Injection mold machining device and process for suppressing internal stress

Abstract

This invention provides an injection mold processing device and process for suppressing internal stress, relating to the field of mold processing equipment. The device includes a worktable, a processing head, and a tooling module. The tooling module is fixed to the working surface of the worktable for clamping workpieces. The tooling module is equipped with a rotatable angle adjustment plate, and the angle adjustment plate has a mounting platform. A clamping block holds and fixes the workpiece on the working surface of the mounting platform. A reduction motor is also installed on the tooling module to drive the angle adjustment plate to deflect. The tooling module includes a mold plate support seat with a support column. A slider is located at the bottom of the angle adjustment plate. The slider and the arc surface of the support column provide stable follow-up support, while the limiting design of the brake surface ensures rigidity during extreme angle processing. This solves the angle adjustment deviation and stability problems caused by the weight of large molds, ensuring the accuracy of successively adjusting the spatial fold line to horizontal for processing.

Description

Technical Field

[0001] This invention relates to the field of mold processing equipment, and more specifically, to an injection mold processing apparatus and process for suppressing internal stress. Background Technology

[0002] Mudguards are devices used to prevent mud from entering the soil. Currently, mudguards typically employ a smooth, rounded structure. While this structure is easy to manufacture, it is prone to deformation or cracking due to the release of internal stress during prolonged use. This not only reduces the durability of the mudguard but may also affect its original smooth, rounded structure, leading to a decline in product performance.

[0003] To improve the deformation resistance of mudguards, some existing solutions include adding reinforcing ribs or increasing the wall thickness inside the mudguard. However, while these methods enhance structural strength to some extent, they also significantly increase material usage and extend the manufacturing cycle, making them unsuitable for mass production. Another approach is to improve mold design, utilizing mudguard cavities with specific geometries to disperse internal stress. However, this method requires multi-axis CNC machine tools, which are expensive and complex to program. Furthermore, achieving precise angle adjustments is difficult when machining large and heavy molds.

[0004] When machining mudguard cavities with geometric shapes, the mold needs to be adjusted at multiple angles. The following specific problems arise during actual angle adjustment: First, mudguard molds are typically large and heavy. During deflection, the overturning moment generated by their own weight can easily deform the angle adjustment mechanism, causing a deviation between the actual deflection angle and the set value, making precise angle locking difficult. Second, because the mudguard cavity has multiple spatial inclined surfaces, repeated starting, stopping, and reversing are required to adjust the angle. The angle adjustment mechanism is frequently subjected to alternating loads, which can easily exacerbate the unreliability of angle positioning. Third, multiple milled surfaces overlap, falling within the category of spatial surfaces. In a Cartesian coordinate system, it is impossible to obtain the accurate machining dimensions of at least one edge through projection. This is generally unsuitable for ordinary milling machines and requires multi-axis CNC machine tools, which involve complex programming, high equipment costs, and are prone to malfunctions during machining. Fourth, positioning holes must be reserved at the intersections of multiple milled surfaces for installing hole forming pillars. These four reasons make large-sized, heavy molds with three-dimensional milled surfaces and accessories unsuitable for machining on small multi-axis CNC machine tools. Finally, in order to suppress the internal stress of the mudguard after the mold is formed as much as possible, multiple processes need to be carried out in the corresponding mold cavity. How to achieve equipment integration is also a challenge. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an injection mold processing device and process for suppressing internal stress, which aims to overcome the problem of warping or breakage of mudguards manufactured by existing molds due to the release of internal stress during long-term use.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an injection mold processing device for suppressing internal stress, including a worktable, a processing head, and a tooling module. The tooling module is fixed on the working surface of the worktable for clamping the workpiece. The tooling module is equipped with a rotatable angle adjustment plate, and the angle adjustment plate has a mounting platform. A clamping block clamps and fixes the workpiece on the working surface of the mounting platform. A reduction motor is also installed on the tooling module to drive the angle adjustment plate to deflect. The tooling module includes a mold plate support seat with a support column. A slider is located at the bottom of the angle adjustment plate. When the angle adjustment plate rotates around its rotation axis, the slider abuts against and slides relative to the support column to provide support for the angle adjustment plate. The workpiece has a pyramidal cavity defined by multiple fold lines, which are spatially continuous and form a straight line in the horizontal plane. When the angle adjustment plate deflects, each fold line can be successively adjusted to a horizontal state so that the processing head can complete the milling process in a vertical cutting manner.

[0007] According to one embodiment of the present invention, the top end of the bearing column is provided with a first arc surface, and the lower end surface of the slider is provided with a second arc surface adapted to the first arc surface; when the angle adjustment plate deflects, the second arc surface abuts against the first arc surface and slides relative to it.

[0008] According to one embodiment of the present invention, when the slider slides to the edge of the first arc surface, the slider abuts against the brake surface provided on the side of the bearing column to prevent the slider from continuing to slide, thereby limiting the maximum rotation angle of the angle adjustment plate.

[0009] According to one embodiment of the present invention, a roller is installed in the second arc surface, and the roller causes the first arc surface and the second arc surface to form a rolling contact.

