Hydraulic drive device of hydraulic pile hammer

Abstract

The present invention relates to a construction machinery, in particular to a hydraulic driving device of a hydraulic pile hammer. The technical solution is as follows: A hydraulic driving device of a hydraulic pile hammer includes a hydraulic cylinder body. At both axial ends of the hydraulic cylinder body, a cylinder head and a valve body are respectively provided. A piston and a piston rod are arranged inside the hydraulic cylinder body. An oil inlet is formed on the hydraulic cylinder body. A piston cylinder is sleeved inside the hydraulic cylinder body. The piston and the piston rod are located inside the piston cylinder. The space between the hydraulic cylinder body and the piston cylinder is a hydraulic oil return space. The piston cylinder has a lifting chamber and a driving chamber. The oil inlet is communicated with the hydraulic oil return space. A lifting chamber oil inlet channel is provided at the lifting chamber. On the valve body, there are channels for making the hydraulic oil return space communicate with the driving chamber and a return channel for making the hydraulic oil in the driving chamber flow back to an external oil tank. By adopting the above technical solution, a hydraulic driving device of a hydraulic pile hammer is provided, which is convenient for maintenance, increases the flow area of hydraulic oil, has stable sealing and prevents leakage.

Description

Technical Field

[0001] The present invention relates to a construction machinery, and particularly to a hydraulic driving device of a hydraulic pile hammer. Background Art

[0002] A hydraulic pile hammer is an impact pile driving machine, which mainly strikes the pile body by the way of free fall, and after being lifted to the expected height by the hydraulic system, obtains acceleration energy from the hydraulic system to increase the impact speed to strike the pile body.

[0003] The hydraulic driving source for lifting its acceleration in the hydraulic system is a hydraulic cylinder body. A cylinder head is provided at one axial end of the hydraulic cylinder body, and a switching valve is provided at the other end. A piston that reciprocates axially in the hydraulic cylinder body and piston rods respectively provided at both axial ends of the piston are provided. The piston rods at both ends can respectively penetrate through the cylinder head and the switching valve and extend outside the hydraulic cylinder body. The spaces at both axial ends of the piston in the hydraulic cylinder body are respectively a lifting chamber for promoting the piston to lift towards the upper part of the hydraulic cylinder body and a driving chamber for promoting the piston to quickly strike towards the lower part of the hydraulic cylinder body. An oil inlet that is communicated with the lifting chamber or the driving chamber and at least three oil return pipes that can be respectively communicated with the lifting chamber and the driving chamber are provided on the hydraulic cylinder body. The axial ends of the oil return pipes are respectively connected to the cylinder head and the switching valve, and there are sealing points between each oil return pipe and the cylinder head and the switching valve respectively.

[0004] The setting of the three oil return pipes in such a hydraulic cylinder body causes at least six upper and lower sealing points for the oil return. Each sealing point needs to ensure its sealing respectively, otherwise there will be a risk of oil leakage. The flow area of the hydraulic oil is small, and when the hydraulic oil is in a high-pressure state, its temperature is likely to rise. Moreover, when the hydraulic cylinder is damaged, it needs to be disassembled and replaced as a whole. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a hydraulic driving device of a hydraulic pile hammer that is convenient for maintenance, increases the flow area of hydraulic oil, has stable sealing and prevents leakage.

[0006] To achieve the above object, the present invention provides the following technical solution: A hydraulic drive device for a hydraulic pile hammer, comprising a hydraulic cylinder body, with cylinder heads and valve bodies respectively provided at both axial ends of the hydraulic cylinder body. A piston and piston rods respectively provided at both axial ends of the piston are arranged inside the hydraulic cylinder body, and the piston rods at both ends can respectively penetrate through the cylinder heads and valve bodies and extend outside the hydraulic cylinder body. An oil inlet is provided on the hydraulic cylinder body. It is characterized in that: A piston cylinder whose axial ends are respectively sealed and connected to the cylinder heads and valve bodies at both axial ends of the hydraulic cylinder body is sleeved inside the hydraulic cylinder body. The piston and the piston rods are located inside this piston cylinder and can reciprocate axially along the piston cylinder. The space between the hydraulic cylinder body and this piston cylinder is a hydraulic oil return space. The spaces at both axial ends of the piston cylinder where the piston is located are respectively a lifting chamber that promotes the piston to lift upward towards the upper part of the piston cylinder and a driving chamber that promotes the piston to quickly impact downward towards the lower part of the piston cylinder. The oil inlet is communicated with this hydraulic oil return space. A lifting chamber oil inlet passage that is communicated with the hydraulic oil return space is provided at the lifting chamber. A passage that promotes the hydraulic oil return space to be communicated with the driving chamber and a return passage that promotes the hydraulic oil in the driving chamber to flow back into the external oil tank are provided on the valve body located at the driving chamber.

