CN117145379B

CN117145379B - Reverse circulation impactor

Info

Publication number: CN117145379B
Application number: CN202311423058.2A
Authority: CN
Inventors: 杨日平; 朱自佳; 杨湘龙
Original assignee: Changsha Heijingang Industrial Co Ltd
Current assignee: Changsha Heijingang Industrial Co Ltd
Priority date: 2023-10-31
Filing date: 2023-10-31
Publication date: 2024-01-30
Anticipated expiration: 2043-10-31
Also published as: CN117145379A

Abstract

The application discloses a reverse circulation impactor comprising a collection tube; the air distribution rod is fixedly sleeved on the outer side of the acquisition tube; the outer cylinder is sleeved on the outer side of the air distribution rod and fixedly connected with the collecting pipe, two ends of the outer cylinder are respectively connected with the drill bit assembly and the joint assembly, and the outer cylinder, the air distribution rod, the collecting pipe, the joint assembly and the drill bit assembly form a containing cavity; the piston is movably sleeved on the outer side of the gas distribution rod, the piston divides the accommodating cavity into a first cavity and a second cavity, a gas passing channel is formed among the piston, the gas distribution rod and the collecting pipe, and the piston moves along the axial direction of the gas distribution rod so that the gas passing channel is alternately communicated with the first cavity and the second cavity; the inclined surface is arranged at one end of the piston, which is close to the drill bit assembly, and is communicated with the air passage and used for pushing the piston to move in a direction away from the drill bit assembly. Compared with the prior art, the reverse circulation impactor provided by the application does not need to be provided with the air passing groove on the end face of the drill bit, has higher strength, and prolongs the service life of the drill bit.

Description

Reverse circulation impactor

Technical Field

The present application relates to the technical field of impactors, and more particularly, to a reverse circulation impactor.

Background

With the development of industry, various infrastructure projects are continuously advancing. The down-the-hole impactor is widely used as drilling equipment for engineering construction projects such as foundation construction, water wells, mines, hydropower stations, ports, roads, tunnels and the like, and is used for cutting pile foundation holes, blastholes and the like. The down-the-hole hammer is characterized in that high-pressure water or compressed air is provided by a compressor to enter the hammer, a piston positioned in the hammer is driven to reciprocate at a high speed, the reciprocating motion of the piston strikes a drill bit once, rock breaking is realized through alloy teeth at the front end of the drill bit, and rock slag generated in the rock breaking process is discharged by the high-pressure water or the high-pressure air through a slag discharge channel of the hammer.

The commercial impactors are of two types, namely a down-the-hole positive circulation impacter, a drill rod is a single-layer pipe, high-pressure gas is blown into the impacter through the drill rod to enable a piston to move up and down to apply work, the high-pressure gas after the work flows into the bottom of a drilled hole through an inner hole airflow channel of the drill bit, rock slag is blown to the outside of the drill bit by the high-pressure gas at the bottom of the hole, then the rock slag is blown into a gap between the outer wall of the impacter and the wall of the drilled hole, and finally the rock slag is discharged out of a drilling hole; the other is a down-the-hole reverse circulation impactor, the drill rod is a double-layer pipe, high-pressure gas is blown into the impactor through the outer pipe of the drill rod, so that the piston moves up and down to apply work, the high-pressure gas after applying work is blown into the bottom of a drilled hole through the gas flow channel of the handle of the drill bit, the high-pressure gas at the bottom of the hole blows rock slag into the rock slag collecting hole in the drill bit, and then the rock slag is blown into the inner pipe of the drill rod through the collecting pipe, and finally the rock slag is collected through the dust collecting device of the drill machine.

The prior art reverse circulation impactor is shown in the attached figure 1, the prior art inner cylinder is arranged in the reverse circulation impactor to divide the cavity inside the impactor into the prior art front cavity and the prior art rear cavity, the prior art rear cavity is particularly close to one end of the prior art connector, the prior art front cavity is particularly close to one end of the prior art drill bit, the prior art piston reciprocates in the impactor, in order to facilitate the discharge of high-pressure waste gas in the prior art rear cavity, the prior art air passing groove is formed in the end face of the drill bit, the strength of the prior art drill bit is affected, and the drill bit is easily broken when the prior art piston impacts the end face of the drill bit, and the service life of the drill bit is affected.

Therefore, there is a need for a reverse circulation impactor that does not require an air passage on the end face of the drill bit, has higher strength, and extends the service life of the drill bit.

Disclosure of Invention

For solving above-mentioned technical problem, this application provides a reverse circulation impacter, need not to set up the air groove at the terminal surface of drill bit, and the intensity of drill bit is higher, has prolonged the life of drill bit.

The technical scheme provided by the application is as follows:

A reverse circulation impactor comprising:

a collection tube;

the air distribution rod is fixedly sleeved on the outer side of the acquisition tube;

the outer cylinder is sleeved on the outer side of the gas distribution rod and fixedly connected with the collecting pipe, two ends of the outer cylinder are respectively connected with the drill bit assembly and the joint assembly, and the outer cylinder, the gas distribution rod, the collecting pipe, the joint assembly and the drill bit assembly form a containing cavity;

the piston is movably sleeved on the outer side of the air distribution rod, the piston divides the accommodating cavity into a first cavity and a second cavity, an air passing channel is formed among the piston, the air distribution rod and the collecting pipe, and the piston moves along the axial direction of the air distribution rod so that the air passing channel is alternately communicated with the first cavity and the second cavity;

the inclined surface is arranged at one end of the piston, which is close to the drill bit assembly, and is communicated with the air passage and used for pushing the piston to move in a direction away from the drill bit assembly.

Preferably, the gas passing channel comprises:

the air distribution channel is arranged between the air distribution rod and the acquisition pipe;

and the gas channel is arranged in the piston and communicated with the gas distribution channel, and the piston moves along the axial direction of the gas distribution rod, so that the gas channel is alternately communicated with the first chamber and the second chamber.

Preferably, the drill bit assembly comprises:

the impact drill bit is coaxially sleeved at the front end of the collecting pipe, and an air blowing channel is arranged in the impact drill bit;

the bushing is sleeved on the outer side of the impact drill bit and fixedly connected with the inner wall of the outer cylinder, an air cavity is formed between the bushing and the outer cylinder, and a first exhaust hole which is communicated with the air cavity and the air blowing channel is formed in the bushing;

and the second exhaust hole is communicated with the air cavity, and the piston moves along the axial direction of the air distribution rod and is used for switching the second exhaust hole to be communicated with the second chamber and the first chamber alternately.

Preferably, the first section, the second section and the third section are sequentially arranged on the bushing from the joint assembly to the drill bit assembly;

the inner diameter of the first section is larger than that of the piston, the second exhaust hole is formed in the first section, the inner diameter of the second section is equal to that of the piston, the inner diameter of the third section is smaller than that of the piston, and the first exhaust hole is formed in the third section.

