A high-energy high-frequency impactor

Abstract

The invention discloses a high-energy high-frequency impactor, wherein the upper joint is connected to the outer cylinder through a thread, the lower end of the outer cylinder is connected to the spline sleeve through a thread, the spline of the drill bit is matched with the spline groove on the spline sleeve and is provided with a semicircular clamp, and inside the outer cylinder, the sealing sleeve, the cylinder sleeve, the inner cylinder and the gland are sealed and docked in sequence from bottom to top; the upper sliding sealing sleeve of the piston is in the inner cylinder, the middle part of the piston passes through the cylinder sleeve with a gap, the lower part of the piston is radially reduced and extends out to contact the top surface of the drill bit after sliding and sealing through the sealing sleeve; the lower core tube is inserted into the central hole of the piston, the top cap brim of the lower core tube forms an interference fit with the inner cylinder, the lower tube of the upper core tube is sealed and docked with the upper tube mouth of the lower core tube, the valve core is clamped between the outer periphery of the middle part of the upper core tube and the gland and the inner cylinder joint for sliding sealing; the upper part of the upper core tube passes through the gland center hole. The technical effect of the invention is: the service life of the valve core is improved, the cross-sectional area of ​​the fluid channel controlled by the valve core is increased, and the radial vibration of the drill body is overcome.

Description

Technical Field

[0001] The invention belongs to drilling tools, and in particular relates to a hydraulic impactor used for various types of boreholes for rapid drilling of hard rocks. Background Art

[0002] The hydraulic impact rotary drilling method is the most energy-efficient down-the-hole impact drilling method at present. Compared with the air down-the-hole hammer rotary drilling method, the hydraulic impact rotary drilling method has the advantages of no dust pollution at the hole mouth and low working noise. However, the impact power and frequency of existing hydraulic impactors are both low, and the average mechanical drilling speed is significantly lower than that of pneumatic down-the-hole hammers.

[0003] Chinese patent document CN 113585960 A disclosed a center rotary valve hydraulic impactor on November 2, 2021. The patent 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 located at the high-pressure end and the low-pressure end respectively, the center rotary valve is subjected to unbalanced pressure. After a period of use, the rear end of the center rotary valve will be severely worn, resulting in stuck rotation, discontinuous impact, etc. Its service life is short and cannot meet engineering requirements.

[0004] Chinese patent document CN 111877978 A disclosed a hydraulic impactor on November 3, 2020. In the tube consisting of an upper joint, an outer cylinder, and an outer tube, the patent sequentially arranges a valve cover, a valve seat, a cylinder sleeve, an inner cylinder, an inner cylinder cover, a piston, and a hammer from top to bottom. The valve seat is equipped with a valve sleeve and a valve core, and the bottom surface of the hammer strikes the top surface of the drill bit. The patent has the following problems:

[0005] 1. Two groups of radial holes are opened on the valve core, forming the upper chamber fluid inflow control port b and the upper chamber fluid discharge control port e, and realize flow distribution with the c fluid channel on the valve sleeve and the upper chamber emptying channel d. Since the valve core will cooperate with the piston to make high-frequency reciprocating motion during the entire working process of the impactor, the multiple groups of small holes on the valve core significantly reduce the structural strength of the valve core, resulting in a short life of the valve core during use. At the same time, in order to ensure that the valve core can quickly respond to the piston switching signal, the valve core is required to be small enough in quality during design, resulting in a small size of the entire valve core. The flow cross-sectional area of ​​the small hole b on the valve core and the c fluid channel of the valve sleeve to achieve flow distribution is small, the pressure loss is large, and the energy utilization rate of the impactor is low.

[0006] 2. The outer ring of the impactor cylinder sleeve is provided with an upper cavity emptying channel d, which reduces the radial space of the impactor, reduces the cross-sectional area of ​​the piston, and reduces the impact power of the piston. The piston and the hammer are separated. Since there is a large gap between the hammer and the outer tube, the hammer produces radial movement during high-speed reciprocating motion, resulting in the impact of the outer tube, causing the radial vibration of the drill body to disturb the drilling hole, resulting in drilling accidents such as hole collapse and drill stuck.

