A hydraulic forming device and method for small round-corner parts

Abstract

The present invention relates to the technical field of small-round-corner parts, and provides a hydroforming device and method for small-round-corner parts, which are used to form a sheet metal into a shell part, including: a punch, connected to the first downward pressing arm of a press, a through hole is formed on the bottom surface of the punch, and the through hole is used to convey hydraulic oil to the lower part of the bottom surface of the punch, a sealing ring is arranged on the bottom surface of the punch, and the sealing ring is arranged around the through hole; a plurality of side push plates, the plurality of side push plates enclose a cavity with a set shape, a distance is provided between the plurality of side push plates, and the plurality of side push plates are adapted to move towards the cavity simultaneously by the press; a plurality of blocking structures, arranged in one-to-one correspondence with the plurality of side push plates, and the blocking structures are used to prevent the side push plates from moving away from the cavity; and a bottom push plate, the bottom push plate is arranged in linkage with the plurality of side push plates, so that when the plurality of side push plates move towards the cavity simultaneously, the bottom push plate moves upward simultaneously.

Description

Technical Field

[0001] The present invention relates to the technical field of small-round-corner parts, and more particularly, to a hydroforming device and method for small-round-corner parts. Background Art

[0002] Deep cavity thin-wall sheet metal parts are widely used in the fields of aerospace, rail transit, energy and chemical engineering, etc. Such products are usually called small-round-corner parts. The smaller the radius of the fillet area at the intersection of multiple surfaces of such products, the larger the accommodation space that the cavity of such products can have, so that the cavity space utilization rate of such products is higher and the structure is more compact. However, the forming of small-round-corner parts is extremely difficult, especially the forming of the aforementioned fillet area to meet the requirements is even more difficult, which brings great difficulties to production. At the same time, in recent years, with the increasingly significant development trend of all walks of life towards structural lightweight, volume miniaturization and high power, the demand for small-round-corner parts is very urgent, but the defect problems of thinning and cracking and compressive instability in the forming process of the fillet area of small-round-corner parts still cannot be effectively solved. Summary of the Invention

[0003] The present invention aims to solve the defect problems that the prior art cannot effectively solve the thinning and cracking and compressive instability in the forming process of the fillet area of small-round-corner parts.

[0004] To solve the above problems, the present invention provides a hydroforming device for small-round-corner parts, which is used to form a sheet metal into a shell part, and includes:

[0005] A punch, which is connected to the first lower pressing arm of a press. A through hole is opened on the bottom surface of the punch, and the through hole is used to convey hydraulic oil to the lower part of the bottom surface of the punch. A sealing ring is arranged on the bottom surface of the punch, and the sealing ring is arranged around the through hole;

[0006] A plurality of side pushing plates, all of which are arranged below the sealing ring. The plurality of side pushing plates enclose a cavity with a set shape. The plurality of side pushing plates are arranged at intervals, and the plurality of side pushing plates are adapted to move towards the cavity simultaneously through the press;

[0007] A plurality of blocking structures, which are arranged in one-to-one correspondence with the plurality of side pushing plates, and the blocking structures are used to prevent the side pushing plates from moving away from the cavity; and

[0008] A bottom pushing plate, which is arranged below the plurality of side pushing plates, and the bottom pushing plate is arranged in a linkage manner with the plurality of side pushing plates, so that when the plurality of side pushing plates move towards the cavity simultaneously, the bottom pushing plate moves upward simultaneously.

[0009] Optionally, the hydroforming device for small-round-corner parts further includes:

[0010] A plurality of upward pushing seats, which are respectively connected to the second downward pressing arms of the press, and the plurality of upward pushing seats are arranged around the punch. The bottom end of the upward pushing seat is a first inclined surface structure. Wherein, as the bottom of the upward pushing seat extends downward, the inclined surface of the first inclined surface structure gradually moves away from the punch;

[0011] A plurality of downward pushing seats, which are respectively connected to the plurality of side pushing plates in one-to-one correspondence. A second inclined surface structure is arranged on the side wall of the downward pushing seat. The first inclined surface structure and the second inclined surface structure are arranged in one-to-one correspondence. The inclined surface of each second inclined surface structure is arranged parallel to the inclined surface of the corresponding first inclined surface structure; and

[0012] A base, on which the plurality of downward pushing seats are arranged, and the plurality of downward pushing seats are adapted to move on the base.

[0013] Optionally, a groove is formed in the bottom surface of the downward pushing seat, and the groove is recessed upward.

