Micro injection mold for mixing three colors
By designing mixed three-color micro injection molds, the mold structure and runner design are simplified, and the problems of high mold manufacturing costs, long cycles and serious waste of plastic particles in the prior art are solved, thereby achieving shortening of runners and cost savings.
Patent Information
- Application Number
- CN202421710132.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-07-18
AI Technical Summary
In the prior art, the mixed three-color injection mold has a complex structure and a large processing volume, resulting in high manufacturing cost and long cycles of molds, and requires a large injection molding machine, with large power consumption and long product runners, resulting in serious waste of plastic particles.
A mixed three-color micro injection mold was designed. Through the design of the front template and the rear template, the transformation of the one-color cavity and the two-three-color cavity is achieved, simplifying the mold structure, shortening the runner length, and reducing the mold processing workload and manufacturing cost.
The runner of the mold is shortened, the waste of plastic particles is reduced, the manufacturing cost and manufacturing cycle of molds is reduced, and the problem of traditional molds requiring a large injection molding machine and high power consumption is solved.
Smart Images
Figure CN222972664U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of injection molds, and particularly relates to a three-color mixed micro injection mold. Background Art
[0002] In recent years, with the popularization of new energy vehicles, the competition between new energy vehicle manufacturers and traditional vehicle manufacturers has become increasingly fierce. The mold development cycle is getting shorter and shorter, and cost control is getting stricter and stricter.
[0003] The Loadspace switch is an important part of automotive interior switches. As an exterior part, the surface of the Towbar deploy button requires laser engraving after painting to achieve the working indication of the light guide body (PC foggy transparent) and the symbol backlight indication (PC grayish white). The whole needs to be formed by three-color mixed injection molding. The traditional mold opening method is usually the combined injection molding of two sets of molds to form three-color products. The mold with such a structure is relatively large, the mold structure is complex, the processing amount is large, the mold manufacturing cost is high and the cycle is long, and a relatively large injection molding machine is required. Usually, a 160T injection molding machine is needed, which has high power consumption. Moreover, such a mold structure results in a very long product runner, and the waste of plastic particles is serious. Summary of the Invention
[0004] The purpose of the utility model: In order to overcome the defects of the prior art, the utility model provides a three-color mixed micro injection mold, which greatly reduces the length and size of the mold runner, saves the cost of plastic particles, and only one set of mold is needed to form three-color mixed injection molding, reducing a lot of mold processing work, greatly reducing the mold manufacturing cost and shortening the mold manufacturing cycle, and solving the problem that the injection of three-color products requires the use of a relatively large injection molding machine to inject two sets of molds, with high power consumption and serious waste of injection particle cost.
[0005] Technical solution of the utility model: A three-color mixed micro-injection mold, including a front template, a rear template, a first-color injection port, a second-color injection port and a third-color injection port. A sprue ejector plate is arranged above the front template, and an upper fixing plate is arranged above the sprue ejector plate. The front template, the rear template, the upper fixing plate and the sprue ejector plate are all arranged to be opened and closed. The first-color injection port is arranged on the upper fixing plate. There are two identical and centrosymmetric bottom cavities on the rear template. The front template includes two mold cores with different shapes on the bottom surface, which respectively extend into the two bottom cavities to form a first-color cavity and a second-and-third-color cavity. A second-color runner and a third-color runner are formed between the front template and the rear template. The second-color runner and the third-color runner are respectively communicated with the second-color injection port and the third-color injection port, and respectively form a second-color pin gate and a third-color pin gate on the second-and-third-color cavity. A first-color runner is arranged on the front template, and the first-color runner is communicated with the first-color injection port. The first-color runner forms a first-color pin gate on the first-color cavity. A sprue puller is fixedly arranged on the upper fixing plate. The sprue puller includes a neck for clamping the injection molded part of the first-color runner. The neck of the sprue puller penetrates through the front template and the sprue ejector plate and enters the first-color runner. A ejecting component is arranged at the bottom of each bottom cavity.
[0006] Adopting the above technical solution, by respectively arranging the same parts and different parts of the first-color cavity and the second-and-third-color cavity on the rear template and the front template, the transformation between the first-color cavity and the second-and-third-color cavity can be realized by rotating the rear template. And the injection runner of the first-color cavity is relatively independent. After injecting the first-color cavity, the separated runner can be taken out without affecting the first-color injection molded part. Then rotate the rear template to change the first-color cavity into the second-and-third-color cavity for subsequent injection of the second and third colors, so that the second-and-third-color products are injection molded simultaneously to wrap the first-color product to realize the product assembly structure. Finally, the product assembly is obtained by using the ejecting component. The overall injection mold is small, and the injection ports of the first, second and third colors are integrated in one injection mold. The length and size of the mold runner are greatly reduced, which greatly saves the cost of plastic particles.
