Ultrahigh-speed impact equipment with nitrogen energy storage and gravity combined type hydraulic speed-increasing cylinder

Abstract

Nitrogen energy storage and gravity combined type hydraulic acceleration cylinder ultra-high-speed impact equipment comprises a rack mechanism, an acceleration hydraulic cylinder mechanism and a return stroke mechanism are connected in the rack mechanism, the acceleration hydraulic cylinder mechanism is connected with the return stroke mechanism, the upper portion of the rack mechanism is connected with an energy accumulator mechanism, and the energy accumulator mechanism is connected with the acceleration hydraulic cylinder mechanism through a main unloading valve 7; the bottom of the rack mechanism is connected with a shearing mold 29, an energy accumulator mechanism, an acceleration hydraulic cylinder mechanism, a return stroke mechanism and a hydraulic system; the energy accumulator and the impact cylinder are designed to have the area difference, so that the speed increasing effect is achieved, and the requirement for the output flow of the hydraulic pump is greatly lowered.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-speed impact shearing, and particularly relates to a nitrogen energy storage and gravity composite hydraulic speed increasing cylinder ultra-high speed impact device. Background Art

[0002] In bar processing, high-speed impact shearing with a slider speed of 3 m / s to 6 m / s is a high-efficiency blanking process without chip waste and can obtain a high cross-section quality. For the high-speed impact shearing process, the shearing rate is one of the key factors affecting the shearing quality. The higher the shearing rate, the better the cross-section quality. High-speed shearing can apply high stress in a short time, thereby reducing plastic deformation and weakening the formation of the passivation layer. Especially when the speed is in the range of 10 m / s to 30 m / s, the quality of the sheared cross-section can be greatly improved. Therefore, this ultra-high speed bar shearing method has excellent application prospects in precision blanking.

[0003] In order to achieve high-speed impact shearing with a slider speed of 3 m / s to 6 m / s, the principle of gravity free fall is often used in the laboratory to drop from a sufficient height to generate high speed, that is, the speed v of the slider free fall is v = (2gh) 0.5 . To generate a speed of 10 m / s to 30 m / s, the required falling height reaches 5.1 m to 45.92 m. Such a height significantly exceeds the adaptation range of the actual production workshop. Therefore, the free fall shearing method using gravity as the power source is hardly used in actual production.

[0004] Among the current forging equipment, only the traditional hydraulic pneumatic hammer and hydraulic hammer in the hammer-type equipment have a slider speed significantly exceeding that of the mechanical press. The main structural feature of the hydraulic pneumatic hammer is to use a single-rod hydraulic cylinder as the driving component. The upper chamber is the rodless chamber connected to the pneumatic system, the lower chamber is the rod chamber connected to the hydraulic system, and the piston rod is connected to the hammer body. When striking downward, the lower cylinder is quickly drained through the reversing valve, and the hammer body loses the supporting force and is quickly struck under the action of the high-pressure gas in the upper chamber. A feature of this structural design is that the areas of the hydraulic cylinder and the air cylinder are the same, resulting in a large flow rate of hydraulic oil required when the hammer body impacts, and the large piston area reduces the flow rate of the hydraulic oil, thereby resulting in a low impact speed of the hammer body. The maximum impact speed of the hydraulic pneumatic die forging hammer is within 6.6 m / s.

[0005] The hydraulic hammer means that both the rod chamber and the rodless chamber of the hydraulic cylinder are filled with hydraulic oil. The hydraulic pump supplies oil to the rodless chamber to drive the hammer head to move quickly. The advantage of this structure is that the structure and driving method are simple, but its disadvantage is that it has extremely high requirements for the output flow rate and output power of the hydraulic pump. And limited by the installation cost of the hydraulic pump with high output flow rate and high output power, it is very difficult to further increase the impact speed of the hammer body, and the maximum impact speed is generally within 5.5 m / s.

[0006] As can be seen from the working principles of the main cylinders of the above-mentioned liquid-gas hammers and hydraulic hammers: when the oil is discharged from the piston rod chamber of the main cylinder, in order to reduce the frictional resistance loss of the hydraulic oil along the pipeline, the speed of the hydraulic oil in the pipeline is restricted by the above-mentioned maximum pipeline flow rate. The flow rate at the short pipes and local contractions is 5 - 7 m / s, so that the downward ultimate impact speed of the liquid-gas hammer and the hydraulic hammer generally does not exceed 7 m / s. To achieve an impact speed of 10 - 30 m / s, the current liquid-gas hammers and hydraulic hammers cannot reach it, and there is an urgent need to develop a new principle of ultra-high speed impact equipment that can be used industrially and is not restricted by the pipeline oil discharge speed of 5 - 7 m / s.