Preferably, the drill bit assembly further comprises:

the axial positioning step is arranged on the inner wall of the outer cylinder and is abutted with the end face of the first section, and the inner diameter of the axial positioning step is larger than the outer diameter of the piston;

And the bush O-shaped ring is arranged on the inner wall of the outer cylinder and is abutted with the end face of the third section.

Preferably, the drill bit assembly further comprises:

the drill clamping sleeve is sleeved on the outer side of the impact drill bit and fixedly connected with the front end of the outer cylinder;

the wear-resistant sleeve is sleeved on the outer side of the impact drill bit and connected with the drill clamping sleeve, and the outer diameter of the wear-resistant sleeve is not larger than the maximum outer diameter of the impact drill bit.

Preferably, an exhaust passage is provided between the outer wall of the piston and the inner wall of the outer cylinder;

when the gas channel is communicated with the second chamber, the first chamber is communicated with the second exhaust hole through an exhaust channel;

when the gas channel is communicated with the first chamber, the second chamber is communicated with the second exhaust hole.

Preferably, the exhaust passage includes:

the outer diameter of the third gas sealing section is equal to the inner diameter of the outer cylinder;

the third air passing groove is formed in the inner wall of the outer cylinder, and the outer diameter of the third air sealing section is smaller than the inner diameter of the third air passing groove.

Preferably, the gas channel includes:

a first gas sealing section, a first gas passing groove and a second gas sealing section are sequentially arranged on the inner wall of the piston from the joint assembly to the drill bit assembly;

The outside of gas distribution pole is equipped with second gas groove and bulge in proper order, the external diameter of bulge equals the internal diameter of first gas seal section, just be less than the internal diameter of first gas groove, the internal diameter of second gas groove is less than the internal diameter of first gas seal section, the internal diameter of second gas seal section equals the external diameter of gas distribution pole.

Preferably, the gas channel further comprises:

the oil groove is arranged on the inner wall of the piston and matched with the air distribution rod, and the oil groove is arranged at one end of the piston away from the joint assembly.

Preferably, the joint assembly comprises:

the connecting pipe is sleeved on the outer side of the collecting pipe, the connecting pipe is fixedly arranged between the joint and the collecting pipe, a high-pressure air passage is arranged on the connecting pipe, and the high-pressure air passage is used for communicating with the air distribution passage;

the check valve assembly is arranged between the collecting pipe and the connector and comprises a flexible piece sleeved on the outer side of the collecting pipe, the flexible piece is provided with a closed state and a separated open state which are abutted to the outlet end face of the high-pressure air passage, and the flexible piece moves along the axis direction of the collecting pipe and is used for switching the closed state and the open state.

Preferably, the check valve assembly further comprises:

the check valve body is fixedly connected with one end of the flexible piece, which is far away from the connecting pipe, and is sleeved on the outer side of the collecting pipe;

the elastic buffer piece is sleeved on the outer side of the collecting pipe, one end of the elastic buffer piece is in contact with the check valve body, and one end of the elastic buffer piece, which is far away from the check valve body, is in butt joint with the end face of the air distribution rod.

Preferably, the method further comprises:

the positioning step is arranged on the air distribution rod;

the positioning protruding block is arranged on the inner wall of the joint and matched with the positioning step for use;

and a third O-ring arranged between the positioning lug and the positioning step.

Preferably, the gas distribution channel comprises:

the air inlet is arranged on the air distribution rod and communicated with the high-pressure air channel;

the first channel is arranged between the outer side of the collecting pipe and the air distribution rod and is communicated with the air inlet;

the air outlet holes are arranged on the outer side of the air distribution rod and are used for communicating the first channel with the air channel.

The invention provides a reverse circulation impactor, which is characterized in that a collecting pipe, an air distribution rod, a piston and an outer cylinder are arranged, wherein the collecting pipe is used for collecting residues in drilling, the collecting pipe blows the residues into a drill pipe inner pipe, finally, the residues are collected through a drilling machine dust collecting device, the air distribution rod is fixedly sleeved on the outer side of the collecting pipe, the outer cylinder is sleeved on the outer side of the air distribution rod, the outer cylinder is fixedly connected with the collecting pipe, two ends of the outer cylinder are respectively connected with a joint assembly and a drill bit assembly, the outer cylinder, the air distribution rod, the collecting pipe, the joint assembly and the drill bit assembly form a containing cavity, the piston is movably sleeved on the outer side of the air distribution rod, the containing cavity is divided into a first cavity and a second cavity by the piston, the collecting pipe, the air distribution rod, the joint assembly and the outer cylinder, a second cavity by the piston, the drill bit assembly and the collecting pipe, an air passing channel is formed among the piston, the air distribution rod and the collecting pipe, and the piston are moved along the axial direction of the air distribution rod so as to be alternately communicated with the first cavity and the second cavity, thereby providing pulse acting force for the drill bit assembly. Secondly, in the initial state, the terminal surface and the drill bit subassembly butt of piston, in order to make the second cavity not damage the intensity of drill bit when with crossing the gas passageway intercommunication, still be provided with the inclined plane on the terminal surface of piston, wherein, the inclined plane sets up on the terminal surface that the piston is close to the drill bit subassembly, and inclined plane and crossing the gas passageway intercommunication, the high-pressure gas in the gas passageway acts on the inclined plane, promote the piston to move towards the direction of keeping away from the drill bit subassembly, it enters into in the second cavity to cross the gas passageway through the clearance between piston and the drill bit subassembly, through setting up the inclined plane on the terminal surface of piston, in the initial state, high-pressure gas in the gas passageway is through inclined plane promotion piston to move towards the direction of keeping away from the drill bit subassembly, in order to realize crossing gas passageway and second cavity intercommunication, so, need not to set up the gas groove on the drill bit, the working strength of drill bit is higher, the piston reciprocating motion in the outer jar, for the drill bit provides impulse effort, avoid being provided with the gas groove on the drill bit and easy rupture. Therefore, compared with the prior art, the reverse circulation impactor disclosed by the embodiment of the invention has the advantages that the air passing groove is not required to be arranged on the end face of the drill bit, the strength of the drill bit is higher, and the service life of the drill bit is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a prior art reverse circulation impactor according to an embodiment of the present invention;

FIG. 2 is a schematic view of a reverse circulation impactor according to an embodiment of the present invention;

FIG. 3 is a schematic view of a drill bit assembly according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

FIG. 5 is a schematic view of a bushing according to an embodiment of the present invention;

FIG. 6 is an enlarged view of a portion of a reverse circulation impactor provided by an embodiment of the invention;

FIG. 7 is a schematic structural diagram of a valve rod according to an embodiment of the present invention;

FIG. 8 is a schematic view of a piston according to an embodiment of the present invention;

FIG. 9 is a schematic view of an outer cylinder according to an embodiment of the present invention;

FIG. 10 is a schematic view of a joint assembly according to an embodiment of the present invention;

FIG. 11 is a schematic view of a check valve assembly according to an embodiment of the present invention;

fig. 12 is a schematic view of a structure of an operating state of a reverse circulation impactor according to an embodiment of the present invention.

