A down-the-hole hammer

Abstract

The application discloses a down-the-hole hammer, which comprises an outer cylinder, a joint assembly connected to the rear end of the outer cylinder, a drill bit assembly connected to the front end of the outer cylinder, an inner cylinder fixedly sleeved in the outer cylinder, a piston sleeved in the inner cylinder, a gas distribution rod sleeved in the inner cylinder and connected to the joint assembly, a gas distribution valve sleeved on the outer side of the gas distribution rod, the gas distribution valve separating a rear chamber into a first chamber and a second chamber, an isolation surface arranged on the inner surface of the inner cylinder and used in cooperation with the gas distribution valve, and the gas distribution valve having an axial pressure difference at both ends, so that the gas distribution valve has a first state and a second state, when the gas distribution valve is in the first state, the gas distribution valve is attached to the isolation surface, and when the gas distribution valve is in the second state, a gap exists between the gas distribution valve and the isolation surface. Compared with the prior art, the down-the-hole hammer provided by the application has small gas pressure loss, can improve the output power of the hammer, and prolongs the service life of the hammer.

Description

Technical Field

[0001] This application relates to the field of drilling equipment technology, and more specifically, to a down-the-hole impactor. Background Technology

[0002] The pneumatic down-the-hole hammer uses high-pressure air as a power source to drive a piston inside the hammer to reciprocate at high speed and frequency, giving the piston enough energy to impact the drill bit and perform drilling operations. The impact force acts on the drill bit in the form of stress waves, generating enormous impact energy in a very short time, which can effectively break rocks, quickly form holes, and achieve the purpose of rock drilling.

[0003] Currently, down-the-hole hammers typically include an outer cylinder, a connector, a drill bit, an inner cylinder, and a piston. The connector and the drill bit are respectively located at both ends of the outer cylinder. The inner cylinder is fixedly located inside the piston, which is slidably located inside the inner cylinder, dividing the cavity inside the outer cylinder into two chambers. There is a pressure difference between the two ends of the piston, which pushes the piston to move back and forth along the axial direction of the inner cylinder, providing a pulse force to the drill bit.

[0004] In the existing technology, the inner wall of the outer cylinder is provided with multiple annular grooves, and the piston is provided with a number of air distribution channels. The piston and the outer cylinder cooperate to distribute air. On the one hand, the air distribution channels on the piston have turns and long distances, resulting in large gas pressure loss and easy generation of large amounts of heat. Long-term high-temperature operation can easily cause stress concentration. On the other hand, the air distribution channels on the piston reduce the piston's strength and shorten the service life of the impactor.

[0005] Therefore, there is an urgent need for a down-the-hole impactor with low gas pressure loss, which can improve the output power of the impactor and extend its service life. Summary of the Invention

[0006] To solve the above-mentioned technical problems, this application provides a down-the-hole impactor. By changing the gas distribution method of the impactor, the gas pressure loss is small, which can improve the output power of the impactor and extend its service life.

[0007] The technical solution provided in this application is as follows:

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

[0009] Outer cylinder, connector assembly connected to the rear end of the outer cylinder, and drill bit assembly connected to the front end of the outer cylinder;

[0010] An inner cylinder is fixedly sleeved inside the outer cylinder, and a piston is sleeved inside the inner cylinder. A rear chamber is formed between the piston, the inner cylinder, and the joint assembly, and a front chamber is formed between the piston, the drill bit assembly, and the outer cylinder.

[0011] A valve rod is fitted inside the inner cylinder and connected to the connector assembly. A valve valve is fitted on the outer side of the valve rod, and the valve valve divides the rear chamber into a first chamber and a second chamber.

[0012] An isolation surface is disposed on the inner surface of the inner cylinder and used in conjunction with the valve. The valve has an axial pressure difference on both sides, which allows the valve to have a first state and a second state. When the valve is in the first state, the valve is in contact with the isolation surface and the first chamber is connected to the front chamber. When the valve is in the second state, there is a gap between the valve and the isolation surface and the first chamber is connected to the second chamber.

[0013] Preferably, the gas distribution valve and the gas distribution rod are slidably connected, and there is an axial pressure difference between the front end face and the rear end face of the gas distribution valve, which pushes the gas distribution valve to move along the axial direction of the gas distribution rod to switch between the first state and the second state.

[0014] Preferably, it further includes:

[0015] A limiting surface is provided on the outer surface of the connector. The limiting surface is used in conjunction with the air distribution valve to limit and constrain the axial movement of the air distribution valve.

[0016] Preferably, the gas distribution valve is provided with a first surface and a second surface, the first surface is in contact with the first chamber, the second surface is in contact with the second chamber, and the radial projection area of ​​the second surface is greater than the projection area of ​​the first surface.

[0017] Preferably, the gas distribution valve is provided with a first assembly hole and a second assembly hole, the second assembly hole is adapted to the outer surface of the gas distribution rod, the first assembly hole is adapted to the outer surface of the connector assembly, and the first assembly hole and the connector assembly, as well as the second assembly hole and the gas distribution rod, are connected by a sealing element.

[0018] Preferably, the valve stem comprises:

[0019] ontology;

[0020] A sleeve fitted on the outside of the main body forms an air passage between the inner surface of the sleeve and the outer surface of the main body, and an air cavity is formed between the connector, the outer surface of the sleeve and the rear end face of the air distribution valve.