[0010] According to one embodiment of the present invention, by replacing the slider or bearing column with different mating surfaces, the rotation amplitude requirements of different workpieces can be adapted; the radius of curvature of the second arc surface is consistent with that of the first arc surface.

[0011] According to one embodiment of the present invention, the workpiece used is a lower mold of an injection mold. The cavity of the lower mold of the injection mold is provided with a recess of a pyramidal structure. There is a dashed line in the cavity. The dashed line coincides with two generatrices centered in the pyramidal recess on the horizontal projection plane, so that the entire cavity forms a folding effect along the dashed line.

[0012] According to one embodiment of the present invention, the tooling module further includes a side support plate; the template bearing seat and the side support plate form a U-shaped support frame, and are fixedly installed on the worktable through the template bearing seat; the angle adjustment plate is rotatably installed on the side support plate, and the output shaft of the reduction motor is fixedly connected to the ear plate of the angle adjustment plate to drive the angle adjustment plate and the mounting table to deflect around the rotation axis.

[0013] According to one embodiment of the present invention, the machining head includes a spindle box, on which a drill and milling cutter holder and a laser are mounted side by side. The drill and milling cutter holder and the laser are each connected to an independently controlled telescopic mechanism to achieve independent switching between drilling and milling machining and laser machining stations. A camera is also mounted on the side of the spindle box for visual recognition of the machined polylines on the cavity surface. The machine head also includes a control system configured to: when the secondary reference line is partially obscured by chips or cutting fluid, extract the clearly visible machined polylines, the boundary edges of the reference plane, and the edge features of the machined milled surfaces in the cavity image captured by the camera, establish a correspondence between them and the spatial position equations of the corresponding features in the pre-stored model, thereby calculating the spatial attitude and position information of the partially obscured polylines.

[0014] This invention also provides a molding process for suppressing internal stress in injection molds, comprising the following steps: S1, fixing the lower mold of the injection mold on the mounting platform, and making the pre-set dotted line in the lower mold cavity perpendicular to the rotation axis of the angle adjustment plate; S2, using a camera to capture images of the processed polylines and establish a visual reference, adjusting each polyline in the cavity to a horizontal state sequentially using the angle adjustment plate, and processing the pyramidal recessed portion in the cavity; S3, milling a flat surface at the bottom cone of the pyramidal recess, and drilling a hole on the flat surface to obtain a hole that matches the hole forming post; S4, welding and installing the hole forming post in the hole; S5, after completing the processing of the pyramidal recessed portion and the hole forming post in the cavity, continuing to process the remaining part of the cavity until the entire lower mold of the injection mold is processed; S6, performing micropore processing on the surface of the cavity.

[0015] According to one embodiment of the present invention, the specific steps of S6 are as follows: S61, based on the position information of the processed pyramidal recess and each fold line, the cavity surface is divided into a key suppression area and a general dredging area in the control system; S62, the angle adjustment plate is driven to adjust each fold line corresponding to the key suppression area to be processed to be perpendicular to the axis of the processing head; S63, the laser on the processing head is used to process the micropores one by one along the corresponding fold line in a pulse dotting manner.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. This invention, by setting up a tooling module with an angle adjustment plate, a slider and a support column, provides stable follow-up support when adjusting the angle of a large mold to process the spatial fold line in its cavity. The arc surface cooperation of the slider and the support column can provide stable follow-up support, while the limiting design of the brake surface ensures rigidity when processing at extreme angles. This solves the problem of angle adjustment deviation and stability caused by the weight of the large mold, and ensures the accuracy of adjusting the spatial fold line to the horizontal for processing.

[0017] 2. The processing technology provided by the present invention adjusts the spatial lines constituting the concave pyramid to a horizontal state step by step using tooling modules, and then mills them in a vertical cutting manner, replacing the traditional multi-axis linkage CNC machining. While ensuring the machining accuracy of the concave pyramid, it greatly reduces equipment costs and programming difficulty.

[0018] 3. This invention uses a laser to process regularly distributed micropores on the surface of the molded cavity, especially in key suppression areas such as the edges of folded lines, in a pulsed dotting manner. This creates a micro-protrusion structure on the surface of the formed mudguard. This structure can effectively disrupt and dissipate residual stress inside the material, suppressing edge warping and overall deformation of the mudguard from a microscopic level, and improving the long-term stability of the product. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the injection mold lower die after milling to suppress internal stress in this invention; Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle; Figure 3 This is a structural diagram of the injection mold processing device in Embodiment 1 of the present invention; Figure 4 for Figure 3 A partial structural diagram of the processing device; Figure 5 for Figure 4 Enlarged structural diagram at point E in the middle; Figure 6 This is a structural diagram of the tooling module in this invention; Figure 7 This is a structural diagram of the tooling module in this invention. Figure 8 for Figure 7 Enlarged structural diagram at point B; Figure 9 This is a partial structural diagram of the bearing column and slider in Embodiment 2 of the present invention; Figure 10 for Figure 2 An exploded view of the broken lines corresponding to the dashed lines in the lower cavity of the injection mold; Figure 11This is a schematic diagram of the lower mold of the injection mold on the mounting platform in this invention; Figure 12 This is a schematic diagram of the second broken line angle deflection state in Embodiment 3 of the present invention.

