Test coal seam punch assembly

Abstract

The application discloses a coal seam punching assembly for test, which comprises a punching feeding system and a punching execution system. The punching feeding system comprises a servo motor and a screw rod and nut mechanism. The punching execution system comprises a center pipe column, an outer pipe column and a nozzle. The center pipe column is fixedly installed in the outer pipe column and coaxially arranged. The left end of the center pipe column is located outside the outer pipe column and extends to the punching interface through a flange plate. The nozzle is fixedly installed at the left end of the center pipe column. A punching liquid outlet pipe is also arranged on the flange plate and connected to the interlayer between the center pipe column and the outer pipe column. A liquid supply pipeline is arranged on the side wall of the center pipe column and connected to the liquid supply pipeline. A liquid discharge pipeline is arranged on the outer pipe column and connected to the liquid discharge pipeline. The coal seam punching and cracking simulation can be realized by the coal seam punching assembly for test. The control precision is high, and the punching and cracking with different jetting distances can be realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal seam mining simulation test, and particularly relates to a coal seam punching assembly for test. BACKGROUND

[0002] The existing true triaxial coal seam test specimen simulation test system generally adopts hydraulic punching, and mainly has the following problems: (1) the inlet and outlet passages of the punching liquid have a complex structure, the control precision is not high, and the punching at different jetting distances cannot be performed; (2) the model size adopted is small, and there is a certain space limitation, and the real scene of punching induced cracking of multiple coal seams under true triaxial stress cannot be accurately simulated. SUMMARY

[0003] The present application provides a coal seam punching assembly for test, which can be used for coal seam punching induced cracking simulation, has high control precision, and can perform punching induced cracking at different jetting distances.

[0004] To this end, the technical scheme adopted by the present application is as follows: a coal seam punching assembly for test, the punching induced cracking assembly is connected into a test punching interface through a flange plate; the punching induced cracking assembly comprises a punching feeding system and a punching execution system;

[0005] The punching feeding system comprises a servo motor and a screw nut mechanism.

[0006] The punching execution system comprises a central pipe column, an outer pipe column and a nozzle, the central pipe column is fixedly installed in the outer pipe column and coaxially arranged, the left end of the central pipe column is located outside the outer pipe column and extends into the punching interface through the flange plate, the nozzle is fixedly installed at the left end of the central pipe column, a punching liquid outlet pipe is further provided through the flange plate and connected into the interlayer between the central pipe column and the outer pipe column, a liquid supply pipeline is provided on the side wall of the central pipe column and connected transversely, and a liquid discharge pipeline is provided on the outer pipe column and connected transversely.

[0007] The servo motor controls the central pipe column, the outer pipe column and the nozzle to move left and right together through the screw nut mechanism, so as to adjust the jetting distance of the nozzle, the feeding displacement of the nozzle is measured by a displacement sensor, and the displacement sensor is installed on the nut of the screw nut mechanism.

[0008] As a preferred scheme of the above scheme, the liquid supply pipeline comprises a carbon dioxide gas source, a pressure reducing valve, a first pressure gauge, an electromagnetic flowmeter, a first stop valve, a one-way valve, a pressure sensor, a high-pressure pump, an accumulator, a second pressure gauge and a second stop valve connected in sequence and connected in sequence on the liquid supply pipeline between the one-way valve and the pressure sensor; and a bag filter is arranged on the liquid discharge pipeline.

[0009] Further preferably, the device further comprises a main body model and a main body frame for supporting the main body model, the main body model comprises a main body high-pressure cavity module and a test piece box module, the main body high-pressure cavity module is a high-pressure closed pressure chamber structure with an outer circle and an inner circle, surrounded by a cylinder and left and right circular end covers, the test piece box module is a rectangular test piece accommodating cavity, and the rectangular test piece accommodating cavity is collinear with the axis of the high-pressure closed pressure chamber, and a cushion block is installed between the main body high-pressure cavity module and the test piece box module; a row of lifters are installed in slots left and right on the top of the lower cushion block, the lifters can protrude out of the lower cushion block or sink into the lower cushion block; a row of rollers are installed left and right on the bottom of the test piece box module through a lining plate, when the test piece box module is pushed into the main body high-pressure cavity module, the lifters are supported below the rollers;