Reference numerals:

prior art reference numerals: 01. an outer cylinder of the prior art; 02. a prior art drill bit assembly; 03. a prior art joint assembly; 04. an inner cylinder of the prior art; 05. a prior art piston; 06. a prior art collection tube; 07. a prior art rear chamber; 08. a prior art front chamber; 09. a gas passing groove in the prior art;

the reference numerals in this application: 1. a collection tube; 2. a joint assembly; 3. a drill bit assembly; 4. a gas distribution rod; 5. a piston; 6. an outer cylinder; 7. a first chamber; 8. a second chamber; 9. a gas channel; 21. a connecting pipe; 22. a joint; 23. a high pressure airway; 25. positioning the protruding blocks; 26. a third O-ring; 241. a flexible member; 242 a valve stop body; 243. an elastic buffer member; 31. percussion drill bits; 32. a blowing channel; 33. a bushing; 34. a first exhaust hole; 35. a second exhaust hole; 36. a bushing O-ring; 37. a drill rod clamping sleeve; 38. a wear-resistant sleeve; 39. a clasp; 311. a slag discharge port; 331. a first section; 332. a second section; 333. a third section; 41. a gas distribution channel; 42. positioning the step; 411. an air inlet; 412. a first channel; 413. an air outlet hole; 414. a first seal; 51. an inclined surface; 61. axially positioning the step; 62. an exhaust passage; 621. a third gas sealing section; 622. a third air passing groove; 91. a first gas seal section; 92. a first gas passing groove; 93. a second gas sealing section; 94. a second gas passing groove; 95. a protruding section; 96. an oil groove.

Detailed Description

In order to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" or "a number" is two or more, unless explicitly defined otherwise.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the scope of the present disclosure, since any structural modifications, proportional changes, or dimensional adjustments made by those skilled in the art should not be made in the present disclosure without affecting the efficacy or achievement of the present disclosure.

The embodiment of the invention is written in a progressive manner.

As shown in fig. 2 to 12, an embodiment of the present invention provides a reverse circulation impactor comprising: a collection tube; the air distribution rod is fixedly sleeved on the outer side of the acquisition tube; the outer cylinder is sleeved on the outer side of the air distribution rod and fixedly connected with the collecting pipe, two ends of the outer cylinder are respectively connected with the drill bit assembly and the joint assembly, and the outer cylinder, the air distribution rod, the collecting pipe, the joint assembly and the drill bit assembly form a containing cavity; the piston in the outside of gas distribution pole is established to the movable sleeve, and the piston separates into first cavity and second cavity with the holding chamber, forms the gas passage between piston, gas distribution pole and the collection pipe, and the piston is used for making the gas passage alternate with first cavity and second cavity intercommunication setting up the inclined plane that is close to the one end of drill bit subassembly at the piston along the axis direction of gas distribution pole, inclined plane and gas passage intercommunication for promote the piston to move towards the direction of keeping away from drill bit subassembly.

The prior art reverse circulation impactor as shown in fig. 1, the reverse circulation impactor comprises a prior art outer cylinder 01, the front end of the prior art outer cylinder 01 is connected with a prior art drill bit assembly 02, the rear end of the prior art outer cylinder 01 is connected with a prior art joint assembly 03, a prior art inner cylinder 04 is sleeved in the prior art outer cylinder 01, the prior art inner cylinder 04 is fixedly connected with the prior art joint assembly 03, a prior art piston 05 is movably sleeved outside a prior art collecting tube 06, a prior art piston 05 is arranged inside the prior art inner cylinder 04, a prior art rear chamber 07 is formed among the prior art joint assembly 03, the prior art inner cylinder 04, the prior art collecting tube 06 and the prior art piston 05, the prior art front chamber 08 is formed among the prior art piston 05, the prior art drill bit assembly 02 and the prior art outer cylinder 01, and in the working state, the prior art drill bit assembly 02 of the reverse circulation impactor is at the lowest, the prior art piston 05 is abutted with the end face of the prior art drill bit assembly 02 under the action of gravity, high-pressure gas in the prior art joint assembly 03 enters into the prior art front chamber 08 through a gap between the prior art inner cylinder 04 and the prior art outer cylinder 01, the prior art piston 05 is pushed to move towards the prior art joint assembly 03, and exhaust gas in the prior art rear chamber 07 is exhausted through a gap between the prior art piston 05 and the prior art collecting tube 06 and the prior art gas passing groove 09 on the prior art drill bit assembly 02. In the working process of the reverse circulation impactor, the piston 05 in the prior art reciprocates in the outer cylinder 01 in the prior art to provide pulse acting force for the end face of the drill bit, and the use intensity of the drill bit can be influenced by the arrangement of the air passing groove 09 in the prior art on the drill bit, so that the service life of the drill bit is influenced.

For convenience of understanding, the front end and the rear end in this description are expressed in terms of the direction of the impactor in the working state, where "front end" means the end of the impactor near the drill bit, and "rear end" means the end of the impactor near the joint.

In order to solve the technical problem, the reverse circulation impactor provided by the invention is provided with the collecting pipe, the gas distribution rod, the piston and the outer cylinder, wherein the collecting pipe is used for collecting residues in drilling, the collecting pipe blows the residues into the drill pipe inner pipe, finally the residues are collected through the drilling machine dust collecting device, the gas distribution rod is fixedly sleeved on the outer side of the collecting pipe, the outer cylinder is sleeved on the outer side of the gas distribution rod and is fixedly connected with the collecting pipe, two ends of the outer cylinder are respectively connected with the joint assembly and the drill bit assembly, the outer cylinder, the gas distribution rod, the collecting pipe, the joint assembly and the drill bit assembly form a containing cavity, the piston is movably sleeved on the outer side of the gas distribution rod, the containing cavity is divided into a first cavity and a second cavity by the piston, the collecting pipe, the gas distribution rod, the joint assembly and the outer cylinder, the drill bit assembly and the collecting pipe form a second cavity, the piston, the gas distribution rod and the collecting pipe form a gas passing channel, and the piston are moved along the axial direction of the gas distribution rod so as to be alternately communicated with the first cavity and the second cavity, and the piston is not required to be matched with the piston in the reverse circulation impactor, and the diameter of the drill bit is larger than the piston. Secondly, in the initial state, the terminal surface and the drill bit subassembly butt of piston, in order to make the second cavity not damage the intensity of drill bit when with crossing the gas passageway intercommunication, still be provided with the inclined plane on the terminal surface of piston, wherein, the inclined plane sets up on the terminal surface that the piston is close to the drill bit subassembly, and inclined plane and crossing the gas passageway intercommunication, the high-pressure gas in the gas passageway acts on the inclined plane, promote the piston to move towards the direction of keeping away from the drill bit subassembly, it enters into in the second cavity to cross the gas passageway through the clearance between piston and the drill bit subassembly, through setting up the inclined plane on the terminal surface of piston, in the initial state, high-pressure gas in the gas passageway is through inclined plane promotion piston to move towards the direction of keeping away from the drill bit subassembly, in order to realize crossing gas passageway and second cavity intercommunication, so, need not to set up the gas groove on the drill bit, the working strength of drill bit is higher, the piston reciprocating motion in the outer jar, for the drill bit provides impulse effort, avoid being provided with the gas groove on the drill bit and easy rupture. Therefore, compared with the prior art, the reverse circulation impactor disclosed by the embodiment of the invention has the advantages that the air passing groove is not required to be arranged on the end face of the drill bit, the strength of the drill bit is higher, and the service life of the drill bit is prolonged.

