A modified jack mining pressurization oil pump and its modification method

Abstract

This invention relates to a modified mining hydraulic pump and its modification method, comprising a mining hydraulic jack body, a sealing cover, a pressure control assembly, and an oil reservoir. The sealing cover is threadedly connected to the cylinder bore of the mining hydraulic jack body, sealing the inside of the cylinder to form a high-pressure oil chamber, which is connected to the oil outlet of the plunger pump assembly. The annular cavity between the outer shell of the mining hydraulic jack body and the cylinder serves as an oil reservoir, which is connected to the oil inlet of the plunger pump assembly. The pressure control assembly is connected to the sealing cover and is used to achieve pressure regulation, pressure holding control, and real-time pressure monitoring during pressurization operations. It can also be connected to the tested hydraulic components in the mine. An oil passage hole is provided on the side wall of the outer shell, connecting to the oil reservoir. The oil reservoir and the oil reservoir are normally connected. The beneficial effect is that it facilitates the rapid transfer of operators between multiple detection points underground, effectively improving the work efficiency of underground hydraulic equipment maintenance.

Description

Technical Field

[0001] This invention relates to the field of coal mining equipment technology, and in particular to a mining pressure pump modified from a jack and a modification method thereof. Background Technology

[0002] In the underground working environment of coal mines, it is necessary to regularly conduct pressure resistance tests and sealing tests on hydraulic support safety valves, high-pressure hydraulic pipes, and various mining pressure vessels. Currently, commonly used pressure testing devices are mostly portable manual pressure pumps, which typically consist of a base, piston pump, support rod, handle, and external water tank. The piston pump is vertically fixed to the base, and the handle drives the plunger inside the piston pump to reciprocate through a linkage mechanism to generate high-pressure medium. Simultaneously, the piston pump's inlet needs to be connected to the external water tank via a pipeline, and the outlet is connected to a pressure gauge and the component being tested.

[0003] In existing technologies, because the inlet pipe of the piston pump must be connected to an external water tank, and components such as pressure gauges, pressure relief valve assemblies, and pipe joints are all distributed on the base, the entire device is large in size and has an irregular structural layout. In narrow and obstacle-ridden working environments such as underground coal mine roadways, this type of pressure pump is bulky and difficult to move and transport, making it inconvenient for operators to quickly move and operate between multiple locations, which seriously affects the efficiency of underground equipment maintenance. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a mining pressure pump modified from a jack and a modification method, which solves the technical problem that the prior art is large in size and difficult to transport, thus affecting the efficiency of maintenance work.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] On one hand, this invention provides a mining hydraulic pump modified from a jack, comprising a mining hydraulic jack body, a sealing cover, a pressure control assembly, and an oil reservoir; the mining hydraulic jack body is equipped with a plunger pump assembly, a pressure rod, and a reset bolt; the sealing cover is threadedly connected to the cylinder bore of the mining hydraulic jack body, sealing the inside of the cylinder to form a high-pressure oil chamber, which is connected to the oil outlet of the plunger pump assembly; the annular cavity between the outer shell of the mining hydraulic jack body and the cylinder is an oil reservoir, which is connected to the oil inlet of the plunger pump assembly; the pressure control assembly is connected to the sealing cover for pressurizing. The system features pressure regulation, pressure holding control, and real-time pressure monitoring, and can also interface with the hydraulic components being tested in mining applications. The outer casing has an oil passage hole on its side wall that connects to the oil reservoir, which is normally open to the reservoir. During pressurization, the reciprocating pressure rod drives the plunger pump assembly, drawing in and pressurizing the medium from the reservoir before sending it to the high-pressure oil chamber. The high-pressure oil is then injected into the hydraulic components being tested in mining applications through the sealing cover and pressure control assembly. The pressure is monitored in real-time by the pressure control assembly, and once the set pressure is reached, pressure holding is achieved through the pressure control assembly. After pressure holding is completed, the pressure control assembly is opened, and pressure is released through the reset bolt.

[0009] Optionally, the pressure control assembly includes a first shut-off valve, a three-way valve, a pressure gauge, and a second shut-off valve; the first shut-off valve is connected to the top of the sealing cap, the three-way valve is connected to the top of the first shut-off valve, the pressure gauge is connected to the top interface of the three-way valve, the second shut-off valve is connected to the side interface of the three-way valve, and the pipeline is connected to the outlet of the second shut-off valve for connecting to the tested hydraulic component in the mine.

[0010] Optionally, the sealing cover is an integral coaxial structure, which includes a connecting body and a connector from bottom to top; the connecting body has a central through hole that runs through the entire section, the lower end of the central through hole is connected to the high-pressure oil chamber of the cylinder, and the upper end of the central through hole is connected to the first shut-off valve through the connector.

[0011] Optionally, the connecting body includes a threaded connecting section, a disc section, and a hexagonal section connected sequentially from bottom to top; the threaded connecting section is connected to the open thread of the cylinder, and the bottom surface of the disc section abuts against the end face of the cylinder and the end face of the outer shell to simultaneously achieve the sealing of the cylinder and the axial pressing and fixing of the outer shell; the outer peripheral surface of the hexagonal section forms a hexagon for tool turning.

[0012] Optionally, the tee is an integral structure; the bottom of the tee is provided with a first interface for cartridge connection to the first shut-off valve, the top of the tee is provided with an internal thread interface for thread connection to the pressure gauge, and the side of the tee is provided with a second interface for cartridge connection to the second shut-off valve; the tee has a T-shaped flow channel inside that connects the first interface, the internal thread interface and the second interface.

[0013] Optionally, both the first and second interfaces are quick-connect structures and are locked and fixed to the first and second shut-off valves respectively by U-shaped clips.

