Dual pump controlled hydraulic pile hammer

Abstract

The present invention discloses a dual-pump joint-controlled hydraulic pile hammer, comprising a hammer core and a hydraulic cylinder, wherein the hydraulic cylinder is respectively provided with a lower cylinder chamber oil port and an upper cylinder chamber oil port which are connected with the upper and lower cylinder chambers thereof; the oil outlet of the lower cylinder chamber oil pump is connected to the pressure oil port P of the lower cylinder chamber hydraulic valve, the oil port A of the lower cylinder chamber hydraulic valve is connected to the lower cylinder chamber oil port, the oil outlet of the upper cylinder chamber oil pump is connected to the pressure oil port P of the upper cylinder chamber hydraulic valve, and the oil port A of the upper cylinder chamber hydraulic valve is connected to the upper cylinder chamber oil port; the pressure oil port P of the lower cylinder chamber hydraulic valve is connected to the control oil port X of the upper cylinder chamber hydraulic valve, the oil port A of the lower cylinder chamber hydraulic valve is connected to the control oil port X of the upper cylinder chamber hydraulic valve through a first throttle; the pressure oil port P of the upper cylinder chamber hydraulic valve is connected to the control oil port X of the lower cylinder chamber hydraulic valve, and the oil port A of the upper cylinder chamber hydraulic valve is connected to the control oil port X of the lower cylinder chamber hydraulic valve through a second throttle. The pile hammer has the advantages of simple and compact structure, efficient and reliable operation.

Description

Technical Field

[0001] The present invention relates to a pile driving machine used for foundation construction of a building project, in particular to a hydraulic pile hammer with a double oil supply pump. Background Art

[0002] Hammer pile drivers are the most commonly used pile-driving machinery. They have the characteristics of large impact energy, high pile driving efficiency and convenient construction. Therefore, the pile sinking construction of large foundation piles can often only be carried out using hammer pile drivers.

[0003] Hammer pile drivers mainly include diesel pile hammers and hydraulic pile hammers. Diesel pile hammers are gradually being banned due to noise, vibration, and fume pollution issues that their inherent structure cannot address. Also, due to the limitations of their heat capacity and efficiency, the theoretical maximum diesel hammer's impact hammer core mass can only reach 15 tons, which cannot meet the construction requirements of large precast piles. Hydraulic pile hammers, on the other hand, offer high piling efficiency, low noise and vibration, and no fume pollution. Their advanced nature has been widely recognized, and their replacement for diesel pile hammers is inevitable. In developed Western countries and Asian countries and regions such as Japan, South Korea, and Singapore, hydraulic pile hammers have completely replaced diesel pile hammers, becoming the absolute mainstay of the piling market.

[0004] On October 24, 2017, the applicant filed an invention patent application for a "Guide-Rod Pile Hammer with Hydraulic Cartridge Valves," with patent application number 201711003379.1. The hydraulic control circuit of this hydraulic pile hammer includes hydraulic valves, including a pilot control valve, a cartridge valve, and a relief throttle valve. Its operating structure and principle constitute a single-acting hydraulic impact pile hammer, in which the hammer core strikes the pile body in a free-fall manner. During the hammer raise, pressure oil from the hydraulic pump, under the control of the pilot control valve, is pumped into the lower chamber of the hydraulic cylinder at a specific pressure through the first and second cartridge valves, thereby raising the hammer. Because the first cartridge valve must be closed before the second cartridge valve is opened during the hammer lowering and lowering operations, each hammer raise and lowering operation results in a significant amount of cartridge valve opening and closing time and hydraulic oil flow loss, impacting the hammer's impact energy and frequency. Its hydraulic control circuit requires the coordinated switching of multiple main valves when reversing, which not only increases the complexity of the oil circuit and reduces the reliability of the transmission system, but also the multi-stage switching increases the time of the reversing action, slowing down the response speed and the working time of each striking cycle, making it difficult to achieve high-frequency piling, affecting the improvement of pile foundation construction efficiency.

