A mold for automatic cut-off of a glue joint and a method of using the same

Abstract

The application provides a mold for automatically cutting off a glue joint and a using method thereof. An injection molding bevel is designed in a molding area of a glue joint mold frame to realize that a lower end of a side far from a molded product when the glue joint mold frame is molded has a downward "8" type pre-folding slot, the glue joint mold frame is first lifted by a cutter insert in a mold opening process, the glue joint mold frame is separated from the molded product, the mold opening is completed, and a residual glue joint protrusion on a product surface is reduced. The glue joint mold frame is easier to bend, and the mold opening process is more convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to a mold for small injection parts, which comprises a plurality of cavities, and several cavities are communicated with the main runner through the mold cavity runner, and in particular to a mold for automatically cutting off the glue port and a method thereof. BACKGROUND

[0002] The multi-cavity mold is a new mold with an "H" type structure runner system, which can produce at least four injection products at the same time. Compared with the traditional molding mold, the glue port mold is formed at the position of the "H" type structure runner, and after molding, secondary processing is required to separate the product and the glue port mold.

[0003] In order to save the secondary processing process and improve the production efficiency, a cutting tool can be arranged below the glue port mold, and the cutting tool is lifted to make the glue port mold break and realize the mold separation. However, the traditional mold separation mold has the following problems:

[0004] 1. The glue port mold is lifted by the cutting tool as a whole, and the separation from the product is a tearing type separation, which is easy to cause the glue port to protrude from the product surface or cause defects at the connection between the product and the glue port, and the product needs to be repaired in the later stage, and even the defective product is produced and the product is scrapped.

[0005] 2. The lifting force of the cutting tool is large, and the glue port mold cannot be separated from the product, and the secondary processing step cannot be saved.

[0006] 3. There is much residual molding material in the runner, which causes waste. SUMMARY

[0007] In order to solve the above problems, the present application provides a mold for automatically cutting off the glue port and a method thereof, which is realized as follows:

[0008] A mold for automatically cutting off the glue port, comprising:

[0009] A mold base is provided with a ejector plate, a detachable lower mold plate and an upper mold plate are arranged above the ejector plate, a face plate is detachably arranged at the upper end of the upper mold plate, the lower mold plate and the upper mold plate are closed and tightly held by a closing device or are separated from each other by the ejector pins of the ejector plate, a front mold core and a rear mold core are detachably arranged inside the lower mold plate and the upper mold plate, and a cutting tool device is slidably arranged in the front mold core and the rear mold core;

[0010] The cutter device specifically comprises a compression spring fixed on the upper end surface of the lower mold plate, an upper end of the compression spring is fixedly provided with a cutter insert, an upper portion of the cutter insert is separately provided with a pressing cutter insert, an upper end of the pressing cutter insert is fixedly provided with an insert pressing plate, the insert pressing plate is fixedly provided on the injection port of the face plate, a middle portion of the insert pressing plate is embedded with an injection hopper for injecting material into the mold, a first water gap is formed on the upper end surface of the cutter insert, and a second water gap is formed on the lower end surface of the pressing cutter insert;

[0011] The front mold core is provided with a feeding flow channel communicated with the injection hopper, the lower end surface of the front mold core is provided with a first feeding groove communicated with the feeding flow channel, the front mold core is provided with a plurality of insert movable holes for the pressing cutter insert to penetrate, the lower end opening end of each insert movable hole is respectively communicated with the first feeding groove flow channel, and the lower end surface of the front mold core is provided with an upper forming groove on the side away from the first feeding groove.

[0012] The upper end surface of the rear mold core is provided with a second feeding groove matched with the first feeding groove, the second feeding groove is provided with an injection bevel inclined upward first and then downward at the position corresponding to the insert movable hole, and the injection bevel is provided with a cutter movable hole penetrating through the rear mold core for the cutter insert of the cutter insert at one end away from the second feeding groove.

[0013] When the lower mold plate and the upper mold plate are tightly closed and the front mold core and the rear mold core are tightly locked, the pressing cutter insert presses the cutter insert, the first feeding groove, the second feeding groove, the first water gap, the injection bevel and the second water gap are combined to form a water gap flow channel, and the upper forming groove and the lower forming groove are combined to form a product forming cavity.

[0014] When the lower mold plate and the upper mold plate are separated and the front mold core and the rear mold core are still in the tightly locked state, the pressing cutter insert is away from the cutter insert, the cutter insert is lifted by the compression spring, and then the rubber port mold frame formed in the water gap flow channel is lifted, the rubber port mold frame forms a pre-folding position at the injection bevel position, the rubber port mold frame is lifted along the pre-folding position after being lifted by the cutter insert, and finally is separated from the formed product.

