A highly stable combined hydraulic support device and its hydraulic system

Abstract

The present application relates to a highly stable combined hydraulic support device, which includes a base, a top beam, and bottom hydraulic columns arranged between the base and the top beam. An upper inlet and a lower inlet are provided on the side wall of the bottom hydraulic column. A pressure relief component is connected to the lower inlet, a control valve is connected to the upper inlet, and the pressure relief component is connected to the control valve. The pressure relief component includes a housing and a blocking plug. The interior of the housing is an inner cavity, and the blocking plug is fitted in the inner cavity. One end of the housing is provided with a main inlet, the other end is provided with a main outlet, and a pressure relief port is opened on the side wall of the housing. An elastic member is arranged in the inner cavity. The elastic member is used to push the blocking plug to separate the main outlet from the pressure relief port. When the bottom hydraulic column is relieved of pressure, the blocking plug is pressed by the pressure of the hydraulic oil to squeeze the elastic member, so that the main outlet is communicated with the pressure relief port after the blocking plug moves. A liquid flow channel is provided in the center of the blocking plug. The present application has the advantages of improving the stability of the bottom hydraulic column during use and reducing the damage of the bottom hydraulic column when it is impacted.

Description

Technical Field

[0001] This application relates to the technical field of a hydraulic support device, and in particular to a highly stable combined hydraulic support device and its hydraulic system. Background Art

[0002] The hydraulic support device is used in the fully mechanized coal mining process. In the hydraulic support device, a hydraulic system is applied to provide a supporting force and can also provide power for the self - movement of the hydraulic support device. The hydraulic support device is a mechanical device for controlling the mine pressure in the coal mining face and provides the coal mining face. During the coal mining process, as the working face advances, the hydraulic support device also moves accordingly.

[0003] The prior art patent document CN220979552U discloses a combined hydraulic support for an integral roof beam in coal mines, including a base, a hydraulic support column, a roof beam, and a shield beam. The base is hinged to the bottom end of the hydraulic support column, the top end of the telescopic shaft of the hydraulic support column is hinged to the roof beam, and the rear end of the roof beam is hinged with a shield beam; it also includes a quick - support device. The shield beam and the base are hinged and matched through a connecting rod, and a quick - support device is arranged on the side of the base. The quick - support device includes a support beam, a hoop, a connecting rod, and a length - adjusting mechanism. A support beam is arranged on the side of the base, the top end of the support beam is hinged with the hoop, the hoop is sleeved and fixed on the surface of the telescopic shaft of the hydraulic support column, a connecting rod is hinged and installed on the side of the base, the end of the connecting rod is hinged with the middle part of the support beam, and a length - adjusting mechanism is arranged on the support beam.

[0004] The prior art patent document CN217176674U discloses a combined hydraulic support, including a base, a fixing member, a lower connecting rod, an upper connecting rod, a roof beam, a front beam, a rib - protecting plate, and a support assembly. At the top of one end of the base, bottom hydraulic columns are symmetrically and fixedly installed. On one side of the top of the base, a fixing member is fixedly installed. The top of the fixing member is movably installed with a lower connecting rod through a shaft rod. One end of the lower connecting rod is movably installed with an upper connecting rod through a shaft rod. One end of the roof beam rotates with the upper connecting rod, and the other end rotates with the front beam. One end of the front beam is rotatably connected to the rib - protecting plate. Top hydraulic rods are fixedly installed between the roof beam and the front beam, and between the front beam and the rib - protecting plate. The support assembly includes a connecting rod, a rotating rod, a screw rod, a sliding rod, and a limiting sliding plate. The limiting sliding plate is slidably installed in a limiting chute, the sliding rod is limit - slidably installed inside the limiting sliding plate, the bottom of the rotating rod is fixedly installed with a screw rod, the screw rod is movably installed inside the sliding rod through a thread, the top of the rotating rod is movably installed with a connecting rod through a rotating shaft, and the connecting rod is movably installed on one side of the lower connecting rod through a rotating shaft. The support assembly can move as the lower connecting rod rotates, and the support of the lower connecting rod is increased through the rotating rod and the screw rod to improve stability.

