High-pressure foam expansion cracking rock breaking system and using method thereof

Abstract

The invention relates to the technical field of rock breaking equipment, in particular to a high-pressure foam expansion cracking rock breaking system and a using method thereof. Through the precisely-designed structure, effective storage and release of high-pressure foam are achieved. Through the unique design of the conical foam outlet and the piston rod, the foam storage cavity can be kept in a sealed state under the action of the pressure adjusting spring, and the foam storage cavity is opened until the pressure in the foam storage cavity reaches a preset value. Once the pressure is enough, the piston moves leftwards under the action of the foam pressure and collides with the limiting block, the foam outlet is opened instantly, and high-pressure foam is released. According to the foam releasing mode, stress waves and quasi-static force generated when the foam impacts the rock holes are effectively increased, so that the expansion cracking force of the foam can instantly act in the rock holes, and efficient crushing of the rock is achieved. Meanwhile, through the design of the partition cavity in the device, the pressure relief cavity can form a negative pressure state when the foam is instantaneously released, the suction force to the left side of the piston rod is further enhanced, and quick release of the foam is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of rock breaking equipment, and specifically to a high-pressure foam expansion rock breaking system and a method of using the same. Background Art

[0002] At present, blasting is mostly used to break rocks in mining tunnels and traffic tunnel excavation projects. The working steps of the blasting method are: first drill a hole on the rock surface, then place high-energy chemical explosives at a suitable position in the rock hole and seal the hole, and finally detonate the explosives to break the rock. The results of relevant theoretical and experimental studies show that the rock is broken by the combined effect of the shock stress wave generated by the explosion of the explosive and the quasi-static force generated by the high-temperature and high-pressure gas. However, conventional blasting methods will produce sparks, toxic and harmful smoke, dust, etc. during the rock breaking process, posing a threat to the normal operation of equipment and the health and safety of personnel at the rock breaking working face. Chemical explosives are strictly controlled products, and there are strict requirements for their application, storage, transportation, and use, which limits the application of chemical explosives in rock and soil excavation projects.

[0003] As a brittle material, rock has the characteristic that its tensile strength is much smaller than its compressive strength. Based on this characteristic, the high-pressure foam expansion and rock breaking technology is proposed by utilizing the compressibility and high viscosity of gas-liquid two-phase foam. This technology instantly releases high-pressure foam into the sealed rock expansion hole, so that the rock is broken under the impact stress wave and the quasi-static force of the high-pressure foam. Therefore, it is necessary to design a high-pressure foam expansion and rock breaking system and its use method to provide support for the research and application of high-pressure foam expansion and rock breaking technology.

[0004] Researchers have designed relevant mechanical devices for high-pressure foam fracturing and rock-breaking technology, such as stamping and instant injection high-pressure foam fracturing devices ([1] Li Zhiqiang. Design and performance research of high-pressure foam fracturing and rock-breaking device [D]. China University of Mining and Technology, 2021; [2] Liu Songyong, Cui Song, Gu Congcong. Experimental study on high-pressure foam fracturing and rock-breaking characteristics [J / OL]. Journal of Geotechnical Engineering, 1-10 [2024-6-24].). However, due to the high compressibility of foam, the foam actually involved in the fracturing of the stamping high-pressure foam fracturing device is limited to the foam in the sealed tube, and the foam volume is small, making it difficult to effectively fracture the rock. Although the instant injection type stores a large volume of foam, the release speed of the high-pressure foam depends on the opening speed of the high-pressure pneumatic ball valve. The commonly used valve opening speed is too slow, making it difficult to generate impact stress waves inside the rock, and thus difficult to fractur e the rock. Therefore, it is urgent to solve this problem. Summary of the invention

[0005] In order to avoid and overcome the technical problems existing in the prior art, the present application provides a high-pressure foam expansion and cracking rock breaking system and a method for using the same. The present application can effectively increase the impact stress wave of the foam.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] A high-pressure foam expansion and rock-breaking system comprises a cylinder body, and the left and right ends of the cylinder body are respectively sealed with a left cylinder head and a right cylinder head; a through hole connected to the atmospheric environment is opened on the left cylinder head; a conical foam outlet is opened through the right cylinder head, and the aperture of the foam outlet gradually decreases from the inside of the cylinder body to the outside, and a foam release pipe connected to the foam outlet and used for conveying foam to the rock hole is installed on the outer side of the right cylinder head; a piston rod is installed in the cylinder body, a pressure-adjusting spring is compressed between the tail end of the piston rod and the left cylinder head, and the conical front end of the piston rod is coaxially inserted in the foam outlet under the action of the elastic force of the pressure-adjusting spring, and blocks the foam outlet; a piston is slidably installed on the piston rod in a dynamic seal, and an energy storage spring is compressed between the piston and the left cylinder head Spring, and the piston divides the inner cavity of the cylinder into two cavities that are not connected to each other; the cavity on the right is the foam storage cavity, and the foam storage cavity is connected to the foaming system; the cavity on the left is the pressure relief cavity connected to the through hole 1; a limit block is installed on the piston rod, and the limit block is located on the path of the piston moving to the left, and the piston can collide with the limit block when moving to the left to separate the piston rod and the foam outlet from each other, and a flow channel connecting the foam storage cavity and the foam release tube is formed between the piston rod and the foam outlet after separation; when the flow channel is generated, the piston moves quickly to the right and makes the pressure relief cavity a negative pressure state, and the sum of the leftward thrust on the conical surface at the front end of the piston rod and the negative pressure suction of the pressure relief cavity on the piston rod is greater than the force of the pressure regulating spring on the piston rod to the right.