[0007] In summary, the current liquid-gas hammers and hydraulic hammer high-speed shearing equipment for bar shearing have the following deficiencies: 1) When the slider of the high-speed forging and punching equipment of the liquid-gas hammer and the hydraulic hammer moves downward to achieve bar impact shearing, the maximum speed will not exceed 7 m / s, which cannot meet the process requirements of the ultra-high speed of 10 - 30 m / s; 2) The return strokes of the sliders of both the liquid-gas hammer and the hydraulic hammer are achieved by the oil inlet of the piston rod chamber. When the slider moves downward, the piston rod chamber needs to quickly discharge oil, so the forging and punching speed of the slider moving downward will not exceed 7 m / s; 3) The upward and downward movements of the slider are both achieved by the series action of the oil inlet and outlet of the upper and lower chambers of the same piston driven by power, so the impact frequency of the equipment is reduced and the production efficiency is low. Summary of the Invention

[0008] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a nitrogen energy storage and gravity compound hydraulic speed increasing cylinder ultra-high speed impact equipment, which obtains a speed increasing effect by designing the accumulator and the impact cylinder in a form with an area difference, and greatly reduces the requirement for the output flow rate of the hydraulic pump.

[0009] To achieve the above purpose, the present invention adopts the following technical solutions:

[0010] A nitrogen energy storage and gravity compound hydraulic speed increasing cylinder ultra-high speed impact equipment, comprising a frame mechanism, an acceleration hydraulic cylinder mechanism and a return stroke mechanism are connected inside the frame mechanism, the acceleration hydraulic cylinder mechanism is connected with the return stroke mechanism, the upper part of the frame mechanism is connected with an accumulator mechanism, and the accumulator mechanism is connected with the acceleration hydraulic cylinder mechanism through a main unloading valve 7; a shearing die 29 is connected to the bottom of the frame mechanism, and the accumulator mechanism, the acceleration hydraulic cylinder mechanism, the return stroke mechanism and the hydraulic system are connected.

[0011] The frame mechanism includes a base 16, a tension screw 17, an upper support plate 5, an upper sleeve 19, an intermediate support plate 8, and a lower sleeve 15; the upper sleeve 19 is located between the upper support plate 5 and the intermediate support plate 8, and the lower sleeve 15 is located between the intermediate support plate 8 and the base 16; the first tension bolt 17 sequentially connects the upper support plate 5, the upper sleeve 19, the intermediate support plate 8, the lower sleeve 15 and the base 16; the shearing die 29 is connected to the base 16.

[0012] The accumulator mechanism described above includes an accumulator end cap 1 and an accumulator cylinder barrel 2. The accumulator end cap 1, the accumulator cylinder barrel 2 and the upper support plate 5 are fixed by the second tension bolt 3.

[0013] The accelerating hydraulic cylinder mechanism described above includes a hydraulic cylinder barrel 10, a striking piston 11, a hammer head 13, and an ejecting hydraulic cylinder 12. The hydraulic cylinder barrel 10 is inserted below the intermediate support plate 8. The rodless cavity of the hydraulic cylinder barrel 10 is connected to the main unloading valve 7. The upper end of the main unloading valve 7 is connected to the accumulator cylinder barrel 2 of the accumulator mechanism through a sealing sleeve 4. The sealing sleeve 4 is connected to the upper support plate 5. The lower end of the main unloading valve 7 is connected to the intermediate support plate 8. A striking piston 11 is provided inside the hydraulic cylinder barrel 10, and a hammer head 13 is connected to the bottom end of the striking piston 11. The ejecting hydraulic cylinder 12 is fixed on the mounting plate 24. The mounting plate 24 is connected to the bottom side of the hydraulic cylinder barrel 10. The ejecting hydraulic cylinder 12 is connected to the push head 25 and cooperates with the return mechanism of the push head 25.

