Screw propelling mechanism

Abstract

The utility model provides a screw propelling mechanism, and relates to the technical field of rotational molding. The screw propelling mechanism provided by the utility model can be applied to a rotational molding mold, and comprises a screw sleeve, a limiting sleeve and a propelling screw, wherein the screw sleeve is inserted into a through hole of the rotational molding mold; the limiting sleeve is coaxially and fixedly connected with the screw sleeve; and after penetrating through the limiting sleeve, the propelling screw rod can rotate and move along the internal thread of the thread sleeve. During use, the propelling screw rod is screwed out firstly, and then after the end part of a rotational molding product is plasticized and molded but is not cured, the propelling screw rod is screwed in and fully extruded, so that the plastic molded in the screw sleeve is extruded into the mold main body, the plastic at the corresponding position is in a solid state, and poor molding and influence on the appearance are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of rotational molding, in particular to a screw propulsion mechanism. Background Art

[0002] Roto-molding is a manufacturing technology that first adds plastic raw materials into a mold, then rotates the mold continuously along two vertical axes and heats it. Under the action of gravity and heat energy, the plastic raw materials in the mold are gradually and evenly coated, melted and adhered to the entire surface of the mold cavity, forming into the desired shape, and then cooled and shaped into a finished product.

[0003] In the related art, during the rotational molding process under normal conditions, the ends of the molded products have narrow spaces, which leads to plastic flow obstruction and shrinkage pores, which are prone to poor molding, unsightly appearance, or even damage. In view of this, it is necessary to take countermeasures. Utility Model Content

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies of the prior art, the utility model provides a screw propulsion mechanism, which solves the technical problem of shrinkage pores caused by plastic flow obstruction during rotational molding production.

[0006] (II) Technical solution

[0007] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0008] A screw advancing mechanism, applied to a rotational molding mold, comprises a screw sleeve, a limiting sleeve and an advancing screw;

[0009] The screw sleeve is used to be inserted into the through hole of the rotational molding mold;

[0010] The limiting sleeve is coaxially and fixedly connected to the threaded sleeve;

[0011] After the advancing screw rod passes through the limiting sleeve, it can rotate and move along the internal thread of the screw sleeve.

[0012] Preferably, the screw sleeve is in the form of a stepped shaft as a whole, and the cross-sectional diameter of the end portion inserted into the through hole is smaller than the cross-sectional diameter of the end portion away from the through hole.

[0013] Preferably, the limiting sleeve consists of two semicircular rings.

[0014] Preferably, the advancement screw is provided with an external threaded sleeve corresponding to the internal thread of the screw sleeve, and the cross-sectional diameter of the external threaded sleeve is larger than the cross-sectional diameter of the advancement screw.

[0015] Preferably, the advancement screw is provided with a hexagonal end.

[0016] Preferably, the threaded sleeve, the limiting sleeve and the advancing screw are all made of steel.

[0017] (III) Beneficial effects

[0018] The utility model provides a screw propulsion mechanism. Compared with the prior art, it has the following beneficial effects:

[0019] The screw pushing mechanism provided by the utility model can be applied to a roto-molding mold, and includes a screw sleeve, a limiting sleeve, and a pushing screw. The screw sleeve is inserted into the through hole of the roto-molding mold; the limiting sleeve is coaxially fixedly connected with the screw sleeve; after the pushing screw passes through the limiting sleeve, it can rotate and move along the internal thread of the screw sleeve. When in use, the pushing screw is first screwed out, and then the pushing screw is screwed in after the end of the roto-molded product is plasticized but before solidification, and the plastic formed in the screw sleeve is squeezed into the interior of the mold body after sufficient extrusion, so that the plastic at the corresponding position is in a solid state, avoiding poor molding and affecting the appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 An exploded diagram of a screw propulsion mechanism provided in an embodiment of the utility model;

[0022] Figure 2 A cross-sectional view of a screw propulsion mechanism provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] The embodiment of the present application solves the technical problem of plastic flow obstruction and shrinkage pores during rotational molding production by providing a screw propulsion mechanism, overcomes the defect of poor molding of this type of parts, and greatly improves the qualified rate of finished products.

[0025] The technical solution in the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0026] The embodiments of the utility model can be applied to but not limited to narrow product space areas such as circular bosses. As analyzed in the background technology, due to the structural characteristics of this area, the plastic flow is blocked to produce shrinkage pores, which are prone to poor molding, unsightly appearance design, or even damage. Especially when drilling is required later, it is easy to cause damage, deflection, large dimensional deviation, etc., and the drilling quality cannot be guaranteed.

[0027] The screw propulsion mechanism is used to extrude plastic to form a solid structure, thereby avoiding poor molding and affecting the appearance, and greatly improving the quality of subsequent drilling.

[0028] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0029] Example:

[0030] like Figure 1 As shown, an embodiment of the utility model provides a screw propulsion mechanism, which is applied to a rotational molding mold and includes a screw sleeve 1, a limiting sleeve 2 and a propulsion screw 3.

