A height adjusting system of a coal mining machine and a mounting design method of a height adjusting oil cylinder

Abstract

The present application belongs to the technical field of mining machinery, and discloses a height adjusting system of a coal mining machine and a height adjusting oil cylinder mounting design method, the system comprising a rocker arm and a height adjusting oil cylinder, the lower end of the height adjusting oil cylinder being hingedly connected to one side of a support leg through a lower taper shaft; the method comprising the following steps: one, establishing a simplified model of the height adjusting system of the coal mining machine; two, determining the relationship between the swing angle and the mining height; three, determining the mining height gain; four, determining the height adjusting oil cylinder mounting position. The present application adopts an innovative lower-mounted oil cylinder whole machine architecture, can efficiently adapt to and fully utilize the rocker arm lower swing angle, through precise adjustment of the position of the height adjusting oil cylinder, greatly releases the swing efficiency of the rocker arm, effectively utilizes the efficiency of the rocker arm lower swing angle, directly breaks the technical bottleneck of limited mining height under the traditional architecture, not only reduces the cumbersome problem of layered mining, but also greatly improves the efficiency of coal mining operation and the resource recovery rate, and provides important technical support for efficient and safe mining of thick coal seams.

Description

Technical Field

[0001] This invention belongs to the field of mining machinery technology, specifically relating to a coal mining machine height adjustment system and its height adjustment cylinder installation design method. Background Technology

[0002] Due to limitations in current fully mechanized mining equipment technology, the industry primarily relies on top-coal caving technology for mining coal seams thicker than 10 meters. However, this method generally suffers from inherent drawbacks such as low resource recovery rates and difficulty in precisely controlling coal quality. To overcome this bottleneck, existing technologies typically employ double-drum or triple-drum mining machines for thick coal seam mining. While triple-drum mining machines can theoretically increase mining height, their complex mining process and difficulty in guaranteeing system reliability make them unsuitable as the primary machine type for thick coal seam mining.

[0003] Currently, most mainstream twin-drum coal mining machines use a traditional structural layout, namely, an upper-mounted height adjustment cylinder design. This traditional structure overemphasizes the upward swing angle range of the rocker arm to achieve maximum mining height, but neglects the effective development and full utilization of the downward swing angle. This design imbalance results in poor performance when adapting to complex floor undulations, failing to fully realize the potential for single-pass full-height mining and limiting the efficient and high-recovery mining of thick coal seams. Furthermore, the traditional lower-mounted cylinder connection to the machine body involves one end of the cylinder connecting to the rocker arm connecting frame and the other end connecting to the traction unit. If the connection method of the lower-mounted cylinder in a thick coal seam mining machine remains the same as in traditional mining machines, with both ends connected to the connecting frame and the traction unit lugs respectively, the cylinder's height adjustment range will be reduced. This will lead to the critical technical problem of motion interference between the traction unit and the cylinder. This interference directly limits the normal extension and retraction of the cylinder and the swing range of the rocker arm, making it difficult to increase the mining height and failing to meet the requirement of single-pass full-height mining in thick coal seams.

[0004] Therefore, it is urgent to propose a coal mining machine height adjustment system and its height adjustment cylinder installation design method, aiming to overcome the limitations of the traditional top-mounted cylinder layout, significantly increase the adaptability of the coal mining machine by optimizing the swing characteristics of the rocker arm, cover efficient mining of coal seams of 10 meters and below, and break through the technical bottleneck of one-time full-height mining of extra-thick coal seams above 10 meters. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a coal mining machine height adjustment system and its height adjustment cylinder installation design method. This system innovatively adopts a bottom-mounted cylinder overall structure, which can efficiently adapt to and fully utilize the rocker arm's downward swing angle. Through the scientific downward movement of the height adjustment cylinder position and precise adjustment of the force-bearing structure, the swing efficiency of the rocker arm is significantly released, and the effective utilization efficiency of the rocker arm's downward swing angle is improved. This directly breaks through the technical bottleneck of limited mining height under traditional structures, not only reducing the cumbersome procedures caused by layered mining but also significantly improving the efficiency of coal mining operations and resource recovery rate, providing important technical support for the efficient and safe mining of thick coal seams.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a coal mining machine height adjustment system, including a rocker arm and a height adjustment cylinder. The lower end of the height adjustment cylinder is hinged to the outside of the support leg through a lower conical shaft, and the upper end of the height adjustment cylinder is hinged to the lower connecting frame of the rocker arm through an upper conical shaft. The support leg and the traction part are connected by a three-point connection structure. The three-point connection structure includes a first pin, a second pin, and a third pin. The first and second pins are located on the upper sides of the support leg and are used to connect the support leg and the traction part. The third pin is located above the connection point between the height adjustment cylinder and the support leg. The bottom of the traction part has a connecting lug for the third pin to connect to. The inner side of the support leg is bent outward to form a connecting lug for the third pin to connect to. The third pin is used to connect the connecting lug and the connecting lug.

[0007] In the aforementioned height adjustment system for a coal mining machine, the support leg is further provided with a lower ear seat for mounting a lower conical shaft. The lower ear seat has a through lower mounting hole. The lower ear plate of the height adjustment cylinder extends into the lower ear seat. The lower ear plate of the height adjustment cylinder has a lower ear plate hole coaxial with the lower mounting hole. Lower conical sleeves that mate with the ends of the lower conical shaft are press-fitted at both ends of the lower mounting hole. The lower conical shaft passes through the lower ear plate hole. The lower conical shaft is connected to the two lower conical sleeves by a lower long bolt. The lower long bolt passes through the lower conical shaft. One end of the lower mounting hole is sealed by a first lower pressure cap, and the other end of the lower mounting hole is sealed by a second lower pressure cap. Both the first lower pressure cap and the second lower pressure cap are connected to the lower ear seat by screws.

[0008] In the aforementioned coal mining machine height adjustment system, the connecting frame is further provided with an upper ear seat for mounting the upper conical shaft. The upper ear seat has a through upper mounting hole. The upper ear plate of the height adjustment cylinder extends into the upper ear seat. The upper ear plate of the height adjustment cylinder has an upper ear plate hole coaxial with the upper mounting hole. The two ends of the upper mounting hole are respectively press-fitted with upper conical sleeves that mate with the end of the upper conical shaft. The upper conical shaft passes through the upper ear plate hole. The upper conical shaft is connected to the two upper conical sleeves by an upper long bolt. The upper long bolt passes through the upper conical shaft. One end of the upper mounting hole is sealed by a first upper pressure cover and a second upper pressure cover. The other end of the upper mounting hole is sealed by a third upper pressure cover.