[0020] Figure label: 1. Workbench; 2. Processing the machine head; 201. Spindle box; 202. Drill and milling cutter holder; 203. Laser; 204. Camera; 3. Tooling modules; 301. Profile plate support seat; 302. Side support plate; 303. Angle adjustment plate; 3031. Ear plate; 304. Mounting platform; 305. Fixture block; 306. Gear motor; 307. Support column; 3071. First arc surface; 3072. Brake surface; 308. Slider; 3081. Second arc surface; 3082. Needle roller; 4. Lower mold of injection mold; 401. First milled surface; 402. Second milled surface; 403. Third milled surface; 404. Fourth milled surface; 405. Fifth milled surface; 406. Sixth milled surface; 407. Seventh milled surface; 408. Hole forming post; 41. First broken line; 42. Second broken line; 43. Third broken line; 44. Fourth broken line; 45. Fifth broken line; 46. Sixth broken line. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1, see Figures 1 to 8 This embodiment provides an injection mold processing device for suppressing internal stress, wherein the injection mold to be processed is a lower mold 4 for molding mudguards. The mudguard formed by injection molding has an arched portion, and the mudguard as a whole is slightly folded along the arched portion. Correspondingly, a recess corresponding to the arched portion is provided in the cavity on the upper surface of the lower mold 4. In order to enable the molded mudguard to have the ability to strengthen support and resist internal stress deformation, the recess in this embodiment is set as a pyramidal structure, and further set as a pentagonal pyramidal recess, the cavity surface of which is surrounded by a first milling surface 401, a second milling surface 402, a third milling surface 403, a fourth milling surface 404, a fifth milling surface 405, a sixth milling surface 406 and a seventh milling surface 407 respectively.

[0023] A virtual fold line is defined at the recessed location within the cavity, such as... Figure 2 The dashed line C is shown. This dashed line C is a virtual auxiliary line introduced to describe the macroscopic geometry of the cavity. It coincides with the two generatrices centered within the pentagonal pyramid recess on the horizontal projection plane. Using this virtual fold line as the geometric framework, the machined surfaces on both sides of the cavity are spatially folded, thus creating a folded effect for the entire cavity. It is important to emphasize that the dashed line C itself is not a physical fold line obtained from the surface machining of the cavity, but rather a theoretical baseline used to guide mold design and machining clamping. Through this structure, a pyramidal protrusion will be formed on the molded mudguard, with bolt holes opened at the top of the protrusion. This protrusion structure effectively enhances the overall support strength of the mudguard, and combined with the folded structure, it can significantly suppress deformation caused by internal stress.

[0024] However, since the overall geometry of the pyramidal concavity is formed by folding around a non-solid virtual fold line, the multiple spatial fold lines constituting the concavity are not on the same horizontal plane, and there is a lack of a physical reference for measurement. This leads to the following difficulties in processing: Firstly, since the virtual fold lines are not solid edges on the surface of the cavity, they cannot serve as a physical benchmark for measurable or aligned machining, resulting in a lack of unified reference for the segmented positioning and connection of spatial fold lines.

[0025] Secondly, among the milled surfaces that form the concave shape of the pyramid, the first milled surface 401 and the second milled surface 402 are conventional inclined surfaces, which can be machined by a conventional milling machine by establishing a coordinate system. However, the third milled surface 403 and the fourth milled surface 404 belong to the category of spatial surfaces. In the Cartesian coordinate system, it is impossible to obtain the accurate machining dimensions of at least one side through projection. They usually require multi-axis CNC machine tools, which are complex to program, have high equipment costs, and are prone to failure during machining.

[0026] Third, mudguard molds are generally large in size and weight. When making large-angle deflections, conventional support devices cannot accurately adjust the angle of the mold while maintaining stability and fixation, which further limits the feasibility of replacing multi-axis linkage with single-axis angle step-by-step processing.

[0027] Therefore, this embodiment provides a tooling module 3 installed on the workbench 1. (See reference...) Figures 3 to 8The tooling module 3 includes a mold plate support 301 and a side support plate 302 fixed thereon. The mold plate support 301 and the side support plate 302 form a U-shaped support frame, which is fixedly installed on the working surface of the worktable 1 via the mold plate support 301. An angle adjustment plate 303 is rotatably mounted on the support frame via ear plates 3031. A mounting platform 304 is fixed on the angle adjustment plate 303. Multiple clamping blocks 305 are fitted on the working surface of the mounting platform 304 according to the shape of the workpiece to clamp the lower mold 4 of the injection mold. When installing the lower mold 4 of the injection mold, its center should be located as close as possible to the rotation axis D of the angle adjustment plate 303. Figure 11 The rotation axis D shown is to ensure smoothness during angle adjustment.

[0028] Furthermore, a geared motor 306 is installed on the outer side of the side support plate 302 on one side, and its output shaft is fixedly connected to the ear plate 3031 on one side of the angle adjustment plate 303, so that the angle adjustment plate 303 and the lower mold 4 of the injection mold can be driven to deflect around the rotation axis D.

