Cam-based mold core pulling mechanism

Abstract

The utility model discloses a mould core-pulling mechanism based on cam, it belongs to mould field, it includes the pivot, is provided with eccentric cam on the pivot, eccentric cam rotatablely set up in the guide hole of long axle and short axle on slider, when the pivot rotates, the working profile surface of eccentric cam periodically promotes two opposite side wall surface of short axle direction, is provided with the core on the slider, and the core is along the short axle direction of guide hole setting. The utility model discloses a mould core-pulling mechanism based on cam can improve the core-pulling precision, and reduce the phenomenon of hole wall scratch.

Description

Technical Field

[0001] This utility model relates to the field of molds, specifically a cam-based mold core-pulling mechanism. Background Technology

[0002] In molding production such as injection molding and die casting, in order to form through holes or blind holes that intersect with the mold opening direction on the product, a corresponding core-pulling mechanism must be set up to complete the core pulling before the product is demolded. This is especially true for core pulling of small-diameter holes (such as those with a diameter of about 3 mm). Such core pulling is characterized by a short core pulling stroke, a slender core, and high precision. Existing inclined guide post core pulling mechanisms require a large guide post inclination angle and have significant lateral force, which can easily cause elastic deformation of the core during the core pulling process. This may not meet the coaxiality requirements of small holes and may easily cause hole wall scratches. Utility Model Content

[0003] The purpose of this invention is to address the above problems by providing a cam-based mold core-pulling mechanism that can improve core-pulling accuracy and reduce hole wall scratches.

[0004] To achieve the above objectives, the present invention employs a cam-based mold core-pulling mechanism. This mechanism includes a rotating shaft with an eccentric cam rotatably mounted within a guide hole on a slider, which has a major and a minor axis. As the shaft rotates, the working contour surface of the eccentric cam periodically pushes two opposing sidewalls along the minor axis of the guide hole. A core is mounted on the slider, positioned along the minor axis of the guide hole. During the rotation of the eccentric cam with the shaft, its protrusion periodically contacts the sidewalls at both ends of the minor axis of the guide hole, thereby pushing the slider to move along the core-pulling direction, thus completing the core-pulling and insertion into the mold cavity.

[0005] Furthermore, to control the rotation of the shaft, a gear concentric with it is provided on the shaft, the gear meshing with the rack, and the rack moving in a straight line under the drive of the linear drive mechanism.

[0006] The beneficial effects of this invention are as follows: When the rotating shaft is driven to rotate by external power, the eccentric cam fixed to it rotates synchronously. The protrusion of the eccentric cam periodically contacts the sidewalls at both ends of the short axis of the guide hole. When the protrusion of the eccentric cam contacts the sidewall of the guide hole away from the cavity end, the eccentric cam pushes the slider to move linearly along the short axis, allowing the core to be accurately withdrawn from the product hole. When the protrusion of the eccentric cam contacts the sidewall of the guide hole near the cavity end, the eccentric cam pushes the slider to move towards the cavity side, allowing the core to be inserted into the cavity, thus completing the core pulling or insertion action, in order to complete the demolding and mold closing. This process completes the entire core pulling stroke within a very short turning angle, which is suitable for small hole molding with a short stroke. The thrust direction of the eccentric cam protrusion is in the same direction as the core axis. Compared with the inclined guide post core pulling method, it reduces or even eliminates the lateral component force, avoids elastic bending of the core, thereby improving the core pulling accuracy, improving the roundness and coaxiality of the small hole, and reducing the risk of hole wall scratches. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of the present invention in its molded state.

[0008] Figure 2 This is a schematic diagram of the structure of the present invention in the core-pulling state.

[0009] Figure 3 This is a schematic diagram of a rotating shaft transmission structure.

[0010] Figure 4 This is a schematic diagram of the three-dimensional structure of the slider.

[0011] The text labels in the figure represent: 1. Rotating shaft; 2. Eccentric cam; 3. Slider; 4. Guide hole; 5. Core; 6. Gear; 7. Rack; 8. Linear drive mechanism; 9. Product. Detailed Implementation

[0012] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of this utility model in any way.

[0013] Example 1, as Figure 1-4 As shown, the structure of this embodiment is: a cam-based mold core-pulling mechanism, which includes a rotating shaft 1, on which an eccentric cam 2 is provided. The eccentric cam 2 is rotatably disposed in a guide hole 4 with a long axis and a short axis on a slider 3. The guide hole 4 is a closed structure, including but not limited to a waist-shaped hole, an oblong hole, or an elliptical hole. The length of its short axis is adapted to the working contour surface of the eccentric cam. The short axis of the guide hole 4 is in the same direction as the axis of the small hole. The long axis of the guide hole 4 provides redundant space for the rotation of the eccentric cam 2, avoiding interference with the rotation of the eccentric cam 2.

[0014] When the rotating shaft 1 rotates, the protrusion of the eccentric cam 2 periodically contacts the two side walls in the short axis direction of the guide hole 4, thereby pushing the slider 3 to reciprocate. The rotating shaft 1 can be driven to rotate by a servo motor or the like. In this embodiment, a gear 6 concentric with the rotating shaft 1 is provided on the rotating shaft 1. The gear 6 meshes with the rack 7. The rack 7 moves linearly under the drive of the linear drive mechanism 8, which can be a hydraulic cylinder or the like. A core 5 is provided on the slider 3 on the mold core side, and the core 5 is arranged along the short axis direction of the guide hole 4.

[0015] In actual operation, the mold core is provided with a core hole that mates with the core 5, which allows the core 5 to extend into the cavity and also serves as a guide; a guide seat is provided on the mold core sleeve plate, which mates with the keyway of the slider 3 to further guide the movement of the slider.

[0016] The linear drive mechanism 8 drives the rack 7 to move, and the rack 7 drives the gear 6 to rotate 180 degrees, thereby causing the eccentric cam 2 on the rotating shaft 1 to rotate 180 degrees. The protrusion of the eccentric cam 2 abuts against the side wall of the guide hole 4 away from the cavity end, so as to push the slider 3 away from the cavity along the short axis direction, so that the core 5 can be accurately withdrawn from the small hole on the product 9. When the linear drive mechanism 8 resets, it drives the eccentric cam 2 on the rotating shaft 1 to rotate 180 degrees in the opposite direction, and the protrusion abuts against the side wall of the guide hole 4 near the cavity end, thereby pushing the slider 3 to reset and insert into the cavity along the short axis direction, completing the mold closing preparation.

[0017] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0018] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The above examples are only for the purpose of helping to understand the method and core ideas of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of textual expression, there are objectively infinite specific structures. For those skilled in the art, several improvements, modifications, or changes can be made without departing from the principles of this utility model, and the above technical features can also be combined in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without modification, should all be considered within the protection scope of this utility model.

Claims

1. A cam-based mold core-pulling mechanism, characterized in that, Includes a rotating shaft (1), on which an eccentric cam (2) is provided. The eccentric cam (2) is rotatably disposed in a guide hole (4) with a major axis and a minor axis on a slider (3). When the rotating shaft (1) rotates, the working contour surface of the eccentric cam (2) periodically pushes the two opposite side walls of the guide hole (4) in the direction of the minor axis. The slider (3) is provided with a core (5), which is disposed along the direction of the minor axis of the guide hole (4).

2. The cam-based mold core-pulling mechanism according to claim 1, characterized in that, The rotating shaft (1) is provided with a gear (6) concentric with it. The gear (6) meshes with the rack (7), and the rack (7) moves in a straight line under the drive of the linear drive mechanism (8).

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