[0010] The main body frame is in a rectangular frame structure, the main body model is placed in the rectangular frame structure, and both ends of the main body model extend out of the main body frame, a transfer sliding rail is arranged on the right side of the main body frame, and the transfer sliding rail extends directly below the main body high-pressure cavity module, the width of the transfer sliding rail is smaller than the inner empty width of the main body frame; a test piece box lifting and transfer frame and a right circular end cover transfer frame are slidably installed on the transfer sliding rail, the test piece box lifting and transfer frame can move up and down and is used for supporting the test piece box module; the top of the right circular end cover transfer frame is arc-shaped for supporting the right circular end cover, after the test piece box lifting and transfer frame is lifted, the test piece box module can be horizontally pushed into the main body high-pressure cavity module, after the test piece box lifting and transfer frame is lowered, the top is lower than the bottom of the main body high-pressure cavity module, so as to be slid into the lower part of the main body high-pressure cavity module, and the right circular end cover transfer frame can be slid to the left to a set position for installation of the right circular end cover.

[0011] The main body model has the following characteristics:

[0012] (1) The test piece box module is installed in an environment with an outer circle and an inner square, the internal pressure resistance is stronger, the sealing capacity is better, and the internal pressure resistance can be as high as 10 MPa, which provides a better test environment for multi-field coupling coal rock mass dynamic disaster prevention and control simulation test;

[0013] (2) A row of lifters that can protrude or sink into the lower cushion block are installed in slots left and right on the top of the lower cushion block, and a row of rollers are installed left and right on the bottom of the test piece box module through a lining plate, when the test piece box module is pushed into the main body high-pressure cavity module, the lifters are supported below the rollers, the test piece box module can be pushed in and pulled out more easily and labor-savingly, the degree of automation of installation is improved, and large-scale simulation test operation is more easy and labor-saving;

[0014] (3) the main body model is placed in the main body frame of rectangular frame structure, the main body frame is used for bearing the main body model; and is equipped with transfer sliding rail, specimen box lifting transfer frame and right circular end cover transfer frame, the specimen box lifting transfer frame can move up and down, and is used for supporting the specimen box module; the top of the right circular end cover transfer frame is arc-shaped and used for supporting the right circular end cover; the specimen box lifting transfer frame is just capable of horizontally pushing the specimen box module into the main body high-pressure cavity module after being lifted, the top of the specimen box lifting transfer frame is lower than the bottom of the main body high-pressure cavity module after being lowered, so as to be slid into the lower part of the main body high-pressure cavity module, so that the right circular end cover transfer frame can be slid to the left to the set position to install the right circular end cover; the structure form that the double transfer frames specially designed for large specimen boxes share the transfer sliding rail is easy to operate and has high automation degree.

[0015] Further preferably, the inner cavity of the specimen box module can be installed with a rectangular specimen with a length of 1000 mm, a width of 400 mm and a height of 400 mm, and the internal pressure of the main body high-pressure cavity module is 10 MPa.

[0016] Further preferably, each of the lifters adopts a double-support structure that is spaced and symmetrically arranged, each of the lifters is driven by a separate hydraulic drive, and all the lifters are synchronously lifted.

[0017] Further preferably, the main body frame is welded by section steel.

[0018] The present application has the advantages that: the servo motor + screw nut mechanism is used as the drive for punching feeding, the control precision is high, and the operation is convenient; the punching execution system composed of the center pipe column, the outer pipe column and the nozzle is used for the feeding and discharging of the punching liquid, and the punching execution system can be advanced and retreated synchronously, so that the jet distance of the nozzle can be adjusted, and the punching and cracking simulation test with different jet distances can be carried out; the center pipe column and the outer pipe column adopt the coaxial sleeve structure, the punching liquid is laterally connected into the center pipe column and discharged through the interlayer between the center pipe column and the outer pipe column, and the structure is simple and ingenious. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The use state diagram of the present application.

[0020] Figure 2 The state before the specimen box module is loaded into the main body high-pressure cavity module.

[0021] Figure 3 The structural schematic diagram of the main body model.

[0022] Figure 4 The internal left view of Figure 3 .

[0023] Figure 5 The structural schematic diagram of the specimen box module.

[0024] Figure 6 is an internal left view. Figure 5 is an internal left view.

[0025] Figure 7 is a simple diagram of the arrangement of the heating pipe, temperature control probe and ultrasonic probe.

[0026] Figure 8 is a simple diagram of the anti-channeling plate. DETAILED DESCRIPTION

[0027] The application will be further described below by way of examples and with reference to the accompanying drawings:

[0028] As shown in the figure, a coal seam perforation assembly for testing is connected into a test perforation interface through a flange b; the perforation assembly is mainly composed of a perforation feeding system and a perforation execution system. Figure 1 The perforation feeding system is mainly composed of a servo motor s and a screw nut mechanism c. The servo motor s drives the screw to rotate, and the screw drives the nut to move left and right.

