An injection mold

Abstract

The utility model belongs to mould technical field discloses a kind of injection mould, for manufacturing sensor, the injection mould includes front mould component and the rear mould component being oppositely arranged with the front mould component;The front mould component includes front mould plate and the front mould kernel being located in the inside of the front mould plate, the front mould kernel is equipped with first polishing part and first rough part;The rear mould component includes rear mould plate and the rear mould kernel being located in the inside of the rear mould plate, the rear mould kernel is oppositely arranged with the front mould kernel, the rear mould kernel is equipped with second polishing part and second rough part, the second polishing part and the first polishing part are correspondingly arranged, the second rough part and the first rough part are correspondingly arranged.The injection mould of the utility model simplifies the injection process of sensor, reduces positioning frequency and reduces artificial error, improves product consistency and precision, while improving production efficiency, reduce cost.

Description

Technical Field

[0001] This utility model belongs to the field of mold technology and relates to an injection mold. Background Technology

[0002] In the field of photoelectric sensor manufacturing, the lens and indicator area are core functional components, and their molding process directly affects the sensor's detection accuracy and stability. Since the lens and indicator area need to be made of transparent PC material, while the main shell is made of opaque material, the mainstream production method in the industry is to manufacture the lens, indicator area, and main shell separately by injection molding.

[0003] Specifically, each injection molding process requires individual positioning of the product within the mold. If there are multiple different colors or material requirements, the positioning and injection molding process must be repeated. This traditional process has significant drawbacks: Firstly, the multiple positioning processes involving manual intervention are prone to introducing errors, resulting in differences between each part and making it difficult to ensure the consistency of the focal length of the lens and the light-emitting hole, thus affecting the detection accuracy of the sensor. Secondly, the cumbersome procedures not only increase processing time and reduce production efficiency, but also drive up the manufacturing cost of a single product due to the cumulative labor costs. At the same time, the connection process of multiple injection moldings may reduce the product qualification rate and affect the overall production stability.

[0004] Therefore, there is an urgent need in this field for an injection mold to solve the above-mentioned technical problems. Utility Model Content

[0005] In view of this, the purpose of this utility model is to solve the problems of complex injection molding process of sensors in the prior art, multiple positioning and human operation errors, poor product consistency and insufficient accuracy.

[0006] This utility model provides an injection mold for manufacturing sensors, including a front mold assembly and a rear mold assembly disposed opposite to the front mold assembly; The front mold assembly includes a front template and a front mold core disposed inside the front template. The front mold core is provided with a first polished part and a first roughened part. The rear mold assembly includes a rear mold plate and a rear mold core disposed inside the rear mold plate. The rear mold core is disposed opposite to the front mold core. The rear mold core is provided with a second polished part and a second roughened part. The second polished part and the first polished part are disposed correspondingly to each other, and the second roughened part and the first roughened part are disposed correspondingly to each other.

[0007] As a further improvement of this utility model, the front mold assembly further includes a front mold fixing plate, which is fixedly connected to the front template. The front mold fixing plate has a liquid injection hole at its center, which passes through the front mold fixing plate, the front template, and the front mold core in sequence. The lower surface of the front mold core has a plurality of first mold cavities symmetrically arranged around the liquid injection hole. The bottom of the front mold core has a first liquid injection channel, which communicates with each of the first mold cavities. The bottom of the liquid injection hole communicates with the first liquid injection channel. The upper surface of the rear mold core is provided with a second injection channel corresponding to the first injection channel; the upper surface of the rear mold core is provided with a second mold cavity corresponding to the first mold cavity, and the second injection channel is connected to each second mold cavity. When the front mold core and the rear mold core are closed, the second mold cavity is embedded in the interior of the first mold cavity, and the first injection channel is closed on the second injection channel to form a complete injection channel.

[0008] As a further improvement of this utility model, the rear mold assembly further includes a rear mold fixing plate, and an ejection assembly is provided between the rear mold fixing plate and the rear mold plate. The ejection assembly includes a first top plate, a second top plate, and a plurality of ejector pins disposed between the first top plate and the rear mold plate. The top of the ejector pins is correspondingly inserted into the bottom of the second mold cavity. The rear mold fixing plate is provided with a top hole. The first top plate and the second top plate push the ejector pins to move toward the rear mold plate to eject the sensor housing formed in the second mold cavity.

[0009] As a further improvement of this utility model, the first mold cavity is recessed inward on the lower surface of the front mold core, the first polishing part and the first roughening part are disposed on the surface of the first mold cavity, the first polishing part includes a first stepped polishing part and a first circular polishing part, and the first roughening part is disposed on the periphery of the first stepped polishing part and the first circular polishing part. The second mold cavity protrudes towards the lower surface of the front mold core. The second polishing part and the second roughening part are disposed on the surface of the second mold cavity. The second polishing part includes a second stepped polishing part and a second circular polishing part. The second roughening part is disposed on the periphery of the second stepped polishing part and the second circular polishing part. The second step polishing part and the first step polishing part are respectively arranged correspondingly, and the second circular polishing part and the first circular polishing part are respectively arranged correspondingly.

[0010] As a further improvement of this utility model, the second mold cavity is provided with an undercut surface at one end away from the polished part of the second step, and the first mold cavity is provided with an undercut groove at one end away from the polished part of the first step. The undercut surface and the undercut groove cooperate to form an undercut hole.

[0011] As a further improvement of this utility model, the rear template is provided with a slider facing the front template, and the slider abuts against the undercut surface; The rear mold core is provided with an elastic element, which is connected to the slider. The elastic element is used to pop out the slider so that the slider separates from the undercut surface.

