter of the telescopic oil cylinder 1; and γ is the efficiency loss of the telescopic oil cylinder 1, and is 0.8.

[0121] In this embodiment, the theoretical pressure strength P of the single telescopic oil cylinder 1 is calculated according to step S2, and is 3 MPa.

[0122] Step S3: Controlling the movement of the telescopic oil cylinder 1 based on the theoretical pressure strength.

[0123] It can be understood that controlling the movement of the telescopic oil cylinder 1 based on the theoretical pressure strength can ensure that the chain tension is in a theoretically ideal tension state.

[0124] Step S4: Detecting the instantaneous tension of the chain.

[0125] In the formula, the instantaneous tension of the chain is consistent with the formula:

[0126]

[0127] In the formula, is the instantaneous tension of the chain; is the actual tension of the chain at the exit point of the driven sprocket; is the actual tension of the chain at the entry point of the driven sprocket; is the actual tension of the chain at the exit point of the driving sprocket; and is the actual tension of the chain at the entry point of the driving sprocket.

[0128] In the formula, and are consistent with the formula:

[0129] F = AEε

[0130] In the formula, F is the tension, used to represent and A is the cross-sectional area of the chain, for a chain with a regular shape, such as a chain composed of circular steel rings, the cross-sectional area of the chain can be calculated by measuring the diameter of the steel ring and using the area formula of a circle (S = πr 2 , where r is the radius); E is the elastic modulus of the chain, and is 210 GPa; and ε is the strain value of the chain.

[0131] The scraper conveyor further comprises a tension detection module 6. The tension detection module 6 is used to respectively sense the strain values at the outfeed point and the infed point of the driven sprocket and the outfeed point and the infed point of the driving sprocket in the chain, and then is brought into the formula F = AEε for calculation to obtain and Further determine the instantaneous tension of the chain in actual application

[0132] Specifically, the chain comprises a plurality of steel rings, the tension detection module 6 comprises at least two wireless receivers 61 and a plurality of wireless collectors 62 and a plurality of strain sensors 63, the at least two wireless receivers 61 are respectively arranged at the head and the tail, and the plurality of wireless collectors 62 and the plurality of strain sensors 63 are arranged on the plurality of steel rings in one-to-one correspondence.

[0133] It can be understood that the wiring groove and the sunken groove can be machined on the steel ring, the wiring groove is used for the arrangement of the cable, the sunken groove is used for the installation of the wireless collector 62, and the patch area is polished and machined on the outer side of the straight section of the steel ring and is used for the installation of the strain sensor 63. The wireless receiver 61 is respectively installed at the head and the tail of the scraper conveyor. In actual application, the strain generated by the force during the operation of the chain can be detected by the strain sensor 63, and the chain strain value ε is transmitted to the wireless collector 62 through the cable. After the wireless collector 62 acquires the data, the data is sent to the wireless receiver 61 in a wireless manner. Since the wireless transmission mode has a transmission distance limit, the wireless receiver 61 can only collect the strain value ε of the chain at the head and the tail.

[0134] Further, in order to fully realize the scheme proposed in the present application, the scraper conveyor further comprises a data analysis control module. The wireless receiver 61 transmits data to the data analysis control module through Ethernet. The data analysis control module is used for analyzing and processing data.

[0135] Step S5: Real-time comparison of the instantaneous tension and the pre-tightening force, adjustment of the working state of the telescopic oil cylinder 1 based on the comparison result.

[0136] The real-time comparison of the instantaneous tension and the pre-tightening force and the adjustment of the working state of the telescopic oil cylinder 1 based on the comparison result comprise: real-time comparison of the instantaneous tension and a preset setting interval; in the case that the instantaneous tension is in the preset setting interval, the telescopic cylinder is kept unchanged; in the case that the instantaneous tension is greater than the upper limit value of the preset setting interval, the telescopic oil cylinder 1 is controlled to reduce the extension amount; and in the case that the instantaneous tension is less than the lower limit value of the preset setting interval, the telescopic oil cylinder 1 is controlled to increase the extension amount.

