A rolling plastic oil tank forming mechanism

Abstract

The utility model discloses a rolling plastic oil tank forming mechanism relates to rolling plastic oil tank technical field, including upper die, lower die and pipe, and the bottom of upper die is detachably sealed with the top of lower die Connection, the stress area of upper die and lower die is provided with pipe and is penetrated, and the both ends of pipe are connected with upper die or lower die respectively, rolling plastic oil tank forms in the inner chamber of upper die and lower die. The design of the through type of the hole structure in the high stress area of the tank body is penetrated, and its mechanical strengthening principle is: the internal tie system is formed to the continuous axial stress transmission path of the hole structure, and the local load is dispersed to the whole structure (analogy truss principle), and the tensile / compression stress peak value of the key area is reduced significantly. The bending stiffness of the wallboard of the buckling instability through structure is improved, and the buckling risk of the thin wall caused by the fluid static pressure is reduced. The material transverse strain of the poisson expansion hole interconnection structure is resisted, and the "bulging effect" of the tank body under the fluid pressure is offset.

Description

Technical Field

[0001] This utility model relates to the field of rotational molding oil tank technology, and in particular to a rotational molding oil tank forming mechanism. Background Technology

[0002] In existing rotomolded oil tanks with a volume greater than 200L, the hydrostatic pressure of the liquid inside the tank increases significantly with depth due to its own gravity, creating a non-uniform load. Simultaneously, the inherent properties of the plastic material (low Young's modulus, Poisson's effect, creep tendency) cause the tank walls to bear combined stresses, easily leading to elastic bulging, bending deflection, and irreversible plastic deformation of the tank walls. Utility Model Content

[0003] The purpose of this invention is to provide a rotational molding oil tank forming mechanism to solve the problems existing in the prior art, distribute local loads to the overall structure, and reduce the risk of buckling of thin walls due to hydrostatic pressure.

[0004] To achieve the above objectives, the present invention provides the following solution: The present invention provides a rotational molding oil tank forming mechanism, including an upper mold, a lower mold, and a pipe fitting. The bottom end of the upper mold and the top end of the lower mold are detachably and sealed together. The pipe fitting is provided through the stress area of ​​the upper mold and the lower mold, and the two ends of the pipe fitting are respectively connected to the upper mold or the lower mold. The rotational molding oil tank is formed in the inner cavity of the upper mold and the lower mold.

[0005] In one embodiment, the upper mold includes an upper mold body and an upper mold side drawer, the upper mold side drawer being detachably mounted on one side of the upper mold body.

[0006] In one embodiment, the upper mold side pull is attached to one side of the upper mold body via a hook and latch.

[0007] In one embodiment, both ends of the pipe are connected to the upper mold or the lower mold via pipe positioning positions.

[0008] In one embodiment, the fitting is made of metal tubing or hard ceramic tubing.

[0009] In one embodiment, the stress areas are the bottom of the rotomolded oil tank, the lower middle part of the side wall, and the structural joints.

[0010] In one embodiment, one or more of the pipe fittings are disposed through the stress areas of the upper and lower molds.

[0011] In one embodiment, the pipe fitting is provided with a through hole corresponding to the stress area of ​​the rotomolded oil tank.

[0012] In one embodiment, the through hole is a tapered channel structure.

[0013] In one embodiment, the lower mold is placed on a mold holder.

[0014] The present invention achieves the following beneficial technical effects compared to the prior art:

[0015] This utility model provides a rotational molding oil tank forming mechanism, including an upper mold, a lower mold, and a pipe fitting. The bottom end of the upper mold and the top end of the lower mold are detachably and sealed together. A pipe fitting is installed through the stress areas of the upper and lower molds, with both ends of the pipe fitting connected to the upper or lower mold respectively. The rotational molding oil tank is formed within the inner cavities of the upper and lower molds. A through-hole structure is designed in the high-stress area of ​​the tank body. Its mechanical strengthening principle is: forming an internal tie system with through-holes creating a continuous axial stress transmission path, distributing local loads to the overall structure (analogous to truss principle), significantly reducing the peak tensile / compressive stress in critical areas. The through-hole structure suppresses buckling instability, improves the bending stiffness of the wall panel, and reduces the buckling risk of thin walls due to hydrostatic pressure. It resists Poisson expansion by constraining the lateral strain of the material through the inter-hole connection structure, offsetting the "bulging effect" of the tank body under fluid pressure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the rotational molding fuel tank forming mechanism.

