A medicine delivery device, method and charge structure for bench blasting

Abstract

This invention relates to bench blasting technology, specifically a charging device, method, and charging structure for bench blasting. The charging device includes a delivery cylinder that can be placed inside a borehole. A charge cartridge is placed inside the delivery cylinder. A clamping mechanism is fitted around the delivery cylinder to hold the charge cartridge. An outer cylinder is provided on the clamping mechanism. The outer cylinder pushes the delivery cylinder and the clamped charge cartridge into the borehole. After the clamping mechanism releases the charge cartridge through the outer cylinder, the outer cylinder pulls the delivery cylinder and clamping mechanism out of the borehole. The invention uses a clamping mechanism to flexibly clamp the charge cartridge inside the delivery cylinder, and the outer cylinder can push the charge cartridge to the bottom of the borehole. This not only facilitates installation but also provides a high safety factor. Simultaneously, a positioning mechanism adjusts the charge cartridge to be installed on the central axis of the borehole, ensuring the accuracy of the explosive installation position and thus improving the effectiveness of decoupled installation.

Description

Technical Field

[0001] This invention relates to bench blasting technology, specifically to a delivery device, method, and charge structure for bench blasting technology. Background Technology

[0002] The charge structure of bench blasting technology can be divided into coupled charges and decoupled charges. When using decoupled charge technology, the explosive energy generated after detonation is mainly divided into blast shock wave energy and explosive gas expansion energy. The former is mainly consumed in crushing rocks and forming tensile-shear fractures; the latter is mainly consumed in forming blast heaves, throwing fragmented rock blocks, and air shock waves. Decoupled charge blasting relies primarily on a spacer medium to achieve energy transfer, ensuring that the energy excessively wasted in the crushing zone is fully utilized and converted into "useful" energy in the fracture zone to achieve the desired rock-breaking effect. Currently, when using decoupled charge technology, the explosive is mainly installed manually into the borehole. This is not only cumbersome and has a low safety factor, but also often results in the explosive being misaligned or leaning against the sidewall of the borehole, leading to inaccurate installation and poor decoupled installation effect, making it difficult to achieve the desired rock-breaking effect. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a delivery device for step blasting technology that ensures accurate installation of the explosive cartridges.

[0004] The present invention provides the following technical solution: a delivery device for step blasting technology, comprising a delivery cylinder that can be placed inside a blast hole, a charge cartridge placed in the inner cavity of the delivery cylinder, a clamping mechanism for clamping the charge cartridge being sleeved on the outside of the delivery cylinder, an outer cylinder being provided on the clamping mechanism, the outer cylinder pushing the delivery cylinder and the clamped charge cartridge into the blast hole, and after the clamping mechanism releases the charge cartridge through the outer cylinder, the outer cylinder pulling the delivery cylinder and the clamping mechanism out of the blast hole.

[0005] Preferably, the clamping mechanism includes a screw sleeve threaded to the outer wall of the conveying cylinder and a conical cylinder fixedly sleeved on the outer wall of the conveying cylinder. Several guide holes communicating with the inner cavity of the conveying cylinder are provided radially inside the conical cylinder. Each guide hole has a ball on its outer side and a clamping block on its inner side, and a spring is provided between the ball and the clamping block. The lower end of the screw sleeve is formed with a conical cavity that cooperates with the conical cylinder, and each ball abuts against the inner wall of the conical cavity. Rotating the screw sleeve causes it to move downward along the conveying cylinder. During the downward movement of the conical cavity, each ball is pushed to move along the corresponding guide hole. Under the elastic force of the corresponding spring, the balls push several clamping blocks to extend into the inner cavity of the conveying cylinder to clamp the medicine roll.

