A three-dimensional curved surface metal plate forming device for a steam turbine low-pressure cylinder guide ring

Abstract

The application discloses a steam turbine low-pressure cylinder guide ring three-dimensional curved surface metal plate forming device, which comprises a rigid male die, a plurality of flexible female dies and a hydraulic mechanism, the top of the rigid male die is provided with a plurality of cavities, the plurality of cavities are all in the shape of a sector, the plurality of flexible female dies are matched with corresponding cavities respectively, the flexible female die comprises a rigid block, the bottom of the rigid block is connected with a flexible hydraulic capsule, the flexible hydraulic capsule is filled with a hydraulic medium, and the hydraulic mechanism is used for driving the plurality of flexible female dies to move downwards into corresponding cavities at the same time, so that a plurality of arc-shaped guide plates are cold-pressed and formed between the flexible hydraulic capsule and the bottom surface of the cavity. The application has the advantages of improving the forming quality of the guide ring.

Description

Technical Field

[0001] This application relates to the field of sheet metal forming technology, and in particular to a three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring. Background Technology

[0002] In existing technologies, hydroforming technology is often used to manufacture metal sheet components with complex three-dimensional curved surfaces. When using this technology to form the guide ring of the low-pressure cylinder of a steam turbine, an integral thermoforming method is generally adopted. This forming method has the following drawbacks: First, for sheets with high yield strength or large deformation, the sheet needs to be heated to above the recrystallization temperature to reduce its yield strength, increase plasticity, and make it easier to form. However, the thermoforming process consumes a lot of energy, requires additional heating equipment, has a long production cycle, and the high temperature will cause oxidation and coarse grains on the sheet surface, affecting the mechanical properties and surface quality of the final product. At the same time, there is also a large uncertainty in thermal deformation. Second, when the guide ring is integrally formed, the stress is concentrated in the curved part of the guide ring near the center, which can easily lead to problems such as local wrinkling of the guide ring during forming, ultimately resulting in poor forming accuracy. Utility Model Content

[0003] The main objective of this application is to provide a three-dimensional curved metal sheet forming device for the guide ring of a steam turbine low-pressure cylinder, which aims to solve the technical problem of poor forming quality of existing integral thermoforming methods for guide rings.

[0004] To achieve the above objectives, this application provides a three-dimensional curved metal sheet forming device for a steam turbine low-pressure cylinder guide ring, comprising a rigid punch, multiple flexible dies, and a hydraulic mechanism. The top of the rigid punch is provided with multiple cavities, each of which is fan-shaped. The multiple flexible dies are respectively fitted with corresponding cavities. Each flexible die includes a rigid block, and the bottom of the rigid block is connected to a flexible hydraulic bladder filled with hydraulic medium. The hydraulic mechanism is used to drive the multiple flexible dies to move down simultaneously into the corresponding cavities, so as to cold-press and form multiple arc-shaped guide plates between the flexible hydraulic bladder and the bottom surface of the cavity.

[0005] Optionally, the hydraulic mechanism includes a first hydraulic cylinder with a fixed position, a first lifting plate connected to the bottom of the first hydraulic cylinder, and multiple connecting rods connected to the bottom of the first lifting plate, with the multiple connecting rods respectively connected to the top of the rigid block.

[0006] Optionally, the first lifting plate includes a first connecting plate connected to the bottom of the first hydraulic cylinder and a second connecting plate connected to the top of a plurality of connecting rods. A flexible thin-film pressure sensor is disposed between the first connecting plate and the second connecting plate. The flexible thin-film pressure sensor is electrically connected to a controller, and the controller is electrically connected to the first hydraulic cylinder.

[0007] Optionally, inverted L-shaped plates are connected to both ends of the second connecting plate, and the inverted L-shaped plates are movably hung on the top of both ends of the first connecting plate.

[0008] Optionally, when the second connecting plate is hung below the first connecting plate via an inverted L-shaped plate, the flexible thin-film pressure sensor has a gap with the top surface of the second connecting plate.

[0009] Optionally, the rigid punch includes a base plate, on which multiple first templates are provided. A punch module is movably provided between each of the first templates. The top surface of the punch module is a profile surface, and a cavity is formed between the punch module and the side wall of the first template.

[0010] Optionally, each end of a plurality of first templates is connected to an arc-shaped pressure plate, which is used to fit the two end faces of the plurality of convex modules, and the arc-shaped pressure plate is higher than the end face height of the convex module.

[0011] Optionally, it also includes a guiding mechanism, which includes a second hydraulic cylinder with a fixed position, a second lifting plate connected to the bottom of the second hydraulic cylinder, and connecting rods that move through the second lifting plate. Multiple second templates are connected to the bottom of the second lifting plate, and a flexible concave mold is movably attached between each pair of adjacent second templates. The multiple second templates are used to attach to the top of the corresponding first template.

