Drill rod and breaking hammer adopting same

Abstract

The invention relates to a drill rod which is positioned below a piston, is arranged in an inner cavity of a cylinder body and is provided with a hit end hit by the piston and an operation end for hitting a crushed object. Wherein the drill rod is of a hollow structure. Due to the fact that the drill rod is of the hollow structure, the diameter of the drill rod with the same weight can be increased, the expansion cracking effect is effectively improved, and on the other hand, the drill rod with the same size can reduce the weight, reduce the inertia of the drill rod and reduce the impact force attenuated by the inertia of the drill rod.

Description

Technical Field

[0001] The present invention relates to a hydraulic breaker. Background Art

[0002] In order to break stones, concrete and other building materials, a hydraulic hammer can be attached to various machines, such as an excavator, a backhoe or other similar machines. The hydraulic hammer is mounted on the arm of the machine and connected to a hydraulic system. High-pressure fluid in the hydraulic system is supplied to the hydraulic hammer to drive a piston contacting an operating tool to reciprocate, and strike the operating tool to complete the breaking task.

[0003] The existing hydraulic breaker hammer core mainly includes: a cylinder block, and a piston disposed in the inner cavity of the cylinder block. A pressure gas chamber (filled with nitrogen) is formed in the cylinder block space at the top of the piston; a stroke oil pressure chamber is formed by concave inward the circumferential wall of the upper part of the piston, and the stroke oil pressure chamber intermittently connects high pressure and return oil;. The lower end of the cylinder block is connected to a drill rod seat, and a drill rod for breaking rocks, an inner sleeve and an outer sleeve for guiding and protecting the drill rod seat from being worn, and a flat pin for limiting the drill rod are provided in the drill rod seat. The inner sleeve is limited by an inner sleeve retaining pin, and the outer sleeve is limited by an outer sleeve retaining pin.

[0004] Its working principle is as follows: In the initial state, due to the air pressure in the pressure gas chamber, the piston is at one end close to the drill rod. In the piston return stroke stage, at the moment when high-pressure oil is introduced, the return oil circuit of the stroke oil pressure chamber is connected. On the basis of the initial state, under the action of the high-pressure oil introduced into the return stroke oil pressure chamber, the piston moves upward to compress nitrogen, and the hydraulic oil in the stroke oil pressure chamber flows back to the fuel tank; when the piston moves upward to a predetermined return stroke, the piston return stroke ends. During the process of the piston reciprocating along its axis, along with the storage and release of the nitrogen energy, the piston moves upward to compress nitrogen, and the energy is stored. In the piston stroke stage, high-pressure oil enters the stroke oil pressure chamber. Since the acting area of the hydraulic oil in the stroke oil pressure chamber is larger than that of the return stroke oil pressure chamber, the downward force is greater than the upward force. The piston moves downward. Under the combined action of the oil pressure and the nitrogen pressure, the hydraulic pressure and the nitrogen work together to push the piston to strike the drill rod until the piston returns to the initial state, completing a working cycle. The piston repeats the above working process to complete the breaking task.

[0005] The existing drill rod is usually of a solid structure, resulting in a large weight and thus a large inertia, and the impact force of the piston cannot be effectively transmitted to the object to be broken.

[0006] Chinese patent document CN 217249103 U discloses a breaker with increased gravity and striking force, in which the idea of setting the drill rod as a hollow structure is proposed. A chisel head is provided at the bottom end of the drill rod, and lead blocks are arranged in the hollow of the drill rod. A plug is provided at the top of the drill rod and at the top of the lead block. A plug reinforcement assembly is provided on the side of the plug and on the side wall of the drill rod. The plug is threadedly connected to the top end of the drill rod, and a cover plate is provided at the top end of the plug. A connecting rod is provided at the top end of the cover plate, and a suspension hook is provided at the top end of the connecting rod. This technical solution mainly sets lead blocks in the hollow of the drill rod to increase the gravity and striking force of the breaker, so as to improve the crushing efficiency. However, the technical solution proposed is a drill rod suitable for gravity crushing, and the essence of its technical means is still to increase the weight of the drill rod to improve the inertia force of the drill rod. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is that the existing drill rod cannot effectively transmit the impact force of the piston to the object to be broken.