[0009] In the above-mentioned coal mining machine height adjustment system, the lower conical shaft and the upper conical shaft have the same structure. Both the lower conical shaft and the upper conical shaft include a cylindrical shaft section and conical sections respectively provided at both ends of the shaft section and whose diameter gradually decreases outward along the axial direction. Both end faces of the lower conical shaft and the upper conical shaft are provided with inwardly recessed positioning grooves. The lower and upper conical sleeves have the same structure. Both the lower and upper conical sleeves have conical grooves that match the conical section, and the conical grooves have protrusions that match the positioning grooves.

[0010] In the aforementioned coal mining machine height adjustment system, protective covers are provided on both ends of the first, second, and third pins. The protective covers on the outside of the first and third pins are fastened to the traction part by screws, and the protective cover on the outside of the second pin is connected to the support leg by screws.

[0011] In the above-mentioned height adjustment system for a coal mining machine, the piston rod of the height adjustment cylinder further includes a core substrate and a surface strengthening layer. The core substrate is made of alloy structural steel forgings and undergoes quenching and tempering treatment and surface nitriding heat treatment in sequence. The surface strengthening layer is a nickel-containing corrosion-resistant alloy layer formed by laser cladding process. The piston rod of the height adjustment cylinder has a tensile strength of not less than 1100MPa and a yield strength of not less than 835MPa. The thickness of the surface strengthening layer is 0.4mm to 0.5mm, and its surface hardness is not less than HRC55.

[0012] Meanwhile, this invention also discloses a design method for installing the height-adjusting cylinder of a coal mining machine height-adjusting system, including the following steps: Step 1: Establish a simplified model of the coal mining machine height adjustment system: The coal mining machine height adjustment system is simplified into a planar swing guide rod mechanism with the rotation hinge point O between the rocker arm and the machine body as the origin of the frame. Step 2: Determine the relationship between the swing angle and the mining height: Based on the simplified planar swing guide rod mechanism, and according to the structural dimensions of the coal mining machine body and the rocker arm, establish the rocker arm swing angle. With actual effective mining height The geometric function relationship between them is used to determine the limiting swing angles corresponding to the maximum and minimum mining heights; Step 3: Determine the sampling height gain: based on the rocker arm angle. Calculate the sampling gain The high-sensitivity linear adjustment region and the saturation region are divided into a high-gain region, wherein the high-sensitivity linear adjustment region is... The saturation region is or The saturation range regulation efficiency drops sharply and causes structural instability; By measuring the rocker arm swing angle exist The mining height gain is calculated within the interval to determine the efficient adjustment range of the mining height gain; among which, when the rocker arm angle is at... When it is within the range, it is determined to be in the high-efficiency adjustment zone, and then... The high slope characteristic in this range enables sensitive response to sampling height; when the rocker arm swing angle exceeds this range and enters the saturation region, the swing angle is limited to prevent further increase in sampling height gain and rocker arm force imbalance. Step 4: Determining the installation position of the hydraulic cylinder: Based on the partitioning of the mining height gain in Step 3, the maximum mining height is less than 10m when using an upper-mounted hydraulic cylinder within the efficient adjustment range of the mining height gain; therefore, a lower-mounted hydraulic cylinder layout is selected, and the maximum mining height can be increased to more than 10m by simultaneously expanding the effective stroke of the upper and lower swing angles.

[0013] The above-mentioned method for installing the height-adjusting cylinder of a coal mining machine height adjustment system further includes, in step two, the rocker arm swing angle... With actual effective mining height The process of determining the geometric functional relationship between them is as follows: ;in, The vertical height of the center of the cutting drum; To cut the diameter of the drum; Vertical height of the cutting drum center ;in, The reference height of the pivot point O between the rocker arm and the machine body from the bottom plate of the well; The effective swing length of the rocker arm is the straight-line distance from the pivot point O between the rocker arm and the machine body to the center of the cutting drum. Therefore, the swing angle of the rocker arm With actual effective mining height The geometric functional relationship between them is as follows: .

[0014] The above-mentioned design method for installing the height-adjusting cylinder of a coal mining machine height adjustment system further includes the following: when the rocker arm of the coal mining machine swings up to its upper limit swing angle... At that time, the maximum mining height of the coal mining machine Calculate using the following formula: ; When the rocker arm of the coal mining machine swings down to its lower limit angle At that time, the minimum mining height of the coal mining machine Calculate using the following formula: ; Among them, the lower limit swing angle corresponding to the minimum mining height .

[0015] The above-mentioned method for installing the height-adjusting cylinder of a coal mining machine height adjustment system further includes, in step three, the height gain... Calculate using the following formula: ; in, The initial swing angle of the rocker arm; high gain is adopted. That is, the swing angle of the rocker arm from Change to High-increase mining volume at that time A positive value indicates a higher extraction rate. A negative value indicates a decrease in the extraction rate. Used to quantify the contribution of the swing angle to the mining height.

[0016] Compared with the prior art, the present invention has the following advantages: 1. This invention, by hinged the height adjustment cylinder between the support leg and the lower connecting frame of the rocker arm, adopts a bottom-mounted cylinder overall structure, which can efficiently adapt to and fully utilize the rocker arm's swing angle. Through the scientific downward movement of the height adjustment cylinder and the precise adjustment of the force structure, the swing efficiency of the rocker arm is greatly released, directly breaking the technical bottleneck of limited mining height under the traditional structure, and providing important technical support for efficient and safe mining of high-mining-height working faces.

[0017] 2. This invention increases the effective working stroke of the height-adjusting cylinder by moving the lower hinge point of the height-adjusting cylinder from the traditional traction part to the outside of the support leg. This ensures that the extension and retraction of the height-adjusting cylinder is always within the safe range of its stroke during the large-angle height adjustment of the rocker arm connecting frame, thereby avoiding the problem of motion interference with the traction part caused by the limited stroke and improving the operational reliability and structural safety of the whole machine.

[0018] 3. This invention establishes a three-point connection structure by setting a third pin above the connection point between the height-adjusting cylinder and the support leg, thus connecting the support leg and the traction unit. This constructs a multi-dimensional, high-strength support and connection system, effectively reducing the load at the cylinder connection lugs, effectively offsetting the stress concentration phenomenon generated at the cylinder connection points, significantly reducing the risk of local overload, and significantly improving the stability and reliability of the overall connection structure, providing a reliable guarantee for the 10-meter coal mining machine.

