Positive cycle pneumatic impactor

Abstract

The present invention relates to the technical field of impactors for drilling, and in particular to an invented positive cycle pneumatic impactor, wherein an upper air chamber is formed between the top of the piston and the attachment part of the gas distribution pipe, and a lower air chamber is formed in the cylinder body corresponding to the lower outer side of the piston; the interior of the piston has an upper gas distribution chamber and a lower gas distribution chamber in the axial direction, the lower end of the gas distribution pipe extends into the upper gas distribution chamber of the piston, and a first air flow channel is provided on the extended pipe section, which is always connected with the upper gas distribution chamber, and the lower gas distribution chamber is always connected with the lower gas distribution chamber of the piston. The impact piston can be pushed by a gas medium to move axially back and forth relative to the gas distribution pipe to form impact work on the drill bit body; by means of the axial reciprocating movement of the impact piston, the upper gas distribution chamber can switch and connect between the lower gas distribution chamber and the upper gas chamber. The present invention not only has a simple structure, but also has a large force-bearing area of ​​the piston, a high impact terminal velocity and an impact frequency, and all components of the drilling tool are relatively "solid", and the service life is significantly increased.

Description

Technical Field

[0001] The invention relates to a pneumatic impactor for drilling, in particular to a positive cycle pneumatic impactor suitable for various types of boreholes for fast drilling of hard rocks. Background Art

[0002] Pneumatic impactor is a relatively efficient hard rock drilling tool. It uses compressed air as the power medium and is widely used for a series of advantages such as high drilling efficiency and good drilling quality.

[0003] In the prior art, the positive cycle pneumatic impactor usually has an inner cylinder, which occupies the radial dimension of the impactor, resulting in a thinner outer tube thickness, a smaller piston diameter and an effective force-bearing area on the end face, which easily leads to problems such as piston breakage, low impact power and frequency. To solve this problem, a down-the-hole impactor without an inner cylinder has appeared in the prior art, such as disclosed in Chinese patent CN216240401U. However, the patent still has problems such as low piston movement frequency, low impact efficiency, and thin wall thickness of the outer cylinder.

[0004] In order to overcome the above problems, the applicant of the present patent has previously proposed a new positive cycle pneumatic down-the-hole hammer, specifically Chinese patent CN115977525B, which arranges a flow channel on the piston, cancels the cylinder sleeve and its peripheral gas distribution structure, thereby simplifying the down-the-hole hammer structure, significantly increasing the wall thickness of the outer cylinder, thereby enhancing the wear resistance and greatly increasing the service life. However, the technical solution disclosed in the patent has the following technical problems: since it is necessary to open a fluid channel on the wall of the piston, the processing is relatively complicated and the processing cost is relatively high; at the same time, since it is necessary to open a fluid channel on the wall of the piston, the strength of the load that the piston can withstand is weakened, and under high-intensity operation, it is easy to cause cracks or cracks in the fluid channel of the piston, thereby affecting the service life of the piston, and then affecting the service life of the entire impactor; in addition, since the reciprocating movement of the piston is switched by means of a narrow and long air flow channel opened on the wall of the piston, the instantaneous responsiveness required for the rapid switching of high and low pressures is relatively slow, that is, the impact frequency will be affected.

[0005] Based on this, it is necessary to improve the existing positive cycle pneumatic impactor to overcome the above technical problems. Summary of the invention

[0006] In view of this, the present invention provides a positive cycle pneumatic impactor, which eliminates the scheme of setting a fluid channel on the wall of the piston in the prior art, and instead sets a gas distribution chamber structure for driving the piston to reciprocate up and down in the original inner cavity of the piston, so that there is no need to set a fluid channel for switching on the wall of the piston, thereby ensuring the overall structural strength of the piston and improving the service life. Moreover, since the cavities used to achieve the switching of the gas flow direction are arranged in the same direction, that is, both in the axial direction of the cylinder body, this not only makes it possible to switch between the gas flow channels by means of the axial reciprocating movement of the piston, but also makes the gas flow direction switching stroke shorter after the gas flow channels are connected, so that the movement of the piston in the opposite direction is quickly realized and responded, thereby better improving the impact frequency of the piston, and the structure is simple and easy to implement.

[0007] The present invention discloses a positive cycle pneumatic impactor, comprising a cylinder body of a cylindrical structure, an impact piston, an air distribution pipe and a drill bit body, wherein the drill bit body is attached to the end of the cylinder body, and the piston is arranged in the cylinder body in a manner that it can be pushed by gas to perform axial reciprocating movement relative to the cylinder body so as to perform impact work on the drill bit body; the air distribution pipe has an attachment portion and a pipe body portion, and the attachment portion is supported and arranged in the cylinder body in a manner having a circumferential seal.