[0012] As a further improvement of this utility model, the front template is provided with a pressure block, and the pressure block is correspondingly arranged with the slider; The pressure block is provided with an inclined rail facing the slider, and the slider is provided with an inclined groove facing the pressure block. When the front template and the rear template are closed, the inclined rail slides along the inclined groove so that the slider abuts against the undercut surface.

[0013] As a further improvement of this utility model, the first polishing part and the second polishing part are formed by polishing; The surfaces of the first roughened portion and the second roughened portion are provided with textures.

[0014] As a further improvement of this utility model, the top of the injection hole is provided with a tapered opening.

[0015] As a further improvement of this utility model, the rear mold fixing plate is fixedly provided with a plurality of positioning rods, and the first top plate and the second top plate are provided with support blocks on both sides, and the top of the positioning rod passes through the support block and is fixedly connected to the rear mold plate. The rear template has guide posts along its edge, and the front template has guide bushings along its edge. The guide posts and guide bushings are arranged correspondingly.

[0016] The technical advantages of this invention are as follows: Compared with existing technologies, the injection mold provided by this invention, through the corresponding design of polished and roughened parts, ensures optical performance by having the smooth polished part correspond to key light-transmitting areas such as the sensor's lens and indicator window, while the roughened part corresponds to the main body shell, achieving light-shielding, anti-slip, or aesthetic effects, thus meeting the integrated structural and functional requirements of the sensor. Compared to traditional processes where the light-transmitting area and the non-light-transmitting main body of the sensor need to be separately injection molded or processed, this invention allows for the simultaneous molding of both smooth and rough surfaces in a single injection molding process, eliminating the need for multiple positioning or processing steps, significantly reducing procedures and improving production efficiency. The precise alignment of the polished part ensures the surface smoothness of the sensor's light-transmitting area, reducing optical interference and ensuring the accuracy of light transmission or reception. The fixed structure of the mold cavity avoids positioning errors caused by multiple processing steps, resulting in highly consistent surface characteristics of sensors produced in batches and improving product reliability. Eliminating the need for manual polishing and multiple injection molding processes reduces labor costs and material waste. Furthermore, single-stage molding reduces the risk of product scrap due to multiple operations, indirectly lowering production costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model, not all embodiments. For those skilled in the art, other drawings obtained from these drawings without creative effort are all within the protection scope of this utility model.

[0018] Figure 1 This is a perspective view of an injection mold provided in an embodiment of this utility model; Figure 2 This is an exploded view of an injection mold provided in an embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of the front mold core provided in this embodiment of the utility model; Figure 4 This is a schematic diagram of the structure of the rear mold core provided in an embodiment of this utility model.

[0019] Among them, 10 is the front mold assembly, 11 is the front template, 111 is the pressure block, 1111 is the inclined rail, 112 is the guide bushing, 12 is the front mold core, 121 is the first polishing part, 1211 is the first step polishing part, 1212 is the first round polishing part, 122 is the first rough part, 123 is the first mold cavity, 1231 is the undercut groove, 124 is the first injection channel, 13 is the front mold fixing plate, 131 is the injection hole, and 1311 is the conical opening; 20 is the rear mold assembly, 21 is the rear template, 211 is the slider, 2111 is the inclined groove, 212 is the guide post, 22 is the rear mold core, 221 is the second polishing part, 2211 is the second step polishing part, 2212 is the second round polishing part, 222 is the second rough part, 223 is the second mold cavity, 2231 is the undercut surface, 224 is the second injection channel, 225 is the elastic element, 23 is the rear mold fixing plate, 231 is the top hole, 232 is the positioning rod, 24 is the ejector assembly, 241 is the first top plate, 242 is the second top plate, 243 is the ejector pin, and 244 is the support block. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0021] To make the description of this disclosure more detailed and complete, illustrative descriptions of the embodiments and specific examples of this utility model are provided below; however, this is not the only form of implementing or using the specific embodiments of this utility model. The embodiments cover the features of multiple specific embodiments and the methods, steps, and sequences for constructing and operating these specific embodiments. However, other specific embodiments can also be used to achieve the same or equivalent functions and sequence of steps. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0023] It should be understood that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in sequences other than those illustrated or described herein.

[0024] In the description of this utility model, the terms "front", "rear", "top", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0025] Please refer to Figures 1-4 One embodiment of this utility model provides an injection mold to solve the problems of complicated injection processes of sensors in the prior art, errors caused by multiple positioning and human operation, poor product consistency and insufficient accuracy.

