Positive cycle hydraulic impactor

Abstract

The present invention relates to the technical field of drilling impactors, and in particular to a positive circulation hydraulic impactor, wherein a valve member is provided on the upper body of the inner cylinder thereof, and is configured to be driven to perform vertical linear sliding based on the hydraulic pressure difference generated on the valve member itself, so as to cut off and open the connection between the liquid inlet flow path on the piston and the liquid inlet main flow channel, thereby realizing the axial movement of the impact piston. Since the valve member is switched in a linear sliding motion mode, this can be realized based on the pressure difference at both ends of the valve member of the hydraulic impactor, which solves the problem of rapid wear caused by the hydraulic pressure difference at both ends of the valve core of the central rotary valve hydraulic impactor, and significantly prolongs the service life of the impactor.

Description

Technical Field

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

[0002] The core tool of hydraulic impact rotary drilling technology is hydraulic down-the-hole hammer, also known as hydraulic impactor. This technology has the advantages of long drilling footage, long drill bit life, good drilling quality, few accidents in the hole, and wide application range. However, compared with air down-the-hole hammer rotary drilling technology, the impact frequency and average drilling speed of hydraulic impactor are still slightly insufficient.

[0003] In the prior art, patent CN113585960A, named center rotary valve type hydraulic impactor, adopts a center rotary valve structure to realize high-frequency and high-speed movement of the hydraulic impactor piston. However, because the upper and lower cavities of the center rotary valve are respectively located at the high-pressure end and the low-pressure end, the center rotary valve is subjected to unbalanced pressure. After a period of use, the rear end surface of the center rotary valve will be severely worn, resulting in jamming of its rotation action and discontinuous impact, resulting in a short service life, which still cannot meet engineering requirements.

[0004] Therefore, it is necessary to design a new type of hydraulic impactor, which can effectively solve the above-mentioned problems existing in the center rotary valve type hydraulic impactor. Summary of the invention

[0005] In view of this, the present invention provides a high-energy high-frequency impactor based on valve control, which uses high-pressure water as the pressure medium to provide a technical solution for efficient drilling of hard rock to solve the technical problems mentioned above.

[0006] The present invention discloses a positive circulation hydraulic impactor, comprising an outer cylinder and an impact piston arranged in the outer cylinder, and also comprising an inner cylinder, which is axially positioned and arranged inside the outer cylinder. The impact piston can be operated to perform axial reciprocating motion relative to the outer cylinder and the inner cylinder based on the fluid hydraulic pressure difference. The impact piston is at least partially located in the inner cylinder. The inner cylinder comprises an upper body and a lower body axially abutting with the upper body. The upper piston section of the impact piston is received in the piston receiving cavity of the upper body, and the space between the upper end of the impact piston and the bottom of the piston receiving cavity forms an upper piston liquid cavity; a lower piston liquid cavity is formed between the lower piston section of the impact piston close to the bottom of the inner cylinder and the inner wall of the lower body. The upper body is provided with an upper liquid inlet path for piston and a lower liquid inlet path for piston, the upper liquid inlet path for piston is always connected with the upper liquid chamber for piston, so as to introduce the fluid into the upper liquid chamber for piston; the lower liquid inlet path for piston is always connected with the lower liquid chamber for piston, so as to introduce the fluid into the lower liquid chamber for piston; a main liquid inlet channel is provided between the outer wall of the upper body and the inner wall of the outer cylinder, wherein the lower liquid inlet path for piston is always connected with the main liquid inlet channel; a valve member is also provided on the upper body, which is constructed to be driven to perform vertical linear sliding relative to the upper body based on the hydraulic pressure difference generated on itself, so as to cut off and open the connection between the upper liquid inlet path for piston and the main liquid inlet channel.

[0007] In the present invention, the so-called "up" and "down" are relative based on the drilling direction of the drill bit body, that is, relatively speaking, the position toward or close to the drilling direction of the drill bit body can be designated as down, and the position away from or away from the drilling direction of the drill bit body can be designated as up.

[0008] Since the valve member is constructed to be able to produce linear sliding based on the axial movement of the impact piston, this can be achieved by means of the hydraulic pressure difference that is inevitably formed during the operation of the hydraulic impactor. This solves the problem of rapid wear caused by the hydraulic pressure difference at both ends of the valve core that the central rotary valve hydraulic impactor is not adapted to, and significantly prolongs the service life of the impactor.