[0012] Optionally, a frame is provided on the base plate, the first hydraulic cylinder and the second hydraulic cylinder are both located on the top of the frame, and the guide mechanism and the rigid punch are both located inside the frame.

[0013] Optionally, both inner sidewalls of the frame are provided with guide rails that slide in cooperation with the side ends of the second lifting plate.

[0014] The beneficial effects that this application can achieve are as follows: This application changes the traditional method of integral molding of the guide ring by splitting the guide ring into multiple arc-shaped guide plates. The stress distribution of the small guide plates is uniform during molding, and wrinkling is not easy. Therefore, it is only necessary to splice the multiple molded guide plates into a guide ring. When molding the guide plates, multiple blank workpieces are placed in the cavity of a rigid punch. Then, a hydraulic mechanism drives multiple flexible dies to move down into the corresponding cavities to cold press the blank workpieces. During the cold pressing process, the flexible hydraulic bladder contacts the blank workpiece, which allows the blank workpiece to deform slowly and prevents defects such as cracks caused by direct rigid pressing. Therefore, this application combines the simultaneous cold pressing of multiple small guide plates with flexible pressing molding, which not only improves the molding quality but also ensures a certain molding efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0016] Figure 1 This is a schematic diagram of the structure of a three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring according to an embodiment of this application; Figure 2 This is a schematic diagram (side view) of the flexible die structure in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of the first lifting plate in an embodiment of this application; Figure 4 This is a schematic diagram (top view) of the rigid punch in an embodiment of this application. Figure 5 This is a schematic diagram of the docking structure of the first template and the second template in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the guide plate cold-pressed in an embodiment of this application.

[0017] Figure label: 100-Rigid punch, 110-Base plate, 120-First template, 130-Punch module, 140-Arc-shaped pressure plate, 200-Flexible die, 210-Rigid block, 220-Flexible hydraulic bladder, 300-Hydraulic mechanism, 310-First hydraulic cylinder, 320-First lifting plate, 321-First connecting plate, 322-Second connecting plate, 323-Flexible thin-film pressure sensor, 324-Inverted L-shaped plate, 330-Connecting rod, 400-Controller, 500-Guide mechanism, 510-Second hydraulic cylinder, 520-Second lifting plate, 530-Second template, 600-Frame, 700-Guide rail.

[0018] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0021] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] Example Reference Figures 1-5 This embodiment provides a three-dimensional curved metal sheet forming device for a steam turbine low-pressure cylinder guide ring, including a rigid punch 100, multiple flexible dies 200, and a hydraulic mechanism 300. The top of the rigid punch 100 is provided with multiple cavities, all of which are fan-shaped. The multiple flexible dies 200 respectively cooperate with the corresponding cavities. The flexible die 200 includes a rigid block 210, and the bottom of the rigid block 210 is connected to a flexible hydraulic bladder 220. The flexible hydraulic bladder 220 is filled with hydraulic medium. The hydraulic mechanism 300 is used to drive the multiple flexible dies 200 to move down into the corresponding cavities at the same time, so as to cold press and form multiple arc-shaped guide plates between the flexible hydraulic bladder 220 and the bottom surface of the cavity.

[0024] In this embodiment, by changing the traditional method of integral molding of the guide ring, the guide ring is split into multiple arc-shaped guide plates. The stress distribution of the small guide plates is uniform during molding, and wrinkling is not easy. Therefore, it is only necessary to splice (e.g., weld) the multiple molded guide plates to form the guide ring. When forming the guide plates, multiple blank workpieces are placed in the cavity of the rigid punch 100. Then, the hydraulic mechanism 300 drives multiple flexible dies 200 to move down into the corresponding cavity at the same time to cold press the blank workpieces. During the cold pressing process, the flexible hydraulic bladder 220 contacts the blank workpiece, which can slowly deform the blank workpiece and prevent defects such as cracks caused by direct rigid pressing. Therefore, this embodiment combines the simultaneous cold pressing of multiple small guide plates with the use of flexible pressing molding, which not only improves the molding quality but also ensures a certain molding efficiency.

[0025] It should be noted that the aforementioned flexible hydraulic bladder 220 should be made of a material that has elastic deformation and can withstand large pressure and friction, such as rubber.

[0026] As an optional implementation, the hydraulic mechanism 300 includes a first hydraulic cylinder 310 with a fixed position, a first lifting plate 320 connected to the bottom of the first hydraulic cylinder 310, and a plurality of connecting rods 330 connected to the bottom of the first lifting plate 320, with the plurality of connecting rods 330 respectively connected to the top of the rigid block 210.