[0008] According to the positive cycle pneumatic impactor of the present invention, an upper air chamber capable of receiving a gas medium is formed between the top of the piston and the attachment portion of the gas distribution pipe in the cylinder body, and a lower air chamber capable of receiving a gas medium is formed on the outer side of the lower portion of the piston corresponding to the cylinder body; the interior of the piston has an upper gas distribution chamber and a lower gas distribution chamber in the axial direction, the lower end of the pipe body of the gas distribution pipe extends into the upper gas distribution chamber of the piston, and a first air flow channel that is constantly connected to the upper gas distribution chamber is provided on the extended pipe section, and the lower gas distribution chamber is constantly connected to the lower gas distribution chamber of the piston.

[0009] According to the positive cycle pneumatic impactor of the present invention, the impact piston is constructed to be able to be pushed by the gas medium to perform axial reciprocating movement relative to the gas distribution pipe to perform impact work on the drill bit body; with the help of the axial reciprocating movement of the impact piston, the upper gas distribution chamber can switch and connect between the lower gas distribution chamber and the upper gas chamber.

[0010] The so-called "upper" and "lower" are relative terms based on the drilling direction of the drill bit body, that is, relatively speaking, the position facing or close to the drilling direction of the drill bit body can be designated as the lower side, and the position facing away from or away from the drilling direction of the drill bit body can be designated as the upper side. In the present invention, the upper gas distribution chamber and the lower gas distribution chamber are both formed by the inner cavity of the piston, wherein the upper gas distribution chamber is located above the lower gas distribution chamber, and the two can be connected through the inner hole of the radial inner flange of the second piston mentioned below.

[0011] In the present invention, the upper air cavity, the upper gas distribution cavity and the lower gas distribution cavity are coaxially arranged, that is, from the overall view of the impactor, the upper air cavity, the upper gas distribution cavity and the lower gas distribution cavity are arranged in sequence from top to bottom.

[0012] Specifically, the piston and the gas distribution pipe are constructed in such a way that, in an initial state, the upper gas distribution chamber and the upper gas chamber remain disconnected, and the upper gas distribution chamber is connected with the lower gas distribution chamber, so that the gas medium can enter the lower gas chamber, pushing the piston to produce an axial movement upward relative to the gas distribution pipe; with the help of the upward axial movement of the piston relative to the gas distribution pipe, the connection between the upper gas distribution chamber and the lower gas distribution chamber can be disconnected, and the upper gas distribution chamber can be connected with the upper gas chamber, so that the gas medium can enter the upper gas chamber, pushing the piston to produce an axial movement downward relative to the gas distribution pipe.

[0013] The so-called disconnection refers to disconnection of connectivity, that is, there is no connectivity between the two.

[0014] In the present invention, the piston can be driven reciprocally by switching the upper gas distribution chamber between the lower gas distribution chamber and the upper gas chamber, which not only greatly simplifies the gas flow channel structure of the impactor, but also makes it easier to switch the flow channels between the gas flow channels for reciprocating the piston. That is, the flow channel switching and / or the switching of the reciprocating piston drive that require a complex structure in the prior art can be achieved through an extremely simple structure.

[0015] Moreover, more importantly, by configuring an upper gas distribution chamber and a lower gas distribution chamber in the inner cavity of the piston, and allowing the upper gas distribution chamber to switch between the lower gas distribution chamber and the upper gas distribution chamber with the help of the reciprocating movement of the piston, there is no need to arrange a fluid channel on the piston as in the prior art, thereby greatly improving the overall structural strength of the piston and further increasing its service life.

[0016] According to the positive cycle pneumatic impactor of the present invention, a first piston radial inner flange protruding radially inward is provided at a position near the top end in the inner cavity of the piston, and a first tube body radial outer flange protruding radially outward is provided on the outer side of the tube body, and the tube body extends into the upper gas distribution cavity after passing through the channel of the radial inner flange; in the initial state, the first piston radial inner flange and the first tube body radial outer flange are in contact with each other and form a tight and / or sealed fit with each other, so that the upper gas distribution cavity and the upper air cavity are kept disconnected; by means of the upward axial movement of the piston relative to the gas distribution pipe, the first piston radial inner flange can be separated from the contact with the first tube body radial outer flange, so that the upper gas distribution cavity and the upper air cavity are connected.

[0017] According to the positive cycle pneumatic impactor of the present invention, a second piston radial inner flange is arranged between the upper gas distribution chamber and the lower gas distribution chamber in the inner cavity of the piston; a second tube body radial outer flange is arranged on the outer side of the tube body below the radial outer flange of the first tube body; in an initial state, the second piston radial inner flange remains disengaged from the second tube body radial outer flange so that the upper gas distribution chamber and the lower gas distribution chamber remain connected; by means of the upward axial movement of the piston relative to the gas distribution pipe, the second piston radial inner flange can form a tight and / or sealed contact fit with the second tube body radial outer flange so that the connection between the upper gas distribution chamber and the lower gas distribution chamber is disconnected.