[0019] 4. The method adopted in this invention simplifies the coal mining machine height adjustment system into a planar swing guide rod mechanism, which not only quantitatively reveals the relationship between the swing angle and the mining height, but also clarifies the core position of optimizing the swing angle in the entire coal mining process. This provides key theoretical support for the one-time and efficient realization of 10-meter full-height mining operations and has important practical guiding significance for promoting the development of thick coal seam mining technology.

[0020] In summary, this invention innovatively adopts a bottom-mounted hydraulic cylinder overall structure. This structure can efficiently adapt to and fully utilize the rocker arm's downward swing angle. Through the scientific downward movement of the height-adjusting hydraulic cylinder position and the precise adjustment of the force-bearing structure, the swing efficiency of the rocker arm is significantly released. Compared with other existing series of thick coal seam mining machines, its effective utilization efficiency of the rocker arm's downward swing angle is improved, directly breaking through the technical bottleneck of limited mining height under the traditional structure. For the mining of thick coal seams, it not only reduces the cumbersome process problems caused by layered mining, but also greatly improves the efficiency of coal mining operations and resource recovery rate, providing important technical support for the efficient and safe mining of thick coal seams.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the coal mining machine height adjustment system of the present invention.

[0023] Figure 2 This is a schematic diagram of the connection structure between the height-adjusting cylinder and the support leg of the present invention.

[0024] Figure 3 This is a schematic diagram of the connection structure between the height-adjusting cylinder and the connecting frame of the present invention.

[0025] Figure 4 This is a schematic diagram of the connection structure of the support leg, traction part, first pin and third pin of the present invention.

[0026] Figure 5 This is a schematic diagram of the connection structure of the support leg, traction part, first pin, and second pin of the present invention.

[0027] Figure 6This is a cross-sectional view of the connection structure of the support leg, traction part, second pin and third pin of the present invention.

[0028] Figure 7 This is a schematic diagram of the mounting structure of the height-adjusting cylinder of the present invention. Figure 1 .

[0029] Figure 8 This is a schematic diagram of the mounting structure of the height-adjusting cylinder of the present invention. Figure 2 .

[0030] Figure 9 This is a schematic diagram of the mounting structure of the height-adjusting cylinder of the present invention. Figure 3 .

[0031] Figure 10 This is a schematic diagram of the mounting structure of the height-adjusting cylinder of the present invention. Figure 4 .

[0032] Figure 11 This is a flowchart of the method of the present invention.

[0033] Figure 12 The graph shows the relationship between high gain and rocker arm swing angle in this invention.

[0034] Explanation of reference numerals in the attached figures: 1. Rocker arm; 2. Connecting frame; 3. Height adjustment cylinder; 4. Support leg; 5. Traction unit; 6. Lower conical shaft; 7. Lower ear seat; 8. Lower conical sleeve; 9. Lower long bolt; 10. Lower nut; 11. First lower pressure cover; 12. Second lower pressure cover; 13. Upper conical shaft; 14. Upper ear seat; 15. Upper conical sleeve; 16. Upper long bolt; 17. Upper nut; 18. First upper pressure cover; 19. Second upper pressure cover; 20. Third upper pressure cover; 21. First pin; 22. Second pin; 23. Third pin; 24. Protective cover; 25. Connecting ear plate; 26. Connecting ear seat; 27. Scraper conveyor; 28. Hydraulic support side guard plate; 29. ​​First chain guide device; 30. First hoisting rope; 31. Hydraulic support top beam; 32. Second chain guide device; 33. Second hoisting rope; 34. Traveling box; 35. Third chain guide device; 36. Third hoisting rope; 37. Third chain guide device. Detailed Implementation

[0035] like Figures 1 to 6The diagram shows a height adjustment system for a coal mining machine, comprising a rocker arm 1 and a height adjustment cylinder 3. The lower end of the height adjustment cylinder 3 is hinged to the outside of a support leg 4 via a lower conical shaft 6, and the upper end of the height adjustment cylinder 3 is hinged to a connecting frame 2 on the lower side of the rocker arm 1 via an upper conical shaft 13. The support leg 4 and the traction unit 5 are connected by a three-point connection structure, which includes a first pin 21, a second pin 22, and a third pin 23. The first pin 21 and the second pin 22 are located on the upper sides of the support leg 4 and are used to connect the support leg 4 to the traction unit 5. The third pin 23 is located above the connection point between the height adjustment cylinder 3 and the support leg 4. The bottom of the traction unit 5 has a connecting lug 26 for the third pin 23 to connect to. The inner side of the support leg 4 is bent outward to form a connecting lug 25 for the third pin 23 to connect to. The third pin 23 is used to connect the connecting lug 26 and the connecting lug 25.

[0036] In this embodiment, by hinged the height-adjusting cylinder 3 between the support leg 4 and the lower connecting frame 2 of the rocker arm 1, a bottom-mounted cylinder overall structure is adopted. This allows for efficient adaptation and full utilization of the rocker arm's downward swing angle. Through the scientific downward movement of the height-adjusting cylinder 3 and the precise adjustment of the force-bearing structure, the swing efficiency of the rocker arm is significantly released. Compared with other existing series of high-mining coal mining machines, the effective utilization efficiency of the rocker arm's downward swing angle is improved by more than 40%. This significant performance breakthrough directly breaks through the technical bottleneck of limited mining height under traditional structures, successfully achieving the goal of mining a full height of 10 meters in one operation. This not only reduces the cumbersome procedures caused by layered mining but also significantly improves the efficiency of coal mining operations and resource recovery rate, providing important technical support for the efficient and safe mining of high-mining faces.

[0037] In this embodiment, by moving the lower hinge point of the height adjustment cylinder 3 from the traditional traction part 5 to the outside of the support leg 4, the effective working stroke of the height adjustment cylinder 3 is increased. This ensures that during the large-angle height adjustment or height adjustment of the rocker arm connecting frame, the extension and retraction of the height adjustment cylinder is always within the safe range of its stroke, thereby avoiding the problem of motion interference with the traction part 5 due to stroke limitation, and improving the operational reliability and structural safety of the whole machine.