[0137] Specifically, the instant tension within the preset setting interval is used to represent that the chain is in an ideal tension state, the pressure of the telescopic oil cylinder 1 is maintained unchanged, and the telescopic oil cylinder 1 stops moving; the instant tension greater than the upper limit value of the preset setting interval is used to represent that the chain is too tight, the pressure of the telescopic oil cylinder 1 is reduced, the telescopic oil cylinder stroke is controlled to be reduced, and the extension amount is reduced; the instant tension less than the lower limit value of the preset setting interval is used to represent that the chain is too loose, the pressure of the telescopic oil cylinder 1 is increased, the telescopic oil cylinder stroke is controlled to be increased, and the extension amount is increased.

[0138] The preset setting interval is T0±⊿T, and ⊿T=10%T0.

[0139] Specifically, if the chain is in an ideal tension state, the pressure of the telescopic oil cylinder 1 is maintained unchanged, and the telescopic oil cylinder 1 stops moving; if the chain is too tight, the pressure of the telescopic oil cylinder 1 is reduced, the telescopic oil cylinder stroke is controlled to be reduced, and the extension amount is reduced; if the chain is too loose, the pressure of the telescopic oil cylinder 1 is increased, the telescopic oil cylinder stroke is controlled to be increased, and the extension amount is increased.

[0140] It should be noted that when the scraper conveyor further comprises a data analysis control module, the data analysis control module can pre-store the calculation formula and control logic of steps S1, S2, S3, S4 and S5, so as to achieve the automatic tensioning function of the chain.

[0141] Specifically, in the embodiment, first, the real-time load of the scraper conveyor is calculated by using the laser coal load scanner, and the obtained data is transmitted to the data analysis control module. Then, the data analysis control module calculates the theoretical pressure strength of the telescopic oil cylinder 1 and the pre-tightening force of the chain according to the real-time load of the scraper conveyor, and transmits the theoretical pressure strength control signal of the telescopic oil cylinder 1 to the telescopic oil cylinder 1 to make it perform telescopic action. After that, the tension detection module 6 measures the actual tension of the chain at the head and tail of the machine, and transmits the data to the data analysis control module, which calculates the instant tension of the chain. Finally, the data analysis control module compares the instant tension with the pre-tightening force, and controls the movement of the telescopic oil cylinder 1 accordingly.

[0142] It can be understood that in the case of or , the extension amount of the telescopic oil cylinder 1 is changed, and steps S4 and S5 are repeated until the telescopic oil cylinder 1 stops moving, and the chain is in an ideal tension state.

[0143] In the present application, by acquiring the conveying capacity of the scraper conveyor in real time and calculating the chain pre-tightening force and the theoretical pressure strength of the telescopic oil cylinder 1, the tensioning degree of the chain can be accurately controlled, avoiding problems such as accumulation, chain breakage or chain jamming due to the chain being too loose, and preventing excessive wear and damage of the equipment caused by the chain being too tight, greatly improving the stability and reliability of the scraper conveyor operation. At the same time, the instantaneous tension of the chain is compared with the pre-tightening force in real time, and the working state of the telescopic oil cylinder 1 is adjusted according to the comparison result, ensuring that the chain is always in the best tensioning state, reducing the probability of equipment failure and prolonging the service life of the equipment.

[0144] Further, the chain automatic tensioning method provided by the present application can quickly respond to changes in the conveying capacity of the scraper conveyor, adjust the chain tensioning force in a timely manner, and ensure that the equipment can operate efficiently under different working loads, thereby improving the production efficiency of the entire coal transportation system. At the same time, frequent manual intervention to adjust the chain tensioning degree is not required, saving labor costs and time costs and improving the operation efficiency of the equipment.

