A down-the-hole hammer

Abstract

The application relates to a down-the-hole hammer, which comprises an outer cylinder, an impact assembly for impacting a down-the-hole drill, the impact assembly comprising a large piston, a small piston and a connecting structure, a first inner cylinder arranged in the outer cylinder, the large piston being slidably connected in the first inner cylinder, a second inner cylinder arranged in the outer cylinder, the small piston being slidably connected in the second inner cylinder, and the connecting structure being used for separating and connecting the large piston and the small piston, when the large piston moves to one side of the down-the-hole drill, the large piston is connected with the small piston and impacts the down-the-hole drill, when the large piston moves to the side away from the down-the-hole drill, the large piston first drives the small piston to move to a first position away from the down-the-hole drill to separate the small piston from the large piston, and then the small piston moves to the side of the down-the-hole drill to impact the down-the-hole drill. Through the double-impact assembly of the large piston and the small piston, twice independent impacts, i.e. the impact of the large piston driving the small piston and the independent rebound impact of the small piston, are realized, and the impact frequency and the breaking efficiency of the down-the-hole drill are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of impactors, in particular to a down-the-hole impactor. Background Art

[0002] The down-the-hole hammer is a key component of down-the-hole drilling rigs and is widely used in drilling operations in metallurgy, coal, chemical, and building materials industries, as well as in water conservancy, hydropower, highway, railway, national defense, and construction projects. Its operating principle is as follows: compressed gas enters the hammer through the drill pipe, pushing the internal piston in high-speed reciprocating motion. The downward movement of the piston impacts the drill bit, breaking the rock. Simultaneously, the exhaust gas from the drill bit is used to remove slag.

[0003] The down-the-hole impactors in the prior art are all based on the above-mentioned piston reciprocating impact principle. During operation, the gas injection interval determines the impact frequency, resulting in a low impact frequency of the down-the-hole impactor and low drilling efficiency. Summary of the Invention

[0004] In order to improve and increase the impact frequency of a down-the-hole impactor, the present application provides a down-the-hole impactor.

[0005] The present application provides a down-the-hole impactor that adopts the following technical solution:

[0006] A down-the-hole impactor comprises an outer cylinder, two ends of the outer cylinder are respectively provided with a rear joint and a front joint connected to a down-the-hole drill, and also comprises an impact assembly for impacting the down-the-hole drill, the impact assembly comprising a large piston, a small piston and a connecting structure, a first inner cylinder is provided in the outer cylinder, an air inlet passage is provided between the outer cylinder and the first inner cylinder, the large piston is slidably connected in the first inner cylinder, a second inner cylinder is provided in the outer cylinder, an air outlet passage is provided between the outer cylinder and the second inner cylinder, the small piston is slidably connected in the second inner cylinder, the small piston is located between the large piston and the down-the-hole drill, and the connecting structure is used to separate and connect the large piston and the small piston, when the large piston moves toward the down-the-hole drill, the large piston moves to connect with the small piston and impact the down-the-hole drill, when the large piston moves toward the side away from the down-the-hole drill, the large piston first drives the small piston to move toward the side away from the down-the-hole drill to a first position to separate the small piston from the large piston, and then the small piston moves toward the down-the-hole drill to impact the down-the-hole drill.

[0007] By adopting this technical solution and employing a dual impact assembly consisting of a large piston and a small piston, two independent impacts are achieved: the large piston driving the small piston impact and the small piston independently rebounding. This significantly improves the impact frequency and crushing efficiency of the down-the-hole drill. The separation and connection functions of the connecting structure enable the large and small pistons to work together at different stages of the stroke, optimizing the dynamic performance of the impactor and reducing energy loss.

[0008] Preferably, the connection structure includes a plurality of opening and closing blocks, and the plurality of opening and closing blocks are respectively slidably connected to the small piston, and the plurality of opening and closing blocks are evenly distributed around the circumference of the small piston. The plurality of opening and closing blocks are respectively provided with matching grooves, and the large piston is provided with a matching ring. When the large piston moves toward the side of the down-the-hole drill, the plurality of opening and closing blocks can be moved to the matching groove and the matching ring to match. When the large piston moves toward the side away from the down-the-hole drill, the plurality of opening and closing blocks can be moved to the matching groove and disengage from the matching ring.