[0021] An air inlet is provided at one end of the sleeve near the piston for communication with the ventilation channel;

[0022] It is located at one end of the sleeve near the connector and is used to connect the air chamber with the exhaust port of the ventilation channel.

[0023] Preferably, it further includes:

[0024] An exhaust passage is provided inside the piston, the exhaust passage extends along the axial direction of the piston, and the inner diameter of the exhaust passage is adapted to the outer diameter of the sleeve.

[0025] A valve ring is installed inside the exhaust passage and is sealed to the valve stem.

[0026] Preferably, at least two air inlets are provided, and the ventilation channel is connected to only one of the air inlets. The air inlets are arranged in a staggered manner around the circumference of the sleeve.

[0027] Preferably, the ventilation channel includes:

[0028] A groove is provided on the outer surface of the body, the groove extending along the axial direction of the body;

[0029] An annular groove disposed on the body and communicating with the groove;

[0030] A positioning mechanism is disposed between the sleeve and the body, the positioning mechanism fixing the sleeve to the outside of the body, such that one of the air inlets communicates with the groove and the exhaust port communicates with the annular groove.

[0031] Preferably, the positioning mechanism includes:

[0032] The positioning groove is provided on the body, and the positioning groove is located on the side of the annular groove away from the groove.

[0033] A mating groove provided on the inner surface of the sleeve and used in conjunction with the positioning groove;

[0034] A positioning element disposed within the positioning groove and the mating groove to limit and constrain the relative rotation between the sleeve and the body;

[0035] The mating grooves are provided one-to-one with the air inlets, and the mating grooves are spaced around the inner surface of the sleeve.

[0036] Preferably, the drill bit assembly includes:

[0037] A rock-breaking drill bit is disposed at the end of the outer cylinder away from the joint assembly;

[0038] A snap-fit ​​sleeve is fitted onto the outside of the rock-breaking drill bit and fixedly connected to the front end of the outer cylinder;

[0039] A bushing fitted on the outside of the rock-breaking drill bit and fixedly connected to the inner surface of the outer cylinder;

[0040] A retaining ring is disposed between the bushing and the retaining sleeve. The front end face of the retaining ring is provided with a first conical surface that contacts the rear end face of the retaining sleeve, and the rear end face of the retaining ring is provided with a second conical surface that contacts the front end face of the bushing.

[0041] Preferably, the connector assembly includes:

[0042] The connector that is fixedly connected to the outer cylinder;

[0043] A channel is provided inside the connector and fixedly connected to the air distribution rod, the channel extending along the axial direction of the connector;

[0044] An air outlet is provided on the outer surface of the connector and communicates with the channel;

[0045] A fixed sleeve is fitted on the outside of the connector for opening and closing the connector valve of the air outlet. The connector valve has an open state and a closed state. When the connector valve is in the closed state, the connector valve is in contact with the outer surface of the connector. When the connector valve is in the open state, there is a gap between the connector valve and the connector. The gap is used to connect the channel and the first chamber.

[0046] Preferably, the connector assembly further includes:

[0047] A connector sleeve is fitted on the outside of the connector. The outer diameter of the connector sleeve gradually decreases along the direction from the connector to the piston. The inner cylinder is fitted on the outside of the connector sleeve, and the inner surface of the inner cylinder is adapted to the outer surface of the connector sleeve.

[0048] The down-the-hole impactor provided by this invention comprises an outer cylinder, an inner cylinder, a piston, a valve rod, and a valve. The rear end of the outer cylinder is connected to a connector assembly, and the front end is connected to a drill bit assembly. The inner cylinder is fixedly fitted inside the outer cylinder, and the piston is fitted inside the inner cylinder. A rear chamber is formed between the piston, the inner cylinder, and the connector assembly, and a front chamber is formed between the piston, the drill bit assembly, and the outer cylinder. The valve rod is fitted inside the inner cylinder and fixedly connected to the connector assembly. The valve is fitted outside the valve rod, dividing the rear chamber into a first chamber and a second chamber. In existing technology, a valve distribution channel is provided on the piston, alternately communicating with the first and second chambers to create a pressure difference between them, thus driving the piston to reciprocate within the inner cylinder. However, this valve distribution method not only reduces the piston's strength but also causes pressure loss. To address this issue, the down-the-hole impactor provided by this invention further includes an isolation surface disposed on the inner surface of the inner cylinder. This isolation surface works in conjunction with a distribution valve, which has a first state and a second state. When the distribution valve is in the first state, it is in contact with the isolation surface, and the first chamber is connected to the front chamber. When the distribution valve is in the second state, a gap exists between the distribution valve and the isolation surface, and the first chamber is connected to the second chamber. This eliminates the need for a distribution channel on the piston. By providing the distribution valve, an axial pressure difference exists between its two ends, allowing the distribution valve to perform distribution in both the first and second states. Therefore, compared to existing technologies, the down-the-hole impactor in this invention eliminates the need for a distribution channel on the piston. By changing the distribution method of the impactor, gas pressure loss is reduced, thereby increasing the impactor's output power and extending its service life. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A schematic diagram of a down-the-hole impactor provided in an embodiment of the present invention (the air distribution valve is in the second state).

[0051] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0052] Figure 3 for Figure 2 A magnified view of a section at point C;

[0053] Figure 4A schematic diagram of a down-the-hole impactor provided in an embodiment of the present invention (air distribution valve in the first state).

