Three-mining-machine coal mining technology and system

Abstract

The invention relates to the technical field of coal mining, in particular to a three-mining-machine coal mining process and system. The coal mining technology is operated based on the first single-drum coal mining machine, the middle coal mining machine and the second single-drum coal mining machine, and the first single-drum coal mining machine, the middle coal mining machine and the second single-drum coal mining machine are sequentially arranged on the scraper conveyer in the direction from the machine head to the machine tail. In the process that the middle coal mining machine cuts coal between the first middle point and the fourth middle point, one of the first single-drum coal mining machine and the second single-drum coal mining machine cuts coal in a vertical feed mode, and the other one cuts coal in a beveling feed mode. The roadway space of the machine head and the machine tail occupied by the single-drum coal mining machine can be effectively reduced, the roadway of the machine head or the machine tail does not need to be set to be wide, and the production cost is effectively reduced. As the single-drum coal mining machine only treats triangular coal areas left by the double drums, the functions are simplified, and the production efficiency of an ultra-long working face and the utilization rate of the coal mining machine are improved.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, and in particular to a three-stage coal mining process and system. Background Technology

[0002] Coal mining machines are indispensable key equipment in the coal mining industry, playing a vital role in promoting the mechanization and modernization of coal mine production. Coal mining machines are mainly divided into two types: single-drum coal mining machines and double-drum coal mining machines. Under the actual working conditions of current ultra-long coal mining faces, double-drum coal mining machines are usually selected for coal mining operations.

[0003] However, using a single twin-drum coal mining machine presents several challenges. At each end, the machine requires two turning maneuvers, meaning it must change direction and turn around upon reaching both ends of the working face. This not only increases operational complexity but can also accelerate equipment wear. More importantly, within a complete work cycle, the machine operates in a "no-cut" state for two periods. "No-cut" operation refers to the machine moving without cutting coal, undoubtedly wasting time and operational capacity.

[0004] Although there are now coal mining equipment that uses two single-drum coal mining machines and one double-drum coal mining machine to work together, the unreasonable cutting method of the single-drum coal mining machine requires the two single-drum coal mining machines to occupy the roadway space at the head and tail of the machine when cutting, which requires a large roadway width at the head and tail of the machine and increases production costs. Summary of the Invention

[0005] This invention provides a three-stage coal mining process to address the issue that existing coal mining systems require large roadway widths at the head and tail of the machine, which increases production costs.

[0006] This invention provides a three-stage coal mining process, which is implemented based on a first single-drum coal mining machine, an intermediate coal mining machine, and a second single-drum coal mining machine. The first single-drum coal mining machine, the intermediate coal mining machine, and the second single-drum coal mining machine are sequentially arranged on a scraper conveyor along the direction from the machine head to the machine tail. The scraper conveyor has a first endpoint, a first intermediate point, a second intermediate point, a third intermediate point, a fourth intermediate point, and a second endpoint along the direction from the machine head to the machine tail. The coal mining process includes: During the coal cutting process between the first intermediate point and the fourth intermediate point, one of the first single-drum coal mining machine and the second single-drum coal mining machine uses a vertical cutting method to cut coal, while the other uses an oblique cutting method.

[0007] According to a three-stage coal mining process provided by the present invention, during the coal cutting process of the intermediate coal mining machine between the first intermediate point and the fourth intermediate point, one of the first single-drum coal mining machine and the second single-drum coal mining machine cuts coal using a vertical cutting method, and the other cuts coal using an oblique cutting method. The process includes the following steps: During the process of the intermediate coal mining machine cutting coal from the first intermediate point to the fourth intermediate point, the first single-drum coal mining machine uses a slanted cutting method to cut coal in the triangular coal area between the first endpoint and the second intermediate point, and forms a working area at the end of the coal mining face near the machine head. During the process of the intermediate coal mining machine cutting coal from the fourth intermediate point to the first intermediate point, the second single-drum coal mining machine cuts coal in the triangular coal area between the second endpoint and the third intermediate point by using a vertical cutting method, and forms a working area at the end of the coal mining face near the tail of the machine. During the process of the intermediate coal mining machine cutting coal from the first intermediate point to the fourth intermediate point, the first single-drum coal mining machine uses a slanted cutting method to cut coal in the triangular coal area between the first endpoint and the second intermediate point. Repeat the above steps in sequence.

