A hydraulic rock drill with back-hitting function

Abstract

The present invention relates to related devices of a hydraulic rock drill, specifically to a hydraulic rock drill with a back-hitting function, comprising a drill tail, a piston and a pull rod device, wherein the drill tail is arranged at the front of a machine body, the piston is arranged at the rear of the machine body, an annular boss is provided in the middle of the outer wall of the drill tail, the pull rod device comprises a front back-hitting sleeve, a rear back-hitting pad, a connecting rod and a return spring, the connecting rod is fixedly connected to the front back-hitting sleeve and the rear back-hitting pad respectively, the front back-hitting sleeve is located in front of the annular boss and can be movably mounted on the outer wall of the drill tail, the rear back-hitting pad is arranged directly behind the piston, the return spring is mounted on the outer wall of the drill tail, the front end face of the return spring abuts the front end cover of the machine body, and the rear end face thereof abuts the front back-hitting sleeve, and a guide mechanism for guiding the pull rod mechanism to move forward and backward is also provided on the machine body. The hydraulic rock drill has the advantages of strong and reliable rotational torque, low failure rate and reliable operation, large impact force, small size and good maintainability.

Description

Technical Field

[0001] The invention relates to a related device of a hydraulic rock drill, in particular to a hydraulic rock drill with a back-hitting function. Background Art

[0002] Hydraulic rock drills are widely used in the fields of tunnel construction, blast furnace ironmaking and tapping. Hydraulic rock drills include pistons, drill tails, rotary drive mechanisms and other auxiliary mechanisms such as cooling, dust removal, and lubrication. When in use, the drill rod is connected to the front end of the drill tail through the drill rod sleeve. The drill tail is repeatedly hit in the axial direction of the piston. The rotary drive mechanism drives the drill tail to rotate. The drill rod rotates with the drill tail and simultaneously vibrates axially to achieve forward propulsion. Affected by the rotary drilling fluid, when the rock drill is withdrawn, the drill rod can easily be stuck in the rotary drilling fluid, resulting in a drill jam. Some existing hydraulic rock drills have a piston set at the rear end of the drill tail. The piston can only hit the rear end face of the drill tail. This type of hydraulic rock drill cannot achieve the function of returning the drill. For existing hydraulic rock drills with a return function, see Figure 5 The piston is mounted on the outer wall of the middle part of the drill tail, and an annular boss is provided at the rear end of the drill tail. When drilling, the piston hits the rear end face of the drill pipe sleeve to push the drill pipe forward. When the drill is stuck, the drill tail moves forward relative to the piston, and the annular boss at its rear end enters the stroke of the piston. The rear end face of the piston repeatedly hits the front end face of the annular boss to hit the drill tail back, so that the drill tail retreats and the drill pipe is freed from the constraints of the working medium. The existing hydraulic rock drill with a back-hitting function has the following disadvantages: first, since the piston is sleeved on the outer wall of the drill tail, the piston and the drill tail move at a relatively high speed, resulting in a very high concentricity requirement for the piston and the drill tail. Since the drill tail is in a high-temperature (for example, blast furnace tapping) and high-pressure environment during rock drilling, it is subjected to high impact and high-frequency vibration. After the guide copper sleeve of the drill tail is worn, the drill tail is prone to deflection during movement, which in turn damages the piston and affects the impact, is prone to failure, and has a shortened service life. Second, the drill tail of the existing rock drill with a back-hitting function runs through the entire body and is very long in the axial direction. The drill tail vibrates at a high speed during operation. In order to ensure reliable strength, the drill tail must be configured with a large diameter to match its length. Since the piston is sleeved on the outer wall of the drill tail, the piston diameter must also be large, thereby increasing the radial size of the body, resulting in a large and bulky rock drill, which increases the difficulty of disassembly and maintenance. Third, it is inconvenient to replace the drill pipe sleeve. The drill pipe sleeve cannot be empty-punched back, making replacement of the drill pipe sleeve difficult. Summary of the Invention

[0003] The object of the present invention is to provide a hydraulic rock drill with a piston and a drill tail separated and a back-driving function, which has the advantages of strong and reliable rotation torque, low failure rate, reliable operation, large impact force, small size, and good maintainability.