[0029] To share the load on the output shaft of the geared motor 306 and provide stable support, a slider 308 is also provided at the bottom of the angle adjustment plate 303. Correspondingly, a support column 307 for supporting the slider 308 is installed on the upper end face of the profile support seat 301. The top of the support column 307 is provided with a first arc surface 3071, and the lower end face of the slider 308 is provided with a second arc surface 3081 that matches the first arc surface 3071. When the angle adjustment plate 303 rotates around the rotation axis D, the second arc surface 3081 abuts against the first arc surface 3071 and slides, providing follow-up support for the angle adjustment plate 303.

[0030] The width of the mating surface between the first arc surface 3071 and the second arc surface 3081 determines the maximum rotation angle range of the angle adjustment plate 303. When the slider 308 rotates with the angle adjustment plate 303 to the edge of the first arc surface 3071, the second arc surface 3081 on the slider 308 abuts against the side of the support column 307, creating a limiting effect and preventing the angle adjustment plate 303 from continuing to deflect, thus achieving a "braking" effect. In other words, by setting the side of the support column 307 as the braking surface 3072, a definite limit rotation angle is obtained.

[0031] Furthermore, the brake surface 3072 can be designed as a conical surface, making the overall support column 307 trapezoidal, to provide more stable oblique support force at this extreme position. In practical use, different sizes of sliders 308 or support columns 307 can be replaced to adapt to the rotation amplitude requirements of different workpieces. When the workpiece is relatively light, the curvature of the second arc surface 3081 can be slightly greater than or equal to the curvature of the first arc surface 3071; when the workpiece is relatively heavy, the curvature of the second arc surface 3081 should be consistent with the curvature of the first arc surface 3071 to ensure smoothness and support reliability during heavy-load rotation.

[0032] See Figure 4 and Figure 5 The machining head 2 includes a spindle box 201, a drill and milling cutter holder 202, and a laser 203. The drill and milling cutter holder 202 and the laser 203 are mounted side by side on the spindle box 201. Each of the drill and milling cutter holder 202 and the laser 203 is connected to an independently controlled telescopic mechanism, which can drive the drill and milling cutter holder 202 and the laser 203 to rise or fall independently relative to the spindle box 201, thereby realizing independent switching between drilling and milling machining and laser machining positions. The spindle box 201 can move up and down vertically to drive the drill and milling cutter holder 202 or the laser 203 to complete the feed motion. A camera 204 is also mounted on the side of the spindle box 201 via a bracket. When the tooling module 3 moves to below the camera 204, it can visually identify the processed fold lines and virtual fold lines on the cavity surface to assist the control system in calibrating the actual spatial position of each fold line after the angle adjustment plate 303 is deflected.

[0033] Example 2, see Figure 9 Based on Embodiment 1, to further improve the smoothness of the angle adjustment process and the tooling life, multiple needle rollers 3082 are embedded on the second arc surface 3081 of the slider 308. The needle rollers 3082 form rolling contact with the first arc surface 3071 of the bearing column 307, converting sliding friction into rolling friction, reducing wear, and improving the overall service life of the tooling module 3.

[0034] In Example 3, the present invention also provides an injection mold processing technology for suppressing internal stress, which is based on the processing device of Example 1. By decomposing the processing task of the pyramidal recess in the lower cavity of the injection mold, and using the angle adjustment function of the tooling module, the various lines defining the spatial structure are successively adjusted to a horizontal state, thereby using the vertical cutting method of a conventional milling machine to complete the complex spatial surface that originally required a multi-axis linkage CNC machine tool to process.

[0035] This process not only ensures machining accuracy but also significantly reduces the programming difficulty and operating cost of the equipment. For the cavity in this embodiment, Figure 2 At point C, there are multiple projectable polylines; see [reference needed]. Figure 10 and Figure 11 Specifically, it can be decomposed into a first broken line 41, a second broken line 42, a third broken line 43, a fourth broken line 44, and a fifth broken line 45 and a sixth broken line 46 defined in the processing depth direction. Each broken line is spatially continuous, and the intersection of the second broken line 42 and the third broken line 43 is used for subsequent positioning and processing of the mounting hole of the hole forming column 408.

[0036] Furthermore, a camera 204 connected to the control system is installed above the tooling module 3 to accurately identify each segment of the broken line.

[0037] In this embodiment, the following mechanism is adopted to accurately process the above-mentioned broken line: First, a polyline is machined as the primary reference line. Then, a second polyline is machined based on the primary reference line. When the second polyline is completed, it is defined as the secondary reference line. The first polyline is combined with the second polyline to machine a third polyline. At this point, the third polyline replaces the original second polyline as the secondary reference line, becoming the secondary reference line of the fourth polyline. If machining debris or cutting fluid obscures the secondary reference line area, the system can perform multi-segment fusion judgment by integrating the machined and clearly identifiable polylines to ensure positioning continuity.

