A method of designing an injection mold

Abstract

The application provides an injection mold design method, and belongs to the technical field of molds. The method solves the problem of poor product quality caused by molding defects at the joint position of an injection product. The injection mold design method comprises the following steps: S1, determining a heating area: according to the position of the molding defects at the joint of the product, the corresponding position of the injection mold cavity is found out and determined as the heating area; S2, setting an embedding groove and a heating wire: a plurality of embedding grooves arranged along the edge of the cavity are formed on the parting surface, the embedding grooves correspond to the heating area one by one, each embedding groove comprises a body section in the form of a strip arranged along the edge of the cavity, and a heating wire is embedded in each embedding groove; S3, setting an air vent groove: an air vent groove is formed on the parting surface at both ends of the body section of each embedding groove, the air vent groove is arranged along the edge of the cavity and is separated from the heating wire, the air vent groove is connected with the embedding groove and communicates with the outside. The injection mold designed by the method can make the joint position of the injection product evenly heated and reduce molding defects.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of molds and relates to a design method of an injection mold. BACKGROUND

[0002] With the development of the automobile industry, automobile models are no longer single, and automobile lampshade models are also diversified, and a multi-color lampshade is one of the development directions. Most of the automobile lampshades are formed by injection molding through a mold, the injection mold comprises a fixed mold and a movable mold, the fixed mold and the movable mold form a cavity after being combined, the lampshade is formed in the cavity, and a parting surface is formed between the fixed mold and the movable mold, and the parting surface is located outside the cavity. The multi-color lampshade is generally formed by corresponding multiple sets of molds, and each set of mold forms a structure of one color. Taking a double-color lampshade as an example, during processing, a first part structure of a first color is formed in a first set of molds, and then the formed first part structure is moved to a second set of molds, and a second part structure of a second color is formed directly on the first part structure in the second set of molds, and a joint is formed at a parting surface between the second part structure and the first part structure.

[0003] In order to make the mold temperature uniform to reduce the forming defects of the product, a water channel is generally arranged in the mold at present, and hot water or steam is conveyed through the water channel to heat. For example, an SMC hot-press forming mold disclosed in Chinese patent document [publication number: CN101733891B] comprises an upper mold and a lower mold, a mold cavity is formed after the upper mold and the lower mold are combined, the mold cavity is provided with a forming surface of a formed product, and the upper mold or the lower mold is provided with a heating system for uniformly heating the forming surface. The heating system comprises a plurality of water wells, the distance between the bottom of each water well and the forming surface is the same, and the water wells are connected through a series water channel to realize the working temperature.

[0004] Due to the limitation of the existing processing technology, the water well structure can only be processed by drilling a straight hole. For the forming surface designed to adapt to the complex structure of the double-color lampshade, the water well structure often cannot be arranged according to the shape of the forming surface, so that the temperature of the forming surface (especially the edge of the cavity) cannot be uniformly distributed. When the second part structure of the double-color lampshade is injection molded, if the temperature of the edge of the mold cavity is not uniform, a false joint will be formed at the position of the joint of the double-color lampshade, and a bright line or a bright spot will appear at the position of the joint on the appearance, and even cracking and other situations will occur.

[0005] In order to improve the uniformity of the temperature of the forming surface, the density of the water well can be increased at the edge of the forming surface, but the increase of the density of the water well will cause the structural strength of the mold to be weakened, which is not conducive to the structural stability of the mold. Alternatively, a combined mold can be arranged according to the shape of the forming surface, such as the patent document with the publication number CN105058730A, but this method is equivalent to increasing at least two structures of the forming surface in the mold, which greatly increases the manufacturing cost of the mold. SUMMARY

[0006] The purpose of the present application is to solve the technical problem that the product quality is poor due to the molding defects at the joint position of the existing injection molding product.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] An injection mold design method, the injection mold comprises a mold body, the mold body is provided with a cavity and a parting surface, characterized in that the injection mold design method comprises the following steps:

[0009] S1, determining a heating area: according to the position of the product joint forming defect, find out the corresponding injection mold cavity position and determine it as a heating area;

[0010] S2, setting the slot and the heating wire: a plurality of slots arranged along the edge of the cavity are opened on the parting surface, the slots correspond to the heating areas one by one, each slot comprises a body section arranged in a strip along the edge of the cavity, and a heating wire is embedded in each slot;

[0011] S3, setting the vent groove: a vent groove is opened on the parting surface at both ends of the body section of each slot, which is arranged along the edge of the cavity and is separated from the heating wire, the vent groove is connected with the slot and communicates with the outside.

