Water injection hydraulic pile hammer with large-diameter hammer core

Abstract

The invention discloses a water injection large-diameter hammer core hydraulic pile hammer which comprises a steel pile, a hollow cylinder and a pile cap barrel, the hollow cylinder is formed by welding and serves as a hammer core, water is injected into the hollow cylinder, and the total mass of the hollow cylinder filled with water is increased by one time. The hollow cylinder is composed of an upper top plate, a middle cylinder, a reinforcing cylinder and a lower bottom plate, the pile cap cylinder is arranged on the circumference of the steel pile in a sleeved mode, and the circumference of the hollow cylinder is surrounded by the guide rail. According to the method for increasing the mass of the hammer core by installing the injected water, due to the fact that the specific gravity of the water is 1 / 1.8 of the specific gravity of steel, on the basis that the guiding length of the hammer core is not reduced, the diameter of the hollow cylinder with the larger diameter is equal to the diameter of a steel pile, and the contact area during impacting is increased; and therefore, the hammer core can be used for directly impacting the steel pile or impacting the steel pile driven by the driving ring, and damage to parts caused by stress concentration is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic pile hammers, and specifically relates to the hammer core structure and usage method in hydraulic pile hammers. Background Art

[0002] In recent years, driven by technological progress, industrial upgrading, and energy demand, the capacity of wind turbines has been increasing. So far, the world's largest 26 MW-class offshore wind turbine has a hub center height of 185 meters, equivalent to the height of a 63-story residential building, and also needs to be able to withstand super typhoons of level 17. The diameter of the foundation steel pile of the wind turbine that can carry such a large load reaches 10 - 12 meters, and the depth of implantation into the seabed is also getting deeper, which means that the impact energy required for the hydraulic pile hammer is getting larger.

[0003] The hydraulic pile hammer is a key device for implanting the foundation steel pile into the seabed. It relies on hydraulic energy to lift the hammer core, and by switching the position of the impact valve spool, the oil supply direction of the oil circuit is changed. The hammer core either falls by its own weight, or falls by the thrust of compressed air in the upper chamber plus the weight of the hammer core, or falls rapidly under the action of the thrust of differential hydraulic pressure plus the weight of the hammer core. The hammer core falls and impacts the stepped lower anvil of the pile hammer, and the stepped lower anvil then transfers the impact energy to the steel pile to be implanted, realizing the implantation of the steel pile. The magnitude of the impact energy of the hydraulic pile hammer depends on the mass of the hammer core and the magnitude of the instantaneous (impact) velocity of the hammer core when it falls. From the kinetic energy formula ( ) it can be obtained that: the greater the mass of the hammer core and the instantaneous (impact) velocity, the greater the impact energy. Currently, the impact acceleration of hydraulic pile hammers is all 1.5 g, and the instantaneous (impact) velocity of the hammer core has reached 6 - 8 m / s. However, research shows that too high an instantaneous (impact) velocity of the hammer core has a certain impact on the fatigue life of the steel pile. Therefore, under the same impact energy, increasing the weight of the hammer core of the hydraulic pile hammer and reducing the impact speed are effective measures to extend the fatigue life of the steel pile.

[0004] Facing the actual demand for an increasing impact energy of hydraulic pile hammers, a hammer core of a larger mass is required. For a solid hammer core, the greater the weight, the greater the manufacturing difficulty and the manufacturing cost.

[0005] Since the hammer cores of hydraulic pile hammers are all steel solid hammer cores, in order to make the hammer core have a certain guiding length, the hammer core is often made into a long cylinder with a diameter smaller than that of the steel pile. This requires a stepped lower anvil with a smaller upper diameter and a larger lower diameter as a transition piece to transfer the impact energy of the small-diameter hammer core to the large-diameter steel pile. For small-diameter steel piles, the required diameter of the stepped lower anvil is relatively small. For stepped lower anvils with a diameter less than 8 meters, there are currently a few large forging factories in China that can manufacture them.

[0006] As the capacity of wind turbines increases, the diameter of the foundation steel piles also grows larger. Currently, the maximum diameter of steel piles has reached 12 meters, which requires a reducing bottom anvil with a diameter of 12 meters. However, such a large-diameter reducing bottom anvil exceeds the limit manufacturing capacity of the largest forging factories in our country. To solve this problem, a reducing ring with a small upper end and a large lower end is often added under the reducing bottom anvil. The disadvantages brought about by this are that in addition to the great manufacturing difficulty and a sharp rise in manufacturing costs, the addition of the reducing ring further reduces the transmission efficiency of the impact energy of the pile hammer.