[0015] As a further improvement, the first water gap comprises a semicircular arc groove-shaped first mold frame forming part which can communicate with the injection slope when the front mold core and the rear mold core are locked, a 1 / 4 spherical groove-shaped first booster part is arranged on the side of the first mold frame forming part away from the injection slope, a gradually widened parting part is arranged on the side of the first booster part away from the injection slope and inclined upward, and a connecting part which communicates with the product forming cavity is formed on the side wall surface of the cutter insert through the parting part away from the injection slope;

[0016] The second water gap comprises a semicircular arc groove-shaped second mold frame forming part corresponding to the position of the injection slope and the first mold frame forming part, a 1 / 4 spherical groove-shaped second booster part corresponding to the first booster part is arranged on the side of the second mold frame forming part away from the first feeding groove, a sealing part is formed on the lower end surface of the cutter insert around the second water gap, the sealing part corresponds to the position of the parting part and the area of the upper end surface of the cutter insert which is not arranged with the first water gap, and when the front mold core and the rear mold core are locked, the sealing part tightly fits the position of the upper end surface of the cutter insert which is not arranged with the first water gap.

[0017] As a further improvement, the cutter insert comprises a base body, a guide rib is protruded on the side surface of the base body close to the product forming cavity, a limiting block is protruded on the lower end surface of the base body away from the product forming cavity, the first mold frame forming part is arranged on the upper end surface of the base body, and the first booster part and the parting part are arranged on the upper end surface of the guide rib.

[0018] A guide groove which is matched with the guide rib is recessed on the side of the cutter movable hole close to the product forming cavity, and a limiting groove which can accommodate the limiting block is recessed and arranged on the side of the lower end opening of the cutter movable hole away from the product forming cavity.

[0019] Preferably, the depth of the limiting groove is 2-5 mm longer than the height of the limiting block.

[0020] As a further improvement, the injection slope comprises a first pre-folding forming part which is arranged inclined upward and communicates with the second feeding groove, the upper end of the first pre-folding forming part extends horizontally to form a flat easy-folding forming part, and a second pre-folding forming part which is mutually symmetrical with the first pre-folding forming part is arranged inclined downward on the end of the easy-folding forming part away from the first pre-folding forming part.

[0021] The cross-sectional area of the flow passage formed by the first mold frame forming part and the second mold frame forming part is defined as A, the cross-sectional area of the flow passage formed by the easy-folding forming part and the second mold frame forming part is defined as a, and a=0.4-0.6A.

[0022] Preferably, the angle between the lower end of the first pre-folding forming part or the second pre-folding forming part and the horizontal plane is 30-60°.

[0023] Preferably, the extension length of the easy-folding forming part is 1.5-3 mm.

[0024] Preferably, the length of the first die forming part is 15-25 mm, and the distance between the lower end of the first pre-folding forming part and the second feeding groove is 2-5 mm.

[0025] Preferably, the diameter of the flow passage cross section defined by the first die forming part and the second die forming part is D, and the ball diameter of the first booster part is the same as the diameter of the flow passage cross section defined by the first die forming part and the second die forming part.

[0026] The parting part starts at the position 1 / 4-1 / 3D below the upper end of the first booster part, the angle between the parting part and the horizontal plane is 15-30°, and the angle of the two side walls of the parting part widening outward is 5-10°.

[0027] The application further provides a use method of the mold for automatically cutting off the glue port, which is applied to the mold for automatically cutting off the glue port and includes the following steps:

[0028] S1. Calculation, mold flow analysis is performed using injection molding simulation software, and the glue port deformation is determined, and then the ratio of a / A, the angle between the lower end of the first pre-folding forming part or the second pre-folding forming part and the horizontal plane, the extension length of the easy-folding forming part, and the length of the first die forming part and other parameters are determined.

[0029] S2. The corresponding cutter insert and the pressure cutter insert are selected according to the parameters determined in S1, and the cutter insert and the pressure cutter insert are assembled.

[0030] S3. Mold clamping and injection, and segmented pressure is applied during the injection process.

[0031] S4. Forming, after the injection is completed, the pressure is maintained for 1-3 s, and the natural cooling is maintained for 3-8 s.

[0032] S5. Parting, after the cooling is completed, the cutter device is pulled away, then the upper mold plate and the lower mold plate are separated, the front mold core and the rear mold core are separated, and the ejector plate ejects the separated glue port die and the formed product.