[0014] Optionally, the second inclined surface structure is located at the side wall of one side of the downward pushing seat. A third inclined surface structure is arranged on the side wall of the other side of the downward pushing seat. The third inclined surface structure is arranged close to the bottom pushing plate, and the third inclined surface structure is arranged opposite to the second inclined surface structure. Wherein, as the side wall of the other side of the downward pushing seat gradually approaches the bottom pushing plate, the height of the inclined surface of the third inclined surface structure gradually decreases,

[0015] A plurality of fourth inclined surface structures are arranged at the bottom of the bottom pushing plate. The fourth inclined surface structure and the third inclined surface structure are arranged in one-to-one correspondence. The inclined surface of each third inclined surface structure is arranged parallel to the inclined surface of the corresponding fourth inclined surface structure, and the bottom pushing plate is lapped on the plurality of third inclined surface structures.

[0016] Optionally, the blocking structure includes a limiting groove and a limiting block,

[0017] A plurality of the limiting grooves are formed in the top surface of the base. Each downward pushing seat is placed in one of the limiting grooves. The downward pushing seat is adapted to slide reciprocally between the inner end and the outer end of the limiting groove. The plurality of limiting grooves are arranged around the bottom pushing plate, and the inner ends of the plurality of limiting grooves converge and communicate below the bottom pushing plate,

[0018] The limiting blocks are arranged in the limiting grooves in one-to-one correspondence, and the limiting blocks are placed between the downward pushing seat and the outer end of the limiting groove.

[0019] Optionally, the side walls of two adjacent sides of the plurality of side pushing plates are fifth inclined surface structures. The fifth inclined surface structures of the plurality of side pushing plates are arranged parallel to each other, and the fifth inclined surface structures of the plurality of side pushing plates are adapted to fit together.

[0020] Optionally, when multiple said side push plates simultaneously move towards the cavity and the bottom push plate moves upwards to the highest position, a gap is provided between multiple said side push plates and the bottom push plate simultaneously.

[0021] Optionally, when multiple said side push plates simultaneously move towards the cavity and multiple said side push plates are in contact with each other, the intersection of the inner surfaces of the cavity surrounded by multiple said side push plates is in arc transition.

[0022] In addition, the present invention also provides a hydroforming method for small-round-corner parts, using the hydroforming device for small-round-corner parts as described above, including:

[0023] According to the shape and size of the shell part, determine the shape of the cavity surrounded by multiple said side push plates and determine the spacing between multiple said side push plates;

[0024] According to the shape of the cavity surrounded by multiple said side push plates and the spacing between multiple said side push plates, set the corresponding multiple said blocking structures;

[0025] According to the shape and size of the shell part, or according to the shape of the cavity surrounded by multiple said side push plates, adjust the position of the sealing ring;

[0026] Place the sheet metal on top of multiple said side push plates;

[0027] Drive the first downward pressing arm of the press to move the punch downwards so that the sealing ring presses the sheet metal tightly;

[0028] Inject hydraulic oil into the through hole to form the sheet metal into a shell part;

[0029] Control the press to make multiple said side push plates and the bottom push plate move towards the cavity simultaneously.

[0030] Optionally, during the process of controlling the press to make multiple said side push plates and the bottom push plate move towards the cavity simultaneously, keep the pressure of the hydraulic oil injected into the through hole unchanged or increase the pressure of the hydraulic oil injected into the through hole.

[0031] Compared with the prior art, the present invention has the following technical effects:

[0032] In the present invention, first, the hydraulic oil conveyed through the through-hole causes the top of the sheet metal to deform slowly and uniformly downward, thereby forming the main structure of the housing part uniformly and stably. During this process, a plurality of blocking structures are used to prevent the side push plates from moving away from the cavity, so as to ensure that the housing part of the set shape is formed by hydroforming. In this way, the sheet metal is pre-drawn and formed by the liquid medium, and the liquid medium is used as the internal support during the rounding and shaping process. Especially, due to the high controllability of the hydraulic pressure, high process freedom, small friction, and high forming limit, the effect of forming the sheet metal into the housing part is good. However, considering that only one side of the sheet metal is extruded and formed in this way, it is easy to have insufficient hydroforming at the edges and corners far from the through-hole, resulting in thinning and cracking and compressive instability. Therefore, the press is used to make the plurality of side push plates move towards the cavity simultaneously, and the bottom push plate is linked with the plurality of side push plates, so that the bottom push plate moves upward simultaneously. In this way, an external load is applied to the housing part from the outside of the housing part, especially to the edges and corners far from the through-hole, so as to adopt the method of forming with the liquid medium and synchronous external multi-directional loading, so that the edges and corners of the housing part are fully formed, effectively suppressing the defects of thinning and cracking and compressive instability in the rounding area of the small-round-corner parts during the forming process, thus solving the defect problem in the prior art that the defects of thinning and cracking and compressive instability in the rounding area of the small-round-corner parts during the forming process cannot be effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a schematic structural cross-sectional view of the hydroforming device for the small-round-corner parts of the present invention before hydroforming;

