Injection mold capable of preventing flow channel sticking
By setting a locking structure and an inclined ejector mechanism in the runner of the injection mold, the problem of adhesion between the solidified material in the runner and the fixed mold is solved, achieving smooth demolding and high-quality molding, and simplifying the demolding process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGHAI FIRST RATE INJECTION MOULD FACTORY
- Filing Date
- 2025-07-18
- Publication Date
- 2026-07-14
AI Technical Summary
In injection molds, the runner material tends to stick to the mold base, causing it to break off during mold opening and affecting the quality of the molded product.
A locking structure is installed in the runner to lock the solidified material in the runner when the mold is opened, preventing it from adhering to the fixed mold. The design of the top opening of the runner being smaller than the projected area of the bottom surface and the sharp angle are combined with the undercut or groove to form a locking mechanism. The smooth demolding is achieved in conjunction with the inclined ejector mechanism and ejector pin.
It effectively prevents the solidified material in the runner from adhering to the mold, ensuring smooth release, improving product molding quality, simplifying the demolding process, and reducing costs.
Smart Images
Figure CN224489889U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of mold technology, and in particular to an injection mold that can prevent runner sticking to the mold. Background Technology
[0002] In injection molds, the runner is the core component of the gating system. Its core function is to transport molten plastic from the nozzle of the injection molding machine to each cavity, ensuring that the plastic fills the mold cavity evenly and efficiently.
[0003] like Figure 1 As shown in the enlarged view, after the product is formed, a runner material that is integrated with the product will form at the moving mold runner; as... Figure 2 As shown, the runner material has runner ribs (designed to facilitate gripping by a robotic arm). Therefore, during mold opening, these ribs easily adhere to the fixed mold, causing the entire runner material to be forcibly pulled apart from the product, affecting the molding quality. Therefore, how to improve the existing runner structure to overcome these problems is a problem urgently needing to be solved by those skilled in the art. Utility Model Content
[0004] One of the objectives of this application is to provide an injection mold that prevents runner sticking.
[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: an injection mold that prevents runner sticking, comprising a fixed mold and a moving mold, wherein the moving mold has a runner, the runner cooperates with the fixed mold to form the runner solidified material, and a locking structure is provided on the inner side of the runner to cooperate with the runner solidified material; when the mold is opened, the locking structure is adapted to lock the runner solidified material in the mold opening direction, so as to allow the runner solidified material to smoothly separate from the fixed mold.
[0006] Preferably, the projection of the top opening of the flow channel in the vertically downward direction completely overlaps with the projection of the bottom surface of the flow channel in the vertically downward direction, and the projected area of the top opening of the flow channel is smaller than the projected area of the bottom surface of the flow channel, thereby forming the locking structure.
[0007] Preferably, the angle between the side surface of the flow channel and the bottom surface is an acute angle.
[0008] Preferably, the angle between the side surface of the flow channel and the bottom surface is θ, where 90° < θ ≦ 80°.
[0009] Preferably, the side of the flow channel is recessed inward to form a groove, thereby forming a protrusion on the side of the formed flow channel solidified material, and the protrusion and the groove cooperate to form the locking structure.
[0010] Preferably, the locking structure includes an inverted fastener disposed on the bottom surface of the flow channel; the inverted fastener is in one of the shapes of triangle, cone and trapezoid.
[0011] Preferably, the moving mold is provided with an inclined ejector mechanism for forming the inner side of the product, and an ejector rod is vertically slidably provided in the flow channel; during demolding, the inclined ejector mechanism is adapted to engage with the ejector rod in a wedge-shaped extrusion fit, thereby causing the ejector rod to move vertically upward to push the solidified material in the flow channel until it separates from the flow channel.
[0012] Preferably, the ejector pin is connected to the moving mold via an elastic element; during mold closing, the ejector pin is adapted to move downward and reset under the action of elastic force.
[0013] Compared with the prior art, the beneficial effects of this application are as follows:
[0014] This invention incorporates a locking structure between the runner and the formed runner solidified material. During mold opening, this locking structure locks the runner solidified material in the mold opening direction, preventing it from being forcibly adhered to and broken off from the fixed mold when subjected to tensile force in the mold opening direction. This ensures smooth separation of the runner solidified material from the fixed mold, effectively preventing runner sticking and improving product molding quality. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the moving model and a partially enlarged structure of this utility model.
[0016] Figure 2 This is a schematic diagram of the flow channel condensate and flow channel rib structure of this utility model.
[0017] Figure 3 This is a schematic diagram of the inclined top mechanism of this utility model.
[0018] Figure 4 This is a schematic diagram of the core block's motion principle structure according to this utility model.
[0019] Figure 5 This is a schematic diagram illustrating the working principle of the core block and the push rod of this utility model.
[0020] Figure 6 This is a schematic diagram of the first embodiment of the locking structure of this utility model.