[0033] The application has the following beneficial effects:

[0034] 1. By setting the injection slope first upwardly inclined and then downwardly inclined, the pre-folding position of the molded glue port mold frame at the injection slope position is formed, that is, a downwardly inclined "8" shaped slot, so that the glue port mold frame is easily bent and raised upwardly from the pre-folding position during the lifting process of the cutter insert, and the separation of the glue port and the product is realized by the cutting of the cutter insert, and the protrusion on the surface of the product is reduced by the cutting of the cutter, and the secondary processing process is saved.

[0035] 2. Since the injection slope is set to be first upwardly inclined and then downwardly inclined, the cross section of the top end of the injection slope is reduced, the flow rate of the material is accelerated under the condition of constant pressure, the material in the flow channel is quickly entered to avoid condensation at the injection slope position. The pre-folding position which needs to be avoided during the injection molding process is automatically generated due to the setting of the injection slope in the present application, thereby avoiding shrinkage or shrinkage during the injection molding process, and reducing the difficulty of in-mold separation.

[0036] 3. In order to facilitate the bending of the glue port mold frame, the length of the water channel of the traditional mold is usually extended to increase the length of the glue port mold frame and thus reduce its compression stiffness. The present application generates a pre-folding position by setting an injection slope, without the need to extend the water channel to reduce the compression stiffness of the glue port mold frame, greatly reducing the amount of material required for filling in the flow channel, reducing the total amount of material required for each injection molding, and greatly saving production costs. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a schematic diagram of the overall explosion structure of the present application.

[0038] Figure 2 It is a schematic diagram of the cut structure of the present application in the mold closing state.

[0039] Figure 3 It is a schematic diagram of the explosion structure of the panel, injection port, insert pressing plate and pressing cutter insert of the present application.

[0040] Figure 4 It is a schematic diagram of the structure of the injection port, insert pressing plate, injection hopper and pressing cutter insert of the present application from the bottom in the combined state.

[0041] Figure 5 It is a schematic diagram of the structure of the lower mold plate, compression spring and cutter insert of the present application in the combined state.

[0042] Figure 6 It is a schematic diagram of the structure of the upper mold plate of the present application from the bottom.

[0043] Figure 7 It is a schematic diagram of the front mold core and the pressing cutter insert cooperating structure of the present application from the bottom in the mold closing state.

[0044] Figure 8 A schematic view of the structure of the front die core of the present application.

[0045] Figure 9 A schematic view of the structure of the rear die core of the present application and the cooperating structure of the cutter insert in the closed die state.

[0046] Figure 10 A schematic view of the structure of the rear die core of the present application. Figure 9 A partial enlarged view of region A.

[0047] Figure 11 A schematic view of the structure of the rear die core of the present application from the bottom.

[0048] Figure 12 A schematic view of the partial section of the cutter insert and the pressure insert after cooperation in the closed die state of the present application.

[0049] Figure 13 A schematic view of the state of the mold frame and the molded product after the molding of the present application.

[0050] Figure 14 A schematic view of the structure of the mold frame of the present application. Figure 13 A front view of the structure of the mold frame of the present application.

[0051] Figure 15 A schematic view of the state of the mold frame being lifted and bent by the cutter insert and the molded product being separated from each other. DETAILED DESCRIPTION

[0052] In order to make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0053] In the description of the present application, the terms “first” and “second” are only used for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first” and “second” can explicitly or implicitly include one or more of the features.

[0054] An automatic die for cutting off a glue joint, comprising:

[0055] Die seat 1, the die seat 1 is provided with ejector plate, the upper side of ejector plate is provided with separable lower die plate 3 and upper die plate 4, the upper end of upper die plate 4 is detachably provided with faceplate 2, lower die plate 3 and upper die plate 4 are mutually closed and tightly closed by closing device or mutually far away from each other by ejector pin of ejector plate, the inside of lower die plate 3 and upper die plate 4 is provided with separable front die core 5 and rear die core 6 from top to bottom, the cutter device 7 is slidably arranged in front die core 5 and rear die core 6 from top to bottom;

[0056] The cutter device 7 specifically includes a compression spring 71 fixedly arranged on the upper end surface of the lower die plate 3, the upper end of the compression spring 71 is fixedly provided with a cutter insert 72, the upper side of the cutter insert 72 is separately provided with a pressure cutter insert 73, the upper end of the pressure cutter insert 73 is fixedly provided with an insert pressure plate 74, the insert pressure plate 74 is fixedly arranged on the injection port 21 of the faceplate 2, the middle part of the insert pressure plate 74 is embedded with an injection hopper 22 for material injection into the mold, the upper end surface of the cutter insert 72 is provided with a first water gap 721, and the lower end surface of the pressure cutter insert 73 is provided with a second water gap 731;