[0038] In this embodiment, a three-point connection structure is formed by setting a third pin 23 above the connection point between the height adjustment cylinder 3 and the support leg 4, connecting the support leg 4 and the traction part 5. This constructs a multi-dimensional, high-strength support and connection system, effectively reducing the load at the cylinder connection lug, effectively offsetting the stress concentration phenomenon generated at the cylinder connection part, significantly reducing the risk of local overload, and significantly improving the stability and reliability of the overall connection structure, providing a reliable guarantee for the 10-meter coal mining machine.

[0039] In practical implementation, under the condition that the swing angle on the rocker arm is basically the same, the actual working swing angle of the traditional height adjustment cylinder is less than 10°. This excessively small swing angle prevents the cylinder piston rod from bearing load reasonably along the axial direction during operation, resulting in a significantly larger radial lateral load on the piston rod cross-section. Under continuous alternating radial force, this easily leads to problems such as piston rod bending deformation, accelerated wear of the guide sleeve, abnormal scoring of the seals, and even shear failure, resulting in internal and external leakage, motion jamming, and other malfunctions, significantly shortening the overall service life of the cylinder. In contrast, under the design of this patented structure, the height adjustment cylinder piston rod mainly bears the axial force along the axial direction. The load transmission direction is highly consistent with the cylinder's motion axis, resulting in uniform force distribution on the cylinder body and piston rod. The guide sleeve and seals are in an ideal stress state, without eccentric load compression or abnormal wear. The height adjustment cylinder operates smoothly and reliably, effectively improving its working stability and service life. In this structure, all the force provided by the height adjustment cylinder for mining height is borne by the connecting lugs between the outrigger and the height adjustment cylinder, while the outrigger itself is fixed to the traction unit. If the traditional two-point connection method is used at this time—that is, the outrigger is connected to the outer surface of the traction unit through the lug seat—considering that the coal mining machine with a mining height of 10 meters is heavy and the thrust generated by the hydraulic cylinder is also large, this will cause the lug seat connecting the hydraulic cylinder and the outrigger to bear extremely high load, which will cause the outrigger to face the risk of breakage due to uneven force distribution.

[0040] In specific implementation, the outer side of the support leg 4 refers to the side of the support leg 4 facing the outer side of the fuselage, and the inner side of the support leg 4 refers to the side of the support leg 4 facing the inner side of the fuselage. There is a gap between the lifting cylinder 3 and the side of the traction unit 5 facing the outer side of the fuselage.

[0041] like Figure 3 As shown, in this embodiment, the support leg 4 is provided with a lower ear seat 7 for mounting the lower conical shaft 6. The lower ear seat 7 is provided with a through lower mounting hole. The lower ear plate of the height adjustment cylinder 3 extends into the lower ear seat 7. The lower ear plate of the height adjustment cylinder 3 has a lower ear plate hole coaxial with the lower mounting hole. The two ends of the lower mounting hole are respectively press-fitted with lower conical sleeves 8 that cooperate with the end of the lower conical shaft 6. The lower conical shaft 6 passes through the lower ear plate hole. The lower conical shaft 6 and the two lower conical sleeves 8 are connected by a lower long bolt 9. The lower long bolt 9 passes through the lower conical shaft 6. One end of the lower mounting hole is sealed by a first lower pressure cover 11, and the other end of the lower mounting hole is sealed by a second lower pressure cover 12. The first lower pressure cover 11 and the second lower pressure cover 12 are both connected to the lower ear seat 7 by screws.

[0042] In actual use, the first lower pressure cover 11 is fixed to the lower ear seat 7 by 6 M16×100 screws, and the second lower pressure cover 12 is fixed by 6 M12×25 bolts.

[0043] like Figure 2As shown, in this embodiment, the connecting frame 2 is provided with an upper ear seat 14 for mounting the upper conical shaft 13. The upper ear seat 14 has a through upper mounting hole. The upper ear plate of the height adjustment cylinder 3 extends into the upper ear seat 14. The upper ear plate of the height adjustment cylinder 3 has an upper ear plate hole coaxial with the upper mounting hole. The two ends of the upper mounting hole are respectively press-fitted with upper conical sleeves 15 that mate with the ends of the upper conical shaft 13. The upper conical shaft 13 passes through the upper ear plate hole. The upper conical shaft 13 and the two upper conical sleeves 15 are connected by upper long bolts 16. The upper long bolts 16 penetrate the upper conical shaft 13. One end of the upper mounting hole is sealed by a first upper pressure cover 18 and a second upper pressure cover 19, and the other end of the upper mounting hole is sealed by a third upper pressure cover 20. The first upper pressure cover 18 and the third upper pressure cover 20 are both connected to the upper ear seat 14 by screws.

[0044] In actual use, the first upper pressure cover 18 is fixed to the upper ear seat 14 by 6 M16×45 screws, and the second upper pressure cover 19 is fixed to the first upper pressure cover 18 by 6 M16×30 screws.

[0045] It should be noted that traditional bottom-mounted hydraulic cylinder structures are mainly designed for thin coal seam mining machines. These machines are lightweight and have low load-bearing capacity. Therefore, the hydraulic cylinders, connecting frames, and traction unit hinges often use open holes for direct engagement with pins or ordinary steel or iron sleeves. This structure has poor lubrication and a high coefficient of friction. Under heavy loads of 10 meters, impacts, and harsh underground conditions, problems such as wear and jamming, pin seizing, and rapid increase in clearance can easily occur, severely affecting the flexibility and service life of the height adjustment cylinder. In this patent, the rod head and cylinder bottom trunnion connecting pin hole bushing of the height adjustment cylinder 3 both adopt a self-lubricating wear-resistant copper sleeve structure. The copper sleeve has a hardness ≥HB250. Relying on the inherent lubrication properties of the material itself, effective lubrication can be achieved without continuous external oil supply. This significantly reduces the frictional resistance and wear between the pin and the bushing, improves the wear resistance, smoothness, and reliability of the hinge, avoids direct wear between the pin and the hole seat, and extends the overall service life of the height adjustment cylinder.

[0046] In this embodiment, the lower conical shaft 6 and the upper conical shaft 13 have the same structure. Both the lower conical shaft 6 and the upper conical shaft 13 include a cylindrical shaft body section and conical sections respectively provided at both ends of the shaft body section and whose diameter gradually decreases outward along the axial direction. Both end faces of the lower conical shaft 6 and the upper conical shaft 13 are provided with inwardly recessed positioning grooves. The lower conical sleeve 8 and the upper conical sleeve 15 have the same structure. Both the lower conical sleeve 8 and the upper conical sleeve 15 have conical grooves that match the conical section, and the conical grooves have protrusions that match the positioning grooves.

