High-pressure expansion process for a water cup shell

Abstract

In order to solve the problems in the prior art, the high-pressure expansion process of the water cup shell is provided, first, the pipe material is rebounded by the first sealing pre-expansion back-off water pressure head pressure relief through steps S1-S5; then, the second sealing and five times of pressure expansion are carried out through the continuous sub-steps S6-S10, and the pressure value of each pressure is gradually increased, so that the elongation of the pipe material can be increased, finally, the pressure is released and the mold is opened in step S11, the thread shape of the expanded water cup shell is full, the bending angle is clear and not broken, and the problem of expansion and breakage of the thin-wall pipe material of the water cup shell can be solved.

Description

Technical Field

[0001] This invention relates to the manufacturing process of water cup shells, and more particularly to a high-pressure expansion molding process for water cup shells. Background Technology

[0002] Currently, the existing water cup shell processing process generally involves water expansion molding first, followed by metal processing or shaping to create threads, sealing necks, and other structures. This requires a large number of steps, resulting in high labor and processing costs. Moreover, the more processing steps there are, the lower the first-pass yield.

[0003] High-pressure expansion molding can form the shape and threads of the water cup shell in one go, avoiding the problems of the traditional process mentioned above; however, the wall thickness of the tube used to process the water cup shell is generally 0.5mm, and the tube is prone to bursting at the step during high-pressure expansion molding. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a high-pressure expansion molding process for water cup shells, ensuring that the water cup shell will not burst during the high-pressure expansion molding process.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution.

[0006] A high-pressure expansion molding process for a water cup shell, characterized by the following steps: Step A: First sealing pre-forming A1: Take the pipe material of the predetermined specifications and place it in the cavity of the high-pressure expansion mold; A2: The upper and lower molds of the high-pressure expansion mold are closed; A3: The sealing heads on both sides of the high-pressure expansion mold move simultaneously toward the pipe material until both ends of the pipe material are completely sealed. A4: Air is injected into the pipe material through the sealing water pressure heads on both sides to make the air pressure reach the first pressure value P1, and the pressure is maintained for a predetermined time T to complete the preforming. A5: Stop inflation and retract the water sealing heads on both sides, causing the pre-formed pipe to spring back and release some of the deformation; Step B: Second sealing and continuous pressure expansion B1: Start the sealing water pressure heads on both sides to move towards the pipe material at the same time until both ends of the pipe material are completely sealed; and inflate the pipe material with air through the sealing water pressure heads on both sides until the air pressure reaches the second pressure value P2, and the pressure holding time is T. B2: Continue to pressurize the pipe until the air pressure reaches the third pressure value P3, and then maintain the pressure for a predetermined time of T. B3: Continue to pressurize the pipe until the air pressure reaches the fourth pressure value P4, and then maintain the pressure for a predetermined time of T. B4: Continue to pressurize the pipe until the air pressure reaches the fifth pressure value P5, and then maintain the pressure for a predetermined time of T. B5: Continue to pressurize the tube until the air pressure reaches the third pressure value P6. Hold the pressure for a predetermined time T, and the expansion of the water cup shell is complete. Step C: Depressurize and remove material C1: The sealing heads on both the left and right sides retract, and the mold is opened to remove the water cup shell.

[0007] Preferably, the pressure holding time T is 2 to 3 seconds.

[0008] Preferably, the pressure holding time T is 3 seconds.

[0009] Preferably, the second pressure value P2 is 1.3 times that of P1.

[0010] As a preferred option, the third pressure value P3 is 1.6 times that of P2.

[0011] As a preferred option, the fourth pressure value P4 is 1.4 times that of P3.

[0012] As a preferred option, the fifth pressure value P5 is 1.2 times that of P4.

[0013] As a preferred option, the sixth pressure value P6 is 1.3 times that of P5.

[0014] As a preferred option, during the expansion process, the sealing pressure heads on both the left and right sides feed the pipe material in real time to apply force and seal both ends of the pipe material.

[0015] Preferably, the head of the sealing pressure head is conical.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By adopting the above technical solution, the pipe material is first depressurized by retracting the sealing water pressure head after the first sealing pre-forming expansion in steps S1-S5, so that the pipe material rebounds; then, after the second sealing and five pressurization expansions in consecutive steps S6-S10, the pressure value of each pressurization is gradually increased, which can increase the elongation rate of the pipe material; finally, in step S11, the pressure is released and the mold is opened. The expanded water cup shell has a full thread shape, clear bends and no cracks, which can solve the problem of the thin-walled pipe material of the water cup shell bursting.

[0017] Further beneficial effects include: setting the pressure holding time to 2-3 seconds, especially 3 seconds, ensures complete shaping under each pressurization state; and setting the second pressure value P2 to 1.3 times P1, the third pressure value P3 to 1.6 times P2, the fourth pressure value P4 to 1.4 times P3, the fifth pressure value P5 to 1.2 times P4, and the sixth pressure value P6 to 1.3 times P5, ensures that the pressure under each pressurization state is sufficient to cause the pipe to expand outward while preventing it from bursting.