[0008] As a further solution of the present application: the sum of the leftward thrust on the conical surface at the front end of the piston rod and the negative pressure suction of the pressure relief chamber on the piston rod is F, and the calculation formula of F is as follows:

[0009]

[0010] Where P represents the pressure acting vertically on the conical surface at the front end of the piston rod when the foam is released; P x It represents the component force of the pressure P that points to the tail end of the piston rod along the axial direction of the piston rod; θ represents the cone angle of the conical surface at the front end of the piston rod; P0 represents the atmospheric pressure; V0 represents the volume of the pressure relief chamber before the foam outlet is opened; V1 represents the volume of the pressure relief chamber after the foam outlet is opened; S represents the cross-sectional area of ​​the piston rod.

[0011] As a further solution of the present application: a sliding sleeve is provided on the outer coaxial sleeve of the tail of the piston rod, and the sliding sleeve constitutes the limit block; the tail of the sliding sleeve is a sealed end, and a threaded through hole is coaxially opened on the sealed end, and a second threaded blind hole is coaxially opened at the tail of the piston rod, and the thread rotation direction of the second threaded blind hole is opposite to that of the threaded through hole; the second threaded blind hole and the threaded through hole are simultaneously threadedly connected to the same pressure-regulating screw, and the pressure-regulating screw is coaxially penetrated in the first through hole at the same time; the pressure-regulating spring is compressed between the sliding sleeve and the left cylinder head.

[0012] As a further solution of the present application: the outer diameter of the pressure regulating screw is smaller than the aperture of the through hole 1, so that a flow gap for ventilation and throttling is formed between the two.

[0013] As a further solution of the present application: a hydraulic hole sealer is installed at the front end of the foam release tube extending into the rock hole, and the hydraulic hole sealer includes a rubber sleeve with a sealing sleeve arranged on the outside of the foam release tube. The rubber sleeve and the foam release tube cooperate to form a high-pressure water chamber, and the high-pressure water chamber is connected to the water pump through a two-position three-way solenoid valve; the water pump can inject high-pressure water into the high-pressure water chamber to make the rubber sleeve expand circumferentially to seal the rock hole.

[0014] As a further solution of the present application: the outer side of the front end of the foam release tube is coaxially sealed with a left joint and a right joint, and the left joint and the right joint are arranged apart from each other, and the left joint is welded and fixed to the foam release tube; the two ends of the rubber sleeve are respectively sealed on the outer side of the left joint and the right joint.

[0015] As a further solution of the present application: a guide hole is provided on the left joint, and the axis of the guide hole is parallel to the axis of the left joint, and the guide hole is connected to the water pump through the high-pressure water interface at the front end thereof.

[0016] As a further solution of the present application: the foaming system includes a water tank, a foaming agent tank and an air pump; the water tank is connected to the water pump, and the output end of the water pump is connected to the input end of the foamer; the foaming agent tank is connected to the foaming agent pump, and the output end of the foaming agent pump is connected to the input end of the foamer; the output end of the air pump is connected to the input end of the foamer; the output end of the foamer is connected to the foam storage chamber.

[0017] As a further solution of the present application: a one-way valve to prevent backflow is installed on the pipeline connecting the water pump and the foamer, the pipeline connecting the foaming agent pump and the foamer, and the pipeline connecting the air pump and the foamer.

[0018] As a further solution of the present application: a flow meter and a pressure gauge are installed in sequence on the pipeline connecting the foamer and the foam storage chamber.

[0019] A method for using a high-pressure foam expansion and cracking rock breaking system, the method for using the above-mentioned high-pressure foam expansion and cracking rock breaking system, comprising the following steps:

[0020] a. Use a drill bit to drill a hole on the rock surface, insert the hydraulic hole sealer on the foam release tube into the rock hole, and place the rubber sleeve completely inside the rock hole;

[0021] b. Turn on the water pump to allow high-pressure water to enter the high-pressure water chamber, and the rubber sleeve expands and deforms between the foam release tube and the rock hole to seal the rock hole;

[0022] c. While step b is being performed, turn on the foaming agent pump and the air pump, adjust the ratio of water, foaming agent and air, and the foam pressure, and fill the foam into the foam storage chamber through the foaming device; as the foam pressure in the foam storage chamber gradually increases, the piston is pushed to the left, and the energy storage spring is compressed, and the gas in the pressure relief chamber flows out from the flow gap, and the volume of the pressure relief chamber gradually decreases;