[0034] Figure 2 FIG. is a schematic structural cross-sectional view of the hydroforming device for the small-round-corner parts of the present invention during hydroforming;

[0035] Figure 3 FIG. is a schematic structural cross-sectional view of the hydroforming device for the small-round-corner parts of the present invention during rounding and shaping;

[0036] Figure 4 is Figure 3 a schematic top view of the hydroforming device for the small-round-corner parts in;

[0037] Figure 5 FIG. is a schematic flow chart of the hydroforming method for the small-round-corner parts of the present invention;

[0038] Figure 6 FIG. is a schematic structural diagram of the housing part obtained after hydroforming using the hydroforming device for the small-round-corner parts of the present invention;

[0039] Figure 7Schematic structural diagram of a housing part obtained after rounding and shaping using the hydroforming device for the small rounded corner part of the present invention.

[0040] Description of reference numerals:

[0041] Through hole 1, upper push seat 2, punch 3, sealing ring 4, sheet metal 6, side push plate 7, second inclined surface structure 8, bottom push plate 9, limit block 10, base 11, first inclined surface structure 12, lower push seat 13, limit groove 14, blocking structure 15, third inclined surface structure 16, fourth inclined surface structure 17, fifth inclined surface structure 18, housing part 19. Detailed implementation manners

[0042] To make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings.

[0043] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0044] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "arranged", "installed", "connected", "coupled" 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; 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 situations.

[0045] In the description of this specification, the descriptions referring to terms such as "embodiment", "one embodiment" and "one implementation manner" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or implementation manner are included in at least one embodiment or implementation manner of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or implementation manner. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or implementation manners in a suitable manner.

[0046] To solve the above technical problems, as Figures 1 to 7 shown, this embodiment provides a hydroforming device for small rounded corner parts, which is used to form a sheet metal 6 into a housing part 19, including:

[0047] The punch 3 is connected to the first downward pressing arm of the press. A through hole 1 is formed in the bottom surface of the punch 3, and the through hole 1 is used to convey hydraulic oil to the lower part of the bottom surface of the punch 3. A sealing ring 4 is arranged on the bottom surface of the punch 3, and the sealing ring 4 is arranged around the through hole 1;

[0048] A plurality of side push plates 7 are all arranged below the sealing ring 4. The plurality of side push plates 7 enclose a cavity with a set shape. The plurality of side push plates 7 are arranged at intervals. By means of the press, the plurality of side push plates 7 are adapted to move towards the cavity simultaneously;

[0049] A plurality of blocking structures 15 are arranged in one-to-one correspondence with the plurality of side push plates 7. The blocking structures 15 are used to prevent the side push plates 7 from moving away from the cavity; and

[0050] The bottom push plate 9 is arranged below the plurality of side push plates 7. The bottom push plate 9 is arranged in a linkage manner with the plurality of side push plates 7, so that when the plurality of side push plates 7 move towards the cavity simultaneously, the bottom push plate 9 moves upwards simultaneously.

[0051] It should be noted that the through hole 1 is connected to a hydraulic station through a corresponding pipeline, and the hydraulic station conveys hydraulic oil to the through hole 1.

[0052] Here, the side push plates 7 can be four, so as to form a cuboid-shaped housing member 19.

[0053] In addition, the housing member 19 here can refer to a thin-walled housing structure with a concave cavity formed in its top surface.

[0054] During use, according to the shape and size of the housing member 19, determine the shape of the cavity enclosed by the plurality of side push plates 7, and determine the spacing between the plurality of side push plates 7.

[0055] According to the shape of the cavity enclosed by the plurality of side push plates 7 and the spacing between the plurality of side push plates 7, set the corresponding plurality of blocking structures 15 to prevent the side push plates 7 from moving away from the cavity;

[0056] According to the shape and size of the housing member 19, or according to the shape of the cavity enclosed by the plurality of side push plates 7, adjust the position of the sealing ring 4 to ensure that after the punch 3 presses downwards, the sealing ring 4 and the sheet material 6 can completely seal the hydraulic oil ejected from the through hole 1.

