A pneumatic down-the-hole impact hammer

Abstract

The present invention relates to a pneumatic down-the-hole impact hammer, which belongs to the technical field of rock drilling equipment. It is composed of an outer cylinder, a piston, a gas distribution rod, a front joint, a rear joint and a drill bit. The rear joint is installed at one end of the outer cylinder, and the drill bit is installed at the other end of the outer cylinder; a check valve is fixedly installed in the reducing hole of the rear joint through an assembly seat, and a gas distribution rod is installed on one side of the check valve, and a piston is slidably installed on the gas distribution rod. When the impact hammer is working, the end face of the rear joint can limit the axial movement of the piston during the process of the piston completing the reset of the drill bit after impacting, thereby avoiding the problem of fracture of the existing impactor caused by reset impact at the tail of the piston; at the same time, the gas in the rear air chamber can enter the slag discharge channel through the airway; it is directly used to blow the rock powder at the bottom of the well, thereby improving the cleaning effect and work efficiency of the bottom of the well; it has the characteristics of simple structure and convenient replacement of parts; it greatly improves the drilling efficiency and adaptability to hard and complex bottom layers.

Description

Technical Field

[0001] The invention relates to a pneumatic down-the-hole impact hammer, belonging to the technical field of rock drilling equipment. Background Art

[0002] In the process of actual engineering applications, traditional impactors often break at the tail of the piston. This problem causes huge losses to engineering applications, so it is necessary to improve it. Summary of the invention

[0003] The purpose of the present invention is to provide a pneumatic down-the-hole impact hammer which can effectively improve the rock crushing efficiency of a drill bit, has a simple structure, is convenient for replacing parts, and solves the problem that the existing impactor is prone to breakage at the tail of the piston.

[0004] The technical solution of the present invention is:

[0005] A pneumatic down-the-hole impact hammer, which consists of an outer cylinder, a piston, a gas distribution rod, a front joint, a rear joint and a drill bit, and is characterized in that: a rear joint is threadedly installed on one end of the outer cylinder, and a drill bit is movably installed on the other end of the outer cylinder through the front joint and a limit ring; a check valve is fixedly installed in the reducing hole of the rear joint through an assembly seat, a gas distribution rod is fixedly installed on the rear joint on one side of the check valve through a mounting seat ear, a piston is slidably installed on the gas distribution rod, and one end of the piston is intermittently contacted and connected with the drill bit; the gas distribution rod is a tubular body, and the gas distribution rod is connected to the reducing hole of the rear joint.

[0006] The circumference of the assembly seat is evenly distributed with connecting holes, and the gas distribution rod is connected with the reducing hole of the rear joint through the connecting holes.

[0007] A front air chamber and a rear air chamber formed by assembling pistons are arranged in the outer cylinder between the front joint and the rear joint.

[0008] The inner wall of the outer cylinder is provided with a divided inner boss A, a divided inner boss B and a divided inner boss C; the piston is respectively connected with the divided inner boss A, the divided inner boss B and the divided inner boss C in a sliding and sealing manner.

[0009] An air passage is arranged on the outer cylinder around the divided inner boss A, the divided inner boss B and the divided inner boss C, one end of the air passage is communicated with the front air chamber, and the other end of the air passage is communicated with the rear air chamber.

[0010] The piston is a variable diameter body, a gas distribution concave hole is arranged at the center of the piston, and the piston is slidably connected with the gas distribution rod through the gas distribution concave hole.

[0011] The piston circumference is radially evenly distributed with gas distribution holes A, which are connected with the gas distribution recessed holes; a gas distribution hole B is arranged on the piston circumference on one side of the gas distribution hole A; one end of the gas distribution hole B is connected with the rear air chamber.

[0012] The front joint is threadedly connected to the outer cylinder; the limiting ring is threadedly connected to the front joint; the drill head is a reducer, a slag discharge channel is arranged at the center of the drill head, and the drill head is respectively connected to the front joint and the limiting ring in a sliding and sealing manner.

[0013] The limiting ring is formed by two semicircular rings buckled together, and the circumferential outer surface of the limiting ring is provided with external threads.

[0014] The non-return valve is composed of a valve sleeve, a spring and a valve head. The valve sleeve is provided with a valve head through a spring. The valve head is a T-shaped body. One end of the valve head is sealed and contacted with the reducing hole port of the rear joint.