[0026] Specifically, please refer to Figure 1 A perspective view of an injection mold provided for an embodiment of this utility model. Figure 2 This is an exploded view of an injection mold according to an embodiment of the present invention. The injection mold includes a front mold assembly 10 and a rear mold assembly 20 disposed opposite to the front mold assembly 10. The front mold assembly 10 includes a front mold plate 11 and a front mold core 12 disposed inside the front mold plate 11. Please refer to [link to relevant documentation]. Figures 3-4The front mold core 12 is provided with a first polished portion 121 and a first roughened portion 122; the rear mold assembly 20 includes a rear mold plate and a rear mold core 22 disposed inside the rear mold plate 21. The rear mold core 22 is disposed opposite to the front mold core 12. The rear mold core 22 is provided with a second polished portion 221 and a second roughened portion 222. The second polished portion 221 and the first polished portion 121 are correspondingly disposed, and the second roughened portion 222 and the first roughened portion 122 are correspondingly disposed. When the injection mold is closed, the front mold core 12 and the rear mold core 22 are precisely aligned: the first polished portion 121 of the front mold core 12 and the second polished portion 221 of the rear mold core 22 are completely aligned, together forming areas on the surface of the plastic part that require smooth characteristics, such as the lens and indicating area of ​​a sensor; the first roughened portion 122 of the front mold core 12 and the second roughened portion 222 of the rear mold core 22 are completely aligned, together forming areas on the surface of the plastic part that require rough characteristics, such as the main body shell of a sensor, anti-slip or light-shielding areas, etc. During injection molding, the molten material fills the complete cavity formed by the closing of the front mold core 12 and the rear mold core 22. The molten material is in close contact with the mold surface, and the surface of the final molded sensor component will replicate the surface characteristics of the mold. The area in contact with the polished part forms a smooth surface, while the area in contact with the rough part forms a textured or rough surface. It should be noted that PC (Polycarbonate) is actually used as the molten material during injection molding.

[0027] The injection mold provided in this embodiment features a design that corresponds polished and roughened sections. The smooth polished section corresponds to key light-transmitting areas of the sensor, such as the lens and indicator window, ensuring optical performance. The roughened section corresponds to the main body shell, providing light-shielding, anti-slip, or aesthetic effects, thus meeting the integrated structural and functional requirements of the sensor. Compared to traditional processes where the light-transmitting area and the non-light-transmitting body of the sensor need to be separately injection molded or processed, this method allows for the simultaneous molding of both smooth and rough surfaces in a single injection molding process. This eliminates the need for multiple positioning or processing steps, significantly reducing procedures and improving production efficiency. The precise alignment of the polished section ensures the surface smoothness of the sensor's light-transmitting area, reducing optical interference and guaranteeing the accuracy of light transmission or reception. The fixed structure of the mold cavity avoids positioning errors caused by multiple processing steps, resulting in highly consistent surface characteristics of sensors produced in batches and improving product reliability. Eliminating the need for manual polishing and multiple injection molding processes reduces labor costs and material waste. Furthermore, single-stage molding reduces the risk of product scrap due to multiple operations, indirectly lowering production costs.

[0028] As a further improvement of this utility model, the front mold assembly 10 further includes a front mold fixing plate 13, which is fixedly connected to the front template 11. The front mold fixing plate 13 has a liquid injection hole 131 at its center, which sequentially penetrates the front mold fixing plate 13, the front template 11, and the front mold core 12. The lower surface of the front mold core 12 has a plurality of first mold cavities 123 symmetrically arranged around the liquid injection hole 131. The bottom of the front mold core 12 has a first liquid injection channel 124, which communicates with each of the first mold cavities 123. The bottom of the liquid injection hole 131 communicates with the first liquid injection channel 124. The front mold assembly 10 adds a front mold fixing plate 13, whose central liquid injection hole 131 serves as the main inlet for molten material, vertically penetrating the front mold fixing plate 13, the front template 11, and the front mold core 12, forming a top-to-bottom main channel. The bottom of the front mold core 12 is provided with a first injection channel 124, which laterally connects the bottom of the injection hole 131 to multiple first mold cavities 123 on the lower surface of the front mold core 12, forming a branch flow path on the front mold side. The upper surface of the rear mold core 22 is provided with a second injection channel 224 corresponding to the first injection channel 124; the upper surface of the rear mold core 22 is provided with a second mold cavity 223 corresponding to the first mold cavity 123, and the second injection channel 224 communicates with each of the second mold cavities 223. The upper surface of the rear mold core 22 is correspondingly provided with the second injection channel 224 and the second mold cavity 223, wherein the shape of the second injection channel 224 matches that of the first injection channel 124, and the positions of the second mold cavity 223 correspond one-to-one with those of the first mold cavity 123. When the front mold core 12 and the rear mold core 22 are closed, the second mold cavity 223 is embedded inside the first mold cavity 123, and the first injection channel 124 is closed on the second injection channel 224 to form a complete injection channel. During mold closing, the first injection channel 124 and the second injection channel 224 precisely align to form a complete closed flow channel. The second mold cavity 223 is embedded inside the first mold cavity 123, forming multiple independent molding cavities. The molten material flows through the injection hole 131 to the complete injection channel and finally reaches each cavity to complete the filling. After the molten material is injected from the injection hole 131, it is simultaneously distributed to multiple cavities through symmetrically distributed injection channels. Multiple sensor structural components are formed in one go using the closed space after the mold is closed, and the filling pressure and speed of each cavity are consistent. The multiple symmetrical cavity design can realize the molding of multiple products in one injection, which improves the production efficiency by several times compared with single-cavity molds. At the same time, the integrated design of the injection channels avoids the waiting time of injection in multiple sessions, significantly shortening the production cycle. The injection channels are symmetrically distributed with the injection hole 131 as the center, ensuring that the molten material is evenly distributed to each cavity and avoiding part size deviations caused by differences in filling volume. The precise fitting structure of the second mold cavity 223 into the first mold cavity 123 ensures the consistency of the molding space each time the mold is closed, reduces errors caused by manual adjustment or mold misalignment, and makes the precision of the sensor components produced in batches highly uniform.The integrated injection and multi-cavity design eliminates the repetitive positioning and demolding steps of traditional multi-stage injection molding, reducing manual intervention, lowering labor costs, and avoiding material waste and increased scrap rates caused by multiple operations. The docking design of the injection channels reduces melt flow resistance, avoiding problems of excessive or insufficient local pressure, and reducing the probability of injection molding defects such as bubbles, short runs, and shrinkage marks. This is especially beneficial for molding thin-walled structures or complex curved surfaces of sensors. The symmetrical layout of the injection holes 131 and the cavities ensures uniform stress on the mold, reducing local wear during long-term use. Combined with a precise fitting structure, this effectively extends the mold's service life and maintenance cycle.