[0057] Place the sheet material 6 on the tops of the plurality of side push plates 7;

[0058] Drive the first downward pressing arm of the press to move the punch 3 downwards, so that the sealing ring 4 presses the sheet material 6 tightly;

[0059] Inject hydraulic oil into the through hole 1 to form the sheet metal 6 into a housing part 19;

[0060] Control the press to move multiple side push plates 7 and the bottom push plate 9 towards the cavity simultaneously, so as to extrude the outer surface of the housing, thereby fully extruding the transition fillets of the housing part 19.

[0061] In the present invention, first, the hydraulic oil conveyed through the through hole 1 causes the top of the sheet metal 6 to deform slowly and evenly downwards, thereby uniformly and stably forming the main structure of the housing part 19. During this process, multiple blocking structures 15 are used to prevent the side push plates 7 from moving away from the cavity, thereby ensuring that a housing part 19 with a set shape is formed by hydroforming. In this way, the sheet metal 6 is pre-drawn and formed by a liquid medium, and the liquid medium is used as the internal support during fillet shaping. Especially, due to the characteristics of hydraulic control, high process freedom, small friction, and high forming limit, the effect of forming the sheet metal 6 into the housing part 19 is good. However, considering that only one side of the sheet metal 6 is extruded and formed in this way, it is easy to have insufficient hydroforming at the edges and corners far from the through hole 1, resulting in thinning and rupture and compressive instability. Therefore, the press is used to make multiple side push plates 7 suitable for moving towards the cavity simultaneously, and the bottom push plate 9 is linked with multiple side push plates 7 so that the bottom push plate 9 moves upwards simultaneously. In this way, external loading is applied to the outside of the housing part 19, especially to the edges and corners far from the through hole 1. Thus, by using the method of forming with a liquid medium and external multi-directional synchronous loading, the edges and corners of the housing part 19 are fully formed, effectively suppressing the defects of thinning and rupture and compressive instability in the fillet area of small fillet parts during the forming process, thereby solving the defect problem in the prior art that the defects of thinning and rupture and compressive instability in the fillet area of small fillet parts during the forming process cannot be effectively solved.

[0062] Figures 1 to 7 , further, the hydroforming device for the small fillet part further includes:

[0063] Multiple upper push seats 2, which are respectively connected to the second lower pressing arms of the press. Multiple upper push seats 2 are arranged around the punch 3. The bottom end of the upper push seat 2 is a first inclined surface structure 12. Among them, as the bottom of the upper push seat 2 extends downwards, the inclined surface of the first inclined surface structure 12 gradually moves away from the punch 3;

[0064] Multiple lower push seats 13, which are connected to multiple side push plates 7 in one-to-one correspondence. The side wall of the lower push seat 13 is provided with a second inclined surface structure 8. The first inclined surface structure 12 and the second inclined surface structure 8 are arranged in one-to-one correspondence. The inclined surface of each second inclined surface structure 8 is arranged parallel to the inclined surface of the corresponding first inclined surface structure 12; and

[0065] Base 11, a plurality of the push-down seats 13 are arranged on the base 11, and the plurality of the push-down seats 13 are adapted to move on the base 11.

[0066] The press here can be a double-action press, which has a first lower pressing arm and a second lower pressing arm, and the first lower pressing arm and the second lower pressing arm can press down independently respectively.

[0067] After the first lower pressing arm pushes the punch 3 downward and extrudes the sheet material 6, the hydraulic station injects hydraulic oil into the through hole 1 and forms the sheet material 6 into a shell part 19. Then, the second lower pressing arm pushes the plurality of upper push seats 2 to move downward simultaneously, so that the first inclined surface structure 12 pushes against the second inclined surface structure 8. By virtue of the fact that as the bottom of the upper push seat 2 extends downward, the inclined surface of the first inclined surface structure 12 gradually moves away from the punch 3, and the inclined surface of each second inclined surface structure 8 is arranged parallel to the inclined surface of the corresponding first inclined surface structure 12, thereby enabling the upper push seat 2 to push the push-down seat 13, and enabling the corresponding plurality of side push plates 7 to move toward the cavity simultaneously, realizing the simultaneous extrusion of the outer side wall of the shell part 19.