[0009] This technical solution allows the opening and closing block to quickly connect and disconnect via a mating groove and the mating ring of the large piston, resulting in a simple structure and high reliability. When the large piston moves toward the down-the-hole drill, the opening and closing block locks with the mating ring, ensuring synchronous movement of the large and small pistons for a combined impact. When the large piston moves in the opposite direction, the opening and closing block disengages the mating ring, allowing the small piston to rebound and impact independently, creating a two-stage impact cycle.

[0010] Preferably, the second inner cylinder is provided with a plurality of guide rails, the plurality of opening and closing blocks respectively correspond to the plurality of guide rails, and the plurality of opening and closing blocks are respectively slidably connected to the corresponding guide rails along an axial direction inclined to the second inner cylinder.

[0011] By adopting this technical solution, when the large piston approaches the small piston, the opening and closing blocks converge toward the center along the inclined slide rails, engaging the mating groove with the mating ring of the large piston. When the large piston moves in the opposite direction, the opening and closing blocks spread outward along the inclined slide rails, disengaging the mating groove from the mating ring. This ensures the reliability of the connection and separation action, reduces the possibility of the opening and closing blocks engaging failure or accidental separation, and improves the stability of the impactor's operation.

[0012] Preferably, an abutment block is provided at one end of the large piston close to the small piston, and when the large piston slides toward the down-the-hole drill, the abutment block preferentially abuts against the small piston.

[0013] By adopting the above technical solution, the reliable connection timing of the large piston and the small piston is ensured, and the abutment block bears the impact force of the initial contact, avoiding the opening and closing block from being subjected to excessive load when it is not fully matched, thereby reducing the risk of wear of the opening and closing block and the mating ring, and extending the maintenance cycle and service life of the impactor.

[0014] Preferably, a central channel is coaxially opened on the large piston, the small piston includes a piston portion and an abutting portion, a docking air channel is opened on the abutting portion, and an air relief channel is opened on the piston portion. When the large piston moves to connect with the small piston, the central channel is connected to the docking air channel, and when the small piston moves to the second position toward the side of the down-the-hole drill, the air relief channel is connected to the air outlet channel.

[0015] By adopting this technical solution, when the large and small pistons are connected, the central channel communicates with the docking airway, allowing compressed gas to pass directly through the interior of the large piston and act directly on the abutment of the small piston, storing energy for the small piston's rebound impact. When the small piston moves independently to its second position, the air vent and outlet channels connect, rapidly discharging exhaust gas. The gas pressure differential then drives the small piston to rebound at high speed, achieving a second impact.

[0016] Preferably, the diameter of the abutment portion is smaller than the diameter of the piston portion, and a compressed air chamber is formed between the abutment portion, the piston portion and the second inner cylinder. The compressed air chamber is always connected to the docking air channel. When the small piston and the large piston are docked, the gas enters the compressed air chamber through the docking air channel.

[0017] By adopting this technical solution, the abutment portion, with a smaller diameter than the piston portion, forms a compressed air chamber, which stores compressed gas energy when the large and small pistons are connected. When the two pistons separate, the gas in the compressed air chamber expands, rapidly propelling the small piston toward the down-the-hole drill, achieving independent, gas-driven impact and reducing reliance on the movement of the large piston. The continuous ventilation design of the compressed air chamber ensures a continuous energy storage process, making the rebound impact of the small piston more explosive and enhancing the crushing effect.

[0018] Preferably, a second check valve is provided in the docking air duct.

[0019] By adopting this technical solution, the check valve prevents the compressed gas from flowing in the opposite direction during the rebound impact of the small piston, ensuring that the gas energy is used only to propel the small piston toward the down-the-hole drill, thus preventing energy leakage. The one-way airflow control improves the stability of the impact process, ensuring that the small piston can reliably complete its independent impact action after separation, and reducing the possibility of impact failure or reduced efficiency due to reverse airflow.