[0014] The main unloading valve 7 described above includes a valve core 7-1, a spring 7-2, and a valve body 7-3. The spring 7-2 is located inside the valve core 7-1. The lower end of the spring 7-2 is limited on the boss of the valve body 7-3. The valve core 7-1 acts through the spring �. The upper end conical surface of the valve core 7-1 contacts the lower end conical surface of the sealing sleeve 4, and sealing is achieved through conical surface fit.

[0015] The return mechanism described above includes a return cylinder barrel 20, a return piston 22, and a return hook 26. The return cylinder barrel 20 is fixed on the intermediate support plate 8. The lower end of the return piston 22 provided inside the return cylinder barrel 20 is connected to the return hook 26 through a pin shaft. The return hook 26 is connected and cooperated with the push head 25 to realize the combination or disengagement of the return hook 26 and the hammer head 13.

[0016] The return hook 26 described above adopts an arc bottom edge. When the return hook 26 is located above the hammer head 13 and oil is filled into the return cylinder barrel 20 to make the return piston 22 move downward, the return hook 26 is driven to move downward. When the arc bottom edge of the return hook 26 touches the hammer head 13, the return hook 26 rotates clockwise around the pin shaft under the action of the contact resistance. When the return piston 22 continues to move downward until the return hook 26 is separated from the hammer head 13, the return hook 26 resumes its initial posture under the action of gravity, and the hook part is located below the hammer head 13. At this time, only need to make the return piston 22 move upward in the opposite direction, so that the return hook 26 hooks the hammer head 13 and drives the hammer head 13 to move upward together to complete the return action of the hammer head 13.

[0017] The described hydraulic system includes a hydraulic pump 32. The outlet of the hydraulic pump 32 is connected to a first two-position two-way electromagnetic directional control valve 28, a two-position four-way electromagnetic directional control valve 27, and a two-position three-way directional control valve 23 respectively through an oil filter device 31. The first two-position two-way electromagnetic directional control valve 28, the two-position four-way electromagnetic directional control valve 27, and the two-position three-way directional control valve 23 are connected to the hydraulic oil circuits of an accumulator cylinder 2, a return cylinder 20, and a main unloading valve 7. The two-position two-way electromagnetic directional control valve 28 controls the replenishment of hydraulic oil in the accumulator cylinder 2. The two-position four-way electromagnetic directional control valve 27 controls the movement direction of a return piston 22. The two-position three-way directional control valve 23 controls the flow direction of the hydraulic oil in the control chamber of the main unloading valve 7. The hydraulic oil circuit of a hydraulic cylinder barrel 10 and the hydraulic oil circuit of the main unloading valve 7 are connected through a second two-position two-way electromagnetic directional control valve 14. When the second two-position two-way electromagnetic directional control valve 14 controls the return of the hydraulic cylinder barrel 10, the hydraulic oil in the cavity of the hydraulic cylinder barrel 10 and the flow channel of the main unloading valve 7 is discharged.

[0018] During the impact process, the nitrogen in the accumulator mechanism is used for energy storage, and the impact energy is quickly released by opening the main unloading valve 7. Specifically, the second two-position two-way electromagnetic directional control valve 14 is commutated to seal the hydraulic oil in the hydraulic cylinder barrel 10. The two-position three-way electromagnetic directional control valve 23 is controlled to commutate, so that the hydraulic oil of the main unloading valve 7 quickly flows into the fuel tank. At this time, the valve core 7-1 quickly opens, and the high-pressure oil in the accumulator mechanism enters the hydraulic cylinder barrel 10 and pushes the impact piston 11 to accelerate downward. The impact piston 11 moves to the bottom dead center to complete the impact process at the highest speed.

[0019] The described return mechanism is an independent hydraulic system that can work independently with the accumulator mechanism. When a working process is completed, while the return piston 22 lifts the hammer head 13 to return, the accumulator cylinder 2 stores energy for impact at the same time, preparing for the next impact process and improving the working frequency.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) Using high-pressure gas rapid adiabatic expansion as the impact power source, the adiabatic expansion acceleration is up to hundreds of times the gravitational acceleration, making the speed of hydraulic movement reach more than 10 m / s. At the same time, the main unloading valve 7 with an area difference is used to further produce a speed increasing effect, and the speed increasing ratio is between 3 and 7. The maximum speed of the hammer head can reach 30.97 m / s, and it is easy to reach an ultra-high impact speed of 10 m / s to 30 m / s.