[0068] In this embodiment, it is very simple to achieve "enabling the plurality of side push plates 7 to be adapted to move toward the cavity simultaneously through the press". Just by the second lower pressing arm moving downward and enabling the corresponding first inclined surface structure 12 to press against the corresponding second inclined surface structure 8, it is very easy to realize the transformation of the downward movement of the second lower pressing arm into the simultaneous movement of the side push plates 7 toward the cavity.

[0069] Figures 1 to 7 , further, the second inclined surface structure 8 is located at the side wall of one side of the push-down seat 13, the side wall of the other side of the push-down seat 13 is provided with a third inclined surface structure 16, the third inclined surface structure 16 is arranged close to the bottom push plate 9, the third inclined surface structure 16 is arranged opposite to the second inclined surface structure 8. Wherein, as the side wall of the other side of the push-down seat 13 gradually approaches the bottom push plate 9, the inclined surface height of the third inclined surface structure 16 gradually decreases, the bottom of the bottom push plate 9 is provided with a plurality of fourth inclined surface structures 17, the fourth inclined surface structures 17 are arranged in one-to-one correspondence with the third inclined surface structures 16, the inclined surface of each third inclined surface structure 16 is arranged parallel to the inclined surface of the corresponding fourth inclined surface structure 17, and the bottom push plate 9 is lapped on the plurality of third inclined surface structures 16.

[0070] Utilize the inclined plane characteristics of the third inclined plane structure 16: As the other side wall of the lower push seat 13 gradually approaches the bottom push plate 9, the inclined plane height of the third inclined plane structure 16 gradually decreases, and the inclined plane of each third inclined plane structure 16 is arranged parallel to the inclined plane of the corresponding fourth inclined plane structure 17. Thus, during the process of multiple side push plates 7 moving towards the cavity simultaneously, multiple lower push seats 13 simultaneously lift the bottom push plate 9 upwards, thereby realizing the linkage between the bottom push plate 9 and multiple side push plates 7, enabling the bottom push plate 9 to simultaneously extrude the transition fillets at all the edges of the bottom surface of the housing part 19, and making the extrusion forming of the transition fillets at all the edges of the bottom surface of the housing part 19 uniform.

[0071] Figures 1 to 7 , further, the blocking structure 15 includes a limiting groove 14 and a limiting block 10.

[0072] Multiple limiting grooves 14 are formed on the top surface of the base 11. Each lower push seat 13 is placed in one of the limiting grooves 14. The lower push seat 13 is used to reciprocate between the inner end and the outer end of the limiting groove 14. Multiple limiting grooves 14 are arranged around the bottom push plate 9, and the inner ends of multiple limiting grooves 14 converge and communicate below the bottom push plate 9.

[0073] The limiting blocks 10 are arranged in the limiting grooves 14 in one-to-one correspondence. The limiting blocks 10 are placed between the lower push seat 13 and the outer end of the limiting groove 14.

[0074] By using the fact that the limiting blocks 10 are placed between the lower push seat 13 and the outer end of the limiting groove 14, the movement of the lower push seat 13 is restricted by the limiting blocks 10, thereby restricting the movement range of the side push plate 7 connected to the lower push seat 13. During the process of injecting hydraulic oil into the through hole 1 to perform hydroforming on the sheet metal 6, the limiting blocks 10 and the limiting grooves 14 cooperate with each other to prevent the side push plate 7 from moving away from the cavity.

[0075] Here, the size of the limiting block 10 can be adjusted according to the size of the formed housing part 19, so that the hydroforming device for small fillet parts of the present invention can be applicable to the forming of multiple housing parts 19 with different sizes.

[0076] Figures 1 to 7 , further, the two adjacent side walls of multiple side push plates 7 are fifth inclined plane structures 18. The fifth inclined plane structures 18 of multiple side push plates 7 are arranged parallel to each other, and the fifth inclined plane structures 18 of multiple side push plates 7 are adapted to fit together.

[0077] That is to say, when looking down at the side push plate 7, the side push plate 7 is an isosceles trapezoid structure, and the fifth inclined plane structure 18 is the two waists.

[0078] The fifth inclined surface structures 18 of the plurality of side pushing plates 7 are arranged in parallel with each other, so as to avoid interference between the plurality of side pushing plates 7 during the simultaneous movement towards the cavity, enabling the plurality of side pushing plates 7 to simultaneously extrude the outer side wall of the housing part 19, thereby making the texture of the rounded corner areas of each edge on the outside of the housing part 19 uniform and avoiding thinning rupture and compressive instability during the forming process.