[0005] Between the top beam and the base, multiple bottom hydraulic columns are usually used for support. When the top beam is impacted, the bottom hydraulic columns bear the impact, making it easy for the bottom hydraulic columns to be damaged after being extended. Summary of the Invention

[0006] In order to improve the stability of the bottom hydraulic columns during use and reduce damage to the bottom hydraulic columns when they are impacted, the present application provides a highly stable combined hydraulic support device and its hydraulic system.

[0007] The present application provides a highly stable combined hydraulic support device, adopting the following technical solutions:

[0008] A highly stable combined hydraulic support device includes a base, a top beam, and bottom hydraulic columns arranged between the base and the top beam. An upper inlet and a lower inlet are provided on the side wall of the bottom hydraulic column. A pressure relief component is connected to the lower inlet. The upper inlet is connected to a control valve, and the pressure relief component is connected to the control valve. The pressure relief component includes a housing and a blocking plug. The interior of the housing is an inner cavity, and the blocking plug is fitted inside the inner cavity. A main inlet is provided at one end of the housing, and a main outlet is provided at the other end. A pressure relief port is opened on the side wall of the housing. An elastic member is arranged inside the inner cavity. The elastic member is used to push the blocking plug to separate the main outlet from the pressure relief port. When the bottom hydraulic column is depressurized, the blocking plug is pressed by the pressure of the hydraulic oil to squeeze the elastic member, causing the blocking plug to move and the main outlet to communicate with the pressure relief port. A liquid flow channel is opened in the center of the blocking plug.

[0009] Adopting the above technical solutions, during use, bottom hydraulic columns are arranged between the top beam and the base for support. The lower inlet of the bottom hydraulic column is connected to the pressure relief component. When the bottom hydraulic column is providing support, the internal pressure of the bottom hydraulic column is relatively high, and the internal pressure oil directly acts on the position of the main outlet of the housing from the lower inlet. The blocking plug is used to separate the main outlet from the pressure relief port. When the pressure at the main outlet suddenly increases, the blocking plug will be subjected to a large force and move, causing the pressure relief port to communicate with the main outlet, thereby releasing a small part of the pressure oil in the bottom hydraulic column. Then, under the action of the elastic member, it returns to the state of separating the main outlet from the pressure relief port, timely restoring the support state of the bottom hydraulic column, enabling the bottom hydraulic column to buffer the impact, reducing damage to the bottom hydraulic column when it is impacted, and improving the safety and stability of the bottom hydraulic column during use.

[0010] Preferably, an inner retaining edge is provided inside the inner cavity. The two sides of the inner retaining edge are respectively an upper cavity and a lower cavity. The blocking plug is located in the lower cavity. A control plug is provided in the upper cavity. An elastic member is also provided between the control plug and the inner retaining edge. The control plug includes an upper cylindrical portion and a lower cylindrical portion. The diameter of the lower cylindrical portion is larger than that of the upper cylindrical portion, and the lower cylindrical portion is fitted with the upper cavity. A top cavity is also provided inside the housing, and the top cavity is communicated with the main inlet. The upper cylindrical portion is fitted in the top cavity. A main oil passage is opened in the control plug. One end of the main oil passage is located at the connection between the upper cylindrical portion and the lower cylindrical portion, and the other end is located at the end face of the lower cylindrical portion away from the upper cylindrical portion.

[0011] Preferably, a cylinder one is provided on the surface of the control plug facing the blocking plug, and a cylinder two is provided on the surface of the blocking plug facing the control plug. One end of the cylinder two is fitted inside the cylinder one, and a filter is provided inside the cylinder two.

[0012] Preferably, a slag discharge port is opened on the housing, and a hand valve is installed on the slag discharge port. The end of the slag discharge port away from the hand valve is used to connect to the connection between the upper cavity and the top cavity.

[0013] Preferably, a cylindrical head is provided at the end of the blocking plug away from the cylinder two, and the diameter of the cylindrical head is larger than that of the cylinder two.

[0014] Preferably, an opening cavity is formed between the surface of the blocking plug connected to the cylindrical head and the inner cavity of the housing. The opening cavity is connected with an opening port. The opening port is used to introduce hydraulic oil into the opening cavity simultaneously when hydraulic oil enters from the upper inlet. A radial passage is opened on the blocking plug. One end of the radial passage is used to connect to the liquid flow passage, and the other end is on the side wall of the blocking plug.