[0014] Optionally, the first shut-off valve is the system's main control pressure relief valve, and the second shut-off valve is the pressure holding control valve on the side of the tested hydraulic component in the mine; the pressure gauge is normally open to the inner cavity of the three-way valve, and when the second shut-off valve is closed during the pressure holding stage, the pressure gauge can continuously monitor the internal pressure of the tested hydraulic component in the mine; wherein, the tested hydraulic component in the mine includes a safety valve for a coal mine hydraulic support, a high-pressure hydraulic pipe, and a mine pressure vessel.

[0015] Optionally, the oil storage tank includes an oil drum, a lid, and a bend; the top opening of the oil drum is provided with an internal thread, and the bottom end of the lid is threaded to the top opening of the oil drum; one end of the bend is connected to the bottom opening of the oil drum, and the other end of the bend is connected to the oil passage hole on the side wall of the outer shell.

[0016] Optionally, the reset bolt is disposed on the bypass oil passage of the plunger pump assembly, the bypass oil passage connecting the high-pressure oil chamber and the oil reservoir; the reset bolt has a tightened position and a loosened position, the bypass oil passage is cut off when the reset bolt is tightened, and the bypass oil passage is opened when the reset bolt is loosened to realize the pressure relief from the high-pressure oil chamber to the oil reservoir.

[0017] On the other hand, the present invention also provides a method for modifying the above-mentioned mining pressurization oil pump, comprising the following steps:

[0018] S1. Remove the cylinder end cap and piston rod inside the cylinder of the mining hydraulic jack;

[0019] S2. Thread the sealing cap to the cylinder bore and abut it against the end face of the outer shell of the mining hydraulic jack;

[0020] S3. Install the pressure test assembly on the top of the sealing cover; open an oil passage hole on the side wall of the outer casing and connect it to the oil reservoir.

[0021] (III) Beneficial Effects

[0022] The beneficial effects of this invention are:

[0023] This invention provides a mining pressure pump modified from a jack. Through an integrated structural design based on a mining hydraulic jack, it specifically solves the core problems of existing portable manual pressure pumps, such as large size, fragmented structure, and inconvenience in handling and moving in the narrow working environment of coal mines. By removing the original piston rod and end cap of the jack and sealing the cylinder with a sealing cap to form a high-pressure oil chamber, the original plunger pump assembly, pressure rod, and reset bolt structure of the jack can be directly reused. There is no need to set up a special pump body, fixed base, and transmission mechanism. The overall size of the equipment is basically the same as the original jack used for modification. It can be operated with one hand and can adapt to the narrow and obstructed working environment such as underground coal mine roadways and gaps between hydraulic supports. At the same time, the original annular cavity between the jack shell and the cylinder is used as an oil storage chamber. Combined with the oil storage tank directly connected to the side wall of the shell, an integrated oil supply structure is formed. There is no need to set up the external liquid storage tank and external liquid inlet pipeline required by the existing pressure test pump. This reduces the equipment volume redundancy caused by the dispersed layout of components and facilitates the rapid transfer of operators between multiple inspection points underground. It can effectively improve the work efficiency of maintenance of underground hydraulic equipment. This solution can directly reuse a large number of idle hydraulic jacks awaiting scrapping at the coal mine site for modification, which can reduce the procurement and maintenance costs of mine pressure testing equipment, and has good portability, practicality and economy.

[0024] This invention provides a method for modifying a jack into a mining pressure pump. Through a standardized process of step-by-step disassembly, functional reconstruction, and assembly, it achieves rapid and efficient modification of idle mining hydraulic jacks into mining pressure pumps. First, by removing the original cylinder end cap and piston rod inside the cylinder of the mining hydraulic jack, the pressurization potential of the original high-pressure cylinder and plunger pump assembly can be released without destructive modification to the core pressure-bearing structure and pressurization mechanism of the jack, thus fully preserving the original mature high-pressure resistance and manual pressurization function. Next, by threading the sealing cap to the cylinder end and abutting against the end face of the jack's outer shell, reliable sealing of the high-pressure chamber of the cylinder and axial fixation of the jack's outer shell can be simultaneously achieved, ensuring the high-pressure sealing performance and structural stability of the modified equipment. Finally, by installing a pressure testing assembly on the top of the sealing cap and opening an oil passage hole in the side wall of the outer shell and connecting it to the oil reservoir, the integration of all functions—pressurization, pressure holding, pressure testing, and pressure release—can be quickly completed. The entire reform process is simple and requires minimal processing equipment. All operations can be completed using conventional tools in underground coal mine repair workshops. It can be quickly reformed and put into use in emergency repair scenarios, achieving resource reuse, reducing equipment waste, lowering the manufacturing cost of mining pressure equipment, and meeting the conditions for promotion and application in coal mining enterprises. It also has good operability, emergency response capability, and economic efficiency. Attached Figure Description

[0025] Figure 1This is a schematic diagram of the overall structure of a mining pressure pump modified from a jack according to Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of a mining pressure pump modified from a jack according to Embodiment 1 of the present invention from another angle.

[0027] Figure 3 This is an exploded view of the structure of a mining pressure pump modified from a jack according to Embodiment 1 of the present invention;

[0028] Figure 4 This is an exploded view of the structure of a mining pressure pump modified from a jack according to Embodiment 1 of the present invention from another angle.

[0029] Figure 5 This is a cross-sectional view of the sealing cap of Embodiment 1 of the present invention.