[0023] d. When the piston moves to the left and just collides with the sleeve, the piston drives the sleeve and the piston rod to move to the left, the foam outlet is opened, and the foam flows through the gap through the foam release tube and is released into the rock hole, and the rock is cracked and broken; at the same time, the water pump, the foaming agent pump and the air pump are turned off, the foam pressure in the foam storage chamber is reduced, and the piston moves to the right;

[0024] e. When the piston gradually moves to the far right, the piston rod moves to the right and resets under the action of the pressure-adjusting spring, and blocks the foam outlet again, and the foam outlet is closed;

[0025] f. Adjust the two-position three-way solenoid valve. The water in the high-pressure water chamber flows back to the water tank under the action of pressure difference. The rubber sleeve returns to its initial state and the rock crushing work is completed.

[0026] Compared with the prior art, the beneficial effects of this application are:

[0027] Advantages of high pressure foam expansion rock breaking system:

[0028] 1. The present application realizes the effective storage and release of high-pressure foam through a precisely designed structure. Its unique conical foam outlet and piston rod design can keep the foam storage chamber sealed under the action of the pressure-adjusting spring until the pressure in the foam storage chamber reaches a preset value and then opens. Once the pressure is sufficient, the piston will move to the left under the action of the foam pressure and collide with the limit block, instantly opening the foam outlet and releasing the high-pressure foam. This foam release method effectively increases the stress wave and quasi-static force generated when the foam impacts the rock hole, so that the foam expansion force can act instantly in the rock hole, achieving efficient rock crushing. At the same time, the partition cavity design inside the device enables the pressure relief chamber to form a negative pressure state when the foam is released instantly, further enhancing the suction to the left side of the piston rod, ensuring the rapid release of the foam.

[0029] 2. At the moment when the foam outlet is opened, on the one hand, when the high-pressure foam passes through the foam outlet, since the right end face of the piston rod is a conical surface, part of the foam pressure acts between the two conical surfaces of the injection gap, forming a leftward thrust on the piston rod, causing the piston rod to tend to move to the left. On the other hand, the piston moves quickly to the right, causing the volume of the pressure relief chamber on the left side of the piston to increase and the air pressure to decrease, while the flow gap between the through hole 1 on the left cylinder head and the pressure regulating screw is small, which plays a throttling role. The air pressure in the cavity on the left side of the piston is difficult to recover to atmospheric pressure in a short time. Under the action of negative pressure on the left side (lower than atmospheric pressure) and positive pressure (foam pressure) on the right side, the piston rod keeps the foam outlet open, and the high-pressure foam is instantly released into the sealed rock hole, causing the rock to expand and break.

[0030] 3. The sleeve coaxially sleeved at the end of the piston rod not only simplifies the structure of the limit block, but also improves the stability and reliability of the system. The sleeve and the piston rod are fixed by a threaded pressure-adjusting screw, making the connection between the two more secure. At the same time, the pressure-adjusting spring is compressed between the sleeve and the left cylinder head, which effectively utilizes the space and improves the compactness of the system. In addition, the design of the pressure-adjusting screw also facilitates the adjustment of the position of the sleeve, thereby achieving precise control of the opening pressure of the foam release.

[0031] 4. The outer diameter of the pressure regulating screw is smaller than the aperture of the through hole 1, so that a ventilated and throttling flow gap is formed between the two, which not only ensures smooth ventilation of the pressure relief chamber, but also avoids abnormal pressure in the pressure relief chamber caused by the pressure regulating screw completely blocking the through hole 1.

[0032] 5. The hydraulic hole sealer installed at the front end of the foam release tube injects high-pressure water into the high-pressure water cavity between the rubber sleeve and the foam release tube, causing the rubber sleeve to expand circumferentially to seal the rock hole. The use of the hydraulic hole sealer simplifies the operation process and reduces the labor intensity of workers.

[0033] 6. The design of the left and right joints enables the rubber sleeve to be firmly sealed on the outside of the foam release tube, which not only improves the sealing performance of the system, but also avoids the foam leakage problem caused by the loose rubber sleeve. At the same time, the separation of the left and right joints also facilitates the formation of the high-pressure water chamber.

[0034] 7. The diversion hole opened on the left joint allows high-pressure water to smoothly enter the high-pressure water chamber, thereby driving the rubber sleeve to expand and deform. This not only improves the response speed of the hydraulic hole sealer, but also ensures that the high-pressure water can be evenly distributed on the entire rubber sleeve, thereby improving the sealing effect.

[0035] 8. The foaming system achieves precise control of foam pressure, gas-liquid ratio and flow rate through the cooperation of water tank, foaming agent tank and air pump, which not only improves the quality of foam, but also ensures that the foam can be stably filled into the foam storage chamber. At the same time, the one-way valve design inside the system avoids the backflow problem and improves the stability and reliability of the system.