[0057] The front die core 5 is provided with a feed flow channel 51 communicated with the injection hopper 22, the lower end surface of the front die core 5 is provided with a first feed slot 52 communicated with the feed flow channel 51, the front die core 5 is provided with a plurality of insert movable holes 54 for the pressure cutter insert 73 to penetrate, the lower end opening end of each insert movable hole 54 is respectively communicated with the feed flow channel 52, the lower end surface of the front die core 5 is provided with an upper forming groove 53 on the side away from the first feed slot 52, the upper die plate 4 and the faceplate 2 are provided with insert limiting holes 41 corresponding to the insert movable holes 54;

[0058] The upper end surface of the rear die core 6 is provided with a second feed slot 62 matched with the first feed slot 52, the second feed slot 62 is provided with an injection bevel 64 inclined upward first and then downward at a position corresponding to the insert movable hole 54, the end of the injection bevel 64 away from the second feed slot 62 is provided with a cutter movable hole 61 penetrating through the rear die core 6 for the cutter insert 72, the upper end surface of the rear die core 6 is provided with a lower forming groove 63 corresponding to the upper forming groove 53 on the side away from the cutter movable hole 61 of the second feed slot 62;

[0059] When the lower mold plate 3 and the upper mold plate 4 are tightly closed and the front mold core 5 and the rear mold core 6 are locked, the cutting knife insert 73 is pressed against the cutting knife insert 72, the first feeding groove 52, the second feeding groove 62, the first water gap groove 721, the injection slope 64 and the second water gap groove 731 are combined to form a water gap runner, and the upper forming groove 53 and the lower forming groove 63 are combined to form a product forming cavity.

[0060] When the lower mold plate 3 and the upper mold plate 4 are separated, the front mold core 5 and the rear mold core 6 are still locked, the cutting knife insert 73 is away from the cutting knife insert 72, the cutting knife insert 72 is lifted by the compression spring 71, and the rubber port mold frame 8 formed in the water gap runner is also lifted, the rubber port mold frame 8 forms a pre-folding position 81 at the position of the injection slope 64, and the rubber port mold frame 8 is folded upward along the pre-folding position 81 after being lifted by the cutting knife insert 72, and finally separated from the formed product.

[0061] As a further improvement, the first water gap groove 721 includes a semicircular arc groove-shaped first mold frame forming part 7211 which can communicate with the injection slope 64 when the front mold core 5 and the rear mold core 6 are locked, a 1 / 4 spherical groove-shaped first booster part 7212 is arranged on the side away from the injection slope 64 of the first mold frame forming part 7211, a gradually widening parting part 7213 is inclined upward on the side away from the injection slope 64 of the first booster part 7212, and a connecting part 7214 which communicates with the product forming cavity is formed through the side wall surface of the cutting knife insert 72 on the side away from the injection slope 64 of the parting part 7213.

[0062] The second water gap groove 731 includes a semicircular arc groove-shaped second mold frame forming part 7311 corresponding to the position of the injection slope 64 and the first mold frame forming part 7211, a 1 / 4 spherical groove-shaped second booster part 7312 is arranged on the side away from the first feeding groove 52 of the second mold frame forming part 7311, a sealing part 7313 is formed on the outer periphery of the second water gap groove 731 on the lower end surface of the cutting knife insert 73, the sealing part 7313 corresponds to the position where the first water gap groove 721 is not arranged on the upper end surface of the cutting knife insert 72 and the parting part 7213, and when the front mold core 5 and the rear mold core 6 are locked, the sealing part 7313 tightly fits the position where the first water gap groove 721 is not arranged on the upper end surface of the cutting knife insert 72.

[0063] The first booster 7212 and the second booster 7312 form a hemispherical pressurized flow channel area, which has the effect of changing the cross-sectional area of the flow channel and accelerating the material compared to the traditional columnar flow channel. The side of the traditional flow channel close to the product forming cavity is constricted to form a circular truncated cone shape. The connection strength between the curved surface of the molded product and the connecting piece 82 formed by the parting portion 7213 is higher than that of a flat surface. This can ensure that the glue port mold frame 8 will not separate from the connecting piece 82 first after being lifted by the cutter insert 72, but the connecting piece 82 will separate from the molded product first.