[0012] The waterway heating can be retained on the mold body, and the heating wire can be arranged in the slot on the parting surface to supplement the heating. The slots are arranged along the edge of the cavity, and the body section of the slot is arranged along the edge of the cavity, so that the heat generated by the heating wire is distributed along the edge of the cavity; the heat generated by the heating wire not only conducts to the mold body, but also heats the air in the slot. For the position outside the two ends of the slot without heating wire, due to the existence of the vent groove, the air in the slot is heated and flows out of the slot and along the vent groove, and the hot air carries part of the heat generated by the heating wire to supplement the heating of the position near the vent groove. At the same time, it can also prevent the local temperature at the slot from overheating. Therefore, the structure of the parting surface of the injection mold is beneficial to uniform temperature distribution of the edge of the cavity, so as to uniformly heat the joint position of the injection molding product, reduce the molding defects, and improve the product quality.

[0013] In addition, the slot and the vent groove are arranged on the parting surface, which can be formed by milling or directly cast, so that the manufacturing cost of the mold is not greatly increased, the processing difficulty is not great, and the influence on the overall structure strength of the mold body is also not great. And the setting of the vent groove can dredge the hot air in the slot and discharge it to the outside, preventing the hot air from entering the cavity and causing product molding defects.

[0014] In the injection mold design method, in step S2, the distance from the cavity edge to the center surface of the body section is the same along the length direction of the embedding groove body section; in step S3, the distance from the cavity edge to the vent groove center surface is the same along the length direction of the vent groove, and the distance from the cavity edge to the vent groove center surface is equal to the distance from the cavity edge to the body section center surface.

[0015] Designing the embedding groove and the vent groove not only makes the embedding groove and the vent groove easy to process, but also is conducive to temperature uniformization and improves product quality.

[0016] In the injection mold design method, in step S2, the heating wire is provided in a variable-diameter structure, and the diameter of the heating wire is proportional to the distance from the heating wire axis to the parting surface.

[0017] In the case of the same heat source power, the farther away from the heat source, the lower the temperature. The larger the diameter of the heating wire, the smaller the resistance of the heating wire. In the case of the same heating wire voltage, the larger the diameter of the heating wire, the greater the power of the heating wire, that is, the greater the heat generated by the heating wire. Since the diameter of the heating wire is proportional to the distance from the heating wire axis to the parting surface, the temperature generated by the heat conducted to the cavity edge by the large-diameter heating wire can be approximately the same as the temperature generated by the heat conducted to the cavity edge by the small-diameter heating wire, so that the temperature distribution at the cavity edge can be more uniform.

[0018] In the injection mold design method, when the embedding groove is provided with a plurality of embedding grooves, different power heating wires are embedded in each embedding groove, and the power of the heating wire is determined according to the severity of the molding defect of the product joint, wherein the greater the molding defect, the greater the power of the heating wire.

[0019] The more serious the molding defect, the lower the temperature of the corresponding cavity position in the original injection mold. The greater the power of the heating wire, the greater the heat generated, so that the temperature of the corresponding cavity position of the molding defect can be increased, thereby improving the uniformity of the cavity position temperature and improving the product quality.

[0020] In the injection mold design method, in step S3, the vent grooves between the adjacent two embedding grooves are connected as a whole.

[0021] Through the connected vent grooves, the heat generated by the heating wires in the adjacent two embedding grooves can be integrated, which is conducive to improving the uniformity of the temperature and improving the product quality.

[0022] In the injection mold design method, in step S2, each embedding groove further includes two extension sections arranged away from the cavity and connected to the two ends of the body section, respectively, and the two ends of each heating wire are respectively extended from the two extension sections of the corresponding embedding groove.

[0023] The extension section can not only make the two ends of the heating wire extend out of the mold body, but also guide the hot air in the embedding groove to flow along the embedding groove and flow out of the extension section, which is beneficial to the temperature homogenization of the edge of the cavity and can avoid the local over-high temperature of the embedding groove and the hot air in the embedding groove entering the cavity to affect the product quality. In addition, the heat generated by the heating wire at the extension section can be more quickly conducted to the vent groove, thereby being beneficial to further supplement heating of the edge of the cavity near the vent groove and improving the temperature homogeneity of the edge of the cavity.

[0024] In the injection mold design method, in step S2, a heat insulation plate is covered and fixed at the slot opening of each embedding groove, the heat insulation plate is located in the embedding groove, the surface of the heat insulation plate away from the embedding groove is lower than the parting surface, and a gap is arranged between the heating wire and the heat insulation plate; in step S3, a gap is arranged between the bottom surface of the vent groove and the heat insulation plate.

