Cavitation water jet incremental forming equipment

Abstract

According to the cavitation water jet incremental forming equipment, a workpiece is formed through huge impact force generated by cavitation collapse, a working water tank is arranged, and a cavitation nozzle is driven by a driving unit to move in the working water tank, so that the workpiece can be formed by the cavitation nozzle in the underwater submerging environment of the working water tank. And meanwhile, through switching of the electromagnetic valve between the first state and the second state, rapid opening or closing of the cavitation nozzle can be achieved based on the on-off state of the electromagnetic valve. And when the cavitation nozzle is in a closed state, the main pump is connected with the water storage tank through the electromagnetic valve, and the water flow pumped out by the main pump returns to the water storage tank again at the moment, so that circulation in the closed state of the cavitation nozzle is completed. Compared with the prior art, the special equipment for underwater forming is provided, the impact force of cavitation collapse is used for forming, the two-position three-way electromagnetic valve is used for controlling on-off of high-pressure water, and compared with a traditional refitted milling machine, the mechanical arm is used for controlling the track, so that the track is more gentle.

Description

Technical Field

[0001] The present invention relates to the technical field of forming equipment, and in particular to a cavitation water jet incremental forming equipment. Background Art

[0002] Water jet incremental forming is a new type of metal sheet forming technology. According to the sheet metal water jet incremental forming process, the forming of sheet metal parts no longer requires a mold, but directly uses high-pressure water acting on the surface of the sheet metal. When the pressure of the high-pressure water jet exceeds the limit value of the material, the sheet metal will undergo local plastic deformation. Its forming principle is to spray a water column with a certain jet pressure onto the metal sheet to cause local plastic deformation. Under computer control, the high-pressure water column moves along a given path to perform step-by-step layer processing on the part until the final forming.

[0003] Cavitation is a phase change phenomenon. When the water pressure drops to the saturated vapor pressure of water, it changes from the liquid phase to the gas phase. According to cavitation dynamics, when a cavitation bubble collapses under the stagnation pressure near the wall surface, under the same conditions, the impact pressure generated is 8.6 to 124 times that of an ordinary water jet.

[0004] However, in the process of traditional incremental forming processing, the common practice is to use a modified milling machine as the water jet incremental forming equipment. However, these equipments often cannot work in a submerged environment, so the operation of cavitation water jet incremental forming cannot be realized, and there is no specific equipment for underwater forming in the prior art. Summary of the Invention

[0005] In order to solve the problem that cavitation water jet incremental forming needs to be carried out in a submerged environment and there is currently no specific equipment for underwater forming, the present invention proposes a cavitation water jet incremental forming equipment.

[0006] The technical solution adopted by the present invention is a cavitation water jet incremental forming equipment, which includes a driving unit. The driving unit drives a cavitation nozzle to move in a working water tank. A water storage tank, a main pump, and a solenoid valve are connected in sequence. The solenoid valve has a first state and a second state. In the first state, the main pump is connected to the cavitation nozzle through the solenoid valve, and in the second state, the main pump is connected to the water storage tank through the solenoid valve. This solution performs forming in a submerged environment and utilizes the impact force of cavitation bubble collapse. When a cavitation bubble collapses under the stagnation pressure near the wall surface, under the same conditions, the impact pressure generated is 8.6 to 124 times that of an ordinary water jet.

[0007] In some embodiments, a two-way three-way solenoid valve is used to control the on-off of high-pressure water, so as to achieve the purpose of quickly switching the flow path.

[0008] In some embodiments, the driving unit is a six-axis rotary joint type robotic arm. The device innovatively uses a robotic arm as the execution device and uses the built-in teach pendant for system programming. The operation is simple, and more processing parameters can be adjusted, such as the target distance, feed speed, lateral layer spacing, etc., greatly increasing flexibility. The forming process is completed in the working water tank. The two-position three-way solenoid valve is connected to the control cabinet of the robotic arm. Through teach pendant programming, it can be powered on and off as needed, which is more precise compared to manual switches. Compared with traditional modified milling machines, using a robotic arm to control the trajectory is gentler.