[0029] The perforation execution system is mainly composed of a center pipe column d, an outer pipe column e and a nozzle (not shown in the figure). The center pipe column d is fixedly installed in the outer pipe column e and coaxially arranged. The left end of the center pipe column d is located outside the outer pipe column e and extends into the perforation interface a through the flange b. The nozzle is fixedly installed at the left end of the center pipe column d. A perforation liquid outlet pipe (not shown in the figure) is also provided on the flange b.

[0030] The perforation liquid outlet pipe is connected into the interlayer between the center pipe column d and the outer pipe column e. A liquid supply pipe is provided on the side wall of the center pipe column d, and a liquid discharge pipe is provided on the outer pipe column e.

[0031] The servo motor controls the center pipe column d, the outer pipe column e and the nozzle to move left and right together through the screw nut mechanism, so as to adjust the jetting distance of the nozzle. The displacement of the nozzle is measured by a displacement sensor (not shown in the figure). A pressure sensor m displays the real-time injection value of liquid carbon dioxide, and an electromagnetic flowmeter i displays the real-time flow of the injected fluid.

[0032]

[0033] ​The liquid supply pipeline comprises a carbon dioxide gas source f, a pressure reducing valve g, a first pressure gauge h, an electromagnetic flowmeter i, a first stop valve j, a one-way valve k, a pressure sensor m, a high-pressure pump n, an accumulator p, a second pressure gauge q, a second stop valve r, and a liquid supply pipeline connected in sequence.

[0034] A bag filter r is arranged on the liquid discharge pipeline. The servo motor s is fixedly installed on the base t, and the front end of the screw rod of the screw nut mechanism is also installed on the base t through a support. The front end of the screw rod is not threaded, and a rotating bearing is installed between the front end of the screw rod and the support.

[0035] As shown in Figure 2 , it also includes a main body model and a main body frame 37 for supporting the main body model, and a transfer sliding rail 36, a test piece box lifting transfer frame 34, and a right circular end cover transfer frame 35. The main body model includes a main body high-pressure cavity module and a test piece box module. The main body high-pressure cavity module is a high-pressure closed pressure chamber structure with an outer circle and an inner circle, which is surrounded by a cylinder and left and right circular end covers. The test piece box module is a rectangular test piece accommodating cavity, and the axis of the high-pressure closed pressure chamber is collinear with the rectangular test piece accommodating cavity. A cushion block is installed between the main body high-pressure cavity module and the test piece box module.

[0036] The main body frame 37 is a rectangular frame structure, and the left and right ends of the main body model extend out of the main body frame 37. The transfer sliding rail 36 is arranged on the right side of the main body frame 37, and extends directly below the main body high-pressure cavity module. The width of the transfer sliding rail 36 is less than the inner width of the main body frame 37. The test piece box lifting transfer frame 34 and the right circular end cover transfer frame 35 are slidingly installed on the transfer sliding rail 36. The test piece box lifting transfer frame 34 can move up and down and is used to support the test piece box module. The top of the right circular end cover transfer frame 35 is arc-shaped to hold the right circular end cover 5. When the test piece box lifting transfer frame 34 is raised, the test piece box module can be horizontally pushed into the main body high-pressure cavity module. When the test piece box lifting transfer frame 34 is lowered, the top is lower than the bottom of the main body high-pressure cavity module, so that the test piece box lifting transfer frame can slide into the lower part of the main body high-pressure cavity module, and the right circular end cover transfer frame 35 can slide to the left to the set position for installation of the right circular end cover 5.

[0037] As shown in Figure 3 — Figure 4 , the main body model mainly consists of a main body high-pressure cavity module and a test piece box module.

[0038] The shell 1 of the main body high pressure cavity module is a high pressure closed pressure chamber structure with an outer circle and an inner circle formed by a circular ring 3, a left circular end cover 4, a right circular end cover 5 and bolts. A front pad 2, a rear pad 9, an upper pad 10 and a lower pad 11 are respectively installed on the inner wall of the circular ring 3. The front pad 2, the rear pad 9, the upper pad 10 and the lower pad 11 form a rectangular cavity for accommodating the specimen box module.

[0039] An axial hydraulic cylinder 6 is installed through the left circular end cover 4. The right circular end cover 5 is divided into three types of punching, seepage and protrusion. Punching, seepage and protrusion interfaces are respectively installed through the middle part of the right circular end cover 5. When the right circular end cover 5 is in the punching type, the punching interface is installed through the middle part of the right circular end cover 5 for punching test. When the right circular end cover 5 is in the seepage type, the seepage interface is installed through the middle part of the right circular end cover 5 for seepage test. When the right circular end cover 5 is in the protrusion type, the protrusion interface is installed through the middle part of the right circular end cover 5 for protrusion test. Different tests can be carried out by replacing the right circular end cover 5 and installing different interfaces on the right circular end cover 5.