[0018] Figure 2 This is the front view of the rotomolded oil tank;

[0019] Figure 3 This is a snap-fit ​​forming diagram of the rotational molding fuel tank forming mechanism;

[0020] The components include: 1. Rotational molding oil tank; 2. Upper mold; 3. Lower mold; 4. Pipe positioning slide; 5. Conical pipe fitting; 6. Hook and latch; 7. Upper mold side drawer; 8. Mold frame. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] The purpose of this invention is to provide a rotational molding oil tank forming mechanism to solve the problems existing in the prior art, distribute local loads to the overall structure, and reduce the risk of buckling of thin walls due to hydrostatic pressure.

[0023] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-3 As shown, this utility model provides a rotational molding oil tank forming mechanism, including an upper mold 2, a lower mold 3 and a pipe fitting. The bottom end of the upper mold 2 and the top end of the lower mold 3 are detachably and sealed. The stress area of ​​the upper mold 2 and the lower mold 3 is provided with a pipe fitting, and the two ends of the pipe fitting are respectively connected to the upper mold 2 or the lower mold 3. The rotational molding oil tank 1 is formed in the inner cavity of the upper mold 2 and the lower mold 3.

[0025] In one embodiment, the upper mold 2 includes an upper mold 2 body and an upper mold side drawer 7, which is detachably mounted on one side of the upper mold 2 body.

[0026] In one embodiment, the upper mold side drawer 7 is assembled to one side of the upper mold 2 body via a hook and latch 6.

[0027] In one embodiment, both ends of the pipe are connected to the upper mold 2 or the lower mold 3 via the pipe positioning slide 4.

[0028] In one embodiment, the fitting is made of metal or hard ceramic tubing, and the shape of the fitting may be a tapered fitting 5.

[0029] In one embodiment, the stress areas are the bottom, lower middle part of the side wall, and structural joints of the rotomolded oil tank 1.

[0030] In one embodiment, one or more pipes are provided through the stress areas of the upper mold 2 and the lower mold 3.

[0031] In one embodiment, a through hole is formed in the stress area of ​​the rotomolded oil tank 1 corresponding to the pipe fitting.

[0032] In one embodiment, the through hole is a tapered channel structure.

[0033] In one embodiment, the lower mold 3 is placed on the mold holder 8.

[0034] The rotational molding mechanism for the oil tank 1 of this utility model consists of an upper mold 2 and a lower mold 3. One or more tubular components are installed through the lower mold 3, forming through holes in the product tank body. The tubular components are fixed to the mold via positioning slides 4 on both sides. The upper mold 2 has a side pull-out 7 for easy demolding. After rotational molding, the upper and lower molds 3 are separated, the positioning slides 4 and the tubular components are removed, the side pull-out 7 is separated, and then the rotationally molded oil tank 1 can be removed.

[0035] The rotational molding mechanism of this utility model for the oil tank 1 overcomes the risk of elastic deformation and creep of the 200-liter plastic tank under gravity load (medium + self-weight) by embedding a through-hole structure in the high stress area to form a distributed axial reinforcing rib network.

[0036] A through-hole structure is designed in the high-stress areas of the box-type structure (bottom, lower middle part of the side walls, and structural joints). Its mechanical strengthening principle is as follows: the through-holes form a continuous axial stress transfer path through an internal tie-bar system, distributing local loads to the overall structure (analogous to truss principles), significantly reducing the peak tensile / compressive stress in critical areas. This structure also suppresses buckling instability, improves the bending stiffness of the wall panels, and reduces the risk of buckling due to hydrostatic pressure in thin-walled structures. Furthermore, it resists Poisson expansion by constraining the lateral strain of the material through the inter-hole connection structure, counteracting the "bulging effect" of the box-type structure under fluid pressure.