[0015] Preferably, the control valve is a two-position five-way directional control valve. The control valve has a P port, a T port, an A port, a B port, and a C port. The P port is connected to the pump, the T port is connected to the fuel tank, the B port and the C port are communicated. When the control valve controls the elongation of the bottom hydraulic column, the P port is communicated with the A port, and the B port is communicated with the T port; when the control valve controls the contraction of the bottom hydraulic column, the P port is communicated with the B port, and both the T port and the A port are in a closed state. The A port is connected to the main inlet, the B port is connected to the upper inlet, the C port is connected to the opening port, and the T port is also connected to the pressure relief port.

[0016] Preferably, the end of the hand valve away from the slag discharge port is connected to the T port.

[0017] The present application also provides a hydraulic system for a highly stable combined hydraulic support device, adopting the following technical solution:

[0018] A hydraulic system for a highly stable combined hydraulic support device controls the bottom hydraulic column by adopting the above-mentioned highly stable combined hydraulic support device.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] 1. When the bottom hydraulic column is impacted, the lower inlet of the bottom hydraulic column is connected to the main outlet of the housing, increasing the pressure at the main outlet. Then, the pressure at the main outlet exerts a force on the blocking plug, causing the blocking plug to move within the inner cavity and connecting the main outlet to the pressure relief port. This enables the impact on the bottom hydraulic column to be reduced through the buffering of the pressure relief port, improving the stability of the bottom hydraulic column during use;

[0021] 2. The control plug is arranged in the upper cavity. When hydraulic oil enters from the main inlet, the control plug moves to connect the main inlet to the main outlet through the top cavity and the main oil passage. When maintaining the position of the bottom hydraulic column, the control plug disconnects the main inlet from the main oil passage, thereby reducing the impact transmitted by the bottom hydraulic column to the control valve. Since the upper cylindrical part of the control plug cooperates with the top cavity, the control plug automatically opens when hydraulic oil enters from the main inlet. After the control plug is in the open state, the lower cylindrical part can further bear the force of the elastic member, enabling the control plug to remain open under the condition of hydraulic oil, that is, the control plug can be relatively stable in the open state after opening, and the hydraulic oil flows stably into the bottom hydraulic column. The hydraulic oil is decompressed through the main oil passage to ensure the smooth elongation of the bottom hydraulic column;

[0022] 3. A cylinder I is arranged on the control plug, and a cylinder II is arranged on the blocking plug. The cylinder I and the cylinder II can form a sealed space without affecting the movement of the cylinder I and the cylinder II. The filter in the cylinder II filters the hydraulic oil that enters the bottom hydraulic column through the cylinder I and the cylinder II, thereby reducing the impact on the bottom hydraulic column when the bottom hydraulic column bears a large pressure under the support. If there are impurities in the hydraulic oil, the impurities may affect the bottom hydraulic column and easily reduce the service life of the bottom hydraulic column. For the space of the filter in the cylinder I and the cylinder II, the filter is closer to the bottom hydraulic column to reduce the entry of impurities in the pipeline into the bottom hydraulic column.

[0023] 4. A slag discharge port is provided on the housing. When it is necessary to regularly clean the impurities in the filter, the position of the hand valve can be opened when the bottom hydraulic column needs to contract. Since the hand valve connects the slag discharge port to the main oil passage, the hydraulic oil flowing back through the contraction of the bottom hydraulic column in the main oil passage will pass through the filter, thereby being able to wash the filter and reducing the replacement of the filter.

[0024] 5. The opening port is in communication with the opening cavity. When the bottom hydraulic column needs to contract, first introduce pressure oil into the opening cavity through the opening port, so that the blocking plug connects the radial channel with the pressure relief port, and the hydraulic oil at the lower part of the bottom hydraulic column is discharged through the pressure relief port. The opening sequence of the opening port and the oil discharge of the slag discharge port is that when the slag discharge port is opened, even if pressure oil enters at the opening port, it cannot be opened. Since the hydraulic oil passing through the filter flows out directly, and when the opening port is opened, the elastic member abutting against the blocking plug must be moved by a relatively large pressure first. Therefore, when the slag discharge port is opened, the hydraulic oil can only flow out through the filter and will not flow out directly from the opening port, and the filter cannot be backflushed.