[0007] Further setting of the utility model: A three-color mixed micro-injection mold further includes several guide columns for guiding the actions of the front template, the rear template and the upper fixing plate, a thimble screw for connecting the upper fixing plate and the sprue ejector plate, several pull rods for guiding the sprue ejector plate and the front template, several nylon hooks for connecting the front template and the rear template, and several precision positioning sleeves and several precision positioning posts respectively arranged on the front template and the rear template;
[0008] The dowel screw includes a threaded portion connected to the sprue ejector plate and a smooth portion that slides relative to the upper fixing plate. The pull rod includes a threaded portion connected to the sprue ejector plate, a sliding portion that slides relative to the front template, and a nut portion that can only act in the rear template. A guide sleeve for assisting the sliding of each guide post is provided between the front template and the sprue ejector plate respectively.
[0009] With the above further settings, the sliding between the front template, rear template, upper fixing plate, and sprue ejector plate is realized by using the dowel screw, the pull rod, and the nylon hook respectively, and the position between the front template and the rear template is determined by using the precision positioning sleeve and precision positioning post, so that the sliding opening and closing between the components can be realized for the injection molding step.
[0010] A further setting of the present utility model: The ejection assembly includes an ejector pin fixing plate provided at the bottom of the rear template, an ejector pin bottom plate fixedly provided at the bottom of the ejector pin fixing plate, and a push rod provided on the ejector pin bottom plate. A plurality of pressing blocks are circumferentially provided on the ejector pin fixing plate, and each pressing block is fixedly connected to the rear template. Each pressing block includes a stepped surface for limiting the ejector pin fixing plate, and the ejector pin fixing plate is above the stepped surface;
[0011] The push rod passes through the ejector pin bottom plate and contacts the bottom surface of the ejector pin fixing plate. The push rod includes a rod cap portion for preventing the push rod from sliding out in the direction away from the ejector pin fixing plate;
[0012] An ejector pin assembly for ejecting the injection molded part and a plurality of reset rods are provided on the ejector pin fixing plate. There are a plurality of countersunk through holes on the ejector pin fixing plate for limiting the ejector pin assembly and the reset rods;
[0013] A plurality of countersunk through holes for passing through the reset rods are provided on the rear template. Both ends of each reset rod are respectively abutted against the front template and the ejector pin fixing plate. A telescopic spring is wound around each reset rod, and both ends of the telescopic spring are respectively abutted against the ejector pin fixing plate and the countersunk surface of the countersunk through hole on the reset rod.
[0014] With the above further settings, by pushing the push rod, the assembled product and the injection molded products in the two-color runner and three-color runner can be ejected, avoiding blockage in the next two-color or three-color injection molding process, and the ejection assembly can realize the automatic reset of the push rod through the pressing block and the telescopic spring.
[0015] Further setting of the present utility model: On each of the bottom cavities, there is fixedly arranged an insert for defining the shapes of the single-color cavity and the two-color and three-color cavities. The ejector pin assembly includes several flat ejector pins for extending into the bottom cavities, and several round ejector pins passing through the rear template and extending into the two-color runner and the three-color runner. The flat ejector pins and the insert constitute the bottom surface of the bottom cavity.
[0016] With the above further setting, by setting the insert as the bottom mold of the whole mold, which is made separately from the rear template, it can process details more precisely. And there is a groove on the side of the insert for placing the flat ejector pins, which is convenient for positioning the flat ejector pins, can push the assembled product out of the mold more accurately. Moreover, the round ejector pins and the rear template constitute the bottom surface of the runner, and can push the injection-molded products in the two-color runner and the three-color runner for demolding.
[0017] Further setting of the present utility model: The ejector pin assembly further includes two symmetrically arranged angled ejector parts, which are fixedly arranged on the ejector pin fixing plate. The top of the angled ejector part has a stepped structure, and its stepped surfaces are respectively in contact with the bottom surface and the side surface of the bottom cavity.
[0018] With the above further setting, when injecting into the two-color and three-color cavities, the two angled ejector parts can serve as part of the side wall and part of the bottom surface of the cavity. During demolding, they can push both sides of the assembled product simultaneously, making the force on the assembled product symmetric and uniform during demolding, and further reducing the probability of deformation of the assembled product.