[0009] According to the positive cycle hydraulic impactor of the present invention, in the initial state of the impactor, the valve member is located at its initial position, at which time the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel is cut off, and in the process where the valve member is driven to perform a vertical downward linear sliding relative to the upper body based on the hydraulic pressure difference generated on itself, the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel can be opened.

[0010] That is, the valve member has an initial position and a connecting position, wherein the initial position is the position of the valve member in the initial state of the impactor, in which the valve member cuts off the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel; the other connecting position is located below the initial position, and the valve member can be driven to move downward based on the hydraulic pressure difference, thereby moving from the initial position to the connecting position; when the valve member moves to the connecting position, it can open the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel, so that the high-pressure liquid fluid can enter the liquid inlet flow path on the piston from the main liquid inlet flow channel, and thus enter the liquid chamber on the piston.

[0011] According to the positive circulation hydraulic impactor of the present invention, an upper valve liquid chamber, a lower valve liquid chamber, a lower valve liquid inlet channel and an upper valve liquid inlet channel are also provided on the upper body, wherein the lower valve liquid inlet channel is always connected with the lower valve liquid chamber for introducing the fluid into the lower valve liquid chamber; the upper valve liquid inlet channel is always connected with the upper valve liquid chamber for introducing the fluid into the upper valve liquid chamber; the lower valve liquid inlet channel is always connected with the main liquid inlet channel, and by means of the linear sliding of the valve member, the lower valve liquid inlet channel can be connected and disconnected with the upper liquid inlet flow path of the piston, so as to realize the connection and disconnection of the upper liquid inlet flow path of the piston with the main liquid inlet flow path.

[0012] According to the positive cycle hydraulic impactor of the present invention, a piston internal pressure relief channel is formed inside the impact piston, and the upper valve liquid inlet flow channel is switched and connected between the lower piston liquid inlet flow path and the piston internal pressure relief channel by means of the axial movement of the impact piston; in an initial state, the upper valve liquid inlet flow channel is connected with the lower piston liquid inlet flow path, while the upper valve liquid inlet flow channel is disconnected from the piston internal pressure relief channel; when the impact piston is driven to move upward due to the hydraulic pressure difference between the lower piston liquid chamber and the upper piston liquid chamber, the upper valve liquid inlet flow channel can be connected with the piston internal pressure relief channel to relieve pressure on the valve member, while the upper valve liquid inlet flow channel is disconnected from the lower piston liquid inlet flow path.

[0013] According to the positive circulation hydraulic impactor of the present invention, the impactor also includes a core shaft, which is tightly fitted inside the upper piston section of the impact piston, and a pressure relief transition channel that is always connected to the pressure relief channel in the piston is formed inside the core shaft, and a pressure relief connecting hole is arranged on the side wall of the core shaft; a valve pressure relief hole is arranged on the side wall of the upper piston section of the impact piston, and in the initial state of the impactor, the valve pressure relief hole is disconnected from the pressure relief connecting hole; when the impact piston moves upward until the valve pressure relief hole is connected to the pressure relief connecting hole, the liquid inlet channel on the valve is connected to the pressure relief transition channel and the pressure relief channel in the piston.

[0014] According to the positive cycle hydraulic impactor of the present invention, the interior of the valve member has an in-valve pressure relief channel, which is always connected with the pressure relief transition channel; a piston pressure relief hole is provided on the lower side wall of the valve member, which is connected with the piston upper liquid inlet flow path in the initial state of the impactor, and when the valve member is driven to perform a vertical downward linear sliding relative to the upper body based on the hydraulic pressure difference generated on itself, the piston pressure relief hole can be disconnected from the piston upper liquid inlet flow path, and at this time, the piston upper liquid inlet flow path is connected with the valve lower liquid inlet flow channel.

[0015] According to the positive circulation hydraulic impactor of the present invention, a groove is formed on the upper piston section of the impact piston at the position corresponding to the valve pressure relief hole, and a gap is provided between the groove and the inner wall of the upper body to form a groove flow channel; in the initial state, the upper liquid inlet flow channel of the valve is connected with the lower liquid inlet flow path of the piston by means of the groove flow channel; the side wall of the upper piston section located below the groove is constructed to be able to form a close fit with the inner wall of the upper body to disconnect the connection between the groove flow channel and the lower liquid inlet flow path of the piston during the upward movement of the impact piston.

[0016] According to the positive circulation hydraulic impactor of the present invention, the interior of the outer cylinder has a flange protruding radially inward, the inner cylinder also includes a sealing sleeve, the sealing sleeve abuts against the flange in an axially positioned manner, and the lower end of the impact piston extends from the sealing sleeve; the bottom of the lower body is supported on the top of the sealing sleeve, and the lower body is tightly matched with the inner wall of the outer cylinder; the bottom of the upper body is supported on the top of the lower body.