[0047] In actual use, the upper long bolt 16 is threaded with an upper nut 17, and the lower long bolt 9 is connected with a lower nut 10. The lower tapered sleeve 8 has a through hole for the screw end of the lower long bolt 9 to pass through, and the upper tapered sleeve 15 has a through hole for the screw end of the lower long bolt 9 to pass through. The outer ends of the lower tapered sleeve 8 and the upper tapered sleeve 15 are provided with countersunk holes, and the through holes communicate with the corresponding countersunk holes. The head of the upper long bolt 16 and the upper nut 17 are respectively located in the countersunk holes of the two upper tapered sleeves 15, and the head of the lower long bolt 9 and the lower nut 10 are respectively located in the countersunk holes of the two lower tapered sleeves 8.

[0048] It should be noted that the tapered shaft and tapered sleeve achieve a tight fit through an interference fit of the tapered surfaces, and the self-locking effect of the tapered surfaces effectively prevents loosening during operation. A long screw runs through the tapered sleeve and tapered shaft in sequence, and the nut is pressed against the center of the end face of the tapered sleeve to form an axial fastener, further improving the overall connection reliability and providing double protection to prevent loosening of components under operating conditions.

[0049] like Figure 4-6 As shown, in this embodiment, protective covers 24 are provided on both ends of the first pin 21, the second pin 22 and the third pin 23. The protective covers 24 on the outside of the first pin 21 and the third pin 23 are fastened to the traction part 5 by screws. The protective cover 24 on the outside of the second pin 22 is connected to the support leg 4 by screws.

[0050] In actual use, when the protective caps 24 corresponding to the first pin 21 and the third pin 23 are fastened to the traction part 5 by screws, matching washers are provided. The protective cap 24 corresponding to the third pin 23 is fastened to the connecting lug 26 of the traction part 5 by screws.

[0051] In practice, the protective cover 24 is fastened to the corresponding washer or support leg 4 with eight M16×40 screws.

[0052] In this embodiment, the piston rod of the height-adjusting cylinder 3 includes a core substrate and a surface strengthening layer. The core substrate is made of alloy structural steel forging and is subjected to quenching and tempering treatment and surface nitriding heat treatment in sequence. The surface strengthening layer is a nickel-containing corrosion-resistant alloy layer formed by laser cladding process.

[0053] In this embodiment, the tensile strength of the piston rod of the height adjustment cylinder 3 is not less than 1100MPa, and its yield strength is not less than 835MPa. The thickness of the surface strengthening layer is 0.4mm to 0.5mm, and its surface hardness is not less than HRC55.

[0054] In actual use, the height adjustment cylinder of a thick coal seam mining machine needs to withstand heavy loads, strong impacts, and high lateral forces during operation. To meet the height adjustment requirements of the entire machine, the cylinder diameter, piston rod diameter, and stroke are all increased accordingly, and the piston rod length is significantly increased, making it prone to bending deformation, fatigue fracture, surface scratches, and corrosion failure. Traditional piston rods are mostly made of 40Cr forgings after quenching and tempering, and some are only supplemented with a chrome-plated surface layer. They have defects such as insufficient base strength and toughness, poor hardenability, poor wear and corrosion resistance, and short service life, making it difficult to meet the heavy load and long service life requirements under the conditions of thick coal seam mining. Therefore, the core base of the piston rod of the height adjustment cylinder 3 in this patent is made of 40CrNiMoA alloy structural steel forging; its impact toughness is significantly better than that of 40Cr material, which can effectively reduce the risk of brittle fracture; after quenching and tempering + surface nitriding composite treatment, the mechanical properties of the piston rod are uniform and stable across the entire cross section. The tempering treatment refers to a composite heat treatment process in which the core substrate of the piston rod is quenched and then tempered at high temperature, aiming to obtain a uniform tempered sorbite structure in the substrate and improve its overall mechanical properties. The surface nitriding heat treatment refers to a nitriding chemical heat treatment performed on the surface of the substrate after tempering treatment to form a high-hardness diffusion layer and compound layer on the surface. At the same time, the piston rod surface of the height-adjusting cylinder 3 is strengthened by laser cladding with a nickel-containing corrosion-resistant alloy. The cladding layer is free of cracks and slag inclusions, and forms a reliable metallurgical bond with the substrate, significantly improving the wear resistance, corrosion resistance and overall service life of the piston rod.

[0055] like Figure 7-10 As shown, in actual use, traditional top-mounted hydraulic cylinders can be directly installed on the upper part of the machine body via hoisting, making installation convenient. However, the bottom-mounted hydraulic cylinders of the 10-meter coal mining machine are difficult to install due to their large diameter, heavy weight, and the fact that they are installed between the rocker arm and the support leg, resulting in limited installation space. Therefore, the specific process for installing the height-adjusting hydraulic cylinders of the coal mining machine's height adjustment system is as follows: Step a: Transport the height adjustment cylinder 3 to below the rocker arm 1 via scraper conveyor 27; Step b: Fix the first chain guide device 29 at the hydraulic support side plate 28 at the corresponding position. The two chain hoists corresponding to the first chain guide device 29 are respectively connected to the two ends of the cylinder body of the height adjustment cylinder 3 through the first hoisting rope 30. Use the first chain guide device 29 to move the height adjustment cylinder 3 from the scraper conveyor 27 to the outside of the coal mining machine near the coal wall. At this time, the position of the height adjustment cylinder 3 moves from ① to ②, as shown. Figure 7 As shown; Step c: Fix the second chain guide device 32 at the top beam 31 of the hydraulic support at the corresponding position of the height adjustment cylinder 3. The two chains of the second chain guide device 32 are connected to both ends of the cylinder body of the height adjustment cylinder 3 through the second hoisting rope 33, respectively. Lift the height adjustment cylinder 3 to the height adjustment cylinder mounting platform at the support leg 4. At this time, the position of the height adjustment cylinder 3 moves from ② to ③, as shown. Figure 8As shown; after the second guide chain device 32 is tightened, the first guide chain device 29 and the first lifting rope 30 are disassembled; Step d: Fix the third guide chain device 35 to the back of the traveling box 34. Connect the middle part of the height adjustment cylinder 3 using the third hoisting rope 36. At this time, tighten the third guide chain device 35 and simultaneously loosen the second guide chain device 32 to pull the height adjustment cylinder 3 into the support leg cylinder mounting platform. At this time, the position of the height adjustment cylinder 3 moves from ③ to ④. Figure 9 As shown; Step e: At this time, adjust the side hinge shaft of the cylinder body of the hydraulic cylinder 3, that is, adjust the lower cone shaft 6 between the hydraulic cylinder 3 and the support leg; Finally, the third lifting rope 36 is passed through the auxiliary lifting hole opened in the traction part 5 above the height-adjusting cylinder 3. The third guide chain device 37 is installed at the corresponding position of the hydraulic support top beam 31. Using the third guide chain device 37 and the third lifting rope 36, the height-adjusting cylinder 3 is lifted to a suitable height. The piston rod side hinge shaft of the height-adjusting cylinder 3, i.e., the upper conical shaft 13, is then connected. At this point, the installation of the height-adjusting cylinder 3 is complete. Figure 10 As shown.