[0020] The technical effects of the present invention are mainly reflected in the following aspects:

[0021] 1. The present invention utilizes a dual impact assembly consisting of a large piston and a small piston to achieve two independent impacts: the large piston driving the small piston impact and the small piston independently rebounding and impacting, significantly improving the impact frequency and crushing efficiency of the down-the-hole drill. The separation and connection functions of the connecting structure enable the large and small pistons to work together at different stroke stages, optimizing the dynamic performance of the impactor and reducing energy loss.

[0022] 2. The opening and closing block of the present invention achieves rapid connection and separation through the mating groove and the mating ring of the large piston, with a simple structure and high reliability. When the large piston moves toward the down-the-hole drill, the opening and closing block locks with the mating ring, ensuring that the large and small pistons move synchronously and achieve a combined impact. When the large piston moves in the opposite direction, the opening and closing block disengages the mating ring, allowing the small piston to rebound and impact independently, forming a two-stage impact cycle.

[0023] 3. The present invention ensures the reliable connection timing of the large piston and the small piston by setting an abutment block. The abutment block bears the impact force of the initial contact, avoiding the opening and closing block from bearing excessive load when it is not fully matched, thereby reducing the wear risk of the opening and closing block and the matching ring, and extending the maintenance cycle and service life of the impactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the overall structure of the embodiment of the present application Figure 1 .

[0025] Figure 2 This is a structural diagram of the connection state of the large piston and the small piston in an embodiment of the present application.

[0026] Figure 3 It is along Figure 1 Enlarged view of point A in the middle.

[0027] Figure 4 It is along Figure 2 Enlarged view of point B in the middle.

[0028] Figure 5 It is a schematic diagram of the small piston structure of an embodiment of the present application.

[0029] Figure 6 This is a schematic diagram of the overall structure of the embodiment of the present application Figure 2 .

[0030] Figure 7 This is a schematic diagram of the large piston structure of an embodiment of the present application.

[0031] Explanation of the accompanying drawings: 1. Outer cylinder; 2. Rear joint; 3. Front joint; 4. Down-the-hole drill; 5. Impact assembly; 6. Large piston; 7. Small piston; 8. Connecting structure; 9. First inner cylinder; 10. Air inlet duct; 11. Second inner cylinder; 12. Air outlet duct; 14. Opening and closing block; 15. Matching groove; 16. Matching ring; 17. Guide rail; 18. Abutment block; 19. Center channel; 20. Piston part; 21. Abutment part; 22. Docking air duct; 23. Air discharge duct; 24. Compressed air chamber; 25. Second check valve. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-7 The present application is further described in detail to make the technical solution of the present application easier to understand and grasp.

[0033] The embodiment of the present application discloses a down-the-hole impactor.

[0034] Reference Figure 1 and Figure 6The present embodiment is a down-the-hole impactor, comprising an outer cylinder 1, a rear joint 2 and a front joint 3 connected to a down-the-hole drill 4, respectively fixedly connected at both ends of the outer cylinder 1, and an impact assembly 5 for impacting the down-the-hole drill 4. The impact assembly 5 comprises a large piston 6, a small piston 7 and a connecting structure 8. A first inner cylinder 9 is fixedly connected to the outer cylinder 1, an air inlet 10 is provided between the outer cylinder 1 and the first inner cylinder 9, the large piston 6 is slidably connected to the first inner cylinder 9 along the axial direction of the outer cylinder 1, a second inner cylinder 11 is fixedly connected to the outer cylinder 1, and an air outlet 12 is provided between the outer cylinder 1 and the second inner cylinder 11. The small piston 7 is slidably connected in the second inner cylinder 11. The small piston 7 is located between the large piston 6 and the down-the-hole drill 4. The connecting structure 8 is used to separate and connect the large piston 6 and the small piston 7. When the large piston 6 moves toward the side of the down-the-hole drill 4, the large piston 6 moves to connect with the small piston 7 and impact the down-the-hole drill 4. When the large piston 6 moves toward the side away from the down-the-hole drill 4, the large piston 6 first drives the small piston 7 to move toward the side away from the down-the-hole drill 4 to the first position to separate the small piston 7 from the large piston 6. Then, the small piston 7 moves toward the side of the down-the-hole drill 4 to impact the down-the-hole drill 4.