[0004] The technical solution for achieving the above-mentioned purpose includes the following contents.

[0005] A hydraulic rock drill with a back-hitting function comprises a drill tail, a piston arranged in the inner cavity of a machine body, the front part of the drill tail protruding from the central hole of the front end cover of the machine body, and a pull rod device. The drill tail is arranged at the front of the machine body, and the piston is arranged at the rear of the machine body. A front-hitting gap is provided between the front end face of the piston and the rear end face of the drill tail. An annular boss is provided in the middle of the outer wall of the drill tail, and a limiting boss is provided on the inner wall of the front part of the machine body. The limiting boss is located behind the annular boss. The pulling rod device comprises a front back-hitting sleeve and a rear back-hitting pad. , connecting rod and return spring, the connecting rod is parallel to the axial direction of the piston, and its front and rear ends are fixedly connected with the front return sleeve and the rear return pad respectively. The front return sleeve is in front of the annular boss and can be movably mounted on the outer wall of the drill tail. The rear return pad is arranged directly behind the piston, and a rear return gap is provided between the rear end face of the piston and the rear return pad. The return spring is mounted on the outer wall of the drill tail, and the front end face of the return spring abuts the front end cover of the machine body, and the rear end face abuts the front return sleeve. The machine body is also provided with a guide mechanism for guiding the pull rod mechanism to move back and forth.

[0006] Furthermore, a buffer pad is provided between the limiting boss and the annular boss. The buffer pad is mounted on the outer wall of the drill tail. The buffer pad is provided to play a buffering role, which is beneficial to protecting the limiting boss on the body and avoiding the annular boss directly colliding with the limiting boss to cause damage to the body. The buffer pad can be replaced after being damaged, which is beneficial to improving the service life of the body.

[0007] Furthermore, the invention further includes a water atomizing device, comprising a water pipe joint and a water seal sleeve. The water seal sleeve is fixed to the inner wall of the body and is sheathed on the outer wall of the drill tail. The water pipe joint is connected to the opening in the side wall of the body. The side walls of the water seal sleeve and the drill tail are both provided with through holes, the through holes in the side walls of the water seal sleeve facing the opening in the side wall of the body. A water chamber is provided between the inner wall of the water seal sleeve and the outer wall of the drill tail, and the through holes in the side walls of the water seal sleeve and the drill tail are both connected to the water chamber. Cooling water enters the water chamber through the water pipe joint. When the drill tail vibrates back and forth, the through holes in the side walls of the drill tail move within the water chamber and do not leave the axial range of the water chamber, thereby ensuring that cooling water continuously enters the water conduit at the center of the drill tail and is directly atomized at the tail end of the drill pipe, thereby cooling the drill pipe and the drill tail.

[0008] Furthermore, the water seal is arranged between the buffer block and the limiting boss, thereby further buffering the impact of the shank tail on the machine body, which is beneficial to extending the service life of the machine body.

[0009] Furthermore, the guide mechanism includes a longitudinal groove provided on the outer wall of the body, the longitudinal groove being parallel to the axial direction of the piston, and the connecting rod being adaptively provided in the longitudinal groove. The longitudinal groove guides the connecting rod to move forward and backward along the axial direction, making the pull rod device operate more smoothly.

[0010] Furthermore, the guide mechanism includes an elongated hole provided at the rear end of the body, the direction of the elongated hole being parallel to the axial direction of the piston, and the back-strike rear pad being adaptively provided in the elongated hole. The elongated hole guides the back-strike rear pad to move forward and backward, making the pull rod device operate more smoothly.

[0011] Furthermore, two connecting rods are provided, symmetrically arranged on both sides of the machine body. An appropriate number of connecting rods can ensure sufficient strength and reduce the complexity of the rock drill structure.