[0079] On the one hand, the present invention performs pre-drawing forming through a liquid medium, uses the liquid medium as the internal support during fillet shaping, realizes controllable hydraulic pressure, has a high degree of process freedom, small friction, and a high forming limit. On the other hand, through the mutual cooperation of the first inclined surface structure 12, the second inclined surface structure 8, the third inclined surface structure 16, the fourth inclined surface structure 17, and the fifth inclined surface structure 18, the present invention realizes the transformation of the downward movement of the second downward pressing arm into the horizontal loading of the surrounding side pushing plates 7 and the vertical loading of the bottom pushing plate 9, and ensures the good synchronization of the movement of the plurality of side pushing plates 7 and the bottom pushing plate 9. The forming quality of the small fillet parts is high, and no other complex mechanical transmission structures are required, thus making the linkage structure of the entire hydraulic forming device for small fillet parts simple, with low equipment investment and low manufacturing cost of the hydraulic forming device. On yet another aspect, the present invention only requires a set of hydraulic forming device, integrates the pre-drawing and fillet shaping of the housing part 19 into one process and completes them all in the hydraulic forming device of the present invention, shortening the production cycle. Moreover, the structure of this hydraulic forming device is simple and easy to operate, and can be realized only by a double-action press. And through the mutual linkage and cooperation of the first inclined surface structure 12, the second inclined surface structure 8, the third inclined surface structure 16, the fourth inclined surface structure 17, and the fifth inclined surface structure 18, the full automation of pre-drawing and fillet shaping is realized, eliminating manual operation, thereby greatly improving the production efficiency, shortening the production cycle of the product, and reducing the manufacturing cost of the housing part 19.

[0080] Figures 1 to 7 , Further, a groove is formed on the bottom surface of the lower pushing seat 13, and the groove is recessed upward. Through the groove formed on the bottom surface of the lower pushing seat 13, the contact area between the bottom surface of the lower pushing seat 13 and the upper surface of the base 11 is reduced, thereby reducing the forming load on the outer surface of the housing part 19.

[0081] Figures 1 to 7 , Further, when the plurality of side pushing plates 7 simultaneously move towards the cavity and the bottom pushing plate 9 moves upward to the highest position, the plurality of side pushing plates 7 are simultaneously arranged with a gap from the bottom pushing plate 9. By using this gap, the rounded corner transition at the bottom edge of the housing part 19 is naturally generated, and the material used at the intersection of the side pushing plates 7 and the bottom pushing plate 9 is reduced.

[0082] Figures 1 to 7, Further, when multiple said side push plates 7 move towards the cavity simultaneously and multiple said side push plates 7 are in contact with each other, the intersection of the inner surfaces of the cavity formed by multiple said side push plates 7 is in arc transition. Thus, by using this arc transition, the edges and sharp corners of the housing part 19 are formed into this arc transition shape.

[0083] Figures 1 to 7 , Further, the punch 3 is a horizontally arranged plate-like part, the through hole 1 is an L-shaped structure, the bottom end of the vertical part of the through hole 1 is communicated with the bottom surface of the punch 3, and the end of the horizontal part of the through hole 1 is communicated with the side wall of the punch 3.

[0084] By using the through hole 1 with an L-shaped structure, the structural characteristics of the punch 3 are fully utilized to reduce the external volume of the hydroforming device of the present invention.

[0085] Figures 1 to 7 , Further, an installation groove is formed on the bottom surface of the punch 3, and the sealing ring 4 is placed in the installation groove.

[0086] Figures 1 to 7 , In addition, the present invention also provides a hydroforming method for small-round-corner parts, using the hydroforming device for small-round-corner parts as described above, including:

[0087] S100. According to the shape and size of the housing part 19, determine the shape of the cavity formed by multiple said side push plates 7, and determine the distance between multiple said side push plates 7;

[0088] S200. According to the shape of the cavity formed by multiple said side push plates 7 and the distance between multiple said side push plates 7, set the corresponding multiple said blocking structures 15;

[0089] S300. According to the shape and size of the housing part 19, or according to the shape of the cavity formed by multiple said side push plates 7, adjust the position of the sealing ring 4;

[0090] S400. Place the sheet metal 6 on the top of multiple said side push plates 7;

[0091] S500. Drive the first downward pressing arm of the press to move the punch 3 downward, so that the sealing ring 4 presses the sheet metal 6 tightly;

[0092] S600. Inject hydraulic oil into the through hole 1 to form the sheet metal 6 into the housing part 19;

[0093] S700. Control the press to make multiple said side push plates 7 and the bottom push plate 9 move towards the cavity simultaneously to extrude the outer surface of the housing.

