Down-hole hammer

Abstract

The down-the-hole hammer comprises an outer sleeve, the rear end of the outer sleeve is connected with a connector assembly, the front end of the outer sleeve is connected with a drill bit assembly, and a first exhaust channel is formed in the drill bit assembly; the piston is movably arranged in the outer sleeve; the lining sleeves the outer side of the front end of the piston and is fixedly connected with the outer sleeve, a second exhaust channel is arranged in the lining, the piston, the outer sleeve and the connector assembly form a first air chamber, a second air chamber is formed among the piston, the outer sleeve and the lining, when the piston moves to a first position, the first air chamber is isolated from the first exhaust channel, and when the piston moves to a second position, the second air chamber is isolated from the second exhaust channel; and the second air chamber is communicated with the first exhaust channel through a second exhaust channel. Compared with the prior art, the down-hole hammer has the advantages that the slag discharging effect can be improved, abrasion of rock slag to the impact face of the drill bit assembly is reduced, and the situation that the piston is stuck and does not work due to slag returning is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of drilling equipment, and more specifically, to a down-the-hole impactor. Background Art

[0002] With the development of industry and the continuous advancement of various infrastructure projects, down-the-hole hammers are widely used as drilling equipment in blasting projects in mines, hydropower stations, ports, roads, tunnels and other engineering construction projects, for excavating blasting holes, etc.

[0003] The down-the-hole hammer comprises a first outer sleeve, a first joint assembly, and a first drill bit assembly. The first drill bit assembly is provided with an air passage, and a first piston is movably disposed within the first outer sleeve. The first piston divides the space within the first outer sleeve into a front air chamber and a rear air chamber. The down-the-hole hammer utilizes high-pressure air as its power source. High-pressure gas sequentially enters the front and rear air chambers, creating a pressure differential between the front and rear chambers. This drives the first piston to reciprocate at high speed and frequency, providing the first piston with sufficient energy to impact the first drill bit assembly and perform the drilling operation. The resulting exhaust gas is discharged through the air passage to blow away slag. The impact force acts on the drill bit in the form of a stress wave, generating enormous impact energy in a very short period of time, effectively breaking rock and quickly forming a hole, achieving the purpose of rock drilling.

[0004] Current down-the-hole impactors encounter a problem when drilling deep holes or when there are large amounts of water, mud, and rock debris in the hole. When the first piston moves axially to the first position, the front and rear air chambers are isolated from the airway. At this time, there is no high-pressure gas in the airway to blow out the debris, resulting in the rock debris at the bottom of the hole not being discharged in time. The rock debris left at the bottom of the hole will repeatedly grind the drill bit alloy and the body, causing the drill bit to wear too quickly, thereby reducing the drill bit's service life and increasing its cost. Even more serious is that when there is a large amount of accumulated water in the hole, very high water pressure will be generated. In this way, the pressure outside the airway is high and the pressure inside the airway is low. The water pressure will push the mud and rock debris at the bottom of the hole from the airway back into the interior of the down-the-hole impactor, causing the first piston to get stuck and unable to work, affecting the user's construction.

[0005] Therefore, there is an urgent need for a down-the-hole impactor that can improve the slag removal effect, reduce the wear of the rock slag on the impact surface of the drill bit assembly, and avoid the situation where the piston is stuck and does not work due to slag return. Utility Model Content

[0006] In order to solve the above technical problems, the present application provides a down-the-hole impactor that can improve its slag removal effect, reduce the wear of rock slag on the impact surface of the drill bit assembly, and avoid the situation where slag return causes the piston to get stuck and stop working.

[0007] The technical solutions provided in this application are as follows:

[0008] A down-the-hole impactor, comprising:

[0009] an outer sleeve, wherein the rear end of the outer sleeve is connected to the joint assembly, the front end of the outer sleeve is connected to the drill assembly, and a first exhaust passage is provided in the drill assembly;

[0010] a piston movably disposed in the outer sleeve;

[0011] A bushing is sleeved on the outside of the front end of the piston and fixedly connected to the outer sleeve, and a second exhaust channel is provided in the bushing. The piston, the outer sleeve and the joint assembly form a first air chamber, and a second air chamber is formed between the piston, the outer sleeve and the bushing. When the piston moves to the first position, the first air chamber is isolated from the first exhaust channel, and the second air chamber is connected to the first exhaust channel through the second exhaust channel.