[0019] Further setting of the present utility model: The two-color pin gate and the three-color pin gate are respectively located on the two side walls of the two-color and three-color cavity, and both the two-color pin gate and the three-color pin gate are submarine gates.
[0020] With the above further setting, the submarine gate makes the injection-molded part enter the cavity obliquely, so that the feeding gate is located at the concealed side of the injection-molded product, with little impact on the appearance. And during demolding, the connection between the injection-molded product and the injection runner is easily cut off, realizing the separation of the injection-molded product from the injection runner.
[0021] Further setting of the present utility model: In the sprue push plate, the front template and the rear template, there are water pipelines for cooling the single-color runner, the two-color runner, the three-color runner, the single-color cavity and the two-color and three-color cavities. At the connection of each water pipeline extending outside the mold, there is a water stop bolt.
[0022] With the above further setting, the waterways provided in the circumferences of each injection port runner and each cavity can facilitate the rapid cooling and molding of the injection-molded part. And the water stop bolt can regulate the flow direction of the water in the waterway, ensuring that during the injection process, the water can flow correctly to each part of the mold, avoiding mixed cross-flow and guaranteeing the quality of the injection-molded product.
[0023] Further arrangement of the utility model: The upper fixing plate includes a fixing step for positioning and fixing the position of the overall mold. Heat insulation plates are arranged on the upper fixing plate. A pressing plate groove is provided on the rear template, and a pressing plate for fixing the rear template to the injection molding machine is provided on the pressing plate groove.
[0024] With the above further arrangement, the mold is fixedly arranged on the injection molding machine through the fixing step and the pressing plate, which facilitates the subsequent mold opening and closing actions. Moreover, the setting of the heat insulation plate can prevent the heat on the injection molding machine from being excessively conducted into the mold, so as to affect the cooling and solidification speed of the molding material. Description of the drawings
[0025] Figure 1 It is a schematic diagram of the overall structure of a specific embodiment of the utility model;
[0026] Figure 2 It is a schematic diagram of the overall structure of another perspective of a specific embodiment of the utility model;
[0027] Figure 3 It is a top view structure schematic diagram of a specific embodiment of the utility model;
[0028] Figure 4 It is Figure 3 The sectional structure schematic diagram of A-A in
[0029] Figure 5 It is Figure 3 The sectional structure schematic diagram of B-B in
[0030] Figure 6 It is Figure 3 The sectional structure schematic diagram of C-C in
[0031] Figure 7 It is a sectional view of the overall structure of a specific embodiment of the utility model;
[0032] Figure 8 It is another sectional view of the overall structure of a specific embodiment of the utility model;
[0033] Figure 9 It is a schematic diagram of the overall structure of the front template in a specific embodiment of the utility model;
[0034] Figure 10 It is a top view structure schematic diagram of the front template in a specific embodiment of the utility model;
[0035] Figure 11 It is a sectional view of the overall structure of the front template in a specific embodiment of the utility model;
[0036] Figure 12 It is a schematic diagram of the overall structure of the rear template in a specific embodiment of the utility model;
[0037] Figure 13 This is a schematic diagram of the overall structure of the rear template from another perspective in a specific embodiment of the present utility model;
[0038] Figure 14 This is a cross-sectional view of the overall structure of the rear template in a specific embodiment of the present utility model;
[0039] Figure 15 This is a schematic diagram of the overall structure of the upper fixing plate in a specific embodiment of the present utility model;
[0040] Figure 16 This is a schematic diagram of the overall structure of the sprue push plate in a specific embodiment of the present utility model;
[0041] Figure 17 This is a schematic diagram of the overall structure of the lifter in a specific embodiment of the present utility model.
[0042] In the figure: 1, front template; 2, rear template; 3, upper fixing plate; 4, first-color injection port; 5, second-color injection port; 6, third-color injection port; 7, bottom cavity; 8, first-color cavity; 9, second- and third-color cavity; 10, second-color runner; 11, third-color runner; 12, first-color runner; 13, first-color pin point gate; 14, thimble screw; 15, sprue puller; 17, precision alignment bushing; 18, precision alignment pin; 19, second-color pin point gate; 20, third-color pin point gate; 21, sprue push plate; 22, guide pillar; 23, tie rod; 24, guide bushing; 25, nylon latch; 26, insert; 27, ejector plate; 28, ejector assembly; 281, flat ejector pin; 282, round ejector pin; 29, return rod; 30, lifter; 31, ejector retainer plate; 32, pressure block; 321, stepped surface; 33, push rod; 331, rod cap; 34, fixed step; 35, heat insulation plate; 36, pressure plate groove; 37, pressure plate; 38, upper channel; 39, lower channel. Specific Embodiment
[0043] Next, the technical solutions in this embodiment will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0044] It should be noted that in the description of the present utility model, all directional indications (such as up, down, front, back...) are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.