[0025] The heat insulation plate can reduce the heat generated by the heating wire from being radiated and dissipated to the outside of the slot opening of the embedding groove and ensure the heating effect of the heating wire on the edge of the cavity. In addition, the blocking effect of the heat insulation plate can also make the heated air in the embedding groove flow along the embedding groove and flow to the vent groove, which is beneficial to the temperature homogenization of the edge of the cavity. The heat insulation plate is located in the embedding groove, and the surface of the heat insulation plate away from the embedding groove is lower than the parting surface, so that the air at the slot opening of the embedding groove is separated from the heating wire by the heat insulation plate, the air at the slot opening of the embedding groove is prevented from mixing with the air heated by the heating wire, and the heating effect of the heating wire is affected. The existence of the gap is beneficial to the flow and drainage of the air in the embedding groove and is beneficial to the temperature homogenization of the edge of the cavity. The existence of the gap makes the air heated by the heating wire enter the vent groove from the embedding groove, which is also beneficial to the temperature homogenization of the edge of the cavity.

[0026] In the injection mold design method, the following steps are further included:

[0027] S4, an exhaust structure is arranged: a plurality of along grooves one are arranged on the parting surface between the embedding groove main section and the cavity, the along groove one communicates the embedding groove main section and the cavity, the bottom surface of the along groove one is located between the parting surface and the heat insulation plate, and an exhaust passage one that communicates the embedding groove with the outside is arranged on the parting surface on the side of the embedding groove main section away from the cavity.

[0028] In the injection process, the air in the cavity can be sequentially discharged from the cavity through the along groove one, the embedding groove and the exhaust passage one, and the discharged air is separated from the heating wire by the heat insulation plate, so that the heat generated by the heating wire is prevented from being taken away by the discharged air in the cavity, the heating effect of the heating wire on the edge of the cavity is ensured, the molding defects of the joint position of the injection product are reduced, and the product quality is improved.

[0029] In the injection mold design method, in step S4, a second along groove is arranged on the parting surface between the vent groove and the cavity, the second along groove communicates the vent groove and the cavity, and a second exhaust passage communicating the vent groove and the outside is arranged on the parting surface away from the cavity.

[0030] In the injection process, the air in the cavity can also be sequentially discharged from the cavity through the second along groove, the vent groove and the second exhaust passage, the mold body is in a whole heating state during injection, and the air in the cavity is also heated, so that the air in the cavity can bring part of the heat of other positions of the cavity when passing through the second along groove and the vent groove, which has the effect of supplementary heating on the positions near the vent groove, is beneficial to improve the temperature uniformity of the edge of the cavity and improve the product quality.

[0031] In the injection mold design method, the following steps are further included:

[0032] S5, temperature detection position is arranged: a plurality of temperature detection positions are arranged on the parting surface, the temperature detection positions correspond to the grooves one by one, the temperature detection positions are away from the cavity on the side of the main body section of the groove, and the distance from each temperature detection position to the center surface of the corresponding main body section of the groove is the same.

[0033] The temperature sensor is installed on the temperature detection position and is used for detecting the temperature of the parting surface, the temperature sensor transmits the detected temperature to the controller, the controller controls the on-off of the heating wire according to the detected temperature, so as to control the temperature of the parting surface, avoid local high temperature, and be beneficial to ensure the uniformity of the temperature.

[0034] Compared with the prior art, the injection mold design method has the following advantages:

[0035] The grooves and the vent grooves are arranged on the parting surface, the main body section of the groove and the vent groove are arranged along the edge of the cavity, the heating wire with different power can be embedded in the groove, the edge of the cavity is uniformly heated, the forming defects of the joint position of the injection product are reduced, and the product quality is improved. The heating wire and the air discharged from the cavity are separated by the heat insulation plate, the heating effect of the heating wire is ensured, and the heat dispersion effect brought by the hot air flow in the groove and the vent groove is ensured, which is beneficial to ensure the temperature uniformity of the edge of the cavity and improve the product quality. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a flowchart of the injection mold design method.

[0037] Figure 2 is a perspective view of the injection mold designed according to the design method.

[0038] Figure 3 is Figure 2 is a partial perspective view of the hidden heat insulation plate in A of

[0039] Figure 4 is Figure 2 a partial sectional view of the injection mold in the B-B (the embedding groove) position.

[0040] Figure 5 is Figure 2 a partial sectional view of the injection mold in the C-C (the vent groove) position.

[0041] Figure 6 is Figure 2 a partial sectional view of the injection mold in the D-D (the joint position of the embedding groove and the vent groove) position.

[0042] In the figure, 1, the mold body; 1a, the cavity; 1b, the parting surface; 1c, the overflow port; 1d, the positioning groove; 1e, the positioning hole; 1f, the positioning convex strip; 2, the embedding groove; 2a, the main body section; 2b, the extension section; 2c, the shoulder; 3, the heating wire; 4, the mounting groove; 5, the heat insulation plate; 5a, the fixed part; 6, the fixed groove; 7, the vent groove; 8, the gap; 9, the along groove one; 11, the exhaust passage one; 12, the along groove two; 13, the exhaust passage two; 14, the temperature detection position. DETAILED DESCRIPTION

[0043] The following is a specific embodiment of the present application and further describes the technical solution of the present application in conjunction with the accompanying drawings, but the present application is not limited to these embodiments.