[0031] The screw sleeve 1 is used for being inserted into the through hole 100 of the rotational molding mold.

[0032] The limiting sleeve 2 is coaxially and fixedly connected to the threaded sleeve 1 .

[0033] After passing through the limiting sleeve 2 , the advancing screw rod 3 can rotate and move along the internal thread of the screw sleeve 1 .

[0034] In an optional embodiment, if Figures 1-2 As shown, the screw sleeve 1 is a stepped shaft as a whole, and the cross-sectional diameter of the end inserted into the through hole 100 is smaller than the cross-sectional diameter of the end away from the through hole 100 , so that the screw sleeve 1 can be inserted into the through hole 100 easily.

[0035] In an optional embodiment, if Figure 1 As shown, the limiting sleeve 2 is composed of two semicircular rings to play a limiting role.

[0036] In an optional embodiment, if Figures 1-2 As shown, the advancing screw 3 is provided with an external thread set 31 corresponding to the internal thread of the screw sleeve 1, and the cross-sectional diameter of the external thread set 31 is larger than the cross-sectional diameter of the advancing screw 3. Thus, the advancing screw 3 can be rotated and moved along the internal thread of the screw sleeve 1 through the external thread set 31 without affecting the extrusion process.

[0037] In an optional embodiment, if Figure 1 As shown, the push screw 3 is provided with a hexagonal end, which is convenient for operating the push screw 3 using tools such as a wrench.

[0038] In an optional embodiment, the screw sleeve 1, the limiting sleeve 2 and the advancing screw 3 are all made of steel, and the rotational molding mold can be made of aluminum.

[0039] In order to help understand the working principle of the embodiment of the utility model, the following description is given:

[0040] Before use, the screw propulsion mechanism needs to be assembled. First, the external threaded sleeve 31 of the propulsion screw 3 is screwed into the screw sleeve 1, and then the limiting sleeve 2 composed of two semicircular rings is sleeved on the side of the propulsion screw 3 close to the hexagonal end, and fixedly connected to the screw sleeve 1 by welding or the like. Finally, the screw sleeve 1 is used to be inserted into the through hole 100 of the rotational molding mold.

[0041] When in use, first unscrew the advancing screw 3, see Figure 2 , leaving a pushing distance D1; then after the end of the rotationally molded product is plasticized but before solidification, the pushing screw 3 is screwed in and advanced by an extrusion distance D2. After sufficient extrusion, the plastic formed in the screw sleeve 1 is squeezed into the interior of the mold body, so that the plastic at the corresponding position is solid, avoiding poor molding and affecting the appearance.

[0042] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0043] The screw pushing mechanism provided by the utility model can be applied to a roto-molding mold, and includes a screw sleeve, a limiting sleeve, and a pushing screw. The screw sleeve is inserted into the through hole of the roto-molding mold; the limiting sleeve is coaxially fixedly connected with the screw sleeve; after the pushing screw passes through the limiting sleeve, it can rotate and move along the internal thread of the screw sleeve. When in use, the pushing screw is first screwed out, and then the pushing screw is screwed in after the end of the roto-molded product is plasticized but before solidification, and the plastic formed in the screw sleeve is squeezed into the interior of the mold body after sufficient extrusion, so that the plastic at the corresponding position is in a solid state, avoiding poor molding and affecting the appearance.

[0044] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A screw propulsion mechanism, characterized in that: Applicable to a rotational molding mold, comprising a screw sleeve (1), a limiting sleeve (2) and a pushing screw (3); The screw sleeve (1) is used to be inserted into the through hole (100) of the rotational molding mold; The limiting sleeve (2) is coaxially fixedly connected to the screw sleeve (1); After the advancing screw rod (3) passes through the limiting sleeve (2), it can rotate and move along the internal thread of the screw sleeve (1).

2. The screw propulsion mechanism according to claim 1, characterized in that: The screw sleeve (1) is in the form of a stepped shaft as a whole, and the cross-sectional diameter of the end portion inserted into the through hole (100) is smaller than the cross-sectional diameter of the end portion away from the through hole (100).

3. The screw propulsion mechanism according to claim 1, characterized in that: The limiting sleeve (2) is composed of two semicircular rings.

4. The screw propulsion mechanism according to claim 1, characterized in that: The advancing screw rod (3) is provided with an external threaded sleeve (31) corresponding to the internal thread of the screw sleeve (1), and the cross-sectional diameter of the external threaded sleeve (31) is larger than the cross-sectional diameter of the advancing screw rod (3).

5. The screw propulsion mechanism according to claim 1, characterized in that: The advancing screw (3) is provided with a hexagonal end.

6. The screw propulsion mechanism according to any one of claims 1 to 5, characterized in that: The screw sleeve (1), the limiting sleeve (2) and the advancing screw rod (3) are all made of steel.

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