[0145] In some possible implemented embodiments disclosed in the present application, before acquiring the real-time conveying capacity of the scraper conveyor, the method further comprises:

[0146] determining whether the scraper conveyor is started, if the scraper conveyor is in a stopped state, controlling the telescopic oil cylinder 1 to be completely retracted, and if the scraper conveyor is in a started state, controlling the scraper conveyor to enter an automatic tensioning mode.

[0147] When the scraper conveyor is in a stopped state, controlling the telescopic oil cylinder 1 to be completely retracted can avoid the oil cylinder continuously bearing pressure in unnecessary cases, reduce the fatigue loss of the oil cylinder, and prolong its service life. At the same time, it is also helpful to reduce the energy consumption of the equipment in the stopped state, achieving the purpose of energy saving.

[0148] When the scraper conveyor is in a started state, controlling the scraper conveyor to enter an automatic tensioning mode can ensure that the chain always maintains a suitable tensioning degree during equipment operation. This can effectively prevent problems such as coal accumulation, chain breakage or chain jamming caused by the chain being too loose, and improve the operation efficiency and stability of the equipment.

[0149] Specifically, when it is necessary to determine whether the scraper conveyor is started or not, the data analysis control module receives the running state signal from the scraper conveyor. This signal can be obtained by connecting with the control system of the scraper conveyor or installing a specific sensor. If the data analysis control module determines that the scraper conveyor is in a shutdown state, it will immediately issue a control instruction to make the telescopic oil cylinder 1 fully retract. When the data analysis control module determines that the scraper conveyor is in a startup state, it will start the automatic tensioning mode. In this mode, the data analysis control module first calculates the pre-tightening force of the chain and the theoretical pressure strength of the telescopic oil cylinder 1 according to the pre-stored calculation formula and control logic, using the real-time data of the scraper conveyor obtained from the laser coal quantity scanner and other devices. Then, the data analysis control module transmits the theoretical pressure strength control signal to the telescopic oil cylinder 1 to control the telescopic oil cylinder 1 to move to the appropriate position to achieve the tensioning of the chain. Next, the tension detection module 6 measures the instantaneous tension of the chain and transmits the data back to the data analysis control module. The data analysis control module compares the instantaneous tension with the pre-tightening force in real time, and continuously adjusts the working state of the telescopic oil cylinder 1 according to the comparison result, to ensure that the chain always maintains an ideal tensioning degree to meet the normal operation requirements of the scraper conveyor.

[0150] It is easy for those skilled in the art to understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0151] The above is only a preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only a preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can be made, which should be regarded as the protection scope of the present application.

Claims

1. A chain automatic tensioning method for a scraper conveyor, the scraper conveyor comprising a telescopic oil cylinder (1) and a tail, a middle section and a head connected in sequence along a coal conveying direction, chain wheels (2) are arranged at the head and the tail, and the chain wheels (2) are used for winding a chain, characterized in that, The method comprises: acquiring the real-time conveying capacity of the scraper conveyor; calculating the pre-tightening force of the chain and the theoretical pressure intensity of the telescopic oil cylinder (1) based on the real-time conveying capacity; controlling the telescopic oil cylinder (1) to move based on the theoretical pressure intensity; detecting the instantaneous tension of the chain; comparing the instantaneous tension with the pre-tightening force in real time, and adjusting the working state of the telescopic oil cylinder (1) based on the comparison result; The pre-tightening force of the chain meets the formula: wherein is the pre-tension of the chain; is the theoretical tension of the point of exit of the sprocket (2) provided at the tail of the machine for the chain; is the theoretical tension of the point of entry of the sprocket (2) provided at the tail of the machine for the chain; is the theoretical tension of the point of exit of the sprocket (2) provided at the head of the machine for the chain; is the theoretical tension of the point of entry of the sprocket (2) provided at the head of the machine for the chain; the value range of the force F is 2-3 kN; Formula: wherein is the coefficient of resistance of the chain around the sprocket (2); Formula: wherein is the length of the apron conveyor laid out; is the weight of the chain per unit length; is the equivalent friction coefficient of the lower chain of the apron conveyor; is the angle of inclination of the working surface of the apron conveyor; Formula: wherein is the coal load per unit length of the flighted conveyor; is the equivalent coefficient of friction of the upper chain of the flighted conveyor; equivalent friction coefficient of the lower chain of the flight conveyor comply with the formula: equivalent friction coefficient of the upper chain of the flight conveyor complies with the formula: wherein is the speed of movement of the chain; is the efficiency loss of the telescopic cylinder (1); is the coal loading height of the scraper conveyor; Coal loading height of the scraper conveyor Complies with the formula: wherein is the slot width of the middle slot; is the slot depth of the middle slot; The coal load per unit length of the scraper conveyor Complies with the formula: In the formula, W is the real-time transport volume of the scraper conveyor; is the gravitational acceleration.