[0006] Preferably, the conveying cylinder is provided with several stepped holes in the radial direction that communicate with the guide hole. The large hole of each stepped hole has the same diameter as the guide hole, and the small hole of each stepped hole communicates with the inner cavity of the conveying cylinder. The clamping block includes a clamp and a stop block fixedly connected to the clamp. The stop block is connected to the spring. When the clamp is pushed by the spring and the stop block to extend into the inner cavity of the conveying cylinder from the small hole, the stop block can abut against the stepped surface of the stepped hole.

[0007] Preferably, the outer wall of the sleeve is provided with a reverse thread that is opposite to the thread direction of the outer wall of the conveying cylinder, and the outer cylinder is threadedly connected to the sleeve through the reverse thread; the cylinder wall of the conveying cylinder is provided with a slot along the axial direction, and a rod inserted from the outer cylinder can be inserted into the slot; when the rod inserted into the slot is fixed, the outer cylinder, which is screwed onto the sleeve, is rotated to drive the sleeve to rotate relative to the conveying cylinder.

[0008] Preferably, the sleeve is provided with a positioning mechanism for positioning the conveying cylinder. The positioning mechanism includes a rotatable gear disposed inside the sleeve and racks meshing with the gear from four quadrant points respectively. When the gear is rotated, the four racks extend or retract from the sleeve at the same time, and the extended ends of the four racks are located on the same circle concentric with the gear.

[0009] Preferably, the upper end face of the gear is provided with an annular groove, and several locking pins are provided radially inside the annular groove. The inner cylinder, which passes through the outer cylinder, extends into the annular groove. When the inner cylinder is rotated, the inner cylinder engages with the corresponding locking pins through several locking slots provided on its bottom wall to drive the gear to rotate.

[0010] Preferably, the lower end face of the gear is provided with a circumferential upper guide groove, and the sleeve is provided with a corresponding lower guide groove, with several steel balls extending into the upper guide groove in the lower guide groove.

[0011] As can be seen from the above technical solutions, the present invention uses a clamping mechanism to flexibly clamp the explosive cartridge in the conveying cylinder, and the outer cylinder can push the explosive cartridge to the bottom of the borehole, which is not only convenient to install, but also has a high safety factor; at the same time, the positioning mechanism adjusts the explosive cartridge to be installed at the central axis position of the borehole, ensuring the accuracy of the explosive installation position, thereby improving the effect of decoupled installation.

[0012] The present invention also provides a method for a delivery device using the above-mentioned step blasting technology, comprising the following steps:

[0013] (1) Place the conveyor sleeve around the outer circumference of the prepared medicine roll, rotate the sleeve, and move the sleeve down to make several clamping blocks flexibly clamp the medicine roll;

[0014] (2) Take out the outer cylinder and screw it onto the screw sleeve; then lift the outer cylinder and push the conveyor cylinder together with the clamped propellant roll into the borehole until the propellant roll is placed at the bottom of the borehole.

[0015] (3) Next, insert the inner cylinder into the annular groove from the inner cavity of the outer cylinder and make the slot engage with the pin; rotate the inner cylinder to make the gear rotate, and the gear drives the four racks to extend out of the sleeve until the extended ends of the four racks abut against the hole wall of the blast hole, and stop rotating.

[0016] (4) After adjusting the position of the cartridge to the center axis of the borehole, rotate the inner cylinder in the opposite direction to drive the gear to rotate in the opposite direction, so that the four racks retract into the sleeve, and then take the inner cylinder out from the inner cavity of the outer cylinder.

[0017] (5) Next, insert the insert rod into the slot and hold it in place; then rotate the outer cylinder to make the sleeve rotate relative to the conveying cylinder, and move the sleeve upward to make the clamping block retract to release the medicine roll;

[0018] (6) Then take out the insert rod, lift the outer cylinder, and take the conveying cylinder out of the blast hole.

[0019] As can be seen from the above technical solutions, the method of the present invention can adjust the installation of the medicine roll to the accurate position by rotating the inner and outer cylinders. It is convenient, practical and has a high safety factor.