[0012] Preferably, when the piston moves to the first position, the first air chamber is isolated from the first exhaust channel, and a third air chamber is formed between the piston, the bushing and the drill bit assembly. The third air chamber is connected to the first exhaust channel, and the second air chamber is connected to the third air chamber through the second exhaust channel.

[0013] Preferably, the second exhaust channel includes:

[0014] an air groove provided on the outer peripheral side of the rear end of the bushing and used to communicate with the second air chamber;

[0015] An air hole communicated with the air groove is configured to communicate with the third air chamber when the piston moves to the first position.

[0016] Preferably, the inner diameter of the pore is 1 mm to 5 mm.

[0017] Preferably, a first mating hole and a second mating hole that are connected to each other are provided in the bushing, the first mating hole is used for use with the piston, the air outlet of the air hole is provided on the inner wall of the first mating hole, the second mating hole is used for use with the drill bit assembly, and the inner diameter of the second mating hole is larger than the inner diameter of the first mating hole.

[0018] Preferably, a first mating shaft and a second mating shaft are connected to each other on the outer peripheral side of the front end of the piston, and the outer diameter of the second mating shaft is smaller than the inner diameter of the first mating hole. When the first mating shaft is mated with the inner wall where the air outlet of the air hole is located, the third air chamber is isolated from the second air chamber. When the second mating shaft is mated with the inner wall where the air outlet of the air hole is located, the second air chamber is connected to the third air chamber through the second exhaust channel.

[0019] Preferably, at least two groups of the second exhaust channels are provided, and the second exhaust channels are arranged at intervals around the axial direction of the bushing.

[0020] Preferably, the air groove extends along the axial direction of the bushing, and the air hole extends along the radial direction of the bushing.

[0021] Preferably, a positioning surface is provided on the inner wall of the front end of the outer sleeve, and a positioning step is provided on the outer peripheral side of the bushing, and the rear end surface of the positioning step abuts against the positioning surface;

[0022] A positioning stop wire is further provided on the inner wall of the outer sleeve. The positioning stop wire is detachably connected to the outer sleeve, and the positioning stop wire abuts against the front end surface of the positioning step.

[0023] Preferably, an intermediate air passage is provided in the piston, and the intermediate air passage is coaxially arranged with the first exhaust passage. A gas distribution rod used in conjunction with the intermediate air passage is provided on the joint assembly. When the second air chamber is isolated from the first exhaust passage, the gas distribution rod is disengaged from the intermediate air passage, and the first air chamber is connected to the first exhaust passage through the intermediate air passage.

[0024] The down-the-hole impactor provided by the utility model is firstly provided with an outer sleeve, a joint assembly, a drill bit assembly and a piston, wherein the rear end of the outer sleeve is connected to the joint assembly, the front end of the outer sleeve is connected to the drill bit assembly, a first exhaust channel is provided in the drill bit assembly, exhaust gas is discharged through the first exhaust channel, and the piston is movably arranged in the outer sleeve and can move along the axial direction of the outer sleeve. Secondly, a bushing is also provided. The bushing is arranged on the outside of the front end of the piston and is fixedly connected to the outer sleeve. A second exhaust channel is provided in the bushing. A first air chamber is formed between the piston, the outer sleeve and the joint assembly, and a second air chamber is formed between the piston, the outer sleeve and the bushing. There is an air pressure difference between the first air chamber and the second air chamber, which pushes the piston to move along the axial direction of the outer sleeve, providing a pulse force to the drill bit assembly. The first exhaust channel is alternately connected with the first air chamber and the second air chamber to discharge exhaust gas. When the piston moves to the first position, the first air chamber is isolated from the first exhaust channel, and the second air chamber is connected to the first exhaust channel through the second exhaust channel. The high-pressure gas in the second air chamber is discharged through the second exhaust channel and the first exhaust channel to achieve slag blowing, thereby improving the slag discharge effect and the hole opening speed. Since the rock slag at the bottom of the hole can be discharged in time, the wear of the rock slag on the drill bit assembly is reduced, and the service life of the drill bit assembly is increased. For working conditions where the hole is very deep or there is a large amount of water, mud and rock slag in the hole, the situation where the piston is stuck and does not work due to returned slag is avoided. It can be seen that compared with the prior art, the down-the-hole impactor in the embodiment of the utility model can improve the slag removal effect, reduce the wear of the impact surface of the drill bit assembly by rock slag, and avoid the situation where the piston is stuck and does not work due to slag return. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic diagram of the structure of a down-the-hole impactor provided in the prior art;