[0005] On March 30, 2018, the applicant filed an invention patent application for a "high-frequency, high-energy hydraulic pile hammer," with patent application number 201810291946.6. The hydraulic cylinder in this invention application utilizes a differential cylinder-in-cylinder structure, thus forming a double-acting hydraulic pile hammer. However, its hydraulic control circuit also includes multiple hydraulic control components, such as cartridge valves. When lifting the hammer, the second cartridge valve closes, while the first cartridge valve opens. Pressure oil from the hydraulic pump is directly charged into the hydraulic cylinder's straight-rod chamber. When striking, the second cartridge valve opens, while the first cartridge valve closes. At this point, the hydraulic cylinder forms a differential connection circuit. This hydraulic control circuit, composed of multiple cartridge valves that open and close in sequence, still suffers from low flow rates, high pressure losses, and low actuation sensitivity, limiting improvements in the hammer's striking energy and speed.

[0006] Therefore, while existing hydraulic pile hammers offer advantages unmatched by diesel pile drivers, their hydraulic control circuits are relatively complex, including a high-power hydraulic pump and main control reversing valve, as well as hydraulic components such as a pilot valve and a relief throttle valve. During the lifting and lowering operations, excessive overflow and throttling can lead to significant losses in high-pressure oil flow. Therefore, increasing the hammer's striking power requires a higher system flow rate for the hydraulic pump and control circuit, resulting in greater energy loss. This makes the hydraulic control system and power components more complex and bulky, directly impacting the efficiency of converting hydraulic energy into striking energy. This increased energy loss and reduced conversion efficiency, in turn, increases system heat generation, leading to higher hydraulic system temperature rise, lower hydraulic oil viscosity, and increased leakage, significantly reducing the volumetric efficiency of the hydraulic pump and overall system efficiency. Especially during high-frequency piling, the hydraulic oil viscosity decreases, thinning or even breaking the oil film on moving components such as the slide valve, increasing frictional resistance, and causing increased wear and resulting in higher temperature rise. Increased temperature rise in the hydraulic system can also cause rubber seals to deform, accelerating seal aging; it can also reduce clearances between hydraulic moving parts or cause them to become stuck, leading to malfunction. Complex hydraulic systems can also cause hydraulic pipelines to become longer, increase the number of connecting joints, and increase the failure rate, affecting the continuous and stable operation of the pile hammer. Especially under conditions of strong impact and high vibration of the pile hammer, complex hydraulic systems are more prone to failure, affecting the efficient operation of the pile hammer. The existing pile hammer hydraulic control system uses a single hydraulic pump as the drive source, and several hydraulic reversing valves control the reversing of the hydraulic cylinder. This control method often makes it difficult to instantly adjust the hydraulic hammer's striking energy and striking stroke according to the construction conditions, limiting the hydraulic hammer's flexibility and scope of application. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a double-pump joint-controlled hydraulic pile hammer with a simple and compact structure and efficient and reliable operation.

[0008] In order to solve the above technical problems, the dual-pump joint-controlled hydraulic pile hammer of the present invention includes a hammer core and a hammer core guide. The hammer core can be reciprocatingly slidably supported on the hammer core guide. A hydraulic cylinder is fixedly installed on the hammer core guide. The extended end of the piston rod of the hydraulic cylinder is connected to the hammer core. The hydraulic cylinder is provided with a lower cylinder chamber oil port connected to the lower cylinder chamber of the hydraulic cylinder, and the hydraulic cylinder is also provided with an upper cylinder chamber oil port connected to the upper cylinder chamber of the hydraulic cylinder; the oil outlet of the lower cylinder chamber oil pump is connected to the pressure oil port P of the lower cylinder chamber hydraulic valve, and the oil port A of the lower cylinder chamber hydraulic valve is connected to the lower cylinder chamber Oil port, the oil outlet of the upper cylinder chamber oil pump is connected to the pressure oil port P port of the upper cylinder chamber hydraulic valve, and the oil port A of the upper cylinder chamber hydraulic valve is connected to the upper cylinder chamber oil port; the pressure oil port P port of the lower cylinder chamber hydraulic valve is connected to the control oil port X port of the upper cylinder chamber hydraulic valve, and the oil port A of the lower cylinder chamber hydraulic valve is connected to the control oil port X port of the upper cylinder chamber hydraulic valve through the first throttle; the pressure oil port P port of the upper cylinder chamber hydraulic valve is connected to the control oil port X port of the lower cylinder chamber hydraulic valve, and the oil port A of the upper cylinder chamber hydraulic valve is connected to the control oil port X port of the lower cylinder chamber hydraulic valve through the second throttle.