[0027] In this embodiment, when it is necessary to move the flexible die 200 downward, the first lifting plate 320 is moved downward by the first hydraulic cylinder 310, which can drive all the connecting rods 330 and the flexible die 200 at the bottom to move downward synchronously. The degree of automation is high, and the forming force on the workpiece can be precisely controlled by the first hydraulic cylinder 310.

[0028] As an optional implementation, the first lifting plate 320 includes a first connecting plate 321 connected to the bottom of the first hydraulic cylinder 310 and a second connecting plate 322 connected to the top of a plurality of connecting rods 330. A flexible thin film pressure sensor 323 is disposed between the first connecting plate 321 and the second connecting plate 322. The flexible thin film pressure sensor 323 is electrically connected to a controller 400, and the controller 400 is electrically connected to the first hydraulic cylinder 310.

[0029] In this embodiment, when the first lifting plate 320 moves down to the corresponding height position, the flexible die 200 presses the blank workpiece. At this time, the corresponding pressing force can be detected by the flexible thin film pressure sensor 323. When the preset pressure threshold is reached, the flexible thin film pressure sensor 323 can send a signal to the controller 400 so that the controller first hydraulic cylinder 310 stops pressurizing and can maintain pressure for a period of time at any time to accurately control the forming force.

[0030] It should be noted that the first hydraulic cylinder 310 can drive the first lifting plate 320 to move slowly downwards, so as to facilitate subsequent precise control; the flexible thin film pressure sensor 323 can be an RX-M1616M piezoresistive array distributed flexible thin film pressure sensor or an FSR flexible resistive thin film pressure sensor; the controller 400 can be a PLC controller of model S7-200 to meet the usage requirements.

[0031] As an optional implementation, both ends of the second connecting plate 322 are connected to an inverted L-shaped plate 324, which is movably hung on the top of both ends of the first connecting plate 321.

[0032] In this embodiment, when the flexible die 200 is not pressed against the blank workpiece, the second connecting plate 322 can be suspended below the first connecting plate 321 by the inverted L-shaped plate 324, so that the second connecting plate 322 will not exert gravitational pull on the flexible thin film pressure sensor 323, thereby reducing the risk of the flexible thin film pressure sensor 323 detaching from the first connecting plate 321 due to the pulling force. Only when the flexible die 200 is pressed against the blank workpiece will the flexible thin film pressure sensor 323 be squeezed on the top of the second connecting plate 322 under the action of the first connecting plate 321. The structure is ingeniously designed, which not only ensures the anti-detachment function of the flexible thin film pressure sensor 323, but also ensures the pressure detection function.

[0033] As an optional implementation, when the second connecting plate 322 is hung below the first connecting plate 321 via the inverted L-shaped plate 324, the flexible thin film pressure sensor 323 has a gap with the top surface of the second connecting plate 322.

[0034] In this embodiment, when the second connecting plate 322 is suspended below the first connecting plate 321 via the inverted L-shaped plate 324, there can be a certain buffer gap between the flexible thin-film pressure sensor 323 and the top surface of the second connecting plate 322. Thus, when the flexible die 200 presses against the blank workpiece, the second connecting plate 322 will no longer move downwards, while the first connecting plate 321 can drive the flexible thin-film pressure sensor 323 to continue to move downwards slowly for a distance based on the buffer gap. This prevents the instantaneous reaction force from being too large and damaging the flexible thin-film pressure sensor 323, thereby improving the service life of the flexible thin-film pressure sensor 323.

[0035] As an optional implementation, the rigid punch 100 includes a base plate 110, on which a plurality of first templates 120 are provided. A punch module 130 is movably disposed between each of the first templates 120. The top surface of the punch module 130 is a profile surface, and a cavity is formed between the punch module 130 and the side wall of the first template 120.

[0036] In this embodiment, by movably setting the convex module 130 between the first templates 120, the convex module 130 with different curvature surfaces on the top surface can be replaced to form guide plates with different curvature surfaces, thereby improving versatility. At the same time, the flexible hydraulic bladder 220 can also adapt to different curved guide plates without replacement.

[0037] It should be noted that when the convex module 130 needs to be replaced, it can be pulled out directly using a suction cup, making the operation convenient and quick.

[0038] As an optional implementation, each end of one of the multiple first templates 120 is connected to an arc-shaped pressure plate 140. The arc-shaped pressure plate 140 is used to fit the two end faces of the multiple convex modules 130, and the arc-shaped pressure plate 140 is higher than the end face height of the convex module 130. The arc-shaped pressure plate 140 can limit the two ends of the blank workpiece to prevent the blank workpiece from elongating during the cold pressing process.