[0018] In the present invention, the so-called radial inner flange refers to a flange structure formed by radially protruding inward from the inner surface of the channel in which it is located, and the so-called radial outer flange refers to a flange structure formed by radially protruding inward from the outer surface of the side wall in which it is located on the outer side wall. When the corresponding inner flange and outer flange form contact, the connection between the upper and lower chambers or the upper and lower channels at their locations is disconnected, and when the corresponding inner flange and outer flange are separated (that is, no longer in contact), the connection between the upper and lower chambers or the upper and lower channels at their locations will be opened.

[0019] That is to say, in the present invention, the switching connection between the upper gas distribution chamber and the lower gas distribution chamber and the upper gas chamber is realized by means of a simple flange structure, so there is no need to separately set up an additional reversing valve as in the prior art, thereby greatly simplifying the number of required parts, reducing the complexity of the impactor structure, and further reducing the manufacturing cost.

[0020] According to the positive cycle pneumatic impactor of the present invention, a second air flow channel is provided on and / or near the lower end of the piston, and is used to maintain communication with the lower air chamber.

[0021] According to the positive cycle pneumatic impactor of the present invention, a first radial inner flange of the cylinder and a second radial inner flange of the cylinder are provided in the cylinder body, the inner area of ​​the first radial inner flange of the cylinder body forms an upper air cavity, the lower outer side of the piston forms a tight and / or sealed fit with the second radial inner flange of the cylinder body, the lower outer side of the piston forms a necking section near the end, and the annular space between the necking section and the inner wall of the second radial inner flange of the cylinder body forms a lower air cavity; the attachment portion of the distribution pipe is seated on the upper end of the flange in the cylinder body.

[0022] According to the positive circulation pneumatic impactor of the present invention, a scavenging air flow channel for removing slag from the bottom of the hole is also provided in the cylinder body, and the air outlet side of the scavenging air flow channel is connected with the internal air channel of the drill bit body; in the initial state, the air inlet side of the scavenging air flow channel is connected with the upper air cavity; by means of the upward axial movement of the piston relative to the air distribution pipe, the connection between the air inlet side of the scavenging air flow channel and the upper air cavity can be disconnected; by means of the downward axial movement of the piston relative to the air distribution pipe, the air inlet side of the scavenging air flow channel and the upper air cavity are reconnected.

[0023] According to the positive cycle pneumatic impactor of the present invention, a piston accommodating chamber is arranged adjacent to the upper air chamber inside the cylinder body, and the inner diameter of the cross section of the piston accommodating chamber is larger than the inner diameter of the cross section of the upper air chamber, so that a scavenging air flow inlet flow passage of the scavenging air flow passage is formed between the outer wall of the piston and the chamber wall of the piston accommodating chamber; by means of the upward axial movement of the piston relative to the gas distribution pipe, when the first fluid channel is connected with the upper air chamber by means of the gas distribution upper chamber, the upper part of the piston enters the upper air chamber and forms a tight and / or sealed fit with the radial inner flange of the first cylinder body, so that the connection between the intake side of the scavenging air flow inlet flow passage and the upper air chamber is disconnected; by means of the downward axial movement of the piston relative to the gas distribution pipe, when the first fluid channel is connected with the gas distribution lower chamber by means of the gas distribution upper chamber, the upper outer side of the piston is separated from the contact with the radial inner flange of the first cylinder body, so that the intake side of the scavenging air flow inlet flow passage and the upper air chamber are reconnected.

[0024] According to the positive cycle pneumatic impactor of the present invention, a sweeping air flow intermediate channel is formed inside the wall of the cylinder body and is always connected with the sweeping air flow inlet channel.

[0025] According to the positive cycle pneumatic impactor of the present invention, it also includes a spline sleeve, the lower end of the cylinder body is connected to the spline sleeve through a thread, and the splines on the drill body match the spline grooves on the spline sleeve.

[0026] The positive cycle pneumatic impactor according to the present invention further comprises:

[0027] A retaining ring is clamped in an annular groove on the upper part of the spline of the drill body and blocks the top surface of the spline sleeve;

[0028] A limiting bushing is sleeved on the outer periphery of the upper part of the drill body, and the upper top surface of the limiting bushing is pressed against the lower end surface of the radial inner flange of the second cylinder body, and the lower bottom surface is pressed on the retaining ring to limit the retaining ring;

[0029] The limiting bushing is provided with a cleaning airflow transition channel communicating with the cleaning airflow intermediate channel and the internal airway of the drill body.

[0030] Beneficial effects: In the positive cycle pneumatic impactor of the present invention, a gas distribution cavity structure for driving the piston to reciprocate up and down is arranged in the original inner cavity of the piston, so that there is no need to arrange a fluid channel for switching on the wall of the piston, thereby ensuring the overall structural strength of the piston and improving the service life. Moreover, since the cavity for realizing the switching of the gas flow direction is arranged in the same direction, that is, in the axial direction of the cylinder body, this not only enables the switching between the gas flow channels to be realized by means of the axial reciprocating movement of the piston, but also enables the movement of the piston in the opposite direction to be quickly realized and responded, thereby better improving the impact frequency of the piston, and the structure is simple and easy to realize.