[0044] As Figure 1 shown, a design method of an injection mold, the injection mold comprising a mold body 1, the mold body 1 having a cavity 1a and a parting surface 1b thereon, the design method comprising the following steps:

[0045] S1, determining a heating zone: according to the position of the product joint defect, finding out the corresponding position of the injection mold cavity 1a and determining it as a heating zone.

[0046] The area of the heating zone is larger than the area of the molding defect, so as to facilitate the homogenization of the temperature of the cavity 1a edge position after heat diffusion, and avoid the appearance of new molding defects at other positions after the original molding defects disappear. The number of heating zones corresponds to the number of molding defects one by one, and when the molding defects are one, the heating zones are one, and when the molding defects are multiple, the heating zones are multiple.

[0047] S2, setting the embedding groove 2 and the heating wire 3: as Figure 2 , Figure 3 and Figure 4 shown, a plurality of embedding grooves 2 arranged along the edge of the cavity 1a are opened on the parting surface 1b, the embedding grooves 2 correspond to the heating zones one by one, each embedding groove 2 comprises a main body section 2a arranged in a strip shape along the edge of the cavity 1a, and a heating wire 3 is embedded in each embedding groove 2.

[0048] The distance from the cavity 1a edge to the center surface of the body section 2a is D1, which is generally 10-15 mm, and can be 11 mm, 12 mm, 13 mm, or 14 mm, etc.

[0049] The heat insulation plate 5 is covered and fixed at the notch of each slot 2, and the surface of the heat insulation plate 5 facing away from the slot 2 is lower than the parting surface 1b. A notch is formed at the opening of the slot 2, and a shoulder 2c is formed on the two side surfaces of the slot 2. The heat insulation plate 5 is inserted into the notch, and the two sides of the heat insulation plate 5 abut against the shoulder 2c. The thickness of the heat insulation plate 5 is 0.8-1.2 mm, and can be 1.0 mm. The distance from the shoulder 2c to the parting surface 1b is greater than the thickness of the heat insulation plate 5, and the difference between them is generally 0.5-1.0 mm, and can be 0.75 mm. A gap 8 is provided between the heating wire 3 and the heat insulation plate 5, and the gap 8 is 0.1-1.2 mm, and can be 0.25 mm, 0.55 mm, 0.75 mm, or 1.05 mm, etc. The side of the heat insulation plate 5 facing away from the cavity 1a is protruded outward to form a fixing part 5a, and a fixing groove 6 corresponding to the fixing part 5a is formed on the parting surface 1b. The fixing part 5a is inserted into the fixing groove 6 and fixed by screws or bolts. The depth of the fixing groove 6 is the same as the height of the shoulder 2c to the parting surface 1b. The size of the fixing part 5a and the fixing groove 6 can be adapted to the installation of M6 or M8 screws or bolts, and the number and position of the fixing part 5a can be determined according to the stability of the heat insulation plate 5.

[0050] When multiple slots 2 are provided, different power heating wires 3 can be inserted into each slot 2. The power of the heating wire 3 is determined according to the severity of the product joint forming defects. The more severe the forming defects, the greater the power of the heating wire 3. For example, a position with severe forming defects such as cracking can be selected to use a heating wire 3 with large power, and a position with less severe forming defects such as bright spots can be selected to use a heating wire 3 with small power.

[0051] The heating wire 3 can have a variable diameter structure, and the diameter of the heating wire 3 is proportional to the distance from the axis of the heating wire 3 to the parting surface 1b. For example, according to the power of the heating wire 3, the diameter of the heating wire 3 is 6 mm, and the distance from the axis of the heating wire 3 to the parting surface 1b is 5 mm. When the diameter of the heating wire 3 is 8.4 mm, the distance from the axis of the heating wire 3 to the parting surface 1b is 7 mm. The proportional coefficient between the diameter of the heating wire 3 and the distance from the axis of the heating wire 3 to the parting surface 1b can be adjusted as needed, but it is necessary to ensure that there is a gap 8 between the heat insulation plate 5 and the heating wire 3. The diameter of the heating wire 3 opposite the position of the forming defects is generally larger, thereby generating more heat.

[0052] Each nest 2 further comprises two extension segments 2b arranged away from the cavity 1a and connected to the two ends of the body segment 2a respectively, and the two ends of each heating wire 3 respectively extend from the two extension segments 2b of the corresponding nest 2. An installation groove 4 is arranged on the parting surface 1b at the outer end of the extension segment 2b, the installation groove 4 penetrates through the outer side of the mold body 1, and the end of the heating wire 3 extends into the installation groove 4. The installation groove 4 is in the shape of a cuboid, and the width and depth of the installation groove 4 are greater than those of the nest 2, so as to facilitate the connection of the heating wire 3 with the power supply.