[0027] Figure 2 A schematic structural diagram of a down-the-hole impactor provided in an embodiment of the utility model;

[0028] Figure 3 for Figure 2 A structural schematic diagram of a partial enlarged view at D in the middle;

[0029] Figure 4 A schematic structural diagram of a bushing provided in an embodiment of the utility model;

[0030] Figure 5 A structural schematic diagram of a half-section view of a bushing provided in an embodiment of the present utility model;

[0031] Figure 6 A schematic structural diagram of a down-the-hole impactor provided in an embodiment of the present utility model (when the first air chamber is in communication with the first exhaust channel);

[0032] Figure 7 A structural schematic diagram of a down-the-hole impactor provided in an embodiment of the present utility model (when the second air chamber is connected to the first exhaust channel).

[0033] Reference numerals:

[0034] Existing technology: 01, first outer sleeve; 02, first joint assembly; 03, first drill bit assembly; 04, air channel; 05, first piston; 06, front air chamber; 07, rear air chamber;

[0035] This application: 1. outer sleeve; 2. joint assembly; 3. drill bit assembly; 4. first exhaust channel; 5. piston; 6. bushing; 7. positioning stop wire; 51. first matching shaft; 52. second matching shaft; 53. intermediate air channel; 61. air groove; 62. air hole; 63. first matching hole; 64. second matching hole; 21. joint; 22. air distribution seat; 23. check valve assembly; 24. high-pressure air channel; 25. air distribution rod; 26. inner sleeve; 31. drill bit; 32. drill clamp sleeve; 33. retaining ring. DETAILED DESCRIPTION

[0036] In order to help those skilled in the art better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of this application.

[0037] It should be noted that when an element is referred to as being “fixed on” or “set on” another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0038] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" or "several" means two or more, unless otherwise specifically defined.

[0040] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the efficacy and purpose that can be achieved by this application.

[0041] The embodiments of the present invention are written in a progressive manner.

[0042] It should be noted that the front end in this application refers to the end of the outer sleeve 1 close to the drill bit assembly 3, and the rear end in this application refers to the end of the outer sleeve 1 close to the joint assembly 2.

[0043] like Figures 2 to 7 As shown, it needs to be explained that Figures 2 to 7 The arrows in the figure indicate the direction of high-pressure gas flow. A in the figure indicates the first air chamber, B in the figure indicates the second air chamber, and C in the figure indicates the third air chamber.

[0044] An embodiment of the present utility model provides a down-the-hole impactor, comprising: an outer sleeve 1, the rear end of the outer sleeve 1 is connected to a joint assembly 2, the front end of the outer sleeve 1 is connected to a drill bit assembly 3, and a first exhaust channel 4 is provided in the drill bit assembly 3; a piston 5 movably arranged in the outer sleeve 1; a bushing 6 which is sleeved on the outside of the front end of the piston 5 and fixedly connected to the outer sleeve 1, and a second exhaust channel is provided in the bushing 6. The piston 5, the outer sleeve 1 and the joint assembly 2 form a first air chamber A, and a second air chamber B is formed between the piston 5, the outer sleeve 1 and the bushing 6. When the piston 5 moves to the first position, the first air chamber A is isolated from the first exhaust channel 4, and the second air chamber B is connected to the first exhaust channel 4 through the second exhaust channel.