[0030] [Explanation of Labels in the Attached Image]

[0031] 11: Piston pump assembly; 12: Pressure rod; 13: Return bolt; 14: Cylinder barrel; 15: Housing;

[0032] 2: Sealing cap; 21: Connector pair; 22: Threaded connection section; 23: Disc section; 24: Hexagonal section;

[0033] 31: First shut-off valve; 32: Tee; 33: Pressure gauge; 34: Second shut-off valve; 35: U-shaped clamp;

[0034] 4: Oil reservoir; 41: Oil drum; 42: Drum cover; 43: Bend. Detailed Implementation

[0035] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0036] Example 1:

[0037] like Figures 1-4As shown, this embodiment provides a modified mining hydraulic pump, including a mining hydraulic jack body, a sealing cover 2, a pressure control assembly, and an oil reservoir 4. The mining hydraulic jack body is equipped with a plunger pump assembly 11, a pressure rod 12, and a reset bolt 13. The sealing cover 2 is threadedly connected to the cylinder port of the cylinder 14 of the mining hydraulic jack body, sealing the interior of the cylinder 14 to form a high-pressure oil chamber, which is connected to the oil outlet of the plunger pump assembly 11. The annular cavity between the outer shell 15 of the mining hydraulic jack body and the cylinder 14 serves as an oil reservoir, which is connected to the oil inlet of the plunger pump assembly 11. The pressure control assembly is connected to the sealing cover 2. It is used to achieve pressure regulation, pressure holding control and real-time pressure monitoring for pressurization operations, and can also be connected to the hydraulic components under test in mining. The side wall of the outer shell 15 has an oil passage hole that connects to the oil storage chamber. The oil passage hole connects to the oil storage cylinder 4, and the oil storage cylinder 4 and the oil storage chamber are normally connected. During pressurization operations, the reciprocating rocking rod 12 drives the plunger pump assembly 11 to work, drawing the medium in the oil storage cylinder 4 into the high-pressure oil chamber after pressurization. The high-pressure oil is injected into the hydraulic components under test in mining through the sealing cover 2 and the pressure control assembly. The pressure is monitored in real time by the pressure control assembly. After the set pressure is reached, the pressure is held by the pressure control assembly. After the pressure is held, the pressure control assembly is opened and the pressure is released by the reset bolt 13.

[0038] Specifically, through an integrated structural design based on a mining hydraulic jack, the core problems of existing portable manual pressure testing pumps—namely, their large size, fragmented structure, and inconvenience in transporting them in the narrow working environment of coal mines—are addressed. By removing the original piston rod and end cap of the jack and sealing the cylinder 14 with the sealing cap 2 to form a high-pressure oil chamber, the original piston pump assembly 11, pressure rod 12 and reset bolt 13 of the jack can be directly reused. There is no need to set up a special pump body, fixed base and transmission mechanism. The overall size of the equipment is basically the same as the original jack used for modification. It can be operated with one hand and can be adapted to the narrow and obstructed working environment such as underground roadways and gaps between hydraulic supports in coal mines. At the same time, the original annular cavity between the outer shell 15 and the cylinder 14 of the jack is used as an oil storage chamber. Together with the oil storage tank 4 directly connected to the side wall of the outer shell 15, an integrated oil supply structure is formed. There is no need to set up the external liquid storage tank and external liquid inlet pipeline required by the existing pressure test pump. This reduces the redundancy of equipment volume caused by the dispersed layout of components and facilitates the rapid transfer of operators between multiple inspection points underground. It can effectively improve the work efficiency of maintenance of underground hydraulic equipment. This solution can directly reuse a large number of idle hydraulic jacks awaiting scrapping at the coal mine site for modification, which can reduce the procurement and maintenance costs of mine pressure testing equipment, and has good portability, practicality and economy.

[0039] Specifically, such as Figures 3-5As shown, the sealing cover 2 is an integral coaxial structure, machined from high-strength mining carbon steel. From bottom to top, it includes a connecting body and a connector 21. The entire structure is seamless, ensuring structural strength and sealing reliability under high-pressure conditions. A central through-hole, a straight hole of equal diameter, is provided in the center of the connecting body. The diameter matches the outlet diameter of the plunger pump assembly 11. The lower end of the central through-hole is directly connected to the high-pressure oil chamber of the cylinder 14, and the upper end is connected to the pressure control assembly via the connector 21. This provides a stable, non-throttling, and turbulent flow path for the high-pressure medium, preventing pressure loss during high-pressure medium flow.

[0040] Furthermore, such as Figure 5 As shown, the connecting body includes a threaded connection section 22, a disc section 23, and a hexagonal section 24, which are coaxially integrally formed from bottom to top. The external thread specification of the threaded connection section 22 is completely matched with the internal thread hole of the cylinder bore 14. It adopts the standard sealing pipe thread for mining, and the thread engagement length is not less than 15mm to ensure the sealing performance and pull-out resistance of the threaded connection. The threaded connection section 22 is tightened and fixed to the open thread of the cylinder 14. The bottom surface of the disc section 23 is completely fitted and abutted against the upper end face of the cylinder 14 and the upper end face of the outer shell 15. This can simultaneously achieve end face sealing of the high-pressure chamber inside the cylinder 14 and axial compression and fixing of the outer shell 15, preventing axial movement of the outer shell 15. The outer circumference of the hexagonal section 24 is a standard regular hexagonal structure. The dimensions of the opposite sides are adapted to the open-end wrench and adjustable wrench commonly used in underground machine repair workshops in coal mines. The tightening, disassembly, and fastening operations of the sealing cover 2 can be completed without special tooling, which is suitable for the on-site modification needs in underground mines.

[0041] Preferably, the bottom surface of the disc section 23 is provided with two coaxially arranged annular sealing grooves. The two annular sealing grooves correspond one-to-one with the upper end face of the cylinder 14 and the upper end face of the outer shell 15, respectively. Each annular sealing groove is fitted with a mining high-pressure resistant sealing ring. The sealing ring is made of emulsion-resistant nitrile rubber with a rated working pressure of not less than 40MPa. It can be adapted to the two media commonly used in coal mines: hydraulic oil and emulsion. The bottom surface of the disc section 23 forms a double independent static seal with the upper end face of the cylinder 14 and the upper end face of the outer shell 15 through the two mining high-pressure resistant sealing rings. This not only prevents the high-pressure medium in the high-pressure oil chamber from leaking outward, but also prevents the medium in the oil storage chamber from leaking outward, while isolating underground coal dust and rock powder from entering the equipment.