[0009] In some embodiments, a fixture is connected to the output end of the six-axis rotary joint type robotic arm, and the fixture is connected to the water pipe between the solenoid valve and the cavitation nozzle.

[0010] In some embodiments, a filtering unit is provided between the water storage tank and the main pump.

[0011] In some embodiments, a booster pump is provided between the main pump and the solenoid valve.

[0012] In some embodiments, a workbench is provided at the bottom of the working water tank. The workbench includes fasteners, an upper pressing plate, and a lower pressing plate. The workpiece is located between the upper pressing plate and the lower pressing plate and is fixed by the fasteners.

[0013] In some embodiments, the working water tank has a water outlet pipeline, and the solenoid valve has a third state. In the third state, the main pump is connected to the water outlet pipeline through the solenoid valve, and the main pump is a two-way pump.

[0014] In some embodiments, the cavitation nozzle has a cavitation state and a water injection state. In the cavitation state, the ejected liquid is cavitated, and in the water injection state, the liquid is ejected normally.

[0015] In some embodiments, a blower is connected to the working water tank, and the blower forms a wind wall at the opening of the working water tank.

[0016] In some embodiments, a water depth sensor and a water storage and discharge unit are provided in the working water tank. The water storage and discharge unit is connected to the working water tank, and the water depth sensor is electrically connected to the water storage and discharge unit. The water depth sensor emits a water depth signal according to the water depth, and the water storage and discharge unit receives the water depth signal to absorb or discharge water from the working water tank.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present application discloses a cavitation water jet incremental forming device, which uses the huge impact force generated by the collapse of cavitation bubbles to form workpieces. By setting up a working water tank and driving a cavitation nozzle to move in the working water tank by a driving unit, the cavitation nozzle can form the workpieces in the underwater submerged environment of the working water tank. At the same time, by switching the solenoid valve between the first state and the second state, the rapid opening or closing of the cavitation nozzle can be realized based on the on-off state of the solenoid valve. When the cavitation nozzle is in the closed state, the main pump is connected to the water storage tank through the solenoid valve. At this time, the water flow pumped out by the main pump returns to the water storage tank again, completing the cycle in the closed state of the cavitation nozzle. During this process, the high-pressure water flow formed by the main pump is not in a stopped flowing state, avoiding the need for the main pump to start for a long time to reach the rated pressure value due to the opening and closing actions of the main pump, and preventing being affected by the starting characteristics of the pump.

[0019] Compared with the prior art, a cavitation water jet incremental forming device disclosed in the present application provides a specific device for underwater forming, enabling cavitation water jet incremental forming to be carried out in a submerged environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be described in detail below in conjunction with the embodiments and the drawings, where:

[0021] Figure 1 shows a schematic structural diagram of a cavitation water jet incremental forming device provided according to an embodiment of the present invention;

[0022] Figure 2 shows according to Figure 1 a schematic structural diagram of a fixture in a cavitation water jet incremental forming device provided;

[0023] Figure 3 shows according to Figure 1 a schematic structural diagram of a workbench in a cavitation water jet incremental forming device provided.

[0024] Reference numerals:

[0025] 1, main pump; 2, booster pump; 3, solenoid valve; 4, water storage tank; 5, six-axis rotating joint type robotic arm; 6, fixture; 7, water pipe; 8, cavitation nozzle; 9, working water tank; 10, workbench. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below in conjunction with the drawings. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar components or components with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0027] The present invention discloses a cavitating water jet incremental forming device. Please refer to Figures 1 to 3 , which includes a driving unit. The driving unit drives a cavitating nozzle 8 to move in a working water tank 9. A water storage tank 4, a main pump 1, and a solenoid valve 3 are connected in sequence. The solenoid valve 3 has a first state and a second state. In the first state, the main pump 1 is connected to the cavitating nozzle 8 through the solenoid valve 3. In the second state, the main pump 1 is connected to the water storage tank 4 through the solenoid valve 3.