[0045] Please Figure 1 As shown, Figure 1 The single arrow in the figure indicates the direction of high-pressure gas flow, and the double arrow indicates the direction of mud and slag returning from the bottom of the hole. Figure 1 The first piston 05 is in the first position. The down-the-hole hammer comprises a first outer sleeve 01, a first joint assembly 02, and a first drill bit assembly 03. An air passage 04 is provided within the first drill bit assembly. A first piston 05 is movably disposed within the first outer sleeve 01. The first piston 05 divides the space within the first outer sleeve 01 into a front air chamber 06 and a rear air chamber 07. The down-the-hole hammer utilizes high-pressure air as its power source. A pressure differential exists between the front air chamber 06 and the rear air chamber 07, thereby driving the first piston 05 to reciprocate at high speed and frequency. This allows the first piston 05 to obtain sufficient energy to impact the first drill bit assembly 03 and perform drilling operations. The generated exhaust gas is discharged through the air passage to blow away the slag.

[0046] Current down-the-hole impactors encounter a problem when drilling deep holes or when there are large amounts of water, mud, and rock debris in the hole. When the first piston 05 moves axially to the first position, the front air chamber 06 and the rear air chamber 07 are both isolated from the airway 04. At this time, there is no high-pressure gas in the airway 04 to blow out the debris, resulting in the rock debris at the bottom of the hole not being discharged in time. The rock debris remaining at the bottom of the hole will repeatedly grind the drill bit alloy and the drill body, causing the drill bit to wear too quickly, thereby reducing the drill bit's service life and increasing its cost. Even more serious is that when there is a large amount of water in the hole, high water pressure is generated. In this case, the pressure outside the airway is high, while the pressure inside the airway is low. The water pressure will push the mud and rock debris at the bottom of the hole back into the interior of the down-the-hole impactor from the airway, causing the first piston to become stuck and unable to work, affecting the user's construction.

[0047] The down-the-hole impactor provided by the present invention is firstly provided with an outer sleeve 1, a joint assembly 2, a drill bit assembly 3 and a piston 5, wherein the rear end of the outer sleeve 1 is connected to the joint assembly 2, and the front end of the outer sleeve 1 is connected to the drill bit assembly 3. A first exhaust channel 4 is provided in the drill bit assembly 3, and exhaust gas is discharged through the first exhaust channel 4. The piston 5 is movably provided in the outer sleeve 1. Secondly, a bushing 6 is also provided. The bushing 6 is fitted on the outside of the front end of the piston 5. The bushing 6 is fixedly connected to the outer sleeve 1. A second exhaust channel is provided in the bushing 6. A first air chamber A is formed between the piston 5, the outer sleeve 1 and the joint assembly 2, and a second air chamber B is formed between the piston 5, the outer sleeve 1 and the bushing 6. There is an air pressure difference between the first air chamber A and the second air chamber B, thereby pushing the piston 5 to move along the axial direction of the outer sleeve 1, providing a pulse force to the drill bit assembly 3. The first exhaust channel 4 is alternately connected with the first air chamber A and the second air chamber B, thereby discharging exhaust gas. When the piston When the drill bit 5 moves to the first position, the first air chamber A is isolated from the first exhaust channel 4, and the second air chamber B is connected to the first exhaust channel 4 through the second exhaust channel. The high-pressure gas in the second air chamber B is discharged through the second exhaust channel and the first exhaust channel 4 to achieve slag blowing, thereby improving the slag removal effect and the hole opening speed. Since the rock debris at the bottom of the hole can be discharged in time, the wear of the rock debris on the drill bit assembly 3 is reduced, and the service life of the drill bit assembly 3 is increased. For working conditions where the hole is very deep or there is a large amount of water, mud and rock debris in the hole, the situation where the piston 5 is stuck and does not work due to slag return is avoided. It can be seen that compared with the prior art, the down-the-hole impactor in the embodiment of the utility model can improve the slag removal effect, reduce the wear of the rock debris on the impact surface of the drill bit assembly 3, and avoid the situation where the piston 5 is stuck and does not work due to slag return.