[0031] The positive cycle pneumatic impactor of the present invention is disclosed in detail below with reference to the embodiments shown in the accompanying drawings and the reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The overall structural diagram of the present invention is shown.

[0033] Reference numerals

[0034] 1 cylinder body, 2 impact piston, 3 distribution pipe, 4 drill body, 5 upper joint, 6 valve body, 7 valve spring, 8 spline sleeve, 9 retaining ring, 10 limit bushing, 11 cleaning air flow transition channel.

[0035] 101 upper air cavity, 102 lower air cavity, 103 radial inner flange of the first cylinder body, 104 radial inner flange of the second cylinder body, 105 impact piston accommodating cavity, 106 scavenging air flow inlet flow passage, 107 scavenging air flow intermediate flow passage.

[0036] 201 is an upper gas distribution chamber, 202 is a lower gas distribution chamber, 203 is a radial inner flange of a first piston, 204 is a radial inner flange of a second piston, 205 is a second air flow channel, and 206 is a necking section.

[0037] 301 attachment portion, 302 pipe body portion, 303 air distribution pipe air inlet passage; 304 air distribution pipe internal passage, 305 first air flow passage, 306 first pipe body radial outer flange, 307 second pipe body radial outer flange.

[0038] 401 drill bit internal air passage.

[0039] 501 connector is the air inlet, 502 connector is the expansion cone channel. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0042] Figure 1 The overall structural diagram of the present invention is shown.

[0043] Combination Figure 1 As shown, the present invention discloses a positive cycle pneumatic impactor, comprising a cylindrical cylinder 1, an impact piston 2, a gas distribution pipe 3 and a drill body 4. In addition, it also includes an upper joint 5, an opening and closing valve, a spline sleeve 8, a retaining ring 9 and a limit bushing 10.

[0044] Its specific structure is as follows: the lower end of the cylinder body 1 is connected to the spline sleeve 8 through a thread, the spline on the drill body 4 cooperates with the spline groove on the spline sleeve 8, the retaining ring 9 is clamped in the annular groove on the upper part of the spline of the drill body 4, and is blocked on the top surface of the spline sleeve 8 to prevent the drill body 4 from falling off the spline sleeve 8. In a preferred embodiment, the retaining ring is a semicircular clamp; the limiting bushing 10 is sleeved on the upper periphery of the drill body 4, and the upper top surface of the limiting bushing 10 presses against the lower end surface of the radial inner flange of the second cylinder body 1 and the lower bottom surface presses on the retaining ring 9 to limit the retaining ring 9. The piston is arranged in the cylinder body 1 through a sliding clearance fit, and can be pushed by gas to move axially back and forth relative to the cylinder body 1 to form impact work on the drill body 4. The gas distribution pipe 3 has an attachment portion 301 and a pipe body portion 302. The attachment portion 301 is supported and arranged in the cylinder body 1 in a circumferentially sealed manner. The lower end of the pipe body portion 302 of the gas distribution pipe 3 extends into the piston. The upper joint 5 has a joint air inlet 501, and the lower part of the upper joint is expanded to form a joint expansion cone channel 502. The upper end of the pipe body portion 302 of the gas distribution pipe 3 extends into the joint expansion cone channel 502 of the upper joint 5, and an opening and closing valve is arranged at the upper part of the pipe body portion 302 of the gas distribution pipe 3. The opening and closing valve includes a valve body 6 and a valve spring 7. The valve body 6 and the valve spring 7 are arranged in sequence from top to bottom in the upper part of the pipe body portion 302 of the gas distribution pipe 3. The bottom cylinder of the valve body 6 is interference fit and embedded in the valve spring 7. The top surface of the valve body 6 has a closed state in which it is tightly engaged with the joint expansion cone channel 502, and an open state in which it is separated from the joint expansion cone channel 502.

[0045] In the present invention, an upper air chamber 101 capable of receiving gas medium is formed between the top of the piston and the attachment portion 301 of the gas distribution pipe 3 in the cylinder body 1, and a lower air chamber 102 capable of receiving gas medium is formed on the outer side of the lower portion of the piston in the cylinder body 1; the interior of the piston has an upper gas distribution chamber 201 and a lower gas distribution chamber 202 in the axial direction, the lower end of the pipe body 302 of the gas distribution pipe 3 extends into the upper gas distribution chamber 201 of the piston, and a first air flow channel 305 is provided on the extended pipe section to be constantly connected with the upper gas distribution chamber 201, and the lower gas distribution chamber 202 is constantly connected with the lower gas distribution chamber 102 of the piston. The impact piston 2 is constructed to be able to be pushed by the gas medium to axially reciprocate relative to the gas distribution pipe 3 to perform impact work on the drill bit body 4; by means of the axial reciprocating movement of the impact piston 2, the upper gas distribution chamber 201 can switch between the lower gas distribution chamber 202 and the upper gas chamber 101. The so-called switching connection means that one of the upper gas distribution chamber 201, the lower gas distribution chamber 202 and the upper gas chamber 101 is connected and disconnected from the other; when connected to the other, it is disconnected from the previous one.