[0053] S3, setting a ventilation groove 7: as shown in Figure 2 、 Figure 3 and Figure 5 , a ventilation groove 7 is arranged on the parting surface 1b at the two ends of the body segment 2a of each nest 2, which is separated from the heating wire 3 and arranged along the edge of the cavity 1a, and the ventilation groove 7 is connected with the nest 2 and communicates with the outside. The ventilation grooves 7 between the adjacent two nests 2 are communicated integrally.

[0054] Along the length direction of the ventilation groove 7, the distance from the edge of the cavity 1a to the center surface of the ventilation groove 7 is the same, and the distance is d1. The distance from the edge of the cavity 1a to the center surface of the ventilation groove 7 is the same as the distance from the edge of the cavity 1a to the center surface of the body segment 2a, that is, D1=d1. The depth of the ventilation groove 7 is greater than the distance from the shoulder 2c to the parting surface 1b, and a gap 9 needs to be arranged between the bottom surface of the ventilation groove 7 and the heat insulation plate 5. The depth of the ventilation groove 7 is 1.6mm-2.5mm, which can be set to 2.0mm, and the width of the ventilation groove 7 is 5.0mm-6.0mm, which can be set to 5.5mm.

[0055] S4, setting an exhaust structure: as shown in Figure 2 、 Figure 3 and Figure 6 , a plurality of along grooves 10 are arranged on the parting surface 1b between the body segment 2a of the nest 2 and the cavity 1a, the along grooves 10 communicate the body segment 2a of the nest 2 with the cavity 1a, the bottom surface of the along groove 10 is located between the parting surface 1b and the heat insulation plate 5, and an exhaust passage 11 is arranged on the parting surface 1b at the side of the body segment 2a of the nest 2 away from the cavity 1a, which communicates the nest 2 with the outside. An along groove 12 is arranged on the parting surface 1b between the ventilation groove 7 and the cavity 1a, the along groove 12 communicates the ventilation groove 7 with the cavity 1a, and an exhaust passage 13 is arranged on the parting surface 1b at the side of the ventilation groove 7 away from the cavity 1a, which communicates the ventilation groove 7 with the outside.

[0056] The structure of the groove one 10 and the groove two 12 is the same, the depth of the groove one 10, that is, the distance from the bottom surface of the groove one 10 to the parting surface 1b, is less than the difference between the distance from the shoulder 2c to the parting surface 1b and the thickness of the heat insulation plate 5, and the depth of the groove one 10 is generally 0.1mm-0.5mm, and can be 0.15mm. The width of the groove one 10, that is, the distance between the two side surfaces of the groove one 10, is 5mm-8mm, and can be set to 6mm. The number of the groove one 10 and the groove two 12 is generally designed according to the volume of the cavity 1a to ensure that the air in the cavity 1a can be discharged as soon as possible through the groove one 10 and the groove two 12.

[0057] The exhaust passage one 11 includes an exhaust groove one connected with the main body section 2a, and the cross-sectional shape of the exhaust groove one is in the shape of a circular arc. A plurality of exhaust groove ones are arranged corresponding to each main body section 2a, and these exhaust groove ones are arranged in sequence along the length direction of the main body section 2a. The exhaust passage two 13 includes an exhaust groove two connected with the air passage groove 7, and the cross-sectional shape of the exhaust groove two is in the shape of a circular arc. The depth and width of the exhaust groove one are the same as those of the air passage groove 7, and the depth and width of the exhaust groove two are the same as those of the air passage groove 7. The exhaust groove one and the exhaust groove two can penetrate to the outer side surface of the mold body 1, or can penetrate to the fixing groove 6, the mounting groove 4, the positioning groove 1d, the positioning convex strip 1f and other structures, as long as they can be connected with the outside.

[0058] S5, setting temperature detection sites 14: as shown in Figure 2 and Figure 3 A plurality of temperature detection sites 14 are arranged on the parting surface 1b, and the temperature detection site 14 corresponds to the heating wire 3 one by one. The temperature detection site 14 is located on the side of the main body section 2a of the embedding groove 2 away from the cavity 1a, and the distance from each temperature detection site 14 to the center surface of the corresponding main body section 2a of the embedding groove 2 is the same. The position of the temperature detection site 14 needs to avoid the fixing groove 6, the positioning groove 1d, the positioning hole 1e, the mounting groove 4 and the like.

