Nozzle-baffle servo valve prestage vortex street phenomenon visualization experiment device

Abstract

The invention relates to a nozzle-baffle servo valve prestage vortex street phenomenon visualization experiment device. The device comprises a valve body; the nozzle assemblies are symmetrically arranged on the left side and the right side of the valve body and used for spraying oil; the main flow cavity is formed in the center of the valve body, communicates with the nozzle assemblies on the left side and the right side at the same time, and is used for receiving oil sprayed out of the nozzle assemblies; the baffle assembly is vertically arranged on the center line of the main flow cavity, and the baffle assembly is used for injecting the oily liquid dye into the main flow cavity and reducing the flowing state of the oily liquid dye at the oil liquid position; and the observation block is arranged in front of the wake flow area of the baffle assembly and used for observing the prestage vortex street phenomenon of the nozzle-baffle servo valve. Compared with the prior art, the front-stage vortex street phenomenon of the nozzle-baffle servo valve is visually observed, so that the mechanism of the vortex street oscillation phenomenon is better explored.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic control valves, and in particular to an experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve. Background Technique

[0002] The electro-hydraulic servo valve is one of the key components affecting the performance of the hydraulic servo system, which is used to connect the electrical part and the hydraulic part in the system to achieve the functions of electro-hydraulic conversion and power amplification. Among them, the research on the nozzle-flapper servo valve started earlier, with fast dynamic response speed, high sensitivity, good linearity, and small zero drift of temperature and pressure. It is widely used in numerical control machine tools, locomotives, ships, radars, flight devices, and other automatic control devices requiring high-precision control.

[0003] To meet the application requirements, the volume of the nozzle-flapper servo valve is getting smaller and smaller, the core velocity of the pre-stage jet is getting larger and larger, and the high-speed jet flows out of the nozzle. Most of the fluid will flow along the baffle to the wake area and separate at the tail of the baffle, forming two rows of vortices. As the Reynolds number of the fluid increases, vortices that shed periodically in an alternating manner will form on both sides of the baffle, forming a vortex street, which causes the vortex street oscillation in the pre-stage of the servo valve. Due to the alternating stress generated by the oscillation, the bourdon tube may undergo fatigue fracture, resulting in the failure of the servo valve. Therefore, in-depth research on the mechanism of the vortex street phenomenon and exploration of methods to suppress the vortex street oscillation are of great significance for improving the reliability and service life of the servo valve.

[0004] At present, domestic and foreign scholars' research on the nozzle-flapper servo valve mainly focuses on jet characteristics, pressure distribution, cavitation phenomenon, etc. For example, Chinese Patent CN118746432A discloses an experimental device for observing the cavitation phenomenon and noise in the pre-stage of a nozzle-flapper servo valve. This patent can realize the observation of the cavitation phenomenon between the nozzle and the baffle, but only retains the flow field between the nozzle and the baffle and cannot observe the wake area of the baffle. And the wake area of the baffle is exactly the key area for the formation and evolution of the vortex street. The lack of visualization observation means for this area limits the in-depth research on the mechanism of the vortex street. Summary of the Invention

[0005] The purpose of the present invention is to provide an experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve, so as to realize the visual observation of the vortex street phenomenon in the pre-stage of the nozzle-flapper servo valve, and thus better explore the mechanism of the vortex street oscillation phenomenon.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve, comprising:

[0008] A valve body;

[0009] Nozzle assembly: It is symmetrically arranged on the left and right sides of the valve body, and the nozzle assembly is used to spray oil.

[0010] Main flow cavity: It is arranged at the center of the valve body. The main flow cavity is simultaneously connected to the nozzle assemblies on both the left and right sides, and the main flow cavity is used to receive the oil sprayed by the nozzle assemblies.

[0011] Baffle assembly: It is vertically arranged on the center line of the main flow cavity. The baffle assembly is used to inject oily liquid dye into the main flow cavity to restore the flow state of the oil at the position where the oily liquid dye is located.

[0012] Observation block: It is arranged directly in front of the wake region of the baffle assembly. The observation block is used to observe the vortex street phenomenon of the pre-stage of the nozzle-flapper servo valve.

[0013] In an embodiment of the present invention, a blocking block is provided at the end of the main flow cavity.