[0054] Figure 5 for Figure 4 A magnified view of a section at point D;

[0055] Figure 6 A schematic diagram of the structure of the body provided in an embodiment of the present invention;

[0056] Figure 7 A schematic diagram of a sleeve provided in an embodiment of the present invention;

[0057] Figure 8 for Figure 1 A magnified view of a section at point B in the middle;

[0058] Figure 9 This is a schematic diagram of a retaining ring provided in an embodiment of the present invention.

[0059] Reference numerals: 1. Outer cylinder; 4. Inner cylinder; 5. Piston; 6. Valve stem; 7. Valve valve; 11. Front chamber; 12. First chamber; 13. Second chamber; 22. Connector; 23. Connector valve; 24. Connector sleeve; 31. Rock-breaking drill bit; 32. Crimping sleeve; 33. Bushing; 34. Snap ring; 41. Isolation surface; 51. Exhaust passage; 52. Valve ring; 71. First surface; 72. Second surface; 73. Third surface; 74, First seal; 61, Body; 62, Sleeve; 63, Vent channel; 64, Air chamber; 65, Positioning element; 66, Second seal; 611, Groove; 612, Annular groove; 613, Positioning groove; 614, Sealing groove; 622, Exhaust port; 623, Fitting groove; 6211, Inlet groove; 6212, First air inlet; 6213, Second air inlet; 6214, Third air inlet. Detailed Implementation

[0060] To enable those skilled in the art to 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 described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0062] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0063] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0064] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0065] The embodiments of this invention are written in a progressive manner.

[0066] like Figures 1 to 8 As shown, an embodiment of the present invention provides a down-the-hole hammer, comprising: an outer cylinder 1, a connector assembly connected to the rear end of the outer cylinder 1, and a drill assembly connected to the front end of the outer cylinder 1; an inner cylinder 4 fixedly sleeved inside the outer cylinder 1, a piston 5 sleeved inside the inner cylinder 4, a rear chamber formed between the piston 5, the inner cylinder 4, and the connector assembly, and a front chamber 11 formed between the piston 5, the drill assembly, and the outer cylinder 1; and a valve stem 6 sleeved inside the inner cylinder 4 and connected to the connector assembly, with a valve stem 6 sleeved on its outer side. Valve 7, the air distribution valve 7 divides the rear chamber into a first chamber 12 and a second chamber 13; an isolation surface 41 is provided on the inner surface of the inner cylinder 4 and is used in conjunction with the air distribution valve 7. The air distribution valve 7 has a first state and a second state. When the air distribution valve 7 is in the first state, the air distribution valve 7 is in contact with the isolation surface 41, and the first chamber 12 is connected to the front chamber 11. When the air distribution valve 7 is in the second state, there is a gap between the air distribution valve 7 and the isolation surface 41, and the first chamber 12 is connected to the second chamber 13.

[0067] It should be noted that, in this embodiment of the invention, the front end refers to the end of the outer cylinder 1 near the drill bit assembly, and the rear end refers to the end of the outer cylinder 1 near the connector assembly. In this invention, "axial" refers to the direction along the axis of the outer cylinder 1, and "radial" refers to the direction perpendicular to the axial direction of the outer cylinder 1.

[0068] In this embodiment of the invention, the "first chamber 12" is formed by a connector assembly, a valve rod 6, a valve 7, and an inner cylinder 4. In this embodiment of the invention, the "second chamber 13" is formed by an inner cylinder 4, a valve 7, a valve rod 6, and a piston 5.

[0069] The down-the-hole impactor provided by this invention comprises an outer cylinder 1, an inner cylinder 4, a piston 5, a valve rod 6, and a valve 7. The rear end of the outer cylinder 1 is connected to a connector assembly, and the front end is connected to a drill bit assembly. The inner cylinder 4 is fixedly fitted inside the outer cylinder 1, and the piston 5 is fitted inside the inner cylinder 4. A rear chamber is formed between the piston 5, the inner cylinder 4, and the connector assembly. A front chamber 11 is formed between the piston 5, the drill bit assembly, and the outer cylinder 1. The valve rod 6 is fitted inside the inner cylinder 4 and fixedly connected to the connector assembly. The valve 7 is fitted outside the valve rod 6, dividing the rear chamber into a first chamber 12 and a second chamber 13. In the prior art, a valve channel is provided on the piston 5, which alternately communicates with the front chamber 11 and the second chamber 13, creating a pressure difference between the second chamber 13 and the front chamber 11, thereby driving the piston 5 to reciprocate within the inner cylinder 4. However, this valve distribution method not only reduces the strength of the piston 5 but also causes pressure loss. To address this problem, the down-the-hole impactor provided by this invention further includes an isolation surface 41. The isolation surface 41 is disposed on the inner surface of the inner cylinder 4 and works in conjunction with the air distribution valve 7. The air distribution valve 7 has a first state and a second state. When the air distribution valve 7 is in the first state, please refer to... Figure 4 and Figure 5 As shown ( Figure 4 (The thin arrows indicate the direction of gas flow, and the thick arrows indicate the direction of piston movement.) The gas distribution valve 7 is in contact with the isolation surface 41, and the first chamber 12 is connected to the front chamber 11. When the gas distribution valve 7 is in the second state, please... Figures 1 to 3 As shown ( Figure 1 (The arrows in the diagram indicate the direction of gas flow). A gap exists between the gas distribution valve 7 and the isolation surface 41. The first chamber 12 and the second chamber 13 are connected. There is no need to create a gas distribution channel on the piston 5. By setting the gas distribution valve 7, a pressure difference exists between its two ends, allowing the gas distribution valve 7 to perform gas distribution in both a first state and a second state. Therefore, compared with the prior art, the down-the-hole impactor in this embodiment of the invention does not require a gas distribution channel on the piston 5. By changing the gas distribution method of the impactor, the gas pressure loss is small, which can improve the output power of the impactor and extend its service life.