[0012] Furthermore, a longitudinal through hole for heat dissipation is provided in the center of the piston, so as to increase the service life of the piston.

[0013] Furthermore, the connecting rod is connected to the front return sleeve and the rear return pad via a threaded mechanism. The threaded mechanism connection mode is convenient for assembly and disassembly and has good maintainability.

[0014] When the hydraulic rock drill of the present invention is in use, the drill rod is connected together by the drill rod sleeve and the front end of the drill tail. During forward driving, the front end face of the piston hits the rear end face of the drill tail to achieve positive driving. When the drill rod is stuck by the working medium and the drill is stuck, the machine body is pulled backward and the drill tail moves forward relatively. The annular boss of the drill tail pushes the return-hitting front sleeve forward, the front-hitting gap increases, and it is out of the range of the piston stroke. At the same time, the connecting rod drives the return-hitting rear pad to move forward synchronously, the rear-hitting gap decreases, and the return-hitting rear pad enters the range of the piston stroke. The rear end face of the piston repeatedly hits the front end face of the return-hitting rear pad, and the return-hitting rear pad retreats relative to the machine body. The connecting rod leads the return-hitting front sleeve to retreat, and the rear end face of the return-hitting front sleeve repeatedly hits the front end face of the annular boss to retreat, so that the drill tail retreats relative to the machine body, and the drill tail and the drill rod exit from the working medium.

[0015] The hydraulic rock drill of the present invention utilizes a pull rod device and adopts a structure in which the piston and the drill tail are separated to realize the return-hitting function. When the piston hits forward, it directly hits the rear end face of the drill tail. Compared with the prior art, the drill tail will not pull the piston failure, the working reliability is strong, and a larger mass piston can be used without increasing the size of the machine body, thereby generating a greater impact force on the drill tail, better rock drilling, a shorter drill tail, more effective torque transmission, and stronger rotational torque. Under the action of the return spring, the return-hitting front sleeve has a tendency to retreat. When the drill tail is hit empty, the rear end face of the return sleeve is tightly against the front end face of the annular boss, ensuring that the rear end face of the drill tail is always within the piston stroke range. The drill tail is reversed, and the piston hits the rear end face of the drill tail empty to loosen the drill pipe sleeve, and the drill pipe sleeve is automatically removed from the drill tail. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the appearance of a hydraulic rock drill with a back-hitting function according to an embodiment;

[0017] Figure 2 This is a diagram showing the internal structure of a hydraulic rock drill with a back-hitting function according to an embodiment of the present invention;

[0018] Figure 3 for Figure 2 Enlarged view of part A in the middle;

[0019] Figure 4 A structural schematic diagram of a hydraulic rock drill with a back-hitting function in an embodiment of the present invention in a back-hitting working state;

[0020] Figure 5 The figure is a schematic diagram of the structure of a hydraulic rock drill with a back-hitting function in the prior art.

