Limiting device for limiting drilling depth of anchor rod in coal mine and using method

Abstract

The invention relates to the technical field of coal mine anchor rod drilling, in particular to a limiting device for limiting the drilling depth of an anchor rod in a coal mine and a using method. The device comprises a fixed frame, a sleeve, a movable plate and an adjusting mechanism; the fixing frame comprises an upper fixing plate, a lower fixing plate and a plurality of threaded rods, the upper fixing plate and the lower fixing plate are horizontally arranged, the threaded rods are vertically arranged, the two ends of each threaded rod are rotatably connected with the upper fixing plate and the lower fixing plate respectively, the sleeve is vertically arranged between the upper fixing plate and the lower fixing plate, and the bottom end of the sleeve is detachably installed on the lower fixing plate. The anchor rod can be inserted into the sleeve and is in threaded connection with the sleeve; the adjusting mechanism is installed in the upper fixing plate and connected with the threaded rods respectively, the movable plate is in threaded connection with the threaded rods, and the top end of the sleeve is flush with the top face of the movable plate or arranged in the movable plate. And the adjusting mechanism can drive the multiple threaded rods to synchronously rotate, so that the distance between the movable plate and the lower fixed plate is accurately adjusted, and the effect of limiting the drilling depth of the anchor rod is achieved.

Description

Technical Field

[0001] This invention relates to the field of coal mine anchor bolt drilling technology, and in particular to a limiting device and its method for limiting the drilling depth of anchor bolts in coal mines. Background Technology

[0002] Rock bolts are one of the most basic and core components in current coal mine roadway support systems. Their working mechanism is to connect the surrounding rock of the roadway into a whole, enabling the surrounding rock to achieve self-support and stability through its own structure. With the continuous expansion of application scenarios, rock bolts have extended from mining engineering to various geotechnical engineering fields, and are widely used in main structure reinforcement projects such as slope reinforcement, tunnel support, and dam protection.

[0003] Anchor bolts, as tension members extending deep into the ground, are connected to the engineering structure at one end and anchored to the ground at the other. Their overall structure is mainly divided into a free section and an anchored section. The function of the free section is to transfer the tension at the end of the anchor bolt to the anchor body, primarily by applying prestress to the anchor bolt to enhance the overall stability of the support structure.

[0004] According to Article 39, Item 3 of the "Regulations on the Management of Anchor Bolt Support in Coal Mine Roadways," the drilling depth for anchor bolt installation must strictly comply with the design standards, and the drilling depth error should be controlled within the range of 0-50mm. During underground tunneling operations, the drilling depth of anchor bolts is difficult to control precisely, and the drilling depth directly determines the quality of anchor bolt installation, easily leading to problems such as excessively long or insufficient exposed length after installation.

[0005] According to the tunneling operation regulations, the exposed length of the anchor bolts should be controlled between 10mm and 50mm. If the exposed length exceeds 50mm, the anchor bolts must be replaced. If the exposed length is insufficient, a pneumatic pick must be used to trim the coal and rock wall, and the anchor bolts must be tightened again to meet the construction requirements.

[0006] However, traditional anchor bolts lack effective limiting structures during drilling, making it difficult for operators to accurately control the drilling depth and the exposed length of the anchor bolt after installation. Furthermore, issues such as hole deviation and drilling direction offset are prone to occur during drilling, affecting both the quality of anchor bolt installation and reducing on-site construction efficiency. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a limiting device and method for limiting the drilling depth of anchor bolts in coal mines, which solves the technical problems of traditional anchor bolts being unable to accurately control the drilling depth during the drilling process, and the drilling being prone to deviation, which affects the support quality and construction efficiency.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0011] On one hand, the present invention provides a limiting device for limiting the drilling depth of anchor bolts in coal mines, including a fixed frame, a sleeve, a movable plate, and an adjusting mechanism; the fixed frame includes a horizontally arranged upper fixed plate, a lower fixed plate, and a plurality of vertically arranged threaded rods, the two ends of which are rotatably connected to the upper fixed plate and the lower fixed plate respectively; the sleeve is vertically arranged between the upper fixed plate and the lower fixed plate, and the bottom end of the sleeve is detachably installed on the lower fixed plate; the anchor bolt can be inserted into the sleeve and screwed to the sleeve, and the anchor bolt and the sleeve are always coaxial to limit the drilling direction of the anchor bolt; the adjusting mechanism is installed in the upper fixed plate and connected to the plurality of threaded rods respectively; the movable plate is screwed to the plurality of threaded rods, the movable plate is sleeved outside the sleeve, the top end of the sleeve is flush with the top surface of the movable plate or placed inside the movable plate; the adjusting mechanism can drive the plurality of threaded rods to rotate synchronously, so that the movable plate can move along the axis of the threaded rods; the end of the anchor bolt away from the lower fixed plate can pass through the upper fixed plate and abut against the top surface of the movable plate.