[0029] As a further improvement of this utility model, the rear mold assembly 20 further includes a rear mold fixing plate 23, and an ejection assembly 24 is provided between the rear mold fixing plate 23 and the rear template 21. The rear mold assembly 20 adds a rear mold fixing plate 23 as the mounting base for the ejection mechanism, and a reserved space is provided between the rear mold fixing plate 23 and the rear template 21 for the ejection assembly 24. The ejection assembly 24 includes a first top plate 241, a second top plate 242, and a plurality of ejector pins 243 disposed between the first top plate 241 and the rear mold plate 21. The tops of the ejector pins 243 are respectively inserted into the bottom of the second mold cavity 223. The rear mold fixing plate 23 has a top hole 231. The ejection assembly 24 consists of the first top plate 241, the second top plate 242, and the plurality of ejector pins 243. The ejector pins 243 are installed between the first top plate 241 and the rear mold plate 21, and their tops pass through a pre-drilled hole at the bottom of the second mold cavity 223, contacting the bottom surface of the sensor housing formed inside the cavity. The top hole 231 is provided on the rear mold fixing plate 23 to provide operating space for the movement of the top plate. In actual production, the ejector rod of the injection molding machine pushes the top plate through the top hole 231. The first top plate 241 and the second top plate 242 push the ejector pins 243 toward the rear mold plate 21 to eject the sensor housing formed in the second mold cavity 223. After the sensor housing is formed and cooled to solidify in the second mold cavity 223: the front mold assembly 10 and the rear mold assembly 20 separate to complete the mold opening. The injection molding machine ejector pin pushes the first ejector plate 241 and the second ejector plate 242 towards the rear mold plate 21 through the ejector hole 231. The first ejector plate 241 drives the ejector pin 243 to move axially towards the rear mold plate 21. The top of the ejector pin 243 extends from the bottom of the second mold cavity 223, smoothly ejecting the formed sensor housing from the cavity and completing the demolding. The mechanical drive design of the ejector assembly 24 replaces the traditional manual removal method, and realizes automated demolding in conjunction with the mold opening action, reducing manual intervention time, adapting to the continuous operation requirements of batch production, and significantly improving the overall production efficiency. The multiple ejector pins 243 correspond to the force points at the bottom of the second mold cavity 223, so that the sensor housing is subjected to uniform force during the ejection process, avoiding deformation, warping or surface scratches caused by single-point force. The rigid connection between the top plate and the ejector pin 243 ensures synchronous ejection, preventing the shell from getting stuck in the cavity and reducing product scrap rate. The ejection assembly 24 is integrated between the rear mold fixing plate 23 and the rear mold plate 21, without occupying the cavity molding space. The precise fit between the ejector pin 243 and the second mold cavity 223 avoids affecting the sensor functional surfaces, such as the polished parts. It works in synergy with the injection system and cavity structure of the front and rear molds to ensure the overall compactness and functionality of the mold. The fit design between the ejector pin 243 and the bottom of the cavity reduces wear during long-term ejection. At the same time, the stacked structure of the first top plate 241 and the second top plate 242 disperses the driving force, reduces the stress on individual components, and indirectly extends the maintenance cycle and service life of the mold.For complex structures such as steps and undercuts that may exist in the sensor housing, the multi-point ejector pin 243 layout can apply ejection force in a targeted manner, ensuring smooth demolding even in areas where the local cavity fits tightly, thus broadening the mold's adaptability to different sensor structures.