[0007] By adopting the above technical solution, by arranging a piston cylinder for installing the piston inside the hydraulic cylinder body and making the space between the piston cylinder and the hydraulic cylinder body form a hydraulic oil return space, the oil return circuit is integrated inside the hydraulic cylinder body, reducing the sealing points generated by the traditional three oil return pipes and lowering the probability of oil leakage, thus further ensuring the sealing performance. The through-flow area of the hydraulic oil return space formed between the piston cylinder and the hydraulic cylinder body can prevent the hydraulic oil from heating up due to high pressure; and when the piston cylinder is damaged, only the piston cylinder needs to be replaced, which is convenient for disassembly and assembly.

[0008] The present invention is further arranged as follows: The lifting chamber oil inlet passage is a number of through holes uniformly distributed on the piston cylinder.

[0009] By adopting the above technical solution, such an arrangement can accelerate the oil inlet speed of the lifting chamber, thereby shortening the lifting time of the piston inside the piston cylinder, shortening the preparation time of the pile hammer, and indirectly accelerating the working efficiency.

[0010] The present invention is further arranged as follows: An installation hole is provided in the middle of the valve body. An oil seal cover detachably connected to the valve body is arranged inside the installation hole. An installation hole for the piston rod to penetrate through is provided on the oil seal cover. A sealing member is provided between the oil seal cover and the piston rod. There is a disassembly and assembly filling space between the inner wall of the installation hole of the valve body and the inner wall of the piston cylinder, and the inner diameter of the installation hole of the valve body is larger than the inner diameter of the inner wall of the piston cylinder.

[0011] With the above technical solution, when the piston and the piston rod malfunction and need to be removed. Since there are several channels in the valve body, if the oil seal cover is directly removed and the piston is pulled out from the installation hole of the valve body, the seal on the piston will expand into the channels of the valve body and be damaged. Therefore, after the oil seal cover is removed, a sleeve whose inner wall fits with the installation hole of the valve body and whose outer wall is on the same plane as the inner wall of the piston cylinder is inserted into the disassembly and assembly filling space. The sleeve blocks the channels on the valve body, so that when the piston is removed, the seal on it will not be damaged.

[0012] The present invention is further configured as follows: The cylinder head is connected to the hydraulic cylinder body through fasteners. A lower oil seal cover is provided inside the cylinder head. A seal is provided between the lower oil seal cover and the cylinder head. An installation through hole for the piston rod to penetrate is provided on the lower oil seal cover. A seal is provided between the installation through hole and the piston rod. One end of the lower oil seal cover facing the piston cylinder has a protrusion, and there is a positioning space for the cylinder wall of the piston cylinder to be inserted and positioned between the outer peripheral surface of the protrusion and the lower cylinder head.

[0013] With the above technical solution, such a setting has a simple structure and stable sealing performance.