Compared with the prior art, the key point of the application is that under the initial state, how the gas in the gas passing channel enters the second cavity, in the prior art, the gas passing groove is formed in the end face of the drill bit, the gas passing groove is communicated with the second cavity, and the piston moves back and forth along the gas distribution rod at high frequency to provide pulse acting force for the drill bit, so that the drill bit is easy to break. The utility model discloses a gas pressure that the piston passes through the gas passageway, the gas that passes through the gas passageway is provided with the initial power that moves to the direction of joint assembly for the piston on the preceding terminal surface of piston sets up the inclined plane on, inclined plane and the gas passageway intercommunication that passes through, the gas in the gas passageway that passes through can enter into the second cavity through the clearance between piston and the drill bit subassembly when the piston begins to remove, so, need not to set up the gas groove on the drill bit, the intensity of drill bit is higher, on the other hand, the area of contact between preceding terminal surface of piston and the drill bit is little, the pressure to the drill bit is big under the effect of the pressure under the impact force effect is more obvious.

Further, in order to realize the communication between the high-pressure gas and the first chamber and the second chamber alternately, the air grooves are often required to be formed along the radial direction of the piston, and the air passing channels are formed among the inner wall of the piston, the air distribution rod and the outer wall of the collecting pipe, and are communicated with the first chamber and the second chamber alternately through the air passing channels, so that the air grooves do not need to be formed along the radial direction of the piston, and the strength of the piston is higher.

Specifically, in the above-described structure, as one of the embodiments of the present invention, the gas passing passage includes the gas distribution passage 41 provided between the gas distribution rod 4 and the collecting pipe 1, the gas distribution passage being for communication with the high-pressure gas, the gas passage 9 being provided in the piston 5, and the gas passage being in communication with the gas distribution passage 41, the piston 5 being moved in the axial direction of the gas distribution rod 4 so that the gas passage 9 is alternately in communication with the first chamber 7 and the second chamber 8.

In the above structure, as one of the embodiments, the drill bit assembly 3 in the present invention includes the impact drill bit 31 and the bushing 33, where the impact drill bit 31 is coaxially sleeved on the outer side of the front end of the collecting tube 1, a slag discharging channel is disposed in the collecting tube 1, a slag inlet communicating with the slag discharging channel is disposed in the impact drill bit 31, in order to ensure that the piston 5 can reciprocate in the outer cylinder 6 to discharge the generated exhaust gas, an air blowing channel 32 is further disposed in the impact drill bit 31, the exhaust gas is discharged from the air blowing channel 32, the rock slag is blown into the slag inlet and the slag discharging channel to discharge, the bushing 33 is sleeved on the outer side of the impact drill bit 31, and the bushing 33 is fixedly connected with the inner wall of the outer cylinder 6, an air cavity is formed between the bushing 33 and the outer cylinder 6, a first air outlet 34 and a second air outlet 35 are disposed on the bushing 33, the air cavity is communicated with the air cavity through the first air outlet 34, the second air outlet 35 is communicated with the air cavity, and the piston 5 moves along the axial direction of the air distribution rod 4 to switch the second air outlet 35 to alternately communicate with the first cavity 7 and the second cavity 8. In the process of reciprocating the piston 5 on the air distribution rod 4, high-pressure waste gas in the first chamber 7 and the second chamber 8 is discharged through the second air outlet 35, the air cavity, the first air outlet 34 and the air blowing channel 32, and rock slag is blown into the slag inlet and the slag discharging channel to be discharged.

In the above structure, as one embodiment, the bushing 33 in the embodiment of the present invention is sequentially provided with the first section 331, the second section 332, and the third section 333, where the first section 331, the second section 332, and the third section 333 are sequentially provided from the joint assembly 2 to the drill bit assembly 3, the inner diameter of the first section 331 is greater than the inner diameter of the piston 5, the second exhaust hole 35 is provided on the first section 331, the inner diameter of the second section 332 is equal to the diameter of the piston 5, the inner diameter of the third section 333 is equal to the inner diameter of the percussion drill bit 31, and the inner diameter of the third section 333 is smaller than the inner diameter of the second section 332, and the first exhaust hole 34 is provided on the third section 333. The front end of the piston 5 in the embodiment of the invention is limited and restrained to axially move through the second section 332, the rear end of the piston 5 is sleeved on the air distribution rod 4, and the axial displacement of the piston 5 is limited and restrained through the air distribution rod 4, so that the straightness of the movement of the piston 5 is better, the risk of air leakage and pressure relief is reduced, the pressure maintaining effect is better, and the service life of the reverse circulation impactor is longer.

Further, the bushing 33 in the embodiment of the present invention is fixed in the outer cylinder 6, and as a specific implementation manner, the reverse circulation impactor in the embodiment of the present invention further includes an axial positioning step 61 disposed on the inner wall of the outer cylinder 6 and abutting against the end surface of the first section 331, where the inner diameter of the axial positioning step 61 is larger than the outer diameter of the piston 5; a bush O-ring 36 provided on the inner wall of the outer cylinder 6 and abutting against the end face of the third section 333 fixes the bush 33 in the outer cylinder 6 by the axial positioning step 61 and the bush O-ring 36.

Further, the inner diameter of the first section 331 in the embodiment of the invention increases in a direction away from the second section 332.

In the above structure, as one of the embodiments, the drill bit assembly 3 of the present invention further includes the drill rod clamping sleeve 37 and the wear-resistant sleeve 38, wherein the drill rod clamping sleeve 37 is sleeved on the outer side of the impact drill bit 31, the drill rod clamping sleeve 37 is fixedly connected with the front end of the outer cylinder 6, the wear-resistant sleeve 38 is sleeved on the outer side of the impact drill bit 31, and the wear-resistant sleeve 38 is fixedly connected with the drill rod clamping sleeve 37, and the outer diameter of the wear-resistant sleeve 38 is not greater than the maximum outer diameter of the impact drill bit 31, and the wear-resistant sleeve 38 is arranged on the outer side of the impact drill bit 31, so that frictional wear of the outer surface of the impact drill bit 31 is avoided, and the service life of the impact drill bit 31 is influenced.