[0030] As a further improvement of this utility model, the first mold cavity 123 is recessed inward toward the lower surface of the front mold core 12. The first polishing part 121 and the first roughening part 122 are disposed on the surface of the first mold cavity 123. The first polishing part 121 includes a first stepped polishing part 1211 and a first circular polishing part 1212. The first roughening part 122 is disposed around the first stepped polishing part 1211 and the first circular polishing part 1212. The first mold cavity 123 is recessed in the lower surface of the front mold core 12, and its inner surface is divided into functional areas. The first polishing part 121 includes the first stepped polishing part 1211, the first circular polishing part 1212, and the first roughening part 122. Among them, the stepped polishing part corresponds to the stepped high-precision mating surface of the sensor, such as the indicator light area; the circular polishing part corresponds to the circular optical surface of the sensor, such as the lens; and the roughening part is distributed around the periphery of these functional surfaces, corresponding to the non-functional areas of the sensor, such as the main body shell. The second mold cavity 223 protrudes towards the lower surface of the front mold core 12. The second polishing portion 221 and the second roughening portion 222 are disposed on the surface of the second mold cavity 223. The second polishing portion 221 includes a second stepped polishing portion 2211 and a second circular polishing portion 2212. The second roughening portion 222 is disposed around the second stepped polishing portion 2211 and the second circular polishing portion 2212. The second mold cavity 223 protrudes onto the upper surface of the rear mold core 22, precisely matching the concave shape of the first mold cavity 123. Its outer surface is also divided into corresponding functional areas. The second polishing portion 221 includes a second stepped polishing portion 2211, a second circular polishing portion 2212, and a second roughening portion 222, each corresponding to a region of the first mold cavity 123. The second stepped polishing portion 2211 and the first stepped polishing portion 1211 are correspondingly disposed, and the second circular polishing portion 2212 and the first circular polishing portion 1212 are correspondingly disposed. During mold closing, the protruding second mold cavity 223 is embedded in the recessed first mold cavity 123, forming a closed molding space: the first stepped polished part 1211 and the second stepped polished part 2211 fit together to jointly form the stepped smooth mating surface of the sensor; the first circular polished part 1212 and the second circular polished part 2212 fit together to jointly form the circular smooth optical surface of the sensor; the rough parts of both fit together to jointly form the rough surface of the sensor's periphery, such as the frosted texture of the main body shell. After the molten material is filled, the smoothness and shape characteristics of the mold surface are directly replicated to form the complex functional structure of the sensor in one step. The stepped polished part corresponds to the indicator light display area of ​​the sensor, and high-precision polishing ensures the accuracy of the indicator light display and improves structural stability. The circular polished part corresponds to the optical components such as the lens, and high-precision polishing ensures the efficiency of light transmission and reception and avoids optical loss caused by surface roughness. The peripheral rough part can enhance the anti-slip, light-shielding, or marking adhesion of the sensor shell to meet the needs of multiple application scenarios.In traditional manufacturing processes, the optical and mating surfaces of sensors require separate polishing, while the main housing needs roughening treatments such as sandblasting, resulting in cumbersome procedures. This solution utilizes a partitioned design of the mold cavity surface, allowing surfaces with different finish requirements to be formed simultaneously in a single injection molding process, eliminating secondary processing and reducing production and time costs. The precise fit of the concave and convex mold cavities ensures the dimensional accuracy of complex structures such as sensor steps and arcs, avoiding shape deviations caused by multiple processing steps. The fixed correspondence between the polished and roughened sections ensures high consistency in functional surface accuracy and surface texture across mass-produced sensors, improving product reliability. Considering the multi-feature, multi-functional structural characteristics of sensors, the refined design of the polished and roughened sections can flexibly match the performance requirements of different areas, broadening the mold's applicability to various types of sensors.

[0031] As a further improvement of this utility model, the second mold cavity 223 is provided with an undercut surface 2231 at one end away from the second step polishing part 2211, and the first mold cavity 123 is provided with an undercut groove 1231 at one end away from the first step polishing part 1211. The undercut surface 2231 and the undercut groove 1231 cooperate to form an undercut hole. At the end of the second mold cavity 223 away from the second step polishing part 2211, i.e. the end of the cavity, an outwardly protruding undercut surface 2231 is provided, the surface contour of which matches the inner shape of the sensor undercut hole; correspondingly, at the end of the first mold cavity 123 away from the first step polishing part 1211, an inwardly recessed undercut groove 1231 is provided, the shape of which precisely matches the undercut surface 2231 of the second mold cavity 223. When the mold is closed, the undercut surface 2231 of the second mold cavity 223 is embedded in the undercut groove 1231 of the first mold cavity 123. The two work together to form a closed molding space with an inner undercut feature, i.e. the undercut hole structure required by the sensor. When the molten material fills the cavity, it completely fills the space formed by the undercut surface 2231 and the undercut groove 1231. After cooling and solidification, the inner wall of the hole structure replicates the shape of the undercut surface 2231, and the outer side fits with the undercut groove 1231 to form the outer contour of the hole. Thus, an undercut hole is directly formed on the sensor housing without secondary processing. In traditional processes, the undercut hole of the sensor needs to be formed by secondary processing such as milling and grinding after injection molding, which is a complex process and easily damages the surrounding structure. The injection mold provided in this embodiment directly forms the undercut structure of the mold, eliminating the secondary processing step, shortening the production cycle, and reducing labor and equipment costs.

[0032] The precise fit between the undercut surface 2231 and the undercut groove 1231 ensures stable dimensions and regular shape of the formed undercut hole. The high consistency of its inner undercut features allows for accurate matching during subsequent assembly, preventing assembly loosening or sealing failure due to dimensional deviations and improving the overall structural reliability of the sensor. This embodiment utilizes integrated molding to ensure the connection strength between the undercut hole and the sensor housing, avoiding stress concentration or breakage risks caused by secondary processing. This is particularly suitable for miniaturized, highly integrated sensor designs. The undercut structure is only located at the end of the mold cavity, away from critical functional areas such as the stepped polishing section and the circular polishing section, avoiding interference with the forming accuracy of the sensor's optical and mating surfaces. This synergizes with the overall polishing and roughening zoning design of the mold, ensuring the compatibility of all sensor functions.