[0046] The specific implementation process of switching the connection in the present invention is: in the initial state, the upper gas distribution chamber 201 and the upper gas chamber 101 remain disconnected, and the upper gas distribution chamber 201 is connected to the lower gas distribution chamber 202, so that the gas medium can enter the lower gas chamber 102, pushing the piston to produce an upward axial movement relative to the gas distribution pipe 3; with the help of the upward axial movement of the piston relative to the gas distribution pipe 3, the connection between the upper gas distribution chamber 201 and the lower gas distribution chamber 202 can be disconnected, and the upper gas distribution chamber 201 can be connected to the upper gas chamber 101, so that the gas medium can enter the upper gas chamber 101, pushing the piston to produce a downward axial movement relative to the gas distribution pipe 3.

[0047] In the present invention, the piston can be driven reciprocally by switching the upper gas distribution chamber 201 between the lower gas distribution chamber 202 and the upper gas chamber 101, which not only greatly simplifies the gas flow channel structure of the impactor, but also makes it easier to switch the flow channels between the gas flow channels for reciprocating the piston. That is, the flow channel switching and / or the switching of the reciprocating piston drive that require a complex structure in the prior art can be achieved through an extremely simple structure.

[0048] Moreover, more importantly, by configuring an upper gas distribution chamber 201 and a lower gas distribution chamber 202 in the inner cavity of the piston, and making the upper gas distribution chamber 201 switch between the lower gas distribution chamber 202 and the upper gas chamber 101 with the help of the reciprocating movement of the piston, there is no need to arrange a fluid channel on the piston as in the prior art, thereby greatly improving the overall structural strength of the piston and further increasing its service life.

[0049] In a preferred embodiment, the switching connection between the upper gas distribution chamber 201 and the lower gas distribution chamber 202 and the upper gas chamber 101 is achieved by the following structure:

[0050] A first piston radial inner flange 203 protruding radially inward is provided at a position near the top end in the inner cavity of the piston, and a first tube body radial outer flange 306 protruding radially outward is provided on the outer side of the tube body 302, and the tube body 302 extends into the upper gas distribution chamber 201 after passing through the channel of the radial inner flange; in the initial state, the first piston radial inner flange 203 and the first tube body radial outer flange 306 are in contact with each other and form a tight and / or sealed fit with each other, so that the upper gas distribution chamber 201 and the upper gas chamber 101 are kept disconnected; by means of the upward axial movement of the piston relative to the gas distribution pipe 3, the first piston radial inner flange 203 can be separated from the contact with the first tube body radial outer flange 306, so that the upper gas distribution chamber 201 and the upper gas chamber 101 are connected.

[0051] In the inner cavity of the piston, a second piston radial inner flange 204 is arranged between the upper gas distribution chamber 201 and the lower gas distribution chamber 202; below the first tube body radial outer flange 306, a second tube body radial outer flange 307 is arranged on the outer side of the tube body portion 302; in the initial state, the second piston radial inner flange 204 and the second tube body radial outer flange 307 remain disengaged, so that the upper gas distribution chamber 201 and the lower gas distribution chamber 202 remain connected; with the help of the upward axial movement of the piston relative to the gas distribution pipe 3, the second piston radial inner flange 204 can form a tight and / or sealed contact fit with the second tube body radial outer flange 307, so that the connection between the upper gas distribution chamber 201 and the lower gas distribution chamber 202 is disconnected.

[0052] Specifically, the axial position of the first air flow channel 305 is located between the first tube radial outer flange 306 and the second tube radial outer flange 307, and the radial cross-sectional outer diameter of the tube section where the first air flow channel 305 is located is smaller than the outer diameters of the first tube radial outer flange 306 and the second tube radial outer flange 307, so that the first air flow channel 305 can maintain constant communication with the upper valve distribution chamber 201 regardless of whether the first tube radial outer flange 306 is in contact with the first piston radial inner flange 203 or the second tube radial outer flange 307 is in contact with the second piston radial inner flange 204.

[0053] Preferably, the outer diameters of the first tube body radial outer flange 306 and the second tube body radial outer flange 307 are equal. Also, preferably, the outer diameter of the tube section of the tube body portion 302 of the gas distribution pipe 3 located in the upper gas cavity 101 is smaller than the outer diameters of the first tube body radial outer flange 306 and the second tube body radial outer flange 307, so that when the piston moves upward until the first piston radial inner flange 203 is separated from the first tube body radial outer flange 306, the gas distribution upper cavity 201 and the upper gas cavity 101 can be connected.

[0054] In the present invention, a second air flow channel 205 is provided on and / or near the lower end of the piston, and is used to maintain communication with the lower air cavity 102 .