[0014] In an embodiment of the present invention, the experimental device further includes an oil return channel and an oil inlet channel. The two oil inlet channels are symmetrically arranged below the nozzle assemblies on the left and right sides, and the nozzle assemblies on the left and right sides are respectively connected to an oil inlet channel.

[0015] The oil return channel is arranged in the blocking block, and the oil return channel is connected to the main flow cavity.

[0016] In an embodiment of the present invention, the nozzle assembly is composed of a nozzle body, a jet channel, a connecting channel, and a nozzle mounting base.

[0017] One end of the nozzle body is provided with a nozzle mounting base. A jet channel is arranged in the nozzle body. The jet channel is connected to the main flow cavity through a nozzle orifice, and the jet channel is connected to the oil inlet channel through a connecting channel.

[0018] In an embodiment of the present invention, nozzle mounting positioning holes are provided on the nozzle mounting base, screw holes are provided at the left and right ends of the valve body, and the nozzle mounting base is fixed to the side end of the valve body by nozzle fixing screws sequentially passing through the nozzle mounting positioning holes and the screw holes.

[0019] As a preferred technical solution, the diameter of the jet end of the jet channel gradually decreases.

[0020] As a preferred technical solution, through holes are symmetrically arranged on the left and right sides of the valve body.

[0021] The structural dimensions of the nozzle assemblies on the left and right sides are exactly the same, and they are respectively symmetrically installed in the symmetric through holes on both sides of the valve body.

[0022] The distances from the jet ends of the jet channels on the left and right sides to both sides of the baffle assembly are exactly equal.

[0023] In an embodiment of the present invention, the experimental device further includes a plug, which is used to seal the jet channel.

[0024] In an embodiment of the present invention, the baffle assembly is composed of a baffle fixing member, a baffle body, a dye vertical flow channel, and a dye horizontal through hole.

[0025] A baffle fixing member is provided at the top end of the baffle body, and the baffle fixing member is fixedly connected to the top end of the center of the valve body.

[0026] A dye vertical flow channel is provided inside the baffle body. The dye vertical flow channel is externally connected to a micro-injection pump, and an oily liquid dye is contained in the micro-injection pump.

[0027] A dye horizontal through hole is provided at the lower end of the baffle body. The dye horizontal through hole is communicated with the dye vertical flow channel, and the dye horizontal through hole is used to inject the oily liquid dye in the dye vertical flow channel into the main flow chamber.

[0028] As a preferred technical solution, the baffle fixing member is a sunken four-lobe structure, which is symmetric in the front, back, left, and right directions, realizing the precise positioning of the baffle assembly and ensuring that the baffle assembly is vertically installed on the center line of the main flow chamber.

[0029] As a preferred technical solution, the dye vertical flow channel and the dye horizontal through hole are located at the central position on the front side of the baffle body, and the side where the dye vertical flow channel and the dye horizontal through hole are located faces the direction of the observation block.

[0030] As a preferred technical solution, the diameters of both the dye vertical flow channel and the dye horizontal through hole are 1.2 mm, and the dye horizontal through hole is located 1.0 mm away from the end of the baffle body.

[0031] In an embodiment of the present invention, a baffle installation positioning hole is provided on the baffle fixing member, a screw hole is provided at the top end of the valve body, and the baffle fixing member is fixed to the top end of the valve body by a baffle fixing screw passing through the baffle installation positioning hole and the screw hole in sequence.

[0032] In an embodiment of the present invention, the observation block is made of transparent acrylic material.

[0033] The valve body, the nozzle assembly, the baffle assembly, the blocking block, etc. are made of aluminum alloy material.

[0034] As a preferred technical solution, the observation block is fixedly connected to the valve body by an observation block fixing screw.

[0035] In an embodiment of the present invention, a first sealing ring is provided at the connection between the nozzle assembly and the valve body.

[0036] A second sealing ring is provided at the connection between the lower end of the blocking block and the experimental pumping station.