[0040] Wire harness pipeline lead-out holes 7 are respectively formed through the left circular end cover 4 and the right circular end cover 5. A column of lifters 8 are installed in the left and right slots on the top of the lower pad 11. The lifters 8 can protrude out of the lower pad 11 or sink into the lower pad 11. Each lifter 8 adopts a double-wheel structure symmetrically arranged in front and back, realizing front and back double support, force balance and stability. Each lifter 8 is driven by a separate hydraulic pressure. All the lifters 8 are controlled to move synchronously by a control system.

[0041] As shown in the combination Figure 3 — Figure 6 The specimen box module is a rectangular specimen containing cavity formed by a left side plate 12, a bottom plate 13, a top plate 14, a right side plate 15, a front side plate 23 and a rear side plate 24 combined with bolts. The rectangular specimen containing cavity is collinear with the axial line of the high pressure closed pressure chamber, ensuring that the rectangular specimen is centrally arranged in the main body model. A left pressure plate 16 is installed on the left side of the rectangular specimen containing cavity. A plurality of upper pressure plates 17 are installed in sequence on the top left and right. A plurality of front pressure plates 18 are installed in sequence on the front left and right. The axial hydraulic cylinder 6 is connected to the left pressure plate 16 through the left side plate 12. Each upper pressure plate 17 is connected to a top hydraulic cylinder 20 through an upper pad 19 installed through the top plate 14. The top hydraulic cylinder 20 is provided with a hydraulic piston 20a. The upper pad 19 is acted on by the hydraulic piston 20a, and then the rectangular specimen is loaded by the upper pressure plate 17. Each front pressure plate 18 is connected to a lateral hydraulic cylinder 22 through a side pad 21 installed through the front side plate 23. The lateral hydraulic cylinder 22 is also provided with a hydraulic piston. The side pad 21 is acted on by the hydraulic piston, and then the rectangular specimen is loaded by the front pressure plate 18.

[0042] As shown in the combination Figure 3 —Figure 7 As shown, a plurality of heating pipes 27 and temperature control probes 28 are installed on the upper pressing plate 17, the front pressing plate 18, the bottom plate 13, and the rear side plate 24. A plurality of ultrasonic probes 29 are installed on the upper pressing plate 17, the front pressing plate 18, the left pressing plate 16, the bottom plate 13, the rear side plate 24, and the right side plate 15. A row of rollers 26 are installed on the bottom of the specimen box module through the spacer plates 25. When the specimen box module is pushed into the main high-pressure cavity module, the lifter 8 is supported below the rollers 26.

[0043] Preferably, a high-frequency vibrator is installed on the cavity of the axial hydraulic cylinder 6. Under the action of the high-pressure gas source, high-speed vibration is generated, and the high-frequency vibration force can be transmitted to the specimen through the corresponding hydraulic cavity, hydraulic piston, and left pressing plate 16.

[0044] A flow-preventing plate 30 corresponding to the upper pressing plate 17 is arranged directly above the bottom plate 13. Figure 6 As shown, the flow-preventing plate 30 is provided with a central air inlet hole 30a and a plurality of annular grooves 30b surrounding the central air inlet hole 30a. All the annular grooves 30b are in communication with the central air inlet hole 30a through the diverging communication grooves 30c. The annular grooves 30b are rectangular or circular and are equally spaced.

[0045] The inlet pipe transversely penetrates the side wall of the specimen box module and enters the bottom of the central air inlet hole 30a. The air-permeable partition plate 31 is installed above the flow-preventing plate 30. The filter plates 32 are installed at the left and right ends of the specimen, and the sealing pads 33 are installed at the upper and lower front and rear of the specimen.

[0046] The inner cavity of the specimen box module can install a rectangular specimen with a length of 1000 mm, a width of 400 mm, and a height of 400 mm. The internal pressure of the main high-pressure cavity module is 10 MPa. However, the specifications and sizes are not limited to this.