[0042] Specifically, such as Figure 3 and Figure 4As shown, the pressure control assembly includes a first shut-off valve 31, a tee 32, a pressure gauge 33, a second shut-off valve 34, and piping. All components use standard mining parts commonly used in coal mines, with a rated working pressure of no less than 40 MPa, suitable for high-pressure testing conditions underground. The first shut-off valve 31 is connected to the connector 21 at the top of the sealing cover 2. The tee 32 is connected to the top of the first shut-off valve 31. The pressure gauge 33 is connected to the top interface of the tee 32. The second shut-off valve 34 is connected to the side interface of the tee 32. The piping is connected to the outlet of the second shut-off valve 34. The end of the piping is equipped with a standard mining quick-connect fitting, which can quickly connect to the tested hydraulic components in the mine, forming a complete high-pressure medium conduction and pressure control path.

[0043] Preferably, the tee 32 is a mining high-pressure forged one-piece structure, made of 45# steel, integrally forged and machined, with no welded structure, and can withstand high-pressure impact loads. The bottom of the tee 32 has a first interface for insert connection with the first shut-off valve 31, the top of the tee 32 has an internal thread interface for threaded connection with the pressure gauge 33, and the side of the tee 32 has a second interface for insert connection with the second shut-off valve 34. The tee 32 has an internal T-shaped flow channel connecting the first interface, the internal thread interface, and the second interface. The three interfaces of the T-shaped flow channel have the same diameter, with no throttling steps, enabling smooth diversion and conduction of high-pressure media, while ensuring that the pressure gauge 33 can simultaneously monitor the real-time pressure of the entire passage without any monitoring blind spots.

[0044] Preferably, both the first and second interfaces are standard quick-connect plug-in structures for mining. The interfaces are equipped with positioning slots and sealing rings, which are locked and fixed to the first stop valve 31 and the second stop valve 34 respectively by U-shaped clips 35. During assembly, the corresponding connectors only need to be inserted into the interfaces. After insertion, the U-shaped clips 35 are passed through the locking holes on the interfaces and connectors to complete the locking. Quick assembly and disassembly can be completed without screwing, which is convenient for assembly, maintenance and replacement of vulnerable parts in the underground field. At the same time, the U-shaped clip 35 locking structure can withstand high pressure impacts of more than 40MPa without the connectors coming off, ensuring the connection sealing and structural reliability under high pressure conditions.

[0045] Specifically, the first shut-off valve 31 is the system's main control pressure relief valve, which controls the opening and closing of the passage between the high-pressure oil chamber and the three-way valve 32. The second shut-off valve 34 is the pressure-holding control valve on the side of the tested hydraulic component, which controls the opening and closing of the passage between the three-way valve 32 and the tested component. The pressure gauge 33 is normally open to the inner cavity of the three-way valve 32. During the pressure holding stage, only the second shut-off valve 34 is closed, and the oil circuit on the side of the tested component is completely closed for pressure holding. The pressure gauge 33 remains connected to the oil circuit on the side of the tested component, which can continuously monitor the internal pressure of the tested hydraulic component. This allows operators to monitor the pressure changes in real time during the pressure holding process and accurately judge the sealing performance of the tested component. The tested hydraulic components include safety valves for coal mine hydraulic supports, high-pressure hydraulic pipes, mine pressure vessels, and sealing cavities of hydraulic support columns, which can cover the pressure resistance testing and sealing performance inspection needs of most hydraulic equipment in underground coal mines.

[0046] Specifically, such as Figure 3 and Figure 4 As shown, the oil storage tank 4 includes an oil tank 41, a tank cover 42, and a bend 43. The oil tank 41 is integrally rolled and welded from a seamless welded steel pipe for mining, with a wall thickness of not less than 3mm. It has strong resistance to impact and collision, and is suitable for complex downhole operating environments. The top opening of the oil tank 41 is provided with an internal thread, and the bottom end of the tank cover 42 is connected to the top opening of the oil tank 41 by an external thread, which can achieve a reliable dustproof seal, preventing impurities such as coal dust and rock powder from entering the oil tank and contaminating the hydraulic medium, and preventing wear and jamming of the plunger pump assembly 11. The top of the tank cover 42 is provided with a cross-shaped screw protrusion, which can be disassembled and assembled by hand without tools, facilitating the on-site addition of hydraulic medium. One end of the bend 43 is fully welded to the bottom opening of the oil cylinder 41, and the weld is treated with anti-rust and anti-corrosion measures. The other end of the bend 43 is rigidly connected to the oil passage hole on the side wall of the outer shell 15 of the main body of the mining hydraulic jack through a mining standard connector seat, so as to achieve stable and constant communication between the oil storage cylinder 4 and the oil storage chamber, and continuously supply hydraulic medium to the plunger pump assembly 11 without the occurrence of cavitation.

[0047] Preferably, an anti-loss chain is welded to the outside of the cylinder cover 42, and the other end of the anti-loss chain is welded and fixed to the outer wall of the oil cylinder 41. This can prevent the cylinder cover 42 from falling off and being lost or rolling into the gap between roadway equipment when disassembling and adding medium downhole, thereby improving the convenience and safety of on-site operations.

[0048] Furthermore, the reset bolt 13 is located on the bypass oil passage of the plunger pump assembly 11. The bypass oil passage is located on the cylinder body of the main body of the mining hydraulic jack. The two ends of the bypass oil passage are connected to the high-pressure oil chamber and the oil storage chamber, respectively. The reset bolt 13 has two working positions: a tightened position and a loosened position. When the reset bolt 13 is in the tightened position, the sealing cone surface at the front end of the bolt presses against the sealing surface of the bypass oil passage, and the bypass oil passage is completely cut off, ensuring the airtightness of the high-pressure oil chamber during the pressurization and pressure holding stages and preventing pressure drop. When the reset bolt 13 is in the loosened position, the sealing cone surface at the front end of the bolt separates from the sealing surface, and the bypass oil passage is fully opened, realizing the safe pressure relief from the high-pressure oil chamber to the oil storage chamber. The system pressure can be smoothly unloaded without disassembling the pipeline, making the operation convenient and safe.