[0022] (2) The lower cavity of the impact piston 11 in the hydraulic cylinder barrel 10 is directly connected to the atmosphere, avoiding the limitation of the maximum pipeline oil discharge speed of 7 m / s, so that the bar shear impact speed can reach the set ultra-high impact speed of 10 m / s to 30 m / s.

[0023] (3) The return mechanism arranged independently and symmetrically is adopted to complete the return movement of the hammer head. During the return process of the hammer head 13, the hydraulic oil of the hydraulic pump station can be transported into the accumulator cylinder 2 to compress the gas at the top of the accumulator cylinder 2 to complete the energy storage action. That is to say, while the hammer head 13 returns, the accumulator mechanism stores energy, and the two actions are carried out simultaneously, saving time and significantly increasing the number of bar shears per unit time, thus improving the production efficiency. Brief Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0025] Figure 2 It is a left view of the structure of the main unloading valve 7 of an embodiment of the present invention.

[0026] Figure 3 It is a schematic process diagram of the automatic hooking of the return mechanism of an embodiment of the present invention. Detailed Embodiment

[0027] The present invention will be described in detail below in conjunction with the embodiments and the drawings.

[0028] Refer to Figure 1 , a nitrogen energy storage and gravity compound hydraulic speed increasing cylinder ultra-high speed impact device, including a frame mechanism, an accumulator mechanism, an accelerating hydraulic cylinder mechanism, a return mechanism, and a hydraulic system; an accelerating hydraulic cylinder mechanism and a return mechanism are connected inside the frame mechanism, the accelerating hydraulic cylinder mechanism is connected to the return mechanism, the upper part of the frame mechanism is connected to the accumulator mechanism, and the accumulator mechanism is connected to the accelerating hydraulic cylinder mechanism through the main unloading valve 7; a shearing die 29 is connected to the bottom of the frame mechanism, and the accumulator mechanism, the accelerating hydraulic cylinder mechanism, the return mechanism and the hydraulic system are connected.

[0029] Refer to Figure 1 , the described frame mechanism includes a base 16, a tensioning screw 17, an upper support plate 5, an upper sleeve 19, an intermediate support plate 8, and a lower sleeve 15; the upper sleeve 19 is located between the upper support plate 5 and the intermediate support plate 8, and the lower sleeve 15 is located between the intermediate support plate 8 and the base 16; the first tensioning bolt 17 sequentially passes through the upper support plate 5, the upper sleeve 19, the intermediate support plate 8, the lower sleeve 15 and the base 16, and both ends of the first tensioning screw 17 are locked by the first nuts 18 to fix each part; the shearing die 29 is connected to the base 16.

[0030] Refer to Figure 1 , the described accumulator mechanism includes an accumulator end cap 1 and an accumulator cylinder 2; the accumulator end cap 1, the accumulator cylinder 2 and the upper support plate 5 are fixed by the second tensioning bolt 3, and both ends of the second tensioning bolt 3 are locked by the second nuts 6 to form a whole.

[0031] Refer to Figure 1 、Figure 2 The main unloading valve 7 includes a valve core 7-1, a spring 7-2, and a valve body 7-3. The spring 7-2 is located inside the valve core 7-1. The lower end of the spring 7-2 is limited on the boss of the valve body 7-3. The valve core 7-1 acts through the spring 7-2. The upper end conical surface of the valve core 7-1 contacts the lower end conical surface of the sealing sleeve 4, and sealing is achieved through the conical surface fit.

[0032] Refer to Figure 1 The acceleration hydraulic cylinder mechanism includes a hydraulic cylinder barrel 10, a striking piston 11, a hammer head 13, and an ejecting hydraulic cylinder 12. The hydraulic cylinder barrel 10 is inserted below the intermediate support plate 8 and fixed by a third nut 9. The rodless cavity of the hydraulic cylinder barrel 10 is connected to the main unloading valve 7. The upper end of the main unloading valve 7 is connected to the accumulator cylinder 2 of the accumulator mechanism through the sealing sleeve 4. The sealing sleeve 4 is connected to the upper support plate 5. The lower end of the main unloading valve 7 is connected to the intermediate support plate 8. A striking piston 11 is provided inside the hydraulic cylinder barrel 10, and a hammer head 13 is connected to the bottom end of the striking piston 11. The ejecting hydraulic cylinder 12 is fixed on the mounting plate 24. The mounting plate 24 is connected to the bottom side of the hydraulic cylinder barrel 10. The ejecting hydraulic cylinder 12 is connected to the push head 25 and cooperates with the return mechanism of the push head 25.