[0056] Through the above step-by-step operation, the height adjustment cylinder can be safely and efficiently assembled to the designed position on the lower side of the coal mining machine body, completely solving the industry problem of high difficulty and low safety of manual installation of large-diameter lower-mounted cylinders, and greatly improving on-site assembly efficiency and operational reliability.

[0057] like Figure 11 The method for installing the height-adjusting cylinder of a coal mining machine height-adjusting system, as shown, includes the following steps: Step 1: Establish a simplified model of the coal mining machine height adjustment system: The coal mining machine height adjustment system is simplified into a planar swing guide rod mechanism with the rotation hinge point O between the rocker arm and the machine body as the origin of the frame. Step 2: Determine the relationship between the swing angle and the mining height: Based on the simplified planar swing guide rod mechanism, and according to the structural dimensions of the coal mining machine body and the rocker arm, establish the rocker arm swing angle. With actual effective mining height The geometric function relationship between them is used to determine the limiting swing angles corresponding to the maximum and minimum mining heights; Step 3: Determine the sampling height gain: based on the rocker arm angle. Calculate the sampling gain And plot the high gain With the swing angle of the rocker arm The change curve, such as Figure 12 As shown, the high-sensitivity linear adjustment region and the saturation region are divided into a high-gain region, wherein the high-sensitivity linear adjustment region is... The saturation region is or The saturation range regulation efficiency drops sharply and causes structural instability; By measuring the rocker arm swing angle exist The mining height gain is calculated within the interval to determine the efficient adjustment range of the mining height gain; among which, when the rocker arm angle is at... When it is within the range, it is determined to be in the high-efficiency adjustment zone, and then... The high slope characteristic in this range enables a sensitive response to the sampling height; when the rocker arm swing angle exceeds this range and enters the saturation region, the swing angle is limited to prevent the sampling height gain from decreasing and the rocker arm from becoming unbalanced. Step 4: Determining the installation position of the hydraulic cylinder: Based on the partitioning of the mining height gain in Step 3, the maximum mining height is less than 10m when using an upper-mounted hydraulic cylinder within the efficient adjustment range of the mining height gain; therefore, a lower-mounted hydraulic cylinder layout is selected, and the maximum mining height can be increased to more than 10m by simultaneously expanding the effective stroke of the upper and lower swing angles.

[0058] In practical application, by simplifying the coal mining machine height adjustment system into a planar swing guide rod mechanism with the rotation hinge point O between the rocker arm and the machine body as the origin of the frame, this not only quantitatively reveals the relationship between the swing angle and the mining height, but also clarifies the core role of optimizing the downward swing angle in the entire coal mining process. This research provides key theoretical support for the efficient one-time realization of 10-meter full-height mining operations and has important practical guiding significance for promoting the development of thick coal seam mining technology.

[0059] It should be noted that by innovatively adopting a bottom-mounted hydraulic cylinder overall structure, this architecture can efficiently adapt to and fully utilize the rocker arm's downward swing angle. Through the scientific downward shift of the height-adjusting hydraulic cylinder position and precise adjustment of the force-bearing structure, the swing efficiency of the rocker arm is significantly released. Compared with other existing series of thick coal seam mining machines, the effective utilization efficiency of its rocker arm's downward swing angle is improved by more than 40%. This significant performance breakthrough directly breaks through the technical bottleneck of limited mining height under traditional architectures. For thick coal seam mining, it not only reduces the cumbersome procedures caused by layered mining but also significantly improves the efficiency of coal mining operations and resource recovery rate, providing important technical support for the efficient and safe mining of thick coal seams.

[0060] In this embodiment, in step two, the rocker arm swing angle With actual effective mining height The process of determining the geometric functional relationship between them is as follows: ;in, The vertical height of the cutting drum center relative to the downhole floor plate varies with the swing angle. change; The diameter of the cutting drum is a fixed value, designed to match the requirements of mining heights above 10m. Vertical height of the cutting drum center ;in, The reference height of the rotation hinge point O between the rocker arm and the machine body from the bottom plate of the well is positively correlated with the height of the machine surface and is a fixed value, which meets the requirements of the downhole working space. The effective swing length of the rocker arm is the straight-line distance from the pivot point O between the rocker arm and the machine body to the center of the cutting drum. Therefore, the swing angle of the rocker arm With actual effective mining height The geometric functional relationship between them is as follows: .

[0061] In actual use, the actual effective mining height of the coal mining machine The vertical height of the upper edge of the cutting drum is the core evaluation indicator for the full height of a single cut.

[0062] It should be noted that the formula for calculating the vertical height of the cutting drum center reflects the variation of the drum center height with the rocker arm swing angle. When the rocker arm swing angle is positive (i.e., swinging upward), the drum center rises; when the rocker arm swing angle is negative (i.e., swinging downward), the drum center falls, providing a basis for calculating the effective mining height.

[0063] In practical implementation, the rocker arm swing angle The actual effective mining height is the sum of the drum center height and the drum radius, which directly determines the single mining thickness of the coal mining machine and is the core objective parameter of this modeling. Upper limit swing angle and lower limit swing angle Together, they determine the range of mining height adjustment; increasing the lower limit angle can significantly expand the mining height adjustment range.

[0064] In practical implementation, high gain is adopted. The relationship curve between the swing angle and the swing angle is as follows: Figure 12 As shown, the horizontal axis represents the rocker arm swing angle, and the vertical axis represents the mining height gain. The horizontal axis ranges from 0° to 90°, representing the upward swing angle, and from 0° to -90°, representing the downward swing angle. Analysis of the curves shows that the rocker arm swing angle has a significant impact on the mining height gain when it is within the range of 55° to -55°; however, the impact decreases when the upward swing angle is greater than 55°. Therefore, the upward swing angle should not be increased indiscriminately. The impact on the mining height gain can be improved by increasing the downward swing angle.

