Coal mine underground heading machine and temporary supporting device thereof

Abstract

The invention discloses an underground coal mine heading machine and a temporary supporting device thereof. The temporary supporting device comprises a bottom plate, a supporting assembly and an overturning oil cylinder and has a folded state and an unfolded state. The supporting assembly is rotationally installed at the front end of the bottom plate, one end of the overturning oil cylinder is rotationally connected and hinged to the rear end of the bottom plate, and the other end of the overturning oil cylinder is hinged to the rear end of the supporting assembly. When the temporary supporting device is in a folded state, the supporting assembly is located over the bottom plate. In the process that the temporary supporting device is switched from the folding state to the stretching state, the supporting assembly moves upwards and forwards relative to the bottom plate. The temporary support and the tunneling machine are effectively integrated, continuous operation of tunneling and supporting is achieved, and the problems that at present, the labor intensity of workers is large, the safety of the workers is poor, and the tunneling and supporting efficiency is low are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine tunnel equipment, and in particular relates to an underground coal mine tunneling machine and a temporary support device thereof. Background Art

[0002] my country's coal mining is mainly carried out in underground mining. When the tunnel boring machine completes the excavation, a certain distance between the top and the top is formed. It is necessary to promptly support the front working face to strengthen the stability of the surrounding rock of the coal tunnel, improve safety, and prevent accidents such as roof collapse and injury. During the tunnel boring machine support operation, the advance temporary support props up the metal mesh and steel belt to fit the top of the tunnel, providing protection for the next step of anchor bolting and cable anchoring operations, so that workers can carry out anchor bolting operations within a safe support range.

[0003] Tunnel support is a complex and arduous task. After tunnel excavation, temporary support must be carried out at the head of the working face, and permanent support of the tunnel must be carried out under the protection of the temporary support. The traditional excavation process adopts alternating intermittent operations of excavation and support. After the tunnel boring machine completes excavation, manual mesh is laid at the head. The equipment and processes are scattered, the labor intensity is high, the construction efficiency is low, the safety of operations under empty roofs is poor, and the safety of operators cannot be protected. Summary of the invention

[0004] The purpose of the present invention is to provide a coal mine underground tunneling machine and a temporary support device thereof, which effectively integrates the temporary support and the tunneling machine to achieve continuous operation of tunneling and support, solve the current problems of high labor intensity for workers, poor safety of operators, low tunneling and support efficiency, improve the support working environment, reduce the labor intensity of workers, increase the safety of support personnel, and improve the efficiency of tunneling; so as to solve at least some of the problems in the prior art.

[0005] A first aspect of an embodiment of the present disclosure provides a temporary support device, which is installed on a tunnel boring machine. The temporary support device includes a base plate, a support assembly and a flip cylinder, and has a folded state and an extended state; the support assembly is rotatably installed on the front end of the base plate, one end of the flip cylinder is rotatably connected and hinged to the rear end of the base plate, and the other end of the flip cylinder is hinged to the rear end of the support assembly; when the temporary support device is in the folded state, the support assembly is located directly above the base plate; during the process of switching the temporary support device from the folded state to the extended state, the support assembly moves upward and forward relative to the base plate.

[0006] Optionally, the support assembly includes a connecting member, an adjusting member and a support body; one end of the connecting member is hinged to the front end of the base plate, the other end of the connecting member is hinged to the rear end of the support body, and the middle part of the connecting member is hinged to the flip cylinder; the adjusting member is installed between the connecting member and the support body, and is used to drive the support body to rotate relative to the connecting member.

[0007] Optionally, the connecting member includes a lifting cylinder.

[0008] Optionally, the adjusting member includes a supporting cylinder, one end of which is rotatably mounted on the connecting member, and the other end of the supporting cylinder is hinged to the supporting body, and its hinge point is located in front of the hinge point between the connecting member and the supporting body.

[0009] Optionally, the support assembly further includes a left flip beam and a right flip beam respectively located on the left and right sides of the support body; the left flip beam is rotatably connected to the support body, and the right flip beam is rotatably connected to the support body.