[0007] The existing defects are as follows: 1. Patent document 202410198091.8 discloses an embedded hydraulic pile hammer core. "This invention discloses an embedded hydraulic pile hammer core, which solves the problems of large forging difficulty, difficult heat treatment, and long processing cycle of the core of existing large hydraulic pile hammers. When the core weight exceeds 200 tons, it can still ensure the safe and reliable use of large hydraulic pile hammers." 2. Patent document 202211547088.X discloses an integral hydraulic hammer core buffer structure. "This invention discloses an integral hydraulic hammer core buffer structure. This buffer structure changes the existing elastic connection buffer to a non-contact airtight air compression buffer, improving the ability to absorb and dissipate the rebound force of the core body, avoiding damage or failure of related components caused by connection failures, reducing the vibration and noise generated by the rebound of the core body, improving the working efficiency and stability of the core, enabling it to be applied to large and super-heavy double-acting hydraulic pile hammers, and extending the service life of the equipment." The above technologies cannot fundamentally solve the problems of the limit manufacturing capacity of the core and the reducing bottom anvil of the hydraulic pile hammer and the high manufacturing cost of the hydraulic pile hammer. Summary of the Invention

[0008] The technical problem to be solved by the present invention is as follows: A hollow cylindrical cylinder is used, and the cylinder is filled with water. The cylinder filled with water serves as the core, and the total mass of the core filled with water reaches the required total mass of the core in the design. It is lifted to a certain height by a hydraulic cylinder and then dropped. The core directly impacts the steel pile or impacts a driving collar to push the steel pile, transferring the energy to the steel pile to achieve the implantation of the steel pile.

[0009] To achieve the above object, the present invention provides the following technical solution: a large-diameter hydraulic pile hammer with a water-filled hammer core, comprising a steel pile, a hollow cylindrical cylinder, and a pile cap cylinder. The hollow cylindrical cylinder is formed by welding and serves as the hammer core. Water is injected into the hollow cylindrical cylinder, and the total mass of the water-filled hollow cylindrical cylinder increases by 8-10 times. The hollow cylindrical cylinder consists of an upper top plate, an intermediate cylinder, a reinforcing cylinder, and a lower bottom plate. The pile cap cylinder is sleeved around the circumference of the steel pile. The circumference of the hollow cylindrical cylinder is surrounded by a guide rail, and a middle cylinder is installed on the outer wall of the guide rail. Behind the guide rail is an air passage. A power head is installed at the top of the middle cylinder, and the output end of the power head is connected to the top of the hollow cylindrical cylinder. The guide rail and the middle cylinder are welded into one body.

[0010] Preferably, the air passage is formed by the gap between the guide rail welded inside the middle cylinder, and the hollow cylindrical cylinder is formed with an upper cavity and a lower cavity.

[0011] Preferably, the upper cavity and the lower cavity of the hollow cylindrical cylinder breathe through the air passage.

[0012] Preferably, the diameter of the hollow cylindrical cylinder is equivalent to the diameter of the steel pile, and the hollow cylindrical cylinder directly acts on the surface of the dolly ring.

[0013] Preferably, a dolly ring is installed inside the pile cap cylinder, the dolly ring is placed on the upper end face of the steel pile, and a buffer is installed between the dolly ring and the middle cylinder.

[0014] Preferably, the power head is filled with hydraulic oil.

[0015] Preferably, reinforcing rib plates are provided inside the hollow cylindrical cylinder, and the reinforcing rib plates are strengthened at the joints between the upper top plate and the intermediate cylinder, and the reinforcing rib plates are strengthened at the joints between the lower bottom plate and the intermediate cylinder.