[0025] 6. When the control valve controls the elongation of the bottom hydraulic column, the P port is in communication with the A port, and the B port is in communication with the T port. Since the P port is in communication with the A port, the hydraulic oil entering from the P port can flow out from the A port. The A port is connected to the main inlet, so that the hydraulic oil enters the housing, opens the control plug, and enables the main oil passage to conduct oil. Then the hydraulic oil enters the bottom hydraulic column along the liquid flow channel. For the hydraulic oil in the upper part of the bottom hydraulic column, it can enter the position of the T port from the B port connected to the upper inlet, and thus can flow back to the fuel tank to realize the elongation of the bottom hydraulic column. On the contrary, when the control valve controls the contraction of the bottom hydraulic column, the P port is in communication with the B port, and both the T port and the A port are in a closed state. The hydraulic oil in the P port directly flows out from the B port and the C port. The C port is directly connected to the opening port, so that the pressure relief port separated by the blocking plug can be connected to the main outlet first, and the hydraulic oil at the lower part of the bottom hydraulic column can directly flow out from the pressure relief port, and the hydraulic oil at the B port can flow into the bottom hydraulic column from the upper inlet, and then can push the bottom hydraulic column to contract downward. Therefore, after the control valve switches positions, it can accurately control the telescopic movement of the bottom hydraulic column. Description of the Drawings

[0026] Figure 1 is the overall structural schematic diagram of the embodiment of the present application;

[0027] Figure 2 is the structural schematic diagram of the bottom hydraulic column in the embodiment of the present application;

[0028] Figure 3 is the structural schematic diagram of the pressure relief assembly in the embodiment of the present application;

[0029] Figure 4 is the connection structural schematic diagram of the control valve in the embodiment of the present application.

[0030] Description of reference numerals: 1, base; 11, upper connecting rod; 12, lower connecting rod; 13, top beam; 14, bottom hydraulic cylinder; 141, lower inlet; 142, upper inlet; 2, pressure relief assembly; 21, housing; 211, main inlet; 212, main outlet; 213, slag discharge port; 214, pressure relief port; 215, opening port; 22, blocking plug; 221, liquid flow channel; 222, cylindrical head; 23, inner cavity; 231, upper cavity; 232, lower cavity; 24, top cavity; 25, opening cavity; 31, first sealing ring; 32, second sealing ring; 33, third sealing ring; 34, fourth sealing ring; 35, fifth sealing ring; 4, elastic member; 5, inner retaining edge; 51, guiding hole; 6, control plug; 61, upper cylindrical part; 62, lower cylindrical part; 63, annular groove; 64, main oil passage; 65, stepped surface; 71, first cylinder; 72, second cylinder; 73, filter; 8, hand valve; 9, radial passage; 10, control valve. Detailed implementation manners

[0031] The following further elaborates on this application Figures 1-4 in conjunction with the attached drawings.

[0032] An embodiment of this application discloses a highly stable combined hydraulic support device. Referring to Figure 1 , it includes a base 1, an upper connecting rod 11, a lower connecting rod 12, a top beam 13, and four bottom hydraulic cylinders 14. The base 1 is horizontally arranged, the top beam 13 is located directly above the base 1 and is parallel to the base 1. The top beam 13 is used to support the top of the roadway. One end of the upper connecting rod 11 is connected to one end of the top beam 13, and the other end is rotatably connected to one end of the lower connecting rod 12. The four bottom hydraulic cylinders 14 are arranged in a rectangle on the base 1. The four bottom hydraulic cylinders 14 are connected to the base 1 by spherical hinges, and the upper ends of the four bottom hydraulic cylinders 14 are hinged to the top beam 13 by rotating shafts. By extending the four bottom hydraulic cylinders 14, the top beam 13 can be lifted and lowered, enabling the top beam 13 to support or release. The four bottom hydraulic cylinders 14 are all double-stage hydraulic cylinders.

[0033] Referring to Figure 2 , the side wall of the bottom hydraulic cylinder 14 is provided with a lower inlet 141 and an upper inlet 142. When hydraulic oil enters through the lower inlet 141, it is used to extend the bottom hydraulic cylinder 14. When hydraulic oil enters through the upper inlet 142, it is used to contract the bottom hydraulic cylinder 14. After the bottom hydraulic cylinder 14 extends, the top beam 13 can abut against the top of the roadway to support the roadway. Since the bottom hydraulic cylinder 14 needs to bear a large support force, the pressure of the hydraulic oil entering through the lower inlet 141 is greater and the bottom hydraulic cylinder 14 requires high tightness, so that the support capacity of the bottom hydraulic cylinder 14 is higher.