[0012] Preferably, the adjusting mechanism includes a driving gear, an output rod, a chain, and multiple driven gears; the upper fixed plate has an installation space inside, and the driving gear, chain, and multiple driven gears are all horizontally arranged in the installation space. The top ends of multiple threaded rods pass through the upper fixed plate and are placed in the installation space; the driving gear is fixedly connected to the top end of one of the threaded rods, and the top ends of the remaining threaded rods are respectively connected to multiple driven gears one by one. The output rod includes an installation end and an output end. The installation end of the output rod passes through the upper fixed plate and is fixedly connected to the end of the driving gear away from the threaded rod. The output end of the output rod is used to drive the driving component. The chain is sleeved on the driving gear and multiple driven gears and meshes with them; the driving component can drive the driving gear to rotate through the output rod, so as to drive multiple driven gears to rotate simultaneously through the chain, thereby driving multiple threaded rods to rotate synchronously.

[0013] Preferably, the limiting device further includes a scale plate, which is vertically fixedly installed on the same side wall of the upper fixed plate and the lower fixed plate.

[0014] Preferably, the sleeve includes a sleeve body and multiple limiting strips; the sleeve body is vertically arranged and has internal threads inside; the multiple limiting strips are all vertically arranged and circumferentially around the axis of the sleeve body and fixedly installed on the outer wall of the sleeve body; the movable plate has a limiting hole, the inner contour of which is consistent with the outer contour of the sleeve, so as to limit the vertical movement direction of the movable plate.

[0015] Preferably, the top surface of the lower fixing plate has a slot that matches the outer contour of the sleeve, the bottom end of the sleeve is inserted into the slot, and the sleeve can be locked in the slot by a locking device.

[0016] Preferably, the locking device includes multiple locking mechanisms; each locking mechanism is horizontally inserted through the lower fixed plate and can be inserted into a corresponding limit bar to lock the sleeve.

[0017] Preferably, the locking mechanism includes a locking rod, an elastic element, a fixing ring, and a pull ring; the limiting strip has an insertion hole on the outer wall of the slot away from the sleeve body; one end of the locking rod is horizontally inserted through the lower fixing plate and can be inserted into the insertion hole to lock the sleeve; the other end of the locking rod is placed on the outside and fixedly connected to the pull ring; an elastic space is provided inside the lower fixing plate; the locking rod passes through the elastic space; the elastic element and the fixing ring are both placed in the elastic space; the fixing ring is fixedly sleeved on the outer wall of the locking rod; the side of the fixing ring facing the limiting strip can abut against the inner wall of the elastic space near the limiting strip; the elastic element is sleeved on the locking rod; and the two ends of the elastic element abut against the side of the fixing ring away from the limiting strip and the inner wall of the elastic space away from the limiting strip, respectively, to provide buffering force and rebound force for the fixing ring and the locking rod.

[0018] Preferably, the limiting device further includes a buffer pad; the buffer pad is horizontally attached to the bottom surface of the lower fixing plate, and the bottom surface of the buffer pad is provided with anti-slip texture.

[0019] Preferably, the anchor bolt includes an anchor bolt body, a drill bit, and a connecting plate. The drill bit is detachably connected to the bottom end of the anchor bolt body, and the connecting plate is fixedly connected to the top end of the anchor bolt body, and the connecting plate is horizontally arranged. The upper fixing plate has a clearance hole, which is circular and the diameter of the clearance hole is greater than the diagonal distance of the connecting plate.

[0020] On the other hand, the present invention provides a method of using the limiting device according to the above description, comprising the following steps:

[0021] S1: The adjusting mechanism drives multiple threaded rods to rotate synchronously, thereby causing the movable plate to move vertically along the axis of the threaded rods to move the movable plate to the designated position;

[0022] S2: Select a suitable sleeve, pass it through the movable plate, and install it on the lower fixed plate, making the top of the sleeve flush with the top surface of the movable plate;

[0023] S3: Pass the anchor rod through the upper fixing plate and screw it into the internal thread of the sleeve;

[0024] S4: The bottom surface of the lower fixed plate abuts against the target position, driving the anchor rod to rotate, causing the anchor rod to move toward the target position and drill a hole at the target position until the end of the anchor rod away from the lower fixed plate abuts against the top surface of the movable plate.

