Cavity structure of runner-free injection mold

Abstract

The utility model relates to the technical field of injection molds, in particular to a cavity structure of a runner-free injection mold. The die comprises a lower die, the lower die is provided with at least one circular pit, the shape of the bottom of the pit is matched with the shape of the lower surface of a workpiece to form a forming cavity, guide grooves communicated with the forming cavity are symmetrically formed in the positions, on the two sides of the forming cavity, of the upper surface of the lower die, and extrusion blocks are arranged in the guide grooves. The extrusion block is in sliding fit with the guide groove, a protrusion matched with the side wall of the workpiece is arranged at one end of the extrusion block, and a pushing mechanism used for pushing the extrusion block is arranged on the other side of the extrusion block. A pressing plate is arranged right above the lower die, a recess is formed in the position, corresponding to the forming cavity, of the pressing plate, and the recess is matched with the upper surface of a workpiece in shape. The device solves the problem of low injection molding precision.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to a cavity structure of an injection mold without a runner. Background Art

[0002] Injection molded products refer to plastics that are heated and melted by an injection molding machine, and then injected into the cavity of an injection mold for molding. After cooling and the melt solidifies, it is demoulded. Injection molding is a processing method used in mass production of certain complex-shaped parts.

[0003] The currently commonly used double-parting surface injection mold is used for complex mold design and product molding through the cooperation of two parting surfaces. However, there are small gaps on both sides of the mold, and a process of removing the residues on both sides is often added, resulting in low injection precision and low production efficiency. Utility Model Content

[0004] In order to solve the problems in the related art, the utility model provides a cavity structure of a flow channel-free injection mold, and the device solves the problem of low injection molding precision.

[0005] In order to solve the above problems, the following technical solutions are provided:

[0006] The utility model provides a cavity structure of a runner-free injection mold, comprising a lower mold, wherein the lower mold is provided with at least one circular concave pit, the bottom shape of the concave pit is matched with the shape of the lower surface of the workpiece to form a molding cavity, the upper surfaces of the lower mold on both sides of the molding cavity are symmetrically provided with guide grooves connected with the molding cavity, the guide grooves are provided with extrusion blocks, the extrusion blocks and the guide grooves are slidably matched, one end of the extrusion block is provided with a protrusion matched with the side wall of the workpiece, and the other side of the extrusion block is provided with a pushing mechanism for pushing the extrusion block; a pressing plate is provided directly above the lower mold, and a depression is provided on the pressing plate at a position corresponding to the molding cavity, and the depression is matched with the shape of the upper surface of the workpiece.

[0007] In the above scheme, the pressure plate is first driven to move downward, so that the fixed block moves vertically downward, driving the pushing mechanism to move, thereby pushing the extrusion block to move toward the molding cavity in the horizontal direction, forming a molding cavity for product molding, and the plastic flow material is rapidly injected into the molding cavity through the feed port, and is cooled and solidified to form a plastic product. The shape of the side can be formed by the extrusion blocks on both sides, without the need for subsequent trimming, and molding can be completed in one step, thus solving the problem of low injection molding precision.

[0008] The pushing mechanism includes a slider, a groove for accommodating the slider is arranged on the outer side of the extrusion block, the slider and the groove are slidably matched, the slider is a right-angled trapezoid, the slider is tilted on the side away from the molding cavity, the other side of the slider is fixedly connected to the extrusion block by a screw, a spring is arranged between the slider and the lower mold, and a fixed block arranged vertically downward is arranged at a position on the pressure plate corresponding to the groove, and the fixed block is adapted to the groove.

[0009] In the above scheme, by setting the slider and the fixed block, the fixed block is pressed down to push the slider to move, thereby driving the extrusion block to move to a suitable position.

[0010] The molding cavities are arranged in groups of two, and the molding cavities in a group are located on the same horizontal plane, and the molding cavities in a group share a pair of slide blocks.

[0011] In the above solution, at least two molding cavities are provided, which greatly improves production efficiency and saves costs.

[0012] A push rod is arranged below the forming cavity.

[0013] In the above scheme, the plastic product is cooled and solidified by setting the push rod. After the mold is opened, the push rod pushes upward against the bottom of the mold to demould the product.

[0014] A guide hole arranged obliquely is provided in the middle of the slider, a guide column matched with the guide hole is provided on the lower surface of the pressure plate, a shell is provided on the outer side of the lower mold, positioning holes are provided at the four corners of the shell, and the pressure plate is provided with positioning columns matched with the positioning holes.

