Method for manufacturing anisotropic compression prestressed winding mold

Abstract

The present application relates to a mold, in particular to a manufacturing method of an anisotropic compression prestressed winding mold. The method is performed according to the following steps: S1, determining the winding pre-tightening force required to offset the mold expansion stress in each direction; S2, manufacturing a core mold lining plate; S3, manufacturing a mold core cylinder; S4, fixing a baffle at both ends of the outer wall of the mold core cylinder; S5, winding a steel wire layer on the outer wall of the mold core cylinder between the two baffles; S6, manufacturing an upper punch, the cross-sectional shape of the upper punch is the same as that of the core mold lining plate cavity; S7, installing the core mold lining plate and the mold core cylinder, inserting the core mold lining plate into the installation hole of the mold core cylinder, and connecting the core mold lining plate and the mold core cylinder through a flange; S8, installing a lower ejection punch in the ejection hole of the core mold lining plate. The present application realizes the arbitrary regulation and control of the steel wire prestress along the closed loop, can accurately control the pre-tightening pressure, and solves the problem of mismatching of the winding mold prestress under the anisotropic condition of the core mold expansion pressure and the local compression strength redundancy waste.

Description

Technical Field

[0001] This invention relates to molds, and more particularly to a method for manufacturing an anisotropic compressive prestressed winding mold. Background Technology

[0002] A prestressed wire winding mold is a structural device that applies a preload of steel wire to the outside of the mold core cylinder to generate centripetal prestress, thereby offsetting most or all of the mold expansion stress and improving the mold's load-bearing capacity. Prestressed winding molds exhibit small load fluctuations, good fatigue strength, and high load-bearing capacity. Under the same internal pressure conditions, winding molds are lighter and less expensive.

[0003] Currently, the structure of winding molds mainly uses a circular mold core as the wound body. Pre-tension is provided by winding steel wire around the outer wall of the core. When the mold cavity shape is symmetrical, it can evenly offset the internal pressure, achieving the designed pressure resistance effect. However, most molded products have varying shapes, and the compressive strength requirements in each direction are proportional to the mold cavity expansion pressure. Because the load-bearing capacity of a circular core winding mold is the same in all directions, it is impossible to distribute the centripetal prestress according to the cavity expansion pressure ratio, thus limiting the application scope of prestressed winding technology in the mold field. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, thereby providing a method for manufacturing an anisotropic compressive prestressed winding mold, which distributes anisotropic prestress by changing the outer wall shape of the mold core cylinder, and adapts to the load-bearing requirements of anisotropic compressive mold.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A method for manufacturing an anisotropic compressive prestressed winding mold, comprising the following steps:

[0007] S1. Determine the required winding preload in each direction of the mold to counteract the expansion stress.

[0008] S2. Making the core mold liner.

[0009] The core mold liner is polygonal and has a cavity with an open top. The bottom plate of the core mold liner has an ejection hole, and the bottom of the core mold liner is fitted with a flange.

[0010] S3. Making the mold core cylinder

[0011] The mold core cylinder bears a force proportional to the pressure projected onto the cavity in the normal direction. The outer wall of the mold core cylinder is machined into an arc shape according to this projection ratio. The outer wall of the mold core cylinder is composed of multiple arc segments and straight segments. Two adjacent arc segments are connected by straight segments. The mold core cylinder has mounting holes with the same shape as the core mold liner.

[0012] S4. Baffles are fixed to both ends of the outer wall of the mold core cylinder;

[0013] S5, The outer wall of the mold core between the two baffles is wrapped with a layer of steel wire;

[0014] S6. Making the upper punch

[0015] The cross-sectional shape of the upper punch is the same as the cross-sectional shape of the core mold liner cavity;

[0016] S7. Installation of core mold liner and mold core cylinder

[0017] The core mold liner is inserted into the mounting hole of the mold core cylinder, and the core mold liner is connected to the mold core cylinder through a flange;

[0018] S8. Install the lower ejector punch in the ejector hole of the core mold liner.

[0019] Compared with the prior art, the present invention, which adopts the above technical solution, has the following beneficial effects:

[0020] It enables arbitrary adjustment of the prestress of the steel wire along a closed loop. Combined with the distribution of the expansion pressure of the mold core and liner plates of the formed product, it can accurately control the pre-tightening pressure, thereby solving the problem of uneven stress distribution and local redundant waste of compressive strength caused by the mismatch of the prestress of the winding mold under the anisotropic condition of the expansion pressure of the core mold. It improves the precision compressive design of the prestressed winding mold, reduces the manufacturing cost, and expands the application fields.