[0036] 9. The flow meter and pressure gauge installed in sequence on the pipeline connecting the foamer and the foam storage chamber can monitor the flow and pressure status of the foam in real time, which not only provides accurate data support for the system, but also facilitates the staff to adjust the system parameters in time to ensure the best working state of the system.

[0037] 10. This method of use ensures the correct operation and use of the high-pressure foam expansion and rock breaking system through detailed step-by-step guidance. Each link from drilling, sealing, filling with foam to releasing foam and restoring the state is explained in detail, which not only improves work efficiency but also reduces operational difficulty and risk. At the same time, this method also focuses on the safety and stability of the system, ensuring the smooth progress of rock crushing work. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 An overall layout diagram of a high-pressure foam expansion and rock breaking system provided in an embodiment of the present application.

[0039] Figure 2 This is a three-dimensional overall diagram of the high-pressure foam expansion and rock breaking device in an embodiment of the present application.

[0040] Figure 3 This is a structural diagram of the high-pressure foam storage system in an embodiment of the present application.

[0041] Figure 4 This is a structural diagram of the foam release and pressure regulation system in the embodiment of the present application.

[0042] Figure 5 This is a structural diagram of the hydraulic hole sealer in the embodiment of the present application.

[0043] Figure 6 This is a layout diagram of the foaming system in the embodiment of this application.

[0044] Figure 7 for Figure 1 Schematic diagram of medium and high pressure foam energy storage state.

[0045] Figure 8 for Figure 1 Schematic diagram of medium and high pressure foam release state.

[0046] In the figure: 1, cylinder body; 1-1, left cylinder head; 1-2, right cylinder head; 1-3, bolt; 1-4, foam storage chamber; 1-5, threaded blind hole 1; 1-6, foam outlet; 1-7, foam inlet; 1-8, through hole 1; 2, energy storage spring; 3, piston; 3-1, through hole 2; 4, foam release tube; 4-1, screw; 5, hydraulic sealer; 5-1, left joint; 5-2, rubber sleeve; 5-3, right joint; 5-4, high Water pressure chamber; 5-5, high-pressure water interface; 6, two-position three-way solenoid valve; 7, foaming system; 7-1, one-way valve; 7-2, flow meter; 7-3, foamer; 7-4, water pump; 7-5, water tank; 7-6, foaming agent tank; 7-7, foaming agent pump; 7-8, air pump; 7-9, pressure gauge; 8, piston rod; 8-1, pressure regulating screw; 8-2, pressure regulating spring; 8-3, sleeve; 8-4, threaded blind hole II; 8-5, threaded through hole. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] like Figure 1 and Figure 2 As shown, a high-pressure foam expansion and rock breaking system includes a high-pressure foam storage system, a foam release and pressure regulating system, a hydraulic sealer 5 and a foaming system 7.

[0049] like Figure 3 As shown, the high-pressure foam storage system includes a cylinder body 1, an energy storage spring 2, a piston 3, a left cylinder head 1-1 and a right cylinder head 1-2. The cylinder body 1 is a hollow cylindrical shape, and the left and right sides of the cylinder body 1 are respectively connected with the left cylinder head 1-1 and the right cylinder head 1-2, and the left cylinder head 1-1 and the right cylinder head 1-2 are connected and fixed by four sets of bolts 1-3. A through hole 1-8 for installing a pressure regulating screw 8-1 is provided at the central axis of the left cylinder head 1-1, and the inner diameter of the through hole 1-8 is slightly larger than the outer diameter of the pressure regulating screw 8-1, so that a flow gap is formed between the pressure regulating screw 8-1 and the through hole 1-8, so as to facilitate the gas to enter and exit the cylinder body 1. A trumpet-shaped foam outlet 1-6 is provided at the central axis of the right cylinder head 1-2, and a foam inlet 1-7 and four threaded blind holes 1-5 for connecting the foam release pipe 4 are also provided on the right side of the right cylinder head 1-2. The piston 3 is arranged inside the cylinder body 1, and an energy storage spring 2 is compressed between the piston 3 and the left cylinder head 1-1. The space between the piston 3 and the right cylinder head 1-2 forms a foam storage chamber 1-4, and a through hole 3-1 for coaxial dynamic sealing and mounting the piston rod 8 is arranged at the central axis of the piston 3.