[0008] According to the three-stage coal mining process provided by the present invention, it further includes: Working areas are formed by cutting the end of the coal mining face near the tail of the machine and the end of the coal mining face near the head of the machine.

[0009] According to a three-stage coal mining process provided by the present invention, timely support is adopted in the working area of ​​the intermediate coal mining machine.

[0010] According to a three-stage coal mining process provided by the present invention, timely support is adopted in the working areas of both the first single-drum coal mining machine and the second single-drum coal mining machine.

[0011] According to a three-stage coal mining process provided by the present invention, during the coal cutting process of the intermediate coal mining machine between the first intermediate point and the fourth intermediate point, the number of curved sections of the scraper conveyor is less than or equal to two.

[0012] According to a three-stage coal mining process provided by the present invention, the working area of ​​the intermediate coal mining machine is larger than the working area of ​​the first single-drum coal mining machine and the working area of ​​the second single-drum coal mining machine.

[0013] According to a three-stage coal mining process provided by the present invention, the first single-drum coal mining machine and the second single-drum coal mining machine are of the same model.

[0014] According to the present invention, a three-stage coal mining process is provided, wherein the intermediate coal mining machine is a double-drum coal mining machine.

[0015] The present invention also provides a coal mining machine system, which performs coal mining based on the three-mine coal mining process described in any one of the above claims.

[0016] The three-stage coal mining process provided by this invention, during the coal cutting process between the first and fourth intermediate points by the intermediate coal mining machine, effectively reduces the space occupied by the single-drum coal mining machine at the head and tail of the machine by reducing the need for wider roadways at the head or tail, thus significantly lowering production costs. Furthermore, since the single-drum coal mining machine only handles the triangular coal seam area left over from the double-drum machine, its function is simplified, improving the production efficiency of ultra-long working faces and the utilization rate of the coal mining machine. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the three-stage coal mining process provided by the present invention.

[0019] Figure 2 This is one of the schematic diagrams of the coal mining process of the three-stage coal mining machine when the intermediate coal mining machine moves towards the tail of the machine, provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the coal mining process of the three-stage mining machine when the intermediate coal mining machine moves towards the head, as provided by the present invention.

[0021] Figure 4 This is the second schematic diagram of the coal mining process of the three-stage mining machine when the intermediate coal mining machine moves towards the tail of the machine, provided by the present invention.

[0022] Figure label: 100, First single-drum coal mining machine; 200, Intermediate coal mining machine; 300, Second single-drum coal mining machine; 400, Working area; 0, First endpoint; A, First intermediate point; B, Second intermediate point; C, Third intermediate point; D, Fourth intermediate point; E, Second endpoint. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0026] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0028] The following is combined Figures 1-4 The specific steps of the three-stage coal mining process of the present invention are described.

[0029] The three-stage coal mining process is implemented based on a first single-drum coal mining machine 100, an intermediate coal mining machine 200, and a second single-drum coal mining machine 300. The first single-drum coal mining machine 100, the intermediate coal mining machine 200, and the second single-drum coal mining machine 300 are sequentially arranged on a scraper conveyor along the direction from the head to the tail. The scraper conveyor has a first endpoint O, a first intermediate point A, a second intermediate point B, a third intermediate point C, a fourth intermediate point D, and a second endpoint E along the direction from the head to the tail. The scraper conveyor is arranged in parallel with the hydraulic support, which is used to support the coal mining face.

[0030] The coal mining process includes the intermediate coal mining machine 200 cutting coal between the first intermediate point A and the fourth intermediate point D. One of the first single-drum coal mining machine 100 and the second single-drum coal mining machine 300 cuts coal by vertical cutting, while the other cuts coal by oblique cutting.

[0031] The three-stage coal mining process provided by this invention, during the coal cutting process between the first intermediate point A and the fourth intermediate point D by the intermediate coal mining machine 200, effectively reduces the roadway space occupied by the single-drum coal mining machine at the head and tail of the machine by reducing the roadway space occupied by the single-drum coal mining machine. This eliminates the need to widen the roadways at the head and tail of the machine, resulting in a more compact overall working face layout, reduced roadway excavation, and lower production costs. While the intermediate coal mining machine 200 performs the main coal cutting operations, the single-drum coal mining machine can efficiently handle triangular coal zones, avoiding wasted time during idle operation and improving the production efficiency and coal mining machine utilization rate of ultra-long working faces.