[0015] In the above scheme, the guide hole is matched with the guide column, and the positioning hole is matched with the positioning column, so as to improve the accuracy of mold clamping.

[0016] The above solution has the following advantages:

[0017] 1. The cavity structure of a flow channel-free injection mold of the utility model includes a lower mold, the lower mold is provided with no less than one circular pit, the bottom shape of the pit is adapted to the shape of the lower surface of the workpiece to form a molding cavity, the upper surface of the lower mold on both sides of the molding cavity are symmetrically provided with guide grooves connected to the molding cavity, and extrusion blocks are provided in the guide grooves, the extrusion blocks and the guide grooves are slidingly matched, one end of the extrusion block is provided with a protrusion adapted to the side wall of the workpiece, and the other side of the extrusion block is provided with a pushing mechanism for pushing the extrusion block, a pressing plate is provided just above the lower mold, and a depression is provided on the pressing plate at a position corresponding to the molding cavity, and the depression is adapted to the shape of the upper surface of the workpiece, the pressing plate is first driven to move downward, so that the fixed block moves vertically downward, driving the pushing mechanism to move, thereby pushing the extrusion block to move toward the molding cavity in the horizontal direction, forming a molding cavity for product molding, and the plastic flow material is rapidly injected into the molding cavity through the feed inlet, and a plastic product is formed after cooling and curing, and the shape of the side can be formed by the extrusion blocks on both sides, without the need for later trimming, and one-time molding, which greatly improves the accuracy of injection molding.

[0018] 2. The pushing mechanism contains a slider, which is in a right-angled trapezoid. A groove is arranged on one side of the slider in an inclined manner. A fixed block arranged vertically downward is arranged above the groove. The fixed block is pressed down to push the slider to move, thereby driving the extrusion block to move to a suitable position. The molding cavities are grouped in pairs, and a group of molding cavities shares a pair of sliders. The molding cavities are located on the same horizontal plane, which greatly improves production efficiency and saves costs. A push rod is arranged under the molding cavity. The plastic product is cooled and solidified. After the mold is opened, the push rod pushes upward against the bottom of the mold for demolding the product. The guide hole is adapted to the guide column, and the positioning hole is adapted to the positioning column to improve the accuracy of mold closing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a cavity structure of a runner-free injection mold;

[0020] Figure 2 It is an enlarged schematic diagram of the cavity structure A of a runner-free injection mold;

[0021] Figure 3 A cross-sectional view of a cavity structure of a runner-free injection mold;

[0022] Figure 4 It is an enlarged schematic diagram of the cavity structure B of a runner-free injection mold;

[0023] Figure 5 A bottom view of a cavity structure of a runner-free injection mold;

[0024] Figure 6 It is an enlarged schematic diagram of the C part of the cavity structure of a runner-free injection mold;

[0025] Explanation of the accompanying drawings: 1. lower mold; 2. molding cavity; 3. extrusion block; 4. protrusion; 5. pressure plate; 6. depression; 7. slider; 8. groove; 9. screw; 10. spring; 11. fixing block; 12. guide hole; 13. guide column; 14. housing; 15. positioning hole; 16. positioning column. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in 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.

[0027] like Figures 1 to 6 As shown, a cavity structure of a flow channel-free injection mold of the utility model includes a lower mold 1, and the lower mold 1 is provided with no less than one circular pit, and the bottom shape of the pit is adapted to the shape of the lower surface of the workpiece to form a molding cavity 2, and the molding cavities 2 are grouped in pairs, and a group of molding cavities 2 are located on the same horizontal plane, and a group of molding cavities 2 share a pair of sliders 7, which greatly improves production efficiency and saves costs. The upper surface of the lower mold 1 on both sides of the molding cavity 2 is symmetrically provided with guide grooves connected to the molding cavity 2, and extrusion blocks 3 are provided in the guide grooves. The extrusion blocks 3 are matched with the guide grooves in a sliding manner, and one end of the extrusion block 3 is provided with a protrusion 4 adapted to the side wall of the workpiece, and the other side of the extrusion block 3 is provided with a pushing mechanism for pushing the extrusion block 3, and the pushing mechanism includes a slider 7. A groove 8 for accommodating a slider 7 is provided on the outside of the extrusion block 3. The slider 7 and the groove 8 are slidably matched. The slider 7 is a right-angled trapezoid. The slider 7 is arranged obliquely on one side away from the molding cavity 2. The other side of the slider 7 is fixedly connected to the extrusion block 3 by a screw 9. A spring 10 is provided between the slider 7 and the lower mold 1. A fixed block 11 arranged vertically downward is provided on the pressure plate 5 at a position corresponding to the groove 8. The fixed block 11 is adapted to the groove 8. A pressure plate 5 is provided directly above the lower mold 1. A depression 6 is provided on the pressure plate 5 at a position corresponding to the molding cavity 2. The depression 6 is adapted to the shape of the upper surface of the workpiece. The extrusion blocks 3 arranged on both sides of the molding cavity 2 can form the side of the workpiece into the desired shape without the need for subsequent trimming. One-time molding greatly improves the accuracy of injection molding.