[0045] In addition, in the present utility model, descriptions such as "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present utility model, the meaning of "a number of" is at least two, such as two, three, etc., unless otherwise specifically defined.
[0046] In addition, the technical solutions between the various embodiments of the present utility model can be combined with each other, but it must be based on the fact that those skilled in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.
[0047] As Figure 1-17 shown, a three-color mixed micro-injection mold includes a top fixing plate 3, a sprue push plate 21, a front template 1, and a rear template 2 arranged in sequence. A first-color injection port 4 is provided on the top fixing plate 3, and a second-color injection port 5 and a third-color injection port 6 are provided between the front template 1 and the rear template 2. The front template 1, the rear template 2, the top fixing plate 3, and the sprue push plate 21 are all arranged to be slidably opened and closed. The top fixing plate 3 and the rear template 2 are installed on an injection molding machine. The rear template 2 is the fixed end, and the top fixing plate 3 is the movable end. The injection molding machine can control the movement of the top fixing plate 3.
[0048] Two identical and centrally symmetric bottom cavities 7 are provided on the rear template 2. Inserts 26 are provided on both of the two bottom cavities 7 to define the bottom die shapes of the first-color cavity 8 and the second- and third-color cavity 9. The inserts 26 are fixed to the rear template 2 by screws. The inserts 26 serve as the bottom die of the entire mold, are separated from the rear template 2, and can be separately processed, which can make the mold more accurate.
[0049] The front template 1 includes two different-shaped mold cores on the bottom surface, namely a first-color upper mold core and a second- and third-color upper mold core. The first-color upper mold core and the second- and third-color upper mold core respectively form a first-color cavity 8 and a second- and third-color cavity 9 with the two bottom cavities 7. Specifically, the same parts at the bottom of the first-color cavity 8 and the second- and third-color cavity 9 are on the rear template 2, and the different parts at the top are on the front template 1. By rotating the rear template 2, the transformation between the first-color cavity 8 and the second- and third-color cavity 9 can be realized.
[0050] There are two upper channels on the bottom end face of the front template 1. The two upper channels 38 penetrate through the two side faces of the front template 1 from the outside to connect the two-color and three-color cavities 9. The two upper channels 38 respectively penetrate through the two-color and three-color upper die cores to form a two-color pin gate 19 and a three-color pin gate 20. Between each bottom cavity 7 on the top end face of the rear template 2 and the two side faces of the rear template 2, there are two lower channels 39 provided. The two bottom cavities 7 and their respective corresponding two lower channels 39 are centrosymmetric. The two upper channels 38 on the front template 1 and the two lower channels 39 corresponding to any one of the bottom cavities 7 on the rear template 2 form a two-color runner 10 and a three-color runner 11. The two-color runner 10 and the three-color runner 11 form a two-color injection port 5 and a three-color injection port 6 on the two side walls of the mold.
[0051] Both the two-color pin gate 19 and the three-color pin gate 20 are submarine gates. The submarine gates enable the injection molded parts to enter the cavity obliquely, making the feeding gate located at the concealed side of the injection molded product, with little impact on the appearance. And during demolding, the connection between the injection molded product and the injection runner is easily cut off, realizing the separation of the injection molded product from the injection runner.
[0052] There is a one-color runner 12 on the front template 1. The one-color runner 12 penetrates through the front template 1 as a whole. The one-color runner 12 is connected to the one-color injection port 4. The one-color runner 12 penetrates through the one-color upper die core at the bottom surface of the front template 1 to form a one-color pin gate 13 at the top of the one-color cavity 8.
[0053] The injection runner of the one-color cavity 8 is set separately from the two-color runner and the three-color runner, and is located on the front template 1 alone, making the one-color injection independent of the two-color and three-color injections. The one-color injection process does not affect the two-color and three-color injections.