[0010] Optionally, the support assembly also includes a front telescopic beam and a front telescopic cylinder; the front telescopic beam is slidably mounted on the support body, one end of the front telescopic cylinder is connected to the support body, and the other end of the front telescopic cylinder is connected to the front telescopic beam.

[0011] A second aspect of the disclosed embodiments provides an underground coal mine tunneling machine, the tunneling machine comprising a tunneling device and a temporary support device as described above, which is arranged on the tunneling device.

[0012] Optionally, the tunnel boring machine further includes a hydraulic circuit, and the hydraulic circuit is used to control the alternating operation of the tunnel boring device and the temporary supporting device.

[0013] Optionally, the hydraulic circuit includes a hydraulic pump, a two-position three-way reversing valve, a four-way valve group, a tunneling valve group and a pump station oil tank; the oil inlet of the hydraulic pump is connected to the pump station oil tank, the oil outlet of the hydraulic pump is connected to the oil inlet of the two-position three-way reversing valve, the first oil outlet of the two-position three-way reversing valve is connected to the oil inlet of the four-way valve group, and the oil return port of the four-way valve group is connected to the pump station oil tank; the second oil outlet of the two-position three-way reversing valve is connected to the oil inlet of the tunneling valve group, and the oil return port of the tunneling valve group is connected to the pump station oil tank; wherein the four-way valve group is connected to the temporary support device, and the tunneling valve group is connected to the tunneling device.

[0014] Optionally, the hydraulic circuit also includes a shuttle valve; the shuttle valve is arranged on the feedback oil circuit connecting the four-valve group and the two-position three-way reversing valve, and is also arranged on the feedback oil circuit connecting the tunneling valve group and the two-position three-way reversing valve.

[0015] The main technical effects achieved by the embodiments of the present disclosure are: the support device and the tunnel boring machine are effectively integrated into an integrated design; the support device is installed above the cutting part of the tunnel boring machine and does not occupy the space on both sides of the cutting part; the structure is compact and the operation is smooth; the support device is quickly deployed and has a large support range, which is conducive to the forward advancement of the airborne anchor drill to perform support operations; temporary support is provided for the front working face of the tunnel boring machine to ensure the safety of the anchoring workers; the support device is mounted on the tunnel boring machine and advances forward with the tunnel boring machine, thereby realizing continuous operations of tunneling and support, reducing support time, improving support efficiency, reducing the labor intensity of workers, and improving tunnel boring efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A structural diagram of a temporary support device in one embodiment of the present disclosure Figure 1 ;

[0017] Figure 2 A structural diagram of a temporary support device in one embodiment of the present disclosure Figure 2 ;

[0018] Figure 3 is a schematic diagram of a hydraulic circuit in an embodiment of the present disclosure;

[0019] Figure 4 It is a structural schematic diagram of a coal mine underground tunneling machine in one embodiment of the present disclosure.

[0020] Explanation of the reference numerals: 1. bottom plate; 2. tilting cylinder; 3. first support seat; 4. first support shaft; 5. second support shaft; 6. second support seat; 7. lifting cylinder; 8. first ear seat; 9. second ear seat; 10. left tilting beam; 11. supporting body; 12. front telescopic beam; 13. right tilting beam; 14. front telescopic cylinder; 15. supporting cylinder; 16. tilting cylinder ear seat; 17. third ear seat; 18. fourth ear seat; 19. Five-ear seat; 20. Longitudinal beam; 21. Hydraulic pump; 22. Shuttle valve; 23. Two-position three-way reversing valve; 24. Four-valve group; 25. First balancing valve; 26. Second balancing valve; 27. Third balancing valve; 28. Fourth balancing valve; 29. ​​Tunneling machine operating valve; 30. Return oil filter; 31. Cooler; 32. High-pressure filter; 33. Pump station oil tank; 34. Pressure gauge; 35. Support device; 36. Anchor drilling rig; 37. Tunneling machine. DETAILED DESCRIPTION

[0021] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The modes described in the following exemplary embodiments do not represent all modes consistent with the present disclosure. Instead, they are merely examples of devices consistent with some aspects of the present disclosure as detailed in the appended claims.