[0038] Specifically, see Figure 10 After installing the lower mold 4 of the injection mold, the first fold line 41 is milled out. Then, keeping the angle adjustment plate 303 in a horizontal position, the camera 204 captures the surface of the cavity. The control system extracts the image of the first fold line 41, and after edge detection and straight line fitting, the first fold line 41 is defined as the main reference line. The second fold line 42 is then milled based on the position of the first fold line 41. At this point, the second fold line 42 is used as the secondary reference line, and the third fold line 43 is machined by combining the first fold line 41 and the second fold line 42. Thereafter, all fold line machining uses the first fold line 41 as the main reference line. After each fold line machining is completed and passes the inspection by the camera 204, the newly generated fold line is automatically updated as the current secondary reference line.

[0039] The specific processing steps for the cavity are as follows: Step S1: Workpiece clamping and initial positioning.

[0040] Securely fix the lower mold 4 of the injection mold onto the working surface of the mounting table 304, ensuring stable placement. During installation, ensure that the projection of the preset virtual fold line C in the cavity onto the horizontal plane is perpendicular to the projection of the rotation axis D of the angle adjustment plate 303 onto the horizontal plane. Figure 11 The direction of the dashed line is perpendicular to the rotation axis D to facilitate subsequent angle machining. This alignment establishes a direct mathematical relationship between the macroscopic geometric folding features of the cavity and the rotation axis of the tooling, enabling accurate calculation of the angular deflection required for leveling each spatial polygon.

[0041] To overcome the cutting forces during processing, two sets of clamping blocks 305 are used on each side of the lower mold 4 along its length to clamp it in a snap-fit ​​manner. While the clamping blocks 305 are being tightened, a dial indicator is used to check the upper surface of the lower mold 4 to inspect its flatness and levelness.

[0042] Step S2: Machining the pyramidal recessed portion in the cavity.

[0043] Step S21: Keep the lower mold 4 of the injection mold in a horizontal position. First, start the milling cutter holder 202 of the machining head 2 to work in conjunction with the XY axis of the worktable 1. Based on the preset depth of the fifth fold line 45 and the sixth fold line 46, mill the reference plane I and reference plane II on the upper surface of the lower mold 4 of the injection mold, which will serve as the Z-axis height reference for all subsequent machining steps.

[0044] Subsequently, based on the pre-simulated calculations and input system parameters, a standard angle milling cutter (such as a 45° chamfering cutter) is installed on the milling cutter holder 202 of the machining head 2. On the reference plane I, the first milling surface 401 and the second milling surface 402 are milled respectively by oblique feed. The intersection line of the two milling surfaces is the first broken line 41. At this time, a roughness sample block should be used for comparison and inspection to ensure that the outline of the first broken line 41 is clear and the edges are free of vibration marks, thereby ensuring the subsequent docking and docking quality of spatial broken lines.

[0045] After the first milling surface 401 and the second milling surface 402 are milled, the camera 204 immediately captures the entire length of the tool mark along the first zigzag line 41. The system automatically judges the milling cutter status based on the tool mark image and decides whether to continue machining accordingly. The tool mark image includes the smoothness of the tool mark edge, the consistency of the groove width, and micro-notches on the tool mark. Specifically, the edge contour of the cutting edge is extracted along the entire length of the tool mark, the edge smoothness is analyzed to identify built-up edge or micro-chipping reflected by periodic sawtooth fluctuations, and the groove width is measured at equal intervals to determine whether there is radial wear exceeding tolerance or monotonous expansion trend. Micro-notches are detected through morphological processing to capture cutting edge breakage defects.

[0046] If any of the above indicators exceed the limit, the control system will automatically pop up a tool change prompt, and the machining head 2 will return to a safe point to await operator verification. If the tool mark quality is qualified, the system will record the tool mark characteristics in the tool life database and update the baseline based on this line. This tool mark-based milling cutter status monitoring mechanism is simultaneously applied to the post-machining inspection of the third to sixth milled surfaces in steps S22 and S23, ensuring that the tool generated by each line is in good condition, preventing cavity surface defects and subsequent visual baseline blurring caused by tool dulling or chipping from the source.

[0047] Step S22: Start the reduction motor 306 to drive the angle adjustment plate 303 and the lower mold 4 of the injection mold to slowly rotate in the forward direction. (See reference...) Figure 12 The second broken line 42, which defines one side of the spatial plane of the pyramid, is adjusted from an inclined state to a horizontal state.

[0048] The specific steps are as follows: The geared motor 306 has a built-in encoder that provides real-time feedback of the rotation angle to the control terminal. The system presets the angle to be compensated between the second broken line 42 and the reference horizontal plane as α. For example, if the cavity design slope is 35°, then α is set to 35°. Finally, it needs to be deflected to a horizontal state with α=0°. At this time, it is considered that the second broken line 42 is completely horizontal.

[0049] The tooling module 3 is locked in position, and the machining head 2 is replaced with a ball end mill. Since the second fold line 42 is now on the horizontal plane, the third milling surface 403 and the fourth milling surface 404, which originally defined this spatial relationship, have now become programmable two-dimensional contour cutting in the coordinate system of the drill and milling cutter holder 202. According to the preset depth parameters, the system controls the milling cutter to mill the third milling surface 403 and the fourth milling surface 404 respectively, obtaining a clear second fold line 42, and completing the machining of one side of the concave spatial surface of the pyramid.