[0020] The present invention further provides a charge structure obtained by the above-mentioned charging device using the stepped blasting technology, wherein the charge roll is divided into a small-diameter upper charge roll and a large-diameter lower charge roll, and both the upper and lower charge rolls have gaps between them and the blast hole; the clamping mechanism first clamps the middle part of the lower charge roll and adjusts the position of the lower charge roll to the central axis of the blast hole through the positioning mechanism, then clamps the middle part of the upper charge roll and places it on the lower charge roll, and then adjusts the position of the lower charge roll to the central axis of the blast hole through the positioning mechanism.

[0021] Preferably, the amount of propellant per meter of the lower propellant roll is 1.2-2.2 times that of the amount of propellant per meter of the upper propellant roll.

[0022] As can be seen from the above technical solutions, the present invention adopts a decoupled charge structure technology with upper and lower explosive sections. Due to the presence of air in the gap, the initial impact pressure and tensile stress acting on the borehole wall after the explosive detonates are greatly reduced, the radius of the crushing ring is reduced, and the energy utilization rate is increased. Moreover, the radius of the crushing ring of the upper explosive section is smaller than that of the lower explosive section, which greatly reduces the generation of powder ore. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the drug delivery device of the present invention.

[0024] Figure 2 for Figure 1 A top view of the positioning mechanism.

[0025] Figure 3This is a schematic diagram of the charge loading structure of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. The accompanying drawings are for illustrative purposes only, representing schematic diagrams only, not actual physical objects, and should not be construed as limiting the present invention.

[0027] See Figure 1 and Figure 2 This invention provides a propellant delivery device for stepped blasting technology, comprising a delivery cylinder 2 that can be placed inside a blast hole 1, a propellant cartridge 8 placed in the inner cavity of the delivery cylinder, and a clamping mechanism 3 that clamps the propellant cartridge on the outside of the delivery cylinder. To ensure the stability of the propellant cartridge, the clamping mechanism clamps the middle position of the propellant cartridge. The clamping mechanism of this invention is provided with an outer cylinder 4, which pushes the delivery cylinder and the clamped propellant cartridge into the blast hole. After the clamping mechanism releases the propellant cartridge through the outer cylinder, the outer cylinder pulls the delivery cylinder and the clamping mechanism out of the blast hole, thereby completing the installation of the propellant cartridge. This invention, through the pushing and pulling of the delivery cylinder by the outer cylinder, makes the installation of the propellant cartridge convenient, quick, and with a high safety factor.

[0028] Specifically, the clamping mechanism 3 includes a screw sleeve 31 threadedly connected to the outer wall of the conveying cylinder and a conical cylinder 32 fixedly sleeved on the outer wall of the conveying cylinder. Several guide holes 33 are radially arranged within the conical cylinder, communicating with the inner cavity of the conveying cylinder. Each guide hole has a ball bearing 34 on its outer side and a clamping block 35 on its inner side. A spring 36 is provided between the ball bearing and the clamping block. The lower end of the screw sleeve is formed with a conical cavity 37 that mates with the conical cylinder. Each ball bearing abuts against the inner wall of the conical cavity, ensuring that the ball bearing does not fall off during the up-and-down movement of the screw sleeve. During implementation, rotating the screw sleeve causes it to move downwards along the conveying cylinder. As the conical cavity moves downwards, the gap between the conical cavity and the conical cylinder decreases. Therefore, during the downward movement of the conical cavity, each ball bearing is pushed to move along the corresponding guide hole. Under the elastic force of the corresponding springs, several balls bearing push several clamping blocks into the inner cavity of the conveying cylinder, thereby clamping the medicine roll from the outer periphery. Because the invention uses springs, the clamping blocks act flexibly on the medicine roll, resulting in high safety; and the synchronous movement of several clamping blocks ensures that the medicine roll is located at the central axis of the conveying cylinder.