[0025] (III) Beneficial Effects

[0026] The beneficial effects of this invention are:

[0027] This invention discloses a limiting device and method for limiting the drilling depth of anchor bolts in coal mines. By setting up an adjustment mechanism, a movable plate, and multiple threaded rods, the adjustment mechanism drives the multiple threaded rods to rotate synchronously. This ensures that the movable plate remains horizontal and moves vertically along the axis of the threaded rods, allowing for precise adjustment of the distance between the movable plate and the lower fixed plate. This effectively limits the drilling depth of the anchor bolt, preventing further drilling and ensuring that the exposed length of the anchor bolt after installation meets the construction standard of 10mm-50mm. This avoids the problems of excessive exposure requiring re-drilling or insufficient exposure requiring pneumatic hammer trimming, significantly reducing rework. Furthermore, by setting up a sleeve, the bottom end of which is detachably installed on the lower fixed plate, different specifications of sleeves can be selected for different distances between the movable plate and the lower fixed plate to limit the drilling direction of the anchor bolt, improving the applicability of the limiting device. Meanwhile, by aligning the top surface of the movable plate with the top of the sleeve, or placing the top of the sleeve inside the movable plate, not only is it possible to ensure stable sleeve installation after the distance between the movable plate and the lower fixed plate is fixed, but it also ensures that when the anchor rod is drilled to a specified depth, the end of the anchor rod furthest from the lower fixed plate can pass through the upper fixed plate and abut against the top surface of the movable plate. This prevents the top of the sleeve from extending beyond the top surface of the movable plate, which would cause the end of the anchor rod furthest from the lower fixed plate to abut against the top of the sleeve during drilling, resulting in an excessively long exposed length of the anchor rod and affecting its anchoring effect. Furthermore, by screwing the sleeve and anchor rod together and keeping them coaxial at all times, it effectively restricts the drilling direction of the anchor rod, preventing hole deviation and drilling direction offset during drilling, ensuring the quality of anchor rod installation, ensuring that the anchor rod can stably transmit tension and apply prestress, and improving the overall stability of the support structure. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a limiting device and its usage method for limiting the drilling depth of anchor bolts in coal mines, according to the present invention.

[0029] Figure 2 This is a schematic diagram of the overall three-dimensional structure of a limiting device for limiting the drilling depth of anchor bolts in coal mines and its usage method, according to the present invention.

[0030] Figure 3 This is a three-dimensional disassembly diagram of the limiting device for limiting the drilling depth of anchor bolts in coal mines and its usage method, according to the present invention.

[0031] Figure 4 This is a schematic diagram of the overall three-dimensional structure of the fixing frame of a limiting device and its usage method for limiting the drilling depth of anchor bolts in coal mines according to the present invention.

[0032] Figure 5 for Figure 4Schematic diagram of the cross-sectional structure at point AA;

[0033] Figure 6 for Figure 5 Enlarged structural diagram at point A in the middle;

[0034] Figure 7 This is a schematic diagram of the overall three-dimensional structure of an anchor bolt, which is a limiting device for limiting the drilling depth of anchor bolts in coal mines and a method for using it, according to the present invention.

[0035] Figure 8 This is a schematic diagram of the overall three-dimensional disassembly structure of an anchor bolt, which is a limiting device for limiting the drilling depth of anchor bolts in coal mines and a method for using it, according to the present invention.

[0036] [Explanation of Labels in the Attached Image]

[0037] 1: Fixed frame; 11: Upper fixed plate; 111: Installation space; 112: Clearance hole; 12: Lower fixed plate; 121: Slot; 122: Elastic space; 13: Threaded rod; 2: Sleeve; 21: Sleeve body; 22: Limiting strip; 221: Insertion hole; 3: Movable plate; 31: Limiting hole; 4: Adjustment mechanism; 41: Driving gear; 42: Output rod; 43: Chain; 44: Driven gear; 5: Anchor rod; 51: Anchor rod body; 511: Mounting groove; 52: Drill bit; 53: Connecting plate; 54: Insertion post; 6: Scale plate; 7: Locking mechanism; 71: Locking rod; 72: Elastic element; 73: Fixed ring; 74: Pull ring; 8: Buffer pad; 9: Bearing. Detailed Implementation

[0038] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0039] Example 1

[0040] This embodiment of a limiting device for limiting the drilling depth of anchor bolt 5 in a coal mine includes a fixed frame 1, a sleeve 2, a movable plate 3, and an adjustment mechanism 4.

