A plastic insert pin for positioning a steel sheet in a mold

Abstract

The utility model relates to the technical field of plastic mould, concretely relates to a kind of insert needle of plastic mould inner positioning steel sheet, including columnar main body, the columnar main body includes positioning part, positioning part is used to cooperate with the positioning hole on steel sheet, the positioning part includes guide section and positioning section, the positioning section is configured to have a certain height, the height is adapted to the thickness of the steel sheet, to realize the axial positioning of steel sheet and minimize the axial contact area between both, the cross section shape of the positioning part is not complete circular, to form a continuous gap space on its circumferential surface, the gap space is configured to be used to reduce the circumferential contact area with steel sheet, and provide escape channel for injection molding flash.The utility model, by the synergic design of "axial minimization" and "radial escape", systematically solves the technical problems that the ejection resistance is too large, leading to steel sheet jam and product strain.

Description

Technical Field

[0001] This utility model relates to the field of plastic mold technology, and in particular to an insert pin for a positioning steel sheet inside a plastic mold. Background Technology

[0002] Embedding steel sheets (or other metal inserts) in plastic products is a common process. In existing technology, the positioning section on the insert typically has a high positioning height, resulting in a large friction area between the steel sheet and the insert, making it prone to damage and jamming during ejection. Currently, most commonly used positioning inserts are complete cylindrical structures with relatively high positioning sections. This traditional design has the following significant drawbacks:

[0003] 1. Prone to jamming and tearing: The high positioning section results in an excessively large contact area between the insert pin and the inner hole of the steel sheet. During product ejection, this generates significant frictional resistance, which can easily cause the steel sheet to be torn or even jammed onto the insert pin, leading to production interruption and product scrap.

[0004] 2. Sensitive to overflow: During injection molding, even a small amount of molten plastic (overflow) can easily seep into the gap between the steel sheet and the insert. In a complete circular insert, the cooled overflow will form a 360° encircling plastic pin, generating huge shearing forces, which is the main cause of jamming. Utility Model Content

[0005] In view of this, the purpose of this utility model is to propose an insert for positioning steel plates in plastic molds, so as to solve the problem that the positioning section of the existing inserts is mostly a complete cylindrical structure and the positioning section used for positioning is relatively high, resulting in an excessively large frictional contact area between the insert and the steel plate. This can easily damage the plastic product or jam the steel plate in the mold when the product is ejected, causing production interruption and yield loss.

[0006] Based on the above objectives, this utility model provides an insert for positioning steel plates in a plastic mold, which is installed on the rear mold core to position the steel plate in the mold cavity. It includes a columnar body, and the columnar body includes a positioning part for cooperating with a positioning hole on the steel plate. The positioning part includes a guide section and a positioning section.

[0007] Axial minimization design: The positioning section is configured with a height adapted to the thickness of the steel sheet. This design aims to achieve axial positioning of the steel sheet while minimizing its axial contact area with the steel sheet, thereby fundamentally reducing axial frictional resistance.

[0008] Radial escape design: The cross-sectional shape of the positioning part is not a complete circle, thus naturally forming a continuous gap space on its circumferential surface. This gap space is cleverly configured to serve a dual purpose: firstly, to reduce the circumferential contact area with the inner hole of the steel sheet; secondly, and more importantly, to provide a dedicated escape and release channel for plastic overflow that may occur during injection molding, effectively avoiding radial mechanical jamming caused by the cooling and solidification of overflow.

[0009] Preferably, the height of the positioning segment is equal to the thickness of the steel sheet.

[0010] Preferably, the cross-sectional shape of the positioning segment is not a complete circle, and its circumferential contour includes a straight line segment and an arc segment, and a guide angle is provided at the corner of the straight line segment and the arc segment.

[0011] Preferably, the central angle corresponding to the arc length of the arc segment is greater than 240° and less than 300°.

[0012] Preferably, the central angle corresponding to the arc length of the arc segment is 270°.

[0013] Preferably, the columnar body further includes a fixing part for fixing to the rear mold core.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. By shortening the height of the positioning section (the height of the positioning section is equal to the thickness of the steel sheet), the axial positioning function of the steel sheet is achieved while minimizing the axial contact area between the steel sheet and the steel sheet, thereby fundamentally reducing axial frictional resistance and significantly reducing the axial clamping force caused by machining tolerances and thermal expansion accumulation.

[0016] Second, the non-circular cross-section of the positioning section naturally creates a continuous gap space on its circumferential surface, breaking the traditional full-circumferential constraint. This gap space reduces the circumferential contact area with the inner hole of the steel sheet and provides a dedicated escape and release channel for plastic overflow that may occur during injection molding, avoiding radial mechanical jamming caused by solidified overflow.

[0017] III. In summary, through the synergistic design of "axial minimization" and "radial escape", the technical problems of excessive ejection resistance, which lead to steel plate jamming and product damage have been systematically solved. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the columnar main body of this utility model after positioning the steel sheet in the mold;

[0020] Figure 2 This is a schematic diagram of the columnar main body and steel sheet of this utility model;

[0021] Figure 3 This is a schematic diagram of the columnar main body of this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the guide section and the positioning section of this utility model;

[0023] Figure 5 This is a structural schematic diagram of the cross-section of the positioning section of this utility model.