[0065] In this embodiment, when the rocker arm of the coal mining machine swings up to its upper limit swing angle... At that time, the maximum mining height of the coal mining machine Calculate using the following formula: ; When the rocker arm of the coal mining machine swings down to its lower limit angle At that time, the minimum mining height of the coal mining machine Calculate using the following formula: ; Among them, the lower limit swing angle corresponding to the minimum mining height .

[0066] In actual use, the upper limit swing angle The traditional top-mounted hydraulic cylinder structure mainly utilizes the swing angle range; while the lower limit swing angle... This invention focuses on developing and utilizing the swing angle range.

[0067] In this embodiment, in step three, the high-gain sampling... Calculate using the following formula: ; in, The initial swing angle of the rocker arm is typically set to 0°, indicating a horizontal rocker arm position; high gain is used. That is, the swing angle of the rocker arm from Change to High-increase mining volume at that time A positive value indicates a higher extraction rate. A negative value indicates a decrease in the extraction rate. Used to quantify the contribution of the swing angle to the mining height.

[0068] In specific implementation, such as Figure 12 As shown, high gain swing angle It changes according to a sine function; its instantaneous rate of change (slope) with respect to the swing angle is... It is directly proportional to the angle of inclination and decreases as the angle of inclination increases, reflecting the difference in sensitivity at different angle positions. Approximately 60% of the maximum slope (cos0°=1 at 0°) is taken as the sensitivity baseline: 1×0.6≈0.6, corresponding to an angle of approximately 55°. =0.5736 (corresponding to) The threshold range is divided into intervals of 55° and 55°, which ensures sufficient adjustment sensitivity for the swing angle within the range of -55° to 55°, while avoiding the problem of unbalanced rocker arm force under large swing angle conditions.

[0069] In actual use, by adjusting the rocker arm angle... exist The gain calculation within the interval yielded a key conclusion: when the rocker arm angle... exist When the interval is, The slope changes significantly with the swing angle, requiring high gain. Significant changes occur within this range, which is the high-efficiency zone for mining height gain; even a small adjustment in the swing angle can result in a noticeable change in mining height. exist or When the interval is, When the curve enters the saturation region, the slope decreases sharply, and high gain is adopted. If the height is significantly reduced, even if the swing angle is greatly increased, the lifting effect will be very limited, and it will lead to an imbalance of force on the rocker arm and a decrease in the overall stability of the machine.

[0070] In conclusion, simply increasing the upper swing angle ( This is not an efficient way to increase mining height; on the contrary, it may bring safety hazards. Fully utilizing the downward swing angle (in...) Within the range, this is the most scientific and safest technical approach to increase the overall mining height without altering the dimensions of key components.

[0071] In this embodiment, the height of the coal mining machine face is 4500mm, the rocker arm structure and length are 4677mm, the machine body length is the same, and the drum diameter is 4800mm.

[0072] If a top-mounted hydraulic cylinder is used, the cylinder is installed at the top of the machine body, above the rocker arm. One end of the cylinder is hinged to the rocker arm, and the other end is fixed to the traction part of the machine body or the upper part of the frame. The upward swing angle is 51.09°, and the downward swing angle is 18.26°. Because the cylinder needs to occupy a certain amount of space, at this time... The value is 3329mm, calculated using the formula above: If the mining height cannot meet the 10m requirement, the downward swing angle cannot be increased due to the limitations of the upper-mounted hydraulic cylinder structure. The effective mining height increase corresponding to the mining height gain is limited, which can only meet the basic underground operation requirements and cannot provide effective support for the total mining height to exceed 10m. If the upward swing angle is increased, the mining height gain will saturate sharply and will lead to the rocker arm force imbalance and the overall stability of the machine will decrease. Therefore, the mining height gain of the upper-mounted hydraulic cylinder structure has reached its limit and cannot achieve a mining height of more than 10m through swing angle optimization.

[0073] If a bottom-mounted hydraulic cylinder is used, the upper swing angle increases to 52.39°, and the lower swing angle increases significantly to 27.26°. It is 3926mm, which is derived from the above formula: At this time, because the height gain of the lower swing angle is increased by 0.678m compared with the upper swing angle, the maximum height of the lower swing cylinder can reach 10.709m. Combining the dual effects of the increase in the upper swing angle and the increase in the lower swing angle gain, the maximum height of the lower swing cylinder can reach 10.709m, which fully meets the operation requirements of full height mining in one go above 10m.

[0074] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A coal mining machine height adjustment system, characterized in that: The system includes a rocker arm (1) and a height adjustment cylinder (3). The lower end of the height adjustment cylinder (3) is hinged to the outside of the support leg (4) via a lower conical shaft (6), and the upper end of the height adjustment cylinder (3) is hinged to the lower connecting frame (2) of the rocker arm (1) via an upper conical shaft (13). The support leg (4) and the traction unit (5) are connected by a three-point connection structure, which includes a first pin (21), a second pin (22), and a third pin (23). The first pin (21) and the second pin (22) are connected by a three-point connection structure. The third pin (23) is located on the upper part of both sides of the support leg (4) and is used to connect the support leg (4) and the traction part (5). The third pin (23) is located above the connection point between the height adjustment cylinder (3) and the support leg (4). The bottom of the traction part (5) has a connecting ear seat (26) for the third pin (23) to connect. The inner side of the support leg (4) is bent outward to form a connecting ear plate (25) for the third pin (23) to connect. The third pin (23) is used to connect the connecting ear seat (26) and the connecting ear plate (25).

2. The coal mining machine height adjustment system according to claim 1, characterized in that: The support leg (4) is provided with a lower ear seat (7) for mounting the lower conical shaft (6). The lower ear seat (7) is provided with a through lower mounting hole. The lower ear plate of the height adjustment cylinder (3) extends into the lower ear seat (7). The lower ear plate of the height adjustment cylinder (3) is provided with a lower ear plate hole coaxial with the lower mounting hole. The two ends of the lower mounting hole are respectively press-fitted with lower conical sleeves (8) that cooperate with the end of the lower conical shaft (6). The lower conical shaft (6) passes through the lower ear plate hole. The lower conical shaft (6) and the two lower conical sleeves (8) are connected by a lower long bolt (9). The lower long bolt (9) passes through the lower conical shaft (6). One end of the lower mounting hole is sealed by a first lower pressure cover (11). The other end of the lower mounting hole is sealed by a second lower pressure cover (12). The first lower pressure cover (11) and the second lower pressure cover (12) are both connected to the lower ear seat (7) by screws.