[0050] like Figure 4 As shown, the foam release pressure regulating system includes a piston rod 8, a pressure regulating screw 8-1, a pressure regulating spring 8-2 and a sleeve 8-3. The right end of the piston rod 8 is processed into a cone that can fit with the foam outlet 1-6 to block the foam outlet 1-6, and a threaded blind hole 8-4 for connecting the pressure regulating screw 8-1 is provided at the left central axis of the piston rod 8. A sleeve 8-3 is also connected to the left side of the piston rod 8, and the sleeve 8-3 is coaxially arranged with the piston rod 8. A threaded through hole 8-5 is provided at the central axis of the sleeve 8-3. The thread rotation direction in the threaded through hole 8-5 is opposite to the thread rotation direction in the threaded blind hole 8-4. A pressure regulating spring 8-2 is compressed and installed on the left end of the sleeve 8-3, and the left end of the pressure regulating spring 8-2 is installed on the right end surface of the left cylinder head 1-1. The pressure regulating screw 8-1 passes through the through hole 1-8 on the left cylinder cover 1-1, and is threadedly connected with the threaded through hole 8-5 on the sleeve 8-3 and the threaded blind hole 8-4 on the piston rod 8. The sleeve 8-3 can slide along the axial direction of the piston rod 8 within a certain distance range under the action of the pressure regulating screw 8-1.

[0051] like Figure 5 and Figure 6 As shown, the hydraulic hole sealer 5 includes a left joint 5-1, a rubber sleeve 5-2, a right joint 5-3 and a high-pressure water interface 5-5. The left joint 5-1 is fixed to the outside of the foam release tube 4 by welding, and the right joint 5-3 is arranged on the outside of the foam release tube 4. The right joint 5-3 can slide along the axial direction of the foam release tube 4 in a dynamic seal. The left and right ends of the rubber sleeve 5-2 are tightly pressed on the left joint 5-1 and the right joint 5-3 respectively, and a closed high-pressure water chamber 5-4 is formed between the rubber sleeve 5-2 and the foam release tube 4. A high-pressure water interface 5-5 is arranged on the left side of the left joint 5-1, and the high-pressure water interface 5-5 is communicated with the high-pressure water chamber 5-4. The high-pressure water interface 5-5 is connected to a two-position three-way solenoid valve 6, and the two-position three-way solenoid valve 6 is connected to a water pump 7-4 through a one-way valve 7-1.

[0052] like Figure 6 As shown, the foaming system 7 includes a water tank 7-5, a foaming agent tank 7-6, a water pump 7-4, a foaming agent pump 7-7, an air pump 7-8 and a foamer 7-3. One end of the water pump 7-4 is connected to the water tank 7-5, and the other end of the water pump 7-4 is connected to the foamer 7-3 through a one-way valve 7-1. The foaming agent tank 7-6 contains a surfactant, and the foaming agent tank 7-6 is connected to the foaming agent pump 7-7. The foaming agent pump 7-7 and the air pump 7-8 are connected to the foamer 7-3 through the one-way valve 7-1 respectively. Water, foaming agent and air are fully mixed in the foamer 7-3 to form high-pressure foam. The foamer 7-3 is then connected to a flow meter 7-2, a one-way valve 7-1 and a pressure gauge 7-9 in sequence, and finally connected to the foam inlet 1-7.

[0053] like Figure 1 and Figure 4 As shown, the pressure regulating principle of the foam release pressure regulating system is: since the threaded through hole 8-5 on the sleeve 8-3 and the threaded blind hole 8-4 on the piston rod 8 have opposite thread rotation directions, and a limit pin is provided on the sleeve 8-3, the distance between the sleeve 8-3 and the piston rod 8 can be changed by rotating the pressure regulating screw 8-1, thereby adjusting the relative position of the piston 3 when it just contacts the sleeve 8-3 when it moves to the left. Since the foam pressure of the piston 3 is different when the piston 3 is in different positions, the maximum bursting pressure during foam release can be changed by adjusting the position of the piston 3 when the foam outlet 1-6 is opened, thereby adjusting the foam bursting pressure according to different working parameters.

[0054] like Figure 7 As shown, the diameter of the rock hole is no more than 5 mm compared with the outer diameter of the hydraulic sealer 5. Figure 6 As shown, the air volume fraction of the foam produced by the foamer 7-3 ranges from 50% to 95%.

[0055] like Figure 2 As shown, the left end of the foam release tube 4 is fixed to the threaded blind hole 8-4 on the right cylinder cover 1-2 by four screws 4-1.

[0056] Assuming that the volume increase of the pressure relief chamber on the left side of the piston 3 is an instantaneous adiabatic process, ignoring the gas flowing in through the through hole 1-8, ignoring the volume occupied by the cavity special-shaped structure and the pressure regulating structure, the foam pressure and the negative pressure of the pressure relief chamber act on the piston rod to generate a leftward thrust F, and the calculation formula of F is shown in formula (1):

[0057]

[0058] Wherein, P represents the pressure acting vertically on the conical surface at the front end of the piston rod 8 when the foam is released; P x It represents the component force in the pressure P that points to the rear end of the piston rod 8 along the axial direction of the piston rod 8; θ represents the cone angle of the conical surface at the front end of the piston rod 8; P0 represents the atmospheric pressure; V0 represents the volume of the foam storage chamber 1-4 before the foam outlet 1-6 is opened; V1 represents the volume of the foam storage chamber 1-4 after the foam outlet 1-6 is opened; S represents the cross-sectional area of ​​the piston rod 8.