[0017] According to the positive circulation hydraulic impactor of the present invention, the inner cylinder also includes an upper end cover abutting against the top of the upper body, and the upper end cover and the end of the upper body together form a valve upper liquid chamber; in the initial state, the upper end of the valve member abuts against the bottom of the upper end cover.

[0018] According to the positive circulation hydraulic impactor of the present invention, the impactor also includes a liquid inlet joint attached to the liquid inlet end of the outer cylinder and a flow guide member arranged in the liquid inlet joint, the lower end of the flow guide member abuts against the upper end cover in an end-sealed manner, and the upper end of the flow guide member is axially compressed by means of a step structure inside the liquid inlet joint, so that the flow guide member and the inner cylinder are axially fixed in the outer cylinder.

[0019] According to the positive circulation hydraulic impactor of the present invention, there is a gap between the flow guide member and the liquid inlet joint to form an initial liquid inlet flow channel, which forms a constant connection between the liquid inlet port of the liquid inlet joint and the liquid inlet main flow channel.

[0020] Beneficial effect: In the positive cycle hydraulic impactor of the present invention, a valve member is arranged in its inner cylinder, and the valve member is constructed to be driven to perform vertical linear sliding based on the hydraulic pressure difference generated on itself, so that the present invention can be realized based on the hydraulic pressure difference generated during the operation of the hydraulic impactor, thereby solving the problem of rapid wear caused by the hydraulic pressure difference at both ends of the valve core that the central rotary valve hydraulic impactor is not adapted to, and significantly prolongs the service life of the impactor.

[0021] The positive cycle hydraulic 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

[0022] Figure 1 The overall structural schematic diagram of the positive cycle hydraulic impactor of the present invention is shown, which is in an initial state.

[0023] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0024] Reference numerals

[0025] 1 outer cylinder, 2 impact piston, 3 upper body, 4 lower body, 5 piston upper liquid chamber, 6 piston lower liquid chamber, 7 piston upper liquid inlet flow path, 8a piston lower liquid inlet port, 8b piston lower liquid inlet flow channel, 9 inlet main flow channel, 10 valve member, 11 valve upper liquid chamber, 12 valve lower liquid chamber, 13 valve lower liquid inlet flow channel, 14 valve upper liquid inlet flow channel, 14a valve upper liquid flow channel port, 15 piston internal pressure relief channel, 16 core shaft, 17 Pressure relief transition channel, 18 pressure relief connecting hole, 19 valve pressure relief hole, 20 valve internal pressure relief channel, 21 piston pressure relief hole, 22 groove flow channel, 23 flange, 24 sealing sleeve, 25 upper end cover, 26 liquid inlet joint, 27 guide member, 28 liquid inlet initial flow channel, 29 liquid inlet, 30 drill body, 31 spline sleeve, 32 retaining ring, 33 limit bushing, 34 drill internal channel, 35 outflow channel, 36 sealing gasket. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] Figure 1 The overall structural schematic diagram of the positive cycle hydraulic impactor of the present invention is shown, which is in an initial state. Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0029] Combination Figure 1 and Figure 2 As shown, the impactor of the present invention comprises a liquid inlet joint 26, an outer cylinder 1, an inner cylinder, an impact piston 2, a spline sleeve 31 and a drill body 30, and also comprises a flow guide member 27 and a valve member 10. Among them, the liquid inlet joint 26 is connected to the outer cylinder 1 through a matching thread, and the inner cylinder comprises an upper body 3, a lower body 4 and a sealing sleeve 24 connected to the lower body 4 and axially positioned on the inner wall of the outer cylinder 1. The upper body 3, the lower body 4 and the sealing sleeve 24 are axially installed in the outer cylinder 1 in sequence, and the axial position is fixed by the liquid inlet joint 26 and the step on the outer cylinder 1; the impact piston 2 is installed in the inner cylinder by sliding fit, and the lower end extends from the sealing sleeve 24. The axial position of the inner cylinder as a whole is fixed by the flow guide member 27 and the liquid inlet joint 26. The valve member 10 is installed in the upper body 3 of the inner cylinder, and the axial movable position is limited by the upper end cover; the spline sleeve 31 is connected to the outer cylinder 1 by a thread.