[0064] In addition, the parting portion 7213 is gradually widened, which allows the material entering the product forming cavity from the parting portion 7213 to diffuse outwardly, better filling the product forming cavity and reducing the occurrence of shrinkage and porosity. The inclined upward arrangement forms a sharp corner at the connection between the parting portion 7213 and the connecting portion 7214, which acts as a "blade" during the lifting process of the cutter insert 72, cutting off the formed connecting piece 82 after molding and reducing the residual glue port protrusion on the product surface.

[0065] As a further improvement, the front mold core 5 is detachably embedded in the lower end surface of the upper mold plate 4 through fasteners.

[0066] As a further improvement, the cutter insert 72 includes a rectangular columnar base body, a guide rib is protruded on the side surface close to the product forming cavity, a limiting block 722 is protruded on the lower end of the side surface away from the product forming cavity, the first mold frame forming portion 7211 is opened on the upper end surface of the base body, the first booster 7212 and the parting portion 7213 are opened on the upper end surface of the guide rib; a guide groove matching the guide rib is recessed on the side close to the product forming cavity in the cutter movable hole 61, and a limiting groove 611 capable of accommodating the limiting block 722 is recessed and opened upward on the side away from the product forming cavity at the lower end opening of the cutter movable hole 61. The limiting and guiding arrangement can prevent the cutter insert 72 from deflecting due to pressure during the injection molding process, causing molding defects, while ensuring that the cutter insert 72 is lifted vertically upward by the compression spring 71 during the later mold splitting process instead of being offset sideways, which can smoothly complete the cutting of the connecting piece 82 and realize in-mold parting.

[0067] Preferably, the groove depth of the limiting groove 611 is 2-5 mm longer than the height of the limiting block 722. The difference between the groove depth of the limiting groove 611 and the height of the limiting block 722 is the stroke amount of the cutter insert 72 after the mold is split. If the stroke is too short, the glue joint mold frame 8 will be lifted to a low height, and the connecting piece 82 cannot be separated from the molded product. If the stroke is too long, the connecting guide rod or other guide functional parts between the upper mold plate 4 and the lower mold plate 3 will also need to be increased, otherwise the cutter insert 72 will be damaged due to misalignment. At the same time, the guide rod between the upper mold plate 4 and the lower mold plate 3 will cause the corresponding structure of the mold to change, which will not have additional effects and will increase the amount of materials used, which is not beneficial to the original design direction. In addition, a longer mold split stroke will require a higher stroke amount for the mold split auxiliary equipment, which is not conducive to reducing production costs.

[0068] As a further improvement, the injection slope 64 includes a first pre-folding forming part 641 inclined upward and in communication with the second feeding groove 62, the upper end of the first pre-folding forming part 641 extends horizontally to form a flat easy folding forming part 642, and the end of the easy folding forming part 642 away from the first pre-folding forming part 641 is inclined downward to form a second pre-folding forming part 643 symmetrical to the first pre-folding forming part 641. If the lower ends of the first pre-folding forming part 641 and the second pre-folding forming part 643 are inclined towards each other, the glue joint mold frame 8 will be clamped on the injection slope 64, making it difficult to lift the glue joint mold frame 8 with the cutter insert 72, and ultimately unable to achieve in-mold parting. If the first pre-folding forming part 641 and the second pre-folding forming part 643 are vertical surfaces, compared to the upper ends of the two inclined towards each other, the pre-folding position 81 of the molded glue joint mold frame 8 will be more difficult to bend upwards when subjected to the upward lifting force of the cutter insert 72 due to internal material stress, thus requiring an increase in the elastic coefficient of the compression spring 71. In addition, shrinkage and shrinkage will occur at the position of the injection slope 64 during molding, and the pre-folding position 81 will break during lifting rather than the connecting piece 82, ultimately resulting in the need for secondary processing to complete in-mold parting.

[0069] Among them, the horizontal extension of the easy folding forming part 642 can make the included angle between the groove wall and the groove bottom in the pre-folding position 81 formed after molding be obtuse, and the tensile capacity of the glue joint mold frame 8 at this point is further reduced.

[0070] Preferably, the angle between the lower end of the first pre-folding forming part 641 or the second pre-folding forming part 643 and the horizontal plane is 30-60°. If the angle is too large, as described above, the pre-folding position 81 of the formed die holder 8 is more difficult to bend upward when subjected to the upward lifting force of the cutter insert 72 due to the internal stress of the material, and thus the spring constant of the compression spring 71 needs to be increased. In addition, a too large angle will reduce the guiding ability of the material during injection molding, and material accumulation will easily occur at the injection groove 64. If the angle is too small, the length of the injection groove 64 will be reduced under the condition of constant a / A, which will result in the need to extend the water flow channel or reduce the size of the cutter insert 72. Extending the water flow channel will increase the amount of material needed for injection molding and the injection molding time, which is not conducive to reducing production costs. Preferably, the angle between the lower end of the first pre-folding forming part 641 or the second pre-folding forming part 643 and the horizontal plane is 45°.