[0070] In the above structure, when the air distribution valve 7 is in the first state, the air distribution valve 7 is in contact with the isolation surface 41, the first chamber 12 is isolated from the second chamber 13, the high-pressure gas in the first chamber 12 enters the front chamber 11 through the gap between the piston 5 and the outer cylinder 1, pushing the piston 5 to move towards the joint assembly, the air pressure in the second chamber 13 increases, and there is a pressure difference between the two ends of the air distribution valve 7, so that the air distribution valve 7 switches from the first state to the second state. There is a gap between the air distribution valve 7 and the isolation surface 41, and the high-pressure gas in the first chamber 12 directly enters the second chamber 13 through the gap, the pressure in the second chamber 13 increases, and as the pressure in the second chamber 13 increases, there is a pressure difference between the second chamber 13 and the front chamber 11, pushing the piston 5 to move towards the drill bit.

[0071] Therefore, in this embodiment of the invention, the gas in the first chamber 12 directly enters the second chamber 13 through the gap, resulting in less loss of high-pressure gas and higher output power of the impactor.

[0072] In the above structure, as a first embodiment, the valve 7 is fixedly sleeved on the outside of the valve stem 6. The valve 7 is capable of elastic deformation, allowing it to switch from a first state to a second state. The valve 7 is also capable of elastic reset deformation, allowing it to switch from the second state back to the first state. In this embodiment, the valve 7 is specifically made of an elastic material. Due to the pressure difference between the two ends of the valve 7, it undergoes elastic deformation and elastic reset deformation, thereby enabling it to achieve both the first and second states.

[0073] In the above structure, as a second implementation, the air distribution valve 7 and the air distribution rod 6 in this embodiment of the invention are specifically slidably connected. High-pressure gas enters the impactor and drives the piston 5 to move along the axial direction of the inner cylinder 4, so that there is an axial pressure difference between the two ends of the air distribution valve 7. Under the action of the axial pressure difference, the air distribution valve 7 is pushed to move along the axial direction of the air distribution rod 6 to switch between the first state and the second state.

[0074] In this embodiment of the invention, the gas distribution valve 7 and the isolation surface 41 cooperate, forming a first state in which they are in close contact. In this first state, the first chamber 12 and the second chamber 13 are isolated, and the first chamber 12 is connected to the front chamber 11. In a second state, the gas distribution valve 7 and the isolation surface 41 have a gap, and in this second state, the first chamber 12 and the isolation surface 41 are connected through the gap, and the first chamber 12 is isolated from the front chamber 11. Any prior art implementation that achieves either a close contact or a gap between the sealing surface and the isolation surface 41 is within the scope of protection of this invention.

[0075] In the above structure, as one embodiment, the down-the-hole impactor of the present invention further includes a limiting surface, wherein the limiting surface is disposed on the joint assembly and is used in conjunction with the air distribution valve 7 to limit and constrain the axial movement of the air distribution valve 7. More specifically, when the air distribution valve 7 is in the first state, the air distribution valve 7 is in contact with the isolation surface 41 and is separated from the limiting surface; when the air distribution valve 7 is in the second state, the air distribution valve 7 is in contact with the limiting surface and is separated from the isolation surface 41, and the high-pressure gas in the first chamber 12 enters the second chamber 13 through the gap between the air distribution valve 7 and the isolation surface 41.

[0076] In the above structure, the movement of the air distribution valve 7 along the axial direction of the air distribution rod 6 in this embodiment of the invention is due to the axial pressure difference between the two ends of the air distribution valve 7. The axial pressure on the air distribution valve 7 is equal to the pressure multiplied by the radial projection area. In order to enable the second chamber 13 to push the air distribution valve 7 to move along the axial direction of the air distribution rod 6 even when the pressure is relatively low, as a preferred embodiment, the air distribution valve 7 in this embodiment of the invention is provided with a first surface 71 and a second surface 72. The first surface 71 contacts the first chamber 12, and the second surface 72 contacts the second chamber 13. The radial projection area of ​​the second surface 72 is greater than the radial projection area of ​​the first surface 71. With this configuration, when the pressure in the second chamber 13 is less than the pressure in the first chamber 12, since the radial projection area of ​​the second surface 72 is greater than the radial projection area of ​​the first surface 71, the axial pressure on the second surface 72 of the air distribution valve 7 is also greater than the axial pressure on the first surface 71, thereby pushing the air distribution valve 7 to move along the axial direction of the air distribution rod 6, so that there is a gap between the air distribution valve 7 and the isolation surface 41.

[0077] In the above structure, as one embodiment, the gas distribution valve 7 of the present invention is provided with a first assembly hole and a second assembly hole. The first assembly hole is adapted to the outer surface of the connector assembly, and the second assembly hole is adapted to the outer surface of the gas distribution rod 6. The gas distribution valve 7 is fitted on the gas distribution rod 6 and is fitted on the outside of the connector assembly through the first assembly hole. The second assembly hole and the gas distribution rod 6, and the first assembly hole and the connector assembly are specifically clearance fits. In order to prevent high-pressure gas leakage, a first sealing element is provided between the first assembly hole and the connector assembly, and between the second assembly hole and the gas distribution rod 6 in the present invention embodiment.