[0037] Rotational molding relies on mold rotation and heat conduction to melt, adhere, and solidify powder, ultimately forming the desired product. Existing rotational molding molds with volumes greater than 200L cannot achieve through-hole molding processes, resulting in defects such as uneven wall thickness, deformation, unevenness, and perforation.

[0038] The rotational molding oil tank 1 forming mechanism of this utility model directly determines the local heat transfer efficiency by selectively choosing and embedding mold materials with different thermal conductivity to form the overall mold and combining the thermal conductivity of the materials.

[0039] Thick-walled region: strong heat storage capacity, slow melt solidification → forming a solid structure; thin-walled region or region with high thermal conductivity: fast heat dissipation, preferential melt solidification → forming a porous structure.

[0040] The steps for achieving through-hole perforation are as follows: In the mold design, a thin-walled tapered copper tube is embedded in the stress concentration area of ​​the product (bottom, lower middle part of the side wall, and structural joints) to establish a high heat transfer channel, which induces the melt to adhere and solidify quickly to form a hole. After cooling in the furnace, the demolding is performed. During the heating stage, the temperature is precisely controlled: 300℃ in the non-hole area and 280℃ in the perforated area (ΔT=20℃). During the cooling stage, the perforated area is forced to be air-cooled (wind speed ≥15m / s) to achieve gradient solidification (first the periphery of the hole → then the whole) to prevent the hole structure from collapsing due to shrinkage deformation.

[0041] Stress diffusion network: Perforation forms a continuous axially stiffened beam (beam width ≥ 2 times the hole diameter), which converts the hydrostatic pressure of the fluid at the bottom into axial tensile stress.

[0042] The rotational molding mechanism of this invention, through a heat conduction gradient design (embedded thin-walled conical copper tube positioning + local temperature control) and dynamic curing control (directional air cooling), precisely generates a through-hole structure during the rotational molding process. Its rib network allows the tank body to: convert the hydrostatic pressure of the bottom fluid into axial tensile stress and disperse it; and improve the bending stiffness of the sidewalls, eliminating the risk of creep deformation. The scientific essence lies in utilizing the differences in the thermophysical properties of the materials to simultaneously construct the macroscopic structure and microscopic reinforcing phase during the molding stage, overcoming the technical bottleneck of the rotational molding process's inability to form complex internal ribs.

[0043] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A rotational molding mechanism for fuel tanks, characterized in that: It includes an upper mold, a lower mold, and a pipe fitting. The bottom end of the upper mold and the top end of the lower mold are detachably and sealed together. The pipe fitting is provided through the stress area of ​​the upper mold and the lower mold, and the two ends of the pipe fitting are respectively connected to the upper mold or the lower mold. The rotational molding oil tank is formed in the inner cavity of the upper mold and the lower mold.

2. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: The upper mold includes an upper mold body and an upper mold side drawer, the upper mold side drawer being detachably mounted on one side of the upper mold body.

3. The rotational molding oil tank forming mechanism according to claim 2, characterized in that: The upper mold side pull is assembled to one side of the upper mold body via a hook and latch.

4. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: Both ends of the pipe fitting are connected to the upper mold or the lower mold respectively through pipe fitting positioning slides.

5. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: The fittings are made of metal or hard ceramic tubing.

6. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: The stress areas are the bottom, lower middle part of the side wall, and structural joints of the rotomolded oil tank.

7. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: One or more of the aforementioned pipe fittings are provided through the stress areas of the upper and lower molds.

8. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: The pipe fitting is provided with a through hole corresponding to the stress area of ​​the rotomolded oil tank.

9. The rotational molding oil tank forming mechanism according to claim 8, characterized in that: The through hole is a tapered channel structure.

10. The rotational molding oil tank forming mechanism according to claim 1, characterized in that: The lower mold is placed on the mold rack.

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