[0029] Preferably, the conveying cylinder is provided with several stepped holes 21 radially communicating with the guide hole. The large hole of each stepped hole has the same diameter as the guide hole, so that the stop block can move without obstruction. The small hole of the stepped hole communicates with the inner cavity of the conveying cylinder. The clamping block includes a clamp 351 and a stop block 352 fixedly connected to the clamp. The stop block is connected to one end of the spring, and the other end of the spring contacts the ball bearing but is not fixedly connected to the ball bearing. This allows the ball bearing to roll during the rotation of the sleeve downward or upward, reducing friction on the one hand and avoiding damage to the spring due to the fixed connection on the other hand. When the clamp is pushed into the inner cavity of the conveying cylinder through the small hole by the spring and the stop block, the stop block can abut against the stepped surface of the stepped hole. Specifically, during the downward rotation of the sleeve, as the gap between the cone cylinder and the cone cavity decreases, the balls move along the guide hole under pressure, thereby compressing the spring and generating elastic force to push the stop block. The chuck then moves along the stepped hole and gradually extends into the inner cavity of the conveying cylinder from the small hole until the stop block abuts against the stepped surface of the stepped hole. This invention, with its stepped hole and stop block, prevents the chuck from falling into the inner cavity of the conveying cylinder.

[0030] During implementation, the outer wall of the sleeve is provided with a reverse thread opposite to the thread direction of the outer wall of the conveying cylinder. The outer cylinder is threadedly connected to the sleeve through this reverse thread. The cylinder wall of the conveying cylinder is provided with a slot 22 along the axial direction. The insert rod 5, which passes through the outer cylinder, can be inserted into the slot. When the insert rod inserted into the slot is fixed, the outer cylinder, which is tightened on the sleeve, is rotated to drive the sleeve to rotate relative to the conveying cylinder, thereby causing the chuck to retract into the stepped hole and thus releasing the drug roll. If the sleeve is screwed clockwise onto the conveying cylinder, the sleeve rotates downward and pushes the ball to move and clamp the drug roll. The outer cylinder is screwed counterclockwise onto the sleeve. When the outer cylinder is rotated counterclockwise, with the insert rod fixing the conveying cylinder, the sleeve will rotate counterclockwise with the outer cylinder, that is, the sleeve rotates upward. The gap between the cone cylinder and the cone cavity increases, the ball moves outward under the action of elasticity, and the stop block and chuck move outward as well, thereby releasing the drug roll. During implementation, handles can be installed at the ends of the outer and inner cylinders for easy rotation, and handles can also be installed at the ends of the insertion rods to fix the conveying cylinder.

[0031] The present invention includes a positioning mechanism 6 on the sleeve for positioning the conveying cylinder. This positioning mechanism adjusts the position of the propellant cartridge to the central axis of the borehole via the conveying cylinder. Specifically, the positioning mechanism 6 includes a rotatable gear 61 disposed within the sleeve and racks 62 meshing with the gear at its four quadrant points. That is, one gear drives four racks to move synchronously, ensuring consistent movement distances. During implementation, when the gear is rotated, the four racks simultaneously extend or retract from the sleeve. The extended ends of the four racks are located on the same circle concentric with the gear. Thus, provided that the gear is sleeved on the outside of the propellant cartridge and coincides with the central axis of the cartridge, the center of the circle containing the extended ends of the four racks is also on the central axis of the cartridge. As the four racks extend from the sleeve simultaneously, the extended ends of the racks gradually approach the borehole wall. By adjusting the position of the conveying cylinder, the extended ends of the four racks are all pressed against the borehole wall. At this time, the circle containing the inner wall of the borehole coincides with the circle containing the extended ends of the four racks, and the central axis of the propellant cartridge coincides with the central axis of the borehole, thus installing the propellant cartridge on the central axis of the borehole and ensuring the accuracy of the installation.