[0022] The terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the present disclosure specification and claims do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limitation, but indicate that there is at least one, and if only "one" is referred to, it will be separately described. "Multiple" or "several" means two or more. Unless otherwise specified, similar words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation, and are not limited to one position or one spatial orientation. Similar words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect. The singular forms "a", "said" and "the" used in this disclosure and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0023] like Figure 1 and Figure 2As shown, the embodiment of the present disclosure provides an underground coal mine tunneling machine, which is installed on the tunneling machine. The temporary support device 35 includes a base plate 1, a support assembly and a tilting cylinder 2, and has a folded state and an extended state; the support assembly is rotatably installed on the front end of the base plate 1, one end of the tilting cylinder 2 is rotatably connected and hinged to the rear end of the base plate 1, and the other end of the tilting cylinder 2 is hinged to the rear end of the support assembly; when the temporary support device 35 is in the folded state, the support assembly is located directly above the base plate 1; in the process of switching the temporary support device 35 from the folded state to the extended state, the support assembly moves upward and forward relative to the base plate 1. The support device 35 is effectively integrated with the tunnel boring machine in an integrated design. The support device 35 is installed above the cutting part of the tunnel boring machine and does not occupy the space on both sides of the cutting part. It has a compact structure and is stable to operate. The support device 35 is quickly deployed and has a large support range, which is conducive to the airborne anchor drill rig 36 to advance forward to perform support operations; temporary support is performed on the head working face of the tunnel boring machine to ensure the safety of the anchoring operators. The support device 35 is airborne on the tunnel boring machine and advances forward with the tunnel boring machine, realizing continuous operations of tunneling and support, reducing support time, improving support efficiency, reducing the labor intensity of workers, and improving tunnel excavation efficiency.

[0024] The support assembly includes a connecting piece, an adjusting piece and a supporting body 11; one end of the connecting piece is hinged to the front end of the base plate 1, the other end of the connecting piece is hinged to the rear end of the supporting body 11, and the middle part of the connecting piece is hinged to the flip cylinder 2; the adjusting piece is installed between the connecting piece and the supporting body 11, and is used to drive the supporting body 11 to rotate relative to the connecting piece.

[0025] As an optional embodiment, the connecting member includes a lifting cylinder 7. The connecting member is set as a lifting cylinder 7, so that when the connecting member is rotated to an angle perpendicular to the bottom plate 1, the connecting member can continue to rise, so that the space under the support assembly can accommodate workers to stand normally. Of course, in other embodiments, the connecting member can also be a connecting rod; the present disclosure is not limited to this.

[0026] As an optional embodiment, the adjusting member includes a supporting cylinder 15, one end of which is rotatably mounted on the connecting member, and the other end of the supporting cylinder 15 is hinged to the supporting body 11, and its hinge point is located in front of the hinge point between the connecting member and the supporting body 11. Of course, in other embodiments, the adjusting member can also be a motor or other components, and the present disclosure is not limited to this.

[0027] Specifically, Figure 1 , Figure 2 and Figure 4 As shown, the bottom plate 1 is arranged on the upper part of the cutting part of the tunnel boring machine, and the first support seat 3 and the second support seat 6 are symmetrically arranged on the front and rear sides of the bottom plate 1.

[0028] The first support shaft 4 is disposed in an axial hole of the symmetrically arranged first support seat 3 , and the second support shaft 5 is disposed in an axial hole of the symmetrically arranged second support seat 6 .

[0029] The supporting body 11 is formed by welding a plurality of longitudinal beams and transverse beams into a rectangular structure.

[0030] A turning cylinder 2 is arranged between the first supporting shaft 4 and the third ear seat 17 , the cylinder end of the turning cylinder 2 is hingedly connected to the first supporting shaft 4 , and the piston rod end of the turning cylinder 2 is hingedly connected to the third ear seat 17 via a pin shaft.

[0031] The tilting cylinder 2 drives the support body 11 to unfold and retract.