[0049] Preferably, the outer operating end of the reset bolt 13 is provided with an anti-misoperation cap. The anti-misoperation cap is an internally threaded plastic cap that is threadedly connected to the external thread section on the outer shell 15 of the main body of the mining hydraulic jack. It completely covers the operating end of the reset bolt 13, which can prevent the reset bolt 13 from being accidentally loosened and depressurized due to equipment collisions or personnel accidental contact during underground operations. This prevents safety hazards such as pressure holding failure and accidental jetting of high-pressure media, and further improves the safety of underground operations.

[0050] Preferably, the external oil reservoir 4 can be replaced by an oil filling hole with a sealing cap 2 directly opened on the outer shell 15 of the main body of the mining hydraulic jack. The annular cavity between the outer shell 15 of the main body of the mining hydraulic jack and the cylinder 14 is used as the only oil storage structure. There is no need to set up an external oil tank, which can further reduce the overall size of the machine and form a compact structure that is suitable for operation in the ultra-narrow space of underground coal mines, and is suitable for emergency maintenance scenarios with limited space.

[0051] The mining hydraulic pump modified from a jack in this embodiment can be prepared on-site through standardized modification steps, adapting to the conventional processing conditions of underground coal mine repair shops. It requires no specialized precision machining equipment and enables the rapid modification and reuse of idle mining hydraulic jacks. The specific modification steps include:

[0052] Step S1: Remove the cylinder end cap and piston rod inside cylinder 14 of the mining hydraulic jack. Select an idle mining hydraulic jack from the maintenance and replacement of a coal mine hydraulic support. First, clean the coal dust and oil stains from the outer surface of the jack. Fix the jack cylinder body with a wrench, loosen and remove the original lifting end cap at the cylinder mouth, and then completely remove the lifting main piston rod, matching guide sleeve, and seals inside cylinder 14. During the process, retain the plunger pump assembly 11, matching check valve group, pressure rod 12, and reset bolt 13 structure at the bottom of the jack cylinder body without disassembling them to ensure that the original pressurization function is intact and usable. At the same time, clean the residual oil stains and impurities inside cylinder 14 to ensure that the inner wall of cylinder 14 is free of scratches and rust, providing a foundation for subsequent sealing assembly.

[0053] Step S2: Thread the sealing cap 2 to the cylinder bore of the cylinder 14 and abut against the end face of the outer shell 15 of the mining hydraulic jack. First, install the corresponding mining high-pressure resistant sealing rings into the two annular sealing grooves on the bottom surface of the disc section 23 of the sealing cap 2. Then, align the threaded connection section 22 at the bottom of the sealing cap 2 with the internal threaded hole of the cylinder bore of the cylinder 14. Tighten the hexagonal section 24 at the top of the sealing cap 2 with a wrench to fully tighten the sealing cap 2 into the cylinder 14 until the bottom surface of the disc section 23 of the sealing cap 2 is completely flush against the upper end face of the cylinder 14 and the upper end face of the outer shell 15, while ensuring that the thread engagement length meets the sealing requirements. After tightening, the sealing rings achieve a double independent seal between the high-pressure chamber and the oil storage chamber of the cylinder 14, completing the modification and sealing assembly of the jack base.

[0054] Step S3: Install the pressure control assembly on the top of the sealing cover 2; open an oil passage hole on the side wall of the outer casing 15 and connect it to the oil reservoir 4. First, insert the first shut-off valve 31 into the connector 21 at the top of the sealing cover 2 and lock it in place with a U-shaped clamp 35. Then, insert the first interface at the bottom of the tee 32 into the top of the first shut-off valve 31 and lock it in place with a U-shaped clamp 35. After wrapping Teflon tape around the internal threaded interface at the top of the tee 32, tighten and fix the pressure gauge 33. Insert the second shut-off valve 34 into the second interface on the side of the tee 32 and lock it in place with a U-shaped clamp 35. Connect the pipeline to the outlet end of the second shut-off valve 34 to complete the overall assembly of the pressure control assembly. At the same time, drill oil passage holes at the corresponding positions on the side wall of the jack housing 15 using a bench drill. The oil passage holes are fully connected to the oil storage chamber between the housing 15 and the cylinder 14. After cleaning the metal debris around the oil passage holes, weld and fix the mining standard connector seat at the oil passage holes. Then, weld the connector seat to the bottom opening of the oil storage tank 4 using a bent pipe 43 to complete the assembly of the oil storage tank 4. Finally, complete the modification of the entire pressure pump.

[0055] Preferably, after the modification is completed, a no-load test run and a sealing test are required. First, add mining hydraulic oil or emulsion to the oil reservoir 4, fully open the first shut-off valve 31 and the second shut-off valve 34, and shake the pressure rod 12 back and forth several times to expel the air inside the system. Then close the second shut-off valve 34, continue to shake the pressure rod 12 to increase the pressure to the rated working pressure, maintain the pressure for 5 minutes, and check that there is no leakage or pressure drop at each sealing surface and joint. Then it can be put into field use.