In the above structure, as one implementation manner, the wear-resistant sleeve 38 and the drill sleeve 37 in the embodiment of the present invention are specifically detachably connected. Further, as a specific implementation manner, the wear-resistant sleeve 38 in the embodiment of the invention is sleeved on the outer side of the drill rod clamping sleeve 37, the outer surface of the drill rod clamping sleeve 37 is provided with a first step surface, the inner wall of the wear-resistant sleeve 38 is provided with a second step surface which is in contact with the first step surface, during the installation process, the drill bit is sleeved in the drill rod clamping sleeve 37, the wear-resistant sleeve 38 is arranged on the outer side of the drill rod clamping sleeve 37 so that the second step surface is in contact with the first step surface, the drill rod clamping sleeve 37 is fixed in the outer cylinder 6, and the end surface of the outer cylinder 6 is in contact with the wear-resistant sleeve 38 so as to fix the wear-resistant sleeve 38.

In the above-described structure, as one embodiment, a snap ring 39 is provided on the inner wall of the outer cylinder 6 in the example of the present invention, wherein the snap ring is provided between the bush O-ring 36 and the click sleeve 37, and the impact bit 31 is positioned by the snap ring 39.

In the above-described structure, as one of the embodiments, an exhaust passage 62 is provided between the outer wall of the piston 5 and the inner wall of the outer cylinder 6 of the reverse circulation impactor in the example of the invention, wherein when the gas passage 9 communicates with the second chamber 8, the first chamber 7 communicates with the second exhaust hole 35 through the exhaust passage 62, and when the gas passage 9 communicates with the first chamber 7, the second chamber 8 communicates with the second exhaust hole 35. In the embodiment of the invention, the gas distribution rod 4 is arranged, the gas distribution channel 41 is arranged between the gas distribution rod 4 and the collecting pipe 1, the piston 5 is slidably sleeved outside the gas distribution rod 4, the gas channel 9 is arranged between the piston 5 and the gas distribution rod 4, in an initial state, high-pressure gas in the gas channel 9 pushes the piston 5 to move in a direction far away from the drill bit assembly 3 through the inclined surface 51, the high-pressure gas in the gas channel 9 enters the second chamber 8 through a gap between the piston 5 and the drill bit assembly 3, exhaust gas in the first chamber 7 is exhausted through the exhaust channel 62, the second exhaust hole 35, the air cavity, the first exhaust hole 34 and the air blowing channel 32, when the piston 5 moves to a preset position, the gas channel 9 is communicated with the first chamber 7, the high-pressure gas in the gas channel 9 enters the first chamber 7, the piston 5 is pushed to move in a direction of the drill bit assembly 3, and the high-pressure exhaust gas in the second chamber 8 is directly exhausted through the second exhaust hole 35, the air cavity, the first exhaust hole 34 and the air blowing channel 32.

In the above-described structure, as one of the embodiments, the exhaust passage 62 of the present embodiment includes the third gas seal segment 621 and the third gas passing groove 622, wherein the third gas seal segment 621 is provided on the outer wall of the piston 5, the outer diameter of the third gas seal segment 621 is equal to the outer diameter of the outer cylinder 6, the third gas passing groove 622 is provided on the inner wall of the outer cylinder 6, the inner diameter of the third gas passing groove 622 is larger than the outer diameter of the third gas seal segment 621, the third gas passing groove 622 is provided on the outer side of the third gas seal segment 621 when the piston 5 moves to the gas passage 9 to communicate with the second chamber 8, the first chamber 7 communicates with the second exhaust hole 35, the third gas seal segment 621 is provided in a staggered manner with the third gas passing groove 622 when the piston 5 moves to the gas passage 9 to communicate with the first chamber 7, the first chamber 7 is isolated from the second exhaust hole 35, and the second chamber 8 communicates with the second exhaust hole 35.

In the above structure, in the reverse circulation impactor provided by the embodiment of the invention, since the inner cylinder is not arranged, the piston 5 is sleeved on the air distribution rod 4 to move, the size of the piston 5 is larger, and the strength of the piston 5 is higher.

Further, as one of the implementation manners, the gas channel 9 in the embodiment of the present invention includes a first gas sealing section 91, a first gas passing groove 92 and a second gas sealing section 93, where the first gas sealing section 91, the first gas passing groove 92 and the second gas sealing section 93 are sequentially arranged from the joint component 2 to the drill bit component 3, and are all arranged on the inner wall of the piston 5, the outer side of the gas distribution rod 4 is sequentially provided with a second gas passing groove 94 and a protruding section 95, where the outer diameter of the protruding section 95 is equal to the inner diameter of the first gas sealing section 91 and smaller than the inner diameter of the first gas passing groove 92, the inner diameter of the second gas sealing section 93 is equal to the outer diameter of the gas distribution rod 4, the outer diameter of the second gas passing groove 94 is smaller than the outer diameter of the gas distribution rod 4, the gas outlet 413 is arranged in the first gas passing groove 92, when the piston 5 moves to the first gas sealing section 91 and the protruding section 95, the second gas sealing section 93 and the gas distribution rod 4 are alternately arranged, the high-pressure gas in the first gas passing groove 92 passes through the second gas sealing section and the second gas sealing section 1 and the gas distribution rod 4 to push the gas outlet hole 34 to the second gas outlet hole 35, and the gas outlet hole 34 to the gas outlet hole 35 from the gas outlet hole 35 to the gas outlet chamber 3; when the piston 5 moves to the second air sealing section 93 to be matched with the air distribution rod 4, the first air passing groove 92 is arranged on the outer side of the protruding section 95, the first air sealing section 91 is arranged on the outer side of the second air passing groove 94, high-pressure air entering through the air outlet 413 enters into the first chamber 7, the piston 5 is pushed to move towards the direction of the drill bit assembly 3, and waste gas in the second chamber 8 is directly discharged through the second air outlet 35.

Further, as one of the embodiments, the gas channel 9 further includes an oil groove 96, where the oil groove 96 is disposed on the inner wall of the piston 5, and the oil groove 96 is used in cooperation with the gas distribution rod 4, and the sealing effect between the piston 5 and the gas distribution rod 4 is achieved through the oil groove 96, and the oil groove 96 is disposed at an end of the piston 5 away from the gas distribution rod 4.

Further, as one embodiment, at least two oil grooves 96 are provided and are spaced along the axial direction of the piston 5, so that the sealing effect is better, but in order to ensure the use strength of the piston 5, the number of oil grooves 96 is not too large, and in this embodiment, two oil grooves 96 are preferably provided.

The embodiment of the invention provides a joint assembly 2, which comprises: the connecting pipe 21 is sleeved on the outer side of the collecting pipe 1, the connecting pipe 21 is fixedly arranged between the joint 22 and the collecting pipe 1, a high-pressure air passage 23 is arranged on the connecting pipe 21, and the high-pressure air passage 23 is arranged on the outer side of the collecting pipe 1; the check valve assembly is arranged between the collecting pipe 1 and the joint 22, and comprises a flexible piece 241 sleeved on the outer side of the collecting pipe 1, wherein the flexible piece 241 is provided with a closed state and a separated open state which are abutted against the outlet end face of the high-pressure gas channel 23, and the flexible piece 241 moves along the axial direction of the collecting pipe 1 so as to switch the closed state and the open state.