[0030] In addition, the impactor of the present invention can also include a retaining ring 32 and a limiting bushing 33, and the specific structure can be: the lower end of the outer cylinder 1 is connected to the spline sleeve 31 through a thread, the spline on the drill body 30 cooperates with the spline groove on the spline sleeve 31, the retaining ring 32 is stuck in the annular groove on the upper part of the spline of the drill body 30, and is blocked on the top surface of the spline sleeve 31 to prevent the drill body 30 from falling off the spline sleeve 31. In a preferred embodiment, the retaining ring 32 is a semicircular clamp; the limiting bushing 33 is sleeved on the upper periphery of the drill body 30, and the upper top surface of the limiting bushing 33 is pressed against the upper and lower bottom surfaces of the limiting step on the inner wall of the outer cylinder 1 to press on the retaining ring 32 to limit the retaining ring 32. Of course, those skilled in the art can also understand that the drill body 30 can be installed on the end of the outer cylinder 1 of the impactor through any other existing connection structure, as long as the drill body 30 can be impacted by the impact piston 2 to perform drilling work.

[0031] In an embodiment of the present invention, a positive cycle hydraulic impactor comprises an outer cylinder 1 and an impact piston 2 arranged in the outer cylinder 1, and also comprises an inner cylinder, which is axially positioned and arranged inside the outer cylinder 1, and the impact piston 2 can be operated to perform axial reciprocating motion relative to the outer cylinder 1 and the inner cylinder based on the fluid hydraulic pressure difference, and the impact piston 2 is at least partially located in the inner cylinder, and the inner cylinder comprises an upper body 3 and a lower body 4 axially abutting with the upper body 3, and the upper piston section of the impact piston 2 is received in the piston receiving cavity of the upper body 3, and the space between the upper end of the impact piston 2 and the bottom of the piston receiving cavity forms a piston upper liquid cavity 5; a piston lower liquid cavity 6 is formed between the lower piston section of the impact piston 2 near the bottom of the inner cylinder and the inner wall of the lower body 4. The upper body 3 is provided with a piston upper liquid inlet flow path 7 and a piston lower liquid inlet flow path, and the piston lower liquid inlet flow path comprises a piston lower liquid inlet port 8a and a piston lower liquid inlet flow channel 8b. In a specific embodiment, the piston lower liquid inlet port 8 a is formed by an opening on the lower side of the upper body, and the piston lower liquid inlet channel 8 b is formed by a gap between the impact piston 2 and the lower body 4 .

[0032] Specifically, the upper liquid inlet flow path 7 of the piston is constantly connected with the upper liquid chamber 5 of the piston, so as to introduce the fluid into the upper liquid chamber 5 of the piston; the lower liquid inlet flow path of the piston is constantly connected with the lower liquid chamber 6 of the piston, so as to introduce the fluid into the lower liquid chamber 6 of the piston; a main liquid inlet channel 9 is provided between the outer wall of the upper body 3 and the inner wall of the outer cylinder 1, wherein the lower liquid inlet port 8a of the lower liquid inlet flow path of the piston is constantly connected with the main liquid inlet channel 9; a valve member 10 is also provided on the upper body 3, which is constructed to be driven to perform vertical linear sliding relative to the upper body 3 based on the hydraulic pressure difference generated on itself, so as to cut off and open the connection between the upper liquid inlet flow path 7 of the piston and the main liquid inlet channel 9.

[0033] Since the valve member 10 is configured to generate linear sliding based on the axial movement of the impact piston 2, this can be achieved by means of the hydraulic pressure difference that is inevitably formed during the operation of the hydraulic impactor. This solves the problem of rapid wear caused by the hydraulic pressure difference at both ends of the valve core that the central rotary valve hydraulic impactor is not adapted to, and significantly prolongs the service life of the impactor.

[0034] In an embodiment of the present invention, in the initial state of the impactor, the valve member 10 is located at its initial position, at which time the connection between the liquid inlet flow path 7 on the piston and the main liquid inlet flow channel 9 is cut off, and in the process where the valve member 10 is driven to perform a vertical downward linear sliding relative to the upper body 3 based on the hydraulic pressure difference generated on itself, the connection between the liquid inlet flow path 7 on the piston and the main liquid inlet flow channel 9 can be opened.

[0035] That is, the valve member 10 has an initial position and a connecting position, wherein the initial position is the position of the valve member 10 in the initial state of the impactor, in which the valve member 10 cuts off the connection between the upper liquid inlet flow path 7 on the piston and the main liquid inlet channel 9; the other connecting position is located below the initial position, and the valve member 10 can be driven to move downward based on the hydraulic pressure difference, thereby moving from the initial position to the connecting position; when the valve member 10 moves to the connecting position, it can open the connection between the upper liquid inlet flow path 7 on the piston and the main liquid inlet channel 9, so that the high-pressure liquid fluid can enter the upper liquid inlet flow path 7 on the piston from the main liquid inlet channel 9, and then enter the upper liquid chamber 5 on the piston.