[0094] Further, during the process of the control press moving the plurality of side push plates and the bottom push plate towards the cavity simultaneously, the pressure of the hydraulic oil injected through the through hole is kept constant, or the pressure of the hydraulic oil injected through the through hole is increased.

[0095] During the process of "determining the shape of the cavity surrounded by the plurality of side push plates 7 according to the shape and size of the housing part 19, and determining the spacing between the plurality of side push plates 7", it can be achieved by performing numerical simulation optimization on the preformed housing part 19 in a computer to determine the size of the preformed housing part 19 and the movement amount (i.e., the feed amount) of the plurality of side push plates 7 and the bottom push plate 9 during extrusion shaping. Based on this data, the size of the limit block 10 is configured to ensure that the sheet material 6 is formed into a housing part 19 with a set size.

[0096] During the process of the control press moving the plurality of side push plates 7 and the bottom push plate 9 towards the cavity simultaneously, the pressure of the hydraulic oil injected through the through hole 1 is kept constant, or the pressure of the hydraulic oil injected through the through hole 1 is increased. Thereby, the flatness of the side wall and the bottom surface of the target formed part is ensured.

[0097] Preferably, the angle between the mating inclined surface of the first inclined surface structure 12 and the second inclined surface structure 8 relative to the horizontal plane is generally taken as 45°. This angle can also be selected as different angles according to actual requirements, but it is generally between 30° and 75°. When a larger extrusion load is required, the inclined surface with the aforementioned smaller degree is preferably selected.

[0098] Preferably, the slope of the mating inclined surface of the first inclined surface structure 12 and the second inclined surface structure 8 needs to be determined according to the relationship between the fillet design size of the target formed part and the preformed fillet size. If the preformed sizes and the design sizes of the side wall corner and the bottom fillet are both the same, then the aforementioned 45° angle is selected. If they are not the same, then the slope relationship needs to be inversely calculated according to the required angular relationship to achieve the matching relationship of the extrusion strokes of the side push plate 7 and the bottom push plate 9.

[0099] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will all fall within the protection scope of the present invention.

Claims

1. A hydraulic forming device for small rounded corner parts, which is used to form a sheet into a shell part, and is characterized in that, Comprising: A punch (3) connected to the first downward pressing arm of a press. A through hole (1) is formed in the bottom surface of the punch (3), and the through hole (1) is used to convey hydraulic oil below the bottom surface of the punch (3). A sealing ring (4) is arranged on the bottom surface of the punch (3), and the sealing ring (4) is arranged around the through hole (1); A plurality of side pushing plates (7), all arranged below the sealing ring (4). The plurality of side pushing plates (7) enclose a cavity of a set shape. The plurality of side pushing plates (7) are arranged at intervals, and the plurality of side pushing plates (7) are adapted to move towards the cavity simultaneously by the press; A plurality of blocking structures (15), arranged in one-to-one correspondence with the plurality of side pushing plates (7). The blocking structure (15) is used to prevent the side pushing plate (7) from moving away from the cavity; And A bottom pushing plate (9), arranged below the plurality of side pushing plates (7). The bottom pushing plate (9) is arranged in a linkage manner with the plurality of side pushing plates (7), so that when the plurality of side pushing plates (7) move towards the cavity simultaneously, the bottom pushing plate (9) moves upwards simultaneously.

2. The hydroforming device for small rounded corner parts according to claim 1, characterized in that, The hydraulic forming device for the small rounded corner part further comprises: A plurality of upper pushing seats (2), respectively connected to the second downward pressing arm of the press. The plurality of upper pushing seats (2) are arranged around the punch (3). The bottom end of the upper pushing seat (2) is a first inclined surface structure (12). Wherein, as the bottom of the upper pushing seat (2) extends downwards, the inclined surface of the first inclined surface structure (12) gradually moves away from the punch (3); A plurality of lower pushing seats (13), connected to the plurality of side pushing plates (7) in one-to-one correspondence. A second inclined surface structure (8) is arranged on the side wall of the lower pushing seat (13). The first inclined surface structure (12) and the second inclined surface structure (8) are arranged in one-to-one correspondence. The inclined surface of each second inclined surface structure (8) is arranged parallel to the inclined surface of the corresponding first inclined surface structure (12); and A base (11), on which the plurality of lower pushing seats (13) are arranged. The plurality of lower pushing seats (13) are adapted to move on the base (11).