[0037] A third sealing ring and a fourth sealing ring are provided at the connection between the lower end of the valve body and the experimental pumping station.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] Starting from the vortex street oscillation phenomenon in the wake region of the baffle, the present invention designs an experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-baffle servo valve, fully restoring the real flow field structure of the pre-stage of the nozzle-baffle servo valve. A transparent acrylic observation block is arranged directly in front of the wake region of the baffle, and an oily liquid dye is slowly injected into both sides of the baffle through a micro-injection pump and the dye channels on the baffle. On the premise of ensuring that the flow rate of the dye does not interfere with the flow rate of the jets on both sides of the baffle, the vortices in the wake region of the baffle are dyed to realize the visualization of the vortex street phenomenon in the pre-stage of the nozzle-baffle servo valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the experimental device for visualizing the vortex street phenomenon in the pre-stage of the nozzle-baffle servo valve in the present invention;

[0041] Figure 2 It is a schematic diagram of the structure of the baffle assembly of the present invention;

[0042] Figure 3 It is a schematic diagram of the structure of the nozzle assembly of the present invention;

[0043] Description of the reference numerals in the drawings: 1. Valve body, 2. Nozzle assembly, 201. Jet channel, 202. Connecting hole channel, 203. Nozzle mounting base, 204. Nozzle mounting positioning hole, 3. Plug, 4. Nozzle fixing screw, 5. Observation block, 6. Oil return channel, 7. Baffle assembly, 701. Baffle mounting positioning hole, 702. Dye vertical flow channel, 703. Dye horizontal through hole, 8. Baffle fixing screw, 9. Main flow chamber, 10. First sealing ring, 11. Oil inlet channel, 12. Blocking block, 13. Second sealing ring, 14. Third sealing ring, 15. Fourth sealing ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it 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 the present invention can be understood according to specific circumstances.

[0048] The following will describe in detail some embodiments of the present invention with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0049] Embodiment 1

[0050] See Figures 1 to 3 , this embodiment provides an experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve, including:

[0051] Valve body 1;

[0052] Nozzle assembly 2: symmetrically arranged on the left and right sides of the valve body 1, and the nozzle assembly 2 is used to eject oil;

[0053] Main flow chamber 9: arranged at the center of the valve body 1, and the main flow chamber 9 is simultaneously connected to the nozzle assemblies 2 on both the left and right sides, and the main flow chamber 9 is used to receive the oil ejected by the nozzle assemblies 2;

[0054] Baffle assembly 7: vertically arranged on the center line of the main flow chamber 9, and the baffle assembly 7 is used to inject an oily liquid dye into the main flow chamber 9 to restore the flow state of the oil where the oily liquid dye is located;

[0055] Observation block 5: arranged directly in front of the wake region of the baffle assembly 7, and the observation block 5 is used to observe the vortex street phenomenon in the pre-stage of the nozzle-flapper servo valve.

[0056] In this embodiment, a plug block 12 is provided at the end of the main flow chamber 9.

[0057] In this embodiment, the experimental device further includes an oil return channel 6 and an oil inlet channel 11. The two oil inlet channels 11 are symmetrically arranged below the nozzle assemblies 2 on the left and right sides. The nozzle assemblies 2 on the left and right sides are respectively connected to an oil inlet channel 11.

[0058] The oil return channel 6 is arranged in the blockage block 12, and the oil return channel 6 is connected to the main flow chamber 9.

[0059] In this embodiment, the nozzle assembly 2 is composed of a nozzle body, a jet flow channel 201, a connection channel 202, and a nozzle mounting base 203.

[0060] One end of the nozzle body is provided with a nozzle mounting base 203. A jet flow channel 201 is arranged in the nozzle body. The jet flow channel 201 is connected to the main flow chamber 9 through a nozzle orifice, and the jet flow channel 201 is connected to the oil inlet channel 11 through a connection channel 202.

[0061] In this embodiment, the nozzle mounting base 203 is provided with a nozzle mounting positioning hole 204. Screw holes are provided at the left and right ends of the valve body 1. The nozzle mounting base 203 is fixed to the side end of the valve body 1 by nozzle fixing screws 4 sequentially passing through the nozzle mounting positioning hole 204 and the screw holes.

[0062] As a preferred technical solution, the diameter of the jet end of the jet flow channel 201 gradually decreases.

[0063] As a preferred technical solution, through holes are symmetrically arranged on the left and right sides of the valve body 1.

[0064] The structural dimensions of the nozzle assemblies 2 on the left and right sides are exactly the same, and they are respectively symmetrically installed in the symmetric through holes on both sides of the valve body 1.