[0055] The space between the upper air chamber 101 and the lower air chamber 102 is formed by the following structure: a first cylinder radial inner flange 103 and a second cylinder radial inner flange 104 protruding radially inward are provided in the cylinder body 1, the inner area of ​​the first cylinder radial inner flange 103 forms the upper air chamber 101, the lower outer side of the piston forms a tight and / or sealed fit with the second cylinder radial inner flange 104, a necking section 206 is formed near the end of the lower outer side of the piston, and the annular space between the necking section 206 and the inner wall of the second cylinder radial inner flange 104 forms the lower air chamber 102; the attachment portion 301 of the distribution pipe 3 is seated on the upper end of the inner flange of the cylinder body 1.

[0056] In a preferred embodiment, the lower portion of the piston is always held in the second cylinder radial inner flange 104. That is, when the piston generates an upward axial movement stroke, the lower portion of the piston will not escape from the second cylinder radial inner flange 104. In this case, the lower portion of the piston has a fitting section that forms a tight and / or sealed fit with the interior of the second cylinder radial inner flange 104, so that the second cylinder radial inner flange 104 can form a certain retaining and guiding effect on the axial reciprocating movement of the piston.

[0057] In the initial state, the lower air chamber 102 is formed by the outer side of the necked end of the lower part of the piston and the inner wall of the radial inner flange 104 of the second cylinder body, and the gas distribution lower chamber 202 of the piston is connected with the lower air chamber 102 by means of the second air flow channel 205. When the piston generates an upward axial movement, the lower end of the piston moves away from the upper top surface of the drill body 4, so that the distance space between the lower end of the piston and the upper top surface of the drill body 4 also forms a part of the lower air chamber 102.

[0058] In addition, in the present invention, there is also a cleaning air flow channel that forms pressure on the upper air cavity 101 by means of the upward movement of the piston, so that the bottom of the hole of the drill bit body 4 can be cleaned and slag removed, and the air outlet side of the cleaning air flow channel is kept connected with the internal air channel of the drill bit body 4; in the initial state, the air inlet side of the cleaning air flow channel is connected with the upper air cavity 101; by means of the upward axial movement of the piston relative to the gas distribution pipe 3, the connection between the air inlet side of the cleaning air flow channel and the upper air cavity 101 can be disconnected; by means of the downward axial movement of the piston relative to the gas distribution pipe 3, the air inlet side of the cleaning air flow channel and the upper air cavity 101 are reconnected.

[0059] The sweep airflow path is achieved through the following structures:

[0060] An impact piston accommodating chamber 105 is provided inside the cylinder body 1, adjacent to the upper air chamber 101. The cross-sectional inner diameter of the impact piston accommodating chamber 105 is larger than the cross-sectional inner diameter of the upper air chamber 101, so that a scavenging air flow inlet passage 106 of a scavenging air flow passage is formed between the outer wall of the piston and the cavity wall of the piston accommodating chamber; a scavenging air flow intermediate passage 107 is formed inside the wall of the cylinder body 1, which is always connected with the scavenging air flow inlet passage 106. A scavenging air flow transition passage 11 connecting the scavenging air flow intermediate passage 107 and the internal air passage of the drill body 4 is provided on the limiting bushing 10. With the help of the upward axial movement of the piston relative to the gas distribution pipe 3, when the first fluid channel is connected with the upper air chamber 101 by means of the gas distribution upper chamber 201, the upper part of the piston enters the upper air chamber 101 and forms a tight and / or sealed fit with the radial inner flange 103 of the first cylinder body, so that the connection between the intake side of the scavenging air intake channel 106 and the upper air chamber 101 is disconnected; with the help of the downward axial movement of the piston relative to the gas distribution pipe 3, when the first fluid channel is connected with the gas distribution lower chamber 202 by means of the gas distribution upper chamber 201, the upper outer side of the piston is separated from the contact with the radial inner flange 103 of the first cylinder body, so that the intake side of the scavenging air intake channel 106 and the upper air chamber 101 are connected again.

[0061] With the aid of the scavenging air flow channel of the present invention, when the piston produces an upward axial movement, the gas in the upper air chamber 101 will be compressed, thereby entering the scavenging air flow inlet channel 106, and then entering the scavenging air flow transition channel 11 through the scavenging air flow intermediate channel 107, and then entering the internal air channel of the drill bit body 4, and finally being discharged through the air outlet arranged at the lower bottom of the drill bit body 4, thereby realizing slag removal at the bottom of the hole.