[0078] In the above structure, as one specific implementation, the first sealing element in this embodiment of the invention is a sealing ring.

[0079] In the above structure, as one embodiment, the down-the-hole impactor of the present invention further includes an air passage groove disposed on the inner surface of the inner cylinder 4 and a sealing section disposed between the outer surfaces of the piston 5. The air passage groove is recessed from the inner surface of the outer cylinder 1 toward the inward side away from the axis, and the sealing section protrudes from the outer surface of the piston 5 toward the outward side away from the axis. The outer diameter of the sealing section is equal to the inner diameter of the outer cylinder 1 and smaller than the inner diameter of the air passage groove. The length of the air passage groove is greater than the length of the sealing section. When the sealing section and the air passage groove are engaged, an air passage gap is formed between the air passage groove and the sealing section. The high-pressure gas in the first chamber 12 can enter the front chamber 11 through the air passage gap. As the piston 5 moves along the axial direction of the inner cylinder 4, when the sealing section and the air passage groove are staggered, the first chamber 12 and the front chamber 11 are isolated.

[0080] In the above structure, as one embodiment, the air distribution rod 6 in this embodiment of the invention includes a body 61 and a sleeve 62. The sleeve 62 is fitted on the outside of the body 61. There is a ventilation channel 63 between the inner surface of the sleeve 62 and the outer surface of the body 61. An air cavity 64 is formed between the connector assembly, the outer surface of the sleeve 62 and the rear end face of the air distribution valve 7. The surface of the air cavity 64 that contacts the air distribution valve 7 is a third surface 73. An air inlet is provided at one end of the sleeve 62 near the piston 5. The air inlet communicates with the ventilation channel 63. An exhaust port 622 is also provided at one end of the sleeve 62 near the connector assembly. The exhaust port 622 is used to communicate with the air cavity 64 and the ventilation channel 63. Because an air chamber 64 is provided, and the air chamber 64 is in contact with the rear end face of the air distribution valve 7, gas can enter the air chamber 64 through the air inlet, the air passage 63, and the exhaust port 622, acting on the third surface 73, increasing the axial force on the rear end face of the air distribution valve 7. At this time, the axial force on the rear end face of the air distribution valve 7 is equal to the sum of the axial force on the first surface 71 and the axial force on the third surface 73. When the axial force on the rear end face of the air distribution valve 7 is greater than the axial force on the front end face of the air distribution valve 7, it pushes the air distribution valve 7 to move towards the piston 5, so that the air distribution valve 7 switches from the second state to the first state.

[0081] In the above structure, as one embodiment, the down-the-hole impactor of the present invention further includes an exhaust channel 51, wherein the exhaust channel 51 is disposed inside the piston 5, the exhaust channel 51 extends along the axial direction of the piston 5, and the inner diameter of the exhaust channel 51 is adapted to the outer diameter of the sleeve 62. There is a pressure difference between the front chamber 11 and the second chamber 13, which pushes the piston 5 to move toward the air distribution valve 7. When the piston 5 separates from the air distribution rod 6, the high-pressure gas in the second chamber 13 is discharged through the exhaust channel 51. When the air distribution rod 6 is inserted into the exhaust channel 51 of the piston 5, as the piston 5 moves, the air pressure in the second chamber 13 increases. The air pressure on the second chamber 13 acts on the second surface 72. When the axial pressure of the second surface 72 is greater than the axial pressure of the first surface 71, it pushes the air distribution valve 7 to move toward the connector assembly. The high-pressure gas in the first chamber 12 enters the second chamber 13 through the gap between the connector valve 23 and the isolation surface 41. As the air pressure in the second chamber 13 increases, it pushes the piston 5 to move toward the drill bit assembly. The amount of high-pressure gas entering the second chamber 13 from the first chamber 12 determines the stroke of the piston 5. The greater the amount of gas entering the second chamber 13, the shorter the stroke of the piston 5 and the higher the frequency of the down-the-hole impactor. Furthermore, a gas distribution ring 52 is provided on the inner wall of the venting channel 63 of the piston 5 to prevent the gas distribution rod 6 from rigidly jamming and rubbing against the piston 5.

[0082] Furthermore, as one embodiment, the present invention provides at least two air inlets, with the ventilation channel 63 communicating with one air inlet, and the air inlets being arranged in a staggered manner around the circumference of the sleeve 62. The staggered arrangement of the air inlets around the sleeve 62 means that the air inlets are spaced apart in both the circumferential direction around the sleeve 62 and along the axial direction of the sleeve 62. Adjust the rotation angle of the body 61 and the sleeve 62. The ventilation channel 63 is connected to only one air inlet. The ventilation channel 63 of the piston 5 is fitted on the outside of the valve rod 6. When the air inlet is connected to the second chamber 13, the compressed gas in the second chamber 13 enters the air chamber 64 through the air inlet, ventilation channel 63 and exhaust port 622, providing axial pressure to the rear end face of the valve 7. As the piston 5 continues to move, the air inlet is connected to the exhaust channel 51 of the piston 5. The exhaust channel 51 is connected to the outside of the downhole impactor. The pressure of the compressed gas in the air chamber 64 decreases, the axial pressure on the third surface 73 decreases, and the compressed air in the second chamber 13 can more easily push the valve 7 open. The high-pressure gas in the first chamber 12 enters the second chamber 13. Because the intake ports are positioned differently along the axial direction, the intake port closer to the piston 5 requires a shorter movement of the piston 5 to connect the intake port with the exhaust passage 51. This allows the compressed gas in the second chamber 13 to push open the valve 7 in a shorter time, allowing the high-pressure gas in the first chamber 12 to enter the second chamber 13 and push the piston 5 towards the drill bit assembly. If the ventilation passage 63 connects to the intake port furthest from the piston 5, the piston 5 needs to move a longer distance towards the connector assembly within the inner cylinder 4. The longer the stroke of the piston 5, the lower the frequency of the piston 5 impacting the drill bit assembly.