[0041] Specifically, such as Figure 1As shown, the fixed frame 1 includes a horizontally arranged upper fixed plate 11, a lower fixed plate 12, and a plurality of vertically arranged threaded rods 13. The two ends of the threaded rods 13 are rotatably connected to the upper fixed plate 11 and the lower fixed plate 12, respectively. A sleeve 2 is vertically arranged between the upper fixed plate 11 and the lower fixed plate 12, and the bottom end of the sleeve 2 is detachably installed on the lower fixed plate 12. Anchor rods 5 can be inserted into the sleeve 2 and screwed onto it. The anchor rods 5 and the sleeve 2 are always coaxial, thus limiting the drilling of the anchor rods 5. Direction; The adjustment mechanism 4 is installed inside the upper fixed plate 11 and is connected to multiple threaded rods 13 respectively. The movable plate 3 is screwed to multiple threaded rods 13. The movable plate 3 is sleeved outside the sleeve 2. The top end of the sleeve 2 is flush with the top surface of the movable plate 3 or placed inside the movable plate 3. The adjustment mechanism 4 can drive multiple threaded rods 13 to rotate synchronously so that the movable plate 3 can move along the axis of the threaded rods 13. The end of the anchor rod 5 away from the lower fixed plate 12 can pass through the upper fixed plate 11 and abut against the top surface of the movable plate 3. By setting up an adjustment mechanism 4, a movable plate 3, and multiple threaded rods 13, the adjustment mechanism 4 can drive the multiple threaded rods 13 to rotate synchronously. This allows the movable plate 3 to always remain horizontal and move vertically along the axis of the threaded rods 13, so as to precisely adjust the distance between the movable plate 3 and the lower fixed plate 12. This achieves the function of limiting the drilling depth of the anchor rod 5, ensuring that the anchor rod 5 cannot be drilled further, and ensuring that the exposed length of the anchor rod 5 after installation meets the construction standard of 10mm-50mm. This avoids the problem of excessive exposure requiring re-drilling or insufficient exposure requiring pneumatic hammer trimming, significantly reducing rework. Moreover, by setting up a sleeve 2, the bottom end of which is detachably installed on the lower fixed plate 12, different specifications of sleeve 2 can be selected for installation according to different distances between the movable plate 3 and the lower fixed plate 12, so as to limit the drilling direction of the anchor rod 5, improving the applicability of the limiting device. Meanwhile, by ensuring the top surface of the movable plate 3 is flush with the top surface of the sleeve 2, or by placing the top surface of the sleeve 2 inside the movable plate 3, it not only ensures the stable installation of the sleeve 2 after the distance between the movable plate 3 and the lower fixed plate 12 is fixed, but also ensures that when the anchor rod 5 is drilled to a specified depth, the end of the anchor rod 5 furthest from the lower fixed plate 12 can pass through the upper fixed plate 11 and abut against the top surface of the movable plate 3. This prevents the top surface of the sleeve 2 from extending beyond the top surface of the movable plate 3, which would cause the end of the anchor rod 5 furthest from the lower fixed plate 12 to abut against the top surface of the sleeve 2 during drilling, resulting in an excessively long exposed length of the anchor rod 5 and affecting its anchoring effect. Furthermore, by screwing the sleeve 2 and the anchor rod 5 together and keeping them coaxial at all times, it effectively restricts the drilling direction of the anchor rod 5, preventing hole deviation and drilling direction offset during drilling, ensuring the installation quality of the anchor rod 5, ensuring that the anchor rod 5 can stably transmit tension and apply prestress, and improving the overall stability of the support structure.

[0042] Furthermore, such as Figure 2 and Figure 3As shown, the adjusting mechanism 4 includes a driving gear 41, an output rod 42, a chain 43, and multiple driven gears 44. The upper fixed plate 11 has an installation space 111 inside, where the driving gear 41, chain 43, and multiple driven gears 44 are horizontally arranged. The top ends of multiple threaded rods 13 pass through the upper fixed plate 11 and are placed within the installation space 111. The driving gear 41 is fixedly connected to the top end of one threaded rod 13, and the top ends of the remaining threaded rods 13 are respectively connected to one driven gear 44. The output rod 42 includes an installation end and an output end. The installation end of the output rod 42 passes through the upper fixed plate 11 and is fixedly connected to the end of the driving gear 41 away from the threaded rod 13. The output end of the output rod 42 is used to drive the driving component. The chain 43 is sleeved on the driving gear 41 and the multiple driven gears 44 and meshes with them. The drive unit can drive the drive gear 41 to rotate via the output rod 42, which in turn drives multiple driven gears 44 to rotate simultaneously via the chain 43, thereby driving multiple threaded rods 13 to rotate synchronously. By setting up the drive gear 41, chain 43, output rod 42, and driven gears 44, it is possible to drive the drive gear 41 to rotate only by driving the output rod 42 via the drive unit, and then transmit power through the chain 43 to achieve synchronous rotation of multiple driven gears 44, thereby driving all threaded rods 13 to rotate synchronously. This ensures that the movable plate 3 moves smoothly and horizontally along the axis of the threaded rods 13, avoiding the limit depth error caused by the offset of the movable plate 3, and further improving the control accuracy of the drilling depth. At the same time, by opening an installation space 111 inside the upper fixed plate 11, the drive gear 41, chain 43, and multiple driven gears 44 are all placed in the installation space 111. This can effectively prevent the adhesion of impurities such as coal dust and gravel in the well, prevent the drive gear 41 and driven gears 44 from jamming, prevent the chain 43 from rusting, extend the service life of the adjustment mechanism 4, and reduce the maintenance cost of the limit device.