3. The hydroforming device for small rounded corner parts according to claim 2, characterized in that, A groove is formed in the bottom surface of the lower pushing seat (13), and the groove is recessed upwards.

4. The hydroforming device for small rounded corner parts according to claim 2, characterized in that, The second inclined surface structure (8) is located at the side wall of one side of the lower pushing seat (13). A third inclined surface structure (16) is arranged on the side wall of the other side of the lower pushing seat (13). The third inclined surface structure (16) is arranged close to the bottom pushing plate (9). The third inclined surface structure (16) is arranged opposite to the second inclined surface structure (8). Wherein, as the side wall of the other side of the lower pushing seat (13) gradually approaches the bottom pushing plate (9), the height of the inclined surface of the third inclined surface structure (16) gradually decreases, A plurality of fourth inclined surface structures (17) are arranged at the bottom of the bottom pushing plate (9). The fourth inclined surface structures (17) are arranged in one-to-one correspondence with the third inclined surface structures (16). The inclined surface of each third inclined surface structure (16) is arranged parallel to the inclined surface of the corresponding fourth inclined surface structure (17). The bottom pushing plate (9) is lapped on the plurality of third inclined surface structures (16).

5. The hydroforming device for small rounded corner parts according to claim 2, characterized in that, The blocking structure (15) includes a limit groove (14) and a limit block (10). A plurality of the limit grooves (14) are formed in the top surface of the base (11). Each of the push-down seats (13) is placed in one of the limit grooves (14). The push-down seat (13) is configured to reciprocally slide between the inner end and the outer end of the limit groove (14). The plurality of limit grooves (14) are arranged around the bottom push plate (9), and the inner ends of the plurality of limit grooves (14) converge and communicate below the bottom push plate (9). The limit blocks (10) are correspondingly arranged in the limit grooves (14), and the limit blocks (10) are placed between the push-down seats (13) and the outer ends of the limit grooves (14).

6. The hydroforming device for small rounded corner parts according to any one of claims 1 to 5, characterized in that, Two adjacent side walls of each of the plurality of side push plates (7) are fifth inclined surface structures (18). The fifth inclined surface structures (18) of the plurality of side push plates (7) are arranged in parallel with each other, and the fifth inclined surface structures (18) of the plurality of side push plates (7) are adapted to fit together.

7. The hydroforming device for small rounded corner parts according to any one of claims 1 to 5, characterized in that, When the plurality of side push plates (7) simultaneously move towards the cavity and the bottom push plate (9) moves upwards to the highest position, the plurality of side push plates (7) are simultaneously arranged with a gap from the bottom push plate (9).

8. The hydroforming device for small rounded corner parts according to any one of claims 1 to 5, characterized in that, When the plurality of side push plates (7) simultaneously move towards the cavity and the plurality of side push plates (7) are in contact with each other, the intersection of the inner surfaces of the cavity surrounded by the plurality of side push plates (7) has an arc transition.

9. A hydroforming method for a small rounded corner part, using the hydroforming device for a small rounded corner part according to any one of claims 1 to 8, characterized in that, Including: Determine the shape of the cavity surrounded by the plurality of side push plates (7) and determine the spacing between the plurality of side push plates (7) according to the shape and size of the housing part; Arrange the corresponding plurality of blocking structures (15) according to the shape of the cavity surrounded by the plurality of side push plates (7) and the spacing between the plurality of side push plates (7); Adjust the position of the sealing ring (4) according to the shape and size of the housing part or according to the shape of the cavity surrounded by the plurality of side push plates (7); Place the sheet material on the tops of the plurality of side push plates (7); Drive the first downward pressing arm of the press to move the punch (3) downwards so that the sealing ring (4) presses the sheet material tightly; Inject hydraulic oil into the through hole (1) to form the sheet material into the housing part; Control the press to move the plurality of side push plates (7) and the bottom push plate (9) towards the cavity simultaneously.

10. The hydroforming method of the small rounded corner part according to claim 9, characterized in that, During the process of controlling the press to move the plurality of side push plates (7) and the bottom push plate (9) towards the cavity simultaneously, keep the pressure of the hydraulic oil injected into the through hole (1) unchanged or increase the pressure of the hydraulic oil injected into the through hole (1).

Images