[0033] Refer to Figure 1 、 Figure 3 The return mechanism includes a return cylinder barrel 20, a return piston 22, and a return hook 26. The return cylinder barrel 20 is tightened and fixed on the intermediate support plate 8 by a fourth nut 21. The lower end of the return piston 22 provided inside the return cylinder barrel 20 is connected to the return hook 26 through a pin shaft. The return hook 26 is connected to the push head 25 in a cooperative manner to achieve the combination or disengagement of the return hook 26 and the hammer head 13.

[0034] Refer to Figure 1, the described hydraulic system includes a hydraulic pump 32, an oil filter device 31, a relief valve 30, a first two-position two-way solenoid directional control valve 28, a two-position four-way solenoid directional control valve 27, a two-position three-way directional control valve 23, and a second two-position two-way solenoid directional control valve 14; the outlet of the hydraulic pump 32 is connected to the first two-position two-way solenoid directional control valve 28, the two-position four-way solenoid directional control valve 27, and the two-position three-way directional control valve 23 respectively through the oil filter device 31, and the first two-position two-way solenoid directional control valve 28, the two-position four-way solenoid directional control valve 27, and the two-position three-way directional control valve 23 are connected to the hydraulic oil circuits of the accumulator cylinder 2, the return cylinder 20, and the main unloading valve 7. The relief valve 30 controls the system pressure. The two-way solenoid directional control valve 28 controls the replenishment of hydraulic oil to the accumulator cylinder 2. The two-position four-way solenoid directional control valve 27 controls the movement direction of the return piston 22. The two-position three-way directional control valve 23 controls the flow direction of the hydraulic oil in the control chamber of the main unloading valve 7, thereby controlling the opening state of the valve core 7-1; the hydraulic oil circuit of the hydraulic cylinder barrel 10 and the hydraulic oil circuit of the main unloading valve 7 are connected through the second two-position two-way solenoid directional control valve 14. When the second two-position two-way solenoid directional control valve 14 controls the return of the hydraulic cylinder barrel 10, the hydraulic oil in the cavity of the hydraulic cylinder barrel 10 and the flow channel of the main unloading valve 7 is discharged.

[0035] The working principle of the present invention is as follows:

[0036] The hydraulic oil provided by the hydraulic pump 32 passes through the filter device 31 and then the maximum oil supply pressure is controlled by the relief valve 30, and it is supplied with oil to the accumulator cylinder 2, the return cylinder 20, and the hydraulic cylinder barrel 10 in three ways.

[0037] In the initial use preparation stage, the main oil circuit pre-supplies oil to the accumulator cylinder 2 through the two-way solenoid directional control valve 28. At the beginning, the return piston 22 and the impact piston 11 are at the bottom dead center. The solenoid directional control valve 28 works in the left position and the accumulator is filled with oil; at the same time, the two-position three-way solenoid valve 23 works in the left position, the control chamber of the main unloading valve 7 is pressurized, and the valve core 7-1 is locked; the second two-position two-way solenoid directional control valve 14 works in the left position, so that the hydraulic oil in the hydraulic cylinder barrel 10 is connected to the fuel tank. At this time, the return piston 22 can drive the impact piston 11 to move upward; the two-position four-way solenoid directional control valve 27 works in the right position, the return piston 22 moves upward, and the return hook 26 hooks the hammer head 13 to complete the return action of the hammer head. When the accumulator mechanism is fully charged, the first two-position two-way solenoid directional control valve 28 that controls the charging of the accumulator mechanism is reversed and works in the right position, and the equipment completes the preparation stage before the first operation and can perform the first impact action.