[0048] In the above structure, as one embodiment, when the piston 5 moves to the first position, the first air chamber A is isolated from the first exhaust passage 4, and a third air chamber C is formed between the piston 5, the bushing 6, and the drill assembly 3. The third air chamber C is connected to the first exhaust passage 4, and the second air chamber B and the third air chamber C are connected via the second exhaust passage. This allows the second air chamber B to communicate with the third air chamber C and the first exhaust passage 4 via the second exhaust passage, allowing part of the high-pressure gas in the second air chamber B to enter the first exhaust passage 4 to blow out slag, thereby improving the slag removal effect.

[0049] It should be noted that the structure of the second exhaust channel in the above example of the present invention is not limited. It only needs to be that when the piston 5 moves to the first position, the second air chamber B can be connected to the first exhaust channel 4 through the second exhaust channel to provide high-pressure gas to the first exhaust channel 4.

[0050] As one specific implementation method, Figures 3 to 5As shown, the second exhaust passage in the embodiment of the present invention includes an air groove 61 and an air hole 62, wherein the air groove 61 is disposed on the outer peripheral side of the rear end of the bushing 6, and the rear end of the air groove 61 is connected to the second air chamber B. The air hole 62 is configured such that when the piston 5 moves to the first position, the air hole 62 is connected to the third air chamber C. Furthermore, by disposing the air groove 61 on the outer peripheral side of the rear end of the bushing 6, it is more suitable for processing. If the processing difficulty is not considered, the air groove 61 can also be disposed inside the bushing 6.

[0051] More specifically, if the inner diameter of the air hole 62 is too large, the strength of the bushing 6 will be affected. If the inner diameter of the air hole 62 is too small, the flow rate of the high-pressure gas in the second air chamber B into the third air chamber C will be small. Depending on the size of the impactor, the inner diameter of the air hole 62 is specifically 1 mm to 5 mm.

[0052] In the above structure, as one of the embodiments, a first matching hole 63 and a second matching hole 64 are provided in the bushing 6 in the embodiment of the utility model. The second matching hole 64 is connected to the first matching hole 63. The first matching hole 63 is used to cooperate with the piston 5. The air outlet of the air hole 62 is provided on the inner wall of the front end of the first matching hole 63. The second matching hole 64 is used to cooperate with the drill bit assembly 3. The inner diameter of the second matching hole 64 is larger than the inner diameter of the first matching hole 63.

[0053] Furthermore, a first mating shaft 51 and a second mating shaft 52 are provided on the outer peripheral side of the front end of the piston 5. The second mating shaft 52 is connected to the first mating shaft 51. The first mating shaft 51 is provided on the side of the second mating shaft 52 away from the drill bit assembly 3. The outer diameter of the second mating shaft 52 is smaller than the inner diameter of the first mating hole 63. When the first mating shaft 51 is mated with the surface where the air outlet of the air hole 62 is located, the third air chamber C is isolated from the second air chamber B. When the second mating shaft 52 is mated with the surface where the air outlet of the air hole 62 is located, the second air chamber B can be connected with the third air chamber C through the second exhaust channel. When the piston 5 moves to the first position, the second mating shaft 52 of the piston 5 is mated with the first mating hole 63, and part of the high-pressure gas in the second air chamber B enters the third air chamber C through the air groove 61 and the air hole 62, thereby providing high-pressure gas to the first exhaust channel 4 for blowing slag. It can also avoid the pressure difference between the first exhaust channel 4 and the air pressure at the bottom of the hole, which causes water, rock slag, and mud in the bottom of the hole to return to slag, causing the piston 5 to get stuck and not work.

[0054] In the above structure, as one of the embodiments, at least two groups of second exhaust channels are provided in the embodiment of the utility model, and the second exhaust channels are spaced apart in the axial direction of the bushing 6. By providing at least two groups of second exhaust channels, more high-pressure gas in the second air chamber B can enter the third air chamber C.

[0055] In the above structure, in order to facilitate processing, the air groove 61 in the embodiment of the present invention extends along the axial direction of the bushing 6 , and the air hole 62 extends along the radial direction of the bushing 6 .