[0050] Step S23: After completing S22, unlock the attitude lock of tooling module 3 and drive angle adjustment plate 303 to deflect in the opposite direction. The operation method is the same as S22, and the goal is to make the third fold line 43 horizontal.

[0051] Furthermore, after confirming that the third fold line 43 is horizontal, the machining head 2 cuts down to mill the fifth milling surface 405 and the sixth milling surface 406, thus obtaining the third fold line 43. The intersection of the second fold line 42 and the third fold line 43 is the reserved position for the hole forming post 408.

[0052] In step 23, the secondary reference line has been updated to the second broken line 42. However, debris and cutting fluid generated in the previous process may partially obscure the second broken line 42, preventing the camera from fully recognizing the current secondary reference line. At this point, the camera no longer relies on the obscured secondary reference line, i.e., the second broken line 42, but instead comprehensively detects multiple types of machined features that are clearly visible from the current viewpoint to solve for the second broken line 42.

[0053] Specifically, camera 204 captures the cavity area from the current perspective, automatically adjusting exposure to suppress cutting fluid reflection. After filtering and edge enhancement, it extracts clearly identifiable first slant line 41, fifth slant line 45, and sixth slant line 46 from the image, as well as the boundary edges of reference planes I / II and the outer edge of the completed seventh milled surface 407, and other unobstructed straight line features. The control system establishes a spatial correspondence between these extracted image lines and the spatial position equations of corresponding features in the pre-stored model, and calculates the spatial orientation of the second slant line 42. After obtaining the actual orientation of the second slant line 42, it calculates the angle deviation between the second slant line 42 and the horizontal plane, thereby determining the driving speed reducer motor 306 until the third slant line 43 is adjusted to a horizontal state. Through the above multi-segment geometric calculation, even if the secondary reference line is temporarily invisible, the system can still ensure the continuity of the machining reference.

[0054] In step S24, the lower mold 4 of the injection mold is restored to a horizontal state by means of a mechanism. According to the preset cutting depth and slope parameters of the seventh milling surface 407, the machining head 2 performs flat-bottom milling to obtain a smooth seventh milling surface 407.

[0055] Step S3: After completing the overall milling of the pyramidal concave shape, drilling is required at the bottom conical part, i.e., the reserved position of the hole forming column 408. At this time, the control system first confirms the working status of the drill and milling cutter holder 202 and the laser 203, so that the drill and milling cutter holder 202 is in the working position and the laser 203 is in the raised and stored state.

[0056] A milling cutter head is clamped on the drill and milling cutter holder 202. A small planar boss perpendicular to the mounting surface of the hole forming post 408 is milled first as the starting point for drilling to prevent the drill bit from slipping or deviating on the conical surface. Subsequently, the drilling process begins. The drill and milling cutter holder 202, through its configured automatic tool changer, removes the milling cutter head currently clamped on the drill and replaces it with a drill bit to carry out the drilling operation.

[0057] In step S3, the state of the drill and milling cutter holder 202 will switch from milling state to drilling state.

[0058] Step S4: After drilling is completed, the lower mold 4 of the injection mold is removed from the mounting table 304 and transferred to the press-fitting station. The hole-forming post 408 is pressed into the drilled hole to achieve interference fit. After press-fitting is completed, the lower mold 4 of the injection mold with the hole-forming post 408 installed is hoisted back onto the mounting table 304 and re-clamped and fixed by the clamping block 305. During re-clamping, the dotted line C is used for alignment. The coordinate system of the drill and milling cutter holder 202 is re-established in conjunction with the first fold line 41, the second fold line 42, the third fold line 43, and the fourth fold line 44 to ensure that the clamping posture of the lower mold 4 of the injection mold is consistent with that before drilling.

[0059] After clamping and alignment are completed, the workstation is switched to laser welding operation. The control system controls the telescopic mechanism of the drill and milling cutter holder 202 to lift and store it, and then the telescopic mechanism of the laser 203 lowers the laser 203 to the working position to perform the welding work of the hole forming column 408.

[0060] In step S4, the state of the drill and milling cutter holder 202 is a switch from the drill and milling station to the laser processing station.

[0061] Step S5: After completing the machining of the pyramidal recessed part and the hole forming pillar in the cavity, continue machining the remaining part of the cavity until the machining of the entire injection mold lower mold 4 is completed.

[0062] The other independent molding pillars in the cavity can also be drilled and then embedded in accordance with this process to reduce the risk of overall heat treatment deformation.

[0063] Example 4: Based on Examples 1 to 3, this example further provides a process method for suppressing internal stress through micropores.

[0064] While the lower mold of the injection mold relies on macroscopic structures (such as pyramidal protrusions) for enhanced support, significantly improving the overall deformation resistance of the mudguard, internal stress can still accumulate locally at the microscopic level, especially at edges and curved transition areas. Long-term use may lead to warping of the mudguard. To further disperse and release internal stress, this embodiment adds a microporous forming process to the surface of the machined cavity, creating a regularly distributed micro-protrusion structure on the surface of the injection-molded mudguard. These micro-protrusions effectively disrupt the orientation of residual stress within the material, concentrating and dissipating stress to multiple micro-areas, thereby better suppressing edge warping and breakage.