[0059] As shown in Figure 2As shown, the injection mold designed by the above design method is used for injection molding of an injection molded product (such as a second part structure of a two-color lampshade), which comprises a mold body 1. In the figure, the mold body 1 is a fixed mold of the injection mold. The mold body 1 has a cavity 1a and a parting surface 1b. The parting surface 1b is located outside the cavity 1a. The surface of the mold body 1 at the cavity 1a is a molding surface. The position of the edge of the cavity 1a is also the position of the edge of the molding surface. In the figure, the mold body 1 is designed according to the structure of the two-color lampshade. The cavity 1a of the mold body 1 is in a strip shape, that is, the molding surface is a strip-shaped curved surface. The two ends of the molding surface are upwardly curved. Overflow ports 1c are arranged on the parting surface 1b at the two ends of the cavity 1a. A water channel is arranged below the cavity 1a and the parting surface 1b in the mold body 1. During operation of the injection mold, hot water or steam is generally introduced into the water channel to heat the mold body 1. The parting surface 1b is provided with a positioning groove 1d, a positioning hole 1e and a positioning convex strip 1f for positioning with a movable mold. The cavity 1a, the positioning groove 1d, the positioning hole 1e and the positioning convex strip 1f are all existing structures. For example, Figure 2 The arrangement is shown.

[0060] As Figure 2 , Figure 3 and Figure 4As shown, the parting surface 1b is provided with a plurality of embedding grooves 2 arranged along the edge of the cavity 1a in sequence, and each embedding groove 2 is embedded with a heating wire 3. The embedding groove 2 includes a main body segment 2a arranged in a strip shape along the edge of the cavity 1a, and each embedding groove 2 further includes two extension segments 2b arranged away from the cavity 1a and connected to the two ends of the main body segment 2a respectively, and the two ends of each heating wire 3 respectively extend out of the two extension segments 2b of the corresponding embedding groove 2. In order to facilitate the connection of the heating wire 3 and the power supply, the outer end of the extension segment 2b of the parting surface 1b is provided with a mounting groove 4, the mounting groove 4 is in the shape of a cuboid, the width and depth of the mounting groove 4 are greater than those of the embedding groove 2, and the end of the heating wire 3 extends into the mounting groove 4. In the cross-sectional structure of the embedding groove 2, the two side surfaces of the embedding groove 2 are parallel to each other, and the bottom surface of the embedding groove 2 is in the shape of a circular arc. Along the length direction of the main body segment 2a, the distance from the edge of the cavity 1a to the center surface of the main body segment 2a is the same, which is conducive to the uniformization of the temperature of the edge position of the cavity 1a. In the cross-sectional structure of the heating wire 3, the heating wire 3 is in the shape of a circle, the heating wire 3 is embedded into the embedding groove 2, and the bottom side surface of the heating wire 3 is attached to the bottom surface of the embedding groove 2. The heating wire 3 is in a variable-diameter structure, and the diameter of the heating wire 3 is proportional to the distance from the axis of the heating wire 3 to the parting surface 1b. The opening of each embedding groove 2 is covered and fixed with a heat insulation plate 5, and the heat insulation plate 5 is located in the embedding groove 2. The opening of the embedding groove 2 is provided with a notch, and a stop shoulder 2c is formed on the two side surfaces of the embedding groove 2. The heat insulation plate 5 is embedded into the notch, and the two sides of the heat insulation plate 5 abut against the stop shoulder 2c. The stop shoulder 2c not only has a positioning effect on the heat insulation plate 5, but also forms a seal with the heat insulation plate 5 abutting against each other, so as to separate the heating wire 3 from the opening position of the embedding groove 2, so that the air around the heating wire 3 cannot be mixed with the air at the opening position of the embedding groove 2 at will. The surface of the heat insulation plate 5 away from the embedding groove 2 is lower than the parting surface 1b, that is, the distance from the stop shoulder 2c to the parting surface 1b is greater than the thickness of the heat insulation plate 5. In order to fix the heat insulation plate 5, the side of the heat insulation plate 5 away from the cavity 1a protrudes outward to form a fixing portion 5a, the parting surface 1b is provided with a fixing groove 6 corresponding to the fixing portion 5a, the fixing portion 5a is embedded into the fixing groove 6 and fixed by screws or bolts. Each heat insulation plate 5 has at least two fixing portions 5a, and for the heat insulation plate 5 with a longer length, three fixing portions 5a or four fixing portions 5a can also be provided.

[0061] As shown in Figure 2 , Figure 3 and Figure 5 , the parting surface 1b is provided with a plurality of embedding grooves 2 arranged along the edge of the cavity 1a in sequence, and each embedding groove 2 is embedded with a heating wire 3. The parting surface 1b is provided with a plurality of embedding grooves 2 arranged along the edge of the cavity 1a in sequence, and each embedding groove 2 is embedded with a heating wire 3. Figure 2The two sides of the cavity 1a are provided with three embedding slots 2 respectively. On the parting surface 1b of the same side of the cavity 1a, the air vent grooves 7 between the adjacent two embedding slots 2 are connected as a whole. The cross-sectional structure of the air vent groove 7 is in the form of a circular arc, and the bottom surface of the air vent groove 7 is located far away from the parting surface 1b. As shown in Figure 4 and Figure 5 , the distance between the edge of the cavity 1a and the center surface of the main body segment 2a of the embedding slot 2 is D1, and the distance between the edge of the cavity 1a and the center surface of the air vent groove 7 is d1, and D1 and d1 are equal, which is convenient for processing and is beneficial to the temperature uniformity of the edge of the cavity 1a.