[0024] In the diagram: 1. Steel sheet; 2. Columnar main body; 21. Fixing part; 22. Positioning part; 221. Guide section; 222. Positioning section; 223. Straight section; 224. Curved section. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown, an insert for positioning a steel sheet in a plastic mold is installed on the rear mold core to position the steel sheet 1 in the mold cavity. It includes a columnar body 2, which includes a positioning part 22 for engaging with a positioning hole on the steel sheet 1. The columnar body 2 also includes a fixing part 21, which can be a fixing post for fixing to the rear mold core. The positioning part 22 includes a guide section 221 and a positioning section 222. The guide section 221 can be a guide frustum with a guide angle at the top. The positioning section 222 can be a positioning post and is configured to have a certain height that is adapted to the thickness of the steel sheet 1 to achieve axial positioning of the steel sheet 1 and minimize the axial contact area between them.

[0028] The height of the positioning section 222 is equal to the thickness of the steel sheet 1, and the positioning section 222 is the core of this invention. Its height is determined according to the thickness of the steel sheet 1. In one embodiment, the thickness of the steel sheet 1 is 0.5mm, then the height of the positioning section is also set to 0.5mm. This equal-height design ensures that the axial contact area reaches the theoretical minimum while satisfying the positioning function, thereby reducing axial frictional resistance caused by plastic overflow or tolerance accumulation during ejection.

[0029] The cross-sectional shape of the positioning part 22 is not a complete circle, so as to form a continuous gap space on its circumferential surface. This gap space is configured to reduce the circumferential contact area with the steel sheet 1 and provide an escape channel for the injection overflow.

[0030] The cross-sectional shape of the positioning part is not a complete circle, thus naturally forming a continuous gap space on its circumferential surface. This gap space is cleverly configured to serve a dual purpose: firstly, to reduce the circumferential contact area with the inner hole of the steel sheet; secondly, and more importantly, to provide a dedicated escape and release channel for plastic overflow that may occur during the injection molding process, effectively avoiding radial mechanical jamming caused by the cooling and solidification of the overflow.

[0031] In another preferred embodiment of the present invention, the cross-sectional shape of the positioning segment 222 is not a complete circle, and its circumferential contour includes a straight segment 223 and an arc segment 224, and a guide angle is provided at the corner of the straight segment 223 and the arc segment 224.

[0032] The central angle corresponding to the arc length of arc segment 224 is greater than 240° and less than 300°;

[0033] The central angle corresponding to the arc length of arc segment 224 is 270°.

[0034] The cross-section of the positioning segment 222 is not a complete circle; it is specifically enclosed by a straight segment 223 and an arc segment 224. The central angle θ corresponding to the arc length of the arc segment 224 is 270°. This cut-off 90° portion forms a gap space that runs through the height of the positioning segment 222 and the guide segment 221.

[0035] Its working principle is as follows: Before mold closing, the operator or robot places the steel sheet 1 onto the positioning section 222 of the insert. The guide section 221 acts as a guide. Since the height of the positioning section 222 is consistent with the thickness of the steel sheet 1, the steel sheet 1 is precisely positioned axially. After mold closing, plastic is injected into the cavity. At this time, if any overflow material enters the gap between the steel sheet 1 and the positioning section 222, it will enter the gap space and will not form a complete circumferential surround.

[0036] After the mold opens, the ejection system pushes the insert pin forward. Due to the small axial contact area, the friction is already very small. At the same time, the overflow material in the notch space cannot generate strong shear force and will be easily compressed or torn under the action of the ejection force, thereby allowing the steel sheet 1 to separate smoothly from the insert pin and effectively avoiding jamming.

[0037] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0038] The embodiments of this utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pin for positioning a steel sheet in a plastic mold, installed on the rear mold core, for positioning the steel sheet (1) in the mold cavity, comprising a columnar body (2), the columnar body (2) comprising a positioning part (22), the positioning part (22) being used to cooperate with a positioning hole on the steel sheet (1), characterized in that, The positioning part (22) includes a guide section (221) and a positioning section (222). The positioning section (222) is configured to have a certain height, which is adapted to the thickness of the steel sheet (1) in order to achieve axial positioning of the steel sheet (1) and minimize the axial contact area between the two. The positioning part (22) has a non-circular cross-sectional shape to form a continuous gap space on its circumferential surface. This gap space is configured to reduce the circumferential contact area with the steel sheet (1) and provide an escape channel for the injection overflow.

2. The insert pin for a positioning steel sheet inside a plastic mold according to claim 1, characterized in that, The height of the positioning segment (222) is equal to the thickness of the steel sheet (1).

3. The insert pin for a positioning steel sheet inside a plastic mold according to claim 1, characterized in that, The cross-sectional shape of the positioning segment (222) is not a complete circle. Its circumferential outline includes a straight line segment (223) and an arc segment (224), and a guide angle is provided at the corner of the straight line segment (223) and the arc segment (224).

4. The insert pin for a positioning steel sheet inside a plastic mold according to claim 3, characterized in that, The central angle corresponding to the arc length of the arc segment (224) is greater than 240° and less than 300°.

5. The insert pin for a positioning steel sheet inside a plastic mold according to claim 4, characterized in that, The central angle corresponding to the arc length of the arc segment (224) is 270°.

6. The insert pin for a positioning steel sheet inside a plastic mold according to claim 1, characterized in that, The columnar body (2) also includes a fixing part (21), which is used to fix it on the rear mold core.

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