[0065] The distances from the jet ends of the jet flow channels 201 on the left and right sides to both sides of the baffle assembly 7 are exactly equal.

[0066] In this embodiment, the experimental device further includes a plug 3, and the plug 3 is used to seal the jet flow channel 201.

[0067] In this embodiment, the baffle assembly 7 is composed of a baffle fixing member, a baffle body, a dye vertical flow channel 702, and a dye horizontal through hole 703.

[0068] A baffle fixing member is provided at the top end of the baffle body, and the baffle fixing member is fixedly connected to the top center of the valve body 1.

[0069] A dye vertical flow channel 702 is arranged in the baffle body. The dye vertical flow channel 702 is externally connected to a micro-injection pump, and an oily liquid dye is contained in the micro-injection pump.

[0070] A dye horizontal through-hole 703 is provided at the lower end of the baffle body. The dye horizontal through-hole 703 communicates with the dye vertical flow channel 702, and the dye horizontal through-hole 703 is used to inject the oily liquid dye in the dye vertical flow channel 702 into the main flow chamber 9.

[0071] As a preferred technical solution, the baffle fixing member is a sunken four-lobe structure, which is symmetrical in the front, back, left, and right directions, realizing the precise positioning of the baffle assembly 7 and ensuring that the baffle assembly 7 is vertically installed on the center line of the main flow chamber 9.

[0072] As a preferred technical solution, the dye vertical flow channel 702 and the dye horizontal through-hole 703 are located at the central position on the front side of the baffle body, and the side where the dye vertical flow channel 702 and the dye horizontal through-hole 703 are located faces the direction of the observation block 5.

[0073] As a preferred technical solution, the diameters of both the dye vertical flow channel 702 and the dye horizontal through-hole 703 are 1.2 mm, and the dye horizontal through-hole 703 is located 1.0 mm away from the end of the baffle body.

[0074] In this embodiment, a baffle installation positioning hole 701 is provided on the baffle fixing member, a screw hole is provided at the top end of the valve body 1, and the baffle fixing member is fixed to the top end of the valve body 1 by a baffle fixing screw 8 passing through the baffle installation positioning hole 701 and the screw hole in sequence.

[0075] In this embodiment, the observation block 5 is made of transparent acrylic material.

[0076] The valve body 1, the nozzle assembly 2, the baffle assembly 7, the plugging block 12, etc. are made of aluminum alloy material.

[0077] As a preferred technical solution, the observation block 5 is fixedly connected to the valve body 1 by an observation block fixing screw.

[0078] In this embodiment, a first sealing ring 10 is provided at the connection between the nozzle assembly 2 and the valve body 1.

[0079] A second sealing ring 13 is provided at the connection between the lower end of the plugging block 12 and the experimental pumping station.

[0080] A third sealing ring 14 and a fourth sealing ring 15 are provided at the connection between the lower end of the valve body 1 and the experimental pumping station.

[0081] In addition, this embodiment also provides a use method of an experimental device for visualizing the vortex street phenomenon of the pre-stage of a nozzle-baffle servo valve, and the specific steps are as follows:

[0082] The oil fluid flows from the pumping station into the oil inlet channels 11 on both sides of the valve body 1, and flows into the jet flow channel 201 through the connection holes 202 on the left and right sides.

[0083] The flow rate of the oil fluid is increased at the jet end of the jet channel 201, and then injected into the main flow chamber 9 through the nozzle orifice. After impacting the baffle assembly 7, a part of the oil fluid flows downward along the baffle body;

[0084] When the flow of the oil fluid gradually stabilizes, the micro-injection pump is turned on, and the micro-injection pump slowly injects the oily liquid dye into the dye vertical flow channel 702;

[0085] After the oily liquid dye flows through the dye vertical flow channel 702, it slowly flows out symmetrically from both sides of the dye horizontal through hole 703 and flows downward under the entrainment of the oil fluid in the wake regions on both sides of the baffle body. The flow rates of the oil fluid and the dye are vastly different and can be ignored, thereby restoring the flow state of the oil fluid where the dye is located;

[0086] Combined with the transparent acrylic observation block 5, the visualization observation of the vortex street phenomenon is realized.