[0032] To achieve gear rotation, an annular groove 63 is provided on the upper end face of the gear, and several locking pins 64 are radially arranged in the annular groove. The inner cylinder 7, which passes through the outer cylinder, extends into the annular groove. When the inner cylinder rotates, it engages with the corresponding locking pins 64 through several locking slots 71 provided on its bottom wall to drive the gear to rotate. That is, the inner cylinder drives the gear to rotate through the locking slots and locking pins. Preferably, the lower end face of the gear is provided with a circumferential upper guide groove 65, and the sleeve is provided with a corresponding lower guide groove 66. Several steel balls 67 extending into the upper guide groove are provided in the lower guide groove to position the gear and prevent it from moving. During implementation, a small gap should be reserved between the sleeve and the upper end face of the gear to avoid interfering with the rotation of the gear. The several steel balls of the present invention can support the lower end face of the gear, and when the gear rotates, the several steel balls roll in the upper and lower guide grooves, which can reduce the friction of the lower end face of the gear.

[0033] The present invention also provides a method for a delivery device using the above-mentioned step blasting technology, comprising the following steps:

[0034] First, prepare the pill rolls. According to design requirements, divide the pill rolls into a small-diameter upper roll and a large-diameter lower roll. Screw the sleeve onto the conveyor cylinder, ensuring the sleeve and cylinder are connected and cannot detach. Initially, the gap between the sleeve's conical cavity and the cylinder should be at its maximum, trapping the ball bearings within this gap. Next, place the conveyor cylinder around the prepared pill rolls, passing the rolls through it until the center of the roll aligns with the sleeve. Then, rotate the sleeve, causing it to move downwards, allowing several clamping blocks to flexibly clamp the center of the roll, ensuring stable clamping. The specific clamping method is as described above.

[0035] Next, remove the outer cylinder and place it around the outer circumference of the sleeve. Then, fix the sleeve and rotate the outer cylinder using a reverse thread that rotates in the opposite direction to the downward movement of the sleeve relative to the conveying cylinder, thus tightening the outer cylinder onto the outer circumference of the sleeve. Then, lift the outer cylinder and push the conveying cylinder along with the clamped propellant cartridge into the borehole through it until the propellant cartridge is at the bottom of the borehole. Next, insert the inner cylinder into the annular groove from the inner cavity of the outer cylinder and engage the locking pin. Then, rotate the inner cylinder to drive the gear to rotate, causing the four racks to extend out of the sleeve until the extended ends of the four racks abut against the borehole wall, then stop rotating. This adjusts the conveying cylinder to the central axis position of the borehole, and consequently, the position of the propellant cartridge is also adjusted to the central axis of the borehole. Next, rotate the inner cylinder in the opposite direction to drive the gear to rotate in the opposite direction, causing the four racks to retract into the sleeve, allowing the conveying cylinder to be removed. Then, remove the inner cylinder from the inner cavity of the outer cylinder. The specific operation method of the positioning mechanism is as described above.

[0036] Next, insert the insert rod into the slot and hold it in place to ensure the conveying cylinder does not rotate. Then, continue rotating the outer cylinder in the same direction as tightening it. Since the outer cylinder is tightened and there is no longer relative movement between it and the rotating sleeve, the rotating outer cylinder, while the conveying cylinder is not rotating, drives the rotating sleeve to rotate, causing the rotating sleeve to rotate relative to the conveying cylinder. That is, the rotating sleeve rotates and moves upward, thereby causing the clamping block to retract and release the cartridge. At this point, the positioning mechanism has been released first, followed by the clamping mechanism. Now, simply remove the insert rod and lift the outer cylinder to remove the conveying cylinder from the borehole, thus achieving the installation and positioning of the cartridge. It can be seen that this invention can adjust the cartridge to the accurate position by rotating the inner and outer cylinders, which is convenient, practical, and has a high safety factor.