[0062] Based on the above specific embodiments, the working principle of the overall structure of the present invention is as follows: in the initial state, the air compressor operates to compress the compressed air into the joint air inlet 501 of the upper joint 5, pushes the valve body 6 of the opening and closing valve, enters the internal channel of the air distribution pipe 3 through the air inlet channel of the air distribution pipe 3, and then enters the air distribution upper cavity 201 (specifically, the fluid channel gap formed by the air distribution pipe 3 and the piston) through the first air flow channel 305 on the air distribution pipe 3, and then enters the air distribution lower cavity 202 of the piston, and then enters the lower air cavity 102 of the piston through the second air flow channel 205. In the lower air chamber 102, the compressed gas pushes the piston to produce an upward axial movement; when the axial upward movement begins, the fluid in the upper air chamber 101 of the piston flows into the scavenging air inlet flow channel through the connection with the scavenging air inlet flow channel 106, and enters the drill bit body 4 through the scavenging air flow intermediate flow channel, the scavenging air flow transition channel 11, and the drill bit internal air channel 401 of the drill bit body 4. The compressed air entering the drill bit body 4 enters the bottom of the drill hole through the central exhaust hole at the bottom of the drill bit body 4 to blow away the drill cuttings, thereby achieving slag removal at the bottom of the hole. When the piston moves upward to a certain stroke, specifically when the first piston radial inner flange 203 and the first tube radial outer flange 306 are separated, the first airflow channel 305 is connected with the upper air chamber 101 by means of the gas distribution upper chamber 201. At this moment, not only the connection between the upper air chamber 101 and the purge air inlet channel 106 is disconnected, but also the connection between the gas distribution upper chamber 201 and the gas distribution lower chamber 202 is disconnected. The compressed air then passes through the internal channel of the gas distribution pipe 3, the first airflow channel 305, and the gas distribution upper chamber 201 in sequence, and enters the upper air chamber 101 to form a pressure-blocking; at this time, since the connection between the gas distribution upper chamber 201 and the gas distribution lower chamber 202 is disconnected, the pressure difference between the upper air chamber 101 and the lower air chamber 102 causes the piston to decelerate upward and accelerate downward to impact the tail of the drill bit. Repeat the above process to achieve impact drilling.

[0063] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0064] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0065] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0066] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A positive cycle pneumatic impactor, comprising a cylinder body (1) of a cylindrical structure, an impact piston (2), an air distribution pipe (3) and a drill body (4), wherein the drill body (4) is attached to the end of the cylinder body (1), the impact piston (2) is arranged in the cylinder body (1), the air distribution pipe (3) has an attachment portion (301) and a pipe body portion (302), and the attachment portion (301) is supported and arranged in the cylinder body (1) in a circumferentially sealed manner; It is characterized in that An upper air chamber (101) is formed in the cylinder body (1) between the top of the impact piston (2) and the attachment portion (301) of the gas distribution pipe (3), and a lower air chamber (102) is formed in the cylinder body (1) corresponding to the outer side of the lower portion of the impact piston (2) for receiving a gas medium; The interior of the impact piston (2) has an upper gas distribution chamber (201) and a lower gas distribution chamber (202) in the axial direction, the lower end of the pipe body (302) of the gas distribution pipe (3) extends into the upper gas distribution chamber (201), and the extending pipe section has a first air flow channel (305) which is always connected to the upper gas distribution chamber (201), and the lower gas distribution chamber (202) is always connected to the lower gas chamber (102) of the impact piston (2); The impact piston (2) can be driven by the gas medium to perform axial reciprocating movement relative to the gas distribution pipe to perform impact work on the drill bit body (4); by means of the axial reciprocating movement of the impact piston (2), the gas distribution upper chamber (201) can be switched and connected between the gas distribution lower chamber (202) and the upper gas chamber (101); The cylinder body (1) also has a purge air flow channel for removing slag from the bottom of the hole, and the air outlet side of the purge air flow channel is connected to the drill bit internal air channel (401) of the drill bit body (4); in the initial state, the air inlet side of the purge air flow channel is connected to the upper air cavity (101); An impact piston accommodating chamber (105) is provided inside the cylinder body (1) adjacent to the upper air chamber (101); the inner diameter of the cross section of the impact piston accommodating chamber (105) is larger than the inner diameter of the cross section of the upper air chamber (101), so that a scavenging air flow inlet passage (106) of a scavenging air flow passage is formed between the outer wall of the impact piston (2) and the cavity wall of the impact piston accommodating chamber (105); a scavenging air flow intermediate passage (107) is formed inside the wall of the cylinder body (1) and is always connected to the scavenging air flow inlet passage (106); When the impact piston moves upward axially, the gas in the upper air chamber (101) is compressed and enters the purge air inlet passage (106), then enters the internal air passage of the drill bit body (4) through the purge air intermediate passage (107), and finally is discharged through the air outlet provided at the bottom of the drill bit body (4), thereby achieving bottom hole slag removal; By means of the impact piston (2) continuing to move axially upward relative to the gas distribution pipe (3), the connection between the air intake side of the purge air flow channel and the upper air chamber (101) can be disconnected; by means of the impact piston (2) moving axially downward relative to the gas distribution pipe (3), the air intake side of the purge air flow channel and the upper air chamber (101) can be connected again.

2. The positive cycle pneumatic impactor according to claim 1, characterized in that: The impact piston (2) and the gas distribution pipe (3) are structured in cooperation such that, in an initial state, the gas distribution upper chamber (201) and the upper gas chamber (101) are disconnected, and the gas distribution upper chamber (201) and the gas distribution lower chamber (202) are connected, so that a gas medium can enter the lower gas chamber (102) to push the impact piston (2) to generate an axial movement upward relative to the gas distribution pipe (3); by means of the upward axial movement of the impact piston (2) relative to the gas distribution pipe (3), the connection between the gas distribution upper chamber (201) and the gas distribution lower chamber (202) can be disconnected, and the gas distribution upper chamber (201) can be connected to the upper gas chamber (101), so that a gas medium can enter the upper gas chamber (101) to push the impact piston (2) to generate an axial movement downward relative to the gas distribution pipe (3).