[0028] The huge impact force generated by the collapse of the cavitation bubbles is utilized to form the workpiece. By providing the working water tank 9 and driving the cavitating nozzle 8 to move in the working water tank 9 by the driving unit, the cavitating nozzle 8 can form the workpiece in the underwater submerged environment of the working water tank 9. At the same time, through the switching of the solenoid valve 3 between the first state and the second state, the rapid opening or closing of the cavitating nozzle 8 can be realized based on the on-off state of the solenoid valve 3. When the cavitating nozzle 8 is in the closed state, the main pump 1 is connected to the water storage tank 4 through the solenoid valve 3. At this time, the water flow pumped out by the main pump 1 returns to the water storage tank 4 again, completing the cycle in the closed state of the cavitating nozzle 8. During this process, the high-pressure water flow formed by the main pump 1 is not in a stopped flowing state, avoiding the need for the main pump 1 to start for a long time to reach the rated pressure value due to the opening and closing actions of the main pump 1, and preventing the influence of the starting characteristics of the pump. Compared with the prior art, a cavitating water jet incremental forming device disclosed in the present application provides a specific device for underwater forming, enabling cavitating water jet incremental forming to be carried out in a submerged environment.

[0029] In actual operation, the starting characteristic of the pump means that it will experience a starting and accelerating process when starting to run. During this process, the water flow pressure may gradually increase until it reaches the rated pressure value in the stable working state. For the cavitating water jet incremental forming device, it is very important to realize the rapid opening or closing of the cavitating nozzle 8 for the processing efficiency and processing accuracy of the workpiece. If the rated pressure value is not satisfied, the effective removal of the part to be removed of the workpiece cannot be achieved, and at the same time, the starting stage will also cause waste of time.

[0030] In addition, since the water storage tank 4 is connected to the main pump 1, and the solenoid valve 3 can also make the main pump 1 connected to the water storage tank 4 through the solenoid valve 3 in the second state, a circulation loop is formed between the water storage tank 4 and the main pump 1. And on the other hand, when the water flow pumped out by the main pump 1 enters the water storage tank 4, it can cause the turbulence inside the water storage tank 4, making more air bubbles form in the water in the water storage tank 4, so that more cavitation bubbles can be formed when pumped to the cavitating nozzle 8 by the main pump 1 next time, thereby improving the processing efficiency.

[0031] The present invention has been experimentally verified, demonstrating that the forming effect of using this device is good. When the pressure is 20 Mpa, the target distance is 60 mm, the feeding speed is 20 mm / s, and the horizontal layer spacing is 1 mm, a conical component with a radius of 60 mm is formed, and the measured forming thickness is 4.85 mm.

[0032] The basic transformation of a traditional water jet forming device into a milling machine makes it difficult to adapt to the forming under the underwater submerged environment, and it can only adjust the degrees of freedom in the X, Y, and Z directions. When programming for a specific path, the operation is complex, and it is difficult to form parts with complex shapes. It is necessary to manually operate to shut down the water pump. Therefore, in some embodiments, the driving unit is a six-axis rotary joint type robotic arm 5. Compared with the traditional modified milling machine, using a robotic arm to control the trajectory is more flexible.

[0033] This device innovatively uses a robotic arm as the execution device and uses the built-in teach pendant for system programming. The operation is simple, and more processing parameters can be adjusted, such as the target distance, feeding speed, horizontal layer spacing, etc., greatly increasing the flexibility. The forming process is completed in the working water tank 9. The two-position three-way solenoid valve 3 is connected to the control cabinet of the robotic arm. The teach pendant programming is used to turn on and off the power according to needs, which is more accurate compared with the manual switch.

[0034] Among them, the six-axis rotary joint type robotic arm 5 can select an ABB robotic arm.