[0021] Figure 7 This is a schematic diagram of the first embodiment of the locking structure of this utility model.
[0022] Figure 8 This is a schematic diagram of the second embodiment of the locking structure of this utility model.
[0023] Figure 9 This is a schematic diagram of the third embodiment of the locking structure of this utility model.
[0024] In the diagram: 1. Moving mold; 2. Product; 3. Runner sprue; 4. Runner ribs; 5. Angled ejector mechanism; 501. Core block; 6. Ejector pin; 7. Elastic element; 8. Groove; 9. Undercut. Detailed Implementation
[0025] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.
[0026] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. They should not be construed as limiting the specific protection scope of this application.
[0027] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0028] One preferred embodiment of this application, such as Figures 1 to 9 As shown, an injection mold for preventing runner sticking includes a fixed mold and a moving mold 1 (the fixed mold is not shown). The moving mold 1 has a runner, which cooperates with the fixed mold to form the runner solidified material 3. A locking structure that cooperates with the runner solidified material 3 is provided on the inner side of the runner.
[0029] Understandably, during mold opening, the locking structure can lock the runner solidified material 3 in the mold opening direction. This prevents the runner solidified material 3 from being forcibly adhered to and broken off from the fixed mold when subjected to tensile force in the mold opening direction, thus ensuring smooth separation of the runner solidified material 3 from the fixed mold. This effectively prevents runner sticking and improves the molding quality of product 2. Of course, the locking structure of this application is not only suitable for structures with runner ribs 4 on the runner solidified material 3; it can be applied to any runner solidified material 3 that is prone to sticking during mold opening.
[0030] This application does not limit the specific structure of the locking mechanism; the following three embodiments are provided for reference:
[0031] Structure 1: such as Figure 6 and Figure 7 As shown, the projection of the top opening of the flow channel in the vertically downward direction completely overlaps with the projection of the bottom surface of the flow channel in the vertically downward direction, and the projected area of the top opening of the flow channel is smaller than the projected area of the bottom surface of the flow channel, thus forming a locking structure.
[0032] For ease of understanding, such as Figure 7 As shown, we will use the downward projection length of the cross-section of the runner as an example. The vertical downward projection length of the top opening of the runner is bc, and the vertical downward projection length of the bottom surface of the runner is ad, with bc located within ad. In simple terms, the runner is narrower at the top and wider at the bottom, thus forming an inverted structure. This structure can effectively lock the solidified material 3 in the runner during mold opening, preventing it from forcibly adhering to and breaking off from the fixed mold.
[0033] As a further description of the above embodiments: such as Figure 6 As shown, the angle between the side and bottom surfaces of the runner is acute. This means that the space within the runner increases from top to bottom. It should be understood that if we define the angle between the side and bottom surfaces of the runner as θ, the smaller θ is, the greater the locking force on the runner solidified material 3. However, in practical applications, we also need to consider the subsequent demolding of the runner solidified material 3 from the moving mold 1; therefore, θ cannot be too small. In this embodiment, we preferably use an angle θ less than 90° and greater than or equal to 80°. Of course, this angle θ can be adjusted adaptively according to specific application scenarios and actual needs.
[0034] Structure 2: such as Figure 8 As shown, the side of the flow channel is recessed inward to form a groove 8, which in turn causes a protrusion to form on the side of the formed flow channel solidified material 3. This protrusion and the groove 8 cooperate to form a locking structure, or in other words, a snap-fit relationship. It can be understood that the number and size of the grooves 8 can be set according to actual needs, as long as an effective locking structure can be formed. On the other hand, the grooves 8 can be a point-like structure or a (multi-)segment-like structure (i.e., set along the length direction inside the flow channel).
[0035] Structure 3: such as Figure 9 As shown, the locking structure includes an inverted fastener 9, which is disposed on the bottom surface of the runner. The shape of the inverted fastener 9 can be triangular, (inverted) conical, or trapezoidal, as long as it can effectively lock the solidified material 3 in the runner during mold opening. Furthermore, to improve the locking effect of the locking structure, there can be multiple inverted fasteners 9, which are spaced apart along the length of the runner. This allows the solidified material 3 in the runner to be subjected to locking forces in multiple directions during mold opening, greatly improving the locking effect.
[0036] Furthermore, the undercut 9 can be fixed to the flow channel using screws / bolts, which facilitates the assembly and disassembly of the undercut 9 and makes it easy to replace if damaged. This simplifies the design of the undercut 9, makes it easy to manufacture, and reduces costs.