[0083] In the above structure, as one embodiment, the ventilation channel 63 of this invention includes a groove 611, an annular groove 612, and a positioning mechanism. The groove 611 is disposed on the outer surface of the body 61 and extends along the axial direction of the body 61. The annular groove 612 is disposed on the body 61 and surrounds the circumference of the body 61, communicating with the groove 611. Both the groove 611 and the annular groove 612 are formed by recesses from the surface of the body 61 towards the axial direction. The positioning mechanism is disposed between the sleeve 62 and the body 61, and is used to fix the sleeve 62 to the outside of the body 61, such that the air inlet on the sleeve 62 communicates with the groove 611, and the exhaust port 622 on the sleeve 62 communicates with the annular groove 612. Gas enters between the sleeve 62 and the body 61 through the air inlet, and then enters the cavity via the groove 611, the annular groove 612, and the exhaust port 622.

[0084] Furthermore, in this embodiment of the invention, the exhaust port 622 may be provided with one or at least two. When there are at least two exhaust ports 622, the exhaust ports 622 are arranged circumferentially around the sleeve 62.

[0085] In the above structure, the ventilation channel 63 is connected to one of the air inlets by a positioning mechanism. The closer the air inlet connected to the ventilation channel 63 is to the piston 5, the shorter the stroke of the piston 5 inside the down-the-hole impactor, and the higher the frequency of the piston 5 impacting the drill bit assembly. Conversely, the farther the air inlet connected to the ventilation channel 63 is from the piston 5, the longer the stroke of the piston 5 inside the down-the-hole impactor, and the lower the frequency of the piston 5 impacting the drill bit assembly. In this invention, the position of the air inlet connected to the ventilation channel 63 is adjusted by setting a positioning mechanism, thereby adjusting the impact frequency according to the operating conditions of the down-the-hole impactor and the hardness of the rock.

[0086] More specifically, as one embodiment, the positioning mechanism in this invention includes a positioning groove 613, a mating groove 623, and a positioning element 65. The positioning groove 613 is disposed on the outer surface of the body 61, and is located on the side of the annular groove 612 away from the recess 611. The mating groove 623 is disposed on the inner surface of the sleeve 62, and is used in conjunction with the positioning groove 613. The positioning element 65 is disposed within the positioning groove 613 and the mating groove 623, and is used to limit and constrain the relative rotation between the sleeve 62 and the body 61. The positioning element 65 is installed within the positioning groove 613, and the sleeve 62 is fitted onto the outer side of the body 61. Positioning is achieved through the positioning element 65 and the mating groove 623. Furthermore, in this embodiment, the mating grooves 623 are arranged one-to-one with the air inlets, and are spaced apart around the inner surface of the sleeve 62.

[0087] Furthermore, in this embodiment of the invention, the body 61 and the sleeve 62 are specifically fitted with a clearance, making installation more convenient. Furthermore, in order to prevent leakage of high-pressure gas, as one implementation, the down-the-hole impactor in this embodiment of the invention also includes a second sealing element, wherein the second sealing element is disposed between the body 61 and the sleeve 62. More specifically, the body 61 in this embodiment of the invention is also provided with a sealing groove 614 that cooperates with the second sealing element, and the sealing groove 614 is disposed between the annular groove 612 and the positioning groove 613.

[0088] More specifically, in this embodiment of the invention, the second sealing element is an O-ring.

[0089] Please Figure 6 and Figure 7As shown, the air inlet in this embodiment of the invention is provided with four ports, including an air inlet groove 6211, a first air inlet hole 6212, a second air inlet hole 6213, and a third air inlet hole 6214 provided on the inner wall of the sleeve 62. The air inlet groove extends along the axial direction of the sleeve 62 to the front end face of the sleeve 62. The first air inlet hole, the second air inlet hole, and the third air inlet hole are arranged alternately around the outer circumferential surface of the sleeve 62. The air inlet groove, the first air inlet hole, the second air inlet hole, and the third air inlet hole are arranged sequentially in the direction away from the piston 5. There are four mating grooves 623. When the positioning component is fixed between the first mating groove 623 and the positioning groove 613, the air inlet groove is connected to the ventilation channel 63. When the piston 5 moves to the outside of the air distribution rod 6, the cavity is connected to the outside of the impactor. The piston 5 has the shortest stroke and the highest frequency. When the ventilation channel 63 is connected to the third air inlet hole, the piston 5 has the longest stroke and the lowest frequency.