[0035] In some embodiments, please refer to Figure 2 , the output end of the six-axis rotary joint type robotic arm 5 is connected with a fixture 6, and the fixture 6 is connected to the water pipe 7 between the solenoid valve 3 and the cavitation nozzle 8.

[0036] Specifically, to facilitate the control of the movement of the cavitation nozzle 8 in the working water tank 9, a fixture 6 is connected to the output end of the six-axis rotary joint type robotic arm 5. The fixture 6 is fixed on the water pipe 7, and the movement of the cavitation nozzle 8 is controlled by controlling the movement of the water pipe 7. Compared with directly controlling the cavitation nozzle 8, clamping the water pipe 7 by the fixture 6 can have more fixed areas to obtain a better fixing effect.

[0037] In other embodiments, the output end of the six-axis rotary joint type robotic arm 5 can also directly fix the cavitation nozzle 8 through the fixture 6.

[0038] In some embodiments, a filtering unit is provided between the water storage tank 4 and the main pump 1.

[0039] It should be noted that in order to enable the main pump 1 to operate normally without being interfered by impurities in the water, a filtering unit is provided between the water storage tank 4 and the main pump 1. The filtering unit can be filtering components such as filter cotton, filter net, and filter element.

[0040] In some embodiments, a booster pump 2 is provided between the main pump 1 and the solenoid valve 3.

[0041] To further obtain a stable water flow pressure, a booster pump 2 is provided between the main pump 1 and the solenoid valve 3, which is used to further pressurize the water flow pumped out by the main pump 1. In the case where the booster pump 2 is provided, the main pump 1 may not be set as a high-pressure water pump.

[0042] In some embodiments, please refer to Figure 3 , a workbench 10 is provided at the bottom of the working water tank 9. The workbench 10 includes fasteners, an upper pressing plate and a lower pressing plate. The workpiece is located between the upper pressing plate and the lower pressing plate and is fixed by the fasteners.

[0043] Specifically, since the forming of the workpiece is carried out in a submerged environment, in order to prevent the workpiece with a smaller density from easily shaking in the submerged environment, the present application provides a workbench 10 at the bottom of the working water tank 9. The workbench 10 includes an upper pressing plate and a lower pressing plate. Different from the ordinary circumferential limiting workbench 10, since it is in a submerged environment, an upper pressing plate is provided to prevent the workpiece from floating. The workpiece is located between the upper pressing plate and the lower pressing plate and is clamped by fasteners. The fasteners can be bolts, claw catches, magnetic structures, etc.

[0044] In a particularly specific embodiment, the entire device includes a high-pressure water generation system, an execution system, a forming system, a sheet metal fixture, and a water circulation system. The specific working processes of each system are as follows:

[0045] The high-pressure water generation system includes a main pump 1, a booster pump 2, an aluminum alloy water pipe 7, and a cavitation nozzle 8. The main pump 1 undertakes the main work of fluid transportation in the system and transports the water in the water storage tank 4 to the booster pump 2. The booster pump 2 is responsible for increasing additional pressure on the fluid output by the main pump 1 to ensure the normal operation and stability of the high-pressure environment. The high-pressure water is transported to the cavitation nozzle in the submerged environment through the aluminum alloy water pipe 7 to generate a large number of cavitation bubbles.

[0046] The execution system includes an ABB robotic arm 5, a fixture 10, and a two-way three-way solenoid valve 3. The designed workbench 10 is used to fix the nozzle 8 on the ABB robotic arm, and the robotic arm 5 drives the nozzle to move along the programmed path. The solenoid valve 3 is connected to the serial port of the robotic arm control cabinet, and a 24V power supply is output by the programmed program to control the on-off of the solenoid valve 3.

[0047] The sheet metal workbench is as Figure 3 shown. Since the working condition is forming underwater, the workbench material is 304 stainless steel, which is more corrosion-resistant. The upper and lower pressing plates are pressed tightly and fixed with bolts. No support die is provided under the sheet metal, and the forming parts are formed by a die-less forming method.