[0028] A push rod is provided below the molding cavity 2. After the plastic product is cooled and solidified, the push rod pushes upward against the bottom of the mold after the mold is opened, so as to facilitate demoulding of the product.

[0029] An inclined guide hole 12 is provided in the middle of the slider 7, a guide column 13 matched with the guide hole 12 is provided on the lower surface of the pressure plate 5, a shell 14 is provided on the outer side of the lower mold, positioning holes 15 are provided at the four corners of the shell 14, and the pressure plate 5 is provided with a positioning column 16 matched with the positioning hole 15. The guide hole 12 is matched with the guide column 13, and the positioning hole 15 is matched with the positioning column 16, so as to improve the accuracy of mold closing.

[0030] First, drive the pressing plate 5 to move downward, drive the fixed block 11 to move vertically downward, move the fixed block 11 into the groove 8, push the slider 7 to move toward the molding cavity 2, squeeze the spring 10, and drive the extrusion block 3 to slide along the guide groove to a fixed position to form a molding cavity 2 for product molding, complete the mold closing, and then quickly inject the plastic flow material from the feed port into the molding cavity 2 until the entire molding cavity 2 is filled. After cooling and solidification, open the mold, push the push rod against the bottom of the mold and push upward, demold the product, and then close the mold. Repeat the operation to obtain more products.

[0031] In the description of the present utility model, it should be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cavity structure of a runnerless injection mold, characterized in that: The invention comprises a lower die (1), wherein the lower die (1) is provided with at least one circular concave pit, the bottom shape of the concave pit is adapted to the shape of the lower surface of the workpiece to form a forming cavity (2), the upper surface of the lower die (1) on both sides of the forming cavity (2) is symmetrically provided with guide grooves connected to the forming cavity (2), the guide grooves are provided with extrusion blocks (3), the extrusion blocks (3) and the guide grooves are slidably matched, one end of the extrusion block (3) is provided with a protrusion (4) adapted to the side wall of the workpiece, and the other side of the extrusion block (3) is provided with a pushing mechanism for pushing the extrusion block (3); a pressing plate (5) is provided directly above the lower die (1), and a depression (6) is provided on the pressing plate (5) at a position corresponding to the forming cavity (2), and the depression (6) is adapted to the shape of the upper surface of the workpiece.

2. The cavity structure of a runnerless injection mold according to claim 1, characterized in that: The pushing mechanism comprises a slider (7), a groove (8) for accommodating the slider (7) is arranged on the outer side of the extrusion block (3), the slider (7) and the groove (8) are matched in a sliding manner, the slider (7) is in a right-angled trapezoid, the slider (7) is arranged at an angle on the side away from the molding cavity (2), the other side of the slider (7) is fixedly connected to the extrusion block (3) by a screw (9), and a spring (10) is arranged between the slider (7) and the lower mold (1).

3. The cavity structure of a runnerless injection mold according to claim 2, characterized in that: A fixing block (11) arranged vertically downward is provided on the pressing plate (5) at a position corresponding to the groove (8), and the fixing block (11) is adapted to the groove (8).

4. The cavity structure of a runnerless injection mold according to claim 1, characterized in that: The molding cavities (2) are grouped in pairs, a group of molding cavities (2) are located on the same horizontal plane, and a group of molding cavities (2) share a pair of slide blocks (7).

5. The cavity structure of a runnerless injection mold according to claim 1, characterized in that: A push rod is arranged below the molding cavity (2).

6. The cavity structure of a runnerless injection mold according to claim 2, characterized in that: The slider (7) is provided with an inclined guide hole (12) in the middle, the lower surface of the pressure plate (5) is provided with a guide column (13) adapted to the guide hole (12), the outer side of the lower mold (1) is provided with a shell (14), the four corners of the shell (14) are provided with positioning holes (15), and the pressure plate (5) is provided with positioning columns (16) adapted to the positioning holes (15).

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