2. The automatic chain tensioning method according to claim 1, wherein A plurality of middle grooves are provided, and a plurality of coal quantity scanners (5) are provided one by one in one-to-one correspondence at the plurality of middle grooves, and the coal quantity scanners (5) are used to acquire the real-time conveying capacity of the scraper conveyor. The interval distance between adjacent two coal quantity scanners (5) is the groove length of the middle groove.

3. The automatic chain tensioning method according to claim 1, wherein The theoretical pressure intensity of the telescopic oil cylinder (1) meets the formula: In the formula, is the number of the telescopic oil cylinders (1); is the inner diameter of the telescopic oil cylinder (1); is the efficiency loss of the telescopic oil cylinder (1).

4. The automatic chain tensioning method according to claim 1, wherein The instantaneous tension of the chain meets the formula: wherein is the instantaneous tension of the chain; is the actual tension of the chain at the point of exit of the sprocket (2) arranged at the tail; is the actual tension of the chain at the point of entry of the sprocket (2) arranged at the tail; is the actual tension of the chain at the point of exit of the sprocket (2) arranged at the head; is the actual tension of the chain at the point of entry of the sprocket (2) arranged at the head; wherein , , and all conform to the formula: wherein is the tension; is the cross-sectional area of the chain; is the modulus of elasticity of the chain; is the strain value of the chain.

5. The automatic chain tensioning method according to claim 4, wherein The scraper conveyor further comprises a tension detection module (6) for sensing the strain values at the positions of the winding-out point and the winding-in point of the sprocket (2) arranged at the tail and the positions of the winding-out point and the winding-in point of the sprocket (2) arranged at the head of the chain. The chain comprises a plurality of steel rings, and the tension detection module (6) comprises at least two wireless receivers (61) and a plurality of wireless collectors (62) and a plurality of strain sensors (63). The at least two wireless receivers (61) are arranged at the head and the tail respectively, and the plurality of wireless collectors (62) and the plurality of strain sensors (63) are arranged one by one on the plurality of steel rings.

6. The automatic chain tensioning method according to claim 1, wherein The real-time comparison of the instantaneous tension with the pre-tightening force and the adjustment of the working state of the telescopic oil cylinder (1) based on the comparison result comprises: comparing the instantaneous tension with a preset setting interval in real time; keeping the telescopic oil cylinder (1) unchanged in the case that the instantaneous tension is in the preset setting interval, reducing the telescopic oil cylinder (1) in the case that the instantaneous tension is greater than the upper limit value of the preset setting interval, and increasing the telescopic oil cylinder (1) in the case that the instantaneous tension is less than the lower limit value of the preset setting interval. The preset setting interval is , .

7. The automatic chain tensioning method according to claim 6, wherein Before acquiring the real-time conveying capacity of the scraper conveyor, the method further comprises: judging whether the scraper conveyor is started, controlling the telescopic oil cylinder (1) to be completely retracted in the case that the scraper conveyor is in a shutdown state, and controlling the scraper conveyor to enter an automatic tensioning mode in the case that the scraper conveyor is in a startup state.

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