[0062] As shown in Figure 4 , Figure 5 and Figure 6 , the heating wire 3 and the heat insulation plate 5 have a gap 8, and the bottom surface of the air vent groove 7 and the heat insulation plate 5 have a gap 9, which are used for air circulation. A plurality of guide grooves 10 are arranged on the parting surface 1b between the main body segment 2a of the embedding slot 2 and the cavity 1a, and the guide grooves 10 corresponding to the same main body segment 2a are arranged along the edge of the cavity 1a in sequence. The guide groove 10 connects the main body segment 2a of the embedding slot 2 and the cavity 1a, and the bottom surface of the guide groove 10 is located between the parting surface 1b and the heat insulation plate 5, that is, the bottom surface of the guide groove 10 is lower than the parting surface 1b but higher than the surface of the heat insulation plate 5 facing away from the embedding slot 2. An exhaust passage 11 is arranged on the parting surface 1b away from the cavity 1a on the side of the main body segment 2a of the embedding slot 2, and the exhaust passage 11 connects the embedding slot 2 and the outside. The exhaust passage 11 includes an exhaust groove 1 connected with the main body segment 2a, and the cross-sectional shape of the exhaust groove 1 is in the form of a circular arc. A plurality of exhaust grooves 1 are arranged corresponding to each main body segment 2a, and the exhaust grooves 1 are arranged in sequence along the length direction of the main body segment 2a. A guide groove 12 is arranged on the parting surface 1b between the air vent groove 7 and the cavity 1a, and the guide groove 12 connects the air vent groove 7 and the cavity 1a. The structure of the guide groove 12 is the same as that of the guide groove 10, and both are rectangular grooves. An exhaust passage 13 is arranged on the parting surface 1b away from the cavity 1a on the side of the air vent groove 7, and the exhaust passage 13 connects the air vent groove 7 and the outside. The exhaust passage 13 includes an exhaust groove 2 connected with the air vent groove 7, and the cross-sectional shape of the exhaust groove 2 is in the form of a circular arc.

[0063] As shown in Figure 2 and Figure 3As shown, the parting surface 1b is provided with a plurality of temperature detection positions 14, the temperature detection positions 14 are provided one by one corresponding to the heating wires 3, and the temperature detection positions 14 are located on the side of the main body section 2a of the embedding groove 2 away from the cavity 1a. A temperature sensor is installed on the temperature detection position 14, which is used to detect the temperature at the parting surface 1b, and the temperature sensor transmits the detected temperature to the controller, and the controller controls the on-off of the heating wires 3 according to the detected temperature, so as to control the temperature at the parting surface 1b, avoid local high temperature, and be beneficial to ensure the uniformity of the temperature. The distance from the temperature sensor to the axis of the heating wire 3 is substantially the same as the distance from the edge of the cavity 1a to the axis of the heating wire 3, so that the temperature detected by the temperature sensor is substantially the same as the temperature at the edge of the cavity 1a.

[0064] When the injection mold designed by the design method works, hot water or steam is introduced into the water channel, the heating wires 3 are powered on, and the two jointly heat the mold body 1. When the heating wires 3 are powered on, the heat generated by the heating wires 3 is conducted to the edge position of the cavity 1a to heat the joint between the first part structure and the second part structure of the double-color lampshade, so that the joint between the first part structure and the second part structure realizes integrated fusion, wherein the power of the heating wires 3 in each embedding groove 2 is different, and the heating wires 3 are variable-diameter structures. At the same time, the embedding groove 2 main body section 2a and the air passage 7 arranged along the edge of the cavity 1a are used to make the heating air in the embedding groove 2 flow and disperse heat, and then the temperature is controlled by the controller and the temperature stabilizing sensor, so that the temperature at the edge position of the cavity 1a is better uniformized, the forming defects such as bright lines, bright spots, and even cracking between the joint positions of the double-color lampshade are reduced, and the processing quality of the product is improved. The injection mold also provides a heat insulation plate 5 at the slot opening of the embedding groove 2, and the along-groove 10 on the parting surface 1b is higher than the heat insulation plate 5, so that the heating wires 3 are separated from the air discharged from the cavity 1a, reducing the possibility that the heat generated by the heating wires 3 is taken away by the air flowing out of the cavity 1a, and at the same time, ensuring that the hot air below the heat insulation plate 5 can flow along the embedding groove 2 and the air passage 7 to disperse heat, which is beneficial to better uniformization of the temperature at the edge position of the cavity 1a.

