A down-the-hole hammer

Abstract

A kind of down-the-hole hammer, including caliper sleeve, one end of the caliper sleeve is connected with the outer cylinder of impactor, the other end is equipped with connecting sleeve, connecting sleeve is linked rotation with caliper sleeve, drill bit is installed in caliper sleeve by spline cooperation, the inner wall of connecting sleeve is equipped with force transmission inner square, the outer wall of drill bit is equipped with the first force transmission outer square matched with the force transmission inner square of connecting sleeve, when impact rotary drilling state, the first force transmission outer square of drill bit is inserted in the force transmission inner square of connecting sleeve, and down-the-hole hammer is cooperated by spline and the first force transmission outer square of force transmission inner square to transmit torque jointly;The utility model can effectively solve the phenomenon that drill bit spline is easily broken and causes the premature failure of drill bit by dispersing and reducing the force of spline;To improve the utilization of drill bit body, reduce the use cost of drilling tool, cooperate with air passage again, prevent the rock slag blockage phenomenon when re-drilling after lifting and milling hole, prevent the non-impact phenomenon caused by rock slag blockage.

Description

Technical Field

[0001] This utility model relates to a down-the-hole impactor. Background Technology

[0002] With the development of rock drilling engineering and the widespread application of down-the-hole drilling technology, down-the-hole hammers and down-the-hole drill bits are widely used as drilling tools in rock drilling and blasting, water wells, geological exploration holes, pile foundations, and engineering fields such as natural disaster prevention and environmental protection. As engineering demands increase, the diameter of drilling holes and the drilling depth also increase, leading to higher requirements for the reliability of drill bits. At the same time, shortcomings of existing down-the-hole drilling tools have been identified. 1. Large-diameter impactors are used in conjunction with drill bits. Due to the easy wear of the nylon strips between the splines, the splines of the drill bit and the impactor caliper sleeve are severely worn, reaching the scrap standard, or even the drill bit splines break. 2. When the impactor is used with an oversized drill bit, the wear on the drill bit teeth is not significant, but the drive spline of the drill bit body breaks, resulting in low utilization of the drill bit. 3. During the drilling process, the impactor and drill bit are lifted up and then re-drilled, resulting in the impactor not being able to re-drill; The aforementioned issues lead to longer retrieval times, resulting in increased operating costs and time, or even drilling failure. Based on these shortcomings, there is an urgent need for a more reliable and longer-lasting down-the-hole hammer and drill bit. Utility Model Content

[0003] This utility model addresses the shortcomings of existing technologies by providing a down-the-hole impactor that can disperse and reduce spline stress, reduce premature drill bit failure, improve drill bit utilization, and reduce drilling tool usage costs.

[0004] To achieve the above objectives, this utility model first proposes a down-the-hole impactor, including a caliper sleeve. One end of the caliper sleeve is connected to the outer cylinder of the impactor, and the other end is provided with a connecting sleeve. The connecting sleeve and the caliper sleeve rotate in linkage. The drill bit is installed in the caliper sleeve through a spline fit. The inner wall of the central hole of the connecting sleeve is provided with a force-transmitting inner square, and the outer wall of the drill bit is provided with a first force-transmitting outer square that matches the force-transmitting inner square of the connecting sleeve. In the impact rotary drilling state, the first force-transmitting outer square of the drill bit is inserted into the force-transmitting inner square of the connecting sleeve. The down-the-hole impactor transmits torque through the spline and the coordinated cooperation of the force-transmitting inner square and the first force-transmitting outer square.

[0005] In this embodiment, the inner wall of the caliper sleeve is provided with an internal spline, and the drill bit is provided with an external spline that mates with the internal spline. A nylon strip is installed in each keyway of the internal spline on the side closest to the rotation direction of the drill bit. In the impact rotary drilling state, the working surface of the external spline abuts against the nylon strip, and the thickness of the nylon strip is greater than the fit error between the inner force transmission side and the first outer force transmission side.