[0034] Referring to Figure 2 and Figure 3, a pressure relief component 2 is provided on one side of the bottom hydraulic column 14. The pressure relief component 2 comprises a housing 21 and a blocking plug 22. The housing 21 is cylindrical and can be fixed on the side wall of the bottom hydraulic column 14. The central axis of the housing 21 is parallel to the central axis of the bottom hydraulic column 14. A main inlet 211 is provided at the upper end of the housing 21, and a main outlet 212 is provided at the lower end of the housing 21. The main inlet 211 is used for allowing hydraulic oil to enter the housing 21, and the main outlet 212 is used for allowing hydraulic oil to flow out of the housing 21. The interior of the housing 21 is a hollow structure forming an inner cavity 23, and the blocking plug 22 is located inside the inner cavity 23. A first sealing ring 31 is further provided on the outer wall of the cylindrical blocking plug 22. Through the first sealing ring 31, the blocking plug 22 is in sealing fit with the inner cavity 23, and the blocking plug 22 can be slidably connected inside the inner cavity 23. The blocking plug 22 is located at a position of the housing 21 close to the main outlet 212, and a liquid flow channel 221 is formed through the center of the blocking plug 22. The liquid flow channel 221 is used for allowing hydraulic oil to pass through. An elastic member 4 is further provided in the housing 21. The elastic member 4 is a helical spring. The axis of the elastic member 4 coincides with the axis of the blocking plug 22, and the acting force of the elastic member 4 is used to drive the blocking plug 22 to move to one end of the housing 21 close to the main outlet 212. A pressure relief port 214 is provided at one end of the side wall of the housing 21 close to the main outlet 212. When the blocking plug 22 moves through the elastic member 4 to abut against the lower bottom surface of the inner cavity 23, the blocking plug 22 separates the pressure relief port 214 from the main outlet 212. When pressure relief is required, for example, when the bottom hydraulic column 14 is subjected to a large impact force and pressure relief must be carried out to protect the bottom hydraulic column 14, the main outlet 212 is connected to the lower inlet 141. At this time, the pressure inside the bottom hydraulic column 14 increases, causing the pressure at the main outlet 212 to also increase. The blocking plug 22 moves upward under the action of the oil pressure, enabling the pressure relief port 214 to communicate with the main outlet 212. As a result, the hydraulic oil at the main outlet 212 can flow out through the pressure relief port 214, so as to buffer the impact received by the bottom hydraulic column 14.

[0035] An inner retaining edge 5 is provided inside the housing 21. The middle part of the inner retaining edge 5 is a circular guiding hole 51. The inner retaining edge 5 divides the inner cavity 23 into an upper cavity 231 and a lower cavity 232. The blocking plug 22 is located in the lower cavity 232. A control plug 6 is provided in the upper cavity 231. The control plug 6 includes an integrally provided upper cylindrical part 61 and a lower cylindrical part 62. Annular grooves 63 are formed on the side walls of both the upper cylindrical part 61 and the lower cylindrical part 62. A second sealing ring 32 is provided in the annular groove 63 of the upper cylinder. A third sealing ring 33 is provided in the annular groove 63 on the side wall of the lower cylindrical part 62. The third sealing ring 33 is in sealing cooperation with the inner wall of the upper cavity 231. The diameter of the upper cylindrical part 61 is smaller than that of the lower cylindrical part 62. There is also a top cavity 24 in the housing 21 that cooperates with the upper cylinder. The top cavity 24 is located above the upper cavity 231 and is connected to the main inlet 211. A main oil passage 64 is formed inside the control plug 6. The main oil passage 64 is opened at the position where the upper cylindrical part 61 and the lower cylindrical part 62 are connected and extends towards the center of the end face of the lower cylindrical part 62 away from the upper cylindrical part 61. When hydraulic oil enters the housing 21 from the main inlet 211, the control plug 6 first moves downward due to the pressure of the hydraulic oil, separating the upper cylindrical part 61 from the top cavity 24. Thus, the hydraulic oil enters the top cavity 24 from the main inlet 211 and then enters the upper cavity 231, and enters the liquid flow passage 221 along the main oil passage 64, so that the hydraulic oil pushes the bottom hydraulic column 14. When the elongation of the bottom hydraulic column 14 is completed, the pressure at the main inlet 211 decreases, and the control plug 6 moves upward, blocking the hydraulic oil inside the housing 21 and reducing the pressure exerted on the control valve 10 connected to the main inlet 211, thereby protecting the control valve 10. One end of the elastic member 4 abuts against the inner retaining edge 5, and the other end abuts against the blocking plug 22. At the same time, an elastic member 4 is also provided in the upper cavity 231. One end of the elastic member 4 in the upper cavity 231 abuts against the inner retaining edge 5, and the other end abuts against the control plug 6.