[0007] Based on this, in order to realize a hydraulic impactor with a drilling speed and drilling capacity comparable to that of a pneumatic down-the-hole hammer, structural improvements must be made to the existing technology. Summary of the invention

[0008] In view of the problems existing in the existing hydraulic impactors, the technical problem to be solved by the present invention is to provide a high-energy and high-frequency impactor, which can not only improve the service life of the rotary valve or valve core, but also reduce the fluid pressure loss, improve the energy utilization rate of the impactor, and overcome the radial vibration of the drill body.

[0009] The technical problem to be solved by the present invention is achieved through such a technical solution, which includes an upper joint, a gland, an upper core tube, a valve core, a lower core tube, an inner cylinder, a piston, a cylinder sleeve, a sealing sleeve, an outer cylinder, a semicircular clamp, a spline sleeve and a drill bit; the upper joint is connected to the outer cylinder through a thread, the lower end of the outer cylinder is connected to the spline sleeve through a thread, the drill body spline of the drill bit cooperates with the spline groove on the spline sleeve to form an axially movable assembly, the semicircular clamp is clamped in the annular groove on the upper part of the drill body spline, and is blocked on the top surface of the spline sleeve;

[0010] Inside the outer cylinder, the sealing sleeve, cylinder sleeve, inner cylinder and gland are sealed and connected in sequence from bottom to top, wherein the sealing sleeve and cylinder sleeve are sealed and connected with the inner wall of the outer cylinder, and the inner cylinder and gland are gap-matched with the inner wall of the outer cylinder; the bottom of the sealing sleeve is axially limited by the boss of the outer cylinder, and the top of the gland is axially limited by the bottom end face of the upper joint;

[0011] The upper piston sliding sealing sleeve is in the inner cylinder, the middle piston passes through the cylinder sleeve with a gap, the lower piston is radially reduced and extends out to contact the top surface of the drill bit after sliding sealing by the sealing sleeve; the upper piston cavity is composed of the inner wall of the inner cylinder, the outer periphery of the lower core tube and the middle step of the inner cylinder on the top surface and the joint of the top cap edge of the lower core tube, and the top cap edge of the lower core tube is provided with a through hole connected to the upper piston cavity; the lower piston cavity is composed of the sealing sleeve, the cylinder sleeve and the reduced diameter circumferential wall of the lower piston;

[0012] The lower core tube is inserted into the center hole of the piston with a sliding seal. The top cap edge of the lower core tube forms an interference fit with the inner cylinder and is limited by the step shaft in the middle of the inner cylinder. The lower tube of the upper core tube is connected with the upper pipe mouth of the lower core tube with an interference seal. The upper core tube is a cylinder with small ends and a large middle part. A countersunk hole is opened on the bottom surface of the upper core tube. The valve core is clamped between the outer periphery of the middle part of the upper core tube and the joint of the pressure cover and the inner cylinder for sliding sealing. The upper part of the upper core tube passes through the center hole of the pressure cover, and the top surface of the upper core tube is axially limited by the step of the inner hole of the upper joint.

[0013] The advantages of the present invention are:

[0014] 1. The present invention does not provide a flow distribution hole on the valve core, thereby ensuring the structural strength of the valve core and prolonging the service life of the valve core;

[0015] 2. The cross-sectional area of ​​the fluid channel controlled by the valve core is increased to more than 4 times the valve core opening area of ​​the prior art, which effectively improves the energy utilization rate of the impactor;

[0016] 3. The upper cavity emptying channel in the prior art is located at the outer ring of the cylinder sleeve, but is arranged at the center hole of the piston, which greatly saves the radial space of the impactor to increase the cross-sectional area of ​​the impactor piston, and greatly shortens the piston length under the condition of the same quality piston. The piston and the hammer in CN 111877978 A are made into one piece, and the lower section of the piston and the outer cylinder are strictly sealed with a sealing sleeve, so that the piston and the cylinder body can be closely matched, solving the problem of radial vibration of the drill body caused by the large gap between the hammer and the outer tube in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings of the present invention are as follows:

[0018] Figure 1 It is a schematic diagram of the upper structure of an embodiment of the present invention;

[0019] Figure 2 It is a schematic diagram of the lower structure of an embodiment of the present invention;

[0020] Figure 3 for Figure 1 Enlarged view of part A in the middle;

[0021] Figure 1 and Figure 2 constitute a whole.