[0009] In the above structure, since the hydraulic cylinder is used as the power source of the pile hammer, the operation process does not generate severe combustion and explosion vibrations and high-intensity noise caused by the explosion impact, nor does it generate air pollution caused by pollutants such as harmful smoke particles. This allows for clean construction, minimizes environmental impact, and easily meets increasingly stringent environmental protection requirements. The hydraulic cylinder as a power source is also highly energy-efficient, with most of the hydraulic energy generated by the hydraulic pump being converted into potential energy for striking the hammer. The hydraulic cylinder has become a serialized, standardized product with a reasonable structure, making it easy to implement and maintain. Furthermore, since two hydraulic pumps are used to drive the upper and lower hydraulic chambers of the hydraulic cylinder, respectively, the upper and lower chambers of the hydraulic cylinder are independently driven. This allows for convenient adjustment of the hammer raising speed and the hammer dropping energy by adjusting the oil flow into the upper and lower chambers. Furthermore, this independent driving of the upper and lower chambers of the hydraulic cylinder also facilitates adjustment of the hammer core's striking stroke. By quickly adjusting the hammer's striking energy and striking stroke, the hammer can be well adapted to meet the construction requirements of various pile foundation soil conditions, greatly improving the flexibility and adaptability of the pile hammer. Furthermore, the hydraulic control circuit of the present invention utilizes a linked control structure in which one pump controls the corresponding reversing valve of another pump, resulting in an extremely compact and efficient hydraulic control circuit. This significantly simplifies the power unit of the pile hammer and significantly reduces flow losses caused by overflow and throttling in the control circuit. This effectively improves the efficiency of converting hydraulic energy into hammering energy, effectively reduces energy loss, and avoids the disadvantages of excessive system temperature rise. This further leverages the hydraulic pile hammer's high striking energy, making it more adaptable to pile driving operations in various pile types and geological conditions. This increased energy conversion efficiency also avoids the adverse operating conditions caused by excessive temperature rise in the hydraulic circuit, ensuring stable hydraulic oil viscosity and reducing the probability of hydraulic oil leakage. This improves the operational stability and reliability of hydraulic moving components such as the slide valve, while also effectively increasing the flexibility and service life of seals and mechanical components. The compact hydraulic control circuit also significantly reduces and shortens piping lengths and pipe joints, effectively reducing malfunctions caused by the hammer's impact vibration, resulting in more reliable and efficient operation.

[0010] In a preferred embodiment of the present invention, the lower cylinder chamber hydraulic valve and the upper cylinder chamber hydraulic valve are both two-position three-way hydraulic reversing valves, thereby realizing the reversing control of the hydraulic cylinder.

[0011] In a preferred embodiment of the present invention, the driving motors of the lower and upper cylinder chamber oil pumps are servo motors or variable frequency motors, which can conveniently control the system flow rate, thereby flexibly adjusting the striking energy and striking stroke of the pile hammer.

[0012] In a preferred embodiment of the present invention, the first throttle and the second throttle are straight-through fixed throttle valves, which are conducive to forming a reliable control oil pressure of the hydraulic reversing valve.

[0013] Preferably, the hydraulic cylinder is a single-rod piston hydraulic cylinder.