[0015] The beneficial effects of the present invention are:

[0016] When the pneumatic down-the-hole impact hammer is working, the high-pressure gas provided by the air compressor enters the piston through the check valve and the gas distribution rod and pushes the piston to reciprocate. In the process of the piston completing the reset of the impact drill bit, the end face of the rear joint can limit the axial movement of the piston, thereby avoiding the problem of fracture of the existing impactor at the tail of the piston due to the reset impact. At the same time, since the airway is connected with the front air chamber and the rear air chamber, during the reciprocating movement of the piston, the gas in the rear air chamber can enter the slag discharge channel through the airway and be directly used to blow away the rock powder at the bottom of the well, thereby improving the cleaning effect of the bottom of the well, assisting the drilling of the drill bit, and thus improving the work efficiency. The pneumatic down-the-hole impact hammer has the characteristics of simple structure and convenient replacement of parts and components, and greatly improves the drilling efficiency and adaptability to hard and complex substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 It is a schematic diagram of the initial working state of the present invention;

[0019] Figure 3 A schematic diagram of the piston striking the drill bit of the present invention;

[0020] Figure 4 It is a schematic diagram of the piston resetting process of the present invention.

[0021] In the figure: 1, outer cylinder, 2, piston, 3, gas distribution rod, 4, front joint, 5, rear joint, 6, drill bit, 7, valve sleeve, 8, spring, 9, valve head, 10, connecting hole, 11, mounting seat ear, 12, limiting ring, 13, slag discharge channel, 14, gas distribution concave hole, 15, front air chamber, 16, rear air chamber, 17, divided inner boss A, 18, divided inner boss B, 19, divided inner boss C, 20, air duct, 21, gas distribution through hole A, 22, gas distribution through hole B. DETAILED DESCRIPTION

[0022] The pneumatic down-the-hole impact hammer is composed of an outer cylinder 1, a piston 2, a gas distribution rod 3, a front joint 4, a rear joint 5 and a drill bit 6. The rear joint 5 is threadedly installed at one end of the outer cylinder 1. The central through hole of the rear joint 5 is a reducing hole. A check valve is fixedly installed in the reducing hole of the rear joint 5 through an assembly seat. Communication holes 10 are evenly distributed on the circumference of the assembly seat. The check valve is composed of a valve sleeve 7, a spring 8 and a valve head 9. The valve head 9 is installed in the valve sleeve 7 through the spring 8. The valve head 9 is a T-shaped body. One end of the valve head 9 is sealed and contacted with the reducing hole port of the rear joint 5.

[0023] A gas distribution rod 3 is fixedly mounted on the rear joint 5 on one side of the check valve through a mounting seat ear 11, a retaining ring and an adjusting gasket. The gas distribution rod 3 is a tubular body and is connected to the reducing hole of the rear joint 5 through a connecting hole 10.

[0024] The other end of the outer cylinder 1 is movably mounted with a drill bit 6 through a front joint 4 and a limiting ring 12; the front joint 4 is a tubular body, the front joint 4 and the outer cylinder 1 are threadedly connected, the limiting ring 12 is formed by two semicircular rings that are buckled together, and the circumferential outer surface of the limiting ring 12 is provided with an external thread; the limiting ring 12 and the front joint 4 are threadedly connected; the drill bit 6 is a reducer, and a slag discharge channel 13 is provided at the center of the drill bit 6, and the drill bit 6 is respectively connected to the front joint 4 and the limiting ring 12 in a sliding and sealing manner.

[0025] The piston 2 is a reducer, and a gas distribution concave hole 14 is provided at the center of the piston 2. The piston 2 is slidably inserted and connected with the gas distribution rod 3 through the gas distribution concave hole 14. One end of the piston 2 is intermittently contacted and connected with the drill bit 6;

[0026] The outer cylinder 1 between the front joint 4 and the rear joint 5 is provided with a front air chamber 15 and a rear air chamber 16 formed by the piston 2. The inner wall of the outer cylinder 1 is provided with a split inner boss A17, a split inner boss B18 and a split inner boss C19; the large diameter section of the piston 2 is slidably and sealedly connected to the split inner boss A17 and the split inner boss B18; the small diameter section of the piston 2 is slidably and sealedly connected to the split inner boss C19.