[0008] To solve the above technical defects, a drill rod provided by the present invention is arranged in the inner cavity of the cylinder block below the piston, and has a struck end that is struck by the piston and a working end that strikes the object to be broken; the drill rod is a hollow structure.

[0009] Furthermore, the struck end is provided with a convex curved surface that fits with the concave curved surface formed by the acting surface for transmitting the impact force of the piston.

[0010] Furthermore, the concave curved surface and the convex curved surface are spherical curved surfaces that cooperate with each other.

[0011] Furthermore, the working end of the drill rod is inlaid with cemented carbide.

[0012] A hydraulic breaker includes

[0013] A cylinder block having an inner cavity;

[0014] A piston slidably arranged axially in the inner cavity;

[0015] The above-mentioned drill rod is arranged in the inner cavity below the piston.

[0016] Furthermore, a buffer assembly is provided between the piston and the drill rod, and the contact surface of the buffer assembly with the struck end of the drill rod is the acting surface for transmitting the impact force of the piston.

[0017] Furthermore, the buffer assembly includes

[0018] An upper buffer pad, the outer circle of which is a cylinder that is hermetically and slidably connected to the inner wall of the inner cavity, and its upper end receives the impact of the piston;

[0019] A lower cushion pad is provided below the upper cushion pad and is radially movable relative to the upper cushion pad, and the acting surface is formed at its bottom end;

[0020] A connecting member connects the lower cushion pad and the upper cushion pad.

[0021] Further, a cylindrical cavity for accommodating the lower cushion pad is formed in the lower part of the upper cushion pad, the diameter of the cylindrical cavity is larger than the outer diameter of the lower cushion pad, and the connecting member confines the lower cushion pad in the cylindrical cavity.

[0022] Further, the connecting member has an external thread and is screwed with an internal thread provided at the lower end of the inner wall of the cylindrical cavity to limit the lower cushion pad in the cylindrical cavity; a through hole adapted for the struck end of the drill rod to pass through is formed in the center of the connecting member, and the inner diameter of the through hole is smaller than the outer diameter of the lower cushion pad.

[0023] The technical solution of the present invention has the following advantages:

[0024] Since the drill rod has a hollow structure, a drill rod of the same weight can have a larger diameter, effectively improving the cracking effect. On the other hand, for a drill rod of the same size, the weight can be reduced, the inertia of the drill rod can be reduced, and the impact force attenuated due to the inertia of the drill rod can be reduced.

[0025] The struck end of the drill rod adopts a convex curved surface, and the curved surface support transmits the impact force to the pipe wall of the drill rod as much as possible, avoiding the deformation of the drill rod caused by the impact.

[0026] A buffer assembly is provided between the piston and the drill rod, avoiding the loss rate of the drill rod and the piston caused by the huge impact force of the piston directly hitting the top of the drill rod, and eliminating the damage probability of the contact surface between the drill rod and the piston. The buffer assembly is composed of an upper cushion pad and a lower cushion pad, so that the upper and lower layers can be finely adjusted, which is conducive to the upper and lower cushion pads to always maintain flexible and full contact with the piston and the drill rod respectively, and is beneficial to the effective transmission of the impact force. Description of the Drawings

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 A three-dimensional view of an embodiment of a drill rod of the present invention;

[0029] Figure 2 For Figure 1Schematic diagram of the half-section structure of the illustrated embodiment;

[0030] Figure 3 This invention is equipped with Figure 1 Schematic diagram of the front-section structure of the breaker with the drill rod shown;

[0031] Figure 4 is Figure 3 Schematic diagram of the half-section decomposition structure of the buffer assembly in the illustrated embodiment.