[0022] In the figure, 1, upper joint; 2, filter; 3, gland; 4, upper core tube; 5, valve core; 6, lower core tube; 7, inner cylinder; 8, piston; 9, cylinder sleeve; 10, sealing sleeve; 11, outer cylinder; 12, limit sleeve; 13, semicircular clamp; 14, spline sleeve; 15, drill bit;

[0023] i, piston upper chamber; m, piston lower chamber; I, inner cylinder step; II, piston step. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0025] In order to clearly describe the content of the invention, this patent application uses the directional words "upper" and "lower" for distinction. The "upper" and "lower" are determined based on the layout orientation of the above drawings. When the actual use direction of the present invention changes, the directional designation changes accordingly, which cannot be regarded as a limitation on the scope of patent protection.

[0026] like Figure 1 and Figure 2As shown, an embodiment of the present invention includes an upper joint 1, a filter 2, a gland 3, an upper core tube 4, a valve core 5, a lower core tube 6, an inner cylinder 7, a piston 8, a cylinder sleeve 9, a sealing sleeve 10, an outer cylinder 11, a limiting sleeve 12, a semicircular clamp 13, a spline sleeve 14 and a drill bit 15; the upper joint 1 is connected to the outer cylinder 11 by a thread, and the lower end of the outer cylinder 11 is connected to the spline sleeve 14 by a thread, and the drill bit body spline of the drill bit 15 cooperates with the spline groove on the spline sleeve 14 to form an axially movable assembly, and the semicircular clamp 13 is clamped in the annular groove on the upper part of the drill bit body spline and blocked on the top surface of the spline sleeve 14 to prevent the drill bit 15 from falling off from the spline sleeve 14; the limiting sleeve 12 is sleeved on the outer periphery of the drill bit body, the upper top surface of the limiting sleeve 12 is pressed against the boss of the outer cylinder 11, and the lower bottom surface of the limiting sleeve 12 is pressed on the semicircular clamp 13 to limit the semicircular clamp 13;

[0027] A sealing sleeve 10, a cylinder sleeve 9, an inner cylinder 7 and a gland 3 are installed inside the outer cylinder 11 from bottom to top, wherein the sealing sleeve 10 and the cylinder sleeve 9 are sealedly engaged with the inner wall of the outer cylinder 11, and the inner cylinder 7 and the gland 3 are gap-matched with the inner wall of the outer cylinder 11; the sealing sleeve 10, the cylinder sleeve 9, the inner cylinder 7 and the gland 3 are sealedly butted against each other, the bottom of the sealing sleeve 10 is axially limited by the boss of the outer cylinder 11, and the top of the gland 3 is axially limited by the bottom end face of the upper joint 1;

[0028] The upper part of the piston 8 slides in the inner cylinder 7, the middle part of the piston 8 passes through the cylinder sleeve 9 with a gap, the lower part of the piston 8 is radially reduced and extends out to contact the top surface of the drill bit 15 after sliding and sealing through the sealing sleeve 10; the upper piston chamber i is composed of the inner wall of the inner cylinder 7, the outer periphery of the lower core tube 6 and the middle step of the inner cylinder 7 on the top surface and the joint of the top cap edge of the lower core tube 6, the top cap edge of the lower core tube 6 is opened with a through hole connected to the upper piston chamber i, and the lower piston chamber m is composed of the sealing sleeve 10, the cylinder sleeve 9 and the reduced diameter circumferential wall of the lower part of the piston 8;