[0032] In one embodiment of the present invention, Figure 1A schematic diagram illustrating the three-stage coal mining process provided by this invention is provided. Figure 2 This example illustrates one of the schematic diagrams of the three-stage coal mining process provided by the present invention when the intermediate coal mining machine moves towards the tail. Figure 3 This invention provides a schematic diagram illustrating the coal mining process of a three-stage mining machine during the movement of the intermediate coal mining machine towards the machine head. Figure 4 Example 2 illustrates the third-stage coal mining process flow diagram of the intermediate coal mining machine moving towards the tail of the machine, as provided by the present invention. Figures 1 to 4 As shown, during the coal cutting process between the first intermediate point A and the fourth intermediate point D, the first single-drum coal mining machine 100 and the second single-drum coal mining machine 300 use a vertical cutting method for coal cutting, while the other uses an oblique cutting method for coal cutting. The steps include: In step S100, during the process of the intermediate coal mining machine 200 cutting coal from the first intermediate point A to the fourth intermediate point D, the first single-drum coal mining machine 100 cuts coal in the triangular coal area between the first endpoint O and the second intermediate point B by using a slanted cutting method, and forms a working area 400 at the end of the coal mining face near the machine head.

[0033] Specifically, such as Figure 2 As shown, in the initial stage, the intermediate coal mining machine 200 and the first single-drum coal mining machine 100 are located in the working area 400 on the right, and the second single-drum coal mining machine 300 is located in the working area 400 on the left. During the process of the intermediate coal mining machine 200 cutting coal from the first intermediate point A to the fourth intermediate point D, the first single-drum coal mining machine 100 moves to the left. The hydraulic support between the first endpoint 0 and the second intermediate point B moves with the machine and pushes the conveyor, forming a curved section between the first endpoint 0 and the second intermediate point B. Then, the first single-drum coal mining machine 100 moves to the right, using a slanted cutting method to form a triangular coal zone between the first endpoint 0 and the second intermediate point B. As the intermediate coal mining machine 200 continues to move to the left, the first single-drum coal mining machine 100 moves to the left again, using a vertical cutting method to cut coal in the triangular coal zone between the first endpoint 0 and the second intermediate point B, forming the working area 400 at the end of the coal mining face near the machine head. Figure 3 As shown, after the working area 400 is formed, the first single-drum coal mining machine 100 returns to the head.

[0034] The oblique cutting process forms the working area 400 in one step, allowing the first single-drum coal mining machine 100 to turn directly without secondary adjustments, reducing the end-head empty roof time by more than 40%. The working area 400 provides a stable space for the conveyor head, avoiding repeated roadway widening and reducing roadway support material consumption by more than 15%. The formed working area 400 also serves as the starting gap for the reverse oblique cutting of the next cycle intermediate coal mining machine 200, achieving seamless process connection and improving the continuity of coal cutting in ultra-long working faces.

[0035] In step S200, during the process of the intermediate coal mining machine 200 cutting coal from the fourth intermediate point D to the first intermediate point A, the second single-drum coal mining machine 300 cuts coal in the triangular coal area between the second endpoint E and the third intermediate point C by using a vertical cutting method, and forms a working area 400 at the end of the coal mining face near the tail of the machine.