[0043] It should be noted that the driving component in this embodiment can be an electric drill. When it is necessary to adjust the distance between the movable plate 3 and the lower fixed plate 12, simply connect the connecting end of the electric drill to the output rod 42 to start the electric drill and drive the output rod 42 to rotate, thereby realizing the rotation of the drive gear 41. This allows the drive gear 41 to drive multiple driven gears 44 to rotate synchronously via the chain 43, which in turn enables multiple threaded rods 13 to rotate synchronously. The driving component only connects to the output rod 42 when it is necessary to adjust the distance between the movable plate 3 and the lower fixed plate 12. When no adjustment is needed, the driving component does not need to connect to the output rod 42. That is, the driving component is a separate device. Therefore, after the anchor rod 5 is stably fixed, the weight of the limiting device can be reduced, avoiding the anchor rod 5 from becoming loose due to excessive weight of the limiting device, thus improving the anchoring stability of the anchor rod 5.

[0044] To prevent stable meshing between the driving gear 41, driven gear 44, and chain 43, limit plates are fixedly installed at the top and bottom of the driving gear 41 and driven gear 44 to limit the position of chain 43, prevent disengagement between the driving gear 41, driven gear 44, and chain 43, and ensure stable transmission between the driving gear 41, multiple gears, and chain 43.

[0045] Among them, such as Figure 3 As shown, the bottom end of the threaded rod 13 is rotatably connected to the lower fixed plate 12 via a bearing 9, and the top end of the threaded rod 13 is also rotatably connected to the upper fixed plate 11 via a bearing 9, ensuring smooth rotation of the threaded rod 13. Furthermore, the outer wall of the end of the threaded rod 13 located in the installation space 111, and the outer wall connected to the bearing 9, are not threaded, ensuring stable rotation of the threaded rod 13 and preventing the upper fixed plate 11 from moving due to the rotation of the threaded rod 13. In this embodiment, there are four threaded rods 13, and correspondingly, three driven gears 44 are provided. The four threaded rods 13 are symmetrically arranged along the centerline of the upper fixed plate 11 and the lower fixed plate 12, improving the stability of the fixed frame 1.

[0046] Furthermore, such as Figures 1-3 As shown, the limiting device also includes a scale plate 6, which is vertically fixed on the same side wall of the upper fixed plate 11 and the lower fixed plate 12, so that the operator can intuitively read the moving distance and current limiting height of the movable plate 3 through the scale plate 6 without the need for additional measuring tools.

[0047] Furthermore, such as Figures 1-3 As shown, the sleeve 2 includes a sleeve body 21 and multiple limiting strips 22. The sleeve body 21 is vertically arranged and has internal threads. The multiple limiting strips 22 are vertically arranged and circumferentially around the axis of the sleeve body 21 and fixedly installed on the outer wall of the sleeve body 21. The movable plate 3 has a limiting hole 31, the inner contour of which is consistent with the outer contour of the sleeve 2, to limit the vertical movement of the movable plate 3, prevent the movable plate 3 from deviating or tilting during movement, and ensure that the movable plate 3 always remains coaxial with the sleeve 2, thereby ensuring the accuracy of the drilling direction of the anchor rod 5.

[0048] Furthermore, such as Figure 3 and Figure 4As shown, the top surface of the lower fixing plate 12 has a slot 121 that matches the outer contour of the sleeve 2. The bottom end of the sleeve 2 is inserted into the slot 121, enabling quick positioning and installation of the sleeve 2, simplifying the assembly and disassembly process, and facilitating operators to quickly replace the sleeve 2 according to the specifications of the anchor rod 5 and drilling requirements. Simultaneously, the sleeve 2 can be locked in the slot 121 by a locking device, ensuring that the sleeve 2 remains fixed during drilling, preventing loosening or displacement, ensuring the accuracy of drilling depth and direction, and improving the overall stability of the limiting device.