[0029] The lower core tube 6 is inserted into the center hole of the piston 8 in a sliding seal, and the top cap edge of the lower core tube 6 forms an interference fit with the inner cylinder 7 and is limited by the step shaft in the middle of the inner cylinder 7; the lower tube of the upper core tube 4 is connected to the upper tube mouth of the lower core tube 6 in an interference seal, and the upper core tube 4 is a cylinder with small ends and a large middle part. A countersunk hole is opened on the bottom surface of the upper core tube 4, and the valve core 5 is clamped between the outer periphery of the middle part of the upper core tube 4 and the joint of the pressure cover 3 and the inner cylinder 7 for sliding sealing; Figure 3 As shown, the middle of the valve core 5 is an arched curved body, and a micro-step is provided on the arched curved body, and a gap is left in the inner cylinder 7 corresponding to the lower part of the arched curved body of the valve core 5, and a micro-convex is provided at the stroke of the valve core moving downward to fit the lower part of the arched curved body. The upper part of the upper core tube 4 passes through the center hole of the gland 3, and a filter 2 is also installed between the top surface of the upper core tube 4 and the step of the inner hole of the upper joint 1, which can limit the axial position of the top surface of the upper core tube 4. The filter 2 is used to filter the slag in the high-pressure fluid.

[0030] The center hole of the upper joint 1 constitutes a fluid channel, the built-in space at the lower part of the upper joint 1 constitutes b fluid channel, the inner wall of the gland 3, the upper outer wall of the upper core tube 4 and the top surface of the valve core 5 constitute c fluid space, the through hole on the top surface of the gland 3 and the gap between the gland 3 and the outer wall of the inner cylinder 7 and the outer cylinder 11 form d fluid channel; Figure 3 As shown, the upper part of the inner cylinder 7 is radially opened with a g fluid channel corresponding to the position of the sliding section of the valve core 5, and the e fluid space is surrounded by the lower bottom surface of the pressure cover 3, the upper step expansion hole wall of the inner cylinder 7 and the outer wall of the arched curved body of the valve core 5. The inner wall of the arched curved body of the valve core 5 and the outer wall of the upper core tube 4 constitute the f fluid channel, and the upper radial opening of the counterbore of the upper core tube 4 constitutes the h fluid channel. The middle radial opening of the center hole of the lower core tube 6 forms the j fluid channel, the vertical through hole of the inner cylinder 7 and the bottom opening of the through hole form the n fluid channel, the lower radial opening of the inner cylinder 7 forms the k fluid channel, and the inner cylinder 7 is provided with an inner cylinder step I on the upper edge of the k fluid channel opening; the upper radial opening of the center hole of the piston 8 constitutes l Fluid channel, piston 8 in l A piston step II is provided below the fluid channel opening, and a fluid channel is formed by the countersunk hole of the upper core tube 4, the center hole of the lower core tube 6, the center hole of the piston 8 and the center hole of the drill bit 15.

[0031] The working principle of the embodiment of the present invention is as follows:

[0032] In the initial state, the high-pressure fluid enters the b fluid channel, c fluid space, and d fluid channel from the a fluid channel through the filter 2, and enters the piston upper chamber i and the piston lower chamber m respectively through the g fluid channel and the k fluid channel. The fluid entering the piston lower chamber m simultaneously enters the e fluid space through the n fluid channel. Since there is a micro-step with a reduced lower portion on the arched curved body in the middle of the valve core 5, the sum of the cross-sectional areas of the valve core 5 in the c fluid space and the e fluid space is greater than the cross-sectional area in the piston upper chamber i. Although the pressures above and below the valve core 5 are equal, the force on the upper end face of the valve core 5 is greater than that on the lower cross-section. The valve core 5 moves downward under the action of the force difference and isolates the g fluid channel from the piston upper chamber i, while connecting the piston upper chamber i with the f fluid channel, the h fluid channel, and the o fluid channel (the o fluid channel connects to the external space of the drill bit 15, and the drill bit cross-sectional view does not cut through this connecting position). The fluid pressure in the piston upper chamber i decreases, and the piston moves upward under the action of the high-pressure fluid in the piston lower chamber m.