[0056] The application of the modified jack-type mining pressure pump provided in this embodiment is as follows: During the maintenance and pressure testing of hydraulic equipment in the fully mechanized mining face of a coal mine, the pump is first connected to the safety valve, high-pressure hydraulic pipe, or mining pressure vessel of the hydraulic support to be tested via the quick-connect fitting at the end of the pipeline. Then, the cap 42 of the oil storage tank 4 is opened, and suitable mining hydraulic oil or underground general emulsion is added into the oil tank 41. After tightening the cap 42, the first shut-off valve 31 and the second shut-off valve 34 are fully opened, and the pressure rod 12 is reciprocated 3-5 times to drive the plunger pump assembly 11 to operate, expel residual air in the oil circuit system, and ensure that the medium fills the entire flow channel without suction. After confirming that the venting is complete, continue to rotate the pressure rod 12 at a constant speed to drive the plunger pump assembly 11 to continuously draw in and pressurize the medium in the oil reservoir 4. The high-pressure medium is continuously injected into the component under test through the high-pressure oil chamber, the central through hole of the sealing cap 2, the first shut-off valve 31, the three-way valve 32, the second shut-off valve 34, and the pipeline. During the process, the pressure gauge 33 displays the system pressure in real time, and the operator can intuitively read the current pressure value. When the value displayed by the pressure gauge 33 reaches the test pressure set by the component under test, stop rotating the pressure rod 12 and immediately close the second shut-off valve 34. The component under test enters the closed pressure holding state. During the process, the pressure gauge 33 remains connected to the oil circuit on the side of the component under test and can continuously monitor the pressure changes during the pressure holding stage. The operator can accurately judge the sealing performance and pressure resistance performance of the component under test based on the pressure changes. After the specified pressure holding time is reached, first slowly open the second shut-off valve 34 to smoothly release the high-pressure medium on the side of the component to be tested, then loosen the reset bolt 13 to make the high-pressure oil chamber and the oil storage chamber connected through the bypass oil passage to complete the overall depressurization of the system. After the pressure gauge 33 returns to zero, the connection between the pipeline and the component to be tested can be disconnected to complete this pressure resistance test.

[0057] Example 2:

[0058] This embodiment provides a mining pressure pump modified from a jack, which includes all the structures of the mining pressure pump modified from a jack described in Embodiment 1.

[0059] In this embodiment, the sealing cover 2 is a universal sealing structure that can be adapted to multiple specifications of jack cylinder 14. The central through hole of the sealing cover 2 integrates a filter component to prevent impurity contamination. At the same time, an anti-air suction and flow stabilizing component is provided at the connection between the oil storage cylinder 4 and the bend pipe 43. In addition, the operating handwheels of the first shut-off valve 31 and the second shut-off valve 34 are both provided with anti-misoperation pressure holding and locking mechanisms adapted to the strong vibration environment downhole.

[0060] Specifically, the general-purpose sealing cover 2 is a segmented coaxial assembly structure, including a base cover body, a replaceable threaded bushing, and a multi-specification sealing pressure ring. The base cover body is an integral high-strength carbon steel structure machined for mining. From bottom to top, a hexagonal operating section, a disc sealing section, and a top connector pair 21 are coaxially arranged. A central through hole of equal diameter is opened in the center, penetrating the entire section. The bottom of the base cover has a coaxial cylindrical bushing mounting groove. The inner wall of the bushing mounting groove is provided with a standard metric internal thread. The replaceable threaded bushing is a cylindrical structure with an external thread on the outer wall that is completely matched with the internal thread of the bushing mounting groove. The replaceable threaded bushing is fixed in the bushing mounting groove by screwing the thread. The inner wall of the replaceable threaded bushing is provided with a standard external thread that matches the internal thread of the cylinder bore 14 of the jack commonly used in coal mines. The replaceable threaded bushing of the corresponding specification can be replaced according to the inner diameter and thread specification of the cylinder bore 14 of the jack to be modified, without having to re-process the entire sealing cover 2, which greatly improves the versatility of the sealing cover 2 and adapts to the modification needs of idle jacks with different cylinder diameters and thread specifications in coal mines.

[0061] Furthermore, the bottom surface of the disc sealing section has three coaxially arranged annular sealing grooves. The diameters of the three annular sealing grooves correspond to the outer diameters of the cylinder 14 and outer shell 15 of standard cylinder diameter jacks commonly used in coal mines (100mm, 125mm, and 160mm). Each annular sealing groove can be fitted with a mining-grade high-pressure nitrile rubber sealing ring of the corresponding size. The bottom surface of the disc sealing section is also equipped with replaceable multi-specification sealing pressure rings. The multi-specification sealing pressure rings are annular flat gasket structures. Their inner diameter matches the outer diameter of the corresponding jack cylinder 14, and their outer diameter matches the outer diameter of the jack outer shell 15. The corresponding specification sealing pressure ring can be replaced according to the size of the cylinder 14 and outer shell 15 of the jack to be modified. In conjunction with the sealing rings in the annular sealing grooves, a double end face static seal is achieved between the cylinder 14 and outer shell 15 of different specifications of jacks. There is no need to re-process the disc section 23 of the sealing cover 2 for different sizes of jacks, further improving the versatility of modification.

[0062] Preferably, a high-pressure filter assembly is integrated within the central through-hole of the sealing cap 2. The filter assembly includes a stainless steel sintered filter element, an elastic positioning spring for the hole, and a conical anti-clogging guide head. The stainless steel sintered filter element has a cylindrical structure with a filtration accuracy of 50μm and is coaxially embedded at the lower liquid inlet of the central through-hole. The inner wall of the central through-hole has an annular groove that matches the positioning spring. The positioning spring is fitted into the annular groove to axially limit the upper end of the stainless steel filter element. The conical anti-clogging guide head is coaxially welded and fixed to the lower end of the stainless steel filter element. The large diameter end of the conical anti-clogging guide head faces downward, and the small diameter end communicates with the filter element. Six guide holes are evenly opened on the circumference of the surface, which can evenly guide the medium in the high-pressure oil chamber into the filter element, while avoiding large particles of impurities from directly impacting the filter element and causing blockage. The filter assembly can filter the high-pressure medium entering the pressure control assembly throughout the entire process, intercepting solid impurities such as coal dust and metal shavings in the medium, preventing impurities from entering the shut-off valve and pressure gauge 33 and causing jamming or damage. At the same time, it prevents impurities from wearing the precision mating surfaces of the plunger pump, greatly extending the service life of the equipment and reducing the frequency of maintenance in the downhole field.