[0035] Reference Figure 1 and Figure 2 By providing a dual impact assembly 5 comprising a large piston 6 and a small piston 7, two independent impacts are achieved: the large piston 6 driving the small piston 7 to impact, and the small piston 7 independently rebounding to impact. This significantly improves the impact frequency and crushing efficiency of the down-the-hole drill 4. The separation and connection functions of the connecting structure 8 enable the large piston 6 and the small piston 7 to work together at different stages of the stroke, optimizing the dynamic performance of the impactor and reducing energy loss.

[0036] Reference Figure 5 and Figure 7 The connecting structure 8 includes a plurality of opening and closing blocks 14, which are respectively slidably connected to the small piston 7 along the central axis perpendicular to the small piston 7, and the plurality of opening and closing blocks 14 are respectively evenly distributed around the circumference of the small piston 7. A matching groove 15 is respectively provided on the plurality of opening and closing blocks 14, and a matching ring 16 is coaxially and fixedly connected to the large piston 6. When the large piston 6 moves toward the side of the down-the-hole drill 4, the plurality of opening and closing blocks 14 can move to the matching groove 15 and the matching ring 16 to match. When the large piston 6 moves toward the side away from the down-the-hole drill 4, the plurality of opening and closing blocks 14 can move to the matching groove 15 and disengage from the matching ring 16.

[0037] Reference Figure 3 and Figure 4 The second inner cylinder 11 is provided with a plurality of guide rails 17 , and the plurality of opening and closing blocks 14 correspond to the plurality of guide rails 17 respectively. The plurality of opening and closing blocks 14 are slidably connected to the corresponding guide rails 17 along an axial direction inclined to the second inner cylinder 11 .

[0038] Reference Figure 3 and Figure 4The opening and closing block 14 realizes quick connection and separation through the matching groove 15 and the matching ring 16 of the large piston 6, with a simple structure and high reliability. When the large piston 6 moves toward the down-the-hole drill 4, the opening and closing block 14 is locked with the matching ring 16 to ensure that the large piston 6 and the small piston 7 move synchronously to achieve a combined impact; when the large piston 6 moves in the opposite direction, the opening and closing block 14 disengages from the matching ring 16, allowing the small piston 7 to rebound and impact independently, forming a two-stage impact cycle. The opening and closing block 14 gathers toward the center along the inclined slide rail, so that the matching groove 15 engages with the matching ring 16 of the large piston 6; when the large piston 6 moves in the opposite direction, the opening and closing block 14 spreads outward along the inclined slide rail, so that the matching groove 15 disengages from the matching ring 16. Ensure the reliability of the connection and separation action, reduce the possibility of the opening and closing block 14 failing to engage or separating by mistake, and improve the stability of the impactor.

[0039] Reference Figure 3 、 Figure 4 and Figure 7 The end of the large piston 6 near the small piston 7 is fixedly connected to an abutment block 18. When the large piston 6 slides toward the side of the down-the-hole drill 4, the abutment block 18 preferentially abuts against the small piston 7. To ensure the reliable connection sequence between the large piston 6 and the small piston 7, the abutment block 18 bears the impact force of the initial contact, preventing the opening and closing block 14 from bearing excessive load when it is not fully engaged, thereby reducing the risk of wear between the opening and closing block 14 and the mating ring 16, and extending the maintenance cycle and service life of the impactor.

[0040] Reference Figure 1 and Figure 2 A central channel 19 is coaxially provided on the large piston 6, and the small piston 7 includes a piston portion 20 and an abutting portion 21. A docking air passage 22 is provided on the abutting portion 21, and an air vent 23 is provided on the piston portion 20. When the large piston 6 moves to connect with the small piston 7, the central channel 19 is connected to the docking air passage 22. When the small piston 7 moves to the second position toward the side of the down-the-hole drill 4, the air vent 23 is connected to the air outlet 12. When the large piston 6 is connected to the small piston 7, the central channel 19 is connected to the docking air passage 22, so that the compressed gas can directly act on the abutting portion 21 of the small piston 7 through the inside of the large piston 6, thereby reserving energy for the rebound impact of the small piston 7. When the small piston 7 moves independently to the second position, the air vent 23 is connected to the air outlet 12, quickly discharging the exhaust gas, and utilizing the gas pressure difference to drive the small piston 7 to rebound at high speed, thereby achieving a second impact.