[0032] Explanation of reference numerals:

[0033] 1 - Drill rod, 2 - Piston, 3 - Cylinder block, 4 - Impact end, 5 - Working end, 6 - Cemented carbide, 7 - Buffer assembly, 8 - Upper buffer pad, 9 - Lower buffer pad, 10 - Lower cylinder block annular step, 11 - Cylindrical cavity, 12 - Connecting piece, 13 - Acting surface. Specific implementation mode

[0034] Next, the technical solution of this invention will be clearly and completely described in conjunction with the accompanying drawings.

[0035] Refer to Figure 1-3 , in this embodiment, the drill rod 1 is arranged below the piston 2 in the inner cavity of the cylinder block 3. The drill rod 1 is a tubular hollow structure, as shown in Figure 2 , 3 , it has an impact end 4 that is impacted by the piston 2 and a working end 5 that strikes the object to be broken. An outwardly convex curved surface is formed at the impact end 4 of the drill rod 1. The curved surface shown in the figure is a spherical curved surface. And the working end 5 is formed as a drill bit, and cemented carbide 6 is inlaid at the working end 5 serving as the drill bit.

[0036] Refer to Figure 3 , showing a hydraulic breaker using the drill rod 1 in the above embodiment. In this embodiment, it includes a cylinder block 3 with an inner cavity, a piston 2 slidably arranged axially in the inner cavity, and the drill rod 1 is arranged in the inner cavity below the piston 2.

[0037] A buffer assembly 7 is provided in the cylinder block 3 between the piston 2 and the drill rod 1. Refer to Figure 4, the buffer assembly 7 includes an upper buffer pad 8 with a cylindrical outer circle and a lower buffer pad 9 disposed below the upper buffer pad 8. The upper buffer pad 8 is sealingly and slidably connected to the inner wall of the inner cavity. The upper buffer pad 8 is resisted by a lower cylinder annular step 10 formed in the inner cavity of the cylinder block 3 to limit its upward stroke, and the upper end of the upper buffer pad 8 receives the impact of the piston 2. The lower buffer pad 9 is disposed below the upper buffer pad 8 so as to be radially movable. A cylindrical cavity 11 for accommodating the lower buffer pad 9 is formed in the lower part of the upper buffer pad 8, and the diameter of the cylindrical cavity 11 is larger than the outer diameter of the lower buffer pad 9. An internal thread is provided at the lower end of the inner wall of the cylindrical cavity 11, and a connecting member 12 having an external thread is adapted to be screwed with the internal thread in the cylindrical cavity 11 to limit the lower buffer pad 9 in the cylindrical cavity 11 to form the buffer assembly 7. A through hole adapted for the impacted end 4 of the drill rod 1 to pass through is formed in the center of the connecting member 12, and the inner diameter of the through hole is smaller than the outer diameter of the lower buffer pad 9. This solution provides the buffer assembly 7 to relieve the impact of the piston 2 on the impacted end 4 of the drill rod 1, reduce the impact sound, and improve the service life of the components.

[0038] The contact surface between the lower end of the lower buffer pad 9 and the impacted end 4 of the drill rod 1 is a working surface 13 for transmitting the impact force of the piston 2. In order to transmit the impact force to the pipe wall of the drill rod 1 as much as possible and avoid the deformation of the drill rod 1 caused by the impact, the bottom end surface of the buffer assembly 7 as the working surface 13 is formed with an inner concave spherical surface that matches the outer convex curved surface of the impacted end 4 to adapt to the radial swing of the drill rod 1 during operation and maintain the surface contact between the lower buffer pad 9 and the impacted end 4 of the drill rod 1.