[0036] In an embodiment of the present invention, an upper valve liquid chamber 11, a lower valve liquid chamber 12, a lower valve liquid inlet channel 13 and an upper valve liquid inlet channel 14 are also provided on the upper body 3, wherein the lower valve liquid inlet channel 13 is always connected with the lower valve liquid chamber 12 for introducing the fluid into the lower valve liquid chamber 12; the upper valve liquid inlet channel 14 has an upper valve liquid channel opening 14a, and the upper valve liquid inlet channel 14 is always connected with the upper valve liquid chamber 11 for introducing the fluid into the upper valve liquid chamber 11; the lower valve liquid inlet channel 13 is always connected with the main liquid inlet channel 9, and by means of the linear sliding of the valve member 10, the lower valve liquid inlet channel 13 can form a connection and disconnection with the upper liquid inlet flow path 7 of the piston, so as to realize the connection and disconnection of the upper liquid inlet flow path 7 of the piston with the main liquid inlet channel 9.

[0037] In an embodiment of the present invention, a piston internal pressure relief channel 15 is formed inside the impact piston 2, and the valve upper liquid flow channel port 14a of the valve upper liquid inlet channel 14 is switched and connected between the piston lower liquid inlet port 8a of the piston lower liquid inlet flow path and the piston internal pressure relief channel 15 by means of the axial movement of the impact piston 2; in an initial state, the valve upper liquid inlet channel 14 is connected with the piston lower liquid inlet flow path, while the valve upper liquid inlet channel 14 is disconnected from the piston internal pressure relief channel 15; when the impact piston 2 is driven to move upward due to the hydraulic pressure difference between the piston lower liquid chamber 6 and the piston upper liquid chamber 5, the valve upper liquid inlet channel 14 can be connected with the piston internal pressure relief channel 15 to relieve the pressure of the valve member 10, while the valve upper liquid inlet channel 14 is disconnected from the piston lower liquid inlet flow path.

[0038] In an embodiment of the present invention, the impactor further includes a core shaft 16, which is tightly fitted inside the upper piston section of the impact piston 2, and a pressure relief transition channel 17 that is always connected to the pressure relief channel 15 in the piston is formed inside the core shaft 16, and a pressure relief connecting hole 18 is provided on the side wall of the core shaft 16; a valve pressure relief hole 19 is provided on the side wall of the upper piston section of the impact piston 2, and in the initial state of the impactor, the valve pressure relief hole 19 is disconnected from the pressure relief connecting hole 18; when the impact piston 2 moves upward until the valve pressure relief hole 19 is connected to the pressure relief connecting hole 18, the valve upper liquid inlet channel 14 is connected to the pressure relief transition channel 17 and the pressure relief channel 15 in the piston.

[0039] In an embodiment of the present invention, the interior of the valve component 10 has an intra-valve pressure relief channel 20, which is always connected with the pressure relief transition channel 17; a piston pressure relief hole 21 is provided on the lower side wall of the valve component 10, and in the initial state of the impactor, it is connected with the piston upper liquid inlet flow path 7. When the valve component 10 is driven to perform a vertical downward linear sliding relative to the upper body 3 based on the hydraulic pressure difference generated on itself, the piston pressure relief hole 21 can be disconnected from the piston upper liquid inlet flow path 7, and at this time, the piston upper liquid inlet flow path 7 is connected with the valve lower liquid inlet flow channel 13.

[0040] Based on the above structure, in the present invention, the pressure relief of the valve member 10 and the pressure relief of the piston upper liquid chamber 5 can share the same pressure relief channel, that is, the same pressure relief channel formed by the valve inner pressure relief channel 20, the pressure relief transition channel 17 and the piston inner pressure relief channel 15. This greatly simplifies the arrangement of the pressure relief channel, and there is no need to set up multiple additional pressure relief channels, thereby reducing the grooving of the inner cylinder and further improving the overall service life of the impactor.

[0041] In addition, the shared pressure relief passage also includes an inner channel 34 and an outflow channel 35 of the drill bit.