[0021] Furthermore, the optimized solution of the present invention is:

[0022] Each of the arc segments corresponds to one side of the mounting hole, and the diameter of the arc segment on the long side of the mounting hole is larger than the diameter of the arc segment on the short side.

[0023] The shape of the baffle is the same as the shape of the outer wall of the mold core.

[0024] The steel wire layer is made of flat steel.

[0025] The steel wire layer is made of 65Mn.

[0026] The upper end of the upper punch is provided with a rectangular transition flange.

[0027] The steel wire layer is covered with a protective layer. Attached Figure Description

[0028] Figure 1 This is a longitudinal sectional view of an embodiment of the present invention;

[0029] Figure 2 This is a cross-sectional view of an embodiment of the present invention;

[0030] Figure 3 This is an isometric view of the core mold liner plate according to an embodiment of the present invention;

[0031] Figure 4 This is an isometric view of the mold core cylinder according to an embodiment of the present invention;

[0032] Figure 5 This is an isometric view of the upper punch according to an embodiment of the present invention.

[0033] In the figure: core mold liner 1; cavity 1-1; ejector hole 1-2; flange 1-3; mold core cylinder 2; mounting hole 2-1; baffle 2-2; flange mounting groove 2-3; upper punch 3; transition flange 3-1; wire layer 4; protective layer 5; lower ejector punch 6. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0035] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] See Figures 1-5 In this embodiment, the product pressed by the mold is rectangular. This embodiment provides a method for manufacturing an anisotropic compressive prestressed winding mold, which is carried out according to the following steps:

[0037] S1. Determine the winding preload required in each direction of the mold to counteract the expansion stress.

[0038] S2. Making the core mold liner.

[0039] The core mold liner 1 is rectangular and thick-walled, with a rectangular cavity 1-1. The top of the cavity 1-1 is open, and the edges of the inner wall of the cavity 1-1 are smoothly rounded. The bottom plate of the core mold liner 1 has a circular ejection hole 1-2, and the bottom of the core mold liner 1 is fitted with a rectangular flange 1-3. The core mold liner 1 is forged from mold alloy steel.

[0040] S3. Making the mold core cylinder

[0041] The expansion force borne by the mold core cylinder 2 is proportional to the normal projection pressure of the cavity 1-1. The outer wall of the mold core cylinder 2 is machined into an arc shape according to this projection ratio. The outer wall of the mold core cylinder 2 consists of four arc segments and a straight segment. Two adjacent arc segments are tangentially connected by a straight segment. The mold core cylinder 2 has mounting holes 2-1 with the same shape as the core mold liner 1. Each arc segment corresponds to one side of the mounting hole 2-1. The size of the arc segment corresponds to the required compressive bearing capacity. The diameter of the arc segment on the long side of the mounting hole 2-1 is larger than the diameter of the arc segment on the short side. The four arc segments are symmetrically arranged. The mold core cylinder 2 is forged from a high-strength alloy steel thick-walled tube. The outer wall of the mold core cylinder 2 serves as the winding layer. The lower end of the mold core cylinder 2 has a flange mounting groove 2-3, and the outer wall of the mold core cylinder 2 has a wire mounting groove.

[0042] S4. Weld baffles 2-2 to both ends of the outer wall of the mold core cylinder 2. The shape of the baffles 2-2 is the same as the shape of the outer wall of the mold core cylinder 2.

[0043] S5. A steel wire layer 4 is wound around the outer wall of the mold core cylinder 2 between the two baffles 2-2. The steel wire layer 4 is made of high-strength flat steel with a material of 65Mn. The winding device is used to continuously wind and tighten the steel wire installation groove of the mold core cylinder 2 to provide pre-tightening force for the mold core cylinder 2. The steel wire layer 4 is covered with a protective layer 5, which is made of thin steel plate.

[0044] S6. Making the upper punch

[0045] The upper punch 3 is forged from mold alloy steel, and its shape and size are set according to the product being formed. The cross-sectional shape of the upper punch 3 is the same as the cross-sectional shape of the cavity 1-1 of the core mold liner 1, and the edges of the upper punch 3 are smoothly rounded. A rectangular transition flange 3-1 is provided at the upper end of the upper punch 3, and the transition flange 3-1 diffuses the concentrated stress generated by extrusion.

[0046] S7. Installation of core mold liner and mold core cylinder

[0047] The core mold liner 1 is inserted into the mounting hole 2-1 of the mold core cylinder 2, with a clearance fit between the core mold liner 1 and the mounting hole 2-1.

[0048] The core mold liner 1 is connected to the mold core cylinder 2 via flange 1-3, which is fitted into the flange mounting groove 2-3.