3. A coal mining machine height adjustment system according to claim 2, characterized in that: The connecting frame (2) is provided with an upper ear seat (14) for mounting the upper conical shaft (13). The upper ear seat (14) is provided with a through upper mounting hole. The upper ear plate of the height adjustment cylinder (3) extends into the upper ear seat (14). The upper ear plate of the height adjustment cylinder (3) is provided with an upper ear plate hole coaxial with the upper mounting hole. The two ends of the upper mounting hole are respectively press-fitted with upper conical sleeves (15) that cooperate with the end of the upper conical shaft (13). The upper conical shaft (13) passes through the upper ear plate hole. The upper conical shaft (13) and the two upper conical sleeves (15) are connected by an upper long bolt (16). The upper long bolt (16) passes through the upper conical shaft (13). One end of the upper mounting hole is sealed by a first upper pressure cover (18) and a second upper pressure cover (19). The other end of the upper mounting hole is sealed by a third upper pressure cover (20).

4. A coal mining machine height adjustment system according to claim 3, characterized in that: The lower conical shaft (6) and the upper conical shaft (13) have the same structure. Both the lower conical shaft (6) and the upper conical shaft (13) include a cylindrical shaft body section and conical sections that are respectively provided at both ends of the shaft body section and whose diameter gradually decreases outward along the axial direction. Both end faces of the lower conical shaft (6) and the upper conical shaft (13) are provided with inwardly recessed positioning grooves. The lower conical sleeve (8) and the upper conical sleeve (15) have the same structure. Both the lower conical sleeve (8) and the upper conical sleeve (15) have conical grooves that match the conical segment, and the conical grooves have protrusions that match the positioning grooves.

5. A coal mining machine height adjustment system according to claim 1, characterized in that: The first pin (21), the second pin (22) and the third pin (23) are all provided with protective covers (24) on both ends. The protective covers (24) on the outside of the first pin (21) and the third pin (23) are fastened to the traction part (5) by screws. The protective cover (24) on the outside of the second pin (22) is connected to the support leg (4) by screws.

6. A coal mining machine height adjustment system according to claim 1, characterized in that: The piston rod of the height-adjusting cylinder (3) includes a core substrate and a surface strengthening layer. The core substrate is made of alloy structural steel forging and is subjected to quenching and tempering treatment and surface nitriding heat treatment in sequence. The surface strengthening layer is a nickel-containing corrosion-resistant alloy layer formed by laser cladding process. The piston rod of the height adjustment cylinder (3) has a tensile strength of not less than 1100MPa and a yield strength of not less than 835MPa. The thickness of the surface strengthening layer is 0.4mm to 0.5mm, and its surface hardness is not less than HRC55.

7. A method for installing the height-adjusting cylinder of the coal mining machine height-adjusting system as described in claim 1, characterized in that, Includes the following steps: Step 1: Establish a simplified model of the coal mining machine height adjustment system: The coal mining machine height adjustment system is simplified into a planar swing guide rod mechanism with the rotation hinge point O between the rocker arm and the machine body as the origin of the frame. Step 2: Determine the relationship between the swing angle and the mining height: Based on the simplified planar swing guide rod mechanism, and according to the structural dimensions of the coal mining machine body and the rocker arm, establish the rocker arm swing angle. With actual effective mining height The geometric function relationship between them is used to determine the limiting swing angles corresponding to the maximum and minimum mining heights; Step 3: Determine the sampling height gain: based on the rocker arm angle. Calculate the sampling gain The high-sensitivity linear adjustment region and the saturation region are divided into a high-gain region, wherein the high-sensitivity linear adjustment region is... The saturation region is or The saturation range regulation efficiency drops sharply and causes structural instability; By measuring the rocker arm swing angle exist The mining height gain is calculated within the interval to determine the efficient adjustment range of the mining height gain; among which, when the rocker arm angle is at... When it is within the range, it is determined to be in the high-efficiency adjustment zone, and then... The high slope characteristic in this range enables sensitive response to sampling height; when the rocker arm swing angle exceeds this range and enters the saturation region, the swing angle is limited to prevent further increase in sampling height gain and rocker arm force imbalance. Step 4: Determine the installation position of the hydraulic cylinder: Based on the partitioning of the mining height gain in Step 3, within the high-efficiency adjustment range of the mining height gain, the maximum mining height when using the top-mounted hydraulic cylinder is less than 10m. Therefore, a bottom-mounted hydraulic cylinder layout was selected, and the maximum mining height was increased to more than 10m by simultaneously expanding the effective stroke of the upper and lower swing angles.

8. The method for installing the height-adjusting cylinder of a coal mining machine height-adjusting system according to claim 7, characterized in that: In step two, the rocker arm swing angle With actual effective mining height The process of determining the geometric functional relationship between them is as follows: ;in, The vertical height of the center of the cutting drum; To cut the diameter of the drum; Vertical height of the cutting drum center ;in, The reference height of the pivot point O between the rocker arm and the machine body from the bottom plate of the well; The effective swing length of the rocker arm is the straight-line distance from the pivot point O between the rocker arm and the machine body to the center of the cutting drum. Therefore, the swing angle of the rocker arm With actual effective mining height The geometric functional relationship between them is as follows: 。 9. The method for installing the height-adjusting cylinder of a coal mining machine height-adjusting system according to claim 8, characterized in that: When the rocker arm of the coal mining machine swings up to its upper limit angle At that time, the maximum mining height of the coal mining machine Calculate using the following formula: ； When the rocker arm of the coal mining machine swings down to its lower limit angle At that time, the minimum mining height of the coal mining machine Calculate using the following formula: ； Among them, the lower limit swing angle corresponding to the minimum mining height .

10. The method for installing the height-adjusting cylinder of a coal mining machine height-adjusting system according to claim 8, characterized in that: In step three, the high-gain sampling... Calculate using the following formula: ； in, The initial swing angle of the rocker arm; high gain is adopted. That is, the swing angle of the rocker arm from Change to High-increase mining volume at that time A positive value indicates a higher extraction rate. A negative value indicates a decrease in the extraction rate. Used to quantify the contribution of the swing angle to the mining height.

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