[0071] In another embodiment, the injection groove 64 includes a first pre-folding forming part 641 inclined upward and communicating with the second feeding groove 62, and the upper end of the first pre-folding forming part 641 is inclined downward to form a second pre-folding forming part 643 symmetrical to the first pre-folding forming part 641. The angle between the lower end of the first pre-folding forming part 641 or the second pre-folding forming part 643 and the horizontal plane is 20-45°. In this embodiment, the pre-folding position 81 is formed as a sharp wedge-shaped notch, and the larger the angle between the lower end of the first pre-folding forming part 641 or the second pre-folding forming part 643 and the horizontal plane, the smaller the angle of the wedge. During the lifting of the cutter insert 72, the die holder 8 is more likely to break at the pre-folding position 81 rather than bend with the cutter insert 72, which will result in the product surface being left with a protruding die. If the angle of the wedge is too large, the water flow channel needs to be extended or the size of the cutter insert 72 needs to be reduced, which will result in an increase in the amount of material needed and the injection molding time, which is not conducive to reducing production costs.

[0072] The cross-sectional area of the flow channel formed by the first mold frame forming part 7211 and the second mold frame forming part 7311 is A, and the cross-sectional area of the flow channel formed by the easy-to-fold forming part 642 and the second mold frame forming part 7311 is a, so a = 0.4-0.6A. If a / A is too small, the mold material at the pre-folding position 81 will be blocked, resulting in product forming defects. If a / A is too large, the strength at the pre-folding position 81 will be higher, making it difficult to be lifted and bent by the cutter insert 72. At the same time, through the mold flow analysis of the injection molding simulation software, with the gradual increase of a / A, under the condition of the same injection pressure, the injection time shows a trend of first greatly reducing, then slightly increasing, and then reducing. It is believed through analysis that when a / A is small, the material is hindered from entering the forming cavity. As a / A increases, the resistance is weakened, and at the same time, the inclined arrangement of the first pre-folding forming part 641 makes the material enter the forming cavity faster. When a / A continues to increase, the flow rate changes little due to the change of cross-sectional area, but the resistance formed by the injection bevel 64 will make the material flow back, thereby increasing the injection time. When a / A = 1, the injection time is the shortest, but there is no pre-folding position 81 at this time, which is contrary to the original design concept.

[0073] Preferably, a = 0.5A.

[0074] Preferably, the extension length of the easy-to-fold forming part 642 is 1.5-3mm. If the easy-to-fold forming part 642 is too long, the overall length of the nozzle flow channel will be extended, which is contrary to the original design concept. If the extension length of the easy-to-fold forming part 642 is too short, a sharp wedge will be formed at the pre-folding position 81. In the case of forming a sharp wedge, the angle selection of the first pre-folding forming part 641 and the second pre-folding forming part 643 is not the same as that in the case of having an easy-to-fold forming part 642. Further preferably, the extension length of the easy-to-fold forming part 642 is 2mm.

[0075] Preferably, the length of the first mold frame forming part 7211 is 15-25mm. If the first mold frame forming part 7211 is too long, the overall length of the nozzle flow channel will be extended, which is contrary to the original design concept. If the first mold frame forming part 7211 is too short, the tensile stiffness of the glue nozzle mold frame 8 will be high, making it difficult to be lifted and bent by the cutter insert 72. Further preferably, the length of the first mold frame forming part 7211 is 20mm.

[0076] Preferably, the distance between the lower end of the first pre-folding forming part 641 and the second feeding groove 62 is 2-5 mm. If the distance is too large, the overall length of the water gap will be extended, which is contrary to the original design concept. If the distance is too small or even cuts into the main mold frame formed by the first feeding groove 52 and the second feeding groove 62, the stress bearing strength at the connection position of the glue port mold frame 8 and the main mold frame during the parting process is high, and it is difficult to be bent to complete the parting. Preferably, the distance between the lower end of the first pre-folding forming part 641 and the second feeding groove 62 is 3 mm

[0077] Preferably, the diameter of the flow passage cross section defined by the first mold frame forming part 7211 and the second mold frame forming part 7311 is D, the ball diameter of the first booster part 7212 is the same as the diameter of the flow passage cross section defined by the first mold frame forming part 7211 and the second mold frame forming part 7311, the parting part 7213 starts at the upper end of the first booster part 7212 and is downwardly inclined by 1 / 4-1 / 3D, the inclination angle between the parting part 7213 and the horizontal plane is 15-30°, and the angle of the two side walls of the parting part 7213 widening outwardly is 5-10°.