[0059] Assuming that at the moment when the foam outlet 1-6 is opened, the foam release pressure P is 15 MPa, the piston 3 moves 20 mm to the right, the air pressure in the pressure relief chamber is 80 kPa, and the diameter of the piston rod 8 is 40 mm, then the thrust F is about 1.3×10 4 N.

[0060] When the foam outlet 1-6 is closed, the pressure regulating spring 8-2 is slightly compressed, exerting a rightward force on the piston rod 8 to seal the foam outlet 1-6. The initial length of the pressure regulating spring 8-2 is 60 mm. The elastic force calculation formula of the pressure regulating spring 8-2 is shown in formula (2):

[0061] F k = k·x (2)

[0062] In the formula, k is the elastic coefficient of the pressure regulating spring 8-2, and x is the displacement of the pressure regulating spring 8-2.

[0063] The elastic coefficient of the pressure regulating spring 8-2 is 50N / m, and the length of the pressure regulating spring 8-2 is 50mm when the foam outlet 1-6 is closed. When the foam outlet 1-6 is opened, assuming that the pressure regulating spring 8-2 continues to be compressed by 10mm, the elastic force of the pressure regulating spring 8-2 is 10N. Since the thrust F is much greater than the elastic force F of the pressure regulating spring 8-2, k , so that the foam outlets 1-6 can be continuously opened.

[0064] As the foam is released, assuming that the foam pressure drops to 3MPa, the air pressure in the pressure relief chamber drops to 20kPa, then the thrust F is about 2665N, which is still greater than the elastic force F of the pressure regulating spring 8-2. k , foam outlets 1-6 can still be opened to achieve continuous foam output.

[0065] A method for using a high-pressure foam expansion and rock breaking system, the detailed steps and working principle are as follows:

[0066] a. First, use a drill bit to drill a hole on the rock surface, insert the hydraulic hole sealer 5 of the high-pressure foam expansion and rock breaking device into the rock hole, and ensure that the rubber sleeve 5-2 of the hydraulic hole sealer 5 is completely placed inside the rock hole.

[0067] b. Figure 7 As shown, turn on the water pump 7-4 and control the direction of the two-position three-way solenoid valve 6 to ensure that high-pressure water enters the high-pressure water chamber 5-4 of the hydraulic hole sealer 5, and the rubber sleeve 5-2 expands and deforms in the limited space between the foam release tube 4 and the rock hole until the rubber sleeve 5-2 fits tightly against the inner wall of the rock hole, thereby achieving sealing of the rock hole.

[0068] c. While step b is being performed, the foaming agent pump 7-7 and the air pump 7-8 are turned on to adjust the ratio of water, foaming agent and air and the foam pressure. As the foam pressure in the foam storage chamber 1-4 gradually increases, the piston 3 is slowly pushed to the left. Figure 7As shown, the elastic potential energy of the energy storage spring 2 is continuously increased, and at the same time, the volume of the left cavity of the piston 3 is gradually reduced. Since there is a flow gap between the through hole 1-8 on the left cylinder cover 1-1 and the pressure regulating screw 8-1, the air in the left cavity of the piston 3 is slowly released into the external environment through the gap.

[0069] d. Figure 8 As shown, when the piston 3 moves to the left side and just contacts the sliding sleeve 8-3, since the sliding sleeve 8-3 and the piston rod 8 are fixed by the thread on the pressure regulating screw 8-1, the piston 3 drives the sliding sleeve 8-3 and the piston rod 8 to move to the left, and the foam outlet 1-6 is opened. At this time, the water pump 7-4, the foaming agent pump 7-7 and the air pump 7-8 are turned off, and the foam pressure in the foam storage chamber 1-4 is rapidly reduced, and the piston 3 moves rapidly to the right. On the one hand, when the high-pressure foam passes through the foam outlet 1-6, since the right end face of the piston rod 8 is a conical surface, a part of the foam pressure acts between the two conical surfaces of the injection gap, forming a leftward thrust on the piston rod 8 and acting on the piston rod 8, prompting the piston rod 8 to have a tendency to move to the left. On the other hand, the rapid rightward movement of the piston 3 causes the volume of the left cavity of the piston 3 to increase and the air pressure to decrease, while the flow gap between the through hole 1-8 on the left cylinder cover 1-1 and the pressure regulating screw 8-1 is small, which plays a throttling role. The air pressure in the left cavity of the piston 3 is difficult to recover to atmospheric pressure in a short time. Under the action of negative pressure (lower than atmospheric pressure) on the left side and positive pressure (foam pressure) on the right side, the piston rod 8 keeps the foam outlet 1-6 open, and the high-pressure foam is instantly released into the sealed rock hole, and the rock is cracked and broken.