[0036] On one side of the control plug 6 facing the blocking plug 22, a first cylinder body 71 is integrally provided. On one side of the blocking plug 22 facing the control plug 6, a second cylinder body 72 is integrally provided. The axis of the second cylinder body 72 coincides with that of the first cylinder body 71. One end of the second cylinder body 72 is inserted into the first cylinder body 71. A fourth sealing ring 34 is provided on the outer wall of the second cylinder body 72 for sealing between the first cylinder body 71 and the second cylinder body 72. The first cylinder body 71 and the second cylinder body 72 can slide relative to each other. A filter 73 is provided inside the second cylinder body 72, and the filter 73 is fixed inside the second cylinder body 72. When the hydraulic oil enters the first cylinder body 71 from the main oil passage 64, the hydraulic oil needs to pass through the filter 73 inside the second cylinder body 72 first and then enter the liquid flow passage 221, so that the hydraulic oil can be filtered again before entering the bottom hydraulic column 14, improving the cleanliness of the hydraulic oil. When the bottom hydraulic column 14 bears a large load, the damage to the bottom hydraulic column 14 caused by impurities can be reduced. The outer wall of the first cylinder body 71 is in sliding fit with the guide hole 51. One end of the lower cylindrical portion 62 connected to the upper cylindrical portion 61 forms a stepped surface 65. The area enclosed by the first cylinder body 71 inside the lower cylindrical portion 62 is larger than the area of the stepped surface 65, ensuring that the hydraulic oil will not open the control plug 6 from one side of the first cylinder body 71.

[0037] Reference Figure 3 and Figure 4 , a slag discharge port 213 is further provided on the side wall of the housing 21 near one end of the main inlet 211. A manual valve 8 is installed on the slag discharge port 213. The slag discharge port 213 is connected to the housing 21 at the connection between the top cavity 24 and the upper cavity 231 and is directly opposite to the opening of the main oil passage 64. The manual valve 8 is normally in a closed state. When the filter 73 needs to be backflushed, the manual valve 8 is opened. The hydraulic oil flowing back when the bottom hydraulic column 14 expands and contracts will backflush the filter 73 through the liquid flow passage 221 and then flow out through the main oil passage 64 and the manual valve 8, thus reducing the operation of removing the filter 73 for cleaning and facilitating the regular cleaning of the filter 73.

[0038] A cylindrical head 222 is provided at one end of the blocking plug 22 away from the second cylinder body 72. A fifth sealing ring is provided on the peripheral wall of the cylindrical head 222. The fifth sealing ring 35 seals the cylindrical head 222 and the inner wall of the main outlet 212. The diameter of the cylindrical head 222 is set according to the maximum bearing capacity of the bottom hydraulic column 14. The diameter of the cylindrical head 222 needs to be larger than the diameter of the second cylinder body 72 so that when the pressure of the hydraulic oil at the main outlet 212 is too high, the hydraulic oil will push the blocking plug 22 upward. The area between the side of the blocking plug 22 connected to the cylindrical head 222 and the inner wall of the housing 21 is the opening cavity 25. The opening cavity 25 is connected to the opening 215. The opening 215 is located on the side wall of the housing 21. When hydraulic oil is introduced into the opening 215, the opening 215 can apply a force to the blocking plug 22 to push the blocking plug 22 upward, and can also connect the pressure relief port 214 and the main outlet 212, which is used for the hydraulic oil in the bottom hydraulic column 14 to flow back when the filter 73 does not need to be cleaned. A radial channel 9 is provided in the middle of the blocking plug 22. One end of the radial channel 9 is connected to the liquid flow channel 221, and the other end leads to the side wall of the blocking plug 22 between the two first sealing rings 31, so that the radial channel 9 and the liquid flow channel 221 connect the main outlet 212 and the pressure relief port 214 to ensure the disconnection between the opening 215 and the main outlet 212.