[0033] As a further improvement of this utility model, the rear mold plate 21 is provided with a slider 211 facing the front mold plate 11. The slider 211 abuts against the undercut surface 2231. A slidable slider 211 is provided on the side of the rear mold plate 21 facing the front mold plate 11. In the mold-closed state, the slider 211 and the undercut surface 2231 are in close contact, forming the molding boundary of the undercut hole. The rear mold core 22 is provided with an elastic element 225. The elastic element 225 is connected to the slider 211. The elastic element 225 is used to eject the slider 211 so that the slider 211 separates from the undercut surface 2231. The rear mold core 22 has a pre-reserved mounting groove and a built-in elastic element 225. In some embodiments, the elastic element 225 can be a spring. One end of the elastic element 225 is fixed to the rear mold core 22, and the other end is connected to the slider 211. Under normal conditions, the elastic element 225 is in a compressed state, providing a thrust to the slider 211 away from the undercut surface 2231. Once the sensor housing is formed, the mold enters the mold opening stage: the front mold assembly 10 separates from the rear mold assembly 20, releasing the squeezing constraint on the slider 211; the elastic element 225 releases its elastic force, pushing the slider 211 to slide away from the undercut surface 2231, causing the slider 211 to separate from the outside of the undercut hole of the sensor housing; at this time, the constraint between the undercut feature inside the undercut hole and the undercut surface 2231 of the second mold cavity 223 is released, and with the action of the ejector pin 243 of the ejection assembly 24, the sensor housing can be completely ejected from the cavity. In traditional injection molded parts with undercuts, the undercut feature is prone to jamming with the cavity during demolding, leading to product deformation, tearing, or breakage. In this embodiment, through the cooperation of the slider 211 and the elastic element 225, the slider 211 is separated from the undercut hole before demolding, eliminating the constraint at the undercut, ensuring that the thin-walled structure around the undercut hole of the sensor housing is not subjected to additional stress during ejection, significantly reducing the scrap rate. During mold closing, the slider 211 and the undercut surface 2231 make tight contact, ensuring the forming accuracy of the inner and outer shapes of the undercut hole, the angle of the undercut features, and the dimensions, and avoiding undercut deformation caused by mold gaps. The precise undercut structure ensures the sealing performance of the fit with the snap-fit ​​and sealing ring during subsequent assembly, improving the overall structural reliability of the sensor. The separation action of the slider 211 driven by the elastic element 225 is linked to the mold opening process, eliminating the need for additional manual operation or power source, realizing an automated process of "mold opening - slider 211 separation - ejection", shortening the single production cycle and adapting to the needs of mass production.

[0034] As a further improvement of this utility model, the front template 11 is provided with a pressure block 111, which is correspondingly arranged with the slider 211; the pressure block 111 is provided on the side of the front template 11 facing the rear template 21, and the position of the pressure block 111 corresponds to the slider 211 on the rear template 21; the pressure block 111 is provided with a sloping rail 1111 facing the slider 211, and the slider 211 is provided with a sloping groove 2111 facing the pressure block 111. When the front template 11 and the rear template 21 are closed, the sloping rail 1111 slides along the sloping groove 2111 so that the slider 211 abuts against the undercut surface 2231. The side of the pressure block 111 facing the slider 211 is machined with an inclined sloping rail 1111, and the side of the slider 211 facing the pressure block 111 is provided with a sloping groove 2111 adapted to the sloping rail 1111. The inclination angle and length of the sloping groove 2111 match the sloping rail 1111, forming a sliding fit pair. During the closing process of the current template 11 and the rear template 21, the pressure block 111 moves with the front template 11 towards the rear template 21. The inclined rail 1111 gradually inserts into the inclined groove 2111 of the slider 211. When the inclined rail 1111 slides along the inclined groove 2111, the vertical mold closing force of the front template 11 is converted into a horizontal force that pushes the slider 211 through the guiding effect of the inclined surface. This causes the slider 211 to move towards the undercut surface 2231 of the second mold cavity 223. When the mold is fully closed, the slider 211 is pushed by the inclined rail 1111 and comes into close contact with the undercut surface 2231, together forming the complete forming boundary of the undercut hole, ensuring the shape accuracy of the undercut structure when the molten material is filled. During mold closing, the slider 211 is pushed by the inclined rail 1111 to compress the elastic element 225; during mold opening, the front template 11 moves the pressure block 111 away, the inclined rail 1111 disengages from the inclined groove 2111, and the elastic element 225 releases its elastic force to push the slider 211 away from the undercut surface 2231, realizing the automated linkage of "mold closing clamping - mold opening separation". Traditional slider 211 clamping relies on manual or single driving force, which is prone to insufficient pressure, resulting in gaps between the slider 211 and the undercut surface 2231 during mold closing, causing flash and burrs during molten material filling. In this embodiment, the rigid cooperation between the inclined rail 1111 and the inclined groove 2111 directly converts the mold closing force into the clamping force of the slider 211, ensuring that the slider 211 and the undercut surface 2231 fit tightly, and the formed undercut hole has smooth edges and accurate dimensions, avoiding jamming or loosening during subsequent assembly. The engagement of the pressure block 111 and the slider 211 is completed automatically during the mold closing process, without the need for additional drive devices or manual operation. This adapts to the needs of automated injection molding production lines, reduces human error, and improves production stability. A closed loop is formed with the elastic element 225 and the slider 211: during mold closing, the pressure block 111 overcomes the elastic force of the elastic element 225 to push the slider 211 to press firmly via the inclined rail 1111; during mold opening, the pressure block 111 disengages, and the elastic element 225 automatically resets the slider 211.The entire process is synchronized with the mold opening and closing actions, ensuring both molding accuracy during mold closing and smooth demolding during mold opening, thus solving the dual problems of difficult molding and demolding of undercut structures. The sliding fit between the inclined rail 1111 and the inclined groove 2111 is a surface contact, resulting in uniform force distribution and a low coefficient of friction. Compared to point contact or rigid collision, this reduces localized wear on the slider 211 and the pressure block 111. Simultaneously, the clamping force is distributed and transmitted through the inclined surface, reducing the risk of deformation of the undercut surface 2231 due to excessive localized force, and extending the service life of key mold components. For sensors with complex undercut features such as multi-angle and deep cavities, the stroke and clamping force of the slider 211 can be precisely controlled by adjusting the angle and length of the inclined rail 1111 and the inclined groove 2111, ensuring the molding quality of different types of undercut holes and improving the mold's adaptability to diverse sensor products.