[0056] In the above structure, as one embodiment, a positioning surface is provided on the inner wall of the front end of the outer sleeve 1 in the embodiment of the utility model, and a positioning step is provided on the outer peripheral side of the bushing 6, and the rear end face of the positioning step abuts the positioning surface; a positioning stop wire 7 is also provided on the inner wall of the outer sleeve 1, and the positioning stop wire 7 is detachably connected to the outer sleeve 1, and the positioning stop wire 7 abuts the front end face of the positioning step. By providing the positioning surface and the positioning stop wire 7 on the outer sleeve 1, the bushing 6 is fixed to the outer sleeve 1, and the positioning stop wire 7 is specifically detachably connected to the outer sleeve 1, which makes it more convenient to assemble the down-the-hole impactor.

[0057] In the above structure, as one of the embodiments, an intermediate air channel 53 is provided in the piston 5 in the embodiment of the utility model, and the intermediate air channel 53 is coaxially arranged with the first exhaust channel 4. A gas distribution rod 25 used in conjunction with the intermediate air channel 53 is provided on the joint assembly 2. When the second air chamber B is isolated from the first exhaust channel 4, the gas distribution rod 25 is disengaged from the intermediate air channel 53, and the first air chamber A is connected to the first exhaust channel 4 through the intermediate air channel 53.

[0058] like Figure 2 As shown, when the piston 5 is in the first position, the gas distribution rod 25 cooperates with the middle air channel 53 of the piston 5, the first air chamber A is isolated from the first exhaust channel 4, the first matching shaft 51 cooperates with the front end of the first matching hole 63, and the second matching shaft 52 cooperates with the surface where the air hole 62 is located, the high-pressure gas in the second air chamber B can be connected to the third air chamber C through the second exhaust channel, thereby providing high-pressure gas to the first exhaust channel 4 for blowing slag.

[0059] like Figure 6 As shown, when the piston 5 moves from the first position toward the drill bit assembly 3, the first mating shaft 51 cooperates with the inner wall where the air hole 62 is located, and the second air chamber B is isolated from the first slag discharge channel. At the same time, the intermediate air channel 53 of the piston 5 is separated from the gas distribution rod 25, and the high-pressure gas in the first air chamber A enters the first exhaust channel 4 from the intermediate air channel 53 to blow the slag.

[0060] like Figure 7 As shown, when the piston 5 continues to move from the first position toward the joint assembly 2, the gas distribution rod 25 cooperates with the middle air channel 53 of the piston 5, the first air chamber A is isolated from the first exhaust channel 4, the first mating shaft 51 is disengaged from the first mating hole 63, and the high-pressure gas in the second air chamber B can directly enter the first exhaust channel 4 through the gap between the first mating shaft 51 and the first mating hole 63 to blow the slag.

[0061] More specifically, the joint assembly 2 in the embodiment of the present invention includes a joint 21, a gas distribution seat 22 and a check valve assembly 23, wherein the joint 21 is fixedly connected to the rear end of the outer sleeve 1, a high-pressure air duct 24 is provided in the joint 21, the matching seat 22 is fixedly provided in the outer sleeve 1, the check valve assembly 23 is provided at the rear end of the gas distribution seat 22, the check valve assembly 23 is used to open and close the high-pressure air duct 24, and the gas distribution rod 25 is provided at the front end of the gas distribution seat 22.

[0062] The joint assembly 2 in the embodiment of the present invention further includes an inner sleeve 26, which is fixedly disposed between the gas distribution seat 22 and the outer sleeve 1. An air distribution passage is formed between the inner sleeve 21, the outer sleeve 1, the gas distribution seat 22, and the piston 5, so that the high-pressure air passage alternately communicates with the first air chamber A and the second air chamber B. Of course, the joint assembly 2 in the prior art may also adopt a structure without an inner sleeve, which also falls within the scope of protection of this application.

[0063] The drill bit assembly 3 includes a drill bit 31, a drill clamping sleeve 32 and a retaining ring 33, wherein the drill clamping sleeve 32 is fixedly connected to the rear end of the outer sleeve 1, the drill bit 31 is sleeved in the drill clamping sleeve 32, the drill bit 31 and the drill clamping sleeve 32 are connected by a spline, the retaining ring 33 is arranged between the bushing 6 and the drill clamping sleeve, and the retaining ring 33 is used in conjunction with the drill bit 31 to limit the axial displacement of the drill bit 31.