[0039] The control valve 10 adopts a two-position five-way directional control valve. The control valve 10 has a P port, a T port, and A ports, B ports, and C ports. The P port is connected to the pump, the T port is connected to the fuel tank, and the B port and the C port are connected. When the control valve 10 controls the elongation of the bottom hydraulic column 14, the P port is connected to the A port, and the B port is connected to the T port; when the control valve 10 controls the contraction of the bottom hydraulic column 14, the P port is connected to the B port, and the T port and the A port are both in a closed state. The A port is connected to the main inlet 211, the B port is connected to the upper inlet 142, the C port is connected to the opening 215, and the T port is also connected to the pressure relief port 214. At the same time, the manual valve 8 can also be connected to the T port, and the impurities are processed after being recovered into the fuel tank.

[0040] Working process of this embodiment: During use, when the P port and the A port are in a connected position and the B port and the T port are in a connected position, when pressure oil enters the position of the A port from the P port, the pressure oil opens the control plug 6 and enters the bottom hydraulic column 14 from the lower inlet 141 after passing through the main oil passage 64 and the filter 73. At the same time, the position of the upper inlet 142 is connected to the B port, and the B port is connected to the T port, so as to directly discharge the hydraulic oil above the bottom hydraulic column 14 into the fuel tank. At this time, the bottom hydraulic column 14 moves in the extending direction; when the P port is connected to the B port and pressure oil enters the position of the B port from the P port, the B port and the C port remain connected. Therefore, the pressure oil first exerts a force on the blocking plug 22 at the opening 215 from the C port, so that the blocking plug 22 can move upward, connecting the main outlet 212 and the pressure relief port 214 through the radial passage 9. Then, the hydraulic oil of the B port enters the bottom hydraulic column 14 from the position of the upper inlet 142, and the hydraulic oil at the lower part of the bottom hydraulic column 14 directly flows back to the fuel tank through the main outlet 212, the radial passage 9 and the pressure relief port 214. Therefore, the bottom hydraulic column 14 will move in the contracting direction under the action of the pressure oil. When the bottom hydraulic column 14 maintains the supporting function, the pump can stop working. Of course, a switching valve can also be set between the pump and the control valve 10 so that the pump can provide pressure oil for multiple hydraulic support devices at the same time, or the control valve 10 can adopt a reversing valve with an intermediate position. In the intermediate position, the P port is not connected to the A port or the B port, and the T port is not connected to the A port or the B port. When the bottom hydraulic column 14 is in a normal supporting state, the control plug 6 prevents the hydraulic oil in the bottom hydraulic column 14 from flowing back, maintaining the supporting force of the bottom hydraulic column 14. At the same time, when the impact on the bottom hydraulic column 14 is too large, the blocking plug 22 can move upward under the action of the hydraulic oil, so that the hydraulic oil in the bottom hydraulic column 14 is released through the pressure relief port 214. After being released under the action of the elastic member 4, it can quickly recover to buffer the impact on the bottom hydraulic column 14. When the impact is relieved, the blocking plug 22 can still block the pressure relief port 214 to prevent the roof beam 13 from falling directly, thereby reducing the damage of the bottom hydraulic column 14 when it is impacted and improving safety and stability.

[0041] This embodiment also discloses a hydraulic system of a highly stable combined hydraulic support device, which controls the bottom hydraulic column by using the above-mentioned highly stable combined hydraulic support device.

[0042] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape and principle of this application should be covered within the protection scope of this application.