[0078] The parting part 7213 is upwardly inclined, and a relatively sharp corner can be formed at the position of the connecting part 7214 and the parting part 7213 to form a cutting edge, so as to complete the cutting parting between the connecting piece 82 and the molded product during the parting process.

[0079] The application also provides a use method of the mold for automatically cutting off the glue port, which is applied to the mold for automatically cutting off the glue port as described above and includes the following steps.

[0080] S1. Calculation, mold flow analysis is performed using injection molding simulation software, and the deformation amount of the glue port is determined, and then the ratio of a / A, the inclination angle between the lower end of the first pre-folding forming part 641 or the second pre-folding forming part 643 and the horizontal plane, the extension length of the easy folding forming part 642, and the length of the first mold frame forming part 7211 and the above parameters are determined;

[0081] S2. The corresponding cutter insert 72 and the pressure cutter insert 73 are selected according to the parameters determined in S1, and the cutter insert 72 and the pressure cutter insert 73 are assembled;

[0082] S3. Clamping and injection molding, and segmented pressure is applied during the injection molding process;

[0083] S4. Molding, after the injection molding is completed, the pressure is maintained for 1-3 s, and the natural cooling is performed for 3-8 s;

[0084] S5. After the cooling is completed, the cutting device 7 is pulled away, then the upper die plate 4 and the lower die plate 3 are separated, the front die core 5 and the rear die core 6 are separated, and the ejector plate ejects the separated rubber mouth mold frame 8 and the formed product.

[0085] The preferred embodiments of the present application have been described above with the preferred embodiments, but the present application is not limited to the above examples, and various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A mold for automatic cut-off of a spout, characterized by, The utility model relates to a mould base is provided with ejector plate, and the lower mould plate and upper mould plate of separable are arranged on the upper surface of ejector plate, and the upper end of upper mould plate is detachably provided with faceplate, and the lower mould plate and upper mould plate are mutually closed and hold tightly through closing device or mutually far away and separate through the ejector pin of ejector plate, and the inside between lower mould plate and upper mould plate is provided with separable front mould core and rear mould core, and the inside of front mould core and rear mould core is slidably provided with cutter device, The cutter device specifically includes a compression spring fixed on the upper end surface of the lower mold plate, the upper end of the compression spring is fixedly provided with a cutter insert, the upper part of the cutter insert is separately provided with a pressure cutter insert, the upper end of the pressure cutter insert is fixedly provided with an insert pressing plate, the insert pressing plate is fixedly provided on the injection port of the faceplate, the middle part of the insert pressing plate is embedded with an injection hopper for injecting material into the mold, the upper end surface of the cutter insert is provided with a first water gap, and the lower end surface of the pressure cutter insert is provided with a second water gap. The front mold core is provided with a feed flow channel communicated with the injection hopper, the lower end surface of the front mold core is provided with a first feed slot communicated with the feed flow channel, and the front mold core is provided with a plurality of insert movable holes for the pressure cutter insert to penetrate, the lower end opening end of each insert movable hole is respectively communicated with the first feed slot flow channel, and the lower end surface of the front mold core is provided with an upper forming groove on the side away from the first feed slot. The upper end surface of the rear mold core is provided with a second feed slot matched with the first feed slot, the second feed slot is provided with an injection bevel inclined upward first and then downward at the position corresponding to the insert movable hole, and the end of the injection bevel away from the second feed slot is provided with a cutter movable hole penetrating through the rear mold core for the cutter of the cutter insert. When the lower mold plate and the upper mold plate are tightly closed and the front mold core and the rear mold core are tightly locked, the pressure cutter insert presses the cutter insert, the first feed slot, the second feed slot, the first water gap, the injection bevel and the second water gap are combined to form a water gap flow channel, and the upper forming groove and the lower forming groove are combined to form a product forming cavity. When the lower mold plate and the upper mold plate are separated and the front mold core and the rear mold core are still in the tightly locked state, the pressure cutter insert is away from the cutter insert, the cutter insert is lifted by the compression spring, and the rubber port mold frame formed in the water gap flow channel is also lifted, the rubber port mold frame forms a pre-folding position at the position of the injection bevel, the rubber port mold frame is folded upward along the pre-folding position after being lifted by the cutter insert, and finally separated from the formed product. ​ The first water gap includes a semicircular arc groove-shaped first mold frame forming part which can communicate with the injection slope when the front and rear mold cores are locked, a 1 / 4 spherical surface groove-shaped first booster part is arranged on the side of the first mold frame forming part away from the injection slope, a gradually widened parting part is upwardly arranged on the side of the first booster part away from the injection slope, and a connecting part which communicates with the product forming cavity is formed on the side wall surface of the cutter insert through the parting part away from the injection slope; The second water gap includes a semicircular arc groove-shaped second mold frame forming part corresponding to the position of the injection slope and the first mold frame forming part, a 1 / 4 spherical surface groove-shaped second booster part corresponding to the first booster part is arranged on the side of the second mold frame forming part away from the first feeding groove, a sealing part is formed on the lower end surface of the cutter insert around the second water gap, the sealing part corresponds to the position of the parting part and the area of the upper end surface of the cutter insert which is not arranged with the first water gap, when the front and rear mold cores are locked, the sealing part tightly contacts the position of the upper end surface of the cutter insert which is not arranged with the first water gap, the injection slope includes a first pre-folding forming part which is upwardly arranged and communicates with the second feeding groove, the upper end of the first pre-folding forming part horizontally extends to form a flat easy folding forming part, a second pre-folding forming part which is symmetric to the first pre-folding forming part is downwardly arranged on the end of the easy folding forming part away from the first pre-folding forming part, the connection strength between the circular arc surface formed after molding and the connecting piece formed by the parting part is higher than that of the flat surface, which ensures that the connecting piece is separated from the product formed after molding rather than from the glue port mold frame after the glue port mold frame is lifted by the cutter insert.