[0064] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A down-the-hole impactor, characterized in that: include: An outer sleeve (1), the rear end of the outer sleeve (1) being connected to the joint assembly (2), the front end of the outer sleeve (1) being connected to the drill assembly (3), and a first exhaust passage (4) being provided in the drill assembly (3); A piston (5) movably disposed within the outer sleeve (1); A bushing (6) is sleeved on the outside of the front end of the piston (5) and fixedly connected to the outer sleeve (1). A second exhaust channel is provided in the bushing (6). The piston (5), the outer sleeve (1) and the joint assembly (2) form a first air chamber. A second air chamber is formed between the piston (5), the outer sleeve (1) and the bushing (6). When the piston (5) moves to the first position, the first air chamber is isolated from the first exhaust channel (4), and the second air chamber is connected to the first exhaust channel (4) through the second exhaust channel.

2. The down-the-hole impactor according to claim 1, characterized in that When the piston (5) moves to the first position, a third air chamber is formed between the piston (5), the bushing (6) and the drill assembly (3), the third air chamber is connected to the first exhaust channel (4), and the second air chamber is connected to the third air chamber through the second exhaust channel.

3. The down-the-hole impactor according to claim 2, characterized in that The second exhaust channel includes: An air groove (61) provided on the outer peripheral side of the rear end of the bushing (6) and used for communicating with the second air chamber; An air hole (62) communicated with the air groove (61), wherein the air hole (62) is configured to communicate with the third air chamber when the piston (5) moves to the first position.

4. The down-the-hole impactor according to claim 3, characterized in that The inner diameter of the air hole (62) is specifically 1 mm to 5 mm.

5. The down-the-hole impactor according to claim 3, characterized in that: A first matching hole (63) and a second matching hole (64) are provided in the bushing (6), the first matching hole (63) is used for matching with the piston (5), the air outlet of the air hole (62) is provided on the inner wall of the first matching hole (63), the second matching hole (64) is used for matching with the drill assembly (3), and the inner diameter of the second matching hole (64) is larger than the inner diameter of the first matching hole (63).

6. The down-the-hole impactor according to claim 5, characterized in that A first mating shaft (51) and a second mating shaft (52) connected to each other are provided on the outer peripheral side of the front end of the piston (5), the outer diameter of the second mating shaft (52) is smaller than the inner diameter of the first mating hole (63), and when the first mating shaft (51) is mated with the inner wall of the air outlet of the air hole, the third air chamber is isolated from the second air chamber, and when the second mating shaft (52) is mated with the inner wall of the air outlet of the air hole, the second air chamber is connected to the third air chamber through the second exhaust channel.

7. The down-the-hole hammer according to any one of claims 3 to 6, characterized in that At least two groups of the second exhaust channels are provided, and the second exhaust channels are spaced apart around the axial direction of the bushing (6).

8. The down-the-hole hammer according to any one of claims 3 to 6, characterized in that The air groove (61) extends along the axial direction of the bushing (6), and the air hole (62) extends along the radial direction of the bushing (6).

9. The down-the-hole hammer according to any one of claims 1 to 6, characterized in that: A positioning surface is provided on the inner wall of the front end of the outer sleeve (1), and a positioning step is provided on the outer peripheral side of the bushing (6), and the rear end surface of the positioning step abuts against the positioning surface; A positioning stop wire (7) is also provided on the inner wall of the outer sleeve (1), and the positioning stop wire (7) is detachably connected to the outer sleeve (1), and the positioning stop wire (7) abuts against the front end surface of the positioning step.

10. The down-the-hole hammer according to any one of claims 1 to 6, characterized in that An intermediate air passage (53) is provided in the piston (5), and the intermediate air passage (53) is coaxially arranged with the first exhaust passage (4). A gas distribution rod used in conjunction with the intermediate air passage is provided on the joint assembly. When the second air chamber is isolated from the first exhaust passage (4), the gas distribution rod is separated from the intermediate air passage, and the first air chamber is connected to the first exhaust passage (4) through the intermediate air passage.

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