Claims

1. A highly stable combined hydraulic support device, comprising a base (1), a top beam (13), and a bottom hydraulic column (14) disposed between the base (1) and the top beam (13), characterized in that: On the side wall of the bottom hydraulic column (14), there are an upper inlet (142) and a lower inlet (141). A pressure relief component (2) is connected to the lower inlet (141). The upper inlet (142) is connected to a control valve (10). The pressure relief component (2) is connected to the control valve (10). The pressure relief component (2) includes a housing (21) and a blocking plug (22). The interior of the housing (21) is an inner cavity (23). The blocking plug (22) is fitted in the inner cavity (23). One end of the housing (21) is provided with a main inlet (211), and the other end is provided with a main outlet (212). A pressure relief port (214) is formed on the side wall of the housing (21). An elastic member (4) is arranged in the inner cavity (23). The elastic member (4) is used to push the blocking plug (22) to separate the main outlet (212) from the pressure relief port (214). When the bottom hydraulic column (14) is depressurized, the blocking plug (22) is pressed by the pressure of the hydraulic oil to squeeze the elastic member (4), so that after the blocking plug (22) moves, the main outlet (212) is communicated with the pressure relief port (214). A liquid flow channel (221) is formed in the center of the blocking plug (22). An inner blocking edge (5) is arranged inside the inner cavity (23). The two sides of the inner blocking edge (5) are respectively an upper cavity (231) and a lower cavity (232). The blocking plug (22) is located in the lower cavity (232). A control plug (6) is arranged in the upper cavity (231). An elastic member (4) is also arranged between the control plug (6) and the inner blocking edge (5). The control plug (6) includes an upper cylindrical part (61) and a lower cylindrical part (62). The diameter of the lower cylindrical part (62) is larger than that of the upper cylindrical part (61). And the lower cylindrical part (62) is fitted with the upper cavity (231). A top cavity (24) is also arranged in the housing (21). The top cavity (24) is communicated with the main inlet (211). The upper cylindrical part (61) is fitted in the top cavity (24). A main oil passage (64) is formed in the control plug (6). One end of the main oil passage (64) is located at the connection between the upper cylindrical part (61) and the lower cylindrical part (62), and the other end is located at the end face of the lower cylindrical part (62) away from the upper cylindrical part (61).

2. The high-stability combined hydraulic support device according to claim 1, characterized in that: A cylinder one (71) is arranged on the side of the control plug (6) facing the blocking plug (22). A cylinder two (72) is arranged on the side of the blocking plug (22) facing the control plug (6). One end of the cylinder two (72) is fitted in the cylinder one (71). A filter (73) is arranged in the cylinder two (72).

3. A highly stable combined hydraulic support device according to claim 2, characterized in that: A slag discharge port (213) is formed on the housing (21). A manual valve (8) is installed on the slag discharge port (213). The end of the slag discharge port (213) away from the manual valve (8) is used to be connected to the connection between the upper cavity (231) and the top cavity (24).

4. A highly stable combined hydraulic support device according to claim 3, characterized in that: A cylindrical head (222) is arranged at the end of the blocking plug (22) away from the cylinder two (72). The diameter of the cylindrical head (222) is larger than that of the cylinder two (72).

5. A highly stable combined hydraulic support device according to claim 4, characterized in that: The blocking plug (22) is connected between one surface of the cylindrical head (222) and the inner cavity (23) of the housing (21) to form an opening cavity (25). The opening cavity (25) is connected with an opening (215). The opening (215) is used for introducing hydraulic oil into the opening cavity (25) simultaneously when the hydraulic oil enters from the upper inlet (142). A radial channel (9) is formed in the blocking plug (22). One end of the radial channel (9) is used for connecting to the liquid flow channel (221), and the other end is located on the side wall of the blocking plug (22).

6. The high-stability combined hydraulic support device according to claim 5, wherein: The control valve (10) is a two-position five-way directional control valve. The control valve (10) has a P port, a T port, and ports A, B, and C. The P port is connected to the pump, the T port is connected to the fuel tank, and ports B and C are communicated. When the control valve (10) controls the elongation of the bottom hydraulic cylinder (14), the P port is communicated with the A port, and the B port is communicated with the T port. When the control valve (10) controls the contraction of the bottom hydraulic cylinder (14), the P port is communicated with the B port, and both the T port and the A port are in a closed state. The A port is connected to the main inlet (211), the B port is connected to the upper inlet (142), the C port is connected to the opening (215), and the T port is also connected to the pressure relief port (214).

7. A highly stable combined hydraulic support device according to claim 6, characterized in that: One end of the hand valve (8) far from the slag discharge port (213) is connected to the T port.

8. The hydraulic system of a highly stable combined hydraulic support device, characterized in that: The bottom hydraulic cylinder is controlled by using a highly stable combined hydraulic support device according to any one of claims 1-7.

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