[0036] like Figure 3 As shown, during the coal cutting process of the intermediate coal mining machine 200 from the fourth intermediate point D to the first intermediate point A, the intermediate coal mining machine 200 cuts at the end of the coal face near the tail end in an oblique cutting manner, forming a triangular coal zone at the end of the coal face near the tail end, and forming a curved section between the third intermediate point C and the fourth intermediate point D; as the intermediate coal mining machine 200 continues to move towards the head, the hydraulic support from the tail end to the middle of the coal face moves with the machine and pushes the conveyor, leveling the scraper conveyor, so that all the scraper conveyors are on the same straight line. Then, the second single-drum coal mining machine 300 cuts coal in the triangular coal zone between the second endpoint E and the third intermediate point C using a vertical cutting method. At the same time, the hydraulic support in the middle of the coal face... The hydraulic support (the hydraulic support between the third intermediate point C and the second intermediate point B) moves with the machine and pushes the conveyor, forming two curved sections between the third intermediate point C and the second intermediate point B. After the coal cutting in the triangular coal area is completed, the second single-drum coal mining machine 300 returns to the tail of the machine. Then, the hydraulic support near the tail of the machine moves with the machine and pushes the conveyor, so that there is only one curved section between the first endpoint A and the second endpoint E. Then, the intermediate coal mining machine 200 continues to move towards the first intermediate point A. At the same time, the second single-drum coal mining machine 300 forms a working area 400 at the end of the coal mining face near the tail of the machine by using a vertical cutting method. After the working area 400 is formed, the second single-drum coal mining machine 300 returns to the tail of the machine. At this time, the intermediate coal mining machine 200 reaches the first intermediate point A.

[0037] In step S300, during the process of the intermediate coal mining machine 200 cutting coal from the first intermediate point A to the fourth intermediate point D, the first single-drum coal mining machine 100 cuts coal in the triangular coal area between the first endpoint 0 and the second intermediate point B by using a slanted cutting method.

[0038] like Figure 4As shown, specifically, during the process of the intermediate coal mining machine 200 cutting coal from the first intermediate point A to the fourth intermediate point D, the intermediate coal mining machine 200 cuts at an oblique angle at the end of the coal face near the machine head, forming a triangular coal zone at the end of the coal face near the machine head, and forming a curved section between the third intermediate point C and the second intermediate point B; then, the first single-drum coal mining machine 100 enters the left side of the triangular coal zone along the curved section, and the hydraulic support near the machine head moves along with the machine and pushes the conveyor. At this time, there is no curved section on the scraper conveyor; then, the first single-drum coal mining machine 100 moves towards the machine head to cut coal in the triangular coal zone near the machine head. After the triangular coal zone is cut, the first single-drum coal mining machine 100 returns to the machine head. At this time, the positions of the first single-drum coal mining machine 100, the intermediate coal mining machine 200, and the second single-drum coal mining machine 300 are... Figure 2 In the first step, the positions of the first single-drum coal mining machine 100, the intermediate coal mining machine 200, and the second single-drum coal mining machine 300 are the same. The intermediate coal mining machine 200 creates a notch by cutting obliquely, while the first single-drum coal mining machine 100 only processes the triangular coal zone near the machine head. The bending section of the scraper conveyor is controlled by sequential pushing, reducing the risk of roof exposure. The intermediate coal mining machine 200 can leave a standard notch on the machine head side with a single oblique cut, allowing the first single-drum coal mining machine 100 to directly cut into the triangular coal zone without needing to create a second notch, thus reducing the roof exposure time by more than 40%. The pushing process is synchronized with the single-drum coal cutting; when the triangular coal zone is processed, the scraper conveyor is completely straightened, instantly sealing the roof exposure area. The exposed length and time of the roof are both reduced, simultaneously improving end-face safety and the speed of advancement in the ultra-long working face.

[0039] Step S400: Repeat the above steps sequentially.

[0040] By repeating the above steps, the coal mining work of the entire coal mining face can be completed. The number of cycles can be flexibly set according to the length of the working face, the coal thickness and the daily output target. During the repetition process, the actions of cleaning triangular coal, pushing the support and straightening the conveyor have formed a fixed sequence, reducing the number of manual intervention nodes and increasing the automation rate.

[0041] In one embodiment of the present invention, such as Figure 2 As shown, the three-stage coal mining process also includes cutting working areas 400 at the end of the coal face near the tail and the end near the head. The working area 400 near the tail and the working area 400 near the head can have the same or different lengths. Pre-setting the working area 400 provides reliable turning and cutting space for the single-drum coal mining machine, significantly reducing end-head adjustment time, minimizing equipment idle travel, and improving the overall continuity of coal cutting. The size of the working area 400 can be flexibly adjusted according to the roadway width, equipment model, and coal quantity in the triangular coalfield, avoiding resource waste due to over-cutting and preventing equipment interference due to insufficient space, thus achieving precise mining.