[0039] During the operation, the piston 2 impacts the upper buffer pad 8 in the buffer assembly 7. Since the upper buffer pad 8 is always in sealed and sliding connection with the inner wall of the inner cavity, the radial relative position between it and the piston 2 remains unchanged. The impact surface of the piston 2 and the impacted surface on the upper buffer pad 8 always maintain a sufficient surface contact impact state. Between the lower end of the lower buffer pad 9 and the contact surface of the impacted end 4 of the drill rod 1, due to the use of relatively mating curved surfaces, especially spherical curved surfaces, on the one hand, the surface contact between them is maintained to ensure the effective transmission of the impact force, and on the other hand, the arched structure of the curved surface is used to transmit the impact force to the tubular wall of the hollow drill rod 1 to ensure that the impacted end 4 of the drill rod 1 does not deform. In this embodiment, the structure that allows the upper buffer pad 8 and the lower buffer pad 9 to move radially relative to each other enables the lower buffer pad 9 to move radially appropriately with the movement of the top of the drill rod 1 when the drill rod 1 shakes due to friction and wear with the cylinder block 3 after working for a certain period of time. Due to the spherical curved surface structure, even if there is relative movement between the top of the drill rod 1 and the bottom end of the lower buffer pad 9, sufficient surface contact between the two can still be maintained, and the effective transmission of the impact force can be maintained.

[0040] In an alternative embodiment, the buffer assembly 7 may also be absent. At this time, in order to transmit the impact force to the tube wall of the drill rod 1 as much as possible and avoid deformation of the drill rod 1 due to impact, the bottom end surface of the piston 2 serving as the acting surface 13 is formed with an inner concave spherical curved surface that mates with the outer convex curved surface of the impacted end 4.

[0041] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A drill rod is disposed in the inner cavity of a cylinder block (3) below a piston (2), and has a struck end (4) that is struck by the piston (2) and a working end (5) for striking an object to be broken. It is characterized in that the drill rod (1) has a hollow structure.

2. The drill rod according to claim 1, it is characterized in that the struck end (4) has a convex curved surface that fits with a concave curved surface formed on a force application surface (13) for transmitting the impact force of the piston (2).

3. The drill rod according to claim 2, it is characterized in that the concave curved surface and the convex curved surface are spherical curved surfaces that cooperate with each other.

4. The drill rod according to any one of claims 1 - 3, it is characterized in that the working end (5) of the drill rod (1) is inlaid with cemented carbide (6).

5. A hydraulic breaker, comprising a cylinder block (3) having an inner cavity; a piston (2) slidably disposed axially in the inner cavity; it is characterized in that the drill rod (1) according to any one of claims 1 - 4 is disposed in the inner cavity below the piston (2).

6. The hydraulic breaker according to claim 5, it is characterized in that a buffer assembly (7) is provided between the piston (2) and the drill rod (1), and the contact surface of the buffer assembly (7) with the struck end (4) of the drill rod (1) is the force application surface (13) for transmitting the impact force of the piston (2).

7. The hydraulic breaker according to claim 6, it is characterized in that the buffer assembly (7) includes an upper buffer pad (8) with a cylindrical outer circumference that is hermetically and slidably connected to the inner wall of the inner cavity, and its upper end receives the impact of the piston (2); a lower buffer pad (9) disposed below the upper buffer pad (8) and radially movable relative to the upper buffer pad (8), and a force application surface (13) is formed at its bottom end; a connecting member (12) that connects the lower buffer pad (9) and the upper buffer pad (8).

8. The hydraulic breaker according to claim 7, it is characterized in that a cylindrical cavity (11) for accommodating the lower buffer pad (9) is formed at the lower part of the upper buffer pad (8), the diameter of the cylindrical cavity (11) is larger than the outer diameter of the lower buffer pad (9), and the connecting member (12) confines the lower buffer pad (9) in the cylindrical cavity (11).

9. The hydraulic breaker according to claim 8, it is characterized in that the connecting member (12) has an external thread and confines the lower buffer pad (9) in the cylindrical cavity (11) by being screwed in cooperation with an internal thread provided at the lower end of the inner wall of the cylindrical cavity (11); a through hole adapted for the struck end (4) of the drill rod (1) to pass through is formed at the center of the connecting member (12), and the inner diameter of the through hole is smaller than the outer diameter of the lower buffer pad (9).

Images