Hydraulic forming mechanism for cup body

Abstract

The cup body hydraulic forming mechanism comprises an upper die and a lower die which can be opened and closed mutually, and at least one end of the lower die is provided with a strong expansion assembly. The strong expansion assembly comprises a pushing block, a sealing block, a mandrel and a plurality of strong supporting blocks. The pushing block drives the sealing block and the mandrel to move, and the mandrel is of a taper structure, so that the strong supporting block expands outwards and supports the threaded structure. The upper die and the lower die are provided with first threaded concave / convex grooves, the strong supporting block is provided with corresponding second threaded concave / convex grooves, and an annular spring can be arranged to eliminate a joint line. Threads are formed through mechanical expansion instead of high-pressure water pressure, the needed water pressure is remarkably reduced, energy consumption and equipment pressure are reduced, meanwhile, the thread precision is improved, a joint line is eliminated, and the service life of a mold is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of thermos cup processing, and in particular to a cup body hydroforming mechanism. Background Art

[0002] In the existing metal cup body manufacturing process, especially in the forming process of thin-walled cup bodies made of stainless steel or aluminum, the hydroforming technology is usually adopted. This technology injects liquid into the mold cavity, and under the action of high pressure, the blank is made to fit the inner wall of the mold, thereby realizing the forming of complex shapes.

[0003] However, when forming the external thread structure of the cup body by the traditional hydroforming method, it usually relies on the prefabricated thread grooves in the cavity after the upper and lower molds are closed to press and form. This forming method requires extremely high internal water pressure to ensure that the material fully fills the thread structure in the mold, resulting in the following problems: the required water pressure is too high, increasing the equipment cost and energy consumption; it is easy to cause mold wear and reduced sealing performance under high pressure; there are obvious "mold closing lines" in the formed thread structure, affecting the appearance quality and sealing performance of the product; it is difficult to guarantee the thread accuracy, and defects are likely to occur due to uneven material flow.

[0004] Therefore, there is an urgent need to provide a new cup body hydroforming and expanding mechanism that can achieve high-quality thread forming under low water pressure, effectively eliminate the mold closing line, and improve the production efficiency and product quality.

[0005] The above content is only used to assist in understanding the technical solution of the present application, and does not represent an admission that the above content is the closest prior art to the present application. Summary of the Invention

[0006] Based on this, the present application provides a cup body hydroforming mechanism to solve the above technical problems.

[0007] The technical solution adopted by the present application to solve its technical problems is: a cup body hydroforming mechanism, including an upper mold and a lower mold that can be closed or opened with each other, and at least one end of the lower mold is provided with a hydroforming and expanding assembly; The hydroforming and expanding assembly includes a pushing block, a sealing block, a mandrel and a strong support block; the pushing block is used to drive the displacement of the sealing block and the mandrel, the mandrel is placed inside the sealing block to move, a taper structure is formed at the outer end of the mandrel, a plurality of strong support blocks are arranged annularly at the taper structure of the mandrel, and a compression spring is arranged between the pushing block and the sealing block to realize the step-by-step movement between the mandrel and the sealing block; The upper mold and the lower mold are provided with first thread concave / convex grooves, and the strong support block is provided with second thread concave / convex grooves corresponding to the first thread concave / convex grooves; During mold closing, the pushing block pushes the sealing block and the mandrel to displace synchronously, so that the sealing block keeps sealing with the inner walls of the lower mold and the upper mold. At this time, the sealing block is stationary, and the pushing block can overcome the acting force of the compression spring to continue pushing the mandrel to displace. Through the taper structure of the mandrel, multiple strong support blocks are all pushed outwards, and the second thread concave / convex groove is matched with the first thread concave / convex groove.

[0008] In some embodiments, the sealing block includes a limiting platform and a convex platform. The limiting platform is used to abut against the ends of the lower mold and / or the upper mold, so that they cannot continue to be pushed by the pushing block. The outer wall of the convex platform is used to keep contact sealing with the inner walls of the lower mold and the upper mold.

[0009] In some embodiments, the inner ends of the strong support blocks are arranged within the convex platform, and the outer ends of the strong support blocks protrude from the convex platform and are sleeved at the taper structure of the mandrel.

[0010] In some embodiments, a return spring is further arranged on the convex platform of the sealing block. The return spring abuts against the strong support blocks to drive them to return.

[0011] In some embodiments, a keyway fit structure is arranged between each of the strong support blocks and the mandrel.

[0012] In some embodiments, multiple strong support blocks form a six-petal structure with annular uniform distribution, which is convenient for uniform expansion.