[0006] In this embodiment, the drill bit is provided with an air passage groove on the outer wall of the area where the first force transmission is located. Multiple air passage grooves are evenly distributed around the impactor. When the drill is being lifted and the slag is being cleaned, the air passage grooves are connected to the air chamber inside the down-the-hole impactor through spline keyways.

[0007] In this embodiment, the number of external splines is a multiple of the number of external splines in the first force transmission direction.

[0008] In this embodiment, the caliper sleeve and the connecting sleeve are designed as separate units. The outer wall of the side where the caliper sleeve and the connecting sleeve are connected is provided with a second force-transmitting outer side that matches the force-transmitting inner side. One end of the connecting sleeve is coaxially fitted onto the second force-transmitting outer side of the caliper sleeve, and the other end is coaxially fitted onto the first force-transmitting outer side of the drill bit.

[0009] In this embodiment, the number of internal splines is a multiple of the number of external splines used for the second force transmission.

[0010] In this embodiment, the caliper sleeve connecting sleeve is an integral design.

[0011] In this embodiment, the connecting sleeve and the caliper sleeve are integrally formed.

[0012] With the above structure, this utility model has the following advantages: 1. This application disperses the force on the spline by coordinating the spline with the inner and outer forces, reducing the force on the spline during operation, effectively reducing the spline breakage phenomenon of the drill bit, thereby preventing premature failure of the drill bit and improving the service life of the down-the-hole impactor.

[0013] 2. This application sets a nylon strip in the keyway of the spline. The thickness of the nylon strip is greater than the fit error of the inner and outer force transmission sides. Therefore, after the drill bit rotates to the point where the nylon strip deforms, the drill bit starts to transmit torque through the outer force transmission side and the connecting sleeve, thereby dispersing and reducing the force on the spline, reducing the possibility of drill bit spline breakage and premature failure. This improves the utilization rate of the drill bit and reduces the cost of using the drill bit.

[0014] 3. In the process of drilling and cleaning slag, the connecting sleeve will block part of the axial movement of the drill bit, thereby preventing rock slag from entering the mating end face. At the same time, high-pressure gas will be discharged from the down-the-hole impactor through the keyway of the spline and the air passage formed between the connecting sleeve and the drill bit, blowing out the rock slag that wants to enter the mating end face. This will prevent rock slag blockage when re-drilling after lifting the milled hole, and prevent the impactor from not working due to rock slag blockage.

[0015] In summary, this device effectively solves the problem of drill bit splines easily breaking and causing premature drill bit failure by dispersing and reducing the stress on the splines. This improves the utilization rate of the drill bit body, reduces the operating cost of the drilling tool, and, in conjunction with the air groove, prevents rock debris from clogging the drill bit when re-drilling after milling, thus preventing the impactor from being blocked by rock debris. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of Embodiment 1 of the present utility model.

[0017] Figure 2 This is a cross-sectional view of Embodiment 2 of the present invention.

[0018] Figure 3 This utility model Figure 1 and Figure 2 A sectional view of DD.

[0019] Figure 4 This utility model Figure 1 A sectional view of EE.

[0020] Figure 5 This utility model Figure 1 and Figure 2 A sectional view of FF.

[0021] Figure 6 This is a perspective view of the caliper sleeve of this utility model.

[0022] Figure 7 This is a perspective view of the connecting sleeve of this utility model.

[0023] Figure 8 This is a perspective view of the drill bit of this utility model.