[0033] When the piston step II moves upward to contact the inner cylinder step I, the n fluid channel is separated from the piston lower chamber m. After continuing to move upward for a certain distance, the n fluid channel passes through lThe fluid channel is connected with the j fluid channel and the o fluid channel, and the high-pressure fluid in the fluid space e flows out. At this time, the force on the lower end of the valve core is greater than that on the upper end. The valve core moves upward under the action of the force difference, so that the fluid channel g is connected with the upper chamber i of the piston, and the upper chamber i of the piston is separated from the h fluid channel. The high-pressure fluid enters the upper chamber i of the piston. Since the cross-sectional area of ​​the piston 8 in the upper chamber i of the piston is greater than the cross-sectional area in the lower chamber m of the piston, the piston 8 first decelerates upward under the action of the force difference and gradually accelerates downward until it impacts the tail of the drill bit, completing a cycle of the movement of the piston and the valve core, and repeats this process to form a high-frequency impact effect.

[0034] The technical effects of the present invention are:

[0035] 1. Compared with the rotary valve structure of document CN 113585960 A, the valve core 5 of the embodiment of the present invention adopts a linear sliding motion mode to achieve switching. The movement process itself requires a certain pressure difference at both ends of the valve core to be realized, which solves the problem of rapid wear caused by the hydraulic pressure difference at both ends of the central rotary valve hydraulic impactor that is not adapted to the valve core, and significantly prolongs the service life of the impactor.

[0036] 2. Compared with the hydraulic impactor of document CN 111877978 A, the embodiment of the present invention realizes flow distribution through the cooperation between the end face of the valve core 5 and the cylinder body, and does not use the valve core opening for flow distribution, thereby ensuring the structural strength of the valve core and improving the service life of the valve core. Moreover, under the condition of the same valve core quality, the cross-sectional area of ​​the fluid channel g controlled by the valve core can be increased to more than 4 times the valve core opening area of ​​the prior art, effectively improving the energy utilization rate of the impactor.

[0037] 3. Compared with the hydraulic impactor in document CN 111877978 A, the embodiment of the present invention changes the exhaust channel of the impactor from the upper cavity exhaust channel d located on the outer ring of the cylinder sleeve to the fluid channel o arranged in the center of the piston, which greatly saves the radial space of the impactor to increase the cross-sectional area of ​​the impactor piston, and greatly shortens the piston length under the condition of pistons of the same quality. At the same time, the piston and the hammer in CN 111877978 A can be made into one piece, and the sealing sleeve 10 is used to strictly seal the lower section of the piston and the outer cylinder 11, so that the piston and the cylinder body can be closely matched, solving the problem of radial vibration of the drill body caused by the large gap between the hammer and the outer tube in the prior art.

[0038] A hydraulic impactor using high-pressure water as a power medium manufactured according to this embodiment has the significant advantages of a large piston impact terminal velocity (the impact terminal velocity can reach 12 m / s when the supplied water pressure is 14 MPa) and a high impact frequency. The drilling speed in hard rock can reach more than twice that of the existing pneumatic down-the-hole hammer, and the drilling efficiency is significantly improved.