[0054] There are two sprue pullers 15 provided on the upper fixing plate 3. The sprue puller 15 includes a nut part at the top and a neck with an annular arc groove. Each sprue puller 15 is pressed into the counterbore of the upper fixing plate 3 by a headless screw to prevent the sprue puller 15 from retreating during injection molding. At the same time, the neck of the sprue puller 15 penetrates through the front template 1 and the sprue ejector plate 21 and enters the one-color runner 12, so that the plastic formed after injection can fill the annular groove of the neck of the sprue puller 15, and the neck is then clamped in the plastic formed in the one-color runner 12. A certain degree of force is required to separate the sprue puller 15 and the plastic formed in the one-color runner 12.
[0055] After injecting the one-color cavity 8, only the plastic formed in the one-color runner 12 is taken out without affecting the one-color injection molded part. Subsequently, the rear template 2 is rotated to transform the one-color cavity 8 into a two-color and three-color cavity 9 for subsequent two-color and three-color injections, so that the two-color and three-color products are injection molded simultaneously to wrap the one-color product to achieve the product assembly structure.
[0056] There are two guide pillars 22 penetrating between the front template 1, the rear template 2, the sprue ejector plate 21 and the upper fixing plate 3, which are used to guide the actions of each plate. A guide bushing 24 is arranged outside each guide pillar 22 and is fixed on the front template 1 and the sprue ejector plate 21 to assist the guide pillar 22 to move more smoothly.
[0057] A stop screw 14 is arranged between the upper fixing plate 3 and the sprue ejector plate 21. The stop screw 14 includes a threaded part connected to the sprue ejector plate 21, a smooth part that slides relative to the upper fixing plate 3, and the smooth part is used to realize the action of the sprue ejector plate 21 relative to the upper fixing plate 3 to achieve opening and closing. It also includes a screw part, whose size is larger than the through-hole size of the smooth part sliding on the upper fixing plate 3 and is used to limit the movement stroke of the upper fixing plate 3 on the stop screw 14.
[0058] Four tie rods 23 are threadedly connected to the sprue ejector plate 21. Each tie rod includes a smooth rod part and a nut part that acts in the rear template 2. The smooth rod part passes through the front template 1 and the rear template 2 and slides relative to the front template 1, which is used to realize the action of the front template 1 relative to the sprue ejector plate 21 to achieve its opening and closing. The width of the nut part is larger than the diameter of the through-hole where the smooth rod part slides on the front template 1, which limits the movement between the sprue ejector plate 21 and the front template 1.
[0059] Four nylon hooks 25 are connected between the front template 1 and the rear template 2. One end is fixed inside the rear template 2, and the other end extends into the front template 1 and fixes the front template 1, which is used to position and align the front template 1 and the rear template 2 and keep the front template 1 and the rear template 2 closed. Only when the mold opening force is greater than the expansion force of the nylon hook 25 can the front template 1 and the rear template 2 be separated to assist the front template 1 to slide relative to the rear template 2.
[0060] Two groups of precision positioning sleeves 17 and precision positioning posts 18 are respectively arranged on the front template 1 and the rear template 2 to further precisely position the front template 1 and the rear template 2.
[0061] There are two cavities at the bottom of the rear template 2. An ejection assembly is arranged in each cavity. The two ejection assemblies are respectively below the two bottom cavities 7. The ejection assembly includes an ejector pin fixing plate 27, an ejector pin bottom plate 31 fixedly arranged at the bottom of the ejector pin fixing plate 27, and a push rod 33 arranged on the ejector pin bottom plate 31. The push rod 33 includes a rod cap 331 for preventing the push rod 33 from sliding out in the direction away from the ejector pin fixing plate 27. The push rod 33 penetrates the ejector pin bottom plate 31 and extends out at its bottom, and the rod cap 331 contacts the bottom surface of the ejector pin fixing plate 27.
[0062] On both sides of the thimble fixing plate 27, there is a pressing block 32 respectively. Each pressing block 32 is fixedly connected to the rear template 2 by bolts. Each pressing block 32 includes a stepped surface 321 for limiting the thimble fixing plate 27. The thimble fixing plate 27 is located on the side of the stepped surface 321 close to the front template 1 to limit the thimble fixing plate 27 and prevent it from detaching from the rear template 2.