[0024] In the attached diagram: 1. Caliper sleeve; 11. Second force transmission outer side; 12. Internal spline; 13. Keyway; 2. Connecting sleeve; 21. Force transmission inner side; 3. Drill bit; 31. Air passage groove; 32. External spline; 33. First force transmission outer side; 4. Nylon strip. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0027] like Figures 1 to 8As shown, a down-the-hole impactor includes a caliper sleeve 1. One end of the caliper sleeve 1 is threadedly connected to the outer cylinder of the impactor, and the other end is provided with a connecting sleeve 2. The connecting sleeve 2 rotates in conjunction with the caliper sleeve 1. A drill bit 3 is installed in the caliper sleeve 1 through a spline engagement. The tail end of the drill bit 3 is limited by a retaining ring located at the tail end of the caliper sleeve 1. The engagement of the spline and the retaining ring allows the drill bit 3 to move axially to achieve impact. The inner wall of the central hole of the connecting sleeve 2 is provided with a force-transmitting inner square 21 (the force-transmitting inner square 21 refers to the connecting sleeve 2). The inner wall of the connecting sleeve 2 has a polygonal inner contour, and the outer wall of the drill bit 3 is provided with a first force-transmitting outer side 33 that matches the force-transmitting inner side 21 of the connecting sleeve 2. The axial length of the part of the connecting sleeve 2 that mates with the drill bit 3 matches the length of the axial movement of the drill bit 3. In the impact rotary drilling state, the first force-transmitting outer side 33 of the drill bit 3 is inserted into the force-transmitting inner side 21 of the connecting sleeve 2. Through the coordinated cooperation of the spline and the force-transmitting inner and outer sides, the force on the spline is distributed, thereby improving the life of the down-the-hole impactor.

[0028] like Figure 3 As shown, the inner wall of the center hole of the caliper sleeve 1 is provided with an inner spline 12, and the outer wall of the drill bit 3 is provided with an outer spline 32 that mates with the inner spline 12. A nylon strip 4 is installed in each keyway 13 of the inner spline 12 on the side closer to the rotation direction of the drill bit 3. In the impact rotary drilling state, the working surface of the outer spline 32 abuts against the nylon strip 4. The thickness of the nylon strip 4 is greater than the fit error of the inner and outer force transmission sides. After the drill bit 3 rotates to the point where the nylon strip 4 is deformed, the drill bit 3 starts to transmit torque through the outer force transmission side and the connecting sleeve 2, dispersing the force on the spline and thus reducing the force on the spline. like Figure 8 , Figure 1 , Figure 2 As shown, the drill bit 3 has an air passage groove 31 on the outer wall of the area where the first force transmission outer surface 33 is located. Of course, the air passage groove 31 can also be set on the inner wall of the area corresponding to the connecting sleeve 2 and the first force transmission outer surface 33, or the air passage groove 31 can be set on both the drill bit 3 and the connecting sleeve 2, and their positions correspond to each other. Multiple air passage grooves 31 are evenly distributed around the impactor. When the drill is in the state of lifting the drill and cleaning the slag, the air passage groove 31 is connected to the air chamber in the down-the-hole impactor. Furthermore, the number of key teeth of the outer spline 32 on the drill bit 3 is a multiple of the number of apex corners of the first force transmission outer surface 33. Example

[0029] like Figure 1 , 4As shown in Figure 5, in this embodiment, the caliper sleeve 1 and the connecting sleeve 2 are designed as separate units. The outer wall of the caliper sleeve 1 and the connecting sleeve 2 is provided with a second force transmission outer unit 11 that matches the force transmission inner unit 21. One end of the connecting sleeve 2 is coaxially fitted on the second force transmission outer unit 11 of the caliper sleeve 1, and the other end is coaxially fitted on the first force transmission outer unit 33 of the drill bit 3, so that the force of the impactor rotation is transmitted to the drill bit 3 through the inner and outer units. The number of key teeth of the inner spline 12 is proportional to the number of apex angles of the second force transmission outer unit 11. Example

[0030] like Figure 2 , 5 As shown, in this embodiment, the caliper sleeve 1 and the connecting sleeve 2 are designed as a single piece. Furthermore, the connecting sleeve 2 and the caliper sleeve 1 are integrally formed, thereby improving the overall strength.