[0041] Reference Figure 5The diameter of the abutment portion 21 is smaller than that of the piston portion 20. A compressed air chamber 24 is formed between the abutment portion 21, the piston portion 20 and the second inner cylinder 11. The compressed air chamber 24 is always connected to the docking air channel 22. When the small piston 7 is docked with the large piston 6, the gas enters the compressed air chamber 24 through the docking air channel 22. The compressed air chamber 24 formed by the abutment portion 21 having a smaller diameter than the piston portion 20 can store compressed gas energy when the large piston 6 and the small piston 7 are connected. When the two are separated, the gas in the compressed air chamber 24 expands, pushing the small piston 7 to move rapidly in the direction of the down-the-hole drill 4, realizing gas-driven independent impact and reducing dependence on the movement of the large piston 6; the continuous ventilation design of the compressed air chamber 24 ensures the continuity of the energy storage process, making the rebound impact of the small piston 7 more explosive and improving the crushing effect.

[0042] Reference Figure 3 and Figure 4 A second check valve 25 is fixedly connected to the docking air passage 22. This check valve prevents the compressed gas from flowing in the opposite direction during the rebound impact of the small piston 7, ensuring that the gas energy is used only to propel the small piston 7 toward the down-the-hole drill 4 and preventing energy leakage. This one-way airflow control improves the stability of the impact process, ensuring that the small piston 7 can reliably complete its independent impact action after separation, and reducing the possibility of impact failure or reduced efficiency due to reverse airflow.

[0043] Reference Figure 3 、 Figure 4 and Figure 6 , in summary, the working process of the down-the-hole impact drill is:

[0044] S1, intake stage: compressed air enters the first inner cylinder 9 through the intake duct 10 between the outer cylinder 1 and the first inner cylinder 9, pushing the large piston 6 to move toward the down-the-hole drill 4; at this time, the large piston 6 and the small piston 7 are in a separated state;

[0045] S2, impact stage of connection between the large piston 6 and the small piston 7: During the forward movement of the large piston 6, the abutment block 18 at its front end first contacts the small piston 7, pushing the small piston 7 forward synchronously; when the large piston 6 continues to move forward to a specific position, the matching groove 15 of the opening and closing block 14 and the matching ring 16 of the large piston 6 engage with each other, rigidly connecting the large piston 6 and the small piston 7 to form an integral impact structure; the two move forward together, making the first impact on the down-the-hole drill 4, transferring kinetic energy to the drill bit to break the rock;

[0046] S3, return stage: After the impact is completed, the compressed air reverses direction, and the large piston 6 begins to move away from the down-the-hole drill 4. Since the connecting structure 8 is still in the engaged state, the large piston 6 drives the small piston 7 to move back synchronously until it moves to the first position; the opening and closing block 14 disengages the mating groove 15 and the mating ring 16 due to the inclined design of the guide rail 17, and the large piston 6 and the small piston 7 are separated;

[0047] S4, independent impact stage of the small piston 7: the large piston 6 continues to retreat, while the small piston 7 loses its restraint after separation and moves rapidly toward the side of the down-the-hole drill 4 under the action of the compressed air in the second inner cylinder 11; when the small piston 7 moves to the second position, the air discharge channel 23 of its piston part 20 is connected to the air outlet channel 12 between the outer cylinder 1 and the second inner cylinder 11, and the compressed air pushes the small piston 7 to complete the second impact, again applying kinetic energy to the down-the-hole drill 4;

[0048] S5, exhaust and circulation stage: After the small piston 7 impacts, the exhaust gas is discharged through the outlet duct 12; at the same time, the large piston 6 retreats to the initial position, and the compressed air is introduced into the inlet duct 10 again; the impactor as a whole moves toward the side of the down-the-hole drill 4, so that the small piston 7 and the down-the-hole drill 4 are reset relative to the second inner cylinder 11; the above process is repeated to achieve continuous impact rock breaking.