[0032] The lifting cylinder 7 is symmetrically arranged between the second supporting shaft 5 and the first ear seat 8. The cylinder end of the lifting cylinder 7 is hingedly connected to the second supporting shaft 5, and the piston rod end of the lifting cylinder 7 is hingedly connected to the first ear seat 8 through a pin shaft.

[0033] The supporting body 7 is driven by the lifting cylinder 7 to move upward or downward relative to the base plate 1 .

[0034] The first ear seat 8 , the second ear seat 9 , the fourth ear seat 18 , and the fifth ear seat 19 are symmetrically arranged on both sides of the supporting body 11 .

[0035] The left flip beam 10 and the right flip beam 13 are arranged on the left and right sides of the supporting body 11 through the second ear seat 9. The left flip beam 10 and the right flip beam 13 are flipped around the axis of the pin shaft through the second ear seat 9.

[0036] A supporting cylinder 15 is arranged between the third ear seat 17 and the fourth ear seat 18 . The cylinder end of the supporting cylinder 15 is hingedly connected to the third ear seat 17 through a pin shaft, and the piston rod end of the supporting cylinder 15 is hingedly connected to the fourth ear seat 18 through a pin shaft.

[0037] The supporting oil cylinder 15 drives the front end of the supporting body 11 to rotate upward or downward.

[0038] A front telescopic oil cylinder 14 is arranged between the front telescopic beam 12 and the supporting body 11 , and the front telescopic oil cylinder 14 drives the front telescopic beam 12 to slide forward and backward relative to the supporting body 11 .

[0039] When the tunnel boring machine is working, the support device is folded and retracted to the upper part of the cutting part of the tunnel boring machine through the flip cylinder 2. When the tunnel boring machine's excavation progress reaches the anchor rod spacing, the tunnel boring machine stops excavating, retreats to the anchor rod spacing position, and the cutting head falls to the ground.

[0040] When the tunnel boring machine is working in support operation, the hydraulic pump 21 of the tunnel boring machine is used to supply oil, and the high-pressure oil passes through the two-position three-way reversing valve, enters the four-valve group, then enters the balance valve, and then enters each oil cylinder.

[0041] The supporting body 12 is turned over to the front of the cutting head, and the anchor net and steel belt are pre-placed on the supporting body of the bracket device, and fixed with magnets or wires according to the designed spacing and position.

[0042] Open the power lock, operate the control handle of the tilting cylinder 2, and cooperate with the control handle of the supporting cylinder 15 to allow the supporting device to open slowly and steadily from the folded state. The safety limit for opening the tilting cylinder is that the lifting cylinder 7 tilts forward 30 degrees.

[0043] Operate the control handle of the lifting cylinder 7, and in combination with the raising and lowering of the supporting body, raise the supporting body so that it is parallel to the top plate of the tunnel and gradually approaches the top plate, and push the steel belt and the anchor net bottom beam onto the top plate of the tunnel.

[0044] When the tunnel boring machine is powered off and locked, the operator can operate the anchor drilling rig to safely carry out anchor and cable support operations under the safety protection of the support device.

[0045] After the anchor rod and cable support operation is completed, the support device is operated to be retracted and contracted to the upper part of the cutting part, and then the next tunnel boring machine operation cycle can be entered.

[0046] When the support device is folded, open the power lock, first lower the lifting cylinder to the lowest position, then move the folded support body backward until it is lying above the cutting part of the tunnel boring machine, return to the initial state, return the two-position three-way valve to the initial position, lock the onboard temporary support device, and the tunnel boring machine enters the working state.

[0047] like Figure 3 As shown, the hydraulic circuit of the support device is provided with a hydraulic pump 21, a shuttle valve 22, a two-position three-way reversing valve 23, a four-valve group 24, a first balancing valve 25, a second balancing valve 26, a third balancing valve 27, a fourth balancing valve 28, a tunneling machine operating valve 29, an oil return filter 30, a cooler 31, a high-pressure filter 32, and a pump station oil tank 33.

[0048] The first of the four-valve group 24 controls the turning cylinder 2, and the oil pipe reaches the turning cylinder 2 through the first balance valve 25. The valve handle is operated to make the support body unfold upward or fall down for recovery. The first balance valve 25 ensures synchronization when the turning cylinder is opened.