[0035] As a further improvement of this utility model, the first polishing part 121 and the second polishing part 221 are formed by polishing. The first step polishing part 1211 and the first circular polishing part 1212 of the first polishing part 121, and the second step polishing part 2211 and the second circular polishing part 2212 of the second polishing part 221 are processed by mechanical polishing. Through grinding, waxing and other processes, the surface of the mold cavity achieves a high-precision surface finish. This smooth surface ensures that when in contact with the molten material, the corresponding area of ​​the formed sensor, such as the lens and indicator light display area, replicates the smooth characteristics of the mold, meeting the requirements of optical transmission or precision assembly. The surfaces of the first rough part 122 and the second rough part 222 are provided with textures. The surfaces of the first rough part 122 and the second rough part 222 are formed with preset textures, such as grid patterns, stripes, and frosted patterns, through processes such as etching, sandblasting or electrical discharge machining. The depth and density of the textures can be adjusted according to the functional requirements of the sensor. These textures create a microscopic uneven structure on the mold cavity surface. After the molten material fills the cavity, it replicates the texture pattern, resulting in a rough surface on the sensor's main housing and anti-slip grip areas. This fulfills functions such as light shielding, anti-slip properties, and label adhesion. The high-precision surface finish of the polished areas ensures the light transmittance of the sensor's optical areas, reducing light scattering or refraction losses and improving detection accuracy. The textured design of the roughened areas provides the sensor housing with anti-slip properties, facilitating installation and operation; simultaneously, the texture enhances surface diffuse reflection, reducing interference from ambient light on sensor detection.

[0036] In traditional processes, smooth surfaces of sensors require manual polishing after injection molding, while rough surfaces require additional sandblasting or film application. These processes are cumbersome and prone to damaging the product. This embodiment utilizes pre-processing of the mold surface, allowing different surface characteristics to be formed in a single injection molding process, eliminating secondary processing steps and reducing production and time costs. The polishing and texturing of the mold surface are industrially precise processes, resulting in minimal differences in surface characteristics within the same batch of molds. This ensures high consistency in transmittance, friction, and appearance among mass-produced sensors, avoiding individual differences caused by manual post-processing and improving product reliability. The dense surface formed by polishing reduces molten material residue and corrosion, extending the mold cleaning cycle. The texturing process, using physical etching and other techniques, is less prone to wear from long-term injection molding, ensuring the mold can stably replicate surface characteristics during long-term use, reducing mold maintenance frequency and costs. By adjusting the polishing precision and texturing type, the personalized needs of different sensors can be met, broadening the applicability of injection molds.

[0037] As a further improvement of this utility model, the top of the injection hole 131 is provided with a conical opening 1311. The diameter of the conical opening 1311 gradually decreases from the top to the bottom, forming a funnel-shaped transition structure, and finally smoothly connects with the vertical channel of the injection hole 131. The injection hole 131 serves as the main inlet for molten material to enter the mold. When the injection molding machine nozzle aligns with the injection hole 131, the conical opening 1311 can guide the nozzle to precise alignment, while allowing the molten material to smoothly transition along the conical surface to the main channel of the injection hole 131 after flowing out of the nozzle, reducing flow resistance. The funnel-shaped structure of the conical opening 1311 has a guiding effect on the injection molding machine nozzle, which can reduce the accuracy requirements of manual or mechanical alignment. Even with slight deviations, the nozzle can slide into the correct position along the conical surface, ensuring a tight seal. This effectively reduces the leakage and waste of molten material at the inlet of the injection hole 131, while avoiding mold surface contamination caused by leakage. The buffering effect of the tapered opening 1311 can reduce the impact force generated by the hard contact between the injection molding machine nozzle and the injection hole 131, and reduce the wear of both. At the same time, the smooth transition structure reduces the retention of molten material at the inlet, avoids mold corrosion or nozzle blockage caused by long-term high-temperature molten material accumulation, and indirectly extends the maintenance cycle of the mold and injection equipment.

[0038] As a further improvement of this utility model, the rear mold fixing plate 23 is fixedly provided with multiple positioning rods 232. Support blocks 234 are provided on both sides of the first top plate 241 and the second top plate 242. The top of the positioning rod 232 passes through the support block 234 or the first top plate 241 and the second top plate 242 and is fixedly connected to the rear template 21. Multiple positioning rods 232 are vertically fixed on the rear mold fixing plate 23. Their tops pass through the first top plate 241 and the second top plate 242 or the support block 234 and are rigidly connected to the rear template 21, forming a rigid support structure that penetrates the ejection assembly 24 and the rear template 21. The arrangement of the support block 234 and the positioning rod 232 allows the top plate to slide along the axial direction of the positioning rod 232, while restricting its lateral displacement, ensuring that the ejector pin 243 always moves in the vertical direction during the ejection process. The edge of the rear template 21 is provided with guide posts 212, and the edge of the front template 11 is provided with guide bushings 112. The guide posts 212 and the guide bushings 112 are correspondingly arranged. Cylindrical guide posts 212 are provided along the edge of the rear template 21, and guide bushings 112 with internal holes are provided at corresponding positions on the front template 11. During mold closing, the guide posts 212 are inserted into the guide bushings 112 to guide the front and rear templates 21 to precise alignment until they are completely closed, ensuring that the cavities of the front mold core 12 and the rear mold core 22 fit together without misalignment. The cooperation between the positioning rod 232 and the support block restricts the lateral sway of the top plate, so that the ejector pin 243 is subjected to uniform force and moves smoothly when ejecting, avoiding excessive local force on the sensor housing caused by the misalignment of the ejector pin 243, effectively reducing the risk of product deformation and tearing, and improving demolding quality. The precise cooperation between the guide posts 212 and the guide bushings 112 ensures that the front and rear templates 21 maintain coaxiality throughout the mold closing process, ensuring precise alignment of the first mold cavity 123 and the second mold cavity 223, the first injection channel 124 and the second injection channel 224, and the polished part and the rough part, avoiding product dimensional deviations or blockage of injection channels due to misalignment. The precise guiding structure allows the mold to remain stable at higher mold opening and closing speeds, reducing downtime for adjustments due to positioning deviations. At the same time, the smooth movement of the ejector assembly 24 can shorten the demolding cycle, adapting to the high-speed operation requirements of automated production lines and indirectly improving overall production efficiency.