[0014] Preferably, the hydraulic cylinder is a double-rod piston hydraulic cylinder.

[0015] Preferably, the hammer core guide adopts a cylindrical guide structure, and the hammer core is slidably arranged in the guide cylinder.

[0016] Preferably, the hammer core guide comprises two guide rods parallel to each other, and the hammer core is slidably supported on the guide rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The dual-pump joint-controlled hydraulic pile hammer of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a structural diagram of the mechanical part of a specific embodiment of a dual-pump joint-controlled hydraulic pile hammer of the present invention;

[0019] Figure 2 yes Figure 1 Schematic diagram of the hydraulic control circuit and the oil circuit structure of the hydraulic cylinder in the embodiment shown;

[0020] Figure 3 It is a schematic diagram of the oil circuit structure of a hydraulic control circuit and a hydraulic cylinder according to another embodiment of the present invention.

[0021] In the figure, 1 is a hydraulic cylinder, 2 is an oil port of a lower cylinder chamber, 3 is a cylinder seat, 4 is an oil port of an upper cylinder chamber, 5 is a cylinder support, 6 is a cylinder head, 7 is a piston rod, 8 is a connecting sleeve, 9 is a coupling, 10 is a hammer core guide, 11 is a hammer core connecting rod, 12 is a butterfly spring, 13 is a hammer core, 14 is a replacement piston, 15 is a replacement piston sleeve, 16 is an inner cylinder sleeve, 17 is an outer cylinder sleeve, 18 is an oil pump of a lower cylinder chamber, 19 is a one-way valve of an oil pump of a lower cylinder chamber, 20 is a hydraulic valve of a lower cylinder chamber, 21 is a first throttle, 22 is a second throttle, 23 is a hydraulic valve of an upper cylinder chamber, 24 is a one-way valve of an oil pump of an upper cylinder chamber, 25 is an oil pump of an upper cylinder chamber, and 26 is an oil tank. DETAILED DESCRIPTION

[0022] like Figure 1The double-pump linked hydraulic pile hammer shown (the hammer core is in the piling position) has a hammer core 13 of a cylindrical alloy steel casting weighing 50 tons. The outer diameter of the cylindrical hammer core is 1.5 meters and the height is 5.1 meters. The hammer core guide 10 adopts a cylindrical guide structure, that is, the hammer core guide 10 is a steel cylindrical structure, and the hammer core 13 can be placed in the barrel of the hammer core guide 10 so as to slide back and forth up and down. A replacing piston sleeve 15 is fixedly connected to the lower end of the cylindrical hammer core guide 10 through a guide connecting flange. The replacing piston sleeve 15 also adopts a tubular structure. A replacing piston 14 is movably placed in the replacing piston sleeve 15. When striking, the upper top surface of the replacing piston 14 is directly hit by the falling hammer of the hammer core 13, and the lower bottom surface of the replacing piston 14 is an arc-shaped surface. The replacing piston 14 is supported on the top of the foundation pile through the arc-shaped surface; the falling hammer striking force of the hammer core 13 is transmitted to the foundation pile through the replacing piston 14, thereby effectively protecting the pile head from being injured or damaged.

[0023] The hydraulic cylinder 1 of the pile hammer has a cylinder head 6 at its lower end fixedly connected and supported on a lower support flange. The upper end of the hydraulic cylinder 1 is fixedly supported on an upper support flange via the cylinder bottom and cylinder base 3. The upper and lower support flanges are fixedly connected to each other via a cylinder support 5, forming a stable frame structure. The hydraulic cylinder 1 is located at the center of this rigid frame. A hydraulic cylinder sleeve is also mounted on the outer surface of the hydraulic cylinder 1 and fixedly mounted between the upper and lower support flanges. The lower support flange is fixedly mounted to the upper end of the cylindrical hammer core guide 10 via a connecting sleeve 8 and a sleeve connecting flange. This structure facilitates the installation and maintenance of the hydraulic cylinder. A hammer lifting barrel is fixedly connected to the upper support flange. The barrel houses hydraulic components such as an integrated valve block and a hydraulic pump. A hammer lifting lug is provided at the top of the barrel to facilitate lifting the entire pile.