[0047] There is only one axial hydraulic cylinder 6, and the maximum loading pressure is 5000 kN. There are four groups of top hydraulic cylinders 20 and lateral hydraulic cylinders 22, respectively. Each group of hydraulic cylinders is equipped with two parallel hydraulic loading systems for pressurization. One is a static load loading system, and the other is a dynamic load loading system. The maximum loading pressure of a single hydraulic loading device is 3000 kN. Each group of hydraulic loading systems independently controls one pressing plate and is centrally arranged on the corresponding pressing plate. The axial hydraulic cylinder 6, the top hydraulic cylinder 20, and the lateral hydraulic cylinder 22 can load dynamic and static loads.

Claims

1. A test coal seam punching assembly, characterized in that: The punching assembly is connected to the test punching interface via a flange; the punching assembly includes a punching feed system and a punching execution system; The punching feed system includes a servo motor and a lead screw and nut mechanism; The punching execution system includes a central tube column, an outer tube column, and a nozzle. The central tube column is fixedly installed inside the outer tube column and is coaxially arranged. The left end of the central tube column is located outside the outer tube column and extends through the flange into the punching interface. The nozzle is fixedly installed at the left end of the central tube column. A punching fluid outlet pipe is also provided on the flange. The punching fluid outlet pipe is connected to the interlayer between the central tube column and the outer tube column. A horizontally connected liquid supply line is provided on the side wall of the central tube column, and a horizontally connected liquid discharge line is provided on the outer tube column. The servo motor controls the central column, outer column, and nozzle to move left and right together through a lead screw and nut mechanism, thereby adjusting the nozzle's spray distance. The nozzle feed displacement is measured by a displacement sensor, which is mounted on the nut of the lead screw and nut mechanism. It also includes a main model and a main frame (37) for supporting the main model. The main model includes a main high-pressure chamber module and a test specimen box module. The main high-pressure chamber module is a high-pressure closed pressure chamber structure with an outer circle and an inner circle, which is surrounded by a cylinder and left and right circular end caps. The test specimen box module is a rectangular test specimen receiving cavity, and the rectangular test specimen receiving cavity is collinear with the axis of the high-pressure closed pressure chamber. A pad is installed between the main high-pressure chamber module and the test specimen box module. A row of lifters (8) is installed on the top of the lower pad (11) below the test specimen box module with grooves spaced on the left and right. The lifters (8) can protrude out of the lower pad (11) or sink into the lower pad (11). A row of rollers (26) is installed on the bottom of the test specimen box module with lining plate (25) spaced on the left and right. When the test specimen box module is pushed into the main high-pressure chamber module, the lifters (8) are supported under the rollers (26). The main frame (37) has a rectangular frame structure. The main model is placed inside the rectangular frame structure, and both the left and right ends of the main model extend outside the main frame (37). A transfer slide rail (36) is provided on the right side of the main frame (37), and the transfer slide rail (36) extends directly below the main high-pressure chamber module. The width of the transfer slide rail (36) is smaller than the inner width of the main frame (37). A specimen box lifting transfer frame (34) and a right round end cap transfer frame (35) are slidably installed on the transfer slide rail (36) for lifting and transferring the specimen box. The frame (34) can move up and down and is used to support the specimen box module; the top of the right round end cover transfer frame (35) is arc-shaped to support the right round end cover (5). After the specimen box lifting transfer frame (34) is raised, it can push the specimen box module horizontally into the main high pressure chamber module. After the specimen box lifting transfer frame (34) is lowered, the top of it is lower than the bottom of the main high pressure chamber module so that it can slide into the bottom of the main high pressure chamber module, so that the right round end cover transfer frame (35) can slide to the left to the set position to install the right round end cover (5).

2. The experimental coal seam punching assembly according to claim 1, characterized in that: The liquid supply pipeline includes a carbon dioxide gas source, a pressure reducing valve, a first pressure gauge, an electromagnetic flow meter, a first shut-off valve, a check valve, a pressure sensor, a high-pressure pump, an accumulator, a second pressure gauge, and a second shut-off valve connected in series in the liquid supply pipeline between the check valve and the pressure sensor; a bag filter is installed on the liquid discharge pipeline.

3. The experimental coal seam punching assembly according to claim 1, characterized in that: The inner cavity of the specimen box module can accommodate a rectangular specimen with a length of 1000 mm × width of 400 mm × height of 400 mm, and the internal pressure of the main high-pressure chamber module is 10 MPa.

4. The experimental coal seam punching assembly according to claim 1, characterized in that: Each of the lifting devices (8) adopts a double support structure with front and rear spacing and symmetrical arrangement. Each lifting device (8) is driven by a separate hydraulic system, and all lifting devices (8) move synchronously.

5. The experimental coal seam punching assembly according to claim 1, characterized in that: The main frame (37) is made of welded steel profiles.

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