[0063] Specifically, an anti-vacuum flow stabilizing component is installed at the connection between the oil storage tank 4 and the bend 43. The anti-vacuum flow stabilizing component includes a mining-grade oil-resistant flexible suction pipe, a stainless steel weighted suction head, and a low-opening-pressure flow stabilizing check valve. The flexible suction pipe is made of emulsion-resistant nitrile rubber and is placed entirely inside the oil storage tank 4. The upper end of the flexible suction pipe is sealed and fixed to the inlet of the bend 43 located inside the oil storage tank 4. The weighted suction head is fixed to the lower end of the flexible suction pipe. The weighted suction head is made of solid stainless steel and has 8 suction holes evenly distributed around its outer circumference. A 100μm pre-filter screen is installed inside. The flow stabilizing check valve is threadedly installed at the connection between the bend 43 and the connector seat of the outer shell 15. The valve opening pressure is 0.02MPa, and the conduction direction is unidirectional from the oil storage tank 4 to the oil storage cavity. During operation, regardless of whether the equipment is upright, tilted, or even inverted, the counterweight suction head can always keep the lower end of the flexible suction pipe submerged below the liquid level in the oil storage tank 4 under the action of gravity. This avoids problems such as suction cavitation and pressurization failure caused by the suction port being exposed above the liquid level, perfectly adapting to the operational needs of different postures in confined spaces such as the bottom of the downhole support and corners of the roadway. The flow stabilizing check valve can prevent the backflow of the medium when the machine is stopped, and at the same time stabilize the pressure in the suction pipeline, preventing pressure pulsation and cavitation during the plunger pump suction process, thus improving the stability of the pressurization process.

[0064] Specifically, both the first shut-off valve 31 and the second shut-off valve 34 are equipped with anti-misoperation pressure-holding locking mechanisms at their operating handwheels. These mechanisms include an L-shaped fixed base, a cylindrical locking pin, a return spring, and a circular locking gear. The fixed base is welded and fixed to the upper surface of the shut-off valve body, located below the operating handwheel. The locking gear is coaxially fixed to the bottom of the operating handwheel via a key. Twelve rectangular locking slots are evenly distributed around the outer circumference of the locking gear, corresponding one-to-one with the shut-off valve's on / off positions. A circular pin sliding hole corresponding to the locking slot is provided on the horizontal section of the fixed base. The locking pin slidably passes through the pin sliding hole. An annular limiting step is provided in the middle of the locking pin. The return spring is sleeved on the outside of the locking pin, with both ends abutting against the fixed base and the limiting step of the locking pin, respectively. Under normal conditions, the return spring pushes the locking pin into the locking slot of the locking gear, circumferentially locking the operating handwheel and preventing accidental rotation or malfunction of the shut-off valve in a strong downhole vibration environment.

[0065] Furthermore, a ring-shaped pull ring is welded to the outer end of the locking pin. When the shut-off valve needs to be operated, pulling the pull ring outwards causes the locking pin to disengage from the locking slot, releasing the circumferential lock on the operating handwheel. The handwheel can then be turned to control the opening and closing of the shut-off valve. After operation, releasing the pull ring causes the locking pin to automatically insert into the corresponding locking slot under the force of the return spring, re-locking the circumferential lock. The operation is simple and convenient, requiring no additional tools, and is suitable for underground field operations. This locking mechanism can reliably lock the operating handwheel of the shut-off valve throughout the entire process of pressurization, pressure holding, and pressure release, completely preventing malfunctions of the shut-off valve caused by strong vibrations from underground frame movement and coal mining machine operation. It also prevents safety hazards caused by pressure holding failure and sudden pressure increases, significantly improving the safety of underground operations and the accuracy of pressure holding detection.

[0066] The application of the modified jack-type mining pressure pump provided in this embodiment is as follows: In the modification of idle jacks in coal mines, for jacks with different cylinder diameters and thread specifications, only the corresponding replaceable threaded bushings and multi-specification sealing rings need to be replaced to complete the matching and assembly of the sealing cover 2 with the jack. There is no need to customize and process the sealing cover 2 for each jack individually. The modification preparation cycle of a single jack can be significantly shortened, and the versatility of modification is greatly improved. It can realize the rapid modification and reuse of idle jacks of all specifications in coal mines. When working in confined spaces underground, even if the equipment needs to be tilted, inverted and extended into the bottom of the support, or at the corner of the roadway, the anti-vacuum and flow stabilizing components can ensure that the oil suction port is always submerged below the medium liquid surface, and there will be no vacuum or interruption of pressurization. The applicable scenarios are further expanded compared to Embodiment 1. In pressure holding and testing operations with vibration at the working face, the anti-maloperation pressure holding locking mechanism can reliably lock the stop valve handwheel. Even if there is strong vibration caused by the movement of surrounding equipment or operation, the stop valve will not maloperate. The pressure monitoring error during the pressure holding stage can be controlled within 0.2MPa, significantly improving the stability and accuracy of pressure holding. At the same time, the filter component integrated in the sealing cover 2 can intercept impurities in the medium throughout the process. There is no situation of stop valve jamming or pressure gauge 33 damage during continuous operation of the equipment, resulting in a longer maintenance cycle. It is fully adaptable to the complex and harsh working environment of underground coal mines and meets the needs of daily maintenance and emergency repair in all scenarios.

[0067] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a manufacturable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0070] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "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.