[0024] like Figure 2 As shown, the hydraulic cylinder 1 is a single-rod piston hydraulic cylinder. The hydraulic cylinder 1 includes an inner cylinder sleeve 16 and an outer cylinder sleeve 17, which are concentrically spaced and nested together. An oil inlet passage is formed between the inner and outer cylinder sleeves 16, 17. A cylinder block 3 is fixedly welded to the upper ends of the inner and outer cylinder sleeves 16, 17. A cylinder bottom is fixedly connected to the cylinder block 3, and the cylinder bottom is provided with a lower cylinder chamber oil port 2 and an upper cylinder chamber oil port 4. A piston is movably mounted within the inner cylinder sleeve 16, and a piston rod 7 is fixedly connected to the lower end of the piston. The lower cylinder chamber oil port 2 is connected to the oil inlet passage between the inner and outer cylinder sleeves 16, 17 via a corresponding flow channel on the cylinder block. The oil inlet passage is connected to the lower chamber (rod chamber) of the inner cylinder sleeve of the hydraulic cylinder via an oil inlet hole at the lower end of the inner cylinder sleeve 16. The upper cylinder chamber oil port 4 is connected to the upper chamber (rodless chamber) of the hydraulic cylinder. The outwardly extending lower end of the piston rod 7 of the hydraulic cylinder 1 is connected to the hammer core connecting rod 11 through a coupling 9, and the hammer core connecting rod 11 is connected to the hammer core 13 through a butterfly spring 12.

[0025] The hydraulic control circuit of the pile hammer includes a lower cylinder oil pump 18 and an upper cylinder oil pump 25. The oil outlet of the lower cylinder oil pump 18 is connected to the pressure oil port P of the lower cylinder hydraulic valve 20 via a lower cylinder pump check valve 19. Port A of the lower cylinder hydraulic valve 20 is connected to the lower cylinder oil port 2. The oil outlet of the upper cylinder oil pump 25 is connected to the pressure oil port P of the upper cylinder hydraulic valve 23 via an upper cylinder pump check valve 24. Port A of the upper cylinder hydraulic valve 23 is connected to the upper cylinder oil port 4. Both the lower cylinder hydraulic valve 20 and the upper cylinder hydraulic valve 23 are two-position, three-way hydraulic reversing slide valves. The drive motors for the lower cylinder oil pump 18 and the upper cylinder oil pump 25 are variable frequency motors, or alternatively, servo motors, for easier control and speed regulation.

[0026] The pressure oil port P of the lower cylinder chamber hydraulic valve 20 is also connected to the control oil port X of the upper cylinder chamber hydraulic valve 23. The oil port A of the lower cylinder chamber hydraulic valve 20 is also connected to the control oil port X of the upper cylinder chamber hydraulic valve 23 through the first throttle 21. The pressure oil port P of the upper cylinder chamber hydraulic valve 23 is also connected to the control oil port X of the lower cylinder chamber hydraulic valve 20. The oil port A of the upper cylinder chamber hydraulic valve 23 is connected to the control oil port X of the lower cylinder chamber hydraulic valve 20 through the second throttle 22. Both the first throttle 21 and the second throttle 22 are through-type fixed throttle valves.

[0027] The overflow protection oil circuits of the lower cylinder chamber oil pump 18 and the upper cylinder chamber oil pump 25 and the lower cylinder chamber and the upper cylinder chamber of the hydraulic cylinder 1 include corresponding one-way valves and overflow valves connected to the one-way valves. The overflow protection oil circuit adopts the common protection oil circuit, so it is not in the Figure 1 Shown in.