Claims

1. A high-energy high-frequency impactor, comprising an upper joint (1), a gland (3), an upper core tube (4), a valve core (5), a lower core tube (6), an inner cylinder (7), a piston (8), a cylinder sleeve (9), a sealing sleeve (10), an outer cylinder (11), a semicircular clamp (13), a spline sleeve (14) and a drill bit (15); the upper joint (1) is connected to the outer cylinder (11) by a thread, the lower end of the outer cylinder (11) is connected to the spline sleeve (14) by a thread, the drill bit body spline of the drill bit (15) cooperates with the spline groove on the spline sleeve (14) to form an axially movable assembly, the semicircular clamp (13) is clamped in the annular groove on the upper part of the drill bit body spline and blocked on the top surface of the spline sleeve (14), and is characterized in that: Inside the outer cylinder (11), the sealing sleeve (10), the cylinder sleeve (9), the inner cylinder (7) and the gland (3) are sealed and butted in sequence from bottom to top, wherein the sealing sleeve (10) and the cylinder sleeve (9) are sealed and engaged with the inner wall of the outer cylinder (11), and the inner cylinder (7) and the gland (3) are gap-matched with the inner wall of the outer cylinder (11); the bottom of the sealing sleeve (10) is axially limited by the boss of the outer cylinder (11), and the top of the gland (3) is axially limited by the bottom end surface of the upper joint (1); The upper part of the piston (8) slides in the inner cylinder (7), the middle part of the piston (8) passes through the cylinder sleeve (9) with a gap, the lower part of the piston (8) is radially reduced and extends out to contact the top surface of the drill bit (15) after sliding and sealing through the sealing sleeve (10); the upper chamber of the piston is composed of the inner wall of the inner cylinder (7), the outer periphery of the lower core tube (6) and the joint of the middle step of the inner cylinder (7) and the top cap edge of the lower core tube (6); the top cap edge of the lower core tube (6) is provided with a through hole connected to the upper chamber of the piston; the lower chamber of the piston is composed of the sealing sleeve (10), the cylinder sleeve (9) and the reduced diameter circumferential wall of the lower part of the piston (8); The lower core tube (6) is inserted into the center hole of the piston (8) in a sliding seal, and the top cap edge of the lower core tube (6) forms an interference fit with the inner cylinder (7) and is limited by the step shaft in the middle of the inner cylinder (7); the lower tube of the upper core tube (4) is connected to the upper tube mouth of the lower core tube (6) in an interference seal, and the upper core tube (4) is a cylindrical body with small ends and a large middle part. The bottom surface of the upper core tube (4) is provided with a countersunk hole, and the valve core (5) is clamped between the outer periphery of the middle part of the upper core tube (4) and the joint part of the gland (3) and the inner cylinder (7) to form a sliding seal; the upper part of the upper core tube (4) passes through the center hole of the gland (3), and the top surface of the upper core tube (4) is axially limited by the step of the inner hole of the upper joint (1).

2. The high-energy high-frequency impactor according to claim 1 is characterized in that: The middle part of the valve core (5) is an arched curved body, and a micro-step that is reduced in size at the lower part is provided on the arched curved body. The inner cylinder (7) has a gap corresponding to the lower part of the arched curved body of the valve core (5), and a micro-convex platform is provided at the stroke of the valve core moving downward to fit the lower part of the arched curved body.

3. The high-energy high-frequency impactor according to claim 2 is characterized in that: Also includes A filter (2) is installed between the top surface of the upper core tube (4) and the inner hole step of the upper joint (1).

4. The high-energy high-frequency impactor according to claim 3 is characterized in that: It also includes a limiting sleeve (12), which is sleeved on the outer periphery of the drill head body, the upper top surface of the limiting sleeve (12) is pressed against the boss of the outer cylinder (11), and the lower bottom surface of the limiting sleeve (12) is pressed on the semicircular clamp (13), thereby limiting the semicircular clamp (13).

5. The high-energy high-frequency impactor according to claim 2, 3 or 4, characterized in that: The center hole of the upper joint (1) forms a fluid channel a, the built-in space at the lower part of the upper joint (1) forms a fluid channel b, the inner opening wall of the gland (3), the upper outer wall of the upper core tube (4) and the top surface of the valve core (5) form a fluid space c, the through hole on the top surface of the gland (3) and the gap between the gland (3) and the outer wall of the inner cylinder (7) and the outer cylinder (11) form a fluid channel d; the upper part of the inner cylinder (7) is radially opened with a fluid channel g corresponding to the position of the bottom sliding section of the valve core (5), the lower bottom surface of the gland (3), the upper step expansion hole wall of the inner cylinder (7) and the outer wall of the arched curved body of the valve core (5) form a fluid space e, the inner wall of the arched curved body of the valve core (5) and the outer wall of the upper core tube (4) form a fluid channel f, The upper radial opening of the counterbore of the upper core tube (4) forms an h fluid channel; the middle radial opening of the center hole of the lower core tube (6) forms a j fluid channel; the vertical through hole of the inner cylinder (7) and the bottom opening of the through hole form an n fluid channel; the lower radial opening of the inner cylinder (7) forms a k fluid channel; the inner cylinder (7) is provided with an inner cylinder step I at the upper edge of the k fluid channel opening; the upper radial opening of the center hole of the piston (8) forms l The fluid passage, piston (8) l A piston step II is provided below the fluid channel opening, and a fluid channel is formed by the countersunk hole of the upper core tube (4), the center hole of the lower core tube (6), the center hole of the piston (8) and the center hole of the drill bit (15).

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