The high-pressure gas channel in the embodiment of the invention refers to a gas channel through which compressed gas passes. Specifically, the high-pressure air channel 23 in the embodiment of the invention is arranged on the connecting pipe 21, the high-pressure air channel extends along the axial direction of the connecting pipe 21, when the drill rod is arranged in the joint 22, the outer pipe of the drill rod is communicated with the high-pressure air channel 23, and compressed air in the outer pipe of the drill rod can flush the check valve assembly through the high-pressure air channel 23, so that the compressed air enters the impactor.

The end surface of the check valve structure in the prior art, which is in contact with the connecting pipe 21, is a rigid surface, so that when the check valve structure closes the high-pressure air passage 23, the sealing performance is poor, stratum fluid cannot be effectively prevented from entering the impactor, and the service life of the impactor is prolonged.

The joint assembly 2 provided by the invention is provided with the connecting pipe 21, the collecting pipe 1 and the check valve assembly, wherein the connecting pipe 21 is sleeved on the outer side of the collecting pipe 1, the connecting pipe 21 is fixedly arranged between the collecting pipe 1 and the joint 22, the connecting pipe 21 is provided with the high-pressure air passage 23, the high-pressure air passage is arranged on the outer side of the collecting pipe 1, high-pressure air in the outer pipe of the drill rod can enter the impactor through the high-pressure air passage 23, and the check valve assembly is arranged between the collecting pipe 1 and the joint 22 and is used for opening and closing the high-pressure air passage 23. The check valve in the prior art is made of rigid materials, the end face of the check valve is poor in tightness against the outlet end of the high-pressure air channel 23, the check valve assembly provided by the invention comprises the flexible piece 241, the flexible piece 241 is sleeved on the outer side of the collecting pipe 1, the flexible piece 241 is provided with a closed state in butt joint with the outlet end of the high-pressure air channel 23 and an open state separated from the high-pressure air channel 23, the flexible piece 241 can move along the axial direction of the collecting pipe 1 and is used for switching the closed state and the open state, and the flexible piece 241 is in butt joint with the outlet end of the high-pressure air channel 23, so that the sealing is more reliable. Therefore, compared with the prior art, the joint component 2 in the embodiment of the invention has better sealing performance, high stability and long service life of the reverse circulation impactor.

In the above-described structure, as one of the embodiments, the high-pressure air passages 23 in the embodiment of the present invention are provided at least two, and the high-pressure air passages 23 are provided at regular intervals around the circumference of the connection pipe 21.

More specifically, the high-pressure air passages 23 in the embodiment of the invention are provided specifically with 3 to 8.

In the above-described structure, as one of the embodiments, the surface of the flexible member 241 contacting the outlet end face of the high-pressure gas passage 23 in the embodiment of the present invention is specifically a planar surface.

In the above structure, as one of the embodiments of the present invention, the check valve assembly further includes a check valve body 242 and an elastic buffer member 243, wherein, one end of the flexible member 241 away from the connecting pipe 21 is fixedly connected with the check valve body 242, the check valve body 242 is sleeved outside the collecting pipe 1, the elastic buffer member 243 is sleeved outside the collecting pipe 1, one end of the elastic buffer member 243 is abutted with an end surface of the check valve body 242 away from the flexible member 241, and one end of the elastic buffer member 243 away from the check valve body 242 is abutted with the air distribution rod 4. In the initial state, the high-pressure air channel 23 is not communicated with high-pressure air, at this time, the elastic buffer member 243 is in a compressed state, and the elastic restoring force of the elastic buffer member 243 acts on the check valve body 242, so that the end surface of the flexible member 241 is tightly abutted against the outlet end of the high-pressure air channel 23, and the sealing effect is better. When the high-pressure air channel 23 is communicated with high-pressure air, under the action of the high-pressure air, the flexible piece 241 is pushed to move along the axial direction of the collecting tube 1, the elastic buffer piece 243 is further compressed, the flexible piece 241 is separated from the connecting tube 21, the high-pressure air channel 23 is opened, and the high-pressure air enters the impactor.

Still further, the elastic buffer 243 in the embodiment of the present invention is embodied as a spring.

In the above-described structure, the end of the flexible member 241 remote from the connection pipe 21 in the embodiment of the present invention is fixedly connected to the check valve body 242.

Furthermore, in order to make the connection between the flexible member 241 and the check valve body 242 tighter, to avoid the detachment of the flexible member 241 from the check valve body 242, as one preferred embodiment, one end of the flexible member 241, far away from the connecting tube 21, is sleeved in the check valve body 242, thus increasing the area between the flexible member 241 and the check valve body 242, and further, a first step is provided on the flexible member 241, a second step matched with the first step is provided in the check valve body 242, and the first step abuts against the second step, so as to further avoid the detachment of the flexible member 241 and the check valve body 242.

Further, the flexible member 241 in the embodiment of the present invention is made of a rubber material, and the check valve body 242 is made of a steel material.

Further, the flexible member 241 and the check valve body 242 are formed integrally. More specifically, the flexible member 241 and the check valve body 242 in the embodiment of the present invention are formed by injection molding.

Still further, the joint assembly 2 in the embodiment of the present invention further includes a positioning groove, where the positioning groove is disposed at one end of the check valve body 242 away from the flexible member 241, the positioning groove extends along the axial direction of the collecting tube 1, one end of the elastic buffer member 243 is inserted into the positioning groove, and the end surface of the elastic buffer member 243 contacts with the bottom of the positioning groove, and the deformation direction of the elastic buffer member 243 is limited by the inner wall of the positioning groove, so that the situation that the elastic buffer member 243 is deflected during the resetting deformation is avoided, the flexible member 241 cannot be restored to the original position easily, the tightness of the high-pressure air channel 23 is poor, and the service life of the high-pressure air channel 23 is seriously affected.

In the above structure, the flexible member 241 is easy to wear in the process of reciprocating movement and needs to replace the check valve, and as one implementation manner, the joint assembly 2 in the embodiment of the invention further comprises a positioning surface, wherein the positioning surface is arranged on the inner wall of the joint 22, the front end surface of the connecting pipe 21 is abutted through the positioning surface, the rear end surface of the connecting pipe 21 is positioned through the clamping spring, the rear end surface of the connecting pipe 21 is abutted with the clamping spring, the connecting pipe 21 is fixed in the joint 22 through the clamping spring and the positioning surface, the clamping spring is detachably arranged on the inner wall of the joint 22, when the check valve assembly needs to be replaced, the clamping spring is detached from the joint 22, the check valve assembly does not need to be replaced from the rear end surface of the joint 22, and the whole impactor is more convenient to maintain.

More specifically, an installation groove for installing a clamp spring is formed in the inner wall of the joint 22 in the embodiment of the invention, the clamp spring is in an open annular structure, the clamp spring is made of spring steel, the clamp spring is convenient to dismantle from the installation groove, and when the clamp spring is installed in the installation groove, the size of an inner hole of the clamp spring is smaller than the outer diameter of the connecting pipe 21, so that the end face of the connecting pipe 21 is positioned through the clamp spring.