[0039] As an optional implementation, it also includes a guide mechanism 500, which includes a second hydraulic cylinder 510 with a fixed position. The bottom of the second hydraulic cylinder 510 is connected to a second lifting plate 520. The connecting rods 330 all move through the second lifting plate 520. The bottom of the second lifting plate 520 is connected to a plurality of second templates 530. A flexible concave mold 200 is movably attached between each two adjacent second templates 530. The plurality of second templates 530 are used to attach to the top of the corresponding first template 120.

[0040] In this embodiment, when the flexible die 200 moves downward, the second lifting plate 520 can be driven to move downward synchronously by the second hydraulic cylinder 510. By controlling the second hydraulic cylinder 510 and the first hydraulic cylinder 310 to move at the same speed, the flexible die 200 and the second template 530 can remain relatively stationary when moving downward synchronously. When the second template 530 is attached to the top of the first template 120, the second hydraulic cylinder 510 stops moving, and the first hydraulic cylinder 310 continues to work. At this time, the upper and lower second templates 530 and the first template 120 form a guide channel to stabilize and guide the flexible die 200, so that the flexible die 200 can smoothly enter from between the second templates 530 to between the first templates 120.

[0041] As an optional implementation, a frame 600 is provided on the base plate 110, and the first hydraulic cylinder 310 and the second hydraulic cylinder 510 are both located on the top of the frame 600. The guide mechanism 500 and the rigid punch 100 are both located within the frame 600. The frame 600 can provide support and integration for the corresponding mechanisms.

[0042] As an optional implementation, both inner sidewalls of the frame 600 are provided with guide rails 700 that slide in cooperation with the side ends of the second lifting plate 520, which play a stabilizing and guiding role and improve the accuracy of the second template 530 connecting to the top of the first template 120. The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A three-dimensional curved surface metal sheet forming device for a low-pressure cylinder guide ring of a steam turbine, characterized in that, include: A rigid punch, the top of which is provided with multiple cavities, all of which are fan-shaped; Multiple flexible dies are provided, each of which mates with a corresponding cavity. Each flexible die includes a rigid block, and a flexible hydraulic bladder is connected to the bottom of the rigid block. The flexible hydraulic bladder is filled with hydraulic medium. The hydraulic mechanism is used to drive multiple flexible dies to move down into the corresponding cavity at the same time, so as to cold press and form multiple arc-shaped guide plates between the flexible hydraulic bladder and the bottom surface of the cavity.

2. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 1, characterized in that, The hydraulic mechanism includes a first hydraulic cylinder with a fixed position, a first lifting plate connected to the bottom of the first hydraulic cylinder, and multiple connecting rods connected to the bottom of the first lifting plate, with the multiple connecting rods respectively connected to the top of the rigid block.

3. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 2, characterized in that, The first lifting plate includes a first connecting plate connected to the bottom of the first hydraulic cylinder and a second connecting plate connected to the top of a plurality of connecting rods. A flexible thin-film pressure sensor is disposed between the first connecting plate and the second connecting plate. The flexible thin-film pressure sensor is electrically connected to a controller, and the controller is electrically connected to the first hydraulic cylinder.

4. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 3, characterized in that, The second connecting plate has inverted L-shaped plates connected to both ends, and the inverted L-shaped plates are movably hung on the top of both ends of the first connecting plate.

5. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 4, characterized in that, When the second connecting plate is hung below the first connecting plate via an inverted L-shaped plate, there is a gap between the flexible thin-film pressure sensor and the top surface of the second connecting plate.

6. The three-dimensional curved surface metal sheet forming device for the guide ring of a steam turbine low-pressure cylinder as described in any one of claims 2-5, characterized in that, The rigid punch includes a base plate, on which multiple first templates are provided. A punch module is movably arranged between each of the first templates. The top surface of the punch module is a profile surface, and the punch module and the side wall of the first template form a cavity.

7. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 6, characterized in that, Multiple first templates are connected to arc-shaped pressure plates at both ends. The arc-shaped pressure plates are used to fit the two end faces of multiple convex modules, and the arc-shaped pressure plates are higher than the end face height of the convex modules.

8. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 6, characterized in that, It also includes a guiding mechanism, which includes a second hydraulic cylinder with a fixed position. The bottom of the second hydraulic cylinder is connected to a second lifting plate. The connecting rods all move through the second lifting plate. The bottom of the second lifting plate is connected to multiple second templates. A flexible concave mold is movably attached between each two adjacent second templates. The multiple second templates are used to attach to the top of the corresponding first template.

9. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 8, characterized in that, A frame is provided on the base plate, and the first and second hydraulic cylinders are both located on the top of the frame. The guide mechanism and the rigid punch are both located inside the frame.

10. The three-dimensional curved surface metal sheet forming device for a steam turbine low-pressure cylinder guide ring as described in claim 9, characterized in that, Both inner walls of the frame are equipped with guide rails that slide in conjunction with the side ends of the second lifting plate.

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