[0049] Of course, the above are only typical examples of the present application. In addition, the present application may have many other specific implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present application.

Claims

1. A down-the-hole impactor, comprising an outer cylinder (1), two ends of the outer cylinder (1) are respectively provided with a rear joint (2) and a front joint (3) connected to a down-the-hole drill (4), characterized in that: The invention also includes an impact assembly (5) for impacting a down-the-hole drill (4), wherein the impact assembly (5) includes a large piston (6), a small piston (7) and a connecting structure (8), wherein a first inner cylinder (9) is provided in the outer cylinder (1), an air inlet (10) is provided between the outer cylinder (1) and the first inner cylinder (9), the large piston (6) is slidably connected in the first inner cylinder (9), a second inner cylinder (11) is provided in the outer cylinder (1), an air outlet (12) is provided between the outer cylinder (1) and the second inner cylinder (11), the small piston (7) is slidably connected in the second inner cylinder (11), and the small piston (7) is located in the large piston. (6) and the down-the-hole drill (4), the connecting structure (8) is used for separating and connecting the large piston (6) and the small piston (7); when the large piston (6) moves toward the side of the down-the-hole drill (4), the large piston (6) moves to connect with the small piston (7) and impacts the down-the-hole drill (4); when the large piston (6) moves toward the side away from the down-the-hole drill (4), the large piston (6) first drives the small piston (7) to move toward the side away from the down-the-hole drill (4) to the first position to separate the small piston (7) from the large piston (6), and then the small piston (7) moves toward the side of the down-the-hole drill (4) to impact the down-the-hole drill (4); The connection structure (8) includes a plurality of opening and closing blocks (14), and the plurality of opening and closing blocks (14) are respectively slidably connected to the small piston (7). The plurality of opening and closing blocks (14) are evenly distributed around the circumference of the small piston (7). The plurality of opening and closing blocks (14) are respectively provided with matching grooves (15). The large piston (6) is provided with a matching ring (16). When the large piston (6) moves toward the side of the down-the-hole drill (4), the plurality of opening and closing blocks (14) can move to the matching grooves (15) and match with the matching ring (16). When the large piston (6) moves toward the side away from the down-the-hole drill (4), the plurality of opening and closing blocks (14) can move to the matching grooves (15) and disengage from the matching ring (16). The second inner cylinder (11) is provided with a plurality of guide rails (17), and the plurality of opening and closing blocks (14) respectively correspond to the plurality of guide rails (17). The plurality of opening and closing blocks (14) are respectively slidably connected to the corresponding guide rails (17) along an axial direction inclined to the second inner cylinder (11).

2. A down-the-hole impactor according to claim 1, characterized in that: An abutment block (18) is provided at one end of the large piston (6) close to the small piston (7). When the large piston (6) slides toward the side of the down-the-hole drill (4), the abutment block (18) preferentially abuts against the small piston (7).

3. The down-the-hole impactor according to claim 1, characterized in that: The large piston (6) is coaxially provided with a central channel (19), and the small piston (7) comprises a piston portion (20) and an abutting portion (21). The abutting portion (21) is provided with a docking air channel (22), and the piston portion (20) is provided with an air release channel (23). When the large piston (6) moves to connect with the small piston (7), the central channel (19) is connected to the docking air channel (22). When the small piston (7) moves to a second position toward the side of the down-the-hole drill (4), the air release channel (23) is connected to the air outlet channel (12).

4. A down-the-hole impactor according to claim 3, characterized in that: The diameter of the abutting portion (21) is smaller than the diameter of the piston portion (20). A compressed air chamber (24) is formed between the abutting portion (21), the piston portion (20) and the second inner cylinder (11). The compressed air chamber (24) is always connected to the docking air passage (22). When the small piston (7) and the large piston (6) are docked, gas enters the compressed air chamber (24) through the docking air passage (22).

5. A down-the-hole impactor according to claim 4, characterized in that: A second check valve (25) is provided in the docking air passage (22).

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