Furthermore, in the above structure, as one of the embodiments, the connector assembly 2 further includes a first O-ring, wherein the connection pipe 21 and the collection pipe 1, and the connection pipe 21 and the connector 22 are all connected in a sealing manner by the first O-ring, so that the replacement of the check valve assembly is more convenient, and the sealing effect is good.

In the above structure, as a specific implementation manner, the joint assembly 2 in the embodiment of the present invention further includes a fourth O-ring, where the fourth O-ring is disposed at an end of the connection pipe 21 away from the check valve assembly, and the connection pipe 21 is connected with the drill pipe in a sealing manner through the fourth O-ring.

In the above structure, as one of the embodiments, the positioning step 42 is provided on the gas distribution rod 4 in the embodiment of the present invention, the positioning protrusion 25 used for gas distribution with the positioning step 42 is provided on the inner wall of the joint 22, and the axial displacement of the gas distribution rod 4 is limited by the cooperation between the positioning step 42 and the positioning protrusion 25.

In order to adjust the assembly gap between the connector 22 and the valve rod 4 and avoid the valve rod 4 from moving, as one implementation manner, a third O-ring 26 is disposed between the positioning protrusion 25 and the positioning step 42 in the embodiment of the present invention.

In the above structure, as one of the embodiments of the present invention, a specific structure of the gas distribution channel 41 is provided, where the gas distribution channel 41 in the embodiment of the present invention includes the gas inlet 411, the first channel 412 and the gas outlet 413, the gas inlet 411 is disposed on the gas distribution rod 4, and the gas inlet 411 is communicated with the joint assembly 2, the first channel 412 is disposed between the gas distribution rod 4 and the collecting tube 1, and the first channel 412 is communicated with the gas inlet 411, the gas outlet 413 is disposed on the outer side of the gas distribution rod 4, and the gas outlet 413 is used for communicating the first channel 412 and the gas channel 9, the high-pressure gas in the outer tube of the drill rod enters the gas channel 9 through the joint assembly 2, the first channel 412 and the gas outlet 413, and the gas channel 9 is alternately communicated with the first chamber 7 and the second chamber 8 as the piston 5 reciprocates along the axial direction of the gas distribution rod 4.

In the above structure, as one embodiment, the plurality of air outlet holes 413 in the embodiment of the present invention form an air outlet hole group, and the air outlet holes 413 in one air outlet hole group are spaced around the axis direction of the air distribution rod 4.

The air outlet hole groups are at least provided with one group, and further, when the air outlet hole groups are at least provided with two groups, the air outlet hole groups are arranged at intervals along the axis direction of the air distribution rod 4, and more specifically, the air outlet hole groups in the embodiment of the invention are provided with two groups.

Further, the outer side of the collecting tube 1 in the embodiment of the present invention is provided with a groove, and the first channel 412 is specifically formed by the groove and the inner wall of the gas distribution rod 4.

Furthermore, in order to avoid leakage of the high-pressure gas in the first channel 412, as one embodiment, the reverse circulation impactor according to the embodiment of the invention further includes a first sealing member 414, where the first sealing member 414 is disposed on the outer side of the collecting tube 1, and the collecting tube 1 is connected with the gas distribution rod 4 in a sealing manner through the first sealing member 414.

Further, as one implementation, the first seal 414 in the present embodiment is embodied as a collection tube O-ring. Wherein, gather pipe O shape circle setting is kept away from the one end of joint assembly 2 at gas distribution pole 4.

As shown in fig. 12, the motion process of the reverse circulation impactor provided by the invention is specifically as follows:

as shown in fig. 12 (a), in the reverse circulation impactor, under the action of gravity, the front end surface of the piston 5 contacts the drill bit assembly 3, high pressure gas enters the impactor from the joint assembly 2 and enters the gas channel 9 through the gas distribution channel 41, and in the prior art, in order to allow the high pressure gas in the gas channel 9 to enter the second chamber, a means of forming a gas passing groove in the drill bit is adopted, but the gas passing groove affects the strength of the drill bit, and the drill bit is easy to break. In order to avoid the problem, the inclined surface 51 is arranged on the front end surface of the piston 5, the front end surface part of the piston is in contact with the drill bit assembly 3, the front end surface part of the piston is communicated with the gas channel, high-pressure gas acts on the inclined surface of the piston 5 to provide acting force to the direction of the joint assembly for the piston 5, the first chamber 7 is communicated with the atmosphere outside the impactor, and air pressure differences exist at two ends of the piston 5, so that the piston 5 is pushed to move towards the direction of the joint assembly 2 under the action of the air pressure differences.

As shown in fig. 12 (b), after the piston moves toward the joint assembly, the gas passage 9 communicates with the second chamber 8, high-pressure gas enters the impactor from the joint assembly 2, enters the second chamber 8 via the gas distribution passage 41 and the gas passage, and a gas pressure difference exists between the second chamber and the first chamber, so that the piston continues to move toward the mechanism assembly, and the exhaust gas of the first chamber 7 is discharged through the exhaust passage 62 and the air blowing passage 32.

As shown in fig. 12 (c), when the piston moves up to the first limit position toward the joint assembly, the gas passage 9 starts to communicate with the first chamber 7, the first chamber 7 is isolated from the gas blowing passage 32, the gas passage 9 is isolated from the second chamber 8, the second chamber 8 is communicated with the gas blowing passage 32, the high-pressure gas is communicated with the second chamber 8 through the gas passage 9, and the exhaust gas in the first chamber 7 is discharged through the gas blowing passage 32.

As shown in fig. 12 (d), the high-pressure gas enters the first chamber through the joint assembly and the gas channel, the gas pressure in the first chamber is greater than the gas pressure in the second chamber, and the gas pressure difference pushes the piston 5 to move towards the drill bit assembly 3 due to the gas difference between the first chamber 7 and the second chamber 8, so that the high-pressure waste gas in the second chamber 8 is discharged through the gas blowing channel 32.

As shown in fig. 12 (e), the piston 5 continues to move toward the drill bit assembly 3 until the piston 5 contacts the end surface of the drill bit assembly 3, and returns to the initial state.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 reverse circulation impactor comprising:

a collection tube (1);

the air distribution rod (4) is fixedly sleeved on the outer side of the acquisition tube (1);

the outer cylinder (6) is sleeved on the outer side of the air distribution rod (4) and fixedly connected with the collecting pipe (1), two ends of the outer cylinder (6) are respectively connected with the drill bit assembly (3) and the joint assembly (2), and the outer cylinder (6), the air distribution rod (4), the collecting pipe (1), the joint assembly (2) and the drill bit assembly (3) form a containing cavity;

The piston (5) is movably sleeved on the outer side of the air distribution rod (4), the accommodating cavity is divided into a first cavity (7) and a second cavity (8) by the piston (5), an air passage is formed among the piston (5), the air distribution rod (4) and the collecting pipe (1), and the piston (5) moves along the axial direction of the air distribution rod (4) so that the air passage is alternately communicated with the first cavity (7) and the second cavity (8);

and the inclined surface (51) is arranged at one end, close to the drill bit assembly (3), of the piston (5), and the inclined surface (51) is communicated with the overair channel and is used for pushing the piston (5) to move in a direction away from the drill bit assembly (3).