[0028] When the pile hammer is working, as the lower cylinder chamber oil pump 18 and the upper cylinder chamber oil pump 25 work alternately, the hammer core 13 and the piston rod connected to it make reciprocating motions up and down to complete the impact and sinking of the foundation pile. First, start the lower cylinder chamber oil pump 18, and the lower cylinder chamber hydraulic valve 20 is in Figure 2 In the position shown, the A port and the P port are connected, the upper cylinder chamber oil pump 25 is in the off state, and the pressure oil at the outlet of the lower cylinder chamber oil pump 18 flows through the P port and the A port of the lower cylinder chamber oil pump 18 to the lower cylinder chamber oil port 2. The pressure oil flowing through the lower cylinder chamber oil port 2 enters the lower chamber of the hydraulic cylinder and pushes the piston rod 7 and the hammer core 13 upward to complete the hammer lifting. At the same time, the oil of the lower cylinder chamber oil pump 18 also flows into the control X of the upper cylinder chamber hydraulic valve 23 to push the sliding core to move to Figure 2 In another position shown, the A port and the T port of the upper cylinder chamber hydraulic valve 23 are connected, and the hydraulic oil in the upper cylinder chamber of the hydraulic cylinder 1 returns to the oil tank 26.

[0029] When the hammer core 13 reaches the set upper position, the lower cylinder chamber oil pump 18 is closed and the upper cylinder chamber oil pump 25 is started. At this time, the valve core of the lower cylinder chamber hydraulic valve 20 is still in Figure 2In the position shown, the P port and the A port of the lower cylinder chamber hydraulic valve 20 are still in a connected state, and the A port and the T port are disconnected; the P port and the A port of the upper cylinder chamber hydraulic valve 23 are in a disconnected state, and the A port and the T port are connected. The pressure oil pumped out by the upper cylinder chamber oil pump 25 is first pumped into the control oil port X of the lower cylinder chamber hydraulic valve 20 and the A port and T port of the upper cylinder chamber hydraulic valve 23. Due to the setting of the second throttle valve 22 in the control oil circuit, a pressure difference is formed at both ends of the second throttle valve 22. The pressure difference pushes the sliding core of the lower cylinder chamber hydraulic valve 20 to move to the other end position, so that the A port and T port of the lower cylinder chamber hydraulic valve 20 are connected, so that the pressure oil in the lower cylinder chamber returns to the oil tank 26. At the same time, the pressure oil in the control chamber of the upper cylinder chamber hydraulic valve 23 is relieved through the first throttle valve 21 and the A port and T port of the lower cylinder chamber hydraulic valve 20. The sliding core of the upper cylinder chamber hydraulic valve 23 moves to the other end position, so that the P port and A port of the upper cylinder chamber hydraulic valve 23 are connected, and the hammer core 13 is hammered under the action of the pressure oil of the upper cylinder chamber oil pump 25 and gravity.

[0030] Then start the lower cylinder chamber oil pump 18 again. At this time, the A port of the lower cylinder chamber hydraulic valve 20 is still disconnected from the P port and connected to the T port, and the A port of the upper cylinder chamber hydraulic valve 23 is still connected to the P port and disconnected from the T port. The pressure oil from the lower cylinder chamber oil pump 18 first enters the control oil port X of the upper cylinder chamber hydraulic valve 23 and ports A and T of the lower cylinder chamber hydraulic valve 20. Simultaneously, due to the configuration of the first throttle valve 21, a pressure differential is generated across the first throttle valve 21. This pressure differential pushes the slide core of the upper cylinder chamber hydraulic valve 23 to the other position, connecting ports A and T of the upper cylinder chamber hydraulic valve 23, allowing the pressure oil in the upper cylinder chamber of the hydraulic cylinder 1 to return to the oil tank 26. Simultaneously, the pressure oil in the control chamber of the lower cylinder chamber hydraulic valve 20 is relieved through the second throttle valve 22 and ports A and T of the upper cylinder chamber hydraulic valve 23. The slide core of the lower cylinder chamber hydraulic valve 20 moves to the other end position, connecting ports P and A of the lower cylinder chamber hydraulic valve 20. The pressure oil pumped out by the lower cylinder chamber oil pump 18 enters the lower cylinder chamber of the hydraulic cylinder 1 again, completing the raising and lowering of the hammer core 13. This process is repeated to achieve the pile hammer's raising and lowering.