[0065] The micropore machining in this embodiment is applied to the tooling module provided in Embodiment 1 to obtain good rigid support and angular positioning capabilities, as well as the cavity polygon division and reference data determined in Embodiment 3. Under machining conditions with large deflection angles, the stable limiting effect generated by the abutment of the second arc surface 3081 of the slider 308 against the bearing column 307 ensures the machining accuracy of the micropores. Simultaneously, the distribution boundary of the micropores can reuse the surface features such as the first polygon 41, second polygon 42, third polygon 43, fourth polygon 44, and seventh milled surface 407 obtained through successive leveling in Embodiment 3, without the need to re-establish the coordinate system.

[0066] Typically, deformation caused by internal stress in mudguards begins at structural edges and where curvature changes drastically. Therefore, this embodiment divides the cavity surface into a key suppression zone and a general drainage zone.

[0067] The key suppression areas correspond to the parts of the mudguard that are prone to warping after molding, namely the ridge areas near the parting surface and with large curvature bends in the mold cavity. Specifically, these are the 5-10mm bands on both sides of the first bend 41, the second bend 42, and the third bend 43, as well as the edge transition zone of the fourth bend 44. These areas are critical for releasing internal stress and require the installation of high-density micropores.

[0068] Generally, the stress-guiding zone corresponds to the gently curving plane or steeply curved slope of the mudguard after molding, namely the entire area of ​​the seventh milled surface 407, as well as the flat internal areas far from the broken line, such as the third milled surface 403 and the sixth milled surface 406. These areas only need to be arranged with low-density micropores to form stress guiding channels to dissipate residual stress.

[0069] Regarding the distribution of micropores, they should be distributed in a band-like pattern along the direction of each zigzag line, preferably on the outer side of the zigzag line near the edge of the cavity (i.e., the edge of the mudguard), rather than in the center of the cavity. This is because the edge of the mudguard is a free end with the lowest degree of constraint and the most sensitive deformation response. Forming a dense micro-pinching structure at the edge can maximally suppress warping. In contrast, the central region is reinforced by the pyramidal protrusions and only requires sparse micropores for support.

[0070] The specific steps are as follows: Step S6: Machining micropores on the cavity surface.

[0071] Step S61: Based on the pyramidal depression processed in step S2 of Example 3 and the determined spatial coordinates of each broken line, the micropore processing path is pre-planned in the control system of the machining head 2. For key suppression areas, the micropores are arranged in a single or double row along the broken line direction, with a center-to-center distance of 0.8–1.2 mm between adjacent micropores and a surface density of 15–20 micropores / cm². For general drainage areas, the micropores are arranged in a uniform lattice distribution with a center-to-center distance of 2.5–3.5 mm and a surface density of 2–4 micropores / cm².

[0072] The specifications for micropores are uniformly defined as follows: pore diameter Φ0.15~0.3mm, depth 0.08~0.15mm, and shape is either inverted conical or cylindrical with a flat bottom, to ensure complete melt filling during injection molding and to prevent undercutting during demolding.

[0073] In step S62, the angle adjustment plate 303 is driven by the geared motor 306 to adjust each segment of the broken line projected onto the dotted line C to a horizontal state. When processing the key suppression area corresponding to the edges of the second broken line 42 and the third broken line 43, the angle adjustment plate 303 can be intentionally deflected to the extreme position where the second arc surface 3081 abuts against the side of the support column 307. At this time, due to the "braking" effect described in Embodiment 1, the entire tooling module forms a rigid positioning support, and the slight vibration generated when the laser 203 performs pulse dotting is effectively suppressed, ensuring the consistency of the position and depth of the micropores.

[0074] In step S63, the system controls the telescopic mechanism of the drill and milling cutter holder 202 to raise and retract it, and then the telescopic mechanism of the laser 203 lowers the laser 203 to the working position, completing the switch from the drilling and milling station to the laser processing station. The tooling module 3 moves along the planned path with the lower mold, and the laser 203 processes the micropores one by one in a pulse dot pattern. After each area of ​​micropore processing is completed, the camera 204 can re-inspect the shape of the micropores until all areas are processed.

[0075] Step S64 completes the micropore processing.

[0076] After the micropores are machined, the laser 203 is lifted and stored by the telescopic mechanism, and the drill and milling cutter holder 202 is reset to the working position, restoring the drilling and milling station for convenient subsequent processing.

[0077] After the micropores are machined, the lower mold can be removed and cleaned using an ultrasonic cleaner with anhydrous ethanol to remove residual metal powder or slag from the micropores. It is then dried with clean compressed air and coated with a thin layer of rust-preventive oil, which is retained before assembly.