[0042] In a preferred embodiment, the upper body 3 of the inner cylinder has an installation cavity that passes through itself and downward to the piston receiving cavity, which is formed from top to bottom into a valve upper liquid cavity 11, a valve upper matching cavity, a valve lower liquid cavity 12, a liquid inlet cavity of the piston upper liquid inlet flow path 7, and a valve lower receiving cavity. The lower part of the valve member 10 passes through the liquid inlet cavity of the piston upper liquid inlet flow path 7 and is inserted into the valve lower receiving cavity, and the valve member 10 is in constant communication with the pressure relief transition channel 17 of the core shaft 16 by means of the valve lower receiving cavity, wherein the radial cross-sectional width of the liquid inlet cavity of the piston upper liquid inlet flow path 7 is greater than the lower cross-sectional width of the valve member 10, so that it can be connected with the piston pressure relief hole 21 on the valve member 10 in the initial state. The upper part of the valve member 10 is located in the valve upper matching cavity, and the middle part of the valve member 10 is a contracted concave waist, which corresponds to the position of the valve lower liquid cavity 12.

[0043] In an embodiment of the present invention, a groove is formed on the upper piston section of the impact piston 2 at the position corresponding to the valve pressure relief hole 19, and a gap is provided between the groove and the inner wall of the upper body 3 to form a groove flow channel 22; in the initial state, the valve upper liquid inlet flow channel 14 is connected with the piston lower liquid inlet flow path by means of the groove flow channel 22; the side wall of the upper piston section located below the groove is constructed to be able to form a close fit with the inner wall of the upper body 3, so as to disconnect the groove flow channel 22 from the piston lower liquid inlet flow path during the upward movement of the impact piston 2.

[0044] In the embodiment of the present invention, the interior of the outer cylinder 1 has a flange 23 protruding radially inward, and the inner cylinder also includes a sealing sleeve 24, which abuts against the flange 23 in an axially positioned manner, and the lower end of the impact piston 2 extends from the sealing sleeve 24; the bottom of the lower body 4 is supported on the top of the sealing sleeve 24, and the lower body 4 is tightly matched with the inner wall of the outer cylinder 1; the bottom of the upper body 3 is supported on the top of the lower body 4.

[0045] In the embodiment of the present invention, the inner cylinder further includes an upper end cover 25 abutting against the top of the upper body 3. In a preferred embodiment, a sealing gasket 36 is provided between the bottom of the upper end cover and the top of the upper body. In addition, the upper end cover 25 and the end of the upper body 3 together form a valve upper liquid chamber 11; in the initial state, the upper end of the valve member 10 abuts against the bottom of the upper end cover 25.

[0046] In an embodiment of the present invention, the impactor further includes a liquid inlet joint 26 attached to the liquid inlet end of the outer cylinder 1 and a flow guide member 27 arranged in the liquid inlet joint 26, the lower end of the flow guide member 27 abuts against the upper end cover 25 in an end-sealed manner, and the upper end of the flow guide member 27 forms axial compression with the aid of a step structure inside the liquid inlet joint 26, so that the flow guide member 27 and the inner cylinder are axially fixed in the outer cylinder 1.

[0047] In the embodiment of the present invention, there is a gap between the flow guide member 27 and the liquid inlet connector 26 to form an initial liquid inlet flow channel 28, which forms a constant connection between the liquid inlet port 29 of the liquid inlet connector 26 and the liquid inlet main flow channel 9. In a preferred embodiment, the flow guide member 27 is a filter, which is provided with a filter hole that connects the initial liquid inlet flow channel 28 with the inner cavity of the filter.

[0048] The working principle of the impactor of the present invention is as follows: in the initial state, high-pressure liquid passes through the guide member 27 from the liquid inlet 29, enters the initial liquid inlet flow channel 28, and passes through the total liquid inlet flow channel 9, the piston lower liquid inlet 298a, and the piston lower liquid inlet flow channel 8b in sequence to enter the piston lower liquid chamber 6. At this time, due to the connection with the piston pressure relief hole 21 through the piston upper liquid inlet flow path 7, the piston upper liquid chamber 5 is connected with the valve internal pressure relief channel 20 and the piston internal pressure relief channel 15, so that the piston upper liquid chamber 5 is in a pressed state; at this time, the downward cross-sectional area of ​​the high-pressure liquid in the piston lower liquid chamber and the piston lower liquid inlet flow channel 8b is smaller than the upward cross-sectional area, thereby generating a pressure difference that can push the impact piston 2 to move upward, and under this pressure difference, the impact piston 2 is pushed to move upward.