[0049] Furthermore, such as Figures 3-5 As shown, the locking device includes multiple locking mechanisms 7. These mechanisms 7 are horizontally mounted on the lower fixing plate 12 and can be inserted into multiple limiting strips 22 one-to-one to lock the sleeve 2. By setting multiple locking mechanisms 7 to be inserted into the multiple limiting strips 22 of the sleeve 2 in a one-to-one correspondence, the sleeve 2 can be locked from multiple directions, enhancing the installation stability of the sleeve 2 and preventing rotation, displacement, and vibration of the sleeve 2 due to force during the drilling of the anchor bolt 5, further ensuring drilling accuracy. Simultaneously, the locking mechanisms 7 and the limiting strips 22 are connected by an insertion method, which is simple in structure and convenient to operate. Operators can quickly lock and unlock the sleeve 2, facilitating the disassembly and replacement of the sleeve 2 and improving construction efficiency.

[0050] Furthermore, such as Figure 6As shown, the locking mechanism 7 includes a locking rod 71, an elastic element 72, a fixing ring 73, and a pull ring 74. The limiting strip 22 has an insertion hole 221 on the outer wall of the slot 121 away from the sleeve body 21. One end of the locking rod 71 is horizontally inserted through the lower fixing plate 12 and can be inserted into the insertion hole 221 to lock the sleeve 2. The other end of the locking rod 71 is placed externally and fixedly connected to the pull ring 74. An elastic space 122 is provided inside the lower fixing plate 12. The locking rod 71 passes through the elastic space 122. The elastic element 72 and the fixing ring 73 are both placed within the elastic space 122, and the fixing ring 73 is fixedly sleeved on the outer wall of the locking rod 71. The side of the fixing ring 73 facing the limiting strip 22 can abut against the inner wall of the elastic space 122 near the limiting strip 22. The elastic element 72 is sleeved on the locking rod 71, and its two ends abut against the side of the fixed ring 73 away from the limiting strip 22 and the inner wall of the elastic space 122 away from the limiting strip 22, respectively, to provide buffering and rebound force for the fixed ring 73 and the locking rod 71. The sleeve 2 is locked by correspondingly inserting the locking rod 71 into the insertion hole 221 of the limiting strip 22. In conjunction with the elastic element 72 and the fixed ring 73, the elastic element 72 can provide continuous rebound force to the fixed ring 73 and the locking rod 71, ensuring that the locking rod 71 is always tightly inserted into the insertion hole 221 when locking the sleeve 2, avoiding the locking rod 71 from loosening due to downhole vibration and impact, improving locking reliability, and ensuring the stability of the sleeve 2 during the drilling process. Meanwhile, the elastic element 72 also acts as a buffer, providing cushioning force for the fixing ring 73 and the locking rod 71. This allows the elastic element 72 to absorb the vibration generated during the drilling of the anchor bolt 5, reducing the impact of vibration on the locking mechanism 7 and the sleeve 2, preventing damage to the locking rod 71 and the limiting strip 22 due to excessive vibration stress, and extending the service life of the locking mechanism 7 and the sleeve 2. By providing a pull ring 74, operators can quickly pull the locking rod 71 to unlock the sleeve 2. This operation is convenient and labor-saving, requiring no additional tools, further simplifying the disassembly and assembly process of the sleeve 2 and improving construction efficiency.

[0051] Furthermore, such as Figures 1-3As shown, the limiting device also includes a buffer pad 8. The buffer pad 8 is horizontally attached to the bottom surface of the lower fixing plate 12. It absorbs vibrations generated during drilling when the limiting device is placed at the target position, reducing the impact of vibrations on the overall limiting device and preventing it from shifting due to vibration, thus ensuring the accuracy of the drilling depth and direction of the anchor bolt 5. Furthermore, the bottom surface of the buffer pad 8 has anti-slip textures, which increase the friction between the lower fixing plate 12 and the coal and rock wall / soil surface, preventing the limiting device from sliding or shifting due to the reaction force of the anchor bolt 5 during drilling, further improving the placement stability of the limiting device. Simultaneously, the buffer pad 8 also prevents direct contact between the lower fixing plate 12 and the coal and rock wall, preventing scratches and reducing the impact of uneven coal and rock wall on the flatness of the device placement, further ensuring drilling accuracy.