[0049] The second valve of the four-valve group 24 controls the lifting cylinder 7. The oil pipe reaches the lifting cylinder 7 through the second balance valve 26. The valve handle is operated to make the support body rise up or fall down. The second balance valve 26 ensures synchronization when the lifting cylinder is opened.

[0050] The third valve of the four-valve group 24 controls the supporting cylinder 15, and the oil pipe reaches the supporting cylinder 15 through the third balancing valve 27. The valve handle is operated to make the front end of the supporting body rotate upward or downward. The third balancing valve 27 ensures synchronization when the supporting cylinder is opened.

[0051] The fourth valve of the four-valve group 24 controls the front telescopic oil cylinder 14, and the oil pipe reaches the front telescopic oil cylinder 14 through the fourth balance valve 28. The valve handle is operated to extend the front telescopic beam forward or retract it backward. The fourth balance valve 28 ensures synchronization when the front telescopic oil cylinder is opened.

[0052] One end of the two-position three-way reversing valve 23 is connected to the load-sensitive four-way valve group 24, and the other end is connected to the tunnel boring machine operating valve 29. The two-position three-way reversing valve 23 is used to switch the oil circuit so that the tunnel boring machine hydraulic pump 21 supplies fluid to the mechanism of the tunnel boring machine or the support device to prepare for work.

[0053] A shuttle valve 22 is provided on the feedback oil circuit between the four-valve group 24 and the tunnel boring machine operating valve 29 for comparing the feedback signals. The tunnel boring machine hydraulic pump 21 only receives the feedback signal from the working reversing valve, thereby locking the tunnel boring machine operation and the supporting device operation to ensure the safety of the operation.

[0054] The support device uses the tunnel boring machine hydraulic pump 21 as a hydraulic drive power source to provide power oil for all hydraulic cylinders of the support device. The hydraulic circuit of the support device is integrated with the hydraulic circuit of the tunnel boring machine to share resources.

[0055] Each balancing valve group supplies oil to each cylinder to ensure the synchronous extension or retraction of each pair of cylinders, eliminating the instability and jamming of the support device.

[0056] When the hydraulic circuit of the support device is working, the tunnel boring machine pump motor starts, and the high-pressure oil output by the hydraulic pump 21 passes through the two-position three-way reversing valve 23, and reaches the power oil port P of the four-valve group 24 through manual switching selection. After being evenly distributed through the first balancing valve 25, the second balancing valve 26, the third balancing valve 27, and the fourth balancing valve 28, it synchronously reaches the tipping cylinder 2, the lifting cylinder 7, the supporting cylinder 15, and the front telescopic cylinder 14 respectively. The balancing valve group makes each pair of cylinders extend or retract synchronously, and the low-pressure oil flows back to the return oil port R of the four-valve group 24 through the balancing valve, and flows back to the pump station tank 33 through the cooler 31 and the return oil filter 30.

[0057] The feedback signal generated when the four-way valve group 24 is in working state is greater than the feedback signal of the tunnel boring machine operating valve 29 in non-working state. The shuttle valve 22 compares the feedback signals of the two and only conducts the four-way valve group 24. The hydraulic pump 21 only receives the feedback signal of the four-way valve group 21. During the support operation, the tunnel boring machine operating valve 29 loses the pilot oil supply, and the tunnel boring machine will not have any action. When the support device completes the required tunneling operation, the support device is folded on the cutting part of the tunnel boring machine, and the oil circuit is switched to the valve port of the tunnel boring machine operating valve 29 through the two-position three-way reversing valve 23. The tunnel boring machine resumes its working state, while the support device is in the oil-free state and will not have any action. The tunnel boring machine operation and the support device operation are self-locking to ensure the safety of the operation.

[0058] According to the mine tunnel parameters and support requirements, the main support shape can be designed to be flat or arched, and the structure can be designed to be single top frame, front telescopic, side telescopic, large slope, etc.