[0049] At the same time, high-pressure liquid enters the valve lower liquid chamber 12 through the main liquid inlet channel 9 and the valve lower liquid inlet channel 13, and enters the valve upper liquid chamber 11 through the piston lower liquid inlet port 298a, the valve upper liquid flow channel port 14a, and the valve upper liquid inlet channel 14. At this time, the valve component 10 has a pressure difference that can push the valve component 10 to move downward because the downward cross-sectional area of ​​the high-pressure liquid in the upper liquid chamber and the valve lower liquid chamber 12 is greater than the upward cross-sectional area. Under this pressure difference, the valve component 10 is pushed downward.

[0050] At this time, the valve component 10 has moved downward for a certain stroke. When the valve component 10 moves to the valve lower liquid chamber 12 and is connected to the piston upper liquid inlet flow path 7, the high-pressure liquid enters the piston upper liquid chamber 5 through the liquid inlet main channel 9, the valve lower liquid inlet flow channel 13, the valve lower liquid chamber 12, and the piston upper liquid inlet flow path 7. At this time, the impact piston 2 is subjected to a force cross-section of the downward force of the high-pressure liquid in the upper liquid chamber that is greater than the force cross-section of the upward force of the high-pressure liquid in the lower liquid chamber, thereby generating a pressure difference that can push the impact piston 2 to move downward. Under the action of this pressure difference, the impact piston 2 can be pushed to decelerate upward and accelerate downward to impact the drill bit body 30.

[0051] The valve member 10 has a pressure relief channel for helping it to reset. Specifically, when the impact piston 2 moves upward to a certain stroke, specifically, when the valve pressure relief hole 19 is connected to the pressure relief connecting hole 18, the connection between the piston lower liquid inlet 298a and the valve upper liquid flow channel 14a is closed, and the valve upper liquid flow channel 14a is connected to the valve pressure relief hole 19 and the pressure relief connecting hole 18, so that the valve upper liquid inlet flow channel 14 is connected to the pressure relief transition channel 17 and the piston inner pressure relief channel 15, so that the valve member 10 completes the pressure relief. At this time, the pressure difference between the valve upper liquid chamber 11 and the valve lower liquid chamber 12 will push the valve member 10 to move upward until the valve member 10 returns to the initial position, thereby completing a cycle of the impact piston 2 and the valve member 10.

[0052] The above process is repeated in this way, thereby achieving hydraulic positive cycle impact drilling.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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 hydraulic impactor, comprising an outer cylinder, an impact piston disposed in the outer cylinder, and an inner cylinder axially positioned and disposed inside the outer cylinder, wherein the impact piston can be operated to perform axial reciprocating motion relative to the outer cylinder and the inner cylinder based on a fluid pressure difference, characterized in that: The impact piston is at least partially located in the inner cylinder, and the inner cylinder includes an upper body and a lower body axially abutting against the upper body, the upper piston section of the impact piston is received in the piston receiving cavity of the upper body, and the space between the upper end of the impact piston and the bottom of the piston receiving cavity forms an upper piston liquid cavity; a lower piston liquid cavity is formed between the lower piston section of the impact piston close to the bottom of the inner cylinder and the inner wall of the lower body; The upper body is provided with: A liquid inlet flow path on the piston, which is always connected with the liquid chamber on the piston, so as to introduce the fluid into the liquid chamber on the piston; A piston lower liquid inlet flow path, which is always connected with the piston lower liquid chamber, so as to introduce the fluid into the piston lower liquid chamber; A main liquid inlet channel is provided between the outer side wall of the upper body and the inner side wall of the outer cylinder, wherein the liquid inlet channel under the piston is always connected with the main liquid inlet channel; The upper body is also provided with a valve member, which is configured to be driven to slide vertically linearly relative to the upper body based on the hydraulic pressure difference generated on itself, so as to cut off and open the communication between the liquid inlet flow path on the piston and the liquid inlet main flow channel; The upper body is also provided with an upper valve liquid chamber, a lower valve liquid chamber, a lower valve liquid inlet channel which is constantly connected with the lower valve liquid chamber for introducing fluid into the lower valve liquid chamber, and an upper valve liquid inlet channel which is constantly connected with the upper valve liquid chamber for introducing fluid into the upper valve liquid chamber, wherein the lower valve liquid inlet channel is constantly connected with the said total liquid inlet channel, and by means of linear sliding of the valve member, the lower valve liquid inlet channel can be connected and disconnected with the upper liquid liquid inlet flow path of the piston, so as to realize the connection and disconnection of the upper liquid liquid inlet flow path of the piston with the total liquid inlet flow path.