2. The reverse circulation impactor of claim 1, wherein,

the overgas passage comprises:

a gas distribution channel (41) arranged between the gas distribution rod (4) and the collecting pipe (1);

and a gas passage (9) arranged in the piston (5) and communicated with the gas distribution passage (41), wherein the piston (5) moves along the axial direction of the gas distribution rod (4) so that the gas passage (9) is communicated with the first chamber (7) and the second chamber (8) alternately.

3. The reverse circulation impactor of claim 2, wherein,

the drill bit assembly (3) comprises:

the impact drill bit (31) is coaxially sleeved at the front end of the collecting tube (1), and an air blowing channel (32) is arranged in the impact drill bit (31);

the bushing (33) is sleeved on the outer side of the impact drill bit (31) and fixedly connected with the inner wall of the outer cylinder (6), an air cavity is formed between the bushing (33) and the outer cylinder (6), and a first exhaust hole (34) which is communicated with the air cavity and the air blowing channel (32) is formed in the bushing (33);

and the second exhaust hole (35) is communicated with the air cavity, and the piston (5) moves along the axial direction of the air distribution rod (4) so as to switch the second exhaust hole (35) to be communicated with the second chamber (8) and the first chamber (7) alternately.

4. The reverse circulation impactor of claim 3, wherein,

a first section (331), a second section (332) and a third section (333) which are sequentially arranged on the bushing (33) from the joint assembly (2) to the drill bit assembly (3);

wherein,

the inner diameter of the first section (331) is larger than that of the piston (5), the second exhaust hole (35) is formed in the first section (331), the inner diameter of the second section (332) is equal to that of the piston (5), the inner diameter of the third section (333) is smaller than that of the piston (5), and the first exhaust hole (34) is formed in the third section (333).

5. The reverse circulation impactor of claim 4, wherein,

the drill bit assembly (3) further comprises:

an axial positioning step (61) provided on the inner wall of the outer cylinder (6) and abutting against the end face of the first section (331), the inner diameter of the axial positioning step (61) being larger than the outer diameter of the piston (5);

and a bush O-ring (36) provided on the inner wall of the outer cylinder (6) and abutting against the end surface of the third section (333).

6. The reverse circulation impactor of claim 5, wherein,

the drill bit assembly (3) further comprises:

a drill clamping sleeve (37) sleeved on the outer side of the impact drill (31) and fixedly connected with the front end of the outer cylinder (6);

and the wear-resistant sleeve (38) is sleeved on the outer side of the impact drill bit (31) and connected with the drill clamping sleeve (37), and the outer diameter of the wear-resistant sleeve (38) is not larger than the maximum outer diameter of the impact drill bit (31).

7. The reverse circulation impactor of claim 3, wherein,

an exhaust passage (62) is arranged between the outer wall of the piston (5) and the inner wall of the outer cylinder (6);

when the gas channel (9) is communicated with the second chamber (8), the first chamber (7) is communicated with the second exhaust hole (35) through an exhaust channel;

When the gas channel (9) is communicated with the first chamber (7), the second chamber (8) is communicated with the second exhaust hole (35).

8. The reverse circulation impactor of claim 7, wherein,

the exhaust passage (62) includes:

a third gas-sealing section (621) provided on the outer wall of the piston (5), the outer diameter of the third gas-sealing section (621) being equal to the inner diameter of the outer cylinder (6);

and a third air passing groove (622) arranged on the inner wall of the outer cylinder (6), wherein the outer diameter of the third air sealing section (621) is smaller than the inner diameter of the third air passing groove (622).

9. The reverse circulation impactor of any one of claims 2 to 8,

the gas channel (9) comprises:

a first gas sealing section (91), a first gas passing groove (92) and a second gas sealing section (93) are sequentially arranged on the inner wall of the piston (5) from the joint assembly (2) to the drill bit assembly (3);

the outside of gas distribution pole (4) is equipped with second air groove (94) and salient section (95) in proper order, the external diameter of salient section (95) equals the internal diameter of first gas seal section (91), and be less than the internal diameter of first air groove (92), the internal diameter of second air groove (94) is less than the internal diameter of first gas seal section (91), the internal diameter of second gas seal section (93) equals the external diameter of gas distribution pole (4).

10. The reverse circulation impactor of claim 9, wherein the reverse circulation impactor is configured to receive the reverse circulation flow,

the gas channel (9) further comprises:

the oil groove (96) is formed in the inner wall of the piston (5) and matched with the air distribution rod (4), and the oil groove (96) is formed in one end, far away from the joint assembly (2), of the piston (5).

11. The reverse circulation impactor of any one of claims 2 to 8,

the joint assembly (2) comprises:

the connecting pipe (21) is sleeved on the outer side of the collecting pipe (1), the connecting pipe (21) is fixedly arranged between the joint (22) and the collecting pipe (1), a high-pressure air channel (23) is arranged on the connecting pipe (21), and the high-pressure air channel (23) is used for being communicated with the air distribution channel (41);

the check valve assembly is arranged between the collecting pipe (1) and the joint (22), the check valve assembly comprises a flexible piece (241) sleeved on the outer side of the collecting pipe (1), the flexible piece (241) is provided with a closed state and a separated open state which are abutted to the outlet end face of the high-pressure air passage (23), and the flexible piece (241) moves along the axis direction of the collecting pipe (1) and is used for switching the closed state and the open state.

12. The reverse circulation impactor of claim 11, wherein the reverse circulation impactor is configured to receive the reverse circulation flow,

the check valve assembly further comprises:

a check valve body (242) fixedly connected with one end of the flexible piece (241) far away from the connecting pipe (21), wherein the check valve body (242) is sleeved on the outer side of the collecting pipe (1);

and an elastic buffer member (243) sleeved on the outer side of the collecting pipe (1), one end of the elastic buffer member (243) is in contact with the check valve body (242), and one end of the elastic buffer member (243) away from the check valve body (242) is in butt joint with the end face of the air distribution rod (4).

13. The reverse circulation impactor of claim 12, wherein the reverse circulation impactor is configured to receive the reverse circulation flow,

further comprises:

a positioning step (42) arranged on the air distribution rod (4);

the positioning protruding block (25) is arranged on the inner wall of the joint (22) and matched with the positioning step (42);

and a third O-ring (26) arranged between the positioning lug (25) and the positioning step (42).

14. The reverse circulation impactor of claim 13, wherein the reverse circulation impactor is configured to receive the reverse circulation flow,

the gas distribution channel (41) comprises:

An air inlet (411) arranged on the air distribution rod (4) and communicated with the high-pressure air channel (23);

a first channel (412) arranged between the outside of the collection tube (1) and the air distribution rod (4) and communicated with the air inlet (411);

and the air outlet hole (413) is arranged at the outer side of the air distribution rod (4) and used for communicating the first channel (412) and the air channel (9).