[0027] An air passage 20 is provided on the outer cylinder 1 outside the divided inner boss A17 , the divided inner boss B18 and the divided inner boss C19 , one end of the air passage 20 is connected to the front air chamber 15 , and the other end of the air passage 20 is connected to the rear air chamber 16 .

[0028] The piston 2 of the pneumatic down-the-hole impact hammer is radially evenly distributed with gas distribution holes A21, and the gas distribution holes A are connected to the gas distribution recessed hole 14; a gas distribution hole B22 is arranged on the circumference of the piston 2 on one side of the gas distribution hole A21; one end of the gas distribution hole 22B extends to the rear end surface of the piston 2 and is connected to the rear air chamber 16 (see Figure 1 ).

[0029] When the pneumatic down-the-hole impact hammer is working, the pneumatic down-the-hole impact hammer is installed on the air compressor through the rear joint 5; in the initial state, the gas distribution rod 3 blocks the gas distribution through hole A21, the piston 2 blocks the air channel 20, and the split inner boss A17 blocks the gas distribution through hole B22 (see Figure 2 ). During operation, the high-pressure gas provided by the air compressor passes through the central through hole of the rear joint 5, pushes the valve head 9 of the check valve and compresses the spring 8, so that it releases the sealing state with the reducing hole of the rear joint 5, and enters the tool; the high-pressure gas entering the tool enters the central hole of the gas distribution rod 3 through the connecting hole 10, thereby pushing the piston 2 to slide forward along the gas distribution rod and hit the drill bit 6. In this process, the blockage formed by the gas distribution rod 3 on the gas distribution through hole A21, the blockage formed by the piston 2 on the air channel 20, and the blockage formed by the dividing inner boss A17 on the gas distribution through hole B22 are released. During the process of the piston 2 moving forward and hitting the drill bit 6, the split inner boss C19 cooperates with the reducing shoulder of the piston 2 to limit the piston 2 axially. During the process of the piston 2 hitting the drill bit 6, the piston 2 can compress the gas in the front air chamber 15 to accelerate its discharge from the slag discharge channel 13 to blow away the rock powder at the bottom of the well, thereby improving the cleaning effect of the bottom of the well, assisting the drilling of the drill bit, and thus improving work efficiency. At the same time, the excess gas in the front air chamber 15 enters the rear air chamber 16 through the air duct 20 to ensure the pressure balance between the front air chamber 15 and the rear air chamber 16.

[0030] After the piston 2 hits the drill bit 6, the high-pressure gas in the gas distribution rod 3 enters into the sealed chamber formed between the divided inner boss C19 and the divided inner boss B18 through the gas distribution recess 14 and the gas distribution through hole A21, and acts on the reducing shoulder of the piston 2; as the high-pressure gas gathers in the sealed chamber formed between the divided inner boss C19 and the reducing shoulder of the piston 2, the piston 2 is pushed to slide backward (reset) along the gas distribution rod 3.

[0031] During the backward sliding of the piston 2 along the gas distribution rod 3, under the action of inertia, the gas distribution hole A21 enters into the sealed chamber formed between the segmented inner boss B18 and the segmented inner boss A17. At this time, under the action of inertia, the piston 2 continues to reset. At the same time, the high-pressure gas entering into the sealed chamber formed between the segmented inner boss B18 and the segmented inner boss A17 enters the rear air chamber 16 through the gas distribution hole B22, so as to prepare for the piston 2 to hit the drill bit 6 again. When the piston 2 is reset, the gas distribution hole B22 is blocked again by the segmented inner boss A17, and the high-pressure gas in the sealed chamber formed between the segmented inner boss B18 and the segmented inner boss A17 cannot be discharged. The gas entering the center hole of the gas distribution rod 3 can act on the gas distribution concave hole 14, thereby pushing the piston 2 to slide forward along the gas distribution rod and hit the drill bit 6 again. Thus, a working cycle is completed. In this cycle, the piston 2 continuously hits the drill bit 6, causing it to accelerate and break the rock. The pneumatic down-the-hole impact hammer has a simple structure and good practicality. During the process of the piston 2 completing the impact of the drill bit 6 to reset, the end face of the rear joint 5 can limit the axial movement of the piston 2, thereby avoiding the problem of the existing impactor being easily broken at the tail of the piston due to the reset impact; at the same time, since the airway is connected with the front air chamber 15 and the rear air chamber 16, the pressure balance of the front air chamber 15 and the rear air chamber 16 is guaranteed. During the reciprocating movement of the piston 2, the gas in the rear air chamber 16 can enter the slag discharge channel 13 through the airway 20; it is directly used to blow away the rock powder at the bottom of the well, thereby improving the cleaning effect of the bottom of the well, assisting the drilling of the drill bit 6, and thus improving the work efficiency; the pneumatic down-the-hole impact hammer has the characteristics of simple structure and convenient replacement of parts; it greatly improves the drilling efficiency and adaptability to hard and complex bottom layers.