2. The positive cycle hydraulic impactor according to claim 1, characterized in that: In the initial state of the impactor, the valve member is located in its initial position, at which time the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel is cut off, and in the process where the valve member is driven to perform a vertical downward linear slide relative to the upper body based on the hydraulic pressure difference generated on itself, the connection between the liquid inlet flow path on the piston and the main liquid inlet flow channel can be opened.

3. The positive cycle hydraulic impactor according to claim 2, characterized in that: A piston internal pressure relief channel is formed inside the impact piston, and the valve upper liquid inlet flow channel is switched and connected between the piston lower liquid inlet flow path and the piston internal pressure relief channel by means of the axial movement of the impact piston; In the initial state, the liquid inlet channel on the valve is connected with the liquid inlet channel under the piston, while the liquid inlet channel on the valve is disconnected from the pressure relief channel inside the piston; when the impact piston is driven upward due to the hydraulic pressure difference between the liquid chamber under the piston and the liquid chamber on the piston, the liquid inlet channel on the valve can be connected with the pressure relief channel inside the piston to relieve pressure on the valve member, while the liquid inlet channel on the valve is disconnected from the liquid inlet channel under the piston.

4. The positive cycle hydraulic impactor according to claim 3, characterized in that: The impactor also includes a core shaft, which is tightly fitted inside the upper piston section of the impact piston, and a pressure relief transition channel is formed inside the core shaft and is always connected to the pressure relief channel in the piston, and a pressure relief communication hole is provided on the side wall of the core shaft; A valve pressure relief hole is arranged on the side wall of the upper piston section of the impact piston. In the initial state of the impactor, the valve pressure relief hole is disconnected from the pressure relief connecting hole. When the impact piston moves upward until the valve pressure relief hole is connected to the pressure relief connecting hole, the liquid inlet channel on the valve is connected to the pressure relief transition channel and the pressure relief channel inside the piston.

5. The positive cycle hydraulic impactor according to claim 4, characterized in that: The valve member has an inner valve pressure relief passage inside, which is always connected with the pressure relief transition passage; A piston pressure relief hole is provided on the lower side wall of the valve member, and in the initial state of the impactor, it is connected with the liquid inlet flow path on the piston. When the valve member is driven to perform a vertical downward linear sliding relative to the upper body based on the hydraulic pressure difference generated on itself, the piston pressure relief hole can be disconnected from the liquid inlet flow path on the piston, and at this time, the liquid inlet flow path on the piston is connected with the liquid inlet flow channel under the valve.

6. The positive cycle hydraulic impactor according to claim 5, characterized in that: A groove is formed on the upper piston section of the impact piston at a position corresponding to the valve pressure relief hole, and a gap is provided between the groove and the inner wall of the upper body to form a groove flow channel; In the initial state, the liquid inlet channel on the valve is connected with the liquid inlet channel under the piston by means of the groove channel; the side wall of the upper piston section below the groove is constructed to be able to form a tight fit with the inner wall of the upper body, so as to disconnect the connection between the groove channel and the liquid inlet channel under the piston during the upward movement of the impact piston.

7. The positive cycle hydraulic impactor according to claim 6, characterized in that: The outer cylinder has a flange protruding radially inwardly inside, and the inner cylinder also includes a sealing sleeve, which abuts against the flange in an axially positioned manner, and the lower end of the impact piston extends out of the sealing sleeve; The bottom of the lower body is supported on the top of the sealing sleeve, and the lower body is tightly matched with the inner wall of the outer cylinder; the bottom of the upper body is supported on the top of the lower body.

8. The positive cycle hydraulic impactor according to claim 7, characterized in that: The inner cylinder also includes an upper end cover abutting against the top of the upper body, and the upper end cover and the end of the upper body together enclose the valve upper liquid chamber; in the initial state, the upper end of the valve component abuts against the bottom of the upper end cover.

9. The positive cycle hydraulic impactor according to claim 8, characterized in that: The impactor also includes a liquid inlet joint attached to the liquid inlet end of the outer cylinder and a flow guide member arranged in the liquid inlet joint, the lower end of the flow guide member abuts against the upper end cover in an end-sealed manner, and the upper end of the flow guide member is axially compressed by means of a step structure inside the liquid inlet joint, so that the flow guide member and the inner cylinder are axially fixed in the outer cylinder.

10. The positive cycle hydraulic impactor according to claim 9, characterized in that: There is a gap between the flow-guiding member and the liquid inlet joint to form an initial liquid inlet flow channel, which forms a constant connection between the liquid inlet of the liquid inlet joint and the liquid inlet main flow channel.

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