[0037] Based on the aforementioned delivery device and method of use for bench blasting technology, this invention provides a charging structure, such as... Figure 3 In a rock mass 9 subjected to bench blasting, a blast hole 1 is drilled, and a charge cartridge 8 is installed inside the blast hole. This charge cartridge consists of a small-diameter upper charge cartridge 81 and a large-diameter lower charge cartridge 82. A gap 83 is left between the upper and lower charge cartridges and the blast hole, and a sealing section 84 is used at the upper end of the upper charge cartridge 81 to seal the blast hole. Thus, this invention employs a non-uniform, decoupled charging technique, which significantly reduces the initial impact pressure and tensile stress acting on the borehole wall after the explosive detonation, reduces the radius of the pulverization zone, increases energy utilization, and reduces the ore powder rate.

[0038] In the implementation process, the clamping mechanism of the present invention first clamps the middle part of the lower explosive cartridge and adjusts the position of the lower explosive cartridge to the central axis of the borehole through the positioning mechanism. Then, it clamps the middle part of the upper explosive cartridge and places it on the lower explosive cartridge, so that the bottom of the upper explosive cartridge abuts against the top of the lower explosive cartridge. Then, the positioning mechanism adjusts the position of the upper explosive cartridge to the central axis of the borehole, thereby ensuring that the upper and lower explosive cartridges do not deviate from the central axis of the borehole and ensuring that the radial gap between the borehole and the peripheral wall of the explosive cartridge is consistent, thereby improving the effect of decoupled installation and achieving the expected rock breaking effect. Preferably, the charge per meter of the lower explosive cartridge is 1.2-2.2 times that of the upper explosive cartridge, making the radius of the crushing ring in the upper explosive cartridge smaller than that in the lower explosive cartridge. This not only reduces energy consumption and backflush, but also, because the explosive gas acts on the upper and lower explosive sections for different degrees, the inter-hole fissures are formed more completely, the energy is utilized more fully, and the particle size is more uniform. This improves the effective utilization rate of explosive energy, enhances the blasting effect, and achieves the goal of reducing the proportion of powdered ore and large lumps.

Claims

1. A charge delivery device for step blasting technology, comprising a delivery cylinder that can be placed inside a blast hole, wherein a charge cartridge is placed in the inner cavity of the delivery cylinder, characterized in that: The conveying cylinder is externally fitted with a clamping mechanism for clamping the propellant roll. This clamping mechanism has an outer cylinder that pushes the conveying cylinder and the clamped propellant roll into the borehole. After the clamping mechanism releases the propellant roll through the outer cylinder, the outer cylinder pulls the conveying cylinder and the clamping mechanism out of the borehole. The clamping mechanism includes a screw sleeve threaded to the outer wall of the conveying cylinder and a conical cylinder fixedly fitted to the outer wall of the conveying cylinder. Several guide holes are radially arranged within the conical cylinder, communicating with the inner cavity of the conveying cylinder. Each guide hole has a ball bearing on its outer side and a clamping block on its inner side, with a spring between the ball bearing and the clamping block. The lower end of the screw sleeve is formed with a conical cavity that mates with the conical cylinder, and each ball bearing abuts against the inner wall of this conical cavity. Rotating the screw sleeve causes it to move downwards along the conveying cylinder. During the downward movement of the conical cavity, each ball bearing moves along its corresponding guide hole. Under the elastic force of the corresponding springs, the ball bearings push several clamping blocks into the inner cavity of the conveying cylinder to clamp the propellant roll.

2. The delivery device for the step blasting technology according to claim 1, characterized in that: The conveying cylinder is radially provided with several stepped holes that communicate with the guide hole. The large hole of each stepped hole has the same diameter as the guide hole, and the small hole of each stepped hole communicates with the inner cavity of the conveying cylinder. The clamping block includes a clamp and a stop block fixedly connected to the clamp. The stop block is connected to the spring. When the clamp is pushed by the spring and the stop block to extend into the inner cavity of the conveying cylinder through the small hole, the stop block can abut against the stepped surface of the stepped hole.