[0065] The specific embodiments described herein are merely illustrative of the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A method of designing an injection mold, the injection mold comprising a mold body (1) having a cavity (la) and a parting surface (lb) on the mold body (1), characterized by, The injection mold design method comprises the following steps: S1, determining a heating area: according to the position of the product joint forming defect, the corresponding injection mold cavity (1a) position is found out and determined as the heating area; S2, setting the embedding groove (2) and the heating wire (3): a plurality of embedding grooves (2) are arranged along the edge of the cavity (1a) on the parting surface (1b), the embedding grooves (2) correspond to the heating area one by one, each embedding groove (2) comprises a main body segment (2a) arranged in a strip shape along the edge of the cavity (1a), and the heating wire (3) is embedded in each embedding groove (2); S3, setting the vent groove (7): the vent groove (7) is arranged at both ends of the main body segment (2a) of each embedding groove (2) on the parting surface (1b) and is arranged along the edge of the cavity (1a) and is separated from the heating wire (3), the vent groove (7) is connected with the embedding groove (2) and is communicated with the outside; In step S2, the heat insulation plate (5) is covered and fixed at the slot opening of each embedding groove (2), the heat insulation plate (5) is located in the embedding groove (2), and the surface of the heat insulation plate (5) away from the embedding groove (2) is lower than the parting surface (1b), and the gap (8) is arranged between the heating wire (3) and the heat insulation plate (5).

2. The injection mold design method according to claim 1, characterized by, In step S2, along the length direction of the main body segment (2a) of the embedding groove (2), the distance from the edge of the cavity (1a) to the center surface of the main body segment (2a) is the same; in step S3, along the length direction of the vent groove (7), the distance from the edge of the cavity (1a) to the center surface of the vent groove (7) is the same, and the distance from the edge of the cavity (1a) to the center surface of the vent groove (7) is equal to the distance from the edge of the cavity (1a) to the center surface of the main body segment (2a).

3. The injection mold design method of claim 1, wherein In step S2, the heating wire (3) is arranged in a variable-diameter structure, and the diameter of the heating wire (3) is proportional to the distance from the axis of the heating wire (3) to the parting surface (1b).

4. The injection mold design method of claim 1, wherein In step S2, when a plurality of embedding grooves (2) are arranged, different power heating wires (3) are embedded in each embedding groove (2), and the power of the heating wire (3) is determined according to the severity of the product joint forming defect, wherein the more serious the forming defect is, the greater the power of the heating wire (3) is.

5. The injection mold design method according to claim 4, wherein In step S3, the vent grooves (7) between the adjacent two embedding grooves (2) are communicated into one body.

6. The injection mold design method of claim 1, wherein In step S2, each embedding groove (2) further comprises two extension segments (2b) arranged away from the cavity (1a) and connected with both ends of the main body segment (2a) respectively, and both ends of each heating wire (3) respectively extend from the two extension segments (2b) of the corresponding embedding groove (2).

7. The injection mold design method according to any one of claims 1 to 6, characterized by, In step S3, a gap (9) is arranged between the bottom surface of the vent groove (7) and the heat insulation plate (5).

8. The injection mold design method of claim 7, wherein Further comprising the following steps: S4, setting an exhaust structure: a plurality of along grooves (10) are arranged between the main body segment (2a) of the embedding groove (2) and the cavity (1a) on the parting surface (1b), the along groove (10) communicates the main body segment (2a) of the embedding groove (2) and the cavity (1a), the bottom surface of the along groove (10) is located between the parting surface (1b) and the heat insulation plate (5), and an exhaust passage (11) is arranged on the parting surface (1b) away from the cavity (1a) of the main body segment (2a) of the embedding groove (2) to communicate the embedding groove (2) with the outside.

9. The injection mold design method of claim 8, wherein In step S4, along groove two (12) is arranged on the parting surface (1b) between the vent groove (7) and the cavity (1a), the along groove two (12) communicates the vent groove (7) and the cavity (1a), and the exhaust passage two (13) which communicates the vent groove (7) and the outside is arranged on the parting surface (1b) on the side of the vent groove (7) away from the cavity (1a).

10. The injection mold design method of claim 8, wherein Further comprising the following steps: S5, setting temperature detection site (14): a plurality of temperature detection sites (14) are arranged on the parting surface (1b), the temperature detection sites (14) correspond to the recesses (2) one by one, the temperature detection sites (14) are on the side of the main body section (2a) of the recess (2) away from the cavity (1a), and the distance from each temperature detection site (14) to the center surface of the corresponding main body section (2a) of the recess (2) is the same.

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