[0048] The water circulation system includes a working water tank 9 and a storage water tank 4. The working water tank 9 provides a submerged environment for the cavitation nozzle. In the case of power failure, high-pressure water enters the cavitation nozzle through pipeline A. When the forming is completed, the solenoid valve is energized, and high-pressure water enters the storage water tank 4 through pipeline B, facilitating the reuse of water resources.

[0049] In some embodiments, the working water tank 9 has 7 outlet pipes, and the solenoid valve 3 has a third state. In the third state, the main pump 1 is connected to the outlet pipes 7 through the solenoid valve 3, and the main pump 1 is a two-way pump.

[0050] It should be noted that the solenoid valve 3 has a third state in addition to the first state and the second state. In the third state, the main pump 1 is connected to the outlet pipes 7 through the solenoid valve 3, and the main pump 1 is a two-way pump. When the solenoid valve 3 is in the third state, the main pump 1 can perform reverse suction to recover the liquid in the working water tank 9 into the storage water tank 4, thereby realizing the recovery of the liquid in the working water tank 9. And during the next operation, the main pump 1 pumps out normally, and the liquid can quickly return to the working water tank 9 through the outlet pipes 7. There is no need for the operator to perform a water injection operation in the working water tank 9 before each forming, and it is also beneficial for the operator to clean the working water tank 9 and to observe the processed workpiece.

[0051] Among them, when the main pump 1 performs reverse suction, if a filtering unit is provided between the storage water tank 4 and the main pump 1, the filtering unit can also filter the liquid sucked back from the working water tank 9 into the storage water tank 4 at this time. Preferably, another filtering unit is provided between the solenoid valve 3 and the outlet pipes 7, so that impurities will not affect the normal operation of the main pump 1.

[0052] In some embodiments, the cavitation nozzle 8 has a cavitation state and a water injection state. In the cavitation state, the ejected liquid is cavitated, and in the water injection state, the liquid is ejected normally.

[0053] Specifically, the cavitation nozzle 8 has a cavitation state and a water injection state. Among them, no cavitation bubbles are generated in the water injection state. Therefore, on the one hand, the workpiece can be cleaned in the water injection state without damaging the workpiece, and on the other hand, the working water tank 9 can be filled with water in the water injection state.

[0054] In some embodiments, a blower is connected to the working water tank 9, and the blower forms a wind wall at the opening of the working water tank 9.

[0055] It should be noted that in a submerged environment, the working process of the cavitation nozzle 8 will cause splashing of water mist and water droplets, which will splash into the environment outside the working water tank 9. And since the driving unit needs to control the movement of the cavitation nozzle 8 in the working water tank 9 from the outside, a water baffle for hindering the movement of the driving unit cannot be provided at the opening. In this case, a blower is provided on the working water tank 9, and the blower forms a wind wall at the opening of the working water tank 9. When the water mist and water droplets splash towards the opening of the working water tank 9, the water mist and water droplets cannot pass through the wind wall and reach the outside of the working water tank 9, and the setting of the blower will not affect the movement of the driving unit to drive the cavitation nozzle 8.

[0056] In some embodiments, a water depth sensor and a water storage and discharge unit are provided in the working water tank 9. The water storage and discharge unit is communicated with the working water tank 9, the water depth sensor is electrically connected to the water storage and discharge unit, the water depth sensor issues a water depth signal according to the water depth, and the water storage and discharge unit receives the water depth signal to absorb or discharge water from the working water tank 9.

[0057] Among them, the depth of the liquid in the submerged environment when the cavitation nozzle 8 works will also have a certain impact on the quality of the equipment forming. It is beneficial to the growth of cavitation nuclei in a low-pressure environment. When the nuclear radius is greater than the critical radius, the bubbles will become unstable and cavitation will occur. Therefore, how to ensure the immersion depth of the cavitation nozzle 8 is particularly important for the forming accuracy of the equipment. Through the setting of the water depth sensor and the water storage and discharge unit, according to the preset forming movement trajectory, the movement height of the cavitation nozzle 8 can be known in advance. At this time, according to the depth signal issued by the water depth sensor, the water storage and discharge unit performs corresponding water absorption or discharge operations to control the height of the liquid level in the working water tank 9 to the cavitation nozzle 8.