[0038] At the start of the striking phase, the ejection hydraulic cylinder 12 is filled with oil, causing the push head 25 to move rapidly downward and pushing one end of the return hook 26. Under the action of the lever force, the return hook 26 rotates, causing the return hook 26 to disengage from the hammer head 13. At the same time, the second two-position two-way electromagnetic directional control valve 14 changes its direction and works in the right position, sealing the hydraulic oil in the hydraulic cylinder barrel 10. The two-position three-way electromagnetic directional control valve 23 that controls the main unloading valve 7 changes its direction and works in the right position, causing the hydraulic oil in the control chamber of the main unloading valve 7 to quickly flow into the fuel tank. At this time, the valve core 7-1 quickly opens, and the high-pressure oil in the accumulator enters the hydraulic cylinder barrel 10 and pushes the striking piston 11 to accelerate downward. The striking piston 11 moves to the bottom dead center and completes the striking process at the highest speed.

[0039] After the striking phase is completed, the two-position three-way electromagnetic directional control valve 23 that controls the control chamber of the main unloading valve 7 changes its direction and works in the left position, completing the oil supply to the control chamber of the main unloading valve 7 and locking the valve core 7-1. Subsequently, the first two-position two-way electromagnetic directional control valve 28 that controls the filling of the accumulator cylinder 2 changes its direction and works in the left position, and the hydraulic pump 32 starts to charge the accumulator cylinder 2. When the accumulator cylinder 2 is being charged, the second two-position two-way electromagnetic directional control valve 14 changes its direction and works in the left position, connecting the hydraulic cylinder barrel 10 to the fuel tank. The two-position four-way electromagnetic directional control valve 27 that controls the return piston 22 changes its direction and works in the left position, and the return piston 22 moves downward. Referring to Figure 3 , when the arc bottom edge of the return hook 26 touches the hammer head 13, the return hook 26 rotates clockwise around the pin shaft under the action of the contact resistance. When the return piston 22 continues to move downward until the return hook 26 separates from the hammer head 13, the return hook 26 returns to its initial posture under the action of gravity, and the hook-shaped part is located below the hammer head 13. At this time, by changing the direction of the two-position four-way electromagnetic directional control valve 27, the return piston 22 moves upward in the reverse direction, enabling the return hook 26 to hook the hammer head 13 and driving the hammer head 13 to move upward together, completing the return action of the hammer head 13.

[0040] After the return action is completed, the above operation process can be repeated to start the next working stroke.

[0041] According to the principle of fluid mechanics, the calculation formula for the oil discharge flow rate at the valve port is: where q is the oil discharge flow rate, C d is the flow coefficient, A is the flow area of the valve port, ρ is the density of the oil, and Δp is the pressure difference. For the design of the main unloading valve 7 proposed in this embodiment, the calculation formula for the flow area of the valve port is: where d1 is the channel diameter, α is the cone angle, and x is the opening distance of the valve core. In the main unloading valve 7 proposed in this embodiment, d1 = 150 mm, α = 45°, and x = 60 mm. By calculation, the theoretical maximum flow rate that can pass through this valve port is 2.189 m 3 / s, in the ideal case without considering local resistance loss and frictional resistance loss along the way, the maximum achievable flow velocity can reach 77 m / s. This huge liquid impact kinetic energy still needs to be converted to the impact piston 11. According to the kinetic theory, the liquid momentum and energy are converted to the impact piston 11 with a larger mass. The impact piston 11 will absorb the kinetic energy of the fluid, causing the velocity to decrease. Exactly how much it decreases can be theoretically verified through the following analysis and calculation:

[0042] Next, establish the kinematic mathematical model of the nitrogen energy storage and gravity compound hydraulic speed increasing cylinder ultra-high speed device, and calculate the moving speed of the specific hammer head 13:

[0043] In the impact stage, the piston in the accumulator cylinder 2 is pushed downward by the expanding gas above to do work, and the oil fluid below the piston is pushed to flow into the hydraulic cylinder 10. The impact piston 11 in the hydraulic cylinder 10 is pushed downward by the oil fluid thrust to do work. To distinguish the two pistons, the piston in the accumulator cylinder 2 is denoted as piston A, and the impact piston 11 in the hydraulic cylinder 10 is denoted as piston B. The kinematic models of the two pistons can be described as follows. In the following kinematic discussion, it is stipulated that the positive directions of the force vector and the velocity vector are perpendicular to the ground and downward;

[0044] F oil +F inertia +f1 = 0 (1)

[0045] In the formula, F oil is the force exerted by the oil fluid on the impact piston 11, F inertia is the inertial force of the piston, and f1 is the moving resistance of the piston due to the friction between the cylinder wall and the sealing ring.