[0016] Preferably, the pile cap cylinder ensures that the dolly ring and the steel pile are coaxial. Seals are provided between the power head and the middle cylinder, and seals are provided between the middle cylinder and the pile cap cylinder. The upper end of the cylindrical cylinder is connected to the piston rod of the power head and is connected by bolts.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. By installing a method of increasing the mass of the hammer core by injecting water, since the specific gravity of water is 1 / 7.8 of the specific gravity of steel, without reducing the guiding length of the hammer core, the diameter of the cylindrical cylinder is large, and the diameter of the hollow cylindrical cylinder is equivalent to the diameter of the steel pile, increasing the contact area during impact. Thus, it can be used as a hammer core to directly impact the steel pile or impact the dolly ring to push the steel pile, and stress concentration will not occur, resulting in damage to parts. 2. The present invention adopts a method of increasing the mass of the hammer core by injecting water. The diameter of the hollow cylindrical cylinder is equivalent to that of the steel pile. Due to the adoption of a water-injected hammer core and the cancellation of the stepped lower anvil, the steel consumption of the hydraulic pile hammer is reduced. The total mass of the water-injected hammer core and the solid hammer core hydraulic pile hammer with the same striking energy is reduced by 50%, reducing the manufacturing cost of the hydraulic pile hammer. At the same time, the transportation, hoisting and operating costs of the hydraulic pile hammer are also reduced. 3. The present invention adopts a method of increasing the mass of the hammer core by injecting water and cancels the stepped lower anvil, avoiding the manufacturing limit problem of the super-large diameter and super-large mass stepped lower anvil, making it possible to manufacture a hydraulic pile hammer with a greater striking energy. 4. The present invention adopts a method of increasing the mass of the hammer core by injecting water. The diameter of the hollow cylindrical cylinder is equivalent to that of the steel pile. At the same time, the weight of the cylinder filled with water is several times that of the solid hammer head. When designing, the height that the hammer core needs to be lifted is reduced under the same energy, the impact speed is reduced, protecting the dolly ring and the steel pile, and prolonging the service life of the dolly ring and the steel pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view structural schematic diagram of the present invention.

[0019] In the figure: 1, power head; 2, cylinder body; 3, guide rail; 4, air passage; 5, hollow cylindrical cylinder; 7, buffer; 8, dolly ring; 9, steel pile; 10, pile cap cylinder. DETAILED DESCRIPTION OF THE INVENTION

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, terms such as "installation", "provided with", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Embodiment 1: Please refer to Figure 1 , an embodiment provided by the present invention: The hollow cylindrical cylinder 5 is welded and consists of an upper top plate, an intermediate cylinder, a reinforcing cylinder, and a lower bottom plate. Reinforcing rib plates are provided inside to strengthen the joints between the upper top plate and the intermediate cylinder and between the lower bottom plate and the intermediate cylinder, to strengthen the upper top plate and the lower bottom plate, enhance the strength of the upper top plate when lifting the hollow cylindrical cylinder 5, and also enhance the strength of the lower bottom plate when falling, prevent the damage of the hollow cylindrical cylinder 5, and extend the service life of the hollow cylindrical cylinder 5.

[0024] Embodiment 2: Please refer to Figure 1 , an embodiment provided by the present invention: The circumference of the hollow cylindrical cylinder 5 is surrounded by a guide rail 3, and an air passage 4 is behind the guide rail 3. The air passage 4 is formed by the gap between the guide rail 3 welded inside the middle cylinder 2. Before pile driving, lubricating grease needs to be filled between the hollow cylindrical cylinder 5 and the guide rail 3 to reduce the friction between the two components, thereby extending the service life of the hollow cylindrical cylinder 5 and the guide rail 3.

[0025] Embodiment 3: Please refer to Figure 1 , an embodiment provided by the present invention: A buffer 7 is installed between the dolly ring 8 and the middle cylinder 2 to limit the upper limit of the stroke of the dolly ring 8. During pile driving, the buffer 7 bears the weights of the middle cylinder 2, the power head 1, and the hollow cylindrical cylinder 5 filled with water during lifting. It avoids the self-weight impact force of the power head 1 and the middle cylinder 2 caused by the penetration of the steel pile, and at the same time slows down the reverse impact force given by the elastic deformation of the steel pile 9 during pile driving, thereby extending the service life of the power head 1 and the middle cylinder 2.

[0026] Embodiment 4: Please refer to Figure 1 , an embodiment provided by the present invention: The dolly ring 8 is installed inside the pile cap cylinder 10 and sits on the upper end face of the steel pile 9. The pile cap cylinder 10 is sleeved around the circumference of the steel pile 9 and is used to position the hydraulic pile hammer, prevent horizontal displacement between the hydraulic pile hammer and the steel pile 9 during pile driving, ensure that the dolly ring 8 and the steel pile 9 are coaxial, and avoid eccentric impact of the hydraulic pile hammer, thereby protecting the steel pile 9.