[0039] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] The above embodiments only illustrate preferred implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An injection mold for manufacturing sensors, characterized in that, It includes a front mold assembly and a rear mold assembly disposed opposite to the front mold assembly; The front mold assembly includes a front template and a front mold core disposed inside the front template. The front mold core is provided with a first polished part and a first roughened part. The rear mold assembly includes a rear template and a rear mold core disposed inside the rear template. The rear mold core is disposed opposite to the front mold core. The rear mold core is provided with a second polished part and a second roughened part. The second polished part and the first polished part are disposed correspondingly to each other, and the second roughened part and the first roughened part are disposed correspondingly to each other.

2. The injection mold according to claim 1, characterized in that, The front mold assembly further includes a front mold fixing plate, which is fixedly connected to the front template. The front mold fixing plate has a liquid injection hole at its center, which passes through the front mold fixing plate, the front template, and the front mold core in sequence. The lower surface of the front mold core is symmetrically arranged with the liquid injection hole as the center. The bottom of the front mold core has a first liquid injection channel, which communicates with each of the first mold cavities. The bottom of the liquid injection hole communicates with the first liquid injection channel. The upper surface of the rear mold core is provided with a second injection channel corresponding to the first injection channel; the upper surface of the rear mold core is provided with a second mold cavity corresponding to the first mold cavity, and the second injection channel is connected to each second mold cavity. When the front mold core and the rear mold core are closed, the second mold cavity is embedded in the interior of the first mold cavity, and the first injection channel is closed on the second injection channel to form a complete injection channel.

3. The injection mold according to claim 2, characterized in that, The rear mold assembly also includes a rear mold fixing plate, and an ejection assembly is provided between the rear mold fixing plate and the rear mold plate; The ejection assembly includes a first top plate, a second top plate, and a plurality of ejector pins disposed between the first top plate and the rear mold plate. The top of the ejector pins is correspondingly inserted into the bottom of the second mold cavity. The rear mold fixing plate is provided with a top hole. The first top plate and the second top plate push the ejector pins to move toward the rear mold plate to eject the sensor housing formed in the second mold cavity.

4. The injection mold according to claim 2, characterized in that, The first mold cavity is recessed inward toward the lower surface of the front mold core. The first polishing part and the first roughening part are disposed on the surface of the first mold cavity. The first polishing part includes a first stepped polishing part and a first circular polishing part. The first roughening part is disposed on the periphery of the first stepped polishing part and the first circular polishing part. The second mold cavity protrudes towards the lower surface of the front mold core. The second polishing part and the second roughening part are disposed on the surface of the second mold cavity. The second polishing part includes a second stepped polishing part and a second circular polishing part. The second roughening part is disposed on the periphery of the second stepped polishing part and the second circular polishing part. The second step polishing part and the first step polishing part are respectively arranged correspondingly, and the second circular polishing part and the first circular polishing part are respectively arranged correspondingly.

5. The injection mold according to claim 4, characterized in that, The second mold cavity has an undercut surface at one end away from the polished part of the second step, and the first mold cavity has an undercut groove at one end away from the polished part of the first step. The undercut surface and the undercut groove cooperate to form an undercut hole.

6. The injection mold according to claim 5, characterized in that, The rear template is provided with a slider facing the front template, and the slider abuts against the undercut surface; The rear mold core is provided with an elastic element, which is connected to the slider. The elastic element is used to pop out the slider so that the slider separates from the undercut surface.

7. The injection mold according to claim 6, characterized in that, The front template is provided with a pressure block, and the pressure block is correspondingly arranged with the slider; The pressure block is provided with an inclined rail facing the slider, and the slider is provided with an inclined groove facing the pressure block. When the front template and the rear template are closed, the inclined rail slides along the inclined groove so that the slider abuts against the undercut surface.

8. The injection mold according to claim 1, characterized in that, The first polishing portion and the second polishing portion are formed by polishing; The surfaces of the first rough portion and the second rough portion are provided with textures.

9. The injection mold according to claim 2, characterized in that, The injection hole has a tapered opening at the top.

10. The injection mold according to claim 3, characterized in that, The rear mold fixing plate is fixedly provided with multiple positioning rods, and the first top plate and the second top plate are provided with support blocks on both sides. The top of the positioning rod passes through the support block or the first top plate and the second top plate and is fixedly connected to the rear mold plate. The rear template has guide posts along its edge, and the front template has guide bushings along its edge. The guide posts and guide bushings are arranged correspondingly.

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