3. The delivery device for the step blasting technology according to claim 1, characterized in that: The outer wall of the sleeve is provided with a reverse thread that is opposite to the thread direction of the outer wall of the conveying cylinder. The outer cylinder is threadedly connected to the sleeve through the reverse thread. The cylinder wall of the conveying cylinder is provided with a slot along the axial direction. A rod inserted through the outer cylinder can be inserted into the slot. When the rod inserted into the slot is fixed, the outer cylinder, which is tightened on the sleeve, is rotated to drive the sleeve to rotate relative to the conveying cylinder.

4. The delivery device for the step blasting technology according to claim 1, 2, or 3, characterized in that: The sleeve is provided with a positioning mechanism for positioning the conveying cylinder. The positioning mechanism includes a rotatable gear disposed inside the sleeve and racks meshing with the gear from four quadrant points respectively. When the gear is rotated, the four racks extend or retract from the sleeve at the same time. The extended ends of the four racks are located on the same circle concentric with the gear.

5. The delivery device for the step blasting technology according to claim 4, characterized in that: The upper end face of the gear is provided with an annular groove, and several locking pins are radially provided in the annular groove. The inner cylinder, which passes through the outer cylinder, extends into the annular groove. When the inner cylinder is rotated, the inner cylinder engages with the corresponding locking pins through several locking slots provided on its bottom wall to drive the gear to rotate.

6. The delivery device for the step blasting technology according to claim 5, characterized in that: The lower end face of the gear is provided with a circumferential upper guide groove, and the sleeve is provided with a corresponding lower guide groove. Several steel balls extending into the upper guide groove are provided in the lower guide groove.

7. A method for using a delivery device for the step blasting technique of claim 6, characterized by comprising the following steps: (1) Place the conveyor sleeve around the outer circumference of the prepared medicine roll, rotate the sleeve, and move the sleeve down to make several clamping blocks flexibly clamp the medicine roll; (2) Take out the outer cylinder and screw it onto the screw sleeve; then lift the outer cylinder and push the conveyor cylinder together with the clamped propellant roll into the borehole until the propellant roll is placed at the bottom of the borehole. (3) Next, insert the inner cylinder into the annular groove from the inner cavity of the outer cylinder and make the slot engage with the pin; rotate the inner cylinder to make the gear rotate, and the gear drives the four racks to extend out of the sleeve until the extended ends of the four racks abut against the hole wall of the blast hole, and stop rotating. (4) After adjusting the position of the cartridge to the center axis of the borehole, rotate the inner cylinder in the opposite direction to drive the gear to rotate in the opposite direction, so that the four racks retract into the sleeve, and then take the inner cylinder out from the inner cavity of the outer cylinder. (5) Next, insert the insert rod into the slot and hold it in place; then rotate the outer cylinder to make the sleeve rotate relative to the conveying cylinder, and move the sleeve upward to make the clamping block retract to release the medicine roll; (6) Then take out the insert rod, lift the outer cylinder, and take the conveying cylinder out of the blast hole.

8. A charge structure obtained by the method of the charge delivery device using step blasting technology according to claim 7, characterized in that: The propellant cartridge is divided into a small-diameter upper propellant cartridge and a large-diameter lower propellant cartridge, with gaps between the upper and lower propellant cartridges and the borehole. The clamping mechanism first clamps the middle part of the lower propellant cartridge and adjusts its position to the central axis of the borehole through the positioning mechanism. Then, it clamps the middle part of the upper propellant cartridge and places it on the lower propellant cartridge. Finally, the positioning mechanism adjusts the position of the lower propellant cartridge to the central axis of the borehole.

9. The charge structure according to claim 8, characterized in that: The amount of propellant per meter in the lower propellant roll is 1.2 to 2.2 times that in the upper propellant roll.

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