[0090] Please Figure 8 As shown, the drill bit assembly in this embodiment of the invention includes a rock-breaking drill bit 31, a chuck sleeve 32, and a bushing 33. The rock-breaking drill bit 31 is located at the end of the outer cylinder 1 away from the connector assembly. The chuck sleeve 32 is fitted onto the outside of the rock-breaking drill bit 31 and is fixedly connected to the front end of the outer cylinder 1. The chuck sleeve 32 is connected to the drill bit via a spline. The bushing 33 is fitted onto the outside of the rock-breaking drill bit 31 and is fixedly connected to the inner surface of the outer cylinder 1. A retaining ring 34 is located between the chuck sleeve 32 and the bushing 33. The front end face of the retaining ring 34 has a first conical surface that contacts the rear end face of the chuck sleeve 32, and the rear end face of the retaining ring 34 has a second conical surface that contacts the front end face of the bushing 33. The retaining ring 34 and the bushing 33, as well as the retaining ring 34 and the chuck sleeve 32, are positioned by the conical surfaces, making the positioning more reliable and preventing the impact drill bit from swinging or shifting.

[0091] Furthermore, in this embodiment of the invention, the retaining ring includes a first body and a second body, wherein an assembly hole adapted to the rock-breaking drill bit 31 is formed between the first body and the second body, and the first body and the second body are fixed to the outside of the rock-breaking drill bit by an O-ring.

[0092] In the above structure, as one embodiment, the connector assembly in this embodiment of the invention includes a connector 22 and a connector valve 23. The connector 22 is fixedly connected to the outer cylinder 1. A channel is provided inside the connector 22, extending along the axial direction of the connector 22 and fixedly connected to the air distribution rod 6. An air outlet is provided on the outer surface of the connector 22, communicating with the connector 22. The connector valve 23 is fixedly fitted on the outside of the connector 22 and is used to open and close the air outlet. The connector valve 23 has a first state and a second state. When the connector valve 23 is in the first state, there is a gap between the inner surface of the connector valve 23 and the outer surface of the connector 22, and the high-pressure gas in the channel can enter the first chamber 12 through the gap. When the connector valve 23 is in the second state, the inner surface of the connector valve 23 is in contact with the outer surface of the connector 22, which can prevent slag from returning inside the impactor.

[0093] In this embodiment of the invention, the connector valve 23 can undergo elastic deformation to switch the connector valve 23 from a second state to a first state, and the connector valve 23 can undergo elastic reset deformation to switch the connector valve 23 from a first state to a second state.

[0094] Specifically, when no high-pressure gas is introduced into the high-pressure air passage, the connector valve 23 is in the second state. When high-pressure gas is introduced into the high-pressure air passage, the connector valve 23 undergoes elastic deformation under the action of the high-pressure gas, switching from the second state to the first state. A venting gap exists between the inner surface of the connector valve 23 and the outer surface of the connector 22, allowing the high-pressure gas to enter the down-the-hole impactor through this gap. After drilling is completed, the input of high-pressure gas into the high-pressure air passage stops, and the connector valve 23 undergoes elastic reset deformation, switching from the first state to the second state. The outer surface of the connector valve 23 then fits against the outer surface of the connector 22, preventing backflow of slag from the down-the-hole impactor. This invention utilizes the elastic deformation and reset deformation of the connector valve 23 itself, eliminating the need for a separate check valve spring. Its structure is simpler, its sealing effect is better, and it is less prone to failure.

[0095] In the above structure, as one embodiment, the connector assembly of this invention further includes a connector sleeve 24, wherein the connector sleeve 24 is sleeved on the outside of the connector 22. Along the direction from the connector 22 to the piston 5, the outer diameter of the connector sleeve 24 gradually decreases. The inner cylinder 4 is sleeved on the outside of the connector sleeve 24, and the inner surface of the inner cylinder 4 is adapted to the outer surface of the connector sleeve 24. The outer diameter of the outer circumferential surface of the connector sleeve 24 gradually decreases, and the inner diameter of the inner surface of the outer cylinder 1 that mates with the connector sleeve 24 gradually decreases. The inner surface of the positioning section is limited by the tapered outer circumferential surface of the connector sleeve 24, resulting in a better positioning effect.

[0096] Furthermore, in this embodiment of the invention, the outer surface of the inner cylinder 4 is provided with a spiral air passage groove. Compared with the straight groove in the prior art, the spiral air passage groove is longer. When the air passage volume of the inner cylinder 4 and the outer cylinder 1 is the same, the depth of the spiral air passage groove is lower, which can improve the strength of the inner cylinder 4.

[0097] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A down-the-hole impactor, characterized in that, include: Outer cylinder (1), connector assembly connected to the rear end of the outer cylinder (1), and drill bit assembly connected to the front end of the outer cylinder (1); An inner cylinder (4) is fixedly fitted inside the outer cylinder (1), and a piston (5) is fitted inside the inner cylinder (4). A rear chamber is formed between the piston (5), the inner cylinder (4), and the joint assembly. A front chamber (11) is formed between the piston (5), the drill assembly, and the outer cylinder (1). The valve rod (6) is fitted inside the inner cylinder (4) and connected to the connector assembly. A valve (7) is fitted on the outside of the valve rod (6). The valve (7) divides the rear chamber into a first chamber (12) and a second chamber (13). An isolation surface (41) is provided on the inner surface of the inner cylinder (4) and used in conjunction with the valve (7). The valve (7) has an axial pressure difference on both sides, so that the valve (7) has a first state and a second state. When the valve (7) is in the first state, the valve (7) is in contact with the isolation surface (41), and the first chamber (12) is connected to the front chamber (11). When the valve (7) is in the second state, there is a gap between the valve (7) and the isolation surface (41), and the first chamber (12) is connected to the second chamber (13). The valve stem (6) includes: Ontology(61); A sleeve (62) is fitted on the outside of the main body (61), and an air passage (63) is formed between the inner surface of the sleeve (62) and the outer surface of the main body (61). An air cavity (64) is formed between the connector assembly, the outer surface of the sleeve (62) and the rear end face of the air distribution valve (7). An air inlet is provided at one end of the sleeve (62) near the piston (5), and the air inlet is used to communicate with the ventilation channel (63); The sleeve (62) is positioned at one end near the connector assembly to connect the air chamber (64) with the exhaust port (622) of the ventilation channel (63).