[0087] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve, characterized in that, Comprising: Valve body (1); Nozzle assembly (2): symmetrically arranged on the left and right sides of the valve body (1), and the nozzle assembly (2) is used to eject oil; Main flow cavity (9): arranged at the center of the valve body (1), and the main flow cavity (9) is simultaneously connected to the nozzle assemblies (2) on both the left and right sides, and the main flow cavity (9) is used to receive the oil ejected by the nozzle assemblies (2); Baffle assembly (7): vertically arranged on the center line of the main flow cavity (9), and the baffle assembly (7) is used to inject oily liquid dye into the main flow cavity (9) to restore the flow state of the oil at the position where the oily liquid dye is located; Observation block (5): arranged directly in front of the wake region of the baffle assembly (7), and the observation block (5) is used to observe the vortex street phenomenon of the pre-stage of the nozzle-baffle servo valve.

2. The experimental device for visualizing the vortex street phenomenon of the pre-stage of a nozzle-flapper servo valve according to claim 1, wherein, A blocking block (12) is provided at the end of the main flow cavity (9).

3. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 2, characterized in that, The experimental device further includes an oil return passage (6) and an oil inlet passage (11), and the two oil inlet passages (11) are symmetrically arranged below the nozzle assemblies (2) on both the left and right sides, and the nozzle assemblies (2) on both the left and right sides are respectively connected to an oil inlet passage (11), The oil return passage (6) is arranged in the blocking block (12), and the oil return passage (6) is connected to the main flow cavity (9).

4. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 3, characterized in that, The nozzle assembly (2) is composed of a nozzle body, a jet flow passage (201), a connecting hole passage (202) and a nozzle mounting base (203), One end of the nozzle body is provided with a nozzle mounting base (203), a jet flow passage (201) is arranged in the nozzle body, the jet flow passage (201) is connected to the main flow cavity (9) through a nozzle orifice, and the jet flow passage (201) is connected to the oil inlet passage (11) through a connecting hole passage (202).

5. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 4, characterized in that, The nozzle mounting base (203) is provided with a nozzle mounting positioning hole (204), screw holes are provided at both ends of the valve body (1), and the nozzle mounting base (203) is fixed to the side end of the valve body (1) through a nozzle fixing screw (4) sequentially passing through the nozzle mounting positioning hole (204) and the screw hole.

6. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 4, characterized in that, The experimental device further includes a plug (3), and the plug (3) is used to seal the jet flow passage (201).

7. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 1, characterized in that, The baffle assembly (7) is composed of a baffle fixing member, a baffle body, a dye vertical flow passage (702) and a dye horizontal through hole (703), A baffle fixing member is provided at the top of the baffle body, and the baffle fixing member is fixedly connected to the top center of the valve body (1), A dye vertical flow passage (702) is arranged in the baffle body, the dye vertical flow passage (702) is externally connected to a micro-injection pump, and the micro-injection pump is filled with oily liquid dye, A dye horizontal through hole (703) is provided at the lower end of the baffle body, the dye horizontal through hole (703) is connected to the dye vertical flow passage (702), and the dye horizontal through hole (703) is used to inject the oily liquid dye in the dye vertical flow passage (702) into the main flow cavity (9).

8. An experimental device for visualizing the vortex street phenomenon of the pre-stage of a nozzle-flapper servo valve according to claim 7, characterized in that, The baffle fixing member is provided with a baffle mounting positioning hole (701), the top end of the valve body (1) is provided with a screw hole, and the baffle fixing member is fixed to the top end of the valve body (1) by a baffle fixing screw (8) sequentially passing through the baffle mounting positioning hole (701) and the screw hole.

9. An experimental device for visualizing the vortex street phenomenon in the pre-stage of a nozzle-flapper servo valve according to claim 2, characterized in that, The observation block (5) is made of transparent acrylic material, The valve body (1), the nozzle assembly (2), the baffle assembly (7) and the plug block (12) are made of aluminum alloy material.

10. An experimental device for visualizing the vortex street phenomenon of the pre-stage of a nozzle-flapper servo valve according to claim 2, characterized in that, A first sealing ring (10) is provided at the connection between the nozzle assembly (2) and the valve body (1), A second sealing ring (13) is provided at the connection between the lower end of the plug block (12) and the experimental pumping station, A third sealing ring (14) and a fourth sealing ring (15) are provided at the connection between the lower end of the valve body (1) and the experimental pumping station.

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