[0027] Embodiment 5: Please refer to Figure 1, an embodiment provided by the present invention: During pile driving, the power head 1 is filled with hydraulic oil. As the piston rises, the hollow cylinder 5 is lifted simultaneously. When it is lifted to the required height, the power head 1 releases the hydraulic oil, and the piston and the hollow cylinder 5 fall simultaneously onto the upper end face of the dolly ring 8. The dolly ring 8 pushes the steel pile 9 to achieve the implantation action of the steel pile 9. The hollow cylinder 5 filled with water has a total mass several times that of a solid hammer head, thereby greatly reducing the lifting height, lowering the impact speed, and reducing the fatigue damage of the steel pile 9.

[0028] Embodiment 6: Please refer to Figure 1 , an embodiment provided by the present invention: During pile driving, the hollow cylinder 5 filled with water directly impacts the dolly ring 8, eliminating the stepped anvil, ensuring the reliability of the hydraulic pile hammer, extending the service life of the hydraulic pile hammer, and reducing the manufacturing cost of the hydraulic hammer.

[0029] Working principle: The hollow cylinder 5 is welded and consists of an upper top plate, an intermediate cylinder, a reinforcing cylinder, and a lower bottom plate. It is internally provided with reinforcing rib plates to strengthen the joints between the upper top plate and the intermediate cylinder and between the lower bottom plate and the intermediate cylinder, so as to strengthen the upper top plate and the lower bottom plate, enhance the strength of the upper top plate when lifting the hollow cylinder 5, and also enhance the strength of the lower bottom plate during falling, preventing damage to the hollow cylinder 5 and extending the service life of the hollow cylinder 5.

[0030] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A hydraulic pile hammer with a large-diameter water-injected hammer core, comprising a steel pile (9), a hollow cylindrical cylinder (5), and a pile cap cylinder (10), characterized in that: The hollow cylinder (5) is formed by welding and serves as the hammer core. Water is filled inside the hollow cylinder (5). The total mass of the hollow cylinder (5) filled with water increases by 8 - 10 times. The hollow cylinder (5) consists of an upper top plate, an intermediate cylinder, a reinforcing cylinder, and a lower bottom plate. The pile cap cylinder (10) is sleeved on the circumference of the steel pile (9). The circumference of the hollow cylinder (5) is surrounded by a guide rail (3). The outer wall of the guide rail (3) is equipped with a middle cylinder (2). Behind the guide rail (3) is an air passage (4). The top of the middle cylinder (2) is equipped with a power head (1), and the output end of the power head (1) is connected to the top of the hollow cylinder (5). The guide rail (3) and the middle cylinder (2) are welded into one body.

2. The hydraulic pile hammer with a large-diameter water-injected hammer core according to claim 1, characterized in that: The air passage (4) is formed by the gap where the guide rail (3) is welded inside the middle cylinder (2). The hollow cylinder (5) is formed with an upper cavity and a lower cavity.

3. The hydraulic pile hammer with a large-diameter hammer core for water injection according to claim 2, characterized in that: The upper cavity and the lower cavity of the hollow cylinder (5) breathe through the air passage (4).

4. A hydraulic pile hammer with a large-diameter water-injected hammer core according to claim 1, characterized in that: The diameter of the hollow cylinder (5) is equivalent to the diameter of the steel pile (9), and the hollow cylinder (5) acts directly on the surface of the dolly ring (8).

5. The hydraulic pile hammer with a large-diameter water-injected hammer core according to claim 1, characterized in that: A dolly ring (8) is installed inside the pile cap cylinder (10). The dolly ring (8) is placed on the upper end face of the steel pile (9). A buffer (7) is installed between the dolly ring (8) and the middle cylinder (2).

6. The hydraulic pile hammer with a large-diameter water-injected hammer core according to claim 1, characterized in that: The power head (1) is filled with hydraulic oil inside.

7. A large-diameter hammer core hydraulic pile hammer for water injection according to claim 1, characterized in that: Reinforcing rib plates are provided inside the hollow cylinder (5). The reinforcing rib plates are strengthened at the joint of the upper top plate and the intermediate cylinder, and the reinforcing rib plates are strengthened at the joint of the lower bottom plate and the intermediate cylinder.

8. A hydraulic pile hammer with a large-diameter water-injected hammer core according to claim 1, characterized in that: The pile cap cylinder (10) ensures that the dolly ring (8) and the steel pile (9) are in a coaxial state. Seals are provided between the power head (1) and the middle cylinder (2), and seals are provided between the middle cylinder (2) and the pile cap cylinder (10).

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