[0063] On the thimble fixing plate 27, there is a thimble assembly 28 for ejecting the injection molded part and four reset rods 29. The thimble assembly 28 includes four flat thimbles 281 for extending into the bottom cavity 7 and two round thimbles 282 passing through the rear template 2 and extending into the two-color runner 10 and the three-color runner 11 respectively. The round thimbles 282 serve as the bottom surface of the two-color runner 10 and the three-color runner 11, and can push the injection molded parts on the two-color runner 10 and the three-color runner 11 to demold during operation;
[0064] On the four side surfaces of the insert 26, there are grooves for placing the flat thimbles 281, which is convenient for positioning the flat thimbles 281. The top surface of each flat thimble 281 serves as the bottom of the first-color cavity 8 and the second- and third-color cavities 9, assisting in defining the shape of the injection molded part. And the flat thimbles 281 move relative to the insert 26, and can push the injection molded product to demold during operation. The flat thimbles 281 are arranged around the insert 26, so that the bottom surface of the injection molded product is more evenly affected by the driving force of the flat thimbles 281, avoiding tilting and deformation.
[0065] On the thimble fixing plate 27, there are several through holes with countersinks. The countersunk part of its countersunk through holes is close to the thimble bottom plate 31 side. And the reset rods 29, flat thimbles 281 and round thimbles 282 all include a rod cap structure. The rod cap structure is placed in the countersunk part of the through holes on the thimble fixing plate 27 and contacts the thimble bottom plate 31, which is used to fix and limit the flat thimbles 281, round thimbles 282 and reset rods 29, and precisely control the positions of the flat thimbles 281 and round thimbles 282 relative to the insert 26.
[0066] Between the cavity of the rear template 2 and the top end surface of the rear template 2, there are four countersunk through holes for passing through the reset rods 29. The two ends of each reset rod 29 are respectively in contact with the front template 1 and the thimble fixing plate 27. An expansion spring is wound around each reset rod 29. The two ends of the expansion spring are respectively in contact with the thimble fixing plate 27 and the countersunk surface of the countersunk through hole on the rear template 2, which is used to realize that after the ejection component finishes ejection, under the action of the expansion spring, the thimble fixing plate 27 contacts the stepped surface 321 of the pressing block 32 to reset.
[0067] Furthermore, the ejector assembly 28 also includes two symmetrically arranged inclined ejector pieces 30, which are arranged on the ejector fixing plate 27 by pins, and the pins are slidably connected to the grooves provided on the ejector fixing plate 31. The top of the inclined ejector piece 30 is a stepped structure, and its stepped surfaces are respectively fitted with the bottom surface and the side surface of the bottom cavity 7, and a protrusion is provided on the top of the inclined ejector piece 30. When the second and third color cavities 9 are injection molded, the two inclined ejector pieces 30 can serve as part of the side walls and part of the bottom surface of the cavity, and can simultaneously push the two side surfaces of the assembly product during demoulding. Since the inclined ejector piece 30 is tilted as a whole and the bottom pin slides relative to the ejector fixing plate 27, while pushing the bottom surface of the total product, the inclined ejector piece 30 moves sideways, and its protrusion pushes the hook position of the product to achieve demoulding. At the same time, the two inclined ejector pieces 30 are symmetrically arranged relative to the injection molded product, so that the assembly product is subjected to symmetrical and uniform force during demoulding, further reducing the probability of deformation of the assembly product.
[0068] The water inlet push plate 21, the front template 1 and the rear template 2 are all provided with water pipes for cooling the one-color runner 12, the two-color runner 10, the three-color runner 11, the one-color cavity 8 and the two-three-color cavity 9. The water channels provided on the circumference of each injection runner and each cavity can accelerate the cold molding of the injection molded parts. Each connection where the water pipe extends to the outside of the mold is provided with a water stopper. The water stopper can regulate the flow direction of water in the water channel to ensure that during the injection molding process, the water channel can correctly flow to various parts of the mold to avoid mixed cross-flow and ensure the quality of the injection molded product.
[0069] The upper fixed plate 3 includes a fixed step 34 for fixing the position of the entire mold. The rear template 2 is provided with a pressure plate groove 36. The pressure plate groove 36 is fixedly provided with a pressure plate 37 for fixing the rear template 2 on the injection molding machine. The mold is fixed on the injection molding machine through the fixed step 34 and the pressure plate 26 to facilitate subsequent mold opening and closing actions. Insulation plates 35 are provided on the upper fixed plate 3 and above the fixed step 34 to prevent excessive heat from the injection molding machine from being transferred to the mold, thereby affecting the cooling and solidification speed of the molding material.