[0031] With the above structure, in the impact rotary drilling state, the down-the-hole impactor uses compressed air as power to complete the hole formation requirements through impact rotary drilling. During the rotation of the down-the-hole impactor, torque is transmitted through the spline, driving the drill bit 3 to rotate. After the drill bit 3 rotates to the point where the nylon strip 4 deforms, the external force transmission of the drill bit 3 and the chuck sleeve begins to transmit torque. In this way, by utilizing the synergistic effect of the inner and outer transmission sides and the spline, the force on the spline during the working process is dispersed and reduced, effectively reducing the phenomenon of spline breakage of the drill bit 3, preventing premature failure of the drill bit 3, greatly reducing the use cost of the drilling tool, and at the same time improving the utilization rate of the drill bit 3.

[0032] During the drilling and slag removal process, the connecting sleeve 2, on the one hand, blocks part of the axial movement of the drill bit 3, effectively preventing rock debris from entering the mating end face between the drill bit 3 and the caliper sleeve 1. On the other hand, the high-pressure gas in the air chamber composed of the drill bit 3, the caliper sleeve, the outer cylinder of the impactor, and the piston of the impactor is discharged out of the down-the-hole impactor through the spline and the air passage 31 formed between the connecting sleeve 2 and the drill bit 3, further blowing out the rock debris that wants to enter the mating end face between the drill bit 3 and the caliper sleeve 1, thereby solving the problem of rock debris clogging the impactor when re-drilling after lifting the milling hole during the drilling process.

[0033] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A down-the-hole impactor, comprising a caliper sleeve, characterized in that, One end of the caliper sleeve is connected to the outer cylinder of the impactor, and the other end is provided with a connecting sleeve. The connecting sleeve and the caliper sleeve rotate in linkage. The drill bit is installed in the caliper sleeve through spline engagement. The inner wall of the connecting sleeve is provided with a force-transmitting inner square, and the outer wall of the drill bit is provided with a first force-transmitting outer square that matches the force-transmitting inner square of the connecting sleeve. In the impact rotary drilling state, the first force-transmitting outer square of the drill bit is inserted into the force-transmitting inner square of the connecting sleeve. The down-the-hole impactor transmits torque through the spline and the coordinated cooperation of the force-transmitting inner square and the first force-transmitting outer square.

2. The down-the-hole impactor according to claim 1, characterized in that: The caliper sleeve has an internal spline on its inner wall, and the drill bit has an external spline that mates with the internal spline. A nylon strip is installed in each keyway of the internal spline on the side closest to the rotation direction of the drill bit. During impact rotary drilling, the working surface of the external spline abuts against the nylon strip, and the thickness of the nylon strip is greater than the fit error between the inner force transmission side and the first outer force transmission side.

3. The down-the-hole impactor according to claim 1, characterized in that: The drill bit has an air passage groove on the outer wall of the area outside the first force transmission. Multiple air passage grooves are evenly distributed around the impactor. When the drill is being lifted and the slag is being cleaned, the air passage grooves are connected to the air chamber inside the down-the-hole impactor through spline keyways.

4. The down-the-hole impactor according to claim 2, characterized in that: The number of external splines is proportional to the number of external splines in the first force transmission section.

5. The down-the-hole impactor according to any one of claims 1 to 4, characterized in that: The caliper sleeve and the connecting sleeve are designed as separate units. The outer wall of the side where the caliper sleeve and the connecting sleeve are connected is provided with a second force transmission outer side that matches the force transmission inner side. One end of the connecting sleeve is coaxially fitted onto the second force transmission outer side of the caliper sleeve, and the other end is coaxially fitted onto the first force transmission outer side of the drill bit.

6. The down-the-hole impactor according to claim 4, characterized in that: The number of internal splines is proportional to the number of external splines used for the second force transmission.

7. The down-the-hole impactor according to any one of claims 1 to 4, characterized in that: The caliper sleeve connector is a one-piece design.

8. The down-the-hole impactor according to claim 6, characterized in that: The connecting sleeve and the caliper sleeve are molded as a single piece.

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