[0021] In the figure, 1. drill tail; 1-1. annular boss; 2. piston; 3. drill pipe sleeve; 4. drill pipe; 5. pull rod device; 5-1. return front sleeve; 5-2. connecting rod; 5-3. return rear pad; 6. return spring; 7. machine body; 7-1. longitudinal groove; 7-2. long hole; 7-3. limit boss; 8. buffer pad; 9. water seal sleeve; 9-1. water chamber; 10. water pipe joint. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the embodiments. It is apparent that the embodiments described are only a portion of the embodiments of the present invention, rather than all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0023] See also Figures 1 to 4A hydraulic rock drill with a back-hitting function includes a drill tail 1, a piston 2 arranged in the inner cavity of a machine body 7, an atomizing water device and a pull rod device 5. When in use, the front and rear ends of the drill rod sleeve 3 are respectively rotated to sleeve the rear end of the drill rod 4 and the front end of the drill tail 1. The drill tail 1 is arranged at the front of the machine body 7, and the front end of the drill tail 1 extends from the center hole of the front end cover of the machine body 7. The piston 2 is arranged at the rear of the machine body 7. A front-hitting gap is provided between the front end surface of the piston 2 and the rear end surface of the drill tail 1. The outer surface of the drill tail 1 An annular boss 1-1 is provided in the middle of the wall, and the pull rod device 5 includes a front return sleeve 5-1, a rear return pad 5-3, a connecting rod 5-2 and a return spring 6. The connecting rod 5-2 is parallel to the axial direction of the piston 2, and its front and rear ends are respectively connected to the front return sleeve 5-1 and the rear return pad 5-3 through threads. The connecting rod 5-2 is parallel to the axial direction of the piston 2. In this embodiment, there are two connecting rods 5-2, which are arranged on both sides of the body 7. The front return sleeve 5-1 is in front of the annular boss 1-1 and can be It is movably mounted on the outer wall of the drill tail 1, and the back-hitting pad 5-3 is arranged just behind the piston 2. A back-hitting gap is provided between the rear end face of the piston 2 and the back-hitting pad 5-3. The return spring 6 is mounted on the outer wall of the drill tail 1. The front end face of the return spring 6 abuts the front end cover of the machine body 7, and the rear end face abuts the back-hitting front sleeve 5-1. A limiting boss 7-3 is provided on the inner wall of the front part of the machine body 7. The limiting boss 7-3 is located behind the annular boss 1-1. The function of the limiting boss is to limit the position of the drill tail 1. When drilling, if the drill tail 1 moves back too much, the front clearance will be too small, and the maximum impact force of the piston 2 cannot be exerted. In this embodiment, a buffer block 8 is further provided between the limiting boss and the annular boss 1-1. The buffer block 8 is sleeved on the outer wall of the drill tail 1. The provision of the buffer block 8 is beneficial to protecting the limiting boss on the body 7, and preventing the annular boss 1-1 from directly colliding with the limiting boss and causing damage to the body 7. The buffer block 8 can be replaced after being damaged, which is beneficial to improving the service life of the body 7.

[0024] The body 7 of this embodiment is provided with a longitudinal groove 7-1 and an elongated hole 7-2 as a guide mechanism for guiding the pull rod mechanism to move forward and backward. The longitudinal groove 7-1 is parallel to the axial direction of the piston 2. In this embodiment, two longitudinal grooves 7-1 are provided, which are respectively arranged on the outer walls of the body 7 on both sides opposite to each other. The connecting rod 5-2 is adaptively arranged in the longitudinal groove 7-1. The direction of the elongated hole 7-2 is parallel to the axial direction of the piston 2 and is arranged at the rear end of the body 7. The return-beating rear pad 5-3 is adaptively arranged in the elongated hole 7-2. The return-beating rear pad 5-3 and the connecting rod 5-2 move forward and backward under the constraints of the elongated hole 7-2 and the longitudinal groove 7-1, respectively. Therefore, the pull rod device 5 moves forward and backward more smoothly, which is conducive to reducing failures and improving working reliability.

[0025] The atomized water device includes a water pipe joint 10 and a water seal 9. The water seal 9 is fixed to the inner wall of the body 7 and is sleeved on the outer wall of the drill tail 1. The water seal 9 of this embodiment is arranged between the buffer pad 8 and the limiting boss 7-3, thereby further buffering the impact of the drill tail on the body, which is beneficial to extending the service life of the body. A water pipe joint 10 is connected to the opening on the side wall of the machine body 7. The side walls of the water seal sleeve 9 and the drill tail 1 are both provided with through holes. The through holes in the side walls of the water seal sleeve 9 are directly opposite to the opening on the side wall of the machine body 7. A water chamber 9-1 is provided between the inner wall of the water seal sleeve 9 and the outer wall of the drill tail 1. The through holes in the side walls of the water seal sleeve 9 and the drill tail 1 are both in communication with the water chamber 9-1. Cooling water enters the water chamber 9-1 through the water pipe joint 10. When the drill tail 1 vibrates back and forth, the through holes in the side walls of the drill tail 1 move within the water chamber 9-1 and do not deviate from the axial range of the water chamber 9-1, thereby ensuring that the water pipe in the center of the drill tail 1 continuously supplies cooling water. The cooling water is atomized at the tail end of the drill rod 4, thereby cooling the drill rod 4 and the drill tail 1.