[0013] In some embodiments, the inner end of the mandrel is connected to the pushing block, and a water delivery channel that penetrates each other is arranged inside the pushing block and the mandrel, so as to realize the water entering the cavity formed by the upper mold and the lower mold from the outside through the water delivery channel.

[0014] In some embodiments, a first thread groove is arranged on the upper mold and the lower mold, and a second thread groove corresponding to the first thread groove is arranged on the strong support block. An annular spring is wound around the second thread groove, which is used to enhance the sealing performance and eliminate the mold closing line during the thread forming process.

[0015] In some embodiments, a plurality of limit posts are annularly arranged on the pushing block, and the compression spring is sleeved on the limit posts. The two ends of the compression spring respectively abut against the pushing block and the sealing block.

[0016] In some embodiments, the strong expansion assemblies are arranged at both ends of the lower mold.

[0017] The beneficial effects of this application are as follows: First, reduce the water pressure requirement: The thread structure is not completely formed by relying on water pressure, but is formed by the mechanical expansion of the strong support block, which greatly reduces the required water pressure and reduces energy consumption and equipment pressure. Second, eliminate the mold joint line: An annular spring is provided on the thread groove of the strong support block. When the thread is strongly expanded, the annular spring is used to match the thread grooves of the upper and lower molds, and the mold joint line of the thread after production can be eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 is the overall assembly cross-sectional view of this application.

[0020] Figure 2 is the internal structure schematic diagram of the strong expansion component of this application.

[0021] Figure 3 is the front schematic diagram of the external structure of the strong expansion component of this application.

[0022] Figure 4 is the elevation schematic diagram of the external structure of the strong expansion component of this application.

[0023] Figure 5 is the overall assembly drawing of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection of this application.

[0025] Refer to Figures 1 to 5 a cup body hydroforming mechanism shown in the figure. This embodiment provides a strong expansion mechanism for metal cup body thread forming, including an upper mold (not shown in the figure) and a lower mold (200) that can be opened and closed in the vertical direction, where: One end of the lower mold (200) is provided with a strong expansion component (300) for simultaneously forming the threaded structure of the cup body during the hydroforming process; The strong expansion component (300) includes a pushing block (310), a sealing block (320), a mandrel (330) and a plurality of strong support blocks (340); The pushing block (310) is connected to a driving mechanism, such as a hydraulic cylinder, a motor, etc., for driving the entire device to move; A compression spring (350) is arranged between the pushing block (310) and the sealing block (320), and is guided and limited by a plurality of limit posts (311); The sealing block (320) is cylindrical, and its front end is provided with a convex platform (321) that fits against the inner wall of the mold for sealing the cavity; the tail end is provided with a limit platform (322) for abutting against the end of the lower mold (200) when the pushing process reaches the limit position to prevent over-pushing; The mandrel (330) passes through the inside of the sealing block (320) and is fixedly connected to the pushing block (310), and its outer end is a conical structure (331); A plurality of strong support blocks (340) are annularly arranged around the taper structure of the mandrel (330). The inner end of each strong support block is arranged inside the convex platform of the sealing block, and the outer end is sleeved on the taper structure; In addition, a keyway fit structure (not shown in the figure) is provided between the strong support block (340) and the mandrel (330) to prevent rotation; A second thread groove (342) is provided on the outer side of the strong support block (340), corresponding to the first thread groove (201) on the upper mold and the lower mold (200); An annular spring (343) is sleeved on the second thread groove (342) for tightly adhering to the first thread groove after being expanded to eliminate the mold joint line; A through water delivery channel (360) is provided inside the pushing block (310) and the mandrel (330) for introducing water into the mold cavity for hydroforming; A return spring (not shown in the figure) is also provided on the sealing block (320) for driving the strong support block (340) to retract during demolding.

[0026] As a supplementary explanation, but when different threads need to be pressed, the thread grooves on the upper mold and the lower mold (200), as well as the strong support block (340), can be respectively set to be one concave and one convex or both concave or both convex.