[0070] e. In step d, the sleeve 8-3 and the piston rod 8 move to the left, and the pressure-adjusting spring 8-2 is compressed. When the high-pressure foam is released and the piston 3 moves to the far right, the foam pressure acting on the right conical surface of the piston rod 8 gradually decreases. At the same time, the air pressure in the left cavity of the piston 3 gradually increases. The piston rod 8 slowly moves to the right and resets under the action of the pressure-adjusting spring 8-2. The right conical surface of the piston rod 8 fits tightly with the foam outlet 1-6 on the right cylinder cover 1-2, and the foam outlet 1-6 is closed.

[0071] f. Control the direction of the two-position three-way solenoid valve 6 to release the high-pressure water in the hydraulic hole sealer 5 into the water tank 7-5, and the rubber sleeve 5-2 returns to its initial state;

[0072] g. Repeat steps a to complete the rock crushing process.

[0073] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed in the present application according to the technical solution and inventive concept of the present application, which should be covered by the protection scope of the present application.

Claims

1. A high-pressure foam expansion and rock breaking system, characterized in that: The invention comprises a cylinder body (1), wherein the left and right ends of the cylinder body (1) are respectively sealed with a left cylinder head (1-1) and a right cylinder head (1-2); the left cylinder head (1-1) is provided with a through hole (1-8) connected to the atmospheric environment; the right cylinder head (1-2) is provided with a conical foam outlet (1-6), the aperture of the foam outlet (1-6) gradually decreases from the inside of the cylinder body (1) to the outside, and the outer side of the right cylinder head (1-2) is provided with a foam outlet (1-6) connected to the foam outlet (1-6) and used for A foam release pipe (4) is provided for conveying foam into the rock hole; a piston rod (8) is installed in the cylinder body (1); a pressure regulating spring (8-2) is compressed between the rear end of the piston rod (8) and the left cylinder cover (1-1); and the conical front end of the piston rod (8) is coaxially inserted into the foam outlet (1-6) under the action of the elastic force of the pressure regulating spring (8-2) to block the foam outlet (1-6); a piston (3) is dynamically and slidably installed on the piston rod (8); the piston (3) is connected to the left cylinder cover (1-1 ), and the piston (3) divides the inner cavity of the cylinder body (1) into two cavities that are not connected to each other; the cavity on the right is a foam storage cavity (1-4), and the foam storage cavity (1-4) is connected to the foaming system (7); the cavity on the left is a pressure relief cavity connected to the through hole 1 (1-8); a limit block is installed on the piston rod (8), and the limit block is located on the path of the piston (3) moving to the left, and the piston (3) can collide with the limit block when moving to the left to make the activity The plug rod (8) and the foam outlet (1-6) are separated from each other, and a flow channel connecting the foam storage chamber (1-4) and the foam release tube (4) is formed between the piston rod (8) and the foam outlet (1-6) after separation; when the flow channel is generated, the piston (3) moves rightward quickly and makes the pressure relief chamber a negative pressure state, and the sum of the leftward thrust on the front end conical surface of the piston rod (8) and the negative pressure suction force of the pressure relief chamber on the piston rod (8) is greater than the rightward force of the pressure regulating spring (8-2) on the piston rod (8).

2. A high-pressure foam expansion and rock breaking system according to claim 1, characterized in that: The sum of the leftward thrust on the conical surface at the front end of the piston rod (8) and the negative pressure suction force of the pressure relief chamber on the piston rod (8) is F. The calculation formula of F is as follows: Wherein, P represents the pressure acting vertically on the conical surface at the front end of the piston rod (8) when the foam is released; P x represents the component force in the pressure P that points to the rear end of the piston rod (8) along the axial direction of the piston rod (8); θ represents the cone angle of the conical surface at the front end of the piston rod (8); P0 represents the atmospheric pressure; V0 represents the volume of the pressure relief chamber before the foam outlet (1-6) is opened; V1 represents the volume of the pressure relief chamber after the foam outlet (1-6) is opened; S represents the cross-sectional area of ​​the piston rod (8).

3. A high-pressure foam expansion and rock breaking system according to claim 2, characterized in that: The outer coaxial sleeve of the rear end of the piston rod (8) is provided with a sliding sleeve (8-3), and the sliding sleeve (8-3) constitutes the limit block; the rear end of the sliding sleeve (8-3) is a sealed end, and a threaded through hole (8-5) is coaxially opened on the sealed end; the rear end of the piston rod (8) is coaxially opened with a second threaded blind hole (8-4), and the threaded direction of the second threaded blind hole (8-4) is opposite to that of the threaded through hole (8-5); the second threaded blind hole (8-4) and the threaded through hole (8-5) are simultaneously threadedly connected to the same pressure regulating screw (8-1), and the pressure regulating screw (8-1) is simultaneously coaxially penetrated in the first through hole (1-8); the pressure regulating spring (8-2) is compressed between the sliding sleeve (8-3) and the left cylinder cover (1-1); the outer diameter of the pressure regulating screw (8-1) is smaller than the aperture of the first through hole (1-8), so that a ventilated and throttling flow gap is formed between the two.