[0026] In this embodiment, a longitudinal through hole for heat dissipation is provided in the center of the piston 2 to help increase the service life of the piston 2.

[0027] The hydraulic rock drill of this embodiment uses the piston 2 to separate from the drill tail 1 and combines it with the pull rod device 5 to realize the back-hitting function. This structure has a low failure rate, reliable operation, and a smaller size. The piston 2 has a greater impact force on the drill tail 1, the drill tail 1 is shorter, the rotary drive transmission efficiency is high, the rotary torque is strong and reliable, and under the action of the return spring 6, the function of empty-hitting and retracting the drill rod sleeve 3 can be realized, thereby achieving high working efficiency.

Claims

1. A hydraulic rock drill with a back-hitting function, comprising a shank and a piston disposed in a body cavity, wherein the front portion of the shank extends from a central hole of a front end cover of the body, and wherein: The shank is arranged at the front of the body, the piston is arranged at the rear of the body, a front gap is provided between the front end face of the piston and the rear end face of the shank, an annular boss is provided in the middle of the outer wall of the shank, and a limiting boss is provided on the inner wall of the front of the body, and the limiting boss is located behind the annular boss. The shank device includes a front return sleeve, a rear return pad, a connecting rod and a return spring. The connecting rod is parallel to the axial direction of the piston, and its front and rear ends are respectively fixedly connected to the front return sleeve and the rear return pad. The front return sleeve is located in front of the annular boss and can be movably mounted on the outer wall of the shank. The rear return pad is arranged directly behind the piston, and a rear gap is provided between the rear end face of the piston and the rear return pad. The front end face of the return spring abuts the front end cover of the body, and its rear end face abuts the front return sleeve. The body is also provided with a guide mechanism for guiding the pull rod mechanism to move back and forth.

2. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: A buffer block is provided between the limiting boss and the annular boss, and the buffer block is sleeved on the outer wall of the shank.

3. The hydraulic rock drill with back-hitting function according to claim 2, characterized in that: It also includes an atomizing water device, which includes a water pipe joint and a water seal sleeve. The water seal sleeve is fixed to the inner wall of the body and sleeved on the outer wall of the drill tail. The water pipe joint is connected to the opening on the side wall of the body. The side wall of the water seal sleeve and the side wall of the drill tail are both provided with through holes. The through holes in the side wall of the water seal sleeve are opposite to the opening on the side wall of the body. A water containing cavity is provided between the inner wall of the water seal sleeve and the outer wall of the drill tail. The through holes in the side wall of the water seal sleeve and the side wall of the drill tail are both connected to the water containing cavity.

4. The hydraulic rock drill with back-hitting function according to claim 3, characterized in that: The water seal is arranged between the buffer block and the limiting boss.

5. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: The guide mechanism comprises a longitudinal groove arranged on the outer wall of the body, the longitudinal groove is parallel to the axial direction of the piston, and the connecting rod is adaptively arranged in the longitudinal groove.

6. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: The guide mechanism comprises an elongated hole arranged at the rear end of the machine body, the direction of the elongated hole is parallel to the axial direction of the piston, and the back-strike rear pad is adaptively arranged in the elongated hole.

7. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: There are two connecting rods, which are symmetrically arranged on both sides of the machine body.

8. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: The center of the piston is provided with a longitudinal through hole for heat dissipation.

9. The hydraulic rock drill with back-hitting function according to claim 1, characterized in that: The connecting rod is connected with the return-beating front sleeve and the return-beating rear pad through a threaded mechanism.

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