[0049] S8. The lower ejector punch 6 is installed in the ejector hole 1-2 of the core mold liner 1. The lower ejector punch 6 is cylindrical and made of high-strength alloy steel. The bottom of the lower ejector punch 6 is equipped with a mounting flange. The lower ejector punch 6 is connected to the lower ejector cylinder to provide the lifting force required for the blank to be ejected from the mold.

[0050] This embodiment provides a method for manufacturing a prestressed winding mold with a rectangular cavity and varying compressive strength in orthogonal directions. This embodiment utilizes prestressed steel wire wound around a mold core to provide preload force to counteract expansion stress. The mold core, with its wound steel wire, serves as an anti-expansion pressure structure, and is equipped with arc-shaped pressure-bearing sections corresponding to different expansion pressures in orthogonal directions. These arc sections are connected by tangential straight segments. Since the steel wire layer only provides centripetal preload pressure on the arc sections of the wound mold core, and experiences parallel tension on the straight segments, no preload pressure is generated on the straight segments of the mold core. Therefore, the distribution and magnitude of the preload force at any position in the closed loop can be controlled by adjusting the curvature and length of the arc sections, thereby allowing the prestress provided by the winding mold to correspondingly cancel out the expansion pressure.

[0051] This invention enables precise control of the compressive strength of prestressed winding molds. The core mold liner 1 can be manufactured and replaced individually according to usage requirements. When compressive strength requirements in the orthogonal directions are similar, the shape and size of the mold cavity of the core mold liner 1 can be changed. By replacing the core mold liner 1, multiple product specifications can be pressed, modularizing and standardizing the manufacturing of prestressed winding molds. The prestressed winding mold provided by this invention has more precise compressive strength in all directions than ordinary winding molds, and is lighter in size and weight, reducing the material waste caused by redundant compressive strength in all directions in ordinary winding molds. The core mold liner 1 is easy to install and remove, increasing the application range and efficiency of the mold core cylinder 2, and reducing its replacement and maintenance costs. The precise design and controllable manufacturing of the winding mold in this invention fully utilizes mold materials, avoiding increased costs and resource waste caused by excessive local compressive strength. It is a mold design and manufacturing process that simplifies installation, facilitates assembly, and allows for modular maintenance, making it suitable for widespread application.

[0052] Compared with existing prestressed winding dies, this invention allows for arbitrary adjustment of the prestress of the steel wire along a closed loop. By combining the distribution of the expansion pressure of the core mold liner with the formed product, it can precisely control the pre-tightening pressure, thereby solving the problem of uneven stress distribution and localized waste of compressive strength caused by the mismatch of prestress in the winding die under anisotropic conditions of core mold expansion pressure. This invention improves the precision compressive strength design of prestressed winding dies, reduces manufacturing costs, and expands application areas. This invention can also be used for dies with irregular polygonal shapes.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for manufacturing an anisotropic compressive prestressed winding mold, comprising the following steps: S1. Determine the required winding preload in each direction of the mold to counteract the expansion stress. S2. Making the core mold liner. The core mold liner is polygonal and has a cavity with an open top. The bottom plate of the core mold liner has an ejection hole, and the bottom of the core mold liner is fitted with a flange. S3. Making the mold core cylinder The mold core cylinder bears a force proportional to the pressure projected onto the cavity in the normal direction. The outer wall of the mold core cylinder is machined into an arc shape according to this projection ratio. The outer wall of the mold core cylinder is composed of multiple arc segments and straight segments. Two adjacent arc segments are connected by straight segments. The mold core cylinder has mounting holes with the same shape as the core mold liner. S4. Baffles are fixed to both ends of the outer wall of the mold core cylinder; S5, The outer wall of the mold core between the two baffles is wrapped with a layer of steel wire; S6. Making the upper punch The cross-sectional shape of the upper punch is the same as the cross-sectional shape of the core mold liner cavity; S7. Installation of core mold liner and mold core cylinder The core mold liner is inserted into the mounting hole of the mold core cylinder, and the core mold liner is connected to the mold core cylinder through a flange; S8. Install the lower ejector punch in the ejector hole of the core mold liner.

2. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: Each of the arc segments corresponds to one side of the mounting hole, and the diameter of the arc segment on the long side of the mounting hole is larger than the diameter of the arc segment on the short side.

3. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: The shape of the baffle is the same as the shape of the outer wall of the mold core.

4. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: The steel wire layer is made of flat steel.

5. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: The steel wire layer is made of 65Mn.

6. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: The upper end of the upper punch is provided with a rectangular transition flange.

7. The method for manufacturing anisotropic compressive prestressed winding mold according to claim 1, characterized in that: The steel wire layer is covered with a protective layer.

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