[0037] It should be noted that with Structure 1, this design effectively holds the runner material 3 in place during mold opening, preventing it from forcibly adhering to and breaking off from the fixed mold. Simultaneously, the special shape of the runner facilitates the flow of plastic within it, ensuring that the plastic fills the mold cavity evenly and efficiently. With Structure 2, holes / grooves are required on the sides of the runner, which increases the difficulty of processing the runner. With Structure 3, the undercut 9 may obstruct the flow of plastic, and it may be prone to damage over long-term use. Therefore, Structure 1 is preferred in this application; however, all three structures can meet practical needs, and those skilled in the art can make an adaptive selection based on actual requirements.
[0038] In this embodiment, as Figure 3 and Figure 4 As shown, the inner side of product 2 has structures such as undercuts, holes, or hooks. To form and demold these structures on the inner side of product 2, a slanted ejector mechanism 5 is provided in the moving mold 1, thereby enabling lateral core pulling of the inner side of product 2 during mold opening. Figure 4 As indicated by the arrow in the diagram. It should be noted that the inclined ejector mechanism 5 is a standard structure in the mold industry, therefore its structure and principle are common knowledge and will not be elaborated upon here.
[0039] Based on the above embodiments, in this embodiment, as follows: Figure 5 As shown, in order to facilitate demolding of the solidified material 3 after molding, an ejector rod 6 is vertically slidably arranged in the runner (i.e., in the moving mold 1). The ejector rod 6 is linked with the inclined ejector mechanism 5, so that when the inclined ejector mechanism 5 performs lateral core pulling, the ejector rod 6 is driven to demold the solidified material 3 from the runner.
[0040] Specifically, such as Figure 5 As shown, when the core block 501 of the inclined ejector mechanism 5 moves upward along the direction of the arrow to pull the core, the core block 501 exerts a wedge-shaped squeezing effect on the ejector pin 6, causing the ejector pin 6 to move vertically upward and push the runner solidified material 3 upward until it is completely separated from the runner. This design eliminates the need to connect the ejector pin 6 to the ejector pin mechanism in the mold (which is also existing technology), meaning the ejector pin 6 does not need to be very long and penetrate the entire moving mold 1, thus simplifying the structure, improving demolding efficiency, and reducing costs.
[0041] Furthermore, the ejector pin 6 and the moving mold 1 can be connected via an elastic element 7. It can be understood that during the ejection process of the ejector pin 6, the elastic element 7 is in a deformed, energy-storing state; and during the mold closing process, i.e., when the ejector pin 6 loses the function of the angled ejector mechanism 5, the ejector pin 6 can automatically move downwards and reset under the elastic force of the elastic element 7, preparing for the next injection molding. Of course, the elastic element 7 can have various structural forms; for example, it can be a spring, a sheet, or elastic rubber, as long as it can provide sufficient elastic force to allow the ejector pin 6 to automatically move downwards and reset.
[0042] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.
Claims
1. An injection mold for preventing runner sticking, comprising a fixed mold and a moving mold, wherein the moving mold has a runner, the runner cooperating with the fixed mold for molding the runner solidified material, characterized in that: The inner side of the runner is provided with a locking structure that cooperates with the runner solidified material; when the mold is opened, the locking structure is adapted to lock the runner solidified material in the mold opening direction so that the runner solidified material can be smoothly separated from the fixed mold.
2. The injection mold for preventing runner sticking as described in claim 1, characterized in that: The projection of the top opening of the flow channel in the vertically downward direction completely overlaps with the projection of the bottom surface of the flow channel in the vertically downward direction, and the projected area of the top opening of the flow channel is smaller than the projected area of the bottom surface of the flow channel, thereby forming the locking structure.
3. The injection mold for preventing runner sticking as described in claim 2, characterized in that: The angle between the side surface and the bottom surface of the flow channel is an acute angle.
4. The injection mold for preventing runner sticking as described in claim 3, characterized in that: The angle between the side surface and the bottom surface of the flow channel is θ, where 90° < θ ≦ 80°.
5. The injection mold for preventing runner sticking as described in claim 1, characterized in that: The side of the flow channel is recessed inward to form a groove, which in turn causes the side of the formed flow channel solidified material to form a protrusion. The protrusion and the groove cooperate to form the locking structure.
6. The injection mold for preventing runner sticking as described in claim 1, characterized in that: The locking structure includes an inverted fastener disposed on the bottom surface of the flow channel; the inverted fastener is in one of the shapes of triangle, cone and trapezoid.
7. The injection mold for preventing runner sticking as described in any one of claims 1-6, characterized in that: The moving mold is provided with an inclined ejector mechanism for forming the inner side of the product, and an ejector rod is vertically slidably provided in the flow channel; During demolding, the inclined ejector mechanism is adapted to engage with the ejector rod in a wedge-shaped compression fit, thereby causing the ejector rod to move vertically upward to push the solidified material in the runner until it detaches from the runner.
8. The injection mold for preventing runner sticking as described in claim 7, characterized in that: The ejector pin is connected to the moving mold via an elastic element; during mold closing, the ejector pin is adapted to move downward and reset under the action of elastic force.