2. The down-the-hole impactor according to claim 1, characterized in that, The gas distribution valve (7) and the gas distribution rod (6) are specifically slidably connected. There is an axial pressure difference between the front end face and the rear end face of the gas distribution valve (7), which causes the gas distribution valve (7) to move along the axial direction of the gas distribution rod (6) to switch between the first state and the second state.

3. The down-the-hole impactor according to claim 2, characterized in that, Also includes: A limiting surface is provided on the outer surface of the connector assembly. The limiting surface is used in conjunction with the gas distribution valve (7) to limit and constrain the axial movement of the gas distribution valve (7).

4. The down-the-hole impactor according to claim 3, characterized in that, The gas distribution valve (7) is provided with a first surface (71) and a second surface (72). The first surface (71) is in contact with the first chamber (12), and the second surface (72) is in contact with the second chamber (13). The radial projection area of ​​the second surface (72) is greater than the projection area of ​​the first surface (71).

5. The down-the-hole impactor according to claim 4, characterized in that, The gas distribution valve (7) is provided with a first assembly hole and a second assembly hole. The second assembly hole is adapted to the outer surface of the gas distribution rod (6). The first assembly hole is adapted to the outer surface of the connector assembly. The first assembly hole and the connector assembly, and the second assembly hole and the gas distribution rod (6) are connected by a first sealing element.

6. The down-the-hole impactor according to claim 1, characterized in that, Also includes: An exhaust passage (51) is provided inside the piston (5), the exhaust passage (51) extends along the axial direction of the piston (5), and the inner diameter of the exhaust passage (51) is adapted to the outer diameter of the sleeve (62); A valve ring (52) is installed inside the exhaust passage (51) for sealing connection with the sleeve (62).

7. The down-the-hole impactor according to claim 6, characterized in that, At least two air inlets are provided, and the ventilation channel (63) is connected to only one of the air inlets. The air inlets are arranged in a staggered manner around the sleeve (62).

8. The down-the-hole impactor according to claim 7, characterized in that, The ventilation channel (63) includes: A groove (611) is provided on the outer surface of the body (61), and the groove (611) extends along the axial direction of the body (61). An annular groove (612) is provided on the body (61) and communicates with the groove (611). A positioning mechanism is provided between the sleeve (62) and the body (61), the positioning mechanism fixing the sleeve (62) to the outside of the body (61) such that one of the air inlets communicates with the groove (611) and the exhaust port (622) communicates with the annular groove (612).

9. The down-the-hole impactor according to claim 8, characterized in that, The positioning mechanism includes: A positioning groove (613) is provided on the body (61), the positioning groove (613) being located on the side of the annular groove (612) away from the groove (611); A mating groove (623) is provided on the inner surface of the sleeve (62) and used in conjunction with the positioning groove (613). A positioning element (65) is disposed in the positioning groove (613) and the mating groove (623) to limit and constrain the relative rotation between the sleeve (62) and the body (61). The mating groove (623) is provided in a one-to-one correspondence with the air inlet, and the mating groove (623) is provided at intervals around the inner surface of the sleeve (62).

10. The down-the-hole impactor according to claim 1, characterized in that, The drill bit assembly includes: A rock-breaking drill bit (31) is disposed at one end of the outer cylinder (1) away from the joint assembly. A snap-fit ​​sleeve (32) is fitted on the outside of the rock-breaking drill bit (31) and fixedly connected to the front end of the outer cylinder (1). A bushing (33) is fitted on the outside of the rock-breaking drill bit (31) and fixedly connected to the inner surface of the outer cylinder (1). A retaining ring (34) is provided between the bushing (33) and the retaining sleeve (32). The front end face of the retaining ring (34) is provided with a first conical surface that contacts the rear end face of the retaining sleeve (32), and the rear end face of the retaining ring (34) is provided with a second conical surface that contacts the front end face of the bushing (33).

11. The down-the-hole impactor according to claim 1, characterized in that, The connector assembly includes: The connector (22) is fixedly connected to the outer cylinder (1); A channel is provided inside the connector (22) and fixedly connected to the gas distribution rod (6), the channel extending along the axial direction of the connector (22); An air outlet is provided on the outer surface of the connector (22) and communicates with the channel; A connector valve (23) is fixedly fitted on the outside of the connector (22) for opening and closing the air outlet. The connector valve (23) has an open state and a closed state. When the connector valve (23) is in the closed state, the connector valve (23) is in contact with the outer surface of the connector (22). When the connector valve (23) is in the open state, there is a gap between the connector valve (23) and the connector (22). The gap is used to connect the channel and the first chamber (12).

12. The down-the-hole impactor according to claim 11, characterized in that, The connector assembly further includes: The outer diameter of the connector sleeve (24) is gradually reduced along the direction from the connector (22) to the piston (5) and the inner cylinder (4) is fitted on the outer side of the connector sleeve (24), and the inner surface of the inner cylinder (4) abuts against the outer surface of the connector sleeve (24).

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