[0027] The working principle and working process are as follows: Initial state: The mold is in the open mold state, the pushing block (310) is in the retracted position, and the strong support block (340) is in the contracted state and does not extend into the mold cavity; Clamping stage: The upper mold moves downward to clamp with the lower mold (200), and the strong expansion component (300) moves downward to the bottom of the mold cavity accordingly; Sealing stage: The pushing block (310) moves forward, driving the sealing block (320) to move forward synchronously until the limit platform (322) of the sealing block abuts against the end of the lower mold and stops advancing; Expanding stage: The pushing block continues to advance and compresses the compression spring (350), pushing the core shaft (330) to move forward. The tapered structure of the core shaft pushes the strong expansion block (340) to expand outward; Thread matching stage: As the strong expansion block expands, the second thread groove (342) on it aligns and fits with the first thread groove (201) on the mold. At the same time, the annular spring (343) provides an additional elastic pressing force to ensure a tight fit; Hydroforming stage: Water is injected into the mold cavity through the water delivery channel (360), and the pressure is gradually increased, so that the blank fits the cavity surface formed by the mold and the strong expansion block, completing the simultaneous forming of the cup body main body and the thread structure; Pressure relief and return stage: After the water pressure is released, the pushing block (310) moves in the reverse direction, and the compression spring (350) and the return spring (323) push the core shaft and the strong expansion block to return to their original positions, and the strong expansion block retracts to its original position; Demolding stage: The upper mold is lifted, and the finished cup body is ejected, completing a complete processing cycle.

[0028] As another embodiment, referring to Figure 5 As shown, the present application also provides a strong expansion mechanism for double-end forming, that is, a set of strong expansion components (300A, 300B) are respectively arranged at both ends of the lower mold (200). The two sets of strong expansion components have the same structure and are respectively used to form the thread structures at both ends of the cup body. The rest of the structure is the same as that in Embodiment 1, realizing double-end synchronous forming, improving production efficiency, and reducing the error caused by secondary clamping.

[0029] So far, various embodiments of the present application have been described in detail. In order to avoid obscuring the concept of the present application, some details well known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed here based on the above description.

[0030] Finally, it should be noted that the above are only the preferred embodiments of the present application. The foregoing embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A cup body hydraulic forming mechanism, comprising an upper die and a lower die capable of closing or opening each other, characterized in that: At least one end of the lower mold is provided with a strong expansion component; The strong expansion assembly includes a propulsion block, a sealing block, a core shaft and a strong support block; the propulsion block is used to drive the sealing block and the core shaft to move, the core shaft is placed in the sealing block for movement, the outer end of the core shaft is formed with a tapered structure, the strong support block is provided with a plurality of and is annularly arranged at the tapered structure of the core shaft, and a compression spring is provided between the propulsion block and the sealing block; The upper die and the lower die are provided with a first threaded concave / convex groove, and the strong support block is provided with a second threaded concave / convex groove corresponding to the first threaded concave / convex groove; When the mold is closed, the pushing block pushes the sealing block and the core shaft to move synchronously, so that the sealing block maintains a seal with the inner walls of the lower mold and the upper mold. At this time, the sealing block is stationary, and the pushing block can overcome the force of the compression spring and continue to push the core shaft to move. Through the tapered structure of the core shaft, multiple support blocks are pushed outward, and the second threaded concave / convex groove is matched with the first threaded concave / convex groove.

2. A cup body hydraulic forming mechanism according to claim 1, characterized in that: The sealing block includes a limit platform and a boss. The limit platform is used to abut against the end of the lower mold and / or the upper mold to prevent it from being further pushed by the push block. The outer wall of the boss is used to maintain contact sealing with the inner wall of the lower mold and the upper mold.

3. A cup body hydraulic forming mechanism according to claim 2, characterized in that: The inner end of the strong support block is arranged in the boss, and the outer end of the strong support block protrudes from the boss and is sleeved on the tapered structure of the core shaft.

4. A cup body hydraulic forming mechanism according to claim 3, characterized in that: A return spring is also arranged on the boss of the sealing block, and the return spring abuts against the strong support block to drive the strong support block to return.

5. A cup body hydraulic forming mechanism according to claim 1, characterized in that: A keyway matching structure is arranged between each of the strong support blocks and the core shaft.

6. A cup body hydraulic forming mechanism according to claim 1, characterized in that: The plurality of strong support blocks form a six-petal structure evenly distributed in an annular shape.

7. A cup body hydraulic forming mechanism according to claim 1, characterized in that: The inner end of the core shaft is connected to the propulsion block, and the propulsion block and the core shaft are provided with water supply channels that are interconnected, so that water can enter the cavity formed by the upper mold and the lower mold from the outside through the water supply channels.

8. A cup body hydraulic forming mechanism according to claim 1, characterized in that: The upper die and the lower die are provided with a first thread groove, the strong support block is provided with a second thread groove corresponding to the first thread groove, and the second thread groove is surrounded by an annular spring.

9. A cup body hydraulic forming mechanism according to claim 1, characterized in that: A plurality of limiting columns are arranged in an annular manner on the pushing block, the limiting columns are sleeved with the compression spring, and the two ends of the compression spring respectively press against the pushing block and the sealing block.

10. A cup body hydraulic forming mechanism according to claim 1, characterized in that: The strong expansion components are arranged at both ends of the lower mold.

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