[0018] A further beneficial effect is that, because the axial length of the pipe is shortened to compensate for the radial length during the expansion process, the sealing heads on both sides have a real-time force to squeeze and feed the pipe, which can ensure that the sealing heads seal both ends of the pipe in real time; moreover, the head of the sealing head is conical, which can make the sealing effect better. Attached Figure Description

[0019] Figure 1 This is a three-dimensional exploded structural diagram of the cup lid of the present invention.

[0020] Figure 2 This is a cross-sectional view of the structure of the present invention before inflation and pressurization after mold closing.

[0021] Figure 3 This is a cross-sectional view of the structure after the high-pressure expansion molding of the present invention is completed.

[0022] Figure 4 This is a schematic diagram showing the trend of tube elongation during high-pressure expansion according to the present invention. Detailed Implementation

[0023] To make the technical solution of the present invention clearer, the following description is provided in conjunction with the appendix. Figures 1 to 4 This invention will be described in detail below. It should be understood that the specific embodiments described in this specification are merely for explaining the invention and are not intended to limit the scope of protection of the invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] This invention relates to a high-pressure expansion molding process for water cup shells, comprising the following steps: S1: Take the pipe material 1 of the predetermined specifications and place it in the cavity of the high-pressure expansion mold 2; S2: The upper and lower molds of the high-pressure expansion mold 2 are closed; S3: The sealing heads 3 on both sides of the high-pressure expansion mold 2 move towards the pipe material 1 at the same time until both ends of the pipe material 1 are completely sealed. S4: Air is injected into the pipe material 1 through the sealing water pressure heads 3 on both sides, so that the air pressure reaches the first pressure value P1, and the pressure is maintained for a predetermined time T, thereby completing the preforming. S5: Stop inflation and retract the water sealing heads 3 on both sides, causing the pre-formed pipe material 1 to spring back and release some of the deformation; S6: Start the sealing water pressure heads 3 on both sides to move towards the pipe material 1 simultaneously until both ends of the pipe material 1 are completely sealed; and inflate the pipe material 1 with air through the sealing water pressure heads 3 on both sides to make the air pressure reach the second pressure value P2, and the pressure holding time is T. S7: Continue to pressurize the pipe 1 until the air pressure reaches the third pressure value P3, and then maintain the pressure for a predetermined time of T. S8: Continue to pressurize the pipe 1 until the air pressure reaches the fourth pressure value P4, and then maintain the pressure for a predetermined time of T. S9: Continue to pressurize the pipe 1 until the air pressure reaches the fifth pressure value P5, and then maintain the pressure for a predetermined time of T. S10: Continue to pressurize the tube 1 until the air pressure reaches the third pressure value P6. Hold the pressure for a predetermined time T, and the expansion of the water cup shell is completed. S11: The sealing heads 3 on both the left and right sides retract, and the mold is opened to remove the water cup shell.

[0026] Specifically, in the above steps, the predetermined time T is 2 to 3 seconds, preferably 3 seconds.

[0027] Specifically, in the above steps, the second pressure value P2 is 1.3 times P1, the third pressure value P3 is 1.6 times P2, the fourth pressure value P4 is 1.4 times P3, the fifth pressure value P5 is 1.2 times P4, and the sixth pressure value P6 is 1.3 times P5.

[0028] Through the above-described expansion process, the pipe material 1 first undergoes a first sealing and pre-forming expansion in steps S1-S5, followed by depressurization by retracting the sealing water pressure head 3, causing the pipe material 1 to spring back. Then, through continuous steps S6-S10, a second sealing and five pressurization expansion processes are performed, with the pressure value gradually increasing each time. This increases the elongation rate of the pipe material 1. A schematic diagram showing the elongation rate trend of the pipe material 1 corresponding to each pressurization is shown below. Figure 4 As shown, steps S4 to S11 correspond to F1 to F10 respectively. In the final step S11, the pressure is released and the mold is opened. The expanded water cup shell has a full thread shape, clear bends and no cracks, which can solve the problem of expansion and breakage of thin-walled tubular materials for water cup shells.