[0014] The following further describes the present invention with reference to the accompanying drawings. Brief Description of the Drawings

[0015] Figure 1 is a three-dimensional schematic diagram of an embodiment of the present invention;

[0016] Figure 2 is Figure 1 the schematic cross-sectional view A-A of

[0017] Figure 3 is Figure 2 the enlarged schematic view of part I of

[0018] Figure 4 is the schematic structural diagram of the valve body of the embodiment of the present invention;

[0019] Figure 5 is the schematic structural diagram when removing the piston in the embodiment of the present invention that cannot be invented;

[0020] Figure 6 is Figure 5 the enlarged schematic view of part II of Detailed Embodiments

[0021] As Figure 1 — Figure 6A hydraulic driving device of a hydraulic pile hammer shown in the figure includes a hydraulic cylinder body 1. At both axial ends of the hydraulic cylinder body 1, there are respectively a cylinder head 2 and a valve body 3. Inside the hydraulic cylinder body 1, there is a piston 4 and piston rods 41 respectively arranged at both axial ends of the piston 4. The piston rods 41 at both ends can respectively penetrate through the cylinder head 2 and the valve body 3 and extend outside the hydraulic cylinder body 1. An oil inlet 11 is opened on the hydraulic cylinder body 1. A piston cylinder 5 whose axial ends are respectively sealed and connected to the cylinder head 2 and the valve body 3 at both axial ends of the hydraulic cylinder body 1 is sleeved inside the hydraulic cylinder body 1. The piston 4 and the piston rods 41 are located inside the piston cylinder 5 and can reciprocate axially along the piston cylinder 5. The space between the hydraulic cylinder body 1 and the piston cylinder 5 is a hydraulic oil return space 12. The spaces at both axial ends of the piston 4 in the piston cylinder 5 are respectively a lifting cavity 51 that promotes the piston 4 to lift towards the upper part of the piston cylinder 5 and a driving cavity 52 that promotes the piston 4 to quickly impact towards the lower part of the piston cylinder 5. The oil inlet 11 is communicated with the hydraulic oil return space 12. A lifting cavity oil inlet passage 511 that is communicated with the hydraulic oil return space 12 is provided at the lifting cavity 51. On the valve body 3 located at the driving cavity 52, there is a passage 31 that promotes the hydraulic oil return space 12 to be communicated with the driving cavity 52 and a return passage 32 that promotes the hydraulic oil in the driving cavity 52 to flow back into the external fuel tank. In the above solution, by arranging the piston cylinder 5 for installing the piston 4 inside the hydraulic cylinder body 1 and making the space between the piston cylinder 5 and the hydraulic cylinder body 1 form a hydraulic oil return space 12, the oil return circuit is integrated inside the hydraulic cylinder body 1, reducing the sealing points generated by the traditional three oil return pipes, reducing the probability of oil leakage, and further ensuring the sealing performance. The through-flow area of the hydraulic oil return space 12 formed between the piston cylinder 5 and the hydraulic cylinder body 1 can prevent the hydraulic oil from heating up due to high pressure; and when the piston cylinder 5 is damaged, only the piston cylinder 5 needs to be replaced, which is convenient for disassembly and assembly.

[0022] When the oil pump extracts the hydraulic oil in the fuel tank and enters it into the hydraulic oil return space 12 through the oil inlet 11 on the hydraulic cylinder body 1, the hydraulic oil enters the lifting cavity 51 through the lifting cavity oil inlet passage 511 on the piston cylinder 5 and resists the piston 4. The piston 4 lifts towards the upper part of the hydraulic cylinder body 1. At this time, a part of the hydraulic oil enters the driving cavity 52 through the passage 31 on the valve body 3 from the hydraulic oil return space 12; after the piston 4 lifts to a certain height, the hydraulic oil pressure in the driving cavity 52 is greater than the hydraulic oil pressure in the lifting cavity 51, prompting the hydraulic oil in the lifting cavity 51 to gradually enter the hydraulic oil return space 12 through the lifting cavity oil inlet passage 511, and then the hydraulic oil in the hydraulic oil return space 12 continuously compensates the driving cavity 52 through the passage 31 of the valve body 3, so that the piston 4 quickly displaces towards the lower part of the hydraulic cylinder body 1, and the impact speed and impact force of the piston 4 are increased, and the acceleration energy provided to the pile body can further increase the impact speed.

[0023] In the embodiment of the present invention, in order to accelerate the oil inlet speed of the lifting chamber 51, thereby shortening the lifting time of the piston 4 in the piston cylinder 5, shortening the preparation time of the pile hammer, and indirectly accelerating the work efficiency, the oil inlet passage 511 of the lifting chamber is a plurality of through holes uniformly distributed on the piston cylinder 5.