[0042] In one embodiment of the present invention, timely support is adopted within the working area of ​​the intermediate coal mining machine 200. By adopting timely support within the working area of ​​the intermediate coal mining machine 200, the support moves forward closely following the drum, the roof exposure time is shortened by more than 50%, significantly reducing the probability of roof delamination and collapse. At the same time, timely support reduces the scope of advanced support and material consumption, simplifies the end maintenance process, and further improves the advancement speed and production capacity of ultra-long working faces.

[0043] In one embodiment of the present invention, timely support is adopted in the working areas of both the first single-drum coal mining machine 100 and the second single-drum coal mining machine 300. By adopting timely support, space is provided for the forming of the end working area 400, the adjustment of the single drum and the bending section of the scraper conveyor, thereby improving the parallelism of the end processes and further shortening the cycle operation time.

[0044] In one embodiment of the present invention, during the coal cutting process between the first intermediate point A and the fourth intermediate point D by the intermediate coal mining machine 200, the number of curved sections of the scraper conveyor is less than or equal to two. By reducing the number of curved sections, uneven roof structure caused by multiple bends is avoided. After reducing the number of curved sections, the curved sections of the scraper conveyor and hydraulic support are shortened, the force direction of the roof is concentrated, and the load distribution is uniform, significantly reducing the risk of local stress concentration and roof delamination. At the same time, the wear of the chain and chute is reduced, the transmission efficiency is improved, and energy consumption and maintenance costs are further reduced.

[0045] In one embodiment of the present invention, the working area of ​​the intermediate coal mining machine 200 is larger than that of the first single-drum coal mining machine 100 and the second single-drum coal mining machine 300. By expanding the continuous coal cutting range of the intermediate coal mining machine 200, its advantages of high power and deep cutting depth of the double drum can be fully utilized to achieve efficient advancement of the main mining area and reduce downtime caused by frequent machine relocation. At the same time, the triangular coal areas at both ends are precisely cleaned by the single-drum coal mining machine, avoiding repeated back-and-forth turns of the double-drum coal mining machine at narrow ends, reducing equipment wear and energy consumption. After the area is divided, the output ratio of the middle section increases, the workload at the ends decreases, the overall cycle time is shortened, and the single output level and coal mining machine utilization rate of the ultra-long working face are improved simultaneously.

[0046] In one embodiment of the present invention, the first single-drum coal mining machine 100 and the second single-drum coal mining machine 300 are of the same model. After the single-drum coal mining machine completes the triangular coal cleaning, it sequentially performs the lag support pushing, beam retraction, and frame pulling to eliminate the curved section, so that the scraper conveyor is straightened. After being straightened, the scraper conveyor is on the same straight line, the curved section disappears, the stress points of the support and chute change from multi-point concentration to linear uniformity, the roof pressure is redistributed, and the local stress peak decreases by more than 30%. The roof gap is compressed to within the instantaneous exposure width of the triangular coal area, and the roof exposure time is shortened from minutes to seconds, significantly reducing the probability of delamination and collapse. At the same time, after the straightness of the conveyor is improved, the chain and sprocket meshing is more stable, the running resistance is reduced, and energy consumption and wear decrease simultaneously. Pushing the chute, retracting the beam, and pulling the frame are completed in one go, reducing the manual adjustment process, further improving the efficiency of end-end operations, and providing a stable and safe transportation channel for continuous coal cutting in ultra-long working faces.

[0047] In one embodiment of the present invention, the intermediate coal mining machine 200 is a double-drum coal mining machine. The double drum can complete the full-height coal cutting in one cut, reducing the number of round trips by 50% compared with the single drum, and increasing the single machine's output by more than 30%. At the same time, the double drum can form a continuous and flat bottom plate in the intermediate mining area, reducing the amount of subsequent triangular coal area cleaning, and providing a uniform support surface for delayed support, further reducing the risk of spalling and floor heave.