[0029] The following description uses pipe material 1, with a diameter of 55mm, a wall thickness of 0.5mm, and a length of 410mm, as the raw material, and includes the following steps: Step A: First sealing pre-forming: A1: Take a tube 1 with a diameter of 55mm, a wall thickness of 0.5mm, and a length of 410mm, and place it in the cavity of the corresponding high-pressure expansion mold 2; A2: The upper and lower molds of the high-pressure expansion mold 2 are closed; A3: The sealing heads 3 on both sides of the high-pressure expansion mold 2 move towards the pipe material 1 at the same time until both ends of the pipe material 1 are completely sealed. A4: Air is injected into the pipe material 1 through the sealing water pressure head 3 on both sides. After the air pressure of the first pressure value P1 reaches 30MPa, the pressure is maintained for 3s to complete the pre-forming. At this time, the axial length part compensates for the radial direction, and the length is shortened to 406mm. A5: Stop inflation and retract the water sealing heads 3 on both sides, causing the pre-formed pipe material 1 to spring back and release some of the deformation; Step B: Second sealing and continuous pressure expansion: B1: Start the sealing water pressure heads 3 on both sides to move towards the pipe material 1 simultaneously until both ends of the pipe material 1 are completely sealed; and pressurize the pipe material 1 with air through the sealing water pressure heads 3 on both sides until the air pressure of the second pressure value P2 reaches 40MPa, and then maintain the pressure for 3s. B2: Continue to pressurize the pipe material 1 until the air pressure of the third pressure value P3 reaches 65MPa, and then maintain the pressure for 3 seconds; B3: Continue to pressurize the pipe 1 until the air pressure of the fourth pressure value P4 reaches 90MPa, and then maintain the pressure for 3 seconds; B4: Continue to pressurize the pipe material 1 until the air pressure of the fifth pressure value P5 reaches 110MPa, and then maintain the pressure for 3 seconds; B5: Continue to pressurize the tube 1 until the air pressure of the third pressure value P6 reaches 145MPa, then hold the pressure for 3 seconds; the expansion of the water cup shell is completed, and the final length of the formed water cup shell is 401mm; Step C: Depressurize and remove material C1: The sealing heads 3 on both sides retract, release pressure, open the mold, and remove the water cup shell.

[0030] Since the high-pressure expansion mold 2 is usually set up with one output and two outputs, that is, one tube material 1 is expanded into two cup shells, there is also a cup separation step; Step D: Divide the cups D1: The expanded water cup shell is cut in half using a cutting device to divide it into two water cup shells.

[0031] Regarding the above steps, it should be noted that during the expansion process, the axial length of the pipe 1 will be shortened to compensate for the radial length. Therefore, the sealing heads 3 on both sides have a real-time squeezing force on the pipe 1 to ensure that the two ends of the pipe 1 are sealed in real time. Moreover, in order to make the sealing effect better, the head of the sealing head 3 is conical.

Claims

1. A high-pressure expansion molding process for a water cup shell, characterized in that: Includes the following steps: Step A: First sealing pre-forming A1: Take the pipe material (1) of the predetermined specifications and place it in the cavity of the high-pressure expansion mold (2); A2: The upper and lower molds of the high-pressure expansion mold (2) are closed; A3: The sealing heads (3) on both sides of the high-pressure expansion mold (2) move towards the pipe (1) at the same time until both ends of the pipe (1) are completely sealed. A4: Air is injected into the pipe material (1) through the sealing water pressure heads (3) on both sides, so that the air pressure reaches the first pressure value P1, and the pressure is maintained for a predetermined time T, thereby completing the preforming; A5: Stop inflation and retract the water sealing heads (3) on both sides, so that the preformed pipe material (1) rebounds and releases some of the deformation; Step B: Second sealing and continuous pressure expansion B1: Start the sealing water pressure heads (3) on both sides and move them towards the pipe (1) until both ends of the pipe (1) are completely sealed; and pressurize the pipe (1) with air through the sealing water pressure heads (3) on both sides to make the air pressure reach the second pressure value P2, and the pressure holding time is T. B2: Continue to pressurize the pipe (1) until the air pressure reaches the third pressure value P3, and then maintain the pressure for a predetermined time of T. B3: Continue to pressurize the pipe (1) until the air pressure reaches the fourth pressure value P4, and then maintain the pressure for a predetermined time of T. B4: Continue to pressurize the pipe (1) until the air pressure reaches the fifth pressure value P5, and then maintain the pressure for a predetermined time of T. B5: Continue to pressurize the tube (1) until the air pressure reaches the third pressure value P6. Hold the pressure for a predetermined time T, and the expansion of the water cup shell is completed. Step C: Depressurize and remove material C1: The sealing heads (3) on both sides retract, and the mold is opened to remove the water cup shell; The pressure holding time T is 2-3 seconds; The second pressure value P2 is 1.3 times that of P1; the third pressure value P3 is 1.6 times that of P2; the fourth pressure value P4 is 1.4 times that of P3; the fifth pressure value P5 is 1.2 times that of P4; and the sixth pressure value P6 is 1.3 times that of P5.

2. The high-pressure expansion molding process for a water cup shell according to claim 1, characterized in that: The pressure holding time T is 3 seconds.

3. The high-pressure expansion molding process for a water cup shell according to claim 1, characterized in that: During the expansion process, the sealing pressure heads (3) on both the left and right sides feed force onto the pipe material (1) in real time to seal the two ends of the pipe material (1).

4. The high-pressure expansion molding process for a water cup shell according to claim 1, characterized in that: The head of the sealing head (3) is conical.

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