[0059] Through the setting of the above structure, the support device uses the hydraulic pump station of the tunnel boring machine as the hydraulic drive power source to provide oil for all hydraulic cylinders, without adding external power source and electrical control equipment. The hydraulic circuit system sets a two-position three-way reversing valve between the four-valve group and the tunnel boring machine operating valve for oil circuit selection and switching, and the shuttle valve is used for feedback signal comparison. The tunneling operation and the support operation are interlocked with each other to ensure operation safety. At the same time, a balancing valve group is set for each pair of cylinders in the support device to ensure that each pair of cylinders extends and retracts synchronously, eliminating the problem of jamming and asynchronism when the support device is working.

[0060] The above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A temporary support device installed on a tunnel boring machine, characterized in that: The temporary support device comprises a bottom plate, a support assembly and a flip cylinder, and has a folded state and an extended state; the support assembly is rotatably mounted on the front end of the bottom plate, one end of the flip cylinder is rotatably connected and hinged to the rear end of the bottom plate, and the other end of the flip cylinder is hinged to the rear end of the support assembly; when the temporary support device is in the folded state, the support assembly is located directly above the bottom plate; During the switching of the temporary supporting device from the folded state to the extended state, the supporting assembly moves upward and forward relative to the base plate.

2. A coal mine underground boring machine according to claim 1, characterized in that: The support assembly includes a connecting piece, an adjusting piece and a supporting body; one end of the connecting piece is hinged to the front end of the base plate, the other end of the connecting piece is hinged to the rear end of the supporting body, and the middle part of the connecting piece is hinged to the flip cylinder; the adjusting piece is installed between the connecting piece and the supporting body, and is used to drive the supporting body to rotate relative to the connecting piece.

3. A coal mine underground boring machine according to claim 2, characterized in that: The connecting member includes a lifting cylinder.

4. A coal mine underground boring machine according to claim 2, characterized in that: The adjusting member comprises a supporting oil cylinder, one end of which is rotatably mounted on the connecting member, and the other end of which is hinged to the supporting body, and a hinge point thereof is located in front of a hinge point between the connecting member and the supporting body.

5. The underground coal mine boring machine according to claim 2, characterized in that: The support assembly also includes a left flip beam and a right flip beam respectively located on the left and right sides of the support body; the left flip beam is rotatably connected to the support body, and the right flip beam is rotatably connected to the support body.

6. The underground coal mine boring machine according to claim 2, characterized in that: The support assembly also includes a front telescopic beam and a front telescopic cylinder; the front telescopic beam is slidably mounted on the support body, one end of the front telescopic cylinder is connected to the support body, and the other end of the front telescopic cylinder is connected to the front telescopic beam.

7. A coal mine underground boring machine, characterized in that: The tunnel boring machine comprises a tunnel boring device and a temporary supporting device as claimed in any one of claims 1 to 6 arranged on the tunnel boring device.

8. The underground coal mine boring machine according to claim 7, characterized in that: The tunnel boring machine further comprises a hydraulic circuit, and the hydraulic circuit is used to control the tunnel boring device and the temporary supporting device to operate alternately.

9. The underground coal mine boring machine according to claim 8, characterized in that: The hydraulic circuit includes a hydraulic pump, a two-position three-way reversing valve, a four-way valve group, a tunneling valve group and a pump station oil tank; the oil inlet of the hydraulic pump is connected to the pump station oil tank, the oil outlet of the hydraulic pump is connected to the oil inlet of the two-position three-way reversing valve, the first oil outlet of the two-position three-way reversing valve is connected to the oil inlet of the four-way valve group, and the oil return port of the four-way valve group is connected to the pump station oil tank; the second oil outlet of the two-position three-way reversing valve is connected to the oil inlet of the tunneling valve group, and the oil return port of the tunneling valve group is connected to the pump station oil tank; wherein the four-way valve group is connected to the temporary support device, and the tunneling valve group is connected to the tunneling device.

10. The underground coal mine boring machine according to claim 9, characterized in that: The hydraulic circuit also includes a shuttle valve; the shuttle valve is arranged on the feedback oil circuit connecting the four-valve group and the two-position three-way reversing valve, and is also arranged on the feedback oil circuit connecting the excavation valve group and the two-position three-way reversing valve.

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