4. A high-pressure foam expansion and rock breaking system according to claim 1, 2 or 3, characterized in that: A hydraulic hole sealer (5) is installed at the front end of the foam release tube (4) extending into the rock hole. The hydraulic hole sealer (5) comprises a rubber sleeve (5-2) with a sealing sleeve arranged outside the foam release tube (4). The rubber sleeve (5-2) and the foam release tube (4) cooperate to form a high-pressure water chamber (5-4). The high-pressure water chamber (5-4) is connected to a water pump (7-4) via a two-position three-way electromagnetic valve (6). The water pump (7-4) can inject high-pressure water into the high-pressure water chamber (5-4) to make the rubber sleeve (5-2) expand circumferentially to seal the rock hole.

5. A high-pressure foam expansion and rock breaking system according to claim 4, characterized in that: The outer side of the front end of the foam release tube (4) is coaxially sealed with a left joint (5-1) and a right joint (5-3), and the left joint (5-1) and the right joint (5-3) are arranged apart from each other, and the left joint (5-1) is welded and fixed on the foam release tube (4); the two ends of the rubber sleeve (5-2) are respectively sealed and sleeved on the outer sides of the left joint (5-1) and the right joint (5-3).

6. A high-pressure foam expansion and rock breaking system according to claim 5, characterized in that: The left joint (5-1) is provided with a flow guide hole, and the axis of the flow guide hole is parallel to the axis of the left joint (5-1), and the flow guide hole is connected to the water pump (7-4) through the high-pressure water interface (5-5) at the front end thereof.

7. A high-pressure foam expansion and rock breaking system according to claim 6, characterized in that: The foaming system (7) comprises a water tank (7-5), a foaming agent tank (7-6) and an air pump (7-8); the water tank (7-5) is in communication with the water pump (7-4), and the output end of the water pump (7-4) is in communication with the input end of the foamer (7-3); the foaming agent tank (7-6) is in communication with the foaming agent pump (7-7), and the output end of the foaming agent pump (7-7) is in communication with the input end of the foamer (7-3); the output end of the air pump (7-8) is in communication with the input end of the foamer (7-3); and the output end of the foamer (7-3) is in communication with the foam storage chamber (1-4).

8. A high-pressure foam expansion and rock breaking system according to claim 7, characterized in that: One-way valves (7-1) for preventing backflow are installed on the pipeline connecting the water pump (7-4) and the foamer (7-3), the pipeline connecting the foaming agent pump (7-7) and the foamer (7-3), and the pipeline connecting the air pump (7-8) and the foamer (7-3).

9. A high-pressure foam expansion and rock breaking system according to claim 8, characterized in that: A flow meter (7-2) and a pressure gauge (7-9) are installed in sequence on a pipeline connecting the foam generator (7-3) and the foam storage chamber (1-4).

10. A method for using a high-pressure foam expansion and breaking rock system, the method for using the high-pressure foam expansion and breaking rock system according to claim 1, characterized in that: The usage steps include the following: a. Drill a hole on the rock surface using a drill bit, insert the hydraulic hole sealer (5) on the foam release tube (4) into the rock hole, and place the rubber sleeve (5-2) completely inside the rock hole; b. Turn on the water pump (7-4) to allow high-pressure water to enter the high-pressure water chamber (5-4), and the rubber sleeve (5-2) expands and deforms between the foam release tube (4) and the rock hole to seal the rock hole; c. While step b is being carried out, the foaming agent pump (7-7) and the air pump (7-8) are turned on to adjust the ratio of water, foaming agent and air, as well as the foam pressure, and to fill the foam into the foam storage chamber (1-4) through the foamer (7-3); As the foam pressure in the foam storage chamber (1-4) gradually increases, the piston (3) is pushed to the left, and at the same time the energy storage spring (2) is compressed, the gas in the pressure relief chamber flows out from the flow gap, and the volume of the pressure relief chamber gradually decreases; d. When the piston (3) moves to the left and just collides with the sleeve (8-3), the piston (3) drives the sleeve (8-3) and the piston rod (8) to move to the left, the foam outlet (1-6) is opened, and the foam flows through the gap through the foam release pipe (4) and is released into the rock hole, and the rock is expanded and broken; at the same time, the water pump (7-4), the foaming agent pump (7-7) and the air pump (7-8) are turned off, the foam pressure in the foam storage chamber (1-4) is reduced, and the piston (3) moves to the right; e. When the piston (3) gradually moves to the rightmost side, the piston rod (8) moves rightward and resets under the action of the pressure regulating spring (8-2), and blocks the foam outlet (1-6) again, and the foam outlet (1-6) is closed; f. Adjust the two-position three-way solenoid valve (6), and the water in the high-pressure water chamber (5-4) flows back to the water tank (7-5) under the action of the pressure difference, and the rubber sleeve (5-2) returns to the initial state, and the rock crushing work is completed.

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