[0070] The specific steps of mixed three-color injection molding are:
[0071] Step 1: Injection molding: use an injection molding machine to perform injection molding on a single-color cavity 8 at a single-color injection port 4, and at the same time, the injection molding machine performs injection molding on a second-color cavity 9 through a second-color injection port 5 and a third-color injection port 6, and adjust the water stopper to control water flow to the waterway around the single-color flow channel, and complete the single-color injection molding after cooling and molding, and adjust the water stopper to control water flow to cool each cavity and flow channel, and complete the injection molding after cooling and molding;
[0072] Step 2: First mold opening. After Step 1, the injection molding machine controls the upper fixing part 3 to move. The upper fixing part 3 drives the sprue puller pin 15 to move together. The neck of the sprue puller pin 15 has a notch and is clamped with the injection molded part of the first-color runner 12, driving the injection molded part of the first-color runner 12 to move, disconnecting the connection between the first-color point gate 13 of the injection molded part of the first-color runner 12 and the injection molded part of the first-color cavity 8, and continuing to move until the injection molded part of the first-color runner 12 moves away from the front template 1. At this time, the tie rod 23 moves together with the sprue push plate 21 until the nut of the tie rod 23 contacts the front template 1 and the stroke is in place;
[0073] Step 3: Second mold opening. The injection molding machine continues to control the upper fixing part 3 to move. At this time, the sprue push plate 21 cannot move together with the upper fixing part 3 because the stroke of the tie rod 23 is in place. Therefore, the sprue puller pin 15 still drives the injection molded part of the first-color runner 12 to move. After the injection molded part of the first-color runner 12 contacts the end face of the sprue push plate 21, due to the relatively wide injection molded part of the first-color runner 12 being blocked by the sprue push plate 21, the clamping position between the sprue puller pin 15 and the injection molded part of the first-color runner 12 is disengaged, causing the injection molded part of the first-color runner 12 to fall off. The upper fixing part 3 continues to move until the stop screw 14 reaches the stroke;
[0074] Step 4: Third mold opening. The injection molding machine continues to control the upper fixing part 3 to move. At this time, both the stop screw 14 and the tie rod 23 are in place. When the mold opening force of the injection molding machine is greater than the expansion force of the nylon hook 25, the front template 1 and the sprue push plate 21 both move together with the upper fixing part 3, and the front template 1 and the rear template 2 are opened;
[0075] Step 5: Push the push rod 33 at the bottom of the second and third-color cavities 9, causing the ejector plate 27 and the return rod 29 to move. The flat ejector pins 281 and the lifter 30 together push the second and third-color finished parts in the demolding direction. The lifter 30 moves laterally synchronously to push out the position where it hooks the finished product. The round ejector pins 282 push the injection molded parts in the second-color runner and the third-color runner to move. After ejecting the second and third-color finished parts and the injection molded parts in the second-color runner and the third-color runner, the demolding is completed. Release the push rod 33, and the ejector plate 27 returns to complete the ejection of the finished product;
[0076] Step 6: Switch the cavity. The injection molding machine controls the rear template 2 to rotate 180 degrees relative to the front template 2, then controls the entire mold to close, and then repeats Steps 1 to 6 multiple times to inject and produce products.
Claims
1. A three-color mixed micro injection mold, comprising a front template (1), a rear template (2), a single-color injection port (4), a two-color injection port (5) and a three-color injection port (6), a sprue push plate (21) is arranged above the front template (1), an upper fixing plate (3) is arranged above the sprue push plate (21), and the mold is characterized in that: The front template (1), the rear template (2), the upper fixed plate (3) and the sprue push plate (21) are all arranged to be opened and closed, and the single-color injection port (4) is arranged on the upper fixed plate (3); The rear template (2) is provided with two identical and centrally symmetrical bottom cavities (7), and the front template (1) comprises two mold cores of different shapes located on the bottom surface, which extend into the two bottom cavities (7) to form a one-color cavity (8) and a two-three-color cavity (9); A two-color flow channel (10) and a three-color flow channel (11) are formed between the front template (1) and the rear template (2); the two-color flow channel (10) and the three-color flow channel (11) are respectively connected to the two-color injection port (5) and the three-color injection port (6), and form a two-color point gate (19) and a three-color point gate (20) on the two-color and three-color cavities (9); a single-color flow channel (12) is provided on the front template (1); the single-color flow channel (12) is connected to the single-color injection port (4), and the single-color flow channel (12) forms a single-color point gate (13) on the single-color cavity (8); A pulling needle (15) is fixedly provided on the upper fixed plate (3), and the pulling needle (15) includes a neck for clamping the injection molded part of the single-color flow channel (12). The neck of the pulling needle (15) passes through the front template (1) and the water inlet push plate (21) to enter the single-color flow channel (12), and an ejection assembly is provided at the bottom of each bottom cavity (7).