[0071] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A mining pressure pump modified from a jack, characterized in that, include: Mining hydraulic jack main body, sealing cover (2), pressure control assembly, oil reservoir (4); The main body of the mining hydraulic jack is equipped with a plunger pump assembly (11), a pressure rod (12) and a reset bolt (13). The sealing cover (2) is threaded to the cylinder port of the cylinder (14) of the main body of the mining hydraulic jack. The sealing cover (2) seals the inside of the cylinder (14) to form a high-pressure oil chamber. The high-pressure oil chamber is connected to the oil outlet of the plunger pump assembly (11). The annular cavity between the outer shell (15) of the main body of the mining hydraulic jack and the cylinder (14) is an oil storage chamber. The oil storage chamber is connected to the oil inlet of the plunger pump assembly (11). The pressure control assembly is connected to the sealing cover (2) to realize pressure regulation, pressure holding control and real-time pressure monitoring in the pressurization operation. It can also be connected to the tested hydraulic components in the mine. The outer shell (15) has an oil passage hole on its side wall that connects to the oil storage chamber. The oil passage hole connects to the oil storage cylinder (4), and the oil storage cylinder (4) is normally connected to the oil storage chamber. During the pressurization operation, the reciprocating rocking rod (12) drives the plunger pump assembly (11) to work, sucking in the medium in the oil reservoir (4) and pressurizing it before sending it into the high-pressure oil chamber. The high-pressure oil is injected into the mine-use hydraulic component under test through the sealing cover (2) and the pressure control assembly. The pressure is monitored in real time by the pressure control assembly. After the set pressure is reached, the pressure is maintained by the pressure control assembly. After the pressure is maintained, the pressure control assembly is opened and the pressure is released by the reset bolt (13).

2. The mining pressure pump modified from a jack as described in claim 1, characterized in that, The pressure control assembly includes a first shut-off valve (31), a three-way valve (32), a pressure gauge (33), and a second shut-off valve (34). The first shut-off valve (31) is connected to the top of the sealing cover (2), the tee (32) is connected to the top of the first shut-off valve (31), the pressure gauge (33) is connected to the top interface of the tee (32), the second shut-off valve (34) is connected to the side interface of the tee (32), and the pipeline is connected to the outlet of the second shut-off valve (34) for connecting to the tested hydraulic components in the mine.

3. The mining pressure pump modified from a jack as described in claim 2, characterized in that, The sealing cover (2) is an integral coaxial structure, which includes a connecting body and a connector pair (21) from bottom to top. The main body has a central through hole that runs through the entire section. The lower end of the central through hole is connected to the high-pressure oil chamber of the cylinder (14), and the upper end of the central through hole is connected to the first shut-off valve (31) through the connector (21).

4. The mining pressure pump modified from a jack as described in claim 3, characterized in that, The connecting body includes a threaded connecting section (22), a disc section (23), and a hexagonal section (24) connected sequentially from bottom to top; The threaded connection section (22) is connected to the cylinder (14) with an open thread. The bottom surface of the disc section (23) abuts against the end face of the cylinder (14) and the end face of the outer shell (15) to simultaneously achieve the sealing of the cylinder (14) and the axial pressing and fixing of the outer shell (15). The outer circumferential surface of the hexagonal section (24) forms a hexagon for tool turning.

5. The mining pressure pump modified from a jack as described in claim 2, characterized in that, The tee (32) is an integral structure; The bottom of the tee (32) is provided with a first interface for inserting and connecting to the first shut-off valve (31), the top of the tee (32) is provided with an internal thread interface for threading and connecting to the pressure gauge (33), and the side of the tee (32) is provided with a second interface for inserting and connecting to the second shut-off valve (34); the inside of the tee (32) is provided with a T-shaped flow channel connecting the first interface, the internal thread interface and the second interface.

6. The mining pressure pump modified from a jack as described in claim 5, characterized in that, Both the first and second interfaces are quick-connect plug-in structures, and are respectively locked and fixed to the first stop valve (31) and the second stop valve (34) by U-shaped clips (35).

7. The mining pressure pump modified from a jack as described in claim 2, characterized in that, The first shut-off valve (31) is the system's main control pressure relief valve, and the second shut-off valve (34) is the pressure holding control valve on the side of the tested hydraulic component in the mine. The pressure gauge (33) and the three-way valve (32) are normally connected. When the second shut-off valve (34) is closed during the pressure holding stage, the pressure gauge (33) can continuously monitor the internal pressure of the tested hydraulic component in the mine. Among them, the tested hydraulic components for mining include safety valves for coal mine hydraulic supports, high-pressure hydraulic pipes, and mining pressure vessels.

8. The mining pressure pump modified from a jack as described in claim 1, characterized in that, The oil storage tank (4) includes an oil cylinder (41), a cylinder cover (42), and a bend (43); The top opening of the oil cylinder (41) is provided with an internal thread, and the bottom end of the cylinder cover (42) is threaded to the top opening of the oil cylinder (41); one end of the bent pipe (43) is connected to the bottom opening of the oil cylinder (41), and the other end of the bent pipe (43) is connected to the oil passage hole on the side wall of the outer shell (15).

9. The mining pressure pump modified from a jack as described in claim 1, characterized in that, The reset bolt (13) is located on the bypass oil passage of the plunger pump assembly (11), which connects the high-pressure oil chamber and the oil storage chamber. The reset bolt (13) has a tightened position and a loosened position. When the reset bolt (13) is tightened, the bypass oil passage is cut off. When the reset bolt (13) is loosened, the bypass oil passage is opened to realize the pressure relief from the high-pressure oil chamber to the oil storage chamber.

10. A method for modifying a mine-use pressure pump based on a jack as described in any one of claims 1-9, characterized in that, Including the following steps: S1. Remove the cylinder end cap and piston rod inside the cylinder barrel (14) of the mining hydraulic jack; S2. Thread the sealing cap (2) to the cylinder port of the cylinder barrel (14) and abut against the end face of the outer shell (15) of the mining hydraulic jack; S3. Install the pressure test assembly on the top of the sealing cover (2); open an oil passage hole on the side wall of the outer casing (15) and connect it to the oil reservoir (4).

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