Claims

1. A pneumatic down-the-hole impact hammer, which consists of an outer cylinder (1), a piston (2), a gas distribution rod (3), a front joint (4), a rear joint (5) and a drill bit (6), characterized in that: A rear joint (5) is threadedly mounted on one end of the outer cylinder (1), and a drill bit (6) is movably mounted on the other end of the outer cylinder (1) via a front joint (4) and a stop ring (12); a check valve is fixedly mounted in the reducing hole of the rear joint (5) via an assembly seat, a gas distribution rod (3) is fixedly mounted on the rear joint (5) on one side of the check valve via an assembly seat ear (11), a piston (2) is slidably mounted on the gas distribution rod (3), and one end of the piston (2) is intermittently contacted and connected with the drill bit (6); the gas distribution rod (3) is a tubular body, and the gas distribution rod (3) is connected to the reducing hole of the rear joint (5); A front air chamber (15) and a rear air chamber (16) formed by assembling a piston (2) are arranged in the outer cylinder (1) between the front joint (4) and the rear joint (5); The inner wall of the outer cylinder (1) is provided with a divided inner boss A (17), a divided inner boss B (18) and a divided inner boss C (19); the piston (2) is respectively connected to the divided inner boss A (17), the divided inner boss B (18) and the divided inner boss C (19) in a sliding and sealing manner; An air passage (20) is provided on the outer cylinder (1) outside the divided inner boss A (17), the divided inner boss B (18) and the divided inner boss C (19), one end of the air passage (20) is connected to the front air chamber (15), and the other end of the air passage (20) is connected to the rear air chamber (16); The piston (2) is a variable diameter body, and a gas distribution recessed hole (14) is provided at the center of the piston. The piston (2) is slidably connected to the gas distribution rod (3) via the gas distribution recessed hole (14). The drill bit (6) is a reducer, and a slag discharge channel (13) is provided at the center of the drill bit (6). The piston (2) is provided with gas distribution holes A (21) evenly distributed radially on its circumference, and the gas distribution holes A (21) are connected to the gas distribution recessed hole (14); a gas distribution hole B (22) is provided on the circumference of the piston (2) on one side of the gas distribution hole A (21); one end of the gas distribution hole B (22) is connected to the rear air chamber (16); In the initial state, the gas distribution rod (3) blocks the gas distribution through hole A (21), the piston (2) blocks the air passage (20), and the split inner boss A (17) blocks the gas distribution through hole B (22); during operation, the blockage formed by the gas distribution rod (3) on the gas distribution through hole A (21), the blockage formed by the piston (2) on the air passage (20), and the blockage formed by the split inner boss A (17) on the gas distribution through hole B (22) are released.

2. A pneumatic down-the-hole impact hammer according to claim 1, characterized in that: The assembly seat is evenly distributed with communicating holes (10) on its circumference, and the gas distribution rod (3) is connected to the reducing hole of the rear joint (5) through the communicating holes (10).

3. A pneumatic down-the-hole impact hammer according to claim 1, characterized in that: The front joint (4) is threadedly connected to the outer cylinder (1); the limiting ring (12) is threadedly connected to the front joint (4); and the drill bit (6) is respectively connected to the front joint (4) and the limiting ring (12) in a sliding and sealing manner.

4. A pneumatic down-the-hole impact hammer according to claim 3, characterized in that: The limiting ring (12) is formed by two semicircular rings buckled together, and the circumferential outer surface of the limiting ring (12) is provided with an external thread.

5. The pneumatic down-the-hole impact hammer according to claim 1, characterized in that: The check valve is composed of a valve sleeve (7), a spring (8) and a valve head (9). The valve sleeve (7) is provided with a valve head (9) via the spring (8). The valve head (9) is a T-shaped body. One end of the valve head (9) is in sealing contact with the reducing hole port of the rear joint (5).

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