2. A three-color mixed micro injection mold according to claim 1, characterized in that: It also includes a plurality of guide posts (22) for guiding the movement of the front template (1), the rear template (2) and the upper fixed plate (3), a plug screw (14) for connecting the upper fixed plate (3) and the water inlet push plate (21), a plurality of pull rods (23) for guiding the water inlet push plate (21) and the front template (1), a plurality of nylon hooks (25) for connecting the front template (1) and the rear template (2), and a plurality of precision positioning sleeves (17) and a plurality of precision positioning posts (18) respectively arranged on the front template (1) and the rear template (2); The plug screw (14) comprises a threaded portion connected to the water inlet push plate (21) and a smooth portion that slides relative to the upper fixing plate (3). The pull rod (23) comprises a threaded portion connected to the nozzle push plate (21), a smooth rod portion that slides relative to the front template (1), and a nut portion that can only move in the rear template (2). A guide sleeve (24) for assisting the guide column (22) in sliding is provided between each guide column (22) and the front template (1) and the water inlet push plate (21).
3. A three-color mixed micro injection mold according to claim 1, characterized in that: The ejector assembly comprises an ejector fixing plate (27) arranged at the bottom of the rear template (2), an ejector bottom plate (31) fixedly arranged at the bottom of the ejector fixing plate (27), and a push rod (33) arranged on the ejector bottom plate (31); the ejector fixing plate (27) is circumferentially provided with a plurality of pressing blocks (32); each of the pressing blocks (32) is fixedly connected to the rear template (2); each of the pressing blocks (32) comprises a stepped surface (321) for limiting the position of the ejector fixing plate (27); the ejector fixing plate (27) is located above the stepped surface (321); The push rod (33) passes through the ejector bottom plate (31) and contacts the bottom surface of the ejector fixing plate (27), and the push rod (33) includes a rod cap portion (331) for preventing the push rod (33) from sliding away from the ejector fixing plate (27); The ejector fixing plate (27) is provided with an ejector assembly (28) for ejecting an injection molded part and a plurality of reset rods (29); the rear template (2) is provided with a plurality of countersunk through holes for passing the reset rods (29); two ends of each reset rod (29) respectively abut against the front template (1) and the ejector fixing plate (27); a telescopic spring is wound around each reset rod (29); two ends of the telescopic spring respectively abut against the countersunk surfaces of the countersunk through holes on the ejector fixing plate (27) and the reset rod (29).
4. A three-color mixed micro injection mold according to claim 3, characterized in that: Each of the bottom cavities (7) is fixedly provided with an insert (26) for defining the shape of the one-color cavity (8) and the two-color and three-color cavity (9), and the ejector assembly (28) comprises a plurality of flat ejectors (281) for extending into the bottom cavity (7), and a plurality of round ejectors (282) for passing through the rear template (2) and extending into the two-color flow channel (10) and the three-color flow channel (11).
5. The three-color mixed micro injection mold according to claim 3, characterized in that: The ejector assembly (28) further comprises two symmetrically arranged inclined ejector members (30), wherein the inclined ejector members (30) are slidably arranged on the ejector fixing plate (27) via pins, and the top of the inclined ejector member (30) is in a stepped structure, and the stepped surfaces thereof are respectively in contact with the bottom surface and the side surface of the bottom cavity (7).
6. The three-color mixed micro injection mold according to claim 1, characterized in that: The two-color dot gate (19) and the three-color dot gate (20) are respectively located on the two side walls of the two-color and three-color cavity (9), and the two-color dot gate (19) and the three-color dot gate (20) are both latent gates.
7. The three-color mixed micro injection mold according to claim 1, characterized in that: The sprue push plate (21), the front mold plate (1) and the rear mold plate (2) are all provided with water pipes for cooling the one-color flow channel (12), the two-color flow channel (10), the three-color flow channel (11), the one-color cavity (8) and the two-three-color cavity (9), and each connection where the water pipe extends to the outside of the mold is provided with a water stopper.
8. The three-color mixed micro injection mold according to claim 1, characterized in that: The upper fixing plate (3) comprises a fixing step (34) for fixing and positioning the position of the entire mold, the upper fixing plate (3) is provided with a heat insulation plate (35), the rear mold plate (2) is provided with a pressing plate groove (36), and the pressing plate groove (36) is provided with a pressing plate (37) for fixing the rear mold plate (2) on the injection molding machine.