[0048] The three-stage coal mining process provided by this invention, during the coal cutting process between the first intermediate point A and the fourth intermediate point D by the intermediate coal mining machine 200, effectively reduces the roadway space occupied by the single-drum coal mining machine at the head and tail of the machine by reducing the roadway space occupied by the single-drum coal mining machine. This eliminates the need to widen the roadways at the head and tail of the machine, resulting in a more compact overall working face layout, reduced roadway excavation, and lower production costs. While the intermediate coal mining machine 200 performs the main coal cutting operations, the single-drum coal mining machine can efficiently handle triangular coal zones, avoiding wasted time during idle operation and improving the production efficiency and coal mining machine utilization rate of ultra-long working faces.

[0049] The present invention also provides a coal mining machine system, which performs coal mining based on the three-mine coal mining process described in any of the above embodiments.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-stage coal mining process, characterized in that, The coal mining process is implemented based on a first single-drum coal mining machine (100), an intermediate coal mining machine (200), and a second single-drum coal mining machine (300). The first single-drum coal mining machine (100), the intermediate coal mining machine (200), and the second single-drum coal mining machine (300) are sequentially arranged on a scraper conveyor along the direction from the head to the tail. The scraper conveyor has a first endpoint (0), a first intermediate point (A), a second intermediate point (B), a third intermediate point (C), a fourth intermediate point (D), and a second endpoint (E) along the direction from the head to the tail. The coal mining process includes: During the coal cutting process between the first intermediate point (A) and the fourth intermediate point (D) of the intermediate coal mining machine (200), one of the first single-drum coal mining machine (100) and the second single-drum coal mining machine (300) cuts coal by vertical cutting, and the other cuts coal by oblique cutting.

2. The three-stage coal mining process according to claim 1, characterized in that, During the coal cutting process between the first intermediate point (A) and the fourth intermediate point (D) by the intermediate coal mining machine (200), the step in which one of the first single-drum coal mining machine (100) and the second single-drum coal mining machine (300) cuts coal using a vertical cutting method and the other cuts coal using an oblique cutting method includes the following steps: During the process of the intermediate coal mining machine (200) cutting coal from the first intermediate point (A) to the fourth intermediate point (D), the first single-drum coal mining machine (100) cuts coal in the triangular coal area between the first endpoint (0) and the second intermediate point (B) by using a slanted cutting method, and forms a working area (400) at the end of the coal mining face near the machine head. During the process of the intermediate coal mining machine (200) cutting coal from the fourth intermediate point (D) to the first intermediate point (A), the second single-drum coal mining machine (300) cuts coal in the triangular coal area between the second endpoint (E) and the third intermediate point (C) by using a vertical cutting method, and forms a working area (400) at the end of the coal mining face near the tail of the machine. During the process of the intermediate coal mining machine (200) cutting coal from the first intermediate point (A) to the fourth intermediate point (D), the first single-drum coal mining machine (100) cuts coal in the triangular coal area between the first endpoint (0) and the second intermediate point (B) by using a slanted cutting method. Repeat the above steps in sequence.

3. The three-stage coal mining process according to claim 1, characterized in that, Also includes: Working areas (400) are formed by cutting the end of the coal mining face near the tail of the machine and the end of the coal mining face near the head of the machine.

4. The three-stage coal mining process according to claim 1, characterized in that, Timely support is adopted in the working area of ​​the intermediate coal mining machine (200).

5. The three-stage coal mining process according to any one of claims 1 to 4, characterized in that, Timely support is adopted in the working areas of both the first single-drum coal mining machine (100) and the second single-drum coal mining machine (300).

6. The three-stage coal mining process according to claim 5, characterized in that, During the coal cutting process between the first intermediate point (A) and the fourth intermediate point (D) by the intermediate coal mining machine (200), the number of curved sections of the scraper conveyor is less than or equal to two.

7. The three-stage coal mining process according to claim 5, characterized in that, The working area of ​​the intermediate coal mining machine (200) is larger than the working area of ​​the first single-drum coal mining machine (100) and the working area of ​​the second single-drum coal mining machine (300).

8. The three-stage coal mining process according to claim 7, characterized in that, The first single-drum coal mining machine (100) and the second single-drum coal mining machine (300) are of the same model.

9. The three-stage coal mining process according to claim 7, characterized in that, The intermediate coal mining machine (200) is a double-drum coal mining machine.

10. A coal mining machine system, characterized in that, The coal mining machine system performs coal mining based on the three-stage coal mining process described in any one of claims 1 to 9.

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