[0031] Figure 3 FIG. 1 shows another embodiment of the present invention. This embodiment is identical to the above-described embodiment except for the structures of the hydraulic cylinder 1 and the hammer core guide 10. In this embodiment, the hydraulic cylinder 1 is a double-rod piston type hydraulic cylinder, and the hammer core guide 10 comprises two parallel guide rods. The hammer core 13 is slidably supported on these two parallel guide rods. Alternatively, the guide rods may be three or four parallel guide rods.

Claims

1. A dual-pump joint-controlled hydraulic pile hammer, comprising a hammer core (13) and a hammer core guide (10), wherein the hammer core (13) is supported on the hammer core guide (10) in a reciprocatingly slidable manner, a hydraulic cylinder (1) is fixedly mounted on the hammer core guide (10), and an extended end of a piston rod (7) of the hydraulic cylinder (1) is connected to the hammer core (13), characterized in that: The hydraulic cylinder (1) is provided with a lower cylinder chamber oil port (2) connected to the lower cylinder chamber of the hydraulic cylinder, and the hydraulic cylinder (1) is also provided with an upper cylinder chamber oil port (4) connected to the upper cylinder chamber of the hydraulic cylinder; the oil outlet of the lower cylinder chamber oil pump (18) is connected to the pressure oil port P of the lower cylinder chamber hydraulic valve (20), the oil port A of the lower cylinder chamber hydraulic valve (20) is connected to the lower cylinder chamber oil port (2), the oil outlet of the upper cylinder chamber oil pump (25) is connected to the pressure oil port P of the upper cylinder chamber hydraulic valve (23), and the oil port A of the upper cylinder chamber hydraulic valve (23) is connected to the upper cylinder chamber oil port (4); the pressure oil port P of the lower cylinder chamber hydraulic valve (20) and the control port of the upper cylinder chamber hydraulic valve (23) are connected. The oil control port X is connected, and the oil port A of the lower cylinder chamber hydraulic valve (20) is connected to the control oil port X of the upper cylinder chamber hydraulic valve (23) through the first throttle (21); the pressure oil port P of the upper cylinder chamber hydraulic valve (23) is connected to the control oil port X of the lower cylinder chamber hydraulic valve (20), and the oil port A of the upper cylinder chamber hydraulic valve (23) is connected to the control oil port X of the lower cylinder chamber hydraulic valve (20) through the second throttle (22); the lower cylinder chamber hydraulic valve (20) and the upper cylinder chamber hydraulic valve (23) are both two-position three-way hydraulic reversing valves; the driving motors of the lower cylinder chamber oil pump (18) and the upper cylinder chamber oil pump (25) are servo motors or variable frequency motors.

2. The dual-pump joint-controlled hydraulic pile hammer according to claim 1, characterized in that: The first throttle (21) and the second throttle (22) are straight-through fixed throttle valves.

3. The dual-pump joint-controlled hydraulic pile hammer according to claim 1, characterized in that: The hydraulic cylinder (1) is a single-rod piston hydraulic cylinder.

4. The dual-pump joint-controlled hydraulic pile hammer according to claim 1, characterized in that: The hydraulic cylinder (1) is a double-rod piston hydraulic cylinder.

5. The dual-pump joint-controlled hydraulic pile hammer according to claim 1, characterized in that: The hammer core guide (10) adopts a cylindrical guide structure, and the hammer core (13) is slidably arranged in the barrel of the hammer core guide (10).

6. The dual-pump joint-controlled hydraulic pile hammer according to claim 1, characterized in that: The hammer core guide (10) comprises two guide rods parallel to each other, and the hammer core (13) is slidably supported on the guide rods.

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