[0024] In the embodiment of the present invention, when the piston 4 or the piston cylinder 5 needs to be replaced, in order to shorten the disassembly and assembly time and reduce the disassembly and assembly processes. An installation hole 33 is provided in the middle of the valve body 3. An oil seal cover 34 detachably connected to the valve body 3 is provided in the installation hole 33. An installation hole 341 for the piston rod 41 to pass through is provided on the oil seal cover 34. A sealing member is provided between the oil seal cover 34 and the piston rod 41. There is a disassembly and assembly filling space 35 between the inner wall of the installation hole 33 of the valve body 3 and the inner wall of the piston cylinder 5, and the inner diameter of the installation hole 33 of the valve body 3 is larger than the inner diameter of the inner wall of the piston cylinder 5. Since there are several channels ३1 in the valve body 3, if the oil seal cover 34 is directly removed and the piston 4 is pulled out from the installation hole 33 of the valve body 3, the sealing member on the piston 4 will expand into the channels 31 of the valve body 3 and be damaged. Therefore, after the oil seal cover 34 is removed, a sleeve 6 whose inner wall fits with the installation hole 33 of the valve body 3 and whose outer wall is on the same plane as the inner wall of the piston cylinder 5 is inserted into the disassembly and assembly filling space 35. The sleeve 6 blocks the channels 31 on the valve body 3, so that when the piston 4 is removed, the sealing member thereon will not be damaged.

[0025] In the embodiment of the present invention, the cylinder head 2 is connected to the hydraulic cylinder block 1 through fasteners. The fasteners are fastening bolts. A lower oil seal cover 7 is provided in the cylinder head 2. A sealing member is provided between the lower oil seal cover 7 and the cylinder head 2. An installation through hole 71 for the piston rod 41 to pass through is provided on the lower oil seal cover 7. A sealing member is provided between the installation through hole 71 and the piston rod 41. One end of the lower oil seal cover 7 facing the piston cylinder 5 has a protrusion 72. There is a positioning space 73 for the cylinder wall of the piston cylinder 5 to be inserted and positioned between the outer peripheral surface of the protrusion 72 and the cylinder head 2. It should be noted that the sealing member can be an O-ring.

Claims

1. A hydraulic drive device for a hydraulic pile hammer, comprising a hydraulic cylinder body, a cylinder head and a valve body respectively provided at the axial ends of the hydraulic cylinder body, a piston and piston rods respectively provided at the axial ends of the piston, the piston rods at the two ends respectively extending through the cylinder head and the valve body to the outside of the hydraulic cylinder body, an oil inlet being provided on the hydraulic cylinder body, and characterized by: After derrick hoists and puts in place, stamp fixedly derrick of derrick pin, make hydraulic oil lead to the base hydraulic oil cylinder, hoist that base puts in place and fixing with same control mode. A reflux channel, the cylinder head is connected to the hydraulic cylinder body by fasteners, a lower oil seal cover is provided in the cylinder head, a seal is provided between the lower oil seal cover and the cylinder head, a mounting through hole for the piston rod to pass through is provided on the lower oil seal cover, a seal is provided between the mounting through hole and the piston rod, the lower oil seal cover has a protrusion on the end facing the piston cylinder, and a positioning space for the cylinder wall of the piston cylinder to be plugged in and positioned is provided between the outer peripheral surface of the protrusion and the cylinder head, a mounting hole is provided in the middle of the valve body, an oil seal cover detachably connected to the valve body is provided in the mounting hole, a mounting hole for the piston rod to pass through is provided on the oil seal cover, a seal is provided between the oil seal cover and the piston rod, a disassembly and filling space is provided between the inner wall of the valve body mounting hole and the inner wall of the piston cylinder, and the inner diameter of the valve body mounting hole is larger than the inner diameter of the inner wall of the piston cylinder.

2. The hydraulic driving device of the hydraulic pile hammer according to claim 1, characterized in that: The oil inlet passage of the lifting chamber is a plurality of through holes evenly distributed on the piston cylinder.

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