[0052] Furthermore, such as Figure 7 and Figure 8 As shown, the anchor bolt 5 includes an anchor bolt body 51, a drill bit 52, and a connecting plate 53. The drill bit 52 is detachably connected to the bottom end of the anchor bolt body 51. The drill bit 52 is inserted into the anchor bolt body 51 via a pin 54 and a mounting groove 511, and then connected to the anchor bolt body 51 with bolts and nuts. This allows for the replacement of appropriate drill bits 52 according to different soil hardness and drilling requirements, increasing the applicability of the anchor bolt 5 and facilitating maintenance and replacement of the drill bit 52, thus reducing operating costs. The connecting plate 53 is fixedly connected to the top end of the anchor bolt body 51 and is horizontally positioned. The upper fixing plate 11 has a clearance hole 112. The clearance hole 112 is circular and its diameter is larger than the diagonal distance of the connecting plate 53. This ensures that the connecting plate 53 can pass smoothly through the clearance hole 112 when the anchor rod 5 is drilled, avoiding interference between the connecting plate 53 and the inner wall of the clearance hole 112, ensuring smooth installation of the anchor rod 5, and not affecting the abutment and limiting effect of the connecting plate 53, thus ensuring the smoothness of the construction process.

[0053] Example 2

[0054] One method of using the limiting device according to Embodiment 1 in this embodiment includes the following steps:

[0055] S1: The drive component is connected to the output rod 42 and driven to make the output rod 42 rotate, thereby driving the drive gear 41 to rotate. At the same time, the chain 43 drives multiple driven gears 44 to rotate synchronously, which in turn drives multiple threaded rods 13 to rotate synchronously, thereby driving the movable plate 3 to move vertically along the axis of the threaded rod 13, so as to move the movable plate 3 to the designated position.

[0056] S2: Multiple operators pull multiple pull rings 74 to drive multiple locking levers 71 to move synchronously away from the slot 121. At this time, the elastic element 72 is compressed, providing a buffer force for the fixing ring 73 to engage the locking lever 71.

[0057] S3: Select the appropriate sleeve 2 and insert it into the slot 121 of the lower fixed plate 12 through the movable plate 3, so that the top of the sleeve 2 is flush with the top surface of the movable plate 3 or placed in the limiting hole 31 of the movable plate 3. At the same time, release multiple pull rings 74, so that the locking rod 71 and the fixing ring 73 move horizontally toward the sleeve 2 by the rebound force of the elastic element 72, so that the end of the locking rod 71 facing the limiting strip 22 is inserted into the corresponding insertion hole 221, thus completing the locking of the sleeve 2.

[0058] S4: Pass the anchor rod 5 through the upper fixing plate 11 and screw it into the internal thread of the sleeve 2.

[0059] S5: Place the limiting device at the target position, and the buffer pad 8 against the target position. Drive the anchor rod 5 to rotate by the drilling machine, so that the anchor rod 5 moves toward the target position and drills a hole at the target position until the end of the anchor rod 5 away from the lower fixed plate 12 abuts against the top surface of the movable plate 3, thus completing the installation of the anchor rod 5.

[0060] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0063] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A limiting device for limiting the drilling depth of anchor bolts in coal mines, characterized in that, It includes a fixed frame (1), a sleeve (2), a movable plate (3), and an adjustment mechanism (4); The fixed frame (1) includes a horizontally arranged upper fixed plate (11), a lower fixed plate (12) and a plurality of vertically arranged threaded rods (13). The two ends of the threaded rods (13) are rotatably connected to the upper fixed plate (11) and the lower fixed plate (12) respectively. The sleeve (2) is vertically arranged between the upper fixed plate (11) and the lower fixed plate (12), and the bottom end of the sleeve (2) is detachably installed on the lower fixed plate (12). The anchor rod (5) can be inserted into the sleeve (2) and screwed to the sleeve (2). The anchor rod (5) and the sleeve (2) are always coaxial to limit the drilling direction of the anchor rod (5). The adjustment mechanism (4) is installed inside the upper fixed plate (11) and connected to multiple threaded rods (13) respectively. The movable plate (3) is screwed to multiple threaded rods (13). The movable plate (3) is sleeved outside the sleeve (2). The top of the sleeve (2) is flush with the top surface of the movable plate (3) or placed inside the movable plate (3). The adjustment mechanism (4) can drive multiple threaded rods (13) to rotate synchronously so that the movable plate (3) can move along the axis of the threaded rods (13). The end of the anchor rod (5) away from the lower fixed plate (12) can pass through the upper fixed plate (11) and abut against the top surface of the movable plate (3).

2. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 1, characterized in that: The adjustment mechanism (4) includes a drive gear (41), an output rod (42), a chain (43), and multiple driven gears (44). The upper fixed plate (11) has an installation space (111) inside. The drive gear (41), chain (43) and multiple driven gears (44) are all horizontally arranged in the installation space (111). The top ends of multiple threaded rods (13) are all inserted through the upper fixed plate (11) and placed in the installation space (111). The driving gear (41) is fixedly connected to the top end of a threaded rod (13), and the top ends of the remaining threaded rods (13) are respectively connected to one driven gear (44) in a corresponding manner. The output rod (42) includes a mounting end and an output end. The mounting end of the output rod (42) passes through the upper fixing plate (11) and is fixedly connected to the end of the driving gear (41) away from the threaded rod (13). The output end of the output rod (42) is used to drive the driving component. The chain (43) is sleeved on the driving gear (41) and the multiple driven gears (44) and meshes with them. The drive unit can drive the drive gear (41) to rotate via the output rod (42), thereby driving multiple driven gears (44) to rotate simultaneously via the chain (43), and thus driving multiple threaded rods (13) to rotate synchronously.

3. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 1, characterized in that: The limiting device also includes a scale plate (6), which is vertically fixed on the same side wall of the upper fixing plate (11) and the lower fixing plate (12).

4. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 1, characterized in that: The sleeve (2) includes a sleeve body (21) and multiple limiting strips (22); The sleeve body (21) is vertically arranged and has an internal thread. Multiple limiting strips (22) are vertically arranged and circumferentially arranged around the axis of the sleeve body (21) and fixedly installed on the outer wall of the sleeve body (21). The movable plate (3) has a limiting hole (31), the inner contour of which is consistent with the outer contour of the sleeve (2) to limit the vertical movement direction of the movable plate (3).

5. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 4, characterized in that: The top surface of the lower fixing plate (12) is provided with a slot (121) that matches the outer contour of the sleeve (2). The bottom end of the sleeve (2) is inserted into the slot (121) and can be locked in the slot (121) by a locking device.

6. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 5, characterized in that: The locking device includes multiple locking mechanisms (7); Multiple locking mechanisms (7) are horizontally inserted through the lower fixed plate (12) and can be inserted into multiple limit strips (22) one by one to lock the sleeve (2).

7. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 6, characterized in that: The locking mechanism (7) includes a locking lever (71), an elastic element (72), a retaining ring (73), and a pull ring (74); The limiting bar (22) is provided with an insertion hole (221) on the outer wall of the slot (121) away from the sleeve body (21). One end of the locking rod (71) is horizontally inserted through the lower fixing plate (12) and can be inserted into the insertion hole (221) to lock the sleeve (2). The other end of the locking rod (71) is placed on the outside and fixedly connected to the pull ring (74). The lower fixing plate (12) has an elastic space (122) inside. The locking rod (71) passes through the elastic space (122). The elastic element (72) and the fixing ring (73) are both placed in the elastic space (122). The fixing ring (73) is fixedly sleeved on the outer wall of the locking rod (71). The side of the fixing ring (73) facing the limiting strip (22) can abut against the inner wall of the elastic space (122) near the limiting strip (22). The elastic element (72) is sleeved on the locking rod (71), and the two ends of the elastic element (72) abut against the side of the fixed ring (73) away from the limiting strip (22) and the inner wall of the elastic space (122) away from the limiting strip (22), respectively, to provide buffering force and rebound force for the fixed ring (73) and the locking rod (71).

8. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 1, characterized in that: The limiting device also includes a buffer pad (8); The cushioning pad (8) is horizontally pasted on the bottom surface of the lower fixing plate (12), and the bottom surface of the cushioning pad (8) is provided with anti-slip texture.

9. The limiting device for limiting the drilling depth of anchor bolts in coal mines as described in claim 1, characterized in that: The anchor bolt (5) includes an anchor bolt body (51), a drill bit (52) and a connecting plate (53). The drill bit (52) is detachably connected to the bottom end of the anchor bolt body (51), and the connecting plate (53) is fixedly connected to the top end of the anchor bolt body (51). The connecting plate (53) is rectangular and is horizontally arranged. The upper fixing plate (11) has a clearance hole (112). The clearance hole (112) is circular and the diameter of the clearance hole (112) is greater than the diagonal distance of the connecting plate (53).

10. A method of using the limiting device according to any one of claims 1-9, characterized in that, Includes the following steps: S1: The adjusting mechanism (4) drives multiple threaded rods (13) to rotate synchronously, so as to drive the movable plate (3) to move vertically along the axis of the threaded rods (13) to move the movable plate (3) to the designated position; S2: Select a suitable sleeve (2) and install it on the lower fixed plate (12) through the movable plate (3), so that the top of the sleeve (2) is flush with the top surface of the movable plate (3); S3: Pass the anchor rod (5) through the upper fixing plate (11) and screw it into the internal thread of the sleeve (2); S4: The bottom surface of the lower fixed plate (12) abuts against the target position, driving the anchor rod (5) to rotate, so that the anchor rod (5) moves toward the target position and drills a hole in the target position until the end of the anchor rod (5) away from the lower fixed plate (12) abuts against the top surface of the movable plate (3).

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