[0046] During the process of the gas expanding to do work, record the downward displacement of the piston as l(t). According to the ideal gas state equation and Newton's law under adiabatic conditions, the above formula can be written as:

[0047]

[0048] In the formula, p0 is the gas pressure, V0 is the gas volume, S A is the cylinder area, l(t) is the piston displacement, α is the ratio of the impact cylinder area to the accumulator cylinder area, m is the piston mass, and f1 is the piston moving friction.

[0049] Thus, a differential equation system containing the unknown function l(t) is obtained. This differential equation system contains all the kinematic information of the impact piston during the impact process; according to the IFAS model of the pressure oil fluid, the volume compression of the hydraulic oil under pressure is very limited. At a pressure of 20 MPa, the volume compression percentage of the hydraulic oil is only about 0.008%. Therefore, the volume compression of the oil fluid is ignored during the process of formula (2).

[0050] The kinematic differential equation is discretely iteratively solved. To ensure the calculation accuracy, the discrete interval time is taken as 0.00005 s, which is approximately 0.202% of the total calculation duration. A total of 494 steps of iteration are carried out, and the discrete piston displacement information within 0.02465 s is calculated. Some calculation results are shown in the following table:

[0051]

[0052] It can be calculated from the kinematic theoretical differential equation that at the rated working pressure of 10 MPa, the maximum speed of the hammer head can reach 30.97 m / s.

[0053] From the above kinetic analysis, it can be seen that the fluid kinetic energy of the fluid with a velocity of 77 m / s output by the fast drain valve obtained from the previous analysis and calculation can be converted into the velocity of the hammer head 13 to reach 30.97 m / s after energy conversion, thus verifying the correctness of the theoretical analysis of 10 - 30 m / s obtained in this embodiment.

Claims

1. A nitrogen energy storage and gravity compound hydraulic speed increasing cylinder ultra-high speed impact device, comprising a frame mechanism, characterized in that: An acceleration hydraulic cylinder mechanism and a return mechanism are internally connected to the frame mechanism. The acceleration hydraulic cylinder mechanism is connected to the return mechanism. The upper part of the frame mechanism is connected to the accumulator mechanism. The accumulator mechanism is connected to the acceleration hydraulic cylinder mechanism through a main unloading valve (7). The bottom of the frame mechanism is connected to a shearing die (29). The accumulator mechanism, the acceleration hydraulic cylinder mechanism, the return mechanism and the hydraulic system are connected.

2. The device according to claim 1, characterized in that: The frame mechanism includes a base (16), a tension screw (17), an upper support plate (5), an upper sleeve (19), an intermediate support plate (8), and a lower sleeve (15). The upper sleeve (19) is located between the upper support plate (5) and the intermediate support plate (8), and the lower sleeve (15) is located between the intermediate support plate (8) and the base (16). A first tension bolt (17) sequentially connects the upper support plate (5), the upper sleeve (19), the intermediate support plate (8), the lower sleeve (15) and the base (16). The shearing die (29) is connected to the base (16).

3. The device according to claim 2, characterized in that: The accumulator mechanism includes an accumulator end cap (1) and an accumulator cylinder barrel (2). The accumulator end cap (1), the accumulator cylinder barrel (2) and the upper support plate (5) are fixed by a second tension bolt (3).

4. The device according to claim 2, characterized in that: The acceleration hydraulic cylinder mechanism includes a hydraulic cylinder barrel (10), a striking piston (11), a hammer head (13), and an ejecting hydraulic cylinder (12). The hydraulic cylinder barrel (10) is inserted below the intermediate support plate (8). The rodless cavity of the hydraulic cylinder barrel (10) is connected to the main unloading valve (7). The upper end of the main unloading valve (7) is connected to the accumulator cylinder barrel (2) of the accumulator mechanism through a sealing sleeve (4). The sealing sleeve (4) is connected to the upper support plate (5). The lower end of the main unloading valve (7) is connected to the intermediate support plate (8). A striking piston (11) is arranged in the hydraulic cylinder barrel (10), and a hammer head (13) is connected to the bottom end of the striking piston (11). The ejecting hydraulic cylinder (12) is fixed on a mounting plate (24). The mounting plate (24) is connected to the bottom side of the hydraulic cylinder barrel (10). The ejecting hydraulic cylinder (12) is connected to a push head (25), and the push head (25) cooperates with the return mechanism.