[0078] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0079] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A molding die processing device for suppressing internal stress, characterized in that, It includes a workbench (1), a machining head (2), and a tooling module (3); The tooling module (3) is fixed on the working surface of the workbench (1) and is used to clamp the workpiece; The tooling module (3) is provided with a rotatable angle adjustment plate (303), and the angle adjustment plate (303) is provided with a mounting platform (304). The workpiece is clamped and fixed on the working surface of the mounting platform (304) by a clamping block (305). The tooling module (3) is also provided with a geared motor (306) for driving the angle adjustment plate (303) to deflect. The tooling module (3) includes a template support seat (301), a support column (307) is provided on the template support seat (301), and a slider (308) is provided at the bottom end of the angle adjustment plate (303). When the angle adjustment plate (303) rotates around its rotation axis, the slider (308) abuts against the support column (307) and slides relative to it to provide support for the angle adjustment plate (303). The workpiece has a pyramidal recessed cavity defined by multiple fold lines, which are continuous in space and form a straight line in the horizontal plane; when the angle adjustment plate (303) is deflected, each of the fold lines can be adjusted to a horizontal state in turn so that the machining head (2) can complete the milling process in a vertical cutting manner. The top of the support column (307) is provided with a first arc surface (3071), and the lower end surface of the slider (308) is provided with a second arc surface (3081) that is adapted to the first arc surface (3071); when the angle adjustment plate (303) deflects, the second arc surface (3081) abuts against the first arc surface (3071) and slides relative to it. When the slider (308) slides to the edge of the first arc surface (3071), the slider (308) abuts against the brake surface (3072) provided on the side of the bearing column (307) to prevent the slider (308) from continuing to slide, thereby limiting the maximum rotation angle of the angle adjustment plate (303).

2. The injection mold processing device for suppressing internal stress according to claim 1, characterized in that, A needle roller (3082) is installed inside the second arc surface (3081), and the first arc surface (3071) and the second arc surface (3081) are made to roll in contact through the needle roller (3082).

3. The internal stress suppressing injection mold processing apparatus according to claim 2, wherein By replacing the slider (308) or the bearing column (307) with different mating surfaces, the rotation amplitude requirements of different workpieces can be adapted; the radius of curvature of the second arc surface (3081) is consistent with that of the first arc surface (3071).

4. The internal stress suppressing injection mold processing apparatus according to claim 1, wherein The workpiece used is the lower mold of the injection mold (4). The cavity of the lower mold of the injection mold (4) is provided with a recess of pyramidal structure. There is a dashed line in the cavity. The dashed line coincides with the two generatrices in the middle of the pyramidal recess on the horizontal projection plane, so that the cavity as a whole forms a folding effect along the dashed line.

5. The internal stress suppressing injection mold processing apparatus according to claim 1, wherein The tooling module (3) also includes a side support plate (302); the template bearing seat (301) and the side support plate (302) form a U-shaped support frame and are fixedly installed on the workbench (1) through the template bearing seat (301); the angle adjustment plate (303) is rotatably installed on the side support plate (302), and the output shaft of the geared motor (306) is fixedly connected to the ear plate (3031) of the angle adjustment plate (303) to drive the angle adjustment plate (303) and the mounting table (304) to deflect around the rotation axis.

6. A molding die processing apparatus for suppressing internal stress according to any one of claims 1 to 5, characterized in that, The machining head (2) includes a spindle box (201), on which a drill and milling cutter holder (202) and a laser (203) are mounted side by side. The drill and milling cutter holder (202) and the laser (203) are each connected to an independently controlled telescopic mechanism to realize independent switching between drilling and milling and laser processing stations. A camera (204) is also installed on the side of the spindle box (201) for visual recognition of the processed fold lines on the cavity surface. It also includes a control system configured to: when the secondary reference line is partially obscured by debris or cutting fluid, extract the clearly visible machined polyline, the boundary edge of the reference plane and the edge features of the machined milled surface in the cavity image captured by the camera (204), establish a correspondence between them and the spatial position equations of the corresponding features in the pre-stored model, and thus calculate the spatial attitude and position information of the partially obscured polyline.

7. The injection mold processing method for restraining internal stress, applied to the injection mold processing device for restraining internal stress according to claim 6, characterized in that, Includes the following steps: S1, fix the lower mold of the injection mold on the mounting platform, and make the preset dotted line in the lower mold cavity of the injection mold perpendicular to the rotation axis of the angle adjustment plate; S2, use a camera to capture images of the processed polylines and establish a visual reference, and use an angle adjustment plate to adjust each polyline in the cavity to a horizontal state one by one, and process the pyramidal recessed part in the cavity; S3, a flat surface is milled out at the concave bottom cone of the pyramid, and a hole is drilled in the flat surface to obtain a hole that matches the hole-forming column; S4, Weld and install the hole-forming column inside the hole; S5, after completing the processing of the pyramidal recessed part and the hole forming column in the cavity, continue processing the remaining part of the cavity until the entire injection mold lower mold is completed; S6, micropores are machined on the surface of the cavity.

8. A process for the machining of an injection mold to suppress internal stresses according to claim 7, characterized in that, The specific steps for S6 are as follows: S61, based on the position information of the already processed pyramidal recess and each broken line, divides the cavity surface into a key suppression area and a general dredging area in the control system; S62, drive the angle adjustment plate (303) to adjust each line corresponding to the key suppression area to be processed to be perpendicular to the axis of the processing head (2); S63, using the laser (203) on the machining head (2), the micropores are processed one by one in a pulse dot pattern along the corresponding zigzag path.

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