[0058] The above embodiments can all be combined and used.

[0059] In the description of this specification, if terms such as "Embodiment 1", "this embodiment", "in one embodiment", etc. appear, it means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the invention or the invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

[0060] In the description of this specification, terms such as "connection", "installation", "fixation", "setting", "having", etc. are 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 elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0061] In the description of this specification, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0062] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and apply the technology of this case. Those who are familiar with the technology in this field can obviously make various modifications to these examples easily, and apply the general principles described here to other embodiments without creative labor. Therefore, this case is not limited to the above embodiments, and the following modifications should all be within the protection scope of this case: ① A new technical solution implemented based on the technical solution of the present invention and combined with the existing common knowledge, and the technical effect produced by this new technical solution does not exceed the technical effect of the present invention; ② An equivalent replacement of some features of the technical solution of the present invention using well-known technologies, and the technical effect produced is the same as the technical effect of the present invention; ③ Expansion based on the technical solution of the present invention, and the substantial content of the expanded technical solution does not exceed the technical solution of the present invention; ④ Equivalent transformations made using the content of the specification and drawings of the present invention, directly or indirectly applied in other related technical fields.

Claims

1. A cavitation water jet incremental forming device, characterized in that, It includes a driving unit which drives the cavitation nozzle to move in the working water tank. A water storage tank, a main pump, and a solenoid valve are connected in sequence. The solenoid valve has a first state and a second state. In the first state, the main pump is connected to the cavitation nozzle through the solenoid valve. In the second state, the main pump is connected to the water storage tank through the solenoid valve.

2. The cavitation water jet incremental forming device according to claim 1, characterized in that, The driving unit is a six-axis rotary joint type robotic arm.

3. The cavitation water jet incremental forming device according to claim 2, characterized in that, A clamp is connected to the output end of the six-axis rotary joint type robotic arm, and the clamp is connected to the water pipe between the solenoid valve and the cavitation nozzle.

4. A cavitation water jet incremental forming device according to claim 1, characterized in that, A filtering unit is provided between the water storage tank and the main pump.

5. A cavitation water jet incremental forming device according to claim 1, characterized in that, A booster pump is provided between the main pump and the solenoid valve.

6. The cavitation water jet incremental forming device according to claim 1, characterized in that, A workbench is provided at the bottom of the working water tank. The workbench includes fasteners, an upper pressing plate, and a lower pressing plate. The workpiece is located between the upper pressing plate and the lower pressing plate and is fixed by the fasteners.

7. A cavitation water jet incremental forming device according to any one of claims 1 to 6, characterized in that, The working water tank has a water outlet pipeline. The solenoid valve has a third state. In the third state, the main pump is connected to the water outlet pipeline through the solenoid valve, and the main pump is a two-way pump.

8. A cavitation water jet incremental forming device according to any one of claims 1 to 6, characterized in that, The cavitation nozzle has a cavitation state and a water injection state. In the cavitation state, the liquid ejected is cavitated. In the water injection state, the liquid is ejected normally.

9. A cavitation water jet incremental forming device according to any one of claims 1 to 6, characterized in that, The working water tank is connected to a blower, and the blower forms a wind wall at the opening of the working water tank.

10. A cavitation water jet incremental forming device according to any one of claims 1 to 6, characterized in that, A water depth sensor and a water storage and discharge unit are provided in the working water tank. The water storage and discharge unit is connected to the working water tank. The water depth sensor is electrically connected to the water storage and discharge unit. The water depth sensor issues a water depth signal according to the water depth, and the water storage and discharge unit receives the water depth signal to absorb or discharge water from the working water tank.

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