2. The automatic knockout mold of claim 1 wherein, The cutter insert includes a base body, a guide rib is protruded on the side surface of the base body close to the product forming cavity, a limiting block is protruded on the lower end of the side surface of the base body away from the product forming cavity, the first mold frame forming part is arranged on the upper end surface of the base body, and the first booster part and the parting part are arranged on the upper end surface of the guide rib; A guide groove which is matched with the guide rib is recessed on the side of the cutter movable hole close to the product forming cavity, and a limiting groove which can accommodate the limiting block is upwardly recessed on the side of the lower end opening of the cutter movable hole away from the product forming cavity.

3. The automatic knockout mold of claim 2 wherein, The groove depth of the limiting groove is 2-5 mm longer than the height of the limiting block.

4. The automatic glue port cutting mold of claim 1, wherein The cross-sectional area of the flow passage formed by the first mold frame forming part and the second mold frame forming part is defined as A, and the cross-sectional area of the flow passage formed by the easy folding forming part and the second mold frame forming part is defined as a, and a=0.4-0.6A.

5. The automatic knockout mold of claim 4 wherein, The inclination angle between the lower end of the first pre-folding forming part or the second pre-folding forming part and the horizontal plane is 30-60°.

6. The automatic knockout mold of claim 4 wherein, The extension length of the easy folding forming part is 1.5-3 mm.

7. The automatic knockout mold of claim 4 wherein, The length of the first mold frame forming part is 15-25 mm, and the distance between the lower end of the first pre-folding forming part and the second feeding groove is 2-5 mm.

8. The automatic knockout mold of claim 4 wherein, The diameter of the flow channel cross section formed by the first mold frame forming part and the second mold frame forming part is defined as D, and the ball diameter of the first booster part is the same as the diameter of the flow channel cross section formed by the first mold frame forming part and the second mold frame forming part. The parting part starts at the upper end of the first booster part and extends downward to a position 1 / 4-1 / 3D from the upper end, the inclination angle between the parting part and the horizontal plane is 15-30°, and the angle of the two side walls of the parting part widening outward is 5-10°.

9. A method of using an automatic knockout die, comprising: The mold is applied to the automatic cutting of the glue port as claimed in any one of claims 4-8, and comprises the following steps: S1. Calculation, using injection molding simulation software to perform mold flow analysis and determine the glue port deformation, and then determine the ratio of a / A, the inclination angle between the lower end of the first pre-folding forming part or the second pre-folding forming part and the horizontal plane, the extension length of the easy folding forming part, and the length of the first mold frame forming part; S2. According to the parameters determined in S1, select the corresponding cutter insert and pressure cutter insert, and assemble the cutter insert and the pressure cutter insert; S3. Mold clamping and injection, and segmented pressure during injection; S4. Forming, maintaining the pressure for 1-3S after injection, and naturally cooling for 3-8S; S5. Parting, after cooling, the cutter device is removed, then the upper mold plate and the lower mold plate are separated, the front mold core and the rear mold core are separated, and the ejector plate ejects the separated glue port mold frame and the formed product.

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