5. The device according to claim 4, characterized in that: The main unloading valve (7) includes a valve core (7-1), a spring (7-2), and a valve body (7-3). The spring (7-2) is located inside the valve core (7-1). The lower end of the spring (7-2) is limited on the boss of the valve body (7-3). The valve core (7-1) acts through the spring (7-2). The upper end conical surface of the valve core (7-1) contacts the lower end conical surface of the sealing sleeve (4), and sealing is achieved through conical surface fitting.

6. The device according to claim 4, characterized in that: The return mechanism includes a return cylinder barrel (20), a return piston (22), and a return hook (26). The return cylinder barrel (20) is fixed on the intermediate support plate (8). The lower end of the return piston (22) arranged in the return cylinder barrel (20) is connected to the return hook (26) through a pin shaft. The return hook (26) is connected to the push head (25) in a cooperative manner to realize the combination or disengagement of the return hook (26) and the hammer head (13).

7. The device according to claim 6, characterized in that: The described return hook (26) has an arc-shaped bottom edge. When the return hook (26) is above the hammer head (13), when oil is filled into the return cylinder barrel (20) to make the return piston (22) move downward, the return hook (26) is driven to move downward. When the arc-shaped bottom edge of the return hook (26) touches the hammer head (13), the return hook (26) rotates clockwise around the pin shaft under the action of the contact resistance. When the return piston (22) continues to move downward until the return hook (26) separates from the hammer head (13), the return hook (26) returns to its initial posture under the action of gravity, and the hook-shaped part is located below the hammer head (13). At this time, only need to make the return piston (22) move upward in the reverse direction, so that the return hook (26) hooks the hammer head (13) and drives the hammer head (13) to move upward together to complete the return action of the hammer head (13).

8. The device according to claim 1, characterized in that: The described hydraulic system includes a hydraulic pump (32). The outlet of the hydraulic pump (32) is respectively connected to a first two-position two-way electromagnetic reversing valve (28), a two-position four-way electromagnetic reversing valve (27), and a two-position three-way reversing valve (23) through an oil filter device (31). The first two-position two-way electromagnetic reversing valve (28), the two-position four-way electromagnetic reversing valve (27), and the two-position three-way reversing valve (23) are connected to the hydraulic oil circuits of the accumulator cylinder barrel (2), the return cylinder barrel (20), and the main unloading valve (7). The first two-position two-way electromagnetic reversing valve (28) controls the replenishment of hydraulic oil in the accumulator cylinder barrel (2). The two-position four-way electromagnetic reversing valve (27) controls the movement direction of the return piston (22). The two-position three-way reversing valve (23) controls the flow direction of the hydraulic oil in the control chamber of the main unloading valve (7). The hydraulic oil circuit of the hydraulic cylinder barrel (10) and the hydraulic oil circuit of the main unloading valve (7) are connected through a second two-position two-way electromagnetic reversing valve (14). The second two-position two-way electromagnetic reversing valve (14) controls the discharge of the hydraulic oil in the cavity of the hydraulic cylinder barrel (10) and the flow passage of the main unloading valve (7) when the hydraulic cylinder barrel (10) returns.

9. The device according to claim 8, characterized in that: The impact process utilizes the nitrogen energy storage in the accumulator mechanism and quickly releases the impact energy by opening the main unloading valve (7). Specifically: The second two-position two-way electromagnetic reversing valve (14) changes its direction, so that the hydraulic oil in the hydraulic cylinder barrel (10) is sealed. Control the two-position three-way electromagnetic reversing valve (23) to change its direction, so that the hydraulic oil of the main unloading valve (7) quickly flows into the fuel tank. At this time, the valve core (7-1) quickly opens, and the high-pressure oil in the accumulator mechanism enters the hydraulic cylinder barrel (10) and pushes the striking piston (11) to accelerate downward. The striking piston (11) moves to the bottom dead center to complete the striking process at the highest speed.

10. The device according to claim 9, characterized in that: The described return mechanism is an independent hydraulic system and can work independently with the accumulator mechanism. When a working process is completed, while the return piston (22) lifts the hammer head (13) for return, the accumulator cylinder barrel (2) simultaneously stores energy for impact, preparing for the next impact process and improving the working frequency.

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