3. The positive cycle pneumatic impactor according to claim 2, characterized in that: A first piston radial inner flange (203) protruding radially inward is provided at a position near the top end in the inner cavity of the impact piston (2), a first tube body radial outer flange (306) protruding radially outward is provided on the outer side of the tube body (302), and the tube body (302) passes through the channel of the first piston radial inner flange (203) and then extends into the gas distribution upper cavity (201); In the initial state, the radial inner flange (203) of the first piston and the radial outer flange (306) of the first tube body are in contact with each other and form a tight and / or sealed fit with each other, so that the upper gas distribution chamber (201) and the upper gas chamber (101) are disconnected; By means of the upward axial movement of the impact piston (2) relative to the gas distribution pipe (3), the radial inner flange (203) of the first piston can be separated from the radial outer flange (306) of the first tube body, so that the gas distribution upper chamber (201) and the upper air chamber (101) are connected.

4. The positive cycle pneumatic impactor according to claim 3, characterized in that: In the inner cavity of the impact piston (2), a second piston radial inner flange (204) is provided between the gas distribution upper cavity (201) and the gas distribution lower cavity (202); below the first tube body radial outer flange (306), a second tube body radial outer flange (307) is provided on the outer side of the tube body portion (302); In the initial state, the radial inner flange (204) of the second piston and the radial outer flange (307) of the second tube body remain separated, so that the upper gas distribution chamber (201) and the lower gas distribution chamber (202) remain in communication; By means of the upward axial movement of the impact piston (2) relative to the gas distribution pipe (3), the radial inner flange (204) of the second piston can form a tight and / or sealed contact fit with the radial outer flange (307) of the second tube body, so that the connection between the gas distribution upper chamber (201) and the gas distribution lower chamber (202) is disconnected.

5. The positive cycle pneumatic impactor according to claim 4, characterized in that: A second air flow channel (205) is provided on and / or near the lower end of the impact piston (2), and is used to maintain communication with the lower air chamber (102).

6. The positive cycle pneumatic impactor according to any one of claims 1 to 5, characterized in that: A first cylinder radial inner flange (103) and a second cylinder radial inner flange (104) are provided in the cylinder (1), the inner area of ​​the first cylinder radial inner flange (103) forms the upper air chamber (101), the lower outer side of the impact piston (2) forms a tight and / or sealed fit with the second cylinder radial inner flange (104), and a necking section (206) is formed near the end of the lower outer side of the impact piston (2), and the annular space between the necking section and the inner wall of the second cylinder radial inner flange (104) forms the lower air chamber (102); The attachment portion (301) of the gas distribution pipe (3) is seated on the upper end portion of the inner flange of the cylinder body (1).

7. The positive cycle pneumatic impactor according to claim 6, characterized in that: By means of the upward axial movement of the impact piston (2) relative to the gas distribution pipe (3), when the first fluid channel is connected with the upper gas chamber (101) by means of the gas distribution upper chamber (201), the upper part of the impact piston (2) enters the upper gas chamber (101) and forms a tight and / or sealed fit with the radial inner flange (103) of the first cylinder body, so that the connection between the intake side of the scavenging air intake channel (106) and the upper gas chamber (101) is disconnected; By means of the downward axial movement of the impact piston (2) relative to the gas distribution pipe (3), when the first fluid channel is connected with the gas distribution lower chamber (202) by means of the gas distribution upper chamber (201), the upper outer side of the impact piston (2) is separated from the contact with the radial inner flange (103) of the first cylinder body, so that the intake side of the scavenging air intake channel (106) and the upper air chamber (101) are connected again.

8. The positive cycle pneumatic impactor according to claim 7, characterized in that: It also includes a spline sleeve (8). The lower end of the cylinder body (1) is connected to the spline sleeve (8) through a thread, and the splines on the drill body (4) match the spline grooves on the spline sleeve (8).

9. The positive cycle pneumatic impactor according to claim 8, characterized in that: The positive cycle pneumatic impactor also includes: The retaining ring (9) is clamped in the annular groove on the upper part of the spline of the drill body (4) and is blocked on the top surface of the spline sleeve (8).

10. The positive cycle pneumatic impactor according to claim 9, characterized in that: The positive cycle pneumatic impactor also includes: A limiting bushing (10) is sleeved on the upper periphery of the drill head body (4), the upper top surface of the limiting bushing (10) is pressed against the lower end surface of the radial inner flange (104) of the second cylinder body, and the lower bottom surface is pressed on the retaining ring (9), so as to limit the retaining ring (9); The limiting bushing (10) is provided with a purge airflow transition channel connecting the purge airflow intermediate channel (107) and the internal air passage of the drill bit body (4).

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